Protein synthesis in liver following infusion of the catabolic hormones corticosterone, epinephrine, and glucagon in rats

The mediator(s) and mechanism(s) of acute-phase protein synthesis in the liver following injury and sepsis are not fully known. Elevated plasma levels of the catabolic hormones cortisol, glucagon, and epinephrine have been reported in trauma and sepsis. In previous reports, when these hormones were infused simultaneously (triple hormone infusion), several, but not all, of the metabolic alterations characteristic of sepsis occurred. In the current investigation, the effect of triple hormone infusion on hepatic protein synthesis was studied. Rats were infused intravenously during 16 hours with a solution containing corticosterone (4.2 mg/kg/h), glucagon (2.5 micrograms/kg/h), and epinephrine (6 micrograms/kg/h). Control animals were infused with a corresponding volume of vehicle. Total hepatic protein synthesis in vivo was measured with a flooding dose technique using [14C]-leucine. The synthesis of total secretory proteins and of the individual proteins albumin, complement component C3, and alpha 1-acid glycoprotein was measured in isolated, perfused liver using [3H]-leucine and a recirculating technique. Urinary excretion of nitrogen and plasma concentration of glucose were higher and plasma total amino acid concentration was lower in hormone-infused than in control rats. Total hepatic protein synthesis in vivo, expressed as the proportion of the protein pool that was replaced each day, was increased from 39% +/- 2% per day to 48% +/- 3% per day (P less than .05) by hormone infusion, but synthesis of secretory proteins in perfused liver was not significantly altered. The results suggest that although total hepatic protein synthesis may be increased by catabolic hormones, other mediator(s) are probably responsible for the stimulation of acute-phase protein synthesis in sepsis.

Ambulatory care use among the noninstitutionalized elderly. A causal model

While it is recognized that need for care is the dominant factor influencing utilization of health services, little is known regarding the determinants of ambulatory care use by the noninstitutionalized elderly. It is important to examine the relationships among need factors and how physical and mental dysfunctions influence use of services. This study uses a LISREL model to identify the extent to which ambulatory care use was affected by physical or mental functioning and whether strong linkages would be exhibited by both factors.

How many myocardial infarctions should we rule out?

We used computer simulation to estimate the consequences of four admitting strategies (coronary care unit, intermediate care unit, routine ward care, or outpatient follow-up) on cost, outcome, admission threshold probabilities, and false-positive admission rates for patients with acute myocardial infarction. At virtually any probability of acute myocardial infarction, replacing more intensive by less intensive strategies saved money but increased mortality and decreased life expectancy. Therefore, choices among strategies may be made by using the most effective strategy for progressively lower and lower risk patients until the additional cost per additional life saved reaches a cutoff value; then, a less expensive strategy is selected. With sample cutoff values of $1 and $2 million per life saved, the marginal threshold admission probabilities were: (table; see text) These results imply that the acceptable proportion of false-positive admissions may be as high as 70% to 80%; lower rates could indicate excessively restrictive admitting policies. Clinicians may be operating closer to the optimal decision point than has previously been asserted.

Effect of sepsis on calcium uptake and content in skeletal muscle and regulation in vitro by calcium of total and myofibrillar protein breakdown in control and septic muscle: results from a preliminary study

Because high calcium concentration in vitro stimulates muscle proteolysis, calcium has been implicated in the pathogenesis of increased muscle breakdown in different catabolic conditions. Protein breakdown in skeletal muscle is increased during sepsis, but the effect of sepsis on muscle calcium uptake and content is not known. In this study the influence of sepsis, induced in rats by cecal ligation and puncture, on muscle calcium uptake and content was studied. Sixteen hours after cecal ligation and puncture or sham operation, calcium content of the extensor digitorum longus (EDL) and soleus (SOL) muscles was determined with an atomic absorption spectrometer. Calcium uptake was measured in intact SOL muscles incubated in the presence of calcium 45 (45Ca) for between 1 and 120 minutes. Total and myofibrillar protein breakdown was determined in SOL muscles, incubated in the presence of different calcium concentrations (0; 2.5; 5.0 mmol/L), and measured as release into the incubation medium of tyrosine and 3-methylhistidine (3-MH), respectively. Calcium content was increased by 51% (p less than 0.001) during sepsis in SOL and by 10% (p less than 0.05) in EDL muscle. There was no difference in 45Ca uptake between control and septic muscles during the early phase (1 to 5 minutes) of incubation. During more extended incubation (30 to 120 minutes), muscles from septic rats took up significantly more 45Ca than control muscles (p less than 0.05). Tyrosine release by incubated SOL muscles from control and septic rats was increased when calcium was added to the incubation medium, and at a calcium concentration of 2.5 mmol/L, the increase in tyrosine release was greater in septic than in control muscle. Addition of calcium to the incubation medium did not affect 3-MH release in control or septic muscle. The results suggest that calcium uptake and content in skeletal muscle are increased during sepsis and that high calcium concentrations in vitro stimulate nonmyofibrillar protein breakdown. Muscles from septic animals may be more sensitive to the effect of calcium in vitro than muscles from nonseptic rats. Whether increased calcium uptake and content in skeletal muscle is partly responsible for accelerated muscle proteolysis during sepsis remains to be determined.

