Regulation of corticotropin-releasing factor mRNA in neuroendocrine and autonomic neurons by osmotic stimulation and volume loading. Corticotropin-releasing factor (CRF) has been reported to be expressed in oxytocin-containing magnocellular neurosecretory neurons of the paraventricular (PVN) and supraoptic (SON) nuclei, and in Barrington's nucleus, a pontine micturition center. Each of these cell groups is known to play a role in fluid and electrolyte homeostasis. To gain a better understanding of the role of CRF in this context, the effects of osmotic stimulation and volume loading on CRF mRNA levels in the PVN, SON and Barrington's nucleus were examined using in situ hybridization histochemistry with an 35S-labeled cRNA probe. Adult male rats received either normal tap water (control), or hypertonic (2%) saline (HS) for up to 3 days. In a second experiment, normal saline was infused through a jugular vein cannula at 6 ml/h for 3 days; control rats were cannulated but received no infusion. Relative levels of CRF mRNA were compared by estimating both the number of positively hybridized cells and the density of silver grains in emulsion-dipped autoradiograms. HS treatment resulted in marked increases in CRF mRNA in the magnocellular neurosecretory system. All recognized oxytocinergic cell clusters, i.e., the anterior, medial and posterior magnocellural subdivisions of the PVN, the dorsal aspect of the SON, and components of the accessory magnocellular system, displayed this effect. By contrast, HS treatment resulted in significant decreases in CRF mRNA levels in the parvocellular (hypophysiotropic) division of the PVN and in Barrington's nucleus. By contrast, volume loading, which failed to affect plasma osmolality, significantly increased CRF mRNA levels in Barrington's nucleus.(ABSTRACT TRUNCATED AT 250 WORDS)


Hypothalamic GnRH pulse generator activity during the estradiol-induced LH surge in ovariectomized goats. Electrophysiological manifestation of the hypothalamic GnRH pulse generator activity was examined during the LH surge induced by estradiol in ovariectomized goats. The characteristic increases in the frequency of multiple unit activity (MUA volley) associated with the pulsatile secretion of LH were recorded using electrodes implanted bilaterally in the medial basal hypothalamus. Estradiol was infused for 16 h at the rate of 3 micrograms/h, to induce an LH surge 10.0-11.5 h later. Regular recurrence of MUA volley was observed throughout the experimental period including the LH surge, but the interval between the MUA volleys became longer (p < 0.01) after the onset of the LH surge as compared with the pretreatment control period (32.9 +/- 2.1 vs. 60.0 +/- 5.1 min). These results suggest that an increased frequency of LH pulses is not a prerequisite for the LH surge in ovariectomized goats given estradiol, and imply that the positive feedback effects of estradiol on LH secretion appear to be exerted through a neuronal mechanism that is intrinsically different from the GnRH pulse generator.


Effect of [4Cl-D-Phe6,Leu17]VIP on the inhibition of pulsatile LH release by VIP and related peptides in the ovariectomized rat. Pulsatile LH secretion in the ovariectomized (OVX) rat is inhibited by intracerebroventricular (icv) infusion of vasoactive intestinal peptide (VIP). VIP, rat growth hormone-releasing hormone (rGRH) and secretin with and without an antagonist to VIP, [4Cl-D-Phe6,Leu17]VIP (VIPA), were infused icv into OVX rats. Both VIP and rGRH at an infusion rate of 3.5 nmol/h lowered mean LH concentrations and pulse frequency without affecting pulse amplitude, and these effects were blocked by concurrent infusion of VIPA (10.5 nmol/h). Secretin also inhibited pulsatile LH secretion, but was only fully effective at the higher infusion rate of 7 nmol/h. This effect of secretin was also blocked by concurrent infusion of 10.5 nmol/h of VIPA. These results suggest that all three of these peptide hormones inhibit pulsatile LH secretion by an interaction with VIP receptors.


A comparative study of the effects of neonatal androgenization and estrogenization on vasoactive intestinal peptide levels in the anterior pituitary and the hypothalamus of adult female rats. We compared the effects of neonatal androgenization (NA) and estrogenization (NE) on vasoactive intestinal peptide (VIP) levels in the anterior pituitary (AP) and the hypothalamus and on prolactin (PRL) secretion in adult female rats. Twenty-four hours after birth, a total of seven groups were treated as follows. Three NA groups received a single subcutaneous injection of 10, 100, or 1,000 micrograms of testosterone, respectively. Similarly, three NE groups received 1, 10, or 100 micrograms of 17 beta-estradiol, respectively. The remaining one group was injected with oil vehicle only, and served as controls. At 8 weeks of age, animals were sacrificed by rapid decapitation. NA (1,000 micrograms) and NE (100 micrograms) resulted in a similar degree of hyperprolactinemia and hyperestrogenemia, but this effect ratio between NA and NE (about 1:10) was not true with the lower doses, indicating a qualitative difference in the effects of the two treatments. This is in agreement with our previous study. VIP content determined in the suprachiasmatic nucleus, the paraventricular nucleus and the median eminence did not significantly correlate with plasma PRL. In contrast, there were significant correlations among AP VIP, plasma PRL and estradiol. These results suggest the possibility that the NA- and NE-induced hyperprolactinemia may be mediated, at least in part, by a paracrine and/or autocrine effect of the increased AP VIP on the lactotroph which may probably be mediated by hyperestrogenemia. However, the possibility was also suggested that the observed changes in AP VIP were related more to NA and NE's imprinting effects on the developing brain than to the PRL secretion.(ABSTRACT TRUNCATED AT 250 WORDS)


Enzyme-linked immunosorbent assay for rat and human luteinizing hormone. A sensitive and specific enzyme-linked immunosorbent assay (ELISA) suitable for measuring rat and human luteinizing hormone (LH) is described. The LH-ELISA used anti-bLH beta subunit monoclonal antibody-coated plates, an antiserum against rLH or hLH and an antibody against rabbit IgG labelled with peroxidase. Using rLH-RP-3 or hLH WHO IRP 68/40 as standard diluted in assay buffer, the LH-ELISA had a sensitivity of 50 pg/ml and 0.78 mIU/ml, respectively. The LH-ELISA allowed accurate determination of LH in buffer, cell culture media, anterior pituitary extracts and sera and was highly specific for rat and human LH. The use of this ELISA offers improvements in convenience, economy, sensitivity and safety over comparable radioimmunoassay procedures.


Hypoglycemic 'stress' and gonadotropin-releasing hormone pulse generator activity in the rhesus monkey: role of the ovary. Observations of long standing have suggested that the 'stress' of chair restraint inhibits the GnRH pulse generator in normal female monkeys while this phenomenon is rarely observed in ovariectomized animals. The role of the ovary in the response of the GnRH pulse generator to the stress of insulin hypoglycemia was investigated in both intact and ovariectomized rhesus monkeys. Following an overnight fast the animals, previously habituated to restraint, were placed in primate chairs and GnRH pulse generator activity monitored electrophysiologically. Insulin-induced reductions in mean blood glucose concentrations of 10-40% of control values interrupted pulse generator activity in intact monkeys but were without effect in ovariectomized animals. With larger reductions in blood glucose, pulse generator activity was interrupted in both groups but the inhibition was twice as long in intact than in ovariectomized animals. The reduced responsiveness of ovariectomized animals to insulin hypoglycemia was significantly reversed by estradiol replacement. Naloxone administration did not prevent the hypoglycemia-induced inhibition of pulse generator activity in either intact or ovariectomized rhesus monkeys. It is concluded that hypoglycemic 'stress' inhibits the GnRH pulse generator by a nonopioidergic mechanism and that ovarian products, most probably estradiol, exacerbate this effect.


Alteration of endotoxin fever and release of arginine vasopressin by dehydration in the guinea pig. Arginine vasopressin (AVP), synthesized in hypothalamic neurons, is transported in axons either to the pituitary for release into the circulation or to different brain areas. In our previous experiments we documented central antipyretic AVP pathways from the hypothalamus to the ventrolateral septal area in the limbic system. In the present study we investigated if osmotic stimulation is able to activate peripheral and central release of AVP concurrently and if the antipyretic pathways are influenced by this kind of stimulation. In dehydrated animals (24 h water deprivation) the arterial blood plasma level of AVP doubled causing antidiuretic effects. Also the concentration of AVP in push-pull perfusates of the limbic septal area was significantly higher in dehydrated (5.6 pg AVP/ml perfusate) than in control animals (2.6 pg AVP/ml perfusate). The febrile response to bacterial endotoxin was reduced by 50% in dehydrated guinea pigs compared to controls, statistically significant between 30 and 180 min after pyrogen application. A microinfusion of AVP antiserum into the limbic septal area enhanced the fever reaction of dehydrated guinea pigs compared to the effects of a microinfused preimmune serum, in this case statistically significant between 180 and 360 min after application. From these data we assume a simultaneous activation of peripheral and central release of AVP with antidiuretic and antipyretic effects by dehydration.


