[Studies on antiaggregating drugs of horseshoe crab amebocytes]

The effects of drugs on amebocyte spontaneous aggregation and endotoxin induced aggregation were studied. N-Ethylmaleimide, ethylenediamine tetraacetate, propranolol, verapamil and lidocaine but not dibutyryl cyclic AMP could reduce the aggregating rate of amebocytes. The speed of degranulation induced by endotoxin was reduced by N-ethylmaleimide, ethylenediamine tetraacetate, propranolol, verapamil and caffeine. These results suggest that Ca+2 and c-AMP may play an important role in amebocyte spontaneous aggregation and endotoxin induced aggregation. The blocking agent of Ca+2 and c-AMP can also antagonize the aggregation of amebocytes.

Antibodies to hepatitis C virus in prospectively followed patients with posttransfusion hepatitis

In an attempt to investigate the incidence and clinical course of type C viral hepatitis among patients with posttransfusion hepatitis, antibodies to hepatitis C virus (anti-HCV) in sera were measured from 42 prospectively followed cardiovascular surgery patients who developed hepatitis after blood transfusions. Of these, 35 (83.3%) had anti-HCV seroconversion during a 6- to 12-month follow-up period. The mean interval between blood transfusion and onset of active anti-HCV seroconversion was approximately 3 months after the first elevation of serum alanine aminotransferase levels (18.1 vs. 6.4 weeks). There was no correlation between fluctuations in serum alanine aminotransferase levels and anti-HCV titers. Of 26 patients with type C posttransfusion hepatitis who were followed greater than 1 year, 20 (76.9%) continued to have abnormal serum alanine aminotransferase levels. The results indicate that HCV is the major agent of posttransfusion hepatitis in Taiwan. Furthermore, it plays an important role in chronic hepatitis among transfused patients.

A prospective study of post-transfusion non-A, non-B (type C) hepatitis following cardiovascular surgery in Taiwan

In an attempt to investigate the incidence and clinical course of non-A, non-B (NANB) hepatitis following blood transfusion in Taiwan, 288 patients who underwent cardiovascular surgery and received blood transfusion were followed prospectively with serum liver aminotransferase levels and viral hepatitis markers for at least six months. None had any past history of liver disease or drug abuse. All blood donors were tested for serum hepatitis B surface antigen and alanine aminotransferase (ALT) (greater than 45 U/L). Thirty-seven (12.8%) patients developed PTH. 34 (91.9%) were considered to be cases of NANB hepatitis, 2 (5.4%) were cytomegalovirus hepatitis, and one (2.7%) was caused by Epstein-Barr virus. No one developed hepatitis B post-transfusion hepatitis (PTH). Of the 34 NANB PTH patients, 15 (44.1%) were asymptomatic, 16 (47.1%) had clinical symptoms, and 9 (26.5%) had serum total bilirubin levels higher than 2 mg/dl. There was no case of fulminant hepatic failure. Of 26 NANB PTH patients who were followed up for more than one year, 15 (57.7%) still had abnormal serum ALT levels. The incubation period of NANB PTH ranged from 2 to 16 (mean 6.1 +/- 3.2) weeks. Of the 37 PTH patients, 32 (86.5%) were found to have anti-HCV seroconversion during one year follow-up period. NANB PTH is as common in Taiwan as in the United States and Japan, and is demonstrated by this study to be due mostly to HCV.

