The effect of zidovudine treatment on serum neopterin and beta 2-microglobulin levels in mildly symptomatic, HIV type 1 seropositive individuals

Sixty-one subjects with mildly symptomatic human immunodeficiency virus (HIV) infection were included in a double-blind, randomized, placebo-controlled trial of zidovudine (part of AIDS Clinical Trials Group protocol 016, ACTG 016) to evaluate changes in the serum immune activation markers neopterin and beta 2-microglobulin (beta 2M) as early markers of the antiviral effect of zidovudine on HIV type 1 (HIV-1) infection. The mean values of serum neopterin and beta 2M levels in 27 placebo-treated subjects tended to increase with time. The mean value of neopterin in 34 subjects receiving zidovudine decreased at 4 weeks (15.76 nmol/L before treatment to 12.73 nmol/L, p = 0.001). The maximum reduction was seen at 8 weeks of treatment (10.78 nmol/L, p less than 0.0001). Subsequently, the mean value of serum neopterin increased but remained below the pretreatment value for more than a year. Serum beta 2M levels decreased (from 3.01 to 2.69 mg/L at 4 weeks, p = 0.01) and reached the lowest level at 8 weeks (2.45 mg/L, p = 0.0002) in zidovudine recipients. The mean beta 2M level returned to pretreatment value at approximately 24 weeks of the treatment. There was a close correlation between changes from baseline in serum neopterin and beta 2M during the first 16 weeks of the zidovudine therapy, but not later. Subjects with greater reductions of serum neopterin or beta 2M tended to maintain lower levels of these markers with continued zidovudine administration.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel bradykinin antagonist with improved properties

Acylation of the N-terminus of [D-Arg0, Hyp3, Thi5,8, D-Phe7] bradykinin with 1-adamantanecarboxylic acid results in an analogue with enhanced potency of at least 33-fold. The new antagonist has potential as a pharmacological tool in the investigation of the role of endogenous bradykinin in cardiovascular regulation.

Expression and stability of amplified genes encoding 5-enolpyruvylshikimate-3-phosphate synthase in glyphosate-tolerant tobacco cells

Two distinct cDNAs for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) were obtained from a glyphosate-tolerant tobacco cell line. The cDNAs were 89% identical and the predicted sequences of the mature proteins were greater than 83% identical with EPSPS proteins from other plants. Tobacco EPSPS proteins were more similar to those from tomato and petunia than Arabidopsis. One cDNA clone, EPSPS-1, represented a gene that was amplified in glyphosate-tolerant cells, while the gene for EPSPS-2 was unaltered in these cells. Consequently, EPSPS-1 mRNA was more abundant in tolerant than unselected cells, whereas EPSPS-2 mRNA was at relatively constant levels in these cell lines. Exposure of unselected cells and tobacco leaves to glyphosate produced a transient increase in EPSPS mRNA. However, glyphosate-tolerant cells containing amplified copies of EPSPS genes did not show a similar response following exposure to glyphosate. A significant proportion of the EPSPS gene amplification was maintained when tolerant cells were grown in the absence of glyphosate for eight months. Plants regenerated from these cells also contained amplified EPSPS genes.

Differential disruption of simple drawing movements in patients with unilateral brain lesion

In examining the ability of patients with unilateral brain lesion to copy simple drawings of a house and a human face, 18 apoplectic patients confirmed by CT scanning were studied. We found that their drawing of a house was inferior to that of a face in 19 tests (90.5%) of 17 patients (94.4%). Marked differences existed in nearly 90% of these tests. No difference was found between the right-hemisphere and left-hemisphere group, except that more patients of the right-hemisphere group showed contralateral neglect, but in the house drawings only.

Actions of lead on transmitter release at mouse motor nerve terminals

The actions of lead (Pb2+) on transmitter release were studied at neuromuscular junctions in mouse diaphragm in vitro. The quantal content of end-plate potentials (EPPs) was reduced by Pb2+ in a dose-related manner consistent with inhibition of Ca2+ entry into nerve terminals, with a half-maximal effect at 1.4 microM (in 0.5 mM Ca2+ and 2 mM Mg2+). Pb2+ also inhibited the increased frequency of MEPPs (fMEPP where MEPPs denotes miniature EPPs) produced by Ba2+ in the presence of raised K+, blocking the calculated Ba2+ entry half-maximally at 170 microM. However, at concentrations of 50-200 nM, Pb2+ often increased fMEPP in 20 mM K+ in the presence of Ca2+ and acted to promote the irreversible effect of lanthanum (La3+) to raise fMEPP. In nominally Ca(2+)-free solution with 20 mM K+, brief (1 min) application of Pb2+ (20-320 microM) caused rapid dose-dependent reversible rises in fMEPP. With prolonged exposure to Pb2+, fMEPP rose and then slowly declined; after removal of Pb2+, once fMEPP had fallen to low levels, fMEPP responded nearly normally to Ca2+ or ethanol, but not to Pb2+ itself. In 5 mM K+, 0 mM Ca2+ and varied [Pb2+] (where [] denotes concentration), nerve stimulation caused no EPPs, but prolonged tetanic stimulation produced increases in fMEPP graded with [Pb2+] that persisted as a "tail"; results were consistent with growth of fMEPP with the 4th power of intracellular Pb2+ and removal of intracellular Pb2+ with a time constant of about 30 s.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of bradykinin and prostaglandin inhibition on systemic and regional hemodynamics in conscious normotensive rats

