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Biomedical subjects

J W White

Publications and source records attributed to J W White.

At least 19 recordsLinked to original sources
PubMed1992

Effects of acyl chain length on the conformation of myelin basic protein bound to lysolipid micelles.

The interactions of myelin basic protein with micelles of lysophosphatidylcholine detergents of different acyl chain lengths were investigated by circular dichroism (CD), small-angle X-ray scattering, Fourier transform infrared spectroscopy (FT-IR), and 1H, 13C and 31P nuclear magnetic resonance spectroscopy (NMR). Circular dichroic, FT-IR, and 1H NMR measurements indicated that the conformational changes induced in the protein molecules by association with micelles depended on the acyl chain length of the detergents. Size is one of the physical properties of micelles which is a function of the length of the acyl chains. The radii of gyration of detergent micelles in complexes with the protein measured by small-angle X-ray scattering indicated that the average size of the micelles was a quadratic function of the acyl chain length. The dependence of the protein conformational changes on micelle size was used to ascertain the order in which different protein segments associate with the detergents. Several procedures were employed to change the fluidity of micelles formed with detergents of given acyl chain lengths. The conformational changes observed on the MBP molecule by varying the micelle properties without changing the length of the chain, suggested that the changes depended on the size and fluidity of the micelles.

Animals↗
PubMed1991

Physicochemical characterization of dodecylphosphocholine/palmitoyllysophosphatidic acid/myelin basic protein complexes.

The stoichiometry of dodecylphosphocholine/palmitoyllysophosphatidic acid/myelin basic protein complexes and the location of the protein in the micelles have been investigated by electron paramagnetic resonance, ultracentrifugation, small-angle X-ray scattering, 31P, 13C, and 1H nuclear magnetic resonance spectroscopy, and electron microscopy. Ultracentrifugation measurements indicated that well-defined complexes are formed by association of one protein molecule with approximately 133 detergent molecules. The spin-labels 5-, 12-, and 16-doxylstearate have been incorporated into detergent/protein aggregates. Electron paramagnetic resonance spectral parameters and 13C and 1H nuclear magnetic resonance relaxation times showed that the addition of myelin basic protein does not affect the environment and location of the labels or the organization of the micelles. Previous results suggesting that the protein lies primarily near the surface of the micelles have been confirmed by comparing 13C spectra of the detergents with and without protein with spectra of detergent/protein aggregates containing the spin labels. Electron micrographs of the complexes taken by using the freeze-fracture technique revealed the presence of particles with an estimated radius about three times the radius of the micelles measured by small-angle X-ray scattering. The structural integrity of the complexes appears to be based on intramolecular protein interactions as well as protein-detergent interactions.

Animals↗
PubMed1991

National nosocomial infections surveillance system (NNIS): description of surveillance methods.

The National Nosocomial Infections Surveillance System (NNIS) is an ongoing collaborative surveillance system sponsored by the Centers for Disease Control (CDC) to obtain national data on nosocomial infections. The CDC uses the data that are reported voluntarily by participating hospitals to estimate the magnitude of the nosocomial infection problem in the United States and to monitor trends in infections and risk factors. Hospitals collect data by prospectively monitoring specific groups of patients for infections with the use of protocols called surveillance components. The surveillance components used by the NNIS are hospitalwide, intensive care unit, high-risk nursery, and surgical patient. Detailed information including demographic characteristics, infections and related risk factors, pathogens and their antimicrobial susceptibilities, and outcome, is collected on each infected patient. Data on risk factors in the population of patients being monitored are also collected; these permit the calculation of risk-specific rates. An infection risk index, which includes the traditional wound class, is being evaluated as a predictor of the likelihood that an infection will develop after an operation. A major goal of the NNIS is to use surveillance data to develop and evaluate strategies to prevent and control nosocomial infections. The data collected with the use of the surveillance components permit the calculation of risk-specific infection rates, which can be used by individual hospitals as well as national health-care planners to set priorities for their infection control programs and to evaluate the effectiveness of their efforts. The NNIS will continue to evolve in finding more effective and efficient ways to assess the influence of patient risk and changes in the financing of health care on the infection rate.

Centers for Disease Control and Prevention, U.S.↗
PubMed1991

Courtship violence: incidence in a national sample of higher education students.

