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Biomedical subjects

L M Martin

Publications and source records attributed to L M Martin.

At least 19 recordsLinked to original sources

Identification of a microsatellite on chromosome 7B showing a strong linkage with yellow pigment in durum wheat (Triticum turgidum L. var. durum).

The objective of this study is to identify QTLs linked to yellow pigment content in durum wheat. A durum-dicoccoides genetic linkage map was constructed using 124 microsatellites, 149 amplified fragment length polymorphism (AFLPs), and six seed storage proteins (SSP) in a population of 114 recombinant inbred lines (F8). The population has been obtained from a cross between a durum cultivar Omrabi5 and Triticum dicoccoides600545 and backcrossed to Omrabi5. The map consists of 14-durum chromosomes plus an unknown group; and shows a good synteny to the previously published wheat maps. Yellow pigment was measured in the population in three different locations during 3 seasons. Analysis of QTLs was based on simple and simplified composite interval mapping (SIM and sCIM). Three QTLs for yellow pigment were detected on the chromosomal group 7 (7AL and 7BL telomeres) explaining 62% of the total variation. On 7BL, a major microsatellite (Xgwm344) explained by itself 53%, whereas on 7AL, the other two QTLs have contributed 13 and 6%. All determined QTLs showed a strong genetic effect and a weak QTL x E effect. The QTLs effect was consistent across all environments and showed a large effect. Consequently, promising QTLs will be used in the marker assisted breeding program to enhance the selection efficiency for yellow pigment.

Chromosomes↗

The use of buck and ram extenders and two packaging systems to cryopreserve aoudad (Ammotragus lervia) spermatozoa.

Because the aoudad has been hunted to near extinction, cryopreservation of their semen would be useful for DNA conservation and for the possible re-establishment of captive bred animals to their former ranges. This study was conducted to investigate the effectiveness of cryopreserving aoudad spermatozoa. Semen samples from four post-pubertal animals were collected using electro-ejaculation. Microscopic analysis was performed to assess the percentages of progressively and non-progressively motile spermatozoa as well as intact acrosomes in samples prior to freezing and post-thaw. Extended samples (0.2 mL) were frozen using 2 different extenders and packaging systems and stored in LN2 Post-thaw data were arcsine-transformed and analyzed using ANOVA, 2 x 2 factorial. Samples that were processed using the ram/straw method had a significantly higher percentage (P < 0.05) of spermatozoa with intact acrosomes than did any other system. In addition, samples that were processed with the buck/pellet system had significantly greater percentages (P < 0.05) of progressive and non-progressively motile spermatozoa than the samples processed using either extender and packaged in straws. This study illustrates that some aoudad spermatozoa may be cryopreserved using the extender/processing systems developed for the domestic buck and ram.

Animals↗

Validation of self-reported chronic conditions and health services in a managed care population.

BACKGROUND: Self-reported data are commonly used to estimate the prevalence of health conditions and the use of preventive health services in the population, but the validity of such data is often questioned. METHODS: The Behavioral Risk Factor Survey (BRFS) was admin istered by telephone to a stratified, random sample of health maintenanc e organization (HMO) subscribers in Colorado in 1993, and self-reports w ere compared with HMO medical records for 599 adults aged >21. Sensitivity and specificity were calculated for three chronic conditions and use of six preventive services. RESULTS: Sensitivity was highest for hypertension (83%), moderate for diabetes (73%), and lowest for hypercholesterolemia (59%); specificity was >80% for all three conditions. Sensitivity ranged from 86% to 99% for influenza immunization, clinical breast examination, blood cholesterol screening, mammography, Pap test, and blood pressure screening; specificity was <75% for all preventive services. CONCLUSIONS: Self-reports are reasonably accurate for certain chronic conditions and for routine screening exams and can provide a useful estimate for broad measures of population prevalence.

Adult↗

Concordance between results of optic disc tomography and high-pass resolution perimetry in glaucoma.