Differential regulation of the nocturnal and diurnal prolactin surges in pregnant rats revealed by dopamine receptor antagonism. We have explored temporal changes in the magnitude of dopamine (DA) interaction (DA tone) at the anterior pituitary lactotrophs related to both the nocturnal and diurnal prolactin (PRL) surges on day 8 of pregnancy, by utilizing a competitive DA D2 antagonist, domperidone (DOM). After withdrawal of blood from pregnant rats on day 7 in order to demonstrate the presence of a PRL surge, experimental rats received DOM (100 micrograms/kg i.v. or i.a.) at various times on day 8. Blood samples were taken immediately before and following injection of DOM at 5, 15, 30 and 60 min. The peak PRL response to DOM occurred 15 min after injection. Comparisons were made between circulating PRL levels immediately prior to and at several times following DOM administration for the various times of the day, and represented as incremental increases in PRL following DOM. During times on day 8 when PRL levels were normally low (24:00, 06:00, 12:00 and 16:00 h), pregnant rats exhibited a substantial PRL response to DOM. However, during the nocturnal PRL surge (02:00, 04:00 h) the peak PRL response to DOM was significantly lower. In sharp contrast, the PRL response to DOM administered during the diurnal PRL surge (18:00 h) was significantly higher than all other times of the day tested. In a dose-response study in which 10, 100 and 1,000 micrograms/kg DOM was administered at the two critical times when the response to DOM differed greatly, 02:00 and 18:00 h, there was a significantly reduced PRL response to DOM at 02:00 h compared to 18:00 h.(ABSTRACT TRUNCATED AT 250 WORDS)


Mechanisms of norepinephrine mediated corticotropin-releasing factor-41 release from cultured fetal hypothalamic cells. Catecholamines have been shown to activate hypothalamic corticotropin-releasing factor-41 (CRF) synthesis and release. In order to study the mechanisms involved, fetal hypothalamic cells were cultured and CRF release was measured by radioimmunoassay. Norepinephrine (NE) induced CRF release in a dose-dependent manner. Further studies were performed with a protein kinase C inhibitor, H-7(1-(5-isoquinolinesulfonyl)-2-methylpiperazine) and a protein kinase A inhibitor, IP-20. NE-stimulated CRF release was reduced by H-7 (5 and 50 microM) in a dose-dependent fashion, while 5 microM IP-20 resulted in a small but significant inhibition. Pretreatment of the cells for 15 h with 20 and 200 nM 12-O-tetradecanoylphorbol-13-acetate, which down-regulates protein kinase C activity, blocked the release of CRF in response to NE (1 microM), further supporting protein kinase C as a mediator for NE-activated CRF release. Pretreatment with 50 and 500 ng/ml pertussis toxin (15 h) resulted in a dose-dependent inhibition of NE-activated CRF release. Both dexamethasone and aldosterone at the concentrations of 1 microM reduced NE-induced CRF release. These results suggest that CRF can be released from hypothalamic neurons in response to NE through both protein kinase C- and protein kinase A-dependent mechanisms, and that pertussis toxin-sensitive G-proteins are also involved in this response. Furthermore, glucocorticoids and mineralocorticoids can reduce NE-activated CRF release from cultured hypothalamic cells.


Differential startle amplitude and corticosterone response in rats. Different rat strains exhibit large differences in hypothalamic pituitary-adrenal activity that have been used to determine the role of the neuroendocrine system in susceptibility to autoimmune disease. To further characterize potential behavioral correlates of these differences, the amplitude of the acoustic (ASR) and tactile (TSR) startle response and the corticosterone response to acoustic startle stimuli were compared between two histocompatible strains, Lewis (LEW/N) and Fischer (F344/N) rats, as well as outbred Harlan Sprague-Dawley (SD) rats. Startle stimuli elicited larger ASR and TSR in LEW/N rats than in F344/N rats, with SD rats exhibiting an intermediate response. The ASR habituated at a similar rate in LEW/N and F344 rats, while the ASR did not habituate in SD rats. After handling and placement in the startle chambers, the three strains did not differ in control levels of corticosterone. In contrast, exposure to acoustic startle stimuli increased corticosterone 5-fold in F344/N rats and 2-fold in SD rats, but had no effect on corticosterone in LEW/N rats. These findings suggested an inverse relationship between the amplitude of the ASR and hypothalamic-pituitary-adrenal activation across strains. This relationship was further supported by a high negative correlation between corticosterone level and ASR amplitude within the F344/N group.


The presence, characterisation and synthesis of neuromedin B in the human pituitary gland. Neuromedin B is a 10-amino-acid mammalian peptide of the bombesin family. We have used a specific radioimmunoassay and Northern blot hybridisation to investigate the possible synthesis of neuromedin-B-like immunoreactivity in the human pituitary gland. The concentration of immunoreactive neuromedin B in whole human pituitary was 15.2 +/- 4.2 pmol/g wet weight in males and 12.8 +/- 2.7 pmol/g wet weight in females (mean +/- SEM, n = 10). In pituitary tumour extracts, neuromedin B immunoreactivity was 9.1 +/- 1.7 pmol/g wet weight (mean +/- SEM, n = 14) in inactive tumours, 18.4 +/- 6.9 pmol/g wet weight (mean +/- SEM, n = 4) in somatotrophs and 10.4 +/- 2.7 pmol/g wet weight (mean +/- SEM, n = 2) in prolactinomas, with no apparent significant difference between the groups. Gel permeation chromatography of pituitary extracts revealed two immunoreactive peaks, the major one of which corresponded in position to that of neuromedin B-32 and a later minor peak to the position of the neuromedin B-10 standard. On fast protein liquid chromatography, neuromedin-B-like immunoreactivity again eluted in two peaks, a minor peak corresponding to the synthetic neuromedin B standard, and a major more hydrophobic peak which was the big neuromedin B form. Northern blot analysis of poly(A)+RNA from human pituitaries revealed the presence of a hybridising band of between 750 and 850 base pairs. These results suggest that neuromedin B is synthesised in the human pituitary gland where it may be of importance in the regulation of pituitary function. Furthermore, the adenomatous condition is not associated with abnormal levels of this peptide.


Sinoaortic denervation does not increase cardiovascular/endocrine responses to stress. Sinoaortic baroreceptor denervation is reported to produce exaggerated centrally derived cardiovascular and endocrine responses. We examined the effect of sinoaortic denervation (SAD) on the cardiovascular and endocrine responses to two acute stressors, footshock and immobilization, in male Sprague-Dawley rats. Parameters measured were mean arterial pressure (MAP), heart rate (HR) and plasma levels of oxytocin (OT) and vasopressin (VP). Baseline MAP was elevated in the SAD group (approximately 25 mm Hg) and footshock stress increased arterial pressure equivalently in both groups. This stress caused tachycardia and increased plasma OT, with a tendency for the SAD group to show blunted responses. Immobilization increased HR but caused no change in MAP and no significant difference between the groups. This form of stress also increased plasma OT, and again the SAD group showed a diminished response. Plasma VP was not significantly altered by either stressor. The results of these studies indicate that SAD does not uniformly increase the cardiovascular and endocrine responses to all stressors or centrally derived stimuli. These results also suggest that the lack of an increase in plasma VP is not related to baroreceptor-mediated inhibition of secretion under stressful conditions.


Corticotropin-releasing factor induces differential behavioral and cardiovascular effects after intracerebroventricular and lateral hypothalamic/perifornical injections in rats. The contribution of the lateral hypothalamic/perifornical (LH/PFx) area in mediating central effects of corticotropin-releasing factor (CRF) on cardiovascular and behavioral activity was assessed by monitoring blood pressure, heart rate and behavioral responses for a 45-min period after injections of various doses of CRF into the LH/PFx region or the lateral cerebral ventricle (intracerebroventricular, i.c.v.) in conscious, unrestrained rats in a familiar environment. After LH/PFx injection, CRF (3 and 30 ng) dose-dependently induced behavioral activation, predominantly consisting of grooming, eating and locomotor activity. Concomitantly, dose-related increases in mean arterial pressure (delta MAP) and heart rate (delta HR) were observed. Increases in MAP and HR following injection of 3 ng CRF were associated with the paroxysmal occurrence of behavioral activation and as such superimposed on CRF-induced elevation of baseline MAP and HR. Thirty nanograms CRF given i.c.v. produced grooming behavior similar to that observed after the same dose injected into the LH/PFx region, but failed to induce significant changes in cardiovascular concomitants. Rats receiving 100 ng CRF i.c.v., showed a significant increase in behavioral activity, respective to rats treated with 30 ng CRF in the LH/PFx, the tachycardiac responses, however, being similar in these groups. Both doses of CRF i.c.v. failed to induce significant delta MAP. The effects of CRF on cardiovascular and behavioral activity were more marked when the peptide was injected into the caudal part of the LH than those measured after administration into the rostral LH. Similarly, injections of CRF around or dorsal to the fornix (PFx) were more effective than those located ventrally to it. This site specificity of CRF-evoked responses was reflected in differential time response relations of the various effects. In summary, when i.c.v. is the route of administration, a higher dose of CRF is required to induce autonomic and behavioral responses similar to those elicited by CRF injected into the LH/PFx. The cardiovascular and behavioral effects of LH/PFx-CRF indicate that this region may be an important site for central CRF to produce stress-related autonomic and behavioral responses. In addition, the CRF-induced effects, both in magnitude and onset, show site specificity, the caudal LH and perifornical area being more responsive to the peptide than the rostral LH and the area ventral to the Fx. As CRF-evoked behavioral activation does not necessarily coincide with changes in MAP and HR, our data suggest a dissociation of the peptide's central actions to influence behavioral and autonomic responses.


Immunocytochemical identification of oestrogen receptors in preoptic neurones containing calcitonin gene-related peptide in the male and female rat. Using single- and double-labelling immunocytochemistry with antibodies specific for the oestrogen receptor and calcitonin gene-related peptide (CGRP), we have demonstrated oestrogen receptor immunoreactivity in the sexually dimorphic CGRP-immunoreactive (IR) population of the medial preoptic area (MPOA). In the short-term gonadectomised female approximately 80% of preoptic CGRP-IR neurones were immunoreactive for the oestrogen receptor. In short-term gonadectomised males, a small population of CGRP-IR cells was visualised in the MPOA only after colchicine treatment. Approximately 30% of CGRP-IR cells in the male were oestrogen receptor-IR, accounting for 2% of the total population of cells containing oestrogen receptors in this area. In the colchicine-treated female, it is estimated that 10-15% of preoptic oestrogen receptor-IR cells contain CGRP. These results indicate that CGRP is synthesised by preoptic neurones with oestrogen receptors. Furthermore, the identification of oestrogen receptors in the sexually dimorphic CGRP population suggests that these neurones may be directly linked with gonadal steroid-dependent, sex-specific functioning of the MPOA.


Cholinergic nucleus basalis neurons display the capacity for rhythmic bursting activity mediated by low-threshold calcium spikes. Acetylcholine has long been known to play an important role in the cortical activation that accompanies the states of wakefulness and paradoxical sleep (for review, see Refs 17, 21) when this neurotransmitter is released from the cerebral cortex at the highest rates. The major supply of acetylcholine to the cerebral cortex arises from the cholinergic neurons of Meynert's Basal-ganglion or nucleus basalis of the forebrain. Lying in the substantia innominata within the major ascending pathway from the brain stem reticular formation, magnocellular basalis neurons project upon the cerebral cortex as the important ventral, extrathalamic relay of the ascending reticular activating system. Although the cholinergic basalis nucleus neurons have been shown to be important for cortical activation, the precise manner in which they influence cortical activity has not as yet been elucidated, in part because the cholinergic cells of this nucleus have not been identified in electrophysiological studies. Using intracellular recording in guinea-pig brain slices, we were able to record and fill with biocytin nucleus basalis neurons which were subsequently revealed by immunohistochemical staining to be choline acetyltransferase-positive and thus cholinergic. The cholinergic cells displayed rhythmic bursting activity mediated by a low-threshold calcium spike in vitro, which would endow them with a capacity for phasic (in addition to tonic) firing in vivo. By virtue of these different modes, cholinergic basalis neurons may accordingly deter or facilitate the cortical response to sensory input and may furthermore modulate the major frequencies of cortical activity across the different states of the sleep-waking cycle.


