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M Smith

Publications and source records attributed to M Smith.

At least 577 records · Page 32Linked to original sources
PubMed1995

Barosensitive neurons in the rostral ventrolateral medulla of the rat in vivo: morphological properties and relationship to C1 adrenergic neurons.

The aim of this study, conducted in anaesthetized rats, was to examine the morphology of barosensitive neurons in the rostral ventrolateral medulla and their immunoreactivity for a catecholamine synthesizing enzyme, tyrosine hydroxylase. Thirty neurons displaying inhibitory postsynaptic potentials following stimulation of the aortic depressor nerve were intracellularly labelled with Lucifer Yellow or Neurobiotin. Some of these neurons could be excited antidromically from the second thoracic segment of the spinal cord, with conduction velocities of spinal axons ranging from 1.9 to 7.2 m/s. The filled somas were found immediately caudal to the facial nucleus and ventral or ventromedial to compact formation of the nucleus ambiguus. Some dendrites reached the ventral medullary surface. Axons usually projected dorsomedially and then made a sharp rostral and/or caudal turn. The caudally projecting axon could, in some cases, be followed to the first cervical segment of the spinal cord. Seven cells issued fine axon collaterals on the ipsilateral side. These were identified mainly in two areas: in the rostral ventrolateral medulla (or immediately dorsomedial to that region), and within the dorsal vagal complex. Seven of 27 examined cells (26%) were tyrosine hydroxylase-immunoreactive and were classified as C1 adrenergic neurons. No clear relationship was found between the presence or absence of adrenergic phenotype and the morphology of filled cells. However, the amplitude of aortic nerve-evoked inhibitory postsynaptic potentials was significantly larger in tyrosine hydroxylase-positive neurons. Possible reasons for the low percentage of barosensitive cells with tyrosine hydroxylase immunoreactivity found in this study, in comparison with previously published estimates, are discussed. This is the first study describing the morphology of neurons in this part of the medulla identified as barosensitive in vivo, and directly demonstrating adrenergic phenotype in a subset of these neurons.

Adrenergic Fibers↗
PubMed1995

Bedside fluoroscopy to screen for simple extremity trauma in the ED.

Portable fluoroscopy units are commonly used by orthopedic surgeons to assist in fracture reduction and immobilization. The purpose of this study was to determine the diagnostic accuracy of bedside fluoroscopy performed by emergency department (ED) physicians to screen for simple extremity trauma. Eligible adult patients presenting to the ED with isolated injuries to distal extremities were evaluated prospectively over a 6-month study period. ED physicians independently performed fluoroscopy at the bedside, obtained real-time images (frontal, lateral, and oblique), and documented their initial interpretations. Patients then underwent routine diagnostic radiographs of the same areas. Fluoroscopic findings (real-time and photographs) were compared with the radiologists' final report. Ninety-two patients with 108 extremity injuries were enrolled in the study. Fractures were diagnosed fluoroscopically in 26 cases, for a sensitivity of 0.70. Of the 71 standard radiographs without a fracture, the fluoroscopic diagnosis was accurate in 66, for a specificity of 0.93. The overall diagnostic accuracy was 0.85, with a 95% confidence interval of .67 to 1.00. There were 11 false-negative fluoroscopic reports, involving the radius (3), distal tibia (3), metacarpals (2), fifth metatarsal (1), phalanx (1), and cuboid (1). These results suggest that bedside fluoroscopy lacks sufficient sensitivity to screen for simple extremity fractures in the ED.

Adult↗
PubMed1995

Prophylaxis against thromboembolism in neurosurgical patients: a survey of current practice in the United Kingdom.

