Biomedical subjects
Publications and source records attributed to L Chang.
We describe two cases of multiple lymphomatous polyposis in the gastrointestinal tract from the esophagus to the rectum. Clinical findings, histopathologic and immunohistochemical findings in paraffin embedded tissue are discussed. It is important to recognize this rare form of gastrointestinal lymphoma because of the prognostic and therapeutic implications.
This experiment has proven that the drug naomaitong can synchronously increase the blood flow of both dog's internal carotid artery and vertebral artery and also can antagonize the decrease of blood flow of both arteries caused by pituitrin. The increase of blood flow of both internal carotid artery and vertebral artery due to administration of naomaitong (1.2 g/kg) through the dog's duodenum is approximately equal to the increase of blood flow of both arteries resulting from the intramuscular injection of papaverine (1 mg/kg). Besides, the dosage of naomaitong is positively correlated to the effect and action of the drug.
A survey of the level of psychosomatic health influencing by life events and personality trait in 1423 armymen was presented in this paper. The results demonstrated that the level of psychosomatic health was relatively poor in old soldier group, especially more distinct seen in over than 3-year military service group. The psychosomatic health state of private soldier group was relative better. The main factors influencing over the psychosomatic health state were the frequency of the negative life events, negative life change units (LCU) within one year prior to survey, personality trait and length of military service. The subordinate factors were the frequency of the positive life events and LCU within one year prior to survey, age and family of mental disorders.
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Cardiac replacement in neonates and infants with incurable complex heart defects has been performed successfully at the Loma Linda University Medical Center since 1985. Studies of over 125 infant transplants have revealed unique characteristics of the newborn response to foreign tissue. As compared to that of older infants, the neonatal immune system is remarkedly receptive, a phenomenon highlighting the impact of maternal-fetal incompatibility on subsequent neonatal immune development.
We conducted a double-blind, retrospective comparison between low-bleed and non-low-bleed (conventional) mammary implants because no controlled study has shown a difference in the degree of capsular contracture between the two types of implants. Twenty-five patients had conventional implants and form group A; twenty-eight patients had low-bleed implants and form group B. All patients had submuscular augmentation. The mean Baker score was 1.51 for group A and 1.04 for group B for the entire patient population and 1.65 for group A and 1.07 for group B for patients with more than 1 year of follow-up. For the entire population, 34 percent of group A and 3.6 percent of group B had a Baker score of 2 or greater. For the population with more than 1 year of follow-up, 42 percent of group A and 7 percent of group B had a Baker score of 2 or greater. There was significantly (p less than 0.007) less contracture with the low-bleed implants for the entire population as well as for those patients with greater than 1 year of follow-up (p less than 0.015).
Electron microscopy morphometry has been used to study the effects of cumulative exposure of low levels of inhaled O3 on lung proximal alveolar tissue. Six-week-old Fisher 344 rats were exposed to O3 in two different subchronic low-level exposure patterns. The first was a 12 hr/day exposure for 6 weeks and included two O3 concentrations, 0.12 and 0.25 ppm. The second consisted of an exposure profile having a background level of 0.06 ppm with an exposure peak 5 days each week that went from 0.12 to 0.25 ppm and back to 0.12 ppm over a 9-hr period. Rats given the second exposure pattern were exposed for either 3 or 13 weeks. Changes in the volumes of alveolar epithelium were found to be consistent and reproducible markers for cell injury and/or response. Results from the first study indicated that the relative volume of the type I epithelium increased 13 and 23% over the control value (p less than 0.05) following exposures for 6 weeks to 0.12 and 0.25 ppm, respectively. The magnitude of the increases were clearly concentration related. Similarly, when a fixed exposure concentration was employed the relative volume of type I epithelium was found to increase in proportion to the exposure time. In the second exposure, increases of 9 and 33% in relative volume of type I epithelium were found respectively after 3 and 13 weeks of exposure. If the total exposure determined by the product of O3 concentration (including background) and exposure time is plotted against the relative volume of type I epithelium from both the 0.12 ppm (60.5 ppm-hr) and 0.25 ppm (126 ppm-hr) exposures and the 3-week (45.3 ppm-hrs) and 13-week (196.2 ppm-hr) exposures, a linear relationship between increases in type I cell volume and the concentration X time product is observed. The coefficient of correlation (r2) for the linear regression of the animal means is 0.72. Changes in the volume of Type II epithelial cell also correlate with the concentration X time product (r2 = 0.66). This suggests that epithelial cell reactions to low-level subchronic exposure of O3 are directly related to the cumulative oxidant concentration. The pattern of exposure did not appear to affect the resulting degree of injury. Furthermore, a low level of background exposure may contribute to the epithelial cell injuries.
