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Biomedical subjects

B Yu

Publications and source records attributed to B Yu.

250 records · Page 14Linked to original sources

An aspergillus immunodiffusion test in the early diagnosis of aspergillosis in adult leukemia patients.

An Aspergillus fumigatus immunodiffusion test was performed biweekly for one year on 80 hospitalized patients with acute leukemia to determine if serologic conversion accompanied clinical aspergillosis. A micro-ouchterlony technique with agarose was used. The antigens were prepared from concentrated A. fumigatus culture filtrates and the sera were concentrated 3-fold before testing. Of 80 patients, 10 were proved at autopsy, lung biopsy, or closed space culture to have invasive aspergillosis. Six of 10 patients converted from a negative to a positive immunodiffusion test, whereas a seventh patient's weakly positive test became strongly positive. Three patients with documented aspergillosis did not develop a positive immunodiffusion test. Four of the patients who converted from a negative to a positive test were treated early and successfully with amphotericin B. A fifth patient developed immunodiffusion test antibody late in the course and died despite therapy. A sixth patient died of concomitant mucormycosis despite early therapy. Six additional patients who converted from a negative to a positive immunodiffusion test could not be evaluated because of inadequate documentation of aspergillosis. In severely immunosuppressed patients, our immunodiffusion test proved to be a specific but not always a sensitive test for aspergillosis. In 4 patients, biweekly tests showed conversion associated with invasive aspergillosis, which was diagnosed early and treated successfully.

Acute Disease↗

Previously uncharacterized Mycoplasma isolates from an investigation of canine pneumonia.

Mycoplasmas recovered from the respiratory tract and genitourinary system of dogs, with and without respiratory infection, have been characterized by biological and immunological methods. Some of the isolates were indentified as being similar to the three species of canine mycoplasmas described earlier under the designation Mycoplasma spumans, M. canis, and M. maculosum. Other mycoplasmas placed in three groups (A, C, and D) were found to be clearly distinct from the three classified species. Group A strains fermented glucose but not mannose and were serologically distinct from other canine mycoplasmas recovered in this study. These strains were subsequently found to be biologically and serologically related to a previously reported, but unclassified, canine mycoplasma. Group D strains differed in some biological properties but were serologically related. These were found to be nonfermenting mycoplasmas representing isolations from the throat and bladder of dogs. They were serologically distinct from other canine mycoplasmas and were apparently unrelated to other known mycoplasma serotypes. Group C mycoplasmas were recovered only from the lungs of dogs. Within the group, they differ in some immunological properties but appear to be serologically distinct from other canine strains. They can also be separated from other dog strains in their ability to ferment glucose and mannose. Group B strains were found to have biological properties similar to M. canis strains but seemed to be only partially related to this serotype when examined in several serological techniques. It is suggested that these strains might represent antigenic variants of M. canis.

Journal Article↗

Characterization of canine mycoplasmas by polyacrylamide gel electrophoresis and immunodiffusion.

Canine mycoplasmas which had been characterized by biological and serological methods were further studied by using polyacrylamide gel electrophoresis (PGE) and double diffusion in agar gel. The three dog mycoplasmas previously characterized, Mycoplasma canis, M. maculosum, and M. spumans showed distinctive patterns by PGE. Five additional representative isolates from dogs had been characterized serologically and biologically into three new groups, A, C, and D. An additional mycoplasma (group B) was indistinguishable from M. canis by growth inhibition and PGE but was more broadly reactive with field isolates serologically. The group A organisms were distinctive in pattern and similar to those studied by Razin and Rottem, tentatively designated M. edwardii. The group C organisms were represented by two isolates which were similar by fluorescent-antibody studies but different by growth inhibition tests. These two isolates were also different from each other by PGE. The group D serotypes were also distinctive by PGE from all other dog mycoplasmas tested. It was found, during these studies, that two different mycoplasmas showed different PGE patterns at different intervals during incubation. Immunodiffusion studies showed a relationship among all the canine mycoplasmas, and bands of nonidentity between the two group C mycoplasmas were demonstrated.

Animals↗

Vanadate induces normolipidemia and a reduction in the levels of hepatic lipogenic enzymes in obese Zucker rat.

