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Biomedical subjects

T C Peng

Publications and source records attributed to T C Peng.

At least 19 recordsLinked to original sources
PubMed1991

Lower serum osteocalcin in ethanol-fed rats.

Serum osteocalcin was remarkably and significantly (-34 and -41% in two separate experiments; p less than 0.001) lower in rats fed an 8% (w/v) ethanol liquid diet (ELD) for 1 week than in rats fed an isocaloric control liquid diet (CLD). In a longer experiment that spanned 4 weeks, the ELD rats were given 6% ethanol on day 4, increased stepwise to 8% by day 9, and then maintained at 8% until day 28, when the experiment was terminated. Again, serum osteocalcin was much lower (-32%, p less than 0.001) in the ELD-fed rats than in CLD-fed rats. Even in rats fed only a 6% ELD for 12 days, serum osteocalcin was lower (-33%, p less than 0.001) than in controls. Also, the femora were weaker, more compliant, and more ductile in ELD-than in CLD-fed rats, findings that confirmed our earlier, related work. The fall in serum osteocalcin in ELD-fed rats is associated with a fall in femur ash weight and bone strength. There were significant correlations between serum osteocalcin and bone strength (r = 0.80; p less than 0.001) and between serum osteocalcin and bone stiffness (r = 0.83; p less than 0.001). Serum ionized calcium, like osteocalcin, was consistently lower in rats given ethanol for 1 or 4 weeks than in controls. From these experiments we conclude that excessive ethanol consumption inhibits osteoblastic activity as indicated by the reduced serum osteocalcin. The inhibition is also associated with other deleterious effects of ethanol on bone, including ash weight, bone strength, and bone stiffness.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Obstetric complications in a patient with Bernard-Soulier syndrome.

We describe the obstetric complications and management of a patient with Bernard-Soulier syndrome. Severe bleeding at the time of delivery and delayed postpartum hemorrhage were prominent features of her pregnancies. Further complicating this woman's pregnancies was the development of antibodies to platelet glycoprotein IB/IX, leading to neonatal alloimmune thrombocytopenia.

Adult↗
PubMed1991

Precision of umbilical artery Doppler studies. Intraobserver, interobserver, and biologic variability of fetal Doppler velocimetry.

The use of Doppler ultrasound to study fetal blood flow has become commonplace, despite the lack of detailed evaluation of the testing tool for precision. In evaluation of 25 patients, no significant intraobserver differences were found between readings on an individual waveform, nor were there significant differences between different observers on individual waveforms. Temporally separated waveforms within a 30-minute window gave the greatest variation. A multi-way analysis of variance noted significant differences in this category only. This study confirmed the precision of measurements by a single observer and between observers. Only biological alterations over time displayed significant variability.

Analysis of Variance↗
PubMed1991

An integrated, hospital information system based obstetrical medical record and database.

Described in this paper is the implementation and integration of an obstetrical medical record and database into an existing hospital information system. A unique feature of this system was the integration of existing data captured by the established hospital information systems with the newly implemented obstetrical database to form a complete patient data profile. This complete database integrated data from hospital functions such as demographic data obtained at patient registration, outpatient visits and tests, inpatient admission historical data, tests and procedures, newborn data and miscellaneous data required for birth registration. An important second feature was the utilization of physicians and nurses to enter the obstetrical data. This permitted immediate access to patient data from any hospital information system terminal, immediate retrieval for generating reports, and subsequently, ad hoc queries, statistical analysis and the electronic transfer of birth registration data to the State Vital Statistics Registry.

Academic Medical Centers↗
PubMed1990

Vulvar leiomyosarcoma in pregnancy.

To our knowledge, this is the first case of vulvar leiomyosarcoma occurring during pregnancy to be reported. The neoplasm was resected immediately after a term vaginal delivery. A wide local excision of the vulva with bilateral superficial inguinal node sampling was performed 6 weeks post partum. Four previous cases of vulvar sarcoma occurring in pregnancy are reviewed. The need to perform biopsy of vulvar lesions during pregnancy is emphasized.

Adolescent↗
PubMed1990

Prevalence of human papillomavirus infections in term pregnancy.

