Cytogenetic studies of a male with sporadic intestinal lymphangiectasia: 45,X/46,XY mosaicism with pseudo- and hyperdiploid subpopulations in cultured tissues. 45,X/46,XY mosaicism was found in peripheral blood, bone marrow, and tissue cultures of an adult male with intestinal lymphangiectasia (IL). Turner phenotype was not present; his meiotic metaphase analysis was normak, and his dermatoglyphics resembled those of his family. Ten separate tissue culture lines from three biopsies of skin and thyroid gland contained 45,X cells (14.8 to 78.3%). Autosomal aneuploidy, resulting in pseudo- or hyperdiploidy, was also present in 4.3 to 41.6% of the cells. A hyperdiploid clone with a 47,X,+10,+18 karyotype was found in 22.6% of cells in one line. A second hyperdiploid clone with a 48,X,+2,+18,+18 karyotype occurred in 7.6% of cells from another line containing a total of 41.6% pseudo- and hyperdiploid cells. Such clonal abnormalities were not typical of tissue cultures from other patients done in our laboratory. Growth of our patient's tissue cultures was subnormal, and none proliferated beyond the fourth subculture. The significance of this observation remains to be determined. Our results do not allow us to conclude whether our patient's mosaicism of somatic tissues arose during embryogenesis, or whether it originated post-natally. The secondary immunodeficiency which occurs in IL may explain persistence of cells with unusual combinations of autosomal aneuploidy in our patient's tissues.


Gerodermia osteodysplastica hereditaria: report of three affected brothers and literature review. Gerodermia osteodysplastica hereditaria was diagnosed in three Mexican brothers 6, 7, and 8 years old, respectively, who had the distinct facial appearance with sagging cheeks, premature wrinkling of the skin of face, abdomen, and dorsum of hands and feet; malocclusion, span greater than height; hyperextensibility; winging of the scapulae; stooped posture with kyphoscoliosis; protuberant abdomen; and pes planus. Radiologically they had generalized osteoplorosis, platyspondily due to multiple compression fractures, pseudoepiphyses of second metacarpals, and dislocated hips. Three other families with a total of 14 affected individuals have been reported. Inter- and intrafamilial variability can be recognized, particularly regarding the tendency to fractures, upper:lower segment ratio abnormalities, and results of skin biopsies, which have shown fragmentation of the elastic fibers in some cases (including the present family) and not in others. Although inheritance was considered to be X-linked recessive in the first reported family, an analysis of that pedigree together with those of the other reported families, including the present one, suggests that gerodermia osteodrysplastica is inherited in an autosomal recessive manner.


Effect of diabetes mellitus on amniotic fluid lecithin/sphingomyelin ratio and respiratory distress syndrome. Ninety-eight insulin-dependent diabetic patients were cared for during 108 pregnancies following an ambulatory program aimed at close control of blood sugar levels. The incidence of respiratory distress syndrome (RDS) in these patients was not different from that in nondiabetic patients. Fetal pulmonary maturity seemed to progress at a normal rate as evidenced by an equal incidence of mature lecithin/sphingomyelin (L/S) ratios at various stages of gestation in diabetic and nondiabetic patients. There was no evidence that Class B and C diabetic patients have delayed fetal lung maturation or that Class E, F, and R patients have accelerated maturation. It is concluded that careful metabolic control of the pregnant diabetic patient results in a normal process of fetal pulmonary maturation without increased risk of RDS.


Relief of dysmenorrhea with the prostaglandin synthetase inhibitor ibuprofen: effect on prostaglandin levels in menstrual fluid. The prostaglandin synthetase inhibitor ibuprofen was evaluated for relief of severe primary dysmenorrhea in a controlled, double-blind, cross-over study in seven patients for a total of 23 menstrual cycles. In eight untreated cycles, the amount of prostaglandin (PG) in the menstrual fluid was higher than in nondysmenorrheic subjects. There was good to excellent relief of dysmenorrhea in seven ibuprofen-treated cycles, which was associated with a threefold to fourfold reduction in menstrual PG released. When a placebo was given in five cycles, only poor or minimal relief of dysmenorrhea was obtained and the menstrual PG released was similar to that in control cycles. In individual patients, there was a remarkable correlation between the severity of menstrual pain as assessed daily by the patient and the level of menstrual PG released during the corresponding period. The effect of ibuprofen therapy on menstrual fluid volume was inconsistent. The study shows that in severe primary dysmenorrhea there is increased release of PG in the menstrual fluid; this can be effectively suppressed with ibuprofen, which provides excellent relief from the symptoms of dysmenorrhea.


Morphologic features of prognostic significance in uterine smooth muscle tumors: a review of eighty-four cases. Independent microscopic review of the most cellular and pleomorphic areas of 84 smooth muscle tumors of the uterus by two pathologists yielded 23 leiomyosarcomas, 43 cellular leiomyomas, 16 bizarre leiomyomas, and two intravenous leiomyomas. Greater than 5 mitotic figures/10 high-power fields (hpf) correlated with malignant clinical behavior, but this occurred in only 75% of the leiomyosarcomas. Five cases with fewer than 5 mitoses/10 hpf pursued a malignant course. The mean age of the patients with malignant tumors (52.5 years) was similar to the mean age of those with bizarre leiomyomas (48.0 years) but those patients with cellular leiomyomas were significantly younger (42.0 years; p less than 0.01). Gross evidence of extrauterine extension was diagnostic of malignancy as was vascular invasion by anaplastic tumor. Fifteen of the 19 patients with leiomyosarcoma died of disease at an average of 28 months postoperatively. Inadequate sampling and interobserver variation are discussed.


Correlation of ultrasonic and endocrinologic assessment of human follicular development. Human ovarian follicular development measured by peripheral plasma hormone levels and ovarian follicular growth assessed by ultrasonic visualization of the ovary were compared and contrasted in apparently normally menstruating women. The linear correlation coefficient between the mean values for plasma estradiol and follicular diameter on day -5 to day 0 of 15 normal cycles was r = 0.968. When the individual paired data were subjected to multiple linear regression analyses (on days -5 to 0), r = 0.771. These good correlations show that ultrasound measurements of follicular diameter are valuable in the assessment of follicular growth and development. Observations on apparently abnormal cycles are also discussed. Ultrasound measurement of follicular diameter offers an additional technique for the study of ovarian function.


The effect of oral contraceptives on vitamin B12 metabolism. Serum vitamin vitamin B12 levels were determined in 199 women who were on a regimen of oral contraceptives of either the combination or sequential type and in a control group of 196 women. The group using oral contraceptive agents (OCA) had significantly lower serum levels of vitamin B12 vitamin as compared to those of the control group. A total of 19 women using OCAs had serum vitamin B12 levels that were lower than normal values. However, the Schilling test and urinary methylmalonate excretion in this group were normal. The OCA group had a significantly lower total serum vitamin B12 binding capacity, a lower total transcobalamin I level, and a higher transcobalamin III level. Our study suggests that the fall of serum vitamin B12 in OCA users is due to the changes in vitamin B12 binders of serum and does not represent vitamin B12 deficiency. Therefore, according to our data, there is no justification for vitamin B12 supplementation in users of oral contraceptives.


How does one assess the risk of abnormalities from human in vitro fertilization? The procedure of in vitro fertilization, including ova collection and embryo culture and transfer, raises concern about the risk of abnormalities arising from the technique. In vitro versus in vivo comparison might be made in the study of preimplantation embryos and spontaneous abortions, the results of amniocentesis, and the findings among fetal deaths and live births. In vivo, 40% to 50% of implantation blastocysts are estimated to have a chromosomal abnormality, over 99% of which are estimated to be eliminated during the course of pregnancy. In principle, the use of early spontaneous abortions can be more efficient than amniocentesis for detecting an increased risk of chromosomal abnormalities at birth. Unless in vitro fertilization in humans strongly contradicts the experience in domestic animal reproduction, which suggests no increased risk of abnormalities at birth, a large number of births would be required to provide a definitive assessment of risk.


Dimensions of prenatal anxiety and their influence on pregnancy outcome. Wtih the use of perinatal data from a prospective study of 73 primigravid women and their newborn infants, we determined that prenatal anxiety is not a unitary construct, but that it is useful to consider the distinct concerns of pregnancy. From interviews with the pregnant women, three dimensions of anxiety were identified: (1) anxiety about the pregnancy and approaching birth, (2) anxiety about anticipated care of the child, and (3) psychiatric symptomatology. Correlations of the three anxiety dimensions with background and perinatal outcome variables reveal the strongest associations between anxiety about pregnancy and birth with maternal age, education, and preparation for childbirth. Anxieties about pregnancy and birth and about parenting are related to administration of anesthesia during childbirth and the motor maturity of the neonate. The findings thus give evidence that even in a medically uncomplicated population, emotional states of pregnancy are rooted in the woman's background and may have an impact on perinatal events and infant functioning.


Weight gain and the outcome of pregnancy. This study determined the relationship of maternal weight gain in pregnancy to its outcome. Mothers who were overweight at the start of pregnancy had the fewest fetal and neonatal deaths with a 16 pound weight gain at term. The optimal weight gain for normally proportioned mothers was 20 pounds and for underweight mothers 30 pounds. For all three groups perinatal mortality rates increased with weight gains less or more than these optimal values. Very low or very high pregnancy weight gains had only a modest influence on the frequency of common placental and fetal disorders. However, once one of these disorders was established, mortality rates from it usually increased severalfold when mothers had very low or very high weight gains.


Serial relaxin concentrations in human pregnancy. Relaxin is a peptide hormone produced by the corpus luteum during pregnancy in human beings. There are no extraluteal sites of production of relaxin in women. By means of a heterologous porcine radioimmunoassay, serial serum relaxin concentrations were determined in three women throughout pregnancy and into labor. All three demonstrated a first-trimester elevation followed by a second-trimester decline; values then remained stable throughout the second and third trimesters and into labor. This further confirms the functional activity of the corpus luteum throughout pregnancy and the value of relaxin as an index of luteal function during gestation.


Prenatal diagnosis of the hemoglobinopathies: ethical issues. Prenatal diagnosis of the hemoglobinopathies has been increasingly reported. This article discusses those ethical issues stemming from pregnancy studies by fetoscopy or placental aspiration: diagnostic accuracy and safety for mother and fetus, abortion of the fetus diagnosed as homozygous for thalassemia or sickle cell diseases, and access to prenatal diagnosis for those who cannot afford it. The author's position on these issues attempts to mediate between the poles in current ethical debate on abortion in public policy.


