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Biomedical subjects

Y Han

Publications and source records attributed to Y Han.

At least 55 records · Page 3Linked to original sources
PubMed1991

Modulation of Na,K-ATPase expression during early development of Xenopus laevis.

In amphibian and mammalian systems, regulation of Na+ transport via the Na,K-ATPase plays an important role in distinct developmental processes such as blastocoele formation and neurulation. In this study, we have followed the Na,K-ATPase activity, the biosynthesis, and the cellular accumulation of catalytic alpha-subunits after fertilization of Xenopus laevis eggs up to neurula formation. Our data show that Na,K-ATPase activity increases significantly between stages 4 and 6 and again between stages 13 and 24. The four-fold rise in Na,K-ATPase activity during blastocoele formation is not mediated by an increased cellular pool of alpha-subunits. On the other hand, a five-fold increase of the biosynthesis rate around midblastula precedes a progressive accumulation up to neurula stage mainly of alpha 1-subunits and to a lesser extent of a second alpha-immunoreactive species. In contrast, newly synthesized glycoproteinic beta 1-subunits of Na,K-ATPase cannot be detected up to late neurula. These data indicate that (1) upregulation of Na,K-ATPase activity during blastocoele and neurula formation are mediated by different regulation mechanisms and (2) alpha- and possibly beta-isoforms are expressed in a developmentally regulated fashion during early Xenopus development.

Animals↗
PubMed1991

Nutritional evaluation of soybeans varying in trypsin inhibitor content.

A series of experiments was conducted to assess, by various methods, the nutritional value of a raw, Kunitz inhibitor-free, low trypsin-inhibitor soybean variant (LTS) in comparison with raw conventional soybeans (RCS) and heated dehulled soybean meal (HDS). The gross energy, protein, and amino acid concentrations of LTS were similar to those of RCS. The protein quality of the soybeans was compared in two trials in which young chicks were fed 9% or 16% CP diets containing one of the soybeans as the sole source of dietary protein. The protein quality of LTS was superior to that of RCS but inferior to that of HDS. True digestibilities of amino acids and TMEn were determined with a precision-fed cockerel assay using conventional and cecectomized birds. No significant effect of bird type on digestibility was found. The mean digestibility of 16 amino acids in RCS, LTS, and HDS was found to be approximately 68, 83, and 92%, respectively. The TMEn of LTS was greater than that of RCS. Chick growth assays indicated that amino acid bioavailability values of lysine and TSAA for LTS were greater than those for RCS but slightly lower than those for HDS. In an additional chick assay with a corn and HDS diet (22% CP), the dietary HDS protein was replaced with LTS or RCS protein at 25, 50, 75, or 100%. Performance of chicks fed LTS was better than that of chicks fed RCS at all replacement levels, but the difference was not significant at the 25% replacement level. Feed efficiencies of chicks fed 25 or 50% of the dietary soybean protein as LTS were not significantly different from that of chicks fed the corn and HDS control diet. The results of the present study indicated that the nutritive value of LTS is substantially greater than that of RCS but somewhat lower than that of HDS.

Amino Acids↗
PubMed1991

Research note: effect of excess lysine, methionine, threonine, or tryptophan on production performance of laying hens.

An experiment was conducted with laying hens to determine effects of feeding excesses of several individual amino acids in a practical layer diet. Single Comb White Leghorn hens, which were in peak production (31 wk of age), were assigned to one of five dietary treatments: a 16% CP corn and soybean meal positive control diet, or this diet fortified with 1% additional L-Lys, 1% additional DL-Met, 1% additional L-Thr, or 1% additional L-Trp. The diets were fed for ad libitum intake for 4 consecutive wk of production. For the entire production period, hen-day egg production, egg yield, and feed intake were not significantly different among any of the treatments. The study indicated that considerable tolerance exists in high-producing laying hens for individual excesses of the amino acids commonly used as supplements in poultry diets.

Analysis of Variance↗
PubMed1991

Subungual exostosis.

