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Biomedical subjects

S Hall

Publications and source records attributed to S Hall.

At least 73 records · Page 4Linked to original sources
PubMed1998

An immunohistochemical study of palmar and plantar digital nerves.

We present a qualitative and semi-quantitative description of palmar and plantar digital nerves obtained from cadavers prepared for routine class dissection. The fingertips of the three most functionally important and sensitive digits, namely thumb, index and middle fingers, received more myelinated axons than those of the ring and little fingers. In both palmar and plantar nerves the numbers of myelin basic protein (MBP)-positive myelinated axons decreased proximodistally along each digit and also from thumb to little finger and hallux to little toe respectively. Our results suggest that there are up to ten times more myelinated axons in palmar digital nerves than in plantar nerves.

Aged↗
PubMed1998

Is there a doctor in the house? Integrating medical education and home health care.

This article describes how one rural home health agency collaborated with a school of medicine to integrate medical education into the daily operations of the agency. Noteworthy aspects of this project include integration of home care concepts at all levels of the medical school curriculum, use of an advanced practice nurse to coordinate the program, collaboration between the home health agency and the schools of medicine and nursing, and reliance on telecommunication technology to minimize the barriers related to transportation to and scheduling of physician visits.

Clinical Competence↗
PubMed1998

A four year prospective study of age-related cognitive change in adults with Down's syndrome.

BACKGROUND: While neuropathological studies indicate a high risk for Alzheimer's disease in adults with Down's syndrome, neuropsychological studies suggest a lower prevalence of dementia. In this study, cognitive deterioration in adults with Down's syndrome was examined prospectively over 4 years to establish rates and profiles of cognitive deterioration. METHODS: Fifty-seven people with Down's syndrome aged 30 years or older were assessed using a battery of neuropsychological tests on five occasions across 50 months. Assessments of domains of cognitive function known to change with the onset of Alzheimer related dementia were employed. These included tests of learning, memory, orientation, agnosia, apraxia and aphasia. The individual growth trajectory methodology was used to analyse change over time. RESULTS: Severe cognitive deterioration, such as acquired, apraxia and agnosia, was evident in 28.3% of those aged over 30 and a higher prevalence of these impairments was associated with older age. The rate of cognitive deterioration also increased with age and degree of pre-existing cognitive impairment. Additionally, deterioration in memory, learning and orientation preceded the acquisition of aphasia, agnosia and apraxia. CONCLUSIONS: The prevalence of cognitive impairments consistent with the presence of Alzheimer's disease is lower than that suggested by neuropathological studies. The pattern of the acquisition of cognitive impairments in adults with Down's syndrome is similar to that seen in individuals with Alzheimer's disease who do not have Down's syndrome.

Adult↗
PubMed1998

Paediatric cardiac anaesthesia in a developing country. Guatemala Heart Team.

During the week of October 15-24, 1995 a team of 65 medical, anaesthesiology, surgical, nursing and paramedical personnel travelled to Guatemala City, Guatemala to perform cardiac surgery on children with complex congenital and acquired valvular heart disease. During this mission 42 patients had their lesions surgically repaired. Cardiopulmonary bypass was required in 36 cases. There were no anaesthetic or surgical deaths. All six patients who did not require cardiopulmonary bypass were extubated in the operating room. Of the patients who required cardiopulmonary bypass, 23 were extubated in the operating room (64%). There was no intraoperative anaesthetic morbidity nor postoperative respiratory complications. No patients was reintubated after planned extubation. Cardiac surgery in paediatric age patients can safely be performed in developing countries if close attention is paid to proper patient selection and one maintains the standards of care practised in developed countries.

Adolescent↗
PubMed1998

Functional recovery and timing of hospital discharge after primary total hip arthroplasty.