Unilateral hindpaw inflammation produces a bilateral increase in NADPH-diaphorase histochemical staining in the rat lumbar spinal cord. Tissue injury results in several changes in spinal cord neurons that contribute to hyperalgesia arising from the injured tissue. In models of unilateral hindpaw inflammation, changes in the neurochemistry and electrophysiology of dorsal horn neurons ipsilateral, and to a much lesser extent contralateral, to the inflamed paw have been reported. For example, the excitability of dorsal horn neurons increases, receptive field size increases, and the content of various proteins and neuropeptides in the dorsal horn (e.g. FOS, dynorphin, enkephalin) are affected following peripheral inflammatory insult. These changes are typically interpreted on the basis of their relevance to nociception.


Molecular cloning of rat trkC and distribution of cells expressing messenger RNAs for members of the trk family in the rat central nervous system. Tyrosine protein kinases trk, trkB and trkC are signal-transducing receptors for the neurotrophins nerve growth factor, brain-derived nerve growth factor, neurotrophin-3 and neurotrophin-4. Here we report on the isolation of cDNA fragments encoding a part of rat trk and trkB proteins, respectively, and characterization of a full-length cDNA clone encoding rat trkC. Cells expressing mRNAs for the different members of the trk family were identified in the rat central nervous system by in situ hybridization using oligonucleotide probes designed from the isolated cDNA sequences and complementary to mRNA sequences coding for the extracellular region of the receptors. The expression of trk mRNA was found to be restricted to neurons of the basal forebrain, caudate-putamen with features of cholinergic cells and to magnocellular neurons of several brainstem nuclei. In contrast, cells expressing trkB and trkC mRNAs were widely distributed in the brain. Areas expressing high levels of trkB or trkC mRNAs included olfactory formations, neocortex, hippocampus, thalamic and hypothalamic nuclei, brainstem nuclei, cerebellum and spinal cord motoneurons. A similar distribution for trkB and trkC mRNAs was shown in most areas but each probe specific for these mRNAs also provided distinct labeling patterns in different subregions, layers and cells. Comparison between our data and previous analyses of cells expressing mRNAs for neurotrophins and the low-affinity nerve growth factor receptor suggests that different modes of action and different combinations of receptors mediate biological responses to neurotrophins in the adult rat brain.


Input from the frontal cortex and the parafascicular nucleus to cholinergic interneurons in the dorsal striatum of the rat. Evidence derived from many experimental approaches indicates that cholinergic neurons in the dorsal striatum (caudate-putamen) are responsive to excitatory amino acids. Furthermore, evidence from physiological experiments indicate that the excitatory input is derived from the cortex and/or the thalamus. The object of the present experiment was to anatomically test whether cholinergic neurons receive cortical and/or thalamic input in the dorsal striatum using a combined anteograde tracing and immunocytochemical approach at both the light- and electron-microscopic levels. Rats received injections of the anterograde tracers Phaseolus vulgaris-leucoagglutinin or biocytin at multiple sites in the frontal cortex or parafascicular nucleus of the thalamus. Sections of the striatum were stained to reveal the anterogradely transported markers and then immunostained to reveal choline acetyltransferase immunoreactivity. The striata of these animals contained dense networks of anterogradely labelled fibres that were dispersed throughout the neuropil and interspersed with the choline acetyltransferase-immunoreactive (i.e. cholinergic) perikarya and dendrites. The anterogradely labelled fibres were often closely apposed to the choline acetyltransferase-immunoreactive neurons. Examination of electron-microscopic sections failed to demonstrate cortical terminals in synaptic contact with the cholinergic neurons even when choline acetyltransferase-immunoreactive structures were examined that had first been identified in the light microscope as having cortical terminals closely apposed to them. In these cases it was often observed that the cortical terminal, although apposed to the membrane of the labelled neurone, made synaptic contact with an unlabelled spine that was in the vicinity. In contrast to the cortical input, analysis of material that was double-stained to reveal thalamostriatal terminals and choline acetyltransferase-immunoreactive structures, revealed that the thalamostriatal terminals were often in asymmetrical synaptic contact with the perikarya and dendrites of cholinergic neurons. It is concluded that the cholinergic neurons of the dorsal striatum, like those of the ventral striatum or nucleus accumbens [Meredith and Wouterlood (1990) J. comp. Neurol. 296, 204-221] receive very little or no input from the cortex but are under a prominent synaptic control by the thalamostriatal system. Those pharmacological effects of excitatory amino acids on the cholinergic systems of the striatum are therefore presumably related to the thalamostriatal and not the corticostriatal system.


Neuronal firing in the nucleus accumbens is associated with the level of cortical arousal. Because of evidence that the nucleus accumbens mediates the activating effects of many drugs, this study examined the hypothesis that the firing rates of individual nucleus accumbens neurons are positively correlated with spontaneous changes in behavioral arousal that occur during the sleep-wake cycle. The present report examined the firing patterns of 80 neurons in the nucleus accumbens of unanesthetized, unrestrained rats during various electrographically determined levels of arousal. Synaptic responses to stimulation of hippocampal and pallidal nucleus accumbens afferents indicated that the present sample of neurons was similar to a large population of nucleus accumbens neurons previously recorded in anesthetized rats. Confirming the participation of the nucleus accumbens in behavioral arousal, the firing rates of nucleus accumbens neurons were greatest during wakefulness and rapid eye movement sleep and lowest during non-rapid eye movement sleep. Furthermore, the induction of halothane anesthesia decreased behavioral and electrocorticographic arousal concurrent with a suppression of the spontaneous nucleus accumbens unit discharge. These data support the hypothesis that the firing of nucleus accumbens neurons is closely related to arousal.


The initial stages of neural regeneration are dependent upon intracellular calcium levels. The earliest events of neuronal regeneration require resealing of the neurite's membrane after injury and the subsequent formation of a new growth cone. We have investigated these activities in vitro employing the large identified neurons of the snail Helisoma. Regeneration was elicited by transection of neurite processes and assessed by studying the formation of new growth cones from the proximal neurite stumps. Under normal conditions new growth cones formed rapidly in 100% of the preparations. This formation appeared to follow, however, a large rise in intracellular calcium and did not start until after the cells homeostatic machinery had re-established near baseline calcium levels. To test the hypothesis that elevated intracellular calcium levels delayed or inhibited growth cone formation, transections were performed after experimentally increasing intracellular calcium concentrations to different levels by either depolarization or by calcium ionophores. Under these conditions, regeneration was significantly retarded in a fashion dependent upon the intracellular calcium concentration. Another change in the extracellular milieu, namely lowering of the extracellular calcium concentration, also significantly retarded growth cone formation. Under these conditions neurons appeared unable to reseal their cut ends and eventually died. Taken together, these studies demonstrate the importance of both the extracellular and intracellular milieu at times immediately following neurite transection in determining whether or not the earliest stages of neuronal regeneration will occur.


The development of neuropeptide Y-immunoreactive neurons in a model of pure cortical culture. The development of neuropeptide Y-immunoreactive neurons in the rat brain cerebral cortex was studied in a model of a pure cortical culture. In this model, development of neurons devoid of any afferents from other brain structures could be observed. Since mutual interactions between neuropeptide Y and catecholamines have been postulated, such a pure cortical culture offers a possibility of studying the development of neuropeptide Y neurons devoid of any brainstem monoaminergic afferents. A tissue dissected from 16-day-old rat fetuses and cultivated in a dissociated culture for 14 days was examined immunohistochemically for the presence of neuropeptide Y-immunoreactive neurons. Three main types of neuropeptide Y-immunoreactive neurons were found: unipolar, bipolar and multipolar. Cell processes and terminal varicose fibres were also observed. The results obtained indicate that neuropeptide Y-immunoreactive neurons and fibres may develop in a pure culture of the rat cerebral cortex without the influence of any other structures.


Vascularization of fetal neocortical grafts implanted in brain infarcts in spontaneously hypertensive rats. The vascularization of neural grafts in ischemic brain was studied in spontaneously hypertensive rats grafted with a suspension of fetal neocortical tissue into the infarcted area five to six days after ligation of the middle cerebral artery. The brain vasculature was examined by scanning electron microscopy of corrosion vascular casts and the cortical microvasculature was stereologically quantified in light microscopy three months after the occlusion. Patent anastomoses were present between the middle cerebral artery distal to occlusion and the proximal part, as well as to the anterior and posterior cerebral arteries, in both grafted and non-grafted rats. A vascular plexus covering the infarct cavities and the grafts contained leptomeningeal vessels intermingled with a thin capillary network which is not normally found on the brain surface. The graft vessels were derived from this vascular plexus. The regular pattern of arterioles and venules penetrating from the cortical surface in normal neocortex was absent in the grafts but the capillary morphology was similar in both types of tissue. The grafts had a lower capillary density than normal tissue and lacked the laminar distribution of capillaries characteristic of normal neocortex. The results demonstrate the plasticity of the vascular system where remodeling of the vascular tree after an ischemic insult provides suitable conditions for the vascularization of neocortical grafts.