Total and myofibrillar protein breakdown in different types of rat skeletal muscle: effects of sepsis and regulation by insulin

Proteolysis is increased in sepsis, but it is not known whether myofibrillar and non-myofibrillar proteins are broken down in the same fashion, or respond to the same regulatory forces as in non-septic muscle. In this study, therefore, the effect of sepsis on total and myofibrillar protein breakdown in incubated rat extensor digitorum longus (EDL) and soleus (SOL) muscles was determined, and the response in vitro to different concentrations of insulin (10 to 10(5) microU/mL) of protein degradation was studied in incubated EDL muscles from control and septic rats. Sepsis was induced in rats weighing 40 to 60 g by cecal ligation and puncture (CLP). Control animals were sham operated. Sixteen hours after CLP or sham operation, intact EDL and SOL muscles were incubated for two hours in oxygenated Krebs-Henseleit bicarbonate buffer containing glucose (10 mmol/L) and cycloheximide (0.5 mmol/L), and total and myofibrillar protein breakdown was assessed from release into incubation medium of tyrosine and 3-methylhistidine (3-MH), respectively. Tyrosine and 3-MH were determined fluorometrically by high performance liquid chromatography (HPLC). Tissue levels of tyrosine and 3-MH remained stable both in control and septic muscles during incubation for two hours. The rate of tyrosine release was increased during sepsis by 58% (P less than .001) and 15% (NS) in EDL and SOL muscle, respectively. The corresponding figures for 3-MH were 103% (P less than .001) and 21% (NS). Tyrosine release was reduced by insulin at a concentration of 10(3) microU/mL in control muscle and at a concentration of 10(4) microU/mL in septic muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

The comparability of solicited versus clinic subjects in alcohol treatment research

The increasing use of media advertisements to recruit subjects in alcohol treatment research has raised concerns about the comparability of such solicited subjects and subjects drawn from more traditional clinic populations. This paper, based on a study that involved both solicited and clinic subjects, identifies differences between the two types of subjects in terms of sociodemographic variables; pre-treatment drinking and marital adjustment; several dimensions of 'self-definition'; and three outcome measures. These findings suggest that there may be significant differences between solicited and clinic subjects and that these differences should be taken into account in the design of studies utilizing solicited subjects in order to determine the generalizability of the results.

[Subcloning of K88ac antigen gene of enterotoigenic E. coli and the restriction map of recombinant plasmid]

We had reported a recombinant E. coli RR1(pNZ8801) which was obtained from a wild strain E. coli 79-1454. The recombinant plasmid was digested by EcoRI and generated three segments, medium segment (3.2Md) was removed, the largest and the smallest segment was ligased, then the mixture was transformed into E. coli RRI, screening Ap(r) Tc(s) clones, one of recombinants was named E. coli RR1(pNZ8802). The recombinant plasmid molecular weight is smaller, but expression of K88ac antigen is higher than first cloning. Subcloning can adhere to mucosae of piglet's intesting. Therefore, the recombinant can be use for oval living vaccine.

