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Biomedical subjects

C D Malchoff

Publications and source records attributed to C D Malchoff.

At least 19 recordsLinked to original sources
PubMed2000

Treatable lower motor neuron disease due to vitamin D deficiency and secondary hyperparathyroidism.

Vitamin D deficiency and osteomalacia are frequently associated with muscle weakness and atrophy. We present a 78-year-old man with complaints of progressive painless weakness who was referred to us with a diagnosis of suspected motor neuron disease. Results of the neurological examination were remarkable, showing diffuse limb weakness and atrophy, rare fasciculations, normal sensory examination, no bulbar weakness, and no upper motor neuron signs. Electromyography revealed mild chronic changes, denervation and re-innervation, without fibrillations or positive waves. Serum laboratory studies showed an elevated serum parathyroid hormone and markedly reduced vitamin D level. Although the etiology of the vitamin D deficiency was not determined, the patient made a substantial clinical improvement following vitamin D therapy. Vitamin D deficiency and secondary hyperparathyroidism need to be included in the differential diagnosis of patients presenting with a progressive lower motor neuron disease.

Aged↗
PubMed2000

Papillary thyroid carcinoma associated with papillary renal neoplasia: genetic linkage analysis of a distinct heritable tumor syndrome.

Papillary thyroid carcinoma usually is sporadic, but may occur in a familial form. The complete clinical and pathological phenotype of familial papillary thyroid carcinoma (fPTC) has not been determined, and the susceptibility gene(s) is unknown. We investigated the clinical and pathological characteristics of an unusually large three-generation fPTC kindred to characterize more fully the clinical phenotype. We performed linkage analysis to determine the chromosomal location of a fPTC susceptibility gene. In addition to the known association of fPTC with nodular thyroid disease, we observed the otherwise rare entity of papillary renal neoplasia (PRN) in two kindred members, one affected with PTC and the other an obligate carrier. The multifocality of PRN in one subject adds weight to the likelihood of a true genetic predisposition to PRN. Both genetic linkage and sequence analysis excluded MET, the protooncogene of isolated familial PRN, as the cause of the fPTC/PRN phenotype. A genome-wide screening and an investigation of specific candidate genes demonstrated that the fPTC/PRN phenotype was linked to 1q21. A maximum three-point log of likelihood ratio score of 3.58 was observed for markers D1S2343 and D1S2345 and for markers D1S2343 and D1S305. Critical recombination events limited the region of linkage to approximately 20 cM. A distinct inherited tumor syndrome has been characterized as the familial association of papillary thyroid cancer, nodular thyroid disease, and papillary renal neoplasia. The predisposing gene in a large kindred with this syndrome has been mapped to 1q21.

Adult↗
PubMed1999

Lateral transperitoneal laparoscopic adrenalectomy.

Several laparoscopic approaches to the adrenal gland have been described. The lateral transperitoneal approach has several distinct advantages when contrasted with other techniques for laparoscopic adrenalectomy (LA). We present our technique and results obtained in 50 consecutive transperitoneal LAs. We review 50 consecutive laparoscopic adrenalectomies (28 female, 19 male) performed from 1993 to 1998 S.J. Shichman or R.E. Sosa was either the primary surgeon or the first assistant for all cases. The lateral transperitoneal approach described below was used in all cases. Indications for adrenalectomy included Cushing's syndrome (13), aldosteronoma (15), pheochromocytoma (7), nonfunctioning adenoma (11), hyperplasia (2), and 1 case each of Carney's syndrome and metastasis to the adrenal gland. We performed 5 bilateral, 22 left, and 18 right laparoscopic adrenalectomies. The average time needed for bilateral adrenalectomy was 503 min (range 298-690 min); for left adrenalectomy, 227 min (range 121-337 min); and for right LA, 210 min (range 135-355 min). We demonstrated a yearly trend in lower operative times. The largest adrenal gland removed measured 13.8 x 6.7 x 3.5 cm. Intraoperative blood loss was low. Only one patient received a blood transfusion. Conversion to open adrenalectomy was not required. Postoperative analgesic requirements were low. The average length of stay was 3.8 days for bilateral LA and 3 days for unilateral LA. Complications occurred in 5 patients (2 wound infections, 2 hematomas, and 1 pleural effusion). There was no mortality. Lateral transperitoneal adrenalectomy is a safe and efficient technique for the removal of functional and nonfunctional adrenal masses. This technique is associated with low morbidity, a minimal postoperative analgesic requirement, and a short hospital stay and, in our opinion, is more versatile than the retroperitoneal approach.