6-Hydroxydopamine lesions of the nigrostriatal pathway alter the expression of glutamate decarboxylase messenger RNA in rat globus pallidus projection neurons. In situ hybridization was used to study the effect of 6-hydroxydopamine-induced damage to the midbrain dopaminergic neurons on the level of glutamate decarboxylase mRNA in globus pallidus neurons in the rat. Some animals received an injection of Fluoro-gold in the entopeduncular nucleus or the substantia nigra prior to the 6-hydroxydopamine lesion in order to identify glutamic acid decarboxylase mRNA levels in pallidal neurons that project to one of these targets. Analysis was carried out on a sample of all pallidal neurons as well as neurons that were identified as projection neurons in control and lesioned groups. The loss of the dopamine-containing neurons in the substantia nigra resulted in significant increases in the percentage of globus pallidus neurons that expressed glutamate decarboxylase mRNA and in the amount of glutamate decarboxylase mRNA per globus pallidus neuron. These increases were noted in a sample of all pallidal neurons, as well as pallidal neurons that were identified as projecting to either the entopeduncular nucleus or the substantia nigra. In control animals, glutamate decarboxylase mRNA was clearly identified in globus pallidus neurons projecting to the entopeduncular nucleus, indicating that this recently reported projection is at least partially GABAergic. The results of this study indicate that substantia nigra dopaminergic neurons regulate globus pallidus neurons in the rat, and that removal of the dopaminergic input to the corpus striatum results in a significant increase in the amount of glutamate decarboxylase mRNA in pallidal neurons. The decreased firing rate of pallidal neurons that is seen following the loss of dopamine input appears to be accompanied by an increase in the level of glutamate decarboxylase mRNA in these neurons.


Parvalbumin immunoreactivity: a reliable marker for the effects of monocular deprivation in the rat visual cortex. In mammals, monocular deprivation performed during the early stages of postnatal development (critical period) dramatically affects the functional organization of the visual cortex. Since the early work of Hubel and Wiesel, the effects of monocular deprivation are accounted for by the fibers driven by the two eyes competing for the control of cortical territories. In cat and monkey striking structural changes accompany the functional effects of monocular deprivation. Also, in the rat, monocular deprivation causes functional alteration at the level of visual cortex; no structural correlates of these effects, however, have so far been described. Parvalbumin is a calcium binding protein that in the neocortex colocalizes with a subpopulation of GABAergic neurons. Here we report that in the rat monocular deprivation results in a dramatic reduction of parvalbumin-like immunoreactivity in the visual cortex contralateral to the deprived eye. This effect is due to competitive phenomena and not to visual deprivation itself, it is restricted to the binocular portion of the visual cortex and neither binocular deprivation, nor dark rearing can induce it. We conclude that parvalbumin-like immunoreactivity is a useful immunohistochemical marker for the effects of monocular deprivation in the rat visual cortex.


Potentiation of electroencephalographic spindles by ibotenate microinjections into nucleus reticularis thalami of cats. It is well known that the electroencephalogram of the cat in the early stages of slow wave sleep is mainly characterized by rhythmic wave activity at 7-14 Hz, termed spindles, which recur periodically with a slow rhythm of 0.1-0.2 Hz. From early stimulation, decortication and transection studies (see Ref. 14), spindle oscillations were thought to originate in the thalamus. The search for the anatomical substrate of thalamic spindling, however, moved from medial (intralaminar nuclei) to lateral thalamic nuclei, and recently focused on the extreme shell-shaped collection of GABA-ergic cells, the nucleus reticularis thalami. This proposition was based on its structural, hodological, and physiological aspects. There is accumulating evidence that the nucleus reticularis may act as a conditional pacemaker, synchronizing the activity of cortically projecting thalamic neurons. The introduction of glutamate analogues with excitotoxic properties such as ibotenic acid provided the opportunity of studying the immediate effects of chemical excitation of this nucleus on synchronized electroencephalographic activity. We found that, in cats, spindle density was dramatically increased following infusion of ibotenic acid into the rostral pole of the nucleus, supporting the role of this sector in spindle-related rhythmicity.


Identification of a critical period for motor development in neonatal rats. Manipulation of the developing nervous system has provided valuable insights into nervous system function. One important concept to arise from this type of study has been the identification of specific "critical periods" for the development of various functions. A critical period has been most clearly shown for the visual system where monocular eye closure for a few weeks led to functionally significant changes in visually guided behaviors and the connectivity of the visual cortex. Critical periods have also been defined for other sensory systems. Although studies of the effect of manipulating sensory systems during development are sometimes difficult to interpret (e.g. Ref. 7), this difficulty is compounded in the case of the motor system. Problems arise because manipulations of the postnatal motor system are difficult to implement and usually require invasive procedures such as tenotomy, neurotomy, and nerve crush (for review, see Ref. 17). We have approached the problem of manipulating the motor environment by adapting a paradigm widely used to study the experimental effects of simulated weightlessness in adult rats: namely, tail suspension. This method has several advantages for manipulating the motor system: (i) because it is noninvasive, it is less discomforting than neurotomy, tenotomy or nerve crush; (ii) it does not immobilize the animals, they move about the cage and extend and flex their hindlimbs; and (iii) it specifically examines the importance of load-bearing on the development of antigravity muscles and their neuronal circuits.(ABSTRACT TRUNCATED AT 250 WORDS)


Evidence for involvement of nitric oxide in the regulation of hypothalamic portal blood flow. Vasoactive intestinal polypeptide and peptide histidine isoleucine, two peptides with a common precursor and with strong vasodilatory actions, have been suggested to be involved in control of blood flow through the hypothalamic portal blood vessels, in this way regulating the amounts of releasing and inhibitory factors reaching the anterior pituitary. Using the indirect immunofluorescence technique, we now show that this system also contains the enzyme nitric oxide synthase, as well as acetylcholinesterase. It is therefore likely that the control of blood flow through the portal vessels is mediated via relaxation of smooth muscle cells with a high myogenic tone by neuronal release of four vasodilatory compounds, acetylcholine, vasoactive intestinal polypeptide, peptidine histidine isoleucine, and nitric oxide, i.e. a classic neurotransmitter, two neuropeptides and a gas.


Localization of heparan sulfate glycosaminoglycan and proteoglycan core protein in aged brain and Alzheimer's disease. Two monoclonal antibodies, one which recognizes a glycosaminoglycan epitope present in heparan sulfate glycosaminoglycan and another which recognizes the core protein of a basement membrane heparan sulfate proteoglycan, were used to study the distribution and localization of these components in Alzheimer's disease and control brain. The cytoplasm of neurons, and occasional neurofibrillary tangles, senile plaques and astrocytes were immunopositive for the heparan sulfate glycosaminoglycan antibody in control brains. In Alzheimer's tissue, however, the number and intensity of these elements was more extensive than in control brains. In addition, within the Alzheimer's brains studied, the nuclei of select neurons and a small number of microglia were also immunopositive for heparan sulfate glycosaminoglycan in contrast to controls, where nuclei and neuroglia were immuno-negative. Some senile plaques in Alzheimer's tissue also contained strong heparan sulfate glycosaminoglycan-positive neurites which were not seen in controls. In Alzheimer's tissue, double labeling for heparan sulfate glycosaminoglycans and the beta-amyloid protein in adjacent sections revealed that, in general, heparan sulfate glycosaminoglycan- and beta-amyloid protein-immunopositive plaques were co-localized. Occasionally, however, beta-amyloid-positive plaques were seen without heparan sulfate glycosaminoglycan immunoreactivity and vice versa. Heparan sulfate glycosaminoglycan immunoreactivity and Tau immunoreactivity co-localized in many neurofibrillary tangles; however a small number of heparan sulfate glycosaminoglycan-positive neurofibrillary tangles did not co-localize with Tau-positive neurofibrillary tangles. In contrast, the heparan sulfate proteoglycan antibody immunostained only the walls of blood vessels and a few senile plaques in Alzheimer's brains and primarily blood vessels in control brains. Heparan sulfate glycosaminoglycan immunostaining was present within neurons, glia, neurofibrillary tangles and senile plaques in Alzheimer's tissue. These results suggest that heparan sulfate-like molecules play an important role in the pathogenesis of the characteristic lesions of Alzheimer's disease and could serve as a marker reflecting early pathological changes.


Studies of activated microglial cells and macrophages using Alzheimer's disease cerebrospinal fluid in adult rats with experimentally induced lesions. Previous investigations have shown that cerebrospinal fluid from Alzheimer's disease patients contains antibodies that recognize the amoeboid microglia--a nascent and active form of microglia in the developing rat brain [McRae et al. (1991) Neuroscience 41, 739-752]. The present study extended this to show that the same cerebrospinal fluid from Alzheimer's disease patients also labeled the activated microglia and macrophages induced experimentally in adult central nervous system. Thus, in the spinal cord, activated microglia were elicited following the destruction of the motor neurons by the toxic lectin, Ricinus communis agglutinin, injected into the sciatic nerve. The activated microglia which were closely associated with the soma of the degenerating neurons were intensely immunostained with the cerebrospinal fluid from Alzheimer's disease patients. The labeling pattern was comparable to some known monoclonal antibodies including OX-42, OX-18 and OX-6 that mark microglia. The microglia cells on the contralateral normal side remained unstained. In the cerebrum, activated microglia and neural macrophages were induced following an epidural application of the excitotoxin, kainic acid or cryolesion. Immunoelectron microscopy of these cells showed that the immunoreactivity was localized at the plasma membrane and its derivatives suggesting that these are the sites where the antigens are associated. The results obtained in this investigation suggest that these experimental models may be a means to gain further insight to antigens recognized by antibodies in the cerebrospinal fluid of Alzheimer's disease patients.


7 beta-hydroxycholesterol and 7 beta-hydroxycholesteryl-3-esters reduce the extent of reactive gliosis caused by an electrolytic lesion in rat brain. Electrolytic lesions performed in brain cortex of six-day-old or adult rats resulted in the appearance of many reactive astrocytes around the injury site after a postoperative delay of eight days. They were revealed by immunohistochemistry using antibodies against glial fibrillary acidic protein. Injection of tritiated thymidine 24 h prior to autopsy indicated that, in neonates, 50% of the reactive astrocytes were proliferating. Infusion of 2 microliters of liposome suspension made of phosphatidylcholine and a monosialoganglioside, in the injury site, immediately after the electrolytic lesion did not modify the extent of the reactive gliosis. Liposomes containing 3 nmol of either 7 beta-hydroxycholesterol, 7 beta-hydroxycholesteryl-3-stearate or 7 beta-hydroxycholesteryl-3-oleate reduced by about 50% the intensity of the reactive gliosis in the frontal cortex of six-day-old rats and by 40% the number of dividing astrocytes. In the adult rat cortex the intensity of the glial reaction was also decreased by 30% by 15 nmol 7 beta-hydroxycholesteryl-3-oleate. Further investigations demonstrated that it is the 7 beta-hydroxy function which is needed for the biological activity of these oxysterols. These findings, which demonstrate anti-proliferative and anti-inflammatory properties of 7 beta-hydroxycholesterol on astrocytes, facilitate the future investigation of the influence of reactive gliosis on functional recovery following brain injury. This anti-proliferative property could also be used in other kinds of pathologies involving glial cell proliferation, such as glioblastomas.


