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Biomedical subjects

H J Lin

Publications and source records attributed to H J Lin.

At least 163 records · Page 9Linked to original sources
PubMed1992

Endoscopy for upper gastrointestinal bleeding at emergency unit.

From November 1, 1990 to January 31, 1991, 381 patients visited our emergency unit with the chief complaints of hematemesis (n = 153) and melena (n = 228). Of these patients, 298 (78.2%) received UGI endoscopy at the emergency unit, 29 (7.6%) received examination after they were admitted to wards, 3 (0.8%) received endoscopy at outpatient clinic and 51 (13.4%) did not have endoscopy. The percentages of endoscopic diagnoses in 330 patients who had UGI endoscopy were gastric ulcer (GU) 33.6%, duodenal ulcer (DU) 32.7%, esophageal varices (EV) 17.0%, and others 15.5%. Negative findings were noted in 3 cases and no definite bleeding source was found in 1 patient who had blood retention in stomach. The diagnostic rate of endoscopy was 98.8%. Of the 56 patients with EV, 45 (80.4%) had hematemesis; in contrast, 85 of the 108 DU patients (78.8%) complained of melena only. Of the 219 patients with bleeding GU/DU, 64 (29.2%) had endoscopic therapies and 7 (3.2%) needed operation. Sixty-four (29.2%) of them received UGI endoscopy within 6 hours after arrival. They had significantly higher frequency of stigmata of recent hemorrhage (SRH) and more endoscopic therapies than the remaining patients. The overall mortality rate in our patients was 6.0%; the mortality rate in patients with EV was much higher than that of the patients with GU/DU (19.6% vs. 1.8%, P less than 0.001). Of the 23 expired cases, only 11 died of hypovolemic shock. The remaining 12 patients died of deterioration or complications of their underlying diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Functional profile of the human fetal gamma-globin gene upstream promoter region.

We performed a systematic functional analysis of the human gamma-globin promoter to identify its activator domains. We used a panel of truncation and scanning mutants as well as transfection in human K562 fetal erythroid cells. The various mutations produced relatively small changes in promoter function in both transient and stable transfection assays. The CACCC region and the region containing the binding sites for protein GATA-1 behaved as activator domains. We also obtained evidence for a minor activator site in the - 200 to - 190 region. The results are consistent with the interpretation that gamma-globin gene regulation may occur in part through multiple small effects of promoter elements.

Base Sequence↗
PubMed1991

The upstream region of the human gamma-globin gene promoter. Identification and functional analysis of nuclear protein binding sites.

The promoter of the human gamma-globin gene confers tissue specificity as well as developmental stage specificity to gamma gene expression. Earlier work in our laboratory suggested that a fragment of the gamma-globin promoter between -300 and -137 base pairs upstream of the transcription start site contributed to the developmental specificity of the promoter. In this paper, we have mapped potential regulatory elements within this upstream region of the gamma promoter by a combination of in vitro DNA-protein binding assays and functional determinations of promoter strength in transient expression studies. Four sites between -300 and -130 bind proteins present in nuclear extracts of erythroid and non-erythroid cell lines. Mutation of these binding sites by internal base substitution determined that three of the four influence overall promoter strength in transient assays. We have focused on two protein binding sites, -246 to -212 and -195 to -170, that have been reported to bind erythroid-specific factors. The erythroid binding protein NF-E1 and a ubiquitous octamer protein footprint the -195 to -170 site. While internal mutation of this site did not significantly alter promoter strength, a point mutation at position -175 that is associated with hereditary persistence of fetal hemoglobin increased the activity of a promoter construct 20-fold in erythroid cells. A detailed mutational analysis of this site suggests that NF-E1 binding is necessary but not sufficient for activation of the promoter by the -175 mutation, and we propose that a second protein or co-activator is required. The nucleotides between -246 and -212 appear to bind a complex of at least three proteins, at the core of which is a protein binding to a string of dA:dT residues. This complex also appears to form on the 3' A gamma-globin enhancer, and homologous sites have been identified within the locus activating region of the beta-globin cluster, suggesting that this element may mediate long range interactions with distant regulatory elements.

