Effect of dietary acid and calcium on 25-hydroxyvitamin D metabolism by chick kidney

Studies of the effects of acidosis and dietary calcium on 25-hydroxyvitamin D3 (25OHD3) metabolism were conducted utilizing assays of mitochondrial 1-hydroxylase and 24-hydroxylase activity following 96 hours of acid loading. The results showed decreased 1-hydroxylase (206 +/- 6 vs. 132 +/- 22 fmol min-1 mg/mitochondrial protein-1, p less than 0.01), augmented 24-hydroxylase (48 +/- 14 vs. 180 +/- 30 fmol min-1 mg-1, p less than 0.001) and increments in plasma calcium and phosphate following acidosis. High calcium diet also increased 24-hydroxylase activity (48 +/- 14 vs. 160 +/- 24 fmol min-1 mg-1, p less than 0.001) and plasma calcium, but decreased plasma phosphate. The extramitochondrial concentrations of calcium, potassium, and phosphate which maximally stimulated the hydroxylases in vitro were not altered by the in vivo dietary perturbations. The increments in 1-hydroxylase and 24-hydroxylase resulting from the presence of calcium, potassium, or phosphate in optimal concentrations (10(-5) M, 100 mM, and 100 mM, respectively) were changed by both acid loading and high calcium diet, decreasing in the case of 1-hydroxylase and increasing in that of 24-hydroxylase. The data indicate that the suppression of 1-hydroxylase and augmentation of 24-hydroxylase following these dietary perturbations may depend on both changed total enzyme capacity and altered enzyme sensitivity to extramitochondrial ions and are consistent with mediation by calcium of the effects of acidosis.

Serum aluminum levels and erythrocyte dihydropteridine reductase activity in patients on hemodialysis

Aluminum intoxication due to aluminum-containing antacids or dialysate can cause encephalopathy in patients undergoing hemodialysis, but the biochemical mechanism has not been defined. The enzyme dihydropteridine reductase (DHPR) is essential for the maintenance of normal brain concentrations of tetrahydrobiopterin, which is itself required for the synthesis of specific neurotransmitters. This enzyme is also present in erythrocytes. We measured erythrocyte DHPR activity and concentrations of the biopterin derivatives of its substrate and of aluminum in 38 patients on hemodialysis who had no clinical evidence of encephalopathy. Serum aluminum levels ranged from 15 to 190 micrograms per liter (mean, 67.6 +/- 7.7) as compared with 4.9 +/- 0.99 micrograms per liter in normal subjects. DHPR activity was inversely related to the serum aluminum concentration (r = -0.61, P less than 0.001) and was less than the activity predicted from the hemoglobin concentration in these patients. Serum concentrations of biopterin derivatives were markedly elevated. Eighteen patients were given the aluminum-chelating agent deferoxamine in a single dose, after which DHPR activity doubled. These studies suggest that aluminum inhibits DHPR activity in erythrocytes and that aluminum chelation reverses this effect. Although we did not directly measure DHPR activity in the brains of dialysis patients without encephalopathy, we propose that the reduction in activity in erythrocytes may reflect a similar reduction in the brain. Our findings could help to explain the encephalopathy associated with aluminum intoxication.

Partial characterization of the Purkinje cell antigens in paraneoplastic cerebellar degeneration

Serum from seven patients with paraneoplastic cerebellar degeneration contained anti-Purkinje cell antibodies. The samples were examined by immunoblotting to determine whether they recognized common antigens in isolated human Purkinje cell neurons. Two groups of antigens were detected by all seven sera with Mr 62/64 kd and 34 to 38 kd, both of which contributed to the Purkinje cell antigens detected immunohistochemically. These reactivities were absent from all controls tested. These antibodies may play a role in the pathogenesis of paraneoplastic cerebellar degeneration.

Effects of packed cell volume reduction on renal haemodynamics and the renin-angiotensin-aldosterone system in patients with secondary polycythaemia and hypoxic cor pulmonale

Polycythaemia was corrected by erythrapheresis in ten patients with hypoxic cor pulmonale who were stable on regular diuretic therapy. Renal haemodynamics, renal function and the renin-angiotensin-aldosterone system were assessed before and afterwards. Before erythrapheresis effective renal plasma flow (ERPF) was reduced (63% predicted) but glomerular filtration rate (GFR) was preserved (88% predicted) by a rise in filtration fraction (FF) (138% predicted). A negative correlation existed between ERPF and packed cell volume (r = -0.723; P less than 0.02) and also between ERPF and PaCO2 (r = -0.710; P less than 0.05). Polycythaemia was sufficient to maintain renal oxygen delivery (97% predicted). After erythrapheresis systemic blood pressure, blood volume and blood viscosity all decreased. ERPF increased by 18% (P less than 0.02). FF fell by 11% (P less than 0.05) and GFR was unchanged. Renal oxygen delivery diminished by 25% (P less than 0.001). Plasma renin activity was increased in five patients and plasma aldosterone increased in two patients before erythrapheresis. No sustained fall occurred in plasma renin activity or plasma aldosterone, possibly because the haemodynamic consequences of the procedure had opposing actions on renin secretion. Although the reduction in FF would per se tend to enhance renal sodium and water excretion, a diuresis or natriuresis did not occur consistently.