Venous thromboembolism is a life threatening, but preventable complication of major surgery. Many neurosurgical patients are at high risk of developing thromboembolic disease. A postal survey was undertaken of 44 UK neurosurgical centres to assess the use of physical and pharmacological methods of prophylaxis against thromboembolism. Thirty-five replies were received from 31 centres. Seventy-seven per cent of units used antiembolism stockings (TEDs) for elective surgery and 37% for emergency surgery; in approximately two-thirds of these units TEDs constituted the sole method of prophylaxis used during both elective and emergency surgery. Intermittent pneumatic compression (IPC) was utilized in 37 and 11% of units for elective and emergency surgery, respectively. Subcutaneous heparin was used in 32% of units perioperatively including 6% of emergency cases. These findings suggest that neurosurgical patients, who are at moderate to high risk of developing thromboembolic complications, may not receive effective prophylaxis; those undergoing emergency neurosurgery are less likely to receive any form of prophylaxis.

Brain↗
PubMed1995

The effects of elemental diet and subsequent food reintroduction on rheumatoid arthritis.

The role of diet in rheumatoid arthritis (RA) remains controversial and there have been no controlled studies on the use of elemental diet in the treatment of RA. Elemental diet is an hypoallergenic protein-free artificial diet consisting of essential amino acids, glucose, trace elements and vitamins. This study was carried out to assess the role of elemental diet and subsequent food reintroduction in RA. Elemental diet (E028) (and a small number of foods) was given to 24 patients with definite RA in order to induce a remission and then foods were gradually introduced. Where a food was suspected of causing symptoms it was removed from the diet. Twenty-three control patients supplemented their usual diet with E028. After the elemental diet there was a statistically significant improvement in the diet group in grip strength (P = 0.008) and Ritchie score (P = 0.006) but not in ESR, CRP, thermographic joint score or functional score. The diet group lost more weight than the control group and this correlated with the improvement in grip strength. This improvement was not present following food reintroduction. As the improvements took place in more subjective disease parameters and because of the difficulties in adequately blinding studies of diet in arthritis, a placebo effect must be considered. There was a high default rate, only 38% of those patients originally enrolled completed the study. In conclusion, this study shows that elemental diet can cause an improvement in a number of disease parameters in RA but this is not sustained by an individualized diet. It also illustrates some of the difficulties involved in the study of diet in arthritis.

Adult↗
PubMed1995

Nitric oxide mediates interferon-gamma-induced hyperpermeability in cultured human intestinal epithelial monolayers.

OBJECTIVE: Incubation with interferon-gamma has been shown to increase the permeability of cultured monolayers of intestinal epithelial cells. We sought to determine whether this phenomenon is mediated, at least in part, by increased production of nitric oxide. DESIGN: Prospective, controlled, laboratory study. Human intestinal epithelial (Caco-2BBe) cells were grown as monolayers on permeable supports mounted in bicameral chambers. Permeability was assessed by adding fluorescein sulfonic acid (molecular weight = 478 daltons) to the apical compartment and determining the apical-to-basolateral clearance of the probe over a 24-hr period of incubation. SETTING: Basic science laboratory. MEASUREMENTS AND MAIN RESULTS: The permeability of monolayers to fluorescein sulfonic acid was significantly increased after incubation in the presence of interferon-gamma (250 to 1000 U/mL). The effect of interferon-gamma on permeability was dependent on both the concentration of the cytokine and the duration of exposure to it. Concentrations of nitric oxide oxidation products, nitrite and nitrate, in incubation media were increased after exposure of cells to interferon-gamma. When intestinal epithelial (Caco-2BBe) monolayers were incubated with interferon-gamma in the presence of inhibitors of nitric oxide synthase (NG-monomethyl-L-arginine NG-nitro-L-arginine-methyl ester, or NG-nitro-L-arginine), both of the effects of the cytokine (i.e., increased epithelial permeability and increased production of nitrite/nitrate) were attenuated. CONCLUSIONS: These results suggest that upregulation of nitric oxide biosynthesis plays a pivotal role in the increase in permeability of intestinal epithelial (Caco-2BBe) monolayers induced by interferon-gamma. Increased production of nitric oxide induced by proinflammatory cytokines, such as interferon-gamma, may be an important factor contributing to gut mucosal hyperpermeability in sepsis.