Adrenal Gland Neoplasms↗
PubMed1999

Familial papillary thyroid carcinoma is genetically distinct from familial adenomatous polyposis coli.

Familial papillary thyroid carcinoma (fPTC) is an inherited tumor syndrome characterized by isolated papillary thyroid carcinoma (PTC) in affected subjects. Its etiology is unknown. Large multigeneration families with PTC are very rare, and therefore, modern genetic linkage studies have not been applied extensively to this disorder. Familial adenomatous polyposis coli (FAP) is an inherited tumor syndrome enriched in PTC. FAP is caused by germline mutations of the adenomatous polyposis coli (APC) gene that is located in the 5q21 region. It is not known if fPTC is a phenotypic variant of FAP, or if it is a genetically distinct disorder. We report a large 3-generation fPTC kindred and use linkage analysis to test the hypothesis that fPTC and FAP are genetically distinct. In this kindred there are 25 living informative subjects; 5 have PTC, and 1 is an obligate carrier. Inheritance is autosomal dominant with incomplete penetrance. There is vertical transmission, multifocal disease, an average age of onset of 36 years, and 1 subject has colon cancer. The probability is approximately 1 in 2 billion against the clustering of 5 sporadic PTC cases in this kindred. To test for linkage to the APC gene we used 2 highly polymorphic markers, D5S656 and D5S421, which are located within a maximum distance of 1.7 megabase (Mb) of the APC gene and within an estimated genetic region of less than 1 centimorgan (cM) from each other. After polymerase chain reaction (PCR) amplification 18 family members were genotyped. Construction and inspection of haplotypes showed that the affected subjects do not share the same allelic composition. Using a penetrance ratio of 75%, linkage was excluded at 2 cM and 3 cM on both sides of D5S656 and D5S421, respectively. The combined haplotype of these 2 markers provided an exclusion region of 4 cM. We conclude that fPTC is genetically distinct from FAP.

Adenomatous Polyposis Coli↗
PubMed1997

Bilateral laparoscopic adrenalectomy for adrenocorticotropic dependent Cushing's syndrome.

PURPOSE: We report our experience with bilateral laparoscopic adrenalectomy for total adrenal ablation in patients with Cushing's syndrome. MATERIALS AND METHODS: Four women (mean age 63 years) with Cushing's syndrome secondary to nonlocalized ectopic adrenocorticotropic hormone production in 3 and pituitary microadenoma after failed transsphenoidal ablation in 1 underwent bilateral transabdominal laparoscopic adrenalectomy. Preoperatively risk was III or IV according to the American Society of Anesthesiologists classification. RESULTS: In all cases bilateral laparoscopic adrenalectomy was successfully performed. Operative time ranged from 375 to 475 minutes (mean 404) and mean blood loss was 162 cc. All patients resumed oral intake on postoperative day 1, mean number of postoperative parentral narcotic doses was 2.25 and mean postoperative hospital stay was 5.75 days (range 3 to 8). Complications included an abdominal wall hematoma. All patients resumed baseline activity by postoperative day 14. CONCLUSIONS: Our experience in 4 cases of Cushing's syndrome suggests that bilateral laparoscopic adrenalectomy is a safe and effective alternative to open adrenalectomy. Further experience with this technique will likely decrease operative time, and confirm the benefit of a decreased hospital stay and convalescence.

Adrenalectomy↗
PubMed1996

Preferential localization of regional metastases from gastroenteropancreatic endocrine tumors with somatostatin-receptor scintigraphy.

Somatostatin-receptor imaging is an effective method for localizing and staging neuroendocrine tumors. We describe patients with gastroenteropancreatic endocrine tumors who underwent preoperative indium In 111 pentetreotide scintigraphy. In 3 patients without prior resections, the results of a 111In pentetreotide scan were positive because of unsuspected regional lymph node metastases without localization of the primary tumors. In these patients, an extensive intraoperative search was required to identify the primary tumors, despite the positive preoperative scan results. In a fourth patient, who had previously undergone resection of a duodenal gastrinoma, 2 regional nodal metastases were identified by a 111In pentetreotide scan.

Adult↗
PubMed1996

A comparison of open vs laparoscopic adrenalectomy.