Plasma atrial natriuretic peptide and natriuretic response to water immersion in patients with nephrotic syndrome

Eight nonnatriuretic (daily Na excretion less than 50 mEq), 4 natriuretic (daily Na excretion greater than 50 mEq), and 4 steroid-responsive nephrotic patients, and 12 normal controls were studied with a 4-hour water immersion with measurements of electrolytes, plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA), and plasma aldosterone (PA) [corrected]. Four nonnatriuretic patients further received 25 g albumin infusion, with a subsequent 2-hour water immersion study. The results are as follows: (1) In the nonnatriuretic patients, the extremely low basal Na excretion rate, high PRA, and PA levels indicated a state of active Na retention. In spite of the water-immersion induced suppression of PRA and PA and a comparable magnitude of plasma ANP increment, the natriuretic response to water immersion was blunted in the nonnatriuretic patients. (2) In the natriuretic patients, water immersion resulted in a similar magnitude of natriuresis but a higher degree of plasma ANP increment in comparison to the normal controls. (3) Natriuretic and plasma ANP responses to water immersion were not different between the steroid-responsive patients and normal controls. (4) The increase in plasma ANP and the suppression of PRA and PA after 25 g albumin infusion did not result in natriuresis until the further suppression of PRA and PA and the further stimulation of plasma ANP by subsequent water immersion. The above results indicate that the natriuretic and plasma ANP responses to water immersion are related to the basal Na status in nephrotic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Superinfection with hepatitis C virus in patients with symptomatic chronic hepatitis B

11/323 patients (3.4%) with symptomatic chronic hepatitis B were positive for antibody to hepatitis C virus (anti-HCV). The positive rate of anti-HCV in patients with serum alanine aminotransferase (ALT) levels greater than 200 U/l (n = 219) did not exceed that of the patients with ALT less than or equal to 200 U/l (n = 104) (2.7% vs. 4.8%). Of the 219 patients who were positive for hepatitis B e antigen (HBeAg) and/or hepatitis B virus-DNA (HBV-DNA), 5 (2.3%) had anti-HCV, while 6/104 patients (5.8%) who were positive for antibody to HBeAg (anti-HBe) had anti-HCV (p greater than 0.1). In contrast to the anti-HCV-negative patients, the patients with anti-HCV had a higher percentage of cirrhosis in their liver histological findings (36.4% vs 5.4%, p less than 0.005). In conclusion, the prevalence of HCV superinfection in symptomatic chronic hepatitis B patients is low and HCV superinfection is not an important factor in acute exacerbation of chronic hepatitis B. However, the superinfection with HCV may exacerbate the existing liver disease and accelerate its progression.

Study of plasma neuropeptide Y (NPY) and catecholamines levels during isoflurane anesthesia

Twelve ASA physical status I-II patients were studied after obtaining institutional approval and informed contents. All patients were free from endocrine and metabolic disease undergoing elective low risk operation. Pethidine 1 mg/kg i.m. and benzodiazepine 0.01 mg/kg p.o. were given as premedication one hour before anesthesia. Anesthesia was induced with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg for tracheal intubation. Anesthesia was maintained with 2% isoflurane and 50% N2O in oxygen. Ventilation was controlled and adjusted to maintain an end-tidal CO2 concentration of 25-35 torr. Atracurium 0.4 mg/kg was given as muscle relaxant. Blood samples were obtained from radial arterial catheter, 15 minutes before induction of anesthesia and 5 min after anesthesia, 15 min, 30 min, 60 min during operation and 30 min after operation in postanesthesia recovery room. The results showed that there were no statistically significant changes in plasma levels of NPY and catecholamines during operation underwent isoflurane anesthetic technique. This result indicates that isoflurane anesthesia can block the plasma NPY as well as catecholamines during surgical stress.