The prevalence of human papillomavirus (HPV) infections in the lower genital tracts of pregnant and nonpregnant women was studied. Cervical and vaginal exfoliated cells were obtained during a routine pelvic examination in 45 pregnant women in early labor, and in 44 nonpregnant women. A detailed questionnaire with emphasis on sexual history and sexually transmitted diseases was administered. The two groups of women were comparable with respect to mean age, prior pregnancy experiences, and number of lifetime sexual partners. Compared with pregnant women, the nonpregnant women had a more frequent history of sexually transmitted diseases (61% versus 39%; p = 0.06), and of genital warts (16% versus 0%; p = 0.01). Utilizing Southern transfer and hybridization with 32P-labeled viral DNA probes for HPV types 6, 11, 16, 18, and 31, DNAs extracted from cervicovaginal exfoliated cells were assessed for HPV genomic sequences. HPV genomic sequences were identified in 25% of nonpregnant women compared with 13.5% of term pregnant women. This difference was not statistically significant (p = 0.26). Six HPV isolates identified in pregnant women were distributed as follows: type 6/11, 1; type 16, 1, type 31, 1; and unknown type, 3. Eleven isolates were identified in nonpregnant women and were distributed as follows: type 6/11, 2; type 16, 6; type 18, 2; and type 31, 1. HPV type 6/11, the type responsible for laryngeal papillomatosis of juvenile onset, was identified in 2% of the pregnant population and accounted for only one of six isolates. HPV DNA-positive pregnant and nonpregnant women were predominantly asymptomatic and had normal Papanicolaou smears and normal clinical examinations.

Adolescent↗
PubMed1989

Influence of ethanol on stiffness, toughness, and ductility of femurs of rats.

Recently, we reported that the ingestion of alcohol in rats reduced the mechanical strength of femurs. Our results showed that, as the dose exceeded 0.012 g of ethanol per gram of body weight, a significant (p less than 0.001) loss of "strength" occurred that was independent of sex according to the relationship, Strength (N) = 140.4 - 6003 dose (g/g). In the present effort, the same flexure tests were reevaluated to include the parameters of stiffness, toughness, and ductility. These latest results confirm that the femurs of rats fed an ethanol liquid diet for 4 weeks are not only weaker but also more compliant and less energy absorbing. Although the femurs of rats fed ethanol are more ductile, the bones are more prone to fracture in fatigue and impact circumstances as well as under simple loading situations. The rat may be an appropriate model to study the mechanisms that lead to the higher incidence of fractures in the alcoholic human.

Animals↗
PubMed1989

Evaluation of inhospital cardiopulmonary resuscitation.

Of 77 patients who received cardiopulmonary resuscitation (CPR) for an inhospital cardiac arrest from Jan. 1987 to Mar. 1988. 48(68%) survived the initial resuscitation, but only 11(16%) survived to leave hospital. A follow-up survey to Oct. 1988, of these 11 patients showed that one died within 11 months of discharge, but that others were all alive and living independently. The major cause of cardiopulmonary arrest was airway obstruction. Survival rates were lower if resuscitation efforts lasted more than 30 minutes or if the event occurred between midnight and 8:00 AM. Thirty of the 48 patients who were successfully resuscitated initially were transferred to the intensive care unit for prolonged cardiac life support. Of the patients who had underlying disease or severe neurologic impairment due to hypoxic encephalopathy, 19(63%) were dead within a few days or even hours after CPR. Therefore, we recommend (1) programs for routine CPR assessment (2) extension of CPR training for key personnel, especially ward staff working night shifts (3) assessment by CPR providers as to whether or not to continue or to give DNR (do-not-resuscitate) orders.

Adult↗
PubMed1988

Modulation of serum parathyroid hormone and ionized calcium concentrations during reproduction in rats fed a low calcium diet.

Moderate dietary restriction of calcium (0.1% Ca) was used to accentuate the changes in serum immunoreactive parathyroid hormone (iPTH) that had been reported earlier in lactating rats fed 0.4% Ca diet. In addition, the effects of this low-Ca diet on serum total and ionized Ca and iPTH during pregnancy, extended lactation, and weaning were examined. The positive correlation between serum total and ionized Ca was highly significant (r = 0.88, p less than 0.001, n = 120). Serum iPTH was significantly higher (36%) in pregnant rats on the day of parturition compared to nonmated controls, and there was a concomitant decrease in both total and ionized serum Ca. Within 1 day after parturition, however, serum Ca had risen to the control level. Serum iPTH remained significantly elevated during the first 2 weeks of lactation, and increased further during the third week of lactation to a level more than twice that of nonlactating controls. Serum Ca fell gradually during the second week of lactation. The high serum iPTH levels were maintained for another 2 weeks when lactation was extended with foster litters. Within 6 hr of removal of the suckling pups on day 16 of lactation, maternal serum ionized and total Ca had risen and serum iPTH had fallen; all three parameters were at levels similar to those of nonmated controls by 24-48 hr after weaning. The data suggest that serum ionized Ca is a major factor contributing to the hyperparathyroid state during lactation in rats fed a low-Ca diet.

