Report of dysgerminoma in the ovaries of a snapping turtle (Chelydra serpentina) with discussion of ovarian neoplasms reported in reptilians and women. A malnourished, captive, young adult (weight-11 kg, carapace length-25 cm), female snapping turtle (Chelydra serpentina) was presented for examination and treatment of malnutrition and multiple carapace necroses. Because treatment was unsuccessful, the animal was euthanatized and necropsied. The main necropsy observations showed the presence of a 9 cm greyish-white/yellow, soft, fleshy to fatlike mass involving the right ovary near the oviduct opening and multiple similar, pea-to-walnut sized masses involving both ovaries. Microscopic examination of formalin fixed, hematoxylin and eosin and silver stained tissue sections revealed the masses to be composed of primordial germ cells arranged in a pattern morphologically compatible with dysgerminoma as described in women and other mammals. Very rarely have ovarian neoplasms been reported in turtles or other reptiles. This is the first neoplasm described in the snapping turtle ovary and the first dysgerminoma reported in reptilians. A tabulation of previously documented ovarian neoplasia in reptiles and a comparison of this cancer to those occurring in women will be discussed.


Longevity of mammals in captivity--an update. The life span of the various mammalian species differs and is an important parameter in comparative oncology; it should always be expressed as a percentage in relation to the potential life span of each species investigated. Mammals are a highly heterogenous class of animals. This heterogeneity is also reflected in a random variation of their life span by species.


Transmission studies of sarcoma in the soft-shell clam, Mya arenaria. Transmission experiments with adult soft-shell clams (Mya arenaria) demonstrated that clam sarcomas are transmissible with hemolymph from neoplastic animals but not with cell-free ultrafiltrates. Non-neoplastic clams were injected with either hemolymph from neoplastic clams or a cell-free ultrafiltrate prepared from a subsample of the same hemolymph. Injected clams were held in separate flow-through aquaria and examined for sarcomas by histocytology and histology. Data at 17 weeks showed a 44% prevalence of sarcomas in clams injected with neoplastic inoculum. No sarcomas were observed either in clams injected with a cell-free ultrafiltrate or in the control animals. The lack of sarcomas in clams injected with the ultrafiltrate argues against a viral etiology for the disease.


Chronobiologic response modifiers and breast cancer development: classical background and chronobiologic tasks remaining. Mapping the chronome's multi-frequency (about-daily, -weekly, and -yearly) neuroendocrine and immune rhythms can help determine when potential chronobiologic response modifiers (CBRMs) should be applied. Aimed at shielding in time by manipulating rhythms, CBRMs may be pertinent to all stages of carcinogenesis, from prevention to treatment, by forestalling the neuroendocrine, immunologic or cell cycle-related recurrent susceptibility peaks from getting aligned, favoring cancerous growth. Pituitary/hypothalamic isografts in the virus-free Bagg albino mouse and designs described as heterophasic allow the systematic investigation of the effect of internal shifts among neuroendocrines. Rhythm manipulation by CBRMs can then aim at lowering (breast or prostate) cancer risk by reproducing identified favorable low risk chronome configurations such as a circannual amplitude in blood that is small for TSH and large for prolactin in women and vice versa for men.


From experimental units to unique experiments: chronobiologic pilots complement large trials. The timing of treatment affects outcome. For mapping multi-frequency rhythm spectra first to optimize chronochemotherapy, 1000 marker determinations on the subject are more informative than a few determinations on each of hundreds of patients. N-of-6 subgroups should follow, with one subject assigned to each of 6 marker rhythm stages, 60 (e.g. 4 hours on a 24-hour scale) apart. Once the time structure has been mapped, minimal sampling requirements determined, and guidelines for treatment established, the information gained from chronobiologic n-of-1 and n-of-6 test pilot designs can be built cost-effectively into randomized controlled trials to benefit large patient populations. Sequential tests combined with marker rhythmometry and cosinor analysis on single test subjects, small groups and eventually on each patient are powerful tools that can extract information otherwise unattainable even at great cost and bring the P-value from publications to the patients.


Optimization of the chronotherapeutic index in the experimental animal laboratory. Large animal studies show that the effects of fixed doses of anticancer drugs vary predictably with multi-frequency rhythms' stages--components of a genetically--anchored, habitat synchronized, cosmically influenced time structure--the chronome. Both the tolerance by the host of the toxic drugs and the treatment's efficacy in killing cancer cells contribute to these changes. Chronotherapy, timing treatment according to the chronome, attempts to first maximize treatment efficacy while also minimizing toxicity, so as to optimize the therapeutic ratio. Outcomes have been improved by several hundred per cent by treating rodents at the "right" time with single or multiple agents under controlled laboratory conditions, and by chronoradiotherapy of human perioral tumors, using tumor temperature as a marker rhythm.


Black and white differences: narrowing the gap in cancer medicine. Excess mortality is a complex problem involving multiple sub-problems including culture, economics, lifestyle, issues related to cancer biology, and access to medical care among other issues. Consideration has to be given to the multiple influences that lead to this discrepancy in survival related to cancer and the increased incidence of certain tumors. Increased availability of state-of-the-art cancer treatment to the population as a whole will upgrade the level of care by those that participate in clinical trials; the physicians and finally even those patients who are not entered into the trials. Upgrading the access to information about prevention and control of cancer is of equal importance. There are those tumors with possible biological explanations for increases in cancer incidence in the Black population, in particular, multiple myeloma and prostate cancer. There are tumors which are increasing in incidence in this population with no explanation but which must relate to biological factors.


Amphibian tumors: a comparison of anurans and urodeles. Anuran and urodele amphibians develop spontaneous neoplasms in all major organ systems with the integumentary system a frequent target. Anurans and urodeles have spontaneous viral-associated tumors, the biological behavior of which is temperature-related. Anurans seem to have a greater frequency of spontaneous neoplasms than do urodeles and respond to chemical carcinogens in a manner analogous to mammalian species. Urodeles have greater cell regenerative capabilities than do anurans and paradoxically, are more refractory than anurans or mammalian species to chemical carcinogens in their proliferating regenerative blastema.


Nature and frequency of bony tumors in prehistoric and historic populations. The skeletons of the Merovingian population from Kleinlangheim (Southern Germany) were examined by macroscopic, radiological, endoscopic and microscopic techniques. In about 6% skull tumors could be diagnosed. All five cases reported here are examples of benign tumors. Three of these are tumors of the paranasal sinuses. A connection between sinusitis and fibro-osseous tumors of the paranasal sinuses is suggested. The etiology of these tumors and methods of diagnosis of tumors in archaeologic bone are discussed.


Fos expression in the trigeminal sensory nuclei after a chemical lesion of the lower lip mucosa. C-fos containing neurons were investigated in the trigeminal sensory nuclear complex and in the dorsal horns of the cervical spinal cord (C1-C2) of the rat after a chemical noxious stimulus was applied to the lower lip mucosa. Numerous labelled neuronal nuclei were detected in the dorsolateral area of the caudal half of the trigeminal nucleus interpolaris, and in Rexed's laminae I-IIo of the dorsomedial area of the trigeminal nucleus caudalis and rostral C1. A few c-fos-labelled neurons were observed in laminae IIi and V. No Fos expression was detected in the trigeminal oral and principal nuclei.


The possible role of the initial lymph vessels of the skin during metastasis of malignant tumors. The metastasizing potential of a malignant tumor is derived primarily from its biological characteristics. The second most important factor in metastatic spreading lies in the host tissue/organ and host metabolism. The aggressiveness of a malignant skin melanoma depends clinically upon the width and, especially, the depth of the preceding lesions(s). Histological and electron microscopic studies reveal that the increase of malignant aggressiveness is directly related to the arrangement of the initial lymphatic vessels in the different layers of the skin. Sudden increase in the density of lymphatic vessels permits a corresponding increment of malignant seeding via the lymphatic system.


Comparison of arteriosclerosis, neoplasms and diabetes as the three main killers of man in the industrialized world. Arteriosclerosis, neoplasms and diabetes are the three main killers in the industrialized world, complemented by infectious and parasitic diseases in the less developed countries. Neoplasms, the second most frequent killer in the industrialized world, exhibit the highest diversity of pathologic structures involved. Arteriosclerosis, the first killer in the industrialized world, is more complex, dealing with aberrations of the arterial wall. In contrast to neoplasms, cases are restricted to a closed circulatory system as noted in the various phyla. Neoplasms are also known from the kingdom of plants and fungi, whereas arteriosclerosis is restricted to specific animal phyla, at least theoretically. Even more restricted is the distribution of diabetes which is known only in certain vertebrates. All three disease groups have a substantial impact on man's health.


Production of antiserum to [D-Ala2]deltorphin I and its immunohistochemical application to the mouse brain. Antiserum to haptenic [D-Ala2]deltorphin I (DADTI: Tyr-D-Ala-Phe-Asp-Val-Val-Gly.NH2), a highly selective ligand for delta opioid receptors, was produced in rabbits. By immunospot assay, the antiserum recognized 62.5 pmol DADTI but failed to react even with 4 nmol carrier protein of the immunogen. Although the antiserum reacted equally with an isomer [L-Ala2]deltorphin I, virtually no cross-reaction occurred with other analogues such as [D-Ala2]deltorphin II (Tyr-D-Ala-Phe-Glu-Val-Val-Gly.NH2) and similar peptides lacking the C-terminal glycine amide. Therefore, the major epitope for immunorecognition appeared to be in the C-terminal region which is known to be the specific domain for delta opioid receptor selectivity. Immunohistochemical study using this antiserum revealed positive neuronal structures in some specific systems of the mouse brain.


Changes in the course of cancer.

Changes in the course of cancer. Many neoplasms cannot be cured but the life span of the patient afflicted with such diseases has in a remarkable number of cases been prolonged. The course of neoplastic diseases has been changed, improving life-style and survival on the one hand, but resulting in new side effects including multiple primary neoplasms on the other. In contrast to neoplastic diseases with aggressive acute development, we can observe an increasing number of neoplastic diseases with a chronic, prolonged that progress. To understand this it is necessary to remember that neoplastic diseases are heterogenic in nature, and also diseases of autonomic growth comprising modification of the host along with progression of the tumor.


