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Biomedical subjects

K King

Publications and source records attributed to K King.

At least 73 records · Page 4Linked to original sources
PubMed1995

Transabdominal chorionic villus sampling at 9.5-12 weeks' gestation. Placental vascular resistance and fetal cardiovascular responses.

Pregnancies subjected to chorionic villus sampling (CVS) have been associated with transverse limb reduction defects. This study was designed to examine the possible fetal cardiovascular responses to transabdominal CVS. We examined 42 patients referred for CVS between 9.5 and 12 weeks' gestation. CVS was performed transabdominally under ultrasonic guidance with a 20-gauge needle. Placental vascular resistance was evaluated by means of the umbilical artery pulsatility index. Fetal heart rate was ascertained automatically from two successive flow velocity waveforms. Paired t test, regression analysis, power analysis and normal distribution analysis were performed, and statistical significance was set at P < or = .05. Fetal heart rate increased with increasing amounts of tissue, but placental vascular resistance did not change. The earlier the gestation, the larger the amount of tissue obtained. Multiple regression analysis demonstrated that the fetal heart rate change was influenced by neither gestation nor placental vascular resistance after CVS. Analysis of the change (difference before and after CVS) in placental resistance and fetal heart rate according to gestational age and amount of tissue did not change the above findings. Although statistically significant fetal cardiovascular responses can be elicited in relation to the amount of chorionic villi obtained during transabdominal CVS, the clinical significance of these findings remains unclear, given the fact that all the fetuses in this group of patients were normal. These responses may be secondary to various degrees of placental hemorrhage and may represent part of or the total fetal response to various degrees of fetal blood loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Comparison of maximal oxygen consumption with oral and nasal breathing.

The major cause of exercise-induced asthma (EIA) is thought to be the drying and cooling of the airways during the 'conditioning' of the inspired air. Nasal breathing increases the respiratory system's ability to warm and humidity the inspired air compared to oral breathing and reduces the drying and cooling effects of the increased ventilation during exercise. This will reduce the severity of EIA provoked by a given intensity and duration of exercise. The purpose of the study was to determine the exercise intensity (%VO2 max) at which healthy subjects, free from respiratory disease, could perform while breathing through the nose-only and to compare this with mouth-only and mouth plus nose breathing. Twenty subjects (11 males and 9 females) ranging from 18-55 years acted as subjects in this study. They were all non-smokers and non-asthmatic. At the time of the study, all subjects were involved in regular physical activity and were classified, by a physician, as free from nasal polyps or other nasal obstruction. The percentage decrease in maximal ventilation with nose-only breathing compare to mouth and mouth plus nose breathing was three times the percentage decrease in maximal oxygen consumption. The pattern of nose-only breathing at maximal work showed a small reduction in tidal volume and large reduction in breathing frequency. Nasal breathing resulted in a reduction in FEO2 and an increase in FECO2. While breathing through the nose-only, all subjects could attain a work intensity great enough to produce an aerobic training effect (based on heart rate and percentage of VO2 max).

Adolescent↗
PubMed1994

Vocational rehabilitation in maintenance dialysis patients.

When Congress was considering extending Medicare coverage to those with chronic renal failure, it was predicted that 100% of these individuals would be vocationally active. Unfortunately, the actual vocational rehabilitation rate for this population is much below these earlier predictions. A comprehensive review of the literature establishes that there are variables that affect the employability of those on dialysis. These variables can be grouped into four main categories: demographic, psychological, medical, and occupational. In addition, there are barriers to enhanced vocational rehabilitation for individuals receiving dialysis therapy, and these can be grouped accordingly: workplace, financial, dialysis facility/personnel, vocational rehabilitation, and labor market. Enhanced research efforts, intervention with employers and vocational rehabilitation programs, changes within the Social Security system, and modification of renal team practices could all serve to enhance the vocational rehabilitation status of individuals with chronic renal failure.

Chronic Disease↗
PubMed1994

Salt-induced hypertension in normotensive spontaneously hypertensive rats.