Biliary decompression: an institutional comparison of percutaneous and endoscopic methods

Endoscopically performed biliary drainage (EPBD) is now an alternative to percutaneous biliary drainage. The morbidity, mortality, and survival statistics of 97 patients with obstructive jaundice who had undergone percutaneous transhepatic biliary drainage (PTBD) and surgery, PTBD alone, EPBD and surgery, or EPBD alone were compared. Overall, the EPBD group had fewer complications and lower mortality than the other groups. When palliative treatment of patients with malignancies was compared, the complication rates associated with EPBD and PTBD were similar; however, mortality was lower with EPBD. No negative effect on survival was found with EPBD. In addition, EPBD offered several additional advantages over PTBD, including fewer bleeding complications, better patient acceptance, and avoidance of external catheter care. EPBD should be considered as a viable alternative to PTBD. Additional studies are needed to determine whether it is to be considered the initial drainage procedure of choice in patients with obstructive jaundice.

Effect of heavy exercise on mineral metabolism and calcium regulating hormones in humans

The relationship between acid base status and mineral metabolism after heavy exercise has been examined in 12 healthy subjects. Following burst exercise (duration 60-130 sec) to the point of exhaustion, blood pH had decreased (7.42 +/- 0.01 vs. 7.18 +/- 0.02, P less than 0.001) and plasma ionized calcium had increased (1.09 +/- 0.01 vs. 1.22 +/- 0.02 mmol/liter, P less than 0.001). Log ionized calcium concentration showed a significant negative correlation with pH (r = -0.90). Although plasma total calcium increased after exercise (2.47 +/- 0.05 vs. 2.67 +/- 0.04 mmol/liter, P less than 0.001), this change was not seen if the observed values were corrected for the accompanying increase in plasma protein concentration, suggesting that hemoconcentration accounted for these increments. Significant increases were also seen in plasma inorganic phosphate concentration, though not in plasma magnesium. Radioimmunoassay of parathyroid hormone using two different region-specific assays, one directed at the mid-region/carboxy-terminal and the other at the amino-terminal portion of the molecule, and of calcitonin, showed no change during exercise-induced hypercalcemia. The results do not suggest significant skeletal buffering of this type of acidosis and indicate that the changes in ionized calcium associated with short bursts of intense exercise are directly related to acidosis and that those in total calcium are a consequence of hemoconcentration.

Stimulated release of endogenous GABA and glycine from the goldfish retina

The release of endogenous gamma-aminobutyric acid (GABA) and glycine from the isolated goldfish retina, measured by high-pressure liquid chromatography (HPLC), was Ca2+-independent when evoked by L-glutamate or L-aspartate and partially Ca2+-dependent when evoked by 50 mM K+. D-Aspartate potentiated GABA and glycine release evoked by L-glutamate and inhibited that evoked by L-aspartate. These data are similar to those reported for radiolabeled GABA and glycine. However, the relative amount released compared to the total amino acid content in the retina was much less (10%) for the endogenous compounds. We suggest that results obtained with [3H]GABA and [3H]glycine can be generalized in a qualitative manner to their endogenous counterparts in goldfish retina.

Surgical management of infected median sternotomy: closed irrigation vs. muscle flaps

Mediastinitis remains a serious complication of median sternotomy which requires prompt and aggressive surgical management. Debridement and closed irrigation has been the conventional mode of treatment. Failure to respond results in open drainage and delayed healing with its associated increased morbidity and mortality. Secondary closure with rectus muscle flaps has been a marked advance in the treatment of these patients. In an attempt to define guidelines for the treatment of mediastinitis complicating median sternotomy, a retrospective review of 2,400 cardiac surgical cases at St. Vincent's Hospital from 1977 through 1982 was performed. There were 25 cases (1%) of mediastinitis. Debridement and closed irrigation was successful in 16 patients (64%) with an average postoperative hospital stay of 19 days. Failure resulted in open drainage in 2 patients (8%) with an average hospital stay of 66 days and debridement and secondary closure by rectus muscle flaps in 7 patients (28%) with an average hospital stay of 28 days. There were no deaths in the entire series. Failure to respond to closed irrigation was not due to delay in diagnosis. The length of time between operation and the first sign of sternal dehiscence did not vary significantly. Sternal dissolution, the presence of anaerobic organisms, large volumes of purulent and necrotic material, however, were responsible for continued mediastinitis and further sternal dehiscence. Open irrigation and delayed closure with muscle flaps should be reserved for these patients and appears to decrease significantly morbidity and length of hospital stay. Surgical debridement and closed irrigation, however, remains the primary method of treatment of the less virulent forms of mediastinitis following median sternotomy.