Calretinin and calbindin-D28k in rat brain: patterns of partial co-localization. Calretinin and calbindin-D28k are homologous calcium-binding proteins, each present in a variety of neurons in the brain. Their distributions in the rat brain have been compared at the cellular level to determine whether they tend to occur in the same or in different cells, and to determine whether calbindin-positive cells show any common features once crossreaction with calretinin has been eliminated. The results show great heterogeneity. Most cells which contain one of the proteins do not contain the other, but many cells do contain both; even in the ventral cochlear nucleus, where there is abundant calretinin and most calbindin-like immunoreactivity is due to crossreaction, a few cells contain both proteins. In the substantia nigra and ventral tegmental area, many cells are double-positive but some only contain one or the other protein. Only the triangular septal nucleus is uniformly positive for both proteins. Cells which look like local-circuit neurons in many forebrain areas (cortex, hippocampus, olfactory bulb, anterior olfactory nucleus) are exclusively positive for either calretinin or calbindin, in spite of their similar morphology. In the more heterogeneous parts of the brain (including hypothalamus central gray and substantia gelatinosa), there are mixtures of calretinin-positive, calbindin-positive, and double-positive cells. In comparison with previous data on the chick, some aspects of the distributions are conserved, but double-positive cells are more frequent in the rat. The degree of heterogeneity observed, even within comparatively well-defined neuronal populations, makes it difficult to infer in what neuronal properties these proteins could be involved.


Regional expression of c-fos antigen in the basal forebrain following intraventricular infusions of angiotensin and its modulation by drinking either water or saline. The expression of c-fos protein was examined in the basal forebrains of male rats 60 min following intracerebroventricular infusions of 250 pmol angiotensin II. Levels of corticosterone and vasopressin were also measured at the same time point. In animals not allowed access to water after infusion, angiotensin II induced intense c-fos expression in a band of neurons extending throughout the anterior region of the third ventricle region, including the organum vasculosum of the lamina terminalis, the median preoptic nucleus (nucleus medianus) and the subfornical organ. There were also high levels of expression in the hypothalamic supraoptic nucleus and the paraventricular nucleus, particularly its lateral (magnocellular) region, though other, parvicellular areas were also affected. No other area of the hypothalamus was altered. There was increased c-fos expression in the central nucleus of the amygdala and the bed nucleus of the stria terminalis. Allowing rats to drink during the 60-min survival period modified this pattern of response. c-fos was markedly reduced in the supraoptic nucleus and the paraventricular nucleus but not in the other areas examined, including the anterior region of the third ventricle and the amygdala. When water was withheld for 15 min, but then allowed, rats drank the same total volume but c-fos expression was no longer inhibited in either the supraoptic nucleus or paraventricular nucleus. When rats were given 0.9% saline to drink, they ingested about three times as much as water, but angiotensin II-induced c-fos expression was similar to that in rats denied access to water. The pattern was similar following access to 1.8% saline, though levels in the organum vasculosum of the lamina terminalis were reduced. There was a marked correlation between the number of c-fos-positive neurons in the supraoptic nucleus or paraventricular nucleus and plasma levels of corticosterone 60 min after infusion, but not with arginine-vasopressin levels. These experiments show that angiotensin II induces highly localized expression of c-fos in areas known to be concerned with the dipsogenic and endocrine actions of this peptide, and that this pattern is selectively altered by allowing the animal to drink solutions of different tonicity. Immediate-early gene expression is a novel and valuable method of determining the neural response to peptides at the cellular level.


Cortical transynaptic activation of tyrosine kinase receptor trkB messenger RNA expression in rat hippocampus. The trkB gene encodes a tyrosine kinase receptor which is an essential component of the high-affinity cell surface receptor for the neurotrophin brain-derived neurotrophic factor. In this report we have used quantitative in situ hybridization to study the expression of trkB messenger RNA in the rat hippocampus following stimulation of afferents in the entorhinal cortex. A bilateral three-fold increase of trkB messenger RNA levels in the hippocampus was seen 4 h after quisqualate injection into the left entorhinal cortex. The increase was confined to the granule layer of the dentate gyrus. A small increase, however, was also seen bilaterally in the pyramidal cell layer. The increases in all hippocampal areas were completely prevented by pretreatment of the animals with systemic injection of diazepam but not with scopolamine. We suggest that glutamate release from cortical afferents to the hippocampus has the capacity to increase neuronal expression of trkB messenger RNA within the hippocampus. The results from the present study extend the interpretation of our previous evidence of cortical transynaptic activation of brain-derived neurotrophic factor messenger RNA and indicate the presence of a concomitant activation of trkB messenger RNA expression in the hippocampus.


Distribution of thyrotropin-releasing hormone receptor messenger RNA in the rat brain: an in situ hybridization study. Based on the recent cloning of the mouse thyrotropin-releasing hormone receptor, oligonucleotide probes complementary to the DNA sequence were constructed and used for in situ hybridization studies on the rat brain. Thyrotropin-releasing hormone receptor messenger RNA was found in many areas of the brain, mostly showing high degree of overlap with the distribution thyrotropin-releasing hormone binding sites as previously revealed in autoradiographic studies. Thus, a strong signal was observed in the accessory olfactory bulb, the perirhinal sulcus, the ventral aspects of the hippocampal formation, some amygdaloid nuclei, the diagonal band nucleus, parts of nucleus accumbens, the bed nucleus of the stria terminalis, dorsomedial, lateral and perifornical hypothalamic regions, the septohippocampal nucleus, parts of the vestibular complex, as well as many bulbar motoneurons including the facial, dorsal vagal, ambiguus and hypoglossal nuclei, the superficial layer of the spinal trigeminal nucleus, and motoneurons and dorsal horn neurons in the spinal cord. Cells within one and the same nucleus expressed varying levels of thyrotropin releasing hormone receptor messenger RNA suggesting marked differences in rate of receptor synthesis. Most of these areas receive an input by thyrotropin-releasing hormone-positive nerve endings. Taken together these results suggest that thyrotropin-releasing hormone receptors are mostly localized in the vicinity of the cell bodies which express thyrotropin-releasing hormone receptor messenger RNA and mediate the wide range of actions that have been recorded after administration of exogenous thyrotropin-releasing hormone.


Role of GABA in the extraocular motor nuclei of the cat: a postembedding immunocytochemical study. The GABAergic innervation of the extraocular motor nuclei in the cat was evaluated using postembedding immunocytochemical techniques. The characterization of GABA-immunoreactive terminals in the oculomotor nucleus was carried out at the light and electron microscopic levels. GABA-immunopositive puncta suggestive of boutons were abundant in semithin sections throughout the oculomotor nucleus, and were found in close apposition to somata and dendrites. Ultrathin sections revealed an extensive and dense distribution of GABA-immunoreactive synaptic endings that established contacts with the perikarya and proximal dendrites of motoneurons and were also abundant in the surrounding neuropil. GABAergic boutons were characterized by the presence of numerous mitochondria, pleiomorphic vesicles and multiple small symmetrical synaptic contacts. The trochlear nucleus exhibited the highest density of GABAergic terminations. In contrast, scarce GABA immunostaining was associated with the motoneurons and internuclear neurons of the abducens nucleus. In order to further elucidate the role of this neurotransmitter in the oculomotor system, retrograde tracing of horseradish peroxidase was used in combination with the GABA immunostaining. First, medial rectus motoneurons were identified following horseradish peroxidase injection into the corresponding muscle. This was carried out because of the peculiar afferent organization of medial rectus motoneurons that contrasts with the remaining extraocular motoneurons, especially their lack of direct vestibular inhibition. Semithin sections of the oculomotor nucleus containing retrogradely labeled medial rectus motoneurons and immunostained for GABA revealed numerous immunoreactive puncta in close apposition to horseradish peroxidase-labeled somata and in the surrounding neuropil. At the ultrastructural level, GABAergic terminals established synaptic contacts with the somata and proximal dendrites of medial rectus motoneurons. Their features and density were similar to those found in the remaining motoneuronal subgroups of the oculomotor nucleus. Second, oculomotor internuclear neurons were identified following the injection of horseradish peroxidase into the abducens nucleus to determine whether they could give rise to GABAergic terminations in the abducens nucleus. About 20% of the oculomotor internuclear neurons were doubly labeled by retrograde horseradish peroxidase and GABA immunostaining. A high percentage (80%) of the oculomotor internuclear neurons projecting to the abducens nucleus showed immunonegative perikarya. It was concluded that the oculomotor internuclear pathway to the abducens nucleus comprises both GABAergic and non-GABAergic neurons and, at least in part, the GABA input to the abducens nucleus originates from this source. It is suggested that this pathway might carry excitatory and inhibitory influences on abducens neurons arising bilaterally.


Influences from different areas of the cerebral cortex on preoptic neurons: morphological and electrophysiological data. Spatial organization of neurons in the prefrontal and cingulate cortex, cortex of the piriform lobe and the hippocampus which project axons to the preoptic region, has been studied in cats using horseradish peroxidase tracing. Cortical areas were selected taking into consideration their phylogenetical distinctions. The prefrontal cortex was found to send a major portion of fibres to the preoptic region, while the density of units forming such connections was maximal in the cingulate cortex. Field potentials and neuronal reactions of the medial and lateral divisions of the preoptic region and the adjacent hypothalamic zones were studied in ketamine-anaesthetized cats. The most pronounced field potentials were recorded in the preoptic region upon stimulation of the cortex of the piriform lobe and cingulate cortex. There was a close correlation between the responses of single neurons and components of the field potentials. The majority of neurons responding to cortical stimuli were located mainly in the lateral preoptic region, where the larger amount of primary excitatory reactions were recorded. The medial preoptic region contained a smaller number of responsive neurons prevailingly generating the primary inhibitory reactions. For the lateral preoptic region the inhibition/excitation ratio was 0.6:1 at all cortical stimulations, but for the medial region it was 5.8:1. In the preoptic division adjoining the bed nucleus of the stria terminalis, the primary inhibitory reactions considerably prevailed over the primary excitatory; on the other hand, in the supraoptic nucleus the primary excitatory reactions prevailed weakly (ratios of 4.9:1 and 0.7:1, respectively). The preoptic region was found to be a zone of wide convergence of cortical inputs to single cells, where three-quarters of neurons responded to the stimulation of two, three or even four cortical areas.