Base Sequence↗
PubMed1991

A randomised controlled trial of recombinant interferon-gamma in Chinese patients with chronic hepatitis B virus infection.

Nineteen Chinese patients with chronic hepatitis B virus (HBV) infection, seropositive for HBV e antigen (HBeAg) and HBV DNA on at least three occasions in 6 months, were randomised to receive either recombinant human interferon-gamma (rIFN gamma) 0.1 mg/m2 intramuscularly thrice weekly for 16 weeks (n = 11) or no anti-viral therapy (controls, n = 8). Five patients in the treatment group and four patients in the control group had persistently elevated serum alanine aminotransferases (ALT) of over two times the upper limit of normal before entering into the trial. rIFN gamma had no or minimal inhibitory effect on serum HBV DNA during treatment and no patient developed e-seroconversion or sustained loss of serum HBV DNA. Hepatitic flare, which occurred in a proportion of patients responding successfully to interferon-alpha (IFN alpha) therapy, was not observed with rIFN gamma treatment. Side-effects included pyrexia and mild headache that showed tachyphylaxis and were well tolerated by all patients. In the control group, one patient with elevated pre-entry serum ALT lost serum HBV DNA and seroconverted to anti-HBe. Another patient with elevated ALT lost serum HBV DNA transiently during therapy. In the dose given, rIFN gamma was safe but had no apparent anti-viral effects in Chinese patients with chronic HBV infection.

Adolescent↗
PubMed1991

Application of hepatitis B virus (HBV) DNA sequence polymorphisms to the study of HBV transmission.

Short sequences in hypervariable regions of the hepatitis B virus (HBV) genome can be used to identify different strains, providing a novel approach to the study of HBV transmission. The nucleotide sequence in positions 2551-2650 (1:EcoRI site) was determined for serum HBV DNA from 96 Chinese children living in Hong Kong and from 38 of their parents. HBV DNA was extracted and sequenced after amplification with the polymerase chain reaction, using as primers oligonucleotides corresponding to two conserved sequences. Among 82 unrelated children, 32 HBV DNA variants were present. One sequence was present in 33 children and 31 variants were found among the other 49. Siblings within each of nine families had the same variant; in three families siblings had different variants. Six of the eight fathers and 28 of the 30 mothers had HBV DNA sequences identical to those of their offspring. A total of 34 variants were found among the 134 individuals. The hypothesis of random assortment of sequences in parents and children was rejected (P less than .00005). Thus, this new approach proves the occurrence of intrafamilial transmission of HBV among Chinese.

Adult↗
PubMed1991

Endoscopic injection of alcohol to stop peptic ulcer hemorrhage. Experience with 115 cases.

In a period of 33 months, we performed endoscopic injection with pure alcohol (PA) to try to stop peptic ulcer hemorrhage in 115 patients. The sex ratio (M/F) was 104/11. The average age was 59.5 +/- 1.5 years (mean +/- SEM). Sixty-two patients (53.9%) were in shock before endoscopic injection. Thirty-three (28.7%) had spurting hemorrhage, 31 (27%) oozing hemorrhage, and 51 (44.3%) nonbleeding visible vessels (NBVV). We obtained initial success in 92 patients (80%). Rebleeding episodes occurred in 7 patients (7.6%) within 7 days of endoscopic injection. Five of those who rebled received a second injection with PA and bleeding stopped in three of them. In 88 (76.5%) patients, therapy was ultimately successful. The duration of hospitalization was 5.1 +/- 0.6 days (mean +/- SEM). The total volume of blood transfused was 1450 +/- 192 ml (mean +/- SEM). We conclude that endoscopic injection is an inexpensive, convenient, and effective means for arresting peptic ulcer hemorrhage. It can be used as the first therapeutic approach.

Emergencies↗
PubMed1991

Inheritance of Resistance to Crown Gall in Pisum sativum.

