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Biomedical subjects

M Harris

Publications and source records attributed to M Harris.

At least 361 records · Page 20Linked to original sources
PubMed1993

Has social psychiatry met its Waterloo? Methodological and ethical issues in a community study.

The first wave of a longitudinal and prospective community study of minor psychiatric disorder among a cohort of socially disadvantaged women has been completed. The study hopes to extend the social model of depression, as initially proposed by Brown and Harris [1], by examining the mediating effects of personality factors and social support. Findings from previous studies have been largely restricted to associations between variables which may be at least partly attributable to methodological limitations in design and measurement techniques: specifically, the use of inherently biased sampling methods, single interview, retrospective data collection and less standardized diagnostic criteria to determine caseness. This paper discusses design strategies which were adopted to reduce the confounding between variables resulting from these limitations. The effectiveness of these strategies is evaluated in light of some methodological and ethical issues which have arisen during the recruitment of participants and the first wave of data collection.

Adult↗
PubMed1993

Warning signal detection and the acoustic environment of the motorcyclist.

A two-part study was undertaken to investigate warning signal detection by motorcyclists. First the acoustic environment was established for both the helmeted and bareheaded rider between speeds of 0 and 100 mph. For the helmeted rider it was found that below 20 mph vehicle noise was dominant and between 20 and 40 mph there was a variable contribution from both vehicle and wind noise. At 40 mph wind noise became the dominant sound source and increased linearly with the log10 of speed from 90 dB(A) to reach 112 dB(A) at 100 mph. Sound levels were consistently 18 dB(A) greater for the bareheaded rider once above 10 mph, and followed a similar pattern. Recordings of these sounds were sampled into an Amiga computer. Suitable sound combinations were played back at levels appropriate to speed to recreate the rider's acoustic environment at differing speeds. The minimum detection level (MDL) of four traffic warning signals was then measured in 19 normal hearing subjects for three test conditions: no helmet, helmet and helmet with earplugs. The MDL for all warning signals was lowest with a crash helmet in place for sound levels equivalent to speeds of 30 mph or less. The addition of earplugs led to significant reductions in MDLs at sound levels equivalent to speeds of 40 mph, or greater. Signal detection was poorest at all speeds greater than 0 mph, when bareheaded. We would conclude that earplugs are not required for motorcyclists in the urban environment.(ABSTRACT TRUNCATED AT 250 WORDS)

Accident Prevention↗
PubMed1993

The personal health record. Making it work better for general practitioners.

Personal Health Records held by parents are an important initiative towards improved child health in Australia. Although they have now been introduced in most States and Territories, few general practitioners make full use of them. A recent major study conducted in New South Wales suggests ways in which their use and usefulness can be improved for general practitioners.

Attitude of Health Personnel↗
PubMed1993

Immunophenotype and ultrastructure of alveolar soft part sarcoma.

Nine cases of alveolar soft part sarcoma were studied in terms of their immunoreactivity towards intermediate filaments and muscle markers, and their ultrastructure with regard to muscle features and the cytoplasmic crystals characteristic of this tumour. Inconsistent expression of alpha-smooth muscle actin, vimentin and desmin were found. No unambiguous muscle cell characteristics were identified by electron microscopy, although multiple subplasmalemmal densities with overlying lamina were emphasised as a typical but not specific muscle feature. Classical alveolar soft part sarcoma crystals at the ultrastructural level were absent throughout, but pseudo-crystals with a pre-crystalline finely filamentous content were numerous in one case. The results were integrated into a comprehensive comparison with the literature. It is clear that immunohistochemical evidence of striated muscle differentiation is detectable in some but not all cases of ASPS. The detection of Myo D1 protein in the small numbers of ASPSs so far studied for this gene product raises the possibility that in the majority of ASPSs this is the only evidence of early striated muscle differentiation and that only in the minority is it able to induce desmin production. Study of a substantial series for Myo D1 is required to explore this possibility.

Actins↗
PubMed1993

Long-term use of computerized bicycle ergometry for spinal cord injured subjects.

Twenty-eight spinal cord injured subjects who participated in an electrical stimulation bicycle ergometry home program were surveyed to determine perceived benefits, home exercise adherence, and predictors of continued home exercise with electrical stimulation. Subjects were classified as users or nonusers depending upon if they used the electrical stimulation ergometry on a regular basis in the home during the past four months. Nineteen subjects qualified as users and nine were nonusers. Ninety-five percent of the users cycled at least twice per week whereas the majority of the nonusers stopped regular home exercise within one month postclinic discharge. All subjects generally perceived increases in muscle bulk and endurance. Users and nonusers perceived inconsistent results related to spasticity. Minimal effects were noted with neurogenic pain and swelling. Adherence to the home exercise program was significantly related to sex of subject and pre-injury exercise habits. Results are discussed in relation to the costs and benefits of electrical stimulation bicycle ergometry in the home.

Adolescent↗
PubMed1993

A linkage study in seven breast cancer families.

