Contrast sensitivity and central vision in reattached macula

Macular functions were studied in patients recovering after surgery for retinal detachment involving the macula. Central vision was assessed by visual acuity, grating acuity, metamorphopsia, and contrast sensitivity tests for 5 months up to 3 years post-operatively. Impairment of contrast sensitivity was generally observed at high and intermediate spatial frequencies as compared to age-matched controls. In 2 cases, both with low visual acuity, an attenuation was also found at low spatial frequencies. Reductions of visual and grating acuity were closely related indicating that the test target for acuity determination is of minor importance in evaluating recovery in retinal detachments. The majority of the patients studied had different degrees of metamorphopsia. The reduction of the contrast sensitivity at intermediate spatial frequencies corresponded to the reduction in acuity. Our study thus presents no evidence for a selective vulnerability of specific contrast channels unrelated to acuity loss.

Altered adenylate cyclase kinetics in hyperfunctioning human parathyroid glands

Current evidence suggests that parathyroid gland adenylate cyclase is involved in the control of parathyroid hormone (PTH) secretion. Thus, the altered control of PTH release in hyperparathyroidism may relate to altered adenylate cyclase activation. Therefore, we examined adenylate cyclase kinetics in membrane preparations from hyperfunctioning human parathyroid glands and normal human and bovine parathyroid tissues. There were no differences in the affinity for ATP between enzymes of normal and pathological tissue. However, the enzyme in 10 hyperfunctioning glands showed increased affinity for Mg++. The activation constant for Mg++ (KaMg) of adenylate cyclase in normal human glands was 10.6 +/- 2 mM, a value not different from that of normal bovine parathyroid tissue (9.5 +/- 1 mM). In contrast, the adenylate cyclase in membrane preparations from three of four hyperplastic and six of seven adenomatous human glands showed a markedly reduced KaMg, ranging from 0.85-1.64 mM and from 1.58-6.46 mM, respectively. In one adenoma and one hyperplastic gland, the Ka of the enzyme for Mg++ was close to normal. The addition of guanylylimidodiphosphate or GTP to the incubation mixture increased, in a dose-dependent manner, the apparent KaMg of the enzyme in the abnormal tissue toward normal, suggesting a defective nucleotide regulatory site in the adenylate cyclase of hyperparathyroid glands. In addition, the hyperparathyroid gland enzyme was less susceptible to inhibition by calcium, requiring 0.7-1 mM Ca++ for 50% inhibition, whereas comparable inhibition of the normal adenylate cyclase was seen at 0.22-0.28 mM Ca++. We conclude that the abnormal control of PTH secretion in hyperparathyroidism may be related, at least in part, to alterations in the characteristics of parathyroid gland adenylate cyclase.

Stimulation of synthesis and secretion of chorionic gonadotropin subunits by eutopic and ectopic hormone-producing human cell lines

The effects of dibutyryl cyclic adenosine 3'3':-5'-monophosphate (AMP) and sodium butyrate on the synthesis and secretion of human chorionic gonadotropin (HCG) by trophoblastic and nontrophoblastic human cell lines were studied by radioimmunoassay and pulse-chase labeling techniques. Dibutyryl cyclic AMP stimulated synthesis and secretion of HCG-alpha and HCG-beta subunits by the trophoblastic cell lines JAR and BeWo, whereas butyrate had no effect or decreased secretion. On the other hand, a number of nontrophoblastic cell lines (including the breast carcinoma lines ZR-75-31, BT-20, and MCF-7; the bronchogenic carcinoma line ChaGo; and the cervical carcinoma line HeLa S3) were induced to synthesize and secrete increased amounts of HCG subunits by butyrate, but dibutyryl cyclic AMP had less or no stimulatory effect. The nontrophoblastic brain tumor line CBT was an exception to this general rule in that HCG-beta production was stimulated by dibutyryl cyclic AMP but not by butyrate. In all cases, the drug-induced increase in HCG subunit secretion was directly proportional to the elevation of HCG subunit synthesis. These data suggest that the differential effects of dibutyryl cyclic AMP and butyrate on trophoblastic and nontrophoblastic cells reflect differences in the transcription or translation of HCG subunit genes induced by these agents in the two cell types.

