Neural regulation of coronary vascular resistance: role of nitric oxide in reflex cholinergic coronary vasodilation in normal and pathophysiologic states

A number of reflexes participate in the control of coronary vascular resistance through activation of the sympathetic or parasympathetic nervous system. Classically, activation of vagal efferent fibers to the heart results in vasodilation due to the release of acetylcholine and activation of muscarinic receptors. Recently, we have found that activation of a number of reflexes in conscious dogs, the Bezold-Jarisch reflex and the carotid chemoreflex in particular, results in cholinergic coronary vasodilation which is blocked by an inhibitor of nitric oxide synthesis, nitro-L-arginine. After the development of pacing-induced heart failure, the cholinergic dilation subsequent to activation of the Bezold-Jarisch or carotid chemoreflex is essentially abolished, since coronary blood vessels no longer produce nitric oxide. In contrast, after brief exercise training, there is a potentiation of Bezold-Jarisch reflex-induced coronary vasodilation since exercise upregulates nitric oxide production by coronary blood vessels. Since the Bezold-Jarisch reflex may be important as a compensatory mechanism during acute myocardial infarction, and the carotid chemoreflex is the acute mechanisms responsible for ameliorating systemic hypoxemia, the role of nitric oxide in reflex cholinergic coronary vasodilation may be essential in the compensatory vascular adjustments evoked by these and other reflexes.

Herbs of the genus Phyllanthus in the treatment of chronic hepatitis B: observations with three preparations from different geographic sites

It has been suggested that herbs of the Phyllanthus family may have antiviral activity. We therefore tested the effects of three different Phyllanthus extracts on the serologic status of 123 patients with chronic hepatitis B. Eleven patients received an extract of Phyllanthus amarus (L) provided by S.P. Thyagarajan, Madras, India. Forty-two patients received Phyllanthus niruri (L), gathered from Hainan Province in China, and 35 patients received an extract of Phyllanthus urinaria (L), which had been gathered in Henan Province. Thirty-five control patients received no herbal therapy. The patients receiving Phyllanthus urinaria (L) were both more likely to lose detectable hepatitis B e-antigen from their serum and more likely to seroconvert hepatitis B e-antibody status from negative to positive than were patients given either of the other two preparations. No patient changed status with respect to hepatitis B s-antigen.

Chemical vapor deposition fabrication and characterization of silica-coated carbon fiber ultramicroelectrodes

Carbon fiber disk ultramicroelectrodes (UMEs) with well-defined geometries were prepared by chemical vapor deposition techniques. Transparent silica films with thicknesses from 1 to 600 microns were deposited on the cylindrical length of 5 and 10 microns carbon fibers from a SiCl4, H2, and O2 ternary precursor system at 850-1150 degrees C or sequential deposition from Si(OEt)4 as a single source precursor at 700 degrees C followed by the SiCl4, H2, and O2 precursor system. Film thickness, film adhesion to the fiber substrate, and the overall dimensions of the silica-coated carbon fiber were studied and found to be a function of the precursor system, precursor concentrations, fiber diameter, deposition time, and fiber temperature. The silica films were found to be free of microcracks and characterized by a quality seal between the carbon fiber and the coating. As a result, the silica-coated disk UME exhibits an excellent electrochemical response without the need to use an epoxy sealant at the electrode tip. Furthermore, the deposition of hard and inert ceramic materials imparts durability to fragile carbon fibers and facilitates the handling of UMEs in microenvironments. Finally, the advantage of concentric deposition about the fibers to produce a disk UME in the center of an insulating plane was used to examine the effect of the thickness of the insulating coating on the limiting current response.

[The studies on the effect of proliferative response of peripheral blood lymphocyte of healthy persons by preparations of M. vaccea]

This paper present that preparations of M. vaccea, which included suspensions of live bacilli, irradiation-killed bacilli and high temperature killed bacilli, for the effect on lymphocyte proliferative response of peripheral blood in healthy persons were compared by 3H-TdR incorporation method. CPM of control was 448 +/- 131, CPM adding suspensions of live M. vaccea, irradiation-killed bacilli and high temperature killed bacilli were 1037 +/- 194, 2299 +/- 140, 1819 +/- 528, 994 +/- 186, respectively. Stimulative index of all four preparations were more than 2.0, specially suspensions of live and irradiation killed M. vaccea is more effective than BCG and high temperature killed M. vaccea, which were 5.13, 4.06, respectively. In another experiment, suspensions of live, irradiation-killed and high temperature killed M. vaccea plus rIL-2 were found more effective than rIL-2 alone. CPM of them were 9544 +/- 1727, 8530 +/- 714, 8230 +/- 1035, and 3721 +/- 1336, respectively, but BCG was 6904 +/- 1218. The results show that preparations of M. vaccea tested have distinctly promotive effect for proliferative response of lymphocyte in vitro. The addition of rIL-2 to suspendions of live M. vaccea, irradiation killed and high temperature killed M. vaccea cooperatively increased the effects of proliferative response mentioned above.

[Characters and insecticidal polypeptide of a new strain of Bacillus thuringiensis subsp. kenyae in China]

A new strain of Bacillus thurinigiensis Bt with high toxicity against noctuidae larvae has been screened for many generations since isolated from larvae candle of Aphomia gularis in Yiyang County, Jiangxi Province, in China. By comparison and analysis of results of physiological and biochemical test, flagella antigen identification and esterase type, the strain is identified as H4a-4c Bt serovar. kenyae. Since its crystal protein type and plasmid type are different from those of Bt serovar. kenyae's type 023. The strain is assigned a novel strain: Btken-Ag. Btken-Ag's parasporal crystals are multi-morphorous: bipyramid, cube, small irregular sphere and embedded. After UMT dissolve, PAGE and SDS-PAGE separation preparation and analysis, it is found that its major insecticide component to Heliothis armigera is 61kD toxic protein. By ELISA homology analysis, it is found that this toxic protein has high homology with crystal protein of 023 and 7501 (H4a-4c), partly homology with that of HD-1(H3a-3b), but no homology with that of Bti(H14) and (Bacillus sphaericus) Ts-1 strain. In bioassay with larvae from Culex pipiens, Pseudaletia unipuncta and Heliothis armigera, together with other ten Bt strains, Btken-Ag is toxic to 3 star larvae of Culex pipiens; two isolates of Btken-Ag (b1-4 and H4-1) show higher toxicity than type strain 023 and HD-1 do to Pseudaletia unipuncta and Heliothis armigera.

Nitric oxide production and NO synthase gene expression contribute to vascular regulation during exercise

Nitric oxide (NO) is a vasodilator produced under normal physiologic conditions primarily by the vascular endothelium lining all blood vessels. The primary stimulus for the production of nitric oxide by the constitutive endothelial nitric oxide synthase (ECNOS, Type II) found in blood vessels is most likely the shear stress, the frictional force, caused by blood flowing through blood vessels. During exercise there is an increase in cardiac output and redistribution of blood flow to increase blood flow in skeletal muscle and in the coronary circulation. These adjustments provide increased oxygen delivery to support aerobic energy production and to sustain the exercise response. NO may be involved in the regulation of vascular tone in exercising skeletal and cardiac muscle by promoting, enhancing the metabolic vasodilation. In addition, the production of NO by capillary endothelium may regulate oxygen consumption by mitochondria through chemical interactions between NO and the iron-sulfur center of these enzymes. Finally, brief exercise training may alter the gene expression for the enzyme, the constitutive endothelial NO synthase, which forms NO and may be part of the vascular adaptation seen after aerobic exercise training. Furthermore, if there is a genetic predisposition to produce NO, as in world class athletes or animals bred to race, NO may contribute to spectacular exercise performance. These three potential roles of NO will be discussed and data presented to support each of these in our review.

