Secretion of parathyroid hormone by abnormal human parathyroid glands in vitro. The secretory response of abnormal parathyroid glands obtained surgically from eleven patients with primary and secondary hyperparathyroidsm was tested in vitro. Short term flask studies were used to measure release of parathyroid hormone (PTH) at high (3.0 mM) and low (0.5 mM) calcium. Of eight adenomas, all but one showed increased release of hormone when exposed to low calcium ("responsive to calcium"), the degree of stimulation at three hours ranging from 15 to 209%. By comparison, two normal human glands were stimulated an average of 180%. Glands from three patients with secondary hyperplasia were also responsive to calcium. Thus, parathyroid glands from patients with primary and secondary hyperparathyroidism were characterized by a spectrum of responsiveness to calcium, and absolute "autonomy" was unusual. Even at high calcium concentrations, hormone release persisted at a low but definite level ("basal secretion"). The total number of functioning parathyroid cells is therefore a principal determinant in the oversecretion of PTH in hyperparathyroidism.


Hypoparathyroidism: a possible cause of osteomalacia . A 17 year old man with longstanding hypocalcemia and hyperphosphatemia presented with incapacitating bone pain and progressive weakness nad bowing of the legs. The serum abnormalities were due to idiopathic hypoparathyroidism as evidenced by a decreased serum concentration of parathyroid hormone and an appropriate rise in urinary cyclic AMP and phosphate excretion, and serum calcium concentration, in response to exogenously administered parathyroid extract. The serum concentration of 1,25-dihydroxycholecalciferol was appropriately decreased. The bone findings were due to osteomalacia as documented by physical findings, bone roentgenograms, and bone biopsy. Normal renal tubular function, blood pH, and serum concentration of 25-hydroxycholecalciferol and elevated serum alkaline phosphatase excluded the common causes of osteomalacia. The data are consistent with the hypothsis that lack of parathyroid hormone causes both hypocalcemia and a decreased serum concentration of 1,25-dihydroxycholecalciferol which, in turn, limit the availability of calcium and cause defective synthesis of bone matrix resulting in abnormal mineralization.


Effect of simultaneous potassium and saline loading on plasma aldosterone levels. To assess the relative importance of the renin-antiotensin system and potassium in the acute regulation of aldosterone secretion in the salt depleted state, normal subjects were infused with an asotonic saline solution containing potassium chloride (KCl) and the responses compared to the infusions of isotonic saline (500 ml/h) and KCl alone (20 mEq K+/h). Subjects were studied recumbent in balance on a 10 mEq sodium/100 mEq potassium diet. The rates of infusing saline and potassium were selected to produce comparable but opposite effects on the levels of plasma aldosterone. As plasma renin activity (PRA) declined and plama potassium increased during the combined saline-KCl infusions, plasma aldosterone levels appeared to be the arithmetic sum of the changes in these parameters. In fact, the calculated changes in aldosterone levels per unit change in PRA or potassium from each infusion alone, correlated well with the observed levels, further supporting an additive relationship. These data support the concept that in the salt depleted state the renin-angiotensin system and potassium are equally important in the acute regulation of plasma levels of aldosterone.


Plasma renin and angiotensin II measurement in hypertensive and normal subjects: correlation of basal and stimulated states. Plasma renin activity (PRA) and angiotensin II (AII) were measured in peripheral venous samples obtained from the following subgroups: normal ambulant subjects (n = 61): normal subjects after 7 days treatment with a thiazide diuretic (n = 27): hypertensive subjects before and after a thiazide diruretic (n = 35); severely hypertensive subjects after diazoxide treatment (n = 14) and untreated severely hypertensive subjects (n = 27). In addition aortic (n = 27) and renal vein (n =48) samples were taken from the latter group during investigation of possible renovascular hypertension. Values for PRA and AII were clearly correlated in all groups. Further, calculated regression lines of PRA upon AII did not differ significantly from that calculated for normal subjects, with the exception of the intercept of the diazoxide treated group. However, when the regression line for renal venous samples was compared with that calculated for peripheral venous samples of all other subjects (199), there was a relative increase in the ratio of PRA to AII at all values. Thus, except in the renal vein, measurement of AII and PRA appear to reflect changes in activity of the renin-angiotensin system equally well and there is no support for the view that there is a discrepancy between measured AII and PRA in peripheral venous blood in the clinical situations examined here.


The simultaneous radioimmunoassay of seven steroids in human spermatic and peripheral venous blood. Seven unconjugated neutral steroids, including testosterone and some of its precursors and metabolites, were measured in the peripheral and spermatic venous blood males, employing specific radioimmunoassays after the fractionation of steroids on Lipidex-5000 (hydroxyalkoxypropyl Sephadex) microcolumns. Respective mean concentrations (ng/ml) and ranges of steroids estimated in peripheral and spermatic venous blood in all groups of patients were as follows: pregnenolone, 0.71 (0.29-2.39) and 10.97 (0.83-30.1); progesterone, 0.31 (0.02-0.57) and 10.17 (1.51-33.24); 17 alpha-hydroxyprogesterone, 1.04 (0.48-2.20) and 37.33 (1.68-141.00); androstenedione, 1.01 (0.26-2.65) and 11.87 (0.97-30.18); testosterone, 3.84 (0.63-10.64) and 255.1 (2.85-619.1); 5alpha-dihydrotestosterone, 0.19 (0.07-0.28) and 3.74 (0.04-9.71); androsterone, 0.27 (0.12-0.47) and 0.97 (0.20-2.15). Concentrations are similar to those estimated by mass spectrometry and protein binding assays, except for androsterone which has not previously been measured in this context. The low, but significant testicular secretion of both 5alpha-hydrotestosterone and androsterone suggests that these two steroids are testicular androgen metabolites, and that androgen metabolism in this tissue may be monitored by way of their measurement in spermatic vein blood.


Hyperprolactinemia in girls with idiopathic precocious puberty under prolonged treatment with cyproterone acetate. Pasma prolactin response to the acute injection of sulpiride (1.5 mg/k BW im) was measured at 0800-0900h in 4 girls with idiopathic precocious puberty before and after 6 to 11 months of continuous therapy with 50 mg daily of cyproterone acetate (CA) orally administered. Two additional girls were examined after 26 and 28 months of therapy, respectively. Mean baseline prolactin concentrations were significantly higher in untreated girls with precocious puberty as compared to that of normal controls of the same chronological age and of a comparable degree of sexual maturation (14.5 +/- 1.9 SE vs. 7.4 +/- 1.8 SE ng/ml and vs. 9.5 +/- 1.8 ng/ml, respectively; P less than .02). Treatment with CA caused a significant further increase of plasma prolactin concentration (P less than .02 as compared to pre-treatment values); no correlation was observed between prolactin concentration and duration of treatment. No significant change in the integrated areas of prlactin response to sulpiride occurred after prolonged CA therapy. The results suggest that in idiopathic precocious puberty the action of CA upon the hypothalamic-hypophyseal complex is not solely antigonadotropic and that prolactin secretion is enhanced in patients given this drug.


Thyroxine concentration in human milk.

Thyroxine concentration in human milk. Thyroxine (T4) concentrations were measured by RIA in 37 milk samples from 19 healthy eutryroid mothers, obtained between 3-165 days postpartum. The mean milk T4 concentration in the first week postpartum was 0.38 +/- 0.07 microgram/100 ml (mean +/- SEM). The mean T4 concentrations between 8 and 48 days rose to 4.27 +/- 0.50 microgram/100 ml (mean +/- SEM), and decreased to 1.11 +/- 0.25 microgram/100 ml (mean +/- SEM) after 50 days postpartum. The data suggest that human milk can provide a significant exogenous source of T4 to the infant. In the hypothyroid infant, the amount of T4 in human milk may delay clinical recognition of the disease. Although this exogenous source of T4 may alleviate the disease, it is insufficient to prevent the detrimetal effects of hypothyroidism.


Inhibition of the renin-aldosterone response to furosemide by indomethacin. In 12 human volunteers, indomethacin was shown to inhibit renal prostaglandin produciton as reflected by RIA of urinary PGE2. The increases in plasma renin activity and plasma and urinary aldosterone following acute furosemide challenge were markedly blunted in the presence of indomethacin. In light of recent development indicating an intimate relationship between prostaglandins and renin release, these results provide further evidence for a pivotal role of renal prostaglandins in modulating the responsiveness of the renin-angiotensin-aldosterone axis in Mam.


Hypercalcemic hyperparathyroidism in hypophosphatemic rickets. A 25-year-old white woman with sporadic hypophosphatemic rickets presented with a 7 year history of chronic mild hypercalcemia, osteitis fibrosa cystic and hypercalcemic nephropathy. Serum immunoreactive parathyroid hormone was elevated by greater than 100-fold and a 3.5 g parathyroid tumor was found at operation. Survey of the literature reveals that of 9 previous cases in which hypercalcemic hyperparathyroidism occurred in association with hypophosphatemic rickets, only two had classical x-linked familial hypophosphatemic rickets. It appears more than likely that this unusual combination of skeletal diseases represents the chance occurrence of primary hyperparathyroidism in patients with underlying x-linked familial hypophosphatemic rickets rather than a complication of phosphate therapy.


The influence of severe illness on gonadotropin secretion in the postmenopausal female. Severe weight loss in amenorrheic premenopausal women may significantly depress gonadotropin secretion. Gonadotropin leves were studied in 111 postmenopausal women to determine if weight loss and cachexia could similarly affect gonadotropin function. Thirty-three healthy ambulatory postmenopausal women and twenty-seven healthy hospitalized women admitted electively were found to have a wide range of elevated values, whose mean did not differ significantly. Mean levels for both LH and FSH were significantly suppressed (P less than .005) in severely ill postmenopausal women both with or without weight loss. (formula: see text) Recovety from illness in six patients was associated with a rapid rise in FSH levels while LH remained depressed. Two severely ill patients studied over a 6 h period revealed constant depression of both gonadotropins without the characteristic pulses seen in four normal control postmenopausal women. These results indicate that gonadotropin secretion may be suppressed in severely ill postmenopausal women whether weight loss is present of not, and the central nervous regulatory mechanism responsible for intermittant release of gonadotropins is impaired. The disparate FSH and LH recovery indicates that if separate gonadotrophs exist, the LH gonadotroph is more severely affected than the FSH gonadotroph and/or that the responsible regulatory mechanisms are different.


