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Biomedical subjects

J Green

Publications and source records attributed to J Green.

At least 505 records · Page 28Linked to original sources
PubMed1988

Clinical effectiveness of dermatomal evoked cerebrally recorded somatosensory responses.

Among 129 patients with spine pain and radiculopathy in both the cervical and lumbar region, there were significant differences between the upper and lower extremity DSER groups, noting the higher number of normal studies by our criteria in the upper extremities as compared to the lower extremities. This difference may be due to the intertwining of the "nerve circuitry" of the input pathways. It appears that the dermatomal somatosensory evoked response is a study of low sensitivity and of high specificity.

Adult↗
PubMed1988

Mitogenic activity on parathyroid cells in plasma from members of a large kindred with multiple endocrine neoplasia type 1.

We tested plasma from 83 members of a large kindred with familial multiple endocrine neoplasia type 1 (FMEN1) for mitogenic activity on cultured bovine parathyroid cells. We evaluated the age dependency of parathyroid mitogenic activity (PMA) in plasma from affected and unaffected members of the kindred, and we analyzed the relation of plasma PMA to indices of activity of parathyroid, pancreatic islet, and anterior pituitary tissue. Plasma PMA was higher in members expressing the FMEN1 gene than in their unaffected first, second, third, or fourth degree relatives (P less than 0.05), and 10 of 20 members expressing the FMEN1 gene had plasma PMA above the 95% limit of the control range. Plasma PMA was not dependent on sex or age; the lack of age dependency and the high values in FMEN1 gene carriers suggested that plasma PMA is elevated in some FMEN1 gene carriers very early in life. Plasma PMA in known gene carriers varied significantly with one index of parathyroid function [plasma PMA was 2.5 times higher in the group with than in the group without prior parathyroidectomy (P less than 0.005), an indicator of more severe prior parathyroid disease] and correlated positively, although not significantly so, with indices of pancreatic islet function (serum gastrin by RIA) and anterior pituitary function (serum PRL by RIA). In summary, (1) plasma PMA levels are high in many known carriers of the FMEN1 gene, (2) the high plasma PMA levels in FMEN1 may precede overt endocrine hyperfunction; and (3) high plasma PMA levels vary with one index of parathyroid function, but do not correlate with indices of pancreatic islet or anterior pituitary function in members expressing the FMEN1 gene. The high plasma PMA levels in FMEN1 may be the direct cause of hyperfunction of the parathyroids, but the relation of high plasma PMA to hyperfunction of the pancreatic islets and anterior pituitary is uncertain.

Aging↗
PubMed1988

Determination of total respiratory resistance in health and disease by added external resistance.

Previous studies have indicated that total respiratory resistance (Rrs) can be measured by addition of an external resistor. In an earlier study, the apparatus used to accomplish this included a multiperforated steel plate. In this study, we sought to improve the device. Details of this are given in this article. With this device, resistance was found to be reproducible over five consecutive days, and was sensitive to the increase in airway resistance induced by head and neck flexion. We also report on a comparison between this method and a commercially available device that works on the "interruptor" principle. There was no significant difference in either mean or variance of resistance between the two methods. The instrumentation required for the newly designed method is minimal, and its operation is simple. Furthermore, the measurement can be performed without invasive procedures during tidal breathing.

Adult↗
PubMed1988

Percutaneous sonographic needle aspiration biopsy of endoscopically negative gastric carcinoma.

We report here the use of ultrasound-guided percutaneous fine needle aspiration gastric biopsies in three patients with endoscopically negative biopsies. Two men, ages 60 and 64, and one woman, age 64, with signs and symptoms of weight loss, abdominal pain, and early satiety, had barium contrast studies suggestive of thickened gastric walls of the antrum and cardia, yet multiple endoscopic biopsies were negative for malignancy. Using real time sector B-scan ultrasonography, percutaneous fine needle aspiration biopsy retrieved signet cell carcinomatous cytologic material in all three patients. No complications were noted. In patients with clinical and radiographic findings compatible with an infiltrative process but negative endoscopic biopsies, in whom sonography can identify a thickened stomach wall, we suggest that percutaneous fine needle aspiration biopsy be attempted.

Adenocarcinoma, Mucinous↗
PubMed1988

Acute effects of cigarette smoking on total respiratory resistance measured by partial airway occlusion.

Acute effects of inhalation of cigarette smoke on total respiratory resistance (Rrs) were studied by the partial airway occlusion method in five normal subjects. It was found that all five normal subjects were responders, though in two subjects the response was relatively weak. The results also demonstrated that the partial airway occlusion method is sensitive enough to detect the effects of cigarette smoking on Rrs. From the scatter of the individual data, it seems that the variation, or instability of response, is larger immediately after smoking compared with control. Since one of the subjects complained of dizziness when his resistance was not significantly increased, it is possible that systemic absorption of nicotine from inhalation of cigarette smoke is not necessarily related to increased Rrs.