These experiments were designed to study the effects of inhibition of endogenous bradykinin and/or prostaglandins on systemic and regional hemodynamics in conscious normotensive rats, using the radioactive microsphere technique. Administration of either a bradykinin antagonist (50 micrograms/min for 5 min) or indomethacin (10 mg/kg) alone, decreased the cardiac output by an average of 17.58 and 25.94%, respectively (P less than 0.05), without significant change in total peripheral resistance. Regional blood flow decreased and local vascular resistance increased in most organs. Coronary and renal blood flow decreased by an average of 16.45 and 17.26% with bradykinin antagonist and 23.85 and 19.80% with indomethacin, respectively (P less than 0.05). Indomethacin but not bradykinin antagonist also decreased cerebral blood flow by an average of 47.57% (P less than 0.01). Infusion of the bradykinin antagonist following prior prostaglandin inhibition with indomethacin did not induce further changes in either systemic or regional hemodynamics, except in the liver where a significant additional increment in vascular resistance was observed. Our data suggest that most organs have similar patterns of regional vascular sensitivity to bradykinin and prostaglandins (including the heart, kidney, testis, stomach, skin and adrenal). The major differences were in the cerebral vasculature, which was much more sensitive to prostaglandins, and in the liver, spleen and small intestine, which were more sensitive to bradykinin. We conclude that both hormonal systems participate to a varying extent in the maintenance of resting vascular tone in most organs; however, in some cases, their effects may be additive and in others they may work in opposite directions.

Possible dependence of pressor and heart rate effects of NG-nitro-L-arginine on autonomic nerve activity

1. The effects of NG-nitro-L-arginine (L-NNA) on mean arterial pressure (MAP) and heart rate (HR) were investigated in conscious rats. 2. Intravenous bolus cumulative doses of L-NNA (1-32 mg kg-1) dose-dependently increased MAP. Both mecamylamine and phentolamine increased MAP responses to L-NNA, angiotensin II and methoxamine. Propranolol, reserpine, atropine and captopril did not affect MAP response to L-NNA. 3. A significant negative correlation of HR and MAP responses to L-NNA was obtained in control rats but not in rats pretreated with reserpine or mecamylamine. Significant negative correlations also occurred in the presence of atropine, propranolol, phentolamine or captopril. 4. A single i.v. bolus dose of L-NNA (32 mg kg-1) raised MAP to a peak value of 53 +/- 3 mmHg and the effect lasted more than 2 h; the rise and recovery of MAP were accompanied by significant decrease and increase in HR, respectively. While both phentolamine and mecamylamine increased peak MAP response to L-NNA, mecamylamine abolished the biphasic HR response and phentolamine potentiated the bradycardiac component of HR. 5. Blockade of the autonomic nervous and renin-angiotensin systems did not attenuate the pressor effects of L-NNA. However, the biphasic HR response to L-NNA is mediated via modulation of autonomic nerve activities.

Pressor effects of L and D enantiomers of NG-nitro-arginine in conscious rats are antagonized by L- but not D-arginine

The effects of NG-nitro-L-arginine (L-NNA) and NG-nitro-D-arginine (D-NNA) on mean arterial pressure (MAP) were studied in conscious, unrestrained rats. I.v. bolus of either L-NNA (1-64 mg/kg) or D-NNA (2-64 mg/kg) dose dependently increased MAP to similar maximum values of 55 +/- 7 and 52 +/- 4 mm Hg and with ED50 values of 4.0 +/- 0.9 and 8.9 +/- 1.2 mg/kg (P less than 0.05), respectively. The time course of the MAP response to a single dose (32 mg/kg i.v. bolus) of L-NNA and D-NNA were also obtained. The pressor effects of L-NNA and D-NNA each lasted greater than 2 h with the rise phase t 1/2 of 5 and 27 min (P less than 0.05), respectively. I.v. infusions (10 mg/kg per min) of L-arginine (L-Arg) and D-arginine (D-Arg) did not alter the pressor response to noradrenaline nor angiotensin II. L-Arg but not D-Arg attenuated the pressor responses to both L-NNA and D-NNA. Therefore, both L-NNA and D-NNA are efficacious and long-lasting pressor agents; the pressor effects of both can be antagonized by L-Arg but not D-Arg. Our results suggest that the pressor effects of both L-NNA and D-NNA involve the L-Arg/nitric oxide pathway.

Correlation between CT and DNA contents in peripheral lung cancers

The DNA contents of 30 lung cancers were correlated with preoperative chest CT findings. Tumors with diameters less than 4 cm had lower DNA contents than larger ones, and tumors with spiculated margins had lower DNA than those with lobulated or smooth margins. As DNA contents are correlated with prognosis, the border configuration of peripheral lung cancers may be enough to predict prognosis.

Effects of inhalation and intravenous anesthetic agents on pressor response to NG-nitro-L-arginine

The effects of anaesthetic agents on pressor effect of NG-nitro-L-arginine (L-NNA), a potent inhibitor of nitric oxide (NO) synthesis, were examined in rats. I.v. bolus of L-NNA (1-32 mg/kg) in conscious rats dose dependently increased mean arterial pressure (MAP) to a maximum value of 53 +/- 2 mmHg at 16 mg/kg with ED50 value of 4.7 +/- 0.9 mg/kg. The effects of a single i.v. bolus dose (32 mg/kg) of L-NNA were examined in conscious rats and rats anaesthetised with pentobarbital, chloralose, ketamine, althesin (mixture of alphaxalone and alphadolone), urethane, enflurane or halothane. In conscious rats, peak MAP (51 +/- 3 mmHg) was reached 10 min after i.v. injection and the effect lasted more than two hours. The magnitudes of peak MAP differed under the influence of anaesthetic agents with the following rank order: althesin greater than conscious = pentobarbital = chloralose = ketamine = urethane greater than enflurane much greater than halothane (in which there was negligible change in MAP). The onsets were delayed in rats anaesthetised with pentobarbital, althesin, chloralose and enflurane but not altered with ketamine and urethane compared to that in conscious rats. Therefore, L-NNA caused intense and prolonged pressor response in conscious rats and rats anaesthetised with the i.v. anaesthetic agents pentobarbital, chloralose, ketamine, althesin and urethane. MAP effect of L-NNA was markedly attenuated by the inhalation anaesthetics halothane and enflurane.

