Search PubMed⌕ Search

Biomedical subjects

C E Jackson

Publications and source records attributed to C E Jackson.

At least 145 records · Page 8Linked to original sources
PubMed1980

Clinical characteristics distinguishing hereditary from sporadic medullary thyroid carcinoma. Treatment implications.

Distinctive differences between the hereditary and sporadic varieties of medullary thyroid carcinoma include the uniform bilaterality, consistent association of C cell hyperplasia, and the frequent association with other endocrine lesions as characteristics of the hereditary type. Total thyroidectomy is required for hereditary medullary thyroid carcinoma. Lateral cervical lymph node dissections do not appear necessary for the hereditary type when not palpable, detected only by family screening, and when biopsy of midjugular lymph nodes shows no evidence of metastasis. For palpable medullary thyroid carcinoma, the eradication of all cervical locations is unlikely to result in normal or undetectable levels of serum calcitonin postoperatively, even though such appears more likely for the sporadic variety.

Adrenal Gland Neoplasms↗
PubMed1980

Observations on gastric cancer in San Marino. I. Familial factors.

The Republic of San Marino (RSM) is a 23-square mile independent country within Italy with a population of 20,000. A large percentage of deaths have been found to be due to gastic cancer (9.2% of all death certificate diagnoses for 1969 through 1973). The frequency of gastric cancer in the families of all 36 patients (78% male) who were born and died in RSM with this diagnosis for this period was compared with the frequency in relatives of age and sex-matched controls. Although 42--44% of both groups had relatives with death certificate diagnoses of stomach cancer, 25% of the patients had first degree relatives affected versus 5.6% of the controls. A high prevalence has also been reported in the area of Italy near RSM. San Marino's size and stability of population provide unique opportunities for elucidating genetic and environmental etiological factors in stomach cancer.

Adult↗
PubMed1979

Formate dehydrogenase mutants of Salmonella typhimurium: a new medium for their isolation and new mutant classes.

We have designed a new medium for the differentiation of mutants of Salmonella typhimurium defective in the ability to reduce nitrate with formate, and have characterized 24 formate dehydrogenase (FDH) mutants isolated on this medium. The mutants were assayed for the ability to use formate to reduce benzyl viologen and phenazine methosulfate, and were mapped by means of conjugation and P22-mediated transduction. Mutants lacking the ability to reduce either dye were found to map at three distinct sites: at a site co-transducible with xyl (presumably fdhA), at a site or sites between 13U and 33U, but not co-transducible with aroA, bio, purB, pyrC, or pyrD (near, but not identical with fdhB), and at asite 10-20% co-transducible with pyrE, for which we suggest the designation fdhC. Six mutant isolates reduced benzyl viologen, but not phenazine methosulfate. They retained the ability to produce nitrite during growth with nitrate. They mapped between 83U and 89U, but no co-transduction was found with metE, glnA, metB, or argH. The combined biochemical and genetic data suggest the existence of a gene in this area which is essential for the reduction of nitrate with formate, but not for formate hydrogenlyase activity or for nitrate reductase activity.

Aldehyde Oxidoreductases↗
PubMed1979

Linkage analysis using heterozygote detection in phenylketonuria.

This linkage investigation was undertaken utilizing an improved method for phenylketonuria (PKU) heterozygote detection. This method is based on studies of semi-fasting, noon-time, blood specimens obtained from 85 obligate heterozgotes and 45 controls who were neither pregnant nor on birth control medication. The best separation between heterozygotes and normals was achieved with a discriminant function involving the logarithms of the serum concentrations of phenylalanine, tyrosine and tryptophan. The theoretical overlap area between the distributions of heterozygotes and controls, based on the above function, was between the distributions of heterozygotes and controls, based on the above function, was 3.75%. In 19 obligate heterozygotes and 13 controls who were either pregnant or on birth control medication, the best separation was achieved with a discriminant function involving the logarithms of the serum concentrations of phenylalanine and tyrosine. The theoretical overlap area was 8.23%. These equations identified heterozygotes with sufficient accuracy to permit efficient genetic linkage analysis. We were unable to demonstrate genetic linkage between the PKU locus and 15 common blood, serum, and urinary markers. All but loose linkage (theta greater than 0.3) was excluded for Rh, ABO, Gc, Kidd, and AP. Moderate linkage exclusion (theta less than 0.2) was shown for PGM, Duffy, Hp, MNS, HL--A, and Kell. Close linkage (theta less than 0.1) was excluded for Amy2, 6PGD, P, and ADA. We were unable to find linkage heterogeneity between the Amish and non-Amish populations.

