Search PubMed⌕ Search

Biomedical subjects

C Greene

Publications and source records attributed to C Greene.

At least 37 records · Page 2Linked to original sources
PubMed1996

Detection of Toxoplasma gondii in feline and canine biological samples by use of the polymerase chain reaction.

OBJECTIVE: To develop a polymerase chain reaction (PCR) technique to identify Toxoplasma gondii DNA in biological samples from cats and dogs. DESIGN: To artificially create samples that would mimic those acquired in a clinical setting from animals with naturally acquired toxoplasmosis. Using these samples, a PCR test to identify T gondii DNA was developed. SAMPLE POPULATION: Feline and canine aqueous humor, CSF, serum, and blood samples. PROCEDURE: Tachyzoites of several strains of T gondii grown in cell culture were added to feline and canine aqueous humor, CSF, serum, and blood samples. Protocols for identifying T gondii DNA by use of the PCR were developed. RESULTS: The DNA from as few as 10 tachyzoites of T gondii could be identified in feline and canine aqueous humor, CSF, and serum samples. One hundred tachyzoites could be identified in blood samples. CONCLUSIONS: Toxoplasma gondii can be identified in feline and canine biological samples by use of the PCR. CLINICAL RELEVANCE: Correlation of clinical disease to T gondii serum antibodies provides only a presumptive diagnosis of toxoplasmosis. Use of PCR to detect T gondii DNA in biological samples from cats and dogs may provide a sensitive tool for the antemortem diagnosis of toxoplasmosis and may be most beneficial when used in conjunction with serum antibody titers.

Animals↗
PubMed1995

Increased risk of craniosynostosis with higher antenatal maternal altitude.

BACKGROUND: During the 1980s, the Colorado Department of Health received reports from several high-altitude communities of clusters of the malformation craniosynostosis. In a population-based, case-control study, we examined the association between overall and trimester-specific maternal antenatal altitude exposure and the occurrence of infant craniosynostosis. METHODS: We identified case children through a statewide registry and randomly sampled control children from birth records. By telephone interview, each mother provided data on the locations of all antenatal residences and places of employment as well as other factors. Staff mapped all locations and abstracted the corresponding altitudes. RESULTS: The odds ratio (OR) of any synostosis for a time-weighted mean antenatal altitude of > or = 2000 metres (high altitude) versus < 2000 metres (low altitude) was 1.4 (lower bound of the one-sided 95% test-based confidence interval (CI): 0.9). The OR was elevated in smokers but not in non-smokers. As compared to non-smokers, the OR of any synostosis for high-altitude smokers was 4.6 (lower bound of the 95% one-sided exact CI: 1.7). Particularly elevated were the corresponding OR of coronal (18.1, 4.4) and metopic synostosis (16.3, 2.8), and OR for high-altitude exposure during the second trimester (any synostosis: 6.4, 1.99; coronal: 28.6, 6.1; metopic: 26.7, 4.1). CONCLUSIONS: Antenatal maternal high-altitude exposure and smoking are associated with increased risk of infant craniosynostosis, perhaps through generation of intermittent hypoxaemia.

Altitude↗
PubMed1995

Prevalence of Bartonella henselae antibodies in pet cats throughout regions of North America.

Cat exposure has been directly associated with the development of human Bartonella henselae infections, resulting in cat-scratch disease, bacillary angiomatosis, or bacteremia. The prevalence of serum antibody titers to B. henselae was determined for selected pet cats from 33 geographic locations throughout the United States and several areas in western Canada. Seroprevalences paralleled increasing climatic warmth (P < .02) and annual precipitation (P < .03). These warm, humid areas with the highest seroprevalence would also have the highest number of potential arthropod vectors. The southeastern United States, Hawaii, coastal California, the Pacific Northwest, and the south central plains had the highest average prevalences (54.6%, 47.4%, 40.0%, 34.3%, and 36.7%, respectively). Alaska, the Rocky Mountain-Great Plains region, and the Midwest had low average prevalences (5.0%, 3.7%, and 6.7%, respectively). Overall, 27.9% (175/628) of the cats tested were seropositive. The seroprevalence of B. henselae in cats varies throughout the United States and appears to be influenced by climate.

Animals↗
PubMed1995

Parental occupations as risk factors for craniosynostosis in offspring.

