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Biomedical subjects

D B Nelson

Publications and source records attributed to D B Nelson.

120 records · Page 7Linked to original sources
PubMedDate not supplied

Medulloblastoma cell line secretes platelet-derived growth factor.

Medulloblastoma is the most common malignant childhood brain tumor in which aggressive growth produces recurrence in approximately 50% of appropriately treated cases and metastases along the neuraxis in 30%. To date, no studies exist concerning the production of autocrine growth factors by this brain tumor type. Malignant brain tumors in adults often produce platelet-derived growth factor (PDGF). A medulloblastoma cell line, TE-671, has been used for many years in pediatric neuro-oncologic studies. We assayed this medulloblastoma cell line for the production of PDGF. PDGF is produced by medulloblastoma cells grown in monolayer tissue culture and stimulates PDGF-sensitive 3T3 fibroblasts to incorporate tritiated thymidine in a dose-dependent fashion. This biologic activity is blocked by PDGF antibodies in a dose-dependent relationship. We postulate that PDGF produced by medulloblastoma cells plays a role in the growth of this tumor by stimulating mitogenic activity.

Humans↗
PubMedDate not supplied

Postoperative wound infections in a children's hospital.

A prospective study was made of postoperative wound infections at Milwaukee Children's Hospital for 1 year. Essentially all procedures requiring a skin incision were included. The clean surgical wound infection rate was 3.1% (26 infections in 849 cases). There were no significant differences in clean wound infection rates among the individual surgeons or among the four busiest surgical services. The occurrence of postoperative wound infections was associated with administration of prophylactic antibiotics, longer duration of surgical procedures and longer hospital stay before and after surgery. About 50% of patients having a clean surgical procedure were given prophylactic antibiotics. Prophylactic antibiotic were given for 4 days or more in about half the cases.

Anti-Bacterial Agents↗
PubMedDate not supplied

Spontaneous rupture of the liver during pregnancy: a case report.

Hepatic congestion resulting in hepatic rupture during pregnancy is a rare yet catastrophic event carrying a 60 to 70% maternal mortality rate. With preeclampsia and associated epigastric pain continuing to be a major problem confronting pregnant women, hepatic congestion may be more prevalent than believed. Current etiology, treatment, and characteristics of women who experience hepatic rupture are examined. A case report and nursing protocol are presented.

Adult↗
PubMedDate not supplied

Dressing changes by specialized personnel reduce infection rates in patients receiving central venous parenteral nutrition.

In 60 pediatric patients, 75 central venous catheters representing 1866 patient days were placed to provide parenteral nutrition. During the 21-month study period, surgical residents were responsible for dressing changes during the first 16 months and a specially trained nurse was responsible during the final 5 months. Twenty percent of the lines became infected. The infection rate was significantly higher in the lines cared for by residents, 28.8% compared to 3.3% in the lines cared for by the nurse. This occurred in spite of the lines being in place significantly longer in the nurse group (31.7 vs 20.3 patient days/line). These data indicate that a specially trained person using aseptic techniques can reduce infection rates in patients receiving central venous parenteral nutrition.

Bacterial Infections↗
PubMedDate not supplied

Stereopsis testing to reduce overreferral in preschool vision screening.

Three- and 4-year-old children who obtain the minimum failing visual acuity result of one-line difference between eyes in preschool vision screening with isolated optotypes have a high rate of overreferral. We evaluated the Random Dot E Stereotest (RDES) to determine if a passing result at a high threshold on this test, as administered by lay screeners, could safely nullify referral for a minimum failing visual acuity test result. Fifty-eight children with a "one-line difference" result also had the RDES administered to them during screening at distances of 40 cm and 1.5 m. Upon subsequent ophthalmologic examination, 45 of these children were found to be normal, and 13 had abnormal findings. Thirty-nine of the children with normal examinations had correctly passed the RDES at 1.5 m. Seven of the 13 children with abnormal findings had correctly failed the RDES. Thus, the specificity of stereotesting was 87% and the sensitivity was 54%. Among the six children who falsely passed the stereopsis test during screening, best-corrected visual acuity was no worse than 20/40 and no child had greater than a one-line difference in acuity. Therefore, no amblyopia was missed. If a passing result on the stereotest at 1.5 m had been allowed to nullify a one-line difference referral, overreferral would have decreased 87% but underreferral would have increased 46%. We cannot yet recommend modifying current visual acuity referral criteria based on stereopsis testing results until the sensitivity of stereopsis screening by lay screeners at a sufficient threshold is improved.

Child, Preschool↗
PubMedDate not supplied

The effect of a medical journal club on residents' knowledge of clinical epidemiology and biostatistics.

BACKGROUND: We performed a prospective controlled trial of a monthly journal club to determine if it would increase pediatric residents' knowledge of clinical epidemiology and biostatistics. METHODS: Intervention residents received two didactic sessions before the journal club started. Eight monthly journal club sessions followed. Pediatric residents at another institution served as controls. Intervention and control residents completed a pre- and post-test on clinical epidemiology and biostatistics. RESULTS: Neither the intervention nor the control group showed a significant change in test scores over the 9-month period. CONCLUSION: A more intensive and more structured approach is needed to effectively teach clinical epidemiology and biostatistics to residents.

Biometry↗
PubMedDate not supplied

Influenza surveillance of Wisconsin (USA) population-detection of A/New Jersey by isolation and serologic monitoring and vaccine evaluation.

The 1976-77 influenza surveillance in Wisconsin consisted of three major areas of study. Serum and virus isolation specimens were obtained from the practicing medical community and from epidemiologic studies. From all sources 1,132 throat specimens were tested by egg and tissue culture inoculations. Three isolations similar to A/New Jersey/8/76 were recovered from pig farm associated patients. One contact with one of the isolate patients seroconverted to A/New Jersey suggesting patient to patient spread. Serological monitoring of 1,361 patients showed no other A/New Jersey activity in the state. In addition 31 influenza B/Hong Kong and 8 A/Victoria isolates have been recovered as well as 34 B and 11 A seroconversions. A surveillance using primarily syphilis serology premarital serums has been conducted from August 29, 1976 through April 23, 1977. No significant influenza A activity in the state was recognized by this study. However, increased herd immunity from vaccination was detected. The last phase of this surveillance was an evaluation of the mass immunization program and the efficacy of the vaccines. Two-hundred-ninety individuals contributed pre- and post-vaccine serums to this study. Eighty-three percent of those persons with a pre-vaccine titer of 1:80 or less to A/New Jersey/8/76 developed a post-vaccine titer four-fold or greater to that virus type. Those who received vaccine containing A/Victoria/3/75 were less responsive. Refractiveness to vaccine antibody stimulation was greater than or equal to 1:160 for A/New Jersey and less than or equal to 1:40 with A/Victoria.

Adolescent↗