From 1980 through 1990, twenty-two patients with subungual exostosis were treated in PUMC Hospital and the Sixth Hospital of Beijing. The incidence of subungual exostosis was 4.6% among all bone tumors. Post-adolescents and young adults were most commonly affected, and the female to male ratio was 1.75 to 1. The great toe was the most often involved site. Radiological findings were found to be diagnostic, and local tumor excision is the treatment of choice.

Adolescent↗
PubMed1991

[Comparative study of the measured values of different periodontal probes].

A 0.25 N hinged constant force probe (Borodontic) and two inflexible probes (WHO, PCP-11) were used for probing. The mean probing depth differences between WHO and Borodontic as well as between Borodontic and PCP-11 were significant. Deepest probing levels were found with WHO and shallowest levels with Borodontic. Also, the pockets in patients with higher sulcus bleeding index presented shallower probing levels with Borodontic than the other probes.

Adult↗
PubMed1991

Characteristics of HIV-infected adults in acute care hospitals in New York State, 1984-1986.

The New York State acute care, hospital discharge database was used to create a longitudinal case history file for all adult inpatients infected with the human immunodeficiency virus (HIV). From 1984 through 1986, 12,958 individuals with HIV-related diseases were treated in acute care hospitals throughout the state. Approximately 80% of those people resided in New York City, and nearly half of them were between ages 30 and 39 years. Over the three-year period, the proportion of females increased from 11.8% to 16.6%. The per diem charge increased slightly, although the total length of stay for the first year of HIV illness declined sufficiently to decrease the total charge for the year. Examination of the pattern of inpatient stays and intercurrent days shows the first and last hospital stays to be longer than those in between, although the days between stays decreased as the number of admissions increased. The hospital stay in which a patient died was typically of longer duration than earlier stays. The average charge for HIV-related hospital care among inpatients during their first year of illness was approximately $20,000.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Assessment of intestinal amino acid availability in cattle by use of the precision-fed cecectomized rooster assay.

The digestibilities of amino acids in duodenal digesta of steers were measured using a precision-fed cecectomized rooster assay. Freeze-dried duodenal digesta from steers fed five different diets were utilized. Amino acids present in digesta of steers fed diets supplemented with corn gluten meal were more digestible than those from digesta of steers fed diets supplemented with soybean meal, blood meal, fish meal, or no true protein source. Measurements of amino acid digestibility in the cecectomized rooster were similar to those obtained previously when measured with reference to chromic oxide in steers fitted with duodenal and ileal cannulae, suggesting that the precision-fed cecectomized rooster assay is an appropriate technique for estimating small intestinal digestibility of amino acids in cattle.

Amino Acids↗
PubMed1990

Determination of available amino acids and energy in alfalfa meal, feather meal, and poultry by-product meal by various methods.

Several experiments were conducted to evaluate various methodologies for determining availability of amino acids (AA) and energy in alfalfa meal (AM), feather meal (FM), and poultry by-product meal (PBPM). Digestibility of AA was determined with 48-h precision-fed cockerel assays using conventional (CONV) and cecectomized (CEC) cockerels. Amino acid bioavailability was assessed with chick growth assays. True digestibility values of most AA were significantly lower for CEC than for CONV cockerels. In the chick growth assays, partitioning weight gains to reflect only growth attributable to supplemental crystalline AA or test feedstuff AA consumption often yielded higher bioavailability values than when total weight gains were used for FM and PBPM but lower ones for AM. The magnitude of differences between AA digestibility (cockerels) and AA bioavailability (chicks) values varied among feedstuffs; the largest differences were observed for FM. The TMEn values of AM and PBPM were lower for CEC birds than for CONV birds, whereas TMEn of FM was similar for both types of birds.

Amino Acids↗
PubMed1990

AIDS behind bars. Epidemiology of New York State prison inmate cases, 1980-1988.