Serum immune complexes in systemic sclerosis: relationship with precipitating nuclear antibodies

In a comparative study of antinuclear antibodies (ANA) and immune complexes in the serum of 43 patients with systemic sclerosis (SS) ANA were detected by indirect immunofluorescence on Hep 2 cells and/or double immunodiffusion in 90% of patients, while immune complex assays were positive in 32% of patients. The immune complex assays were positive only in sera containing antibodies to Scl 70, n-RNP, Ro, and La. The presence of immune complexes in SS sera is therefore related to ANA specificity. This might explain the variable findings of several previous studies of immune complexes in SS.

Esophageal perforation

A brief synopsis of the clinical and radiographic features of esophageal perforation, including barogenic rupture, is outlined. The dependence of the thoracic surgeon on roentgenograms and their interpretation by the radiologist is emphasized.

Antibody-dependent cellular cytotoxicity of human vascular endothelium in systemic sclerosis

Sera from 39 patients with systemic sclerosis were examined for a cytotoxic effect on human umbilical vein endothelium. Although none of the sera produced direct cytotoxicity of 51Cr-labelled endothelial cells, even with added complement, nine sera did produce increased 51Cr release when co-cultured with endothelial cells and normal human peripheral blood mononuclear cells. The effector cells involved in this cytotoxicity possessed Fc receptors but were non-T and non-adherent while the responsible serum factor(s) was present in IgG containing fractions. This cytotoxicity tended to occur in patients with both circulating immune complexes and precipitating antibodies to nuclear and cytoplasmic antigens who, as a group, had more severe and extensive visceral disease than those without such serological abnormalities. Control studies using sera from both 27 normal controls and 19 patients with either diabetes or extensive athero-sclerotic vascular disease failed to reveal any similar cytotoxicity.

The plasma amino acid response to cafeteria feeding in the rat: influence of hyperphagia, sucrose intake, and exercise

The plasma amino acid response to voluntary hyperphagia was evaluated in rats fed a "cafeteria" diet for 4 to 8 weeks and compared to chow-fed controls. The influence of the sucrose content of the cafeteria diet was examined by studying rats given a low-sucrose, highly palatable, liquid diet (Magnacal). In a second series of studies the cafeteria diet was fed to rats housed in wheel cages and who ran 2.0 +/- 0.1 milles per day and compared with a sedentary cafeteria-fed group housed in standard cages. As expected, the cafeteria diet resulted in hyperphagia (45% to 55%) and in increased weight gain (35% to 50%). In response to cafeteria feeding there was an increase in plasma threonine, serine, proline, citrulline, alpha-amino butyric acid (ABA), and tyrosine. Significant decreases were observed in the branched chain amino acids (BCAA), valine and leucine. All of these changes were also observed when hyperphagia was induced with the low-sucrose diet, with the exception of the rise in ABA. In the exercised cafeteria-fed rats, excessive weight gain did not occur. Nevertheless, the amino acid response to the cafeteria diet was the same as in sedentary rats with excessive weight gain. The plasma amino acid pattern in those rats that developed glucose intolerance during cafeteria feeding and those that maintained normal glucose tolerance was similar. We conclude that hyperphagia induced by cafeteria feeding in the rat results in a specific plasma amino acid profile characterized by elevations in some amino acids (threonine, serine, proline, citrulline, ABA, and tyrosine) and reductions in the BCAA.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful combination chemotherapy for metastatic parathyroid carcinoma

A 54-year-old patient with metastatic parathyroid carcinoma and severe hypercalcemia refractory to conventional treatment was treated with chemotherapy consisting of fluorouracil, 500 mg/sq m intravenously (IV) daily for four days (24-hour infusion), cyclophosphamide, 500 mg/sq m IV daily for four days, and dacarbazine (imidazole carboxamide), 200 mg/sq m IV daily for four days. Complete objective and partial biochemical responses were noted, with the response duration being 5.0 + months. The toxic reaction was moderate and predominantly gastrointestinal.

Carcinoma of the lung and coexistent active pulmonary tuberculosis: diverse morphologic and radiographic presentations

Five patients with coexistent carcinoma of the lung and active tuberculosis within the same pulmonary lesion were studied. These cases represent five distinctly varying radiographic presentations and point out the extreme diversity of the morphological pictures of this particular disease combination. Physicians who regularly deal with patients who might present with either entity alone are cautioned to be alert to the possibility that these two diseases may be present simultaneously within single, specific pulmonary lesions.

