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Biomedical subjects

J C Simmons

Publications and source records attributed to J C Simmons.

At least 37 records · Page 2Linked to original sources
PubMed1994

Effects of renal denervation on postprandial sodium excretion in experimental heart failure.

The hormonal, hemodynamic and renal excretory changes after an oral load of sodium were examined in renal-denervated dogs with an arteriovenous (AV) fistula and the syndrome of compensated high-output heart failure. After ingestion of a meal containing 125 meq of sodium, the total postprandial urinary sodium excretion and fractional sodium excretion were approximately twofold higher in the renal-denervated AV fistula dogs, compared with a control group with intact renal nerves (P < 0.05). The postprandial elevations in right atrial pressure, plasma atrial natriuretic factor, and filtered load of sodium were similar in the two groups (P > 0.05). Mean arterial pressure and plasma renin activity remained unchanged from baseline in the two subsets of animals (P > 0.05). In the renal-denervated AV fistula dogs, ingestion of a low-salt meal containing 2-3 meq of sodium produced elevations in creatinine clearance and filtered load of sodium of similar magnitude to the high-salt meal. However, the increases in sodium excretion and plasma atrial natriuretic factor were modest and inconsistent. These results demonstrate that the renal nerves play an important modulatory role for postprandial sodium metabolism after a high-salt meal in experimental compensated high-output heart failure. It is suggested that the renal nerves attenuate the expression of postprandial natriuretic mechanisms via a direct tubular mechanism of action.

Animals↗
PubMed1987

Operative related infection rates for ventriculoperitoneal shunt procedures in a children's hospital.

We determined the operative related cerebrospinal fluid (CSF) shunt infection rates for our institution over a 3-year period (1982 to 1984) using strictly defined numerator and denominator data. The minimum post-operative follow-up period was 12 months. The average surgical infection risk for a CSF shunt procedure at our institution during the study period was 13.3%. Annual infection rates were relatively constant (13.8%, 13.2% and 12.9%), however both quarterly (5.7% to 23.3%) and surgeon-specific (5.7% to 22.8%) rates varied widely. Infection rates calculated by using "traditional" numerator and denominator data were considerably lower (6.5% to 9.2%). Operative related CSF shunt infection rates should be determined by utilizing strictly defined numerator and denominator values in order to allow valid comparisons of published rates.

Bacterial Infections↗
PubMed1987

Coagulase-negative staphylococci isolated from cerebrospinal fluid shunts: importance of slime production, species identification, and shunt removal to clinical outcome.

We collected and characterized 85 strains of coagulase-negative staphylococci (51 pathogens and 34 contaminants) from cerebrospinal fluid shunts. All isolates were classified by species and characterized by antimicrobial susceptibility and quantitative adherence to plastic tissue culture plates. There were more adherent organisms among pathogens than among contaminants (P less than .01). Species distribution was similar for both groups; however, 20% of the pathogens and none of the contaminants were phosphatase-negative Staphylococcus epidermidis (P less than .05). Resistance to four or more antimicrobial agents was detected in 45% of both groups. Neither species designation nor antimicrobial resistance correlated with clinical outcome. Five (83%) of six infections due to nonadherent (vs. 16 [41%] of 39 due to adherent; P less than .05) coagulase-negative staphylococci were, however, cured with antimicrobial therapy alone. Cure was highly associated with removal of the colonized shunt--38% of infected patients treated with antimicrobial therapy alone were cured, 75% treated with antimicrobial therapy and partial shunt removal were cured, and all treated with antimicrobial therapy and total shunt replacement were cured.

Bacterial Adhesion↗
PubMed1985

Glioblastoma in children.

Both morphologic and clinical features of 72 consecutive cases of brain tumors, collected over 9 years at Le Bonheur Children's Medical Center, were reviewed. We identified 11 cases as glioblastoma, representing 16% of all intracranial neoplasm and 26% of glial tumors. The patients ranged in age from 1 to 15 years with the median age of 10 years. There were 4 females and 7 males; 2 blacks and 9 whites. The median survival was 9 months. The tumor was observed in both cerebrum and cerebellum. Sexual predominance was not appreciable, although there was male excess. The tumor was significantly more frequent in whites than blacks (p less than 0.05). Similar racial predominance was noted in the other, more common brain tumors in children such as astrocytoma and medulloblastoma.

Adolescent↗
PubMed1983

Anterior sacral defects: an autosomal dominantly inherited condition.

Anterior sacral meningoceles and presacral teratomas are rare congenital malformations associated with a sacrococcygeal bony defect. The inheritance of anterior sacral meningoceles has been proposed to be X-linked dominant, whereas presacral teratomas have been reported to be autosomal dominantly inherited. Anterior meningoceles and teratomas may occur independently or in combination. We report a family in whom at least 11 individuals of three generations have partial sacral agenesis and have had either anterior sacral meningoceles, teratomas, or both. Male-to-male transmission has been documented. Although the existing literature differentiates the inheritance of anterior meningoceles from that of the teratomas, the pleiotropic effects of the gene causing these anterior sacral defects in this family is evident and is consistent with autosomal-dominant inheritance.

Adolescent↗