During the last five years, AIDS has become the preeminent health care problem in New York State correctional facilities. Through December 31, 1988, 915 cases of AIDS had been diagnosed among inmates. This represented approximately 1% of the cumulative AIDS cases in the United States, 4% of those in New York State, and 40% of those reported in state correctional systems nationwide. An analysis of epidemiologic data on these cases showed an annual increase in cases from 3 in 1981 to 227 in 1988, with an incidence greater than 400 per 100,000 inmates per year over the past four years. While most cases occurred in males (96%), females had the same high incidence rates (compared to the general population, in which female rates are one-eight of males). Forty-seven percent of infected inmates were Hispanic, 38% black, and 13% white. Pneumocystis carinii pneumonia was the most common diagnosis (65%), while Kaposi's sarcoma was rare (3%). Previous intravenous drug use has been the major risk factor, seen in 95% of cases. A comparison of 54 inmate AIDS cases with 107 matched and 196 unmatched controls showed that inmates in whom AIDS developed had significantly lower white blood cell counts on entry into prison, lower hematocrits and serum albumin levels, and higher serum glutamic oxaloacetic transaminase and globulin counts. Through July 1989, 643 (70%) of these 915 inmates had died of AIDS, and HIV infection and AIDS account for 68% of recent inmate deaths.

Acquired Immunodeficiency Syndrome↗
PubMed1990

HIV infected hospital patients in New York State. The development of longitudinal information from a hospital discharge data system.

Abstracted records of all patients discharged from New York State acute care hospitals from January 1, 1983, through October 1, 1987, containing a diagnosis of HIV infection (N = 36,664) were linked into a longitudinal file of 20,005 patient-specific case histories. A validation study utilizing Medicaid patient-specific discharge information for calendar year 1985 showed that, on the average, each case history of the longitudinal file contained 85% (+/- 5%) of the expected discharges. The number of patients present in the longitudinal file was 10% (+/- 4%)--too large a percentage, due to a failure to link all the discharges to the appropriate case histories. The number of patients with a diagnosis of Pneumocystis carinii pneumonia (PCP) found in the longitudinal file was found to be consistent with the number reported to the New York State AIDS Registry. The longitudinal file appears to be sufficiently accurate and complete to use in evaluating HIV-related acute care in hospitals.

Adolescent↗
PubMed1989

Cross-reaction of immune sera from patients with rickettsial diseases.

Rickettsia rickettsii and Rickettsia conorii are the causative agents of two common and serious diseases, Rocky Mountain spotted fever and Mediterranean spotted fever, respectively. In patients naturally infected with either of these organisms, antibodies are produced which cross-react with antigens of the other so extensively that diagnostic tests usually cannot identify the causative agents. The results of this study indicate that serodiagnostic tests with antigen from one of these two organisms could be used to detect antibodies in patients with either of the two rickettsial diseases.

Antibodies, Bacterial↗
PubMed1989

Relationships between structure and biological activity of the mycolic acid-containing glycolipids from Nocardia asteroides "sensu stricto" and related species.

To reveal the taxonomical situation of Nocardia asteroides "sensu stricto", we compared the mycolic acid and mycolic acid-containing glycolipid composition and their granulomagenic activities in mice. The major glycolipids were glucose mono- and dimycolate, trehalose mono- and dimycolate and several unknown glycolipids, commonly, although the relative amount differed from strain to strains. On the other hand, molecular species composition of mycolic acids differed distinctively among the three closely related species: N. asteroides "sensu strico", N. farcinica and N. nova. GC/MS analysis showed the most abundant species of mycolic acids were C50(52) in N. asteroides, C54(52) in N. farcinica and C58(56) in N. nova, respectively with a different alpha-alkyl branch. Glucose mycolate and trehalose dimycolate possessing C50 mycolic acid showed a strong activity for granuloma formation in mice.

Animals↗
PubMed1988

Effects of reagent and instrument on prothrombin times, activated partial thromboplastin times and patient/control ratios.

Activated partial thromboplastin times accumulated from two proficiency testing surveys were analyzed to determine simultaneously the effects of the method and reagent used. Prothrombin time results were reevaluated concomitantly for comparison. A robust two-way analysis of variance was applied to determine the effect of method and reagent on APTT results. The effect of the reagent and method on the ratio of abnormal to normal plasma clotting times was determined. We found a substantial difference in ratios for the PT using different reagents on the same instrument. There was an even larger effect of reagents on APTT ratios. Our finding of substantial reagent effects for the PT and APTT clearly support the need for standardization. We found standardization to be feasible only for the PT, and only if applied in a form consistent with the inherent error structure of the data. For the APTT, the present methodology and plasma samples did not achieve consistent standardization.

