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Biomedical subjects

N Roos

Publications and source records attributed to N Roos.

114 records · Page 7Linked to original sources
PubMed1982

Identification and characterization of the pore-forming protein in the outer membrane of rat liver mitochondria.

The proteins of the outer membrane from rat liver mitochondria have been subfractionated by means of density gradient centrifugation. The different polypeptides of the membrane were incorporated into asolectin vesicles and black lipid membranes. It was observed that a polypeptide of Mr 32 000 renders asolectin vesicles permeable to ADP and forms pores in bilayer membrane. These pores showed the same properties as the channels which are formed in the lipid membrane after addition of Triton X-100 solubilized complete outer membrane. The properties of the pore are as follows: (1) The formation of pores depends on the type of phospholipid used for the preparation of the black membranes. (2) The pore is inserted asymmetrically into the membrane. (3) The pore is voltage gated but does not switch off completely at higher voltages. The pore seems to show different conductance states decreasing conductance being observed at increasing voltage. The implications of these findings for the regulation of transport processes across the outer membrane are discussed.

Animals↗
PubMed1977

Proprotionate linear measurements in radiographic cephalometric assessments. A methodological study.

Craniofacial structures were studied by radiographic cephalometry in 10 boys and 10 girls at 9-14 years and 13 years later. The linear distances were measured in mm as well as with indices with the sella-nasion distance as denominator. The index measurements proved to be dependent on age to a rather limited extent. This held true for index measurements referring to skeletal points as well as soft-tissue points.

Adolescent↗
PubMedDate not supplied

Pulmonary fungal infections in immunocompromised patients: incidence and risk factors.

In a prospective study, 178 patients with fever > 38.4 degrees C and newly diagnosed pulmonary infiltrates underwent bronchoscopy with bronchoalveolar lavage (BAL), aspiration of bronchial secretions (BS) and, in 71 cases, protected specimen brushing (PSB). In 42/143 immunocompromised patients (haematological malignancies, n = 92; AIDS, n = 22; immunosuppressant therapy, n = 29) and in 4/35 patients with no defined underlying disease fungal pneumonia was present (candidosis, n = 35; aspergillosis, n = 8 mixed fungal infection, n = 3). Candidosis was combined, in 17 cases, with Aspergillus (n = 3), bacterial (n = 15) or cytomegalovirus (n = 2) infection. Aspergillosis was combined in eight cases with infection with Candida (n = 3), Pneumocystis carinii (n = 1) or bacteria (n = 5). The sensitivity of BAL and PSB in Candida pneumonia was 48% and 50%, respectively; specificity was 75% and 74% respectively. Bronchial secretions were more sensitive in detecting Candida pneumonia, but specificity was only 55%. In aspergillosis, the specificity of BAL, BS and PSB in each case was 100%; the sensitivity of BAL, BS and PSB was 38%, 64% and 100%. Twenty-four fungal infections were fatal. Unfavourable prognostic factors were respiratory failure needing mechanical ventilation, diffuse bilateral pulmonary infiltrates, mixed fungal infections and start of i.v. antifungal treatment > 14 days after fever onset, which were associated with a mortality rate of 74%, 67%, 67% and 63% respectively.

Aspergillosis↗
PubMedDate not supplied

Assessing unmet need for services for pediatric undernutrition. HSPH MPH Student Research Team.

Evaluation and treatment of undernourished children in Massachusetts has been provided since 1984 by the seven outpatient Growth and Nutrition (GN) Clinics administered by the Massachusetts Department of Public Health (MDPH). This study explored the potential unmet need for nutritional services among low-income, multiethnic children ages birth to 36 months presenting to an inner-city pediatric emergency department (ED). During March 1992, staff obtained weight and stature on all children under 36 months of age brought to the ED. A structured interview questionnaire obtained data on demographic characteristics, birth history, and participation in means-tested federal benefit programs and MDPH GN Clinics. Among 252 children with complete anthropometric data, 22 (8.9%) had at least one anthropometric index (weight-for-age, height-for-age, weight-for-height) below the fifth percentile. Birthweights < 2500 g were reported by 18.5% of caregivers; 58% of children with height-for-age less than the fifth percentile and 63% of those with weight-for-age less than the fifth percentile were low birthweight (LBW) (Fisher's exact test, P < .002 and P < .006, respectively). Thirteen percent of families had no health insurance, and 77.1% received Medicaid. Among 22 children with anthropometry less than the fifth percentile, one half to three quarters participated in federally funded programs including Special Supplemental Food Program for Women, Infants, and Children (WIC), Aid to Families With Dependent Children (AFDC), and Food Stamps, but only 11% had been referred to the GN Clinics. These findings suggest that federal means-tested benefit programs and MDPH GN Clinic services were underused by groups at nutritional risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗
PubMedDate not supplied

Seasonal variation in weight-for-age in a pediatric emergency room.

OBJECTIVE: The authors assess seasonal variations in the prevalence of low weight-for-age among young children visiting the pediatric emergency room of a city hospital. METHODS: We analyzed data on 11,118 children ages 6 to 24 months who visited the Boston City Hospital Pediatric Emergency Department between July 1989 and June 1992. Medical diagnoses were documented on a randomly selected subsample of 1,569 children. In addition, a questionnaire about food insecurity was administered to a convenience subsample of 269 families with children under 3 years of age. RESULTS: The percentage of children visiting the emergency room with weight-for-age below the fifth percentile was significantly higher for the three months following the coldest months than for the remaining months of the year, controlling for year of measurement. In the subsample, gastrointestinal illness was correlated with both season of measurement and weight-for-age, but the seasonal effect remained for the entire sample after controlling for dehydration. The questionnaire data suggested a relationship between economic stress and food insecurity that might help explain the seasonal effect. Families who were without heat or who were threatened with utility turnoff in the previous winter were twice as likely as other families to report that their children were hungry or at risk for hunger. CONCLUSIONS: Winter and early spring constituted periods of increased nutritional risk in the in this sample of predominantly low-income children, probably because of the increased caloric associated with cold stress and infections. Further research is needed to assess whether decreased caloric availability due to high heating costs, a "heat or eat" effect, also contributes to this phenomenon.

Age Factors↗