Lifetime treatment with oral captopril prevents the development of hypertension in spontaneously hypertensive rats (SHR). We tested the hypothesis that this treatment also prevents the hypertensive response that occurs when untreated NaCl-sensitive SHR are placed on a high NaCl diet. Female SHR were continuously treated with oral captopril before conception and throughout lactation, and the offspring were similarly treated with oral captopril throughout life. At 6 weeks of age, treated male SHR were placed on an 8% (or remained on a 1%) NaCl diet, and systolic arterial pressure, heart rate, and body weight were monitored for 2 weeks. The 8% NaCl diet caused a rapid increase in arterial pressure in the lifetime captopril-treated rats, and 18 days after the initiation of the diet, the mean arterial pressure of this group was 136 +/- 7 mm Hg compared with 100 +/- 2 mm Hg in the 1% NaCl diet rats. The results of a second experiment confirmed the hypertensive effect of the high NaCl diet in lifetime captopril-treated SHR and demonstrated that after 18 days on the diet the dietary NaCl-induced hypertensive response was greater in magnitude in lifetime captopril-treated compared with untreated SHR. The results also demonstrated that lifetime captopril-treated Wistar-Kyoto rats, which are normotensive irrespective of captopril treatment, display no significant increase in arterial pressure when given a high NaCl diet. A third experiment demonstrated that rapidly progressing NaCl sensitivity is also present in female lifetime captopril-treated SHR.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

Elderly with cardiac disease: analysis of current nursing literature.

Demographic trends clearly indicate that the Canadian population is aging. As well, cardiovascular disease is the most common chronic disease in the elderly. The purpose of this project was to undertake a systematic and comprehensive review of nursing literature published from 1980 to 1992 on cardiac disease in the elderly. To date, no critical analysis of nursing knowledge in this area has been conducted. Thirty-eight articles were found to meet the inclusion criteria and were reviewed according to purpose, subject characteristics, variables studied, research method employed, scientific and/or theoretical merit, and relevance for practice. What is known concerning the elderly with cardiac disease, along with recommendations for future nursing research, are presented. Information about the quantity and quality of literature related to cardiac disease in the elderly is important for the development of a scientific base for nursing practice.

Age Factors↗
PubMed1993

Effects of high extracellular calcium and strontium on inositol polyphosphates in bovine parathyroid cells.

The addition of Ca2+ or a variety of divalent cations increases intracellular Ca2+ in parathyroid cells and suppresses secretion. Since 1,4,5-inositol trisphosphate (IP3) and 1,3,4,5-inositol tetrakisphosphate (IP4) mediate Ca2+ mobilization in other systems, we examined high Ca(2+)- and Sr(2+)-induced accumulation of IP3 and IP4 isomers by anion-exchange HPLC and measured 1,4,5-IP3 mass in parathyroid cells. Raising extracellular [Ca2+] from 0.5 to 3.0 mM increased 3H-1,4,5-IP3 within 5 s, which was confirmed by mass measurements. 3H-1,3,4-IP3 rose gradually by 10 s and increased for 60 s after the addition of Ca2+. Although we detected no change in 3H-1,3,4,5-IP4, the increase in 3H-1,3,4-IP3 suggests that 3H-1,3,4,5-IP4 was being formed. The addition of 4 mM SrCl2 produced similar changes in 1,4,5-IP3, which were confirmed by mass assay. 3H-1,3,4,5-IP4 did not change. However, Sr2+ induced a gradual increase in 3H-1,3,4-IP3, which remained above control levels for 5 minutes. Isotopic labeling studies in this system may underestimate changes in 1,4,5-IP3 mass, but both mass and radioisotopic analyses indicate that high extracellular Ca2+ and Sr2+ stimulate substantial increases in 1,4,5-IP3 without significant accumulation of 1,3,4,5-IP4. These studies suggest a role for 1,4,5-IP3 in intracellular Ca2+ mobilization by divalent cations in parathyroid cells.

Animals↗
PubMed1993

Molecular evolution of the intergenic spacer in the nuclear ribosomal RNA genes of cucurbitaceae.

The intergenic spacer (IGS) of a 10-kbp repeat (clone pRZ7D) of the nuclear 18S, 5.8S, and 25S ribosomal RNA genes of Cucurbita pepo (zucchini) was sequenced and compared to the IGS sequences of two other Cucurbitaceae, Curcurbita maxima (squash), and Cucumis sativus (cucumber). The nucleotide sequence and the structural organization of the IGS of C. pepo and C. maxima are rather similar (between 75 and 100% sequence similarity depending on the region compared). The IGS are mainly composed of three different repeated elements interspersed into unique sequences: GC-rich clusters, a 422-bp AT-rich element including the transcription initiation site (TIS) for RNA polymerase I, and 260-bp repeats in the 5' external transcribed spacer (D repeats). The TIS is duplicated in the 10-kbp repeat class of C. pepo, as it is also described for the 11.5-kbp rDNA repeat of C. maxima. The IGS of Cucumis sativus is also composed of different repeated elements; however, obvious sequence identity to the Cucurbita species only occurs around the TIS and the preceding AT-rich region. GC-rich clusters with different primary sequences are present in the IGS of all three plants. Remarkably, the repeated elements in the 5'ETS accumulate TpG and TpNpG motifs, whereas CpG and CpNpG motifs less frequently occur. This accumulation might be caused by the transition of methylated cytosines (in mCpG or mCpNpG motifs) into thymidine via deamination in a previously GC-rich ancestor. The following singular region exhibits 50% G + C in C. pepo, 53% G+C in C. maxima, and 63% G + C in C. sativus.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Composition↗
PubMed1993

Incidence of abdominal tuberculosis in Bangladeshi migrants in east London.