BACKGROUND: Early discharge programmes in hospitals are encouraged to increase financial efficiency and bed availability, but standards of clinical care must not be compromised. Criteria for safe hospital discharge must be established and objective data are needed to assess how rapidly patients can achieve these discharge criteria. METHODS: A prospective study was performed on 65 patients (mean age = 71 years) scheduled for primary total hip arthroplasty (THA). The Modified Barthel Index (MBI) was measured pre-operatively and postoperatively at set intervals to asses recovery of function after THA. A score of 90 out of a possible 100 was used as a discharge criterion and indicated that the patient was functionally independent for safe hospital discharge. In addition, a combined score for thigh flexion and extension isokinetic peak strength was recorded for each patient before and after surgery. The number and nature of comorbidities and complications were also recorded. RESULTS: The length of hospital stay in this sample varied from 5 to 39 days. The MBI scores increased rapidly between days 3 and 5, then began to plateau from day 8 onwards. Based on the MBI, 58% of patients were fit for discharge at or before day 8. The remainder were fit for discharge from day 10 onwards (mean = 14.2 days). The latter group who required an extended hospital stay were older (P = 0.003), had more identified comorbidities (P = 0.01) and were weaker in their hip musculature prior to surgery (P = 0.001), compared to those who were discharged by day 8. A logistic regression analysis indicated that the pre-operative MBI score and hip strength score were strong predictors of timing for hospital discharge. CONCLUSIONS: A clinical pathway with functional milestones laid out over 8 days would be an appropriate criterion for the discharge of the majority of patients. However, approximately 40% of the patients presented in this study required a longer hospital stay before the criteria for safe discharge could be achieved. These patients can be identified pre-operatively by screening their MBI and composite hip strength scores.

Aged↗
PubMed1998

Intercessory Prayer for ill Health: A Systematic Review.

OBJECTIVES: To review the effectiveness of prayer as an additional intervention for those with health problems already receiving standard medical care. SEARCH STRATEGY: Electronic Searches of Biological Abstracts, CINAHL, The Cochrane Controlled Trials Register, EM-BASE, MEDLINE, PsycLIT, and Sociofile were undertaken. All references of articles selected were searched for further relevant trials. SELECTION CRITERIA: Randomised and quasi-randomised trials of personal, focused, committed and organised intercessory prayer on behalf of anyone with a health problem were considered. Outcomes such as achievement of desired goals, death, illness, quality of life and well-being for the recipients of prayer, those praying and the caregivers were sought. DATA COLLECTION AND ANALYSIS: Studies were reliably selected and assessed for methodological quality. Data were extracted by 4 reviewers working independently. Dichotomous data were analysed on an intention-to-treat basis, and continuous data with over 50% completion rate are presented. MAIN RESULTS: There was no evidence that prayer affected the numbers of people dying from leukaemia or heart disease (OR 0.64, CI 0.32-1.27), or that it decreased coronary care complications (OR 1.05, CI 0.49-2.26) or the time participants stayed in hospital. There were significantly fewer 'intermediat//poor outcomes' for those with heart disease in the prayed-for group (OR 0.49, CI 0.30-0.80), and this finding was robust to some changes in definition. CONCLUSIONS: This review provides no guidance for those wishing to uphold or refute the effect of intercessory prayer on the outcomes studied in the available trials. Therefore, in the light of the best available data, there are no grounds to change current practices. There are very few completed trials of the value of intercessory prayer. The evidence presented so far is interesting enough to justify further study. If prayer is seen as a human endeavour it may or may not be beneficial, and further trials could uncover this. It could be the case that any effects are due to elements beyond present scientific understanding that will, in time, be understood. If any benefit derives from God's response to prayer it may be beyond any such trials to prove or disprove.

Journal Article↗
PubMed1998

LPL promoter -93T/G transition influences fasting and postprandial plasma triglycerides response in African-Americans and Hispanics.