Comparative evaluation of three different commercial blood culture media for recovery of anaerobic organisms. A comparison of three different commercial media was made to assess their recovery of anaerobic organisms from the blood stream. The three media used were the 50-ml brain heart infusion broth with added CO2 (Pfizer), the 50-ml Thiol broth with added CO2 (Difco), and the 50-ml prereduced, supplemented peptone broth in a Vacutainer tube with added CO2 (Becton-Dickinson). During a period of 17 consecutive months, 12,216 specimens of blood were processed with each broth. Aerobic or anaerobic bacteria were recovered from 913 specimens (7%). Seventy-four specimens (8%) of the total positive cultures contained anaerobic organisms. When potential contaminants were removed from the totals, 7% of the positive cultures contained anaerobic organisms and 7% of the patients with positive cultures had bacteremia with anaerobic bacteria. Of the three commercial blood culture media studied, the prereduced, supplemented peptone broth recovered more anaerobic organisms than did either the brain heart infusion or Thiol broths.


Pathogenicity of nonpigmented cultures of Chromobacterium violaceum. Nonpigmented cultures of Chromobacterium violaceum have been found to be similar to pigmented cultures in their virulence for mice and the pathology of their infections. Clinicians and microbiologists should be prepared to consider nonpigmented C. violaceum in their differential diagnoses of infections caused by gram-negative bacteria. The laboratorian who is not aware of this possibility is likely to erroneously identify nonpigmented strains of C. violaceum as members of closely associated genera, particularly Aeromonas. It is known that violet pigmentation is not an essential feature or an exclusive character of the genus Chromobacterium. This study has also shown that pigmentation of C. violaceum is not related to its pathogenicity or to the pathology of its infections.


Bacteriocin typing of streptococcal isolates from endocarditis. A typing system based on bacteriocin production and sensitivity for Streptococcus sanguis strains was devised. Bacteriocin producer strains were grown (37degrees C) anaerobically on brain heart infusion-yeast extract agar for 18 h. Bacteriocin indicator strains were suspended to molten brain heart infusion-yeast extract agar and then overlayed onto the producer strain. After an additional 18 to 24 h of incubation, zones of bacteriocin inhibition were recorded. After establishment of the typing system, eight Streptococcus strains from bacterial endocarditis patients were characterized by the typing system. Four patient strains had identical bacteriocin reduction patterns but could be differentiated by differences in their bacteriocin sensitivity. Two isolates from the same patient had identical production and sensitivity patterns. By including both bacteriocin production and bacteriocin sensitivity, all seven epidemiologically unrelated isolates could be differentiated. On the basis of these results, there does not appear to be a correlation between bacteriocin production and infectivity, but the usefulness of the application of a typing system to a clinical situation is demonstrated.


Salt-dependent hemagglutination with Bunyaviridae antigens. Hemagglutination titers of antigens from nine serologic groups of Bunyaviridae were increased by hypertonic NaCl. The effect was predominantly on sonically treated antigens and was additive with the increase from sonic treatment alone.


Selective release of archidonic acid from the phospholipids of human platelets in response to thrombin. Arachidonic acid is unique amongst human platelet fatty acids in that it is the precursor of prostaglandins and thromboxanes. Since a number of these oxygenated products of arachidonic acid have potent effects on platelet function, an understanding of the metabolsim of their precursor is important. Human platelets have a mechanism for incorporating arachidonic acid from plasma into their phospholipids and, in response to thrombin, they reveal mechanisms for hydrolyzing this arachidonic acid from platelet phosphatidylcholine and phosphatidylinositol. This report deals with the specificity of these mechanisms. The present studies show that human platelets contain phospholipase A2 activities that preferentially release arachidonic acid. One of these activities specifically utilizes 1-acyl-2-arachidonyl-phosphatidyl-choline. Another utilizes platelet phosphatidylinositol and/or phosphatidylserine, both of which are highly enriched with arachidonic acid.


The rate of synthesis of glycosaminoglycans and collagen by fibroblasts cultured from adult human liver biopsies. Adult human liver biopsies were cultured from normal, alcoholic hepatitis, chronic active hepatitis, fibrosis plus alcoholic hepatitis (active cirrhosis), inactive cirrhosis, and drug hepatitis. The synthesis of collagen was estimated in cultures from 58 livers by measuring the conversion of [(14)C]proline to the [(14)C]hydroxyproline of collagen; that of glycosaminoglycans in cultures from 57 livers by the incorporation of [(3)H]acetate and (35)SO(4) into glycosaminoglycans (GAG). The synthesis of procollagen was increased only in cultures from alcoholic hepatitis, both in the pulse medium (P < 0.05) and in the chase medium (P < 0.02). The synthesis of insoluble collagen was increased in cultures from chronic (active) hepatitis (P < 0.01), fibrosis plus alcoholic hepatitis (active cirrhosis) (P < 0.001), and inactive cirrhosis (P < 0.05). Essentially all radioactive GAG was soluble in culture media. The predominant GAG were chondroitin-4 or -6-SO(4). The synthesis of GAG was increased only in cultures from fibrosis plus alcoholic hepatitis (active cirrhosis) both in the pulse medium (P < 0.01) and chase medium (P < 0.001). The data indicate that in the absence of immuno-competent cells or their secretory products, tissue cultures from livers showing biopsy evidence of active fibrosis in vivo may demonstrate increased synthesis of collagen and GAG in vitro. Increased (soluble) procollagen synthesis in cultures from alcoholic hepatitis was not associated with histologically demonstrable overt hepatic fibrosis in vivo, nor was it associated with increased GAG synthesis in vitro. No significant difference was demonstrable in collagen or GAG synthesis in paired cultures which contained either 300 mg/dl ethanol or 3.75 mg/dl methylprednisolone compared to their respective controls.


Decreased fluidity of red cell membrane lipids in abetalipoproteinemia. Acanthocytic red cells in patients with abetalipoproteinemia are morphologically similar to the red cells in spur cell anemia. Fluidity of membrane lipids is decreased in spur cells due to their excess cholesterol content. Acanthocyte membranes have an increased content of sphingomyelin and a decreased content of lecithin. To assess the effect of this abnormality of acanthocyte membrane lipid composition on membrane fluidity, we studied red cells from five patients with abetalipoproteinemia and four obligate heterozygote family members. Membrane fluidity was measured in terms of microviscosity ( eta) at 37 degrees C, assessed by means of the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene. It was increased from 3.2+/-0.1 poise in normals to 4.01-4.14 poise in acanthocytes. This was associated with an increase in the sphingomyelin/lecithin ratio from 0.84+/-0.08 in normals in 1.45-1.61 in acanthocytes. The eta of acanthocyte membranes was not influenced by the degree of vitamin E deficiency. Similar changes in eta were observed in liposomes prepared from red cell lipids. Heterozygotes had normal sphingomyelin/lecithin ratios and normal values for eta. The flow activation energy for viscosity, a measure of the degree of order in the hydrophobic portion of the membrane, was decreased from 8.3 kcal/mole in normal red cells to 7.2 kcal/mole in acanthocytes, indicating that acanthocyte membrane lipids are more ordered. Variations in the sphingomyelin/lecithin mole ratio of liposomes prepared from brain sphingomyelin and egg lecithin with equimolar cholesterol caused similar changes in both eta and activation energy. The deformability of acanthocytes, assessed by means of filtration through 3-mum filters, was decreased. These studies indicate that the increased sphingomyelin/lecithin ratio of acanthocytes is responsible for their decreased membrane fluidity. As in spur cells and in red cells enriched with cholesterol in vitro, this decrease in membrane fluidity occurs coincidentally with an abnormality in cell contour and an impairment in cell deformability.


Big and little forms of osteoclast activating factor. We have further characterized osteoclast activating factor (OAF) using a bioassay for bone resorption which utilizes the release of previously incorporated (45)Ca from fetal rat long bones in organ culture. When supernatant media from activated leukocyte cultures were concentrated on Amicon PM10 membranes (assigned molecular weight cutoff 10,000 daltons) and chromatographed on Sephadex G-50 columns, the bone-resorbing activity eluted between the molecular weight markers chymotrypsinogen (25,000 daltons) and cytochrome c (12,500 daltons). This peak of biological activity has been called big OAF. When filtrates from the PM10 membranes were concentrated on Amicon UM2 membranes (assigned molecular weight cutoff 1,000 daltons) and chromatographed on Sephadex G-50 columns, some of the biological activity eluted between the molecular weight markers chymotrypsinogen and cytochrome c (big OAF), but there was a separate peak of biological activity which eluted with [(3)H]proline (140 daltons). This second peak has been called little OAF. Little OAF was eluted from Bio-Gel P6 columns between the molecular weight markers calcitonin (approximately 3,500 daltons) and vitamin B(12) (1,330 daltons), but was retained by Spectrapor dialysis tubing (nominal molecular weight cutoff 3,500 daltons). Big OAF was converted to little OAF by equilibration in 1 M NaCl or 2 M urea. Little OAF was self-associated back to big OAF by equilibration in buffers of low ionic strength (Tris-HCl 10-50 mM). Little OAF was extracted into the organic phase in ethyl acetate after acidification of the sample to pH 3.5. The biological activity remained in the aqueous phase after ethyl acetate extraction at pH 7.5-8.4. Little OAF has been purified more than 6,000-fold compared with the original material so that bone-resorbing activity is maximal in a sample with a protein concentration of 80 ng/ml.


Urinary kallikrein and plasma renin activity as determinants of renal blood flow. The influence of race and dietary sodium intake. We investigated the relationship of the kallikrein-kinin system and the renin-angiotensin system in the regulation of blood pressure, salt and water excretion, and renal blood flow. Normotensive and hypertensive black and white men were studied during unresticted sodium intake as well as on a 10-meq/day sodium intake; potassium intake was held constant throughout the study (80 meq/day). During unrestricted sodium intake, urinary kallikrein activity was greater in white normotensives than white hypertensives or black normotensives. There was no difference (P greater than 0.05) between white and black hypertensives or between black normotensives and black hypertensives. All groups had greater urinary kallikrein activity on low sodium vs. unrestricted sodium intake, but the increase in black hypertensives was small, and they excreted significantly less kallikrein than the ogher groups on the low sodium diet. Plasma renin activity showed similar increments after sodium restriction in all groups. Urinary kallikrein activity correlated with renal blood flow in all groups except the black normotensives on low sodium intake. Renal blood flow could be correlated uniformly with log (urinary kallikrein activity/supine plasma renin activity) in all groups on either diet. Urinary sodium and potassium excretion and urine volume were not different among the groups. We conclude: (a) important racial differences exist in urinary kallikrein activity that are unrelated to sodium or potassium excretion or urine volume; (b) dietary sodium restriction further delineates racial differences and suggests alternative pathophysiologic mechanisms for huma hypertension; (c) urinary kallikrein activity correlates with renal blood flow; and (d) our data support the concept that the kallikrein-kinin system and the renin-angiotensin system contribute to the regulation of renal blood flow and may account for racial differences in renal vascular resistance.