[Clinical and pathological analysis of patients with hepatic metastases from colorectal cancer]

74 patients with colorectal cancer were divided into group A (34) with liver metastasis and group B (40) without by retrospective analysis. Based on the "Japanese General Rules for Clinical and Pathological Studies on Cancer of Colon, Rectum and Anus", the indicators of clinicopathological S, N, P, V, L, and inf were significantly different between the 2 groups (P < 0.01). But tumor size showed no significant difference between the 2 groups (P > 0.05). In the group A, cases of poorly differentiated carcinoma and medullary type carcinoma were more than those in the group B (P < 0.01).

[Effects of coconut juice on the formation of hyperlipidemia and atherosclerosis]

Eight-week old male quails were fed with high-fat fodder supplemented by 20 milliliters of coconut juice daily for each one for 12 weeks. Results showed coconut juice could increase their serum high density lipoprotein cholesterol levels by 46.2% and reduce their index of atherosclerosis by 41.1% and liver total cholesterol levels by 26.3% in quails, all with a P-value of less than 0.01, as compared in those with high-fat fodder only. Coconut juice could inhibit the formation of atherosclerosis in animals obviously. Coconut juice, as a kind of natural and nutritious drink with an action of keeping-fit, can play certain roles in preventing from hyperlipidemia and atherosclerosis with a dose used in animal experiments.

Selenoperoxidase-dependent glutathione cycle activity in peroxide-challenged leukemia cells

Murine leukemia L1210 cells rendered deficient in glutathione peroxidase (GPX) and phospholipid hydroperoxide glutathione peroxidase (PHGPX) by Se deprivation (L.Se(-) cells) were found to be more sensitive to tert-butyl hydroperoxide (t-BuOOH) cytotoxicity than Se-replete controls (L.Se(+) cells). Human K562 cells, which express PHGPX, but not GPX, were also more sensitive to t-BuOOH in the Se-deficient (K.Se(-)) than Se-satisfied (K.Se(+)) condition. In examining the metabolic basis for selenoperoxidase-dependent resistance, we found that glucose-replete Se(-) cells reduce t-BuOOH to t-butanol far more slowly than Se(+) cells, the ratio of the first-order rate constants approximating that of the GPX activities (L1210 cells) or PHGPX activities (K562 cells). Monitoring peroxide-induced changes in GSH and GSSG gave consistent results; e.g., glucose-depleted L.Se(+) cells exhibited a first order loss of GSH that was substantially faster than that of glucose-depleted L.Se(-) cells. Under the conditions used, peroxide-induced conversion of GSH to GSSG could be stoichiometrically reversed by resupplying D-glucose, indicating that no significant lysis or GSSG efflux and/or interchange had taken place. The apparent first-order rate constant for GSH decay increased progressively for L1210 cells expressing a range of GPX activities from approximately 5% to 100%, demonstrating that peroxide detoxification is strictly dependent on enzyme content. The initial rate of 14CO2 release from D-[1-14C]glucose supplied in the medium was much greater for L.Se(+) or K.Se(+) cells than for their respective Se(-) counterparts, consistent with greater hexose monophosphate shunt activity in the former. These results highlight the importance of selenoperoxidase action in the glutathione cycle as a means by which tumor cells cope with hydroperoxide stress.

Selective impairment of vagally mediated, nitric oxide-dependent coronary vasodilation in conscious dogs after pacing-induced heart failure

BACKGROUND

Activation in conscious dogs of the carotid chemoreflex or cardiac receptors results in coronary vasodilation that is mediated by a vagal cholinergic mechanism. Our previous study showed that the coronary vasodilation following activation of carotid chemoreflex is also mediated by nitric oxide (NO). In addition, NO production is depressed after the development of heart failure. Therefore, we hypothesized that the coronary vasodilation after activation of reflexes that elicit efferent vagal coronary vasodilation would be blunted in conscious dogs after pacing-induced heart failure due to the disappearance of NO.

METHODS AND RESULTS

Mongrel dogs were chronically instrumented using sterile techniques for measurements of systemic hemodynamics and left circumflex coronary blood flow (CBF). Without the heart rate controlled, intra-atrial injection of veratrine (4 micrograms/kg) caused bradycardia (-36 +/- 3 beats per minute). With the heart rate controlled, veratrine increased CBF in a dose-dependent manner: for example, 4 micrograms/kg of veratrine increased CBF by 54 +/- 5% from 38 +/- 4.9 mL/min (P < .05). The increases in CBF induced by veratrine were markedly blunted by nitro-L-arginine (NLA). Activation of carotid chemoreflex by nicotine increased CBF by 121 +/- 9% from 32 +/- 4 mL++/min (P < .05) with the heart rate controlled and caused bradycardia (-32 +/- 5 beats per minute) without the heart rate controlled. After the development of heart failure, in response to activation of carotid chemoreflex or cardiac receptors the coronary vasodilation was almost abolished (CBF increased by only 23 +/- 8% or 11 +/- 3%, P < .05 compared with control). There still was a marked bradycardia after injections of nicotine or veratrine (-50 +/- 11 or -48 +/- 7 beats per minute).

CONCLUSIONS

Our results indicate that vagally mediated coronary vasodilation is selectively attenuated in conscious dogs after pacing-induced heart failure, whereas the vagally mediated bradycardia is preserved. Since muscarinic receptor-induced coronary vasodilation is mediated by NO, the disappearance of NO from blood vessels leads to a defect in the integrated neural regulation of coronary blood flow and myocardial function during heart failure.

Biochemical characterization of gapB-encoded erythrose 4-phosphate dehydrogenase of Escherichia coli K-12 and its possible role in pyridoxal 5'-phosphate biosynthesis

One step in de novo pyridoxine (vitamin B6) and pyridoxal 5'-phosphate biosynthesis was predicted to be an oxidation catalyzed by an unidentified D-erythrose-4-phosphate dehydrogenase (E4PDH). To help identify this E4PDH, we purified the Escherichia coli K-12 gapA- and gapB-encoded dehydrogenases to homogeneity and tested whether either uses D-erythrose-4-phosphate (E4P) as a substrate. gapA (gap1) encodes the major D-glyceraldehyde-3-phosphate dehydrogenase (GA3PDH). The function of gapB (gap2) is unknown, although it was suggested that gapB encodes a second form of GA3PDH or is a cryptic gene. We found that the gapB-encoded enzyme is indeed an E4PDH and not a second GA3PDH, whereas gapA-encoded GA3PDH used E4P poorly, if at all, as a substrate under the in vitro reaction conditions used in this study. The amino terminus of purified E4PDH matched the sequence predicted from the gapB DNA sequence. Purified E4PDH was a heat-stable tetramer with a native molecular mass of 132 kDa. E4PDH had an apparent Km value for E4P [Kmapp(E4P)] of 0.96 mM, an apparent kcat catalytic constant for E4P [kcatapp(E4P)] of 200 s-1, Kmapp(NAD+) of 0.074 mM, and kcatapp(NAD+) of 169 s-1 in steady-state reactions in which NADH formation was determined. From specific activities in crude extracts, we estimated that there are at least 940 E4PDH tetramer molecules per bacterium growing in minimal salts medium plus glucose at 37 degrees C. Thin-layer chromatography confirmed that the product of the E4PDH reaction was likely the aldonic acid 4-phosphoerythronate. To establish a possible role of E4PDH in pyridoxal 5'-phosphate biosynthesis, we showed that 4-phosphoerythronate is a likely substrate for the 2-hydroxy-acid dehydrogenase encoded by the pdxB gene. Implications of these findings in the evolution of GA3PDHs are also discussed. On the basis of these results, we propose renaming gapB as epd (for D-erythrose-4-phosphate dehydrogenase).

