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Biomedical subjects

H Wilson

Publications and source records attributed to H Wilson.

At least 37 records · Page 2Linked to original sources

The American Urological Association symptom index: does mode of administration affect its psychometric properties?

PURPOSE: We determine whether self-administration and interviewer administration of the American Urological Association (AUA) symptom index are equivalent. MATERIALS AND METHODS: The AUA symptom index was administered twice to 41 visually impaired or illiterate men. Men who were able were randomized to self-administration first and then interviewer administration (43) or the reverse (40). RESULTS: The scores in each group were reliable. However, because we could not reject a differential carryover effect, the nonsignificant test of mode effect in the crossover design may have been invalid. At time 1 there was no significant difference between group mean scores for randomized patients (p = 0.13). CONCLUSIONS: Although the AUA symptom index should be self-administered when possible, interviewer administration appears to be acceptable.

Aged

Can phage defence maintain colicin plasmids in Escherichia coli?

We examined the role of plasmid-based phage defence in maintaining plasmids, using colicin plasmids in Escherichia coli as a model system. Experimental data indicated that the possession of a colicin plasmid can confer limited protection against bacteriophages. A continuous culture model, using these experimental values, indicated that the observed limited protection alone could selectively maintain colicin plasmids, without requiring a competitive advantage due to colicinogeny. Phage defence might explain the current maintenance of colicin plasmids, given the naturally occurring high levels of resistance to colicins. This model also suggests that many plasmids might be maintained in natural populations, in part, by phage resistance, including 'cryptic' plasmids for which no phenotype is known.

Bacteriocin Plasmids

The development of astrocytes immunoreactive for glial fibrillary acidic protein in the mediobasal hypothalamus of hypogonadal mice.

Numbers of astrocytes immunoreactive for glial fibrillary acidic protein (GFAP) are markedly increased in the mediobasal hypothalamus (MBH) of adult hypogonadal (hpg) mice. The astrocytosis cannot be reversed by administration of gonadal steroids. To investigate whether the glial changes are established in the perinatal period, when crucial developments occur in rodent brain, we determined the distribution of GFAP-IR astrocytes in normal and hpg mouse brain from birth to adulthood. The period up to 3 weeks of age was characterized by the gradual disappearance of radial glia and the increase in mature astrocytes in some brain regions, for example hippocampus. However, there were no apparent differences in GFAP-IR elements between normal and hpg brains and very few astrocytes in the MBH. From age 1 month, increased numbers of GFAP-IR astrocytes were apparent in the hypothalamus in hpg mice and this difference was more obvious at 2 months. By 4 months of age the characteristic astrocytosis in the MBH had been attained and this did not change in older hpg mice. These observations provide no evidence for upregulation of the GFAP gene during the first 2 postnatal weeks when its transcription is highest and astrocytes are proliferating most rapidly. It is more likely that the astrocyte response in the MBH in hpg mice reflects permanent differences in steroid-induced neuronal connectivity, caused by the hypogonadism.

Animals

Antigenicity and immunogenicity of equine influenza vaccines containing a Carbomer adjuvant.

Equine influenza vaccines containing inactivated whole virus and Carbomer adjuvant stimulated higher levels and longer lasting antibody to haemagglutinin in ponies than vaccines of equivalent antigenic content containing aluminium phosphate adjuvants. Five months after the third dose of vaccine containing Carbomer adjuvant, ponies were protected against clinical disease induced by an aerosol of virulent influenza virus (A/equine/Newmarket/79, H3N8). In contrast ponies which received vaccine containing aluminium phosphate adjuvant were susceptible to infection and disease. There was an inverse correlation between prechallenge levels of antibody detected by single radial haemolysis (SRH) and duration of virus excretion, pyrexia and coughing. All ponies with antibody levels equivalent to SRH zones of > or = 154 mm2 were protected against infection and all those with levels > or = 85 mm2 were protected from disease.

Acrylic Resins

Nitrite inhalants: history, epidemiology, and possible links to AIDS.

Nitrite inhalants have been commonly abused substances in the United States. Nitrite inhalants and AIDS was a popular topic in the early 1980s, when the cause of AIDS was not known. With the discovery of HIV, concern about nitrite use in the USA waned. However, nitrite inhalant use is associated with behavioral relapse and HIV transmission among gay men, with decreased lymphocyte counts and natural killer cell activity in a few laboratory studies, and it remains a candidate cofactor in the pathogenesis of AIDS-related Kaposi's sarcoma. Discouraging nitrite use continues to be a worthwhile public health goal.