Peripheral airways as a determinant of ventilatory function in the human lung. We have investigated the morphological differences responsible for the variability in two tests of pulmonary function, maximal expiratory flow rates (MEF) and the frequency dependence of dynamic compliance (CDYN ratio). Functional measurements were obtained from 53 normal and minimally diseased postmortem human lungs. Morphological measurements performed on these same lungs included airway diameter at three levels in the bronchial tree, the amount of bronchial gland mass, and the alveolar surface to volume ratio. Multiple regression analysis suggests that the diameter of the peripheral conduction airways (membranous bronchioles) is the major morphological determinant for both MEF and the CDYN ratio in lungs at any particular age. Age-dependent changes in both functional tests were associated primarily with differences in the alveolar surface to volume ratio. Minimal emphysema and a lesion associated with cigarette smoking, respiratory bronchiolitis, have no demonstrable effect on either MEF or the CDYN ratio. These studies provide further evidence that the peripheral conducting airways are a major determinant of ventilatory function in the normal human lung.


Mechanisms of the puromycin-induced defects in the transglomerular passage of water and macromolecules. To investigate the mechanism(s) of increased filtration of serum proteins after glomerular injury, polydisperse samples of uncharged [(3)H]dextran (D) or anionic [(3)H]dextran sulfate (DS) were infused into 14 control and 16 puromycin aminonucleoside- (PAN) treated Munich-Wistar rats. Fractional clearances of D or DS ranging in radius from 18 to 42A were determined in these rats, together with direct measurements of the forces governing the glomerular filtration rate of water. Whole kidney and single nephron glomerular filtration rates were approximately 40% lower in PAN-treated rats, relative to controls, due mainly to a marked reduction in the glomerular capillary ultrafiltration coefficient and, to a lesser extent, to a small reduction in glomerular plasma flow rate as well. In PAN-treated rats, as in normal controls, inulin was found to permeate the glomerular capillary wall without measurable restriction, and both D and DS were shown to be neither secreted nor reabsorbed. Fractional clearances of uncharged D were reduced after PAN administration, falling significantly for effective D radii from 22 to 38A. Utilizing a theory based on macromolecular transport through pores, these results indicate that in PAN-treated rats, effective pore radius is the same as in controls, approximately 44A. In PAN nephrosis, however, the ratio of total pore surface area/pore length, a measure of pore density, is reduced to approximately one-third that of control, due very likely to a reduction in filtration surface area. In contrast to the results with uncharged D, fractional clearances of DS were found to increase after PAN administration for all DS radii studied. These results with D and DS suggest that proteinuria in PAN nephrosis is due, not to an increase in effective pore radius or number of pores, but rather to a diminution of the electrostatic barrier function of the glomerular capillary wall, thereby allowing increased passage of polyanions such as DS and albumin.


Effects of acetazolamide on proximal tubule C1, Na, and HCO3 transport in normal and acidotic dogs during distal blockade. It has been suggested that the establishment of a tubular fluid to plasma chloride gradient in the late proximal tubule by the reabsorption of bicarbonate (and other anions) in the early proximal tubule is responsible for a significant part of sodium chloride and water reabsorption in the proximal tubule. In the present study the effects of acetazolamide on proximal tubule water and electrolyte excretion were examined in 6 normal dogs and 10 chronic ammonium chloride-loaded dogs during distal blockade produced by ethacrynic acid and chlorothiazide administration. During distal blockade control urine/plasma osmolality and urine/plasma sodium were close to unity in all experiments. Urine/plasma chloride and urine/plasma bicarbonate were 1.21+/-0.02 and 0.75+/-0.07 in normal and 1.24+/-0.01 and 0.04+/-0.01 in acidotic dogs, respectively. After the administration of acetazolamide (20 mg/kg i.v.), there was a significant increase in urine flow, absolute and fractional excretion of sodium, bicarbonate, and chloride in all animals. Associated with these effects, urine/plasma osmolality and urine/plasma sodium remained unchanged but urine/plasma chloride decreased significantly to 1.15+/-0.01 in normal and to 1.19+/-0.01 in acidotic dogs. In acidotic dogs there was a significant correlation between the increase in bicarbonate, sodium, or chloride excretion after acetazolamide and the plasma bicarbonate level (range 6.8-12.5 meq/liter). These data demonstrate a significant effect of acetazolamide on bicarbonate, sodium, and chloride reabsorption in the proximal tubule even in the face of severe acidosis. Moreover, the data suggest that the decrease in chloride reabsorption (and accompanying sodium) after acetazolamide is related to the decrease in bicarbonate reabsorption and the associated decrease in the transtubular chloride gradient.


Activation and function of human Hageman factor. The role of high molecular weight kininogen and prekallikrein. The activation and function of surface-bound Hageman factor in human plasma are dependent upon both high molecular weight (HMW) kininogen and prekallikrein. HMW kininogen does not affect the binding of Hageman factor to surfaces, but it enhances the function of surface-bound Hageman factor as assessed by its ability to activate prekallikrein and Factor XI. The initial conversion of prekallikrein to kallikrein by the surface-bound Hageman factor in the presence of HMW kininogen is followed by a rapid enzymatic activation of Hageman factor by kallikrein. The latter interaction is also facilitated by HMW kininogen. Kallikrein therefore functions as an activator of Hageman factor by a positive feedback mechanism and generates most of the activated Hageman factor during brief exposure of plasma to activating surfaces. HMW kininogen is a cofactor in the enzymatic activation of Hageman factor by kallikrein and it also augments the function of the activated Hageman factor generated. The stoichiometry of the Hagman factor interaction with HMW kininogen suggests that it enhances the activity of the active site of Hageman factor. Since HMW kininogen and prekallikrein circulate as a complex, HMW kininogen may also place the prekallikrein in an optimal position for its reciprocal interaction with Hageman factor to proceed. The surface appears to play a passive role upon which bound Hageman factor and the prekallikrein-HMW kininogen complex can interact.


Cold urticaria. Recognition and characterization of a neutrophil chemotactic factor which appears in serum during experimental cold challenge. Sera were obtained from the venous effluents of cold-challenged arms of patients with idiopathic cold urticaria without plasma or serum cryoproteins; these sera exhibited increased neutrophil chemotactic activity without alterations of the complement system. A two- to fourfold augmentation of the base-line neutrophil chemotactic activity of serum from the immersed extremity began within 1 min, peaked at 2 min, and returned to base-line levels within 15 min, whereas there was no change in the serum chemotactic activity in the control arm. The augmented chemotactic activity in the serum specimens from the challenged arm of each patient appeared in a high molecular-weight region, as assessed by the difference in activity recovered after Sephadex G-200 gel filtration of the paired lesional and control specimens. Sequential purification of this high molecular-weight activity by anion- and cation-exchange chromatography revealed a single peak of activity at both steps. The partially purified material continued to exhibit a high molecular weight, being excluded on Sepharose 4B, and had a neutral isoelectric point. The partially purified material showed a preferential chemotactic activity for neutrophilic polymorphonuclear leukocytes, required a gradient for expression of this function, and exhibited a capacity to deactivate this cell type. This active principle, termed high molecular-weight neutrophil chemotactic factor, exhibited a time-course of release that could be superimposed upon that of histamine and the low molecular-weight eosinophil chemotactic factor and may represent another mast cell-derived mediator.


Spatial and nonspatial influences on the TG-ST segment deflection of ischemia. Theoretical and experimental analysis in the pig. Spatial and nonspatial aspects of TQ-ST segment mapping were studied with the solid angle theorem and randomly coded data from 15,000 electrograms of 160 anterior descending artery occlusions each of 100-s duration performed in 18 pigs. Factors analyzed included electrode location, ischemic area and shape, wall thickness, and increases in plasma potassium (K(+)). Change from control in the TQ-ST recorded at 60 s (DeltaTQ-ST) was measured at 22 ischemic (IS) and nonischemic (NIS) epicardial sites overlying right (RV) and left (LV) ventricles. In IS regions, DeltaTQ-ST decreased according to LV > septum > RV and LV base > LV apex. In NIS regions, LV sites had negative (Neg) DeltaTQ-ST which increased as LV IS border was approached. However, RV NIS had positive (Pos) DeltaTQ-ST which again increased as RV IS border was approached. With large artery occlusion IS area increased 123+/-18%, DeltaTQ-ST at IS sites decreased (-38.1+/-3.6%), and sum of DeltaTQ-ST at IS sites increased by only 67.3+/-10.3%. In RV NIS Pos DeltaTQ-ST became Neg. With increased K(+), DeltaTQ-ST decreased proportionately to log K(+) (r = 0.97+/-0.01) at IS and NIS sites on the epicardium and precordium. TQ-ST at 60 s was obliterated when K(+) = 8.7+/-0.2 mM. All findings were significant (P < 0.005) and agreed with the solid angle theorem. Thus, a transmembrane potential difference and current flow at the IS boundary alone are responsible for the TQ-ST. Nonspatial factors affect the magnitude of transmembrane potential difference, while spatial factors alter the position of the boundary to the electrode site.


Prostaglandin biosynthesis by rabbit renomedullary interstitial cells in tissue culture. Stimulation by angiotensin II, bradykinin, and arginine vasopressin. Rabbit renomedullary interstitial cells were isolated and grown in tissue culture. These cells synthesize 0.8 ng of prostaglandin E2 (PGE2) per microgram cellular protein per hour in monolayer tissue culture; prostaglandins A2 and F2alpha (PGA2 and PGF2alpha) biosynthesis was 10 and 5% of PGE2 biosynthesis, respectively. Arachidonic acid markedly stimulated the production of PGE2 and PGF2alpha, with conversion rates of 0.24 and 0.02%/h, respectively. Angiotensin II, hyperosmolality, bradykinin, and arginine vasopressin each stimulated PGE2 biosynthesis; maximum stimulation was 20, 3.7, 3.6, and 3.2 times basal production, respectively. PGE2 biosynthesis by the renomedullary interstitial cells was inhibited by isoproterenol, potassium, nonsteroidal anti-inflammatory agents (indomethacin, naproxen, ibuprofen, suprofen, meclofenamate, and acetylsalicylic acid), mepacrine (a phospholipase inhibitor), hydrocortisone, and cortisone. The rabbit renomedullary interstitial cell in tissue culture is a model system for the study of hormonal regulation of PGE2 biosynthesis.