Carbon ring-disk ultramicroelectrodes

Novel ring-disk ultramicroelectrodes (RD-UMEs) with analytical tip diameters as small as 25-30 microns were fabricated. Carbon RD-UMEs were reproducibly prepared by the chemical vapor deposition of alternating concentric layers of silica and carbon on resistively heated 10 microns carbon fibers. High-quality films with excellent adhesion at the interfaces between the carbon and silica layers were shown by electrochemical and scanning electron microscopy measurements. Electrochemical measurements of a solution of 1.0 mM ferrocene with 200 mM LiClO4 in CH3CN were used to characterize the single- and dual-electrode response lf the RD-UME. The electrochemical responses of the ring and the disk are sigmoidal in shape and indicated that radial diffusion is the primary mode of mass transport at each electrode at slow scan rates. Diffusion-controlled generation-collection experiments showed that the concentric dual-electrode configuration exhibits high collection efficiencies at the ring electrode with a 2-5 microns separation between electrodes and a 2-4 microns ring thickness. Close proximity of the ring and disk electrodes led to enhanced detection sensitivity due to back diffusion of regenerated molecules of a reversible redox couple from the collector to the generator electrode.

Imidazole acetol phosphate aminotransferase in Zymomonas mobilis: molecular genetic, biochemical, and evolutionary analyses

hisH encodes imidazole acetol phosphate (IAP) aminotransferase in Zymomonas mobilis and is located immediately upstream of tyrC, a gene which codes for cyclohexadienyl dehydrogenase. A plasmid containing hisH was able to complement an Escherichia coli histidine auxotroph which lacked the homologous aminotransferase. DNA sequencing of hisH revealed an open reading frame of 1,110 bp, encoding a protein of 40,631 Da. The cloned hisH product was purified from E. coli and estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to have a molecular mass of 40,000 Da. Since the native enzyme had a molecular mass of 85,000 Da as determined by gel filtration, the active enzyme species must be a homodimer. The purified enzyme was able to transaminate aromatic amino acids and histidine in addition to histidinol phosphate. The existence of a single protein having broad substrate specificity was consistent with the constant ratio of activities obtained with different substrates following a variety of physical treatments (such as freeze-thaw, temperature inactivation, and manipulation of pyridoxal 5'-phosphate content). The purified enzyme did not require addition of pyridoxal 5'-phosphate, but dependence upon this cofactor was demonstrated following resolution of the enzyme and cofactor by hydroxylamine treatment. Kinetic data showed the classic ping-pong mechanism expected for aminotransferases. Km values of 0.17, 3.39, and 43.48 mM for histidinol phosphate, tyrosine, and phenylalanine were obtained. The gene structure around hisH-tyrC suggested an operon organization. The hisH-tyrC cluster in Z. mobilis is reminiscent of the hisH-tyrA component of a complex operon in Bacillus subtilis, which includes the tryptophan operon and aroE. Multiple alignment of all aminotransferase sequences available in the database showed that within the class I superfamily of aminotransferases, IAP aminotransferases (family I beta) are closer to the I gamma family (e.g., rat tyrosine aminotransferase) than to the I alpha family (e.g., rat aspartate aminotransferase or E. coli AspC). Signature motifs which distinguish the IAP aminotransferase family were identified in the region of the active-site lysine and in the region of the interdomain interface.

Kinetic limitation and cellular amount of pyridoxine (pyridoxamine) 5'-phosphate oxidase of Escherichia coli K-12

We report the purification and enzymological characterization of Escherichia coli K-12 pyridoxine (pyridoxamine) 5'-phosphate (PNP/PMP) oxidase, which is a key committed enzyme in the biosynthesis of the essential coenzyme pyridoxal 5'-phosphate (PLP). The enzyme encoded by pdxH was overexpressed and purified to electrophoretic homogeneity by four steps of column chromatography. The purified PdxH enzyme is a thermally stable 51-kDa homodimer containing one molecule of flavin mononucleotide (FMN). In the presence of molecular oxygen, the PdxH enzyme uses PNP or PMP as a substrate (Km = 2 and 105 microM and kcat = 0.76 and 1.72 s-1 for PNP and PMP, respectively) and produces hydrogen peroxide. Thus, under aerobic conditions, the PdxH enzyme acts as a classical monofunctional flavoprotein oxidase with an extremely low kcat turnover number. Comparison of kcat/Km values suggests that PNP rather than PMP is the in vivo substrate of E. coli PdxH oxidase. In contrast, the eukaryotic enzyme has similar kcat/Km values for PNP and PMP and seems to act as a scavenger. E. coli PNP/PMP oxidase activities were competitively inhibited by the pathway end product, PLP, and by the analog, 4-deoxy-PNP, with Ki values of 8 and 105 microM, respectively. Immunoinhibition studies suggested that the catalytic domain of the enzyme may be composed of discontinuous residues on the polypeptide sequence. Two independent quantitation methods showed that PNP/PMP oxidase was present in about 700 to 1,200 dimer enzyme molecules per cell in E. coli growing exponentially in minimal medium plus glucose at 37 degrees C. Thus, E. coli PNP/PMP oxidase is an example of a relatively abundant, but catalytically sluggish, enzyme committed to PLP coenzyme biosynthesis.

[Nationwide survey of the distribution of human parasites in China--infection with parasite species in human population]

The infection rate of main species of parasites and their character by first nationwide survey of human parasites was made. The overall infection rate of human intestinal parasite and the infection rate of most species of parasites were higher in females than that in males. The infection rate according to the age group, the highest infection rate was found in the group aged 5-14 years. With regard to the relation between parasitic infections and occupations of the infected persons, the highest infection rates of Ascaris lumbricoides were exhibited in school children, of hookworm and Clonorchis sinensis were in halfpeasants and halfmerchant and vegetable grower; of Trichuris trichiura were in fishers, of Giardia lamblia, Entamoeba histolytica and Taenia were in herdsmen and halfherdsmen and halfpeasants. In this survey it is also shown that each nationality has their main species of parasites. The family clustering of some main parasites were proved by some province/autonomous region/municipality.

[Aspergilus nasal sinusitis endoscopic surgery]

Five cases of non-invasive fungal sinusitis were reported. Among them were 2 cases of maxillary, 2 of maxillo-ethmoid and sphenoid sinus. All the patients were operated under endoscopic intranasal approach. The pathological diagnosis of all 5 cases was aspergills infection. The pathogenesis were conditional such as unclean working situation, deviation of nasal septum, polyposis and infection. The disease was easily confused with common infectious disease. The pathogenic factor, diagnosis and treatment were discussed.