Aging↗
PubMed1988

Ethanol-induced changes in morphology and strength of femurs of rats.

Chronic ingestion of ethanol resulted in ultrastructural and mechanical changes in rat femurs. Scanning electron microscopy of the distal end of the femur revealed that the trabeculae of bones from ethanol-fed rats were thinner, more columnar, and more extensive than those from control rats. Three-point bending tests of the rat femurs showed that the maximum force or so-called "strength" required to break the bone was less in ethanol- than in control-fed animals. A significant inverse correlation was observed between the strength required to break the femur and the dose of ethanol calculated on a body weight basis. For the first time our study presents quantitative proof that a relationship exists between bone strength and the consumption of ethanol in rats. The study revealed that ethanol consumption resulted in a weaker femur compared to controls. We suggest that a common mechanism may be responsible for the decreased bone strength of ethanol-fed rats and the increased incidence of fractures in human alcoholics.

Alcoholism↗
PubMed1988

Effect of number of suckling pups and dietary calcium on bone mineral content and mechanical properties of femurs of lactating rats.

The bone loss that occurs during lactation in rats was aggravated by increasing the number of suckling pups and was further accentuated by feeding the rats a calcium (Ca)-deficient diet. The bone loss was evenly distributed along the whole length of the femur in severe cases. In less severe cases, the metaphyses were affected more than the midshaft. Mechanical properties of femurs, i.e., bone 'strength', 'stiffness', 'toughness' and 'ductility', were all affected in lactating rats suckling seven to eleven pups and fed the 0.1% Ca diet. The positive correlation between bone 'strength' and ash weight is consistent with the concept that when there is loss of bone, bone becomes more susceptible to fracture. The fall in serum ionized Ca and the rise in serum iPTH were closely related to the intensity of lactation and were profoundly affected by litter size and Ca concentration of the diet. We conclude that the change in Ca homeostasis in lactating rats is due to the large loss of Ca required for milk production and that the loss of Ca is associated with hyperfunction of the parathyroid gland. Furthermore, a Ca-deficient diet severely reduced bone mineral content and affected the mechanical properties of femurs of lactating rats adversely, especially those suckling large litters of pups.

Animals↗
PubMed1987

Influence of lactation and pregnancy + lactation on mechanical properties and mineral content of the rat femur.

The quality of bone was assessed from femurs of rats both during lactation and after pregnancy + lactation. Mechanical properties of stiffness, strength, toughness, and ductility were measured, along with standard measurements of dry weight, ash weight, and total bone mineral. No changes occurred during the first week of lactation. During the second and third weeks of lactation all bone parameters except ductility decreased significantly. These data are consistent with bone losing mineral in order to supplement the dietary calcium intake necessary for milk production. In other experiments, femurs were collected from nulliparous rats and from rats that had previously undergone 1-3 pregnancy + lactations. The largest changes in bone mineral and mechanical properties occurred after a single pregnancy + lactation period, although significant further decreases in stiffness and strength occurred after the second pregnancy + lactation. No additional losses occurred following the third pregnancy + lactation. Even 5 months after only one pregnancy + lactation period, the bone quality was still impaired as all bone properties were lower than in nulliparous controls. Because the changes, especially stiffness and strength, were relatively larger than the changes in dry and ash weights of bone, measurements of these mechanical properties provide a more sensitive method to evaluate the quality of bone.

Animals↗
PubMed1987

Increase in serum parathyroid hormone concentration in the lactating rat: effects of dietary calcium and lactational intensity.