Amino Acid Oxidoreductases↗
PubMed1995

Sociodemographic characteristics, life stressors, and peptic ulcer. A prospective study.

The role of psychosocial factors in peptic ulcer remains controversial. We have investigated the relationship between socioeconomic status, concrete stressors, and ulcers in a longitudinally followed, population-based cohort, taking confounding risk factors into account. A total of 6,928 adults completed the Alameda County Study's baseline questionnaire in 1965; 4,595 ulcer-free on enrollment responded again in 1973-1974. Reported cases of ¿stomach or duodenal¿ ulcer during the year before each of the two surveys were examined with relation to 1965 characteristics: 288 subjects reported ulcers at baseline, and 104 reported new ulcers on follow-up. Sociodemographic characteristics associated with incident ulcers (age-adjusted) were, in women, low education, a blue-collar household, overcrowding, unemployment, marital strain, and children's problems; in men, nonwhite race. Prevalent ulcers were associated in women with sociability and children's problems; in men, with blue-collar occupation, low education, financial difficulties, marital strain, children's problems, and a sense of failure. Adjustment for smoking, alcohol, chronic bronchitis, arthritis, liver disease, and skipping breakfast weakened but did not eliminate these associations; adjustment for socioeconomic status further attenuated the associations of specific problems. Low socioeconomic status and concrete life difficulties are associated with peptic ulcer in the general population cross-sectionally and prospectively after adjustment for major physical risk factors, lending credence to a relationship between psychological stress and peptic ulcer.

Adult↗
PubMed1995

Air embolism during awake craniotomy.

A case of venous air embolism during awake craniotomy is described. Chest pain and electrocardiographic changes were the major presenting features. Capnography detected a decrease in end-tidal carbon dioxide and demonstrates its use as an aid in the diagnosis of air embolism in the awake patient. Following this episode persistent hypoxaemia developed secondary to acute pulmonary oedema and a pleural effusion.

Adult↗
PubMed1995

A study of scleroderma in South Australia: prevalence, subset characteristics and nailfold capillaroscopy.

BACKGROUND: Scleroderma is a systemic rheumatic disorder seen in a wide range of clinical specialties. AIMS: To establish the prevalence and mortality rates of scleroderma in South Australia (SA), to determine the relative frequency and characteristics of the three principal subsets (diffuse, limited and overlap), and to examine the role of nailfold capillaroscopy in subset identification and implied prognosis. METHODS: Outpatient and discharge diagnostic indexes from five major teaching hospitals in SA were reviewed between February 1987 and November 1993. A total of 215 patients with scleroderma were identified. Case notes of 115 of these patients were reviewed in order to validate scleroderma diagnosis, and subset characteristics such as sex, mean age at diagnosis, extent of skin involvement, internal organ involvement and serology were analysed. Fifty-two of these patients were then examined prospectively to confirm positive discharge diagnosis, and nailfold capillaroscopy was performed on these patients. RESULTS: The point prevalence of scleroderma in SA for 1993 was estimated to be 208/10 This figure is a conservative estimate and is higher than most other reported series. The female to male ratio was 4:1. The majority of patients had limited disease with a ratio of 6:1:1.6 limited vs diffuse vs overlap. Systemic involvement excluding the oesophageal components limited disease was found predominantly in the diffuse group. Autoimmune serology was positive in 90% of patients, with Scl-70 being more common in diffuse scleroderma, anti-centromere antibody (ACA) in the limited form and anti-ribonucleoprotein (RNP) in the overlap form. Nailfold capillaroscopy was useful in predicting disease-subtype as capillary dilatation was observed predominantly in limited disease, capillary dropout in diffuse disease. CONCLUSIONS: Scleroderma is more common in SA than previously recognised. Limited disease is more common than diffuse or overlap disease, carries a better prognosis and in associated with ACA. Nailfold capillaroscopy is a useful tool in disease assessment and may provide useful diagnostic and prognostic information.

