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Biomedical subjects

L Jones

Publications and source records attributed to L Jones.

At least 397 records · Page 22Linked to original sources

Vitamin A and retinol-binding protein in patients with myelomatosis and cancer of epithelial origin.

Serum vitamin A and retinol-binding protein (RBP) concentrations were measured in patients comprising 53 myeloma and 28 epithelial cell cancer cases. Vitamin A levels in these patients were found to be significantly lower than those in the 30 healthy subjects, the effect being more marked in the patients with cancer of epithelial origin. The serum concentrations of retinol-binding protein (RBP) fell in parallel with vitamin A in the epithelial cancer patients, while the RBP concentrations remained unaffected in the patients with myeloma, suggesting that the underlying factor for resulting low vitamin A levels may be different in these two groups of patients.

Adult↗

A total population study of diagnosed chromosome abnormalities in Queensland, Australia.

Aneuploidy and structural chromosome rearrangements comprise a significant group of abnormalities in the general population. The true incidence of such abnormalities can be obtained by large research studies of consecutive newborns. In practice, the observed incidence of such chromosome abnormalities is obtained by karyotyping subjects who present for clinical reasons. The difference between the observed clinically indicated rates and the assumed rate (by comparison with data from consecutive newborn studies) would allow the estimation of the unrecognised chromosome abnormality load in the general population. The difference between these two rates would provide valuable data concerning the appropriateness of selection techniques for routine chromosome analysis. This paper reports such a study, from Queensland, Australia. A total population 5-year survey (1976-1980) of the diagnosed chromosome abnormalities in this unselected primary population of 2.2 million people is reported. Five hundred and eighty-nine chromosome abnormalities were detected in a consecutive series of 6092 karyotypes performed (9.7%). This figure is significantly lower than that found in most other reported series where case selection for karyotyping is determined by clinical criteria. In this current study the annual diagnostic rate for chromosome abnormalities was 5.41 per 100,000 of the general population. Cumulative frequency histograms for all types of chromosome abnormality, by age, are presented. In current practice, 32% of chromosome abnormalities are not diagnosed until adult life. Fifty percent of cases of chromosome abnormality (of all types) remain undiagnosed by the age of 1 year, in spite of a relatively liberal acceptance rate on the part of laboratories offering routine karyotyping services. It is concluded that a positive diagnostic rate greater than 10%, in routine chromosome laboratories, probably indicates that more than half the true cases of chromosome abnormality in a population are being missed.

Adolescent↗

Subchronic toxicity of chlorine dioxide and related compounds in drinking water in the nonhuman primate.

Subchronic toxicities of ClO2, NaClO2, NaClO3 and NH2Cl were studied in the African Green monkeys (Cercopithecus aethiops). The chemicals were administered in drinking water during 30-60 days subchronic rising dose protocols. The only unexpected and significant toxic effect was elicited by ClO2; this chemical inhibited thyroid metabolism in the animals at a dose of ca. 9.0 mg/kg/day. A statistically significant decrease of serum thyroxine occurred after the fourth week of exposure to 100 mg/l.concentration. The extent of thyroid suppression was dose dependent in each individual monkey, and was reversible after cessation of exposure. NaClO2 and NaClO3 failed to elicit similar effects in doses up to ca. 60 mg/kg/day. Also, NaClO4 or NH2Cl did not cause T-4 suppression in doses of 10 mg/kg/day. The selective thyroid effect of ClO2 was unexplained and it appeared to be paradoxical since ClO2 was rapidly reduced by the oral and gastric secretions to nonoxidizing species (presumably Cl-). No evidence of thyroid effects were detected in the serum of human volunteers who ingested approximately 1 mg/l. of ClO2 in drinking water as a result of routine use in the community water treatment process. Sodium chlorite induced dose-dependent oxidative stress on hematopoesis, causing decreased hemoglobin and red cell count and increased methemoglobin content. At the same time, serum transaminase (SGPT) levels showed significant subclinical elevation. The hematologic effects of NaClO2 rebounded during exposure indicating compensatory hemopoietic activity taking effect during oxidative stress. Sodium chlorate and chloramine did not induce detectable hematologic changes in the animals.

Animals↗

Memory-for-Designs, intelligence, and achievement of educable mentally retarded children.

Relationships between Memory-for-Designs test, Wechsler Intelligence Scale for Children (WISC), and Wide Range Achievement Test (WRAT) were determined for classes of 12 and 14 educable mentally retarded children. Rank-difference rs showed that Memory-for-Designs errors correlated significantly with WISC Verbal IQs (-0.78), WISC Performance IQs (-0.85), and WISC Full Scale IQs (-0.96) for Class 1, and with WRAT Reading (-0.79) and WRAT Arithmetic (-0.70) for Class 2, implying that Memory-for-Designs may supplement the other tests in placement of children into educable mentally retarded classes. The high r (-0.96) between Memory-for-Designs and WISC Full Scale IQs indicates that a major component in intelligence is visual memory, which accounts for 84% of the variance of intelligence and suggests the possibility of improving intelligence through visual memory training in the schools.

