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Biomedical subjects

K Wilson

Publications and source records attributed to K Wilson.

At least 235 records · Page 13Linked to original sources
PubMed1992

Preserved implicit memory for lexical information in Alzheimer's disease.

Recent studies have suggested that there is a specific impairment of implicit memory for lexical priming in Alzheimer's Disease. However, there are problems in accepting data from the word-stem completion paradigm as evidence of pure implicit-memory performance. To assess whether Alzheimer's Disease patients are relatively impaired on implicit memory for lexical information an anagram-solution task was adopted. A group of 16 early stage Alzheimer's Disease patients and a group of 16 normal elderly subjects were presented a list of 40 target words. Subsequent free recall was significantly poorer in the former group, but while both groups were significantly better at solving anagrams for words they had previously seen, there was no difference between the two groups in the amount of priming. The data are consistent with the view that previous reports of an implicit deficit in Alzheimer's Disease may not generalise to implicit tasks independent of explicit-memory performance.

Aged↗
PubMed1992

The total-contact cast for management of neuropathic plantar ulceration of the foot.

Seventy-one neuropathic ulcers of the foot in sixty-six patients were treated with the use of a total-contact cast. The ulcers had been present for an average of five months (range, one to twenty-nine months) and were graded according to the Wagner classification; only patients who had grade-I or grade-II lesions were treated with a total-contact cast. The diameter of the ulcer averaged 3.5 centimeters (range, 1.5 to 15.5 centimeters). Sixty-four (90 per cent) of seventy-one ulcers were healed at a mean of five and one-half weeks (range, one to fourteen weeks). A deep infection developed in two patients during treatment. Twenty-two ulcers (31 per cent) recurred within eighteen months after initial healing; nineteen (86 per cent) of them healed after an average of two weeks in a second cast. Recurrent ulceration was usually associated with an underlying fixed deformity or osseous prominence. The total-contact cast provided safe, reliable, and cost-effective treatment for patients who had neuropathic ulcers of the foot.

Adult↗
PubMed1991

Advocacy. Necessary to achieve cancer control goals.

As resources become increasingly scarce, oncology professionals and consumers of oncology services are increasingly engaging in advocacy efforts to achieve goals in cancer control. Effective advocacy includes both legislative and direct educational efforts.

Aged↗
PubMed1991

Superiority of granisetron to dexamethasone plus prochlorperazine in the prevention of chemotherapy-induced emesis.

Trials of selective 5-hydroxytryptamine3 receptor antagonists have shown excellent antiemetic activity for chemotherapy containing cisplatin when compared with high-dose metoclopramide. There is little information about the efficacy of these new agents for chemotherapy other than for high-dose cisplatin. We performed a double-blind, randomized trial comparing a single dose of the 5-hydroxytryptamine3 receptor antagonist granisetron (BRL 43694A) as a single intravenous dose with dexamethasone plus prochlorperazine in 152 patients receiving their first course of moderately emetogenic chemotherapy (mainly doxorubicin- and cyclophosphamide-containing combinations). During the first 24 hours, there was a statistically significant advantage for the granisetron group in terms of the prevention of both nausea and emesis. There was no difference in the frequency of reported adverse events. We conclude that granisetron is more effective than dexamethasone plus prochlorperazine in patients who are receiving moderately emetogenic cytotoxic agents.

Antiemetics↗
PubMed1991

X-Ray structure of the antibiotic bacitracin A.

Bacitracins are a group of widely used peptide antibiotics. There has been interest in determining the three-dimensional structure of the bacitracins. However, solution studies indicate significant flexibility in their structure and to date native bacitracins have resisted attempts at crystallisation despite considerable efforts over a number of years by several groups. Here we report the first three-dimensional X-ray structure of a bacitracin, complexed to a subtilisin proteinase. X-Ray diffraction data were collected using synchrotron radiation in combination with the Image Plate Scanner system. The complex structure including two enzymes, two bacitracins, 220 water molecules and two Ca2+ ions was refined by restrained least-squares to a crystallographic R factor ( = sigma [[Fo-Fc]]/sigma [Fo]]) of 16.3% at 2.0 A.

Amino Acid Sequence↗
PubMed1991

The rate and locus of development of rat vallate taste buds.

