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Biomedical subjects

H Goldfarb

Publications and source records attributed to H Goldfarb.

10 recordsLinked to original sources

Adrenal and extra-adrenal retroperitoneal ganglioneuroma: imaging findings in 13 adults.

PURPOSE: To determine the radiologic appearance of ganglioneuromas of the adrenal gland and extra-adrenal retroperitoneum. MATERIALS AND METHODS: A retrospective review was performed of imaging findings in nine patients with ganglioneuroma, two with ganglioneuroma-pheochromocytoma, and two with malignant peripheral nerve sheath tumor (PNST) that arose in a ganglioneuroma. Patients underwent computed tomography (CT) (n = 13), magnetic resonance (MR) imaging (n = 5), and ultrasonography (US) (n = 5). RESULTS: In nine patients with ganglioneuroma, the mass ranged in size from 2 x 4 x 4 cm to 21 x 21 x 22 cm. Imaging findings included attenuation entirely or predominantly less than that of muscle on contrast material-enhanced CT images (n = 9); heterogeneous, predominantly high signal intensity on T2-weighted MR images (n = 5); partial or complete surrounding of one or more major blood vessels with little or no luminal narrowing (n = 4) and calcifications (n = 4) on CT scans; and homogeneous, moderate echogenicity (n = 3) on US scans. CT findings in two patients with ganglioneuroma-pheochromocytoma included central necrosis (n = 1) and calcifications (n = 1). In the two patients with malignant PNST that arose in a ganglioneuroma, contrast-enhanced CT showed a large, markedly heterogeneous mass. CONCLUSION: Diagnosis of ganglioneuroma should be considered when typical CT or MR imaging findings are present. Findings in cases of ganglioneuroma-pheochromocytoma and malignant PNST arising in a ganglioneuroma appear to be nonspecific.

Adrenal Gland Neoplasms↗

Clinical, biochemical, and genetic findings in a large pedigree of male and female patients with 5 alpha-reductase 2 deficiency.

The present report describes a cluster of eight patients with male pseudohermaphroditism from a large pedigree with steroid 5 alpha-reductase 2 deficiency (5 alpha RD), who reside in Southern Lebanon. They were born with unambiguous female external genitalia and reared as girls until puberty, when masculinization occurred, followed by a change of gender role. Semen analysis and testicular histology revealed maturation arrest of spermatogenesis, with low sperm count and motility. Determination of urinary 5 alpha- and 5 beta-reduced adrenal steroids enabled us to diagnose the disease in a male patient with the full-blown clinical syndrome, in another male patient who had undergone bilateral orchidectomy, and in three female individuals with the biochemical derangement. The female patients were unique in this family with respect to their low degree of virilization, but had normal menstrual cycles. Molecular genetic studies were performed on DNA extracted from peripheral leukocytes and from cultured genital skin fibroblasts. The coding sequence of the 5 alpha R2 gene (SRD5A2) was studied by exon-specific PCR, single strand conformation polymorphism, and direct sequencing. A homozygous point mutation was identified in exon 1, leading to a thymidine for adenine substitution, predicting amino acid substitution of leucine for glutamine at position 55.

Adolescent↗

Pulmonary accumulation of neutral diamine dithiol complexes of technetium-99m.

Twenty-two neutral, lipid-soluble 99mTc complexes have been synthesized from diamine dithiol (DADT) ligands which vary in alkyl substitution pattern on nitrogen and carbon. The logarithm of the partition coefficients (log PC), as well as the capacity factor k', of the purified complexes increased linearly with molecular weight. The biodistribution of these complexes was determined in normal mice, and several of the complexes selectively accumulated in the lungs as compared to the liver or other organs. Pulmonary accumulation varied greatly with subtle changes in structure, and a 30-fold range of lung uptake (1-31% of the injected dose/organ) was observed for isomeric technetium complexes which have identical molecular weights and similar log PC. Further, a parabolic relationship between lung uptake and log PC was observed for a subset of the complexes which are derived from a homologous series of tetramethyl-DADT ligands. Neutral and lipophilic radiopharmaceuticals labeled with technetium can therefore be developed which exhibit structurally specific uptake in the lung.

Animals↗

Ambiguous genitalia due to partial activity of cytochromes P450c17 and P450c21.

We describe a patient with male pseudohermaphrodism who has normal basal serum concentrations of cortisol and high basal levels of progesterone and 17 hydroxyprogesterone. Serum concentrations of androstendione, dehydroepiandrosterone sulfate and testosterone were low. On adequate human chorionic gonadotropin (HCG) stimulation, no rise in serum androstendione, dehydroepiandrosterone sulfate or testosterone concentrations was observed. After ACTH stimulation there was an excessive rise in progesterone and 17 hydroxyprogesterone with no rise in androstendione, dehydroepiandrosterone sulfate, testosterone, deoxycorticosterone or cortisol. These clinical and laboratory data suggest that the patient has a combined defect in both cytochromes P450c17 and P450c21. The genes coding for these cytochromes are on different chromosomes, 10 and 6, respectively. Unlike isolated 21 hydroxylase deficiency where all identical HLA siblings suffer from the disease, HLA typing of the patient's family revealed a healthy brother with identical HLA. This suggests that the gene coding for P450c21 on chromosome 6 is not affected and that the lesion might be on a common enzyme which donates an electron to both cytochromes, most probably a flavoprotein.

17-alpha-Hydroxyprogesterone↗

Laboratory monitoring of androgenic activity in benign prostate hypertrophy treated with a 5 alpha-reductase inhibitor.

Testosterone and androstenedione are metabolized by 5 alpha- and 5 beta-reductases to androsterone (A) and etiocholanolone (E), respectively. These are excreted in the urine as conjugates, and the A/E ratio in normal men is usually greater than or equal to 1.5 (as opposed to 1 in women) because of the high 5 alpha-reductase activity in the prostate. The A/E ratio can be determined simply by gas chromatography after acid hydrolysis of a urine sample, extraction of steroids, and formation of trimethylsilyl derivatives. A timed collection of urine is unnecessary because the ratio of A/E is used rather than absolute values. In men suffering from benign prostate hypertrophy who are treated with Finasteride (a 5 alpha-reductase inhibitor), the A/E ratio decreases to less than 0.5. The A/E ratio decrease can be detected long before there is clinical improvement.

5-alpha Reductase Inhibitors↗

Observations on the chemical and physiological properties of urodiolenone, an urinary compound found in hypertension.

Urodiolenone is a substance that appears as the glucuronide in the urine of 1 in 3 hypertensive subjects. It is a potent inhibitor of Na+, K+-ATPase in kidney tissue of the guinea pig, as measured by cytochemical assay. Chemical and mass spectrometric evidence is presented, from which it is concluded that urodiolenone is a sesquiterpenoid substance, is a bicyclic enone with a vicinal diol side chain, and has molecular formula C15H24O3.

Female↗

Tibial arteriovenous fistula: successful use for limb salvage.

Embolization of atheromatous material from abdominal aortic aneurysms to the distal arterial circuit is a well-recognized clinical entity causing the "blue toe syndrome." A case is presented in which this phenomenon resulted in obliteration of the pedal arch and thrombosis of the tibial arteries. As a result, forefoot gangrene, severe leg ischemia and anterior and posterior compartment syndromes occurred. Salvage of the extremity required an extraordinary approach with the construction of an arteriovenous fistula between the posterior tibial vessels. The literature on the use of therapeutic and adjunctive arteriovenous fistulas and their physiology is discussed.

Aortic Aneurysm↗