A retrospective epidemiological study of abdominal tuberculosis in a defined population in the London Borough of Tower Hamlets was conducted between January 1985 and 31 December 1989. The total population of 163,900 included a mean of 20,732 Bangladeshis. Of the 13 cases diagnosed 8 were Bangladeshi, with equal involvement of the peritoneum and intestine. The crude incidence in the Bangladeshi community was 7.7 cases/10(5)/year, which was significantly higher than that in Europeans (0.3 cases/10(5)/year, chi 2 with Yate's correction = 14.0 P < 0.001). The highest age-specific incidence was amongst those aged 16-20 years and 41-45 years. Most patients had a laparotomy or peritoneal biopsy to confirm the diagnosis. The response to therapy was good. Only 62% of cases were notified. This study confirms the importance of tuberculosis in the differential diagnosis of abdominal symptoms in Bangladeshi patients.

Adolescent↗
PubMed1993

Functional asymmetry of the human myometrium documented by color and pulsed-wave Doppler ultrasonographic evaluation of uterine arcuate arteries during Braxton Hicks contractions.

OBJECTIVE: We hypothesized that arcuate arteries supplying placental and nonplacental myometrial portions would respond with different degrees of change in their resistance during Braxton Hicks contractions. STUDY DESIGN: We examined 20 healthy pregnant women between 18 and 24 weeks' gestation with pulsed-wave and color-flow Doppler during focal Braxton Hicks contractions identified by real-time ultrasonography by means of the characteristic thickening of the myometrium. Systolic/diastolic ratio was used as an expression of resistance. Statistical analysis was performed by Wilcoxon signed-ranks and Mann-Whitney test. RESULTS: When the contractions are localized in the subplacental myometrium, the resistance of the arcuate artery did not differ during and after the contraction. In contrast, when the contraction involved only nonplacental myometrium, the resistance during the contraction was significantly higher and in some patients there was complete absence of flow during the diastolic phase. During subplacental myometrial contractions, the main uterine artery resistance was not affected. When the contraction involved the nonplacental myometrium, the resistance of the main uterine artery increased with more pronounced changes when the contraction involved the lateral myometrial wall ipsilateral to the uterine artery under examination. CONCLUSION: We speculate that the differences in the degree of resistance change are the result of different degrees of contractility exhibited by the subplacental and nonplacental myometrium. We conclude that the intact human myometrium manifests functional asymmetry and our Doppler findings confirm previous in vitro studies.

Arteries↗
PubMed1993

Two types of religious internalization and their relations to religious orientations and mental health.

Two types of religious internalization are conceptualized that are presumed to vary in their relative autonomy. Introjection represents a partial internalization of beliefs and is characterized by self- and other-approval-based pressures. Identification represents adoption of beliefs as personal values and is characterized by greater volition. These 2 types of internalization are compared conceptually and empirically with existing measures of religious orientation and are used to predict varied functional outcomes. Results in 4 independent Christian samples show systematic construct validities and relations with mental health and self-related outcomes. Also, evangelical teenagers are shown to be higher on both introjection and identification than controls. Results are discussed both in terms of prior approaches to the psychology of religion and the significance of internalization for personality functioning.

Adaptation, Psychological↗
PubMed1993

Prophylactic administration of calf lung surfactant extract is more effective than early treatment of respiratory distress syndrome in neonates of 29 through 32 weeks' gestation.