PURPOSE: To evaluate concordance between results obtained with the Heidelberg Retina Tomograph (HRT) (Heidelberg Engineering GmbH, Heidelberg, Germany) and those obtained with the high-pass resolution perimeter (HRP) in glaucoma diagnosis. METHODS: A total of 217 patients from the glaucoma services at St. Erik Eye Hospital, Stockholm, Sweden (n = 107) and Sahlgrenska University Hospital, Göteborg, Sweden (n = 110) were included in the study. All patients were examined because of known or suspected glaucoma in at least one eye. The conventional indices presented by the instruments were used, i.e., glaucoma index from the HRT (negative values = abnormal, positive = normal) and combined deviation (upper normal limit 2.1 dB) from the HRP. RESULTS: The concordance regarding the classification of normal or glaucomatous by the two instruments was 71% (153/217 eyes). The HRT indicated glaucoma but HRP findings were normal in 47 patients, and the reverse occurred in 17 patients. There was a significant difference in optic disc area between patients with abnormal HRT findings and normal HRP findings and in patients with normal HRT findings and abnormal HRP findings. The concordance could not be improved by adjusting for disc size. The correlation between combined deviation on HRP and the HRT glaucoma index was r = -0.53. CONCLUSION: A significant correlation was found between the combined index given by HRP and the HRT glaucoma index in 217 patients examined for known or suspected glaucoma. Discordant findings were observed in 64 patients; in 22 this discordance was explained by the influence of disc size. No other reasons for differences in examination results could be detected.

Aged↗

Working with glaucoma patients - prospects for "shared care".

PURPOSE: To investigate the prospects for "shared care" by evaluating to what extent ophthalmic nurses are involved in ophthalmic care decision tasks in the management of glaucoma patients, how well prepared the nurses feel they are for these tasks and their level of satisfaction in those tasks they actually are performing. METHODS: A questionnaire was sent to the ophthalmic nurses at 13 eye clinics in Sweden. The clinics were selected to represent different parts of Sweden as well as university clinics and smaller rural clinics. RESULTS: A difference was found between clinics regarding the number of tasks independently performed by the ophthalmic nurses and a significant correlation was found between level of participation and satisfaction (p=0.008). The nurses felt prepared for (61/62) and satisfied (58/62) when performing the glaucoma management tasks, and a high and very significant correlation (r=0.96, p= 0.0001) was found between the mean preparedness and satisfaction scores for each of the 14 tasks. CONCLUSIONS: The findings in the study show that the ophthalmic nurses feel prepared for their tasks and regard their involvement in glaucoma care as subjectively satisfactory. These observations support the idea of "shared care" in glaucoma management.

Adult↗

A robust method for determining DNA binding constants using capillary zone electrophoresis.

Capillary zone electrophoresis (CZE or CE) with on-line UV detection was utilized to measure the binding constants between purified calf thymus DNA and a library of designed tetrapeptides which had been constructed using unnatural amino acids with thiazole ring side chains. Mixtures containing a constant amount of a tetrapeptide, the neutral marker (mesityl oxide), and varying concentrations of DNA were prepared and equilibrated at 8 degreesC for 12 h. CE was then utilized to separate unbound tetrapeptides from the DNA-peptide complex. The UV absorbance of the peak representing unbound tetrapeptide decreased incrementally as a result of increasing the concentration of DNA in the equilibrium mixture. The absorbance of the peak corresponding to the unbound tetrapeptide was obtained directly from the electropherogram and used in the calculation of the DNA-peptide binding constants. The binding constant for each tetrapeptide to calf thymus DNA was obtained from the negative slope of a Scatchard plot and a comparison of the binding constants for different peptides showed that the tetrapeptides in the library have DNA-binding affinities ranging from 10(2) to 10(6) M-1.

DNA↗

Cerebrospinal fluid hydrothorax caused by transdiaphragmatic migration of a ventriculoperitoneal catheter through the foramen of Bochdalek.

Cerebrospinal fluid hydrothorax is a very rare complication following ventriculoperitoneal shunting. The authors report a case of a 3-year-old girl who developed cerebrospinal fluid hydrothorax (caused by migration of the intra-abdominal catheter through the right vertebrocostal trigone of Bochdalek, the one most unlikely to be congenitally patent) and respiratory distress. The patient was successfully treated with thoracocentesis and shunt revision.

Child, Preschool↗

Antibody fragment separations by capillary zone electrophoresis.