Lithium increases rat striatal beta- and gamma-preprotachykinin messenger RNAs

Previous reports indicate that the antimanic drug, lithium, increases substance P-like immunoreactivity (SP-LI) in the basal ganglia. The aim of this study was to use lithium as a pharmacological tool to further understand the mechanism of this process. We have used solution hybridization-nuclease protection assays to quantitate the specific preprotachykinin (PPT) mRNAs and radioimmunoassays and immunocytochemistry to assess SP-LI levels in the striatum of male Fisher F-344 rats. A regimen of subchronic administration of lithium (4 mEq/kg i.p. for 1, 2, 4 or 6 days) increased SP-LI in a time-dependent fashion. Concurrent administration of a dopamine receptor antagonist, haloperidol (1 mg/kg s.c. for 4 days) with a 4-day lithium regimen partially blocked the lithium-induced increase in SP-LI as well as neurokinin A-like immunoreactivity. An analysis of the abundance of individual PPT mRNAs indicated that lithium increases beta- and gamma-PPT mRNAs in the striatum; coadministration of haloperidol attenuates the lithium-induced increases. These results indicate that lithium affects the tachykinin biosynthetic process by accelerating transcriptional and/or translational processes in striatonigral neurons and that the dopaminergic system appears to be partly involved in this process.

Hemodynamic and metabolic alterations during experimental sepsis in young and adult rats

Cecal ligation and puncture (CLP) has been extensively used as a model of sepsis in adult rats. It is not known if the response to sepsis is similar in young and adult rats. This investigation was done to compare hemodynamic and metabolic alterations in young (four to six weeks of age, 60 to 90 grams) and adult (12 to 14 weeks of age, 270 to 340 grams) rats after CLP. In one series of experiments, survival rate was determined for 96 hours, and in other experiments, mean arterial blood pressure (MAP), heart rate (HR), white blood cell count, hematocrit, platelets, plasma glucose, lactate, amino acids, blood urea nitrogen (BUN), blood and peritoneal cultures and resting energy expenditure (REE) were determined eight and 16 hours after CLP. Levels of glycogen in liver and muscle were determined 16 hours after CLP. Mortality rate was similar in young and adult rats. MAP was stable throughout the course of sepsis, with no significant differences between the two groups of rats. HR was higher in young rats at all times studied. The adult rats became hyperglycemic after CLP while the young were hypoglycemic eight hours after CLP but normalized at 16 hours. Plasma lactate and BUN were similar in the two groups of rats, and no alterations were seen during sepsis. Both young and adult rats became hypoaminoacidemic after CLP. The phenylalanine to tyrosine ratio increased in a similar manner during sepsis in both experimental groups. REE was higher in young than in adult rats, but no significant changes were observed during the course of sepsis in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ciclosporin and protein synthesis inhibitors on cutaneous inflammation in mouse skin

Ciclosporin is clinically effective in a variety of inflammatory skin diseases. We have therefore studied the effects of the drug on cutaneous inflammation in mice. Ciclosporin inhibited the inflammatory response to 12-O-tetradecanoylphorbol-13-acetate (TPA) and to the contact sensitising agent oxazolone when applied topically to mouse skin. The drug had no effect on arachidonic acid-induced inflammation. The protein synthesis inhibitor cycloheximide showed a similar profile of activity. Ciclosporin, like actinomycin D but unlike cycloheximide, was only effective in inhibiting the inflammatory response to TPA if given 0.5 h before, but not 2 h, after TPA. These results suggest that the anti-inflammatory activity of ciclosporin in the skin is due to an effect on the production of proinflammatory proteins.

Bst-1 RFLP at the human lipoprotein lipase (LPL) gene locus

Images

Pharmacological modification of 12-0-tetradecanoylphorbol-13-acetate induced inflammation and epidermal cell proliferation in mouse skin

Topical application of TPA to mouse skin causes oedema (2-6 h) neutrophil influx (3-24 h) and epidermal cell proliferation (24-48 h). Topical application of a cyclooxygenase inhibitor (indomethacin) dual cyclooxygenase and lipoxygenase inhibitors (phenidone and BW755C) a selective lipoxygenase inhibitor (AA861), protein synthesis inhibitors (cycloheximide and actinomycin D) or a glucocorticosteroid (prednisolone) inhibited oedema and neutrophil influx. Systemic administration of an inhibitor of microtubule assembly (colchicine) also prevented neutrophil influx and oedema. These results suggest that the inflammatory response to TPA depends on an interaction between a protein and products of arachidonic acid metabolism to produce a neutrophil dependent oedema. Epidermal cell proliferation was inhibited by topical administration of prednisolone, indomethacin, BW755C and cycloheximide but not systemically administered methotrexate. This suggests that inhibition of the early inflammatory response to TPA prevents the subsequent epidermal proliferation.