Expression of iron-regulated outer membrane proteins by porcine strains of Pasteurella multocida

The outer membrane protein (OMP) profiles of two strains of capsular type A Pasteurella multocida isolated from the lungs of pigs with enzootic pneumonia were studied. Sarkosyl extracted OMPs from P. multocida grown under iron-restricted and iron-replete conditions were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis. Results showed that the iron-regulated outer membrane proteins (IROMPs) with molecular masses of 74 kDa, 94 kDa, 99 kDa and 109 kDa were expressed by strain A52, while 74 kDa, 82 kDa, 94 kDa and 99 kDa IROMPs were expressed by strain B80. Swine immune sera, obtained from pigs which were first immunized with a polyvalent P. multocida type A and type D bacterin and subsequently challenged with type A strain of P. multocida, contained antibodies against the IROMPs. These antibodies cross-reacted with the IROMPs expressed by avian strain P1059 of P. multocida. Convalescent-phase serum obtained from turkeys which survived fowl cholera, also cross-reacted with the IROMPs from porcine strains of P. multocida. These results suggested that IROMPs from porcine and avian strains of P. multocida may share common epitopes that were recognized by swine immune serum as well as turkey convalescent-phase serum.

Role of nitric oxide in the regulation of oxygen consumption in conscious dogs

The role of nitric oxide (NO) in the regulation of O2 consumption was studied in chronically instrumented conscious dogs. A specific NO synthesis inhibitor, nitro-L-arginine (NLA, 30 mg/kg i.v.), significantly increased mean arterial pressure from 100 +/- 4 to 134 +/- 5 mm Hg (mean +/- SEM) and total peripheral resistance by 157 +/- 16% and reduced cardiac output by 47 +/- 3% and heart rate by 34 +/- 6% after 120 minutes. Changes in arterial blood gases were not observed. There were significant changes in PO2 (-14 +/- 2 mm Hg), O2 saturation (-21 +/- 2%), the percentage of hemoglobin as oxyhemoglobin (-21 +/- 2%), and O2 content (-3.0 +/- 0.9 vol%) and a significant increase in percent reduced hemoglobin (21 +/- 1%) in mixed venous blood, associated with an increase in O2 extraction (5.1 +/- 0.2 vol%) (all P < .01). O2 consumption was increased from 124 +/- 6 to 155 +/- 9 mL/min (P < .05). Methoxamine, titrated to have hemodynamic effects similar to those of NLA (eg, mean arterial pressure increased from 97 +/- 4 to 131 +/- 5 mm Hg), had much smaller effects on venous blood gases, hemoglobin, and O2 extraction (2.3 +/- 0.7 vol%) and no significant effect on O2 consumption. NLA also caused an increase in O2 consumption of 37 +/- 8% (P < .01) in quietly resting conscious dogs that had undergone pretreatment with hexamethonium and atropine, but no significant change in O2 consumption in dogs anesthetized with barbiturate.(ABSTRACT TRUNCATED AT 250 WORDS)

An Escherichia coli K-12 tktA tktB mutant deficient in transketolase activity requires pyridoxine (vitamin B6) as well as the aromatic amino acids and vitamins for growth

We show that a tktA tktB double mutant, which is devoid of the two known transketolase isoenzymes of Escherichia coli K-12, requires pyridoxine (vitamin B6) as well as the aromatic amino acids and vitamins for growth. This pyridoxine requirement can also be satisfied by 4-hydroxy-L-threonine or glycolaldehyde. These results provide direct evidence that D-erythrose-4-phosphate is a precursor of the pyridine ring of pyridoxine. In addition, they show that the two major E. coli transketolase isoenzymes are not required for the biosynthesis of D-1-deoxyxylulose, which is thought to be another precursor of pyridoxine.

A study of histology and enzymatic histochemistry on rabbit's retina in acute ocular hypertension

The changes of activities of enzymes relating to energy metabolism in rabbit's retina in acute ocular hypertension were observed. The activities of succinate dehydrogenase and adenosine triphosphatase were found to be reduced, while the activities of the lactatic dehydrogenase and glucose-6-phosphatase increased. The results revealed the metabolic disturbance of energy in retina after acute ocular hypertension might be the underlying factors relating to the defects of the functions and structures of the retina.

Correlation of clinical features and findings on cranial magnetic resonance imaging with urinary myelin basic protein-like material in patients with multiple sclerosis

Immunoreactive material that appears to be a peptide encompassing all or a portion of residues 80 to 89 of myelin basic protein is present in normal unconcentrated urine and is increased in certain patients with multiple sclerosis (MS). Compared with normal controls, urines collected randomly from 158 MS patients or in a clinical research unit from 8 patients with MS had higher mean values of urinary MBP-like material (MBPLM). The level of MBPLM in urine showed no direct relationship to MBPLM in cerebrospinal fluid and did not correlate with clinical relapses of disease. In the other neurological disease control group (26 patients), some patients with other inflammatory diseases, but not stroke or early phase Guillain-Barré syndrome, also showed elevations. Among the subtypes of MS, those with secondary chronic progressive disease had the highest values. Urinary MBPLM showed no definite correlation with or effect of treatment with glucocorticoids and immunosuppressants except that a lower level of urinary MBPLM showed a weak relationship with improvement following treatment with methylprednisolone/prednisone. In a serial study of 8 patients with unenhanced cranial magnetic resonance imaging and 20 patients with gadolinium-enhanced cranial magnetic resonance imaging, urinary MBPLM did not show a direct correlation with new or enhancing lesions. Urinary MBPLM does not parallel acute myelin damage but appears to reflect an ongoing process, possibly linked to attempted efforts at remyelination.

Pseudomonas aeruginosa possesses homologues of mammalian phenylalanine hydroxylase and 4 alpha-carbinolamine dehydratase/DCoH as part of a three-component gene cluster

Pseudomonas aeruginosa possesses a multigene operon that includes phenylalanine hydroxylase (PhhA; phenylalanine 4-monooxygenase, EC 1.14.16.1). phhA encodes PhhA (M(r) = 30,288), phhB (M(r) = 13,333) encodes a homologue of mammalian 4 alpha-carbinolamine dehydratase/homeodomain protein transregulator, and phhC encodes an aromatic aminotransferase (M(r) = 43,237). The reading frames specifying phhB and phhC overlap by 2 bases. The P. aeruginosa PhhA appears to contain iron and is pterin dependent. Unlike the multimeric mammalian hydroxylase, the native P. aeruginosa enzyme is a monomer. The P. aeruginosa PhhA is homologous with mammalian PhhA, tryptophan hydroxylase, and tyrosine hydroxylase. Expression of PhhA from its native promoter required phhB. This may suggest a positive regulatory role for phhB, consistent with the dual catalytic and regulatory roles of the corresponding mammalian homologue.