[False chordae tendineae].

[False chordae tendineae]. False tendons (FT) are fibrous or fibromuscular structures which cross the ventricular cavity with no connections with valvular leaflets. They were considered for a long time as normal structures but now cardiologists are interested because of the possible association with the so-called innocent murmur, and even more so for the role they can have in eliciting ventricular arrhythmias. Some Authors believe that arrhythmias can arise from the false tendons because they contain not only fibrous tissue but also muscular and conduction tissue. Arrhythmias can be triggered either by stretching of the Purkinje fibers or by distortion of the ventricular wall, where false tendons arise. At the same time they can act as reentry circuits due to their non-homogeneous structure. Due to the fact that false tendons may arise anywhere from the ventricular cavity, they have been classified according either to anatomic or echocardiographic criteria: the latter being more complex and difficult than the former for the difficulty in locating the attachment areas. In our echocardiographic laboratory we simply distinguish two types of false tendons: type I which parallel the interventricular septum or bridges from the postero-basal portion of the septum to the posterior left ventricular wall; type II which crosses the ventricular cavity more distally, towards the apex. In the anatomic studies the prevalence of the FT is rather homogeneous, ranging from 46 to 54.9%, while it is extremely variable in the echocardiographic studies, ranging from 0.2 to 71%. This is possibly due not only to the examiner's skills, or the equipment's quality but also to the population studied. Among the patients referred to our cardiac paediatric unit we have found false tendons in 80 (29.3%) out of 273 children without cardiac disease, age ranging from i day to 13 yrs. Males were affected twice more than females, 63.7% vs 36.3%.(ABSTRACT TRUNCATED AT 250 WORDS)


[A critical review of the stable changes in ventricular repolarization in ischemic cardiopathy. A correlation with the angiographic findings]. Unknown is the significance of the abnormalities of repolarization observed at rest in patients with coronary artery disease (CAD) demonstrated by coronary angiography, except for ischemic episodes, myocardial infarction, left ventricular hypertrophy, electrolyte changes or pharmacological interactions. The chronic T wave inversion and ST segment depression are usually considered as an alteration due to ischemia ("chronic myocardial ischemia"); this definition is, in our opinion, erroneous, because myocardial ischemia is an acute episode caused by a sudden lack of balance between demand and availability of myocardial oxygen, corresponding to transient electrocardiographic alterations. Thus, the definition of "chronic myocardial ischemia" referred to stable abnormalities of repolarization is incorrect, because a "chronic" lack of balance between MVO2 and O2 availability would produce necessarily irreversible myocardial damage (necrosis). To contribute to the comprehension of the stable ECG changes at rest, we have selected a group of patients with CAD demonstrated by coronary angiography, presenting stable T wave alterations and ST depression at rest. We have studied the main and regional left ventricular function through radionuclide angiocardiography (ACS). Comparing the abnormalities of repolarization (ECG) on the one hand with angio, EFR and VER on the other, we have obtained different positive correlations, according to the functional parameters considered (EFR and VER). In our study, the lowest positive correlation has been noticed comparing ECG versus angio, VER and EFR (37.5%), while the highest correlation was obtained when ECG was considered versus angio and VER (56.25%). Evaluating ECG versus angio and EFR we have obtained a positive correlation equal to 43.75%. So we have deduced that VER is the functional parameter that better relates to angio and ECG.(ABSTRACT TRUNCATED AT 250 WORDS)


[Cerebrovascular insufficiency: diagnostic technics compared]. The ability of angiodynography (or Color Flow Imaging) to achieve accuracy in image resolution of thin details of venous as well as arterial vessels has made continuous wave Doppler and frequency analysis Doppler almost obsolete techniques. Some controversies exist about the effectiveness of color flow imaging versus duplex scanner imaging, but recent progress in ultrasound imaging technology seems to overcome the problem. Angiodynography can effectively substitute X-ray angiography in some specific instances and is able to limit the use of invasive techniques to cases in which surgical procedures are really foreseeable. The non-invasiveness of angiodynography makes it useful to follow-up the asymptomatic lesions, particularly those of the carotid artery, as well as operated patients. Moreover, people for whom contrast angiography is contraindicated can be operated safely on the bases of angiodynography alone. This paper reports the results of one-year activity of Ultrasound Vascular Laboratory with 1982 patients: 923 (48.7%) had their epiaortic arterial vessels examined, with 180 (19.5%) follow-up controls, 297 (39.9%) negative explorations, 234 (31.5%) hemodynamically not significant lesions, 135 (18.2%) subjects affected with moderate (50-70% stenosis) and non ulcerated carotid stenosis, and 77 (10.4%) patients with ulcerated plaques or > 70% stenosis.


[Surgery of the carotid: the morphology of plaque and the clinical correlations]. A consecutive series of 256 patients operated on of carotid endarterectomy for cerebrovascular atherosclerotic disease from January 1987 through December 1990 is presented. The following parameters were considered: clinical presentation, morphology of the carotid atherosclerotic plaque and topographic distribution of other concomitant atherosclerotic lesions of epiaortic arteries. 422 carotid lesions and 154 lesions of other epiaortic vessels were investigated by means of echo and color flow imaging, digital subtraction angiography and macroscopic observation of the specimen: 143 plaques proved grossly ulcerated. Unilateral lesions were 90 (35.2%) while bilateral disease was present in 166 cases (64.8%): 38.8% of subjects out of the first group and 30.2% out of the second were asymptomatic. Anterior and posterior neurological symptoms were equally distributed among both the 116 (69.8%) symptomatic subjects harboring bilateral lesions and the 55 (61.1%) symptomatic subjects with unilateral lesion (anterior 78.4% and posterior 21.6% for bilateral and 78.2% and 21.8% respectively for unilateral lesions). According to the degree of stenosis, the lesions were divided into three main groups: < 50%; 50-70%; > 70%. As the degree of stenosis increased, the incidence of focal symptoms increased too; moreover, the presence of ulceration of the stenosing plaque carried an increase in the incidence of focal symptoms within each group: respectively from 7.8% to 30% (< 50%), from 18.6% to 53.8% (50-70%), from 27.7% to 55.6% (> 70%). This study supports the relationship of morphological characteristics of the stenosing atherosclerotic plaques of the internal carotid artery to neurological symptomatology.(ABSTRACT TRUNCATED AT 250 WORDS)


[Intraoperative microbiological monitoring in abdominal aortic aneurysms in elective surgery. A review of the literature and the authors' personal experience]. Thirty-one patients, ranging in age from 57 to 78 years (mean 66), with the exclusion of cases with doubtful possible results, underwent abdominal aortic aneurysmectomy for asymptomatic AAA and had cultures from the aneurysmal wall and endovascular thrombus to identify possible microbiological source of future graft infection; 5 (16%) of 31 cultures yielded bacterial growth and the most common organism isolated was staphylococcus epidermidis. During an average follow-up of 15.4 months no graft infection was noted in patients with positive or negative aortic cultured. A literature review stresses the same disparity between positive cultures obtained at the aneurysmectomy and subsequent low graft-infection rate. It is concluded that the aneurysm wall itself does not represent an important source of early or late graft infection and it's suggested that the bacterial presence both in the wall and thrombus could be explained by an exogenous contamination at the operation time.


[Isolated aneurysms of the internal iliac artery. A clinical contribution]. Five patients with isolated aneurysms of the internal iliac artery were identified and submitted to surgical procedure. Two patients were operated on in election, three in emergency with aneurysmatic rupture. The natural course of this pathology is one of progressive expansion and rupture. This lesion is often asymptomatic, but sometimes we found associated, compression symptoms of genito-urinary, intestinal tract and venous and neurological structures. Echography, CT scan and angiography are the most common and useful diagnostic procedure. Endoaneurysmectomy with proximal and distal suture of the stumps is the appropriate treatment in the majority of the cases.


[The predictiveness of the duplex scan method in monitoring a venous femoro-distal bypass]. The medium-term failure of femoro-distal revascularization using venous bypass is often preceded by the onset of intrinsic intraprosthetic lesions which, if not diagnosed, may develop and cause thrombosis in the venous prosthesis. The authors report their experience relating to the monitoring of these bypass operations using an echo-Doppler test which was found to be a sensitive and reliable method. In their opinion, frequent instrumental control may significantly reduce the number of occlusions in the venous prosthesis if a rapid surgical therapeutic approach is adopted towards those intraluminal lesions considered to represent a risk.


[Thrombosis of the right atrial appendage. The two-dimensional echocardiographic aspect and the autopsy finding]. We report the case of an 80-year-old man affected by hypertensive cardiomyopathy and already admitted to our Division for recurrent episodes of heart failure. He was eventually hospitalized for septic shock secondary to disseminated pneumonia with concomitant left pleural effusion. At 2D-echo examination, a highly echo-reflectant mass was detected in the retrocardiac space. As the patient died notwithstanding the intensive pharmacological care, an autoptic procedure was performed which showed a massive thrombosis of the right atrial appendage. We discuss the 2D-echo imaging and advance a pathogenetic hypothesis after a review of the current literature.


[Nontraumatic dissection of the left extracranial internal carotid artery. A clinical case]. The authors report a case of non traumatic dissection of the left extracranial internal carotid artery. Their main topics deal with the clinical-diagnostic aspects and the therapeutic approaches adopted, compared with the specific literature's most recent data. In addition they have discussed--some--investigations aimed at the best follow-up of those diseases.


[Transplantation of the left lung in a 2-month-old piglet. The Study Group for Lung Transplantation]. Experimental surgery in animals remains an irreplaceable model for the clinical application of a new technique. We performed a single lung allotransplantation in young pigs. The pigs were organized into groups: 1) 6 to assess the surgical anatomy; 2) 10 to receive left transplantation; 3) 3 to study the pathophysiology of the transplanted lung. The preliminary results demonstrated that the surgical model is useful.