Chromosome Mapping↗
PubMed1979

The two-mutational-event theory in medullary thyroid cancer.

Comparisons are presented of the ages of onset of 20 cases of hereditary medullary carcinoma of the thyroid (MCT) and of 22 sporadic cases of this same type of cancer. These data are compatible with what might be expected by the two-mutational-event theory of the initiation of cancer postulated by Knudson. It had been previously postulated that C-cell hyperplasia of the thyroid was a premalignant change resulting from the first or genetic mutational event in the initiation of this type of cancer. The finding of C-cell hyperplasia in thyroid glands of each of the 10 patients with the hereditary condition and in none of the 10 sporadic patients is compatible with this theory. The C-cell hyperplasia is believed to be the expression of the genetic mutation, which requires a subsequent somatic mutation to transform the initially mutated cell into a cancer cell.

Adolescent↗
PubMed1978

Management of occult medullary thyroid carcinoma: evidenced only by serum calcitonin level elevations after apparently adequate neck operations.

Following operation for medullary thyroid carcinoma, elevated serum calcitonin levels were present in 18 patients who had no clinically evident residual tumor. In eight of these patients, additional operations have been performed to achieve an appropriate thyroidectomy and cervical lymph node dissection. In six of these eight, elevated serum calcitonin concentrations persist. Extensive clinical examinations failed to identify a metastatic focus of carcinoma. Serum calcitonin concentrations have remained relatively stable for up to six years (average, 3.9 years) of observations in 12 patients after initial or only operations performed from one to 13 years (average 7.3 years) previously. This suggests that microscopic metastases of this carcinoma can remain relatively dormant for years. The management of medullary thyroid carcinoma requires initially adequate cervical operations, periodic serum calcitonin measurements postoperatively, reoperation if adequate neck surgery has not been performed and if serum calcitonin levels remain elevated and only periodic reevaluation for other asymptomatic patients with persistently elevated concentrations of serum calcitonin.

Calcitonin↗
PubMed1978

Evidence for nonlikage of genes for HLA and hereditary angioedema.

Since the genes for several disorders of the complement system have been found to be linked to the HLA loci on chromosome 6, studies of the inhibitor of the activated first component of complement (Cl INH) and HLA in two families with hereditary angioedema (HAE) were undertaken. A total of 17 individuals were found to be affected in these three-generation families. Evidence was provided against close linkage of the genes for HLA and HAE. Other genetic markers studied were generally noninformative, although evidence was obtained against close linkage of the loci for HAE and ABO and HAE and transferrins. The reliable identification of individuals affected with HAE by Cl INH assay provides potential for establishing linkage relationships in the various phenotypes of this dominantly inherited condition.

Angioedema↗
PubMed1978

Phenylketonuria heterozygote detection in families with affected children.

Improved approaches to the problem of heterozygote detection for phenylketonuria (PKU) were developed in this study. The discrimination was based on 85 obligate heterozygotes and 45 controls who were neither pregnant nor on birth control medication. The best separation between hetrozygotes and normals was achieved with a linear discriminant function involving the logarithms of the serum concentrations of phenylalanine, tyrosine, and tryptophan. The theoretical overlap area between the distributions of heterozygotes and controls based on the above function, was 3.75%. In the 19 obligate hetrozygotes and 13 controls who were either pregnant or on birth control medication, the best separation was achieved with a linear discriminant function involving the logarithms of the serum concentrations of phenylalanine and tyrosine. The theoretical overlap area was 8.23%. The genetic accuracy of the discriminant function was confirmed by testing the results with parental-child exclusions, segregation analysis, and the frequency of heterozygosity in nonrelated collateral spouses. Finally, there was evidence suggesting that the antihypertensive agent, aldomet, alters serum tyrosine and tryptophan levels.

Ethnicity↗
PubMed1977

Multicellular origin of parathyroid "adenomas".