Several hundred taste buds develop and mature in the trench walls of the rat's vallate papilla during the first 3 months after birth. The objective of this investigation of taste bud development was to determine: (i) whether the vallate papilla has local growth zones where new taste buds form, (ii) whether new taste buds arise by the division of mature taste buds, (iii) how many days are required for a new taste bud to mature, and (iv) whether a taste pore forms as the taste bud reaches a critical volume. Camera lucida drawings were made of more than 4000 iron hematoxylin-stained, serially sectioned, vallate taste buds. The relative abundance of immature taste buds declined exponentially with age, from 18% of the mature taste buds at day 15 to 2% at day 90. At days 21, 33 and 45 most of the immature taste buds (those lacking a taste pore) were located in growth zones at the anterior and posterior extremes of the vallate trench. A mean of 10.5 days was required for the maturation of each cohort of immature taste buds present at days 15, 21, 33 and 45. Vallate taste buds were added de novo; fission of mature taste buds was rare. Taste buds varied widely in the taste bud volume at which a pore formed and in the final volume of the taste bud.

Animals↗
PubMed1991

Amplification and molecular cloning of the IMP dehydrogenase gene of Leishmania donovani.

A mutant (MPA100) strain of Leishmania donovania was generated from a wild type (D1700) population by virtue of its ability to survive the selective pressure of gradually increasing concentrations of mycophenolic acid (MPA), an inhibitor of IMP dehydrogenase (IMPDH) activity. Comparative growth experiments revealed that the MPA100 strain was 100-fold more resistant to MPA toxicity and cross-resistant to ribavarin, another inhibitor of IMPDH. A direct comparison of IMPDH levels in D1700 and MPA100 cells showed that the latter expressed at least 20-fold higher enzyme activity. In order to evaluate the mechanism by which MPA100 cells overexpressed IMPDH, the leishmanial gene encoding IMPDH was isolated from a genomic library in EMBL3 by cross-hybridization to a mouse IMPDH cDNA, and a 2.3-kilobase EcoRV-PstI fragment was subcloned into a Bluescript vector and sequenced. The EcoRV-PstI fragment contained an open reading frame of 514 amino acids that encompassed the entire leishmanial IMPDH coding sequence. The predicted amino acid sequence showed a 52.5% identity with that of the corresponding human IMPDH. The codon usage of the leishmanial IMPDH gene reflected a strong bias toward codons containing either G or C in the wobble position. The EcoRV-PstI fragment hybridized to a 3.0-kilobase mRNA that was expressed at 10-20-fold greater levels in the MPA100 cells. Using the EcoRV-PstI fragment as a probe, the increased amount of IMPDH activity and IMPDH mRNA in the MPA100 cells could be attributed to an approximately 10-20-fold amplification of the leishmanial IMPDH gene.

Amino Acid Sequence↗
PubMed1991

A randomized, double-blinded study comparing six doses of batanopride (BMY-25801) with methylprednisolone in patients receiving moderately emetogenic chemotherapy.

Several agents in a new class of antiemetic compounds, 5-hydroxytryptamine (5-HT3) antagonists, have shown promise as effective antiemetics with fewer side effects than metoclopramide. One of these agents, batanopride, produced no severe toxicity at doses that prevented emesis due to chemotherapy in early Phase I trials. We conducted a randomized, double-blinded, 7 arm clinical trial to: (1) identify the presence of a dose-response for complete protection from emesis, and (2) compare batanopride with a standard antiemetic, methylprednisolone if a dose-response was found not to exist. Prior to chemotherapy, six patient groups each received a single intravenous dose of batanopride ranging from 0.2 to 6.0 mg/kg whereas a seventh group received methylprednisolone 250 mg intravenously. Chemotherapy-naïve cancer patients scheduled to receive moderately emetogenic chemotherapy were eligible. Primary treatment outcomes that were recorded and analyzed included the number of episodes of emesis, the time to the first episode of emesis as well as the frequency and severity of nausea. Two hundred and eight patients accrued between April 1989 and February 1990 were evaluable for response. A significant dose-response effect for complete protection from emesis was not seen over the first 24 hours after chemotherapy (p = 0.102). However, a linear dose-response effect for time to first emesis was evident in a multivariate analysis (p = 0.029). While the highest batanopride dose group was associated with a higher complete protection rate (CPR) than the control group, this group also exhibited a higher incidence of diarrhea (p = 0.013), hypotension, and electrocardiographic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Effect of central cholinergic stimulation on regional cerebral blood flow in Alzheimer's disease.

Patients with Alzheimer disease (AD) had reduced regional cerebral blood flow (rCBF) in the posterior parietotemporal region compared with controls, as determined with technetium-99m hexamethyl propyleneamine oxime and single photon emission tomography. Central cholinergic stimulation with physostigmine produced a focal increase in rCBF in the posterior parietotemporal region in the patients with AD but not in controls.