[Spur valve jejunal interposition in choledochus cystectomy]

During 1983-1990, 113 patients with congenital choledochus cysts were operated upon with the procedure called the spur valve jejunal interposition following total cystectomy, and satisfactory results were recorded in two years follow-up. However, early complications happened in 26.5% patients e.g. postoperative bile leakage, blood vomiting, small intestinal intussusception, adhesive intestinal obstruction, chyliform ascites, and disruption of wound. Six months-2 years after operation, reflux into bile duct and rapid emptying were observed in some cases in barium examination, and abdominal pain was found in 10% of the patients. The latter was probably due to bile gastritis, which never occurred in conventional Roux-y. An experimental study showed two types of reflux into artificial bile duct. Reflux due to intestinal distention should be checked by an one way valve, while reflux due to normal peristalsis of intestine would be naturally prevented by the intrabiliary pressure formed by the normal bile flow in a narrow bile duct. A spur valve serves an one way stopper and makes the artificial bile duct narrow. In conventional Roux-y, the biliary drainage limb (the artificial bile duct) is the natural path from the distal jejunum while the duodenal drainage limb is just a side-path of the G. I. tract. A wedge anastomosis designed for Roux-Y may convert the natural and side path relationship of the two drainage limbs and would be benefit to avoid reflux into the artificial bile duct.

Efficacy of intraarterial heparin in maintaining microvascular patency: an experimental model

Human-grade sodium heparin was studied to determine thrombosis model patency rates between an intraarterial infusion versus an intravenous method of delivery in a rabbit model. Specific differences in patency and partial thromboplastin times were studied in each group and compared with a saline-perfused group. Three animal groups (New Zealand white rabbits) were established (total = 35 animals). Standardized femoral arterial 5-mm inversion grafts (AIG) were done in each animal in each group. The animals in the control group received intravenous saline infusion, while the two treatment groups received intravenous heparin (12 animals) or intraarterial heparin (12 animals minus 1 anesthesia death). The route of instillation of the infusate was selected at random after completing the inversion grafts. A proximal epigastric branch was utilized for access in those animals randomized to the intraarterial group. Intravenous delivery was accomplished by means of a femoral venous catheter in the vena cava. A 72-hour period of infusion was used in all animals. A dose of 45 units per hour of heparin following a 500-unit bolus was used in the intravenous group. After an identical bolus dose, 25 units per hour of heparin was administered in the intraarterial group. The control (saline group) was given 1 cc saline (in a volume equal to the heparin-dosed groups) daily for 3 days. Arterial inversion graft patency rates were assessed by direct inspection at day 5. Systemic and regional (i.e., distal to the inversion graft) partial thromboplastin times (PTT) were measured in representative control, IV, and intraarterial heparin-treated groups. Complications were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of chronic administration of a vasopressin antagonist with combined antivasopressor and antiantidiuretic activities in rats with left ventricular dysfunction

The present experiments were designed to study the long-term aquaretic effect of [d(CH2)5-D-Tyr(Et)VAVP], an antagonist to arginine vasopressin (AVP) with combined vascular (V1) and renal (V2) receptor inhibiting properties, in rats with left ventricular dysfunction resulting from myocardial infarction (MI). The continuous intravenous infusion of the AVP antagonist (36 micrograms/12 microliters/day) via osmotic minipumps over 11 days resulted in an increase in urine volume and a decrease in urinary osmolality by approximately 10-fold on the first day, but in subsequent days this response decreased in both the post-MI (n = 7) and normal (n = 6) rats. Nevertheless, the daily urine volume remained significantly higher and the urinary osmolality lower in the post-MI rats than in the normal ones throughout the study (p less than 0.05). In two other groups of post-MI (n = 5) and normal (n = 6) rats, intermittent intraperitoneal injections of the AVP antagonist (100 micrograms/kg) every third day resulted in a profound diuresis that was reproducible by each injection and was again significantly greater in the post-MI rats than in the normal rats (p less than 0.05). The cumulative urinary output over the first 10-day period of each treatment was greater with intermittent injections than with continuous infusion in both the post-MI and normal rats, but the difference was significant only in the post-MI rats (398.82 +/- 12.87 ml vs 309.07 +/- 32.44 ml, intermittent vs continuous, respectively, p less than 0.05), even though the cumulative dose of AVP antagonist given intermittently was only about one third of that given continuously.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional water channels and proton pumps are in separate populations of endocytic vesicles in toad bladder granular cells