In a population-based case-control study, we examined relations between maternal and paternal occupations and the risk of infant craniosynostosis. Cases were 212 children born to Colorado residents and diagnosed during 1986-1989 with radiographically confirmed synostosis of unknown etiology. Controls were 291 children randomly selected from state birth records and frequency matched to cases on month and year of birth. Trained staff conducted telephone interviews of mothers of case and control children. Information was obtained about each job held by either parent during the pregnancy, and any job that the father held during the 3 months before the last menstrual period before conception. Jobs were coded using 1980 Census occupation and industry codes. We found no strong associations for maternal occupations. Of paternal occupations, two groups were associated with moderately increased odds ratios after adjustment for maternal smoking and altitude: agriculture and forestry (odds ratio = 2.3; 95% confidence interval = 1.0-5.2), and mechanics and repairmen (odds ratio = 2.7; 95% confidence interval = 1.2-6.1). For both, the odds ratios were higher for males.

Adolescent↗
PubMed1995

Adhesion properties of mutants of Staphylococcus aureus defective in fibronectin-binding proteins and studies on the expression of fnb genes.

Staphylococcus aureus 8325-4 has the potential to express two distinct cell wall-associated fibronectin-binding proteins called FnBPA and FnBPB. In order to test if both proteins are expressed in S. aureus and if both are required for promoting bacterial adhesion to fibronectin-coated surfaces, insertion mutations were isolated in each gene. A DNA fragment encoding tetracycline resistance was inserted into fnbA and a fragment encoding erythromycin resistance was inserted into fnbB. A double fnbAfnbB mutant was also constructed. The fnbA and fnbB single mutants showed no significant reduction in their adhesion to polymethylmethacrylate coverslips that had been coated in vitro with fibronectin. However, the double mutant was completely defective in adhesion. Monospecific antibodies directed against the non-conserved N-terminal regions of both proteins confirmed the lack of expression of FnBPs in the mutant strains. Wild-type fnbA and fnbB genes cloned seperately on a multicopy plasmid were each able to restore fully the adhesion-defective phenotype of the 8325-4 fnbAfnbB mutant. This demonstrates that both fnb genes are expressed in S. aureus and that both contribute to the ability of strain 8325-4 to adhere to fibronectin-coated surfaces. The double mutant was also defective in adhesion to coverslips that had been removed from tissue cages implanted subcutaneously in guinea-pigs, which suggests that fibronectin is important in promoting attachment of S. aureus to biomaterial in vivo.

Adhesins, Bacterial↗
PubMed1995

Differentiation of Bartonella-like isolates at the species level by PCR-restriction fragment length polymorphism in the citrate synthase gene.

The citrate synthase gene (gltA) of Bartonella henselae was cloned and sequenced to compare genetic divergence among alpha and gamma branches of the class Proteobacteria and to develop enhanced genotypic reagents for B. henselae identification. B. henselae gltA is 1,293 nucleotides in length and 63 to 66% homologous with corresponding gene sequences of Rickettsia prowazekii, Escherichia coli, and Coxiella burnetii. The observed genetic variability suggests that gltA sequences can provide a useful means for studying moderate divergence among related bacteria. Oligonucleotides specific for B. henselae gltA were evaluated for the ability to prime PCR amplification within the alpha and gamma branches of the proteobacteria. Under the conditions used, only B. henselae, Bartonella quintana, and R. prowazekii template DNAs yielded amplification products (approximately 380 bp). DNAs from 28 Bartonella-like isolates of feline origin were amplified by B. henselae primers and analyzed for restriction fragment length polymorphism. The resulting patterns for all 28 isolates were similar or identical to that of the recognized B. henselae strain. Current studies are aimed at optimization of PCR conditions for specificity and sensitivity of amplification of Bartonella sequences from clinical isolates.

Amino Acid Sequence↗
PubMed1995

State perspectives on health care reform: Oregon, Hawaii, Tennessee, and Rhode Island.

The general consensus among States which have had their section 1115 demonstration projects approved is that there is no one best way to implement State health care reform. The Health Care Financing Administration (HCFA), however, wished to discern how States were accomplishing the task of implementing the demonstrations, and solicited responses from State representatives whose section 1115 demonstration waivers had been approved. The resulting article gives an overview of this implementation process from four State perspectives. Written by representatives from Oregon, Hawaii, Tennessee, and Rhode Island, the ideas presented here are indicative of the complex undertaking of State health care reform.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1994

Increased risk of craniosynostosis with maternal cigarette smoking during pregnancy.

