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Biomedical subjects

L H Lin

Publications and source records attributed to L H Lin.

At least 73 records · Page 4Linked to original sources

Hepatitis B virus transcripts in a human hepatoma cell line, Hep 3B.

Hep 3B, a human hepatoma cell line was examined for its RNA hybridizable to the hepatitis B virus sequence. Using probes that covered different regions of the hepatitis B virus genome, five species of RNA were observed of sizes 4.0, 3.3, 2.9, 2.6 and 2.2 kilobases. The RNAs covered surface antigen gene, pre-S and X regions. None of them had a core antigen sequence. RNA with a 4.0 kilobase size was the most abundant. Using S1 nuclease analysis, its 5' end of hepatitis B virus sequence was mapped at pre-S region and its 3' end of viral sequence was mapped at DR region.

Antigens, Neoplasm↗

Effects of intrahypothalamically administered norepinephrine, serotonin and bombesin on thermoregulation in the deermouse (Peromyscus maniculatus).

Norepinephrine, serotonin, and bombesin administered intrahypothalamically affected thermoregulation in the deermouse, Peromyscus maniculatus. At a Ta of 22 degrees C, doses of 3 micrograms and 6 micrograms of NE resulted in transient hypothermia (maximum drop of 1.6 +/- 1.0 degrees C and 4.3 +/- 2.3 degrees C, respectively). A 1.5 microgram dose of 5-HT induced a persistent hyperthermia (maximum increase of 1.8 +/- 0.8 degrees C) which persisted for more than 2 h. A 6 microgram dose of 5-HT did not produce any significant effects. At a Ta of 22 degrees C, doses of 1 ng and 10 ng of bombesin produced a transient hyperthermia (maximum increase of 1.8 +/- 0.3 degree C and 2.1 +/- 1.2 degrees C, respectively) immediately postinjection. At a Ta of 5 degrees C, a 1 ng dose of bombesin resulted in a prolonged hypothermia (maximum decrease of 2.0 +/- 0.4 degrees C), while a 10 ng dose of bombesin produced a hyperthermic response (maximum increase of 1.3 +/- 0.8 degree C) at 2 h postinjection.

Animals↗

Stability of ganciclovir sodium (DHPG sodium) in 5% dextrose or 0.9% sodium chloride injections.

The stability of 9-[(1,3-dihydroxy-2-propoxymethyl]) guanine sodium (ganciclovir sodium, also known as DHPG sodium) in two infusion solutions was studied. Lyophilized ganciclovir sodium 500 mg was reconstituted with sterile water 10 mL to give a theoretical concentration of 50 mg/mL. After reconstitution, 6-mL aliquots of the solution were added to 100 mL of 0.9% sodium chloride injection or 5% dextrose injection in polyvinyl chloride i.v. bags. One sample was withdrawn from each of 10 bags of each solution and analyzed by high-performance liquid chromatography (HPLC). Thirty bags of each solution were then stored under each of the following conditions: at room temperature under laboratory light, at room temperature in the dark, and under refrigeration for up to five days. Single potency assays were performed by HPLC on each of three bags of solution at three and five days after initial dilution of the solutions. The solutions were visually inspected, and the pH of the solutions was measured. All solutions of ganciclovir were stable for at least five days under all storage conditions; mean ganciclovir concentrations did not drop below 98% of initial theoretical values throughout the storage period. No important changes in the pH of the solutions occurred during the study period. Under the conditions of this study, ganciclovir sodium is stable for up to five days when prepared in 5% dextrose injection or 0.9% sodium chloride injection.

Acyclovir↗

Expression of c-myc gene in human hepatoma.

The level of c-myc transcript was examined in liver samples from seven hepatoma patients. Transcripts were detected in all the normal liver parts examined; in contrast, in two hepatoma parts, there was a dramatic reduction in c-myc transcripts. The restriction enzyme pattern of c-myc gene appeared the same among samples. The data suggest that c-myc gene expression might not be required for the maintenance of the tumor state in human liver carcinogenesis.

