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Biomedical subjects

J Evans

Publications and source records attributed to J Evans.

At least 307 records · Page 17Linked to original sources
PubMed1993

Congenital cerebrospinal fluid fistula through the inner ear and meningitis.

Congenital deformities of the labyrinth of the inner ear can be associated with a fistulous communication between the intracranial subarachnoid space and the middle ear cavity. We describe seven such cases, six confirmed by high resolution CT and one by postmortem histological section. The seven patients all presented with meningitis although a cerebrospinal fluid fistula was demonstrated at subsequent surgery or postmortem. The lesions were bilateral in three patients, unilateral in three and probably bilateral in the postmortem case although only one temporal bone was obtained. In every case there was a dilated sac instead of the normal two and a half turn cochlea on the affected side and this was confirmed at surgery. The demonstration of the basal cochlear turn is of paramount importance in any deaf child presenting with meningitis. A true Mondini deformity with a normal basal turn and some hearing is not at risk of developing a fistula.

Adult↗
PubMed1993

Inhibition of nuclear protein import by nonhydrolyzable analogues of GTP and identification of the small GTPase Ran/TC4 as an essential transport factor.

We have investigated a possible involvement of GTPases in nuclear protein import using an in vitro transport system involving digitonin-permeabilized cells supplemented with exogenous cytosol. Transport in this system was measured with a novel ELISA-based assay that allows rapid quantitative analysis. GTP gamma S and other nonhydrolyzable analogues of GTP were found to rapidly inhibit the rate of in vitro nuclear import. Transport inhibition by GTP gamma S was dependent on the concentrations of permeabilized cells and cytosol, and was strongly enhanced by a cytosolic factor(s). The predominant cytosolic component responsible for this inhibition was found in a 20-30-kD fraction in molecular sieving chromatography. Furthermore, a component(s) of this 20-30-kD fraction was itself required for efficient nuclear import. Biochemical complementation with bacterially expressed protein demonstrated that this essential GTP gamma S-sensitive transport factor was Ran/TC4, a previously described GTPase of the Ras superfamily found in both nucleus and cytoplasm. Ran/TC4 and its guanine nucleotide release protein RCC1 have previously been implicated in DNA replication, cell cycle checkpoint control, and RNA synthesis, processing and export. Our results suggest that Ran/TC4 serves to integrate nuclear protein import with these other nuclear activities.

Amino Acid Sequence↗
PubMed1993

Lyme disease.

In 1992, reported Lyme disease cases increased, but the majority remained clustered in the northeast and midwest, and in California. The clinical syndromes associated with infection are better understood, and this information can calm public anxiety. The concept of fibromyalgia occurring after infection with Borrelia burgdorferi allows more appropriate treatment in late Lyme disease. The polymerase chain reaction is being applied to gain insights into the pathogenic mechanisms of Lyme disease. Progress has been made toward developing a vaccine through the use of animal models. Together, these advances provide clinicians with more confidence in the diagnosis and treatment of Lyme disease.

Diagnosis, Differential↗
PubMed1993

Neuropsychological and SPECT scan findings during and after transient global amnesia: evidence for the differential impairment of remote episodic memory.

A patient had neuropsychological testing during, and at two days and seven weeks after a transient global amnesia (TGA) attack. During the attack she exhibited a characteristically profound anterograde amnesia but a limited remote memory loss; the most striking impairment was a deficit in personal episodic memory revealed by her performance on the Autobiographical Memory Interview. Personal and general semantic information was less impaired although there were indications of a temporal gradient in the impairment. When tested after the attack, she demonstrated normal anterograde and retrograde memory. A SPECT scan performed during TGA showed a focal reduction in cerebral perfusion in the postero-medial temporal lobes bilaterally which had resolved after seven weeks.

Amnesia↗
PubMed1993

Metabolic responses to head-down suspension in hypophysectomized rats.

