PubMed Health⌕ Search

Biomedical subjects

M Moffat

Publications and source records attributed to M Moffat.

At least 19 recordsLinked to original sources
PubMed2001

Anatomical variations of the scalene triangle: dissection of 10 cadavers.

STUDY DESIGN: Cadaver dissection to study the anatomy of the scaleni muscles and surrounding structures. OBJECTIVES: To analyze in depth the anatomy of the scaleni muscles and surrounding structures, and to further document anatomical variations which have been reported in the literature. BACKGROUND: The literature reported variations in the attachments of the scaleni muscles, as well as the presence of a scalenus minimus muscle. The importance of these muscles in the respiratory and musculoskeletal systems led us to study these muscles with dissection. METHODS AND MEASURES: We performed anatomical dissection on 10 cadavers. The findings from the cadavers were analyzed and reported. RESULTS: The attachments of the 3 primary scaleni muscles (anterior, medius, and posterior) were variable. The actual width of the scaleni muscles (anterior, medius, and posterior) at the C6 tubercle and at the first rib also varied. A scalenus minimus was present in one cadaver and presumably present in 2 others. The scalenus anterior muscle arose in 20% of the specimens from C3 to C6, in 30% of the specimens from C3 to C7, in 20% of the specimens from C4 to C5, and in 30% of the specimens from C4 to C6. The scalenus anterior muscle arose from C3 in 50% of the dissections. An attachment to C7 was observed in 30% of the cadavers. The widths of the scalenus anterior muscles at their insertion were between 8 and 17 mm. The scalenus medius muscle arose in 40% of the specimens from C2 to C6. In 60% of the cadavers, the scalenus medius muscle had an attachment to C7. Fifty percent of the scalenus medius muscles arose from C2 and 50% also had an origin from C1. The widths of the scalenus medius muscles at their insertion were between 10 and 20 mm with a mean of 15.5 mm. Fifty percent of the scalenus posterior muscles arose from C4 to C6 and 50% arose from C5 to C6. CONCLUSIONS: Variations were found in the attachments and the size of the scaleni muscles. These variations may effect the size of the scalene triangle, and thus, may potentially result in varied signs and symptoms in patients who have cervical, thoracic, and rib dysfunctions. Clinical implications were postulated.

Cadaver↗
PubMed1999

Injuries in the adolescent population in Scotland: patterns and types of injuries sustained.

OBJECTIVE: To provide information on the incidence, sex distribution, type, site and severity of injuries requiring medical attention reported in a nationally representative sample of Scottish teenagers studied longitudinally. DESIGN: Health visitors administered structured interviews with parents (usually mothers). Quantitative data were analysed using SPSS-PC, and qualitative and textual data were coded using the Abbreviated Injury Score (AIS). SETTING: Scotland. SUBJECTS: Responses were received in respect of 958 (68%) of the estimated 1,416 teenagers enrolled in the British Cohort Study (BCS 70), and resident in Scotland in 1986/7. RESULTS: 43% of subjects were reported as having experienced one or more unintentional injury events requiring medical attention between the ages of 10 and 16/17. Boys experienced significantly more injuries than girls. Neither social class nor region appeared to be a significant risk factor for reported injury. CONCLUSION: Patterns of accidents in Scottish adolescents are reported. Further areas for study are suggested.

Adolescent↗
PubMed1997

L-Dopa and dopamine-producing gene cassettes for gene therapy approaches to Parkinson's disease.

As an aid in the development of vector systems for use in gene therapy paradigms of central nervous system disorders such as Parkinson's disease, we have developed L-Dopa or dopamine-producing gene cassettes. Specifically, a human tyrosine hydroxylase cDNA (HTH-2) was rendered constitutively active by truncation of the N-terminal regulatory domain (tHTH). In addition, a bicistronic construct capable of directing the production of dopamine was created by inserting an internal ribosome entry site downstream of tHTH followed by the coding sequences of aromatic amino acid decarboxylase. All three constructs generated immunoreactive peptides of the predicted size, were enzymatically active, and produced L-Dopa (HTH-2, tHTH) or dopamine (bicistronic construct) following transient transfection of COS-7 cells. These constructs, in conjunction with viral or nonviral expression systems, may be efficacious in gene therapy approaches to Parkinson's disease.

Animals↗
PubMed1996

A herpes simplex virus-1 vector containing the rat tyrosine hydroxylase promoter directs cell type-specific expression of beta-galactosidase in cultured rat peripheral neurons.