BACKGROUND: To compare the outcome of patients who underwent laparoscopic transabdominal adrenalectomy (LA) with those who had open adrenalectomy (OA). METHODS: A retrospective review of consecutive adrenalectomies performed by a single surgical team at a university hospital. Outcome measurements were operative time, operative blood loss, procedure-related complications, postoperative stay, and return to regular activity. RESULTS: Twenty-nine adrenalectomies were done in 23 patients during a 54-month period. There were 12 OAs performed in nine patients and 17 LAs were done in 14 patients. Both groups were similar in their demographics and their indications for operation. All attempted LAs were successfully completed. The mean operative time was longer for LA than for OA (289 vs 201 min; p = 0.042). Resumption of oral intake (1.0 vs 3.0 days; p = 0.002), postoperative hospital stay (3.0 vs 7.9 days; p = 0.002), and return to regular activity (8.9 vs 14.6 days; p = 0.002) were significantly shorter after LA than after OA. There were no postoperative deaths and there was no difference in operative blood loss between the two groups. Procedure-related complications occurred in three patients having LA and in five patients having OA. CONCLUSIONS: Patients having LA had longer operative procedures but shorter hospital stays and faster return to normal activity than patients having OA. Procedure-related complications for LA were due to bleeding into the retroperitoneum or abdominal wall. Significant postoperative cardiac and respiratory complications occurred only in the OA group.

Adrenal Gland Diseases↗
PubMed1996

Chiasmal herniation as a complication of bromocriptine therapy.

INTRODUCTION: Medical treatment of macroprolactinomas with dopamine agonists decreases tumor mass and improves visual defects. We report an unusual complication of a macroprolactinoma responding to bromocriptine: a visual field defect caused by downward herniation of the optic chiasm. MATERIALS AND METHODS: A 64-year-old woman was found to have a 4.5 cm macroprolactinoma with superior displacement of the optic chiasm, bitemporal hemianopia, and serum prolactin concentration (P) of 17,060 micrograms/L. Bromocriptine was initiated at 2.5 mg/day and increased to 7.5 mg/day over 2 months. RESULTS: After 2 months, visual fields improved significantly and tumor height decreased to 3 cm with resolution of the optic chiasm displacement. P decreased to 1,180 micrograms/L. After 5 months of therapy, visual fields were normal, and P was 8 micrograms/L. After 8 months of therapy, new bilateral visual defects were observed. Magnetic resonance imaging (MRI) revealed further decrease of the tumor height to 1.5 cm, and inferior and leftward traction of the optic chiasm as the probable mechanism for the new visual field deficit. P was < 1 microgram/L. Bromocriptine was decreased to 5 mg/day to allow reduced traction on the optic chiasm and its blood supply. Over the next 4 months, visual field abnormalities resolved. CONCLUSIONS: We report the development of a visual field abnormally that is explained by chiasmal herniation caused by a shrinking macroprolactinoma. This complication resolved with a decrease in the bromocriptine dose. We suggest that patients undergoing bromocriptine therapy for macroprolactinomas be followed for this potential complication.

Bromocriptine↗
PubMed1995

Bronchogenic carcinoma presenting as a pseudopregnancy.

A young woman with an occult bronchogenic carcinoma presented with secondary amenorrhea and an elevated beta subunit of human chorionic gonadotropin that was mistakenly attributed to pregnancy. Physicians should be aware that this carcinoma may present solely with an elevated beta human chorionic gonadotropin value, and the potential exists for confusion with a pregnancy state in women of childbearing age.

Adult↗
PubMed1994

Somatostatin receptor scintigraphy: its value in tumor localization in patients with Cushing's syndrome caused by ectopic corticotropin or corticotropin-releasing hormone secretion.

PURPOSE: To assess the feasibility of somatostatin receptor scintigraphy for patients with Cushing's syndrome caused by tumors secreting ectopic corticotropin or corticotropin-releasing hormone (CRH). PATIENTS AND METHODS: Ten patients with Cushing's syndrome, nine with ectopic corticotropin-secreting tumors and one with a CRH-secreting tumor, were consecutively studied. For comparison purposes, eight patients with corticotropin-secreting pituitary tumors and one patient with an autonomous adrenal adenoma were investigated. In vivo tumor localization was performed for all patients using a radionuclide-coupled somatostatin analog. The results obtained with this technique were compared with those obtained with conventional imaging techniques. For some patients, the clinical effects of octreotide therapy were evaluated. RESULTS: Somatostatin analog scintigraphy successfully identified the primary ectopic corticotropin-secreting and CRH-secreting tumors or their metastases, or both, in 8 of 10 patients; in 2 patients with corticotropin-secreting bronchial carcinoids, the tumors could not be visualized. Normal scans were obtained for the 8 patients with corticotropin-secreting pituitary tumors and the one patient with an adrenal adenoma. CONCLUSION: Somatostatin analog scintigraphy can be included as a diagnostic step in the workup of Cushing's syndrome patients with a suspected ectopic corticotropin-secreting tumor or a CRH-secreting tumor.