We screened a total of 1365 pea (Pisum sativum) lines for response to inoculation with Agrobacterium tumefaciens, strain B6, and characterized resistance in one cultivar, Sweet Snap. Sweet Snap seedlings were highly resistant to tumorigenesis under most conditions. Resistance was overcome at inoculum concentrations of greater than 10(9) bacteria per milliliter. At such high concentrations, very small tumors developed on Sweet Snap in response to four wide-host-range Agrobacterium strains, but tumors on other cultivars were two-to sevenfold larger than those that formed on Sweet Snap. The hypervirulent strain A281 induced larger tumors on Sweet Snap than did other Agrobacterium strains, but tumors on other genotypes were more than 100% larger than those on Sweet Snap. Physiological experiments suggested that tumorigenesis in Sweet Snap is not blocked in early stages of infection, and genetic analysis indicated that inheritance of resistance to crown gall is a quantitative trait. In addition to the observed resistance in Sweet Snap, three ;supersusceptible' genotypes, which developed very large tumors, also were identified.

Journal Article↗
PubMed1991

Gastric acid and pepsin hypersecretion in conscious rabbits.

In conscious, gastric fistula rabbits, gastric acid and pepsin secretion averaged 4.5 +/- 0.1 mmol/h (1.3 mmol.kg-1.h-1) and 4.9 +/- 0.3 IU/h (1.6 IU.kg-1.h-1), respectively; these values represent approximately 40-50% of maximal output. Basal serum gastrin concentrations averaged 24 +/- 4 pg/ml and did not correlate with basal acid secretion. Atropine and vagotomy incompletely inhibited basal acid secretion (by 84 and 50%, respectively) and completely inhibited 2-deoxy-D-glucose-stimulated gastric acid secretion. Atropine and vagotomy similarly inhibited basal pepsin secretion by 50 and 40%, respectively. Ranitidine decreased acid and pepsin secretion, but as with atropine, inhibition was not complete (73 and 37%, respectively). Although omeprazole did not affect pepsin secretion, omeprazole completely inhibited basal acid secretion and elevated postprandial intragastric pH above 5.0. Conscious, gastric fistula rabbits have the highest basal acid and pepsin output among species commonly studied. Both vagal-cholinergic pathways and histamine drive basal acid and pepsin secretion in the rabbit.

Animals↗
PubMed1991

Endoscopic injection to arrest peptic ulcer hemorrhage: a prospective, randomized controlled trial; preliminary results.

Over a period of 10 months, we conducted a prospective randomized controlled trial of endoscopic injection for the arrest of peptic ulcer hemorrhage in 84 patients. We injected pure alcohol (PA, 99.8%), 50% glucose in water (G/W), 3% NaCl solution, and normal saline solution (N/S, controls) to stop bleeding. The ultimate success rates in the four groups were: 81% (17/21) in the PA group, 80% (16/20) in the 50% G/W group, 65.2% (15/23) in the 3% NaCl group, and 80% (16/20) in the N/S group (p greater than 0.05). The volume of blood transfusion (mean +/- s. e. m.) for each patient was 1,200 ml +/- 433 ml in the PA group, 1,130 +/- 356 ml in the 50% G/W group, 1,704 +/- 330 ml in the 3% NaCl group, 1,400 +/- 548 ml in the N/S group (p greater than 0.05). The duration of hospitalization (mean +/- s. e. m.) was 5.7 +/- 1.5 days in the PA group, 3 +/- 1.3 days in the 50% G/W group, 6.1 +/- 1.1 days in the 3% NaCl group, and 5 +/- 1.1 days in the N/S group (p greater than 0.05). No complication of perforation or aspiration pneumonia was observed during hospitalization. We suggest that endoscopic injection with the above solutions be used as the first line of therapeutic endoscopy for arrest of peptic ulcer hemorrhage.

Aged↗
PubMed1991

Effect of recombinant alpha 2 interferon with or without prednisone in Chinese HBsAg carrier children.