The mutL repair gene of Escherichia coli K-12 forms a superoperon with a gene encoding a new cell-wall amidase

We report a molecular genetic analysis of the region immediately upstream from the Escherichia coli mutL DNA repair gene at 94.8 min. An open reading frame ending 9 bp upstream from the start of mutL corresponds to a 48 kDa polypeptide detected previously in minicells. The predicted amino acid sequence of this 48 kDa polypeptide shows homology to the major N-acetylmuramoyl-L-alanine amidase autolysin of Bacillus subtilis, a known amidase of Bacillus licheniformis, and the product of a Salmonella typhimurium gene that maps near 50 min. Insertions in this upstream gene, which we named amiB, or in mutL did not affect cell shape or viability; however, overexpression of the AmiB polypeptide caused cell lysis, hypersensitivity to osmotic shock and treatment with water, and temporary autolysis by low levels of antibiotics, which are all consistent with AmiB acting as a cell-wall hydrolase. Analysis of chromosomal transcription demonstrated that amiB forms a complex operon with mutL and two additional upstream genes. mutL transcripts also originated from an internal promoter, designated PmutL, located in amiB 312 bp upstream from the translational start of mutL. Together, these results suggest that E. coli contains a second amidase possibly involved in cell-wall hydrolysis, septation, or recycling, and that transcription of this amidase is directly linked to a gene central for DNA repair.

[The treatment of enterogenous cyst: a report of 12 cases]

12 cases of enterogenous cysts were treated from 1985 to 1992, and its pathology, definition, clinical manifestation and treatment were discussed. A variety of terms has been used for this entity but enterogenous cyst is more suitable. The clinical manifestation varies with different location. Complications are the most common cause bringing a patient to the hospital. The key point for radical therapy is removal of entire cystic wall. One case was cured by intracystic injection of formalin.

Transverse color tolerances for visual optical systems

We performed psychophysical experiments to determine the effects of transverse chromatic aberration on observer performance through a specially designed telescopic system that presents negligible monochromatic aberration. Our results provide the basis for assessing the performance of visually coupled lenses in detail. The effect of transverse color on contrast sensitivity is more severe than on resolution. Color effects are compared with those of astigmatism: It is shown how one may make detailed predictions of system performance in order to decide on the necessary balance of aberrations at the design stage.

The aroQ-encoded monofunctional chorismate mutase (CM-F) protein is a periplasmic enzyme in Erwinia herbicola

Enteric bacteria possess two species of chorismate mutase which exist as catalytic domains on the amino termini of the bifunctional PheA and TyrA proteins. In addition, some of these organisms possess a third chorismate mutase, CM-F, which exists as a small monofunctional protein. The CM-F gene (denoted aroQ) from Erwinia herbicola was cloned and sequenced for the first time. A strategy for selection by functional complementation in a chorismate mutase-free Escherichia coli background was devised by using a recombinant plasmid derivative of pUC18 carrying a Zymomonas mobilis tyrC insert which encodes cyclohexadienyl dehydrogenase. The aroQ gene is 543 bp in length, predicting a 181-residue protein product having a calculated molecular mass of 20,299 Da. The E. herbicola aroQ promoter is recognized by E. coli, and a putative sigma-70 promoter region was identified. N-terminal amino acid sequencing of the purified CM-F protein indicated cleavage of a 20-residue signal peptide. This was consistent with the monomeric molecular mass determined for the enzyme of about 18,000 Da. The native enzyme is a homodimer. The implied translocation of CM-F was confirmed by osmotic shock experiments which demonstrated a periplasmic location. Immunogold electron microscopy indicated a polar localization within the periplasm. Polyclonal antibody raised against E. herbicola CM-F did not cross-react with the CM-F protein from the closely related Serratia rubidaea, as well as from a number of other gram-negative bacteria. Furthermore, when the E. herbicola aroQ gene was used as a probe in Southern blot hybridizations with EcroRI digests of chromosomal DNA from S. rubidaea and other enteric organisms, no hybridization was detected at low stringency. Thus, the aroQ gene appears to be unusually divergent among closely related organisms. The deduced CM-F amino acid sequence did not exhibit compelling evidence for homology with the monofunctional chorismate mutase protein of Bacillus subtilis.

Cyclohexadienyl dehydratase from Pseudomonas aeruginosa is a periplasmic protein

The gene encoding cyclohexadienyl dehydratase from Pseudomonas aeruginosa, designated pheC, was cloned in Escherichia coli and sequenced recently by Zhao et al. (Journal of Biological Chemistry 267, 2487-2493, 1992). N-Terminal sequencing of the purified cyclohexadienyl dehydratase yielded a run of 11 residues which matched perfectly with the deduced amino acid residues 26-36. This showed that a 25 residue peptide was cleaved from the N-terminus of a preprotein formed in E. coli. The amino acid composition of the 25 residue peptide was typical of signal sequences for periplasmic proteins. Most or all of the cyclohexadienyl dehydratase was released from P. aeruginosa and E. coli carrying the pheC gene following spheroplast formation, osmotic shock or chloroform treatment. The location of the enzyme in the periplasm of both E. coli and P. aeruginosa was confirmed by Western blotting analysis using antibody prepared against PheC. Electron microscopy using immunogold labelling showed an apparent localization of cyclohexadienyl dehydratase at the polar regions of the periplasmic space in E. coli.

Epidemiology of Pasteurella multocida in a farrow-to-finish swine herd

Thirty-eight clinical isolates of Pasteurella multocida, recovered from a continuous flow, farrow-to-finish swine herd, were characterized by capsular serotyping and restriction endonuclease analysis (REA) in order to study the epidemiology of P. multocida pneumonia. Twenty-three of the 38 isolates obtained in the study belonged to serotype A. They displayed three REA patterns after digestion with HpaII, of which one designated A-3 represented 70% of the samples. The remaining 15 isolates were serotype D. Four different REA patterns were observed in the type D isolates. The REA type D-1 was most prevalent and accounted for 47% of the serotype D isolates. All serotype A isolates were nontoxigenic, whereas five (33%) of the serotype D isolates were toxigenic. Vertical transmission of P. multocida could not be demonstrated, and was probably not a major route of infection. The results of this study suggest that strains of P. multocida virulent for pigs exist and cause swine pneumonic pasteurellosis in continuous flow herds by horizontal transmission.

An allosterically insensitive class of cyclohexadienyl dehydrogenase from Zymomonas mobilis

The key enzyme of tyrosine biosynthesis in many Gram-negative prokaryotes is cyclohexadienyl dehydrogenase. The Zymomonas mobilis gene (tyrC) coding for this enzyme was cloned in Escherichia coli by complementation of a tyrosine auxotroph. The tyrC gene was 882 bp long, encoding a protein with a calculated molecular mass of 32086 Da. The Z. mobilis cyclohexadienyl dehydrogenase expressed in E. coli was purified to electrophoretic homogeneity. The subunit molecular mass of the purified enzyme was 32 kDa as determined by SDS/PAGE. The ratio of the activity of arogenate dehydrogenase to that of prephenate dehydrogenase (approximately 3:1) remained constant throughout purification, and the two activities were therefore inseparable. The genetic and biochemical data obtained demonstrated a single enzyme protein capable of catalyzing either of two reactions. Km values of 0.25 mM and 0.18 mM were obtained from prephenate and L-arogenate, respectively. The Km value obtained for NAD+ (0.09 mM) was the same regardless of whether the enzyme was assayed as arogenate dehydrogenase or as prephenate dehydrogenase. Unlike the corresponding enzyme of Pseudomonas aeruginosa or E. coli, the cyclohexadienyl dehydrogenase of Z. mobilis lacks sensitivity to feedback inhibition by L-tyrosine. A typical NAD(+)-binding domain was found to be located at the N-terminus of the protein. Although the deduced amino-acid sequence of the Z. mobilis cyclohexadienyl dehydrogenase showed relatively low identity (19-32%) with the prephenate dehydrogenases of Bacillus subtilis and Saccharomyces cerevisiae, as well as with the cyclohexadienyl dehydrogenase components of the bifunctional T-proteins of E. coli and Erwinia herbicola, a presumptive motif was identified which may correspond to critical residues of the binding site for cyclohexadienyl substrate molecules. Immediately upstream of tryC a portion of a gene was sequenced and found to exhibit clearcut homology of the deduced amino-acid sequence with the B. subtilis hisH gene product. Thus, the Zymomonas gene organization is reminiscent of the linkage of genes encoding a tryosine-pathway dehydrogenase and a histidine-pathway aminotransferase in B. subtilis.