Qualitative real-time cross-sectional echocardiographic imaging of the human fetus during the second half of pregnancy

In this study, we used high-resolution echocardiographic systems to investigate how early in pregnancy normal fetal cardiac anatomy could be noninvasively evaluated. Over a 2-year period, 84 of 88 fetuses were successfully imaged (27 were studied serially). Postnatal images of 73 were obtained during the newborn period. Estimated fetal age varied at initial examination from 19-41 weeks (mean +/- 0.5 weeks [+/- SEM]) of pregnancy. Estimated fetal weight using an ultrasound algorithm varied from 500-3100 g (mean 1580 +/- 80 g [+/- SEM]). To evaluate fetal cardiac anatomy, we reproduced commonly used cross-sectional views of the heart. The four-chamber and the short-axis great artery views have been most successful for cardiac evaluation in the fetus. These views could be obtained in 96% and 95% of the patients, respectively. With these views, cardiac chamber and valve structures, as well as two great arteries, could be imaged in detail. The ascending and descending aorta, as well as the aortic arch and vessels to the arms and head, were visualized in 87% of examinations, and the inferior and superior venae cavae were visualized in 76%. In two of three RH fetuses, changes in cardiac chambers compatible with hydrops fetalis were demonstrated. We examined all fetuses after birth and verified clinically (or noninvasively) that no cardiac malformations were present. It appears, however, that the diagnosis of major congenital heart defects should be possible before birth.

Haversian bone-remodeling measurements in young Beagles

Haversian bone remodeling was measured in Beagles (8.9 to 9.9 months of age) from a colony of laboratory-raised animals. The data were compared with data in published age-related curves. There was no marked dissimilarity between the measurements of haversian bone-remodeling values in Beagles from different sources.

Impaired in vitro beta-adrenergic granulocyte response in chronic obstructive pulmonary disease

Isoproterenol (ISO), histamine (HIS), and prostaglandin E1 (PGE1) inhibit the in vitro release of the lysosomal enzyme, beta-glucuronidase, from polymorphonuclear leukocytes (PMN) during incubation with complement-coated zymosan particles. In asthma, this granulocyte response to ISO and HIS is impaired. Using this in vitro cell model to assess granulocyte beta-adrenergic response, we studied 23 patients with chronic obstructive pulmonary disease (COPD). All had long-standing disease and severe obstruction (FEV1 = 37.5% of predicted). The granulocyte response to HIS challenge in patients with COPD was normal when compared to control subjects, in contrast to the response from the asthmatic group. The granulocyte response to ISO challenge in patients with COPD, however, was reduced compared to control subjects, but not to the degree found in the asthmatics. This demonstrated that reduced granulocyte response to ISO is not limited to asthmatics, but can be found as well in other obstructive diseases of the lung.

Haversian bone-remodelling rates in the beagle after cessation of exposure to chronic low doses of lead

This study reports the changes observed in bone-formation dynamics at the cell, tissue and organ level in cortical bone in four standardization research colony-raised male Beagles that were exposed to 0.7 mg of lead acetate per day for 6 months, followed by a 6-month period when no lead acetate was given. Four similar age-sex matched Beagles of the same origin served as controls. Tissue and blood lead levels were measured. Biochemical and hematological analysis were carried out on a monthly basis. Plasma levels of immunoreactive parathyroid hormone were measured. In the absence of any alteration of the dogs' internal milieu, following 6-months exposure to lead there was a decrease in bone formation at the cell (70 percent), tissue (66 percent) and organ (66 percent) levels. Six months after the lead exposure was interrupted, bone formation returned to normal (93 percent at tissue and 100 percent at organ levels), but there was still some depression of activity at the cell level (70 percent). It is not known whether that cell-level depression of activity is due to persistent enzymatic inhibition following the 6-months exposure or whether it is due to the fact that the cell continued to operate in a micro-environment in which tissue levels of lead are elevated, or both.

