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Biomedical subjects

M Kent

Publications and source records attributed to M Kent.

At least 19 recordsLinked to original sources
PubMed2001

Succimer for treatment of lead toxicosis in two cats.

Two cats from a single household were examined because of neurologic abnormalities suggestive of central vestibular disease. The owner had been renovating her 150-year-old house for the preceding 3 months, and renovations included chipping and sanding of old paint from windowsills and stair railings. Lead toxicosis was diagnosed on the basis of history and concentrations of lead in blood and urine. Both cats were treated with succimer. Treatment was not associated with any adverse effects, and both cats recovered completely. Ingestion of old paint from house renovations is the most common source of lead exposure in cats. Owners of cats with gastrointestinal tract or neurologic abnormalities should be questioned specifically about house renovations.

Animals↗
PubMed2001

Detection of early-stage lung cancer: computed tomographic scan or chest radiograph?

OBJECTIVE: Computed tomography has recently been proposed as a useful method for the early detection of lung cancer. In this study we compared the stage distribution of lung cancers detected by a computed tomographic scan with that of lung cancers detected by a routine chest x-ray film. METHODS: Two groups of patients with biopsy-proven non-small cell lung cancer were reviewed. In the first group of 32 patients, the tumors were detected by a computed tomographic scan. In a second group (n = 101), the lung cancers were detected on routine chest x-ray films. Patients with pulmonary symptoms or a history of cancer were excluded. RESULTS: There was no difference in age, sex, or cell-type distribution between the 2 groups. A significantly greater number of patients undergoing a computed tomographic scan had stage IA disease compared with those having an x-ray film. Of the 32 patients in the group having a scan, 10 had tumors 1 cm or less in size versus 6 of 101 in the group having a chest radiograph. Additionally, there was a significant reduction in advanced stage disease in the group having a scan. CONCLUSIONS: In this retrospective study, a higher incidence of stage IA lung cancers and significantly fewer cases of more advanced disease were observed in patients screened with computed tomography than in those having a chest radiograph. These data suggest that computed tomographic screening may be of value in improving the survival of patients with non-small cell lung cancer.

Adult↗
PubMed2001

Beryllium sensitization, chronic beryllium disease, and exposures at a beryllium mining and extraction facility.

In this study, we examine beryllium sensitization, chronic beryllium disease (CBD), and workplace exposures at a beryllium mining (mine) and extraction facility (mill) in Delta, Utah. Historical airborne beryllium data collected between 1970-1999 included general area (GA), breathing zone (BZ), and personal lapel (LP) measurements and calculations of job-specific quarterly daily-weighted averages (DWVAs). We compared GA, BZ, and DWA data to airborne beryllium data from a mixed beryllium products facility and a beryllium ceramics facility located in Elmore, Ohio and Tucson, Arizona, respectively. At the Delta facility, jobs involving beryllium hydrolysis and wet-grinding activities had the highest air concentrations; annual median GA concentrations were less than 0.3 microg/m3 or both areas. Annual median GA sample concentrations ranged from 0.1-0.4 microg/m(-3) at Delta. These levels were generally lower than Elmore (0.1-1.0 microg/m3) and were comparable to the Tucson facility (0.1-0.4 microg/m3). Median BZ concentrations were higher, whereas DWAs were lower at the Delta facility than at the other two facilities. Among the 87 employees at the Delta facility, 75 participated in the medical survey; there were three persons sensitized, one with CBD. The individual with CBD previously worked at the Elmore facility for 10 years. Cumulative CBD incidence rates were significantly lower at the Delta facility: 0.3 percent compared to 2.0 percent for Elmore and 2.5 percent for the Tucson facility. Sensitization and CBD prevalence rates determined from cross-sectional surveys for the Delta facility were lower than but not significantly different from rates at the other two facilities. There was no sensitization or CBD among those who worked only at the mine where the only exposure to beryllium results from working with bertrandite ore. Although these results are derived from a small sample, this study suggests that the form of beryllium may affect the likelihood of developing CBD. Specifically, exposure to beryl and bertrandite ore dusts or to beryllium salts, in the absence of exposure to beryllium oxide particulates appears to pose a lower risk for developing CBD.

Adult↗
PubMed2000

Anopheles gambiae salivary gland proteins as putative targets for blocking transmission of malaria parasites.