This study investigated methods of improving the separation and identification of an IgA antibody, McPC603, and its pepsin fragments. The problem presented by purification of antibody fragments (Fabs) and the antibody light chain required accurate and informative analysis of highly hydrophobic proteins, which can polymerize and fold to form secondary structures. Capillary zone electrophoresis (CZE) permits the separation of peptides and small proteins by a method which is orthogonal to the traditional method of reversed-phase HPLC. To facilitate planned studies of the antibody's biological activity, our buffer composition was kept as simple as possible. During CZE analysis, if the buffer pH is below the isoelectric point of the protein, or the protein is large (with a heterogeneous distribution of surface charges), it can irreversibly blind to the capillary wall unless the capillary is coated. We found that C1-coatings in RP-capillaries at pH 9.5 adequately prevented the antibody fragments from binding to the wall. However, the coating did not remain stable at such high pH, so different conditions were sought. We achieved adequate separations in several buffers at nearly physiological pH, in a bare silica capillary which had been coated once with a soluble cationic polymer coating (Micro-Coat applied during column conditioning). Antibody electropherograms changed depending on the type of inorganic buffer salt used in a separation. Phosphate binds to the antigen-binding site of the IgA with low affinity, and interesting effects were observed in separations using phosphate buffer. These effects will de discussed.

Antibodies, Neoplasm↗

Cancer prevention in the dental practice: oral cancer screening and tobacco cessation advice.

OBJECTIVES: In this paper we describe the proportion of US adults who report receiving oral cancer screening and tobacco cessation counseling and assistance from dentists and other health professionals. METHODS: Data from the 1992 National Health Interview Survey (NHIS) Cancer Control Supplement, a nationally representative sample of 12,035 adults 18 years of age and older, are analyzed. RESULTS: In 1992, less than 10 percent of adults reported oral cancer screening by a dentist or hygienist within the past three years. White adults (10.1%, 95% CI = 9.3, 10.9) reported an oral cancer screening three times more frequently than black (3.2%, 95% CI = 1.9, 4.5) or Hispanic (3.4%, 95% CI = 2.1, 4.7) adults. About half of adult current smokers had seen a dentist within 12 months, and of those only 24.1 percent (95% CI = 21.7, 26.5) had been advised to quit smoking. Heavy smokers (two or more packs a day) were more likely to have been advised to quit than light (pack or less per day) or occasional smokers. A similar proportion (24.3%, 95% CI = 17.6, 31.0) of white adult men who reported using smokeless tobacco products had been told by a dentist to quit using tobacco. CONCLUSIONS: Results from this population-based survey indicate that cancer screening and tobacco cessation advice are underutilized in the dental practice. Increased patient awareness and implementation of screening and tobacco cessation interventions could improve oral cancer incidence and mortality and have a public health benefit for other tobacco-related morbidity and mortality as well.

Adolescent↗

Nursing faculty practice: challenges for the future.

Just as artists need to create their own art, so nursing instructors need to practise nursing. However, traditional educational settings and clinical placements limit the capacity of nursing instructors to practice nursing directly with clients. The creation of a nursing faculty practice model in Canada, whereby teaching roles and responsibilities are combined with clinical practice, is discussed within the context of a community college environment. A nurse-managed health centre is suggested as an innovative practice arena which is more in line with the changes in the health care system.

Alberta↗

Recognition and management of anxiety and depression in elderly patients.

OBJECTIVE: To describe important aspects of the recognition and management of anxiety and depression in elderly patients. DESIGN: We reviewed pertinent recent articles in the medical literature and compiled guidelines for diagnosing and treating anxiety and depression in the geriatric population. RESULTS: Depression and anxiety are common in the elderly population. The development of depression in elderly subjects is associated with a higher risk of death from suicide than for any other age-group. Recognition of depression in elderly patients is often hampered by an inability or reluctance on the part of these patients to report depressive symptoms. In addition, anxiety and depression are often attributed to organic illness in this age-group. Pharmacotherapy is effective; however, older patients are probably more likely than young patients to experience adverse effects. Using medications at lower doses, choosing drugs with shorter half-lives, and avoiding drugs with potent anticholinergic side effects are often advisable. CONCLUSION: Anxiety and depression are common conditions among the elderly population. Correct recognition, attention to underlying precipitating factors, and compassionate, supportive care can vastly improve the quality of the lives of these patients.

Aged↗

Management of breast cancer in the elderly.