Aged↗
PubMed1991

Effect of daily etidronate on the osteolysis of multiple myeloma.

Progressive bone disease in multiple myeloma frequently leads to osteolysis, bone resorption, pathologic fractures, vertebral compression, and hypercalcemia. We conducted a double-blind study in 173 newly diagnosed multiple myeloma patients of etidronate disodium (EHDP), a diphosphonate compound that reduces bone resorption by inhibiting osteoclastic activity. The patients were randomly assigned to receive oral EHDP 5 mg/kg/d or placebo until death or discontinuation due to intolerance or refusal. The extent of vertebral deformity was measured by a vertebral index as well as height. The frequency of pathologic fractures, hypercalcemia, and bone pain was regularly assessed, as well as size and number of osteolytic lesions. All patients received melphalan and prednisone daily for 4 days every 4 weeks as the primary chemotherapy for their disease. Although the repeated measures analysis showed a significant height loss, there was no difference between treatment arms (P = .98). There was no significant difference in bone pain, episodes of hypercalcemia, or development of pathologic fractures. Patients on EHDP showed less deterioration in their vertebral index, but this difference only approached statistical significance (P = .07). We conclude that EHDP therapy used in this dosage schedule does not have a clinically significant impact in multiple myeloma.

Aged↗
PubMed1991

Metabolism of benzothiazole. I. Identification of ring-cleavage products.

1. The metabolic fate of benzothiazole in guinea pig has been investigated following i.p. administration at a dose of 30 mg/kg. 2. Five ring-cleavage products were identified in urinary extracts by g.l.c.-mass spectra. By reference to authentic compounds the three major metabolites were shown to be 2-methylmercaptoaniline (I), 2-methylsulphinylaniline (II) and 2-methylsulphonylaniline (III). On the basis of the mass spectrometric evidence the remaining two metabolites were postulated to be 2-methylsulphinylphenylhydroxylamine (IV) and 2-methylsulphonylphenylhydroxylamine (V). 3. I, II and III were present in conjugated and unconjugated forms; IV and V were identified only after hydrolysis with sulphatase.

Animals↗
PubMed1990

Purification and crystallization of 15-lipoxygenase from rabbit reticulocytes.

We report a new purification of rabbit reticulocyte 15-lipoxygenase that has resulted in the first crystallization of a mammalian lipoxygenase. The enzyme was purified to homogeneity (greater than 98% pure by SDS-PAGE) using high pressure liquid chromatography on hydrophobic-interaction, hydroxyapatite and cation-exchange columns. Crystals were grown by the vapor diffusion method from concentrated solutions of the protein in sodium phosphate buffer, pH 7.0. The hexagonal, rod-shaped crystals were on average 0.09 mm x 0.09 mm x 0.4 mm, with approximate unit cell dimensions of a = b = 260 A, c = 145 A. The crystals diffract to 5 A resolution.

Animals↗
PubMed1990

Tuberculosis surveillance in the South Australian aboriginal community.

Tuberculosis (TB) is still a significant problem in Aboriginal people. There are higher rates of active TB and evidence of continuing transmission among this group. We sought to define the specific epidemiological risks and best methods of surveillance for TB in Aboriginal people in South Australia. We compared the incidence of active TB in Aboriginal people in South Australia with that of the total number of cases in non-Aboriginal people from 1978 to 1988, and studied the prevalence of infection in four Aboriginal communities in South Australia. Incidence rates of active TB were four times higher in South Australian Aboriginal people than the total South Australian rates. Specific age analysis revealed higher active disease notification rates in Aboriginal people aged 45-54 years and 55-64 years. The notification rate for Aboriginal men was almost three times the rate for women. Standardized incidence ratios of active TB cases for Aboriginal communities were higher in rural and traditional communities than in urban Aboriginal people. Infection prevalence, measured by tuberculin skin testing, varied from 7.7% to 30.8% in the different communities but did not correlate with the standardized incidence ratios. We conclude that (i) South Australian Aboriginal people are suffering a higher rate of active TB disease than the total South Australian community, and (ii) that the disease and infection rates vary between communities and between age and sex groups. The discrepancy between disease notifications rates, as measured by standardized incidence ratios, and infection prevalence requires further investigation. To improve TB control in Aboriginal people, programmes need to be altered to be more appropriate for this group.

Adolescent↗