Functional water channels are retrieved by endocytosis from the apical membrane of toad bladder granular cells in response to vasopressin [Shi, L.-B., & Verkman, A.S. (1989) J. Gen. Physiol. 94, 1101-1115]. To examine whether endocytic vesicles which contain the vasopressin-sensitive water channel fuse with acidic vesicles for entry into a lysosomal pathway, ATP-dependent acidification and osmotic water permeability were measured in endosomes from control bladders and bladders treated with vasopressin (VP) and/or phorbol myristate acetate (PMA). Endosomes were labeled with the fluid-phase markers 6-carboxyfluorescein or fluorescein-dextran. Osmotic water permeability (Pf) was measured by stopped-flow fluorescence quenching and proton ATPase activity by ATP-dependent, N-ethylmaleimide-inhibitable acidification. In a microsomal pellet, Pf was low (less than 0.002 cm/s, 20 degrees C) in labeled endocytic vesicles from control bladders but high (0.05-0.1 cm/s) in a subpopulation (50-70%) of vesicles from VP- and PMA-treated bladders. Following ATP addition, the average drop in pH was 0.1 (control), 0.3 (VP), and 0.2 (PMA) unit. Measurement of pH in individual endocytic vesicles by quantitative image analysis showed that less than 20% of vesicles from VP-treated bladders acidified by greater than 0.5 pH unit. To examine whether water channels and proton pumps were present in the same endocytic vesicles, the pH of endosomes with high and low water permeability was measured from the effect of ATP on the amplitude of the fluorescence quenching signal in response to an osmotic gradient.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone remodeling in hypervitaminosis D3. Radiologic-microangiographic-pathologic correlations

To investigate the mechanism of bone changes in hypervitaminosis D3, we compared contact radiographs, microangiograms by injection of Chinese ink, and corresponding histopathologic macrosections of 66 rabbits that received different doses of vitamin D3. In early stages, radiographs showed subperiosteal bone resorption and porotic cortical bone. The corresponding microangiograms showed proliferating vessels in the periosteum and cortical bone with associated dilatation of the Haversian and Volkmann's canals. When metastatic calcification fills these intracortical caverns or the intertrabecular spaces in the metaphysis and physis, the bone shows a diffuse increased density on radiographs. A dense band in the metaphysis reflects a thickening of calcified chondromatrix due to a hypotrophy of the distal metaphyseal capillaries. Six to 12 weeks after vitamin D3 withdrawal, radiographs showed further increased density of the cortical bone, due to newly formed bone and metastatic calcification. Alternating bands of increased and decreased density in the metaphysis and physis reflect the reinvasion of normal vasculature between growth cartilage and calcified chondromatrix, with normalization of endochondral ossification.

PDGF A-chain gene is expressed by mammalian neurons during development and in maturity

Platelet-derived growth factor (PDGF) may be a critical factor in the temporal differentiation of glial elements in the mammalian central nervous system. We have used in situ hybridization and immunoperoxidase staining to investigate the localization of PDGF A and have observed high levels of PDGF A-chain mRNA and immunoreactive PDGF A in neurons of embryonic and adult mice. PDGF A-chain expression was shown to be developmentally regulated and tissue specific. Every neuronal population examined in the central and peripheral nervous systems expresses PDGF A transcripts. Variable, significantly weaker signals are observed in glial cells. In contrast to known neurotrophic factors, the PDGF A transcripts are widely distributed among neurons. This generalized distribution of PDGF A transcripts, together with the known effects of PDGF on glial cells in vitro, suggests a unique role of neurons in regulating the proliferation and differentiation of glial cells in vivo.

A system control framework for the self-fertilization and selection process of breeding

The self-fertilization and selection process is the main method for speeding up the purifying course of a hybrid population in breeding. This is a complex combinatorial random process with large time delay. To raise the control effectiveness and efficiency of the process, we try, in this paper, to construct a mathematical model of the process by means of effective factors. Then, a control framework for the process is presented which can be used as a guide by breeders for helping them in selecting appropriate control actions.

Study of bilateral histology and meiotic analysis in men undergoing varicocele ligation

Fifty men underwent testicular biopsy at the time of varicocele ligation. The biopsies were scored and also a portion from each biopsy was subjected to meiotic analysis. All men were followed up (mean follow-up 19.3 months). There were no consistent histologic or meiotic abnormalities, and there was no evidence that the varicocele side was more defective than the contralateral side. Thirteen pregnancies were recorded, and these occurred only when the mean Johnsen score from one or other testis was greater than 6.0.

Two highly effective V1/V2 antagonists of vasopressin containing novel thioacids at position 1

In an attempt to develop more effective and selective V1/V2 antagonists of arginine vasopressin (AVP), two analogues have been designed and synthesized. In position 1 they contain thioacids that include a heteroatom in the cyclohexane ring. The 4-thio-4-tetrahydrothiopyraneacetic acid modification of position 1 used in one of them had advantages over the 1-mercaptocyclohexaneacetic acid substituted compound used as reference. The new compound was weaker at lower doses, but elicited a greater response at higher doses, whereas the reference compound reached its plateau earlier. Although the 4-thio-4-tetrahydropyraneacetic acid substitution used in the second compound resulted in a less potent analogue on a weight basis, this substitution also confers enhanced overall efficacy in terms of magnitude of effect.

Metastatic calcification within bone. The main cause of osteosclerosis in hypervitaminosis D3. Radiologic-pathologic correlation

Because the pathogenesis of osteosclerosis in hypervitaminosis D is still not well elucidated, the authors experimentally studied hypervitaminosis D3 in 66 rabbits by injecting different doses of vitamin D3. Contact radiographs of bone specimens showed various signs of osteosclerosis, including dense epiphyses and metaphyses, thickened bony articular surfaces, dense metaphyseal bands, modeling defects at the metaphysis, and dense and thickened cortical bone. The corresponding pathologic sections showed that conspicuous metastatic calcification coated the trabeculae and filled bone marrow cavity and caverns in the original but porotic cortical and periosteal new bone. Rather than being resorbed, the metastatic calcifications were embedded in a thick layer of newly formed bone 6 to 14 weeks after vitamin D3 withdrawal. This study suggests that in hypervitaminosis D3, the osteoblasts and bone marrow undergo degeneration, leading to necrosis and calcification. After vitamin D3 withdrawal, osteoblasts reappear and become overactive, leading to overossification.