Carcinoma, Hepatocellular↗

Serodiagnosis of acute B hepatitis: comparison between a competitive binding radioimmunoassay and an enzyme linked immunosorbent assay for IgM antibody to hepatitis B core antigen.

The standard radioimmunoassay for anti-HBc (CORAB) was modified for the differential detection of anti-HBc IgM by incorporation of a step in which anti-HBc IgG was preferentially absorbed by Staphylococcus aureus cells (Protein A). The ratio (R) of anti-HBc IgM to total anti-HBc was evaluated by computing the ratio of sample cpm's after and before protein A absorption. The R values of acute B hepatitis ranged from 0.9 to 2.1 (mean 1.3 +/- 0.3) while those of chronic HBsAg carriers ranged from 3.1 to 8.3 (mean 4.9 +/- 1.1). Adopting 2.1 as the upper limit of R value for acute B infection, this modified CORAB was shown to have excellent correlation with enzyme immunoassay, and to be capable of differentiating acute from persistent HBV infection in HBsAg positive patients, and discriminating acute B hepatitis from non-A, non-B hepatitis in HBsAg negative but anti-HBc positive acute hepatitis.

Acute Disease↗

Haloacetonitrile excretion as thiocyanate and inhibition of dimethylnitrosamine demethylase: a proposed metabolic scheme.

Haloacetonitriles, contaminants present in chlorinated drinking water, were administered orally to rats, and the urinary excretion of thiocyanate was measured as an index of cyanide release. The urinary excretion of thiocyanate accounted for 14.2% of the dose of monochloroacetonitrile; 7.7-12.8% of the dose of bromochloro-, dichloro-, and dibromoacetonitrile; and 2.25% of the dose of trichloroacetonitrile. The haloacetonitriles inhibited rat-liver microsomal dimethylnitrosamine (DMN) demethylase in an in vitro assay system. Dibromo- and bromochloroacetonitrile were the most potent inhibitors of DMN demethylase, with Ki = 3-4 X 10(-5) M; dichloro- and trichloroacetonitrile were the next most potent, with Ki = 2 X 10(-4) M; and monochloroacetonitrile was the least potent inhibitor, with Ki = 9 X 10(-2) M. Trichloroacetonitrile, but not dibromoacetonitrile, when administered orally inhibited hepatic DMN demethylase activity. The relative capacity of the haloacetonitriles to inhibit DMN demethylase and to be excreted as thiocyanate did not correlate.

Acetonitriles↗

Clones from cultured, B16 mouse-melanoma cells resistant to wheat-germ agglutinin and with altered production of mucin-type glycoproteins.

Several clones resistant to wheat-germ-agglutinin toxicity were isolated from B16 mouse-melanoma cells. The resistance may be explained in part by fewer binding sites for the agglutinin on the variant lines; the total, cellular sialic acid content appeared somewhat reduced. Analysis of cell glycoproteins indicated a decreased content of sialic acid in one glycoconjugate that binds to wheat-germ agglutinin and has O-linked oligosaccharides.

Animals↗

Role of O6-methylation in the initiation of GGTase-positive foci.

The ability of seven methylating agents to form 7-methylguanine and O6-methylguanine was compared to their ability to initiate carcinogenesis as measured by the initiation of GGTase-positive foci. The seven methylating agents studied were methyl-N-nitroso-p-toluenesulfonamide (diazald), dimethylhydrazine (DMH), dimethylnitrosamine (DMN), dimethylsulfate (DMS), methyl methanesulfonate (MMS), methyl-N-nitro-N-nitrosoguanidine (MNNG) and methyl-N-nitrosourea (MNU). The DNA methylation and initiation of GGTase-positive foci was determined in partial hepatectomized rats. The formation of foci was promoted by 500 ppm sodium phenobarbital in the drinking water. While six of the seven compounds (DMH, DMN, DMS, MMS, MNNG and MNU) produced 7-methylguanine, only the four compounds (DMH, DMN, MNNG and MNU) that produced O6-methylguanine initiated GGTase-positive foci. The extent of O6-methylguanine produced by the methylating agents did not correspond with their potency to initiate GGTase-positive foci. Therefore, the initiation of GGTase-positive foci required the formation of O6-methylguanine. However, some sequential event altered the quantitative relationship of O6-methylguanine formation to the incidence of GGTase-positive foci.