The occurrence and effects of human vitamin E deficiency. A study in patients with cystic fibrosis. The role of vitamin E in human nutrition was studied by investigation of patients with cystic fibrosis (CF) and associated pancreatic insufficiency. Vitamin E status was assessed by measurement of the plasma concentration of the principal circulating isomer, alpha-tocopherol. Results of such determinations in 52 CF patients with pancreatogenic steatorrhea revealed that all were deficient in the vitamin. The extent of decreased plasma tocopherol varied markedly but correlated with indices of intestinal malabsorption, such as the serum carotene concentration and percentage of dietary fat absorbed. Supplementation with 5-10 times the recommended daily allowance of vitamin E in a water-miscible form increased the plasma alpha-tocopherol concentrations to normal in all 19 CF patients so evaluated. Studies on the effects of vitamin E deficiency focused on possible hematologic alterations. An improved technique was developed to measure erythrocyte hemolysis in vitro in the presence of hydrogen peroxide. While erythrocyte suspensions from control subjects demonstrated resistance to hemolysis during a 3-h incubation, all samples from tocopherol-deficient CF patients showed abnormal oxidant susceptibility, evidenced by greater than 5% hemoglobin release. The degree of peroxide-induced hemolysis was related to the plasma alpha-tocopherol concentration in an inverse, sigmoidal manner. The possibility of in vivo hemolysis was assessed by measuring the survival of (51)Cr-labeled erythrocytes in 19 vitamin-E deficient patients. A moderate but statistically significant decrease in the mean (51)Cr erythrocyte half-life value was found in this group. Measurement of erythrocyte survival before and after supplementation of 6 patients with vitamin E demonstrated that the shortened erythrocyte lifespan could be corrected to normal with this treatment. Other hematologic indices in deficient subjects, however, were normal and did not change upon supplementation with vitamin E. It is concluded that CF is invariably associated with vitamin E deficiency, provided that the patient in question has pancreatic achylia and is not taking supplementary doses of tocopherol. Concomitant hematologic effects consistent with mild hemolysis, but not anemia, occur and may be reversed with vitamin E therapy. Patients with CF should be given daily doses of a water-miscible form of vitamin E to correct the deficiency.


Intestinal calcium absorption in exogenous hypercortisonism. Role of 25-hydroxyvitamin D and corticosteroid dose. Pharmacologic doses of corticosteroids impair intestinal calcium absorption and contribute to negative calcium balance. However, the relationship between the impaired calcium absorption and a possible defect in the conversion of vitamin D to its physiologically active form, 1,25-dihydroxyvitamin D, is unknown. We compared fractional calcium absorption (double-isotope method, 100-mg carrier) and serum 25-hydroxyvitamin D (25-OH-D) (Haddad method) in 27 patients receiving pharmacologic doses of prednisone with 27 age-, sex-, and season-matched normal subjects. In patients receiving high daily doses of prednisone (15-100 mg/day), calcium absorption (P < 0.02) and serum 25-OH-D (P < 0.001) were decreased. However, in patients receiving low doses (8-10 mg/day) or high doses (30-100 mg) of prednisone on an alternate-day schedule, both of these parameters were normal. Calcium absorption in the patients treated with daily prednisone correlated inversely with the dose of corticosteroids (r = -0.52, P < 0.025) and, in all steroid-treated patients, correlated directly with serum 25-OH-D (r = 0.58, P < 0.01). In four patients who received high-dose corticosteroid therapy for an average of 4 wk, serum 25-OH-D decreased by 35.5% from pretreatment values. Administration of a physiologic or near-physiologic dose of synthetic 1,25-dihydroxyvitamin D(3) (0.4 mug daily for 7 days) to patients receiving high-dose corticosteroids led to an increase in calcium absorption in all patients. These results suggest that calcium malabsorption in the corticosteroid-treated patients is due to a dose-related abnormality of vitamin D metabolism and not to a direct effect of corticosteroids on depressing transmucosal intestinal absorption of calcium.


Complement (C5-a)-induced granulocyte aggregation in vitro. A possible mechanism of complement-mediated leukostasis and leukopenia. Activated plasma complement will induce biphasic aggregation of human granulocytes dectable by standard nephelometric techniques. The responsible active component was suggested to be C5a by molecular weight and heat-stability assays; moreover, aggragating activity was ablated by anti-C5 but not anti-C3 antibodies. C5a prepared by trypsinization of purified C5 reproduced the aggregating activity of whole activated plasma, whereas plasma from a C5-deficient donor did not support aggregation. Embolization of granulocyte aggregates might be a previously unsuspected cause of leukostasis and pulmonary damage in various clinical situations where intravascular complement activation occurs.


A possible role for malonyl-CoA in the regulation of hepatic fatty acid oxidation and ketogenesis. Studied on the oxidation of oleic and octanoic acids to ketone bodies were carried out in homogenates and in mitochondrial fractions of livers taken from fed and fasted rats. Malonyl-CoA inhibited ketogenesis from the former but not from the latter substrate. The site of inhibition appeared to be the carnitine acyltransferase I reaction. The effect was specific and easily reversible. Inhibitory concentrations were in the range of values obtained in livers from fed rats by others. It is proposed that malonyl-CoA functions as both precursor for fatty acid synthesis and suppressor of fatty acid oxidation. As such, it might be an important element in the carbohydrate-induced sparing of fatty acid oxidation.


Metabolic control of circulation. Effects of iodoacetate and fluoroacetate. The circulatory effects of selective metabolic inhibition of glycolysis and of the tricarboxylic acid cycle by iodoacetate and fluoroacetate were studied in intact chloralose-anesthetized dogs. Pulmonary arterial blood pressure and vascular resistance increased after administration of both inhibitors, but neither systemic hemodynamics nor myocardial contractility changed significantly. Coronary blood flow did not change after iodoacetate administration but increased four- to five-fold after fluoroacetate. Administration of normal saline had no effect on any of the parameters. The changes in pulmonary arterial blood pressure and coronary blood flow after fluoroacetate were not mediated via the autonomic nerves or adrenergic neurohumors because they still occurred after autonomic nervous system inhibition. Neither myocardial oxygen consumption nor left ventricular work changed. A selective increase in myocardial blood flow also occurred in conscious dogs after fluoroacetate administration; hepatic artery flow was reduced, but other organ flows did not change significantly. These results indicate that pulmonary pressor and coronary dilator effects may be produced in intact dogs by selective metabolic blockade, in the absence of reduced oxygen supply or impairment in the electron transport system. These results also suggest that the increases in pulmonary arterial blood pressure, coronary blood flow, and cardiac output that occur during hypoxia probably are related to separate metabolic events in the tissue.


Potentiation of the function of Hageman factor fragments by high molecular weight kininogen. Patients lacking high molecular weight (HMW) kininogen have profound abnormalities of the Hageman factor-dependent pathways of coagulation, kinin formation, and fibrinolysis. The ability of HMW kininogen to potentiate the Hageman factor fragments (HFf) activation of prekallikrein and Factor XI in plasma was studied. HFf only partially converted Factor XI to XIa and prekallikrein to kallikrein in plasma deficient in HMW kininogen (Williams trait), while enhanced activation of Factor XI and prekallikrein by HFf resulted after reconstitution with HMW kininogen. In a system using highly purified components, HMW kininogen increased the initial rate of prekallikrein activation whether the kallikrein formed was assayed by arginine esterase activity or kininforming ability. The potentiation of prekallikrein activation occurred over a 12-fold range of enzyme (HFf) concentration and was nonhyperbolic with respect to substrate (prekallikrein). HMW kininogen exerted its effect even in the absence of prekallikrein since the hydrolysis of acetylglycyl-lysine methyl ester by HFf was increased by HMW kininogen. These results suggest that one of the functions of HMW kininogen is to augment the catalytic action of HFf.


Dysfibrinogenemia associated with liver disease. To test the possibility that a functionally abnormal fibrinogen may exist in some patients with liver disease, we studied the plasma and purified fibrinogens of five patients whose plasma thrombin times were prolonged at least 40% over normal controls. In no patient was there evidence of disseminated intravascular coagulation and/or fibrinolysis. No abnormalities were detected by immunoelectrophoresis of plasmas or purified fibrinogens. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of reduced patient fibrinogens showed normal mobility and amount of Aalpha, Bbeta, and gamma chains. Alkaline polyacrylamide gel electrophoresis and gradient elution, DEAE-cellulose chromatography of admixtures of radio-iodinated patient (125)I-fibrinogen and normal (131)I-fibrinogen showed identical mobility in the gel and simultaneous elution from the column, respectively. Thrombin and Reptilase (Abbott Scientific Products Div., Abbott Laboratories, South Pasadena, Calif.) times of purified patient fibrinogens were prolonged, and calcium ions improved but did not completely correct these defects. Increasing amounts of thrombin progressively shortened the clotting times of patient fibrinogens but not to the level of normal. Addition of equal amounts of patient fibrinogen to normal fibrinogen resulted in a prolongation of the thrombin time of the normal protein. Thrombin-induced fibrinopeptide release was normal. Fibrin monomers prepared from patient plasmas and purified fibrinogens demonstrated impaired aggregation at low (0.12) and high (0.24) ionic strength. These studies demonstrate that some patients with liver disease and prolonged plasma thrombin times have a dysfibrinogenemia functionally characterized by an abnormality of fibrin monomer polymerization.


Metabolism of autologous and homologous IgG in rheumatoid arthritis. The metabolism of radioiodinated IgG was studied in 20 patients with rheumatoid arthritis and 11 normal controls using autologous IgG and homologous IgG pooled from normal donors. Fractional catabolic rates in the controls were 4.44% of the autologous- and 4.29% of the homologous-labeled protein per day. The corresponding rates in the rheumatoid patients were 9.67% of the autologous- and 8.64% of the homologous-labeled protein per day. Extravascular catabolism occurred only in the rheumatoid group and accounted essentially for the entire increased catabolism of IgG observed in these patients. 10 patients were especially hypercatabolic, with fractional catabolic rates for autologous IgG greater than 10%. Moreover, they catabolized their autologous IgG significantly faster than the homologous IgG (12.6 vs. 9.9%). The increment of catabolism of autologous over homologous IgG also occurred in the extravascular compartment. These highly hypercatabolic patients had a significantly increased number of manifestations of extra-articular disease. The hypercatabolism of IgG could not be correlated with age, weight, sex, duration of disease, joint erosions, corticosteroid therapy, erythrocyte sedimentation rate, rheumatoid factor titer, serum IgG concentration, or circulating immune complexes as measured by the Raji cell radioimmunoassay. Conceivable sites of extravascular catabolism and possible causes of faster catabolism of autologous (rheumatoid) than of homologous (normal) IgG are discussed.