Adult↗
PubMed1988

Diagnostic value of the history and examination in giant cell arteritis: a clinical pathological study of 81 temporal artery biopsies.

To determine the value of the history and examination in predicting a temporal artery biopsy result, 81 temporal artery biopsies between 1974-1980 were studied. Each biopsy was scored blindly and independently by 2 pathologists and correlated with clinical data and the indications for biopsy at the time of the biopsy. Thirteen biopsies had giant cells and were considered positive, 8 had mononuclear inflammatory cells in the wall (7 cases) or healed arteritis (1 case) and were considered probable, and 60 were negative. In patients with an elevated sedimentation rate, the presence of a sign (tenderness or abnormal temporal artery), or a symptom (visual change or headache) predicted 18 of 21 (86%) positive-probable biopsies, but misclassified 32 of 60 negative biopsies. Attempts to derive a clinical decision rule with improved specificity resulted in unacceptably low sensitivity (missing 5 of 21 positive-probable biopsies). A minimum 5-year followup showed that those patients treated with steroids had a 6-fold increase in fractures and a 4-fold increase in cataracts.

Aged↗
PubMed1988

HLA haplotype discordance.

Previous work on the inheritance of disease has often used certain measures of HLA haplotype concordance (such as the number of haplotypes "identical by descent," IBD) among affected siblings from each of a number of sibships, each of which contains at least two affected siblings. Here we introduce a new measure of HLA haplotype discordance between the affected and unaffected siblings of each sibship (provided there is at least one of each). We show how the measure can be used to give a simple test for inheritance, which we exemplify with data.

Biometry↗
PubMed1987

Purification and some properties of a novel heat-stable cis-toluene dihydrodiol dehydrogenase.

cis-Toluene dihydrodiol dehydrogenase was purified 200-fold from cells of a thermotolerant Bacillus species grown with toluene as the sole source of carbon and energy. The purified enzyme preparation was remarkably heat-stable and exhibited a half-life of 100 min at 80 degrees C, the temperature optimum. The activation energy of the reaction was 36 kJ.mol-1. Isoelectric focusing indicated that the pI of the native enzyme was 6.4 and that of the denatured enzyme 6.5. Although the pH optimum was 9.8, the enzyme was most stable at pH 8. The Mr of the enzyme was approx. 172,000 as determined by gel filtration and 166,000 by polyacrylamide-gel electrophoresis. The enzyme was composed of six apparently identical subunits with Mr values of 29,500. Kinetic analysis revealed that the Km for cis-toluene dihydrodiol was 92 microM and for NAD+ was 80 microM. The apparent Km values for cis-benzene dihydrodiol and cis-naphthalene dihydrodiol were 330 microM and 51 microM respectively. The enzyme was inhibited by mercurials but was unaffected by metal-ion chelators. Steady-state kinetics and product-inhibition patterns suggested that the enzyme mechanism was ordered Bi Bi.

Bacillus↗
PubMed1987

Specific effects and biofeedback versus biofeedback-assisted self-regulation training.

In any field, clear and logical conceptualizations are the basis of accurate models----correct research design----correct results----correct conclusions----advancement in the field. Faulty conceptualizations----faulty models----faulty research design----faulty results----faulty conclusions----confusion. In analyzing the conceptualizations of "biofeedback" as expressed by John Furedy (1987) in, "Specific versus Placebo Effects in Biofeedback Training: A Critical Lay Perspective," we focus on two issues: Does biofeedback have a treatment effect? Is biofeedback necessary for the training effect? In discussing issue (1) we describe the multiple meanings of "biofeedback" and raise the fundamental question: Is biofeedback a treatment? We argue that faulty conceptualizations of clinical biofeedback (1) assume that the treatment in clinical biofeedback is "biofeedback" with specific effects, (2) assume that the scientific basis of biofeedback is dependent upon demonstrations of these specific effects through double-blind design that distinguish "specific" from "placebo effects," and (3) trivialize clinical research by attempting to determine the usefulness of biofeedback information--usefulness that is already understood logically by professionals and consumers and demonstrated by clinical studies in the laboratory and in the clinic. We further argue that accurate conceptualizations of clinical biofeedback (1) identify self-regulation skills as the treatment with specific effects of physiological change and symptom reduction, and (2) describe the use of information from biofeedback instruments as scientific verification of self-regulation skills. Finally, the scientific basis of clinical biofeedback is based on (1) evidence from experimental and clinical control studies that have demonstrated the effectiveness of self-regulation skills for symptom alleviation, and (2) the use of biofeedback instruments to verify the acquisition of self-regulatory skills, thus fulfilling the scientific dictum of verifiability.

Biofeedback, Psychology↗
PubMed1987

Can ultrasonography replace amniocentesis in fetal gender determination during the early second trimester?