Plasma atrial natriuretic peptide in patients with chronic renal failure

Plasma atrial natriuretic peptide (ANP) levels were measured in non-dialyzed and dialyzed chronic renal failure (CRF) patients and in normal subjects. Changes in plasma ANP in response to hemodialysis (HD) and to isolated ultrafiltration (UF) were also investigated in dialyzed CRF patients. Plasma ANP levels were significantly higher in 28 non-dialyzed CRF patients than in 27 normal subjects (mean +/- SEM, 174.0 +/- 25.9 vs 25.0 +/- 1.9 pg/ml, p less than 0.001). Plasma ANP levels did not correlate with blood urea nitrogen or serum creatinine, however patients with advanced renal failure (creatinine clearance less than 10 ml/min) with cardiomegaly (cardiothoracic ratio greater than 50%) or hypertension (BP greater than 140/90 mmHg) had significantly higher plasma ANP levels than those who were not. A 6-hour HD significantly decreased the plasma ANP level (423.4 +/- 71.3 to 220.6 +/- 40.0 pg/ml, p less than 0.001) and body weight in 21 dialyzed CRF patients, and the decrement in plasma ANP showed a positive correlation with the decrement in body weight (r = 0.425, p = 0.056). In 8 dialyzed CRF patients, we further performed a 1-hour isolated UF for removal of isoosmotic intravascular fluid without changes in the solute concentrations, followed by a subsequent 5-hour HD. The decrease in plasma ANP during the 1-hour UF period was 68% of the total ANP decrement for the whole 6-hour study. The average plasma ANP level was decreased with 94.6 +/- 42.5 pg/ml/kg/h in the UF period compared to 3.5 +/- 1.4 pg/ml/kg/h in the HD period (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Metastatic malignant melanoma of upper gastrointestinal tract

A 74-year-old male patient developed intermittent melena and anemia after he had received surgical resection for malignant melanoma of the right foot and radical dissection of the right inguinal metastatic lymph node. The source of bleeding was identified to be metastatic melanoma of stomach and duodenum by panendoscopy and biopsy. Patient refused surgical intervention and died of pneumonia two weeks later.

Clinical study of syncope during acupuncture treatment

From August 1988 to April 1989, we observed 52 patients who developed so-called 'needle fainting' (or what the Chinese call 'Yun-Cheng' phenomenon) 55 times among a total sample of 28,285 procedures of acupuncture therapy at the Center for Traditional Medicine of Veterans General Hospital in Taipei. Of these syncopal patients, 35 were male and 17 were female. Their mean age was 45 years (with a range of 11 to 72 years). All patients were in an upright position when needle fainting occurred. Their usual manifestations were pallor, cold sweating, nausea, and bradycardia. They all recovered soon after lying down; no one developed a complete loss of consciousness. No mortality was noted. When comparing the patients who experienced syncope during their first visit to our Clinic (Group I, n = 27) with the patients who experienced syncope in a follow-up treatment (Group II, n = 25; 3 patients had 2 episodes in sequential treatments), we found a significantly higher incidence of needle fainting (p less than 0.0001) in Group I patients (27 out of 2,855 or 0.94%) than in Group II patients (28 out of 25,430 or 0.11%). The mean age of Group I patients (39 +/- 15.4 years) was significantly less than that of Group II patients (51.6 +/- 18.0 years) (p less than 0.001). The coexistence of other medical problems was significantly higher in Group II patients (72%) than in Group I patients (18.5%) (p less than 0.0001).

Human leukocyte antigen (HLA) frequency among patients with nasopharyngeal carcinoma in Taiwan

In order to assess the association between human leukocyte antigens (HLA) and nasopharyngeal carcinoma (NPC), a total of 10 familial and 10 sporadic NPC patients and 171 unrelated healthy controls were studied. HLA typing was performed using commercial trays which defined 30 specificities of HLA-A, B and C loci and 10 specificities of HLA-D locus according to the method of Tiwari and Terasaki. HLA-A2, B16 and DR1 were found to be higher among patients with NPC than unrelated healthy controls with an odds ratio (OR) and a 95% confidence interval of 5.91 (2.1-16.6), 6.00 (2.0-18.0) and 6.89 (1.3-37.5), respectively. Further analysis showed that A2(+) B16(+) haplotype was significantly associated with a much higher risk of NPC (OR = 15.5) as compared with A2(-) B16(-) haplotype. No difference in frequency distributions of HLA-A, B, C and D antigens was observed between familial and sporadic NPC patients.

