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Biomedical subjects

S W Huang

Publications and source records attributed to S W Huang.

At least 19 recordsLinked to original sources
PubMed1995

Anaphylaxis to carboplatin following multiple previous uncomplicated courses.

Hypersensitivity reactions to carboplatin are rare but potentially life-threatening complications. A patient with an anaphylactic reaction to carboplatin is presented. This patient had received multiple courses of platinum-based chemotherapy including cisplatin and carboplatin. Close patient monitoring during chemotherapy is essential and skin testing to identify the etiologic agent is indicated when hypersensitivity reactions occur in the setting of combination chemotherapy.

Adenocarcinoma↗
PubMed1995

Role of progesterone in regulating the effect of estradiol on the secretion of thyrotropin-releasing hormone and dopamine into hypophysial portal blood in ovariectomized rats.

In this study, an investigation was undertaken regarding the effects of estradiol and progesterone on the secretion of thyrotropin-releasing hormone (TRH) and dopamine into hypophysial portal blood and on the concentrations of arterial plasma thyroid-stimulating hormone (TSH) and prolactin (PRL) in ovariectomized (Ovx) rats. Ovx rats were injected subcutaneously with either estradiol benzoate (25 micrograms/kg BW/day) or progesterone (10 or 50 mg/kg BW/day), or both estradiol benzoate and progesterone daily for 3 days. The control group was injected with sesame oil. The hypophysial portal blood was collected and mixed either with or without 2,3-dimercaptopropanol before extraction by methanol for measuring TRH or by perchloric acid for measuring dopamine. The femoral arterial blood was also collected. The concentrations of TRH in hypophysial portal plasma and that of PRL and TSH in femoral arterial plasma were measured by radioimmunoassay. The concentrations of catecholamine in portal plasma were measured by radioenzymatic assay. Concomitant estradiol benzoate and progesterone caused a dose-dependent increase in TRH concentration in portal plasma and that of PRL in arterial plasma in Ovx rats. Progesterone alone did not alter the concentration of portal plasma TRH and the concentration of arterial plasma PRL, but rather increased the concentrations of dopamine in the hypophysial portal plasma. These above results indicated that the increase in plasma PRL and TSH levels is associated with a rise in hypophysial portal plasma dopamine and TRH following injection of both progesterone and estradiol benzoate. We can conclude that stimulation of progesterone on the secretion of hypothalamic TRH is involved in the increase in plasma PRL following concomitant treatment of estradiol.

Animals↗
PubMed1994

Neuromuscular interactions between suxamethonium and magnesium sulphate in the cat.

In order to study the neuromuscular interactions between suxamethonium and magnesium sulphate (MgSO4), we have determined the dose-response relationship of suxamethonium and the neuromuscular actions of 1.25 x ED50 dose of suxamethonium, both before and after pretreatment with MgSO4. We have also compared the effect of 1.25 x ED50 dose of suxamethonium in the absence and in the presence of 50% neuromuscular block, established previously by infusion of MgSO4. Twenty-one cats were anaesthetized with urethane. Train-of-four stimulation was applied every 12 s to the sciatic nerve and the force of contraction of the tibialis anterior muscle was measured. The potency of suxamethonium decreased in each instance with pretreatment with MgSO4. The ED50 of suxamethonium increased significantly from mean 21.0 (SEM 1.9) micrograms kg-1 before MgSO4 to 25.6 (2.3) micrograms kg-1 after MgSO4 60 mg kg-1 and to 26.6 (2.2) micrograms kg-1 after MgSO4 90 mg kg-1 (P < 0.05). Twitch depression produced by 1.25 x ED50 dose of suxamethonium decreased significantly with MgSO4 pretreatment, from 76.7 (2.6)% before MgSO4 to 61.7 (6.4)% after MgSO4 60 mg kg-1 and 48.7 (7.5)% after MgSO4 90 mg kg-1 (P < 0.05). With stable 50% neuromuscular block, established previously by infusion of MgSO4, the 1.25 x ED50 dose of suxamethonium produced more twitch augmentation (133 (6.3)% vs 108.3 (1.3)%; P < 0.05) and less twitch depression (31.6 (9.6)% vs 74.1 (0.6)%, P < 0.05) than in the absence of MgSO4. The results of all three methods demonstrated that the pharmacological interaction between suxamethonium and magnesium was antagonistic.