The pheA/tyrA/aroF region from Erwinia herbicola: an emerging comparative basis for analysis of gene organization and regulation in enteric bacteria

Extensive knowledge exists in Escherichia coli about the contiguous pheA and aroF-tyrA operons which have opposite transcription orientations and are separated by a bidirectional transcription terminator. The corresponding structural genes and individual components of the terminator and attenuator from Erwinia herbicola have been analyzed from an evolutionary vantage point. A 7.5-kb DNA fragment from E. herbicola carrying the linked pheA, tyrA, and aroF genes was cloned by functional complementation of E. coli auxotrophic requirements. A 3,433-bp segment of DNA consisting of more than half of aroF, all of tyrA, and the entire phenylalanine operon (promoter, leader region encoding the leader peptide and containing the phe attenuator, and pheA) was sequenced. A bidirectional transcription terminator was positioned between the divergently transcribed pheA and tyrA. The adjacent aroF and tyrA genes share a common transcription orientation, consistent with their probable coexistence within an operon. However, tyrA can be expressed efficiently from an internal promoter which appears to lie within the 3' portion of aroF. The gene order is pheA tyrA aroF in E. herbicola, with the same tail-to-tail arrangement of transcription known to exist in E. coli. The pheL coding region of the phe operon was dominated by phenylalanine codons, seven of the 15 amino acid residues of the leader peptide being L-phenylalanine. The E. herbicola pheA and tyrA genes were 1,161 bp and 1,119 bp in length, respectively, and corresponded to deduced gene products having subunit molecular weights of 43,182 and 41,847. The deduced amino acid sequences of PheA and TyrA were homologous at their N-termini, consistent with a common evolutionary origin of the chorismate mutase domains present at the amino terminus of both PheA and TyrA. A detailed comparison of the E. coli and E. herbicola sequences was made. The pheA, tyrA, and aroF genes of E. herbicola exhibited high overall identity with the counterpart E. coli genes. Within the leader region of the phe operon, the leader peptide coding region was highly conserved. Although the 1:2 and 2':3' stems defining the pause structure and the antiterminator, respectively, were also highly conserved, RNA segment 4 of the attenuator terminator exhibited considerable divergence, as did the distal portion of the attenuator region. Within the span of attenuator region encoding the three stem-loop structures of mRNA secondary configuration, hot spots of base-residue divergence were localized to looped-out regions. No changes occurred which would simultaneously disrupt alternative pairing relationships of secondary configuration. The bidirectional terminator between pheA and tyrA has diverged very substantially.(ABSTRACT TRUNCATED AT 400 WORDS)

[Cardiovascular responses to microinjection of atrial natriuretic peptide into ventrolateral medulla of rat]

Application of atrial natriuretic peptides (alpha-ANP and AP III) to glutamate sensitive area of ventrolateral medulla produced a dose-dependent decrease in MAP and HR in anesthetized rats. Lower dosage of AP III induced hypotension without bradycardia, whereas the higher dosage of AP III decreased both blood pressure and heart rate. The results suggested that ANP may inhibit the medullary sympathetic center.

Virus infection and hand papular dermatoses in young children

Four strains of enterovirus and 1 strain of adenovirus were isolated from stool and pharyngeal swabs by inoculation into primary human embryonic kidney cell culture in 25 cases of dorsum manus infantile papular dermatitis. Two strains of Coxsackie A-9 virus and 1 strain of Echovirus-25 were identified. With the isolated virus as antigen, a matched pair study by sera antibody test was carried out in 43 children with papular dermatitis and 40 normal individuals as controls. In 26 cases of Coxsackie A-9 virus positive papular dermatitis, a 4-fold rise (> 1:1.6) in the relative serum antibody was observed in 80.77%, while no high levels were observed in patients with Echovirus-25 and adenovirus dermatitis (< 1:16). The authors can reasonably conclude that epidemic Coxsackie A-9 virus infection is obviously related to infantile papular dermatitis and is probably the main cause of the disease.

A monofunctional prephenate dehydrogenase created by cleavage of the 5' 109 bp of the tyrA gene from Erwinia herbicola

A cohesive phylogenetic cluster that is limited to enteric bacteria and a few closely related genera possesses a bifunctional protein that is known as the T-protein and is encoded by tyrA. The T-protein carries catalytic domains for chorismate mutase and for cyclohexadienyl dehydrogenase. Cyclohexadienyl dehydrogenase can utilize prephenate or L-arogenate as alternative substrates. A portion of the tyr A gene cloned from Erwinia herbicola was deleted in vitro with exonuclease III and fused in-frame with a 5' portion of lacZ to yield a new gene, denoted tyrA*, in which 37 N-terminal amino acids of the T-protein are replaced by 18 amino acids encoded by the polycloning site/5' portion of the lacZ alpha-peptide of pUC19. The TyrA* protein retained dehydrogenase activity but lacked mutase activity, thus demonstrating the separability of the two catalytic domains. While the Km of the TyrA* dehydrogenase for NAD+ remained unaltered, the Km for prephenate was fourfold greater and the Vmax was almost twofold greater than observed for the parental T-protein dehydrogenase. Activity with L-arogenate, normally a relatively poor substrate, was reduced to a negligible level. The prephenate dehydrogenase activity encoded by tyrA* was hypersensitive to feedback inhibition by L-tyrosine (a competitive inhibitor with respect to prephenate), partly because the affinity for prephenate was reduced and partly because the Ki value for L-tyrosine was decreased from 66 microM to 14 microM. Thus, excision of a portion of the chorismate mutase domain is shown to result in multiple extra-domain effects upon the cyclohexadienyl dehydrogenase domain of the bifunctional protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunomodulatory effects of transforming growth factor-beta on T lymphocytes. Induction of CD8 expression in the CTLL-2 cell line and in normal thymocytes

We investigated the role of transforming growth factor-beta 1 (TGF-beta) in regulation of T cell growth and differentiation. Treatment of CTLL-2 cells with TGF-beta inhibited IL-2-dependent proliferation and caused morphologic changes as well as increased adherence. A major change of phenotype in TGF-beta-treated cells was the de novo expression of CD8 alpha chain in 35% of cells, which required the continuous presence of TGF-beta. Of the CD8 alpha+ cells, 20 to 30% co-expressed CD8 beta chain. Increased CD8 expression occurred even in the total absence of cell growth, was not a consequence of growth inhibition, and was not a result of selective growth or survival of CD8+ cells. New RNA synthesis was required for TGF beta-induced CD8 alpha surface expression, inasmuch as this was prevented by treatment with actinomycin D. Northern blot analysis demonstrated that cells treated with IL-2 + TGF-beta rapidly accumulated mRNA encoding both chains of the CD8 dimer, to a level fourfold greater than control by 6 to 12 h. In contrast, the IL-2-dependent increases in IL-2R alpha, IL-2R beta, and Granzyme B mRNA levels in these cultures were profoundly inhibited by TGF-beta. When unfractionated murine thymocytes were stimulated with phorbol dibutyrate plus ionomycin and cultured with IL-2 + TGF-beta, an increase in CD8 alpha mRNA was seen and greater numbers of CD8+ cells with higher levels of CD8 alpha and CD8 beta surface expression resulted, as compared to controls treated with IL-2 alone. Furthermore, similar treatment of CD4-CD8-(double negative) thymocytes with TGF-beta induced de novo CD8 alpha expression by a substantial number of cells, and the majority of these CD8+ cells lacked TCR/CD3. These data suggest that TGF-beta has both positive and negative regulatory effects on the expression of gene products important for T lymphocyte differentiation and function.