Blood Coagulation Tests↗
PubMed1987

Contrasting effects of early and late orchiectomy on hypertension and renal disease in fawn-hooded rats.

Fawn-hooded (FH) rats, primarily males, develop spontaneous low-renin hypertension associated with reduced urinary excretion of kallikrein as early as 2 months of age, followed by progressive glomerular sclerosis and proteinuria as early as 3 months of age. In the present study we determined the effects of early (5-7 weeks) or late (5 months) orchiectomy on the blood pressure and nephropathy of FH rats, compared to sham-operated (control) FH males. Early orchiectomy reduced significantly the progression of glomerular sclerosis and of proteinuria and ameliorated the hypertension but had no significant effect on excretion of urinary kallikrein. Late orchiectomy, in contrast, had no significant effect on the progression of glomerular sclerosis or proteinuria but did significantly reduce the blood pressure and marginally increase the excretion of urine kallikrein. These results suggest that (a) male sex hormones may play a role in the pathogenesis of hypertension and nephropathy in the FH rats and (b) renal disease in this strain progresses in spite of improvement in blood pressure.

Aging↗
PubMed1987

Assessment of enzyme immunoassay and immunofluorescence tests for detection of Chlamydia trachomatis.

Two rapid diagnostic tests for Chlamydia trachomatis (Microtrak, Syva Co., Palo Alto, Calif.; and Chlamydiazyme, Abbott Laboratories, North Chicago, Ill.) were evaluated in comparison with growth of the organism in tissue culture for 2,030 urogenital specimens from men and women. Neither test performed as well as culture, which detected 296 of 310 positive specimens. The overall sensitivity and specificity for Microtrak were 73 and 99%; corresponding values for Chlamydiazyme were 83 and 98%. The majority of false-negative results with both rapid tests occurred when cultures contained less than 10 inclusions per cover slip. There were also areas of unconfirmed reactivity for both tests that led us to suggest that a reporting category of "suspicious" be developed for certain test results. For Microtrak, the suspicious result is a slide containing fewer than 10 elementary bodies; for Chlamydiazyme, it is any absorbance reading less than 0.4. Creation of a "suspicious" category would lower the sensitivity for Chlamydiazyme considerably, to 64%, and increase the positive predictive value for females to 95%. Although this may result in the underreading of some specimens from males, the tests could then be used with greater confidence in females for whom testing is essential for appropriate treatment.

Chlamydia Infections↗
PubMed1987

Nutritive value of high oil corn for poultry.

Several experiments were conducted to evaluate the nutritional value of high oil corn for poultry relative to that of conventional (CONV) corn. The variety of high oil corn (HO1) evaluated in most trials contained 6.0% oil and 9.6% protein on a 10% moisture basis. The protein quality of HO1 and CONV corn was assessed with female crossbred chicks fed corn as the sole source of dietary protein. There was no difference in either protein efficiency ratio or in net protein ratio between the two types of corn. True metabolizable energy (TME) and nitrogen-corrected TME (TMEn) values of HO1 corn were determined using adult roosters. The TME and TMEn values of HO1 corn were approximately 4.5% higher than those of CONV corn. Two experiments were conducted to evaluate the use of high oil corn varieties, containing from 6 to 13% oil, in practical diets of commercial broiler chicks from 8 to 22 days posthatching. Weight gain, gain-to-feed ratio, and skin and plasma pigmentation were improved in chicks fed 24% protein diets containing high oil corns compared with those fed the same diet containing CONV corn; magnitude of response was highly correlated to oil content of the corn. The relative value of HO1 corn in practical laying hen diets was examined in a 15-wk experiment. Hens fed a 17% protein diet containing HO1 corn from 23 to 38 weeks of age had a better feed-to-egg ratio than those fed the same diet containing CONV corn when the corn sources were substituted on an isonitrogenous basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