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Biomedical subjects

L S Wu

Publications and source records attributed to L S Wu.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effects of vitamin A on growth of vitamin A-deficient children: field studies in Nepal.

Inconsistencies have been observed in the impact of vitamin A (VA) supplementation on early child growth. To help clarify this issue, a cohort of 3377 rural Nepalese, nonxerophthalmic children 12-60 mo of age were randomized by ward to receive vitamin A [60,000 microg retinol equivalents (RE)] or placebo-control (300 RE) supplementation once every 4 mo and followed for 16 mo. VA had no impact on annual weight gain or linear growth. However, arm circumference (AC) and muscle area (MA) growth improved in VA recipients, by 0.13 cm and 25 mm2, respectively, over controls. Growth of children with xerophthalmia, who were treated with >/= 120, 000 RE at base line, was also compared to that of nonxerophthalmic children, stratified by initial wasting status, and adjusted for sex, baseline age and measurement status. Among initially nonwasted children (AC >/= 13.5 cm), VA-treated xerophthalmic children (n = 86) gained 0.7 cm more in linear growth than nonxerophthalmic children. Among initially wasted children (AC < 13.5 cm), VA-treated children (n = 34) gained additional weight (672 g), height (approximately 1 cm), muscle (76 mm2) and fat (79 mm2) areas, and subscapular skinfold (1.3 mm) compared to changes observed in nonxerophthalmic children. Relative increments in soft tissue growth occurred within 4 mo of VA treatment, while the effect on linear growth was gradual. Moderate-to-severe VA deficiency, marked by xerophthalmia, is likely to impair normal physical growth, but milder stages of deficiency may not have this effect in rural South Asia.

Anthropometry↗
PubMed1996

The impact of crystallinity on Brequinar sodium hygroscopicity.

The hygroscopicity of Brequinar sodium, an organ transplant immunosuppressant, at 75% relative humidity highly depends on the crystal form or crystallinity of the drug substance. Hygroscopicity and ease of water uptake of three lots of Brequinar sodium were investigated. Those lots contained different impurities at levels ranging from 0.26% to 0.5%. DSC thermograms of the hydrated samples suggest that unbound/loosely bound water was released around 90 degrees C and water of hydration was released at 175 degrees C. At equilibrium, 2% of the water was tightly bound. Stoichiometry suggests that this is a hemihydrate. Unbound/loosely bound water has no impact on the hemihydrate crystal structure as indicated by x-ray powder diffraction patterns. The results suggest that the less perfect crystals exhibited a faster water uptake and converted to a stable hemihydrate when stored at 75% relative humidity. Both the anhydrous and the hemihydrate forms of Brequinar sodium exhibited rapid dissolution rate and comparable water solubility.

Biphenyl Compounds↗
PubMed1995

Epidemiology of xerophthalmia in Nepal. A pattern of household poverty, childhood illness, and mortality. The Sarlahi Study Group.

A case-control study of xerophthalmia (120 cases, two with corneal disease; 3377 children without xerophthalmia, 12 to 60 months of age) was conducted in the rural plains of Nepal. Relative household wealth (ownership of animals and goods, house quality) and social standing (parental education, nondaily laboring, more affluent castes) were inversely related to risk of xerophthalmia. Mothers of cases were more likely to have had children die than mothers of controls (odds ratio, 1.85; 95% confidence interval, 1.22 to 2.78); case households were more likely to have had a young child die in the past year (odds ratio, 2.85; 95% confidence interval, 1.43 to 5.67). Children with xerophthalmia were more wasted and stunted than controls, although these associations largely disappeared after adjusting for socioeconomic influences. Frequency of breast-feeding was highly protective against xerophthalmia in a dose-response manner (odds ratio, 0.32 for 1 to 10 times a day, 0.12 for > 10 times a day) after adjusting for age and other factors. The risk of xerophthalmia rose directly with reported duration of dysentery in the previous week (odds ratio, 2.13 and 5.81 for durations of 1 to 6 days and > or = 7 days, respectively, vs none). Mild xerophthalmia is reflective of a lower, local standard of living within which child health, nutrition, and survival are compromised.