Anopheles gambiae is the primary vector of human malaria in sub-Saharan Africa. Invasion of Anopheles salivary glands by Plasmodium sporozoites is a necessary step in the transmission of malaria and is likely to be mediated by specific receptor-ligand interactions. We are interested in identifying putative an A. gambiae salivary gland receptor or receptors for sporozoite invasion as a possible target for blocking malaria transmission. By using monoclonal antibodies against female-specific A. gambiae salivary gland proteins, two molecules, one of 29 kDa and one of 100 kDa, were identified and characterized with respect to the age and blood-feeding process of mosquitoes. In an in vivo bioassay, the monoclonal antibody against the 100-kDa protein inhibited Plasmodium yoelii sporozoite invasion of salivary glands >/=75%. These results show that A. gambiae salivary gland proteins are accessible to monoclonal antibodies that inhibit sporozoite invasion of the salivary glands and suggest alternate targets for blocking the transmission of malaria by this most competent of malaria vectors.

Animals↗
PubMed2000

Long-term outcome after resection for bronchial carcinoid tumors.

OBJECTIVES: We sought to determine the long-term survival of patients treated for bronchial carcinoid tumors and whether lesser resections have had an effect on outcomes. METHODS: We conducted a retrospective, multi-institutional review of patients treated surgically for primary bronchial carcinoid tumors since 1980. Operative approach, pathologic stage, histology, surgical complications, tumor recurrence, and long-term survival were assessed. RESULTS: There were 50 men and 89 women with a mean age of 52.2+/-17.4 and 58.9+/-13.3 years, respectively (P=0.021). Men were more likely to be current or former smokers than were women. Operations included lobectomy or bilobectomy in 110, pneumonectomy in four, wedge resection in 22, and bronchial sleeve resection only in three patients; resection was performed thoracoscopically in six patients. One patient died postoperatively. Stages were I, 121; II, nine; III, six; and IV, three. Typical carcinoid tumors were stage I in 100 and more advanced (stages II-IV) in nine, whereas atypical carcinoid tumors were stage I in 18 and more advanced in eight (P=0. 002). Median follow-up was 43 months (range 1-149) during which 21 (15%) patients died (four from recurrent cancer) and 19 patients (14%) were lost to follow-up. Recurrent cancer developed in 2/98 patients with typical and 5/25 patients with atypical subtypes (P<0. 001; log-rank test). The likelihood of recurrence was related to histological subtype (relative risk 7.9 for atypical carcinoid; 95% confidence interval 1.4-43.5). Five-year survival was 88% for stage I patients and was 70% for patients with more advanced stages. When stratified by stage, survival was related to age (relative risk=1.9 for a 10 year increase in age; 95% confidence interval 1.2-2.9) and possibly to the histological subtype, but not to patient gender, year of operation, or type of operation performed. CONCLUSIONS: Either major lung resection or wedge resection is appropriate treatment for patients with early stage typical bronchial carcinoid tumors. Survival is favorable for early stage tumors regardless of histological subtype. Local recurrence is more common among patients with atypical subtypes, suggesting that a formal resection may improve long-term outcome.

Adolescent↗
PubMed2000

Cerebellar cortical abiotrophy in a beagle.

A beagle puppy was presented with clinical signs indicative of a cerebellar disease. Histopathological evaluation of the cerebellum revealed a diffuse degenerative cortical lesion. The clinical history and the histopathological findings are consistent with a neonatal cerebellar abiotrophy. Furthermore, the breeding history supports the hypothesis of an inherited genetic disorder that is, most likely, an autosomal recessive trait.

Animals↗
PubMed1999

College students' perception of facial expressions.

95 college students were administered the Facial Expressions subtest of the Diagnostic Analysis of Nonverbal Accuracy to measure perception of nonverbal cues. Participants also completed the Nowicki-Strickland Locus of Control Scale and responded to a short questionnaire regarding their beliefs about their own ability to perceive nonverbal cues as well as how effective they felt others were in perceiving nonverbal cues. A significant correlation between locus of control and perception of adult facial expressions indicated those students with a more internal locus of control had higher scores on correct perception of adult facial expression. There was no significant correlation between locus of control and facial expressions of children. Sex differences were also found in perception of nonverbal cues. Female students scored higher in correctly perceiving facial expressions than the men. Participants also scored higher in correctly perceiving facial expressions of children than of adults.

Adult↗
PubMed1998

An increase in extracellular glutamate is a sensitive method of detecting ischaemic neuronal damage during cranial base and cerebrovascular surgery. An in vivo microdialysis study.