The mechanism of adaptation of left atrial stretch receptors in dogs with chronic congestive heart failure. Chronic congestive heart failure (CHF) was induced in dogs by the construction of an aorto-caval fistula below the level of the renal arteries. Aorto-caval fistula dogs showed signs of CHF which included ascites, hind limb edema, and pulmonary congestion. Ventricular catheterization indicated a significantly higher left ventricular end diastolic pressure and lower maximum velocity of left ventricular pressure development/left ventricular end diastolic pressure in CHF dogs when compared to sham-operated controls. Heart weight/body weight ratios were significantly higher in CHF dogs. Electrophysiological recordings from medullated left atrial type B receptors from the cervical vagus indicated a depressed sensitivity of these receptors in CHF dogs when compared to sham-operated control dogs. For any given change in left atrial pressure, the discharge of left atrial receptors was significantly reduced in CHF dogs compared with sham-operated controls. The mechanism for this depressed sensitivity was investigated. Sonomicrometry of the left atrial appendage indicated a decreased compliance of the left atrial appendage in the dogs with chronic CHF. In addition, microscope examination of the complex unencapsulated receptor endings taken from the left atrial endocardium indicated a marked alteration in receptor morphology. A loss of the end arborization was the most typical finding. It is concluded that chronic CHF brought about by an aorto-caval fistula results in a depressed left atrial stretch receptor response and that both decreased left atrial compliance and structural alterations in the receptor endings may account for this depressed sensitivity.


Phosphate control and 25-hydroxycholecalciferol administration in preventing experimental renal osteodystrophy in the dog. Previous studies from this laboratory demonstrated that secondary hyperparathyroidism in dogs with chronic renal disease may occur, at least in part, as a consequence of the need for progressive adaptation in renal phosphorus (P) excretion that occurs as glomerular filtration rate falls. However, the studies were of relatively short duration. Moreover, no information emerged regarding a potential role of calcium malabsorption in the pathogenesis of secondary hyperparathyroidism. The short duration of the protocol did not lend itself to the study of the effect of P control or the administration of vitamin D in the pathogenesis of renal osteodystrophy. In the present studies, 14 dogs with experimental chronic renal disease were studied serially for a period of 2 yr. Each animal was studied first with two normal kidneys on an intake of P of 1,200 mg/day. Then, renal insufficiency was produced by 5/6 nephrectomy. The dogs then were divided into three groups. In group I, 1,200 mg/day P intake was administered for the full 2 yr. In group II, P intake was reduced from the initial 1,200 mg/day, in proportion to the measured fall in glomerular filtration rate, in an effort to obviate the renal adaptation in P excretion. In group III, "proportional reduction" of P intake also was employed; but in addition, 20 mug of 25(OH)D(3) were administered orally three times a week. In group I, parathyroid hormone (PTH) levels rose throughout the 2-yr period reaching a final concentration of 557+/-70 U (normal 10-60). In group II, values for PTH remained normal throughout the 1st yr, increased modestly between the 12th and the 18th mo, but then did not rise after the 18th mo. In group III, no elevation of PTH levels was observed at any time; however, these animals were hypercalcemic. Histomorphologic analyses of the ribs of these dogs were performed serially throughout the 2-yr period. A linear relationship was obtained between the osteoclastic resorption surface and the concentration of circulating immunoreactive PTH. The osteoid volume was greater in group I animals when compared to those in group II. None of the morphologic abnormalities associated with renal osteodystrophy were observed in the animals in the third group.


Effects of propranolol on regional myocardial function, electrograms, and blood flow in conscious dogs with myocardial ischemia. The effects of coronary occlusion and of subsequent propranolol administration were examined in 18 conscious dogs. Overall left ventricular (LV) function was assessed by measurements of LV pressure and dP/dt, and regional myocardial function was assessed by measurements of segment length (SL), velocity of SL shortening and regional myocardial "work", i.e., pressure-length loops in normal, moderately, and severely ischemic zones. Regional intra-myocardial electrograms were measured from the same sites along with regional myocardial blood flow as determined by the radioactive microsphere technique. Coronary occlusion resulted in graded loss of function from the normal to severely ischemic zones with graded flow reduction and graded elevation of the ST segment. Propranolol depressed overall LV function, function in the normal zone (work fell by 17+/-4%), and in the majority of moderately ischemic segments (work fell by 7+/-3%). In severely ischemic segments the extent of paradoxical motion and post-systolic shortening was reduced by propranolol. After propranolol regional myocardial blood flow fell in the normal zone (11+/-2%) and rose in the moderately (15+/-4%) and severely (63+/-10%) ischemic zones. Thus, in the conscious dog with regional myocardial ischemia, propranolol induces a redistribution of myocardial blood flow, with flow falling in normal zones and rising in moderately and severely ischemic zones. The improvement in perfusion of ischemic tissue was associated with slight but significant depression of shortening, velocity, and work in the moderately ischemic zones and of paradoxical bulging and post-systolic shortening in the severely ischemic zone.


Evidence for hydroxyl radical production by human neutrophils. The possibility that neutrophils produce the hydroxyl radical (OH-) was studied by examining the ability of these cells to support the release of ethylene from methional, a reaction in which it has been shown that OH-, but not O2- or H2O2, may serve as the oxidizing agent. When neutrophils were exposed to opsonized zymosan in the presence of 0.35 mM methional, ethylene was released in quantities amounting to 44.6+/-3.6 pmol/10(6) cells/40 min. Ethylene production required the presence of neutrophils, opsonized zymosan, and methional, indicating that it was formed from methional by stimulated but not resting neutrophils. Ethylene was not produced by zymosan-treated cells from patients with chronic granulomatous disease, confirming the requirement for respiratory burst activity in this process. Ethylene production was suppressed by benzoic acid, an OH- scavenger. Superoxide dismutase (3 microgram/ml) reduced ethylene production to 21% of control levels, but catalase had no significant effect in this system. These findings indicate that stimulated neutrophils produce a highly reactive oxidizing radical, possibly OH-, which releases ethylene from methional, and that the O2-generated during the respiratory burst is involved in the production of this reactive species.


Comparative study of protoporphyrins in erythropoietic protoporphyria and griseofulvin-induced murine protoporphyria. Binding affinities, distribution, and fluorescence spectra in various blood fractions. Excess erythrocyte protoporphyrins of human congenital erythropoietic protoporphyria and of griseofulvin-induced murine hepatic protoporphyria were found to be associated with hemoglobin and stroma fractions in similar relationships. More than 99.5% of total erythrocyte protoporphyrin was bound to hemoglobin in each case. However, profound differences were found when protoporphyrin concentration was measured in erythrocytes that had been segregated into populations of progressive age on discontinuous density gradients. In erythropoietic protoporphyria, porphyrin content diminished rapidly with age; in murine protoporphyria, the aging erythrocyte populations became progressively more porphyrin rich. In vitro diffusion of protoporphyrin from plasma across the intact erythrocyte membrane was demonstrated. The equimolar binding affinity of protoporphyrin to hemoglobin was shown to be 40 times that of protoporphyrin to serum albumin. This strong affinity provides the driving force for the observed transmembrane diffusion, and explains the high erythrocyte/plasma porphyrin ratio in murine hepatic protoporphyria. The opposite rapid efflux of intra-erythrocytic protoporphyrin into plasma previously shown in uncomplicated erythropoietic protoporphyria occurs despite this strong hemoglobin affinity, implying continuous efficient clearance of protoporphyrin from plasma by the liver. Furthermore, these and other data suggest that a hepatic synthetic source for any significant fraction of the blood protoporphyrin in erythropoietic protoporphyria is highly improbable.


The origin of chylomicron phosphatidylcholine in the rat. This study investigates the pathways of origin of chylomicron phosphatidylcholine (PC) using a lymph- and bile-fistulated rat infused with a stabilized triolein emulsion. [(14)C-glycerol]PC was used to evaluate chylomicron PC generated by lyso PC acyltransferase. The percentage of chylomicron PC derived from the PC infused was directly proportional to the PC concentration in the infusate. When the infusate PC concentration was 10 mM, essentially all the chylomicron PC was derived therefrom at 4-6 h of infusion. Incorporation of the radiolabel was not found to be as great in the lymph subnatant PC as in chylomicron PC, suggesting that chylomicron and lymph subnatant PC might be supplied from different PC precursor pools.(32)P(i) was infused into similarly prepared rats to judge chylomicron PC synthesized from de novo sources. In these experiments it was found that the percentage of chylomicron PC derived from de novo synthesis was inversely related to the PC concentration of the infusate. This suggests that exogenously infused PC inhibits de novo PC synthesis. When [(32)P]rat bile PC was infused with [(14)C-glycerol]potato PC, the bile PC was preferred as a chylomicron precursor despite the greater similarity of the saturated fatty acids of potato PC to those of chylomicron PC. When the saturated fatty acids of bile and chylomicron PC were compared, chylomicron PC was significantly richer in stearate, suggesting extensive enterocyte modification of the saturated fatty acids of bile PC.


