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Biomedical subjects

P Allen

Publications and source records attributed to P Allen.

At least 91 records · Page 5Linked to original sources
PubMed1994

Stage, serum LDH, and performance status predict disease progression and survival in HIV-associated lymphomas.

PURPOSE: This is a review of treatment of 44 patients with positive HIV serology (positive HIV) and lymphoma. MATERIALS AND METHODS: Twenty patients had diffuse large-cell lymphoma (DLCL), and 18 had small noncleaved-cell lymphoma (SNCCL). Three had Hodgkin's disease (HD) and 3 had diffuse small- or mixed-cell lymphoma. These patients received intensive chemotherapy regimens for management of their disease; most were regimens in use at our institution for patients with lymphoma who did not have positive HIV. RESULTS: The complete response to treatment (CR) was 77% for all patient, 80% for those with DLCL, and 72% for those with SNCCL. Stage, serum LDH, and performance status were predictors of complete remission and freedom from progression. Though there was a tendency for patients with a T4-cell count of < or = 200 to have a higher risk of opportunistic infections while receiving therapy, most infections were controllable with appropriate antibiotic management. More than one-half of the deaths in this study occurred after completion of therapy in complete remission, with a median survival of only 11 months, and were attributable to AIDS-related complications. CONCLUSIONS: Our data suggest that (1) patients with lymphoma who have positive HIV have responses to chemotherapy similar to those expected for patients who are HIV-negative; (2) most infectious complications are manageable with appropriate therapy during treatment; and (3) after completion of chemotherapy, treatment should focus on control of progression of AIDS-related complications.

AIDS-Related Opportunistic Infections↗
PubMed1994

Adi Quala: application of solar photovoltaic generation in rural medical centres.

Adi Quala is an Eritrean agricultural town of 14,000 people, and is situated about 70 km south of the capital, Asmara and 30 km from the border with Tigray, Ethiopia. On good days electricity was received from Asmara between 0600 h and 2300 h with nothing available outside these hours. These conditions meant the electricity supply had been a constant problem for the Adi Quala hospital which caters for about 50,000 people with 21 staff. It was for this reason that it was chosen for the first solar system, which provides all essential requirements completely independently from the grid connection. This will in turn enable the hospital to increase the range and reliability of services on offer. Three weeks after the arrival of the equipment the elders were able to have a guided tour of their new local facilities. This included 2kW of photovoltaic panels (installed on the roof), batteries and control equipment powering a range of hospital equipment used in the Mother and Child Health Centre, delivery room, wards, dispensary, clinic and laboratory. Their enormous appreciation was very moving and well articulated in an afternoon of music, speeches and feasting. Eritrea's first solar powered hospital was welcomed into capable hands. The pilot project was successfully installed and commissioned in February 1992, and has performed well to date.

Community Health Centers↗
PubMed1994

Medical and dental staffing prospects in the NHS in England and Wales 1993.

This article provides a brief update on current national policies affecting medical education and training, and information on the present medical and dental workforce. Although of general interest, senior medical students and doctors in the training grades may find it particularly helpful when considering choices of future career. As there may be marked local variations in career prospects for any one specialty, further information and advice is available from Regional Postgraduate Medical and Dental Deans, specialty advisors (through Royal College and specialty associations) and clinical tutors. The information in this article relates to the present situation only and a review of previous articles in this series may be useful to observe certain trends.

Career Choice↗
PubMed1994

Cortical deafness: a longitudinal study.

We have studied a patient with MRI-confirmed bilateral absence of considerable portions of her temporal lobes resulting in cortical deafness. Although physiologic measures demonstrate normal peripheral hearing sensitivity, this patient's speech has the inflection and prosodic characteristics associated with profound peripheral hearing loss, and she is unable to understand spoken communication. Behaviorally obtained pure-tone thresholds taken over nearly 20 years range from normal to moderate hearing loss with normal middle ear muscle reflexes and normal ABRs; however, we consistently found abnormal middle latency and cortical evoked potentials. Because of her total inability to communicate auditorily, this patient was ultimately taught American Sign Language and educated at the Louisiana School for the Deaf. This rare case highlights the importance of using multiple audiologic measures sensitive to abnormalities at various levels of the auditory system.