Achievement↗

Alone at last.

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Aged↗

The acute effects of blocking medullary blood supply on regional cortical blood flow in canine ribs as measured by the hydrogen washout technique.

Regional cortical blood flow was measured in 23 adult mongrel dogs using the hydrogen washout technique. Cortical blood flow in the rib was found to be 4.7 +/- 0.8 ml/min/100 ml (n=21). The concept of a dual blood supply to cortical bone is supported since eliminating the medullary supply did not affect the measurable cortical blood flow in most of the animals. Under normal and pathological conditions, adjacent cortical areas within the same bone have different blood flow rates.

Animals↗

Stereotypes of mental illness. A test of the labelling hypothesis.

A questionnaire to discover the existence of stereotypes of mental illness was given to 133 subjects. Three hypotheses were tested: 1. that a stereotype of mental illness exists, and is an accurate impression of the behaviour of the mentally ill. Both aspects were clearly confirmed, in that a stereotype was shown to exist which closely resembled the behaviour of psychiatric patients described in objective studies. 2. stereotypes of mental illness are sex differentiated. This was not clearly supported, and some of the differences perceived between mentally ill women and men might be attributable to 'normal' sex role differentiation. 3. the stereotype of a 'normal' woman more closely approximates that of a mentally ill woman than do the corresponding male stereotypes. Strong confirmation was found that the two female stereotypes correlate quite closely, but the male stereotypes do not. The conclusion is that the data are supportive of certain central labelling hypotheses.

Adolescent↗

Civil defence.

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Attitude↗

Clinical and nasal biopsy response to treatment of perennial rhinitis.

Nasal biopsies of patients with perennial rhinitis were performed at baseline and compared with biopsies performed 4 wk after active flunisolide, 50 micrograms four times per day, or placebo. An effort was made to relate histologic findings to other subjective and objective parameters as an indication of response to treatment. Although patients admitted to the study had severe subjective nasal symptoms, biopsies varied considerably. Some resembled biopsies from normal individuals, and others showed marked edema and inflammation; the latter findings were more typically present in the biopsies of patients with the most severe disease. A decrease in edema and loss of inflammatory cells on biopsy as well as a corresponding decrease in eosinophils on the nasal smear usually accompanied clinical improvement, which occurred in both the active and placebo groups.

Adolescent↗

Glucagon kinetics in fasting: physiological elevations in serum 3,5,3'-triiodothyronine increase the metabolic clearance rate of glucagon.

We have attempted to determine if the elevated plasma glucagon concentration and delayed MCR of glucagon (MCRg) observed during caloric restriction are related to the decreased serum T3 that also occurs during fasting. Twelve obese subjects received a 3-h iv glucagon infusion during a 4-day fed period (1000 kCal/day) and again on approximately the third fasting day. Five patients fasted without receiving exogenous T3 (control group), whereas seven subjects fasted but also received 5 micrograms T3 orally every 4 h (T3 group) to maintain approximately the same serum T3 levels in the fed and fasting periods. Glucagon production rates (GPR) were derived by multiplying the MCRg by the respective basal plasma glucogon concentrations. In the control group, the MCRg was 442 +/- 55 ml/m2 . min in the postabsorptive state and decreased to 312 +/- 49 ml/m2 . min (P < 0.025) during fasting, whereas in the T3-treated group, the postabsorptive MCRg was 304 +/- 22 ml/m2 . min and increased during fasting to 417 +/- 47 ml/m2 . min (P < 0.025). The GPRs in the control group were statistically unaltered between the fed (27.7 +/- 3.0 ng/m2 . min) and fasted (22.9 +/- 1.8 ng/m2 . min) intervals, but GPR increased from 37.9 +/- 6.1 ng/m2 . min during fasting to 49.2 +/- 9.1 ng/m2 . min when T3 was administered (5 micrograms every 4 h). The net plasma glucose increment in response to glucagon decreased from 18 mg/dl (fed) to 5 mg/dl (fast) in the control patients and from 10 mg/dl (fed) to 7 mg/dl (fast) in the T3-treated subjects. In the T3-treated patients, serum T3 averaged 124 ng/dl during both feeding and fasting, and rT3 was 55 +/- 6 ng/dl during feeding and 49 +/- 5 ng/dl during fasting. In summary, the results from this study indicate that during fasting 1) slight physiological alterations in serum T3 influence the MCRg, and 2) T3 increases the GPR and blocks the customary fasting-induced rise in rT3. Conceivably, decreased T3 is an early event in the fasting state which serves to decrease the MCRg, a process which subsequently regulates glucose homeostasis.

Adult↗