Somatosensory input and thalamic projection of pedunculopontine tegmental neurons. The cholinergic pedunculopontine tegmental area of the anesthetized rat was explored for single units responsive to somatosensory stimulation. Units projecting to the intralaminar thalamus were identified by antidromic stimulation. Approximately one half of the somatosensory units consisted of low threshold units responsive to light tapping and stroking; the others were high threshold mechanoreceptive units. Most receptive fields were trigeminal and contralateral. These results suggest that somatosensory information is an important element in a subcortical system linking this area with the basal ganglia, superior colliculus and thalamus.


Some characteristics of the mesenchymal stem cell of soft tissue tumors. "Soft tissue tumors" is an unnatural term, used by clinicians and for convenience by pathologists, which unites the neoplasms of mesenchymal origin as opposed to those of the soft epithelial tissues. Not included are the reticuloendothelial system, glia and supporting tissues. The mesenchymal stem cell, the cell of the embryonal connective tissue, exhibits in man and mammals the most pronounced embryonal potential. A restricted comparison to the embryonal potential in larval and pupal cells of invertebrates, such as in hemi- or holometabolic insects and to meristematic cells in vascular plants is justified. The great embryonal potential may explain why the mesenchymal stem cell, at present a hypothetical unit, is able to transform and differentiate into the connective tissue as such, the muscular, supporting and hematogenic tissues. The musculature comprises the bulk of the mammal's body weight. The development of the normal ontogenetic specialization as well as especially those differentiations leading to soft tissue tumors are comparatively shown in this publication and placed in the framework of vertebrate and invertebrate animals with true tissues.


Effect of REM sleep deprivation on molecular forms of acetylcholinesterase in rats. Since REM sleep deprivation was reported to increase the activity of acetylcholinesterase, an attempt was made to investigate whether the different forms of enzyme could be affected selectively. The flower pot method was used for deprivation and suitable control experiments were conducted. The bound and the soluble forms, if affected would show an increase or a decrease, respectively, on REM deprivation. The former is affected first in the pons while the latter in the medulla. The findings support the pontomedullary cholinergic mechanism for the generation of REM sleep. Though there may be a possibility of conversion of the free to the bound form, the increase in the latter was more than the decrease in the former.


Postsynaptic potentials in cat visual cortex: dependence on polarization. During the investigation of visually evoked postsynaptic potentials (PSPs) of visual cortical neurons, we recorded cell activity under different levels of membrane potential. In some cases, however, dependence of these PSPs on the level of membrane polarization appears to be inconsistent with the conventional scheme. One disagreement was the reduction, instead of an increase, of excitatory potentials during hyperpolarization of the cell. The other point was that depolarization of the cell often leads to increase of the amplitude of both excitatory and inhibitory postsynaptic potentials. This inconsistency may suggest the involvement of voltage-dependent ion channels in generating PSPs to visual stimuli. A possible way of separating the excitatory and inhibitory components of the response by polarization of the cell in spite of the presence of voltage-dependent channels and possible implications of this mechanism in the visual cortex are discussed.


Propagation of colour information across borders. When a part of an image is stabilized on the retina, the part fades to the same colour as its unstabilized surround. The apparent colour of an empty field is therefore assumed to be equal to the colour of its borders. Here, we will show that a similar phenomenon can take place even when the border of a centre field is still visible. A grey square patch with a black frame was surrounded by a coloured background. When the frame had such crossed disparity that the frame appeared in front of the patch, the colour of the patch became perceptually similar to that of the background, indicating that the colour of an empty field is not determined by the colour of its borders alone.


CCKB receptor stimulation mediates [Ca2+]i increase but no PKC activation in Jurkat T-cells. We have investigated the effect of cholecystokinin-octapeptide (CCK-8) on [Ca2+]i and protein kinase C (PKC) activity in Jurkat T-cells. CCK-8 produced a transient [Ca2+]i increase in the presence of extracellular Ca2+. While CCKB receptor antagonist L-365,260 abolished the elevation of [Ca2+]i, CCKA receptor antagonist L-364,718 was without effect. Moreover, the dihydropyridine calcium channel blocker nitrendipine was shown to block the observed calcium response. Results suggest that the calcium effect is caused by an interaction of CCK-8 with CCKB binding sites and an influx of external Ca2+ via dihydropyridine sensitive calcium channels might serve as a source for the increased [Ca2+]i. Because CCK-8 induced no PKC activation CCKB receptor mediated rise of intracellular calcium seems not to include activation of phospholipase C.


Suppression of audiogenic epileptic seizures by intracerebral injection of a CCK gene vector. P77PMC rat is a breed of rat with congenital audiogenic seizure (AS). AS attacks could be suppressed by cholecystokinin octapeptide (CCK-8) injected intracerebroventricularly (i.c.v.). In the present study we made i.c.v. injection of plasmid pSV2-beta Gal or pSV2-CCK encapsulated with lipofectin. Expression of pSV2-beta Gal in brain occurred from d 1 to d 14, with maximal expression at d 3 and d 4. After i.c.v. injection of pSV2-CCK plasmid, the AS of the P77PMC rats was markedly reduced, which was most obvious at d 3 and d 4. The time course of the AS repression was almost identical with that of pSV2-beta Gal expression. The results suggest that the repression of the AS in P77PMC rats is accounted for by the expression of foreign CCK gene in brain tissue.


Angiotensin AT2 receptors regulate cerebral blood flow in rats. LARGE cerebral arteries have been reported to contain angiotensin receptors that are exclusively of the AT2 subtype. We measured the effect of the AT2 receptor selective ligand PD 123319 on cerebral blood flow (CBF) in rats, using laser-doppler flowmetry. PD 123319 (1-10 mg kg-1) dose-dependently inhibited the increase in CBF, when the blood pressure was increased by a norepinephrine infusion. However, PD 123319 did not alter baseline CBF at normal blood pressures. Therefore PD 123319 appears to interfere with the autoregulatory mechanisms of CBF. The participation of AT2 receptors in the regulation of CBF confirms a physiological role for this receptor subtype, and may give clues for future treatment of various cerebrovascular disorders.


Calcium-mediated neuronal degeneration following singlet oxygen production. NONINVASIVE photolytic injury to targeted neuronal subpopulations in vivo causes unique, slowly progressive neuronal degeneration. To examine the mechanisms of degeneration toward development and transplantation studies, cytosolic calcium levels were measured in vitro from neocortical neurons after incorporation of photoactive nanospheres and laser-activated singlet oxygen production within lysosomes. Cytosolic calcium increased irreversibly, predominantly from extracellular sources through channel-mediated mechanisms and increased membrane porosity. Propidium iodide studies demonstrated gradual loss of membrane integrity over hours to days. The calcium channel blocker nimodipine, or calcium-free medium, partially protected neurons from calcium flux and cell death. Results suggest calcium-dependent and independent mechanisms of neuronal degeneration following singlet oxygen production.


Dendritic regrowth of retinal ganglion cells in adult rats. IN adult rat retinal ganglion cells, we investigated how their dendrites are maintained during axonal regeneration induced by a peripheral nerve (PN) graft. Intracellular Lucifer Yellow injection revealed that rapid dendritic retraction occurred immediately after axotomy and grafting. However, dendrites that probably sprouted after axotomy were often found in the regenerating ganglion cells, and their dendritic field tended to recover in area by 3 months after grafting. Although such dendrites were also found in an axotomized cell receiving no PN graft, they are much more frequently observed in the regenerating cells. Therefore, a PN graft can facilitate the rat ganglion cells to regrow their dendrites.


Age-related shrinkage of the mamillary bodies: in vivo MRI evidence. Mamillary body (MB) is a diencephalic structure hypothesized to be involved in memory, a cognitive function that declines with age. In this study, age-related differences in the size of MB were examined in vivo using magnetic resonance (MR) imaging. The cross-sectional area of the MB was estimated from MR images of the brain in healthy volunteers and neurologically intact patients (age 18-78). The cross-sectional area of the tectum was used as a control region of interest. We found a significant age-related reduction in the area of the MB, but not of the tectum. No sex differences were observed in the size of either structure.


Mnemonic and predictive functions of cortical neurons in a memory task. Single-neuron discharge was recorded from prefrontal and posterior parietal cortex in monkeys performing a visuo-motor memory task with temporal and spatial separation between cue (color) and directional manual response. During the delay interval between cue and response, neurons in both cortices engaged in two concurrent and reciprocal trends of discharge: (a) sensory-coupled, decelerating firing apparently related to color retention, or (b) motor-coupled, accelerating firing apparently related to the anticipated response direction. In both cortices, the acceleration of the direction-anticipating activity was related to the probability with which the animal could predict, and prepare for, the correct response site. Our findings suggest that neurons from prefrontal and parietal cortex are part of distributed networks, with representational and operational properties, for visuomotor cognitive processing.


A behavioral study of bilateral middle cerebral artery hemorrhagic ischemia in rats. The middle cerebral artery was severed bilaterally (bMCA) in adult rats, and controls experienced sham operations. Tactile sensorimotor and gross locomotor functions, measured by the tape test and a rod walking test, were initially impaired in the injured animals. However, these deficits had resolved within 9 and 30 days respectively. The animals were trained in a multiple T water maze task to find the location of a hidden escape platform at the rate of one trial per day for 30 days. Analyses of the number of errors committed and latency to find the escape platform revealed that the bMCA injured rats suffered deficient reference memory, but no decline in working memory. These data support further the use of the bMCA preparation as a model of stroke.


Unexpected heterogeneity in E2A/PBX1 fusion messenger RNA detected by the polymerase chain reaction in pediatric patients with acute lymphoblastic leukemia. The t(1;19)(q23;p13) is the most common recurring chromosomal translocation in childhood acute lymphoblastic leukemia (ALL) and has been associated with adverse prognosis. It involves the rearrangement of two genes, PBX1 and E2A, resulting in the production of transforming chimeric DNA-binding proteins. In all previous reports in which the presence of a chimeric transcript was described, the fusion point between the coding sequences of E2A and PBX1 was found to be constant at the RNA level. We have used RNA-based polymerase chain reaction (PCR) for the detection of E2A/PBX1 messenger RNAs (mRNAs) in children with ALL at the time of diagnosis. Of 21 patients exhibiting this rearrangement, 3 (14%) expressed a variant E2A/PBX1 transcript in addition to the expected one. The relative amounts of the two chimeric mRNAs varied between the patients, but remained constant in the same patient during different stages of the disease. Sequence analysis showed an identical insertion of 27 bp at the E2A/PBX1 junction of the variant RNA species, the translation of which would result in the replacement of Val478 by 10 amino acids. The inserted sequence has not been detected in any other human transcript besides the variant E2A/PBX1 RNA species and probably represents a splicing variant of the chimeric RNA. We conclude that a subset of pediatric patients with ALL that carry the E2A/PBX1 rearrangement express two types of the chimeric mRNA. The biologic significance of this additional E2A/PBX1 transcript is discussed.