Ninety Chinese hepatitis B surface antigen (HBsAg) carrier children, aged 2-17 years, positive for hepatitis B e antigen (HBeAg) and hepatitis B virus DNA on at least three occasions in 6 months, were randomized into 3 groups. Thirty children received syrup vitamin B complex as control, 29 received 6 weeks of placebo syrup followed by 16 weeks of recombinant alpha 2b-interferon [intron A (rIFN2b)], 5 x 10(6) u/m2 subcutaneously thrice weekly; and 31 received 6 weeks of syrup prednisone (0.6 mg/kg tailed to 0.2 mg/kg) followed by 16 weeks of recombinant alpha 2b-interferon as above. The placebo/prednisone syrup was given on a double-blind basis. At 24 months of follow-up, persistent loss of hepatitis B virus DNA occurred in none of the children in the control group, in one child receiving recombinant alpha 2b-interferon alone, who also seroconverted to anti-HBe and anti-HBs and in five children receiving interferon with steroid priming (p = 0.0571 compared with controls), with four seroconverting to anti-HBe and one also seroconverting to anti-HBs. A rise of transaminases to above twice the upper limit of normal levels during the first 7 months of follow-up occurred in one subject in the control group, four in the group receiving alpha 2b-interferon alone and nine in the group receiving recombinant alpha 2b-interferon with steroid priming (p = 0.0144 compared with controls). Side effects of the steroid were negligible; those of recombinant alpha 2b-interferon were transient and acceptable. We conclude that 6 weeks of prednisone followed by 16 weeks of recombinant alpha 2b-interferon is of use in inducing persistent loss of hepatitis B virus DNA (16.1 per cent) and e-seroconversion (12.9 per cent) in a proportion of Chinese HBsAg carrier children: the prednisone probably enhances the immunomodulatory effect of recombinant alpha 2b-interferon.

Adolescent↗
PubMed1990

Purification and characterization of a DNA polymerase from the cyanobacterium Anacystis nidulans R2.

A DNA polymerase has been highly purified from Anacystis nidulans R2. Electrophoretic analysis in sodium dodecyl sulfate-polyacrylamide gels revealed that the final fraction contains three bands of Mr 107,000, 93,000, and 51,000, respectively. Analysis of purified DNA polymerase activity in situ indicates that of the three polypeptides the Mr 107,000 species has the catalytic activities. The native molecular weight of the enzyme was estimated by glycerol gradient sedimentation to be 100,000. The enzyme has an absolute requirement for a divalent cation. Mg2+ can be replaced with Mn2+, but the DNA polymerase is less active. Potassium chloride stimulates the enzyme, while potassium phosphate has no apparent effect. The enzyme is active over a pH range from 7.5 to 9.5 in 50mM Tris-HCl buffer. The ability of the cyanobacterial DNA polymerase to use activated DNA as a template, its associated 3'----5' and 5'----3' exonuclease activities, as well as its resistance to N-ethylmaleimide, dideoxynucleotides, arabinosyl-CTP and aphidicolin suggest a similarity between this enzyme and E. coli DNA polymerase I. This is the first characterization of a DNA polymerase from a cyanobacterium.

Cyanobacteria↗
PubMed1990

Genetic evidence of dissociation (generational skips) of electrical from morphologic forms of hypertrophic cardiomyopathy.

The diagnosis of hypertrophic cardiomyopathy (HC) is traditionally based on the demonstration by echocardiography of left ventricular hypertrophy in the absence of apparent cause. This study reports on 5 adults in 4 families who are obligate or highly probable carriers of the HC gene by virtue of their position in the pedigree, but who have normal echocardiographic findings. Four of these 5 patients had abnormal signal-averaged electrocardiograms, a finding suggesting the presence of electrical disease despite the absence of left ventricular hypertrophy. The fifth patient, an identical twin of a patient with familial HC, had neither left ventricular hypertrophy nor a myocardial electrical abnormality. These data indicate that the spectrum of HC includes patients who have a potentially arrhythmogenic left ventricular substrate but who have no evidence of left ventricular hypertrophy. Our data demonstrating generational skips also imply that some instances of HC previously judged to be sporadic may indeed by familial.

Adolescent↗
PubMed1990

Evidence for intrafamilial transmission of hepatitis B virus from sequence analysis of mutant HBV DNAs in two Chinese families.