Case-Control Studies↗
PubMed1995

Pupillary and visual thresholds in young children as an index of population vitamin A status.

A prototype scotopic sensitivity machine was used to evaluate pupillary and visual thresholds for 295 Indonesian children aged 1-5 y, most of whom were initially vitamin A-deficient. Subjects were tested 6 and 9 mo after receiving a high dose of vitamin A. A group of 136 older children was tested at 6 mo after dosing; all subjects underwent testing at 9 mo. After testing at 9 mo, children randomly received either a second high dose of vitamin A or placebo and were tested a final time 2 wk later. Children with abnormal pupillary thresholds had significantly higher relative dose responses (RDRs) (P < 0.01) and significantly lower serum retinol values (P = 0.05) than did normal children. The mean pupillary threshold rose (eg, retinal sensitivity fell) as vitamin A status deteriorated between 6 and 9 mo after initial dosing, and was significantly different from a group of normal American children tested previously (P < 0.001). After placebo-controlled dosing, the decline in pupillary and visual thresholds (rise in retinal sensitivity) was significant for children receiving vitamin A but not for children receiving placebo.

Aging↗
PubMed1995

Mortality of infants < 6 mo of age supplemented with vitamin A: a randomized, double-masked trial in Nepal.

The effect of supplementing 11,918 infants < 1 mo and 1-5 mo of age with vitamin A (15,000 and 30,000 micrograms retinol equivalents or 50,000 and 100,000 IU, respectively) or a placebo on subsequent 4-mo mortality was assessed in a randomized, double-masked community trial in the rural plains of Nepal. There were 130 deaths (51.6/1000 child-y) in the control group and 150 deaths (57.1/1000 child-y) in the vitamin A group, yielding a relative risk of 1.11 (95% CI: 0.86, 1.42), which is indicative of no overall effect on early infant mortality. There was a tendency for the relative risk of mortality among vitamin A recipients to rise with improved nutritional status. These results suggest that distribution of a large oral dose of vitamin A to infants < 5-6 mo of age may not benefit short-term survival. This is in contrast with the results of trials in which older infants and children in this same population were supplemented.

Diarrhea↗
PubMed1995

Effects of ginseng on the blood chemistry profile of dexamethasone-treated male rats.

Ginseng, a panacea in the Orient, has been widely investigated in the last two decades and found to possess a wide range of pharmacological activities including anti-fatigue properties, a transient regulatory action on metabolism and blood pressure, and an increase in the hypothalamo-pituitary-adrenocortical activities. However, a panoramic clinical chemistry study including adrenal and thyroid functions has never been done before. Two experiments with the same design but different concentrations of dexamethasone were performed in this study. The results obtained from the two experiments indicated that ginseng administration at this regime did not influence the blood chemistry profiles in normal rats, but significantly decreased AST and ALT levels from those in dexamethasone-treated ones. It implies that ginseng has a liver-protective effect. Meanwhile, ginseng therapy restores the adrenal and thyroid functions of rats inhibited by dexamethasone treatment.

Animals↗
PubMed1994

Investigation of moricizine hydrochloride polymorphs.

The antiarrhythmic agent moricizine hydrochloride exhibits a single melting-decomposition endotherm peak at temperatures ranging from 209 to 214.5 degrees C (Form I) when recrystallized from polar solvents, as determined by differential scanning calorimetric analysis. However, a different polymorphic form (Form II), with a differential scanning calorimetric melting-decomposition peak temperature of 190 degrees C, was generated by recrystallizing moricizine hydrochloride from nonpolar solvents. These two polymorphic forms can be reversibly converted to one another by selecting recrystallization solvents. The existence of these polymorphs was confirmed by Fourier transform IR microscopy, X-ray powder diffractometry, and solution calorimetry. Polymorphic Form I exhibited a slightly slower initial dissolution rate than Form II, which correlated well with heats of solution data (less heat needed to dissolve Form II). A simulated wet granulation process did not change the polymorphic form, suggesting that wet granulation is feasible for tablet preparation.