Effect of histamine H2-receptor blockade on parathyroid status in normal and uraemic man

Reports of parathyroid suppression during cimetidine therapy suggest that prolonged therapy with H2 antagonists may, by inducing relative hypoparathyroidism, compromise skeletal homeostasis and that under appropriate circumstances, these drugs may serve as a new modality in treating hyperparathyroidism. Using three different region-specific immunoassays, we have been unable to show an effect of cimetidine (1,800 mg/day) on parathyroid hormone concentration, or on urinary cyclic adenosine monophosphate and renal threshold phosphate concentration in 4 normal subjects. Ranitidine given for 8 weeks to 4 haemodialysed patients likewise failed to decrease parathyroid hormone concentration. H2 antagonists appear not to alter parathyroid status in either normal subjects or in uraemics and therefore are unlikely to influence skeletal metabolism in either instance.

5-Fluorouracil and folinic acid: a Phase I-II trial in gastrointestinal malignancy

Fifty-one patients with metastatic adenocarcinoma received Folinic Acid (FA) combined with 5-Fluorouracil (5FU) in a Phase I-II clinical trial. Two different schedules were used: (a) bolus infusion--5FU 7-12 mg/kg/d I.V. d1-5, FA 1.6 mg/kg/d I.V. d1-5; (b) continuous infusion--5FU 600-1200 mg/m2/d I.V. d1-4, FA 60 mg/m2/d I.V. d1-4. Mucositis and myelosuppression were dose-limiting, with recommended dose levels of 5FU for further trials being 10 mg/kg/d I.V. d1-5 and 1000 mg/m2/d I.V. d1-4 on the bolus and continuous infusion schedules, respectively. Forty-one evaluable patients with measurable disease were treated. Thirty-six had metastatic colorectal carcinoma, and 14/36 patients responded (CR-1, PR-13), including responses in three patients who had previously failed 5FU treatment alone. In the two patients with unknown primary sites and three with gastric cancer, no response were seen. 5FU and FA have activity equivalent to 5FU alone, and the responses in patients receiving prior 5FU suggest it may be superior. The possibility that toxicity may be enhanced does exist. Further trials of these two agents are warranted.

Acute, but not chronic, metabolic acidosis disturbs 25-hydroxyvitamin D3 metabolism

Previous studies in vitamin D deficient animals showing that acidosis may impair the production of 1,25(OH)2D3 are in conflict with studies in humans which have not shown convincing disturbances of 25OHD3 metabolism during acidosis. We have investigated the effect on renal 25OHD3 1- and 24-hydroxylase of acid loading for periods of 24 hr to 21 days. Acid loading resulted in immediate and sustained decrements in arterial pH and bicarbonate and increments in blood-ionized calcium. Acute (24-hr) acid loading decreased 1- and increased 24-hydroxylase activity. After 6 days of acid loading, no effect on 1- hydroxylase activity was observed and that on 24-hydroxylase activity was reduced. By 21 days the effect of acidosis on 24-hydroxylase activity was no longer observed. The results show that acidosis disturbs 25OHD3 metabolism in the physiological vitamin D and calcium replete state as well as in the vitamin D deficient state, but only acutely. Our data are consistent with studies in humans and suggest that, while short-term disturbances of 25OHD3 metabolism occur early in acidosis, they are transient and may not be causally related to the development of metabolic bone disease during chronic acidosis.

Increased efficiency of weight gain and altered cellularity of brown adipose tissue in rats with impaired glucose tolerance during diet-induced overfeeding

We examined the relationship among glucose tolerance, efficiency of weight gain, and cellularity of brown adipose tissue (BAT) in rats (initial weight: 362 +/- 1 g) made hyperphagic and obese by feeding on a highly palatable "cafeteria" (CAF) diet for 4-8 wk. As compared with chow-fed controls, CAF feeding resulted in a 45-60% increase in caloric intake (P less than 0.01), a 40-50% increase in weight gain (P less than 0.01), and hyperinsulinemia. Glucose disposal rate (K) on intravenous glucose tolerance test (IVGTT) was greater than or equal to 1.4% in all chow-fed rats, but fell to less than or equal to 1.3 in 10 of 23 CAF-fed rats. As compared with the chow-fed controls, rats with normal glucose tolerance demonstrated a 12% decline in efficiency of weight gain (g/100 kcal of food consumed) in response to CAF feeding (P less than 0.05). In marked contrast, in rats with impaired glucose tolerance, efficiency of weight gain failed to decline in response to overfeeding and was 18% higher than in the overfed group with normal glucose tolerance (P less than 0.01). Although CAF feeding increased the mass of interscapular BAT by 110-130% in rats with normal as well as impaired glucose tolerance, DNA content of BAT rose only in the normal-K CAF-fed rats (0.19 +/- 0.01 mg DNA/100 mg versus 0.12 +/- 0.02 in chow-fed controls and 0.12 +/- 0.01 in low-K rats).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum-induced enhancement of peripheral blood mononuclear cell-mediated cytotoxicity towards human target cells in systemic sclerosis