ACTH Syndrome, Ectopic↗
PubMed1994

An unusual presentation of McCune-Albright syndrome confirmed by an activating mutation of the Gs alpha-subunit from a bone lesion.

The McCune-Albright syndrome (MAS) is characterized clinically by polyostotic fibrous dysplasia, café-au-lait skin lesions, sexual precocity, and various other endocrinopathies. Recent investigations suggest an etiological role for embryonic somatic missense mutations that predict the substitution of a His or Cys for Arg at amino acid 201 of the Gs alpha-subunit (Gs alpha). Identification of these mutations in affected tissues is a sensitive assay that may help define a more complete clinical spectrum of the MAS. We investigated a woman who developed fibrous dysplasia 24 yr after premature menstruation. To determine if this was an unusual MAS variant, DNA and RNA were analyzed from affected and unaffected tissues. From samples of affected rib and normal rib DNA was extracted, amplified by polymerase chain reaction, subcloned, and sequenced. RNA was extracted from affected bone, reverse transcribed, amplified by polymerase chain reaction, subcloned, and sequenced. DNA sequence predicting a His for Arg substitution at Gs alpha amino acid 201 was found in 47% of the recombinant plasmids from DNA of affected bone and 17% of the plasmids from DNA of unaffected bone; a significant (P < 0.05) difference in frequency. The His201 substitution was found in 42% of the recombinant plasmids from RNA of affected bone. We conclude that this clinical variant is qualitatively indistinguishable from presentations of the complete MAS.

Adult↗
PubMed1994

Dexamethasone therapy for isosexual precocious pseudopuberty caused by generalized glucocorticoid resistance.

Generalized glucocorticoid resistance presents with clinical features secondary to excess production of mineralocorticoids and adrenal androgens. It is our hypothesis that these clinical and biochemical features will respond to glucocorticoid therapy. We tested this hypothesis in a boy with generalized glucocorticoid resistance and increased adrenal androgens. Dexamethasone was administered from age 7 6/12 yr until the onset of true puberty at 11 0/12 yr. Serum concentrations of cortisol and adrenal androgens decreased to the normal or near normal range. The accelerated precocity improved. Secondary sex characteristics did not progress; the difference between bone age and chronological age decreased from 3 1/2 yr to 2 yr, and the difference between height age and bone age decreased from 2 yr to 1/2 yr. We conclude that dexamethasone is effective and safe therapy for the sexual precocity of generalized glucocorticoid resistance.

Age Determination by Skeleton↗
PubMed1993

A mutation of the glucocorticoid receptor in primary cortisol resistance.

The precise molecular abnormalities that cause primary cortisol resistance have not been completely described. In a subject with primary cortisol resistance we have observed glucocorticoid receptors (hGR) with a decreased affinity for dexamethasone. We hypothesize that a mutation of the hGR glucocorticoid-binding domain is the cause of cortisol resistance. Total RNA isolated from the index subject's mononuclear leukocytes was used to produce first strand hGR cDNAs, and the entire hGR cDNA was amplified in segments and sequenced. At nucleotide 2,317 we identified a homozygous A for G point mutation that predicts an isoleucine (ATT) for valine (GTT) substitution at amino acid 729. When the wild-type hGR and hGR-Ile 729 were expressed in COS-1 cells and assayed for [3H]-Dexamethasone binding, the dissociation constants were 0.799 +/- 0.068 and 1.54 +/- 0.06 nM (mean +/- SEM) (P < 0.01), respectively. When the wild-type hGR and hGR-Ile 729 were expressed in CV-1 cells that were cotransfected with the mouse mammary tumor virus long terminal repeat fused to the chloramphenicol acetyl transferase (CAT) gene, the hGR-Ile 729 conferred a fourfold decrease in apparent potency on dexamethasone stimulation of CAT activity. The isoleucine for valine substitution at amino acid 729 impairs the function of the hGR and is the likely cause of primary cortisol resistance in this subject.

Adult↗
PubMed1991

Diagnosis and classification of diabetes mellitus.

The diagnosis of diabetes mellitus is established by history, physical examination, and measurements of serum or plasma glucose concentrations under specific conditions. This disorder represents the final common expression of diverse etiologies which are incompletely understood. The treatable causes of diabetes should be identified, and the appropriate therapy initiated. Distinguishing Type I and Type II diabetes is often useful, but not a necessary prerequisite for initiating therapy. As we begin to understand the underlying causes of diabetes, our emphasis is likely to shift from a diagnosis based on metabolic characteristics to a diagnosis based on etiology.

Blood Glucose↗