Animals↗
PubMed1994

Enzyme capture assay for rapid identification of Escherichia coli in blood cultures.

An enzyme capture assay (ECA) for rapid identification of Escherichia coli in blood cultures by using beta-D-glucuronidase as a marker was developed. Microdilution plates coated with antiglucuronidase were used to capture this enzyme from the cell lysates of blood cultures which showed growth of gram-negative bacteria. The assay, using 4-methylumbelliferyl-beta-D-glucuronide as a fluorogenic substrate, had a detection limit of 0.1 ng/ml (3 x 10(-13) M) for the enzyme; this was approximately equal to a cell concentration of 10(6) CFU of E. coli per ml. Among 212 blood cultures showing growth of gram-negative bacteria, 77 specimens were found to contain E. coli by conventional culture procedures and 73 samples were positive by ECA. Among the 135 blood cultures from which E. coli was not isolated, ECA gave one false-positive (Salmonella enteritidis) reaction. Thus, the sensitivity and specificity for the identification of E. coli in blood cultures by ECA were 94.8% (73/77) and 99.3% (134/135), respectively. From the finding of positive growth in the culture bottle, the assay can be completed within 4 h. In view of the high rate of isolation of E. coli from bacteremic patients, the test can be performed in parallel with conventional culture protocols; this may shorten the identification time for E. coli, and proper antimicrobial treatments may be started 24 h earlier than when results of conventional identification systems are used.

Antibodies, Bacterial↗
PubMed1994

Interrelationship between thyroxine and estradiol on the secretion of thyrotropin-releasing hormone and dopamine into hypophysial portal blood in ovariectomized-thyroidectomized rats.

Effects of thyroxine (T4) on the secretion of thyrotropin-releasing hormone (TRH) and catecholamines into hypophysial portal blood and on the concentrations of arterial plasma thyroid-stimulating hormone (TSH) and prolactin (PRL) in ovariectomized and thyroidectomized (Ovx-Tx) rats were studied. Immediately after ovariectomy, rats were Tx or sham Tx. The Ovx-Tx rats were injected subcutaneously with estradiol benzoate (EB, 0.5 microgram/kg b.w.) or sesame oil, and T4 (20 micrograms/kg b.w.) or saline once daily for 2 weeks. The Ovx rats with intact thyroid gland were injected with saline and oil only. The hypophysial portal blood samples were collected and mixed with or without 2,3-dimercaptopropanol before extraction by methanol or perchloric acid, respectively. The femoral arterial blood was also collected. The concentrations of TRH in methanol-extracted portal plasma and that of TSH and PRL in arterial plasma were measured by radioimmunoassay. The concentrations of catecholamines in perchloric acid-extracted portal plasma samples were measured by radioenzymatic assay. Thyroidectomy in Ovx rats resulted in an increase in portal plasma TRH and arterial plasma TSH. Despite the presence or absence of estradiol, T4 replacement in Ovx-Tx rats decreased portal plasma TRH and arterial plasma TSH to euthyroid levels. Combination of the injection of T4 and EB in vivo caused significantly decreased levels of portal plasma dopamine and increased arterial plasma PRL compared with those in vehicle-injected Ovx-Tx animals. Concentrations of neither norepinephrine nor epinephrine in hypophysial portal plasma paralleled the altered concentrations of PRL or TSH in arterial plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Lactational transfer of 3,3',4,4'-tetrachloro- and 2,2',4,4',5,5'-hexachlorobiphenyl induces cytochrome P450IVA1 in neonates. Evidence for a potential synergistic mechanism.

On the first day of lactation, material rats were treated with a single low dose of 5 mg/kg body weight of 3,3',4,4'-tetrachlorobiphenyl (TCB) or 2,2',4,4',5,5'-hexachlorobiphenyl (HCB) or with a combination of both congeners. Lactational transfer of these polychlorinated biphenyls (PCBs) was found in neonates and significant increases in microsomal cytochrome P450, cytochrome b5 and in glutathione-S-transferase activity were observed. Treatment with HCB did not increase neonatal ethoxyresorufin-O-de-ethylation (EROD) activities whereas a more than 26-fold increase in EROD activity was noted in response to exposure to TCB. However, EROD activities were increased more than 65-fold in response to the combined exposure to TCB and HCB. Exposure via milk to TCB caused a significant reduction in the N-demethylation of aminopyrine, but the combined exposure to TCB and HCB produced a significant reduction in the N-demethylation of dimethylnitrosamine. Lactational transfer of either TCB or HCB reduced marginally peroxisomal enzyme activities; however, exposure to a combination of TCB and HCB resulted in the highly significant reduction in KCN-insensitive palmitoyl-CoA oxidation and acetyl-CoA oxidation. Contrary to the reduction of these enzyme activities, the specific concentrations of CYP4A1 were significantly increased when neonates were exposed to either TCB or HCB. The largest induction, however, was observed in response to the combined exposure to both PCBs. Evidence is presented to suggest an induction of CYP4A1 which may be independent of the molecular substitution pattern of the two PCBs used in our studies but on a possible mode of synergistic interaction.