Regulation of antifreeze protein production in winter flounder: a unique function for growth hormone

Salmon pituitary extract and the protein fraction unabsorbed on concanavalin A-Sepharose, the carbohydrate-poor fraction, depressed plasma levels of antifreeze proteins (AFP) when the pituitary fractions were administered to flounder in late fall or winter. The active pituitary protein occurred in the fraction with a mean molecular weight of 25,000. The two major isohormones of growth hormone (GH) were the only biologically active proteins identified from the pituitary. Hypophysectomized flounder synthesize AFP in the spring and the two isohormones of GH suppress the synthesis. The fraction of flounder pituitaries containing putative GH depressed flounder plasma levels of AFP in late fall.

[The role of ADP-cyclic AMP system in horseshoe crab amebocytes aggregation and gel formation]

A study of the effects of ADP and cyclic AMP related drugs on gel formation induced by endotoxin and amebocytes aggregation was conducted. The gel formation induced by endotoxin could be inhibited by ADP, cyclic AMP, ATP and aminophylline. Conversely, Phosphodiesterase enhanced gelation rate. A calmodulin antagonist, trifluoperazine, also inhibited endotoxin-induced gel formation, but this agent was able to induce potentiation in amebocytes aggregation. These results suggest that the cyclic AMP phosphodiesterase system may play an important role in endotoxin-induced gel formation, and it was concluded that, in the presence of both Ca++ and endotoxin, the calmodulin-like protein will activate the cyclic AMP phosphodiesterase system and decrease the concentration of cyclic AMP, thus promoting gel formation.

Isolation of an ammonium or methylammonium ion transport mutant of Escherichia coli and complementation by the cloned gene

During nitrogen-limited growth, Escherichia coli expresses a specific ammonium or methylammonium ion transport system (Amt). Strains carrying defects in Amt have been isolated following Tn10 transposon mutagenesis. These mutants have less than 10% of the transport activity of the parental strain. Glutamate, glutamine, arginine, or high levels (20 mM) of ammonium will serve as the sole nitrogen source for growth of these strains, and glutamine synthetase is normally expressed and repressed by the nitrogen regulatory (Ntr) system. When transformed with plasmid pGln84, containing lacZ fused to an Ntr promoter (glnLp), the Amt mutants expressed a normal level of beta-galactosidase. Furthermore, P1 bacteriophage transduction of the amt mutation into an Ntr mutant, normally constitutive for Amt, gave Amt- transductants. Therefore, the mutations are unlikely to lie within genes affecting Ntr elements. Following transformation with plasmid libraries of E. coli genomic DNA constructed in pUC9, two plasmids conferring the Amt+ phenotype on the amt mutants were isolated. These plasmids were unable to complement the Amt- phenotype of Ntr- mutants. Restriction digestion of these plasmids revealed common fragments, and Southern blot analyses indicated that the Amt-complementing sequence and the site of Tn10 insertion in the genome occur in the same 3.4-kilobase HindIII-SalI fragment. Insertion of TnphoA into this fragment produced amt::phoA fusions which gave high levels of alkaline phosphatase under nitrogen-limiting conditions but low levels during ammonia excess. This suggests that the amt product contains domains which are exported to the periplasm.

Seroepidemiological studies on hepatitis B and D viruses infection among five ethnic groups in southern Taiwan

In order to compare the prevalence of hepatitis B virus (HBV) and hepatitis D virus (HDV) infection among five ethnic groups in Pingtung County of southern Taiwan, a total of 240 serum samples were collected from September to October, 1985, from the following five ethnic groups: Taiwanese, Hakka, Mainland Chinese, aboriginal Paiwanese, and aboriginal Rukaiese. Ages of subjects ranged from 5 to 69 years. All sera were tested for hepatitis B surface antigen (HBsAg), surface antibody (anti-HBs), and core antibody (anti-HBc) by radioimmunoassay (RIA). Hepatitis B e antigen (HBeAg) and antibody to hepatitis D antigen (anti-HDV) were also tested for those with HBsAg-positive sera. Results showed that 44.1% of all sera examined were negative for HBsAG but positive for both anti-HBs and anti-HBc; additionally, 24.6% were negative for both HBsAg and anti-HBs but positive for anti-HBc. Only 134 serum samples showed negative results for HBV markers, indicating an HBV infection rate of 88.8%. The anti-HDV positive rate was estimated to be 2.7% among HBsAg-positive subjects. The HBsAg-positive rates among Rukaiese, Paiwanese, Hakka, Taiwanese, and Mainland Chinese were 25.8, 22.5, 16.7, 12.9, and 10.0%, respectively; while the prevalence rates of HBV infection among the above five groups were 94.2, 94.6, 85.4, 87.5, and 82.5%, respectively. Differences in the HBsAg-positive rate and HBV infection rate among these ethnic groups were statistically significant. We conclude that people living in Pingtung County are more frequently infected with HBV when compared with inhabitants in northern Taiwan.