Sera from 7 of 37 patients with systemic sclerosis (SS) were found to markedly enhance cytotoxicity in several established human target cell lines when co-cultured with normal human peripheral blood mononuclear cells (PBM). Fractionation studies indicated that the cytotoxicity-inducing activity resided in the IgG-containing fractions of serum and that the effector cells were Fc-receptor positive. By contrast, sera from 27 normal controls produced little or no cytotoxicity when co-cultured with the same target cell lines and normal PBM. Any slight enhancement of cytotoxicity that occurred with a single target cell line was, on fractionation, either labile or associated with albumin containing fractions. These findings raise the possibility that antibody-dependent cellular cytotoxicity (ADCC) could provide a pathogenetic mechanism in some patients with SS.

Giant esophageal carcinoma

Carcinoma of the esophagus is a devastating disease that produces various degrees of esophageal obstruction by virtue of its circumferential, constricting type of growth pattern. Because of the relatively small diameter of the esophageal lumen, a limited-sized tumor can produce severe obstructive symptoms. Carcinoma of the esophagus is, as a rule, fairly well localized to its wall or the immediate mediastinal parietes in cases where there is extension beyond the esophageal musculature.(1) Large, bulky, exophytic types of esophageal carcinomas that produce symptoms mainly as a result of extrinsic pressure are unusual.

Laser techniques for the evaluation of wear in Class II restorations

A technique for the quantitative determination of the changes in surface topography of restorations during wear has been developed. This involves the optical contouring of the surface using a laser, and the generation of contour maps. Several different methods for interpreting these maps are discussed. A computer-aided method is the most consistently accurate and measures wear volume to an accuracy of 2--5%.

Apolipoprotein B subspecies in chylomicrons isolated from a patient with chyluria

The diagnosis and the clinical course of a 17-year-old white male with chyluria are reported. Cloudy, milky urine appeared spontaneously, in the absence of edema or any signs or symptoms of parasitic infection. Pedal lymphangiography demonstrated the presence of a lymphatic renal fistula, and digital subtraction angiography showed aneurysmal dilatation of the aorta at the level of the renal arteries. This case provided an opportunity to ascertain which of the forms of apolipoprotein B were present in lymph chylomicrons. Apolipoprotein B is needed for chylomicron secretion. It exists in several forms--B-100, B-74, B-48, and B-26. After a meal consisting of fat, chylomicrons in which apolipoprotein B-48 was virtually the only apolipoprotein B present appeared in the urine, while apolipoprotein B-100 was the only apolipoprotein B present in the plasma very low-density lipoproteins. Chyluria disappeared two weeks after institution of a low-fat diet. This case illustrates an interesting, rare cause of chyluria. Because of the presence of chyluria, it was also demonstrated that chylomicrons in which apolipoprotein B-48 is virtually the only apolipoprotein B present are a physiologically normal product of the intestine.

Serum-induced enhancement of peripheral blood mononuclear cell mediated cytotoxicity towards human target cells in systemic lupus erythematosus

Sera from 6 out of 18 patients with systemic lupus erythematosus (SLE) were found to be capable of producing marked increases of cytotoxicity in several established human target cell lines when co-cultured with normal human peripheral blood mononuclear cells (PBM). Fractionation studies indicated that the cytotoxicity-inducing activity resided in IgG containing fractions and that the effector cells were Fc-receptor positive. By contrast, sera from 27 normal controls produced little or no cytotoxicity when similarly co-cultured with the same target cell lines and normal PBM. Any slight reactivity that occasionally occurred against a single cell line was, on serum fractionation, either labile or associated with albumen containing fractions. These findings raise the possibility that antibody-dependent cellular cytotoxicity could provide an additional pathogenetic mechanism in patients with SLE.

Immune complexes in systemic sclerosis; detection by C1q binding, K-cell inhibition and Raji cell radioimmunoassays

Thirty-four patients with systemic sclerosis (SS) were investigated for the presence of circulating immune complexes by means of a fluid phase C1q binding assay, K-cell inhibition assay and a Raji cell radioimmunoassay and the results compared with those obtained in 21 patients with systemic lupus erythematosus (SLE) and 52 normal healthy controls. Patients with SS showed an incidence of circulating immune complexes comparable to that found in SLE, with 20 patients (58.5%), giving a positive result with at least one of the assays. The presence of circulating immune complexes in patients with SS was found to be associated with both elevation of serum IgG and IgA levels and extensive visceral involvement by the disease. These findings raise the possibility that circulating immune complexes could be involved in the pathogenesis of SS.