The role of the liver in glucagon metabolism. Total plasma immunoreactive pancreatic glucagon (IRG) was measured in samples taken simultaneously from the proximal portal vein and superior vena cava of 26 healthy rats. The portal-peripheral ratio of IRG was 2.80+/-0.25, the portal-peripheral difference (Delta) 124+/-15 pg/ml, and percentage extraction 58+/-3. Gel filtration of paired portal and peripheral vein samples showed that reduction in the 3,500-dalton IRG component (glucagon) in peripheral samples accounted for almost all the differences, there being minimal and inconsistent changes in the high molecular weight (>40,000) fraction. The portal-peripheral ratio of the 3,500-dalton glucagon was 5.24+/-1.10, the portal-peripheral difference 130+/-33 pg/ml, and the percentage extraction 81+/-5. To study the transhepatic differences in the 9,000-dalton "proglucagon-like" material, the experiment was repeated in nine rats 24 h after bilateral nephrectomy, a procedure which increases plasma levels of this fraction. The portal-peripheral ratio for plasma IRG in these rats was 1.48+/-0.12, the portal-peripheral difference 140+/-29 pg/ml, and percentage extraction 28+/-5. Gel filtration revealed no consistent differences between portal and peripheral concentrations of the 9,000- and >40,000-dalton components, which comprised 40 and 13%, respectively, of the mean IRG level of 492+/-35 pg/ml. In contrast, there were marked differences between portal and peripheral levels of the 3,500-dalton component the ratio being 3.42+/-0.63, the portal-peripheral difference 182+/-32 pg/ml, and percentage extraction 64+/-5. Similar studies in a healthy dog, in which species there are significant circulating levels of the 9,000-dalton IRG component, confirmed the selective hepatic extraction of the 3,500-dalton fraction. We conclude that the various IRG fractions are metabolized differently by the liver, and that portal-peripheral ratios based on direct assay of plasma IRG will vary depending on the percentage glucagon immunoreactivity in each fraction; the greater the combined contribution of fractions other than the 3,500-dalton component to total plasma IRG, the lower will be the ratio. Because of the heterogeneity of circulating IRG and significant differences in the metabolism of its various components, gel filtration of plasma samples is necessary for precise quantitation of the hepatic uptake of each particular fraction.


Studies on the role of cephalic-vagal stimulation in the acid secretory response to eating in normal human subjects. These experiments were performed to determine the importance of cephalic-vagal stimulation in the acid secretory response to eating in normal human subjects. Cephalic stimulation was induced by a modified sham feeding (MSF) technique, during which subjects chewed and expectorated appetizing food. The response to MSF was compared with that to gastric distention with 600 ml NaCl, glucose, or food. In addition, we measured the extent to which cephalic stimulation augments acid secretion that has been stimulated simultaneously by these other mechanisms. Our conclusions are as follows: (a) cephalic stimulation accounts for approximately one-third of the acid secreted when all mechanisms act simultaneously (food-distention plus MSF); (b) within the limits imposed by the maximal secretory capacity, the response to MSF is approximately the same, regardless of whether acid secretion is otherwise unstimulated or is stimulated simultaneously by gastric distention with NaCl, glucose, or food; and (c) gastric distention prolongs the response to cephalic stimulation.


Perifusion of isolated rat adipose cells. Modulation of lipolysis by adenosine. Incubation of isolated rat epididymal fat cells is associated with the accumulation of adenosine in the incubation medium. To more clearly define the effect of adenosine on lipolysis, isolated rat epididymal adipocytes were studied with the perifusion system. Various combinations of epinephrine, adenosine, and adenosine deaminase were perifused through the adipocytes. Exogenous adenosine, 0.001-10.0 muM, had no discernible influence upon unstimulated lipolysis; but exogenous adenosine inhibited epinephrine-sensitive lipolysis in a concentration-dependent manner. Cells perifused with 0.3 muM epinephrine plus 0.001 muM adenosine did not show any impairment of the lipolytic response to 0.3 muM epinephrine alone. Adenosine, 0.01 muM, inhibited the response to epinephrine by 50%; response to 0.3 muM epinephrine plus 0.1 muM adenosine was similar to the basal rate. Perifusion with adenosine deaminase significantly increased basal lipolysis to 30% of the epinephrine response. Adenosine deaminase and epinephrine were synergistic in stimulating lipolysis to 180% of the response to epinephrine alone. Isolated fat cells were incubated for 30 min, and the cell-free used medium was perifused through fresh fat cells. Epinephrine in used medium was less effective in promoting lipolysis than epinephrine in fresh buffer. High-pressure liquid chromatography identified adenosine in the used medium. Bovine serum albumin possessed adenosine deaminase activity but accounted for negligible conversion of adenosine to inosine. Adenosine is shown to have a modulating effect upon basal and hormone-stimulated lipolysis in the perifusion system. Sufficient endogenous adenosine (<0.01 muM) is present to maximally affect basal lipolysis. Hormone-stimulated lipolysis, although inhibited somewhat by endogenous adenosine, requires the addition of exogenous adenosine for complete inhibition.


A new antigen system expressed in human endothelial cells. Kidney transplant recipients were previously found to have antibodies that reacted with cells isolated from the endothelium of umbilical cord veins and which were not cytotoxic for lymphocytes from the same donors. Results of the present experiments indicate that endothelial (E) antigens are different from previously known HLA antigens and also from Ia-like antigens of bone marrow-derived (B) lymphocytes. Attempts to absorb E antibodies with lymphocytes from E-positive donors failed in most cases. Antigen redistribution experiments showed that E antigens were located in separate molecules from the products of HLA-A, B, and C. Thus, E cells treated with E antibody became resistant to lysis by the antibody used, but remained susceptible to the effects of typing sera for alleles of HLA-A, B, and C. Antibodies to E cells were also cytotoxic for blood monocytes. Moreover, monocytes were able to absorb E-antibody reactions, indicating that similar antigens were expressed in both cells. E antibodies did not react with B lymphocytes isolated from peripheral blood. In that regard E antibodies were different from antibodies to human Ia-like antigens which reacted with E cells, monocytes, and isolated B lymphocytes. Thus it appears that E antigens constitute a system of human alloantigens which has not been previously identified. The possibility that these antigens play a role in kidney allograft rejection should now be investigated since matching can be performed using monocytes isolated from the blood of recipients and donors.


Massive extranglandular aromatization of plasma androstenedione resulting in feminization of a prepubertal boy. This report describes the mechanism of origin and the quantity of estrogen produced in a prepubertal boy who developed severe feminization at 8 yr of age as the result of a heretofore undescribed metabolic abnormality. The clinical findings were gynecomastia and accelerated linear growth and bone maturation. At the time feminization developed, there were no signs of growth or development of the otherwise normal prepubertal male external genitalia or any increase of muscle mass that normally accompanies male puberty. The hyperestrogenism was found to be the consequence of massive extraglandular conversion of plasma androstenedione to estrone. During a 6-mo period of study, the plasma production rate of androstenedione ranged from 1.2 to 1.6 mg/day. More than 55% of plasma androstenedione was metabolized by aromatization to estrone which, in turn, was extensively sulfurylated in the tissue sites of aromatization before its entry into the blood. Thus, estrone sulfate was the final product in the aromatizing sites, and the plasma production rate of estrone sulfate derived from plasma androstenedione was 782 mug/24 h. The extent of extraglandular conversion of plasma androstenedione to estrone measured in this boy was 50 times that observed in two normal prepubertal boys. Moreover, 94% of the extraglandular aromatization occurred in extrahepatic sites. The metabolic clearance rate of plasma androstenedione, 2,380 liters/day per m(2), was markedly increased in this boy. Approximately 1,500 liters of plasma androstenedione clearance was accounted for by extrahepatic, extraglandular aromatization. The fractional conversion of testosterone to estradiol, 0.16, was 50 times greater in this boy than that observed in normal young adult men. The total extent of aromatization of plasma prehormones was even greater in this boy inasmuch as evidence was obtained that aromatization of 16-hydroxysteroids, e.g. 16alpha-hydroxy androstenedione and 16alpha-hydroxy dehydroisoandrosterone (sulfate), resulted in estriol formation independent of estrone formation. Thus, extensive extrahepatic, extraglandular aromatization resulted in advanced feminization in this prepubertal boy by a previously undescribed metabolic abnormality.


Respiratory muscle blood flow distribution during expiratory resistance. When work load on the respiratory system is increased the relative increase in blood flow to each of the muscles of breathing provides an index of how the augmented effort of breathing is partitioned among the different muscles. We have used a radio-active microsphere technique to measure blood flow to each of the muscles of respiration in supine dogs during unobstructed respiration and breathing against graded expiratory threshold loads. 79% of the augmented flow went to expiratory muscles; of this increased flow to expiratory muscles 74% went to abdominal wall muscles and 26% to internal intercostals. In our earlier studies of hyperventilation induced by CO(2) rebreathing where expiratory work loads were low, 44% of the increase in flow went to expiratory muscles; of this, only 39% went to abdominal wall muscles and 61% to internal intercostals. During inspiratory resistance which produced small increases in expiratory work, 27% of the increase in blood flow went to expiratory muscles; of this, only 37% went to abdominal wall muscles and 63% to internal intercostals. These results suggest that the internal intercostals are predominantly used for expiration when expiratory work loads are low, whereas the abdominal wall muscles are predominantly used when loads are high. For similar rates of pressure-volume work done on the lung, the total respiratory muscle blood flow is significantly greater during expiratory loads than during unobstructed hyperventilation or inspiratory loads. Thus, the abdominal wall muscles that are utilized for overcoming high pressure expiratory loads are relatively inefficient in converting metabolic energy into pressure-volume work.


Activation of rabbit platelets by platelet-activating factor derived from IgE-sensitized basophils. Characteristics of the aggregation and its dissociation from secretion. Platelet-activating factor (PAF) is liberated from antigen-stimulated, IgE-sensitized rabbit basophils and induces aggregation of platelets and secretion of their content of vasoactive amines. Experiments were performed to determine the relationship between these two platelet responses to this stimulus.(a) Aggregation was initiated by appreciably lower concentrations of PAF than were required to produce even minimal release of constituents. PAF-induced aggregation was also resistant to agents which destroy ADP, such as creatine phosphate/creatine phosphokinase or apyrase, and occurred with platelets made unresponsive (refractory) to ADP. It was concluded that PAF can induce aggregation by a mechanism which is distinguishable from the release reaction and from the aggregating effect of ADP.(b) Secretion can probably occur independently of aggregation because incubation without agitation resulted in secretion without detectable aggregation.(c) Despite the suggestion that the two platelet responses can be independent, they may be induced by the same stimulus. This was indicated by experiments in which platelets specifically desensitized to PAF-induced secretion were also found to be unresponsive to PAF-stimulated aggregation. Moreover, identical levels of inhibition and identical inhibition profiles were obtained for both responses with serine esterase inhibitor, diisopropylphosphofluoridate, and with amino acid esters. It was concluded that the same stimulus-specific activable protease (esterase) was most likely involved in PAF-induced aggregation and secretion.


Isolation of Actinomyces viscosus from two patients with clinical infections. The isolation of Actinomyces viscosus from two patients is described. One was a case of multiple myeloma, the organism being found on blood culture; the other was a patient with a submandibular abscess. These are believed to be the first such isolations of A. viscosus in this country.