All patients undergoing neurological surgery are at risk for serious complications. Ischaemic damage presenting with hemiparesis or speech difficulties occurs in up to 6% of patients undergoing cerebral bypass procedures and other complicated neurosurgical procedures. Currently available methods for detection of such damage include the use of somatosensory evoked potentials (SSEPs) and electro-encephalography (EEG). Unfortunately, these techniques have false positives and may remain normal in the presence of severe focal neurological deficits. Early detection of potential deficits may prevent or minimize damage through a change in operative or anaesthetic strategy. With the availability of several potential neuroprotective compounds, it is also possible to treat patients at risk of developing ischaemic complications if the individuals are identified early. The excitatory neurotransmitter glutamate is not only a metabolic product, but is also thought to promote ischaemia induced cell injury if released into the extracellular space. It may be a significant parameter for ischaemic brain metabolism. In this report we describe 10 patients who underwent extracranial-intracranial (EC-IC) high flow bypass procedures with routine intra-operative monitoring (IOM) as well as intra-operative in-vivo microdialysis measurement of glutamate. Our aim was to compare intra-operative microdialytic findings and IOM findings with respect to patients' early postoperative clinical courses. Three patients had significant intra-operative glutamate increases indicating ischaemia. Two of these patients awoke with a new neurological deficit (hemiparesis). Routine IOM findings were either normal or showed only transient changes during the time the glutamate levels were high. Our study shows that an increase in extracellular glutamate, as monitored by in-vivo microdialysis, is an excellent early market of neuronal damage. While our glutamate measurements were done off-line, it may be possible to get in future continuous on-line measurements to serve as an early warning system for potential ischaemic damage.

Adult↗
PubMed1998

TNP-470 is an effective antimicrosporidial agent.

Therapy for microsporidia, which cause diarrhea and a wasting syndrome in persons with AIDS, has had limited success. Fumagillin, a naturally secreted water-insoluble antibiotic, has in vitro activity against microsporidia and has been used successfully in the treatment of superficial keratitis in patients with AIDS, but systemic therapy has been limited by toxicity of the currently available fumagillin salt. TNP-470, a semisynthetic analogue of fumagillin, was studied in vitro and in the athymic nude mouse model of microsporidiosis. RK13 cells were infected with microsporidia of the family Encephalitozoonidae and treated at day 3 with TNP-470. This agent was highly effective, with an ID50 (50% inhibitory dose compared with control) of 0.001 microg/mL. TNP-470 also demonstrated in vivo activity against Encephalitozoon cuniculi, with prolonged survival and the prevention of the development of ascites in infected athymic mice. These data suggest that the fumagillin derivative TNP-470 is a promising agent for the treatment of microsporidiosis.

Animals↗
PubMed1997

Heteropagus conjoined twins due to fusion of two embryos: report and review.

We report on a case of conjoined twinning (CT) consistent with fusion of two embryos followed by resorption of the cranial half of one of them, resulting in a normal male baby with the lower half of a male parasitic twin fused to his chest. Fluorescent in situ hybridization (FISH) studies suggested that the parasitic twin was male, and DNA typing studies demonstrated dizygosity. Although incomplete fission is the usual explanation for conjoined twins, the unusual perpendicular orientation of the parasite to the autosite supports a mechanism observed in mares in which early fusion of two embryos is followed by resorption due to compromised embryonic polarity.

Abnormalities, Multiple↗
PubMed1997

Monoclonal antiphosphatidylserine antibodies react directly with feline and murine central nervous system.

OBJECTIVE: Antiphospholipid antibodies (aPL), especially against phosphatidylserine and cardiolipin, are associated with a variety of neurological disorders. While it is believed aPL react with endothelial cells to cause cerebral thrombosis, it is not known to what degree aPL react with neural tissue nor which particular aPL specificities may be more relevant. We investigated direct aPL reactivity with the central nervous system (CNS) using 3 monoclonal IgM aPL that differentiate between cardiolipin and phosphatidylserine dependent antigens. METHODS: Brain and spinal cord from normal cat Felis domesticus and brain from CD-1 mice were reacted with aPL using indirect immunoperoxidase techniques. Monoclonal aPL were reacted with whole brain myelin by dot immunoblots. RESULTS: Monoclonal D11A4, reactive with cardiolipin and not phosphatidylserine (CL+/PS-), did not react with any portion of the tissue. Both monoclonal 3SB9b (CL-/PS+) and BA3B5C4 (CL+/PS+) reacted in feline and murine CNS. Both labeled myelinated fibers in grey and white matter of brain and spinal cord in an identical pattern with positive control antibody against myelin basic protein and reacted with whole human brain myelin by dot immunoblot. 3SB9b (CL-+PS+) additionally reacted with ependyma and epithelium of the choroid plexus. CONCLUSION: aPL, especially those reactive with phosphatidylserine dependent antigens, react directly with epitopes associated with myelin, brain ependyma, or choroid epithelium. Direct reactivity of aPL with nervous tissue may be relevant to neurological disorders.

Animals↗
PubMed1996

Bacterial population dynamics in three anopheline species: the impact on Plasmodium sporogonic development.