The change in circulating levels of immunoreactive parathyroid hormone (iPTH), measured with an N-terminal specific radioimmunoassay, was examined during lactation in rats. In lactating rats consuming a diet containing 0.4% Ca (basic diet), serum iPTH was a) increased by an average of 53% between days 10 and 18 compared to the level of age-matched nonlactating rats (24.7 +/- 2.1 pg/ml vs 16.1 +/- 0.8 pg/ml, mean +/- SE, p less than 0.01) and b) significantly higher in dams suckling large litters (10-15 pups) than in dams suckling small litters (3 pups) over the period 3-13 days of lactation. Lactating rats consuming a low calcium diet (0.04% Ca), had serum iPTH levels on days 16-18 of lactation approximately twice those of nonlactating rats fed the same diet and 73% higher than those of lactating rats fed the basic diet. Serum Ca concentrations were 22% and 10% lower in dams consuming the 0.04 and 0.4% Ca diets, respectively, than in the nonlactating controls fed the same diets. Regression analysis showed a significant (p less than 0.001) negative correlation between iPTH and total serum calcium. Compared with nonmated controls, net mineral loss from femurs of dams consuming the 0.4% Ca diet was a) insignificant at day 6, b) 27% at day 15, and c) 34% at day 21 of lactation. Our data demonstrate that lactation in the rat is characterized by hyperparathyroidism that appears to be related to lactational intensity and that is accentuated when dietary calcium intake is restricted.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Interrelationships of bone ash and whole bone properties in the lactating and parous rat.

Several investigators have studied the mechanical properties of long bones of rats and have found that bone strength may be associated with bone mineral content. In this study we examined further the interrelationships of whole bone properties and bone ash weight of the rat femur. Using a 3-point bending test, the bones were evaluated during lactation and after one to three pregnancy + lactation periods--experiments in which bone ash was significantly reduced. A relationship was established between the time of lactation and the ash weight, stiffness, strength, and toughness but not the ductility. Using all of the experimental data, a highly significant relationship was observed between ash weight and stiffness. A similar significant correlation was revealed between bone ash and strength or toughness, although drawing individual lines for each experiment rather than a common line for all the experiments appeared more appropriate. Given the inherent inaccuracies in the material property measurements of bone, the results suggest that routine measurements of whole bone properties provide an important and sensitive way to evaluate bone quality and that these properties correlate significantly with the bone ash weight.

Animals↗
PubMed1986

Cytochemical bioassay of circulating concentrations of rat parathyroid hormone: application to a study of age and sex.

We have found that the cytochemical bioassay (CBA) method, originally developed to measure circulating levels of biologically active parathyroid hormone (bioPTH) in humans, also can measure endogenous concentrations of PTH in rats. Therefore, we have applied this assay method to examine the relationships between age and sex and the circulating levels of bioPTH, calcium, and phosphorus in Fischer rats. The concentration of bioPTH increased in both males and females from 5 to 15 months of age (p less than .001) with no significant sex-related difference. Mean bioPTH values ranged from 2.3 to 3.6 pg (human PTH equivalents)/ml; these values were much lower (1 to 2 orders-of-magnitude) than those reported by others who used radioimmunoassays for PTH that do not discriminate between biologically active and inert PTH fragments. The CBA values for bioPTH were also 1/4-1/5 those obtained in rat serum by newer, more sensitive methods, the N-terminal specific PTH radioimmunoassay and the bioassay based on stimulation of chick renal adenylate cyclase. Regression analysis did not reveal any significant correlation between serum calcium and age. However, serum inorganic phosphorus decreased significantly (p less than .001) from 5 to 15 months of age in both male and female rats and was much lower in females than in males (p less than .001). The fall in serum phosphorus was negatively correlated with the rise in bioPTH (p less than .001). This study, the first to our knowledge to use a CBA to detect physiological changes in the circulating levels of bioPTH in rats, demonstrates the usefulness of the assay in experiments in this species.

Aging↗
PubMed1985

Secretion of calcitonin gene-related peptide from baby rat thyroid glands in vitro.

Thyroid glands from 8-day-old rat pups were incubated in serum-free medium for 6 hr. Both calcitonin (CT) and calcitonin gene-related peptide (CGRP) released into medium were measured by radioimmunoassay. In 6 separate experiments CGRP was easily detected in medium in ng/ml concentrations. In 4 of the 6 experiments, where CT release was stimulated by high medium [Ca], the concentration of CGRP in medium showed a positive, significant correlation with the medium CT concentration (r = 0.41-0.69, p less than .05- less than .01). The results are in concert with reports describing the presence of CGRP in the C-cell, and they further show that CGRP, as well as CT, can be secreted by C-cell.

Animals↗