An approximately representative national sample of 2,602 women and 2,105 men was surveyed regarding their frequency of inflicting and sustaining verbal and physical aggression in a heterosexual relationship. Results revealed that approximately 81% of the men inflicted, as well as received, some form of verbal aggression at least once, while the comparable figure for women was 87-88%. The percentage experiencing some form of physical aggression was lower; about 37% of the men and 35% of the women inflicted some form of physical aggression and about 39% of the men and 32% of the women sustained some physical aggression. No differences were found as a function of ethnicity, family income, and institutional characteristics. Regional differences in the use of verbal and physical aggression, and in the receipt of physical aggression, were found for men.

Adult↗
PubMed1990

Mycosis fungoides in children and adolescents.

The clinical and histologic findings in five young patients with mycosis fungoides are reviewed. The skin specimen from a 16-year-old boy had an infiltrate predominantly Leu-1+, Leu-4+, Leu-3a + 3b+, OKT6+, Leu-2a-, Leu-8-, and Leu-9-, and rearrangements were noted in T cell receptor gene (beta chain [constant region probe] and gamma chain [J region probe]); no rearrangements were found in a histologically normal lymph node or peripheral blood. The skin specimen from an 11-year-old girl contained predominantly Leu-4+ and Leu-9+ lymphoid cells. No T cell receptor gene rearrangements were found in the skin or in an involved lymph node. The variations in clinical, histologic, and immunopathologic features suggest that mycosis fungoides in young patients represents a heterogeneous subgroup of cutaneous T cell lymphoma.

Adolescent↗
PubMed1990

Multiple keratoacanthomas treated with oral retinoids.

Multiple eruptive keratoacanthoma of Witten and Zak is a rare disorder characterized by numerous small, eruptive tumors and larger, more typical keratoacanthomas. Affected patients have features of Grzybowski-type keratoacanthomas and Ferguson Smith type. Two patients with multiple keratoacanthomas were treated with oral retinoids. Both patients had hundreds of follicular papules on the trunk and extremities. Less common lesions included nodules with central horn-filled craters more characteristic of classic keratoacanthomas. Retinoid therapy resulted in regression of the larger, more typical keratoacanthomas in both patients. The small follicular keratoacanthomas remained unaffected. Thus oral retinoids are only partially beneficial for the treatment of the Grzybowski type or the Witten and Zak type of multiple eruptive keratoacanthomas.

Administration, Oral↗
PubMed1989

Two LINE 1 repeats in rat.

One LINE 1 repeat has been located 661 bp downstream from the last albumin exon and another approx. 10 kbp downstream from the last alpha-fetoprotein exon in the rat genomic DNA. The LINE 1 repeat following the albumin gene is truncated at its 5' end and is 1204 nucleotides long. The 5' end of the longer repeat downstream from the alpha-fetoprotein gene has not been determined. The two repeats have 95% homology with each other, with the exception of a short diverse 3' end sequence just preceding the putative polyadenylation signal.

Albumins↗
PubMed1989

Family history of convulsions and use of pertussis vaccine.

To evaluate the risk of neurologic events after vaccination with diphtheria-tetanus-pertussis (DTP) vaccine, we used data from the Centers for Disease Control Monitoring System for Adverse Events Following Immunization to compare the family history of convulsions in persons reporting neurologic events with that in persons reporting nonneurologic events; these events have an onset within 3 days of immunization with DTP vaccine, given either alone or with oral poliovirus vaccine. Persons reporting neurologic events were 6.4 times more likely to report a prior personal history of convulsions than those reporting nonneurologic events (95% confidence interval 4.7 to 8.8), and were 2.4 times more likely to report a history of convulsions in first-degree family members, that is, siblings or parents (95% confidence interval 1.7 to 3.4). Similar risks were noted for subgroup analyses controlling for type of event (febrile vs nonfebrile convulsion), age at immunization, source of report, number of previous doses of DTP vaccine, and day of onset. Because the Centers for Disease Control monitoring system receives reports on a nonrandom sample of all adverse events after immunization, selection bias could not be ruled out. On the basis of these data, we conclude that children with a family history of seizures are at increased risk of neurologic events, primarily febrile convulsions, after DTP vaccination. However, this increase in risk may reflect a nonspecific familial tendency for convulsions rather than a specific vaccine effect. Considering the rare occurrence of neurologic events after DTP vaccination, the generally benign outcome of febrile convulsions (which make up the majority of these neurologic events), and the possible increased risk of pertussis in the general population if the estimated 5% to 7% of persons with a first-degree family history of convulsions were exempted from pertussis vaccination, we further conclude that a history of convulsions in siblings or parents should not be a contraindication to pertussis vaccination. Special care in the prevention of postvaccination fever may be warranted in children with a family history of seizures.

