Mutation in internode length affects wheat plant-type.

A mutant form was found in an M(2) population of wheat Triticum aestivum L. em. Thell. (aestivum group) 'Seneca'. The population was derived from soaked grains treated with 3.2 kilorads of gamma rays. The first and second internodes below the spike were reduced in length 33 and 15 percent, respectively, and the total height was 18 percent shorter than the prototype. The flag leaf sheath was normal in length resulting in spike placement below the flag leaf lamina. Segregation data suggest that one dominant gene controls this character. The canopy structure of a population of mutant plants is different from that of the normal type; therefore, this mutant can be used to evaluate light interception and physiological aspects of crop productivity.

Determinants and incidence of depression in multiple sclerosis: A prospective cohort study.

OBJECTIVE: To estimate the incidence and explore potential determinants of incidence of depression in MS. METHODS: A prospective cohort study used a sample of 192 patients from the southern Alberta MS clinic registry. Participants completed baseline risk factor assessment questionnaires using either online, mail or telephone surveys, and completed the Patient Health Questionnaire every 2weeks for 6months to assess depressive symptoms in real time. Risk factors assessed included biopsychosocial variables such as socioeconomic status, illness-related factors, childhood risk factors, psychosocial factors, and health behaviors. Cox proportional hazard models were fit to estimate predictors of incidence. RESULTS: 2-week incidence of depression for females was 0.019 (95% CI 0.013-0.029) and for males was 0.044 (0.026-0.074). Strongest predictor of depression incidence risk included fatigue impact, low mobility, resiliency, self-esteem, self-efficacy, and coping style. CONCLUSION: Depression in MS exhibits a risk factor profile similar to that of depression in the general population, with the additional impact of MS illness-related factors. Potentially modifiable risk factors, such as coping with stress and resiliency, present opportunities for focus of further research in depression in MS treatment and prevention efforts. Some differences in determinants of incidence were found compared to the prevalence risk factors, highlighting the danger of using cross-sectional data to make assumptions about risk. For example, the finding that depression incidence was higher for men is opposite to the higher depression prevalence estimates found for women as well as the consensus in the literature.

Genes for Dwarfness in Wheat, TRITICUM AESTIVUM L.

The genetic control of plant height was studied in crosses of four spring wheats involving the standard height variety Ramona 50 and short-statured selections Olesen, D6301, and D6899. Data from parent, F(1), F(2), and F(3) populations indicated that four independently segregating loci account for most of the differences among the four varieties. Two major genes of a highly recessive nature condition reduced height in Olesen and the Norin 10 derivative D6301. Olesen also carries a third dwarfing gene which is partially dominant in its effects over genes for tallness. This gene, or a gene that acts in a similar manner, is also present in the standard height variety Ramona 50. Dwarfing in D6899, a derivative of Tom Thumb, is controlled primarily by a single gene with mainly additive effects which is not present in any of the other three varieties.Genetic components estimated from generation means (parental, F(1), F(2), F(3), and backcross) indicated that additive gene effects were the major component of variation in four of the six crosses, and of similar magnitude to dominance effects in another cross. The primary source of genetic variation in the cross Olesen x D6899 was due to epistasis with both additive x additive and dominance x dominance effects of major importance. The results of the generation mean analyses were consistent with the models for major-gene control of plant height based on segregation patterns.

Effect of heterozygosity for the methionine synthase 2756 A-->G mutation on the risk for recurrent cardiovascular events.

Increased dietary intake of folate has been shown to significantly reduce the risk for fatal myocardial infarction, possibly by lowering homocysteine levels. We therefore investigated the association between recurrent cardiovascular events and a mutation in methionine synthase (2756 A-->G)--an enzyme directly involved in folate and homocysteine metabolism. This mutation significantly reduced the risk for recurrent cardiovascular events and elevated red blood cell folate levels.

The epidemiology of premenstrual symptoms in a population-based sample of 2650 urban women: attributable risk and risk factors.