OBJECTIVE: Although numerous trials have demonstrated the efficacy of exogenous surfactant for prophylaxis or treatment of neonatal respiratory distress syndrome (RDS), optimum timing of administration remains controversial. One previous study showed that administration of calf lung surfactant extract immediately following birth, to neonates born before 30 weeks postconceptional age, was preferable to delaying administration until after development of RDS. The current study was designed to test a similar hypothesis for babies born between 29 and 32 weeks gestational age. DESIGN: One thousand three hundred ninety-eight neonates with obstetric estimates of 29 through 32 weeks' gestation were randomized to receive CLSE at birth or to wait until development of mild RDS. After exclusions for malformations and other factors, data from 1248 were analyzed. RESULTS: Prophylaxis was associated with less development of moderate RDS (7% vs 12%), less need for retreatment (5% vs 9%), less need for mechanical ventilation or supplemental oxygen during the first 4 days, and fewer deaths or less requirement for supplemental oxygen at 28 days (5% vs 9%). Although 1-minute Apgar scores were significantly lower in the prophylaxis group, the difference disappeared by the 5-minute score and there was no difference in the incidence of asphyxia-related complications. Sixty percent of the neonates assigned to early treatment received endotracheal intubation and 43% received calf lung surfactant extract at a median age of 1.5 hours. When data were analyzed by gestational age and birth weight subgroups, most of the differences could be attributable to babies born at 30 weeks or less or weighing less than 1500 g, probably because of the higher incidence of surfactant deficiency in this more immature subgroup.

Drug Administration Schedule↗
PubMed1992

Molecular cloning of a novel adenosine receptor gene from rat brain.

We have isolated an adenosine receptor gene (RA2) from a rat brain cDNA library. This novel rat adenosine receptor has 410 amino acids, as deduced from its base sequence, and shows 82% amino acid identity with the dog A2 receptor. Amino acid sequence analysis indicates that RA2 protein contains seven transmembrane domains and belongs to the G protein-coupled receptor family. The variations in amino acid sequences between RA2 protein and the dog A2 receptor are largely confined to the extracellular second loop and the carboxyl terminus.

Amino Acid Sequence↗
PubMed1992

Notification of tuberculosis: how many cases are never reported?

BACKGROUND: Notification of tuberculosis is essential for local contact tracing and for assessing the national incidence of tuberculosis. The accuracy of notification figures is uncertain. This study examined the notification rates of all patients diagnosed as having tuberculosis at two hospitals in the East End of London over five years. METHODS: In a retrospective survey of all patients aged 16 years or more presenting with tuberculosis to the London Chest Hospital or the Royal London Hospital from 1 January 1985 to 31 December 1989, cases of tuberculosis were identified from microbiology and histology records, statutory notifications, necropsy reports, coroners' records, hospital activity data, and death certificates. Clinical data were obtained from case notes and notification was determined from the local authority notification lists. RESULTS: Six hundred and nine adult patients with tuberculosis were identified. Notes were available for 580 cases (95%), of which 426 (73%) had been notified. The proportion of cases notified varied according to the specialty of the clinician in charge of the patient at diagnosis. Patients with a past history of tuberculosis and those who died within one year were less likely to have had their tuberculosis notified. Age, race, and lack of microbial or histological confirmation of diagnosis did not influence the proportion of cases notified. One hundred and eighty five patients had smear positive sputum, but 25 of these cases (14%) were not notified. Eighty five patients who had presented with pulmonary tuberculosis did not have their disease notified; 20 (24%) had smear positive sputum. CONCLUSIONS: Many cases of tuberculosis are not notified (27%). Fourteen per cent of all sputum smear positive cases of tuberculosis were not notified, and these patients are a considerable public health risk. The true incidence of tuberculosis in the area studied is at least one third higher than current notification figures suggest.

Adolescent↗
PubMed1992

Auditory and psychological factors in 'auditory disability with normal hearing'.

Patients who have 'Auditory Disability with Normal Hearing' (ADN) complain of hearing difficulties even although their hearing is audiometrically 'normal'. The auditory and psychological factors involved in ADN have been investigated by comparing 20 patients of employment age with 20 controls (matched for age, sex and socioeconomic group) on appropriate auditory tests and questionnaires. From the results it was concluded that both auditory and psychological factors are involved in ADN. The principal finding was that as a result of their problems with discriminating speech in noise, individuals with ADN have a tendency to anxiety, depression and loneliness. In addition the otological history of an individual was found to be important in the development of ADN. Finally, it was suggested that bad coping strategies may lead to increased anxiety in those with ADN.

Adaptation, Psychological↗
PubMed1992

Comparison of fetal cerebellar measurements by two different techniques.

We examined 53 fetuses between 15 and 40 weeks of gestation with transverse and coronal sections of the head in order to evaluate the accuracy and reproducibility of the coronal cerebellar diameter. Intraobserver coefficient of variation was less than or equal to 2.2% and the mean interobserver difference was 2.2% (range, 0 to 6%). A positive linear correlation exists between transverse and coronal measurements (coronal diameter = 1.02 x transverse diameter - 0.48; R2 = 0.99; P less than 0.0001). We conclude that the coronal cerebellar diameter is reproducible and accurate and when indicated clinically can be used instead of the transverse cerebellar diameter when the latter is not obtainable because of fetal position.

Biometry↗