Abnormal 24-hydroxylation of 25-hydroxyvitamin D in the X-linked hypophosphatemic mouse

The effect of extracellular phosphate on the control of 25-hydroxyvitamin D3 24-hydroxylase was studied in normal mice and littermates with X-linked hypophosphatemic rickets (Hyp). 24-Hydroxylase activity and plasma concentrations of 24,25-dihydroxyvitamin D3 were significantly higher in Hyp mice than in normal mice when both groups were fed a normal diet containing 1.22% calcium (Ca) and 0.8% phosphorus (Pi). The differential in 24-hydroxylase activity was exaggerated when serum phosphate was reduced in normal mice by means of a low Pi diet or increased in Hyp mice by means of a high Pi diet. Differences in 24-hydroxylase activity between the two groups of mice were also demonstrated in the presence of varying Pi concentrations in vitro. Thus, in both Hyp and normal mice, 24-hydroxylase activity is influenced in a qualitatively similar manner by serum Pi. Plasma concentrations of 1,25-dihydroxyvitamin D3 were the same in normal and Hyp mice. The data are consistent with the hypothesis that control the renal metabolism of 25-hydroxyvitamin D3 in Hyp mice is reset such tht 24-hydroxylase activity is inappropriate high for the prevailing serum phosphate over a wide range of concentrations.

Energy expenditure in obesity in fasting and postprandial state

Resting metabolic rate (RMR) was determined in 10 obese and 10 nonobese women after an overnight fast and for 3 h after the ingestion of an 800-kcal liquid meal. In the fasting state, absolute energy expenditure in the obese (4.8 +/- 0.2 kJ/min) was 25% greater than in the nonobese (P less than 0.005), but was comparable with the nonobese when expressed in relation to body surface area or lean body mass and was reduced by 20% when expressed per kilogram body weight3/4 (P less than 0.005). Meal ingestion resulted in a 14-16% increase in RMR (postprandial thermogenesis) that was similar in the two groups, so that absolute energy expenditure in the obese remained 22-25% higher than in the nonobese throughout the postprandial period. The estimated overall (fasting and postprandial) increase in resting caloric expenditure in the obese as compared with the nonobese was 350-375 kcal/day.

Progressive vertebral collapse in diffuse angiomatosis

A case of vanishing bone disease is presented, with radiologic, endoscopic, and peritoneoscopic evidence of angiomatous involvement of the bones, surrounding soft tissues, and gastrointestinal tract. The diagnosis was made by a combination of radiologic techniques and endoscopy. Areas of absent bone were shown to opacify after intralymphatic injections of contrast material, providing in vivo demonstrations that these areas of vanishing bone are occupied by abnormal lymphatics. The etiology remains obscure, but our review of the literature suggests that this condition may be one of a large spectrum of disorders due to a basic underlying endothelial dysplasia. The lymphatic system, vascular system, or both may be involved, and the condition may manifest itself as an abnormality of the bones, soft tissues, viscera, or a combination of these.

Hypernatremia induced by maximal exercise

A short burst of intensive exercise (100-m swim lasting one minute and resulting in a 12-fold rise in the level of blood lactate) resulted in frank hypernatremia (serum sodium level, greater than 150 mEq/L) in 30% to 40% of well-trained athletes. In contrast, less intensive exercise (800-m swim lasting ten minutes and resulting in a sevenfold rise in the level of blood lactate) failed to cause a rise in serum sodium level despite comparable elevations in hematocrit reading and serum protein levels. Hypernatremia induced by intensive exercise cannot be explained by losses in body fluid or solute ingestion, but is probably a consequence of a shift of hypotonic fluid from the extracellular to the intracellular compartment. Thus, the mechanism of exercise-induced hypernatremia may be unique, as compared with other clinically recognized forms of hypernatremia.

Cyclic GMP concentration in ovarian tissue after administration of gonadotrophin to prepubertal rats

The weights, protein concentrations, and concentrations of cyclic AMP and cyclic GMP in the ovaries of prepubertal rats have been measured after induction of follicular growth by administration of pregnant mare serum gonadotrophin (PMSG). Three phases of ovarian growth, the follicular growth phase, the preovulatory phase and the luteal phase were investigated. Ovulation was induced by administration of human chorionic gonadotrophin (hCG). During the follicular phase, ovarian weight, protein content and the content of both cyclic AMP and cyclic GMP increased 2-3 days after administration of PMSG. Administration of hCG 65h after PMSG caused a rapid rise in the concentration of cyclic AMP but the concentration of cyclic GMP tended to fall. During the luteal phase the concentrations of both cyclic nucleotides decreased.