Fetal gender was prospectively determined by ultrasonography in 115 patients with singleton pregnancies between 16 and 20 weeks of gestation. Gender determination was performed as a part of the sonographic examination preceding genetic amniocentesis, and the results were compared to the amniotic fluid fetal karyotype results. Our rate of visualization of the fetal external genitalia was 83.5%. The accuracy rate for gender determination was 90% in male infants and 100% in female infants, with an overall rate of prediction of 92.7%.

Amniocentesis↗
PubMed1987

Embryonic trunk circumference: a new biometric parameter for estimation of gestational age.

One hundred thirty-one uncomplicated, singleton pregnancies between 7 and 12 weeks of gestation were ultrasonically examined. Evaluation included confirmation of cardiac activity and measurements of fetal crown-rump length and trunk circumference. Both crown-rump length and trunk circumference were curvilinearly correlated with gestational age. A second- and third-degree polynomial equation best described this curvilinear relationship between trunk circumference and gestational age and between crown-rump length and gestational age. The crown-rump length and trunk circumference were similar in their prediction of gestational age, but the combination of the two parameters did not improve the prediction of gestational age. A nomogram of gestational age as predicted by trunk circumference was generated. These data provide an additional measurement for the estimation of gestational age in the first trimester of pregnancy.

Biometry↗
PubMed1987

The effect of desynchronization on meal patterns of humans living in time isolation.

We analyzed the timing of meals in nine subjects who lived for several weeks in a time isolation environment and whose free-running sleep-wake cycles lengthened markedly and lost synchrony with the body temperature rhythm for part of the study. The long sleep-wake periods (SWP) in free-running desynchrony (mean = 34 +/- 3 hours) as compared to free-running synchrony (25 +/- 1 hours) enabled us to compare meal timing in two distinct temporal frameworks and to relate them to the two major oscillators presumed to underlie circadian rhythms in man. We found that when the SWP lengthened in desynchrony, the intermeal interval (IMI) increased significantly. In half the subjects, the increase in IMI was approximately proportional to the increase in the SWP--the IMI "stretched" along with the SWP. Analysis of prelunch and postlunch IMIs indicated that the lengthening of the IMI during desynchrony was comparable in early and later parts of the subjective day. The increase in meal spacing was not due to increased caloric content of meals. The findings support an interpretation of dual regulation of meal timing. Proportional increases in IMI and SWP suggest that the mechanism governing the timing of the sleep-wake cycle also governs meal timing. The less than proportional increase in some cases suggests that an additional, probably metabolic, mechanism tends to limit the intervals between meals.

Adolescent↗
PubMed1987

Memory enhancement in elderly humans: effects of glucose ingestion.

Recent findings demonstrate that, in rats, posttraining injections of glucose can enhance subsequent memory performance. The purpose of this study was to extend these findings to an elderly human population by testing the hypothesis that acute increases in peripheral blood glucose levels would enhance performance on memory tasks. Eleven subjects ranging in age from 58 to 76 years participated in the study. A within-subject, repeated-measures design was used in which each subject was tested under two different glycemic conditions: with fasting blood glucose levels and with increased blood glucose levels. Blood glucose was manipulated via consumption of beverages sweetened with either saccharin or glucose powder. After beverage consumption, subjects took four tests from the Wechsler Memory Scale. Comparisons of performance under the two glycemic conditions showed that scores were higher after the glucose beverage on narrative memory tests and the total Wechsler Scale. Nine of the eleven subjects had higher total Wechsler Scale scores. These results contribute to the growing evidence that glucose metabolism should be considered in the study of memory processes. The implications of such relationships for age-related memory deficits are discussed.

Aged↗
PubMed1987

Meal size and intermeal interval in human subjects in time isolation.

We analyzed the content and number of meals eaten by eight subjects who lived for several weeks in time isolation and whose free-running sleep-wake periods (SWP) lengthened (to an average of more than 33 hours) and were desynchronized from the stable 25 hour rhythm of body temperature. Recently, in an analysis of meal timing, we reported that the long SWPs of free-running desynchrony (FRD) were associated with significantly longer intermeal intervals (IMI) than the shorter SWPs of free-running synchrony (FRS), suggesting that meals and sleep-wake events are timed by the same mechanism. We now report that in both FRS and FRD, subjects ate approximately three meals per SWP and the average size of a meal was similar across conditions. As a result, mean caloric intake decreased by 21 percent per 24 hours and mean satiety ratio increased by 27 percent on the long biological days of FRD. Despite the decrease in caloric intake, body weight did not change significantly in FRD compared to FRS. Decreased food consumption in FRD was not attributable to lowered core body temperature. The similarity of average meal size in the two FR conditions suggested that increased meal size did not drive the longer IMIs of desynchrony, although variability of caloric intake from meal to meal within conditions correlated with postmeal and premeal intervals. The results are interpreted as further support for the concept that in time isolation, the same mechanisms that governs the timing of sleep and waking is important in regulating the timing of meals.

Adolescent↗