The lipoprotein lipase (LPL) promoter -93T/G transition has previously been reported as having a triglyceride (Tg)-lowering effect, whereas the D9N variant has been shown to have a Tg-raising effect. These two variants were studied in 66 healthy subjects of Hispanic and 42 subjects of African-American origin, who had participated in a study of postprandial lipemia. While the allele frequency of the -93G was significantly different in the Hispanics and African Americans (0.09: 95% CI 0.04-0.13 and 0.28: 95% CI 0.19-0.38; P=0.0001, respectively), the N9 allele frequency was not different (0.06: 95% CI 0.02-0.1 and 0.05: 95% CI 0.002-0.093, respectively). Linkage disequilibrium between the -93T/G and D9N was highly significant in Hispanics (delta=0.67. P=0.0001), compared to delta=0.09 (NS) in African-Americans. In the combined group, compared to individuals with the common genotype (TT/DD; n=71) with fasting plasma Tg of 1.34 (+/-4.5% SEM) mmol/l, carriers of the G/D haplotype (TG/DD + GG/DD; n=25) had significantly lower plasma Tg levels of 1.08 (+/-10% SEM) mmol/l (P < 0.02). After the fat meal, compared to individuals with neither mutation, TT/DD, the effect of the G/D haplotype was to reduce significantly postprandial Tg (P < 0.036). Retinyl palmitate concentration at 5 hrs was significantly lower in G/D carriers than TT/DD individuals (P < 0.05). The lipid-raising effect of the N9 allele in carriers of the -93G (TG/DN + GG/DN) and effect on postprandial Tg clearance was not significant in this group. Thus carriers of the G/D haplotype have lower fasting plasma Tg and reduced alimentary lipemia. This allele may be associated with reduced risk of coronary artery disease.

Adult↗
PubMed1997

Convergence of Schiff base costimulatory signaling and TCR signaling at the level of mitogen-activated protein kinase ERK2.

Schiff base formation on specialized T cell surface amines provides a costimulatory signal to T cells through a mechanism that activates Na+ and K+ transport, substantially enhancing TCR-dependent IL-2 production. Schiff base-forming molecules that mimic the natural carbonyl donor potently enhance immune responses and provide the first mechanism-based, orally active immunopotentiatory agents. In the present study, costimulation by the Schiff base-forming molecule tucaresol was investigated at the level of mitogen-activated protein kinase (MAPK) in T cell lines. Both TCR-directed stimulation by anti-CD3 and Schiff base stimulation by tucaresol produced a distinct mobility shift in MAPK, characterized by direct immunoblotting of cell lysate proteins subjected to SDS-PAGE, that corresponded with increased phosphorylation. Combined TCR-CD3 and tucaresol stimulation substantially enhanced and prolonged the MAPK response, providing a biochemical basis for the costimulatory nature of the pathway utilized by Schiff base signaling. The MAPK affected was identified by immunoprecipitation as ERK2. Both the direct effects and the TCR signal-enhancing effects of tucaresol on MAPK activation were also demonstrated in a functional MAPK assay measuring substrate phosphorylation. Borohydride reduction of tucaresol's Schiff base-forming carbonyl group abolished both enhancement of MAPK phosphorylation and IL-2 production, as did a selective inhibitor of the MAPKK, MEK1. Tucaresol had no effect on TCR-mediated rises in intracellular free Ca2+ or inositol 1,4,5-triphosphate generation, while tucaresol signaling occurred normally in the lck-deficient J.CaM1.6 T cell line, consistent with convergence of tucaresol- and TCR-induced signals downstream of early TCR-mediated events.

Benzaldehydes↗
PubMed1997

Epidemic of asthma in a wood products plant using methylene diphenyl diisocyanate.

Eighteen employees with lower respiratory symptoms later confirmed to be occupational asthma were referred for evaluation. All were employees of a single wood products plant using heated methylene diphenyl diisocyanate (MDI) in the manufacture of a synthetic wood product. Of the 18, 15 had no prior airway symptoms or other known bronchial injury, and 16 had positive methacholine bronchial provocation tests. All cases occurred during a 2.5-year period after exposure to a new manufacturing process using steam-heated MDI resin in a new manufacturing facility. Initially, employees developed symptoms related to the start-up process in the plant, with possible higher MDI exposures and probable higher resin temperatures. Later, most employees who developed new symptoms worked in areas of the plant where they were exposed mostly to heated boards. This suggests MDI sensitization arising at lower temperatures than previously considered likely for this substance.

