Search PubMed⌕ Search

Biomedical subjects

S G Kaler

Publications and source records attributed to S G Kaler.

32 records · Page 2Linked to original sources
PubMed1993

Application of a copper blotting method to the study of Menkes disease.

Menkes disease is an X-linked recessive disorder of copper metabolism. Deficient quantity or functional activity of a molecule involved in intracellular copper transport is believed to represent the basic defect. We applied an in vitro copper binding assay (copper blotting) to tissue proteins from Menkes patients and controls to evaluate differences in copper-binding. Proteins were separated by SDS-PAGE, electrotransferred to nitrocellulose, and probed with 67CuCl2. Copper-binding polypeptides were visualized by autoradiography. No major differences were observed between a Menkes patient and control subjects in copper blots of post-mortem liver, kidney, or brain--tissues affected clinically by the disturbance of copper metabolism in Menkes disease. We also applied the copper blotting technique to fibroblast proteins from an affected female in whom the gene responsible for Menkes disease is interrupted by a chromosomal translocation, and detected no differences in copper-binding proteins relative to normal controls. These experiments suggest that the gene product defective in Menkes disease is not detectable in copper blots, either because normal tissue levels are below the limits of detection of this method, or because the molecule involved does not bind copper under these conditions.

Autoradiography↗
PubMed1993

Spectrum of EEG findings in Menkes disease.

We evaluated electroencephalograms (EEGs) in 10 boys with Menkes disease, ranging in age from 9 days to 27 months. Three of 10 tracings were normal (the newborn, his 27-month-old half-brother with the classic phenotype, and a 27-month-old mildly affected patient). Plasma copper levels were low in all patients except the newborn and tended to be lowest in patients whose EEGs were moderately or severely abnormal. EEG differences in Menkes patients could reflect biochemical and molecular heterogeneity with respect to copper availability and utilization in the brain.

Child, Preschool↗
PubMed1993

Gastrointestinal hemorrhage associated with gastric polyps in Menkes disease.

We describe two infants with Menkes disease who had serious gastrointestinal bleeding from solitary gastric polyps. Hemorrhage in one patient was acute and proved fatal. Histopathologic examinations showed submucosal vascular ectasia with mucosal hyperplasia, edema, and ulceration. Gastric polyps may represent an underappreciated clinical abnormality in Menkes disease.

Gastrointestinal Hemorrhage↗
PubMed1992

New autosomal recessive syndrome of sparse hair, osteopenia, and mental retardation in Mennonite sisters.

We report on 2 Mennonite sisters with a syndrome of sparse hair, osteopenia, mental retardation, minor facial abnormalities, joint laxity, and hypotonia. Their asymptomatic consanguineous parents (inbreeding coefficient F = 1/64) have 6 other offspring, 3 of whom died in infancy of type II osteogenesis imperfecta (OI), and 3 of whom are normal. We analyzed collagens synthesized by cultured fibroblasts from these 2 sisters and their parents and detected no major abnormalities. Results of chromosomal and metabolic evaluations including amino acid analysis of plasma, urine, and hair were unremarkable. A literature search and survey of a computerized syndrome identification database did not disclose an identical phenotype. The sisters bear superficial resemblance to several known syndromes which we excluded on clinical and/or biochemical grounds. We conclude that they represent a new autosomal recessive syndrome, distinct from type II OI and perhaps unique to the Mennonite population or to this particular family.

Bone Diseases, Metabolic↗
PubMed1991

Human manganese superoxide dismutase is readily detectable by a copper blotting technique.

Manganese-superoxide dismutase (MnSOD) in human fibroblast and liver lysates was found to bind copper avidly under the conditions of a copper blotting technique which also detects known copper-binding proteins. Competition studies suggest that the copper-binding site of the molecule under these conditions is distinct from its manganese-binding site. Copper blotting provides a sensitive way to detect MnSOD in human tissues, and may be generally applicable to studies of copper-binding by biological molecules.

Amino Acid Sequence↗
PubMed1990

Swallowing dysfunction in nephropathic cystinosis.

BACKGROUND: Nephropathic cystinosis causes renal failure in most patients at approximately 10 years of age. This can be prevented or retarded by cystine-depleting therapy with oral cysteamine. Many patients who do not receive adequate cysteamine therapy undergo renal transplantation, but the accumulation of cystine continues in other organs, resulting in various clinical abnormalities. We report age-related swallowing dysfunction in patients with nephropathic cystinosis. METHODS: We studied 43 patients with cystinosis (24 who had received a renal transplant and 19 who had not), 3 to 31 years of age. Oral motor function was assessed by a cranial-nerve oral sensorimotor examination, and an oral motor index was calculated for each patient. The oral phase of swallowing was assessed by ultrasonography, and the pharyngeal and esophageal phases were evaluated by videofluoroscopy. RESULTS: Approximately half the patients were slow eaters. Oral motor dysfunction, reflected by a higher oral motor index, increased with age. Speech, oral structure and anatomy, and tongue and lip strength were particularly affected. Seven of nine patients 21 to 31 years old had abnormalities in all three phases of swallowing; the deficits were variable in younger patients. In 28 patients with cystinosis, the mean (+/- SD) duration of oropharyngeal swallowing for a dry swallow (3.06 +/- 1.06 seconds) was longer than in 14 normal subjects (1.89 +/- 0.57 seconds; P less than 0.001). This prolongation reflected impairment of the initiation phase of swallowing. CONCLUSIONS: Swallowing dysfunction is a late complication of nephropathic cystinosis, probably related to muscular dysfunction. Changes in the consistency of foods, swallowing exercises, and long-term cysteamine therapy should be considered for patients with cystinosis who have difficulty in swallowing.

