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Biomedical subjects

L L Wright

Publications and source records attributed to L L Wright.

At least 91 records · Page 5Linked to original sources
PubMed1986

Once daily therapy for streptococcal pharyngitis with cefadroxil.

To determine if a single daily dose of cefadroxil would be effective in the treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis, 196 patients with GABHS pharyngitis were randomly assigned to receive either penicillin V 250 mg three times daily or cefadroxil 30 mg/kg once daily, for 10 days. Outcome was measured by the ability to isolate GABHS from the upper respiratory tract 18 to 24 hours after the onset of therapy, the impact on the clinical course, and the bacteriologic treatment failure rate. There was no significant difference in the number of patients in the cefadroxil and penicillin V treatment groups with throat cultures positive for GABHS at the 18 to 24-hour follow-up visit (0% and 2%, respectively), and the clinical responses of the patients in the two treatment groups were similar. Of the 99 patients in the three times daily penicillin V group, six (6%) had strains of GABHS isolated on one of the follow-up cultures that were identical to the strains isolated from their initial throat cultures and were considered to have bacteriologic treatment failures. Of the 96 patients in the once daily cefadroxil group, two (2%) were considered to have bacteriologic treatment failures. A single daily dose of cefadroxil appears to be as effective in the treatment of GABHS pharyngitis in this population as penicillin V given three times daily.

Adolescent↗
PubMed1986

Antigen detection test for streptococcal pharyngitis: evaluation of sensitivity with respect to true infections.

The clinical significance of false-negative results on antigen detection tests for group A beta-hemolytic streptococcal (GABHS) pharyngitis (negative test results and positive culture) has yet to be determined. We recently compared the Culturette Brand Ten-Minute Group A Strep ID Kit with blood agar cultures in 313 patients with pharyngitis, 257 (82%) of whom had positive throat cultures for GABHS. The Culturette Brand test had a sensitivity of 88%, specificity of 96%, a positive predictive value of 99%, and negative predictive value of 64%. More than half of the false-negative Culturette Brand test results occurred in children with less than 10 GABHS colonies on throat culture (1+ culture). When these 1+ cultures were not considered positive, the sensitivity of the Culturette Brand test was 93%. The sensitivity of the Culturette Brand test increased with an increased degree of positivity of the corresponding throat culture. Of the 31 children with false-negative Culturette Brand test results, 14 (45%) had a significant streptococcal antibody response; of the 224 children with true-positive Culturette Brand test results (positive test results and positive culture) from whom serologic data were available, 114 (51%) had a significant streptococcal antibody response. This difference is not statistically significant. These findings suggest that almost half of patients with false-negative results on antigen detection tests for GABHS pharyngitis have true infections (positive culture and antibody rise) and are not merely streptococcal carriers.

Adolescent↗
PubMed1986

Immature renal tissue in colonic wall of patient with caudal regression syndrome.

We report an incidental microscopic finding of ectopic renal tissue in a newborn with multiple congenital anomalies. The ectopic renal tissue was located in the wall of the distal blind end of the colon. The tissue was composed of undifferentiated renal blastema with primitive and well-formed glomeruli and tubules. The potential for malignant transformation of this lesion into extrarenal Wilms' tumor is not known.

Abnormalities, Multiple↗
PubMed1985

Twice-daily penicillin in the treatment of streptococcal pharyngitis.

An investigation was performed to compare the effectiveness of oral penicillin V given twice daily with penicillin V given three times daily in the treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis. Patients were randomly assigned to receive 250 mg of penicillin V either two or three times daily for ten days. Overall, 23 (23%) of 99 patients had the same strain of GABHS isolated from their follow-up as from their initial throat culture and were considered to have bacteriologic-treatment failures. Of the 50 patients in the three-times-daily group, nine (18%) had bacteriologic-treatment failures, while 14 (28.5%) of 49 patients in the twice-daily group had bacteriologic-treatment failures. The results of this and earlier investigations suggest that penicillin V given twice daily is as effective as penicillin V given three times daily for the treatment of GABHS pharyngitis.

Administration, Oral↗
PubMed1985

Neurotransmitter synthesis, storage, and turnover in neonatally deafferented sympathetic neurons.

