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Biomedical subjects

D Hammer

Publications and source records attributed to D Hammer.

36 records · Page 2Linked to original sources
PubMed1979

Flavanone synthase from Petroselinum hortense. Molecular weight, subunit composition, size of messenger RNA, and absence of pantetheinyl residue.

Flavanone synthase from irradiated cell suspension cultures of parsley was purified to apparent homogeneity. Molecular weights of about 77 000 for the enzyme and about 42 000 for the subunits were determined respectively by sedimentation-equilibrium measurements and disc-gel electrophoresis in the presence of dodecyl sulfate. A specific antiserum was prepared for the enzyme and was used in an assay for flavanone synthase mRNA activity in partially purified RNA preparations. The apparent molecular size of flavanone synthase mRNA was estimated by sucrose gradient centrifugation and gel electrophoresis under partially denaturing conditions. Values of about 17 S and Mr = 0.62 X 10(6) were obtained. The fractionation patterns suggested that flavanone synthase mRNA was homogeneous in size. All together, the results support the idea that the enzyme is composed of two subunits which are probably identical. Amino acid analysis and a microbial assay were carried out to test the possible occurrence of cysteamine, beta-alanine, and pantothenate in the enzyme. The results were negative, indicating the absence of pantetheine or a similar residue. The possible similarity in mechanism between flavanone synthase and 3-oxoacyl-(acyl carrier protein) synthase is discussed.

Acyltransferases↗
PubMed1979

Altered collagen composition in a prolapsing mitral valve with ruptured chordae tendineae.

A patient presented with mitral valve prolapse, ruptured chordae tendineae, severe mitral regurgitation and congestive heart failure. Pathologic studies demonstrated myxomatous changes of both mitral leaflets. Collagen analysis of the valve and of the chordae tendineae revealed the presence of type I collagen in normal quantities and a striking absence of type III and AB collagens. The altered collagen in this patient's mitral valve probably contributed to the development of his mitral valve disorder.

Chordae Tendineae↗
PubMed1979

Developmental trends in eating rates of normal and overweight preschool children.

Eating rates (bites per interval) and other meal behaviors (number of chews, sips, talks with a neighbor, and chews per bite) were observed for 30 normal and 30 overweight white preschool children in their school cafeterias. Children were classified according to weight (overweight or normal), age (1 1/2--2 years, 3--4 years, or 5--6 years) and sex. Analysis of variance revealed that overweight preschool children demonstrated a somewhat higher rate of distinctly fewer chews per bite. Boys showed increasing chew rates with increasing age. Talk rates also increased with age but were unrelated to sex or weight status. Sip rates were not significantly associated with age, sex, or weight status. These results support the hypothesis that overweight persons are characterized by an increased eating rate and show that it is apparent even around the time of first self-feeding.

Age Factors↗
PubMed1977

Getting care to nursing-home patients: a problem and a proposal.

Data abstracted from transportation company records showed that nursing home patients made an average of 3.6 trips per year for care out of the nursing home. The bulk of this care (55 per cent) was provided at University Hospital with over a quarter provided at private physicians' offices and community health centers. On the basis of chart abstracts over half the patients had been seen within the previous month, but the quality of that visit was open to question. A means of providing cost-effective primary medical care in the nursing homes using a team of nurse practitioner and social worker is proposed.

Community Health Services↗
PubMedDate not supplied

Parenting stress and depression in children with mental retardation and developmental disabilities.

Although many types of behavioral and emotional disorders are prevalent in children with developmental delays, the phenomenology of childhood depression in this population remains poorly understood. This study examined the relationships among symptoms of depression, child problem behaviors, and parenting stress in a sample of 29 children with developmental delays. Results supported the usefulness of the Children's Depression Inventory (CDI) in assessing depression in these children initially reported by Matson, Barrett, and Helsel (1988). Parent ratings from the CDI were significantly associated with maternal depression, an index of DSM-III-R depression criteria, and negative self-image, anxiety, and conduct problems in children. A matched subsample of children (n = 12) with high versus low depression ratings revealed significant differences in total scores from the Parenting Stress Index (Abidin, 1986) and the index of DSM-III-R depression criteria. Together, these data suggest that children with developmental delays exhibit a similar pattern of symptoms and associated characteristics to those found in normal children with diagnoses of depression.

Child↗
PubMedDate not supplied

The Nisonger Child Behavior Rating Form: age and gender effects and norms.