Regulation of the formation and water permeability of endosomes from toad bladder granular cells

Osmotic water permeability (Pf) in toad bladder is regulated by the vasopressin (VP)-dependent movement of vesicles containing water channels between the cytoplasm and apical membrane of granular cells. Apical endosomes formed in the presence of serosal VP have the highest Pf of any biological or artificial membrane (Shi and Verkman. 1989. J. Gen. Physiol. 94:1101-1115). We examine here: (a) the influence of protein kinase A and C effectors on transepithelial Pf (Pfte) in intact bladders and on the number and Pf of labeled endosomes, and (b) whether endosome Pf can be modified physically or biochemically. In paired hemibladder studies, Pfte induced by maximal serosal VP (50 mU/ml, 0.03 cm/s) was not different than that induced by 8-Br-cAMP (1 mM), forskolin (50 microM), VP + 8-Br-cAMP, or VP + forskolin. Pf was measured in endosomes labeled in intact bladders with carboxyfluorescein by a stopped-flow, fluorescence-quenching assay using an isolated microsomal suspension; the number and Pf (0.08-0.11 cm/s, 18 degrees C) of labeled endosomes was not different in bladders treated with VP, forskolin, and 8-Br-cAMP. Protein kinase C activation by 1 microM mucosal phorbol myristate acetate (PMA) induced submaximal bladder Pfte (0.015 cm/s) and endosome Pf (0.022 cm/s) in the absence of VP, but had little effect on maximal Pfte and endosome Pf induced by VP. However, PMA increased by threefold the number of apical endosomes with high Pf formed in response to serosal VP. Pf of endosomes containing the VP-sensitive water channel decreased fourfold by increasing membrane fluidity with hexanol or chloroform (0-75 mM); Pf of phosphatidylcholine liposomes (0.002 cm/s) increased 2.5-fold under the same conditions. Endosome Pf was mildly pH dependent, strongly inhibited by HgCl2, but not significantly altered by GTP gamma S, Ca, ATP + protein kinase A, and phosphatase action. We conclude that: (a) water channels cycled in endocytic vesicles are functional and not subject to physiological regulation, (b) VP and forskolin do not have cAMP-independent cellular actions, (c) activation of protein kinase C stimulates trafficking of water channels, but does not increase the number of apical membrane water channels induced by maximal VP, and (d) water channel function is sensitive to membrane fluidity. By using VP and PMA together, large quantities of endosomes containing the VP-sensitive water channel are labeled with fluid-phase endocytic markers.

[Influence of plasma alpha-human atrial natriuretic polypeptide on natriuretic and diuretic effects in patients with nephrotic syndrome]

The physiological mechanism regulating secretion of alpha-human atrial natriuretic polypeptide (alpha hANP) was studied by measuring plasma alpha hANP (P alpha hANP) with radioimmunoassay during water immersion (WI). Twelve healthy volunteers and sixteen patients with nephrotic syndrome were immersed in water for 4 hours. During WI, alpha hANP level and urinary cGMP excretion (UcGV) increased significantly both in volunteers and patients, the urinary volume (UV) and urinary Na excretion (UNaV) also increased significantly. The mean peak values of alpha hANP and UcGV in volunteers were significantly lower than those in the patients, whereas the mean values of UV and UNaV in the former were significantly higher than those in the latter. The increase in alpha hANP level in volunteers correlated positively with the increase of UNaV, UV and UcGV during WI. The close correlations between the increased alpha hANP level and the increased UNaV, UV and UcGV was shown in the patients. These results suggest that alpha hANP is released into the circulation by acute central hypervolemia and plays a physiologically important role in maintaining water and electrolytes homeostasis in normal subjects and that the increased alpha hANP level in nephrotic syndrome makes compensatory regulation in water and electrolytes disorders.

A new highly potent antagonist of bradykinin

We report that the acylation of the N-terminus of [D-Arg0,Hyp3,Thi5,8,D-Phe7]bradykinin, one of the most potent bradykinin antagonists described to date, with 1-adamantane-acetic acid, results in an analogue with more than ten times enhanced potency. The new analogue does not increase the plasma catecholamines, even when administered at doses sufficient to inhibit by more than 90% the vasodepressor response to 250 ng of exogenous bradykinin. This modification suggests new possibilities for the design of even more potent and selective bradykinin antagonists for studying the physiopathology of bradykinin.

Relationship between hormone profiles and the restoration of spermatogenesis in men treated with gossypol

Gossypol acetic acid was administered orally to 35 male volunteers at a dose of 20 mg once a day for 52-70 days in the loading phase and twice a week for 22 months in the maintenance phase. Sperm counts and the serum concentrations of LH, FSH, prolactin, testosterone and oestradiol were monitored regularly during treatment and for a follow-up period of 12 months. At around 90 days after treatment, all treated participants approached or attained azoospermia and remained at this level throughout the maintenance phase. By the end of the follow-up phase, eight treated men were still azoospermic, while sperm counts in the other 27 men were restored to normal levels. The only hormone that changed significantly during and after the treatment was FSH. From the 6th month of the treatment to the end of the follow-up phase, serum concentrations of FSH in the eight participants that reached irreversible azoospermia were significantly higher than in the other 27 men or in controls. It is suggested that monitoring of FSH levels might be of diagnostic use for identifying those participants with irreversible azoospermia during gossypol treatment.