In the superior cervical sympathetic ganglion (SCG) of the rat, a significant amount of morphological and biochemical maturation occurs in the first few postnatal weeks. The specific activity of tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of norepinephrine (NE), increases during this time and is subject to transsynaptic regulation by the preganglionic inputs. In the present study, we examined the normal postnatal development of NE stores in sympathetic neurons and the transsynaptic regulation of this development. NE content undergoes an 8-fold increase from the time of birth, and stabilizes at adult levels at one month. Following neonatal deafferentation, there is a temporary stunting of NE accumulation in sympathetic neurons and a permanent reduction in the activity of TH, whether or not regeneration of the afferents occurs. When regeneration is prevented, the turnover of NE is significantly reduced, while NE levels rise to near normal levels. When regeneration is permitted, however, both the stored amount and turnover of NE attain normal levels. These data suggest that there is a critical period during the first two postnatal weeks when transsynaptic influences from afferents are necessary for the induction of TH in sympathetic neurons. Levels and turnover of transmitter do not have this critical period, but appear to depend solely on the functional integrity of the system.

Animals↗
PubMed1985

Effects of neonatal castration or treatment with dihydrotestosterone on numbers of neurons in the rat superior cervical sympathetic ganglion.

There is a normal sexual dimorphism in the number of neurons in the rat superior cervical sympathetic ganglion (SCG), with adult males having more neurons in this ganglion than females. We confirm this finding here, report that this sex difference is not present at birth and that neonatal castration of males reduces the adult sex difference. These results indicate that perinatal levels of circulating testicular hormones play a role in regulating the numbers of neurons in the SCG. Treatment of neonatal rats with testosterone propionate or estradiol significantly increases the number of neurons in the SCG. To determine whether this effect is primary androgenic or estrogenic, the effects of dihydrotestosterone, on SCG neuron number were investigated. Dihydrotestosterone, unlike testosterone, is not aromatized to estradiol intracellularly. There was no difference in the number of neurons between animals injected from birth with vehicle or dihydrotestosterone. This difference in effects between dihydrotestosterone and testosterone suggests that the actions of testosterone may be via aromatization to estradiol, rather than action at an androgen receptor.

Animals↗
PubMed1985

Synaptogenic effects of neonatal estradiol treatment in rat superior cervical ganglia.

Neonatal rats treated with testosterone propionate or 17-beta-estradiol during the first two postnatal weeks have more neurons and synapses in their superior cervical ganglia (SCGs) at 15 days of age than do vehicle-treated littermates. To determine whether a non-aromatizable androgen would similarly increase the number of SCG synapses, dihydrotestosterone (DHT) was injected into male rats beginning on the day of birth. The animals were sacrificed on postnatal day 15 and the SCGs removed on postnatal day 15. Counts of synapses showed no difference in the number of synapses between control and DHT-treated animals. These results suggest that the actions of testosterone to increase the numbers of SCG synapses may be via aromatization to estradiol. An additional study was done to determine whether the additional synapses formed in SCGs of animals treated with estradiol arise from neurons whose axons are in the cervical sympathetic trunk or from intrinsic neurons, i.e., SIF cells or other principal ganglion neurons. Neonatal males were injected with 17-beta-estradiol or vehicle beginning on the day of birth and continuing until the time of sacrifice on day 15. The number of intrinsic synapses formed under control and estradiol treatments was determined in SCGs of animals whose extrinsic synapses were caused to degenerate by severing the cervical sympathetic trunk bilaterally on postnatal day 13, two days before sacrifice. The total number of synapses (extrinsic plus intrinsic) in the ganglion after vehicle or estradiol treatment was determined in unoperated animals and used to calculate the number of extrinsic synapses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Latex agglutination tests for rapid identification of group A streptococci directly from throat swabs.