We analyzed data from a population-based case control study to determine whether maternal prenatal smoking or alcohol drinking might increase the risk of craniosynostosis. Between 1986 and 1989, the Colorado Craniosynostosis Registry ascertained 233 children whose diagnoses were confirmed by an independent radiologist. Of the 212 (91%) cases who participated 86 had lambdoid, 69 had sagittal, 25 had coronal, 18 had metopic, and 14 had multiple suture synostosis. Random sampling of birth certificate records yielded 367 eligible controls, of whom 291 (79%) participated. Study staff interviewed case and control mothers between 1989 and 1991 for prenatal smoking and alcohol drinking. We used Mantel-Haenszel and polychotomous logistic regression techniques to estimate the relative odds of craniosynostosis for smoking and drinking in all cases and in relevant case subgroups. Smoking was associated with a relative odds of craniosynostosis of 1.7 (95% confidence interval, 1.2-2.6). For smoking of more than one pack per day, the relative odds were 3.5 (1.5-8.4) for all types of synostosis combined, and 5.6 (2.1-15.3) for coronal synostosis. No strong or significant association was noted for drinking. Maternal prenatal smoking may increase the risk of craniosynostosis in this population.

Adult↗
PubMed1994

Consistent occurrence of hemagglutinin variants among avian influenza virus isolates of the H7 subtype.

Several field isolates of avian influenza virus of the H7 subtype were analyzed for the presence of hemagglutinin variants by labeling proteins in cells infected with virus clones, and reacting with monoclonal antibodies. Each strain was shown to contain two distinct electrophoretic variants of the uncleaved hemagglutinin. In the A/Tk/Ore/71 (H7N3) isolate, two variants remained in the population through 35 laboratory passages, indicating both are stable and may be important to expression of the viral phenotype. Nucleotide sequence analysis of the HA gene of these two variants demonstrated differences at several amino acid positions in the HA1 subunit including one glycosylation site. Three additional recent North American isolates were also each found to contain two electrophoretic variants occurring within populations as few as one embryo passage away from the original clinical specimen. Pulse-chase assays indicated none of the variant HA molecules were cleavable in chick embryo fibroblasts. In the highly pathogenic Australian isolate; A/Ck/Victoria/75, both HA variants are cleavable in fibroblasts, without added trypsin, and the differences are localized within the HA1 region. With all the strains tested, the slower migrating HA variant was associated with a consistently higher hemagglutinin titer in embryos. Finally, recent H7 isolates from imported birds (A/Soft Bill/Ill/92) also exhibit similar variants, indicating their occurrence is not limited to domestic poultry. This consistent presence of two distinct electrophoretic variants in several avian H7 isolates suggests multiple allelic forms of the H7 hemagglutinin.

Animals↗
PubMed1993

National Neurofibromatosis Foundation International Database.

The National Neurofibromatosis Foundation International Database is a system for collecting comprehensive information on the clinical manifestations and natural history of neurofibromatosis. Data are entered into personal computers at participating centres and are pooled at the Central Database and coordinating centre in Vancouver, Canada. The system includes special mechanisms to assure consistency among centres and to maintain patient confidentiality. The database is designed to foster collaborative clinical and molecular genetic research in many aspects of neurofibromatosis.

Canada↗
PubMed1993

Enzyme-linked immunosorbent assay for detection of human immunoglobulin G to lipopolysaccharide of spotted fever group rickettsiae.

An enzyme-linked immunosorbent assay for detecting human immunoglobulin G to spotted fever group rickettsiae was developed and tested. The assay uses proteinase K-resistant material, characteristic of the rickettsial lipopolysaccharides shown to be group specific by immunoblots, as the antigen. The results indicate that the assay provides a sensitive, yet specific, alternative method for diagnosing rickettsial diseases.

Endopeptidase K↗
PubMed1992

Metabotropic receptor mediated afterdepolarization in neocortical neurons.

In rat neocortical slices activation of glutamate metabotropic receptors with glutamate, quisqualate and 1S,3R-ACPD caused a spike-evoked afterdepolarization which replaced the normal afterhyperpolarization. In some neocortical neurons the afterdepolarization reached action potential threshold causing prolonged self-sustained firing. These effects of metabotropic receptor activation were similar to the action of muscarinic agonists in the same preparation.

Action Potentials↗
PubMed1991

Developmental profile of patients with maple syrup urine disease.

The progress of nine maple syrup urine disease patients (eight classical, one possible variant) was reviewed to look for similarities in developmental patterns. A consistent developmental profile of stronger Verbal than Performance IQ and lower than familially expected IQ was seen. Younger age at diagnosis was associated with a milder neonatal course. Those who were asymptomatic or suffered mild complications in the newborn period have higher IQs than children experiencing moderate or severe complications. Children with asymptomatic or mild neonatal course also required less special education services. Overall, a picture of ubiquitous motor, visual-analytic and learning deficits is seen.

Age Factors↗