A Chinese familial growth hormone deficiency with a deletion of 7.1 kb of DNA

Using restriction endonuclease analysis and a human growth hormone cDNA probe, we have found a Chinese family with a human growth hormone gene deletion. Two affected sibs are homozygous for a deletion of approximately 7.1 kb of DNA, which contains the normal human growth hormone gene. The patients' parents and grandmothers are heterozygous for the deleted gene. Their grandfathers are normal and homozygous for the hGH-N gene. All of them have normal stature.

Serum beta 2-microglobulin level increases in HIV infection: relation to seroconversion, CD4 T-cell fall and prognosis

Beta 2-microglobulin (beta 2-M), a marker that is increased in serum during immune activation, was investigated during the course of HIV infection. beta 2-M rose promptly in the first phase of HIV infection in people who were participating in a longitudinal study where serum samples and lymphocyte subset data were obtained at 6-monthly intervals. A rise in beta 2-M level in the first seropositive sample was seen in 93% of 50 HIV seroconverters, and those with high (or low) levels of beta 2-M at the end of year 1 tend to remain high (or low) in the ensuing years. Eighty-three per cent of seroconverters experienced a fall in CD4 T cells in the first year. The magnitude of the CD4 T-cell decline, however, did not correlate with the rise in beta 2-M in specific individuals in the first year. Nevertheless, 2-3 years after seroconversion, the initially increased beta 2-M levels did correlate inversely with the (reduced) level of CD4 T cells (P less than 0.001). Thus, the pattern of disease reflected by beta 2-M level is established in the first year of infection and persists through the following 2 years. beta 2-M levels were found to correlate with rate of CD4 T-cell fall in individuals with established HIV infection. Three groups of HIV-seropositive people with similar CD4 T-cell numbers at the first measurements (about 600-800 x 10(6)/l) but different rates of CD4 T-cell fall over the following 2 years were evaluated by beta 2-M levels. The group with stable CD4 T-cell numbers showed a significantly lower level of beta 2-M than the groups with moderately or rapidly declining CD4 T-cell numbers. Increases in beta 2-M levels during the 2 years of observation were found in people exhibiting a rapid decline in CD4 T cells (about 200 cells/year). The level of beta 2-M appears to be an indicator of HIV activity and of the rate of CD4 T-cell fall.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple actions of zinc on transmitter release at mouse end-plates

In mouse diaphragm, the increase in frequency of mini end-plate potentials (fmepp), by Ca2+ or Ba2+ in 20 mM K+, was reversibly inhibited by Zn2+ in a manner consistent with competition between Zn2+ and Ca2+ at a site which interacts with only one atom of Zn with an apparent dissociation constant (Ki) of about 0.015 mM. Between 0.5 mM and 2 mM, Zn2+ caused a rapid and reversible dose-dependent increase in fmepp in 20 mM K+/0 Ca2+. Prolonged or repeated exposure to Zn2+ produced a slow increase in fmepp followed by a decline, which once started, was not modified by of Zn2+. The time course was prolonged in raised Mg2+, bekanamycin, or in 5 mM K+ solution, and graded with Zn2+ concentration, but total numbers of MEPPs induced by 0.1 mM, 1 mM or 4 mM Zn2+ were not significantly different. When fmeppp fell it became insensitive to Ca2+, Ba2+, La3+ (in 20 mM K+), ethanol and raised osmotic pressure. Before complete block of responses to Ca2+, the Ca2+/fmepp dose/response curve in 20 mM K+ was shifted to the right. These results indicate that Zn2+ enters the terminal via voltage-gated Ca2+ channels that interact in a complex way with these ions and then acts (a) as a partial agonist at sites where Ca2+ normally governs transmitter release, and (b) to produce irreversible changes in the nerve terminal, associated with a rise and subsequent fall of fmepp and loss of sensitivity of the release mechanism to Ca2+ and other agents.

Pressor effect of NG-nitro-L-arginine in pentobarbital-anesthetized rats

The pressor effect of NG-nitro-L-arginine (L-NNA), a potent inhibitor of nitric oxide (NO) synthesis, was studied in pentobarbital anesthetized rats. Iv injections of L-NNA from 0.25 to 8 mg/kg caused bradycardia and a dose-dependent increase in mean arterial pressure (MAP) with a maximal response of 43 +/- 5 mmHg and ED50 value of 1.3 +/- 0.2 mg/kg. The time course of the response to the injection of a single dose of L-NNA was also determined. Peak response was reached 60 min after the injection of a single dose (4 mg/kg, iv) and the effect lasted greater than 5 h. The rising phase of the pressor response was accompanied by slight bradycardia while the recovery phase was associated with significant tachycardia. Iv injections of L-arginine (12.5-200 mg/kg) caused transient dose-dependent reductions in MAP. The pressor effect of L-NNA (4 mg/kg, iv bolus) was dose-dependently attenuated by L-arginine. The results show that L-NNA is an efficacious and long-acting pressor agent and are consistent with the hypothesis that endogenous NO plays an important role in the regulation of blood pressure.