Adolescent↗
PubMed1986

Metacarpophalangeal pattern profile analysis in clinical genetics: an applied anthropometric method.

The hand is a complex anatomical structure with the component bones susceptible to a combination of environmental and genetic factors that may affect the bone length and width. The alterations may involve a single bone or specific group of bones. The metacarpophalangeal pattern profile (MCPP) developed by Poznanski, Garn, and others (Poznanski et al. Birth Defects VIII (5): 125-131, 1972) is a graphic representation of the relative lengthening and shortening of the 19 tubular bones of the hand useful for diagnosis, comparison of dissimilar patients, and gene carrier detection. The profile hand bone measurements are derived from posteroanterior hand radiographs and are standardized for age and sex. Specific profiles have been developed for several syndromes. Therefore, MCPP analysis has developed from a method of describing changes in the hand to a technique useful in assigning a diagnosis to a specific syndrome and evaluation of skeletal development. The current status of MCPP analysis in clinical genetics, particularly with the Prader-Labhart-Willi and Sotos syndromes, is discussed.

Adolescent↗
PubMed1983

Brief clinical report: two children with de novo del(9p).

We describe two patients with characteristic manifestations of the del(9p) syndrome. Among the prominent manifestation are moderate mental retardation, trigonocephaly, flat nasal bridge, anteverted nostrils, long philtrum, square and hyperconvex nails, and apparently long digits. The metacarpophalangeal pattern profiles of the patients showed that the clinical impression of long fingers may be due to relative shortness of the metacarpals rather than to elongation of the phalanges.

Abnormalities, Multiple↗
PubMed1982

Metacarpophalangeal pattern profile analysis in Prader-Willi syndrome.

Metacarpophalangeal pattern profile (MCPP) was determined on 16 Prader-Willi patients. Chromosome analysis of 14 patients showed an interstitial deletion of the long arm of chromosome 15 in seven subjects and normal chromosome results for the remaining individuals. Two separate and distinguishable hand profiles for each group based on the chromosome findings were identified. Correlation studies confirmed the homogeneity of the chromosome deletion group relative to the Prader-Willi individuals with normal chromosomes. Discriminant analysis of Prader-Willi versus normal individuals produces a function of three MCPP variables plus age which may provide a useful tool for diagnosis.

Adolescent↗
PubMed1982

Radiographic hand abnormalities in fifteen cases of Crouzon syndrome.

Fifteen patients with Crouzon syndrome were evaluated for abnormalities of hand bone length via metacarpophalangeal pattern profile analysis. Data from this group were compared to that from a normal control sample. A discriminant function, utilizing Z scores based on the lengths of three hand bones, was derived and distinguished between the two samples at a rate of 88.3%. The discriminant variables selected in the function represented hand bones that are prominently involved in ACS type V and ACPS type II, syndromes that feature craniofacial abnormalities not unlike those in Crouzon syndrome. The possibility of a common developmental mechanism affecting the hand skeleton in all three of these different conditions is raised.

Craniofacial Dysostosis↗
PubMedDate not supplied

Metabolic and molecular bases of Menkes disease and occipital horn syndrome.

Menkes disease and occipital horn syndrome (OHS) are related disorders of copper transport that involve abnormal neurodevelopment, connective tissue problems, and often premature death. Location of the gene responsible for these conditions on the X chromosome was indicated by pedigree analysis from the time of these syndromes' earliest descriptions. Characterization of an affected female with an X-autosomal translocation was used to identify the Menkes/OHS gene, which encodes a highly evolutionarily conserved, copper-transporting P-type ATPase. The gene normally is expressed in nearly all human tissues, and it localizes to the trans-Golgi network of cells. However, in over 70% of Menkes and OHS patients studied, expression of this gene has been demonstrated to be abnormal. Major gene deletions detectable by Southern blotting account for 15-20% of patients, and an interesting spectrum of other mutations is evident among 58 families whose precise molecular defects have been reported as of this writing. The center region of the gene seems particularly prone to mutation, and those that influence mRNA processing and splicing appear to be relatively common. Further advances in understanding the molecular and cell biological mechanisms involved in normal copper transport may ultimately yield new and better approaches to the management of these disorders.

Copper↗