Dimaprit inhibition of zymosan-stimulated beta-glucuronidase release from human granulocytes

Histamine inhibits the in vitro release of granulocytic lysosomal beta-glucuronidase when incubated with complement activated zymosan particles and this is an H2-receptor response. The highly specific histamine H2-receptor agonist, dimaprit, also inhibits this secretory enzyme release but is less potent (-log molar ED50 6.71 with histamine vs. -log ED50 5.97 with dimaprit, p less than 0.05). No change in beta-glucuronidase release was found with the H1-agonst, 2-(2 pyridyl)-ethylamine. The antagonist activity of metiamide was similar with the two agonists (KB = 2.9 x 10(-8) M with histamine and KB = 3.6 x 10(-8) M with dimaprit). Diphenhydramine did not change the granulocyte response to either histamine or dimaprit.

Expression of oncodevelopmental gene products by human tumor cells in culture

Sixty-seven human tumor cell lines and 15 lines derived from normal tissue were examined for the production of the oncodevelopmental markers carcinoembryonic antigen, alpha and beta subunits of chorionic gonadotropin, placental and nonplacental forms of alkaline phosphatase, gamma-glutamyltransferase, cystyl aminopeptidase, and calcitonin. Both intracellular and extracellular levels of these markers were determined at three phases during the growth of each culture. Sixty-eight percent of the cell lines produced elevated levels (greater than or equal to 90th percentile) of at least one marker. Of those, 46% produced elevated levels of one marked only, 29% produced two, 22% produced three, and 4% produced four markers. No cell line produced more than four markers at elevated levels. In most instances, however, the expression of any two particular markers was discordant. For approximately 50% of the possible marker pairs, Spearman rank-ordered correlation analyses showed significant negative correlations, indicating that when one marker was produced at elevated levels by a given cell line, other markers were usually absent ot produced at relatively low levels. In no instance was a significant positive correlation found between two markers. These data indicated that, although most human malignant cells examined produced one or more oncodevelopmental gene markers at elevated levels, no predictable coexpression of any two of the markers was seen.

The effect of chronic administration of trisodium nitrilotriacetate (Na3NTA) on the haversian remodelling system in dogs

Trisodium nitrilotriacetate from the environment is reported to accumulate in bone. Two skeletally mature male littermate beagles were administered Na3NTA in a concentration of 2.5 mg/kg body weight in their drinking water for a period of 7 months. Rib biopsies were obtained from the dogs after fluorescent labelling before and at the end of the experimental period. Blood levels of zinc were measured at the same times. Twenty-two similar dogs from the same colony acted as controls. We noticed a decrease in radial closure rates and percent osteoid seams labelled between the experimental and the control animals which was statistically significant at the 0.05 level. The serum levels of iPTH and the bone levels of zinc showed no statistically significant difference. Accepting the fact that the treatment population was small and that the changes observed--although statistically significant--were minimal, it cannot be discounted that the exposure of these animals to Na3NTA for a longer period of time would not have had a more adverse effect on haversian bone remodelling activity.

Content of gonadotropins in cultured human malignant cells and effects of sodium butyrate treatment on gonadotropin secretion by HeLa cells

Twenty-one of 82 human cell lines examined for production of human chorionic gonadotropin and its subunits (HCG-alpha and HCG-beta) produced either one or both subunits at some phase in their growth. Of these, 14 produced an excess amount of free alpha subunit, and seven produced HCG-beta or complete HCG without evidence for free alpha subunit synthesis. Five of the HCG-producing cell lines also contained or secreted the beta subunit of human luteinizing hormone. CBT cells derived from a glioblastoma multiforme and JAR choriocarcinoma cells secreted significant amounts of the beta subunit of human luteinizing hormone, while three other cell lines (breast carcinoma MCF-7, HeLa S3, and melanoma A375) produced small amounts of the beta subunit of human luteinizing hormone but did not appear to secrete it. Two cell lines (the melanoma line A375 and the SV40-transformed line SV80) appeared to contain small amounts of human follicle-stimulating hormone. Sodium butyrate caused a 40-fold induction in the secretion of both HCG-alpha and HCG-beta by HeLa S3 cells, but the total amount of HCG-alpha secretion induced was 800-fold greater than that of HCG-beta. Induction was blocked by actinomycin D (1 microgram/ml) and cycloheximide (5 microgram/ml) but was not affected by 1-beta-D-arabinofuranosylcytosine at a concentration (5 microgram/ml) that blocked DNA synthesis 99%. These results indicate that a number of malignant human cell lines produce the subunits of both placental and pituitary gonadotropins and that there is frequently an excess secretion of the free alpha subunit common to these hormones.