Human peripheral blood hematopoietic progenitors are optimal targets of retroviral-mediated gene transfer. Hematopoietic progenitor cells circulate in the peripheral blood (PB) of cancer patients during the recovery phase that follows treatment with high-dose cyclophosphamide followed by hematopoietic growth factor infusion. We report that when PB progenitors were exposed in vitro to filtered supernatant from cell line PA317-N2, producing amphotropic helper-free N2 vector at conventional titers, successful retroviral-mediated transfer of neomycin resistance gene was documented by polymerase chain reaction in 93% of day 14 myelomonocytic colonies. Under the same conditions, gene transfer was achieved in 22% of steady-state bone marrow-derived myelomonocytic colonies. Neo-resistance gene transfer was documented also in a CD34+/cyclophosphamide-resistant precursor to granulocyte-macrophage colonies, an undifferentiated progenitor close to the hematopoietic stem cell. Neither cocultivation with vector-producing cells nor high vector titer were stringent requisites for efficient gene transfer. The large-scale availability of PB hematopoietic progenitors in cancer patients, together with the high gene transfer rate achieved under safe and clinically feasible conditions, support an optimal approach for gene transfer procedures into the human hematopoietic system.


Autologous bone marrow transplantation in acute leukemia with marrow purged with alkyl-lysophospholipid. Alkyl-lysophospholipids are anticancer agents that are selectively toxic to leukemic cells and relatively sparing of normal bone marrow cells. Thus, they would be likely candidates for purging remission marrows before autologous bone marrow transplant. One of the more promising agents is edelfosine, which could be safely used for purging without prolonging marrow recovery. Assays for marrow progenitor cells were performed before and after purging and cryopreservation in 64 patients. There was no significant reduction in colony formation after purging when compared with unpurged cryopreserved marrow, but there was a significant reduction after cryopreservation. Twenty-four patients with acute leukemia in second (16 patients) or third remission (3 patients), early relapse (3 patients), or in first remission with successfully treated extramedullary relapse (2 patients) received marrow-ablative chemotherapy and total body irradiation followed by infusion of marrow purged for 4 hours with 50 to 100 micrograms/mL of edelfosine. There were 9 lymphoblastic and 15 myelogenous leukemia patients. The median time to granulocyte recovery to 500/microL was 26 and 33 days for the 50 and 75 microgram/mL doses, respectively. The patient whose marrow was purged at the dose of 100 micrograms/mL failed to engraft. The median time to platelet recovery to 25,000/microL was 45 and 37 days for the 50 and 75 micrograms/mL doses, respectively. Twenty-nine percent of the patients remain disease free from 131 to 1,291 days, with a median of 356 days. These results have established that purging with 75 micrograms/mL of edelfosine is a safe dose and is recommended for a phase II trial.


Use of alpha interferon for the treatment of relapse of chronic myelogenous leukemia in chronic phase after allogeneic bone marrow transplantation. Eighteen patients with relapse of chronic myelogenous leukemia (CML) after allogeneic bone marrow transplantation (BMT) were treated with recombinant human alpha 2a interferon (IFN). Relapse was defined as greater than 90% metaphases containing the Philadelphia chromosome (Ph) and hematologic abnormalities consistent with chronic-phase (CP) CML. There were 11 males and seven females, with a median age of 38 years (range, 3 to 55). Three patients relapsed after second BMT. Only one patient had received T-cell-depleted marrow initially. The initial IFN dose of 3 x 10(6) U/m2/d was escalated to the maximum tolerated dose or to a maximum of 6 x 10(6) U/m2/d. IFN controlled the white blood cell (WBC) counts in 14 of 16 patients who had abnormal counts, and in all six patients with an elevated platelet count. Six patients (33%) have had a complete disappearance of the Ph and two have had a partial response (less than 35% Ph+ metaphases). One patient has a decrease in Ph+ metaphases after 9 months of IFN. Five patients had no significant cytogenetic response after 9 to 12 months, and four developed clinical accelerated phase or blast crisis after 3 to 6 months on therapy. Of four patients with a sex marker, the Ph- population was of donor origin in three and of host origin in one. Clonal cytogenetic abnormalities other than Ph were present in 13 patients and did not predict for lack of response to IFN. IFN is effective in suppressing the Ph clone in some patients who relapse with CML after allogeneic BMT and controls the blood counts in the majority.


Growth hormone exerts hematopoietic growth-promoting effects in vivo and partially counteracts the myelosuppressive effects of azidothymidine. Recombinant human growth hormone (rhGH) was administered to mice to determine its effect on hematopoiesis. BALB/c mice and mice with severe combined immune deficiency (SCID), which lack T cells and B cells, were administered intraperitoneal injections of rhGH for 7 days. Upon analysis, both strains of mice exhibited an increase in splenic and bone marrow hematopoietic progenitor cell content and cellularity, indicating that rhGH can act as a hematopoietic growth factor. C57BL/6 mice were then placed on azidothymidine (AZT). AZT is a reverse transcriptase inhibitor currently used as a treatment for acquired immune deficiency syndrome (AIDS), but which also produces significant myelotoxic effects. Treatment of mice with rhGH partially counteracted the myelosuppressive properties of AZT. Bone marrow cellularity, hematocrit values, white blood cell counts, and splenic hematopoietic progenitor cell content were all significantly increased if rhGH (20 micrograms injected intraperitoneally every other day) was concurrently administered with AZT. Administration of ovine GH (ovGH), which, unlike rhGH, has no effect on murine prolactin receptors, also prevented the erythroid-suppressive effects of AZT in mice, but had no significant effect on granulocyte counts. Thus, the effects of GH are mediated at least in part through GH receptors in vivo. Additionally, when mice were initially myelosuppressed by several weeks of AZT treatment, the subsequent administration of ovGH resulted in an increase in splenic hematopoietic progenitor cells. No significant pathologic effects were observed in mice receiving either repeated rhGH or ovGH injections. Thus, GH exerts significant direct hematopoietic growth-promoting effects in vivo and may be of potential clinical use to promote hematopoiesis in the face of myelotoxic therapy.


Effect of human immunodeficiency virus-1 envelope glycoprotein on in vitro hematopoiesis of umbilical cord blood. Although hypercellularity is a common bone marrow finding in patients with human immunodeficiency virus type 1 (HIV-1) infection, the effect of HIV-1 on the hematopoietic system, which has been investigated in in vitro studies, is still controversial. In this study, we have investigated the effects of HIV-1 envelope glycoprotein, gp160, on the differentiation of hematopoietic progenitor cells derived from cord blood. Culture of cord blood mononuclear cells with gp160 resulted in enhancement of the in vitro growth of myeloid hematopoietic progenitors. To investigate the mechanism of the enhancement, adherent cells, T cells, or CD34-bearing hematopoietic progenitors were isolated and cultivated with gp160 in a variety of culture conditions. We have shown that gp160 had no direct effect on highly purified hematopoietic progenitors but exerted its enhancing effect indirectly via T cells, by induction of a humoral colony-stimulating factor(s). The activity of gp160 on T cells was abrogated by preincubation of gp160 with recombinant CD4 molecule and goat anti-gp120 antibody. These data provide evidence for a novel biological activity of HIV envelope glycoprotein, that of T-cell-mediated stimulation of myelopoiesis. Binding of gp160 with the cell surface CD4 molecule appears to be necessary for secretion of the colony-stimulating factor(s).


Identification of lysosome-associated membrane protein-2 as an activation-dependent platelet surface glycoprotein. Platelets undergo biochemical and morphologic changes when stimulated that greatly alter their function and contribute to their role in thrombosis and hemostasis. We recently identified and cloned the cDNA for a platelet surface glycoprotein expressed on activated, not resting cells. We found that this protein, lysome-associated membrane protein-1 (LAMP-1), is an integral membrane protein of the lysosome that translocated to the surface membrane when platelets were stimulated by a strong agonist. We now show with immunofluorescence flow cytometry that LAMP-2, a lysosomal membrane protein that shares approximately 30% homology with LAMP-1, is also expressed preferentially on the surface of activated platelets. Equilibrium binding studies with 125I-anti-LAMP-2 IgG showed approximately 1,100 binding sites per thrombin-stimulated platelet and less than 50 per resting platelet. Sucrose gradient ultracentrifugation fractionation of resting platelet sonicates showed that LAMP-2 colocalized with LAMP-1 and with lysosomal enzymes, and not with thrombospondin or serotonin, which are markers of the two other platelet granule compartments, alpha-granules and dense granules. LAMP-2 surface expression was minimal in response to platelet stimulation by weak agonists such as epinephrine and ADP. These data show that LAMP-2, like LAMP-1, translocates from the lysosomal membrane compartment to the surface membrane when platelets are activated. Regulated surface expression of these heavily glycosylated proteins may play a role in the adhesive, prothrombotic phenotype of these cells.


Partial deletion of an antithrombin III allele in a kindred with a type 1 deficiency. This report details the precise mapping of a partially deleted human antithrombin III (AT-III) allele, found in a kindred with an inherited type 1 AT-III deficiency. Using truncated AT-III probes generated by polymerase chain reaction (PCR) amplification from a full-length AT-III cDNA, as well as other genomic probes specific for the 5' upstream region of the AT-III gene, we were able to characterize a partial deletion on an AT-III allele encompassing exons 1 and 2 of the AT-III gene, and a region 5' to the coding sequences. The absence of the 5' upstream region in the affected AT-III allele was confirmed directly by the PCR amplification of a 1.5-kb polymorphic fragment of genomic DNA samples from family members. The precise determination of the 5' breakpoint of the affected allele was made possible by two different approaches: (1) subcloning plus biotin capture PCR, or (2) inverse PCR. This allowed us to confirm the mapping of the deletion obtained by Southern analysis; to show that the 3' region of the mutant AT-III allele, including exons 3 to 7, was intact; and to sequence approximately 0.7 kb upstream to the breakpoint in the mutant allele. Furthermore, PCR amplification of the region of the breakpoint provided unique products detectable only in affected members of this kindred. The breakpoint in the partially deleted allele is 480 bp upstream from the 5' boundary of exon 3. No significant homology was found between the 0.7-kb sequence upstream to the breakpoint of the mutant allele and known human sequences.