The lung profile. I. Normal pregnancy.

The lung profile. I. Normal pregnancy. The lung profile run by two-dimensional thin-layer chromatography is described, including the L/S ratio and the percentages of disaturated acetone precipitated lecithin, PI, and PG. Results show that the accuracy of this profile increases that of the mature L/S ratio value even further, while decreasing the missed predictions with low L/S ratios to only about 7%.


Origin of the alkaline phosphatases in amniotic fluid. The nature and origins of amniotic fluid ALP activity were investigated early (14 to 22 weeks) and late (25 to 44 weeks) in pregnancy. The total enzyme activities for both stages were significantly different and considerable changes in the activities of individual enzyme components occurred. Early activity consists of intestinal (81%), bone/liver/kidney (15%), and placental (4%) ALP. In late fluids, the values are 5%, 69% and 27%, respectively. The intestinal enzyme is shown to be of fetal origin, presumably arising from the direct entry of desquamated intestinal mucosal cells into the amniotic fluid. The bone/liver/kidney enzyme is mostly of maternal serum origin early with an increased fetal contribution toward term. Early in pregnancy, the placental ALP activity is probably derived both directly from the placenta and from the placental activity in maternal serum. The latter source contributes more toward term.


The effect of diet supplementation and addition of zinc in vitro on the growth-supporting property of amniotic fluid in African women. The effect of diet supplementation throughout pregnancy on third-trimester amniotic fluid growth-supporting activity (GSP) was studied in 100 African women; 32 were given zinc supplementation, 22 each animal and vegetable supplements, respectively, and 24 served as control subjects. No difference in GSP was noted in any of the four groups, the majority of fluids (65%) being noninhibitory. Zinc levels in fluids from African women were much lower than those described for other population groups at corresponding periods of gestation. Although zinc levels in liquor rose following dietary zinc supplementation, these remained lower than values described in white patients. In vitro addition of zinc (up to 153 mu moles per liter final concentration) to 17 noninhibitory African liquors resulted in these fluids becoming inhibitory.


Use of the minor hemoglobin ratio for the determination of gestational age. Maternal and cord blood hemoglobin A1c were quantitated at the time of delivery by radioimmunoassay. Other cord blood hemoglobins were quantitated by column chromatography using Bio-Rex 70. The minor hemoglobin ratio : formula: (see text),showed an excellent linear correlation (r2  = 0.88) with gestational age. Therefore, the ratio of : formula: (see text), could be a useful test to determine gestational age in the third trimester.


Activity and work during pregnancy and the postpartum period: a cross-cultural study of 202 societies. Cross-cultural information on 202 traditional societies was perused for data on customs surrounding the expected work load of pregnant and postpartum women. The most common single pattern of work activity during pregnancy was that of continuing full duties until the onset of labor. A bare majority of societies did encourage a lightening of work at some time during pregnancy. Postnatally, most societies did restrict maternal work activity; however, few suspended usual work duties for prolonged periods of time. About one half of societies expected a return to full duties within 2 weeks. Results suggest that the current American trend toward increased participation of women of childbearing age in the work force may be in keeping with the work loads of women in traditional societies.


Treating the emotional aspects of infertility: counseling services in an infertility clinic. The physician treating the infertile couple, while attempting to diagnose and treat the cause of that problem, all too frequently overlooks the emotional aspects of involuntary sterility. Infertility can cause tremendous strains on the patients, either individually or as a couple. An approach to meeting these needs can be achieved through a program of counseling, provided as a service in an infertility center.


Anatomic and clinical correlates of uterine perforation. We reviewed cases of uterine perforations which occurred at or were referred to the Boston Hospital for Women, Lying-In Division, over the 2 year period from mid-1975 to mid-1977. There were 25 uterine perforations; twenty patients were pregnant and five were not. In the pregnant patients, 16 perforations involved the cervix or the lower uterine segment, whereas only four were located in the uterine fundus; in the nonpregnant patients, all five were fundal perforations. In the pregnant patients, 12 required laparotomy, eight had serious lacerations of the uterine artery, and three had hysterectomy while none of the nonpregnant patients had lacerations or required subsequent procedures. Thus, there is a significant anatomic difference between those perforations which occurred in the pregnant patients and in the nonpregnant patients, the manner in which they presented clinically, and the need for intervention via laparotomy, subsequent morbidity, and outcome as reflected in future reproductive capability. Perforation at or near the cervix may be more common than previously assumed. Furthermore, two distinct clinical entities of cervical perforation exist in pregnant patients as based on the anatomic location of the defect. The anatomy of cervical perforations, their recognition, and their management are discussed.


Vulvar neoplasia in the young.

Vulvar neoplasia in the young. Vulvar intraepithelial neoplasms may be occurring more frequently among younger age groups. Six patients with carcinoma in situ or severe vulvar dysplasia are reported, as well as one patient with microinvasive carcinoma, all under the age of 30 years. The vulvar lesions were noted to be mostly multicentric. They were associated with other intraepithelial neoplasias of the cervix or vagina in four of the six cases. The lesions were most often mistaken for condyloma acuminatum. Histologic changes were primarily Bowen's disease or Bowenoid dysplasia.


Acute pulmonary complications of molar pregnancy. Of 128 patients receiving primary treatment for molar pregnancy at Women's Hospital, Los Angeles County/University of Southern California Medical Center, after uterine evacuation 12 (10.7%) developed self-limited, acute pulmonary complications characterized by tachycardia, tachypnea, and hypoxemia. Multiple contributing factors have been identified which include trophoblastic deportation, hyperthyroidism, fluid overload, dilutional anemia, and pre-eclampsia. While the final outcome was uniformly benign in our group, deaths have been reported. These patients are also at an increased risk for postmolar trophoblastic disease. The diagnosis and management of the postmolar pulmonary complications are discussed.


Evaluation of a balloon dilator before second-trimester abortion by vacuum curettage. We evaluated the cervical dilator device (CDD), an expanding balloon, as a substitute for laminaria tents before abortion at 13 to 16 1/2 weeks by extraction and vacuum curettage. The CDD was found to be an effective dilator, although it did not appear to have any advantage over laminaria tents when placed overnight and was associated with significant pain upon insertion and an apparent increased risk of endometritis. The present CDD or a subsequent modification may offer advantages over laminaria tents for short-term placement.


Vessel density in endometrium of women with and without intrauterine contraceptive devices: a morphometric evaluation. Increased vascularity was found in the endometrial functionalis in uteri of women wearing intrauterine contraceptive devices (IUDs) as compared to uteri of women without IUDs (control subjects). Vessel concentration was highest in endometrial tissue adjacent to that tissue which was depressed by the IUD. In control tissues there was a significant variation in vascularity according to geographic location in the following order of magnitude: fundus greater than corpus greater than cornua greater than isthmus. No significant variation was found, however, among different phases of the ovarian cycle in either control or IUD cases. Increased endometrial vascularity could be a reaction to vessel damage caused by the IUD and for several reasons may contribute to IUD-induced endometrial bleeding.


Corticosteroid-binding globulin and estrogens in maternal and cord blood. Corticosteroid-binding globulin (CBG) is produced by the liver in small concentrations and binds steroids with high affinity. Its concentration in the blood is sensitive to endogenous or exogenous estrogens in a dose-response manner and serves as a biological assay for estrogens. CBG concentrations were measured in sera collected from maternal and umbilical vein blood during labor and delivery and at elective cesarean section and correlated with endogenous estradiol and estriol concentrations. CBG and estradiol concentrations of maternal blood were significantly exceeded those of maternal serum. A highly significant increase in cord blood estriol concentration was found following vaginal delivery compared to elective cesarean section, indicating an increase in adrenal activity due to the stress of labor. CBG levels correlated directly with maternal estradiol but not estriol cencentrations. Cord blood CBG concentration varied little despite a wide range of estrogen concentrations. The physiologic significance of CBG concentrations in maternal and fetal blood is discussed.


Computer analysis of etiology and pregnancy rate in 636 cases of primary infertility. Since the rate of pregnancy is a function of time, conventional pregnancy rates (number of patients achieving pregnancy per number of patients treated) are inadequate for counseling unless the follow-up period is specified. To overcome this problem, the expectancy of pregnancy for 636 cases of primary infertility was calculated with the assumption that the patients were followed up indefinitely. The overall "conventional" pregnancy rate was 38%, whereas the overall expectancy of pregnancy was 64%. Endometriosis was found to be the most common factor, comprising 25% of the cases, with a pregnancy rate of 31% and an expectancy of 52%. The expectancy of future pregnancy in a patient who has not achieved pregnancy by a given time is presented for each etiologic factor. This paper also presents a comparison of expectancies of pregnancy by different treatments, which may be helpful in selecting appropriate therapy.


Cadmium uptake by the rat embryo as a function of gestational age. Maternal blood, liver, kidney, and placental and fetal (embryo) accumulation of cadmium (Cd), a known embryotoxic trace element, was investigated following a single oral dose of various amounts of Cd (10 to 1,000 microgram/rat) as CdCl2 containing 109Cd at days 6, 10, 14, and 17 of gestation. Twenty-four hours after Cd administration the rats were killed and the various tissues were counted in a gamma well counter for determination of 109Cd activity. Maternal liver and kidneys were the main target organs of Cd accumulation at all stages of gestation. Embryo levels of Cd were highest prior to formation of the functional placenta. After placental formation, fetal Cd levels were decreased, while placental accumulation of Cd increased with increasing gestational age. The results indicate that the embryo accumulates the greatest percentage of ingested Cd between implantation and placentation, the early period of organogenesis. The placenta apparently protects the fetus from exposure to this element during the last third of gestation.


Changes in 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D during pregnancy. Serum concentrations of 25-hydroxyvitamin D (25OHD) and 24,25-dihydroxyvitamin D (24,25(OH)2D) were measured in a cross-sectional study of 94 normal pregnant women at various stages of gestation in order to assess the hormonal regulation of calcium homeostasis during gestation. The 40 week gestational period was divided into four 10 weeks quarters. 25OHD concentration were significantly below control levels (32.2 +/- 3.1 (S.E.) ng/ml) by the second quarter of pregnancy and were even lower at term. Serum levels of 24,25(OH)2D did not decrease until the fourth quarter, when the mean concentration (0.8 +/- 0.1 ng/ml) was approximately one half the control values (1.5 +/- 0.3, p less than 0.025). These data suggest that the metabolic pathways of vitamin D are altered during gestation, perhaps in response to increasing mother-to-fetus transport of calcium. There is decreased 24-hydroxylation and, in view of the lowered 25OHD levels, possibly increased production of 1,25-hydroxyvitamin D (1,25(OH)2D).