Effects of a vasopressin antagonist with combined antipressor and antiantidiuretic activities in rats with left ventricular dysfunction

These experiments assessed the hemodynamic and aquaretic effects of an arginine vasopressin (AVP) antagonist with dual V1V2-receptor inhibiting properties in rats with congestive heart failure resulting from ischemic cardiomyopathy. The compound d(CH2)5-D-Tyr(Et)VAVP was used in these studies. Rats with limited or extensive myocardial infarcts (i.e., with less than 50% or greater than 66% necrosis of the left ventricular wall, respectively, induced by left coronary ligation) and sham-operated controls received the AVP antagonist (100 micrograms/kg i.v.) 4 weeks later. This agent produced an 18% increase in cardiac output (p less than 0.05) and 13% decrease in systemic vascular resistance in the severely damaged rats, both changes being significantly different from those seen in the normal controls or the rats with limited infarcts. All animals exhibited increases in urinary output of 4-10-fold over baseline. We conclude that the hemodynamic and renal effects of this agent are beneficial in animals with left ventricular dysfunction.

[Effect of expression of exogenous PDGF-A chain on growth and transformation of CHO cells]

CHO cells were transfected with plasmid pSV2-PDGF-A (containing human PDGF-A cDNA) by calcium phosphate method. Twenty transfected cell lines were obtained after G418 selection. The selected 2 cell lines At1 and Aot7), with prominent changes in morphology and growth behaviour, showed transcription of PDGF-A chain mRNA much higher than CHO cells, strong fluorescent PDGF-specific reaction, appearing that PDGF-like proteins were synthesized in cytoplasm of these cells. At1 and Aot7 cells not only had increased growth rate, but also formed large colonies in soft agar and grew into fibrosarcomas in nude mice. These results suggested that the expression of exogenous PDGF-A gene might cause the uncontrolled growth and malignant transformation of CHO cells.

Treatment of Wilson's disease with zinc. VII. Protection of the liver from copper toxicity by zinc-induced metallothionein in a rat model

Patients with Wilson's disease often have a further increase in hepatic copper when given zinc as an initial treatment, although there is no associated clinical deterioration. To better understand this situation an animal model was developed in which copper-loaded rats are treated with zinc administered subcutaneously. In the presence of equal amounts of copper loading in liver, control rats show hepatic damage but zinc-treated rats do not. Zinc-treated rats have much higher levels of hepatic metallothionein. Gel filtration studies reveal that much of the hepatic copper in zinc-treated rats is in this metallothionein fraction, whereas the copper in control animals is primarily associated with fractions of high or low molecular weight. Subcutaneous zinc therapy also induces intestinal, but not brain, metallothionein. We interpret these findings to indicate that zinc therapy protects against copper toxicity in liver by induction of hepatic metallothionein, which sequesters copper in a nontoxic form.

Positive inotropic effect of cycloprotobuxine-A on isolated guinea pig myocardium

Cycloprotobuxine-A (CPB-A) 0.1-100 mumoles/L produced positive inotropic effects in left and right atria in a concentration-dependent manner. CPB-A 30 mumoles/L enhanced post-rest contraction, augmented the response of left atrium to increase in stimulating frequency, and increased the developing tension evoked by paired pulse stimulation. By taking simultaneous recordings of action potentials and contractile force of papillary muscles, it was found that CPB-A 30 mumoles/L increased the contractile force and prolonged the action potential duration at 50% of depolarization. It is concluded that the positive inotropic effect of CPB-A on myocardium may be associated with an increase in transsarcolemmal influx of calcium as well as an augmentation of the amount of calcium released from intracellular stores.

Measurement of serum transferrin by the gamma-gamma perturbed angular correlation method. Differences between normal and cancer serum

In this work, the average perturbed angular correlation integral attenuation factor G2 of the transferrin in the serums from the normals and the patients with liver cancer were determined using time integral perturbed angular correlation method (PAC). The average values of G2 were 0.1945 +/- 0.0155 for the cancer serum transferrin and 0.2865 +/- 0.0411 for the normal serum transferrin. The difference between these two groups is significant. Mathematical deduction and theoretical analysis suggested that the equivalent radius of the transferrin molecules in the serum of cancer patients becomes smaller than normal, because of a change in the molecular conformation. Similar results were also observed in experiments with rat serum transferrin.

Synthesis and some pharmacologic properties of five novel V1 or V1/V2 antagonists of AVP

Based on [1-(1-mercaptocyclohexaneacetic acid),2-(O-ethyl-D-tyrosine),4-valine]-8-arginine-vasopressin as a model, five new analogues of arginine-vasopressin (AVP) were designed and synthesized. Four of them have in position 1 a large lipophilic substituent, whereas the fifth contains pchloro-D-phenylalanine at position 2. We found that the anti-antidiuretic potency with 1-mercapto-4-methycyclohexaneacetic acid is higher than with 1-mercaptocyclohexaneacetic acid (model peptide) in position 1 and this analogue is among the most potent antagonists of the antidiuretic response to AVP known to date. Upon further increase of the size of substituents, antagonistic potency was significantly decreased or totally eliminated. As for the substitution of p-chloro-D-phenylalanine in position 2, we conclude that this modification leads to substantial decrease of the V2 antagonistic potency.

Anti-arrhythmic action of cycloprotobuxine-A

Cycloprotobuxine-A (CPB-A) 1-4 mg/kg (1/100-1/25 LD50) produced therapeutic and prophylactic effects which were found to be dose-dependent on experimental arrhythmias induced by BaCl2, aconitine and chloroform. Given at equitoxic doses, the anti-arrhythmic action of CPB-A was as potent as cyclovirobuxine-D (CVB-D) and amiodarone (Amio). However, its therapeutic index (LD50/ED50) was 1.8 times that of CVB-D and 1.2 times that of Amio. The most pronounced effects of CPB-A (0.3-30 mumol/L) on the electrophysiology of ventricular muscle of guinea pig were the lengthening of APD50, APD90 and ERP. This may contribute to its anti-arrhythmic action and suggests that CPB-A most likely belongs to class III anti-arrhythmic drugs (prolongation of APD). Perfused with the same concentration (3 mumol/L), CPB-A brought about more significant increases in APD50, APD90 and ERP than CVB-D and Amio did.