[Fetal microsurgery. The past and present of a frontier of surgery]. The concept that the fetus may be a patient is very recent. Modern ultrasonography can detect fetal abnormalities early in utero, and lead to prenatal correction of such malformations. At present three anatomic defects can benefit from fetal surgery: diaphragmatic hernia, urethral obstructions and obstructive hydrocephalus. The feasibility of fetal surgery has been proved both experimentally and clinically. Microsurgery can be of great help in this type of surgery. At this stage, fetal surgery should be pursued only in very qualified centers.


[The role and problems of the surgical approach in adrenal incidentalomas]. The authors report a series of 5 incidentalomas: 4 nonfunctioning adrenocortical adenomas and 1 nonfunctioning pheochromocytoma. They emphasise the importance of US, CT, MRN, and scintigraphy in differential diagnosis compared to laboratory tests. In addition, they affirm that a correct oncological approach necessarily involves radical surgery and rule out the possibility of adopting a "wait and see" policy based on relative factors such as tumour size, function and the patient's age. The authors suggest using a posterior or anterior access route depending on the nature and size of the incidentaloma and recommend reserving the lateral incision for special cases.


[Rare metastases].

[Rare metastases]. The paper reports a number of cases of uncommon metastasis confirmed by histological tests in surgical biopsies; following a brief discussion of the literature on this topic and in particular on the basis of an earlier study by one of the authors, the paper affirms that metastasis is related to general and local biological factors, that the diffusion of neoplastic cells is an early and generalised phenomenon opposed by organic defence mechanisms, and that the concept of uncommon metastasis should be revised, without resorting to fixed anatomical references, according to a general "impregnation" of tumour cells.


[Aneurysm of the subrenal aorta. Comments on 25 cases seen]. The authors report their experience in the diagnosis and treatment of subrenal aortic aneurysms. The incidence of the abdominal aortic aneurysms, in aged population, is increasing, linked, in 95% of cases, to atherosclerotic disease. The diagnosis is essentially clinical with help of various examination techniques, that provide an accurate preoperative morphological assessment, like direct X-ray of the abdomen, echography, angio computerized axial tomography and arteriography. The moment for operating aneurysms of the subrenal aorta is discussed. The rate of operative deaths following elective replacement of abdominal aortic aneurysms is less than 4% and it increase to 40-80% in emergency replacement for rupture. Rupture remains a catastrophic life-threatening complication for cardiovascular, respiratory and renal failure, in spite of improved surgical techniques and postoperative intensive care.


[Early escharectomy in children: the indications and limits in the severely burned patient. A preliminary report]. A trial was carried out to assess the benefit of early eschar excision in order to improve the survival rate in severely burnt children. The study included two groups of patients treated using different methods. The mortality rate, amount of blood lost and length of hospital stay were evaluated for each group. Preliminary results seem to confirm the effectiveness of this technique provided that some conditions are met, namely the quantity of necrotic tissue removed and the amount of blood lost during the entire hospital stay.


[The incidence of tumors of the oral cavity and salivary glands in cervical adenopathies. Case contributions]. The paper report 592 non-selected cases of cervical adenopathies treated using both simple biopsy and more radical surgery. The predominant sites were right (29.7%) and left (25.2%) laterocervical. Histological tests showed that in 206 cases (34.8%) the pathology was benign and/or aspecific, whereas in 386 cases (65.2%) the presence of metastatic or systemic cancer was identified. Within the scope of metastatic adenopathies, tumors of the oral cavity or salivary glands, if taken together, account for the highest percentage of incidence: 14.2%. For this reason, the presence of cervical adenopathies must be given priority in the search for possible primary lesions affecting all the anatomical structures forming the oral cavity and the adjacent salivary glands.


[Choledochocele: a rare cause of chronic pancreatitis of the head of the pancreas]. The authors critically review the literature in order to ascertain the current state of knowledge regarding the anatomopathological, clinical and therapeutic characteristics of choledochocele, or cystic dilation of the terminal portion of the biliary tract. In particular, the Authors examine the etiopathogenetic aspects to explain how the presence of a choledochocele may lead to the onset of chronic pancreatitis. A clinical case which was recently brought to their attention is examined in detail. It concerns a 27-year-old patient in whom the presence of a large choledochocele had led to the onset of severe cephalopancreatitis which resisted all forms of treatment. In the case in question, ERCP played a decisive role in the diagnosis of the choledochocele, whereas ultrasonography, CT and selective arteriography were useful above all in relation to pancreatitis. In the case described ultraradical surgery, namely duodenocephalopancreatectomy, allowed the severe pancreatopathy and its etiological cause (choledochocele) to be efficaciously treated, confirming that this type of surgery currently plays an important role in the treatment of chronic pancreatitis.


[Gastric leiomyoblastoma. A case report]. The authors report a case of gastric leiomyoblastoma, a rare benign neoplasm that can sometimes undergo a malignant course. The main clinical an pathological issues are reviewed, in order to offer guidance as to the best suited surgical approach.


[Compression of the sigmoid of gynecological origin]. The authors report a case of extrinsic stenosis of the sigmoid colon due to inflammation of the uterus and adjoining parts. Attention is drawn to the possibility that the radiological images of this condition may be similar to neoplastic diseases.


[Ganglioneuroma of the adrenal gland associated with a contralateral renal carcinoma]. A case of ganglioneuroma of the adrenal gland associated with contralateral renal cell carcinoma is presented. Both the lesions underwent surgical therapy: of left adrenalectomy and right nephrectomy. The benign nature of the ganglioneuroma and the low staging (T2) of the renal neoplasm explain the positive exitus of the treatment: the patient is alive and free from disease after five years from the operation.


[A clinical and anatomical-histological contribution to the study of lipofibrocalcareous myopathy. Mattioli-Foggia and Raso disease]. The paper reports the clinical and histological biopsy data of a patient suffering from lipo-fibro-calcareous myopathy (Mattioli-Foggia and Raso's disease). It affirms that this pathology may be attributed to the group of phacomatosis and that in this instance this is a case of neurovascular phacomatosis (neuroblastodermosis).


Did Columbus also open the exploration of the modern diet? On the 500th anniversary of Columbus's voyage of discovery, one aspect that merits particular attention is its influence on food and nutrition worldwide. Columbus found an unexpected wealth in food resources rather than the gold he sought. The sailors came from a continent where famine was well known and had subsisted for two months on a typical seamen's diet of preserved foods, primarily hardtack and salt pork. They made landfall in green and fertile islands. The foods that constituted the core of the diet of the Americas before 1492--from maize to potatoes, beans to tomatoes, to numerous other fruits and vegetables--became the true patrimony that the inhabitants of the New World bequeathed to humanity. These foods, new to the Old World, provided the basis for the exchange and evolution of networks of food production and consumption which, with many trials and errors and with no preestablished plan, characterize modern nutrition. The diet of Mediterranean countries, now universally recommended for nutritional health, is high in several foods, tomatoes and beans in particular, that originated in the New World.


Nutrition in acute pulmonary disease.

Nutrition in acute pulmonary disease. Acutely stressed patients with chronic pulmonary disease have a particular need for accurate nutritional assessment and appropriate nutritional therapy. Loss of skeletal muscle, often extensive, can be paralleled by dramatic alterations in cellular function; inadvertent provision of excessive calories or of individual substrates may produce more harm than benefit. In the absence of a single "gold standard" for nutritional assessment and monitoring, no single value should take precedence over the entire clinical picture, which should be thoughtfully assessed and reassessed, with both the patient's nutritional needs and the consequences of their provision kept in mind. In the future, assessments of the impact of nutritional intervention will probably rely more heavily on functional tests of specific organs and of the immune system. Intervention will be based not only on provision of calories, individual substrates, vitamins, and minerals, but also on control of the inflammatory response in order that the nutrients may be properly utilized.


New insights into placental iron transport. The transport of iron from mother to fetus presents a number of challenges, none more perplexing than determining how the flow can be unidirectional, yet avoid mixing the mother's serum proteins with the fetal system. Studies with cultured cell lines suggest a possible mechanism by which this may be achieved.


Glutamine: a conditionally essential nutrient or another nutritional puzzle. Malnutrition and infection are common among patients receiving bone marrow transplant. A recent randomized, double-blind study was conducted to determine whether the addition of glutamine to standard total parenteral nutrition solutions would improve nitrogen retention and reduce hospital morbidity in a group of 45 bone marrow transplant patients. The results showed improved nitrogen balance and reduced incidence of clinical infection in the glutamine-supplemented patients.


Maximizing peak bone mass: calcium supplementation increases bone mineral density in children. Attaining peak skeletal bone mass during childhood may reduce the incidence of osteoporosis in later life. A recent study in six- to 14-year-old identical twins showed that calcium supplementation increased bone mineral density. The effects of supplementation were especially pronounced in prepubertal children.


Access to health care in rural western New York State. Persons living in rural counties often have limited access to health care. From a random sample, 1,332 households in six rural western New York counties were interviewed by telephone to identify what health care facilities are used when seeking professional health care what factors affect the preference for a health care facility and whether individuals perceive a shortage of health services in their communities. Seventy-nine percent of rural western New York individuals surveyed visited a physician between June 1988 and January 1990. The majority (83%) of individuals visited their regular health care source, which in most cases (81%) was a physician's private office. Factors related to a preference for some other health care source for the last visit included having traveled 20 or more miles to the visit (p < 0.01) and lack of overall satisfaction with the last visit (p < 0.001). Factors that varied by county of residency and were significantly associated with satisfaction included the type of health source used (p < 0.001), and the distance traveled to the last health care visit (p < 0.01). The majority of the respondents did not perceive a shortage of health care services in their communities probably because they have a lower expectation of health care accessibility.


Health and economic impact of cigarette smoking in New York State, 1987-1989. This study provides estimates of deaths attributable to smoking, years of potential life lost (YPLL), and economic costs for each of New York's 57 counties and New York City for the period 1987 to 1989. Results show that in New York State, cigarette smoking was responsible for an average of 30,359 deaths, 409,129 YPLL, and nearly $4 billion in economic costs annually. Overall, smoking-attributable deaths comprised 17.7% of all deaths, or more than the combined total from accidents, AIDS, homicide, and suicide. Findings demonstrate the enormous health and economic burden caused by tobacco use and reinforce the need for policies that discourage smoking, such as increased cigarette taxes, limited smoking in public places, enforcement of youth tobacco access laws, and funding for tobacco education programs.