Alkylating Agents↗

Trihalomethanes as initiators and promoters of carcinogenesis.

Chloroform and other trihalomethanes are contaminants of drinking water that have been demonstrated to be carcinogenic in laboratory animals. Determination of the mechanism of carcinogenicity of chloroform is required so that the animal data can be extrapolated to estimate the human health hazard. The extent of the binding of chloroform to rat liver and kidney DNA was approximately 0.1% the level of binding found for dimethylnitrosamine. Neither chloroform nor bromoform, in contrast to diethylnitrosamine-initiated GGTase-positive foci in either intact or partial hepatectomized rats, promoted with phenobarbital. Tumor-promoting activity of chloroform was indicated by the slight significant increase, compared to untreated controls, in the incidence of GGTase-positive foci in rats initiated with diethylnitrosamine (DENA) followed by the administration of chloroform twice weekly for a total of 15 doses. In this study, rats administered only the DENA or the chloroform did not contain an increased incidence of GGTase-positive foci compared to untreated controls. However, the incidence of foci in the group that received DENA followed by chloroform was not statistically different from that in either the group that received only the DENA or only the chloroform. In conclusion, we were unable to demonstrate tumor-initiating activity for chloroform, and the tumor-promoting activity of chloroform indicated by our results requires further confirmation.

Animals↗

Formation of glucoside conjugate of acetaminophen by fungi separated from soil.

The phase II metabolite of acetaminophen in filamentous fungi and actinomycetes separated from soil was investigated. Fifty-four filamentous fungi and twenty-seven actinomycetes were screened to transform acetaminophen. The metabolites of acetaminophen were assayed using liquid chromatography-tandem mass spectrometry. The only metabolite was subject to enzymatic hydrolysis to confirm its structure. Acetaminophen was converted into glucoside conjugate, by filamentous fungi JX1-60, LN17-2, LN20-1 and the yield of the conjugate was 60.01%, 44.27%, 100%, respectively, and no phase I metabolites were detected. Glucoside conjugation of acetaminophen in filamentous fungi differs from the phase II metabolism of glucuronidation in humans. The fungus LN20-1 could be a suitable model to synthesize glucoside conjugate of acetaminophen.

Acetaminophen↗

Recurrent pancreatitis secondary to type V hyperlipidemia: report of one case.

With the exception of cystic fibrosis and hereditary pancreatitis, case reports about pancreatitis in children have rarely been mentioned. We report here an 11-year-old boy with type V hyperlipidemia, who suffered from two episodes of acute pancreatitis. Sudden onset of severe upper abdominal pain, fever, and hypertriglyceridemia were the common presentations. Initial treatments including analgesics, fasting, parenteral nutrition support and following diet control with medium-chain triglycerides seem to be successful in our case.

Child↗

Ultrasound screening of neonatal adrenal hemorrhage.

