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.

Appositional bone formation rates in the Beagle

Measurements of haversian appositional bone formation rates were carried out on 400 haversian systems in 28-month-old standardized research colony-raised Beagles, using the midshaft of the 11th rib. The appositional bone formation rate was gradual and regular when the circumference of the outer tetracycline ring was more than 0.35 mm, but the regularity of the measured rate disappeared when the outer tetracycline ring circumference was less than 0.35 mm. Erroneous conclusions could be drawn from measurements of appositional bone formation rate in these animals if this fact were not taken into consideration, and we concluded that in pre- and postexperimental biopsy sections in the ribs of these animals, haversian systems with tetracycline ring circumferences above 0.35 mm must be measured in both situations if the differences in appositional bone formation rate are to be construed as being truly significant.

Age-related variations in cortical bone-remodeling measurements in male Beagles 10 to 26 months of age

Age-related variations in bone-remodeling rates in the male Beagle were unknown. Variations were examined in 28 male Beagles whose ages were evenly distributed between 10 and 26 months. Results were analyzed by computer and regression lines for a best fit line for each determination were given; the 95% confidence limit for the best-fit line and the 95% confidence limits for the individual measurements were calculated. The results are graphically presented in this paper. There was a slight increase in total cortical area, although there was a decrease in the ratio of total-to-cortical area. Osteoid seams showed a frank decrease. Relatively little variation was found in circumference of osteoid seams and appositional rate. The number of resorption spaces decreased. There was a decrease in radial closure rate. Marked decreases were found in activation frequencies and bone formation rate. Increases were observed in osteon formation times and ratio of resorption to formation. The width of osteoid seams and the percentage of systems labeled decreased slightly. As a result of these experiments concerning variations in bone-remodeling activity carried out on Beagles (using the same dogs as their own controls), it was concluded that results obtained should be compared with the expected age-related activity of bone remodeling and not with the initial preexperimental biopsy results.

Plasma levels of immunoreactive parathyroid hormone in dogs chronically exposed to low levels of cadmium chloride

A previous report had suggested that chronic cadmium intoxication interfered with calcium accumulation in bone and suggested that the mechanism may be a parathyroid-induced bone resorption. We measured C-terminal parathyroid hormone levels in the blood of four male standardized research beagles chronically exposed during 6 months to 25 ppm cadmium chloride in their drinking water while at the same time we performed measurements of the parameters of haversian bone remodelling activity. We failed to demonstrate any statistically significant difference in levels of this hormone in the experimental dogs before or during the exposure, or between samples obtained from the experimental dogs at the end of their period of exposure and normal untreated control dogs from the same colony. We conclude that in the early stages of chronic cadmium intoxication before there is evidence suggestive of intestinal or renal malfunction that may secondarily involve the parathyroid glands, the alteration observed in haversian bone remodelling rates is not mediated through abnormalities of function of the parathyroid glands.

Studies on bone-remodeling rates on the Beagle: A comparison between similar biopsy sites on different ribs

Two male littermate standardized colony-raised Beagles were studied to find out whether there was any statistically significant difference in the measurements of bone-remodeling determinations at similar sites on different ribs of the animal. Tetracycline fluorescent-labeling studies were performed on these animals, the midportion of the proximal, midshaft, and distal thirds being sampled from the 5th, 7th, 9th, and 11th ribs. Statistical analysis of the findings indicates that there is no significant difference in bone-remodeling activity between similar sites on alternate ribs. This fact permits studies on bone-remodeling activity in an animal to be done in which the same animal is used as its own control and in which more than two experimental biopsy samples are required.

Effect of chronic low-level cadmium intoxication on the Haversian remodeling system in dogs

This experiment was carried out in order to determine whether the chronic administration of low doses of cadmium resulted in an alteration of the haversian bone remodeling system in dogs. Two pairs of littermate beagles were administered 25 ppm cadmium chloride in their drinking water for 6 months. Four beagles matched for age and sex from the same colony served as controls. By means of fluorescent labeling, we measured haversian bone remodeling parameters according to the techniques described by Frost. Statistical analysis of the results showed significant changes at the 0.01 level in: activation frequency, appositional rates, and number of osteoid seams. At the 0.05 level, significant differences were found in the number of resorption spaces and the bone formation rate. In the absence of other evidence indicative of an alteration in the internal milieu of the dogs, it is concluded that a direct toxic action of cadmium on the mechanisms of activation of cells responsible for the creation and formation of new haversian systems cannot be excluded.

Bone-remodeling rates of the Beagle: a comparison between different sites on the same rib

The standardized colony-raised male Beagle is being used more frequently for research purposes. The rib of this dog is an ideal bone on which to measure haversian bone-remodeling activity. To date there has been little indication as to whether there has existed any natural statistically significant differences in bone-remodeling rates along the length of the rib of this dog. To answer this question, standard samples were procured from the proximal, mid-shaft, and distal portions of the 5th, 7th, 9th, and 11th ribs after tetracycline labeling. It was found that there exist in the normal state statistically significant differences between the 3 portions on all the ribs examined, as refers to ratio of cortical to total bone area, number of osteoid seams, number of resorption spaces, activation frequency, and bone-formation rate. These differences are significant at the 0.001 level and may give rise to a wrong interpretation by the unwary investigator. The results of this investigation stress the importance of standardizing the biopsy site on the rib that is to be examined.

Dense mineralized perivascular tubules in osteopetrotic bone

Samples of osteopetrotic bone were deorganified and examined with the scanning electron microscope. Densely mineralized tubules with walls measuring from 1-10mu in width and with a luminal diameter of 70-90mu were observed scattered throughout the processed surface of the bone. Adjacent sections of bone prepared by routine histological methods for light microscopy showed that the tubules occur in areas of bone where "hyaline" structures are seen surrounding blood vessels. The tubules are not present in normal bone. The nature of these tubules and their possible significance in the pathological physiology of osteopetrosis requires further investigation.