Adult↗
PubMed1993

Comparison of the levels of inositol metabolites in transformed haemopoietic cells and their normal counterparts.

We have compared the levels of inositol metabolites in three pairs of normal and transformed cells which have been matched with respect to their cell lineage, differentiation and proliferation status: (i) normal human myeloid blast cells and the human promyelocytic leukaemic cell line, HL60; (ii) human umbilical-cord T-helper cells and C8166 cells, a HTLV-1-transformed T-helper cell line; and (iii) an interleukin 3-dependent long-term culture of murine pro-B-cells (BAF3) and BAF3 cells transformed by transfection with the bcr-abl oncogene. Complex patterns of inositol metabolites were present in each of the cell populations. Although there were a number of differences in the levels of certain inositol metabolites between individual cell populations in the paired groups, we did not observe any consistent difference in the levels of inositol metabolites between the proliferating normal and transformed cells. In particular, our data do not support the reported correlation between elevated glycerophosphoinositol (GroPIns) levels and transformation of cells by membrane and cytoplasmic oncogenes which has been reported by other workers. All the cells contained high concentrations of Ins(1,3,4,5,6)P5 (between 12 and 55 microM) and InsP6 (between 37 and 105 microM). The HTLV1-transformed T-helper cells had particularly high levels of total inositol phosphates (predominantly GroPIns, an unidentified inositol bisphosphate and InsP6). The observations are discussed with reference to cell transformation and to the differentiation status of the paired populations.

Animals↗
PubMed1993

Serial imaging of the carotid bifurcation and cerebrovascular reserve after carotid endarterectomy.

A radioisotopic method of quantifying mean cerebral transit time was used to assess the immediate effects of carotid endarterectomy on cerebrovascular reserve (CVR) in 69 patients. In addition, serial postoperative data were acquired on CVR, clinical status and non-invasive imaging of the internal carotid arteries in 56 patients over a period of 6-48 (median 24) months. Twenty-one patients (30 per cent) had preoperative evidence of impaired CVR in the symptomatic hemisphere. Within 4 days of surgery, however, reserve had returned to normal in 17 of the 21 patients. During follow-up, four of the 56 patients developed recurrent stenosis (> 50 per cent) or occlusion of the artery operated on but only two of these had impairment of CVR and none was symptomatic. Three patients suffered recurrent transient ischaemic attacks (TIAs) but none had recurrent internal carotid artery disease or impaired CVR. One patient suffered a TIA in the territory of the non-operated artery during follow-up in association with disease progression and CVR impairment. However, the TIA preceded recognition of either of these changes. Twelve other patients had (or developed) stenosis (> 50 per cent) in the non-operated artery during follow-up but none was symptomatic or developed impairment of CVR. Although assessment of CVR provided useful information on the frequency of haemodynamic compromise before carotid endarterectomy and on the natural history of disease progression, neither serial assessment of reserve nor non-invasive imaging of the carotid bifurcation influenced clinical practice during follow-up.

Blood Flow Velocity↗
PubMed1993

Bone single-photon emission tomography in recent meniscal tears: an assessment of diagnostic criteria.

Bone single-photon emission tomography (SPET) was performed in 40 patients within 6 months of acute knee injury where internal derangement of the knee was suspected, and the results related to the arthroscopy findings. Scan features with high sensitivity, specificity, and predictive accuracy for a meniscal tear could not be obtained on planar imaging. However, a half-crescent or more of increased tibial plateau activity on transaxial SPET gave a sensitivity of 89%, a specificity of 76%, a positive predictive accuracy of 77% and a negative predictive value of 89%. For longitudinal (bucket handle) tears alone the optimum scan pattern was a full crescent of increased tibial plateau activity with adjacent femoral activity and increased blood pool activity which gave corresponding values of 78%, 94%, 78% and 93%. It is concluded that the inclusion of tibial plateau activity of less than a full crescent and the presence of femoral condyle and blood pool activity in the diagnostic criteria improves the ability of bone SPET to detect meniscal tears. The value of bone SPET in the diagnosis of meniscal tears suggests that it could have a significant role to play in the management of knee injuries.

Adolescent↗
PubMed1993

The role of the practice nurse in the management of depression in general practice: treatment adherence to antidepressant medication.

