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Biomedical subjects

Y Guo

Publications and source records attributed to Y Guo.

At least 649 records · Page 36Linked to original sources
PubMed1985

Histopathological evidence for protective immunity induced by sonicated Salmonella vaccine.

The highly susceptible inbred C3H/HeNMTV mice were vaccinated with fragments derived from sonicated Salmonella typhimurium and then infected with the pathogen. All of the vaccinated mice survived an otherwise rapidly fatal challenge of 10(5) organisms, i.e., greater than 10(3) x mean lethal dose (LD50). The vaccine also protected two-thirds of the mice infected with 10(6) bacteria and extended the survival time of the remainder in their fatal disease. Histopathological findings showed that, like the control mice, the vaccinated and infected mice developed abscesses with infiltration of polymorphonuclear leukocytes in the organs of the reticuloendothelial system during the early stage of the infection. However, unlike the primary lesions in the control mice, the lesions of the vaccinated mice tended to be discrete and self-limiting. They began to transform into granulomas after the first week of infection. Recovery and regeneration of tissues were evident 3 weeks after the infection.

Abscess↗
PubMedDate not supplied

HIV-1 drug resistance in newly infected individuals.

CONTEXT: There is concern that the widespread use of antiretroviral drugs to treat human immunodeficiency virus 1 (HIV-1) infection may result in the increased transmission of drug-resistant virus. OBJECTIVE: To determine the prevalence of drug resistance-conferring mutations and phenotypic resistance to antiretroviral agents in a cohort of individuals newly infected with HIV-1. DESIGN: Case series with genetic analyses of the HIV-1 plasma-derived pol gene using reverse transcriptase polymerase chain reaction followed by direct sequencing of polymerase chain reaction products. Phenotypic analysis was performed with a recombinant virus assay. SETTING AND PATIENTS: Eighty individuals referred, on average, 1.7 months after infection with HIV-1 to the Aaron Diamond AIDS Research Center between July 1995 and April 1999. Subjects were from large urban areas (65 from New York, NY; 11 from Los Angeles, Calif); 60 (75%) were white, and 75 (93.8%) were homosexual men. MAIN OUTCOME MEASURES: Prevalence of known resistance-conferring genotypes and reduced susceptibility to individual antiviral agents by phenotype. RESULTS: Thirteen individuals (16.3%) had genotypes associated with drug resistance to any antiretroviral agent. Virus with known resistance-conferring mutations to any nucleoside reverse transcriptase inhibitors was found in 10 individuals, to any nonnucleoside reverse transcriptase inhibitors in 6 subjects, and to any protease inhibitors in 2 cases. Multidrug-resistant virus was identified in 3 individuals (3.8%). Extensive polymorphism in the protease gene was identified. Interpretation of genotypes and phenotypes was concordant in 57 (85%) of the 67 cases in which both studies were performed. CONCLUSION: The prevalence of HIV-1 variants with known resistance-conferring genotypes to any antiretroviral agent in this cohort of 80 newly infected individuals is 16.3%. These data support expanded use of resistance testing in the setting of primary HIV-1 infection. Clinical trials should be initiated to establish whether therapy guided by resistance testing, compared with the use of empirical triple combination antiretroviral therapy, provides additional virological and immunological benefit when treating primary HIV-1 infection. Further efforts to expand the study of transmission of drug-resistant HIV-1 variants, particularly in cohorts with different epidemiological profiles, are indicated.

Adult↗
PubMedDate not supplied

Significantly higher frequency of the MspI 2.2 kb allele of the Duchenne muscular dystrophy intragenic probe P-20 in the Chinese population.

The P-20 intragenic marker was used to test for restriction fragment length polymorphisms in unrelated Chinese patients with Duchenne or Becker muscular dystrophy or X-linked mental retardation. In addition to polymorphism at the 6.0/3.5 kb MspI allelic site, we found an independent and high frequency of polymorphism at the 2.2/1.8 kb site. This differs from results found with other populations.

Alleles↗
PubMedDate not supplied

Abnormal illness behavior of patients with functional somatic symptoms: relation to psychiatric disorders.

Functional somatic symptoms are highly associated with hypochondriasis, anxiety, and depressive disorders. Despite the absence of an organic disorder, underlying psychological distress of patients with functional somatic symptoms may result in abnormal illness behavior such as inadequate treatment seeking or overuse of medical services. Using the Illness Behavior Questionnaire (IBQ), we examined the illness behavior of Japanese patients visiting a general medicine clinic whose physical symptoms were considered functional. We used the General Health Questionnaire-30 to classify patients with functional somatic symptoms as those with and without psychological distress. Patients with distress (n=35) reported more physical complaints and higher IBQ scores than did patients without distress (n=22). The IBQ profile of patients with psychological distress was identical to that of patients diagnosed with either hypochondriasis or major depression. The illness behavior of patients without psychological distress was indistinguishable from that of patients whose physical symptoms were attributed to organic disease. These results further support the hypothesis that functional somatic symptoms may be associated with hypochondriasis and major depression, the pathology of which may contribute to the development of abnormal illness behavior.