Studies on the physiological role and mechanism of action of neuropeptide Y in the regulation of luteinizing hormone secretion in the rat

It has been recently shown that intraventricular or systemic injection of neuropeptide Y (NPY) can produce a decrease in plasma luteinizing hormone (LH) levels in castrated rats of both sexes. In order to evaluate the physiological role of NPY in the regulation of LH secretion in the female rat, we proceeded to immunoneutralization experiments using specific antibodies to NPY. Injection of 0.5 ml antiserum to NPY produce a 20-fold increase of LH plasma levels, whereas injection of preimmune serum did not modify the plasma concentrations of LH. To investigate the possibility that catecholamines or serotonin might be involved in the effect of NPY in LH secretion, castrated rats were treated with alpha-methylparatyrosine (alpha-MPT), an inhibitor of catecholamine biosynthesis, or received an i.c.v. injection of the neurotoxin 5-7-dihydroxytryptamine (5,7-DHT) prior to the intraventricular injections of NPY. The pretreatment with alpha-MPT could not prevent the decrease of plasma LH induced by NPY injection whereas the pretreatment with 5,7-DHT reversed the effect of NPY injection. The anatomical connection between LH-releasing hormone (LHRH) and NPY neuronal systems were also investigated using double immunostaining technique. It appeared that NPY endings are in apposition to LHRH cell bodies in the preoptic area in proximity to the organum vasculosum of the lamina terminalis (OVLT).(ABSTRACT TRUNCATED AT 250 WORDS)

Alteration in chromatin conformation of proliferating and differentiating enzyme genes in normal mouse liver and ascites hepatoma cells and its relation to the gene expression of enzymes

Nuclei from the normal mouse liver were partially digested with micrococcal nuclease, followed by DNA extraction, agarose gel electrophoresis and dot blot hybridization with 32P-labeled cDNA probes of CPS1 and ACT complex. It was clearly shown that the CPS1 genes were distributed on the monomer, dimer. and trimer of nucleosomes, while the genes coding for ACT complex were distributed on the condensed oligonucleosomes. An opposite manner of distribution of CPS1 and ACT complex genes was, however, noted in the case of ascites hepatoma cells, in which the specific activity of ACT was 13 times higher than that in the normal liver, while that of CPS1 was remarkably reduced. Similar patterns of change in mRNA level of CPS1 and ACT complex were observed in the normal mouse liver and ascites hepatoma cells, indicating a close relationship between chromatin structure and gene expression of these enzymes.

The effect of suture material on platelet deposition onto prosthetic material

Previous studies have demonstrated the importance of employing prosthetic material with minimal thrombogenicity. However, the role of different suture materials in early thrombotic events on prosthetic materials has not been examined. Experiments were designed to analyze the effects of suture on platelet graft interaction using an in vivo baboon hemocompatability screen. 111Indium labeled, autologous platelet deposition was determined on expanded polytetrafluoroethylene (ePTFE) containing suture lines of polypropylene (Prolene), polybutester (Novafil), and ePTFE (Gore-Tex). A significant increase in platelet deposition was noted not only at the suture line, but proximal and distal to it as well. The results were different for each of the sutures employed and suggest that the suture line may influence early platelet deposition in the perianastomotic region, not only at the suture line, but proximally and distally as well.

Increasing dextrose concentrations in total parenteral nutrition (TPN) causes alterations in hepatic morphology and plasma levels of insulin and glucagon in rats

Hepatic steatosis is an ongoing problem in total parenteral nutrition (TPN). The etiology of this deranged hepatic morphology is unclear, but lack of enteral stimulation and excess carbohydrate calories have been suggested as altering the intestinal hormone profile. In this study, adult male Sprague-Dawley rats (n = 28) received internal jugular catheters: group 1 (n = 7) received saline (3 cc/hr) and chow ad libitum; groups 2, 3, and 4 (n = 7) received 15, 20, and 25% dextrose-base TPN solutions, respectively, in quantities matching the caloric intake of paired ad libitum animals. At 7 days portal and peripheral venous blood samples were drawn for insulin and glucagon radioimmunoassay, and livers were removed for histologic examination and determination of total hepatic lipid content. Portal and peripheral insulin levels rose in a linear fashion with increasing dextrose concentration. Lipid content increased with elevated portal venous insulin/glucagon ratio in groups 3 and 4. Periportal fatty infiltration increased with increasing dextrose concentrations. The results suggest that the liver's response to altered portal insulin/glucagon ratio may play an important role in changes of hepatic morphology associated with TPN.