Centers for Disease Control and Prevention, U.S.↗
PubMed1989

Cytophagic histiocytic panniculitis is not always fatal.

Two patients with benign cytophagic histiocytic panniculitis are presented and compared with the one benign and ten fatal cases previously reported. Benign-appearing histiocytes which engulf blood cells, nuclear debris, and platelets are the most characteristic feature of the disease. This cytophagia tends to be massive in the subcutaneous tissue and involves extracutaneous organs only in the fatal cases. The course is chronic in the benign form. Patients with the fatal form tend to have fever, hepatosplenomegaly, serosal effusions, ecchymoses, peripheral adenopathy, and mucosal ulcers. Anemia, leukopenia, elevated liver enzyme levels, and coagulopathy are present in almost all and hypocalcemia in many patients with a fatal course. Cytophagic histiocytic panniculitis may represent a form of regional histiocytosis primarily involving subcutaneous tissue. It is midway in the spectrum of the cytophagic histiocytoses.

Adult↗
PubMed1988

Diagnosis of Lafora disease by skin biopsy.

The Lafora type of progressive myoclonus epilepsy is a rare and fatal familial disease characterized by seizures, myoclonus, and dementia. This diagnosis was confirmed in 2 patients by demonstrating the presence of intracytoplasmic polyglucosan bodies, or Lafora bodies, in the peripheral portion of the eccrine sweat gland duct. Exclusive use of the periodic acid-Schiff stain is recommended for demonstrating these diagnostic inclusions. Electron microscopy reveals fine pale-staining filaments, fine dark-staining granules, and dark-rimmed vacuoles within these non-membrane-bound inclusions. Skin biopsy is the preferred method of confirming the diagnosis of Lafora disease.

Adolescent↗
PubMed1988

Structure and evolution of somatostatin genes.

A bovine pancreatic preprosomatostatin cDNA clone has been isolated and sequenced. Although it encodes a predicted 116 amino acid preprosomatostatin that is very similar in primary structure to those deduced from other mammalian preprosomatostatin cDNAs, there are some differences in amino acid composition. Hybridization of this clone to Northern blots of fetal bovine pancreatic poly(A+) RNA reveals a mRNA of 700 nucleotides. Evolution of the preprosomatostatin genes was studied by statistical analysis of anglerfish, catfish, bovine, rat, and human cDNA sequences. The results suggest that the two somatostatin genes present in both anglerfish and catfish were the result of a gene duplication event in a common ancestor of anglerfish and catfish.

Animals↗
PubMed1988

Vesiculobullous cutaneous lymphatic reflux.

Although lymphedema is a fairly common condition, cutaneous vesicles and bullae due to reflux of lymphatic fluid are rare. We describe a patient with adenocarcinoma of the cervix treated by radiation in whom acute secondary lymphedema with overlying clear vesicles and bullae developed. Histopathologic examination revealed a subepidermal vesicle communicating directly with a dermal lymphatic vessel. Vesicles occur only in lymphedema of acute onset. Vesiculobullous cutaneous lymphatic reflux should be recognized as a rare complication of lymphedema and included in the differential diagnosis of cutaneous blistering disease.

Abdomen↗
PubMed1988

Tips from the experts.

Experienced dermatologic therapists share therapeutic pearls they have found valuable in their own practices. These helpful, often ingenious, suggestions cover a wide range of dermatologic conditions.

Humans↗
PubMed1988

A myeloid-related sequence that localizes to human chromosome 8q21.1-22.