1977 National survey of support in space and dollars for departments of obstetrics and gynecology from their medical schools. A questionnaire was sent to all chairpersons in obstetrics and gynecology departments in United States Medical Schools in the fall of 1977 seeking information on the school's support of that department for the year 1977 in terms of space and dollar commitments. A total of 113 schools were contacted; 106 responded (93.8%) and the data were tabulated. There were no significant differences between the private and state school resources. The average space commitment was 9,277 +/- SEM 709 square feet and the average school budget was 441,023 +/- SEM 24,265 dollars/year. These data were adjusted for class size and provide the first data base for assessing the adequacy of a medical school's commitment to a department of obstetrics and gynecology.


The impact of midtrimester abortion techniques on patients and staff. We studied 250 midtrimester abortions by dilatation and extraction (D and E) under general anesthesia and compared them with abortions by the intra-amniotic injection of prostaglandin (amnio) in order to assess the physical and emotional changes experienced by patients and staff under the different circumstances represented by each procedure. We found patients undergoing D and E abortions had fewer physical complications and described the procedure as minor surgery which went smoothly. The patients who had amnio abortions had more pain and reacted with more anger and depression afterward. Nurses were more disturbed by amnio abortions in which they played major roles in supporting the patient as well as in her abortion. Physicians reported the D and E procedures to be emotionally difficult which may limit the adoption of this procedure despite its value to patients.


The evaluation of uterine activity: a comparative analysis. In this study a comparison is made between the most widely accepted method of expressing uterine activity, Montevideo units, and an automated on-line method expressed as uterine activity units. Although the actual numerical expression differs, the percentage of variation when the two values are compared is small at various phases of labor. The variation between the methods for uterine activity required to progress from 4 to 6 cm cervical dilatation and from 6 to 10 cm cervical dilatation is less than 5%. Both methods closely agree on the actual expression of uterine activity or uterine work.


Effect of local anesthetics on intraocular penetration of subconjunctival antibiotics. The combination of the subconjunctival injection of lidocaine HCl or procaine HCl with the subconjunctival injection of penicillin G, methicillin, cephaloridine, or gentamicin did not influence their intraocular penetration or subsequent antibiotic activity in aqueous humor of experimental animals.


Scanning electron microscopy of congenital corneal leukomas (Peters' anomaly). Specimens of three corneas in two patients with Peter's anomaly were obtained at the time of penetrating keratoplasty and studied by scanning and transmission electron microscopy. In one patient, the anomaly was monocular, and the endothelial surface showed a central defect in Descemet's layer with isolated rounded defects in the midperiphery. Fine collagenous material covered the posterior surface. The other two specimens were obtained from a patient with rubella syndrome without cataracts. The cornea showed malformation of Descemet's membrane with fibroblastic overgrowth on the endothelial layer. Epithelial-like cells and leukocytes were also found. The congenital central leukoma we believe was caused by adhesion of the pupillary membrane in our first patient, and possibly was inflammatory in our second patient.


Treatment of Thygeson's superficial punctate keratopathy with soft contact lenses. Three patients had Thygeson's superficial punctate keratopathy; two of whom previously had required prolonged topical corticosteroid therapy for symptomatic relief. The use of therapeutic soft contact lenses provided improved visual acuity as well as symptomatic relief in all three patients. Corneal opacities faded while the soft contact lenses were in place. One patient who had been on long-term topical corticosteroids was gradually taken off this medication with the use of soft contact lens. Another patient noted only mild symptoms from acute episodes while wearing soft contact lenses; only minimal topical corticosteroids were required to control her symptoms. Two additional patients were treated with soft contact lenses. One could not tolerate soft lens wear and the other chose corticosteroid therapy instead of soft lens wear. Soft contact lenses are an acceptable alternative to topical corticosteroid therapy in the treatment of Thygeson's superficial punctate keratopathy.


Results of keratoprosthesis.

Results of keratoprosthesis. The technique of keratoprosthesis was  used in 21 cases of severe and intractable forms of keratopathy during the past 3 1/2 years. The results in terms of visual acuity were satisfactory in more than half the cases. Significant problems that occurred after this procedure included the diagnosis and management of glaucoma, vitreitis, and retroprosthetic membrane. There were no instances of extrusion of the keratoprosthesis nor were there any cases of endophthalmitis. However, one case developed necrosis of the tissue around the optical cylinder on the eyelid after surgery. Although its use is limited to only some forms of keratopathy, keratoprosthesis seems to offer a solution in cases where no other treatment is available.


A comparison of diagnostic techniques in angle-closure glaucoma. We evaluated four diagnostic techniques for angle-closure glaucoma (Koeppe gonioscopy, Goldmann three-mirror gonioscopy, compressive Zeiss four-mirror gonioscopy, and the operative chamber deepening procedure) to ascertain their relative effectiveness in determining: (1) whether the angle was open or closed, and (2) whether the closure was appositional or synechial and permanent. Koeppe gonioscopy was the most reliable way to determine whether the angle was open or closed, because this lens caused no artifactual widening of the peripheral angle and allowed the best view over an often convex iris. Zeiss four-mirror compressive gonioscopy or the operative chamber deepening procedure were equally reliable ways to determine whether the closure was appositional or synechial and permanent. A comparison between compressive Zeiss four-mirror gonioscopy and the operative chamber deepening procedure revealed that the latter has therapeutic value as well as diagnostic value, that is, it can separate recently formed adhesions.


Abnormalities of central contrast sensitivity in glaucoma. The detectability of foveally presented low-contrast flickering stimuli was determined for glaucoma patients, ocular hypertensives, and normal control subjects. Two types of stimuli, a homogeneous flickering field, and a counterphase flickering grating of low spatial frequency, were presented on a screen subtending 4 degrees of visual angle. The average of the contrast sensitivities to these two simuli (defined as the dynamic response coefficient) was consistently lower in glaucomatous than in normotensive eyes. The dynamic response coefficient was also below normal in half the ocular hypertensive eyes.


HLA antigens and acute angle-closure glaucoma. Thirty-five unrelated white patients with acute angle-closure glaucoma and 126 previously healthy unrelated white cadaveric kidney donors were typed for histocompatibility (HLA) antigens. Upon Z-ratio proportionality testing, no association between acute angle closure glaucoma and any specific HLA antigen was noted.


Anterior chamber depth measurement using the split-lamp microscope. I devised a new and simple method to measure the anterior chamber depth that requires only a Haag-Streit 900 slit lamp. Viewing the anterior chamber at 45 degrees and matching the height of the corneal slit beam to the depth of the anterior chamber enables the observer to calculate the anterior chamber depth by multiplying the measured slit height by 1.4 or, more accurately, by use of the table provided. The accuracy over the range of clinically encountered depths of the anterior changer is +/- 0.2 mm relative to standard pachometry.


The effects of intravitreal irrigation during vitrectomy on the electroretinogram. Intravitreal irrigation with Balanced Salt Solution Plus (BSS Plus) produced less decrease in b-wave amplitude than either normal saline solution or Balanced Salt Solution. BSS Plus was more suitable for intravitreal irrigation because it contained the appropriate bicarbonate, pH, and ionic composition necessary for maintenance of normal retinal electrical activity, and it contained glutathione, which is necessary for maintenance of endothelial cell adenosine triphosphatase and for protection against free radical damage and oxidative stress.


Clinical results in vitrectomy for diabetic traction retinal detachment. A series of 75 eyes underwent pars plana vitrectomy for progressive diabetic traction retinal detachment of the macula. In all cases, the media was sufficiently clear to allow preoperative macular examination. The overall visual improvement was higher in phakic eyes (80%) than aphakic eyes (72%) and the rate of neovascular glaucoma was less in phakic eyes. The difference was not statistically significant, however. The final visual acuity corresponded to the degree of preoperative visual deterioration. Thus, surgery during the rapidly evolving proliferative and retracting process did not adversely affect the visual success rate when compared to previous reports on longstanding vitreous hemorrhage.


Orbital hemorrhage.

Orbital hemorrhage. Seventeen patients had spontaneous orbital hemorrhages. The usual symptoms were acute onset of pain, proptosis, and vomiting with decreased vision, limitation of motility, and ecchymosis of the eyelids occurring in some patients. The children often developed a progressive space occupying lesion that simulated a neoplasm. Most patients had underlying venous anomalies, although several elderly patients with atherosclerosis developed arterial hemorrhages with more abrupt and dramatic symptoms. Other associated conditions included hypertension, anemia, labor, and von Willebrand's disease. The visual outcome was good except in the elderly patients, half of whom had severe and permanent visual loss.


A simulator for teaching visual field techniques on Goldmann or Goldmann-type perimeters. We developed a visual field simulator for teaching perimetry on a Goldmann-type perimeter. It can present reproducible normal and defective visual fields, is portable and can be used without being attached to the perimeter, and will provide an easier way to train individuals in the correct techniques of perimetry.


A system for counting endothelial cells from transparencies and negatives. We have developed a system for endothelial cell density calculation and morphologic examination, which has proven to be convenient and reproducible, by using a currently available viewing unit, a few inexpensive materials, and simple arithmetic.


Nontraumatic rupture of the globe secondary to orbital cellulitis. A 53-year-old woman had a spontaneous nontraumatic rupture of the globe secondary to severely increased orbital pressure from an orbital cellulitis. To our knowledge this is the first such case reported.


Increased myocardial catalase in rats fed ethanol. The effects of chronic intake of dietary ethanol upon catalase, an enzyme capable of metabolizing ethanol, as well as upon myocardial morphology and hemodynamics, were studied in the rat. Ethanol, comprising 36% of dietary calories, administered to rats for 5 weeks, was associated with increased myocardial catalase of 45.9 +/- 3.7 IU/mg protein, compared to 21.0 +/- 1.8 IU/mg protein in pair-fed controls. The enzyme activity remained significantly elevated after 18 weeks of ethanol. Hepatic catalase did not differ in these groups. Parallel cytochemical studies confirmed the increase in myocardial catalase by demonstrating an increase in peroxisomes. Gross and light-microscopic examinations revealed no abnormalities at either 5 or 18 weeks. Remarkably few ultrastructural abnormalities were seen in this material fixed by vascular perfusion. Hemodynamic studies after 5 weeks of ethanol revealed decreased left ventricle systolic pressure and decreased mean arterial pressure but no change in ventricular filling pressure. The possibility of catalase playing a metabolic and potentially protective role in rat myocardium chronically exposed to ethanol is discussed.