This epidemiologic survey achieved a reliable measure of the prevalence of premenstrual symptoms by avoiding the biases of small or selected samples, anamnestic error, and subjective expectation. From 6232 women (a 78.8% response), aged 20-49 years, identified through a random sample of urban households, the 24-hour prevalence of symptoms was obtained using the Moos' Menstrual Distress Questionnaire, administered without reference to the menstrual cycle. For 71% of the naturally cycling women, current cycle phase was determined by follow-up (n = 2650); but a higher prevalence of severe or moderately severe affective symptoms in the premenstrual compared to the mid-cycle phase was not found. However, observed risk factor interactions led to the conclusion that premenstrual distress is a discrete mood disorder, affecting women aged 25-35 years, with probable ovulatory cycles, and vulnerable to stress; and that the risk of affective symptoms attributable to the premenstrual state was one percent.

Protein clearance from the air spaces and lungs of unanesthetized sheep over 144 h.

We studied the rate, the routes, and the mechanisms for protein clearance from the air spaces and lungs of 20 unanesthetized sheep over 144 h. We instilled 100 ml of autologous serum labeled with 125I-albumin into one lung. At the end of 24, 48, 96, or 144 h, the lungs were removed and the residual native protein and 125I-albumin in the air spaces were determined by bronchoalveolar lavage. Also the fraction of the instilled 125I-albumin remaining in the rest of the lung was measured in the lung homogenate. Clearance of the 125I-albumin from the lung into the plasma, lymph, thyroid, urine, and feces was also determined. The removal of both the 125I-albumin and the native protein from the air spaces was slow, following a monoexponential decline. The removal rate of the 125I-albumin from the air spaces was slightly but significantly faster (1.6%/h) than the clearance rate of the native protein (0.9%/h). Clearance of the 125I-albumin from the lung also followed a slow monoexponential decline at a rate of 1.4%/h. At all time periods, 75% of the 125I-albumin remaining in the lung was located in the air spaces, thus indicating that the pulmonary epithelium is the principal barrier to protein clearance from the normal lung. Macrophages appeared to play a minor role in alveolar protein clearance because the quantity of 125I-albumin present in the phagocytic cells in the air spaces was less than 1% of the instilled 125I-albumin at all time periods. However, macrophages may play some role in protein clearance after 48 h because we visualized phagolysosomes in macrophages, and there was an increase in free iodine in lung lavage, urine, thyroid, and feces after 48 h. However, gel electrophoretic studies showed that most of the 125I-albumin was cleared from the lung as an intact molecule, although only 24.7 +/- 4.7% of the 125I-albumin was cleared by the lymphatics.

Clinical interpretation of the mini-mental state.

The Mini-Mental Status Examination (MMSE) is a brief, structured test of cognitive function. The test is often used as a screening or case-finding instrument for the detection of organic mental disorders or cognitive impairment. However, many clinicians incorporate the MMSE into their clinical mental status examination. In both contexts, cutoff scores are often utilized to interpret the results, with scores below the cutoff being interpreted as evidence of cognitive dysfunction, and scores above the cutoff being interpreted as evidence against such dysfunction. However, when the test is done as part of a mental status examination, the application of a cutoff score fails to take account of prior clinical information, which is critical to the interpretation of all diagnostic tests. In this paper, an alternative approach to interpretation is proposed. In the proposed method, guidelines for interpretation are based on the probability of being free of organic disease at each potential score. Scores are interpreted in terms of their consistency or inconsistency with a prior diagnostic impression. This takes prior clinical information and clinical judgment into account. Although different from the traditional way of interpreting the MMSE, the proposed method can be implemented on an intuitive level and does not require mathematical calculations, which are inconvenient at the bedside.

Azathioprine for maintaining remission of Crohn's disease.