Heparin enhances active site-dependent binding of tissue-type plasminogen activator to endothelial cells. Human umbilical vein endothelial cells (HUVEC) in culture express two classes of binding sites for tissue-type plasminogen activator (t-PA). The high-affinity binding site has been identified as PA inhibitor type 1 (PAI-1), which binds to the catalytic portion of the molecule, while the second site binds t-PA through an active-site independent domain. Because recombinant t-PA (rt-PA) is often administered concomitantly with heparin, we investigated the effects of heparin on rt-PA binding to HUVEC. Preincubation of HUVEC with heparin at 4 degrees C increased the binding of radiolabeled rt-PA in a time- and dose-dependent manner. One-half maximal increase in binding was observed within 10 minutes of heparin addition. When HUVEC were preincubated with optimal concentrations (5 U/mL) of heparin for 4 hours at 4 degrees C, a 2.5- +/- 0.2-fold increase in specific binding was observed (mean +/- SEM, n = 12, P less than .01). Other highly sulfated glycosaminoglycans and fucoidan (a sulfated polymer of fucose) stimulated rt-PA binding as well, whereas glycosaminoglycans with lower sulfate content than heparin did not. Several results suggested that heparin increased the binding of rt-PA to "cell-associated" PAI-1. First, only active-site-dependent binding was enhanced by heparin, whereas binding of active-site blocked rt-PA was not affected. Second, extracts from HUVEC preincubated with heparin contained increased amounts of rt-PA-PAI-1 complexes as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Third, antibodies to PAI-1 blocked the increased binding entirely. HUVEC preincubated with heparin also bound increased amounts of enzymatically active radiolabeled urokinase-type PAs. However, HUVEC preincubated with heparin did not express increased amounts of immunoreactive PAI-1. Therefore, heparin, at therapeutic concentrations, may enhance or stabilize the association of PAs with endothelial cell-associated PAI-1.


Human eosinophils synthesize and secrete interleukin-6, in vitro. Using the technique of in situ hybridization, we have shown that resting, unstimulated, human peripheral blood eosinophils, obtained from subjects with greater than 8% eosinophilia, transcribe and translate messenger RNA (mRNA) for interleukin-6 (IL-6). After incubation for 24 hours in culture medium alone, approximately 19% of eosinophils were positive for IL-6 mRNA. This may be a reflection of their in vivo activation, but also may suggest that the gene for this cytokine is constitutively expressed in eosinophils. After stimulation with interferon gamma (IFN gamma) (500 U/mL), the percentage of IL-6-mRNA+ cells increased to 51.3%. This was accompanied by an enhancement of intensity of the hybridization signals. The specificity of the IL-6 probe and the hybridization signals was confirmed by the use of an IL-6 sense probe and RNase pretreatment of cell preparations. Evidence for the translation of IL-6 mRNA was obtained by immunocytochemical staining. Normal and activated eosinophils gave IL-6-specific immunoreactivity with a polyclonal antihuman IL-6 antibody. A higher percentage of positive cells was detected among activated eosinophils than those treated with medium alone. Using a specific immunoenzymetric assay, we detected 190.15 +/- 18.1 and 403.32 +/- 213.6 pg/mL of IL-6 in supernatants of unstimulated and IFN gamma-treated (24 and 48 hours) eosinophils, respectively. These data indicate that eosinophils are an important cellular source of IL-6.


Monoclonal anti-idiotype antibody therapy of B-cell lymphoma: the addition of a short course of chemotherapy does not interfere with the antitumor effect nor prevent the emergence of idiotype-negative variant cells. The Ig idiotype of B-cell lymphoma can be used as a tumor-specific target. Prior trials with monoclonal anti-idiotype antibodies alone and combined with alpha-interferon have shown significant antitumor activity. In some patients, idiotype-negative tumors emerged after treatment. In this trial, patients with relapsed non-Hodgkin's lymphoma were treated with two identical courses of monoclonal anti-idiotype anti-body therapy. Concurrent with the second course, at a time when idiotype-negative cells were suspected to be proliferating, a pulse dose of chlorambucil was administered. Tumor biopsies obtained before the first and second courses of treatment and at relapse were analyzed for idiotype expression and proliferation. Thirteen patients received 24 courses of antibody with minimal toxicity. Eleven had tumor regression, with 1 complete remission, 8 partial remissions, and 2 minor remissions, with freedom from progression lasting a median of 7 months in responding patients. Idiotype-negative tumor cells appeared in some relapse specimens despite the use of chlorambucil. In retrospect, this was not surprising because there was no increase in the proliferative rate of these tumors at the time the drug was used. Anti-idiotype antibodies continue to demonstrate antitumor activity against B-cell lymphoma with minimal toxicity. The mechanism of the effect is presumed to involve both direct antiproliferative effects of the antibody on the tumor cells as well as indirect, more long-lasting effects on the host. The addition of a mild chemotherapeutic agent in the dose and schedule used here to the second cycle of antibody therapy did not interfere with the antitumor effect, nor did it decrease the emergence of idiotype-negative cells.


Human lymphotropic retroviruses associated with mycosis fungoides: evidence that human T-cell lymphotropic virus type II (HTLV-II) as well as HTLV-I may play a role in the disease. The human T-cell lymphotropic virus type I (HTLV-I) is causally associated with adult T-cell leukemia, but its role in mycosis fungoides (MF) has remained enigmatic. The virus is suspect because a small percentage of patients with MF have antibodies to it, the cells of others harbor deleted HTLV-I proviral sequences, and particles resembling HTLV-I emerge in cultured blood lymphocytes obtained from most patients. An alternative possibility is that disparate lymphotropic retroviruses may infect or affect a population of epidermotropic lymphocytes, leading to the same outcome, ie, MF. In studies designed to identify the particles detected in lymphocyte cultures of nine patients with a diagnosis of skin involvement characteristic of MF, this concept has gained support. While the cells of four patients provided evidence of HTLV-I infection, molecular hybridization with HTLV-II-specific pol probes showed HTLV-II in the cells of another patient. The 103-bp fragment amplified by the HTLV-II-specific probe was sequenced and proved to have greater than 90% homology with the same fragment amplified from cells known to be infected with HTLV-II. A role for HTLV-II in MF has not been suggested heretofore. Therefore, HTLV-I, HTLV-II, and their incomplete forms may be found in cells of MF patients, suggesting new theories regarding the pathogenesis of this disease.


K562 cells produce an anti-inflammatory factor that inhibits neutrophil functions in vivo. We have previously reported that K562, a chronic myelogenous leukemia cell line, releases a low molecular weight factor (6 to 8 Kd) that inhibits human polymorphonuclear neutrophil (PMN) adherence and adherence-related functions tested in vitro. We now report that this factor, which we have named K562 inhibitory factor (K562-IF), has potent anti-inflammatory activity in mice, associated with an inhibition of PMN functions. Its in vitro actions were less marked with mouse PMN than with human PMN. They included (1) an inhibition of both nonstimulated locomotion and locomotion induced by FMLP or serum; (2) an inhibition of the chemiluminescence induced by opsonized zymosan, but not that induced by phorbol myristate acetate or FMLP; (3) an inhibition of the degranulation stimulated by opsonized zymosan, as reflected by lactoferrin and lysozyme release; and (4) a decrease in arachidonic acid release and leukotriene B4 production by A23187-stimulated PMN. The in vivo actions of K562-IF after intraperitoneal injection included (1) an inhibition of subcutaneous PMN accumulation at the site of injection of opsonized zymosan (PMN accumulated neither outside the vessels nor intravascularly, as shown by means of histochemistry); (2) an inhibition of neutrophil accumulation in the peritoneum of mice having received sodium caseinate or opsonized zymosan intraperitoneally; and (3) lysozyme concentration in neutrophils having reached the peritoneum after opsonized zymosan treatment equal to that in blood, suggesting diminished release. PMN influx and degranulation in the peritoneum were reduced by 50% after 3 hours of treatment with 1 microgram of K562-IF (equivalent to the effect of 120 micrograms of prednisolone). Taken together, these results show that K562-IF is a potent anti-inflammatory agent that acts by inhibiting PMN functions.


Splice site mutations are a common cause of X-linked chronic granulomatous disease. Chronic granulomatous disease (CGD) is characterized by the absence of a respiratory burst in activated phagocytes. Defects in at least four different genes lead to CGD. Patients with the X-linked form of CGD have mutations in the gene for the beta-subunit of cytochrome b558 (gp91-phox). We studied the molecular defect in four patients with X-linked CGD. In a fifth family, we studied the mother of a patient with X-linked CGD who had died before our investigations. Gp91-phox messenger RNA (mRNA) was reverse transcribed into cDNA and the coding region was amplified by polymerase chain reaction into three fragments. Sequence analysis showed the absence of the exon 7, 5, 3, and 2 sequences in patients 1, 2, 3, and 4, respectively. In carrier 5, we found both normal cDNA and cDNA that lacked 57 3'-nucleotides of exon 6. We analyzed the splice sites of the flanking introns of the missing exons. In patients 1, 2, and 3, we found single nucleotide substitutions within the first five positions of the down-stream 5' donor splice sites. In patient 4, a similar substitution was found at position -1 of the 3' acceptor splice site of intron 1. In carrier 5, no mutation was found in the exon 6-intron 6 boundary sequence. Instead, a single substitution was observed in exon 6 (C----A at nucleotide 633) that created a new donor splice site. Apparently, mRNA splicing occurs preferentially at this newly created splice site. We conclude that the absence of the exon sequences in the gp91-phox mRNA of these patients is due to splicing errors. Of 30 European X-linked CGD patients studied by us so far, five appear to be caused by mutations that affect correct mRNA splicing. Thus, such mutations appear to be a common cause of X-linked CGD.