Animals↗
PubMed1992

Laparoscopic nephrectomy in a porcine model.

Laparoscopic nephrectomy was performed in 15 male pigs, the procedure was successful in 14. Extraction of the intact kidney through a 5-cm lower abdomen incision was done in 7 animals; complete destruction and evacuation of the kidney was accomplished by a round-knife suction device through a 1-cm port in another 7 pigs. Grossly, the specimen consisted of sausage-like tubular renal tissue and a small amount of tissue debris. Pathology revealed that the glomerular and tubular structures were well preserved, no interstitial hematoma could be found. Four ports were usually used, one 1-cm umbilical camera port, one 0.5-cm port for ureter traction, and two 1-cm working ports along the midclavicular line. All the pigs recovered uneventfully. The average operation time was 3 h 20 min. The application of endo-GIA (United States Surgical Corporation) for renal hilum reduced the operative time to 2 h 20 min. Complications included renal vein tear during endoclip application and cutting in the first case, mild subcutaneous emphysema in 2 cases. This first pig received exploratory laparotomy for the repair and ligation of the renal vein. No more major complications occurred with increasing experience. From this porcine experiment, we conclude that the combination of laparoscopy, a tissue destroyer and an endobag for the entrapment of kidney seem to be a promising technique for clinical nephrectomy.

Animals↗
PubMed1991

Pertussigen treatment retards, but fails to prevent, the development of type I, insulin-dependent diabetes mellitus (IDDM) in NOD mice.

Current evidence supports an autoimmune etiopathogenesis for Type I, insulin-dependent diabetes mellitus (IDDM) in which the pancreatic beta (beta) cell is the specific target tissue. Recently, the NOD (non-obese diabetic) mouse has become an important model for IDDM, exhibiting many of the pathological features observed in man, including a progressive pancreatic islet leukocytic inflammation referred to as insulitis. The present study was carried out to determine the efficacy of the bacterial-derived bio-product, pertussigen, to retard the progression of insulitis and thereby prevent overt diabetes. Results revealed that (1) the rapid onset of IDDM in female NOD mice is absent if the mothers are treated with pertussigen prior to mating, (2) treatment of young prediabetic NOD mice with repeated injections of pertussigen results in the retardation of onset of IDDM when compared to untreated control NOD mice, and (3) the severity of insulitis in pertussigen-treated NOD mice not developing IDDM was noticeably less severe than age and sex-matched untreated control mice. Since earlier work had shown that pertussis vaccine, which contains pertussigen, could prevent development of IDDM in mice treated with streptozotocin, the present results may indicate basic differences in the inflammatory responses in the genetically-predisposed NOD mice and IDDM-nonsusceptible mice with streptozotocin-induced diabetes.

Animals↗
PubMed1990

Histiocytosis X. S-100 protein, peanut agglutinin, and transmission electron microscopy study.

Twenty-seven cases of histiocytosis X (HX) for which paraffin blocks were available were studied with the use of S-100 protein immunohistochemistry, peanut agglutinin affinity histochemistry, and transmission electron microscopy. The results show that these techniques did enable identification of Langerhans'-type histiocytes in 88.5%, 75%, and 47.4% of cases, respectively. All techniques were proved to be of some diagnostic value for HX, but none was able to confirm the diagnosis in all instances and none could foretell the prognosis of the patients. This study shows that besides the Langerhans' cells, the indeterminate cells of the skin and the interdigitating dendritic reticulum cells of the lymph node may also be involved in this process. Moreover, some multinucleate giant cells and foamy cells may be derived from Langerhans' and related cells.

