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Biomedical subjects

J L Potter

Publications and source records attributed to J L Potter.

At least 19 recordsLinked to original sources
PubMed1988

Methemoglobinemia due to ingestion of N,N-dimethyl-p-toluidine, a component used in the fabrication of artificial fingernails.

An acute cyanotic episode due to methemoglobinemia occurred in a 16-month old girl following the ingestion of N,N-dimethyl-p-toluidine, a commercially available component used in the production of artificial fingernails. The amount of the parent compound ingested was about 6 mg/kg of body weight. Administration of methylene blue was effective in the reversal of the methemoglobinemia. In vitro studies suggest that the activity of the compound was probably due to its biochemical transformation to the toxic metabolite p-methylphenylhydroxylamine. We expand the list of aromatic amino or nitro compounds and their derivatives capable of producing methemoglobinemia and call attention to the hazard of their ingestion.

Accidents, Home↗
PubMed1987

Xanthine lithiasis, nephrocalcinosis, and renal failure in a leukemia patient treated with allopurinol.

An 11-year-old boy who presented in acute renal failure with significant increases of uric acid and phosphorus in his serum was discovered to have acute lymphoblastic leukemia. Five years later, he had a second and similar episode of acute renal failure, which was responsive to hemodialysis. After three months of daily therapy with allopurinol, a third and final episode of renal failure was unresponsive to peritoneal dialysis. Autopsy revealed an obstructive uropathy; focal nephrocalcinosis; and multiple, small, tan calculi in the calyces of both kidneys. Systemic cryptococcosis was also discovered. The stones, characterized by paper chromatography, electrophoresis, x-ray diffraction, and infrared spectroscopy, were 82% xanthine, 15% oxypurinol, and 3% hypoxanthine. We suggest that attention to the effects of accelerated tumor-cell lysis may protect renal function in patients with a large and drug-sensitive tumor cell load. Similarly, early detection of the fungal complications of leukemic therapy is an essential component of the treatment program.

Acute Kidney Injury↗
PubMed1986

Lipoprotein disorder, cirrhosis, and olivopontocerebellar degeneration in two siblings.

Two siblings had olivopontocerebellar degeneration, failure to thrive, hepatic fatty change and cirrhosis, and a dyslipoproteinemia characterized by low cholesterol and elevated triglycerides. This condition was distinct from other cerebellar atrophies and ataxias and was not due to malabsorption or malnutrition. Cerebellar degeneration progressed rapidly during the first year of life, and both children died from intercurrent infections and surgical complications at 11 and 17 months. Stereotyped clinical and pathologic findings in the two patients suggest a previously unreported genetic metabolic disorder affecting the liver and the CNS.

Atrophy↗
PubMed1986

New mutation and prenatal diagnosis in ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) (E.C.2.1.3.3) is an X-linked hepatic enzyme in the urea cycle necessary for ammonia detoxification. Deficiency of OTC results in neonatal hyperammonemia, coma, and death in childhood. Because fibroblasts do not express OTC, prenatal diagnosis in the past has required fetal liver biopsy. Using a complementary DNA (cDNA) for OTC for Southern blot analysis of genomic DNA, we have found probands with complete OTC deficiency from two unrelated families in whom the same TaqI restriction endonuclease site has been altered because of independent, but not necessarily identical, mutations in the OTC gene, suggesting that this site may be a relative hotspot for mutation at a location that is critical for normal gene function. This TaqI alteration has allowed the identification of the individual in each family in whom the mutation originated as well as the exclusion of a recurrence of OTC deficiency in a male fetus at risk for the disease. OTC deficiency joins the growing list of genetic disorders for which Southern blot analysis allows accurate heterozygote detection and prenatal diagnosis in conditions for which they were not previously available.

Child, Preschool↗
PubMed1985

Hepatic amebic abscess masquerading as acute cholecystitis.

Hepatobiliary scintigraphy has disclosed a host of intrahepatic and extrahepatic lesions which mimic gallbladder disease. Two cases of hepatic amebic abscess are reported in which the presentations masqueraded as acute cholecystitis. Correlative, noninvasive imaging rapidly diagnosed both cases and in 1 case identified a serious complication.

Adolescent↗
PubMed1985

Renal and perirenal infection: the role of computerized tomography.