Endocrine cells in the intestinal metaplasia of gastric mucosa. Sections of gastric mucosa removed during surgery for cancer or peptic ulcer and containing regions of intestinal metaplasia were studied by the immunofluorescence technique using several antiserums against intestinal hormones. Endocrine cells such as cells containing somatostatin, glicentin (gut GLI-I), motilin, and probably cholecystokinin were found within metaplastic intestinal epithelium while secretin and neurotensin, which are present in the normal intestinal mucosa, were not detected in metaplastic epithelium. The endocrine-cell population present in the intestinal metaplasia resembles that found in the cryptal region of the normal small intestine, a finding in accordance with the fact that intestinal metaplasia of gastric mucosa usually reproduces structural and histochemical characteristics of small intestinal crypts.


Degenerative vascular disease and myocardial infarction in mice with lupus-like syndrome. The pathogenesis of the degenerative vascular disease and myocardial infarction that develop in mice with lupus-like disease was studied by immunofluorescence, light microscopy, and electron microscopy. Medium and small coronary arteries and arterioles of both infarcted and noninfarcted hearts had focal degenerative lesions consisting of deposits of periodic-acid--Schiff (PAS)-positive or eosinophilic material in the intima and to a lesser extent in the media, degenerative changes in the media without accompanying cellular inflammation, and occasional proliferation or swelling of intimal cells. These lesions often narrowed and, together with platelet aggregation, occasionally occluded the vascular lumens. Granular deposits of mouse immunoglobulin, C3, and occasionally gp70 were present in the walls of medium and small arteries, arterioles, and venules of both infarcted and noninfarcted myocardium. Dense deposits of foreign material were found by electron microscopy in areas corresponding to the immune deposits. These findings are consistent with the interpretation that these noninflammatory vascular lesions are caused by local deposition of antigen--antibody complexes. The immune-complex--mediated injury appears to lead to thrombotic and/or obliterative vascular changes that contribute to decrease of the coronary blood flow and to the development of myocardial infarction.


Eosinophilic fasciitis. A pathologic study of twenty cases. This report presents a detailed light-microscopic evaluation of biopsies obtained from 20 patients with eosinophilic fasciitis, a newly recognized disorder characterized by inflammation and thickening of the deep fascia, hypergammaglobulinemia, and peripheral and tissue eosinophilia. Early in the course of the disease, the deep fascia and lower subcutis are edematous and infiltrated with lymphocytes, plasma cells, histiocytes, and eosinophils; these features are associated with impressive peripheral eosinophilia. As the illness progresses, these structures and eventually the dermis become collagenized, thickened, and sclerotic. Tissue eosinophilia may be focal or diffuse and is usually observed in the fascia and/or lower subcutis. Extracutaneous involvement has been limited to a chronic synovitis and tenosynovitis, the latter frequently associated with the carpal tunnel syndrome. Deposits of immunoglobulin and/or complement were found in five of eight biopsies studied by direct immunofluorescence, which suggests that an immunologic stimulus may be responsible for initiating this syndrome. Differential diagnoses are discussed.


Metaplastic and mitotic activity of the ischemic (endocrine) kidney in experimental renal hypertension. Partial ligation of the aorta between the renal arteries in the rat induces malignant hypertension, metaplasia of smooth-muscle cells of arterioles and arteries into juxtaglomerular cells, and a complex series of events in tubular cells at all levels of the ischemic kidney. The tubular cells of the outer cortex, particularly the proximal convoluted cells, show a very rapid and progressive simple atrophy. In contrast, necrosis of individual cells is followed by mitotic activity in atrophic tubular cells of the inner cortex, medulla, and papilla. Subsequently, polyploidy and hyperplasia occur in the inner cortex. At the same time, hypertrophy of the protein-synthesizing apparatus and an increase in protein, DNA, and RNA, followed by a decrease in the protein content, are seen in the tubular cells of the inner cortex. In the medulla and papilla, necrosis of individual cells proceeds side by side with waves of mitotic activity. These events take place, albeit to a lesser degree, even in cases of very mild renal ischemia. While they may by unrelated to hypertension, these changes are probably involved in the increase in hydrolytic enzyme activity characteristic of the ischemic renal cortex.


Platelet-leukocyte interactions following arterial endothelial injury. Desquamation of canine arterial endothelium was induced by stripping the luminal surface of arteries with an inflated embolectomy catheter. The dogs were killed by intravascular perfusion fixation at intervals varying from 2 hours to 12 weeks after the procedure, and the arteries were studied by light microscopy, transmission electron microscopy, and scanning electron microscopy. A heretofore unreported, apparently specific interaction of aggregated platelets and polymorphonuclear leukocytes (PMNs) was observed on the luminal surface of the denuded arteries. This interaction was abolished by the administration of a single dose of aspirin prior to the application of the catheter. These observations suggest that this platelet--PMN interaction is distinctly different from the classic inflammatory reaction, and that it is an integral part of the arterial response to injury that may affect endothelial regeneration.


Hemochromatosis caused by excessive vitamin iron intake. Rare cases of hemochromatosis have been reported in patients who underwent prolonged oral iron therapy for hemolytic anemia or prolonged self-treatment with iron pills. A proportionately large segment of the South African Bantu tribe, who ingest large quantities of an alcoholic beverage brewed in iron pots, are found to have the disease. Reports of health fadists developing hemochromatosis due to excessive dietary iron intake, however, are extremely rare. This report presents clinical considerations and pathologic findings in a compulsive health fadist who consumed large numbers of vitamins containing iron. Clinical findings included the development and progression of cirrhosis of the liver, bronzing of the skin, and diabetes mellitus, all consistent with a diagnosis of hemochromatosis. Light microscopy of liver biopsies taken late in the course of the disease revealed a massive buildup of iron in the hepatocytes, less in the Kupffer cells, and sparse deposition in the epithelial cells of the bile duct. Minimal periportal fibrosis was noted. Electron microscopy showed numerous pleomorphic siderosomes with varying degrees of crystallization and ferritin attached at uniform intervals to the membranes of residual bodies. Abundant free ferritin was observed in most cells. The aggregated and membrane-associated ferritin was verified by non-dispersive x-ray analysis. An additional finding, noted only by electron microscopy, was the presence of many fat-storing cells of Ito, which are thought to be involved in the onset of fibrosis.


Studies on the rat liver following iron overload. Electron probe x-ray microanalysis of acid phosphatase and iron. Previous electron-microscopic studies on the liver have shown that following excessive administration of iron to experimental animals, small particles believed to represent ferritin and/or hemosiderin (electron-dense iron-containing particles [IPs]) accumulate in membrane-bound bodies--many with a lysosome-like structure--in liver parenchymal and Kupffer cells. Further identification of the IP-containing bodies has been facilitated by the application of histochemical techniques for the demonstration of acid phosphatase. The results have shown that reaction product was deposited over organelles similar in appearance to the IP-containing ones, indicating that they were lysosomes. However, the granular nature of the reaction product makes it difficult or impossible to decide whether IPs are present simultaneously with reaction product in the organelle. In order to clarify this qualitative aspect, x-ray microanalysis has been utilized to identify iron and lead (reaction product) in the various structures thought to represent lysosomes. The results indicate that all IP-containing bodies also show the presence of reaction product, and thus can be regarded as lysosomes. However, in the parenchymal cells there may exist a small population of iron-deficient lysosomes (only lead could be shown). The latter may correspond to "primary lysosomes."


Motility of rabbit alveolar cells: role of unsaturated fatty acids. A mechanism for the specific accumulation of macrophages in alveoli or other biologic cavities following injury is presented. The data herein indicate that unsaturated fatty acids, ie, linoleic and linolenic acids, which accumulate in rat pleura following injection of carrageenan or during incubation of rabbit alveolar macrophages (AMs), strongly activate migration in vitro of AMs but not of human polymorphonuclear leukocytes (PMNLs). Other anionic lipids, ie, phosphatidylglycerol, as well as various nonspecific proteins, such as gelatin, or albumin were also shown to be potent activators of migration of AMs and not of PMNLs. These observations suggest that the elaboration of unsaturated fatty acids, as well as of nonspecific proteins, is responsible for the specific accumulation of macrophages in injured body spaces, such as alveoli or pleura.


Malignant melanoma in the Sinclair miniature swine: an autopsy study of 60 cases. Sinclair miniature swine spontaneously develop multiple cutaneous melanomas which have the ability to metastasize and regress. This study, based on 60 necropsies, documents the similarity of the pathology of the cutaneous malignant melanomas and the organ distribution of metastasis to human melanoma. The invasive cutaneous melanomas have an intraepidermal component analogous to human superficial spreading melanoma. The pathology of the spontaneous regression, characterized by a series of cellular events beginning with a mononuclear inflammatory infiltrate and leading to depigmentation and fibrosis, is likewise similar to cutaneous regression in human melanoma. Just as with human melanoma,metastasis was correlated with deeply invasive cutaneous tumors. Because of both the biologic and histologic similarity of this animal model to human melanoma, the Sinclair miniature swine should serve as an important resource in continuing the study of melanoma.


Alteration of the structure and function of guinea pig peritoneal macrophages by a soybean oil emulsion. Studies in humans who have received Intralipid (IL) have demonstrated the presence of a fat pigment and fat droplets in reticuloendothelial phagocytic cells. Clinical data and in vitro studies suggest that these cells do not function normally. We have studied the effect of IL on the morphology and function of guinea pig peritoneal macrophages in vitro. Starch-induced macrophages were exposed to IL for up to 48 hours. Ingestion of increasing amounts of IL over the 48-hour period was confirmed by transmission electron microscopy and by oil red O stain. The uptake of the IL was associated with marked morphologic changes characterized by a decreased ability of the cells to spread and by a decrease in the number and degree of complexity of the membrane ruffles. The ingestion of IL also resulted in decreased capacity of the cells to associate with latex beads (5.7 mu in diameter) or Candida albicans and decreased capacity to adhere to and ingest sheep erythrocytes coated with IgG. After ingestion of latex beads 0.46 mu in diameter, which are similar in size to IL particles, macrophages had normal morphology and function, indicating that neither the morphologic nor functional abnormalities were due to a nonspecific effect of ingestion of small particles. Alterations of human reticuloendothelial macrophage function similar to the effects observed here could compromise host defense against infection.