[Inhibitory effect of UFT on postoperative lung metastasis of mammary adenocarcinoma in SHR rats]

It is well known that UFT has significant therapeutic effects against experimental and clinical cancers at the primary sites. In this experiment, we studied the inhibitory effect of UFT on the lung metastasis of spontaneously developed rat mammary carcinoma (SST-2) after surgical excision of the primary site. In comparison of UFT-treated (15 or 30 mg/kg/day) with 5-FU-treated (9.7 or 19.5 mg/kg/day) groups, UFT was more effective than 5-FU in the antitumor activity and the inhibitory effect of lung metastasis with/without surgical excision of the primary sites. Rats (5-10 rats per group) were inoculated s.c. with 1 x 10(6) SST-2 cells and administered with UFT orally (15, 30 or 60 mg/kg/day) starting the day after tumor inoculation for 30 days. The therapeutic effect of UFT was studied by the growth rate of primary tumor and the numbers of metastatic colonies in the lung 35 days after tumor inoculation, comparing the UFT-treated with control groups. UFT administration at the doses of 30 or 60 mg/kg/day markedly inhibited the growth of the primary tumors and the number of metastatic lung colonies decreased, compared with that of the control group. However, in the group of rats treated at the dose of 60 mg/kg/day, 60% of rats died from the side effects of UFT such as weight loss, hemorrhage etc. In all groups in which the primary tumors were surgically excised 20 days after tumor inoculation and then treated with UFT (15, 20 or 30 mg/kg/day), we observed marked prolongation of survival period and inhibition of lung metastasis as well. Furthermore, we studied the effect of combination therapy of UFT and lentinan (1 mg/kg/day i.p.) on the metastasis of SST-2 cells after surgical excision of the primary sites. It was more effective than UFT alone. Thus, it is clear that UFT is an effective anticancer drug to inhibit metastasis of tumors in the lung after surgical excision of primary tumor.

Surgical care of submental gunshot wounds

The care of patients with self-inflicted facial gunshot wounds is complex and challenging. The magnitude and self-inflicted nature of the injuries naturally give rise to questions about potential for successful rehabilitation. The surgical care and rehabilitation of ten such patients are described. The initial grotesque disfiguration belies the reasonable chances for functional restoration. Patients in this series who completed reconstruction swallow well enough to maintain body weight, speak understandably, breathe without tracheostomy, and have an appearance sufficiently normal that they can interact socially without embarrassment. Guidelines are proposed for multidisciplinary medical care leading to satisfactory functional, aesthetic, social, and psychiatric rehabilitation.

Lithium increases dynorphin A(1-8) and prodynorphin mRNA levels in the basal ganglia of rats

The aim of this study was to understand the possible influence of the antimanic drug, lithium, and the neuroleptic, haloperidol, alone or in combination, on the regulation of dynorphin biosynthesis in the striatum. The study was done using male Fisher-344 rats subjected to a regimen of subchronic administration of lithium chloride (4 mEq/kg/day for 1,2,4 or 6 days, i.p.) or a regimen of chronic oral administration of a diet containing lithium carbonate (1.5 g/kg of the diet). Subchronic administration of lithium increased striatal dynorphin A(1-8)-like immunoreactivity (DN-LI) in a time-related fashion. Immunocytochemistry revealed an increase in DN-LI in fibers and cells clustered in 'patches' throughout striatum. The increase in DN-LI was reversible on cessation of lithium administration. Concurrent administration of lithium and an opiate antagonist, naltrexone, or a dopamine receptor antagonist, haloperidol, did not influence the changes induced by lithium. Chronic oral administration of lithium for 21 days led to an increase in DN-LI in the striatum. Co-administration of haloperidol with the 21 day regimen of lithium administration failed to affect the increase in DN-LI. The prodynorphin mRNA abundance in the striatum was quantitated by a molecular hybridization procedure using a prodynorphin 32P-cRNA probe generated from the Riboprobe system. Evidence from the Northern blot analysis reveals that lithium increases the prodynorphin mRNA abundance in the striatum. These results indicate that lithium affects the dynamics of prodynorphin biosynthesis in the striatum, presumably increasing transcription and/or translational processes.

Immunohistochemical markers in the normal human epibulbar conjunctiva from fetus to adult

Monoclonal antibodies were used for the study of inflammatory cellular subtypes, Langerhans' cells, and major histocompatibility complex class II antigens on the epibulbar conjunctiva obtained from individuals ranging in age from fetus to the seventh decade to compile basic data for comparison with other inflammatory and proliferative conjunctival diseases. In the fetal conjunctiva, there were significantly fewer T cells and Langerhans' cells than in adult conjunctiva. In the adult conjunctiva, a mild T-cell infiltration was observed. Expression of HLA-DQ in the 20- to 50-year-old age group was significantly lower compared with fetal and other age groups.