Neonatal adrenal hemorrhage (NAH) is frequently overlooked because the majority of cases are asymptomatic. In this study, we investigated the clinical symptoms, echographic characteristics and incidence of NAH from January 1998 to December 1999 at Cathay General Hospital, Taipei, Taiwan. Among 3273 newborns who had ultrasound screening, 18 cases were diagnosed as having NAH. The incidence was 0.55% which was compatible with other reports. But there was a female predominance (10:8) which was different from previous reports. Only one premature baby was diagnosed with NAH. No patients had perinatal asphyxia, and this was different from other reports. The mean birth body weight was 3530 grams which was more than the 75th percentile of normal term baby birth weight. Sixteen cases had right-sided NAH and two cases had left-sided NAH. Eleven cases (61%) within this study were asymptomatic. The incidence of pathologic jaundice was 11%. Four babies (22%) had poor oral feeding combined with vomiting. Only one had severe anemia for which blood transfusion was required. There were no cases of adrenocortical insufficiency in our study. Only one patient received adrenalectomy. In conclusion, NAH can be detected early by sonography and most cases require only supportive treatment. Thus, unnecessary surgery and severe complications due to delayed diagnosis can be avoided.

Adrenal Gland Diseases↗

Food protein-induced enterocolitis syndrome: report of one case.

We report a 76-day old infant who got diarrhea within the first week of life. He was treated as acute gastroenterocolitis and kept on feeding with regular infant formula. Because the symptoms persisted, the feeding formula was shifted to soy-based formula then to the highly-hydrolyzed formula and got improvement. But severe bloody diarrhea, vomiting, dehydration and fever developed after feeding with regular infant formula again. Based on the history and clinical presentations, cow's milk allergy was suspected. He received total parenteral nutrition for 5 days then fed with highly-hydrolyzed formula with slowly increasing amount. Thereafter tests for total eosinophil counts, total serum IgE, milk specific IgE antibodies and milk extract skin prick test were all unremarkable. Under the impression of food protein-induced enterocolitis syndrome (FPIES), a double-blind placebo-controlled food challenge (DBPCFC) with infant formula was performed. Regular infant formula induced severe vomiting, diarrhea, fever, acidosis and elevation of absolute neutrophil counts (ANC) of peripheral blood by 27,640/mm3. Based on the laboratory findings and challenge results, the patient fit the diagnostic criteria of food protein-induced enterocolitis syndrome.

Enterocolitis↗

Internal hernia caused by Meckel diverticulum in an infant: report of one case.

Intestinal obstruction caused by internal hernia due to Meckel diverticulum is a rare disease. The condition is seldom diagnosed preoperatively. In this paper, we present a 10-month-old boy who suffered from abdominal pain, persistent vomiting, and mild fever for 2 days. Abdominal sonography, plain abdomen X-ray, and computed tomography merely showed mechanical ileus and partial malrotation. However, exploratory laparotomy revealed a Meckel diverticulum through which the small bowel had herniated. We introduce the Meckel diverticulum and internal hernia and discuss intestinal obstructions.

Hernia↗

Noise and related events in a neonatal intensive care unit.

The purposes of this study were to explore noise distribution, its timing, and sources of peak noise in the neonatal intensive care unit (NICU) of a University Hospital in Southern Taiwan. Two surveys on noise distribution and peak noise of the warmer bed were conducted. Noise at radiate heated beds located in the central sites of two areas, one near (Area A) and the other away from (Area B) the nursing station, were measured continuously for one week using an electronic sound-meter. Peak noise with a sound level of > 65 on the A-weighted decibel scale (dBA) and associated sources were recorded for 48 hours. Monitoring periods of peak noise consisted of a weekday and a day on the weekend randomly selected for Area A. Results showed that mean noise levels at the warmer bed in Areas A and B were 62 and 61.4 dBA on average. In over 70% of the total observation time for both areas the sound levels were > 59 dBA. The noise intensity was particularly high between 8 a.m. and 4 p.m. The noise level on the weekend was lower than that on weekdays. During the 48-hour observation period, 4994 peak noises were recorded. Eighty-six percent of these peak noises were within ranges of 65-74 dBA and 90% were human-related factors. The primary non-human related source was monitor alarms. Additionally, peak noises occurred primarily during the 8-11 a.m. and 2-4 p.m. hours on the weekdays and weekends. These results indicate that modifications of staff behavior, care procedures, and apparatus may reduce the noise levels in the NICU.

Data Collection↗