Yeast ARS function and nuclear matrix association coincide in a short sequence from the human HPRT locus

A sequence that supports extrachromosomal replication of plasmids in yeast has been identified within the first intron of the human hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene. This represents the first isolation of such an autonomously replicating sequence (ARS) from an exactly known position in the human genome. This ARS shares similarities of imparted yeast phenotype and DNA sequence with other heterologous ARSs. In addition, this sequence is found to be a matrix association region (MAR) on the basis of specific binding to nuclear matrices prepared from several mammalian cell types. It also exhibits anomalous electrophoretic behavior, characteristic of bent DNA, on polyacrylamide gels. The coincidence of these properties supports the possibility that this region may play a role in DNA replication within its normal chromosomal context.

Molecular cloning and expression of salmon prolactin cDNA

Prolactin was purified from chum salmon pituitaries. It was resolved into two variants by reverse-phase high-performance liquid chromatography. A cDNA library was prepared from Pacific chinook salmon pituitaries. Salmon prolactin gene was screened using a synthetic oligonucleotide based on partial protein sequence. A positive clone (PRL-10) was identified and sequenced. It is a full-size clone containing 1.1 kb and coding for a preprolactin of 211 amino acids. A modified prolactin plasmid (PRL-10A), in which the 5' untranslated sequence and the nucleotide sequence coding for the signal peptide of prolactin were deleted, was reconstructed into an expression vector using the heat-inducible lambda pL promotor. Mature prolactin, a single polypeptide of 22 kDa, was efficiently expressed in the bacteria at an elevated temperature.

Plasma vitellogenin in landlocked Atlantic salmon (Salmo salar Ouananiche): isolation, homologous radioimmunoassay and immunological cross-reactivity with vitellogenin from other teleosts

Vitellogenin was isolated by affinity chromatography and gel filtration from landlocked Atlantic salmon plasma. Vitellogenin was labelled with iodine-131 using iodogen and an homologous radioimmunoassay was developed. There was poor immunological cross-reactivity with vitellogenin or plasma from other teleosts. Parallelism of the vitellogenin standard to the displacement by plasma of vitellogenic salmon allowed the assay to be used to evaluate the seasonal concentration profile of vitellogenin in female adult salmon. Extracts of liver or ovary from female Atlantic salmon also yielded displacements parallel to the vitellogenin standard in the assay.

Quantification of Vitellogenin in Atlantic Salmon (Salmo salar) Plasma by Radioimmunoassay

An antibody prepared against salmon egg yolk proteins has been used to quantify Atlantic salmon (Salmo salar) plasma vitellogenin using radioimmunoassay. A low molecular weight fraction isolated from salmon egg yolk was used for radioiodination and as standard solution because plasma vitellogenin could not be iodinated successfully. Parallelism of the egg yolk standard to displacement given by a fraction isolated from vitellogenic salmon plasma and dilutions of plasma samples allowed the assay to be used to evaluate the state of gonadal development of migrating females several months in advance of spawning and for sexing relatively immature salmon. Key words: salmon, plasma vitellogenin; vitellogenin, quantification in salmon plasma; radioimmunoassay, salmon vitellogenin