Adolescent↗
PubMed1995

Attitudes of Dublin accident and emergency department doctors and nurses towards the services offered by local general practitioners.

Good communication at the accident and emergency (A&E)-general practice interface is important. Such communication will be affected by the attitudes of A&E staff towards local general practitioners (GPs). The objectives of this study were to establish and compare, using a questionnaire, the attitudes of Dublin A&E doctors and nurses towards the services offered by local GPs. A questionnaire was sent to all nurses and non-consultant doctors working in four of the six Dublin A&E departments. Completed questionnaires were received from 57 (61%) nurses and 35 (81%) doctors. Only two activities (being accessible to patients during normal surgery hours and providing family planning services) were rated by more than one-fifth of doctors and nurses as being performed 'well'. Six activities (being accessible to patients outside surgery hours, providing long-term care for the chronically ill and debilitated, providing appropriate care for 'difficult' patients, advising patients about the appropriate use of services and performing first aid) were rated by more than 40% of both doctors and nurses as being performed 'badly'. For all activities the nurses consistently rated the performance of the 'average GP' more critically than the doctors. These results must be interpreted cautiously. The implications of these findings and how best they can be addressed are discussed.

Attitude of Health Personnel↗
PubMed1995

TMB-8 and dibucaine induce tyrosine phosphorylation and dephosphorylation of a common set of proteins in platelets.

Dibucaine and 8-(N,N-diethylamino)octyl 3,4,5-trimethoxybenzoate (TMB-8), which are local anesthetics, affect diverse functions of many cell types. For example, platelet aggregation is inhibited by both, and both cause changes in platelet morphology and structure. Little is known of the mechanisms. We found that both dibucaine (0.125-0.5 mM) and TMB-8 (0.25-1.0 mM) induced rapid tyrosine phosphorylation of several platelet proteins (160, 70-75, and 40 kDa) and dephosphorylation of a 62- to 64-kDa protein detectable by a specific antiphosphotyrosine monoclonal antibody (4G10). Platelet aggregation induced by alpha-thrombin (10 nM) was inhibited by the local anesthetics in approximately the same dose range. Neither dibucaine nor TMB-8 induced activation of protein kinase C (PKC) or myosin light-chain kinase. Their activation was not essential for tyrosine phosphorylation induced by local anesthetics. However, an increase in tyrosine phosphorylation of several proteins (95-130 kDa) induced by alpha-thrombin (10 nM) was inhibited by dibucaine (0.5 mM) or TMB-8 (0.5 mM). Furthermore, when dibucaine (0.5 mM) was added 1 min after addition of alpha-thrombin (10 nM), disaggregation was paralleled to dephosphorylation of many proteins, including those mentioned. Tyrosine phosphorylation and dephosphorylation of specific proteins may account for some of the diverse effects of local anesthetics on platelets and other cells. Addition of TMB-8 (0.5 mM) or dibucaine (0.5 mM) also inhibited activation of PKC, induced by alpha-thrombin (10nM), suggesting that some of the inhibitory effects of dibucaine or TMB-8 may be due to inhibitory effects of local anesthetics on PKC.

Blood Platelets↗
PubMed1995

Neurological soft signs in neuroleptic-naive and neuroleptic-treated schizophrenic patients and in normal comparison subjects.

OBJECTIVE: The goal of this study was to assess neurological soft signs and developmental reflexes in schizophrenic patients who had never received neuroleptic medication and those who were receiving neuroleptic medication. METHOD: Neurological soft signs and developmental reflexes were examined in 26 schizophrenic patients who had never received a neuroleptic, 126 schizophrenic patients who were currently receiving neuroleptics, and 117 normal subjects. RESULTS: Soft signs were present in 23% of the neuroleptic-naive and 46% of the medicated schizophrenic patients. Developmental reflexes were present in 19% of the neuroleptic-naive and 12% of the medicated patients. Both soft signs and developmental reflexes were absent in the normal subjects. There were significant differences between patients and normal subjects in neurological soft signs and developmental reflexes. The possibly confounding variables of age, age at onset, duration of illness, number of hospitalizations, Abnormal Involuntary Movement Scale (AIMS) scores, and Simpson-Angus Scale extrapyramidal symptom scores were assessed by using logistic regression in the patients who were receiving neuroleptics. AIMS scores and Simpson-Angus Scale scores correlated with soft signs in these patients. CONCLUSIONS: The presence of neurological soft signs in schizophrenic patients who had never received neuroleptics indicates that these signs are present independent of medication effects, but it is possible that neuroleptics contribute to the prevalence of these abnormalities, as demonstrated by the patients who were receiving neuroleptics.