Adult↗
PubMed1997

Hypertension and identification of toxin in human urine and serum following a cluster of mussel-associated paralytic shellfish poisoning outbreaks.

Following four outbreaks of paralytic shellfish poisoning on Kodiak Island, Alaska, during 1994, medical records of ill persons were reviewed and interviews were conducted. Urine and serum specimens were analyzed at three independent laboratories using four different saxitoxin binding assays. High-performance liquid chromatography was used to determine the presence of specific toxin congeners. Among 11 ill persons, three required mechanical ventilation and one died. Mean peak systolic and diastolic blood pressure measurements were 172 (range 128-247) and 102 (range 78-165) mmHg, respectively, and blood pressure measurements corresponded with ingested toxin dose. All four different laboratory methodologies detected toxin in serum at 2.8-47 nM during acute illness and toxin in urine at 65-372 nM after acute symptom resolution. The composition of specific paralytic shellfish poisons differed between mussels and human biological specimens, suggesting that human metabolism of toxins had occurred. The results of this study indicate that saxitoxin analogues may cause severe hypertension. In addition, we demonstrate that saxitoxins can be detected in human biological specimens, that nanomolar serum toxin levels may cause serious illness and that human metabolism of toxin may occur. Clearance of paralytic shellfish poisons from serum was evident within 24 hr and urine was identified as a major route of toxin excretion in humans.

Adolescent↗
PubMed1997

A novel high-dose chemotherapy protocol with autologous hematopoietic rescue in patients with metastatic breast cancer or recurrent non-Hodgkin's lymphoma.

In this phase II trial, we used a double dose-intensive chemotherapy and stem cell rescue protocol to treat breast cancer (BCA) patients or non-Hodgkin's lymphoma patients (NHL). The first cycle consisted of high-dose melphalan followed by ABMT. The second cycle used a novel chemotherapy combination; thiotepa, etoposide, carboplatin and cyclophosphamide (TECC) followed by ABMT. We treated 12 patients in total, nine with BCA, three with NHL. All nine BCA patients were treated with the two cycle protocol. The three NHL patients were treated with the second cycle only. Bone marrow (BM, 1 patient), peripheral blood stem cells (PBSC, 10 patients) or both (1 patient) were reinfused 60-72 h after completion of each cycle of chemotherapy. Recovery was rapid; the ANC rose to greater than 500/microl on day +11 (+8 to + 20) and the platelet count to greater than 20000/microl on day +12 (+6 to +20). The toxicities included the expected neutropenic fevers, severe mucositis, diarrhea, and a low incidence of mild renal insufficiency. No patients developed veno-occlusive disease, hemorrhagic cystitis or overt bleeding. With a mean follow-up of 37 months, 83.3% of the patients are alive. Six patients are in complete remission; one patient with BCA relapsed and expired; one patient with NHL is in CR now over 18 months after relapse and subsequent treatment with interferon; one patient is too early to evaluate. Progression-free survival overall is 75%, which is at least equivalent to many other recent studies using similar regimens. In addition, we have also found that delayed addition of G-CSF during the mobilization of PBSC was feasible and resulted in excellent CD34+ cell counts and engraftments, and reduced treatment costs. These results indicate that this chemotherapy is effective with good remission rates and high progression-free survival rates. It is also well tolerated with acceptable toxicities that are manageable. Long-term follow-up of a larger cohort of patients will be needed to ascertain the overall efficacy of this type of therapy.

Adult↗
PubMed1997

Axonal regeneration through acellular muscle grafts.