Acquired Immunodeficiency Syndrome

Human herpesvirus 6 is present in lesions of Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a disease characterized by Langerhans cell infiltration of skin and bone, with its most severe form manifested by multifocal infiltration of many organs. The etiology is unknown, although viral infection has been proposed as a potential pathogenic factor. Human herpesvirus 6 (HHV-6), a recently described member of the human herpesvirus family, has been associated with atypical or malignant lymphocytic processes, and immune disorders. Based on these observations, we suspected that HHV-6 may play a role in the pathogenesis of LCH. Lesional tissue of 30 patients with LCH was retrospectively examined for the presence of HHV-6 by using the polymerase chain reaction. Tissue specimens from 63 patients with other benign and malignant histiocytic and lymphocytic diseases served as controls. In addition, all specimens were examined with control primers specific for herpes simplex virus (HSV). HHV-6 DNA was detected in lesions of 14 of 30 patients with LCH (47%). On clinical subgroup analysis, HHV-6 DNA was found in 10 of 16 patients with extraosseous disease (63%) and in four of 14 patients with disease limited to bone (29%). In each case, the prevalence of HHV-6 in LCH lesions was statistically significant, when compared to the control population. HSV DNA was not found in any of the LCH or control specimens. Although the presence of a virus alone does not establish a causal role in the disease, it supports the possibility of an etiologic relationship. From this study, we emphasize the need for further investigation of the potential HHV-6-mediated pathogenesis of LCH.

Adolescent

Peripheral neuroepithelioma of the soft tissues. A retrospective analysis of fifteen pediatric patients.

PURPOSE: The purpose of this study was to determine the clinical outcome for pediatric patients with peripheral neuroepithelioma treated with combined modality therapy and followed long enough to account for late relapses. PATIENTS AND METHODS: Fifteen patients, ages 3 3/12 to 19 10/12 years, with peripheral neuroepithelioma (median follow-up 91 months) were diagnosed at The Children's Hospital, Denver, Colorado over the period 1980-1989. All of these malignancies originated in the soft tissues. A critical review of these cases was performed with particular consideration given to the site and stage of the tumor and to the radiographic findings at presentation. Thirteen patients had bulk (> 5 cm in the greatest dimension) or metastatic disease. Four patients had primary tumors involving the chest wall. All patients received chemotherapy, which included at least doxorubicin, vincristine, and cyclophosphamide. Definitive surgical resections were performed on 13 of 15 patients. RESULTS: Five patients relapsed. Three were late relapses 24-44 months after diagnosis. Three of the five patients who relapsed had chest wall primaries. There were three deaths in this series due to peripheral neuroepithelioma and one due to sepsis. The overall survival was 68.5%, and the recurrence-free, survival 55.2%. Two patients with pulmonary relapses were treated with surgery and intensive chemotherapy and remain free of disease > 51 months following recurrence. CONCLUSIONS: Combined treatment modalities appear to be important for optimal outcome. This series represents the first report of favorable outcome of peripheral neuroepithelioma using a series with follow-up that is long enough to account for late relapses.

Adolescent

Isolation of a cDNA encoding a human serum marker for acute pancreatitis. Identification of pancreas-specific protein as pancreatic procarboxypeptidase B.

A human pancreas-specific protein (PASP), previously characterized as a serum marker for acute pancreatitis and pancreatic graft rejection, has been identified as pancreatic procarboxypeptidase B (PCPB). cDNAs encoding PASP/PCPB were isolated from a human pancreas cDNA library using a combination of nucleic acid hybridization screening and immunoscreening with antisera raised against native PASP. The deduced amino acid sequence of PASP/PCPB cDNA predicts the translation of a 416-amino acid preproenzyme with a 15-amino acid signal/leader peptide and a 95-amino acid activation peptide. The proenzyme portion of this protein has 76% identity with rat PCPB and 84% identity with bovine carboxypeptidase B. DNA and RNA blot analyses indicate that human PCPB mRNA (1,400 nucleotides) is transcribed from a single locus in the human genome in a tissue-specific fashion. N-terminal sequencing of native PASP and the specific immunoreactivity of bacterially expressed PASP/PCPB with native PASP antibodies confirm the identification of PASP as human pancreatic PCPB.

Acute Disease

Lactation, nutrition and fertility and the secretion of prolactin and gonadotrophins in Mopan Mayan women.

The effect of lactation on menstrual cycles, ovulation and conception was studied in a group of non-contracepting Amerindian Mopan Mayan women. Anthropological observations of relevant events were made over a 21-month period. Blood samples were assayed to determine the plasma concentrations of prolactin, luteinising hormone, follicle stimulating hormone, human chorionic gonadotrophin, placental lactogen, oestrogen, progesterone and cortisol. The data show that: frequent and prolonged breast-feeding was associated with a marked increase in plasma prolactin concentrations to levels similar to those in lactating Gaing but higher than those in lactating Scottish women; ovulatory menstrual cycles and pregnancy occurred during frequent lactation; in lactating menstruating women there was an inverse correlation between fat weight and months post-partum. These data suggest that other factors as well as suckling account for the effects of lactation on fecundity.

Belize

Steroid control of central neuronal interactions and function.