Distribution of red cell blood group systems in Yi, Tibetan and Manchu ethnic groups in China

A survey on distribution of ten red cell blood group systems was carried out in 1985 in the Yi, Tibetan and Manchu nationalities in China. Significant differences were found in the distribution of Rh, MNSs, P and especially in the ABO system, while no significant difference was found for Diego, Duffy, Kell, Kidd and XG systems. The DI*a gene frequency was about 0.03, FY*a rather high (0.94), KEL*K extremely low (0.005) and JK*a was about 0.4. In the three nationalities under study, Yi is characterized by high frequencies of the alleles A, M and CDe and by the absence of CDE and Cde. Tibetans show a high frequency of O and a relatively high frequency of P*P1, while Manchus have the lowest frequency of M and in particular of MS.

Melanin-concentrating hormone (MCH) is colocalized with alpha-melanocyte-stimulating hormone (alpha-MSH) in the rat but not in the human hypothalamus

Melanin-concentrating hormone (MCH)-containing neurons have recently been localized in the dorsolateral region of the rat hypothalamus, an area where the second alpha-MSH system is found which contains only alpha-MSH and none of the pro-opiomelanocortin (POMC)-related peptides. In order to study the morphological relationships between the MCH and alpha-MSH neuronal systems, we have studied the immunocytochemical localization of both MCH and alpha-MSH in the rat hypothalamus. The same study was also performed in the human hypothalamus where there is only one alpha-MSH system which contains alpha-MSH as well as the other POMC-related peptides (first alpha-MSH system). In the rat dorsolateral hypothalamus, we could demonstrate that most neuronal cell bodies stained for MCH also contained immunoreactive alpha-MSH. In the human hypothalamus, neuronal cell bodies stained for MCH were observed only in the periventricular area whereas cell bodies containing alpha-MSH were exclusively located in the infundibular (arcuate) nucleus. In the rat, immunoelectron microscopy showed labelling for MCH in the dense core vesicles of positive neurons and double-staining techniques clearly demonstrated that both immunoreactive MCH and alpha-MSH could be consistently detected in the same dense core vesicles. These ultrastructural studies then suggest that these two peptides should be released simultaneously from neurons located in the rat dorsolateral hypothalamus.

Regulation of the concentration of dynorphin A1-8 in the striatonigral pathway by the dopaminergic system

The purpose of this study was to explore the dopaminergic control of the striatonigral dynorphin system by measuring the levels of dynorphin A1-8-like immunoreactivity (DN-LI) after repeated injections of a dopaminergic receptor agonist or antagonist. Seven daily injections of different doses of apomorphine (0.5, 1.0, 2.5 and 5.0 mg/kg, s.c.) caused a significant dose-related increase of DN-LI in the striatum (26, 34, 63, 85% over control at each corresponding dose). Similar increases were observed in the substantia nigra (22, 52, 50 and 62% over control). In another experiment, rats received 5 mg/kg of apomorphine for 1, 3, and 7 days. There was a significant time-related increase in DN-LI both in the striatum (37, 50 and 85% over control at each corresponding period) and in the substantial nigra (32, 78 and 62%). Repeated administration of haloperidol (1 mg/kg, i.p.) failed to change the striatal level of DN-LI, but, when given at the same time as apomorphine, significantly attenuated the effect of apomorphine. These results suggest that dopamine exerts a modulatory influence on the metabolism of dynorphin in the striatonigral pathway.

The role of dopamine in the control of neuropeptide Y neurons in the rat arcuate nucleus

In order to determine the role of dopamine (DA) on neuropeptide Y (NPY) neurons in the arcuate nucleus of the rat hypothalamus, we evaluated the effects of alpha-methylparatyrosine (alpha-MPT), an inhibitor of catecholamines biosynthesis, and haloperidol, a dopaminergic antagonist, on NPY immunoreactive neurons. The two drugs used produced in the arcuate nucleus the appearance of a large number of NPY-containing neuronal bodies which are normally absent in control animals. The density of stained fibers were not significantly modified. These results suggest that DA can exert some negative regulation of NPY neurons activity in the arcuate nucleus.