To study the heterogeneity of hepatitis B virus (HBV) DNAs in Hong Kong, where HBV infection is endemic, serum specimens from 90 HBsAg carrier children were systematically tested with nine oligonucleotide probes representing conserved sequences in the viral genome. In a pair of twins and their cousin (belonging to family H) and an unrelated child (family Y) serum HBV DNA annealed to all but one probe, a sequence located between the core and pre-S regions of the viral genome (positions 2723-2738; EcoRI site 1). Serum from the H twins' aunt and the father and paternal grandparents in the Y family were also HBV DNA-positive. The nucleotide sequences in positions 2701-2800 were analysed. The same point mutation, C to T in position 2735, was present in the HBV DNAs from 7 individuals in the two families. All 4 H family members had the same HBV DNA sequence. The HBV DNA sequences found in the Y daughter, father, and grandfather were identical and they were different from the H family mutant. These results provided evidence at the DNA level of intrafamilial transmission within these Chinese families.

Adolescent↗
PubMed1990

What kind of non-bleeding visible vessel in a peptic ulcer needs aggressive therapy? Long-term clinical observation.

A total of 57 patients with peptic ulcers showing non-bleeding visible vessels were followed for 1-26 months (mean +/- SEM: 13.8 +/- 1.7 months). The age was 56.2 +/- 2.1 years (mean +/- SEM). Blood transfusion with a mean volume of 3.89 units was given. Twenty-five (25/57, 43.9%) patients had rebleeding episodes within one month. Seventeen (17/57, 29.8%) patients were submitted to operation or therapeutic endoscopy due to failure of hemostasis. We analyzed eight clinical parameters on admission of these patients with the aid of a stepwise logistic regression test. Advanced age (over 60), blood transfusion of more than 500 ml and shock were found to be independent predictors of rebleeding. Advanced age (over 60) and coffee ground material in the stomach were found to be independent predictors of ultimate failure of conservative management. We recommend aggressive (either operation or therapeutic endoscopy) rather than conservative management in a patient with a non-bleeding visible vessel who has any of the following characteristics on admission: age over 60, volume of blood transfusion over 500 ml, shock and coffee ground material in the stomach.

Adult↗
PubMed1990

Correlation of Pectolytic Enzyme Activity with the Programmed Release of Cells from Root Caps of Pea (Pisum sativum).

In many plant species, the daily release of hundreds to thousands of healthy cells from the root cap into the soil is a normal process, whose function is unknown. We studied the separation of the cells in pea (Pisum sativum) using an aeroponic system in which separated cells were retained on the root until they were washed off for counting. We found that cell separation is a developmentally regulated, temperature-sensitive process that appears to be regulated independently of root growth. No cells were released from very young roots. When plants were grown aeroponically, cell numbers increased with increasing root length to a mean of 3400 cells per root, at which point the release of new cells ceased. The process could be reset and synchronized by washing the root in water to remove shed cells. Cell separation from the root cap was correlated with pectolytic enzyme activity in root cap tissue. Because these cells that separate from the root cap ensheath the root as it grows and thus provide a cellular interface between the root surface and the soil, we propose to call the cells "root border cells."

Journal Article↗
PubMed1990

Heat probe thermocoagulation and pure alcohol injection in massive peptic ulcer haemorrhage: a prospective, randomised controlled trial.

We conducted a prospective randomised controlled trial of 137 patients with massive peptic ulcer haemorrhage over a period of 12 months to compare the haemostatic effects of endoscopic heat probe thermocoagulation and pure alcohol injection. Seventy eight patients (56.9%) were in shock at the time of randomisation to the trial. The age, sex, number of patients in shock, haemoglobin value at the time of entry to the trial, number of patients with severe medical illness, location of bleeders, and stigmata of recent haemorrhage were comparable among the heat probe, pure alcohol, and control groups. The initial haemostatic effect of the heat probe was better than that of the pure alcohol injection (44 of 45 v 31 of 46, p = 0.0004). The ultimate haemostasis achieved by the heat probe group (41 of 45) was better than that of the pure alcohol group (31 of 46, p = 0.012) and of controls (24 of 46, p = 0.0001). The duration of hospital stay was shorter for patients in the heat probe group than for the control group (6.2 days v 13.8 days, p less than 0.05). The incidence of emergency surgery was less for the heat probe than the control group (three of 45 v 12 of 46, p = 0.027). The mortality rate was less in the heat probe than in the control group (one of 45 v seven of 46, p = 0.031). We suggest that heat probe thermocoagulation should be the first treatment of choice for arrest of massive peptic ulcer haemorrhage.

Electrocoagulation↗