The Chédiak-Higashi syndrome: ring-shaped lysomomes in circulating monocytes. The giant inclusion anomaly of leukocytes from three patients with the Chédiak-Higashi syndrome (CHS) has been reexamined by the ultrastructural and cytochemical techniques placing emphasis on the monocyte. Contrary to previous assumptions that all CHS leukocytes shared a common form of giant granule with similar mechanisms of formation, it is shown that CHS monocytes contain ring-shaped organelles as their principle manifestation of the disease. These granules consist of a double membrane surrounding a segment of cytoplasm, which may or may not be sequestered from the remaining cytoplasm and which usually contains one or more normal-sized azurophilic granules. The material lying between the double membranes contains the specific reaction products for peroxidase and acid phosphatase. Therefore, the ring-shaped organelles share identity with the azurophilic granules and probably share a common origin with the primary lysosomes. The double-ring form of giant CHS organelle has also been found infrequently in neutrophils, eosinophils, and lymphocytes.


A possible role of arachidonic acid in human neutrophil aggregation and degranulation. Chemotactic factors stimulate neutrophils to aggregate and, in the presence of cytochalasin B, to degranulate. Recently, the authors found that arachidonic acid also stimulates human neutrophils to aggregate but does not stimulate cytochalasin-B-treated or untreated cells to degranulate. In this report the authors examined the effect of three blockers of arachidonic acid metabolism on these cellular responses. It was found that the arachidonic acid analog 5,8,11,14-eicosatetraynoic acid and indomethacin, but not aspirin, inhibited no only the arachidonic-acid-induced aggregation response but also the degranulation responses evoked  by C5a or a synthetic oligopeptide chemotactic factor. These results suggest that arachidonic acid may be a precursor of bioactive metabolites that stimulate the aggregation and foster the degranulation responses of neutrophils. Thus, these metabolites may be mediators of neutrophil function. Agents that block their formation may thereby inhibit aggregation and degranulation.


Morphologic studies in the skeletal dysplasias. Considerable progress has been made in the delineation of the genetic skeletal dysplasias, a heterogeneous group of disorders, that consist of over 80 distinct conditions. Morphologic studies have added a further dimension to the delineation of these conditions, their diagnosis, and the investigation of their pathogenetic mechanisms. In certain diseases, the morphologic alterations are characteristic and pathognomonic. In others only nonspecific alterations are observed, whereas in still other disorders growth-plate structure is essentially normal. Histologic, histochemical, and electronmicroscopic studies of growth-plate cartilage have provided new insights into the complexity of morphogenetic events in normal growth through the demonstration of morphologic defects in the genetic disorders of skeletal growth. As yet, very little is known of the biochemical abnormalities underlying the morphologic abnormalities. However, the great variety of morphologic findings points to a number of different pathogenetic defects in the synthesis, release, and assembly of connective tissue macromolecules and in the cells involved in growth-plate metabolism.


Mental health in a fragmented society: the shattered crystal ball. Effects of current social and political forces on mental health are considered, with particular attention to the way in which the unrelenting acceleration of change undermines the individual's sense of temporal continuity. The contributions and limitations of the mental health professions are examined, and it is suggested that the major challenge of psychotherapy in our time may be to aid individuals in coping with a world in flux.


The use of two houses in play therapy.

The use of two houses in play therapy. The use of two miniature house structures equipped with dolls is proposed in play therapy with children who have been traumatized by physical loss, emotional withdrawal, or rejection of family members. The case of a child who worked through unresolved conflicts resulting from separation and placement is described. Feelings of rejection, anger, fear, and guilt were reexperienced in the "old" house, while the second house provided a more positive alternative. Implications of the approach for children who have experienced other types of family crisis are discussed.


The character-disordered family: a community treatment model for family sexual abuse. A collaborative approach to treating sexually abusive families is described, in which such families are viewed as analogous to "character-disordered" individuals. This model, unlike traditional voluntary treatment models, assumes that effective intervention requires authoritative control and careful corrdination of all professional activity. Phases of treatment are outlined and a case history is presented.


A model of the empathic process for teachers of emotionally disturbed children. A model for the demonstration of empathy by teachers, based on interviews with emotionally disturbed youngsters, is described. It is suggested that verbalization of understanding is not the complete process and that at least four interactive modalities are used by teachers to express empathy with a disturbed child.


Infant behavior and maternal adaptations in the first six months of life. This study explored the relationship among infant temperament, maternal concern, and adjustment during early infancy, and the stability of these variables over time. Infants identified as difficult were found to change considerably across three time points (between five weeks and six months), suggesting the need for caution in prognostication with respect to temperament difficulties in infancy. Further implications for the care of young infants and their families are discussed.


Early death of a parent as an etiological factor in schizophrenia. Results of three separate studies comparing adult schizophrenic and other psychiatric patients suggest that premature death of a parent may be a contributing factor in the etiology of schizophrenia. This finding was not attributable to a genetically-linked tendency toward suicide in parents. Parental death was found to occur earlier among schizophrenics than other patients and, in two studies, to be most frequent among schizophrenics with predominantly paranoid symptoms.


The role of cognitive level and sibling illness in children's conceptualizations of illness. Levels of illness conceptualization were studied among children with diabetic siblings. Results revealed a significant association between pretested Piagetian level of cognitive development and illness conceptualization. Children with ill siblings, especially those at the formal operational level,  demonstrated lower conceptualization levels than did children with healthy siblings.


Stimulant drugs and activity level in hyperactive children. This study of 14 hyperactive boys reports that activity and attention span appear to be affected by methylphenidate even in highly stimulating, informal settings. Comparison of the hyperactive boys with a group of 14 normal controls suggests that this drug induced reduction of activity and inattentiveness is not a "normalizing" effect. Implications of the findings are discussed.


Differences in ammonia and adenylate metabolism in contracting fast and slow muscle. The time course of AMP deamination and IMP reamination was studied during in situ stimulation and subsequent recovery in fast-twitch (gastrocnemius) and slow-twitch (soleus) muscles of pentobarbital-anesthetized rats. Muscles were stimulated tetanically at rates that initially produced comparable decreases (40%) in tension development. In fast muscle, progressive decreases in total adenine nucleotide (TAN) contents of up to 50% were balanced by equivalent increases in IMP contents. Ammonia concentration initially increased in a 1:1 stoichiometry with changes in IMP and TAN. During recovery following stimulation, IMP removal matched, but NH3 removal exceeded the rate of TAN resynthesis. In contrast, TAN content in slow muscle was only slightly decreased (10%) during stimulation and there were no increases in IMP or NH3. Stimulation of the soleus following ligation of the blood supply did not increase TAN depletion. In both fast and slow muscle, changes in glutamate, aspartate, and alanine could be accounted for by transamination. These results illustrate a fundamental difference in adenylate metabolism during intense muscle stimulation between fast- and slow-twitch mammalian muscle.


Effect of stretch on conduction velocity and cable properties of cardiac Purkinje fibers. Cardiac Purkinje fibers were studied before and after stretch to 30% and 50% in excess of their slack length, and membrane properties and conduction velocity were measured in relation to the stretch. Conduction velocity increased by 26% with 50% stretch. The resting potentials averaged -77 mV and did not change with stretch. In addition, the action potential height, maximal upstroke velocity, duration, and time constant of the foot did not change. These results suggested that the increase in conduction velocity was not due to a change in membrane excitability. Two geometric models of stretch, called unfolding and uncoiling, were considered. Cable analyses were performed to distinguish between these models. The effects were mixed, with about 2/3 of the length change resulting from unfolding and 1/3 from uncoiling. These results support the concept of redundancy of the surface membrane by folding. The changes are likely to be of importance in activation of the heart by the His-Purkinje system, especially in cardiac dilatation due to disease.


Suppression of myotonia in dystrophic chicken muscle by phenytoin. We describe myotonic electromyographic activity in muscles of genetically dystrophic chickens and show that this activity is antagonized in vivo by doses of phenytoin (DPH) that improve righting ability. To test the possibility that the in vivo effects of DPH can be accounted for by a direct action on skeletal muscle we studied posterior latissimus dorsi fibers in vitro at 23 degrees C with intracellular microelectrodes. Compared to normal fibers, fibers from untreated dystrophic chicks had larger diameters, increased membrane capacitance, longer latencies at rheobase, and a greater tendency to fire repetitively in response to direct stimulation. DPH (10 or 50 micrograms/ml in the bath solution) decreased latencies at rheobase and repetitive firing in fibers from untreated chicks. In DPH-free solution fibers from dystrophic chicks treated chronically with DPH were still abnormal with respect to latencies at rheobase and ease of repetitive firing. The data support the hypothesis that abnormalities of membrane electrical properties are major features of dystrophic chicken muscles and furthermore, show that DPH suppresses, but does not abolish, these abnormalities.


Calcium transport and contractile activity in dissociated mammalian heart cells. A homogeneous population of dissociated myocytes can be obtained by enzymic perfusion of adult rabbit hearts. The external membrane of the dissociated cells is freely permeable to electrolytes and is electrochemically shunted. Nevertheless, in the presence of 0.2--0.6 muM Ca2+, the myocytes undergo phasic contractions. Within the range of Ca2+ concentrations eliciting phasic contractions, the dissociated myocytes exhibit Ca2+ uptake activity that is sustained by endogenous ATP in the presence of oxygen and metabolites, or by hexogenous ATP in the presence of oligomycin and antimycin. The uptake is greatly enhanced by oxalate, an effect that is attributed to the activity of sarcoplasmic reticulum. Addition of the calcium ionophore A23187 prevents the occurrence of both Ca2+ accumulation and phasic contractions. In the presence of the ionophore the myocytes remain relaxed at Ca2+ concentrations (less than 1.0 mM) normally sustaining phasic contractile activity, and undergo irreversible contracture at Ca2+ concentrations (greater than 1.0 muM) sufficient to produce direct activation of the myofibrils. It is concluded that Ca2+ transport by sarcoplasmic reticulum is directly related to the occurrence of phasic contractions in dissociated myocytes prepared from rabbit heart. On the other hand, metabolic activity is required for ATP regeneration.