Frequency of sexual dysfunction in "normal" couples

In analyzing the responses of 100 predominantly white, well educated and happily married couples to a self-report questionnaire, this study examined the frequency of sexual problems experienced and the relations of those problems to sexual satisfaction. Although over 80 per cent of the couples reported that their marital and sexual relations were happy and satisfying, 40 per cent of the men reported erectile or ejaculatory dysfunction, and 63 per cent of the women reported arousal or orgasmic dysfunction. In addition, 50 per cent of the men and 77 per cent of the women reported difficulty that was not dysfunctional in nature (e.g., lack of interest or inability to relax). The number of "difficulties" reported was more strongly and consistently related to overall sexual dissatisfaction than the number of "dysfunctions."

Synovial haemangioma of the knee: light and electron microscopic findings

Venous haemangioma of the synovium of one knee also involved adjacent, skin and muscle of the leg in a 4-yr-old girl. Phleboliths were seen in the knee on X-ray. Histologically, the synovium contained large venous channels and was laden with haemosiderin. On electron microscopy, the synovial cells were morpholgically most like synthetic (B) cells. Erythrocytes were ingested and broken down, stepwise, to siderosomes. The synovial cell cytoplasm also contained electron-dense punctate iron deposits. The synovial response appeared to represent chronic haemarthrosis.

The effect of chronic low level lead intoxication on the Haversian remodeling system in dogs

The greatest portion of lead ingested by human beings or experimental animals is stored in bone. Once in bone, lead is difficult to remove. It may have a half-life of 20 years or more and could interfere with bone metabolism. The effects of lead intoxication on the production of intercellular matrix have been reported previously but the effects of lead on bone turnovers rates were not reported. In this paper we reported the results of a study of the effects of lead on bone turnover in dogs. Differences between experimental and control dogs were found when measuring appositional rates, radial closure rates, activation frequencies, osteon formation times, and bone formation rates. We found that dogs subjected to a low dose (1.3 mg. per kg. per day) of lead over a long period of time (201 days) showed a statistically significant decrease in bone formation activity at the cell (90 per cent), tissue (85 per cent), and organ (78 per cent) levels when compared to controls. Although these observations were made on a small experimental and control sample (four dogs), they suggest that chronic low dose lead intoxication does alter normal bone physiology.

The renal handling of parathyroid hormone. Role of peritubular uptake and glomerular filtration

The mechanisms of uptake of parathyroid hormone (PTH) by the kidney was studied in anesthetized dogs before and after ureteral ligation. During constant infusion of bovine PTH (b-PTH 1-84), the renal arteriovenous (A-V) difference for immunoreactive PTH (i-PTH) was 22+/-2%. After ureteral ligation and no change in renal plasma flow, A-V i-PTH fell to 15+/-1% (P < 0.01), indicating continued and significant uptake of i-PTH at peritubular sites and a lesser role of glomerular filtration (GF) in the renal uptake of i-PTH. Since, under normal conditions, minimal i-PTH appears in the final urine, the contribution of GF and subsequent tubular reabsorption was further examined in isolated perfused dog kidneys before and after inhibition of tubular reabsorption by potassium cyanide. Urinary i-PTH per 100 ml GF rose from 8+/-4 ng/min (control) to 170+/-45 ng/min after potassium cyanide. Thus, i-PTH is normally filtered and reabsorbed by the tubular cells. The physiological role of these two mechanisms of renal PTH uptake was examined by giving single injections of b-PTH 1-84 or synthetic b-PTH 1-34 in the presence of established ureteral ligation. After injection of b-PTH 1-84, renal A-V i-PTH was 20% only while biologically active intact PTH was present (15-20 min). No peritubular uptake of carboxyl terminal PTH fragments was demonstrable. In contrast, after injection of synthetic b-PTH 1-34, renal extraction of N-terminal i-PTH after ureteral ligation (which was 13.4+/-0.6% vs. 19.6+/-0.9% in controls) continued for as long as i-PTH persisted in the circulation. These studies indicate that both GF and peritubular uptake are important mechanisms for renal PTH uptake. Renal uptake of carboxyl terminal fragments of PTH is dependent exclusively upon GF and tubular reabsorption, whereas peritubular uptake can only be demonstrated for biologically active b-PTH 1-84 and synthetic b-PTH 1-34.

Degradation of parathyroid hormone and fragment production by the isolated perfused dog kidney. The effect of glomerular filtration rate and perfusate CA++ concentrations

The renal degradation of intact bovine parathyroid hormone (b-PTH 1-84) was studied with the isolated perfused dog kidney. Disappearance of b-PTH 1-84 from the perfusate occurred concomitantly with the appearance of smaller molecular weight forms of immunoreactive parathyroid hormone (PTH). These smaller molecular weight PTH fragments included both carboxyl and amino terminal regions of the PTH peptide. Perfusate from kidneys with lower glomerular filtration rates (GFR) contained b-PTH 1-84 for longer periods of time than kidneys with higher GFRs, and perfusate from kidneys with lower GFRs demonstrated greater accumulation of carboxyl terminal PTH fragments. Perfusate containing high Ca++ concentrations retarded, and perfusate with low Ca++ concentrations accelerated the rate of degradation of b-PTH 1-84 by the kidney. These studies, therefore document the production of PTH fragments during the course of intact hormone degradation by the kidney. They also demonstrate renal clearance of the PTH fragments produced and define the effects of glomerular filtration rate and calcium concentrations on degradation of intact hormone and the clearance of PTH fragments.