This pilot study demonstrated the feasibility of providing practice nurse support as an adjunct to standard general practitioner treatment to patients with depressive disorders prescribed antidepressant medication. With respect to the measures used and pilot study objectives identified, there were no statistically significant differences between the study groups in treatment adherence to the prescription of antidepressant medication or in the incidence and severity of adverse events to medication. Large-scale randomized controlled trials are in progress to assess the effectiveness of practice nurse interventions in the management of depressive illness in general practice.

Adult↗
PubMed1993

SPECT imaging in the diagnosis of meniscal tears.

Sixty patients scheduled for arthroscopy of a knee because of suspected meniscal tears had preoperative planar and single photon emission computed tomography (SPECT) radionuclide scans. A crescentic pattern of uptake on the SPECT transaxial view was used as a criterion for diagnosing a tear of a meniscus. The sensitivity of the investigation was 77%, specificity 74%, negative predictive value (NPV) 65%, positive predictive value (PPV) 83%, and accuracy 76%. Tears of the posterior horn of the cartilage were also associated with intense focal uptake on the transaxial view as well as increased equilibrium activity in the adjacent femoral condyle. When these appearances were included as additional criteria the sensitivity rose to 90%, NPV 81%, and accuracy 84%. This study confirms the usefulness of SPECT imaging in identifying meniscal tears.

Adolescent↗
PubMed1993

Long-term effects of cimaterol in Friesian steers: I. Growth, feed efficiency, and selected carcass traits.

The objectives of this experiment were: 1) to determine whether feeding cimaterol to male calves from 4 wk of age until slaughter at target live weights of 275, 375, or 475 kg would result in a sustained increase in growth rate and feed conversion efficiency (FCE) and 2) to determine whether the effects of cimaterol on selected carcass traits would increase with increased duration of treatment. Ninety male Friesian calves 4 wk old were assigned at random to either a control or cimaterol group. Each animal was fed 1 kg of chopped barley straw and had ad libitum access to a pelleted diet containing either 0 or 4 ppm of cimaterol. Neither ADG nor FCE was affected by cimaterol during the first 5 wk of treatment. Growth rate of cimaterol-treated steers was 20% higher during wk 25 to 33. However, cimaterol had no overall effect on growth rate. Feed conversion efficiency was improved by 15 and 63% during wk 9 to 16 and wk 25 to 33, respectively. Cimaterol-treatment increased dressing percentage by an average of 3%, improved conformation score (2.2 vs 4.0, 3.0 vs 3.9, and 2.9 vs 3.2), and reduced subcutaneous fat score (1.7 vs 1.9, 1.3 vs 3.1, and 2.1 vs 3.4) for treated and control animals at target slaughter live weights of 275, 375, and 475 kg, respectively, but had no effect on carcass weight. On average, cimaterol treatment decreased carcass length by 2.5 cm, hide weight by 2.75 kg, and the weight of kidney and pelvic fat by 3.5 kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1993

Long-term effects of cimaterol in Friesian steers: II. Carcass composition and meat quality.

The objectives of this study were to examine the effects of long-term administration of cimaterol to steers from 4 wk of age until slaughter at target live weights of 275, 375, and 475 kg on 1) carcass composition; 2) distribution and growth of the dissectible lean, fat, and bone; and 3) selected meat quality traits. Ninety calves were allocated to either control or cimaterol (4 ppm) treatment with 15 from each treatment scheduled for slaughter at the above target live weights. Of the 90 calves, 73 carcasses were dissected. Cimaterol increased the proportion of lean in the carcass of the three target slaughter groups from 653, 629, and 612 g/kg in control steers to 728, 728, and 723 g/kg in treated steers, respectively, and decreased the proportion of fat from 134, 169, and 197 g/kg in control steers to 88, 86, and 99 g/kg in treated steers, respectively. Cimaterol increased the longissimus muscle area from 46.4, 56.7, and 62.4 cm2 in control steers to 61.0, 73.4, and 90.8 cm2 in treated steers in the three target slaughter groups, respectively. The allometric growth coefficients for total lean, bone, and fat were .987, .869, and 1.406, respectively, for treated animals and .898, .771, and 1.654, respectively, for control animals. Cimaterol increased the 2-d drip loss and the fiber-optic probe value of longissimus muscle. Shear force values were 55, 145, and 118% higher in the treated animals in the three target slaughter groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1993

Medical and dental staffing prospects in the NHS in England and Wales 1991.