Predisposing factors, onset of symptoms to diagnosis interval, computerized tomography findings and the impact of computerized tomography on the outcome were studied retrospectively in 24 patients with renal or perirenal infections. The most common predisposing factors were diabetes mellitus and urinary tract calculi. The mean interval from the onset of symptoms to diagnosis was 6.8 days. The most common computerized tomography findings were thickening of Gerota's fascia, renal enlargement, focal decreased renal attenuation, perirenal fluid and focal gas. Four patients died despite early diagnosis and appropriate therapy. Computerized tomography aided in the diagnosis, assessment of the extent of disease, treatment and followup. Computerized tomography is the most direct method to evaluate patients with suspected renal or perirenal infection, although mortality may not be altered significantly.

Abscess↗
PubMed1985

Emphysema in the renal allograft.

Two diabetic patients in whom emphysematous pyelonephritis developed after renal transplantation are described. Clinical recognition of this unusual and serious infection is masked by the effects of immunosuppression. Abdominal radiographic, ultrasound, and computed tomography findings are discussed. The clinical presentation includes urinary tract infection, sepsis, and acute tubular malfunction of the allograft in insulin-dependent diabetics.

Adult↗
PubMed1984

CT appearance of multifocal hepatic steatosis.

The CT appearance of focal and diffuse fatty infiltration of the liver has been described in recent radiologic literature. Previous reports of focal steatosis have emphasized the differential diagnosis of the solitary lesion. We report a case of multifocal hepatic involvement and describe a new radiologic sign that is useful in differentiating this process from neoplasia.

Aged↗
PubMed1983

Occult hepatic sinusoid tumor of infancy simulating neuroblastoma.

Two infants with hepatosplenomegaly and an occult tumor of hepatic sinusoids are reported. Although secretion of biogenic amines of neuroblastoma was not elevated, infrequent neurosecretory granules were observed by electron microscopy in the cytoplasmic processes of the tumor cells. The infants responded to vincristine and prednisone therapy and are tumor free 8 and 2 years later, respectively. The clinical, radiographic, biochemical, and microscopic findings of these cases are presented. The distinction from other infantile hepatic sinusoid small round cell tumors is based on the light and electron microscopic findings. This neuroepithelial tumor is either an unusual form of neuroblastoma or a neoplasm of APUD cell origin. If chemotherapy is utilized, it should be selective and limited.

Drug Therapy, Combination↗
PubMed1983

Neonatal hepatic malignant tumor. A correlative imaging approach.

We report the hepatobiliary study of a neonate with hepatomegaly. Biliary atresia was ruled out. Fortuitous demonstration of massive parenchymal lesions redirected the clinical management of the child. Other imaging modalities were employed to define further the nature of the lesions. Pediatric reports of non-biliary lesions demonstrated by hepatobiliary scintigraphy are uncommon. To our knowledge, the present case of multiple hepatoblastomas discovered by hepatobiliary imaging is the first report in the literature.

Carcinoma, Hepatocellular↗
PubMed1983

Assessment of follicular development by ultrasonography and total serum estrogen in human menopausal gonadotropin-stimulated cycles.

Ovarian follicular development was assessed by serial ultrasonography in infertile women being treated with human menopausal gonadotropin. Both follicular size and number of follicles correlated with serum estrogen values in most patients, and follicles increased in size 2--3 mm per day. Most patients had serum estrogen values greater than 750 pg/ml when one or more follicles larger than 18 mm were present. A comparison of conception cycles with non-conception cycles did not reveal a significant difference in size or number of follicles, or in the rate of rise or peak value of serum estrogen. When women monitored with ultrasonography were compared with patients treated with gonadotropins prior to the availability of ultrasonography, there was no significant difference in the rates of successful conception, although the number of ampules of pergonal used by the former was significantly reduced, permitting more efficient use of an expensive medication.

Estrogens↗
PubMed1982

NMR relaxation of protons in tissues and other macromolecular water solutions.

Nuclear magnetic resonance (NMR) longitudinal (T1) and transverse (T2) relaxation parameters have been evaluated for protein solutions, cellular suspensions and tissues using both data from our laboratory and the extensive literature. It is found that this data can be generalized and explained in terms of three water phases: free water, hydration water, and crystalline water. The proposed model which we refer to as the FPD model differs from similar models in that it assumes that free and hydration water are two phases with distinct relaxation times but that T1 = T2 in each phase. In addition there is a single correlation time for each rather than a distribution as assumed in most other models. Longitudinal decay is predicted to be single exponent in character resulting from a fast exchange between the free and hydration compartments. Transverse decay is predicted to be multiphasic with crystalline (T2 approximately 10 microseconds), hydration (T2 approximately 10 msec) and free (T2 approximately 100 msec) water normally visible. The observed or effective transverse relaxation times for both the hydration and free water phases are greatly affected by the crystalline phase and are much shorter than the inherent relaxation times.

Animals↗