Adult↗
PubMedDate not supplied

Synthesis of a lipid/peptide/drug conjugate: N4-(acylpeptidyl)-ara-C.

A lipid/peptide/drug conjugate, N4-(acylpeptidyl)-ara-C, is synthesized under mild conditions to give an ara-C prodrug protected against cytidine deaminase-catalyzed deactivation. The compounds can be bound, via their hydrocarbon tails, to phospholipid membranes and examined for chymotrypsin-induced drug release. A tripeptide is too short to permit efficient enzyme/membrane contact and subsequent freeing of the drug. Faster rates can, presumably, be achieved by "fine tuning" the length and polarity of the peptide spacer attached to the drug.

Cytarabine↗
PubMedDate not supplied

Control of endotoxemia in burn patients by use of polymyxin B.

A group of patients with severe burns were entered into two sequential prospective randomized trials for reduction of endotoxemia by the use of intravenous polymyxin B. The first group underwent polymyxin administration during the first week after burn injury in a bell-shaped dosage form constructed to resemble the level of endotoxemia as previously documented. This group showed a statistically highly significant reduction in endotoxin levels and a suggestive, but not statistically significant, reduction in wound infection and mortality in the treated group compared with controls. The second group of patients underwent treatment with perioperative polymyxin B given in conjunction with an excisional procedure of the burn wound. In this group, polymyxin B also accomplished a reduction in endotoxemia from preoperative to postoperative cases, but there was no significant reduction in clinical complication rate or mortality. In the dosages used, polymyxin B is nontoxic and promises to be a useful part of the surgeon's armamentarium in dealing with severe complications of gram-negative sepsis.

Adult↗
PubMedDate not supplied

Unique use of botulinum toxin to decrease adductor tone and allow surgical excision of vulvar carcinoma.

Here, we present the case of an 86-year-old woman with vulvar carcinoma requiring surgical resection and with Parkinson's disease with severe spasticity and contractures of the lower extremities. Because of the patient's severe contractures and spasticity (her knees could only be separated by 2 cm with sustained abducting force), surgical positioning and access to the vulva were impossible. The patient was admitted, intending to undergo surgery after injection with botulinum toxin (BTX) to hip adductors and intensive physical therapy. After confirmed healed hip arthroplasty, the patient underwent BTX injection (400 U) to her bilateral adductor brevis, adductor longus, adductor magnus, and semimembranosus and semitendinosus muscles on day 2 of her hospital stay. On day 3, a physical therapist began a twice-a-day stretching program. An adjustable abduction brace was custom-made to provide sustained stretching. On day 9, the patient underwent wide local excision of vulvar carcinoma with the abductor brace in place. The patient tolerated the surgery well and was discharged home on day 11 with continuous physical therapy. Upon discharge, the distance between the patient's knees was 14 cm. This unique case demonstrated a new indication for BTX treatment in the preoperative setting to allow surgical positioning and access.

Aged↗
PubMedDate not supplied

Characterization of Bovidae sex-determining gene SRY.

In mammals, testis determination is under the control of the sex-determining gene SRY. This Y-linked gene encodes a protein with a DNA binding domain similar to those found in high-mobility-group proteins. Here we report the cloning and sequences of the SRY genes of yak and Chinese native cattle. Our data show that SRY genes in Bovidae are less divergent, especially in the coding and 3' regions.

3' Untranslated Regions↗
PubMedDate not supplied

Modulation of rat lung Na+,K(+)-ATPase gene expression by hyperoxia.

Rats exposed to 85% O2 for 5-7 days develop tolerance to otherwise lethal hyperoxia (100% O2). The rate of alveolar fluid clearance increases during adaptation to hyperoxia, due in part to increased alveolar epithelial sodium channel activity. In these studies, we have investigated molecular mechanisms leading to increased lung Na+,K(+)-ATPase activity in hyperoxia. We exposed adult rats to 85% O2 (sublethal hyperoxia) for 7 days, followed by 2, 3, or 4 days in 100% O2. Steady-state levels of the Na+,K(+)-ATPase alpha 1 and beta 1 subunit mRNAs increased in whole lung tissue during hyperoxia exposures. Stability of the Na+,K(+)-ATPase alpha 1 and beta 1 subunit mRNA messages in whole lung RNA did not change significantly. Thus, lung Na+,K(+)-ATPase gene expression in sublethal hyperoxia appears to be regulated in part at the transcriptional level. Alveolar epithelial type II (ATII) cell Na+,K(+)-ATPase alpha 1 and beta 1 subunit proteins, measured by quantitative immunofluorescence, increased significantly after sublethal hyperoxia and 100% O2 exposures. Increases in lung fluid clearance after sublethal hyperoxia are associated with increased ATII cell Na+,K(+)-ATPase protein and whole lung Na+,K(+)-ATPase mRNA expression, which correspond to previously described increases in epithelial sodium channel expression under these conditions.

Animals↗