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In vitro translation in the rabbit reticulocyte system and transient expression in Cos7 cells were performed to characterize the protein encoded by a chromosome 6-linked human cDNA clone, whose nucleotide sequence is homologous to that of Escherichia coli guanosine monophosphate reductase (GMP reductase) cDNA. The molecular weight of the peptide produced by the cDNA was about 37,000 Dalton, and the protein produced in the Cos7 cells exhibited GMP reductase activity, substantiating that the cDNA is for human GMP reductase. The corresponding genomic clones were obtained from two human genomic libraries. The gene spans about 50 kb and is composed of 9 exons, which encode 345 amino acid residues. Organization of exons and introns was established by DNA sequencing of each exon and splicing junctions. The gene contains two potential SpI binding sites within exon 1, and a functional atypical polyadenylation signal in exon 9.
To determine whether the adrenal androgen 11 beta-hydroxyandrostenedione is a more sensitive and specific marker than dehydroepiandrosterone sulfate, we compared these serum androgens in 81 women with anovulatory hyperandrogenism before treatment, after corticotropin and corticotropin-releasing-factor stimulation, and after short- and long-term dexamethasone suppression. Of all subjects, 65% and 57% had elevated levels of 11 beta-hydroxyandrostenedione (greater than 2.0 ng/ml) and dehydroepiandrosterone sulfate (greater than 2.8 micrograms/ml), respectively. However, 11 beta-hydroxyandrostenedione and dehydroepiandrosterone sulfate levels did not correlate in either the women with hyperandrogenism (r = 0.12) or the 26 normal women (r = 0.29). After 0.25 mg corticotropin was administered intravenously (n = 16), 11 beta-hydroxyandrostenedione increased by 157% +/- 53% (mean +/- SEM), whereas dehydroepiandrosterone sulfate, androstenedione, dehydroepiandrosterone, and cortisol increased by 6% +/- 2%, 46% +/- 10%, 416% +/- 80%, and 2326% +/- 371%, respectively. After intravenous administration of 100 micrograms corticotropin-releasing factor to eight patients, the percent change from baseline level to peak was 148% +/- 26%, 24% +/- 5%, 61% +/- 15%, 117% +/- 15%, and 116% +/- 18% for 11 beta-hydroxyandrostenedione, dehydroepiandrosterone sulfate, androstenedione, dehydroepiandrosterone, and cortisol, respectively. After 2 mg dexamethasone for 3 days (n = 10), 11 beta-hydroxyandrostenedione, dehydroepiandrosterone sulfate, androstenedione, and testosterone were suppressed by 95% +/- 2%, 74% +/- 3%, 51% +/- 9%, and 32% +/- 9%, respectively. Suppression with 0.5 mg dexamethasone for 3 months lowered 11 beta-hydroxyandrostenedione and dehydroepiandrosterone sulfate levels equally by 50% +/- 14% and 62% +/- 12%, respectively. 11 beta-Hydroxyandrostenedione is a useful marker of adrenal androgen secretion with a calculated sensitivity and specificity greater than that of dehydroepiandrosterone sulfate. The greater sensitivity of 11 beta-hydroxyandrostenedione over dehydroepiandrosterone sulfate to adrenal stimulation and suppression suggests its unique diagnostic use.
Neuronal cells from established cell lines can offer a well-characterized source of cells for transplantation to the brain that is an alternative to fetal neurons. The infection of members of the PC12 cell line with a retrovirus containing ras-oncogene leads to their neuronal differentiation without the need of nerve growth factor (NGF). We find that neoplastic, naive PC12 cells grafted to the striatum of normal adult rats cause the transient formation of large hemorrhagic cavities and do not survive. After differentiation by infection with Kirsten-ras murine sarcoma virus, and transplantation to the opposite striatum of the same brain, PC12 cells survive for at least 8 weeks and emit neurites. These neuron-like cells and their neurites retain tyrosine hydroxylase and choline acetyl transferase, as detected immunohistochemically. Thus, ras-primed PC12 cells may serve as a continuous source for both cholinergic and adrenergic transmitters, in vivo, without the need of exogenous nerve growth factor.