OBJECTIVES: To assess the effectiveness of azathioprine in maintaining remission of quiescent Crohn's disease. SEARCH STRATEGY: Pertinent studies were selected using the MEDLINE data base (1966 - May 1998), the Cochrane Controlled Trials Register, the Inflammatory Bowel Disease Trials Register, as well as abstracts from major gastrointestinal research meetings and references from published articles and reviews. SELECTION CRITERIA: Five randomized, double-blind, placebo-controlled trials of azathioprine therapy were identified. Two of these trials consisted solely of patients with quiescent Crohn's disease. Three trials had multiple therapeutic arms for both induction of remission and maintenance of remission. DATA COLLECTION AND ANALYSIS: Data were extracted by three independent observers (GRM, GF, LRS) based on the intention to treat principle. Peto odds ratios for the overall maintenance of remission, steroid sparing, and withdrawals due to adverse effects were calculated, and from these, 95% confidence intervals were derived. Numbers needed to treat or harm (NNT, NNH respectively) for the maintenance of remission, steroid sparing, and withdrawals due to adverse effects were also determined. MAIN RESULTS: Azathioprine had a positive effect on maintaining remission. The Peto odds ratio for maintenance of remission was 2.16 (CI 1.35 - 3.47) with an NNT of 7. A higher dose improved response. A steroid sparing effect was noted, with a Peto odds ratio of 5.22 (CI 1.06 - 25.68) and NNT of 3 for quiescent disease. The Peto odds ratio for withdrawals due to adverse events was 4.36 (CI 1.63 - 11.67), the NNH (Number Needed to Harm) was 19. REVIEWER'S CONCLUSIONS: Azathioprine is effective in maintaining remission. There is evidence for a steroid sparing effect.

The effect of elastic bandages on human knee proprioception in the uninjured population.

Elastic bandages are often used to treat musculoskeletal disorders, even though there is little scientific evidence currently to support this generalized practice. We tested the hypothesis that elastic bandages improve proprioception of the bandaged joint during their use, and that this benefit was more than temporary. The uninjured human knee was used as a model. Fifty-four volunteers (54 knees), aged 22 to 40 years, were asked to identify a prior set joint angle as their knee was passively extended. Each knee was tested without the elastic bandage, immediately after bandage application, after 1 hour of bandage wear, and finally after removal of the bandage. Results showed that elastic bandages significantly improved knee joint proprioception in the uninjured knee during the entire interval of their use (mean decrease in inaccuracy of 1.0 degree, equivalent to 25% improvement, P < 0.05), and that this benefit was lost when the bandage was removed. The magnitude of the improvement, or the potential beneficial effect of the bandage, was inversely related to the participant's inherent knee proprioceptive ability, which was demonstrated in the test group before the initial application of the bandage.

The distribution of injuries in men's Canada West university football. A 5-year analysis.

We conducted a prospective cohort study from 1993 to 1997 to determine the frequency and severity of injury in men's Canada West university football. The Canadian Intercollegiate Sport Injury Registry was used to document baseline preseason data, daily athlete participation, and subsequent injury from five varsity football teams. An injury was defined as "any injury resulting in one or more complete or partial sessions of time loss" or "any concussion or transient neck neurologic injury." The annual proportion of injured athletes ranged from 53.5% to 60.4%, with a 5-year total of 1,811 injuries. Regression analysis indicated that the rate of nonconcussion, nonneck neurologic injuries increased. Concussion (N = 110), hamstring strain (N = 88), and brachial plexus (N = 84) injuries were the most common, specific injury diagnoses. Knee injuries resulted in the highest rate of severe (greater than or equal to 7 sessions of time loss) injury and resulted in the most time loss (3,350.5 sessions). Ligament sprains and muscle strains and spasms accounted for approximately half of all injury diagnoses. A total of 1,173 injuries (65%) were related to contact between players or between players and other obstacles. Future studies should be conducted to identify risk factors for the ultimate purpose of implementing injury prevention strategies.

The effect of semirigid dressings on below-knee amputations.