Membrane permeability during low potassium depolarization in sheep cardiac Purkinje fibers. Exposure of sheep Purkinje fibers to low [K]o leads to marked depolarization to a stable potential of about -40 mV. This level is equivalent to the plateau of the Purkinje fiber action potential. The low [K]o depolarization could be prevented by removal of [Na]o and was modified by tetrodotoxin. The membrane potential in the depolarized state was unresponsive to changes in [Cl]o or [Ca]o and it was poorly responsive to changes in [K]o between 0 and 2 mM. Repolarization was induced by decrease in [Na]o with a slope response of 30 mV/10-fold change in [Na]o. Average internal K activity (aK) in the resting state with a [K]o of 5 mM was 121.4 mM for a membrane potential of -80 mV. During low K depolarization aK was 119.7 mM with a membrane potential of -34 mV. The depolarization was therefore due to a change in membrane permeability, with little change in aK. Upon restoration of [K]o the fiber repolarized to values transiently more negative than the prior resting potential. These transient potentials were more negative than the K equilibrium potential (VK), if it is calculated assuming a uniform [K]o. The hyperpolarization was reduced by ouabain [10(-6)] or by low [Ca]o.


Reversible suppression of skeletal myotube formation in vitro obtained by varying [CO2]. In primary cultures of chicken skeletal muscle, decreasing the [CO2] of the gaseous phase below 10(-3)% resulted in inhibition of cell proliferation and cytolysis. With 10(-3)% CO2-air, cell proliferation was slightly retarded and myotube formation was inhibited approximately 90% compared to cultures receiving 5% CO2-air. Changes in pH were not effective. Culture in low [CO2] resulted in the accumulation of lipoidal inclusions and unique cytoplasmic structures. Increasing time in culture with low [CO2] resulted in an increase in the length of G1 of the cell cycle. The inhibition was reversed by the addition of 5% CO2-air at any time in culture up to 2 wk with a minimum time of 3--6 h required. Lipoidal inclusions decreased in number and the unique cytoplasmic structures were absent. During the first 3 days in culture, myoblasts showing dependence on [CO2] for myotube formation increased in number, and the effect of elevated [CO2] on these cells was long lasting. The data suggest that some aspect of myoblast differentiation relating to cell recognition and fusion is affected by decreased [CO2].


Changes in pituitary and thyroid function with increasing age in young male rats. As the age of young adult male rats increased from 30 to 150 days, the serum thyroxine (T4) decreased by 50% and the serum thyroid-stimulating hormone (TSH) increased by 250%. There was no change in the serum triiodothyronine (T3). The increment in serum TSH after injection of thyrotropin-releasing hormone (TRH) was not significantly different at any of the ages studied, but the old animals had significantly lower increments in serum T4 and T3 after subcutaneous administration of bovine TSH. Despite a higher basal serum TSH, the older rats had a lesser increase in serum TSH after thyroidectomy or propylthiouracil. Thus, 1) there is a progressive decline in intrinsic thyroid function between 30 and 150 days of age in male rats, and 2) pituitary TSH response to fall in serum concentration of thyroid hormones is also decreased with age.


Effect of winter sleep on pituitary-thyroid axis in American black bear. During winter sleep the black bear has decreased levels of serum total and free thyroxine (T4) and triiodothyronine (T3) and a prolonged, delayed response of serum thyrotropin (TSH) (bioassay) to thyrotropin-releasing hormone (TRH). Four weeks after the end of winter sleep, levels of serum thyroid hormones increase, and TSH response to TRH is short and brisk. Serum T4 and T3 rise after TRH administration both during and after winter sleep; however, the maximum increment in serum T3 is greater during winter sleep when the TSH rise is also prolonged and exaggerated. These observations suggest that transient hypothyroidism of possible hypothalamic origin occurs in bears during winter sleep.


Steroid secretion by in vitro perfused testes: testosterone biosynthetic pathways. Alternative metabolic pathways for the biosynthesis of testosterone from pregnenolone exist in mammalian testes. The following experiments were designed to identify the preferred testosterone biosynthetic pathway in rat and rabbit testes. The experimental protocol included the infusion of steroidogenic reaction inhibitors and testosterone biosynthetic intermediates into testes perfused in vitro. Under these conditions, the testicular steroid secretions were a measure of specific reaction activities. Infusion of medrogestone (6,17-dimethyl-4,6-pregnadiene-3,20-dione, Ayerst), an inhibitor of delta5-4isomerization, permitted the reactions converting pregnenolone to androstenediol to be studied separately from those converting progesterone to testosterone. For example, the activity of the pregnenolone vector 17alpha-hydroxypregnenolone reaction was measured as the total of the 17alpha-hydroxypregnenolone, dehydroepiandrosterone, and androstenediol secreted by medrogestone-inhibited testes. The reactions convering delta5-3beta-hydroxysteroids to delta4-3-ketosteroids were studied in testes infused with SU-10603 (7-chloro-3,4-dihydro-2-[3-pyridyl]-1(2H)-naphthalenone. Ciba-Geigy), an inhibitor of 17alpha-hydroxylation and C-17, C-20 cleavage reactions. The results indicated that preferred testosterone biosynthetic pathways are present and different in rat and rabbit testes.


Maternal starvation and progesterone secretion, litter size, and growth in the pig. The relationships of maternal nutrition and progesterone secretion to prenatal fetal loss and neonatal survival and growth were investigated in domesticated pigs that normally experience 40% fetal loss. Yorkshire pigs were subjected to prolonged starvation (40 days; 0 kcal/day; water only) in either the middle third or last third of pregnancy and then gradually realimented to a full diet and allowed to advance to parturition; controls received a full diet (7,028 kcal/day) throughout gestation. Pregnancies were maintained in 74% of the pigs starved during either middle or late gestation compared to 100% in controls. In dams starved from days 30--70, progesterone levels remained similar to controls, but were maintained at lower levels during realimentation between days 72 and 99. Progesterone levels in dams starved days 50--90 and controls were similar from days 50 to 130. At parturition, litter size in starved dams (9.4) was similar to full-diet controls (8.0) although birth weight and neonatal growth of piglets were reduced markedly from dams starved in middle or late pregnancy. These results indicate that severe maternal nutrient deprivation during the middle or last third of gestation has little effect on ovarian progesterone secretion and is not a major limitation to fetal survival in this litter-bearing species. Maternal nutrient deprivation imposes a significant detrimental effect, however, on birth weight and neonatal growth to 80 days of age.


Gastric pacemaker rhythm in conscious dog. The pacemaker rhythm in the stomach of six healthy conscious dogs was studied by means of the measurement of sequential electrical control activity (ECA) intervals. Only the rhythm originating in the normal pacemake area was studied. An electrical response activity (ERA) score was used to assess contractile activity. Whereas substantial shortening of nonectopic ECA intervals did not occur, contraction-related interval lengthening was a characteristic phenomenon. The temporal relations between ERA scores and interval durations were found to be dependent on the gastric level at which the signals were derived. The activity front of the interdigestive myoelectric complex (IDMEC) appeared to be correlated with the periodic occurrence of considerably prolonged intervals; this sign could be used for recognition of the IDMEC. The motor quiescence phase of the IDMEC was correlated with small interval-to-interval variation, as was the early postprandial phase.


Lymph capillary pressure of rat intestinal villi during fluid absorption. A newly developed intestinal preparation is described for determining lymph capillary pressure (PL) in the villi in vivo and in vitro. Determination of PL provided an estimate of tissue fluid pressure in the villi. PL was related to the fluid absorption rate and increased by lymphatic obstruction. During fluid absorption from isotonic mucosal fluid, PL was 1.4 +/- 0.5 or 1.1 +/- 0.4 cmH2O determined in vivo or in vitro, respectively. Both pressures were essentially in the same range as that (0.7 +/- 0.3--1.3 +/- 0.5 cmH2O) in which the mucosal fluid was isotonic Na2SO4 solution or Na-free solutions from which little fluid absorption occurred. This range of pressures may be taken as the normal tissue fluid pressure in the villi. At a high rate of fluid absorption from hypotonic mucosal fluid, PL increased to 5.2 +/- 1.4 cmH2O and tissue fluid pressure was also similarly increased. It is concluded that the fluid absorptive process by the epithelium could not develop an appreciable hydrostatic pressure in the villus tissue space or in the lymphatics.


Optical techniques for the evaluation of epithelial transport processes. Light microscopic observation of living epithelial tissues is a powerful analytical tool in the investigation of solute and water transport. New techniques in quantitative microscopy permit the determination of epithelial cell size and shape as well as accurate measurements of lateral intercellular space dimensions. Traditional techniques for the study of epithelial cell function may be used in conjunction with continuous quantitation of tissue morphology. Fluorescent probes of membrane, cell, and interspace function may be monitored at low light levels to obtain information about the dynamic behavior of the preparation. Application of some of these methods to the Necturus gallbladder epithelium has enabled determination of lateral cell membrane compliance, the hydrostatic pressure equivalent to active transport, the intracellular NaCl transport pool, the rate of active NaCl transport, and the flux of NaCl into the cell across the apical membrane. Possible future applications of optical techniques include measurement of water permeability, solute reflection coefficients, fluid flow paterns, and interspace osmolality.


Resistance to the phosphaturic effect of parathyroid hormone in the hamster. The renal effects of parathyroid hormone (PTH) and dibutyryl 3'5'-cyclic AMP (DBcAMP) were studied in thyroparathyroidectomized hamsters. The hamsters were permitted free access to food and water or fasted for 16 h. PTH caused a phosphaturia in the fed hamster (fractional excretion of phosphate (FEPO4) increased from 5.8 +/- 1.3 to 27.4 +/- 4.6%, P less than 0.001) but not in the fasted hamster (from 9.9 +/- 2.5 to 12.4 +/- 2.5%, NS), whereas calcium excretion decreased significantly in both groups. There was no significant difference in blood acid-base or phosphate levels between the two groups. Insulin did not restore the phosphaturic response to PTH (FEPO4 from 7.7 +/- 2.6 to 5.3 +/- 1.7%), whereas phosphate or NH4Cl infusion did, FEPO4 increasing from 20.9 +/- 3.1 to 38.1 +/- 5.4% (P less than 0.02) and from 19.5 +/- 3.8 to 39.0 +/- 7.5%, respectively. DBcAMP caused a phosphaturia both in the fasted (from 9.6 +/- 2.7 to 20.1 +/- 4.5%, P less than 0.01) and fed (from 2.5 +/- 0.5 to 10.7 +/- 1.5%, P less than 0.02) hamster. A fasting state of up to 64 h did not produce resistance to PTH in the rat. It is concluded that fasting produces resistance to the phosphaturic but not the calcium-retaining effects of PTH in the hamster. The resistance may occur, at least partly, prior to the production of cAMP within the renal tubular cell.