Effect of azimexon therapy on host defense parameters and disease-associated symptoms in the acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC)

Azimexon, a 2-cyan-aziridinyl immune modulator, was given at a dose of 250 mg/m2/day for 10 days IV to 12 patients with AIDS and 16 with AIDS related complex (ARC). A decrease in total number of AIDS related symptoms from 43 to 24 and in mean number from 2.6 to 1.5 was observed among ARC patients (p less than .01). The most commonly improved symptoms were diarrhea, fatigue, and weight loss with the least frequently improved being lymphadenopathy. The following improvements in immune parameters were observed among ARC patients. DTH to recall antigens improved with an increase in number of positive tests from 35 to 47 and in mean number of positive skin tests from 2.2 on day 0 to 2.9 on day 14 (P less than .05). The geometric mean of the absolute lymphocyte count was 1.395 X 10(3)/microliter on day 0 with a significant increase of 18.0 percent on day 5 (P less than .01) and a 7.7 percent increase on day 21. The geometric mean of the OKT4+ cells on day 0 was 0.250 X 10(3)/microliter with a 33.3 percent increase on day 5 (P less than .07) and a 14.1 percent increase on day 21. T4/T8 ratio increased by 32.7 percent on day 5 (P less than .05) and by 19.4 percent on day 21 from an initial geometric mean of 0.339 X 10(3)/microliter on day 0. The geometric mean of GVH responses increased by 18.2 percent on day 5 (P less than .05) and by 24.0 percent on day 21 (P less than .07) from an initial value of 41.04 mm3. No symptomatic or immunologic improvements were observed among AIDS patients, but rather a significant decrease in mitogenic responses. PHA responses decreased by 70.3 percent on day 5 (P less than .05) and 42.2 percent on day 21 from an initial geometric mean of 4.02 X 10(3) cpm/10(3). Con-A responses decreased by 75.1 percent on day 5 (P less than .05) and increased by 20.3 percent on day 21 from an initial value of 1.14 X 10(3)/10(5) cells. Pretreatment number of absolute OKT4+ cells was the most significant prognostic survival variable. Thus, 8/9 patients with less than 0.10 X 10(3) OKT4+ blood cell/microliter subsequently died as compared to only 1/17 with greater than or equal to 0.10 X 10(3) OKT4+ cells (p less than .001). The only toxic effect of this treatment was mild hemolysis which disappeared upon cessation of treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Delineation of two distinct regulatory domains in the 5' region of the nar operon of Escherichia coli

A detailed restriction site map was determined for an 8.4-kilobase DNA fragment containing the 5' regulatory and promoter region of the nar operon of Escherichia coli. The 5' end of the nar operon was subcloned as a 2.5-kilobase fragment, and an intact nar operon was constructed from this subcloned fragment and an EcoRI fragment containing the remainder of the nar operon. A set of Bal 31 deletions extending into the 5' region of the intact operon was selected, mapped, and characterized. Based on the synthesis of the alpha and beta subunits of nitrate reductase in a nar::Tn5 mutant, three categories of deletions were found: (i) those which permitted normal expression, (ii) those which completely prevented expression, and (iii) those which permitted anaerobic expression of the operon but prevented any additional induction by nitrate. The nucleotide sequence was determined for a segment of the nar promoter region starting at one of the latter deletion end points and extending into the first structural gene of the operon. The position of the deletion end point relative to the translation start site for the first structural gene, narG, was defined by identifying the nucleotide sequence for the first 20 N-terminal amino acid residues of the alpha subunit of nitrate reductase. Deletions terminating 161 base pairs (bp) and approximately 200 bp upstream from the narG translation start site permitted anaerobic formation of nitrate reductase but interfered with the stimulation of nar operon expression by nitrate. A maximum size for the regulatory region was defined by two Tn5 insertions, which mapped approximately 550 bp 5' from the translation start site and did not interfere with the normal expression of nitrate reductase under anaerobic conditions with or without nitrate. We conclude that the nar operon 5' regulatory region is divided into two distinct regions: the 100 to 150 bp immediately 5' to the narG gene include a transcriptional start site and the signals necessary for anaerobic expression of the operon, and an adjacent region of 50 to 400 bp is required for the stimulation of operon expression by nitrate.