A comparison of the accuracy and practicality of two new latex agglutination tests for the rapid identification of group A beta-hemolytic streptococci directly from throat swabs was performed in a busy pediatric office. The Directigen Group A Strep Test kit had a sensitivity of 84%, specificity 99%, positive predictive value 99%, and negative predictive value 93% when compared with blood agar cultures. The Culturette Brand 10-Minute Group A Strep ID Kit had a sensitivity of 83%, a specificity 99%, positive predictive value 97%, and negative predictive value 93% when compared with blood agar cultures. When cultures with less than 10 colonies of group A beta-hemolytic streptococci per plate were not considered positive, both rapid tests had a sensitivity of 95%. The Culturette Brand test required considerably less time, equipment, supplies, and skill than the Directigen test. Only the Culturette Brand test appeared to be practical for routine use in a pediatrician's office. Further investigations of the accuracy of both of these rapid tests need to be performed before either is accepted as a substitute for the throat culture.

Adolescent↗
PubMed1984

Mouse lactate dehydrogenase (LDH) C4 (testis) is immunochemically cross-reactive with LDH A4 (muscle) and LDHB4 (heart).

It has been reported that lactate dehydrogenase (LDH) purified from testes (LDH C) of homotherms is not immunochemically cross-reactive with somatic forms of LDH purified from heart (LDH B) or muscle (LDH A). On the basis of this premise, LDH C has been considered for use as a contraceptive vaccine. Data presented here indicate that mouse antisera to either mouse or rat LDH C are cross-reactive with LDH A and B purified from muscle and heart tissues of mice. However, rabbit antisera to mouse LDH C are not cross-reactive with either mouse LDH A or B. Thus, the degree of cross-reactivity is dependent on the species from which the immunogen LDH is purified, the antisera are derived, and the LDH used in the assay is purified. The determination that LDH A, B, and C are immunochemically cross-reactive is of importance in evaluating LDH C as an immunogen in an immunologic approach to contraception.

Animals↗
PubMed1983

Developmental neuron death in the rat superior cervical sympathetic ganglion: cell counts and ultrastructure.

Counts of neurons of the rat superior cervical ganglion (SCG) were made at two days before birth and at several postnatal ages. There is a significant decline in the number of apparently normal neurons over the first postnatal week, with the number falling from 39 500 at 3 days to 26 500 at 7 days. Cell numbers then remained constant up to day 60 when the number of neurons was 27 500. The incidence of degenerating neurons, identified by light and electron microscopy, was correlated temporally with the loss of normal neurons. The early manifestations of the neuron degeneration were chromatin clumping and the presence of free monoribosomes. Later stages were characterized by increased chromatin clumping, dense aggregations of monoribosomes, numerous intracytoplasmic vacuoles, and only short segments of rough endoplasmic reticulum. The ultrastructure of the majority of these dying neurons is similar to the 'nuclear' types of degeneration described by Pilar & Landmesser (1976) and Chu-Wang & Oppenheim (1978). Based on the presence of degenerating neurons coincident with the reduction in neuron numbers, we conclude that neuron death is an important aspect of early postnatal development in the rat SCG.

Age Factors↗
PubMed1983

Neuron numbers in the superior cervical sympathetic ganglion of the rat: a critical comparison of methods for cell counting.

Published values for the number of neurons in the superior cervical ganglion of the adult rat range from 13 000 to 45 000. These studies have employed different methods for determining what unit to count (cell body, nucleus, nucleolus), how many sections to count, and how to correct the raw counts for split particles and for profiles that are too small to resolve. The purpose of this study was to examine the extent to which these parameters may influence the calculated value for the total number of neurons, using computer simulations of neuron populations. These simulations permitted us to determine the effects on neuron number of varying the diameter of the neuronal nucleus, the size of the smallest resolvable profile, and the thickness of the section. The data from the simulations were used to test the validity of several methods that are in common use for correction of neuron counts. Our results indicate that most of the methods that are in routine use are unsatisfactory. We propose the use of either one of two methods that consistently result in highly accurate estimates of neuron numbers. These are: (1) a modification of the method proposed by Hendry (1976), using computer analysis; or (2) a modification of the method proposed by Abercrombie (1946), which does not require the use of a computer.

Animals↗
PubMed1983

Neonatal testosterone treatment increases neuron and synapse numbers in male rat superior cervical ganglion.