Chronic acidosis with metabolic bone disease. Effect of alkali on bone morphology and vitamin D metabolism

Chronic metabolic acidosis and osteomalacia developed in two patients following urinary diversion. Good clinical, biochemical, and histologic responses were seen following treatment with alkali alone (vitamin D was not given), despite the presence of markedly impaired glomerular filtration in one of the patients. Plasma 25-hydroxyvitamin D and 1 alpha, 25-dihydroxyvitamin D concentrations were normal before and during treatment in one of the patients and in the other were low before and normal during treatment. The results show that successful treatment of the osteomalacia of chronic acidosis is not necessarily accompanied by changes in the plasma levels of vitamin D metabolites and that even when marked glomerular dysfunction coexists with acidosis and osteomalacia, treatment with alkali may be more appropriate than the administration of vitamin D analogues.

Influence of mediastinal adenopathy on site and frequency of relapse in patients with Hodgkin's disease

Between April 1969 and July 1979, 267 patients with surgically staged IA-IIB Hodgkin's disease and 31 with clinically staged IIE or IV Hodgkin's disease were treated; disease was limited to the area above the diaphragm. Three separate groups of patients with mediastinal adenopathy were identified. Patients with disease limited to the mediastinum had a favorable prognosis, and treatment with mantle followed by para-aortic irradiation has resulted in 85% relapse-free survival and 100% overall survival at 8 years. Surgically staged patients with large diameter mediastinal adenopathy (greater than 0.33 of the thoracic diameter) have a high relapse rate with radiation therapy alone. The use of combined modality therapy has reduced the risk of relapse in these patients, but the survival remains higher whether MOPP is used initially or at relapse. Clinically staged IIE patients or stage IV patients with extensive extranodal disease limited to the thoracic cavity were treated with chemotherapy and involved- or extended-field irradiation. These patients had a 5-year survival of 66% with large mediastinal adenopathy and 90% with lesser mediastinal disease.

Long-term complications of MOPP chemotherapy in patients with Hodgkin's disease

Two hundred and sixty-three patients in long-term remission from Hodgkin's disease were evaluated for complications of chemotherapy. All patients were interviewed by telephone conversation and reported complications were documented by chart review. Treatment consisted of mantle and para-aortic irradiation in 127 patients, total nodal irradiation (TNI) in 32, TNI and MOPP in 34, and mechlorethamine, vincristine, prednisone, and procarbazine (MOPP) chemotherapy alone or with lesser irradiation in 70. In this study, greater than 90% of the men who received MOPP remain infertile. In contrast, a substantial portion of female patients treated with MOPP chemotherapy have retained normal menses (58%) and only a small proportion have had persistent amenorrhea (9%). Five of eight female patients desiring families after MOPP chemotherapy have had normal children. The risk of developing a major infection requiring hospitalization was greatest in those patients who had received TNI and MOPP chemotherapy. The risk of developing a herpes zoster infection was greatest during or within the first year following therapy and was greatest in those patients receiving combined radiation therapy and chemotherapy. Nearly 100% of patients continue to lead normal lives following treatment for Hodgkin's disease. Only a small percent of patients (1.5%) have been totally disabled following treatment.

Serum antibody and opsonic responses after immunization with pneumococcal vaccine in kidney transplant recipients and controls

We immunized 31 renal transplant patients and 6 control subjects with a pneumococcal vaccine containing 14 capsular polysaccharides. Antibody levels to Streptococcus pneumoniae types 3 and 6A were measured by a radioimmunoassay, and opsonic activity to S. pneumoniae types 3 and 6B was determined by using a luminol-enhanced chemiluminescence phagocytic assay on serum samples obtained before and 1 month after immunization. There was a 10.2-fold and a 2.9-fold increase in antibody to S. pneumoniae type 3 (P less than 0.005) and type 6A (P less than 0.01), respectively, but only a 1.3-fold (P greater than 0.05) and 1.1-fold (P greater than 0.05) increase in opsonic activity. For S. pneumoniae type 3, changes in opsonic activity correlated well with antibody concentration (P less than 0.05). However, for S. pneumoniae type 6, these two tests correlated poorly (P greater than 0.05). This poor correlation suggests that concentrations of antibody to type 6A polysaccharide which are achieved after immunization may not be opsonically active in vitro against S. pneumoniae type 6B.