The effects of vanadate administration on the plasma lipids and hepatic lipogenic enzymes were investigated in Zucker (fa/fa) rat, a model for obesity and non insulin-dependent diabetes. These animals were administered sodium orthovanadate through drinking water for a period of four months. The plasma levels of insulin, triacylglycerols and total cholesterol were significantly (p < 0.001) elevated in untreated obese control rats as compared to the lean animals. In the livers of obese rats, the number of insulin receptors decreased by 60% and the activities of lipogenic enzymes acetyl-CoA carboxylase and ATP-citrate lyase increased by 4.7- and 5.6-folds, respectively. The messenger RNA for ATP-citrate lyase as measured by Northern blot analysis showed a parallel increase in obese control rats. Treatment of these rats with vanadate caused 56-77% decreases in the plasma levels of insulin, triacylglycerols and total cholesterol. The insulin receptor numbers in vanadate-treated obese rats increased (119%) compared to levels in untreated obese animals. The elevated activities of acetyl-CoA carboxylase and ATP-citrate lyase observed in livers of obese rats were significantly reduced by vanadate. The messenger RNA for ATP-citrate lyase also decreased in vanadate-treated obese rats back to the lean control levels. This study demonstrates that vanadate exerts potent actions on lipid metabolism in diabetic animals in addition to the recognized effects on glucose homeostasis.

ATP Citrate (pro-S)-Lyase↗

Placental endothelial nitric oxide synthase localization and expression in normal human pregnancy and pre-eclampsia.

1. The aim of the present study was to investigate whether pre-eclampisa, a state of placental hypoxia, is associated with placental abnormalities in the amount, distribution and expression of endothelial nitric oxide synthase (eNOS). 2. Localization and intensity of eNOS was determined by immunohistochemistry using an antibody specific for eNOS. The amount of eNOS mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and the densitometry of gel bands was expressed as a ratio of the band density of the housekeeping gene beta2-microglobulin. 3. Endothelial NOS staining was localized to syncytiotrophoblast cells within the villi and decidual trophoblast cells. It was not present in the endothelium of terminal villous vessels. There was no significant difference in eNOS villous or decidual staining intensity between normal pregnancy (NP; n = 12), pre-eclampsia (n = 14), or gestational hypertension (GH; n = 4). Staining for eNOS was not significantly different in the decidua compared with the villi in NP, GH or pre-eclampsia. Within the decidua, the depth of eNOS staining was similar in NP, pre-eclampisa and GH. 4. There was no significant difference in eNOS mRNA expression between NP (0.70 +/- 0.11), pre-eclampsia (0.5 +/- 0.07) or GH (0.69 +/- 0.26). 5. These findings suggest that the amount of eNOS in the placenta is not deficient in pre-eclampsia, excluding a possible pathogenic role for eNOS in this disease. Furthermore, placental hypoxia, which is associated with pre-eclampsia, did not induce an upregulation of eNOS

Adolescent↗

Psychosocial issues for women with trichotillomania.

Trichotillomania, the compulsive urge to pull out one's hair, is a poorly studied chronic condition affecting 2 to 8 million people, 90% of whom are women. Significant gains have been made about the nature and clinical presentation of this disorder, and yet conceptualizations of trichotillomania remain inconsistent and controversial. Consequently, treatments for trichotillomania have proven to be largely ineffective. Anecdotal case studies have provided us with preliminary data about the impact of this condition on emotional, psychological, and social well-being. To date, there are no empirical studies that focus on patients' subjective experiences with their disorder. The purpose of this report is to identify and discuss the concerns of women with trichotillomania. We have also provided clinical examples to highlight how these concerns are evident in the lives of these women. A total of seven women participated in focused interviews which asked them to reflect on their experiences with compulsive hair pulling. The interview transcripts were analyzed for themes using techniques from the constant comparative method. Additionally, women were asked to complete a demographic self-report. Our analysis identified themes pertinent to negative affects, control, and triggering precipitants. We argue that identifying and integrating these themes in current treatment protocols is the first step to improving the efficacy of treatment for trichotillomania.

Adolescent↗

Outbreak of Mycoplasma pneumoniae infection among hospital personnel.

An outbreak of illness due to Mycoplasma pneumoniae occurred among employees of a large hospital. The spectrum of disease ranged from severe upper respiratory infection to multilobed pneumonia. No unusual increase in the incidence of respiratory illness due to this organism was observed in the surrounding community during the period under investigation. It was not possible to identify any single area of the hospital frequented by enough of the involved personnel to explain the spread of the infection among the hospital's employees. This is the first outbreak of M pneumoniae disease to be reported among hospital personnel.

Cross Infection↗

Electromyographic and kinematic analysis of cutting maneuvers. Implications for anterior cruciate ligament injury.