A myeloid-related sequence (mrs) has previously been identified that is highly expressed in selected subpopulations of myeloid leukocytes. Nucleotide sequence analysis indicates that mrs encodes what is apparently a unique 93-amino acid protein that includes an 18-amino acid leader sequence. Hybridization of an mrs cDNA probe to a Southern blot made from somatic cell hybrid DNAs shows 100% concordance with human chromosome 8, thus indicating that mrs localizes to this chromosome. In situ hybridization to metaphase chromosomes further sublocalizes mrs to bands 8q21.1-23 as 58% of the grains displayed on chromosome 8 were clustered in this region. This area encompasses the translocation breakpoint 8q22, which is rearranged in an estimated 18% of patients diagnosed with the M2 subclassification of acute nonlymphocytic leukemia (M2-ANLL). When Southern blot hybridization was performed by using somatic cell hybrid DNAs harboring either a single 8q- or a single 21q+ chromosome from two different patients with M2-ANLL, a signal was only detected in the hybrid containing the 8q-chromosome.

Amino Acid Sequence↗
PubMed1987

Differential expression of the human thymosin-beta 4 gene in lymphocytes, macrophages, and granulocytes.

A cDNA clone encoding human thymosin-beta 4 was isolated from a cDNA library prepared from peripheral blood leukocytes of a patient with acute lymphocytic leukemia. This clone contained the entire coding sequence of 43 amino acid residues of thymosin-beta 4 and had an initiation codon and two termination codons. The amino acid and nucleotide sequences in the coding region were well conserved between rat and human. Nine of 132 nucleotides were different in the coding sequences (93% homology), but the deduced amino acid sequences were identical. No signal peptide was found in the deduced protein sequence. Human thymosin-beta 4 mRNA, approximately 830 nucleotides in length, was about 30 nucleotides larger than rat thymosin-beta 4 mRNA. Expression of the human thymosin-beta 4 gene in various primary myeloid and lymphoid malignant cells and in a few human hemopoietic cell lines was studied. Northern blot analyses of different neoplastic B lymphocytes revealed that steady state levels of thymosin-beta 4 mRNA varied as a function of differentiation stage. Thymosin-beta 4 mRNA levels were decreased in myeloma cells as are class II human leukocyte antigen, Fc receptor, and complement receptor, suggesting a relationship between thymosin-beta 4 and the immune response. Thymosin-beta 4 mRNA was more highly expressed in mature granulocytes than in immature blastic cells. Treatment of THP-1 cells, a human monocytic cell line, with recombinant human interferon-lambda reduced the levels of thymosin-beta 4 mRNA. Its level decreased after differentiation of THP-1 cells into Ia+ macrophages, but increased after differentiation of HL-60 cells into Ia- macrophages. The pattern of thymosin-beta 4 gene expression suggests that it may play a fundamental role in the host defense mechanism.

Amino Acid Sequence↗
PubMed1987

The financial incentive for hospitals to prevent nosocomial infections under the prospective payment system. An empirical determination from a nationally representative sample.

To clarify the financial incentives for hospitals to prevent nosocomial infections, we analyzed 9423 nosocomial infections identified in 169 526 admissions selected randomly from the adult admissions to a random sample of US hospitals. By classifying each admission into a baseline diagnosis related group (DRG) (after first excluding all diagnoses of nosocomial infection) and a final DRG (after including these diagnoses), we found that only 5% to 18% of nosocomial infections would have caused the admission to be reclassified to a higher-paying DRG, depending on the extent to which physicians recorded nosocomial infection diagnoses in patients' medical records. The extra payment from the reclassification, averaged over all nosocomial infections, would have been no more than $93 per infection (in 1985 reimbursement rates), constituting only 5% of the hospitals' costs for treating these infections. Thus, at least 95% of the cost savings obtained from preventing nosocomial infections represents financial gains to the hospital.

Adult↗
PubMed1987

Localization of an abundant myeloid-related sequence.

Differential screening of a CML-derived cDNA library was used to isolate a cDNA clone representing an abundant mRNA in leukocytes of chronic phase, chronic myelogenous leukemia (CML) patients. This myeloid-related sequence (mrs) comprises approximately 2% of the chronic phase, CML mRNA. Hybridization of the radiolabeled cDNA to the cellular RNAs of intact, morphologically distinguishable, primary hematopoietic cells indicates that the primary cells producing mrs RNA are eosinophils (Eo), basophils (Baso), promyelocytes (Pro) and myelocytes (Mye). In the neutrophilic series, the abundance of mrs RNA decreases as the cells mature. The mrs RNA potentially encodes a 93 amino acid protein that has not been previously described. It has been localized to chromosome 8, region 8q21.1-23.

Base Sequence↗