Rapid detection of Spanish (delta beta)zero-thalassemia deletion by polymerase chain reaction. delta beta-Thalassemia and hereditary persistence of fetal hemoglobin (HPFH) are inherited disorders characterized by the persistent synthesis of fetal hemoglobin (HbF) during adult life. The Spanish type of delta beta-thalassemia is a mild thalassemic condition due to a large deletion starting at the Alu I repeat between the A gamma and delta-globin genes immediately 3' to the RIH probe and extending 11 and 17 kb downstream of the 3' endpoints of HPFH 1 and HPFH 2, respectively. Using probes from the Spanish (delta beta)zero-thalassemic DNA, the 3' breakpoint region has been mapped to a point approximately 8.5 to 9.0 kb downstream from that of HPFH type 1 and, as we know the restriction sites 3' to this breakpoint, the presence of the deletion can be identified with the polymerase chain reaction (PCR). In the present study, a PCR method using three specific oligonucleotides has been developed for the identification of the Spanish (delta beta)zero-thalassemia in 100 patients with delta beta-thalassemia (99 heterozygotes with mild anemia, decreased mean corpuscular volume, and 5% to 15% HbF, and one homozygote with 100% HbF and thalassemia intermedia phenotype). We conclude that the finding of the Spanish type of (delta beta)zero-thalassemia in all the patients studied here suggests Spain as the most probable origin of this thalassemic phenotype. Moreover, the amplification of the fragment encompassing the deletion junction and normal sequence is useful for the rapid molecular detection of Spanish (delta beta)zero-thalassemia.


Developmental switching of messenger RNA expression from the human alpha-globin cluster: fetal/adult pattern of theta-globin gene expression. The alpha-globin gene cluster contains four functional globin genes, zeta, alpha 2, alpha 1, and theta. The developmental regulation of the embryonic zeta and fetal/adult alpha 2- and alpha 1-globin genes is well characterized at the level of protein synthesis. The developmental pattern of the theta-globin gene is not well characterized due to the inability to detect its encoded protein. Direct analysis of the globin switching at the steady-state messenger RNA (mRNA) level has been hampered by the difficulty in obtaining quantities of embryonic and early fetal mRNA sufficient for analysis. We analyzed the relative levels of the steady-state zeta-, alpha-, and theta-globin mRNAs in yolk sac in 5-, 6-, 7-, and 8-week postconception embryonic liver, and in cord and adult blood reticulocytes. We show that the switch in the alpha-globin gene cluster from the embryonic to fetal/adult pattern of expression begins at 5 to 6 weeks of gestation. Both the theta- and alpha-globin genes show similar patterns of developmental control that are reciprocal to zeta. alpha-globin RNA is barely detectable or undetectable at 5 weeks, and increases in the 6- to 8-week period, while theta-globin mRNA shows a parallel increase at 5 to 8 weeks postconception and is expressed in cord blood and adult reticulocytes. These data show that the theta-globin gene represents a fetal/adult gene, albeit expressed at a low level.


Band 3 Memphis: a widespread polymorphism with abnormal electrophoretic mobility of erythrocyte band 3 protein caused by substitution AAG----GAG (Lys----Glu) in codon 56. Band 3 Memphis (b3M) is a variant of the erythrocyte band 3 protein detected in individuals of virtually all ethnic groups and characterized by a reduced mobility of proteolytic fragments derived from the N-terminus of the cytoplasmic domain of band 3 (cdb3). We have sequenced band 3 cDNA corresponding to cdb3 in 12 heterozygotes for the b3M polymorphism including one white, one black, one Chinese, one Philippino, one Malay, and seven Melanesian subjects. In all individuals, we found a single-base substitution in codon 56 of one band 3 allele changing lysine to glutamic acid (AAG----GAG) which, in some of them, was linked with an additional mutation in cdb3. Since the change of codon 56 from AAG to GAG was the only mutation in the studied individuals found within the cDNA segment coding for the abnormally migrating fragment of cdb3, we conclude that it represents the underlying molecular basis of the b3M polymorphism. We further support this conclusion by showing that electrophoresis in the presence of 4 mol/L urea abolished the difference in migration between proteolytic products of b3M and normal band 3, and that a fusion protein prepared from cDNA coding for the b3M allele again exhibits reduced electrophoretic mobility compared with the normal fusion protein. Finally, since most of the previously cloned mouse, rat, and chicken band 3 and band 3-related proteins contain glutamic acid in the position corresponding to amino acid 56 in the human band 3, we propose that the Memphis variant is the evolutionarily older form of band 3.


Relevance of pretransfusion incubation of platelets at 37 degrees C. The effect of pretransfusion incubation of platelets at 37 degrees C was assessed because of the controversial reports about its relevance. A dual-label technique (111indium and 114mindium) was applied in 10 healthy subjects receiving warmed and unwarmed autologous platelets simultaneously. Fresh platelet concentrates were infused into five subjects, whereas the other five subjects received stored platelet concentrates. The mean platelet volume decreased in all platelet concentrates during incubation, reflecting the restoration of the discoid shape of the platelets. The mean decrease was 0.35 fL (P = .003). However, the initial recovery and the mean platelet life-span were not improved by this procedure. It was concluded that there is no evidence that brief warming of platelets has any beneficial effect on platelet viability in healthy volunteers.


Bone marrow transplantation in adult thalassemia. Early trials of allogeneic marrow transplantation for homozygous thalassemia were disappointing in patients older than 16, with four of six patients dying early of graft-versus-host disease-related complications, one patient dying at 9 months of infection due to graft failure, and one dying at 6 years of recurrent thalassemia. Three classes of risk could be identified in analyses of results of transplantation in younger patients using the criteria of degree of hepatomegaly, the presence or absence of portal fibrosis, and a history of adequate or inadequate chelation therapy. Patients for whom all three criteria were adverse constituted a very high risk group (class 3) for marrow transplantation. On the basis of these analyses, a conditioning regimen was designed that yielded superior results for class 3 patients under 17 years of age. Most patients older than 16 years presenting for transplantation have disease characteristics that place them in class 3 and, because of the improved results with the new class 3 regimen in younger patients, a study was designed to treat patients older than 16 years using treatment regimens assigned on the basis of disease class. Twenty patients were treated using this protocol and, with a minimum follow-up of 9 months, there have been three early deaths, one patient has recurrent thalassemia, and 16 patients are alive disease-free. The actuarial probabilities of survival, disease-free survival, and rejection are 0.85, 0.80, and 0.05, respectively, with a survival plateau extending from 6 months to 3 years. Marrow transplantation is a reasonable option for adults with progressive thalassemia who have suitable donors.


Specific marrow ablation before marrow transplantation using an aminophosphonic acid conjugate 166Ho-EDTMP. 166Holmium ethylenediaminetetramethylene phosphonic acid (166Ho-EDTMP) is a short-lived beta-emitting radionuclide complexed to an aminophosphonate ligand that we have investigated in a canine model as a potential agent for specific marrow ablation before marrow transplantation. After intravenous injections, 166Ho-EDTMP distributed principally to bone and after 24 hours the concentrations of 166Ho-EDTMP in bone were more than 200-fold higher than in any other organ. Increasing dosages of 166Ho-EDTMP led to increasingly prolonged and severe myelosuppression, but myeloablation was not achieved. Histologic examination of recovering animals suggested that the spleen may have acted as a reservoir for circulatory hematopoietic precursors. Four splenectomized animals administered 20 to 30 mCi/kg 166Ho-EDTMP without marrow transplantation died with marrow aplasia, while four splenectomized animals administered similar dosages of 166Ho-EDTMP followed by autologous transplantation recovered. The dose-limiting toxicity of 166Ho-EDTMP appeared to be marrow stromal damage resulting in myelofibrosis, which was reversible. These results suggest that 166Ho-EDTMP can be used to specifically ablate marrow function before marrow transplantation.


The social epidemiology of falls among community-dwelling elderly: guidelines for prevention. Social epidemiology offers a conceptual model that organizes the risk factors for falls into demographic, medical and psychosocial host factors, environmental factors and the agent in falls. Once identified in such a manner it is possible to differentiate between those factors which are or are not amenable to change or treatment, thus suggesting methods of fall prevention. Fall prevention strategies are feasible before a fall, at the time of a fall, and following an injurious fall, corresponding to primary, secondary, and tertiary prevention. At each level of prevention, prevention strategies are described, and together they constitute a complete fall prevention programme for community-dwelling elderly. A review of those strategies that have been evaluated shows that their efficacy in reducing the incidence of falls and their adverse complications is generally limited. Thus, further evaluation research is needed in order to incorporate the most effective fall prevention programmes into standard community care for the elderly.


A cross-cultural assessment of perceived health problems in the elderly. To study cross-cultural differences in perceived health problems in the elderly the Nottingham Health Profile (NHP) developed by Hunt et al. was administered to subjects from the People's Republic of China and Australia. The Australian stratum was further categorized according to cardiovascular status. Analyses of covariance (with age as the covariate) on each of the six subscales of the NHP yielded significant differences for 'Energy', 'Pain', 'Emotional reactions', 'Social isolation' and 'Physical mobility'. No differences were found for the 'Sleep' subscale. Through comparisons between the mean scores for the four strata and from normative data it is concluded that it is likely that the NHP is 'culture free' on the dimensions 'Energy', 'Pain', 'Emotional reactions', 'Social isolation' and 'Physical mobility'.


Cyclosporin reduces renal prostanoid excretion in type 1 diabetic patients. Prostacyclin and thromboxane A2 are important regulators of kidney blood flow. To examine whether changes in their metabolism could be involved in the nephrotoxicity of cyclosporin, we determined urinary excretion of 6-keto PGF1a and dinor-6-keto PGF1a (prostacyclin metabolites) and dinor-TxB2 (thromboxane metabolite) in five newly diagnosed type 1 diabetic patients during and after stopping cyclosporin therapy. In the resting state, cyclosporin had no effect on prostanoid excretion. In response to exercise, urinary excretion of 6-keto PGF1a was reduced by 50% (P less than 0.02), dinor-6-keto PGF1a by 15% (P less than 0.05) and dinor-TxB2 by 45% (P less than 0.02), while albumin excretion increased 4.5-fold (P less than 0.05) during cyclosporin therapy. Simultaneously, there was a rise in serum creatinine concentration, and renal biopsy specimens obtained from three patients showed periglomerular and interstitial fibrosis and tubular atrophy. After the discontinuation of cyclosporin therapy, serum creatinine concentrations returned to normal, histological changes improved and there was an associated rise in urinary prostanoid excretion. These data suggest that a reduction in renal prostanoid synthesis by cyclosporin may diminish renal blood flow and function, and lead to histological changes in the kidney.


