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Biomedical subjects

M W Thompson

Publications and source records attributed to M W Thompson.

99 records · Page 6Linked to original sources
PubMedDate not supplied

Serum creatine kinase and pyruvate kinase in Duchenne muscular dystrophy carrier detection.

The incidence of elevated serum creatine kinase (CK) and pyruvate kinase (PK) activities was compared in 20 definite carriers of Duchenne muscular dystrophy (DMD), 47 possible carriers, and 42 female controls. When adult age was not regarded as a variable, 70% of the definite carriers had elevated PK, 55% had elevated CK, and 75% had elevated PK or elevated CK or both, 38% of the possible carriers had elevated PK, 19% had elevated CK, and 40% had elevated PK or elevated CK or both. The detection efficiency of the CK test was influenced by the age of the subjects: the upper normal limit of serum CK in the adult controls was at the minimum between 21 and 35 years of age, and CK activity in some carriers declined from elevated to normal levels with increasing age. With these considerations, 70% of definite carriers had elevated CK and 80% had elevated PK and/or CK; 34% of the possible carriers had elevated CK and 43% had elevated PK and/or CK. On the basis of the PK and CK measurements, only 16 of 24 possible carrier mothers were likely to be DMD carriers, implying that the other 8 were non-carrier mothers of new mutant sons.

Adolescent↗
PubMedDate not supplied

Creatine kinase isozyme transition in chicks with hereditary muscular dystrophy.

In both normal chicks and chicks with hereditary muscular dystrophy the BB (brain) and MB (hybrid) isozymes were the predominant forms of creatine kinase (CK) activity in embryonic skeletal muscle. As myogenesis progressed, activity due to the MM (muscle) isozyme progressively increased, and by 1 week ex ovo, the MM isozyme accounted for approximately 97% of total muscle activity in both genotypes. During this time, the proportion of the MM isozyme was slightly but significantly lower in dystrophic muscles. After hatching the proportion of the MB isozyme and its total activity decreased in normal muscle, but increased in dystrophic pectoral muscle, and by 5 months ex ovo, the MB isozyme accounted for 10% of total CK activity. Prior to hatching there was no consistent difference in total CK activity between normal and dystrophic tissues, but by 1 week after hatching and thereafter, total CK activity was significantly lower in dystrophic pectoral muscle.

Aging↗
PubMedDate not supplied

Malposition of pediatric gastric lavage tubes demonstrated radiographically.

Gastric lavage may be indicated in the initial treatment of toxic substance ingestion. We retrospectively surveyed the charts of 36 pediatric patients who underwent gastric lavage to evaluate the clinical and radiographic evidence indicating proper tube placement. Only 14 patients had a radiograph prior to lavage, and 50% of these documented malposition. The most common was excess tube insertion, stretching the stomach inferiorly towards the pelvis. The traditionally acceptable clinical test by auscultation of insufflated air was favorable in 100% of patients, thus failing to detect all of the malpositionings documented radiographically. We suggest that initial insertion of tube length be based on the patient's height or length using an adaptation of Strobel's previously published formula for esophageal pH probe placement: Tube Insertion Depth (TID), orogastric = 9.7 cm + (0.226 x length of patient in cm) and TID, nasogastric = 8 cm + (0.252 x length of patient in cm). These formulae have been displayed in graphic form for easy use. Diagnostic imaging remains the only certain means to document tube placement. Prospective studies to validate the formulae in clinical use are ongoing.

Adolescent↗
PubMedDate not supplied

Cloning of the breakpoint of an X;21 translocation associated with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder which affects approximately 1 in 3,300 males, making it the most common of the neuromuscular dystrophies. The biochemical basis of the disease is unknown and as yet no effective treatment is available. A small number of females are also affected with the disease, and these have been found to carry X; autosome translocations involving variable autosomal sites but always with a breakpoint within band Xp21 of the X chromosome (implicated by other kinds of genetic evidence as the site of the DMD lesion). In these female patients the normal X chromosome is preferentially inactivated, which it is assumed silences their one normal DMD gene, leading to expression of the disease. In one such affected female the autosomal breakpoint lies in the middle of the short arm of chromosome 21, within a cluster of ribosomal RNA genes. Here we have used rRNA sequences as probes to clone the region spanning the translocation breakpoint. A sequence derived from the X-chromosomal portion of the clone detects a restriction fragment length polymorphism (RFLP) which is closely linked to the DMD gene and uncovers chromosomal deletions in some male DMD patients.

Animals↗
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Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗
PubMedDate not supplied

Clinical nurse specialist: making the shift from critical care to home care.

Because patients are being discharged earlier with more complex medical and nursing needs, now is the time for Critical Care Clinical Nurse Specialists to consider home care as a viable practice arena. The home-care Clinical Nurse Specialist role offers exciting, non-traditional job opportunities that may add a dimension to your practice that you will truly enjoy.

Career Mobility↗