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Biomedical subjects

T L Munsat

Publications and source records attributed to T L Munsat.

At least 55 records · Page 3Linked to original sources
PubMed1992

Needle muscle biopsy with the automatic Biopty instrument.

Needle muscle biopsies are less traumatic and easier to do than open biopsies, but their main disadvantage is the small specimen size. One hundred and five patients underwent needle biopsies with a 14-gauge spring-loaded device that guillotines the muscle automatically (Bard Radiology). Fifty patients had more than one muscle biopsy. One hundred and forty-six of 155 specimens contained over 200 muscle fibers, some as many as 500 fibers. Having evaluated various needles, we found the Bard Biopty instrument more efficient than manual needles and open biopsy techniques, and it provides muscle specimens for pathologic interpretation that are comparable with open surgical procedures.

Adult↗
PubMed1992

Intrathecal thyrotropin-releasing hormone does not alter the progressive course of ALS: experience with an intrathecal drug delivery system.

Evidence that thyrotropin-releasing hormone (TRH) has prominent trophic effects on the motor system led to several negative therapeutic trials in amyotrophic lateral sclerosis, a disease of the motor system. Since TRH crosses the blood-brain barrier poorly, if at all, we postulated that the negative parenteral clinical trials could be a result of insufficient drug-receptor interaction. We thus carried out a blinded, placebo-controlled, crossover study of intrathecal TRH in 36 patients by delivery through an implanted, constant infusion pump achieving a steady-state CSF level comparable with that shown to be effective in tissue culture experiments. Utilizing a quantitative measurement technique to assess motor unit loss, we did not observe any alteration of the progressive course during 6 months on TRH and 6 months on saline placebo. However, the implanted pump delivery system proved to be safe, reliable, and well tolerated.

Adult↗
PubMed1991

Spinal muscular atrophy is not the result of mutations at the beta-hexosaminidase or GM2-activator locus.

The disease locus for the clinically heterogeneous childhood spinal muscular atrophies (SMA) maps to the chromosome 5 subregion, 5q11.2-13.3. The beta-subunit of beta-D-N-acetylhexosaminidase (hexosaminidase) (EC 3.2.1.52) (Hex B) maps to the same region, and the protein required for substrate recognition by this enzyme, GM2-activator protein, likewise maps to chromosome 5. We have investigated the possibility of allelic variation among some forms of SMA and hexosaminidase deficiency. Recombination between the Hex B and SMA loci eliminates this enzyme as a candidate site for defects causing the illness. Furthermore, we show that, despite previous evidence to the contrary, the GM2-activator locus does not map to chromosome 5, thereby eliminating it as a candidate gene for SMA.

Amino Acid Sequence↗
PubMed1990

Phenotypic heterogeneity of spinal muscular atrophy mapping to chromosome 5q11.2-13.3 (SMA 5q).

We made phenotypic analysis of 14 families with spinal muscular atrophy (SMA) linking to chromosome 5q11.2-13.3 (SMA 5q), and 2 that may not map to this locus, to assess clinical symptoms among SMA families known to result from mutation at the identical gene/locus. Although the current number of families is still small, the correlation of clinical phenotype and molecular genotype supports 2 observations. First, SMA mutations at the 5q locus present with a broad continuum of clinical abnormalities, and 2nd, the single clearly unlinked family presents with an unusual phenotype characterized by relatively late onset and early death. Thus, there are as yet no unambiguous cases of typical SMA families that are clearly unlinked to the locus at 5q-ie, no clear cases of nonallelic heterogeneity. Analysis of SMA 5q families supports the view that, with certain exceptions, there is little phenotypic intrafamilial variability. When families were ranked by severity of disease there was a strong correlation with age of onset. Onset within the 1st few months was associated with early death, but not in all cases. With rare exception, onset after 1 year of age was associated with less severe disease and greater longevity.

Chromosome Mapping↗
PubMed1989

Linkage analysis in familial amyotrophic lateral sclerosis.

Familial amyotrophic lateral sclerosis (FALS) constitutes 5 to 10% of cases of ALS and, in most families, its inheritance is consistent with an autosomal dominant trait with age-dependent penetrance. The biochemical abnormality underlying the disorder is unknown. We analyzed DNA from 131 members of 6 multigenerational ALS families, which included 13 affected members, for genetic linkage to 39 expressed and DNA markers, using the techniques of 2-point linkage analysis, multilocus linkage analysis, and exclusion mapping. We identified FALS families with structures suitable for linkage, by computer simulation techniques. A DNA bank established to provide optimum use of available FALS families provided DNA from immortalized lymphoblast cell lines and frozen postmortem tissue. We could not link FALS to any of the markers studied, but excluded chromosome regions unlikely to be a locus of the FALS gene. With the help of this exclusion data, we will concentrate on regions of the human genome that remain unexcluded.

Amyotrophic Lateral Sclerosis↗
PubMed1988

Response to total body irradiation in dermatomyositis.

There were two patients with severe dermatomyositis refractory to immunosuppressive therapy treated with 150 rad of total body irradiation given over a period of 5 weeks. Both patients responded promptly with minimal side-effects and remain in partial remission 42 and 18 months after completion of the treatment. Total body irradiation is effective in some patients with dermatomyositis who are refractory to standard therapy.

Adult↗
PubMed1988

Use of composite scores (megascores) to measure deficit in amyotrophic lateral sclerosis.

The Tufts Quantitative Neuromuscular Exam (TQNE) consists of 28 items that were designed to measure voluntary motor deficit in amyotrophic lateral sclerosis (ALS) and related diseases. Individual raw data were converted to Z scores for standardization and then grouped into five megascores with statistical and clinical relevance. The derived megascores were Mega 1, pulmonary function; Mega 2, bulbar function; Mega 3, timed hand activities; Mega 4, isometric arm strength; and Mega 5, isometric leg strength. Megascores should enhance the usefulness of testing in therapeutic trials and in analyzing the natural history of ALS and related diseases.

Amyotrophic Lateral Sclerosis↗
PubMed1988

The natural history of motoneuron loss in amyotrophic lateral sclerosis.

Using a quantitative, reliable, sensitive and valid measurement technique, we analyzed the rate and pattern of motor deterioration in 50 strictly defined ALS patients for up to 67 months. We observed that the rate of motoneuron loss was linear and symmetric. Bulbar function deteriorated more slowly than respiratory, arm, and leg function. The loss of leg strength was slower than in the arm. No correlation was observed between age at onset and rate of deterioration, or with different regions of onset. Arm strength changed more slowly in women, but other functions showed no male-female differences. These data should prove useful in the design of clinical trials and in generating testable hypotheses of the etiology of this disease.

Adolescent↗