Exercise is not associated with better diabetes control in type 1 and type 2 diabetic subjects. In the clinical setting, the impact of educational efforts on the amount of regular exercise and its effects on diabetes control are unclear. Fifty type 1 diabetic, 50 type 2 diabetic and 70 non-diabetic subjects were evaluated using a questionnaire for type, duration and intensity of exercise to assess weekly energy expenditure. Diabetic subjects did not exercise more than controls: 36% of the type 1, 46% of the type 2 and 46% of the control subjects admitted no physical activity, and those exercising regularly had similar energy expenditure: 1808 +/- 320, 2722 +/- 617, 2523 +/- 304 (mean +/- SEM) kcal/week respectively (P = NS). There was no correlation between the degree of activity and HbA1c levels, or hypoglycaemic events. HbA1c levels were less than 6,8% in 31% of nonactive patients versus 21% of active patients (P = NS). A negative correlation was found between physical activity and daily insulin usage (r = 0.27, P less than 0.05), but differences between patients averaged only 4IU/1000 kcal energy expenditure/day. We conclude that patients' attitude towards exercise was not improved by our educational methods and that physical exercise was not necessarily associated with good blood glucose control.


Identifying safe versus unsafe drivers following brain impairment: the Coorabel Programme. The Coorabel Driver Assessment and Training Programme commenced in January 1988, with the aim of providing assessments of the ability of people with a disability to resume or commence driving. This programme incorporates assessments by a medical practitioner, a neuropsychologist, an occupational therapist and a driving instructor, conducted both off and on the road. The first 129 consecutive referrals were reviewed. Non-brain-impaired clients demonstrated a lower failure rate relative to brain-impaired clients. Diagnosis was not found to have predictive value within the brain-impaired clients, and there was no statistical difference in failure rates between left and right hemispheric strokes. Whilst only six cases failed the medical assessment, in 47 cases the medical practitioner was unable to make a final decision regarding driver competence. Neuropsychological and on-road assessments resulted in definitive decisions for 39 of these 47 cases. Twenty cases passed the medical assessment but subsequently failed the neuropsychological or on-road assessment. Only three cases passed at neuropsychological assessment subsequently failed on-road testing. It is suggested that multidisciplinary assessment of driver competence, inclusive of on-road testing, is essential, as medical guidelines alone are insufficient to predict driver fitness.


Perceptual impairment after stroke: improvements during the first 3 months. The aim of the study was to assess changes in perceptual abilities during the first 3 months after stroke using a prospective observational design. The sample was from a hospital with a catchment population of 205,000. Seventy persons aged 60+ admitted with non-lacunar stroke were given the Rivermead Perceptual Assessment Battery, 2 weeks after stroke. Three months post-stroke subjects were reassessed on subtests they had initially failed. The improvements in performance on all 16 subtests of the RPAB were significant, and large in relationship to the maximal possible improvement had all subjects achieved perfect scores on follow-up. Performance on line bisection and line cancellation also improved significantly. In spite of these improvements 64% of subjects still had perceptual impairment as defined by an RPAB score of 0-12 at 3 months post-stroke. It is concluded that perceptual abilities improved greatly during the first 3 months after non-lacunar stroke but nevertheless perceptual impairments remain common at 3-month follow-up.


The diversity of speech and language therapy services for aphasic adults in the United Kingdom. Data on aphasia management were collected by questionnaires to UK speech and language therapists. Returns representing over 90% of health districts were obtained. Variation amongst districts is evident in levels of staffing for the adult neurological case load, and in speed of response to referral, frequency and types of treatment available, and in other forms of support for patients and carers. Although individual therapists or districts are able to adhere to some of the professional recommendations for a 'quality' service, few are able to provide this high level of care in all aspects of aphasia management.


Long-term fat-feeding-induced insulin resistance in normal NMRI mice: postreceptor changes of liver, muscle and adipose tissue metabolism resembling those of type 2 diabetes. Postreceptor insulin resistance was studied in liver, muscle and adipose tissue from NMRI mice of both sexes made diabetic by long-term fat-feeding. Intravenous glucose tolerance tests showed a combination of impaired glucose tolerance and increased plasma insulin concentrations consistent with insulin resistance and reduced peripheral and hepatic uptake of glucose. In the morning, the fat-fed mice were normoinsulinaemic and hyperglycaemic. Liver glucokinase activity and glycogen content were reduced whereas lactate dehydrogenase activity was enhanced. Fatty acid synthase activity was decreased but glucose 6-phosphate dehydrogenase and the rate limiting enzyme in fatty acid synthesis, acetyl CoA carboxylase, were both unaffected. In muscle, the proportion of glycogen synthase in the active I-form was decreased. Total glycogen synthase activity was not affected. In isolated adipocytes, basal and insulin-stimulated glucose oxidation, as well as basal and insulin-stimulated lipogenesis from glucose were all severely inhibited, oxidation more so than lipogenesis. It is concluded that insulin resistance and postreceptor metabolic disorders in liver, muscle and adipose tissue from mice made diabetic by long-term fat-feeding are very similar to those demonstrated in human type 2 diabetics and may be studied in more detail and with more ease in this particular animal model.


Rehabilitation after a letter-bomb attack causing bilateral hand loss and other injuries: case report. The rehabilitation of patients after terrorist attacks has received scant attention in the literature. A case is reported of a patient injured in a letter-bomb explosion; his injuries were bilateral hand loss, loss of one eye, and perforated ear-drums. The successful rehabilitation of this patient to normal work in 8 months is described. A rehabilitation plan for management of similar patients is given.


A simple clinical approach to discriminate between "true" and "pseudo" secondary failure to oral hypoglycaemic agents. To discriminate between true secondary failure (TF) and pseudo-secondary failure (PF) to oral hypoglycaemic agents, we studied 34 non-obese non-insulin-dependent diabetic patients who were being treated with these drugs. Nine were in good control (GC) with oral treatment, while 25 showed apparent SF. During a controlled hospital diet, fasting blood glucose remained persistently high in 15 of these patients (TF), while in the other 10 patients it clearly improved (PF). Fasting plasma glucose (FPG) and HbA1c were higher and body mass index (BMI) was lower in TF patients than in PF patients (P less than 0.01). C-peptide concentrations differed significantly among the three groups both in the fasting state (TF 0.25 +/- 0.02 nmol/l, PF 0.70 +/- 0.03 nmol/l, GC 0.74 +/- 0.03 nmol/l; P less than 0.0001) and 6 min after glucagon injection (TF 0.50 +/- 0.04 nmol/l, PF 1.02 +/- 0.06 nmol/l, GC 1.14 +/- 0.07 nmol/l; P less than 0.0001). C-peptide and plasma insulin curves obtained after a standard mixed meal also showed significant differences (P less than 0.001). In particular, there was a statistically significant difference between GC and PF versus TF (P less than 0.05), while there was no statistical difference between PF and GC. We conclude that some patients with apparent SF can improve their metabolic control if they strictly adhere to a correct diet (PF); a single measurement of basal C-peptide concentration or examination of the C-peptide and insulin responses to a meal are useful indicators for distinguishing patients with PF from those with TF to oral hypoglycaemic agents.(ABSTRACT TRUNCATED AT 250 WORDS)


Impaired cutaneous reactive hyperaemia during hypoglycaemia in young insulin-dependent diabetic patients and healthy controls. The aim of the present study was to compare the cutaneous postischaemic hyperaemic response in young insulin-dependent diabetic patients and healthy subjects during normoglycaemia, acute insulin-induced hypoglycaemia and in the posthypoglycaemic state. After a night of normoglycaemia the cutaneous postischaemic hyperaemic response in the forearm skin, measured by the transcutaneous PO2 method, was the same in both groups. A reduction of the maximal postischaemic vasodilatory response was observed in diabetic patients from 2.4 +/- 0.3 to 2.0 +/- 0.2 kPa (P less than 0.05) and in control subjects from 2.7 +/- 0.3 to 1.8 +/- 0.2 kPa (P less than 0.02) during insulin-induced hypoglycaemia (plasma glucose less than 2 mmol/l). Complete recovery of the vasodilatory response occurred in subjects in the posthypoglycaemic state. We conclude that hypoglycaemia induced a transient reduction of the vasodilatory response, which was rapidly reversed after glucose counter-regulation, in both diabetic patients and healthy controls. Thus, the prevailing blood glucose concentration must be taken into account when the postischaemic vasodilatory response is investigated in diabetic patients.


Comparison of the metabolic effects of mixed meal and standard oral glucose tolerance test on glucose, insulin and C-peptide response in healthy, impaired glucose tolerance, mild and severe non-insulin-dependent diabetic subjects. Dietary constituents other than glucose can influence insulin secretion in non-insulin-dependent diabetes mellitus and administration of a standard mixed meal has been proposed as a more physiological test in regard to human diet for evaluating the patient both at the time of diagnosis and during follow-up. This study was carried out to compare the effects of a standard meal and the oral glucose tolerance test on glucose, insulin and C-peptide plasma levels in four groups of subjects: healthy controls, subjects with impaired glucose tolerance, patients with mild non-insulin-dependent diabetes, and non-insulin-dependent diabetic patients with secondary failure to oral agents. Plasma glucose values were significantly higher after the oral glucose tolerance test than after the mixed meal in all four groups of subjects. Plasma insulin and C-peptide values were similar during the two tests in all groups of subjects except in non-insulin-dependent diabetics with secondary failure (flattened curves). Insulin and C-peptide responses per unit rise in blood glucose were significantly higher after the oral glucose tolerance test than after the mixed meal both in mild non-insulin-dependent diabetics (P less than 0.05 and P less than 0.05) and in non-insulin-dependent diabetics in secondary failure (P less than 0.01 and P less than 0.05). There was significant correlation between oral glucose tolerance test and mixed meal glucose incremental areas (r = 0.511, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of hyperglycaemia on visual evoked potentials in insulin-dependent diabetic patients. Multimodality evoked potentials frequently reveal subclinical involvement of the central nervous system in patients with insulin-dependent diabetes mellitus. We devised this study to evaluate the possible effects of acute hyperglycaemia on visual evoked potential (VEP) parameters in type 1 diabetic patients. A hyperglycaemic clamp (250 mg/dl for 180 min) was performed in ten patients. Monocular pattern reversal VEPs (check size 15', contrast 50%) were recorded before, and every 30 min after the start of the clamp. Basal VEP latencies and amplitudes were normal bilaterally in nine patients. No significant changes in pattern reversal and flash VEP parameters were observed after the induction or during the clamp period. None of the neurophysiological parameters evaluated during the test was related to the duration of the disease, the basal VEP latency or amplitude or the presence of retinopathy. Our data suggest that the neurophysiological abnormalities detected in insulin-dependent diabetic patients are due to structural involvement of the central nervous pathways and not to functional damage induced by acute short-term hyperglycaemia.