BACKGROUND AND PURPOSE: The effect of using semirigid dressings (SRDs) on the residual limb of individuals who have had below-knee amputations as a consequence of peripheral vascular disease was investigated, with the primary question being: Does the time to readiness for prosthetic fitting for patients treated with the SRDs differ from that of patients treated with soft dressings? SUBJECTS: Forty patients entered the study and were alternately assigned to one of two groups. Nineteen patients were assigned to the SRD group, and 21 patients were assigned to the soft dressing group. METHODS: The time from surgery to readiness for prosthetic fitting was recorded for each patient. Kaplan-Meier survival curves were generated for each group, and the results were analyzed with the log-rank test. RESULTS: There was a difference between the two curves, and an examination of the curves suggests that the expected time to readiness for prosthetic fitting for patients treated with the SRDs would be less than half that of patients treated with soft dressings. CONCLUSION AND DISCUSSION: The results suggest that a patient may be ready for prosthetic fitting sooner if treated with SRDs instead of soft dressings.

Correlations between laparoscopic and hysteroscopic findings in 497 women with otherwise unexplained infertility.

Laparoscopy and hysteroscopy were undertaken simultaneously in 497 women presenting with otherwise unexplained infertility. Of them, 285 complained of primary infertility and 212 of secondary infertility. Laparoscopic evidence of pelvic inflammatory disease in the absence of endometriosis was noted in 103 patients with primary and in 108 women with secondary infertility. Lesions were noted on hysteroscopy in both groups as well as in 34% of women with normal laparoscopic examinations. No specific dependency could be demonstrated between any laparoscopically detected lesion and hysteroscopically detected lesion. A significant dependency was demonstrated only between a history of secondary infertility and uterine adhesions (chi 2 = 12.03, 1 df, p less than 0.01). While the combined endoscopic findings did not demonstrate any dependency, the findings of this study demonstrate the importance of hysteroscopy in assessing all patients with infertility, especially those with secondary infertility.

Legal status of the mentally disabled person in South African law.

Mental illness or insanity has a dramatic influence on a person's legal status. A person's status determines his or her competencies such as legal capacity, capacity to act, accountability and capacity to litigate. A mentally ill person is incapable of performing juristic acts; he or she is not capable of becoming a party to legal proceedings; is virtually incapable of committing a crime or being liable for a delict; etc. However, not all mentally ill persons are precluded from performing legal acts or, for that matter, giving valid consent to medical treatment. The reason being that status is factually determined according to the degree to which the mental illness is present at the time when the mentally ill person participates in the legal traffic. The measure of capability depends on the patient's intellectual and volitional capacities that will decide whether the patient can validly contract, litigate or consent to medical treatment. More specifically medical research of a non-therapeutic nature can only be carried out on mental patients who are capable of consenting thereto. This article endeavours to touch upon the different aspects of the mentally ill person's legal status.

Cost and outcomes of nosocomial bloodstream infections complicating major traumatic injury.

The objective of this study was to assess the incidence, outcomes, and costs of trauma-related nosocomial bloodstream infection (BSI). This was a 3:1 matched cohort study in patients with severe trauma [defined by an injury severity score (ISS)≥12] admitted to adult or paediatric regional trauma centres over a four-year period. Case patients with nosocomial BSI were matched to controls without a BSI based on predetermined criteria. Outcomes of interest included mortality, length of stay (LOS), and cost attributable to nosocomial BSI. Fifty-seven cases were identified, among whom 51 were successfully matched to three controls. The mean ISS among cases was 30.3, and Staphylococcus aureus was the most commonly isolated pathogen (27%). Being a case was accompanied by a 27% relative increase in the hospital LOS (P=0.02). The odds ratio for 30 day mortality associated with being a case was 5.8 (95% confidence interval (CI): 1.1-30.8; P=0.04). Among survivor-matched groups, being a case was associated with 53% relative increase in the geometric mean total hospital cost [$97,993 (95% CI: $70,143-136,899) for cases and $62,297 (95% CI: $52,155-74,411) for controls, P<0.0001]. This is the first study to show that nosocomial BSI complicating severe trauma is associated with a substantial increase in hospital LOS and in total hospital cost. Our data provide justification to support efforts to reduce the adverse impact of BSI in trauma victims.

Quantifying the amount of padding improves the comfort and function of a fibreglass below-elbow cast.