The management of breast cancer in elderly women was analysed by a retrospective study of 150 women over 70 years old referred to our department between 1984 and 1988. 80 were T1-T2, 33 were T3 and 34 were T4. 107 were N0 and 43 were N1-N2. 16 women (11%) were in poor health, preventing conventional treatment. Treatment choice varied with age: 60% of the women aged 70-79 (group 1) and 23% of the oldest women (group 2) were treated conventionally. The use of surgery decreased with age and surgical procedures were conventional in only 85% of the group 1 women and in 56% of the group 2 women. Definitive radiation therapy was used more frequently in the oldest women, as was primary hormone therapy. Quality of follow-up also varied with age. Five-year survival rates were still high in both groups while relapses were frequent. Breast cancer was consequently a frequent cause of death. The increase in the proportion of elderly people with breast cancers over the next few years will require validated guidelines. Specific protocols and specific rules of management must be drawn up.

Age Factors↗

Nicotinamide and carbogen: relationship between pO2 and radiosensitivity in three tumour lines.

The effects of carbogen breathing, nicotinamide injection and their combination on tumour radiosensitivity were correlated with changes in tumour O2 tension to determine the relationship between radiosensitivity and measured pO2. The radiosensitivity (in vivo-in vitro colony assay) and O2 tension (computerized pO2 histograph KIMOC 6650) of two human xenografted tumours (HRT18 and Na11+) and one murine tumour (EMT6) were measured under similar experimental conditions. A single dose of radiation was delivered (8 Gy for HRT18 and Na11+, 12 Gy for EMT6). Carbogen breathing, nicotinamide injection, and their combination all significantly increased radiosensitivity in the three cell lines (p < 0.05); the most efficient treatment was carbogen plus nicotinamide. The radiosensitization was optimum for EMT6 and Na11+. Mean and median pO2 increased with all three treatments, except for carbogen breathing in EMT6. Carbogen breathing had little effect on the proportion of low pO2 values, but induced pO2 values > 30 mmHg in all three tumour lines. Nicotinamide decreased the proportion of low pO2 values. This effect is larger with the combination carbogen plus nicotinamide. Almost all pO2 values < 2.5 mmHg were eliminated for HRT18 and EMT6. The relationship between radiosensitization and pO2 was significant when pO2 was expressed as the percentage of values below 7, 8, 9 and 10 mmHg for the three lines.

Animals↗

Family history, age, and risk of fatal breast cancer.

A family history of breast cancer potentially identifies women at high risk for whom mammography may be especially valuable. The authors examined the association of fatal breast cancer and family history in a large, prospective study of US adults. After 6 years of follow-up, 880 cases of fatal breast cancer were observed in a cohort of 604,412 women who were cancer free at interview in 1982. Cox proportional hazards modeling found that a family history of breast cancer in a mother or sister was significantly related to fatal breast cancer risk (rate ratio = 1.59, 95% confidence interval (CI) 1.29-1.95). The association was greatly modified by age; the rate ratio was 4.91 (95% CI 1.39-17.3) in women aged < 40 years at enrollment compared with 1.28 (95% CI 0.78-2.11) in women aged > or = 70 years. Among young (aged < 50 years) women, the risk associated with a positive family history was greatest if the relative was also young at the time of diagnosis (rate ratio = 5.22, 95% CI 3.00-9.11). These associations were not altered in multivariate analyses controlling for known breast cancer risk factors. In the authors' data, family history is strongly predictive of early fatal breast cancer, particularly when the disease is diagnosed before age 50 in the relative. Women with a family history of early breast cancer should receive special instructions regarding mammography and early detection.

Adult↗

Demographic predictors of mammography and Pap smear screening in US women.

OBJECTIVES: Proven screening technologies exist for both breast and cervical cancer, but they are underused by many women. We sought to evaluate the effect of demographic characteristics on the underuse of mammography and Pap smear screening. METHODS: We analyzed responses from 12,252 women who participated in the 1987 National Health Interview Survey Cancer Control Supplement. Demographic profiles were produced to target severely underserved groups of women. RESULTS: Low income was a strong predictor of mammography underuse, as was Hispanic ethnicity and other race, low educational attainment, age greater than 65, and residence in a rural area. A strong predictor of never having had a Pap smear was never having been married; however, the importance of this characteristic is difficult to interpret in the absence of data on sexual activity. Hispanic women and women of other races of all ages and all income levels underused Pap smear screening, as did older women, particularly older Black women. CONCLUSIONS: The tendency of women to underuse screening technologies varies greatly across levels of basic demographic characteristics. The importance of these characteristics differs for mammography screening versus Pap smear screening.

Adult↗