Calorimetry, Differential Scanning↗
PubMed1994

Crystallinity, hygroscopicity and dissolution of moricizine hydrochloride hemihydrate.

A typical anhydrous moricizine hydrochloride, an antiarrhythmic agent, is a non-hygroscopic crystalline material. Three lots of moricizine hydrochloride were found to deliquesce within a day at 85% relative humidity, exhibit different X-ray powder diffraction (XRPD) patterns and have more rapid dissolution rate than that of typical anhydrous material. No change in XRPD pattern was observed when the solvent (ethanol) was removed from these lots by heating to 80 degrees C. A two-step water release was observed by thermogravimetric analysis (TGA): a surface water release and a water of hydration release, for these heated samples. The stoichiometry of the water of hydration suggests that it is a hemihydrate. The dissolution rate of the hemihydrate was faster than that of typical anhydrous material. This hemihydrate could be converted to a typical anhydrous material by heating to 90 degrees C. The granules obtained by a simulated wet granulation process on typical lots and typical lots containing up to 20% of hemihydrate exhibited similar physical behaviour to that of typical anhydrous material.

Calorimetry, Differential Scanning↗
PubMed1992

Cortisol content of eggs and larvae of teleosts.

The whole-animal content of the cortisol was measured in embryos and larvae of tilapia (Oreochromis mossambicus), rainbow trout (Oncorhynchus mykiss), ayu (Plecoglossus altivelis), milkfish (Chanos chanos), and yellowfin bream (Acanthropagrus latus) by radioimmunoassay following the validation of an extraction method. The total cortisol content in tilapia was 50.3 +/- 19.1 pg immediately following fertilization, then decreased abruptly and maintained a lower level of 10-17 pg until larval hatching; after hatching the cortisol content increased to 47.2 +/- 11.9 pg by the seventh day. Newly hatched rainbow trout had 60.3 +/- 6.4 pg cortisol and then increased their cortisol level slowly to 83.0 +/- 7.2 pg by the fifth day after hatching. Ayu larvae contained 5.2 pg cortisol immediately following hatching. On the other hand, pelagic milkfish revealed a much lower cortisol level, being undetectable from hatching until the second day and ranging from 0.4 to 3.7 pg from the third to seventh day after hatching. Yellowfin bream, demonstrating a similarity to milkfish, were not found to have any detectable cortisol from hatching until the third day, but presented 1.6-7.7 pg from the fifth to seventh day after hatching. The presence and clearance of cortisol during early development of fertilized eggs of tilapia suggest a maternal origin of the hormone. The amount of cortisol deposited in the larval body of tilapia increased after hatching from 25% to nearly 100% of the total cortisol in whole larvae, while that in the larval yolk sac decreased to an undetectable level, implying that the increased cortisol may be produced or secreted by the larva. The possible role of cortisol in larval development is discussed.

Animals↗
PubMed1992

Parenteral formulation of the kappa agonist analgesic, DuP 747, via micellar solubilization.

The nonopioid kappa agonist analgesic amine, DuP 747, as a hydrochloride salt exhibited an aqueous solubility of 3 mg/ml. This solubility was insufficient to provide the desired dose in a solution formulation for intramuscular administration. Aqueous solutions of the hydrochloride salt exerted surface activity behavior; however, the critical micellar concentration (CMC) was not reached at the saturation solubility. Enhanced aqueous solubility required to reach the CMC could lead to micellization of the compound and a possible i.m. solution formula. The methanesulfonate salt was more water soluble than the hydrochloride salt and yielded a micellar solution with a concentration of 60 mg/ml.