Medical futility. Committee on Bioethical Issues of the Medical Society of the State of New York. The term futile is used in many different ways. It is therefore difficult to decide whether a procedure or treatment such as CPR or hemodialysis or blood transfusion would be futile in a given case. The AMA's guidelines on the appropriate use of DNR orders state that DNR decisions should be made openly. Institutions should have policies and physicians should elicit the patient's preferences about CPR. For physicians, the question is no longer whether we should discuss DNR orders with our patients; instead, the issue is how to do so with compassion and caring. Physicians should share with patients their judgment about what medicine can and cannot do. Then physicians must "make decisions about when to withhold or limit resuscitation openly" in honest and trusting conversation between doctor and patient. Often CPR is an exercise in futility. The medical profession should be vested with the authority to make futility decisions if they are the product of open discussion and shared deliberation between physician and patient, family, or surrogate. Rationing, triage, and medical futility in relation to AIDS patients require careful deliberation and consideration. What was considered medically futile five years ago for an AIDS patient may be appropriate care nowadays. The need for appropriate use or non-use of life-sustaining therapy for the elderly, the terminally ill, patients with AIDS and other incurable illnesses is evident to patients, health care providers, policy makers, and the public. CPR should only be administered if it is expected to confer lasting benefit to the patient. However, if 10% of elderly patients benefit from CPR in the case of out-of-hospital cardiac arrest, how can one consider this procedure futile? Although communication between physician and patient about difficult treatment limitation decisions has markedly improved in recent years, it remains a problem, largely because open dialogue with patients and families about futility is a demanding emotional and intellectual task. The medical profession is charged with setting standards for the proper implementation of judgments regarding futility.(ABSTRACT TRUNCATED AT 250 WORDS)


Nutrient intake and weight/height of Saudi patients at King Faisal Specialist Hospital in Riyadh, Saudi Arabia. Nutrition surveys in the past showed some mild and moderate degrees of malnutrition in young children below 10 years of age. Deficiency diseases like anaemia were also reported. This survey is part of a large study of 1005 patients and sitters to see the relationship of diet and disease. Seven hundred and fourteen patients were subsampled and became the subject of this report to find out if the nutritional status of the children surveyed 10 to 15 years ago had any major change. It also presented some new information about nutritional status of older groups up to 96 years of age. It was found that weight for height and height for age of children up 14 years (except the girls GT 10-LE 14 years) could now compare with the US NCHS standard. The adolescent girls' (up to age 18) weight for height were statistically lower than the standard. Later in life, with some influences from the other female members of the household, and because of their limited activity, the women's weights were even higher than the standard. The adolescent males' weights were within standard, but the adult males' from age 18 were statistically lower than NCHS. Height for age from age 14 years for all were statistically lower than standard and was attributed to poor nutritional states in the past. Energy intakes of the adult males and iron intakes of the infants below one year of age were significantly lower than standard. Low energy intakes of the adult males confirm low weight for height performance. The same problem with iron of milk-fed infants of 10 to 15 years ago was still encountered. This shows that some traditional practice of infant feeding still persists despite the improvement in the quality of life and standard of living of the Saudis due to the economic upheaval created by oil. This survey emphasizes the importance of follow-up reports to see the changes in the people's state of health after a period of transition from economic dependence to affluence.


A speculative discussion of some problems arising from the use of ammonium nitrate fertiliser on acid soil. Some personal farming experiences are described, and attention is drawn to four anomalies associated with the use of ammonium nitrate. These can be explained if the changes that took place in the formulation of fertilisers around 1960 have led to acidic soils becoming depleted in calcium, and if crops growing in high nitrogen conditions take up their nitrogen as ammonium. It is concluded that the fertiliser recommendations that have been formulated at Rothamsted are unsuitable for use upon acidic soils in wetter parts of the UK because they result in the soil becoming excessively anaerobic so that the balance of nutrients becomes unsuitable for optimal plant and animal growth.


Retinoblastoma in the first year of life. Children diagnosed with retinoblastoma in the first year of life present with differences in laterality, stage, signs, symptoms, and respond differently to treatments when compared to older children. Of those children diagnosed in the first year of life (between 1958 and 1983 inclusive), 280 were bilateral and 121 were unilateral, the most common stage of diagnosis (for unilateral and bilateral) was Group V, and children were affected equally by sex. Children examined in the first three months of life were more often seen because of a positive family history of retinoblastoma, rather than leukocoria. Children who were treated in the first year of life frequently develop second nonocular tumors because they harbor the germinal mutation and receive radiation.


Mucolipidosis type IV. Presentation of a mild variant. The authors report a 16-year-old girl with mucolipidosis type IV. She was referred because of deteriorating vision over the past three years. Corneal clouding with the appearance of cornea verticillata and retinal dystrophy were the main ophthalmological findings. Except for clumsiness no psychomotor retardation was present. Ultrastructural analysis of a conjunctival biopsy and cultured fibroblasts suggested a diagnosis of mucolipidosis type IV which was confirmed by biochemical studies. This patient represents the mildest described presentation of mucolipidosis type IV.


A Japanese pedigree of autosomal dominant congenital stationary night blindness with variable expressivity. Three cases in three successive generations of one family with autosomal dominant congenital stationary night blindness are presented. Case 1, the proband, and Case 3, his grandfather had the same electroretinographic responses: nonrecordable scotopic electroretinogram (ERG), normal but slightly diminished flicker ERG, and negative-shaped single bright-flash ERG. Their dark adaptation curves were monophasic with no rod segment. However, Case 2, the proband's father, showed different ERG findings; a moderately diminished scotopic ERG, a normal flicker ERG, and a biphasic dark adaptation curve with an elevated final rod threshold. The authors believe that these differences reflect variations in the expressivity of a single gene mutation with the lowest expressivity being seen in Case 2.


Mitochondrial DNA analysis in Leber's hereditary optic neuropathy. A mitochondrial DNA (mtDNA) mutation at nucleotide 11778 has been reported as the genetic defect associated with Leber's hereditary optic neuropathy (LHON), but some pedigrees failed to reveal this mutation. The authors present the genetic analysis of a large Italian LHON family with three probands and 16 asymptomatic maternal relatives. The 11778 mtDNA mutation was present in this family and absent in 52 Italian healthy controls, confirming the association between this genetic defect and LHON. In addition, they found a variable proportion of mutated and wild-type mtDNA (heteroplasmy) in every maternally related family member, including the probands. Different patterns of heteroplasmy were present in the pedigree and lower levels of wild-type mtDNA seemed to correlate with the disease status. Moreover, the authors evaluated the mitotic segregation of mt genomes in blood, hair and urinary tract epithelia of the three patients and they found a similar level of heteroplasmy in these tissues.


A retrospective study of registered retinitis pigmentosa patients in The Netherlands. A retrospective study was performed of patients with retinitis pigmentosa (RP) registered at the Department of Ophthalmogenetics of the Netherlands Ophthalmic Research Institute. The aim was to establish the relative frequencies of the genetic modes and to attempt a clinical subclassification. Of the 575 RP patients, 10.4% were X-linked, 22.4% autosomal dominant, 30.1% autosomal recessive, and 37.1% simplex cases. Clinical classification was inconclusive, and consequently correlation of phenotype to genotype impossible in most cases. One exception was the occurrence of a tapetal reflex, which seemed to differentiate between RP2 and RP3. Gene defects have not been detected so far in Dutch families with either autosomal dominant or autosomal recessive RP. In the future, simplex cases will have to be classified according to their genetic defects. It is probable that results of DNA studies may prove a better basis for classification of RP than clinical data.


Temporomandibular joint dysfunction. Connective tissue variations in skin biopsy and mitral valve function. Ten women with temporomandibular joint dysfunction and general joint hypermobility (score, 4 to 8) and 10 symptom-free female volunteers without systemic laxity (score, 0 to 2) were selected for the study. A biopsy of connective tissue from arm skin found that the total collagen concentrations were lower and the proteoglycan values were higher in the hypermobile TMJ patients than in the control subjects. The mitral region of the heart was inspected by echocardiography. Eight patients and four controls had slightly abnormal echocardiographic findings. Two patients fulfilled the criteria for mitral valve prolapse. The patients had significantly more musculoskeletal complaints than did the controls. The study suggests an association between joint hypermobility, abnormal skin connective tissue composition, mitral valve malfunction, and musculoskeletal disorders in young women with TMJ dysfunction, especially internal derangement.


Use of auricular cartilage in the repair of orbital floor defects. Various materials have been used to repair orbital defects. This article advocates the use of autogenous conchal cartilage, especially in the repair of large posttraumatic defects, where contour, biocompatibility, and strength are most important. The technique for harvesting the cartilage is reviewed, and a case demonstrating its successful use is reported.


Technical modification of the sagittal split mandibular ramus osteotomy. The sagittal split mandibular ramus osteotomy is a versatile surgical option for the correction of mandibular prognathism, retrognathism, and asymmetry. At the same time, it enables the use of internal rigid fixation. However, surgical complications including injury to the inferior dental neurovascular bundle and unfavorable fracture can occur. A technical modification and a concept in instrumentation is suggested with the view of minimizing such complications.


Changes in masseter inhibitory reflex responses in patients with diffuse sclerosing osteomyelitis of the mandible. Masticatory inhibitory mechanisms were studied in 10 patients treated for diffuse sclerosing osteomyelitis of the mandible. Their masseter inhibitory reflex responses were provoked electrically by mental nerve stimulation during maximal clenching of the teeth. The masseter inhibitory reflex was normal in two patients and significantly abnormal in eight patients. The two patients with a normal masseter inhibitory reflex were free of complaints, whereas, of the eight patients with an abnormal masseter inhibitory reflex, two were free of complaints and six had moderate to severe symptoms. In three patients, spasms and involuntary bursts of electromyographic activity were found. The abnormal masseter inhibitory reflex consisted of a loss of early and late components in four patients or a loss of the late component with a normal early one in four patients. These findings seem to support the hypothesis that diffuse sclerosing osteomyelitis of the mandible is a chronic tendoperiostitis caused by muscle overuse. It is suggested that this overuse is caused by central hyperexcitability of trigeminal motoneurons.


Oral myiasis caused by sarcophagidae in an extraction wound. Oral myiasis (infestation by the larvae of Diptera flies) has only rarely been reported in the English-language literature. This article records a case of wound myiasis caused by flies of the family Sarcophagidae that affected a tooth-extraction site, and was a painful complication of the extraction.