Hematoporphyrin derivative photosensitization and cellular fluorescent photoproduct formation

A new fluorescence band with an emission maximum at 460 nm was observed in S180 tumour cells and human cancer tissues photosensitized by Y-HPD. This fluorescence was the result of a photochemical reaction involving specific proteins and Y-HPD in the cells.

Urinary gonadotropin fragments (UGF) in cancers of the female reproductive system. II. Initial serial studies

Levels of UGF, which constitute the free beta-subunit of human chorionic gonadotropin, asialo free beta-subunit, and a core fragment of asialo free beta-subunit, detected by a single immunoradiometric assay, were monitored in the urines of 28 woman undergoing therapy for gynecologic cancer (3 cervical, 8 endometrial, and 17 ovarian). During a 7-month study, 24 of the 28 woman had elevated UGF levels (greater than 0.2 ng/ml). Correlation was observed of UGF levels and changing clinical status during therapy in 23 of these 24. Normal range CA 125 (less than 35 U/ml) was found throughout the study period in 4 of 14 woman undergoing therapy for serous ovarian malignancy. Three of the 4 had elevated UGF levels which accurately followed the course of their disease. These preliminary studies suggest that in monitoring therapy of gynecologic cancers UGF, alone or with CA 125, warrants evaluation.

Urinary gonadotropin fragments (UGF) in cancers of the female reproductive system. I. Sensitivity and specificity, comparison with other markers

UGF is a mixture of human chorionic gonadotropin free beta-subunit and its fragments, and is detected in pregnancy and trophoblast disease urines. An examination of 67 nonpregnant cancer-free women showed average urine levels of 0.13 ng/ml. Six of the 67 (8.9%) had levels exceeding a selected cutoff value, 0.2 ng/ml. Of 112 woman with active gynecologic cancer, 72 (64%) had urine UGF levels exceeding this cutoff value. When urines were limited to those with creatinine greater than 0.5 mg/ml, or to first morning samples (mean creatinine 1.0 ng/ml), the sensitivity of UGF for all gynecologic cancers was raised to 76%. The sensitivity of UGF for cervical (73%), for endometrial (65%), and for ovarian (83%) cancers exceeded that of plasma CA 125 and lipid-associated sialic acid in plasma (LASA) in the same population. UGF is an exciting new tumor marker which warrants further evaluation.

Urinary human chorionic gonadotropin free beta-subunit and beta-core fragment: a new marker of gynecological cancers

Many investigators have shown that a small proportion (13-36%) of subjects with nontrophoblastic gynecological cancers have elevated serum levels of human chorionic gonadotropin (hCG). The low proportion with detectable levels and the accompanying low titers have limited the use of hCG as a tumor marker. hCG is a glycoprotein composed of two noncovalently linked subunits (alpha and beta), which are the products of separate genes. With the intent of expanding the use of hCG as a tumor marker we investigated levels of hCG free beta-subunit and asialo free beta-subunit and its core glycopeptide (composed of beta-subunit residues 6-40 disulfide-linked to 55-92), collectively called urinary gonadotropin fragments (UGF), in healthy and cancer patients. An immunoradiometric assay was developed, using the core glycopeptide-directed antibody B204, that similarly measures the hCG free beta-subunit and the asialo free beta-subunit and its core glycopeptide. Parallel urine and serum samples were collected from 87 women with active gynecological cancer and hCG and UGF were measured. Just 18% of the women tested had detectable serum levels of hCG (greater than 0.2 ng/ml); none had elevated serum levels in the UGF assay (greater than 0.2 ng/ml). Of the same group, 32% had detectable urine hCG levels (mean titer, 0.50 ng/ml) and 74% exhibited elevated urinary levels in the UGF assay (mean titer, 2.0 ng/ml). In a control group (urines from 50 nonpregnant healthy women), 47 negative and three borderline positive results (0.30, 0.35, and 0.48 ng/ml) were observed in the UGF assay. These results suggested a sensitivity of 74% and specificity of 92% for the UGF test for gynecological cancers. By disease, 70% of those with cervical, 73% of those with ovarian, and 77% of those with endometrial cancers had detectable UGF levels (greater than 0.2 ng/ml). By stage, 50, 62, 75, 86, and 100% of those with stage 1, 2, 3, 4, or recurrent disease, respectively, had positive results. UGF is a promising new marker of gynecological malignancies.

Effect of selenium supplementation on platelet selenium, glutathione peroxidase, and aggregation

The selenium content of platelets is extremely high. About half of this selenium originates from irreversible incorporation by bone marrow precursor cells, which satisfy their need for selenium even under conditions of marked selenium deficiency. In order to study the effect of increased dietary selenium supply on the concentration of selenium, glutathione peroxidase (GSH-Px-) activity, and aggregability of platelets, normal healthy subjects were supplemented with 300 micrograms of selenium as Se-rich yeast/d for 3 mo. No significant effect of Se supplementation on platelet Se and GSH-Px were observed, whereas erythrocytes accumulated Se without reaching saturation. Although platelet aggregability was variable during the period of observation, this was traced back to factors other than selenium, including environmental temperature. This study demonstrates that the selenium concentration of platelets is subject to tight physiological control also at high dietary selenium intakes.