AIM: To determine the quantity of cotton underpadding needed for a comfortable, functional, below-elbow fibreglass cast. METHODS: In this randomised, prospective, crossover, clinical trial, 45 people with minimally displaced distal radial fractures were enrolled to randomly receive, 14 days after injury, a fibreglass below-elbow cast with either two or four layers of cotton underpadding. The characteristics of the recipients were recorded. After 2 weeks of immobilisation, participants completed a numerical survey evaluating parameters of comfort and underwent clinical and radiographic assessment. They then crossed over to receive the other fibreglass cast design, the process was repeated, and they indicated their cast preference, if any. RESULTS: Of 37 people who completed the study, 20 preferred the two-layer model, 13 the four-layer model and 4 had no preference. No significant trend for one design over the other was shown (p=0.1), nor any statistical association between preference and participant characteristics or the order in which cast models were received. CONCLUSIONS: Participants did state a preference, but this was not related to recipient characteristics. Neither cast design was significantly the more comfortable; and both models were safe and functionally satisfactory.

A multi-centre randomized controlled trial comparing electrothermal arthroscopic capsulorrhaphy versus open inferior capsular shift for patients with shoulder instability: protocol implementation and interim performance: lessons learned from conducting a multi-centre RCT [ISRCTN68224911; NCT00251160].

BACKGROUND: The shoulder is the most frequently dislocated joint in the body. Multiple causes and pathologies account for the various types of shoulder instability. Multi-directional instability (MDI) and multi-directional laxity with antero-inferior instability (MDL-AII) are similar in pathology, less common and more difficult to treat. These instabilities are caused by ligamentous capsular redundancy. When non-operative management fails for these patients, quality of life is significantly impaired and surgical treatment is required to tighten the ligaments and joint capsule. The current reference (gold) standard treatment for MDI/MDL-AII is an open inferior capsular shift (ICS) surgical procedure. An alternative treatment involves arthroscopic thermal shrinkage of redundant capsular tissue to tighten the joint. However, there is a lack of scientific evidence to support the use of this technique called, electrothermal arthroscopic capsulorrhaphy (ETAC). This trial will compare the effectiveness of ETAC to open ICS in patients with MDI and MDL-AII, using patient-based quality of life outcome assessments. METHODS: This study is a multi-centre randomized clinical trial with a calculated sample size of 58 patients (p = 0.05, 80% power). Eligible patients are clinically diagnosed with MDI or MDL-AII and have failed standardized non-operative management. A diagnostic shoulder arthroscopy is performed to confirm eligibility, followed by intra-operative randomization to the ETAC or ICS surgical procedure. The primary outcome is the disease-specific quality of life questionnaire (Western Ontario Shoulder Instability Index), measured at baseline, 3, 6, 12 and 24 months. Secondary outcomes include shoulder-specific measures (American Shoulder and Elbow Surgeons Score and Constant Score). Other outcomes include recurrent instability, complications and operative time. The outcome measurements will be compared on an intention-to-treat basis, using two-sample independent t-tests to assess statistical significance. A Generalized Estimated Equations (GEE) analysis will determine whether there is an effect over time. DISCUSSION: This ongoing trial has encountered unexpected operational and practical issues, including slow patient enrollment due to high intra-operative exclusion rates. However, the authors have a greater understanding of multi-directional laxity in the shoulder and anticipate the results of this trial will provide the medical community with the best scientific clinical evidence on the efficacy of ETAC compared to open ICS.

Assessment of lack of fit in simple linear regression: an application to serologic response to treatment for syphilis.

A patient treated for infectious syphilis is cured when serologic tests become non-reactive, which may take years to achieve. Our objective is to develop a method to determine, within months, whether the patient has responded adequately to treatment. Previous research and our exploratory graphical analysis suggested that treatment response is linear when we applied logarithmic transformations of the axes. If the response to treatment is linear, titres recorded within the first few months of treatment will determine the slope of the line and one can develop an action line in future research. We used a non-parametric method to assess whether the logarithmic transformation improved the linearity and then we applied three different methods of testing lack of fit in linear regression. Based upon a sample size that reflects a clinically reasonable number of data points, the results of these tests provided no evidence against linearity.