Serum gentamicin assays of 100 clinical serum samples by a rapid 40 degrees C. Klebsiella method compared with overnight plate diffusion and acetyltransferase assays. We have compared the results of gentamicin assay of 100 clinical serum samples by a rapid 40 degrees C plate diffusion method, an overnight plate assay at 37 degrees C, and radioactive acetyltransferase methods. The results of assay obtained by both plate diffusion methods agreed closely. There was excellent correlation between the results of acetyltransferase and plate assays provided that human serum gentamicin standards were used for the acetyltransferase assay and turbid sera were excluded. Lipaemic sera were associated with falsely high results by the acetyltransferase method. There was no difference in specificity between the methods when antibiotics other than gentamicin were present. Much less skilled technician time was required to perform the rapid 40 degrees C plate method than the radioactive acetyltransferase method. The 40 degrees C plate method is preferred for routine serum gentamicin assays in our clinical laboratories.


Estimation of serum gentamicin by quenching fluoroimmunoassay. A new type of non-isotopic immunoassay, applied to the determination of serum gentamicin, is reported. The method is based on partial quenching of fluorescence observed when fluorescein-labelled gentamicin is bound by anti-gentamicin serum. The fluorescence intensity of the labelled gentamicin in an unseparated immunoassay incubation mixture therefore serves to indicate the extent of binding, which is related to the amount of competing unlabelled gentamicin present. Precision and accuracy are shown to be similar to those of the best existing methods for gentamicin, while the new assay is more rapid and technically simpler, and avoids the use of expensive radio-chemicals with their attendant health hazard. Assays of patient samples correlate with established bioassay and polarisation fluoroimmunoassay methods.


Cancer-associated proteins in effusion fluids. Two cancer-associated proteins, carcinoembryonic antigen (CEA) and pregnancy-associated alpha2 glycoprotein (PAG), together with 13 normal serum proteins were measured in the serum and effusion fluid of patients with ascites and pleural effusions. The results indicate that CEA measurement in effusion fluid is more effective than serum measurement in distinguishing cancerous from congestive or inflammatory effusions. Comparisons with the results of cytological examination suggest that fluid CEA estimation may prove a useful clinical tool. Serum PAG levels were higher in patients with cancer, but fluid determination offers no advantage in separating the disease groups. Similarly, the estimation of individual normal serum proteins in effusion fluids is unlikely to be of diagnostic value.


A new coagulation defect associated with a case of melanomatosis. A marked abnormality of the intrinsic coagulation system was observed in a patient with melanomatosis and frank melanuria. With successful treatment of the tumour there was a parallel improvement in the clotting abnormality. This defect was shown to be a deficiency of factor XI together with a previously unrecognised factor. This is distinct from either Fletcher or Fitzgerald factors and appears to act between factors XI and X in the coagulation sequence.


Cerebral involvement with disseminated intravascular coagulation in intestinal disease. Over a two-and-a-half-year period at the Sheffield Royal Infirmary, six patients developed disseminated intravascular coagulation as a serious complication of intestinal disease. There was clinical evidence of cerebral involvement in all six patients, and small vessel thrombi were demonstrated in the brains of all three cases examined post mortem. Where the true significance of the cerebral disorder was not recognised, this led to delay in the diagnosis with serious risk to the patient. In the single case in which the diagnosis was made early, the intravascular coagulation was completely reversed with heparin therapy.


Light and electron microscopy study of capillaries in normal and inflammatory human synovial membrane. Synovium aspirated from the knee joint by trochar was studied by light and electron microscopy in 40 cases of inflammatory arthritis and in 10 controls. The morphology of synovial capillaries, extravascular plasma diffusion, interendothelial vascular gaps, extracapillary blood cell migration, vascular congestion, endothelial hyperplasia, and obliteration of the capillary lumen by endothelial cells were compared in normal and inflammatory synovia. Inflammatory synovitis was characterised by the number and diversity of blood cells migrating through the interendothelial pathway out of the capillary lumen. Polymorphonuclear leucocytes were the blood cells most often seen at interendothelial junctions. No other capillary changes that might be related to synovial inflammation were found.


Macrophage infiltration of breast tumours: a prospective study. In 50 cases of infiltrating breast cancer investigated in a prospective study the number of macrophages within each tumour was assessed. The macrophages were identified by their cytoplasmic acid phosphatase activity. The number of lymphocytes and plasma cells within the tumours were graded by a scoring technique. Significantly fewer cases with metastases were found among those with high macrophage and plasma cell scores. There was no correlation between lymphoreticular infiltration and the degree of tumour differentiation, but in cases without metastases the lymphoreticular infiltration between tumour cells was nearly always only slight when the macrophage score was low.


Evaluation of a teaching hospital necropsy service. The information returned to the hospital clinician after a necropsy was investigated in a series of 1000 patients. It was found that specific clinical queries were answered in 83% of cases, that the necropsy corrected the major clinical diagnosis in 36% of cases, and that 29% of cases were used for undergraduate or postgraduate teaching. The results demonstrate the continuing value of the necropsy as an investigative and educative procedure.


Delayed matching performance after visual Wulst lesions in pigeons. Pigeons were trained preoperatively on a mixed delayed matching-to-sample (DMTS) task in which six different conditions were presented randomly; simultaneous matching, 0-, 1-, 2-, 4-, and 8-sec delays. Subjects that sustained extensive or complete damage to the visual Wulst and moderate damage to hyperstriatum ventrale showed a decrease in accuracy of performance to chance levels at all of the delay conditions as well as on simultaneous matching. After extensive retraining on the 0-sec-delay matching alone, performance on 0-sec-delay and simultaneous matching, presented in mixed DMTS, improved to between 70% and 90% correct. However, performance on delay conditions remained at chance level. All but one bird failed to show signs of postoperative improvement on delay problems in the course of the final testing. The data suggest that the conditional property of the task was a critical factor in the initial drop in accuracy on all of the presented problems. The relatively permanent loss of accuracy on all delay conditions is attributed mainly to the temporal separation of sample and comparison stimuli.


Intensity difference thresholds after lesions of the visual Wulst in pigeons. Visual intensity difference thresholds were studied before and after telencephalic lesions in pigeons. Subjects with visual Wulst lesions showed initial postoperative threshold elevations that represented losses of 19%-49% of their preoperative sensory capacity. This initial loss was correlated with the extent of damage to three components of the visual Wulst: nucleus intercalatus hyperstriati accessorii, hyperstriatum intercalatus suprema, and hyperstriatum accessorium. The damage to hyperstriatum dorsale, another component of the visual Wulst, made no contribution to the initial deficit. The sensory capacity of all but one pigeon improved as a result of postoperative retraining.


Absence of differential associative responses to novel and familiar taste stimuli in rats lacking gustatory neocortex. Rats lacking gustatory neocortex (n = 24) and normal rats (n = 24) were familiarized to either hydrochloric acid (10(-1.6) M) or quinine hydrochloride (10(-4) M) solutions during free-drinking trials. They were trained subsequently to avoid either the familiar or the novel taste stimulus, using a balanced design, by pairing the to-be-associated taste with ip injections of apomorphine hydrochloride. Balanced, nonpaired presentations of the other taste solution and water were presented also. Normal rats more efficiently learned to avoid the novel compared with the familiar taste. Rats with gustatory neocortex lesions did not differentiate novel from familiar tastes. They learned aversions to both in a manner highly similar to the aversion learning of familiar tastes by the normal group. Therefore, rats lacking gustatory neocortex displayed an associative deficiency, relative to normal, only when they were trained on novel stimuli. This observation supports an earlier suggestion that gustatory neocortex lesions disrupt the conditionability of taste stimuli by reducing or eliminating responses to taste novelty. This suggestion is supported further by the absence of a "neophobic" response in the operated rats to the first presentation of a taste stimulus.


Damage to hippocampus and hippocampal connections: effects on DRL and spontaneous alternation. Male albino rats were tested both pre- and postoperatively either on a schedule of differential reinforcement of low-rate responding (DRL 20 sec; Experiment 1) or for spontaneous alternation (Experiment 2). Selective lesions were produced in the hippocampus and its fiber connections. Performance of both behaviors was consistently disrupted by total fornix, medial fornix, and septum lesions, while neither behavior was significantly disrupted by postcommissural fornix or entorhinal cortex lesions. Anterior hippocampus lesions consistently disrupted only DRL performance, while neither posterior hippocampus nor lateral fornix lesions resulted in consistently impaired performance of either behavior. These data are discussed as representing a possible functional differentiation between anterior and posterior portions of the hippocampal system.


Effects of septal lesions on factors of mouse emotionality. Sixty mice from two emotionally divergent inbred strains, BALB/Alb and C57BL/10Alb, were assigned to one of three experimental groups: septal surgery, control surgery, and intact. Subsequently, all animals were administered a battery of five tasks that yielded 19 measures of emotionality. Factor scores were computed on six invariant factors obtained previously from these measures. Each factor was analyzed by an analysis of variance design with main effects for strain, sex, lesion, and days of testing. Strain and lesion main effects were found on Motor Discharge and Autonomic Balance, Strain X Lesion interaction effects on Motor Discharge and Tunneling 1, and a Lesion X Sex interaction effect on Territorial Marking. The results support the interpretation that the septum affects distinct processes modulating Autonomic Balance and Motor Discharge factors.


Plasticity of the acoustic startle response in the acutely decerebrate rat. Plasticity of the acoustic startle reflex was measured in rats in which a complete transection between the forebrain and midbrain was made. During a period from 60 to 100 min after surgery, startle amplitude in the transected rats was relatively stable and comparable with that of the controls (which had been anesthetized with halothane and placed in a stereotaxic instrument). During this period the transection did not alter the temporal recovery process (with intervals of 2, 4, 8, or 16 sec) or auditory prepulse inhibition (with intervals of 25, 50, 100, 500, or 1,000 msec) or the normal reduction in startle caused by high levels of background noise. The transection did prevent the normal increase in startle caused by moderate levels of background noise and eliminated within-session habituation. The effect on habituation was particularly convincing since the curves of the transected and nontransected rats actually crossed. The results are discussed in terms of how the transection procedure can be used to evaluate various hypotheses about underlying mechanisms of startle plasticity.