The objective of this study was to qualitatively characterize quadriceps and hamstring muscle activation as well as to determine knee flexion angle during the eccentric motion of sidestep cutting, cross-cutting, stopping, and landing. Fifteen healthy collegiate and recreational athletes performed the four movements while knee angle and electromyographic activity (surface electrodes) of the vastus lateralis, vastus medialis obliquus, rectus femoris, biceps femoris, and medial hamstring (semimembranosus/semitendinosus) muscles were recorded. The results indicated that there is high-level quadriceps muscle activation beginning just before foot strike and peaking in mid-eccentric motion. In these maneuvers, the level of quadriceps muscle activation exceeded that seen in a maximum isometric contraction. Hamstring muscle activation was submaximal at and after foot strike. The maximum quadriceps muscle activation for all maneuvers was 161% maximum voluntary contraction, while minimum hamstring muscle activity was 14%. Foot strike occurred at an average of 22 degrees of knee flexion for all maneuvers. This low level of hamstring muscle activity and low angle of knee flexion at foot strike and during eccentric contraction, coupled with forces generated by the quadriceps muscles at the knee, could produce significant anterior displacement of the tibia, which may play a role in anterior cruciate ligament injury.

Adult↗

Ankle disk training influences reaction times of selected muscles in a simulated ankle sprain.

Ankle disk training has been used as an exercise in sports medicine clinics to help protect against ankle sprains. This study investigated the effects of ankle disk training on the contraction pattern of the anterior tibialis, posterior tibialis, peroneus longus, and flexor digitorum longus muscles in a simulated ankle sprain. Twenty adults were recruited and divided into a control group and an experimental group. A platform with a trapdoor was used to simulate a lateral ankle sprain. Electromyographic data were recorded from each subject in pretraining and posttraining tests. The experimental group underwent ankle disk training for 8 weeks between the pretraining and posttraining tests. In the pretraining test, the four muscles started to contract simultaneously; in the posttraining test, the contractions of the anterior and posterior tibialis muscles were delayed. This delay favors the correction of excessive ankle inversion. This study examined the effects of one form of proprioceptive training on muscle reaction times, and its results may explain why such training can help protect against ankle sprains.

Adolescent↗

Exploration of the perspectives of persons with schizophrenia regarding quality of life.

OBJECTIVE: This study is the first phase of a two-phase study aimed at exploring the perspectives of consumers with schizophrenia regarding quality of life and developing a quality-of-life assessment that addresses factors experienced as important by consumers. METHOD: Focus groups were used to explore the perspectives of 35 persons with schizophrenia regarding the meaning of quality of life and factors important to quality of life. RESULTS: Seven major factors that had an impact on quality of life resulted from inductive analysis, including activity, social interaction, time, disclosure, "being normal," finances, and management of illness. These factors relate to three overall themes: managing time, connecting and belonging, and making choices and maintaining control. CONCLUSIONS: Although the findings confirm the importance of factors included in existing quality-of-life assessments, they also highlight the need to look at new dimensions of commonly included factors and to include other factors. The findings support beliefs regarding occupation that are central to occupational therapy and the use of occupation as means and ends of therapy.

Adolescent↗

Concomitant chemotherapy and radiotherapy for locally advanced nasopharyngeal carcinoma.

BACKGROUND: The prognosis of stage III and IV nasopharyngeal carcinoma treated with radiation therapy alone is poor. To improve outcome, concomitant chemotherapy was incorporated into the treatment of locally advanced nasopharyngeal carcinoma. METHODS AND PATIENTS: Seventy-four patients with locally advanced nasopharyngeal carcinoma were prospectively treated with a combination of concomitant chemotherapy and computerized-tomography-assisted radiotherapy at Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan, between April 1990 and December 1995. The first 29 patients who had a minimum of 2 years of follow-up were included in this report. Their median interval of follow-up was 42 months. The dose of radiation was 7000 cGy given in 35 fractions. Two courses of chemotherapy, consisting of cisplatin and 5-fluorouracil, were delivered simultaneously with radiotherapy during weeks 1 and 6, and two additional monthly courses were given after radiotherapy. Included in this study were four patients with stage III and 25 patients with stage IV disease. RESULTS: Toxicities of concomitant radiotherapy and chemotherapy were acceptable and reversible. The locoregional control rate at 50 months was 88.2%, and the disease-free survival rate was 74.6%. DISCUSSION: Our results demonstrate an improved survival with the addition of computerized tomography treatment planning and concomitant chemotherapy to radiotherapy in the treatment of locally advanced nasopharyngeal carcinoma when compared with data in the current literature. However, a randomized trial comparing computerized-tomography-assisted radiotherapy with and without chemotherapy is necessary to confirm the contribution of chemotherapy.

Adult↗