Abnormalities of myeloid progenitor cells after "successful" bone marrow transplantation

We studied recovery of peripheral blood- and bone marrow-derived myeloid progenitor cells (CFU-G,M) in 29 patients who received bone marrow transplants 2 mo to 8.5 yr previously. All patients had normal levels of peripheral blood neutrophils, normal bone marrow cellularity, and a normal myeloid-erythroid ratio. Both peripheral blood- and bone marrow-derived CFU-G,M were markedly reduced compared with normal controls and bone marrow donors [5 +/- 1/10(6) vs. 37 +/- 4/10(6) (P less than 0.001) and 23 +/- 5/2 x 10(5) vs. 170 +/- 21/2 x 10(5) (P less than 0.001)]. Five patients had no detectable CFU-G,M even when 10(6) bone marrow cels were plated. These abnormalities of CFU-G,M were unrelated to age, sex, diagnosis, conditioning regimen, dose of bone marrow cells transplanted, and presence or absence of graft-vs.-host disease. Patients who received either autotransplants or transplants from identical twins also had decreased or absent CFU-G,M indicating that allogeneic factors and posttransplant immune suppressor with methotrexate or corticosteroids were not major determinants of this abnormality. Co-culture of normal or donor peripheral blood or bone marrow mononuclear cells with recipients peripheral blood or bone marrow mononuclear cells, purified T cells, or serum failed to show any evidence of active CFU-G,M suppression. Furthermore, the abnormality of CFU-G,M could not be corrected by the addition of normal syngeneic (donor) hematopoietic cells or serum. Depletion of T-cells from recipient bone marrow by physical techniques resulted in marked increase in CFU-G,M (36 +/- 13 vs. 138 +/- 36; P less than 0.05). The abnormality could be reproduced in vitro by readdition of autologous T cells. In contrast to results with T cell depletion by physical techniques, T cell depletion with a monoclonal anti-T antibody (B7) and complement had no effect. These data indicate that most-transplant recipients have a marked abnormality in CFU-G,M when these cells are cultured in vitro. In at least some of these patients, the decreased cloning efficiency of CFU-G,M appears to be mediated by a suppressive effect of autologous T cells.

Current status of activity assays for tissue plasminogen activator

Tissue plasminogen activator (TPA) is a serine protease involved in the fibrinolytic system that dissolves blood clots. The enzyme catalyzes the conversion of a zymogen, plasminogen, to the enzymatically active form, plasmin, by limited proteolysis. In the course of searching for specific activity assays that might be useful in monitoring the purification of TPA, we have developed several coupled photometric assays. In addition, radioactive, agarose-plate, and other activity assays have also been considered and investigated for this purpose (Table 1). We have previously reported the one-step photometric procedure consisting of a thioester, thiobenzyl benzyloxycarbonyl-lysine (Z-Lys-S-Bzl) and fibrinogen-coated plates. It is simpler and more sensitive than the old two-step method without using immobilized fibrinogen. The new assay has been used successfully for protein purification and can be easily adapted to automated processes. Recently, other chromogenic substrates, D-Val-L-Leu-L-Lys-p-nitroanilide (Val-Leu-Lys-pNA) and D-Ile-L-Pro-L-Arg-p-nitroanilide (Ile-Pro-Arg-pNA) were also used in the one-step assay. It is found that TPA activity is greatly enhanced by immobilized fibrinogen and free fibrinogen when either the thioester. Val-Leu-Lys-pNA, or Ile-Pro-Arg-pNA were used in the colorimetric assay (Fig. 1, A-D). Enzyme kinetics studies indicate that the Km for plasminogen assayed on the thioester and fibrinogen-coated plates is 1.5 micrograms per ml, which is substantially lower than that observed in untreated plates (4.8 micrograms per ml). This is not due to the effect of fibrinogen on the second step of the coupled photometric assay because there is no change in the plasmin activity under these conditions (Fig. 1E). Similar results in TPA activation have also been observed, when fibrin-coated plates were used. Free fibrinogen, which is an activator of TPA, has been included in the standard assay mixture. We are able to detect less than 1 ng of TPA activity within a one-hour incubation time at 20 degrees C (Fig. 2A). In the thioester assay, however, high concentrations of reducing agents and nonspecific proteins cause significant background due to the interaction of DTNB with these reagents. 125I-labeled fibrin-coated plates had been extensively used in the past for urokinase and TPA assays. Although the sensitivity of the radioactive procedure is equivalent to that of the thioester photometric method, it appears that the kinetics of the enzyme are not easy to follow nor is the reproducibility great.(ABSTRACT TRUNCATED AT 400 WORDS)