Adult↗
PubMed1995

Renal effects of oral prostaglandin supplementation after ibuprofen in diabetic subjects: a double-blind, placebo-controlled, multicenter trial.

Prostaglandins of the E series (PGE) are known to contribute to the maintenance of renal hemodynamics in subjects with chronic renal insufficiency. Agents that block PGE synthesis, nonsteroidal anti-inflammatory agents (NSAID), are widely used by people with renal insufficiency. This study was undertaken in subjects with renal insufficiency secondary to diabetes to evaluate the acute effects of a PGE1 analog, misoprostol, on NSAID-induced changes in RBF, as calculated by para-aminohippurate clearance, and GFR, as calculated by inulin clearance. Sodium excretion was also assessed. Twenty-five fasting subjects with a mean age of 56 +/- 4 yr received 800 mg of ibuprofen orally. A concomitant dose of either a placebo (PL) or 200 micrograms of misoprostol was also given. This was followed in 1 h by either a placebo or an additional 200-micrograms dose of misoprostol. Measurements for the determination of RBF, GFR, blood pressure, and fractional excretion of sodium were performed every 30 min for the next 5 h. The greatest reduction in both GFR (-25 +/- 7 mL/min per 1.73 m2 PL versus -10 +/- 4 mL/min per 1.73 m2, misoprostol delta GFR; P < 0.05) and RBF (-48 +/- 21 mL/min per 1.73 m2 PL versus -15 +/- 8 mL/min per 1.73 m2, M delta RBF; P < 0.05) occurred approximately 2 h after the NSAID dose. No significant differences were noted in blood pressure, fractional excretion of sodium, or other measured parameters between groups during the entire study. Gastrointestinal upset was the most common side effect observed in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

Nurses helping nurses: development of internal specialists in long-term care.

1. Too often, expert assistance provided by psychiatrists and psychiatric nurse specialists to long-term care (LTC) providers of geriatric patients is short-lived and not effective in helping LTC staff deal with their patient's behavioral and psychological problems. 2. One of the main objectives of the study--and one that was found to have positive results--was to provide a mechanism by which LTC staff could develop their own expertise in the management of behaviorally difficult residents. 3. More collaborative efforts among nursing specialists, subspecialists, and generalists are needed to empower those who work in LTC to utilize the abilities and strengths inherent in their positions.

Humans↗
PubMed1995

Nurses helping nurses. Development of internal specialists in long-term care.

The prevalence of psychiatric disorders and behavioral disturbances among nursing home residents, combined with observed deficits in geriatric mental health/illness expertise among LTC staff, supports the need for creative approaches to improve the knowledge, understanding, and management of such problems among LTC providers. The train-the-trainer model described in this article proved to be a viable method to providing geriatric mental health consultation and training that targets both improved quality of life for residents and quality of work life for the staff in charge of residents' care. More collaborative efforts among nursing specialists, subspecialists, and generalists are needed to empower those who work in LTC to utilize strengths and abilities inherent to their positions. Nursing homes nurses, who are all too familiar with the problems and challenges of their patient population, may act not only as mental health trainers but also as resource persons, role models, liaisons with geropsychiatric specialists, and leaders in the application of geropsychiatric care principles to residents within their facility, thus promoting improved resident and staff care alike.

Aged↗