The Nisonger CBRF is a new informant behavior rating scale that was adapted for assessing children and adolescents with mental retardation. A total of 369 children referred to interdisciplinary diagnostic clinics for children with developmental disabilities were rated on the Nisonger Child Behavior Rating Form by their parents and teachers. Normative data (means, T scores, and percentiles) are presented Subscale scores were analyzed as a function of age and gender. Age influenced 3 of 8 subscales on the parent ratings and 1 subscale on the teacher ratings. Gender did not influence subscale scores. Age and gender results are discussed in relation to previous studies of subject variables.

Adolescent↗
PubMedDate not supplied

The Nisonger CBRF: a child behavior rating form for children with developmental disabilities.

Although the rate of behavior and emotional problems of children with mental retardation is considerably higher than the rate among typically developing children, there is a shortage of tools for assessing persons with mental retardation. The Child Behavior Rating Form (CBRF) was modified by altering instructions and adding new items describing behavior problems known to occur in children with mental retardation. The adapted scale was named the Nisonger CBRF. Three hundred sixty-nine children being assessed at a University Affiliated Program for MR/DD were rated on the CBRF by their parents and teachers. Independent factor analyses of parent and teacher ratings produced two Social Competence subscales and six Problem Behavior subscales. These results were largely consistent across rater types and similar to prior findings with the CBRF. Internal consistency was generally high, parent-teacher agreement was satisfactory, and subscales from the Nisonger CBRF correlated highly with analogous subscales from the Aberrant Behavior Checklist. The Nisonger CBRF appears to be a promising new tool for assessing behavioral and emotional problems in children with mental retardation; however, further psychometric work is warranted.

Adolescent↗
PubMedDate not supplied

Hip arthroscopy without traction: In vivo anatomy of the peripheral hip joint cavity.

PURPOSE: To describe the in vivo anatomy of the peripheral compartment of the hip joint using a systematic sequence of examination without traction. TYPE OF STUDY: Case series. METHODS: We performed 35 hip arthroscopies without traction from an anterolateral portal in the supine position. Free draping and a good range of movement of the hip joint were used to relax parts of the capsule and increase the intra-articular volume of the area that was inspected. Each procedure was documented on a standard protocol including detailed information on technical features and normal and pathologic intra-articular findings. RESULTS: A comprehensive inspection of the peripheral compartment was obtained from the anterolateral portal. A systematic sequence of examination was developed separating the periphery of the hip joint into 7 areas: anterior neck area, medial neck area, medial head area, anterior head area, lateral head area, lateral neck area, and posterior area. The arthroscopic in vivo anatomy of each area is described. In 3 patients, 1 to 3 loose bodies were removed. In 1 patient with a synovial chondromatosis, 40 chondromas were retrieved. In osteoarthritis, impinging osteophytes were trimmed in 3 cases and partial synovectomy was performed in 10 patients. The following complications were observed: a temporary sensory deficit of the lateral femoral cutaneus nerve in 1 patient, scuffing of the anterior surface of the femoral head in 3 patients, detaching of an osteophyte in 1 patient, and partial tears of the anterior synovial fold in 10 patients. CONCLUSIONS: Arthroscopy without traction allows for a complete evaluation of hip anatomy without the loaded articular surfaces, the acetabular fossa, and the ligamentum teres. For a complete overview of both the central and peripheral part of the hip, traction is necessary for the central part.

Arthroscopy↗
PubMedDate not supplied

Changes in the rhizosphere of metal-accumulating plants evidenced by chemical extractants.

The plants Salix viminalis L. (common osier) and Thlaspi caerulescens J. Presl & C. Presl have been studied often because of their high potential to extract heavy metals from soils. The soil properties favoring this phytoextraction are not yet fully known. In this study we compared three frequently used single-extracting agents (NaNO3, diethylenetriaminepentaacetic acid [DTPA], and ethylenediaminetetra-acetic acid [EDTA]) with a sequential extraction procedure to describe changes in the different Cd, Cu, and Zn pools in the rhizosphere of S. viminalis and T. caerulescens grown on calcareous and acidic Swiss soils in a pot experiment. The sequential extraction was used to assess the chemical affinities of these heavy metals (HM) in the soil whereas the single extractants were used for estimating the bioavailable HM pools in the soils. Cadmium depletion in several pools was most apparent in the acidic soil, with a significant decrease observed in the NaNO3-, DTPA-, and EDTA-extractable fractions following T. caerulescens growth compared with control pots. The sequential extraction showed that most Cd extracted by the plant from the acidic soil originated from the organic pool, which implies that heavy metals bound to organic matter may constitute a significant part of the bioavailable Cd pool in soils. In the calcareous soil only a small amount of Cd was taken up by T. caerulescens, and this came mainly from the carbonate-bound fraction. This study shows that T. caerulescens, and to a lesser extent S. viminalis, can alter the heavy metal distribution in different soil pools within 90 d.

Chelating Agents↗