The functional role of bacteria in the midgut of adult mosquitoes is unknown. In this study, we examined the population dynamics of midgut bacteria of laboratory reared Anopheles stephensi, An. gambiae, and An. albimanus. Mosquito midguts were dissected under sterile conditions and examined for the presence of bacteria using standard microbiologic techniques. Ninety percent and 73% (n = 30) of newly emerged An. gambiae and An. stephensi, respectively, harbored bacteria. In contrast, only 17% (n = 23) of An. albimanus harbored any bacteria. The bacterial population increased 11-40-fold in the presence of a blood meal, but then decreased to pre-blood meal levels in 3-5 days. Pseudomonas cepacia, Enterobacter agglomerans, and Flavobacterium spp. were found in all three anopheline species. Midgut bacteria were acquired both transtadially and through the sugar meal. Transtadial transmission was demonstrated by successfully passaging Escherichia coli HS5 from the larval to the adult stage. However, midgut bacteria were acquired more efficiently through the sugar meal than through transtadial passage. An increase in midgut bacterial counts after mosquitoes were exposed to a bacteria/sugar suspension significantly reduced oocyst infection rates and densities in Plasmodium falciparum-infected mosquito cohorts. Since bacteria occur naturally in wild mosquitoes, it may be possible to modify anopheline vector competence using introduced or indigenous bacteria.

Animals↗
PubMed1996

The midgut bacterial flora of wild Aedes triseriatus, Culex pipiens, and Psorophora columbiae mosquitoes.

The midgut bacterial flora of wild-caught Aedes triseriatus, Culex pipiens, and Psorophora columbiae mosquitoes was investigated. Dissected midgut contents were examined using quantitative aerobic bacterial cultures. Individual colonies (n = 134) were subcultured and identified to species. Midgut bacterial counts changed dramatically during mosquito development. A 280-1,100-fold decrease in the bacterial population occurred between the larval stage and pupal emergence, whereas a subsequent 70-16,000-fold increase occurred after blood-feeding. Bacterial identifications revealed a complex flora with up to nine genera identified during any stage of development. Species most frequently isolated were Serratia marcescens, Klebsiella ozonae, Pseudomonas aeruginosa, and Enterobacter agglomerans. The presence of genetically well-characterized bacteria in the midgut flora of mosquitoes may provide a means of expressing novel genetic products in vector species.

Aedes↗
PubMed1993

Auditory stroop effects in children with hearing impairment.

The accurate perception of speech involves the processing of multidimensional information. The aim of this study was to determine the influence of the semantic dimension on the processing of the auditory dimension of speech by children with hearing impairment. The processing interactions characterizing the semantic and auditory dimensions were assessed with a pediatric auditory Stroop task. The subjects, 20 children with hearing impairment and 60 children with normal hearing, were instructed to attend selectively to the voice-gender of speech targets while ignoring the semantic content. The type of target was manipulated to represent conflicting, neutral, and congruent relations between dimensions (e.g., the male voice saying "Mommy," "ice cream," or "Daddy" respectively). The normal-hearing listeners could not ignore the irrelevant semantic content. Instead, reaction times were slower to the conflict targets (Stroop interference) and faster to the congruent targets (Stroop congruency). The subjects with hearing impairment showed prominent Stroop congruency, but minimal Stroop interference. Reduced Stroop interference was not associated with chronological age, a speed-accuracy tradeoff, a non-neutral baseline, or relatively poorer discriminability of the word input. The present results suggest that the voice-gender and semantic dimensions of speech were not processed independently by these children, either those with or those without hearing loss. However, the to-be-ignored semantic dimension exerted a less consistent influence on the processing of the voice-gender dimension in the presence of childhood hearing loss. The overall pattern of results suggests that speech processing by children with hearing impairment is carried out in a less stimulus-bound manner.

Attention↗
PubMed1992

Oligonucleotide labeling methods. 3. Direct labeling of oligonucleotides employing a novel, non-nucleosidic, 2-aminobutyl-1,3-propanediol backbone.

Novel CE-phosphoramidite (7a-e) and CPG (8a, c, d, e) reagents have been prepared from a unique 2-aminobutyl-1,3-propanediol backbone. The reagents have been used to directly label oligonucleotides with fluorescein, acridine, and biotin via automated DNA synthesis. The versatile 2-aminobutyl-1,3-propanediol backbone allows for labeling at any position (5', internal, and 3') during solid phase oligonucleotide synthesis. Multiple labels can be achieved by repetitive coupling cycles. Furthermore, the 3-carbon atom internucleotide phosphate distance is retained when inserted internally. Using this method, individual oligonucleotides possessing two and three different reporter molecules have been prepared.

Automation↗