This article offers some background information to help junior doctors, and those who advise them, to make decisions about their future careers. Further information can be obtained from the Regional tables, which the Department of Health circulate to Regional Postgraduate Deans, Health Authorities and clinical tutors. All the information presented here is retrospective. Comparing this with the previous annual articles in this series may help you to assess the likely future prospects in your particular specialty.

Career Choice↗
PubMed1992

Spectral pattern discrimination by children.

This research measured the ability of 47 children, aged 4-9 years, to use spectral shape cues to discriminate among random-intensity sounds. The children were tested in forced-choice paradigms that were embedded in a video game format. Two classes of sounds were studied: tonal complexes with sinusoidally rippled amplitude spectra, and synthetic speech sounds (isolated vowels and consonants). The discriminability of the sounds was measured both in quiet and in a background of wide-band noise. Although the intersubject variability in performance was high, especially among the youngest children, the results revealed a substantial age effect. For both classes of sounds, the performance of the younger children was significantly poorer than the performance of an adult control group. However, there was no evidence in the data that the masking effect of the noise was greater for the children than for the adults.

Adolescent↗
PubMed1992

Differences in cardiac calcium release channel (ryanodine receptor) expression in myocardium from patients with end-stage heart failure caused by ischemic versus dilated cardiomyopathy.

The molecular basis for the systolic and diastolic dysfunction characteristic of end-stage heart failure in humans remains poorly understood. It has been proposed that both abnormal calcium handling and defects in the contractile apparatus may contribute to the myocardial dysfunction. Two channels, the calcium release channel (CRC) or ryanodine receptor of the sarcoplasmic reticulum (SR), and the slow calcium channel or dihydropyridine receptor (DHPR) of the transverse tubule, play key roles in regulating intracellular calcium concentration and in excitation-contraction (E-C) coupling in the heart. The DHPR serves as the voltage sensor and plasma membrane calcium channel resulting in activation of the CRC during E-C coupling in heart muscle. In this study, we investigated the levels of CRC expression in several forms of end-stage heart failure in humans. A cardiac CRC cDNA was cloned from rabbit and used as a probe for Northern blot analyses to determine mRNA levels in the left ventricles of normal (n = 4) and cardiomyopathic (n = 34) human hearts from patients undergoing cardiac transplantation. Compared with normal patients, patients with ischemic cardiomyopathy (n = 18) showed a 28% decrease in CRC mRNA levels (p less than 0.025) and patients with idiopathic dilated cardiomyopathy (n = 14) a nonsignificant 12% increase. In these same hearts, alpha-actin levels were unchanged in end-stage heart failure, as has been previously reported. This is the first report indicating that the expression of the CRC mRNA is abnormal in end-stage human heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Autoimmune disease of the ovary induced by a ZP3 peptide from the mouse zona pellucida.

We describe a novel experimental system in mice for the study of ovarian autoimmune disease, a condition encountered in women with premature ovarian failure. The ovarian autoimmune disease is induced in B6AF1 mice by a 15-amino acid peptide (Cys-Ser-Asn-Ser-Ser-Ser-Ser-Gln-Phe-Gln-Ile-His-Gly-Pro-Arg) from mouse ZP3, the sperm-binding component of the zona pellucida that surrounds growing and mature oocytes. Whereas the peptide induces both T cell and antibody responses, adoptive transfer of CD4+ T cell lines derived from affected animals causes oophoritis without observable antibodies to the zona pellucida peptide. The primacy of the T cell response in the pathogenesis of disease is further substantiated by defining oophoritogenic peptides as small as eight amino acids (Asn-Ser-Ser-Ser-Ser-Gln-Phe-Gln) that do not elicit an antibody response to the full-length ZP3 peptide. The identification of a well characterized peptide as a causative agent of autoimmune oophoritis should facilitate understanding of the pathogenesis of this T cell-mediated autoimmune disease. Because the proteins of the zona pellucida are conserved among mammals (the mouse and human ZP3 proteins are 67% identical), this murine model may lead to better understanding of the pathogenesis of human autoimmune oophoritis.

Amino Acid Sequence↗