A defective herpes simplex virus-1 (HSV-1) vector system was used to study cell type-specific expression of the tyrosine hydroxylase (TH) gene. HSV-1 particles containing 663 bp (pTHlac 663), 278 bp (pTHlac 278), or 181 bp (pTHlac 181) of the rat TH promoter driving E. coli LacZ were used to infect superior cervical ganglia (SCG: TH-expressing tissue) and dorsal root ganglia (DRG:non-TH-expressing tissue) cultures. One day after infection, expression of beta-galactosidase was visualized by X-gal cytochemistry. Following viral transduction with pTHlac 663 at a multiplicity of infection of 0.2, 14.4% of the SCG neurons were X-gal positive whereas only about 0.9% of DRG neurons were X-gal positive. Infection with either pTHlac278 or 181 resulted in 3-fold more X-gal-positive DRG neurons. These results suggest that (i) the defective HSV-1 vector system may be useful in defining regulatory promoter motifs; (ii) 663 bp of the rat TH promoter contains sufficient information for cell type-specific expression in peripheral nervous system neurons; and (iii) sequences between -278 and -663 contain an element(s) that represses gene expression in non-catecholamingeric neurons.

Animals↗
PubMed1995

Overexpression of Bcl-2 attenuates MPP+, but not 6-ODHA, induced cell death in a dopaminergic neuronal cell line.

In order to investigate the role of Bcl-2 in dopaminergic cells, we established a dopaminergic neuronal cell line (MN9D) stably expressing human Bcl-2 (MN9D/Bcl-2) or neomycin (MN9D/Neo). Overexpression of Bcl-2 in MN9D cells attenuated cell death due to treatment of mitochondrial electron transport inhibitors including N-methyl-4-phenylpyridinium, whereas it did not prevent cell death induced by reagents generating reactive oxygen species including 6-hydroxy-dopamine. Moreover, the rate of glucose uptake in MN9D/Bcl-2 was significantly lower than that in MN9D/Neo after MPP+ treatment. Thus, Bcl-2 may counter aberrations in mitochondrial electron transfer processes by altering energy metabolism within the MN9D cells.

1-Methyl-4-phenylpyridinium↗
PubMed1995

Is Bell's palsy a reactivation of varicella zoster virus?

Despite various pointers to an infectious aetiology, the cause of Bell's palsy remains obscure. We examined paired sera from 62 patients with facial palsy and 50 age and sex matched contemporaneous controls. Significantly more patients than controls had IgM antibodies by ELISA to varicella zoster virus (56.5% vs. 20%, P = 0.0001) and herpes simplex virus (41.9% vs. 18%, P = 0.006). Additionally, significantly more patients than controls were positive for CF antibody to varicella zoster virus (14.5% vs. 0%, P = 0.004) but not to herpes simplex or cytomegalovirus. Significantly more controls than patients (54% vs. 25.8%, P = 0.002) had no evidence of antigenic stimulation by any of the herpesvirus group. No significant difference between patients and controls in seropositivity by IgM ELISA to cytomegalovirus. Epstein-Barr virus and IFA for human herpes virus 6 was found. Furthermore, there was no significant difference between the two groups as to evidence of recent infection by the following agents: rubella virus and Borrelia burgdorferi by IgM ELISA, influenza A. influenza B, adenovirus, respiratory syncytial virus, mumps and measles. Mycoplasma pneumoniae, Coxiella burnetii and chlamydia spp. by complement fixation test. The first reported case of clinically and serologically proven Mycoplasma pneumoniae pneumonia associated with Bell's palsy is described. The rate of complete recovery at 6-8 weeks after onset was not significantly different in patients who were given steroids compared to those who were not. Ear related symptoms were the most common, occurring in 12 of 65 cases, but only three (4.6%) had clinical shingles (vesicles in ear).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

The human aromatic L-amino acid decarboxylase gene can be alternatively spliced to generate unique protein isoforms.

