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Biomedical subjects

M Phelan

Publications and source records attributed to M Phelan.

65 records · Page 4Linked to original sources
PubMed1988

Capsular distension and intracapsular pressure in subcapital fractures of the femur.

It has been shown that raised intracapsular pressure causes avascular necrosis of the femoral head in experimental animals, but the relevance of this to clinical fractures of the femoral neck is controversial. We have studied 19 patients with intracapsular fractures of the femoral neck by pressure measurement and by ultrasonography to demonstrate capsular distension. The intra-articular pressure in Garden Grade I and II fractures averaged 66.4 mmHg with a maximum of 145 mmHg. In 10 Garden Grade III and IV fractures the average pressure was 28 mmHg with a maximum of 65 mmHg. Most of the recorded intracapsular pressures were high enough to have caused possible vascular embarrassment, and it is suggested that early decompression of the haemarthrosis should be considered.

Aged↗
PubMed1987

Spinal cord dysfunction with quadriplegia complicating pneumococcal meningitis.

A case of pneumococcal meningitis complicated by brain-stem herniation and flaccid quadriplegia is described, from which the patient, an 11 year old boy, made a partial recovery. The patient had suffered a head injury with skull fracture some years previously; this was his third episode of meningitis. The aetiology of the quadriplegia has not been fully established, but is presumed to be of vascular nature at spinal cord level, associated with an acute hypotensive episode. Preventative aspects of recurrent bacterial meningitis and brain-stem herniation following lumbar puncture are stressed.

Child↗
PubMed1987

Tobramycin dosing in the puerperal patient.

Serum levels of tobramycin were determined with an enzyme immunoassay technique in 20 puerperal women with postcesarean endometritis who were being treated with metronidazole-tobramycin. Ideal dosing was then calculated to attempt to provide peak serum levels between 5 and 8 micrograms/mL and trough serum levels less than 2 micrograms/mL. In eight patients, therapeutic serum levels could not be attained even at doses greater than the package-insert recommendation of 3 mg/kg/d. Therapeutic levels were achieved in five patients with doses between 3 and 5 mg/kg/d and in seven patients only at doses above the maximum recommended daily dose of 5 mg/kg. The puerperal patient appears to usually require much higher dosages of tobramycin than usual, and serum levels must be monitored for therapeutic reasons rather than for toxicity.

Cesarean Section↗
PubMed1984

Modification of glyceraldehyde-3-phosphate dehydrogenase, EC 1.2.1.12, isolated from rainbow trout during acclimation at 5 or 15 degrees C--I. Changes in the activity of individual muscle isolates as evidence for variable adaptive responses.

The mean Km and Vmax values for G3PDH isolated from the lateral muscle of cold-adapted (5 degrees C) rainbow trout, Salmo gairdneri, were twice those of enzyme from warm-adapted (15 degrees C) trout when assayed at 7 degrees C but not at any other temperature. The entropy of activation of warm enzyme was about 3 times that of cold enzyme. However, enthalpy or free energy of activation among acclimation groups differed less or not at all. Individual G3PDH isolates within either adaptation group differed in kinetic characteristics.

Acclimatization↗
PubMed1984

Modification of glyceraldehyde-3-phosphate dehydrogenase, EC 1.2.1.12, isolated from rainbow trout during acclimation at 5 or 15 degrees C--II. Biochemical characterization of G3PDH muscle isolates.

G3PDH was isolated from the lateral muscle of rainbow trout (Salmo gairdneri) acclimated at 5 degrees C (cold) and 15 degrees C (warm). No differences were found in muscle concentration, molecular weights, isoelectric focusing patterns, amino acid compositions or peptide maps between cold and warm isolates. Cold and warm G3PDH contained mannose in variable concentration but no other prosthetic groups.

Acclimatization↗
PubMed1983

Hemagglutinin-specific antibody responses in immunoglobulin G, A, and M isotypes as measured by enzyme-linked immunosorbent assay after primary or secondary infection of humans with influenza A virus.