Familial insulinoma: description of two cases. We describe cases of isolated functioning insulinoma occurring in two members of the same family (father and daughter). The father had a first encapsulated insulinoma diagnosed at 14 years of age and at the age of 33 years he was operated on for a second insulinoma infiltrating the exocrine pancreas with lymph node metastases. The daughter was operated on for an encapsulated insulinoma in the tail of the pancreas when she was 6 years old. No clinical and laboratory signs of other endocrine disturbances have so far been detected in either care or in any other members of the family. Our report suggests the possibility of multiple familial insulinoma, although this is an extremely rare condition. Our data also indicate that insulinomas, even if well controlled by medical treatment, should always be removed by surgery because malignancy cannot be excluded with certainty. Moreover, patients should be closely followed up, as recurrence may develop up to 15 years after surgery.


Alginate coating of islets of Langerhans: in vitro studies on a new method for microencapsulation for immuno-isolated transplantation. Immuno-isolated transplantation offers the attractive prospect of being able to transplant xenogeneic islets without immunosuppression. This study introduces a completely new method of coating single islets using a homogeneous alginate membrane approximately 10 microns thick. During glucose challenge (perifusion and static incubation) encapsulated islets show the same pattern and quantity of insulin release as non-encapsulated controls. This encapsulation method markedly reduces the amount of transplanted material by reducing the size of the capsule. It is suggested that encapsulated islets may be transplanted into sites such as the renal capsule or omentum or even by intraportal injection into the liver.


Relationship between plasma leucine concentration and clearance in normal and type 1 diabetic subjects. In a series of studies in normal and type 1 diabetic subjects, we analysed the relationship between isotope-calculated leucine clearance and plasma leucine concentration. All studies were performed under euglycaemic conditions. Plasma leucine concentrations were either experimentally decreased by means of insulin infusion, or increased by means of exogenous amino acid infusion in the presence of hyperinsulinaemia. Leucine clearance rates were compared in normal and diabetic subjects at similar plasma insulin levels. The effect of hyperinsulinaemia was examined by measuring clearance rates in normal subjects at comparable leucine levels but different insulin concentrations. Our data show that leucine clearance is inversely related to leucine concentration, and that it is not independently stimulated by hyperinsulinaemia. Type 1 diabetes is not associated with decreased leucine clearance. A general equation relating leucine concentration and clearance is proposed. These data support the view that peripheral leucine utilization is not decreased in type 1 diabetes mellitus.


Interleukin-3 in the treatment of myelodysplastic syndromes. Patients with myelodysplastic syndromes frequently present with anemia, leukopenia and thrombocytopenia due to defective maturation of bone marrow cells. Clinical studies with hematopoietic growth factors, including interleukin-3 (IL-3), have been undertaken to evaluate the possibility to reverse cytopenia. In initial phase I/II trials, treatment with IL-3 has resulted in an increase of neutrophil counts in 59%, of platelet counts in 34%, and in reticulocyte counts in 25% of the patients. Adverse effects were rather mild but in individual patients a reversible decrease in platelet counts and in the number of blast cells in blood and bone marrow were observed. Further clinical trials should concentrate on the combination of an early acting cytokine like IL-3 and later acting hemopoietic growth factors like erythropoietin and granulocyte colony-stimulating factor.


Will a tumor metastasize? Quantitate, semi-quantitate or pseudo-quantitate? A brief review of the microscopic prediction of tumor metastasis. This review examines ways in which histopathologists can attempt to predict whether a neoplasm will metastasize by microscopic examination of surgically removed samples of human neoplasms. These include qualitative description, semi-quantitative analysis of differentiation and proliferation, or of the nature of the edge of the neoplasm, and quantitative analysis of mitotic counts. More recently measurement of DNA content, analysis of DNA turnover, measurement of proliferation antigens, measurement of nucleolar organizing areas, counting nucleoli, morphometry of nuclei and identification of genetic change have become possible. There is no test capable of uniform accurate prediction of prognosis. In certain types of neoplasms in individual sites useful prognostic information can be obtained either by rigorous semi-quantitative microscopic analysis or by quantitative microscopical analysis. There is still doubt as to whether newer quantitative techniques will perform uniformly better than older semi-quantitative techniques. The simple subjective statement "high-grade malignancy, average malignancy, low malignancy" is better than elaborate non-reproducible pseudo-quantitation.


The interleukin-2/interleukin-2 receptor system: structural, immunological, and clinical features. Interleukin-2 (IL-2) has been the first and more extensively studied cytokine, in particular for its central role in the mechanisms of cell growth and differentiation. The function of IL-2 is mediated through specific receptors (IL-2R) present on the membrane of reacting cells. Using hybridoma and recombinant DNA technologies, both IL-2 and IL-2R have been biochemically characterized and purified and are available for in vitro and in vivo studies. The biological and clinical investigations on IL-2/IL-2R system have contributed to opening new avenues for the comprehension of phenomena that are critically important for biology, immunology and medicine.


Interleukin 6: presence and future.

Interleukin 6: presence and future. This review article deals with the basic biological characteristics of the multifunctional cytokine interleukin-6 (IL-6) in man. Three central issues will be addressed more closely: the pathophysiological role of unbalanced IL-6 production in various disease states, the diagnostic usefulness of measurements of IL-6 in biological fluids, and the possible role of IL-6, IL-6 antagonists, and IL-6 derivatives as therapeutic tools in clinical medicine.


The estimation of free light chains of immunoglobulins in biological fluids. Methods for the estimation of the free light chains of immunoglobulins in serum, urine and cerebrospinal fluid are divided into two groups, electrophoretic and immunological, and the analytical performance of each method described. The problems associated with the accurate and precise determination of free light chains by the different methods are discussed and their complementary clinical roles emphasized. It is proposed that an International Reference Preparation for free light chains is established.


Detection of a transcriptional block in the first intron of the human c-myb gene. The levels of expression of the murine c-myb gene, like those of several other proto-oncogenes, can be controlled by a block of transcriptional elongation within the first intron of the gene. We have performed run-off experiments with double- and single-stranded probes on the myelomonocytic cell line U937, and show that this mechanism of transcriptional arrest is true also for the human c-myb gene and takes place within the first intron. Furthermore, we have sequenced the entire first intron of the human c-myb gene, and discuss the sequence structure in relation to its putative ability to arrest RNA polymerase II and its high degree of homology with the equivalent murine intron.


Demonstration of a possible link between high grade malignancy in dimethylbenz[a]anthracene-induced rat mammary carcinoma and increased urokinase plasminogen activator content. Recent reports have suggested that tissue-type plasminogen activator activity is regulated by estrogen in 7,12-dimethylbenz[a]anthracene-induced rat mammary carcinoma type I cells but is not necessarily regulated by estrogen in type II mammary carcinoma cells. We have compared the biological features of these two types of mammary carcinoma cells and have found that, although there is no difference in estrogen receptor content between these two cell types, the plasminogen activator activity markedly differs. Tissue-type plasminogen activator activity is significantly higher in type I carcinoma than in type II carcinoma, urokinase-type activity is significantly higher in type II carcinoma than in type I carcinoma. When these two types were compared in terms of rate of tumor growth, type II carcinomas clearly showed more rapid growth than type I carcinomas. Survival studies showed significantly shorter survival of type II tumor-bearing rats compared with type I tumor-bearing rats. Furthermore, type II carcinomas contained a greater proportion of aneuploid cells than type I carcinomas. These results suggest that type II carcinoma cells, in which estrogen is unable to regulate tissue-type plasminogen activator activity, are considered to be of a higher grade of malignancy than type I carcinoma cells.


Antithrombotic and thrombolytic activity of sulodexide in rats. We evaluated the ability of sulodexide, an extracted glycosaminoglycan, to prevent thrombus formation and to reduce a stabilized thrombus in a rat venous thrombosis model (vena cava ligature). Injection of sulodexide 10 min before induction of venous stasis, prevented thrombus formation in a dose-dependent manner (median effective dose 0.55 mg/kg). When given to rats with 6-h-old thrombi, sulodexide caused a marked reduction in thrombus size which reached 70% after 2 h with the highest dose tested (2 mg/kg). The effect of sulodexide on established thrombi appears to be due, at least in part, to a fibrinolysis-mediated mechanism, since it was significantly inhibited by epsilon-aminocaproic acid, a well-known antifibrinolytic drug. Treatment with sulodexide did not noticeably affect plasma levels of plasminogen activator and its specific inhibitor. We also showed that fluorescein-labelled sulodexide, when given to animals with 6-h-old thrombi, was present within the thrombi harvested 2 h later, but was then absent from blood. The fluorescence was mainly located in areas filled with amorphous material, that was identified as fibrin by staining with phosphotungstic acid-hematoxylin. No fluorescein-labelled material could be detected in rats treated with fluorescein alone. These findings indicate that, besides preventing venous thrombus formation, sulodexide is able to promote thrombus dissolution by a mechanism that is partly related to local fibrinolysis stimulation.


Comparative means of dose reduction in dental radiography. This review on dose reduction in dental radiography focuses on criteria for selecting the frequency and type of radiographs to be performed on patients. By making radiographs only when there is a reasonable probability of a finding that will influence patient care, patient exposure and other radiographic costs may be substantially reduced. Patient dose may also be reduced by half by changing from D-speed film to E-speed film for intraoral radiography and by more than half by changing from calcium tungstate intensifying screens to rare-earth intensifying screens for panoramic and cephalometric radiography. Using rectangular collimation for intraoral radiography will also further reduce patient exposure by about fourfold. Finally, the use of time-temperature processing will prevent overexposure of the patient and underprocessing of the radiographs; optimal radiographs will be provided.


The use of lasers in periodontology.

The use of lasers in periodontology. Clinical lasers are of two types: "soft" and "hard" lasers. Soft lasers are claimed to aid healing and to reduce inflammation and pain. However, few rigorous studies are available to support their use. Surgical hard lasers can cut both hard and soft tissues, and newer varieties can transmit their energy via flexible fiberoptic cables. Many procedures can be performed without local analgesia, and because lasers sterilize as they cut, in spite of current controversies, they promise to find uses in all disciplines of dentistry, including periodontics.


Treatment of failing dental implants.