Acetamides↗
PubMed1991

Treatment of iatrogenic Cushing's syndrome in dogs with electroacupuncture stimulation of stomach 36.

This study was conducted to evaluate the effectiveness of electroacupuncture (EA) on the recovery of adrenocortical function from Iatrogenic Cushings Syndrome (ICS) in dogs. Experiment I: Selection of the most effective Acupuncture point to treat ICS--Six healthy adult female dogs were treated bilaterally with EA for 15 minutes at loci BL22 + BL23 + BL24, ST36, or a non-locus control point on M. brachialis. Each dog was tested at all three sites in rotation. Blood samples were collected before and 0, 15 and 60 minutes after EA, and the serum cortisol levels were measured by radioimmunoassay. The data showed that EA at ST36 resulted in the highest response of serum cortisol levels among the three treatments. Experiment II: Evaluation of the effectiveness of EA ST36 in the treatment of ICS in dogs--Eight healthy adult female dogs were given prednisolone acetate 2mg/kg/day IM for 3 weeks. They were then randomly divided into ST36 and control groups of 4 dogs each. In the ST36 group, ST36 was treated bilaterally with EA for 30 minutes, 3 times per week, for 3 consecutive weeks. For the control, a non-locus point on M. brachialis was treated bilaterally with the same protocol. After the first week of EA, the serum cortisol levels of the ST36 and control groups were 0.9 +/- 0.1 and 0.5 +/- 0.1 micrograms/dl (P less than 0.005) baseline and 2.5 +/- 0.2 and 1.4 +/- 0.4 micrograms/dl (p less than 0.05) and after ACTH stimulation test, respectively. After the third week of EA treatment, the results were 1.0 +/- 0.1 and 0.6 +/- 0.2 micrograms/dl (p less than 0.05) baseline and 4.0 +/- 0.5 and 1.7 +/- 0.5 micrograms/dl (p less than 0.001) after ACTH stimulation respectively. These data indicated that EA at ST36 could restore the adrenocortical hypofunction resulting from ICS in dogs.

Acupuncture Points↗
PubMed1988

Effects of electroacupuncture and gonadotropin-releasing hormone treatments on hormonal changes in anoestrous sows.

The therapeutic effects of acupuncture in treating reproductive disturbances of man and animals have been proven in the past and is used clinically already. However, the mechanism of such therapy is not known yet. In this study, anoestrous sows were used to investigate the mechanism. Anoestrous sows with luteal ovaries were allocated to three groups. Four sows received electroacupuncture treatment at Pai-Hui and Wei-Ken (acupuncture treated group; group 1). Three sows received electroacupuncture treatment at Chiang-Feng and Chou-Shu (acupuncture control group; group 2). Four received 50 micrograms of gonadotropin-releasing hormone (GnRH) intravenously (drug control group; group 3). The concentrations of luteinizing hormone, progesterone, oestradiol and cortisol in serum were measured by radioimmunoassay. Oestrus return was monitored during 14 days after treatment. At the end of this observation period, the number of animals returned to oestrus were 3, 1 and 1 in groups 1, 2 and 3, respectively. It suggests that only treatment with acupuncture at Pai-Hui and Wei-Ken had therapeutic effects in inducing oestrus. This finding is further supported by the changes of serum sex hormone concentrations. Serum LH concentrations decreased for about 2 hours after electro-acupuncture treatment both in groups 1 and 2, whereas those in group 3 increased sharply at 10 minutes, reached to a peak at 20 minutes and returned gradually to basal level between 4 and 6 hours after GnRH injection. Serum progesterone concentrations rose between 4 to 6 hours after treatment in groups 1 and 3 but not in group 2. Five sows become oestrus, showed a decreased progesterone level 2 days after treatments whereas the other six anoestrous sows did not. Oestradiol levels did not have meaningful changes during the blood sampling period of 5 to 7 days in these 3 groups. Cortisol levels elevated in 15 minutes after the electroacupuncture in groups 1 and 2. However, the increment of cortisol induced by the electroacupuncture was less than that induced by the first bleeding, indicating that the adrenal stimulation may not be the main reason of the therapeutic action. The results indicated that the electroacupuncture treatment and GnRH injection could alter the release of LH from the pituitary in different ways but only electroacupuncture at Pai-Hui and Wei-Ken has a specific action on ovary and a significant therapeutic effect. Therapeutic effects of electroacupuncture on reproductive disturbance may involve a synergism of somatic-ovary and uterus reflex and central nervous-endocrine system (the hypothalamo-pituitary-ovary axis).