The isotype-specific antibody responses to purified hemagglutinin of adults undergoing either primary or secondary infection with an influenza A virus were characterized by using an enzyme-linked immunosorbent assay. Twenty-eight military recruits undergoing primary infection with A/USSR/92/77 (H1N1)-like virus had serum antibody rises in the immunoglobulin M (IgM) (86%), IgG (100%), and IgA (96%) isotypes. In contrast, 19 adult volunteers undergoing secondary infection with A/Peking/2/79 (H3N2) wild-type virus had serum antibody titer rises largely restricted to the IgG (68%) and IgA (74%) classes, with only 1 volunteer having a serum IgM antibody titer rise. Nasal wash hemagglutinin-specific antibody responses in the adults undergoing secondary infection were predominantly in the IgA class (74%). There was a correlation between the presence of and the magnitude of nasal wash and serum hemagglutinin-specific IgA antibody responses in these adults. This suggested that there was a common source for the hemagglutinin-specific local IgA antibody and serum IgA antibody produced after infection. The recruits undergoing primary H1N1 influenza virus infection had H1 hemagglutinin-specific enzyme-linked immunosorbent assay antibody in each of the IgA, IgG, and IgM isotypes in their acute-phase serum. However, no role for this cross-reactive antibody in modifying the severity of illness experienced by the recruits could be demonstrated.

Adult↗
PubMed1982

Antigen-specific human T lymphocyte clones: viral antigen specificity of influenza virus-immune clones.

Human T lymphocyte clones (TLC) specific for type A (A/Texas/1/77) influenza virus and maintained in continuous culture with T cell growth factor, were analyzed to define the cellular specificity pattern of virus recognition. A panel of TLC were stimulated with strains of serologically characterized type A influenza subtypes. Five TLC recognized all the viral subtypes; the remaining clones recognized only subtypes that shared serologically defined determinants with the immunizing subtype. In addition, the 11 TLC were analyzed for their fine antigenic specificity by using the purified viral components hemagglutinin (HA), neuraminidase (NA), matrix protein (MP), and nucleoprotein (NP). Five TLC proliferated in response to NA, four to MP, one to HA, and one to NP. None of the clones responded to the unrelated B strain influenza virus, B/Singapore. Furthermore, the fine specificity of an MP-reactive TLC was confirmed by subcloning.

Antigens, Viral↗
PubMedDate not supplied

Transmission of ground squirrel hepatitis virus to homologous and heterologous hosts.

The infectivity and host range of ground squirrel hepatitis virus (GSHV) have been further examined by animal inoculation experiments. Although carrier squirrel sera usually harbor 10(9) to 10(10) virions per ml as determined by physical measurements, titration of one such serum revealed that squirrel infectivity was lost following dilution of the sample over 10(6)-fold. Infectivity is markedly reduced by NP40 pretreatment of infected serum. GSHV infection cannot be readily transmitted to several related ground squirrel species, but chipmunks can be experimentally infected by GSHV virions or by cloned GSHV DNA, and the resulting infection closely resembles that seen in the normal host.

Animals↗
PubMedDate not supplied

First metatarsophalangeal joint arthrodesis: quantitative mechanical testing of six-hole dorsal plate versus crossed screw fixation in cadaveric specimens.

Quantitative strength analysis of first metatarsophalangeal joint arthrodesis was performed using two fixation techniques: a small 6-hole plate with an interfragmentary screw or two crossed lag screws. Twelve matched-pair fresh-frozen cadaveric specimens (24 trials) were used for direct comparison of each of the two fixation techniques. All joint surfaces were prepared with power conical reamers utilizing a standard technique. The fixation construct was stressed to failure on each specimen using a computer-integrated materials tester. Fixation stiffness defined as force (load) over displacement and point of ultimate failure was evaluated. The six-hole plate and interfragmentary screw fixation method was a statistically stiffer form of fixation (p > .01) and displayed a greater point of ultimate failure (p > .002) under the laboratory conditions.

Aged↗
PubMedDate not supplied

Schizophrenia and the environment.

Schizophrenia is more prevalent in urban than rural areas. For a generation this difference was thought to be due to the downward social drift of affected individuals. Recent research suggests that being born and brought up in an inner-city area increases the risk of developing the illness, and brings into question the role of environmental hazards and social factors.

Environmental Health↗