The role of suppressor T cells in the expression of autoimmune haemolytic anaemia in NZB mice

The course of haemolytic anaemia in NZB mice has been altered by injection of spleen cells from diseased mice into younger ones before the onset of clinical disease. Recipients greater than 6 weeks of age developed early-onset autoimmune disease, recipients less than 6 weeks of age developed early-onset autoimmune disease, recipients less than 6 weeks of age recovered from early induced disease and showed a delay in the onset of spontaneous disease as compared with untreated NZB mice. This delay was due to the induction in the young mice of splenic suppressor cells. These cells were non-adherent to nylon wool and suppressed autoantibody formation on transfer to old Coombs-positive recipients. Suppressor cells active against autoantibody formation on transfer to old Coombs-positive recipients. Suppressor cells active against autoantibody-producing cells may be present in young untreated NZB mice, but not in sufficient numbers to suppress autoantibody production on adoptive transfer to Coombs-positive; however, when Ig-negative cells from the spleens of very young NZB mice were transferred together with Ig-positive cells from Coombs-positive donor mice to irradiated NZB recipients, the autoantibody production of the transferred B cells was suppressed in some cases. Suppressor cell activity could also be induced by co-culture of spleen cells from old Coombs-positive and young Coombs-negative NZB mice in vitro.

On the mechanism by which veratridine causes a calcium-independent release of gamma-aminobutyric acid from brain slices

1 The mechanisms by which veratridine increases the release of gamma-aminobutyric acid (GABA) from brain slices have been studied.2 Exposure of superfused cerebro-cortical, nigral or cerebellar slices to veratridine (5 muM) or KCl (50 mM) caused large increases in the efflux of [(3)H]-GABA.3 Reduction of the external Ca concentration [Ca](o) to zero had strikingly different effects on the veratridine and K-evoked release of [(3)H]-GABA. The K-evoked release from all three areas was greatly reduced in Ca-free medium, but the veratridine-evoked release from cerebeller slices was not affected, and the release of [(3)H]-GABA from cortical and nigral slices was increased three fold. The potentiation of the veratridine evoked release of GABA which occurred in Ca-free medium was not due to the reduction in divalent ions, because it still occurred in medium in which the Ca was replaced by an equivalent amount of Mg.4 The veratridine-evoked release of [(14)C]-glycine from slices of spinal cord was also significantly increased in Ca-free medium. In contrast, the release of cortical [(3)H]-noradrenaline and [(14)C]-acetylcholine caused by the alkaloid was greatly diminished in Ca-free medium.5 The veratridine but not the K-evoked release of [(3)H]-GABA was abolished when the external Na concentration [Na](o) was reduced to zero and by tetrodotoxin (TTX) (0.2 muM). Cl-free medium did not affect the veratridine-evoked release of [(3)H]-GABA or its potentiation by Ca-free medium.6 Exposure of the tissue to depolarizing concentrations of external K ([K](o) = 120 mM) did not abolish the veratridine evoked release of [(3)H]-GABA or its potentiation by Ca-free medium.7 Pre-incubation of cortical slices with L-2,4, diaminobutyric acid (DABA), or substitution of Na in the superfusion medium with Li, did not affect the veratridine-evoked release of [(3)H]-GABA, indicating that the alkaloid does not stimulate GABA efflux by a carrier-mediated transport process.8 Exposure of the tissue to ruthenium red (10 muM) increased the veratridine evoked release of [(3)H]-GABA in both normal and in Ca-free medium but almost abolished the K-evoked release.9 It is suggested that veratridine causes GABA release by increasing the permeability of the nerve terminals to Na. In normal medium, the resulting influx of Ca(2+) ions through voltage-dependent Ca(2+) channels may be involved in triggering the release of GABA. However, a major part of the GABA efflux appears to be triggered by the release of Ca(2+) ions from intraterminal mitochondria, which results from the increase in[Na](i). Since Ca(2+) ions antagonize the action of veratridine, the potentiation of the drug-evoked release of GABA that occurs in Ca-free medium, might be due to the absence of the antagonistic Ca(2+) ions. The resulting greater increase in Na entry and [Ca](i) caused by Ca release from intracellular stores, must presumably more than balance the contribution normally made by any influx of extracellular Ca(2+).

Impaired response of plasma renin activity to tilting after renal transplantation

1. Changes in plasma renin activity, plasma noradrenaline, pulse rate and blood pressure after tilting were measured in normal subjects and in patients with renal transplants. 2. There was a marked difference between the renin responses in the two groups, the increases in plasma renin activity in the control subjects being much greater than those in the transplanted patients. 3. Activation of the sympathetic nervous system after tilting, as indicated by changes in pulse rate, blood pressure and plasma noradrenaline, was similar in the two groups. 4. We conclude that the ability of the transplanted kidney to increase plasma renin activity after tilting is impaired, probably as a result of sympathetic denervation of the kidney during transplantation. The results suggest a dominant role of the sympathetic nervous system in the mediation of renin release after tilting.