Treatment of failing dental implants. Recent studies show that the bacterial flora in adult periodontitis and peri-implantitis are identical, but there could be a more pathogenic flora (gram-negative bacteria, spirochetes) in the partially edentulous implant case than in the fully edentulous implant case. These data indicate a possible seeding mechanism from the natural tooth pocket to the implant crevice and may place the implant in the partially edentulous case more at risk. Also, understanding of the importance of loading in a progressive sense to prevent retrograde peri-implantitis involving the dental implant has increased; the density of bone must be evaluated more fully to determine the time frame necessary to gain a compact bone capable of withstanding occlusal forces at the bone-implant interface.


Surgical management of endodontically treated teeth. Surgical endodontics has become an important treatment modality in modern dentistry. The evolution and development of this modality has suffered from decades of empiricism, as techniques, concepts, and root-end filling materials were advocated without supporting scientific evidence. The techniques and concepts of periodontal surgery and oral and maxillofacial surgery were long assumed to directly apply to endodontic surgery. Evidence now suggests that certain procedures adopted from other specialties are not indicated for surgical endodontics and, in fact, may be counterproductive. During the past year, the most important developments have emerged in the area of surgical wound healing as it relates to soft tissue management procedures. New techniques and concepts that enhance rapid wound healing and decrease untoward postsurgical sequelae have been proposed.


Dentin- and enamel-bonding agents.

Dentin- and enamel-bonding agents. The introduction of bonding agents in restorative dentistry has made it possible to adhere restorative materials to tooth structure. Since bonded restorations were introduced by Buonocore in 1955, extensive research has been conducted to develop systems that bond equally effectively to enamel and dentin. Researchers have identified a micromechanical retention mechanism for the attachment of hydrophobic resin restorative materials to both enamel and dentin that works if appropriate conditioning or priming steps are applied. At the dentin site, the modes of action of current adhesive systems converge to create a resin-dentin interdiffusion zone between the deep dentin structures and the filling material. To incorporate or remove the smear layer in this interdiffusion zone, different adhesion strategies are followed to obtain a resin-dentin bond. In the clinical situation, these modern dentin-bonding systems are more technique sensitive; the thickness of the interface, its elastic capacity, the polymerization efficiency and initiation of the bonding agent, and, finally, the application technique used for the restorative material play an important role in the final result.


Composite-resin materials and techniques in dentistry. Important features to consider when selecting composite resins are filler size and amount, radiopacity, and fluoride content. Submicron particles provide the best polishability, and heavily filled resins demonstrate better wear resistance. The radiopacity of the composite resin should slightly exceed that of enamel to allow visualization of the restoration and recurrent decay. Fluoride added to the matrix may arrest the progression of caries. Properly cured composite resins should not cause chronic pulpal irritation; however, infection of the cervical contraction gap resulting from poor bonding to root surfaces may cause pulpal irritation. Techniques to improve curing include incremental build-up, reflective matrices and wedges, and controlling the direction of light vectors. A surface sealant is highly recommended to reduce wear, especially in the posterior region. Porcelain veneers perform better clinically than do composite-resin veneers. Class I and II composite-resin restorations reinforce weakened tooth structure; however, problems with cervical leakage and wear prevent the recommendation of these materials for larger posterior restorations that involve occlusal contacts or that require bonding to root surfaces.


Glass ionomer (polyalkenoate) cement restorations. Glass ionomer cements are recognized for their properties of reliable adhesion to tooth structure and fluoride release. The introduction of light-cured base and liner glass ionomer cements has overcome some of the disadvantages of self-cured materials. During the review period, most papers deal with either fluoride release, microleakage, or adhesion. There were few clinical studies.


Bleaching of vital and nonvital teeth.

Bleaching of vital and nonvital teeth. Although tooth bleaching has been known to the dental profession for over 100 years, new knowledge is continually surfacing. This review discusses the 1990 to 1991 literature on two nonvital bleaching techniques (thermocatalytic and walking) and three classes of vital bleaching techniques (in-office; dentist-prescribed, home-applied; and over-the-counter kits). The choice for nonvital bleaching is the walking bleach technique, with the use of sodium perborate alone having less potential for cervical resorption. The choices for vital bleaching techniques are either the dentist-prescribed, home-applied technique, the in-office technique, or a combination of the two. Bonding should be delayed 2 weeks after bleaching. Microabrasion is a possible second choice for certain discolorations. These chosen bleaching techniques, when used in a professionally appropriate manner, seem as safe as other commonly used dental treatments.


Amalgam in the restoration of posterior teeth. The use of aesthetic restorative materials such as cast ceramic, porcelain, and composite resin for the restoration of posterior teeth has increased in recent years, but amalgam remains the most frequently used material. Although stories in the media recently renewed the debate over amalgam safety, amalgam has remained in the armamentarium of the average clinician in large part because of its long positive clinical history, beneficial physical properties, and forgiving handling characteristics.


Changing paradigms in caries management. Management of dental caries patients is taking on a new look. Caries is the clinical manifestation of an oral infection. The primary organisms involved are Streptococcus mutans. The infective nature of the disease has been well researched and reported. Treatment of this infection with antibacterial measures is becoming routine in developed countries. In the United States, the overall caries rate is decreasing. However, the distribution of caries is now skewed. Twenty percent of the population has 60% of the caries. These individuals have a significant level of infection or a major lack of resistance to the organisms and their by-products. Major strategies are being developed to control these infections and limit their recurrence. This review focuses on the developments in prevalence studies, diagnosis, and treatment of the caries infection.


Comparative imaging of the temporomandibular joint. During this annual review period, the literature reflected the great interest in magnetic resonance imaging as a diagnostic tool for assessing the various types of disk displacement and for postoperative imaging, due to its exceptional visualization of the normal and abnormal temporomandibular joint compared with other imaging modalities. None of the authors doubt the potential of magnetic resonance imaging and the interest shown in defining both the normal range of disk position and the pitfalls in the interpretation is a sound development. Arthrography still has its advantages and seems to be the only competitive imaging modality for the assessment of internal derangement; it also has been shown to detect mediolateral disk displacements. Further improvements may be obtained by double-contrast and digital subtraction techniques. In chronic arthritic diseases such as rheumatoid arthritis, the literature has focused on bone abnormalities depicted with tomography and computed tomography. The potential of magnetic resonance imaging to show other inflammatory changes also has been indicated.


Osseointegrated implant prosthodontics.

Osseointegrated implant prosthodontics. This review covers recent literature on prosthodontic aspects of osseointegrated implants. Long-term prognosis, diagnosis and treatment planning, and clinical impression techniques and fabrication technology are discussed.


Metalloproteinases in the pathogenesis of periodontal diseases. Matrix metalloproteinases are produced by both defense and structural cells of the periodontium. They are capable of a wide range of interstitial tissue degradation activities. Complex regulating mechanisms include cytokine regulation of genetic transcription, secretion in latent form, which requires activation once produced, and inhibition by specific inhibitors. It appears that these proteinases and their inhibitors, regulating molecules, and associated genetic material are all potential diagnostic markers of periodontal disease. In addition, they can be measured from gingival crevicular fluid or whole saliva. Generally, high inhibitor levels indicate health, and high levels of metalloproteinase indicate disease. Metalloproteinases can also be inhibited by the tetracycline family of drugs to produce clinical benefits. The diagnostic and therapeutic potential of matrix metalloproteinases and their central role in the pathogenesis of periodontal disease serve to emphasize their importance to periodontologists.


A review of the developments in dental CAD/CAM systems. At least 1000 CAD/CAM (computer-aided design and computer-aided manufacturing) systems for producing restorations are in dental offices. At least nine different systems have been described; the Cerec system (Siemens, Bensheim, FRG) is the best known and most widely used. Clinical results to date suggest that the automated CAD/CAM systems can provide restorations which perform at least as well as cast restorations. There are some technique sensitivities that must be managed with the new technology. The importance of fit at the margins is a controversial issue that remains to be settled. Bond strength of composite-luted restorations is dependent on margin location and luting material properties, and on the combination of silanating, etching, and curing mechanism of the luting composite. Surface finishes equivalent to cast gold and glazed porcelain can be achieved for machinable CAD/CAM materials.


Diagnosis and treatment of refractory periodontitis. Clinicians are occasionally frustrated in arresting the progress of periodontal destruction. The refractory lesion is a problem with a complex and incompletely articulated cause that results in ill-defined and often misdirected treatment. This paper discusses whether refractory periodontitis is a specific entity or whether other periodontal conditions can become refractory.


Aesthetic partial-coverage dental restorations. The literature on the subject of aesthetic partial-coverage restorations, including laminate veneers, laminate veneer bridges, composite-resin and ceramic inlays and onlays, computer-designed restorations, and etched cast restorations, has continued to expand into the 1990s. Investigations regarding fit, longevity, wear, and microleakage, as well as descriptions of clinical techniques, were well documented world-wide in 1991. The purpose of this review is to discuss some of the more important papers published during the past year.


Periodontal disease activity.

Periodontal disease activity. Periodontal disease activity is defined clinically by progressive loss of probing attachment and radiographically by progressive loss of alveolar bone. The natural history of periodontal disease was originally considered to be nearly continuous and slowly progressive. Clinical research conducted in the last decade suggests that periodontal disease demonstrates periods of exacerbation and remission. Using sensitive automated probes, studies published during the past year have demonstrated that different patterns of disease activity can exist, and that these patterns may be dependent on the disease threshold. Subtraction radiography continues to be refined, but cost and methodology prevent this diagnostic tool from having widespread clinical application. A variety of clinical, microbiologic, and host-response parameters have been studied for their relationship to periodontal disease activity. Many research groups are attempting to develop a diagnostic test that identifies the risk for development of active disease. A relatively simple test based on the presence of a microbial virulence factor, or the host inflammatory or immune response to the subgingival microflora, may be a practical means for clinicians to detect the active phases of periodontal disease.


Diagnostic tests for periodontal diseases. A high level of interest in the development of diagnostic tests capable of detecting factors associated with progressing ("active") periodontal disease has continued in the past year. Notable advances and refinements have occurred in subtraction radiographic techniques and in the development of computer-linked, controlled-force periodontal probes. Development and evaluation of new diagnostic tests have also proceeded at a rapid pace. Particular emphasis has been placed on rapid tests for putative periodontal pathogens and detection in gingival crevicular fluid of host-derived enzymes. An intense effort must be made to determine the clinical value of diagnostic tests in longitudinal studies that use state-of-the-art assessments of disease progression.