Contribution of renal prostaglandins to the natriuretic action of bradykinin in the dog. To study the effects of stimulation of renal prostaglandin biosynthesis by bradykinin, we assessed the changes in renal functions induced by intrarenal infusion of bradykinin (10 ng . min-1 . kg-1) in the dog anesthetized with pentobarbital before and during inhibition of prostaglandin synthesis by sodium meclofenamate (5 mg/kg). Before meclofenamate administration, bradykinin augmented the urinary output of a "PGE"-like substance from 1.00 +/- 0.25 to 3.88 +/- 1.09 ng/min (P less than 0.05) and increased renal blood flow by 65 +/- 9 ml/min (P less than 0.001), urine flow by 0.55 +/- 0.23 ml/min (P less than 0.05), and sodium excretion by 64.8 +/- 18.0 mueq/min (P less than 0.01). Administration of meclofenamate did not affect the bradykinin-induced increase in renal blood flow and urine volume, but suppressed the evoked output of "PGE" and reduced the associated natriuresis, i.e., sodium excretion increased by only 11.1 +/- 4.8 mueq/min (P greater than 0.05). In contrast, meclofenamate did not affect the natriuresis effected by an equidilator dose of PGE2 (5 ng . min-1 . kg-1) infused intrarenally. These observations suggest that a product of prostaglandin synthetase produced by the kidney during intrarenal infusion of bradykinin contributes to the natriuretic action of the peptide.


Regional renin release by the cat kidney in vitro and in vivo. Differences in the rate of renin release by superficial and deep areas of the cat kidney cortex were studied in vitro and in vivo. Renin release in vitro by outer cortical slices was significantly higher than by their inner counterparts: 19.6 +/- 2.3 vs. 12.8 +/- 1.95 ng angiotensin I-h-1-mg fresh tissue-1-h of incubation-1. In vivo blood was sampled from subcapsular (outer cortical) and deep (inner cortical and medullary) renal venous circulation from anesthetized cats. Renal venous minus arterial plasma renin concentration was respectively, 4.3 +/- 1.12 and 1.9 +/- 1.04 ng angiotensin I-ml-1-h-1 (P less than 0.01). By assuming that in these experiments renal blood flow distribution was approximately equal to each of the two areas of venous drainage, as reported in the isolated perfused cat kidney, we infer from the regional differences in arteriovenous concentration that the rate of renin release of the outer cortex is higher than that of the innder cortex in the cat kidney in vivo. Tissue content of renin was found to decrease toward the deep cortex. The results support the concept that the rate of regional renin release correlates with tissue renin content, at least under the conditions of the present experiments.


Effects of lumen volume transit time and pressure on loop of Henle function. Experiments on Henle's loops were designed to demonstrate the relationships of absorption to distal pressure, transit time, and luminal diameter. Loops of superficial nephrons in hydropenic rats, isolated from the rest of the nephron by oil or solid paraffin blocks, were microperfused at 13.6--20 nl/min. Two samples of fluid were collected from the early distal tubule--one with suction in order to lower distal pressure and reduce luminal volume, the other without suction so that the lumen was distended. Transit times were 30 +/- 2 s without and 19 +/- 2 s with suction. Proximal tubule pressure and perfusion rate were not altered by collection with suction. Absolute absorption, however, descreased from 10.6 +/- 0.4 to 8.4 +/- 0.4 nl/min (P less than 0.001). When salt transport was inhibited by 10(-4) M furosemide in the perfusate, water absorption was 7.8 +/- 0.7 nl/min without suction and 6.1 +/- 0.8 nl/min with suction (P less than 0.01). Computer simulation of Henle's loop shows that these observations cannot be explained by changes in transit time, hydrostatic pressure, or unstirred layers. The observations are simulated when radial fluxes depend on wall thickness and surface area in the descending thin limb.


Transport and metabolism of octanoate by the perfused rat kidney. These studies were done to determine the capacity of the perfused rat kidney to metabolize and transport the medium-chain fatty acid, octanoate (C8). Use of C8, which is water soluble, facilitated the study of transport, since protein, normally needed to transport long-chain fatty acids in solution, could be omitted from the perfusate. Using a filtering kidney it was found that total metabolism and incorporation of [1-14C]octanoate occurred at a rate of 3.9 +/- 0.3 micromol-g wet wt-1-20 min-1 when the perfusate octanoate was 2.8 mM, and reabsorptive uptake occurred at the rate of 7.5 +/- 1.3 micromol-g wet wt-1-20 min-1 at the same octanoate concentration. Use of a nonfiltering kidney (10% dextran perfusate) allowed quantitation of peritubular octanoate uptake. This peritubular uptake showed saturation above 0.7 mM perfusate octanoate with an apparent transport maximum (Tmax) at 2.1 micromol-g wet wt-1-20 min-1. Many previous experiments have linked renal fatty acid transport with that of the organic anion transport system. The apparent peritubular Tmax observed for octanoate suggests carrier-mediated transport. However, this transport did not appear to be inhibited by other organic acids such as probenecid (1--2 mM) and p-aminohippurate (1--2 mM).


Effect of potassium deficiency on papillary plasma flow in the rat. Chronic potassium (K+) deficiency has been shown previously to cause a reduction in solute content in the renal papilla, an effect that is potentially important as a contributing factor to the concentrating defect seen in this circumstance. The cause of the decrease in papillary solute content has not been adequately explained. Because alterations in the blood flow rate through the renal papilla may affect the solute content of the papilla, the present experiments examined the effect of chronic K+ deficiency on papillary plasma flow (PPF) in the rat. PPF was measured by the radioactive albumin accumulation technique. Sprague-Dawley rats were fed identical quantities of water and either a normal or a K+-deficient diet for 21 days. Total GRR in the control rats, 1.7 +/- 0.17 (SE) ml/min, was similar to that in K+-deficient rats, 1.4 +/- 0.14 ml/min (P greater than 0.01). Total [3H]PAH clearance was also comparable in the two groups, i.e., 4.4 +/- 0.47 in control and 4.7 +/- 0.45 ml/min in K+-deficient rats (P greater than 0.06). PPF was significantly lower in K+-deficient rats, 19.7 +/- 1.1 ml-min-1-100 g-1, than in control rats, 59.8 +/- 1.6 ml-min-1-100 g-1 (P less than 0.001). The decrease in PPF in the K+-deficient rat may reflect a reduction in perfusion to the juxtamedullary nephrons, thereby resulting in a diminution in both solute delivery and blood flow to the papilla.


Acute and chronic effects of vasopressin on blood pressure, electrolytes, and fluid volumes. Physiological levels of arginine vasopressin (AVP) were continuously infused 24 h/day into six dogs for periods ranging from 7 to 34 days. The acute and chronic responses of the mean arterial pressure (MAP), body fluid volumes, renal function indices, plasma electrolyte concentrations, plasma renin activity, and urinary electrolyte and water excretion rates were measured. MAP was unaffected acutely but rose significantly to a peak on day 9 before declining toward control. MAP was significantly and positively correlated with the plasma volume, but had a diphasic correlation with the plasma sodium concentration and the change in total body sodium. The plasma sodium concentration reached a relatively stable plateau that was maintained in spite of large changes in total body water. We conclude that AVP produces only a transient hypervolemic hypertension; that AVP is a natriuretic agent, either directly or indirectly, both acutely and chronically; and that chronically it is a more potent controller of the plasma sodium concentration than of the total body water except in extreme cases.


Effect of hypoxia on mechanical properties of hyperthyroid cat papillary muscle. It has been previously established that hyperthyroid myocardium exhibits increased performance under well-oxygenated conditions. To date, it is not known whether hyperthyroid cardiac muscle can maintain this increased performance during hypoxia. The responses of isolated right ventricular papillary muscles from hyperthyroid and euthyroid kittens to hypoxia were compared under isometric conditions at 31 degrees C. Under well-oxygenated conditions, the hyperthyroid cardiac muscle exhibited both an increased contractility and an accelerated rate of relaxation. A similar degree of acute hypoxic stress for 15 min resulted in a greater decrease in contractility in the hyperthyroid compared with the euthyroid papillary muscle as indicated by a greater fall in both peak tension development (2.2 +/- 0.25 from 4.2 +/- 0.2 vs. 0.9 +/- 0.15 from 3.2 +/- 0.4 g/mm2, P less than 0.01) and +dT/dt (12.9 +/- 2.3 from 25 +/- 3 vs. 4.0 +/- 0.6 from 14 +/- 1 g-s-1-mm-2, P less than 0.01). In addition, compared with the euthyroid data, hypoxia resulted in impaired myocardial relaxation in the hyperthyroid cardiac muscle. Thus, the hyperthyroid compared with the euthyroid papillary muscle exhibits both a greater decrease in contractility and an impairment of myocardial relaxation during hypoxia, indicating a greater susceptibility to a given hypoxic stress.


Plasma catecholamine and blood pressure responses to sympathetic stimulation in pithed rats. Sympathetic stimulation in pithed rats elicits increases in blood pressure (BP) and plasma levels of catecholamines. The BP is proportional to the logarithm of the plasma norepinephrine (NE) concentration. Adrenal medullectomy diminishes slightly only the initial phase of the BP responses, whereas bretylium blocks completely the BP response and diminishes by about 70% the increase in plasma NE. Adrenal medullectomy completely prevents the increase in plasma epinephrine (Epi) and diminishes by 30% plasma NE. Plasma levels of NE appear to reflect sympathetic neuronal activity, but the NE at sympathetic nerve endings is responsible for the increase in BP. Epi released from the adrenal medulla may enhance and accelerate the initial BP response, but plays only a minor role after the first 15 s.


Cardiac lymph flow in conscious dogs.

Cardiac lymph flow in conscious dogs. The cardiac lymphatic duct was cannulated in dogs and the exteriorized cannula allowed chronic collection of lymph during the awake state for as long as 3 wk. The surgical methodology and inherent difficulties in the technique are describ:d. Cardiac lymph flow ranged from 0.45--5.6 ml/h in the control state in 14 dogs. An occluding device and flow probe were placed on the circumflex coronary artery (CFX); ultrasonic segment length crystals were placed in the left ventricular free wall in 4 dogs. Occlusion of the CFX in these conscious dogs caused lymph flow to fall as great as 46% below control during the 1st half-hour. Reperfusion of the occluded vessel caused an increase in lymph flow as great as 67% above control. The effect on cardiac lymph flow was demonstrated for a few select drugs that have known effects on the cardiovascular system. Cardiac lymph flow was altered from control as follows: isoproterenol, 42 +/- 11% increase; RO 2-2985, 118 +/- 8% increase; verapamil, 101 +/- 10% increase; propranolol caused no significant change. The conscious dog with cardiac lymph vessel cannulated should provide a model to further study the complexities of cardiac metabolism and physiology without interference of anesthesia and surgical stress.