Acupuncture Therapy↗
PubMed1986

Influence of cardiopulmonary bypass on nitroglycerin clearance.

The effect of cardiopulmonary bypass on the clearance of nitroglycerin (NTG) was studied in seven patients scheduled for coronary artery bypass graft surgery. Intravenous NTG was administered through nonadsorbing tubing at a starting dosage of 5-10 micrograms/min and was adjusted as needed. Blood samples were obtained from the radial artery and antecubital vein before bypass and from the arterial outlet of the oxygenator during bypass at least 30 minutes apart during a constant dosage or at least 30 minutes after a dosage change. Serum concentrations were analyzed for NTG by gas chromatography. Venous NTG concentrations were always lower than concurrent arterial concentrations, with an average arteriovenous extraction of 67.2%. Serum concentrations of NTG were generally within the range associated with a therapeutic response in congestive heart failure patients. Consistent with other reports, NTG concentrations varied widely among patients and considerable intrasubject fluctuations in drug concentrations were seen. The mean +/- SD apparent clearance of NTG before bypass of 0.044 +/- 0.02 L/kg/min increased 20% to 0.052 +/- 0.02 L/kg/min during bypass (P = .05). These results suggest that cardiopulmonary bypass increases the clearance of NTG; however, the magnitude appears to be small and only partially explains the reported increased dosage needed during cardiopulmonary bypass.

Adult↗
PubMed1985

The adrenocortical function of alloxan-induced diabetic rats.

The purpose of this study is to investigate the adrenocortical function of alloxan-induced diabetic rats. Male rats of Wistar strain, weighing 200-250 gm were used. The results indicated that the adrenocortical response to stress and exogenous corticotropin (ACTH1-24) is decreased during the early diabetic stages (up to 6 days). Evidence from in vivo and in vitro studies shows that the depression is caused by the toxicity of alloxan on the adrenal cortex cells and not by the sudden rise of blood glucose levels. Streptozotocin (another diabetogen) has the same effect as alloxan on adrenal cortex cells.

Adrenal Cortex↗
PubMed1984

Niacin and tryptophan requirements of mule ducklings fed corn and soy-based diets.

Experiments were conducted to determine the dietary niacin and tryptophan requirements of mule ducklings fed a corn-soy basal diet. In niacin requirement experiments, day-old, straight-run mule ducklings were fed diets supplemented with graded levels of niacin for 3 weeks. The results showed that the minimum niacin requirement was 45 mg/kg of the diet. For the determination of the optimal tryptophan in the diet, day-old ducklings of mixed sexes were fed a starter diet for 1 week, and then fed for 12 days experimental diets with graded tryptophan levels and containing 18.0% crude protein and 3013 kcal ME/kg. The minimum tryptophan requirement for maximum growth and feed efficiency was .23% of the diet or 1.28% of the dietary crude protein. Further experiments were performed by using a 3 (niacin 20, 50, and 80 mg/kg) x 4 (total tryptophan .13, .23, .33, and .43% of air-dried diet) factorial design to investigate the relationship between niacin and tryptophan. It was concluded that excess tryptophan could spare the ducklings' need for niacin. Conversely, excess niacin failed to compensate for a deficiency of tryptophan. Maximum growth was obtained and bowed-leg disorder was prevented by the addition of sufficient niacin or tryptophan to the basal diets.

Animals↗