Neonatal treatment with gonadal steroids has been reported to alter morphological as well as functional development in various regions of the brain and spinal cord. Among the observed alterations are changes in numbers of neurons and in the organization and numbers of synapses. These regions have been found to be sexually dimorphic, and the dimorphism dependent upon gender differences in circulating levels of gonadal steroids. Neonatal treatment with testosterone has been shown to produce an increase in the number of neurons in the superior cervical sympathetic ganglion in female rats. The present studies were designed to investigate the possibility of a normally occurring sexual dimorphism in the SCG of the rat, and to characterize the effect of neonatal treatment with testosterone on neurons and synapses in the male rat. We report a sexual dimorphism in the number of neurons but not in the number of preganglionic axons or ganglionic synapses. In addition, neonatal administration of testosterone propionate results in a 40% increase in the number of superior cervical ganglion neurons in treated male rats over the control male number at 15 and 30 days of age. The testosterone propionate treatment results in a 66% increase in the number of synapses in male superior cervical ganglia, without a concomitant increase in the number of preganglionic axons.

Animals↗
PubMed1983

The effect of early feeding on plasma glucose levels in SGA infants.

Plasma glucose levels were measured during the first day of life in 24 small-for-gestational-age (SGA) infants who began formula feedings within two hours of birth. In contrast to the high incidence of low blood sugar seen previously in fasted SGA infants, no infant had a plasma glucose below 30 mg/dl; after the first feeding, no values below 40 mg/dl occurred. Mean plasma glucose levels were lower in infants born to mothers with preeclampsia (57.2 +/- 2 vs 69.7 +/- 2.3 mg/dl, p less than .005). The results indicate that hypoglycemia (plasma glucose less than 40 mg/dl) can be easily avoided in SGA infants simply by providing adequate calories without delay after delivery.

Black People↗
PubMed1981

Time of cell origin and cell death in the avian dorsal motor nucleus of the vagus.

Cessation of cell proliferation and cell death were studied in the dorsal motor nucleus of the vagus of the chick embryo, hatching, and adult. Most of the cells comprising the nucleus (94%) complete their final DNA synthesis on days 2 and 3 of incubation. There is a caudo-rostral gradient in the cessation of proliferation, with the caudalmost cells withdrawing from the cell cycle slightly in advance of the middle and rostral cells. Cell death in the dorsal motor nucleus results in a 21% loss of cells between days 8 and 12, and 37% loss by hatching. A caudo-rostral gradient was also present with respect to cell death, with more delayed and gradual cell loss occurring in the rostral region. The timing and spatial pattern of cell death may be related to the asynchronous innervation of the several targets of the nucleus.

Animals↗
PubMed1980

The relationship of perceived latitude of choice to morale in a nursing home environment.

An Importance, Locus and Range of Activities Checklist (The Perceived Latitude of Choice Scale) and the Philadelphia Geriatric Center Morale Scale were administered to 17 institutionalized elderly women. The Perceived Latitude of Choice instrument contained 37 items representing activities of daily life which subjects rated for personal importance and range of choice available. The morale scale contained 17 items presented in a dichotomous format that would indicate high or low morale. A number of positive correlations were observed between morale and perceived degree of choice, with Attitude Toward Own Aging the factor on the morale scale showing the strongest relationships to choice. The degree of choice available for privacy stood out as one of the most important items related to morale. A number of methodological considerations were discussed relating to the use of correlations, restrictions of range of scores and selection of subjects from populations.

Activities of Daily Living↗
PubMed1979

Age, sex, and hemisphrere asymmetry differences induced by a concurrent memory processing task.

Subjects in three age groups matched simultaneously presented pairs of visual words or geometric shape stimuli as belonging in a "same" or "different" category. No age effects were observed unless subjects were also required to repeat the sequence of the last three "same-different" responses immediately following each trial. Cerebral asymmetry effects were expected for the word and shape dimensions, but were not observed. Asymmetry effects for the same-different dimensions were noted and allowed inference regarding serial and parallel processing effects. When required to repeat the sequence of past responses following each trial, older males showed an increase in time to make the same judgments. Older females showed increased right vs left visual field processing times when required to repeat the sequence of same-different responses following each trial.

Adolescent↗