Seven breast cancer families are examined for evidence of linkage to a site in the region of 17q12-q21, by using five markers. The families constitute a subset of a larger series of familial breast cancer; the seven families were selected because constitutional DNA was available on informative members, either from clinical samples or extracted from paraffin blocks. Two-point lod scores are reported. The maximum lod score, 0.8824, is obtained with marker NM23 at theta = 0. This is clearly not significant in itself; however, when taken in context with evidence from existing reports, it provides support for linkage to this region.

Adult↗
PubMed1992

Acute myeloid leukemia (AML) in Down's syndrome is highly responsive to chemotherapy: experience on Pediatric Oncology Group AML Study 8498.

The treatment of acute myeloid leukemia (AML) in children with Down's syndrome (DS) has engendered considerable controversy. Because of the concerns for toxicity and increased rate of infections, treatment approaches varied considerably in the past with mixed results. However, experience on the recently completed Pediatric Oncology Group (POG) 8498 AML study suggests that DS children with AML constitute a distinct subgroup that responds well to therapy. Twelve of 285 children on POG 8498 (protocol for newly diagnosed AML) had DS. Children with DS and AML were predominantly male (9 of 12) and were quite younger at diagnosis (< 24 months in 10). The white blood cell count was less than 50 x 10(3)/microL in all 12 and French-American-British types M6 and M7 were frequent (5 of 12). An abnormal cytogenetic marker, in addition to constitutional trisomy 21, was present in 9 of 12 and involved chromosome 8 in 4 of 9. All cases studied (n = 5) were positive for myeloid cell surface markers (CD33, CD13, or CD11b) and, interestingly, were also positive for the CD7 antigen. Chemotherapy included daunorubicin, cytarabine (Ara-C), and 6-thioguanine for remission induction and featured high-dose Ara-C (3 g/m2 per dose) with or without L-asparaginase early in remission. Compared with children without DS, children with DS had a superior event-free survival (EFS at 4 years 100% v 28% +/- 6.2%; P = .003). The EFS remained superior even when compared with non-DS children less than 2 years of age with a white blood cell count less than 10 x 100,000/microL (100% v 48% +/- 17.3%; P = .01).

Acute Disease↗
PubMed1992

Randomised trial of cardiotocography alone or with ST waveform analysis for intrapartum monitoring.

It is possible to record the fetal electrocardiographic waveform (ECG) from the scalp electrode used in labour for detection of fetal heart rate. Animal and observational studies of changes in the ST waveform of the ECG during hypoxia suggest that a combination of heart rate and ST waveform analysis might improve the predictive value of intrapartum monitoring. In a randomised trial, we have studied intervention rates and neonatal outcome for high-risk labours monitored either by conventional cardiotocography (CTG) or by ST waveform analysis plus CTG. 1200 women with pregnancy of at least 34 weeks' gestation were assigned to the groups when the decision to apply a fetal scalp electrode was made. Neonatal outcome was assessed by umbilical-cord blood gas analysis, Apgar scores, resuscitation needed, and postnatal course. All recordings were retrospectively viewed by an observer unaware of clinical details to check adherence to the trial protocol. The addition of ST waveform monitoring to CTG substantially reduced the proportion of deliveries for fetal distress (ST + CTG 27/615 vs CTG 58/606; p less than 0.001). The groups did not differ in rate of operative delivery for other reasons, incidence of asphyxia at birth, or neonatal outcome. Metabolic acidosis and low 5 min Apgar scores were less common in the ST + CTG than the CTG group, but not significantly so. The only case of birth asphyxia in the ST + CTG group was identified by both heart rate and ST changes. The review of recordings showed that the reduction in intervention rate was among cases with CTG patterns classified as normal or intermediate, whereas there was no difference in intervention rates among cases with abnormal recordings. Our findings confirm that ST waveform analysis discriminates CTG changes in labour and that our protocol for interpretation is safe. Further randomised studies are warranted.

Adult↗
PubMed1992

Relationship between immune response to melanoma vaccine immunization and clinical outcome in stage II malignant melanoma.

The authors investigated whether there was a relationship between the induction of a delayed-type hypersensitivity (DTH) response to melanoma vaccine immunization and disease recurrence. They studied prospectively 94 evaluable patients with surgically resected Stage II malignant melanoma who were immunized to a partially purified, polyvalent, melanoma antigen vaccine. The DTH response to skin tests to the vaccine was measured before treatment and at the fourth vaccine immunization. Vaccine treatment induced a strong DTH response in 29 (31%) patients, an intermediate response in 24 (25%), and no response in 41 (44%). The median disease-free survival (DFS) of patients with a strong, intermediate, and no DTH response to vaccine immunization was more than 72 months, 24 months, and 15 months, respectively. The relationship between an increase in the DTH response and a prolonged DFS was statistically significant (P = 0.02); clinically meaningful (the median DFS of patients with a strong DTH response was 4.7 years longer than that of nonresponders); and, by multivariate analysis, independent of disease severity or overall immune competence. These findings suggest, but do not prove, that vaccine treatment can slow the progression of melanoma in some patients.