The management of peripheral nerve injury remains a major clinical problem. Progress in this field will almost certainly depend upon manipulating the pathophysiological processes which are triggered by traumatic injuries. One of the most important determinants of functional outcome after the reconstruction of a transected peripheral nerve is the length of the gap between proximal and distal nerve stumps. Long defects (> 2 cm) must be bridged by a suitable conduit in order to support axonal regrowth. This review examines the cellular and acellular elements which facilitate axonal regrowth and the use of acellular muscle grafts in the repair of injuries in the peripheral nervous system.

Animals↗
PubMed1997

Pectoral muscle stimulation after falling off a ladder.

A-pacemaker that had been implanted correctly was found at follow-up to have "flipped over" as a result of a fall from a ladder. Symptomatic pectoral muscle stimulation ceased immediately when the generator was manually flipped back into the correct position.

Accidental Falls↗
PubMed1997

Hirschsprung's disease: genetic mutations in mice and men.

Hirschsprung's disease is a neuronal dysplasia of the hindgut, characterised by a loss of neurones, which affects about 1 in 5000 live births. Genetic factors have been implicated in the aetiology of this disease in about 20% of cases and a dominant pattern of inheritance has been revealed in several families. The pathogenesis of the aganglionosis is often attributed to a failure of migration of neural crest cells, although this has not been proven. Recently, mutations in a developmentally regulated receptor tyrosine kinase gene, ret, and mutations in the endothelin receptor-B gene (ENDR-B) have both been linked to familial Hirschsprung's disease in humans. Moreover, certain mutant mouse strains--namely piebald lethal and lethal spotted--exhibit striking similarities to the human condition. The mutation which gives rise to piebald lethal has now been found to be in the ENDR-B gene, and the mutation associated with lethal spotted occurs in the gene for endothelin-3 (ET-3), a ligand for ENDR-B. Two transgenic mouse lines have been developed which also reflect the human disease: ret-k-, which has a loss of function mutation of the ret gene, and ENDR-B null. In addition, the introduction of a Lac-Z reporter gene into neural crest cells of aganglionic mice has made it possible to study directly the fate of enteric neuroblasts which are affected by "Hirschsprung's-like" mutations. Here, we review the possible roles of RET and endothelin in the normal development of the enteric nervous system, and the significance of their mutated forms in the pathogenesis of familial aganglionosis. This review focuses on recent advances in our understanding of the genetic basis of the lesions which have been implicated in congenital forms of Hirschsprung's disease. Disruption of these genes in the mouse, either by transgenic "knockout" approaches or in mutant mouse lines, offers the prospect of greater understanding of both the cellular and developmental bases of the human disease.

Animals↗
PubMed1997

A common mutation in the lipoprotein lipase gene promoter, -93T/G, is associated with lower plasma triglyceride levels and increased promoter activity in vitro.

Single-strand conformational polymorphism analysis of the lipoprotein lipase promoter identified a T-->G transition at position -93. The frequency in healthy white men was 3.4% (n = 1575). There was an 83% allelic association between -93T-->G and Asp9-->Asn (D9N); all N9 mutations occurred on a -93G allele, but not all -93G mutations occurred on an N9 allele. It was thus possible to assess the effect on plasma triglyceride (Tg) levels of the rare -93G mutation in the presence of the wild-type D9. Carriers of the -93G, with genotype TG/DD, had significantly lower Tg levels than TT/DD individuals (1.36 versus 1.78 mmol/L, P = .01); carriers of both mutations (TG/DN) had the highest Tg levels (1.93 mmol/L). When the group was stratified above and below the sample mean for body mass index (BMI), carriers of the -93G on a D9 allele (TG/DD) were "protected" against the Tg-raising effect of obesity, as assessed by BMI. In Afro-Caribbeans (n = 91), the carrier frequency of -93G was 18-fold higher (63%), with weaker (17%) allelic association between -93G and N9. In vitro, the -93G promoter had 24% higher activity than the -93T in a rat smooth muscle cell line and 18% higher activity in a human adrenal cell line. A protein identified by band-shift assays bound to the -93G but not to the -93T allele, which may explain the lower Tg levels in -93G carriers.

Adult↗