Water-intake volume regulation in the rat: schedule-induced drinking compared with water-deprivation-induced drinking. Hungry rats drink extremely large amounts of water when they are intermittently fed small amount of food (schedule-induced polydipsia). Are such animals motivated to drink for long durations, to ingest large amounts of fluid, or to do both? When drinking-tube apertures were decreased to slow the rate of water ingestion, each of eight rats spent more time drinking (M = 11.5 min) than when larger apertures were used (M = 7.8 min). The mean volumes ingested were not different. These equal volumes were generated by adjustment of each drink duration in accordance with ingestion rate even during the first few drinks of the sessioons, even when the drinking tubes were frequently switched (every 1-3 min) during the sessions. During drinking induced by water deprivation when food was concurrently available, restriction of the driking-tube apertures reduced intake volumes by 18%-19%. However, when food was not concurrently available during water-deprivation-induced driking, regulation of intake volumes was comparable with that found during schedule-induced polydipsia. These data pose difficulties for theories that ascribe a crucial role to the motor aspects of schedule-induced drinking.


Long-and short-term regulation of feeding patterns in the rat. Analysis of feeding patterns in rats showed that the amount of food eaten in relatively long intervals (24-72 hr) was correlated with mean meal size and was essentially uncorrelated with meal frequency. Similarly, the regulatory adjustment in daily food intake occurring in response to changes in environmental temperature was shown to be the result of an adjustment in mean meal size, with no change in meal frequency. On the other hand, the amount of food eaten in relatively short intervals (3-12 hr) was shown to be more highly correlated with meal frequency than with mean meal size, and a reliable correlation between meal size and the postmeal interval was obtained. It was also shown that the meal size/postmeal interval regression equation predicts the long-term relation between mean meal size and the amount of food eaten. Take together, these results indicate that meal frequency is controlled largely by short-term regulatory signals and that at least some long-term regulatory signals affect meal size directly.


Effects of degree of obesity, age of onset, and weight loss on responsiveness to sensory and external stimuli. Four experiments tested responsiveness to external and sensory stimuli in female human subjects who differed in degree of overweight and in age of onset of their obesity. The effects of weight loss upon external responsiveness were assessed by testing subjects before and after weight reduction in order to determine the role of energy deficit and deprivation in mediating heightened responsiveness to external cues. There was no significant positive correlation between degree of overweight and degree of external responsiveness. In general, the age of onset of the obesity was also not a relevant factor in the degree of externality. Weight loss did not change responses to visual and cognitive cue salience manipulations in measures of feeding, emotionality, time perception, and short-term recall, whereas responsiveness to variations in palatability increased following weight reduction. While external cue responsiveness does not appear to result from adiposity per se or from deprivation, responsiveness to taste stimuli may reflect these parameters. The role of external and sensory cues in the development and maintenance of obesity is discussed.


Generality of learning differences in brain-weight-selected mice. Eight lines of mice from two independent selection programs for high, medium, and low brain weight were raised in enriched environments and tested on active avoidance, water maze, operant discrimination, and passive avoidance tasks. Although statistically reliable performance differences were found on each task within at least one selection, there was no consistent relation within selections and across tests or within tests and across selections between brain weight and performance. The results emphasize the necessity of eliminating confounded performance variables in behavior genetic research on learning phenotypes and suggest that brain weight-learing corrleations in mice are either small or nonexistent.


Tryptophan and tonic immobility in chickens: effects of dietary and systemic manipulations. Consistent with a serotonergic-midbrain raphe model of tonic immobility, four experiments designed to affect changes in serum tryptophan produced reliable effects on the duration of the response in chickens. Systemic injections of tryptophan, the dietary precursor to serotonin, led to a dose-dependent increase in immobility, with optimal effects being observed within 30 min after injection. Dietary depletion of endogenous tryptophan served to attenuate the duration of immobility, and a diet completely free of tryptophan, but supplemented with niacin, practically abolished the reaction. Dietary replacement served to reinstate the response. In a fifth experiment, tryptamine, an alternative metabolic by-product of tryptophan, was found to have no effect on immobility. The data are discussed in light of evidence showing serotonergic involvement in tonic immobility.


Stimulation of specific regions of brain in rats modifies retention for newly acquired and old habits. Three experiments were designed to investigate some effects of low-level stimulation of the amygdaloid complex (AMYG) and the mesencephalic reticular formation (MRF). Experiment 1 used a tilt box to test for motivational and/or reinforcement effects and failed to demonstrate these effects with stimulation of either structure. Experiment 2 used a one-trial fear-conditioning task and revealed that stimulation of the AMYG disrupted retention when given immediately after training or, under some conditions, 4 days after training. In the same task, Experiment 3 showed that stimulation of the MRF enhanced retention when given immediately after training or, under some conditions, 4 days after training. These data indicate that under these conditions, modification of retention by low-level stimulation of specific brain structures is independent of the age of the memory. Some implications of this result are discussed.


Selenium/vitamin E: role in fertilization of bovine ova. The effect of combined supplementation with selenium and Vitamin E upon fertilization of ova was evaluated in beef cattle maintained on either an adequate or inadequate nutrition. Fertilization of ova was 100% in those females receiving supplemental selenium/vitamin E and on an adequate plane of nutrition. Interaction between plane of nutrition and selenium/vitamin E was significant for percent fertility.


Protein, casein, and noncasein protein percentages in milk with high somatic cell counts. More than 1000 milk samples of individual cows with somatic cell counts ranging from 20,000 to 20,000,000 per ml were analyzed by amido black dye binding for total protein, whey protein, and casein. Ten classes of varying somatic cell counts were established. The mean total protein percentage for normal samples (counts less than 500,000/ml) was 3.2% and different from all the other protein class means, ranging from 3.4 to 3.9%. Total protein content increased with somatic cell count. There was no significant difference among any of the ten classes for casein values. Whey protein percentages for normal samples were different from the rest. Whey protein content increased with somatic cell count.


Fetal and maternal mineral concentrations in dairy cattle during late pregnancy. Concentrations of ionic and total calcium, magnesium, and inorganic phosphorus in plasma were determined in bovine fetuses and their mothers within the last month before delivery. Mean fetal concentrations were higher than corresponding maternal contents during the 22 days before delivery. Ionic and total calcium in plasma fell towards term in mother and fetus. Fetal phosphorus was elevated before parturition while maternal phosphorus fell. Maternal magnesium was elevated slightly at parturition.


Assay of prolactin after freezing cow's milk. Concentrations of prolactin were similar in aliquots of the same milk sample stored for 2 days at 4 C or --23 C but averaged lower if prepared for assay at 30 C than if prepared at 40 or 50 C. Average deviations in prolactin between duplicate measurements relative to respective treatment averages were lowest generally when technique of mixing included vortexing for 5 s immediately prior to pipetting volumes of milk for assay. The average deviation of differences in prolactin among duplicate measurements relative to average concentrations of prolactin were about the same for colostrum, milk, and blood plasma (11, 17, and 14%) stored frozen. Prolactin can be measured reliably in frozen cow's milk provided samples are warmed to 40 C to 50 C and mixed thoroughly when prepared for assay.


A clinical comparison of Xe-127 and Xe-133 for ventilation studies. Xenon-133 and xenon-127 were compared by performing ventilation studies with both radionuclides in 19 patients with a variety of lung diseases. Assessment of the counting rate over the chest, relative to the radioactivity in the lungs, permitted the evaluation of each isotope in terms of usable photons detected by a scintillation camera with a large field of view and appropriate collimation. A greater photon yield was obtained with Xe-127. Markedly improved resolution was shown by measurement of a line phantom, but was not apparent on subjective appraisal of scintiphotos except in the washout phase. Xenon-127 appears to be preferable to Xe-133 because of the higher counting rates, lower patient radiation dose, and longer shelf life. In addition, a prior perfusion study using a Tc-99m radiopharmaceutical does not affect the quality of a Xe-127 ventilation study. The use of Xe-127 therefore permits the selection for ventilation studies of only those patients with suspected pulmonary embolism, and eliminates unnecessary radiation exposure. A further improvement in image quality obtained with Xe-127 should be possible with certain modifications of the scintillation camera that would permit use of the 375-keV photopeak along with the 172- and 203-keV gamma energies. Charcoal traps designed for Xe-133 will require additional shielding and longer storage time when used for Xe-127. Xenon-127, however, might be used again after appropriate processing.


Thermography of malignant melanomas.

Thermography of malignant melanomas. Thermography is investigated as a tool for the diagnosis of malignant melanoma. A correlation between hyperthermia and malignancy is demonstrated in about two-thirds of the cases examined.


Dynamic measurement of regional ventilation and perfusion of the lung with Xe-133. A method for measuring regional distribution of ventilation and perfusion with Xe-133 during tidal breathing was developed with normal subjects, and compared with current breath-holding techniques in patients and in animals. Normal values for a ventilation index during washin, a perfusion index, and a washout slope index were determined in both supine and upright normal subjects. Comparisons of tidal-breathing and breath-holding measurements in patients with localized bullous disease of the lung showed roughly equal values for perfusion index by the two methods, but the tidal-breathing method was more sensitive to abnormalities in ventilation index. During occlusion of branches of the pulmonary artery in animals, the tidal-breathing and breath-holding methods were again comparable in the measurement of perfusion indices, but the tidal-breathing method provided a more sensitive assessment of ventilatory changes due to partial bronchial occlusion in animals. This technique appears superior to standard methods and is well suited to dynamic measurement of regional ventilation and perfusion in a number of experimental and clinical circumstances.


Treatment of melanotic freckles by radiotherapy. Uncomplicated cases of melanotic freckles respond well to radiotherapy with grenz rays. If, however, a conversion into melanoma is in progress or already established, the prognosis is poorer and treatment with harder rays combined with surgical excision should be practiced.


Noninvasive experimental determination of the individual kidney filtration fraction by means of a dual-tracer technique. A noninvasive method for measurement of the individual kidney filtration fraction (FF) is presented, based on an analysis of the early rise of the kidneys' time-activity curves obtained after simultaneous injection of tubular [131I] ortho-iodohippurate and glomerular (Tc-99m DTPA) tracers. The analysis is based on the assumption that an insignificant amount of tracer leaves the kidney during the first few moments following injection. Therefore the kidney activity during this period is directly proportional to the integral of the blood (heart) activity. The dual-tracer technique allows the direct calculation of the ratio of glomerular to tubular clearances, i.e., the FF. In vivo studies were performed on 12 dogs, including normals as well as others with acute ureteral ligation or Benemid-induced tubular blockade. The calculated FF correlated well with the FF obtained from single-shot clearances performed simultaneously. We conclude that the FF can be calculated directly for each kidney, noninvasively, from the early part of the tubular and glomerular time-activity curves by noninvasive external detection.