Individual and combined effects of three heavy metals; namely, copper, chromium and nickel, on growth, photosynthesis and chlorophyll a synthesis of the unicellular green alga, Chlorella pyrenoidosa 251, were determined. Within the concentration range of 0.1 to 1.0 mg litre(-1) of the three heavy metals tested on growth, photosynthesis and chlorophyll a synthesis of the alga, the order of toxicity of the three heavy metals was copper > chromium > nickel. The presence of one of the three heavy metals interacted synergistically with the other two heavy metals in various bimetallic combinations on growth, photosynthesis and chlorophyll a synthesis of the alga.
The extent and duration of changes on lymphocyte function and serum immunoglobulin (Ig) levels were examined in 12 women who walked 45 min at 60% VO2 max in a laboratory setting. A 2-factor, 2 x 6 design with repeated measures on both factors was utilized. The first factor was condition (exercise and rest), and the second factor was time (six times of measurement over a 24-h period), with treatment order counterbalanced. The 45-min walk, in comparison to rest in a seated position, was not associated with significant changes in circulating numbers of interleukin-2-activated T cells (CD5 and CD25) or on spontaneous or concanavalin-A-stimulated lymphocyte proliferation. A trend for decreased phytohemagglutinin-stimulated lymphocyte proliferation in comparison to the rest condition, however, was seen 1.5 h following the exercise bout (p = 0.047). The patterns of change for serum IgG, IgA, and IgM were significantly different (p = 0.001, p less than 0.001, p = 0.010, respectively) between conditions. IgG rose 7.2% immediately following exercise, and then returned to baseline 1.5 h later, which contrasted significantly with changes in the rest condition. These same patterns of change occurred also with IgA and IgM, but increases immediately following exercise were not significant, although a trend was seen for IgA (p = 0.03). The 45-min walk had no effect on plasma cortisol and epinephrine levels relative to the rest condition, but was associated with a significant 89% increase in norepinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)
Twenty-six patients with acute cerebral infarction were imaged by 99Tcm-hexamethylpropyleneamine oxime (HMPAO)-labelled white blood cell brain (Tc-WBC) single photon emission computed tomography (SPECT). The regions of interest were equally placed in the whole hemispheres of both sides with summation of all transaxial slices in the Tc-WBC SPECT. The asymmetric indices (AI) were calculated as 200[[(right - left)]/(right + left)]. Grouping of patients with cerebral infarction was based on activities of daily living (ADL) at outcome. The results showed that the poor outcome patient group had a higher AI of Tc-WBC than that of the other patients (13.0 +/- 3.0 S.E.M. versus 5.4 +/- 1.0 S.E.M., and P less than 0.05 by Wilcoxon rank sum test). In conclusion, the Tc-WBC SPECT may be considered as a new prognostic index to predict patient outcome in human cerebral ischaemic infarctions consistent with newly established ischaemic injury theories.
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We have studied 495 sera that were referred to us from patients suspected on clinical and/or histological grounds to have a small vessel vasculitis. These sera were tested for antibodies against neutrophil cytoplasm antigens (anti-neutrophil cytoplasm antibodies, ANCA) using assays based on neutrophil acid extract, myeloperoxidase and elastase. Such antibodies are commonly found in Wegener's granulomatosis (WG) and microscopic polyarteritis (MPA), and sometimes in other small vessel vasculitides. One hundred and twenty-six of these sera (25%) were positive in the acid extract ELISA, 68 (14%) in the assay for anti-myeloperoxidase antibodies and 35 (16%) in the assay for anti-elastase antibodies. A total of 166 sera (34%) were positive for antibodies against neutrophil cytoplasm constituents. No ANCA, anti-myeloperoxidase or anti-elastase antibodies were detected in 26 convalescent sera from patients either with WG or MPA, or who had previously been positive. The mean time between positive and negative sera was eight weeks (range three weeks to six months) and three out of three who relapsed again developed ANCA of the same specificity as the original sera. Of the 228 sera also tested for anti-GBM antibodies, 13 (5.7%) were positive. All these contained antibodies against neutrophil cytoplasm constituents (three against the acid extract, eight against myeloperoxidase and two against elastase). Forty-nine of the 74 sera (66%) tested for ANA were positive. Twenty-nine (39%) had a speckled and 20 (27%) had a homogeneous pattern.(ABSTRACT TRUNCATED AT 250 WORDS)
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