Adolescent↗
PubMed1990

Enhancement of suppressor T cell activity by lymphocyte promoting factor of Bordetella pertussis.

Lymphocyte promoting factor (LPF), a bioproduct of Bordetella pertussis shown previously to exert immunosuppressive effects, was examined for its effect on Concanavalin A (Con A) induced T lymphocyte suppressor activity by human lymphocytes. Suppressor cells (5 x 10(4) cells/well) first generated with Con A (10 micrograms/ml) for 24h were co-cultured with responder cells (5 x 10(4) cells/well) for another 72h in the presence of Con A (2.5, 5, 20 micrograms/ml). In this culture condition, LPF (20 micrograms) and/or histamine 10(-5) M or 10(-6) M/well were added for comparison. The suppressor activity was assessed by the reduction of the uptake of radioactivity of [3H] thymidine compared to that of Con A alone. Lymphocytes treated with LPF exhibited increase of suppression by 22 to 41%, while LPF and histamine (10(-5) M) together further increased the suppression by 35 to 63% compared to controls. Serial studies on cell population in the culture indicated OKT8(+) cells proliferated after day 6 in culture. These results indicated LPF exerts selective enhancement of T cell suppressor activity by 72h in culture, prior to cell expansion, and that activity can be further strengthened by sensitizing cells to histamine.

Bordetella pertussis↗
PubMed1990

Renovascular hypertension in China--report of 200 cases.

Renal arteritis and fibromuscular dysplasia are two common causes of renovascular hypertension in China. The diagnostic approach now is arteriography or digital subtraction arteriography first, followed by renal vein renin assays to evaluate the functional significance. Surgical treatment is preferred if clinical status of the patients permits.

Adolescent↗
PubMed1989

The effect of swimming in asthmatic children--participants in a swimming program in the city of Baltimore.

Forty-five asthmatic children were enrolled in a swimming program in Baltimore. After participating in a 2-month swimming session, the children showed significant improvement in all clinical variables including symptoms, hospitalizations, emergency room visits, and school absenteeism compared with their previous medical history or to those of age-matched controls. These health benefits continued to be observed even 12 months after the session had been completed. The implications of these findings and the potential usefulness of adding sports programs as adjunct therapy in the comprehensive care of asthma in children are discussed.

Asthma↗
PubMed1988

Fibrin configuration on glass led to decrease of neutrophil adherence in systemic lupus erythematosus.

Using a previously developed in vitro assay of glass adherence of neutrophils following blood clotting, we compared the results of new patients with systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA) and those of normal controls. In acute phase of the disease, all 33 patients (100%) of SLE, 2 of 35 patients (5.7%) with JRA had a significantly low neutrophil adherence to glass surface (less than 25% of the normal values). During 2 years follow-up in 18 patients with SLE from the onset of the disease, we consistently observed the low cell adherence during the relapses of the disease in all the patients. When remains of glass surfaces were examined under scanning electron microscope (SEM), we found a notable morphologic difference of fibrin configuration between the specimens of active SLE and normal controls. We conclude that the varied results of neutrophil adherence on glass may reflect the forming of different fibrin configuration induced by the in vitro contact system of coagulation. The findings may explain the increased thrombotic complications reported in patients with active SLE.

Adolescent↗
PubMed1987

Plasma thrombospondin as an indicator of intravascular platelet activation in patients with vasculitis.

The use of plasma thrombospondin (TSP) concentration was investigated as an indicator of intravascular platelet activation. Patients (n = 20) with diseases that have known vasculitis were included in the study. The range and the mean of plasma TSP concentrations of patients with vasculitis were 117 ng/ml to 6500 ng/ml and 791 +/- 1412 ng/ml (mean +/- SD); the range and the mean of plasma TSP concentrations of control individuals (n = 33) were 13 ng/ml to 137 ng/ml and 59 +/- 29 ng/ml. When plasma TSP concentrations were correlated with plasma concentrations of another platelet activation marker, beta-thromboglobulin (beta-TG), it was found that the TSP concentration increased exponentially as the plasma beta-TG level rose. A positive correlation between plasma levels of plasma TSP and serum fibrin degradation products was also observed. The results suggest that platelets are the primary source of plasma TSP in patients with various vasculitis and that plasma TSP can be a better indicator than beta-TG to assess intravascular platelet activation due to its longer circulation half life.

Blood Platelets↗