Aromatic L-amino acid decarboxylase (AADC) is expressed in a wide variety of tissues, including those where it is known to convert L-DOPA and 5-hydroxytryptophan to dopamine and serotonin, respectively. AADC has been cloned from many species and shown to undergo alternative splicing within its 5' untranslated region. Here, we report that the human AADC gene can undergo additional alternative splicing of exon 3, generating two different protein isoforms (termed AADC480 and AADC442). Both transcripts are widely expressed, with AADC442 predominating in many neuronal and nonneuronal tissues. When homogenates were prepared from COS-7 cells transfected with expression vectors containing either cDNA, AADC480 catalyzed the decarboxylation of both L-DOPA and 5-hydroxytryptophan. AADC442 was inactive in either assay. These findings suggested that AADC442 may have a different function in non-monoamine-expressing tissues. Taken together, these results suggest that the human AADC gene undergoes complex processing, leading to the formation of both tissue-specific transcripts as well as unique protein isoforms.

5-Hydroxytryptophan↗
PubMed1992

Case mix management education in a Canadian hospital.

The Sunnybrook Health Science Centre's matrix organization model includes a traditional departmental structure, a strategic program-based structure and a case management-based structure--the Clinical Unit structure. The Clinical Unit structure allows the centre to give responsibility for the management of case mix and volume to decentralized Clinical Unit teams, each of which manages its own budget. To train physicians and nurses in their respective roles of Medical Unit directors and Nursing Unit directors, Sunnybrook designed unique short courses on financial management and budgeting, and case-costing and case mix management. This paper discusses how these courses were organized, details their contents and explains how they fit into Sunnybrook's program of decentralized management.

Cost Allocation↗
PubMed1991

Activated neutrophils depress myocardial function in the perfused rabbit heart.

OBJECTIVE: To examine the effect of activated neutrophils on myocardial function in the absence of ischemic and/or reperfusion injury. DESIGN: Studies were carried out in five groups of Langendorff perfused rabbit hearts: control; nonactivated rabbit neutrophil infusion; phorbol myristate acetate-activated rabbit neutrophil infusion; nonactivated human neutrophil infusion; and phorbol myristate acetate-activated human neutrophil infusion. RESULTS: Both groups receiving activated neutrophils showed significant deterioration in ventricular force, rate of ventricular force development (dF/dt) and rate of ventricular relaxation (-dF/dt), and significant increases in coronary vascular resistance. Myocardial lipid peroxidation was assessed but there was no significant difference among groups. Myocardial prostacyclin production was significantly increased in hearts receiving the phorbol myristate acetate-activated human neutrophil infusion. CONCLUSION: It is concluded that myocardial perfusion with activated neutrophils results in depression of myocardial function and an increase in coronary vascular resistance even in the absence of ischemic/reperfusion injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Species and regional differences in the expression of cell-type specific elements at the human and rat tyrosine hydroxylase gene loci.

The expression of the catecholamine biosynthetic enzyme, tyrosine hydroxylase (TH), is confined to several different types of neuroendocrine cells. Using a transient assay system, we examined more than 10 kb of the human TH gene and 6.5 kb of 5' flanking sequences of the rat TH gene for DNA elements that confer cell-type specific expression. Surprisingly, these elements do not appear to be conserved in position or sequence across species. When plasmids containing DNA sequences - 749 bp from the transcription start site of the rat gene were introduced into PC12 cells, up to sixfold higher levels of expression were observed as compared to the same fragments introduced into HepG2 cells or LAN-1 cells. In contrast to the rat gene, analogous fragments of the human 5' promoter failed to confer cell-type specific expression. However, when plasmids containing a truncated thymidine kinase promoter and either orientation of a 760 by 3' human TH gene fragment were introduced into PC12 and LAN-1 cells, we observed a six- and 3.5-fold increase, respectively, over that observed for HepG2 cells. Subsequent deletion of this fragment led to significant activation of transcription in PC12 and HepG2 cell lines. These data indicate the presence of multiple elements contributing to the cell-type specific expression of tyrosine hydroxylase genes.

Adrenal Gland Neoplasms↗
PubMed1985

Isometric torque of the quadriceps femoris after concentric, eccentric and isometric training.

Twenty-seven normal, healthy women participated in this study, which investigated three methods of increasing the isometric strength of the quadriceps femoris through a six-week training program. Three experimental exercise groups were formed: A, eccentric, B, concentric, and C, isometric. The peak isometric torque of the quadriceps femoris was determined on the Cybex II Isokinetic Dynamometer before and after training. A total of 18 exercise sessions per subject were held. A two-way ANOVA with repeated measures revealed that while all three experimental groups significantly increased in isometric strength, no one method of training was superior. No interaction occurred in the population between the effects of pre- and posttraining scores and the type of training. The relationship between the experimental design and knee joint biomechanics may have precluded significant differences in strength gain among the experimental groups.

Adult↗