Rats exposed to head-down suspension (HDS) exhibit reductions in maximal O2 consumption (VO2max) and atrophy of select hindlimb muscles. This study tested the hypothesis that an endocrine-deficient rat exposed to HDS would not exhibit reductions in VO2max or hindlimb muscle mass. Hypophysectomized (HYPX) and sham-operated (SHAM) rats were tested for VO2max before and after 28 days of HDS or cage control (CC) conditions. No significant reductions in VO2max were observed in HYPX rats. In contrast, SHAM-HDS rats exhibited a significant reduction in absolute (-16%) and relative (-29%) measures of aerobic capacity. Time course experiments revealed a reduction in VO2max in SHAM-HDS rats within 7 days, suggesting that cardiovascular adjustments to HDS occurred in the 1st wk. HDS was associated with atrophy of the soleus (-42%) in SHAM rats, whereas HYPX rats exhibited atrophy of the soleus (-36%) and plantaris (-13%). SHAM-HDS rats had significantly lower (-38%) soleus citrate synthase activities per gram muscle mass than SHAM-CC, but no significant differences existed between HYPX-HDS and -CC rats. HDS rats had an impaired ability to thermoregulate, as indicated by significantly greater temperature increases per unit run time, compared with their CC counterparts. Pretreatment plasma epinephrine levels were significantly lower in HYPX than in SHAM rats. Norepinephrine concentration was similar for all groups except HYPX-HDS, in which it was significantly higher. HDS had no significant effect on thyroxine or triiodothyronine. SHAM-HDS rats had significantly lower concentrations of testosterone and growth hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Influence of cold preservation on the cytoskeleton of cultured pulmonary arterial endothelial cells.

In donor lungs preserved for transplantation, pulmonary arterial endothelial cells become thin and partially detached from the basement membrane at 4 degrees C, recovering slowly after transplantation. These changes have now been modeled in vitro. Porcine pulmonary arterial endothelial cell monolayers were incubated at 4 degrees C for 2 or 4 h, rewarmed to 37 degrees C, and incubated for up to 24 h. Responses were studied using wound healing assays, bead phagocytosis, immunostaining of cytoskeletal components, and quantification of actin by SDS-PAGE and immunoblotting. Cooling caused cessation of cell movement and phagocytosis associated with depolymerization of the cytoskeleton. Depolymerization of microtubules was complete after 2 h but 14.6% of actin filaments remained (SDS-PAGE) after 4 h at 4 degrees C. Loss of actin stress fibers paralleled the disappearance of vinculin/talin co-labeling focal adhesions. However, a fiber network at the inner surface of the cell membrane labeling for talin was stable at 4 degrees C. After rewarming, the rate of cell movement and phagocytosis immediately returned to normal. Actin filaments and thin stress fibers were present by 1 h, although poorly organized, and actin had increased to 68.2% of control. Many small vinculin/talin focal adhesions had formed. Microtubules redeveloped by 1 h. The cytoskeleton of cultured human pulmonary arterial endothelial cells showed similar changes. In conclusion, the cytoskeletal changes help explain in vivo observations. On rewarming, the endothelial cells appeared to recover rapidly, but the abnormal appearance of the reformed cytoskeleton suggests an interim period of instability which may have metabolic and mechanical consequences.

Actins↗
PubMed1993

Racial variation in human leukocyte antigen frequency in insulin-dependent diabetic nephropathy. The South-Eastern Organ Procurement Foundation.