Inotropic responsiveness of atrial myocardium bathed in Tris- or bicarbonate-buffered solutions. Atrial muscle of guinea pigs was used to study the inotropic influences of substituting a tris(hydroxymethyl)-aminomethane-buffered solution aerated with 100% O2 for a bicarbonate-buffered solution aerated with 95% O2-5% CO2 under otherwise equivalent in vitro conditions. Basal values of isometric contractile tension and its first derivative (dT/dt) were smaller and time to peak tension and time to 90% relaxation were longer in Tris- than in bicarbonate-bathed muscles. Both groups responded similarly to changes in stimulation frequently (0.1--2.2 Hz) and Ca2+ concentration (1.0--7.0 mM); however, maximal inotropic responses to these variables were smaller in the Tris-bathed atria. The negative inotropic effects of D600 and gentamicin were greater in the Tris group. Tris-bathed atria developed pulsus alternans when exposed to Mn2+ or a reduced Ca2+ concentration, whereas pulsus alternans did not occur in the bicarbonate group. A transient increase in contractility occurred in bicarbonate-bathed atria after treatment with 0.125 mM Mn2+, but only a negative response occurred in the Tris group. Thus important, and seemingly Ca2+-dependent, differences exist between the inotropic influences of Tris and bicarbonate solutions that may affect the utility of Tris-buffered (and/or bicarbonate deprived) heart muscle for studying certain inotropic interventions.


Uncoupling cation effects on cardiac contractility and sarcolemmal Ca2+ binding. Studies have been performed correlating the effects of cationic uncouplers on intact cardiac muscle and on Ca2+ bound to isolated cardiac plasma membranes. Sarcolemmal vesicles were isolated from neonatal rat hearts. Ca2+ binding experiments were performed and Scatchard plot analysis indicated two classes of Ca2+ binding sites. The ability of certain cations to displace Ca2+ bound to these vesicles was measured. The effects of these same cations on the tension developed by neonatal rat papillary muscles and on the Ca2+ content of tissue culture cells (from neonatal rat heart) were measured. The results show that a) the selectivity sequence (Y3+ greater than Nd3+ greater than La3+, Cd2+ greater than Co2+ greater than Mg2+) of sarcolemmal Ca2+ binding sites is the same as the effective uncoupling sequence; b) the amount of Ca2+ bound at these sites (approximately 700 micromol/kg wet wt) is more than adequate to support tension development; c) the dependence of sarcolemmal Ca2+ binding at low-affinity sites and tension development on [Ca2+]o is essentially the same. It is then reasonable to propose that the Ca2+ bound to these sarcolemmal sites plays an important role in controlling the amount of Ca2+ available to the myofilaments and thus myocardial contractility.


Application of an isolated heart model to investigate blood-oxygen delivery. To avoid the compensatory hemodynamic responses, which have limited interpretation of hemoglobin-oxygen affinity modifications in animal experimentation, an isolated blood-perfused rabbit heart model providing metabolic, functional, and vectorcardiographic measurements has been developed. Fixed-flow perfusions of unchanged or affinity-modified red blood cell suspensions were carried out to assess the benefits of high affinity during hypoxic hypoxia and of low affinity during posthypoxic recovery. Using fully saturated suspensions, the influence of affinity level during restricted flow and reperfusion was also studied. Higher myocardial oxygen consumption (MVO2) was associated with high-affinity blood during mild hypoxia and low-affinity blood during posthypoxic recovery. At low flows, heart rate and MVO2 tended to be lower in high-affinity perfusions, and to recover more completely during low-affinity reperfusions. Ventricular function, vectorcardiographic patterns, and lactate levels were affected by hypoxia and ischemia, but not by level of affinity. The relevance of these observations to the therapeutic potential of hemoglobin-oxygen affinity modification is discussed.


Interaction of thrombin with mammalian platelets. In this study we have explored the interaction of thrombin with platelets from human and rat. Compared to human platelets, rat platelets suspended in plasma required a higher concentration of thrombin for aggregation. This difference in sensitivity to thrombin was maintained when platelets were washed and suspended in buffer. Platelets from both mammals bound thrombin and showed a similar number of binding sites. However, the apparent dissociation constant of thrombin binding for rat platelets was approximately 15-fold higher than that for human. Thus, the decreased aggregation response of rat platelets may be due to a reduced binding of thrombin to its receptor. It is known that the thrombin receptor is located on the platelet surface. Gel electrophoresis of platelets followed by specific staining as well as fluorography showed significant differences in the surface glycoproteins of human and rat platelets. Human platelets showed labeled components corresponding to 210,000 and 160,000 daltons, whereas rat platelets showed glycoproteins with molecular weights of 240,000 and 190,000. A 135,000-dalton component was present in platelets from both sources. These results suggest that either or both glycoproteins of 210,000 and 160,000 daltons may be involved in the interaction of thrombin with human platelets.


Aortic nerve activation: effect of stimulus train composition on heart rate. The central end of the sectioned left aortic nerve was stimulated within one heart cycle by a train of electrical pulses, producing a reflex reduction in heart rate in the anesthetized rabbit. Relative importance of the stimulation variables (train duration, pulse frequency, and pulse number) in producing bradycardia was investigated by maintaining one variable constant, while altering the other two over a wide range. At each fixed pulse frequency, maximal bradycardia was obtained by the longest train duration that corresponded with the greatest pulse number. At each fixed train duration, maximal bradycardia was achieved with pulse frequencies between 80--120 Hz and remained maximal up to 160 Hz. Stimulating over wide variations in train duration and pulse frequency at any fixed pulse number produced no significant differences in heart rate reduction at that pulse number. These results indicate the dominant importance of total pulse number per cardiac cycle in determining the magnitude of the heart rate response and reveal an apparent frequency limitation within the reflex.


Early changes in collateral blood flow during myocardial infarction in conscious dogs. We studied the early changes in collateral blood flow (CBF) after acute coronary artery occlusion and the relation of these changes to subsequent necrosis. We measured CBF with 7--9 microns radioactive microspheres before and at various times after circumflex artery occlusion in 42 conscious dogs that were killed 48 h later. CBF increased from 20 s postocclusion to later measurements (5 min, 15 min, 1 h, or 6 h) and did so in both necrotic and nonnecrotic areas of the occluded bed. However, the increase in CBF over time was not gradual, but appeared to occur between 20 s and 5 min, with no further changes for up to 6 h. There was a gradation of CBF in the occluded bed, from periphery to center and subepicardium to subendocardium. Central and subendocardial regions with CBF less than 0.40 ml-min-1-g-1 at 5--15 min postocclusion subsequently showed necrosis whereas epicardial and lateral regions with CBF greater than 0.50 ml/min did not. Thus CBF increases very early throughout the occluded coronary bed, and the level of CBF by 5 min appears to determine whether necrosis ultimately occurs.


Vascular responses in canine subcutaneous adipose tissue to hypothalamic stimulation. The present studies investigated vascular responses to electrical stimulation of the posterior hypothalamus in isolated but perfused and innervated subcutaneous adipose tissue in adult dogs. Three groups of dogs were distinguished: in one, electrical stimulation elicited vasodilation; in another, vasoconstriction, and in a third, neither significant vasodilation nor vasoconstriction occurred. Histological examination revealed that electrode placements were in the medial posterior hypothalamus, the lateral posterior hypothalamus, and the medial septal region, respectively. Hypothalamic stimulation failed to alter concentrations of free fatty acids or glycerol in venous blood from subcutaneous fat. Local beta-adrenergic block (propranolol) reversed the vasodilation to vasoconstriction while local alpha-adrenergic block (dihydroergotamine) abolished the vaso constrictor response. These results suggest that selective stimulation of the posterior hypothalamus results in neurogenic activation of both alpha- and beta-adrenergic mechanisms in adipose tissue vasculature. beta-Adrenergic vasodilation appears to predominate if the electrode is located medially, and alpha-adrenergic vasoconstriction appears to predominate if the electrode is located in the lateral posterior hypothalamus.


Intracellular recording from beating heart in situ using a special micropipette holder. Use of a motion-compensated micropipette holder, which senses cardiac motion and lifts and lowers the micropipette and supporting apparatus in synchrony with the heart beat, allows for stable recording of transmembrane action potentials from subepicardial cells of an in vivo beating heart in an open-chest dog without significantly impairing cardiac hemodynamics. This technique may be used to study the effects of ischemia, hypertrophy, or pharmacologic agents on the cellular electrophysiological parameters of subepicardial ventricular cells of an in vivo beating heart.


On-line analysis of intracellular electrophysiological data using a microcomputer system. Automated analysis of intracellular action potentials from cardiac Purkinje fibers was implemented using a microcomputer system. A dual sampling rate was used during analog-to-digital conversion of action potentials recorded from stimulated fibers. The rapid phase of depolarization was sampled at 42.55 kHz. The repolarization and the diastolic phases were sampled at 1 kHz. The resting potential, action potential amplitude, conduction time, action potential duration measured at 50% and at 90% of repolarization, and the maximum upstroke velocity were obtained on-line. The digital form of the action potential was stored on cassette tape and a table containing the various measurements was assembled during the experiment. In unstimulated fibers, the time interval between consecutive action potentials was measured on-line along with the maximum diastolic potential, the action potential overshoot, and the slope of the diastolic depolarization.


Forum on osmosis. II. A criticism of "solvent tension" in osmosis. Concepts about the liquid state that are inconsistent with the facts are noted, and solvent under tension is one of them. Osmosis is not present in a solution: it is a process in the presence of a semipermeable membrane that can be quantified by the operation of applying a hydrostatic pressure. The classical derivation of the van't Hoff equation from Raoult's law is reviewed. The soundness of the early views of G. H. Lewis has not changed.


Forum on osmosis. IV. More on osmosis and diffusion. A brief summary is presented of the Gibbsian view of chemical drives and of its mechanical interpretation, including a description of the "diffusion force" that arises from an interplay between fluctuations and dissipation. Osmotic flows are shown to be driven by diffusion forces acting at the membrane interface, and not by the effects of Hammel and Scholander's "solvent tension."