Steroids have potent actions on the brain which can be categorized as; (i) fast (approximately ms-s), (ii) intermediate (h-days), (iii) long-term reversible (days-weeks) and (iv) long-term irreversible. Here attention is focussed on the intermediate and long-term reversible effects of steroids with emphasis on glucocorticoids and oestrogen. Glucocorticoid negative feedback is generally classified as fast, delayed and long-term. Fast negative feedback would appear to depend mainly on a reduction in pituitary responsiveness to corticotrophin releasing factor-41 (CRF-41) and possibly arginine vasopressin (AVP). Delayed feedback is mediated by reduced AVP release into hypophysial portal blood and blockade of the ACTH response to CRF-41. Long-term negative feedback is a consequence of reduced CRF-41 and AVP release into portal blood. Lesion and electrical stimulation studies pinpoint the paraventricular nuclei as the main site at which glucocorticoids act to control ACTH release. Oestrogen at physiologically low plasma concentrations inhibits gonadotrophin secretion. At physiologically high plasma concentrations, such as those that occur during the preovulatory surge, oestradiol-17 beta stimulates the biosynthesis of LHRH mRNA and LHRH and the release of LHRH into hypophysial portal blood. Oestradiol also increases pituitary responsiveness to LHRH. The action of oestrogen on LHRH neurons is probably mediated by interneurons and may involve disinhibition; this view is supported by our in situ hybridization studies which show that oestrogen, in its positive feedback mode, significantly reduces the synthesis of proopiomelanocortin mRNA in arcuate neurons which when active are likely to inhibit LHRH neurons. The mechanism of action of oestrogen on the pituitary gland is not yet established, but clues from the action of the priming effect of LHRH suggests that oestrogen may potentiate phosphoinositide second messenger cascades. LHRH priming involves the synthesis of a 70 kDa protein the N-terminus of which is identical to an oestrogen-induced protein in the ventromedial hypothalamic nucleus involved in lordosis, and to that of phospholipase C alpha. Attention is drawn to the remarkable economy of the system by which a single steroid, oestrogen, has effects on the brain and pituitary gland which result in a co-ordinated sequence of amplifier cascades which lead first to the ovulatory surge of luteinizing hormone and then to mating behaviour, both of which are obviously essential for continuation of the species.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenocorticotropic Hormone

The provision of ophthalmic services for a rehabilitation day care centre population with multiple physical handicaps.

The provision of the wide variety of support services necessary for patients with multiple handicaps is often poorly coordinated. In this study a group of 108 adults, aged from 19 to 90 years, who suffered from multiple physical handicaps and attended a rehabilitation day care centre, had their visual functions and requirements assessed by a multidisciplinary team. The programme consisted of five stages. Each patient was initially screened and subsequently referred for more detailed optometric, ophthalmological, low vision or rehabilitation assessments, where appropriate. Results indicated that many of the patients had not been receiving regular ocular assessments and would benefit from the provision of an optical appliance or ophthalmological treatment. The survey provided staff at the rehabilitation centre with information on the visual status of individual patients and enhanced general eye-care awareness.

Adult

Significance of blasts in low-cell-count cerebrospinal fluid specimens from children with acute lymphoblastic leukemia.

The purpose of this study was to determine whether the presence of more than 5% blasts in a differential count of cytocentrifuged cerebrospinal fluid (CSF) with less than 6 leukocytes/microliter was predictive of central nervous system (CNS) relapse in children with acute lymphoblastic leukemia (ALL). A double concentrate method of cytocentrifuge preparation was used to analyze 4543 consecutive CSF specimens from 349 children with ALL between January 1, 1982, and September 30, 1988. One hundred nine CSF specimens from 58 evaluable children had less than 6 leukocytes/microliter and more than 5% blasts on cytocentrifuge differential count (low-cell-count specimen with blasts [LCB]). During the study period, 25 of 332 evaluable children (7.5%) had CNS leukemic recurrence. In 22 of 25 (88%), the CNS relapse was preceded by at least one abnormal low-cell-count CSF specimen. One of 34 patients with a single LCB at diagnosis (3%) had subsequent CNS relapse compared with five of eight patients (62.5%) with a single LCB during remission (P = 0.0002). Of 16 children with two or more LCB during remission, nine (56%) had CNS relapse defined by standard criteria, whereas six additional patients in this group were declared to be in CNS relapse on the basis of their repetitive LCB. Whether diagnosing CNS recurrence earlier in its course based on a modification of the definition of CNS leukemia will change the frequency of subsequent adverse events or make possible decreased intensity of CNS retreatment remains to be determined.

Adolescent

Reduced plasma oestrogen stimulated neurophysin and delayed response to oestrogen challenge in Alzheimer's disease.

Plasma concentrations of oestrogen stimulated neurophysin (ESN) were reduced in 28 patients with Alzheimer's disease (AD) compared with 14 age-matched controls, 16 patients with other presenile dementias and 12 patients with major depressive disorder. The ESN response to oestrogen challenge was delayed in 10 AD patients compared with 7 age-matched controls. Reduced basal and oestrogen stimulated plasma ESN may be related to impaired responsiveness of the hypothalamo-neurohypophysial neurons and/or a reduction in the amount of pituitary ESN available for release. Plasma ESN measurements may be of value for excluding the diagnosis of AD in patients with dementia who present before the age of 65.

Administration, Oral