Immunomodulatory effects of transforming growth factor-beta on T lymphocytes. Induction of CD8 expression in the CTLL-2 cell line and in normal thymocytes

We investigated the role of transforming growth factor-beta 1 (TGF-beta) in regulation of T cell growth and differentiation. Treatment of CTLL-2 cells with TGF-beta inhibited IL-2-dependent proliferation and caused morphologic changes as well as increased adherence. A major change of phenotype in TGF-beta-treated cells was the de novo expression of CD8 alpha chain in 35% of cells, which required the continuous presence of TGF-beta. Of the CD8 alpha+ cells, 20 to 30% co-expressed CD8 beta chain. Increased CD8 expression occurred even in the total absence of cell growth, was not a consequence of growth inhibition, and was not a result of selective growth or survival of CD8+ cells. New RNA synthesis was required for TGF beta-induced CD8 alpha surface expression, inasmuch as this was prevented by treatment with actinomycin D. Northern blot analysis demonstrated that cells treated with IL-2 + TGF-beta rapidly accumulated mRNA encoding both chains of the CD8 dimer, to a level fourfold greater than control by 6 to 12 h. In contrast, the IL-2-dependent increases in IL-2R alpha, IL-2R beta, and Granzyme B mRNA levels in these cultures were profoundly inhibited by TGF-beta. When unfractionated murine thymocytes were stimulated with phorbol dibutyrate plus ionomycin and cultured with IL-2 + TGF-beta, an increase in CD8 alpha mRNA was seen and greater numbers of CD8+ cells with higher levels of CD8 alpha and CD8 beta surface expression resulted, as compared to controls treated with IL-2 alone. Furthermore, similar treatment of CD4-CD8-(double negative) thymocytes with TGF-beta induced de novo CD8 alpha expression by a substantial number of cells, and the majority of these CD8+ cells lacked TCR/CD3. These data suggest that TGF-beta has both positive and negative regulatory effects on the expression of gene products important for T lymphocyte differentiation and function.

Use of restriction endonuclease analysis and ribotyping to study epidemiology of Pasteurella multocida in closed swine herds

One hundred and sixty-four clinical isolates of Pasteurella multocida recovered from two swine herds in Minnesota were characterized by restriction endonuclease analysis (REA) and rRNA gene restriction fragment length patterns. Bacterial DNA was digested with HpaII and electrophoresed in 0.55% agarose. Restriction fragments were transferred by Southern blot to nylon membranes and then hybridized with digoxigenin-dUTP-labeled Escherichia coli rRNA. Four different REA patterns were observed among the 156 serotype A strains isolated from herds A and B. The two most common REA types (1 and 2) represented 92% of the strains analyzed, while REA types 3 and 4 were observed only in lung samples and accounted for 8% of the isolates. Two different ribotypes were observed for these serotype A isolates. Ribotype I consisted of the most common types, 1 and 2, found by DNA fingerprinting. Ribotype II included REA types 3 and 4. Results from both herds suggest that in closed swine populations, a single strain of P. multocida predominates and causes disease. It is concluded that these genomic fingerprinting techniques were highly discriminatory and that capsular serotyping in combination with REA or ribotyping is an appropriate technique for epidemiological studies of P. multocida of swine origin.

[Central cardiovascular and renal effects of atrial natriuretic peptide]

In 54 anesthetized rats, the changes in arterial blood pressure, heart rate and/or urine volume, urinary sodium excretion were observed following intracarotid, intrathecal and intracerebroventricular (ICV) injection of atrial natriuretic peptide (ANP). The effects of ANP on the central actions of angiotensin II (AG II) were also examined. The results were as follows: (1) In the cross-circulation preparation of rat head, MAP of the recipient was unchanged and that of the donor was decreased in response to the administration of alpha-hANP (15 micrograms/kg) into the carotid artery of the recipient. (2) By injecting AP III (5 micrograms/kg) intrathecally, MAP, HR and urine volume (V) of the rats (n = 7) showed no change. (3) The ICV injection of AP III (20 micrograms/kg) did not result in changes in MAP, HR, and urinary sodium excretion (UNaV), but there was a transient and significant increase in V. (4) ICV injection of AG II (1 microgram/kg) resulted in an increase of MAP by 1.3 +/- 0.17 kPa (10 +/- 1.3 mmHg, n = 10, P less than 0.001), V by 106% (n = 6, P less than 0.01) and UNaV by 642% (P less than 0.01). (5) ICV injection of AP III 2 min prior to the injection of AG II by the same route, the central hypertensive effect induced by AG II was not affected, while the increments in V and UNaV were decreased significantly (P less than 0.05). The results indicate that (1) ANP is incapable of penetrating the blood-brain barrier owing to its large molecular size and therefore, the central mechanism is not involved in the hypotensive effect induced by intravenous injection of ANF and (2) the central diuretic and natriuretic actions of AG II may be markedly inhibited by ICV injection of ANP, thus indicating the existence of some central antagonistic interactions between AG II and ANP.

[The facilitating effect of atrial natriuretic factor on the carotid sinus baroreflex function]

Effects of atriopeptin II (APII) on the carotid sinus baroreflex in anesthetized rats and on the sinus nerve afferent activity in the anesthetized rabbits were investigated. The results were as follows: (1) By perfusing the isolated left carotid sinus with APII (1 microgram/ml) in anesthetized rats (n = 10), the threshold pressure (TP) of the carotid baroreflex did not show any change, while the equilibrium pressure (EP), the saturation pressure (SP) and the operating range (OR) were decreased from 101 +/- 2.8 to 95 +/- 2.0 mmHg (P less than 0.05), 202 +/- 5.2 to 168 +/- 6.1 mmHg (P less than 0.001) and 128 +/- 5.5 to 93 +/- 6.3 mmHg (P less than 0.001), respectively. The function curve of the baroreflex was shifted to the left and downward with a peak slope (PS) increased during perfusing with APII. In contrast, by perfusing the carotid sinus with sodium nitroprusside (NP, 0.5 micrograms/ml), TP and EP remained unchanged, whereas SP and OR were increased from 188 +/- 6.4 to 218 +/- 6.0 mmHg (n = 6, P less than 0.01) and from 107 +/- 6.9 to 132 +/- 7.6 mmHg (P less than 0.05), respectively. The function curve of the baroreflex and its PS were not affected by NP. The sinus nerve afferent activity was quite stable with the perfusion of carotid sinus at constant intrasinus pressure (ISP) in the rabbits (n = 6) and increased during the elevation of ISP.(ABSTRACT TRUNCATED AT 250 WORDS)