Adult↗
PubMed1992

Evaluation of CHIP (iproplatin) in recurrent pediatric malignant solid tumors. A phase II study (Pediatric Oncology Group).

CHIP (325 mg/M2), a second generation cisplatin derivative, was administered intravenously every 3 weeks to 85 pediatric patients with recurrent sarcomas (19), osteosarcomas (20), neuroblastoma (23), germ cell tumors (10), and other malignant tumors (7). Thirty-eight of them had been previously exposed to cisplatin. Partial remissions were only observed in 3 of 23 (13% SE = 7%) patients having neuroblastoma. Severe thrombocytopenia (65%) and neutropenia (35%) were the dose limiting factors.

Adolescent↗
PubMed1992

Interleukin-1: the principal osteolytic cytokine produced by keratocysts.

Fragments of keratocysts removed at operation were maintained in explant culture and the media were assayed for the biological activity of the potent osteolytic cytokines--interleukin (IL)-1, interleukin (IL)-6 and tumour necrosis factor (TNF). Media were also assayed for their ability to stimulate bone resorption. All six cysts examined released IL-1 and IL-6 bioactivity but TNF bioactivity was unmeasurable. Dialysed cyst media stimulated bone resorption and this could be completely inhibited by a monospecific antibody which neutralized IL-1 alpha and IL-1 beta. Immunohistochemical staining of cryostat sections of keratocysts revealed the presence of IL-1 alpha and IL-6 in cyst epithelial cells but not in other cell types. Sections did not react with antibodies to IL-1 beta or TNF. It is therefore proposed that IL-1 alpha is the major osteolytic cytokine produced by keratocysts and that IL-6 and IL-1 may contribute to keratocyst growth by promoting epithelial cell proliferation and bone resorption, respectively.

Adult↗
PubMed1992

6-Methyl-1,3,8-trichlorodibenzofuran (MCDF) as an antiestrogen in human and rodent cancer cell lines: evidence for the role of the Ah receptor.

6-Methyl-1,3,8-trichlorodibenzofuran (MCDF) is a relatively nontoxic analog of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Treatment of aryl hydrocarbon (Ah)-responsive MCF-7 human breast cancer cells with 100 nM MCDF resulted in the inhibition of 17 beta-estradiol-induced proliferation and the secretion of the 34-, 52-, and 160-kDa proteins. After treatment of the cells with 17 beta-[3H]estradiol, 100 nM of MCDF caused a decrease in the accumulation of the radiolabeled nuclear estrogen receptor (ER) complex in these cells. In parallel experiments, the antiestrogenic effects of MCDF were also determined in Ah-responsive wild-type Hepa 1c1c7 cells and Ah-nonresponsive class 1 and class 2 mutant cells. Treatment of the wild-type cells with 17 beta-[3H]estradiol and 100 nM MCDF caused a decrease in the accumulation of radiolabeled nuclear ER complex in these cells whereas no significant effects were observed in the mutant cells as determined by velocity sedimentation analysis. Comparable results were obtained using ER antibodies to measure the decrease in immunoreactive nuclear ER. In addition, both actinomycin D and cycloheximide inhibited the MCDF-mediated decrease of nuclear ER levels in the Hepa 1c1c7 wild-type cells. Although 100 nM MCDF did not induce cytochrome P-450-dependent monooxygenases in the MCF-7 or Hepa 1c1c7 cell lines, incubation of nuclear extracts from the MCF-7 cells treated with 100 nM MCDF with a synthetic consensus dioxin responsive element (an oligonucleotide duplex of 26 bases) gave a retarded band in a gel-retardation assay. The data suggest that the antiestrogenic effects of MCDF does not require the induction of the CYP1A1 gene expression but may involve the induction of other genes.

Animals↗
PubMed1992

Retinal speed gradients and the perception of surface slant.

Previous work has demonstrated a difference in human sensitivity to compressive and shearing speed gradients. This raises the possibility that the ability to estimate the slant of a surface may vary with its direction of tilt. No such variance was found here, which may indicate that slant estimation depends upon deformation rather than upon compression or shear.

Humans↗
PubMed1992

The conservative management of osteoradionecrosis of the mandible with ultrasound therapy.

A regimen of ultrasound with local debridement and metronidazole has proved to be an effective and practicable treatment for osteoradionecrosis, achieving healing in 10/21 (48%) cases without the need for surgery or sophisticated technology. Nine further patients were successfully treated by covering the preserved mandible with a local intra-oral flap. Only 2 patients required mandibular resection with reconstruction. An ultrasound programme of 1 watt/cm2, 3 mega Hz. pulsed 1:4, 15 min a day for 60 days would seem to be optimum. However, a range of dosage needs to be further explored for inducing neovascularity and neocellularity in the irradiated tissues.

Brachytherapy↗