Most cases of primary hyperparathyroidism are associated with enlargement of a single gland (i.e., an "adenoma") or with chief-cell hyperplasia, but there is controversy about the relative frequency of each of these entities. It has even been postulated that adenomas do not arise spontaneously, bu- result from prolonged hyperplasia in response to unknown stimuli. We studied four parathyroid adenomas from three women with heterozygosity (GdB/GdA) for the X-chromosome-linked enzyme, glucose-6-phosphate dehydrogenase, to determine the number of cells from which the growths arise. Unicellular origin would be compatible with a rare oncogenic event, whereas multicellular origin might be seen with hyperplasia. Both B and A isoenzymes were found in each "adenoma" in proportions similar to those observed in normal tissues, indicating that the lesions have multicellular origin. Thus, parathyroid hyperplasia and adenomas, which at best are difficult to distinguish from one another pathologically, may also be similar biologically.

Adenoma↗
PubMed1976

Primary diffuse microscopical hyperplasia of the parathyroid glands: surgical importance.

In two of 182 patients with verified primary hyperparathyroidism, microscopical hyperplasia was present in all parathyroid glands that were normal in size or only slightly enlarged. All parathyroid glands in another two patients showed microscopical hyperplasia and varied from a normal size of 190 mg. In seven additional patients, microscopical hyperplasia was present in one, several, or all parathyroid glands, which varied in weight from normal to 350 mg. Familial hyperparathyroidism or multiple endocrine neoplasia was evident in five of 11 patients. Contributing to difficulties was the experience in five patients in whom removal of mildly enlarged parathyroid glands corrected hypercalcemia, but definite microscopical abnormalities were not evident by routine histologic study of the glands. Thus, there appears to be a spectrum of abnormalities relative to size and microscopical changes in parathyroid glands of patients with primary hyperparathyroidism. The surgeon should be aware of these patterns of parathyroid hyperplasia that require a search for a fifth parathyroid gland and a subtotal parathyroidectomy.

Adult↗
PubMed1976

Craniosynostosis, midfacial hypoplasia and foot abnormalities: an autosomal dominant phenotype in a large Amish kindred.

An unusual spectrum of craniofacial and foot abnormalities has been detected within a large midwestern Amish kindred. Enlarged great toes and craniofacial abnormalities suggested Pfeiffer acrocephalosynadactyly type V; however, thumb abnormalities were not present. Eighty-eight affected individuals were observed and another 50 were reliably reported to be affected. An autosomal dominant inheritance pattern was observed associated with variable expressivity. All affected individuals had some clinical or radiologic abnormality of the feet. The phenotypic expression was so variable that the entire spectrum of dominantly inherited craniofacial dysotoses-acrocephalosyndactylys (except the typical Apert syndrome) was seen within this kindred.

Child, Preschool↗
PubMed1976

Geriatric primary hyperparathyroidism.

Primary hyperparathyroidism occurs in a significant number of patients over 60 years of age; about one-third of the 182 patients we studied were in this age group. Primary hyperparathyroidism has been recognized with greater frequency in recent years, particularly in patients without manifestations of renal lithiasis or osteitis fibrosa cystica and in older patients. Age alone is not critical in the occurrence of serious complications from hypercalcemia, the presence of other life-endangering disease, or the development of major postoperative complications in the management of primary hyperparathyroidism. A liberal but selective policy is advocated in advising operation for primary hyperparathyroidism in the elderly. Different clinical patterns of primary hyperparathyroidism are recognized in all age groups. The operative procedure for primary hyperparathyroidism is determined primarily by the surgeons at the time of operation, on the basis of gross characteristics of the parathyroid glands. A precise correlation is not found between microscopic changes, gross changes, and clinical features of primary hyperparathyroidism.

Aged↗
PubMed1976

The physicochemical properties of hair in the BIDS syndrome.

The physicochemical properties of hair from a new recessive syndrome associated with brittle hair, intellectual impairment, decreased fertility, and short stature have been studied. Electrophoresis of the SCM-structural proteins showed that the alpha polypeptides appeared normal, but the matrix component was markedly reduced. This was confirmed by finding a normal alpha X-ray diffraction pattern but a reduced 1/2 cystine content of hair and an abnormal stress-strain curve. Electron-microscopic studies revealed extreme disorganization of the filaments which most likely resulted from the absence of normal cross-linking. Nails, which contain structural proteins similar to hair, also showed the abnormality. Since the matrix component seen by electrophoresis consists of more than one component the defect cannot be explained as a single structural gene abnormality.

Amino Acids↗