Black patients with insulin-dependent diabetes mellitus are at increased risk for the development of diabetic nephropathy compared with white patients. To determine if genetic differences associated with the HLA system account for racial variation in insulin-dependent diabetes mellitus-induced nephropathy, serologically defined HLA phenotypes from renal transplant recipients and donors in the South-Eastern Organ Procurement Foundation database from 1982 to 1986 were analyzed. Renal transplant recipients (N = 1,531) with insulin-dependent diabetes mellitus-induced renal failure as the cause of ESRD (patients) were compared with 4,506 race-matched, nondiabetic cadaveric kidney donors (controls). Log-linear models were used to assess the relationship between insulin-dependent diabetes mellitus-induced renal failure and prevalence of each HLA phenotype. Bonferroni adjustments of P values were used to correct for multiple comparisons. A comparison of HLA frequencies in patients with insulin-dependent diabetes mellitus-induced renal failure demonstrated the presence of racial differences beyond those normally present between the black and white populations. Blacks, compared with whites, had increased frequencies of HLA-B62 (odds ratio [OR] black:white, 6.13:1.97; P < 0.02) and HLA-DR9 (OR black:white, 4.82:1.57; P < 0.008) and decreased frequencies of HLA-A1 (OR white:black, 1.56:0.8; P < 0.008) and HLA-DR3 (OR white:black, 4.9:2.82; P < 0.004). These results suggest that differences in HLA frequency may account, in part, for the observed racial variation in incidence of diabetic nephropathy. In addition, several antigens in positive and negative association with diabetic nephropathy were identified within each race.

Adult↗
PubMed1993

Child-care programmes for health and family support.

Demographic, social and economic factors have affected the types of health and social service support that the people require. For many, child care is a necessity, not an option. Child care refers to group care of children in creche, child minding, family day care, kindergarten and day care in different settings. Maternal and child health services are often seen as sources of curative rather than preventive care. Planning by the health and social sectors has failed to incorporate many of the perceived needs of the communities. As a result, the services that are available have neither attracted the attention, nor inspired the confidence of the people. One possible strategy is to integrate health care into the rapidly expanding systems of child care that are developing out of family and community needs. These health services can be developed and delivered by adequately trained child-care as well as health-care personnel. With appropriate and simple back-up technologies and skills and referral mechanism, the child-care personnel can undertake some of the MCH care activities in child-care centres. When needed, either a primary health worker or nurse-midwife from health sector should deliver services. Early-childhood care programmes are in increasing demand. Such programmes have potential to reach more than half of the population consisting of the children under-five years of age and their parents. Child-care and development programmes have a social attractiveness and acceptability that invites participation from families that might not avail themselves of primary health-care services.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1993

Evaluating community practice teaching in Doncaster.

Managers in Doncaster health district were concerned to ensure community practice teachers give a high quality standard of teaching to students. June Evans and Dorothy Sedgwick describe the process of introducing audit to the community practice teaching of health visitor and district nurse students.

Community Health Nursing↗
PubMed1993

Needlestick injuries: the shock and reality.

It has been a typically busy Saturday night in the emergency department. Then, near midnight, a trauma casualty was admitted and an incident occurred that would occupy Suzanne Smith's thoughts for months to come. When starting an intravenous line on this patient, Suzanne spiked herself with a needle. Later the patient was taken to the intensive care unit and placed on a ventilator. Suzanne was overcome with fear that she might have contracted AIDS. Her fears intensified when she learned that the patient, Mr. Norman, was a heroin addict.

Fear↗
PubMed1993

Influence of thumb sucking on peer social acceptance in first-grade children.

Chronic thumb sucking in school-age children may reduce peer social acceptance, an important contributor to social development. The influence of thumb sucking on social acceptance was assessed among 40 first-grade children, who were shown four slides of two 7-year-old children (one boy, one girl) in two poses (one thumb sucking, one not). After viewing each slide in their classrooms, the children answered 10 numerically weighted questions related to peer acceptance. To limit the possibility that the children would determine the girl and boy were the same in each pose, the slide presentation was counterbalanced across two sessions 1 week apart. Using a repeated-measures analysis of variance, the authors compared composite scores on each question for both poses. The results indicate that while in the thumb-sucking pose, the children were rated as significantly less intelligent, happy, attractive, likeable, and fun and less desirable as a friend, playmate, seatmate, classmate, and neighbor than when they were in the non-thumb-sucking pose. These findings suggest that the risk of reduced social acceptance should be added to the list of potentially harmful effects of chronic thumb sucking in school-age children.

Analysis of Variance↗