[Inherited metabolic aberration of phenylalanine in the family members of patients with essential hypertension and stroke]

L-2H-Leu, L-2H-Val, L-2H-Ile, L-2H-Phe, 14N-Lys were chosen for comparing their metabolic kinetic variables among those with prominent genetic predisposition of essential hypertension (FH*, 10 subjects), of stroke (FS*, 12 subjects) and those without (F-, 12 subjects) groups by gas chromatography-mass spectrometry. Results showed that only the metabolic kinetics of phenylalanine was dearranged: (1) The plasma pools of FH* and FS* groups were enlarged; (2) The turnover rate constant between plasma pool and cell pool of FH* was constricted; (3) The cell pool of FH* was larger, while the turnover rate constant was smaller than that of FS* group. The aberration of phenylalanine metabolism in essential hypertension and stroke might relate with hyperfunction of sympathetic nervous activity genetically. These diseases possibly belong to the category related to the inherited amino-acid metabolic aberration.

Cloning, sequencing, and expression of the P-protein gene (pheA) of Pseudomonas stutzeri in Escherichia coli: implications for evolutionary relationships in phenylalanine biosynthesis

The pheA gene encoding the bifunctional P-protein (chorismate mutase:prephenate dehydratase) was cloned from Pseudomonas stutzeri and sequenced. This is the first gene of phenylalanine biosynthesis to be cloned and sequenced from Pseudomonas. The pheA gene was expressed in Escherichia coli, allowing complementation of an E. coli pheA auxotroph. The enzymic and physical properties of the P-protein from a recombinant E. coli auxotroph expressing the pheA gene were identical to those of the native enzyme from P. stutzeri. The nucleotide sequence of the P. stutzeri pheA gene was 1095 base pairs in length, predicting a 365-residue protein product with an Mr of 40,844. Codon usage in the P. stutzeri pheA gene was similar to that of Pseudomonas aeruginosa but unusual in that cytosine and guanine were used at nearly equal frequencies in the third codon position. The deduced P-protein product showed sequence homology with peptide sequences of the E. coli P-protein, the N-terminal portion of the E. coli T-protein (chorismate mutase:prephenate dehydrogenase), and the monofunctional prephenate dehydratases of Bacillus subtilis and Corynebacterium glutamicum. A narrow range of values (26-35%) for amino acid matches revealed by pairwise alignments of monofunctional and bifunctional proteins possessing activity for prephenate dehydratase suggests that extensive divergence has occurred between even the nearest phylogenetic lineages.

Preliminary result of mixed bacterial vaccine as adjuvant treatment of hepatocellular carcinoma

Mixed bacterial vaccine (MBV) was employed in the multi-modality treatment of hepatocellular carcinoma (HCC) during 1985-1988. Thirty eight patients undergoing palliative resection and cisplatin therapy (Series 1) and 48 patients with unresectable HCC who received hepatic artery ligation + intraarterial cisplatin infusion + radiotherapy (Series 2) were randomized to receive MBV or not. In series 1, the 1- and 2-year survival rates of MBV group and control were 75% vs 58% (P = 0.19) and 45% vs 39% (P = 0.23). In series 2, the 1-, 2- and 3-year survival rates were 59%, 41% and 41% for MBV group and 39%, 25% and 20% for the control, respectively (P1 = 0.07, P2 = 0.09, P3 = 0.07). In addition, MBV improved the "second look" resection rate to 40% as compared to 17% in the control (P greater than 0.05). MBV could also prevent such immunosuppression as decrease of macrophage activity caused by radiotherapy. We consider MBV a potential nonspecific immunostimulant in the multimodality treatment of HCC.

Long survival and prognostic factors in hepatocellular carcinoma

We studied survival and prognostic factors in all cases of hepatocellular carcinoma seen at a Midwestern teaching hospital from 1947 through 1986. Of the 70 cases, 56 were diagnosed during life and 14 at autopsy. There were 47 males and 23 females with age at diagnosis ranging from 14 to 88. Median survival for the 56 patients diagnosed during life was 106 days. Only 11 patients lived longer than one year. Two patients were long survivors and presumed cured, one living 27 years after diagnosis and surgical treatment and the other 19 years. Cox regression model showed young age at diagnosis and low stage of disease at diagnosis to be significant predictors of long survival. White patients survived nearly twice as long as black patients but the difference was not significant. Gender and year of diagnosis did not appear to be important determinants of survival. Pathologic material was still available for one of the two long survivors and the histology was that of fibrolamellar carcinoma of young adults.

[Calcium binding capacity of erythrocyte membrane in human hypertension and spontaneous hypertensive rats]

Several abnormalities of calcium transport have been reported in human essential hypertension (EHT) and spontaneous hypertensive rat (SHR). 45Ca binding capacity to erythrocyte membrane was measured in this study by filtration technique in the presence of 80 nmol/L Ca concentration. Results showed: (1) It was much lower in EHT (33 cases) than normal control (19 men) group, being 0.22 +/- 0.13 versus 0.35 +/- 0.18 nmol Ca2+/mg membrane protein (P less than 0.01), and correlated positively with blood pressure levels. (2) The average Ca binding capacity in young offsprings (15 adolescents) with both parents hypertensive was lower, but statistically not significant. (3) The average Ca binding capacity was also lower in SHR (9 rats) than control WKY (10 rats) group, being 0.83 +/- 0.27 versus 0.98 +/- 0.24 nmol Ca2+/mg membrane protein, yet statistically not significant. Therefore a decrement of membrane binding capacity might be related to the occurrence and maintenance of hypertension.

[Effects of atrial natriuretic polypeptide on arterial pressure and renal sympathetic nerve activity in anesthetized rats]

The effects of atriopeptin III (AP III) on the arterial pressure (AP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were investigated in anesthetized rats. The results were as follows: (1) In intact rats (n = 12), following intravenous injection of AP III (50 micrograms/kg), systolic arterial pressure (SAP) decreased by 23.0 +/- 1.66 mmHg (M +/- SE, P less than 0.001), HR decreased by 9 +/- 3.5 beats/min (P less than 0.05), and RSNA decreased by 4.89 +/- 2.95% (P greater than 0.05). After vagotomy, the decrease in SAP following iv. AP III showed no significant difference with that of intact rats. HR showed no change, while there was a small increase in RSNA (P greater than 0.05); (2) In the intact vagi but sinoaortic denervated rats (n = 7), intravenous AP III decreased SAP by 27.4 +/- 3.25 mmHg (P less than 0.001), HR by 13 +/- 3.1 beats/min (P less than 0.01), and RSNA by 11.67 +/- 1.95% (P less than 0.001). After vagotomy, the decrease in SAP following i.v. AP III was attenuated, HR showed no significant change, but there was a small but significant increase in RSNA (P less than 0.05); (3) Following intravenous injection of nitroprusside, SAP decreased significantly. Such a hypotensive effect was associated with an increase in RSNA in either the intact or the vagotomized rats. The results indicate that (1) the hypotensive effect of AP III was mediated partly by vagi; (2) in the sinoaortic denervated rats AP III could reflexly inhibit RSNA by activation of vagal afferent fibers.