Characteristic ground-reaction forces in baseball pitching

Overhand throwing requires contributions from and interaction between all limb segments. Most previous investigations have concentrated on the throwing arm itself, yet poor mechanics at the arm may originate in the lower extremities. Multicomponent ground-reaction forces of both the push-off and landing limbs were measured in six collegiate and one high school level baseball pitchers. Full body kinematics were simultaneously recorded to correlate phases in the pitching cycle with the force data. Pitchers were found to generate shear forces of 0.35 body weight in the direction of the pitch with the push-off leg and to resist forces of 0.72 body weight with the landing leg. Wrist velocity was found to correlate highly with increased leg drive. This study validates the clinical impression that the lower extremity is an important contributor to the throwing motion. Based on this study, strengthening of the lower extremities could be inferred to be important both to enhance performance and to avoid injury.

Health-related quality of life for patients with progressive multiple sclerosis: influence of rehabilitation

BACKGROUND AND PURPOSE

The health-related quality of life of patients with multiple sclerosis (MS) is an important aspect of care outcome. The purpose of this study was to compare health-related quality of life between patients who received weekly comprehensive outpatient rehabilitation for 1 year and a group that did not receive rehabilitation.

SUBJECTS

Twelve patients receiving outpatient care for chronic progressive MS (mean age = 44.5 years, SD = 11.6) were compared with 19 similar patients (mean age = 49.2 years, SD = 9.2) on a waiting list who were not receiving outpatient care.

METHODS

A pretest-posttest longitudinal design was used to descriptively compare outcome measures. Multivariate regression analyses were used to determine which variables, controlled for baseline health status and other relevant patient characteristics, were related to the best outcomes at the time of the 1-year follow-up.

RESULTS

The treatment group showed improvements in six health status measures on the Rand 36-Item Health Survey 1.0 (SF-36) that were not improved in the wait-listed group. Outpatient treatment was the sole predictor of positive outcome for energy/fatigue (partial R2 = .43) and change in general health (partial R2 = .19). In addition, the treatment group was associated with a positive outcome (together with other independent variables) in the domains of social function and social support.

CONCLUSION AND DISCUSSION

Patients with chronic progressive forms of MS appear to derive benefits from an ongoing comprehensive outpatient rehabilitation program. [Di Fabio RP, Choi T, Soderberg J, Hansen CR. Health-related quality of life for patients with progressive multiple sclerosis: influence of rehabilitation.

CENP-E is an essential kinetochore motor in maturing oocytes and is masked during mos-dependent, cell cycle arrest at metaphase II

CENP-E, a kinesin-like protein that is known to associate with kinetochores during all phases of mitotic chromosome movement, is shown here to be a component of meiotic kinetochores as well. CENP-E is detected at kinetochores during metaphase I in both mice and frogs, and, as in mitosis, is relocalized to the midbody during telophase. CENP-E function is essential for meiosis I because injection of an antibody to CENP-E into mouse oocytes in prophase completely prevented progression of those oocytes past metaphase I. Beyond this, CENP-E is modified or masked during the natural, Mos-dependent, cell cycle arrest that occurs at metaphase II, although it is readily detectable at the kinetochores in metaphase II oocytes derived from mos-deficient (MOS-/-) mice that fail to arrest at metaphase II. This must reflect a masking of some CENP-E epitopes, not the absence of CENP-E, in meiosis II because a different polyclonal antibody raised to the tail of CENP-E detects CENP-E at kinetochores of metaphase II-arrested eggs and because CENP-E reappears in telophase of mouse oocytes activated in the absence of protein synthesis.

The Mos/mitogen-activated protein kinase (MAPK) pathway regulates the size and degradation of the first polar body in maturing mouse oocytes

Mos is an upstream activator of mitogen-activated protein kinase (MAPK) and, in mouse oocytes, is responsible for metaphase II arrest. This activity has been likened to its function in Xenopus oocytes as a component of cytostatic factor. Thus, Mos-deficient female mice (MOS-/-) are less fertile and oocytes derived from these animals fail to arrest at metaphase II and undergo parthenogenetic activation [Colledge, W. H., Carlton, M. B. L., Udy, C. B. & Evans, M. J. (1994) Nature (London) 370, 65-68 and Hashimoto, N., Watanabe, N., Furuta. Y., Tamemoto, B., Sagata, N., Yokoyama, M., Okazaki, K., Nagayoshi, M., Takeda, N., Ikawa, Y. & Aizawa, S. (1994) Nature (London) 370, 68-71]. Here we show that maturing MOS-/- oocytes fail to activate MAPK throughout meiosis, while p34cdc2 kinase activity is normal until late in metaphase II when it decreases prematurely. Phenotypically, the first meiotic division of MOS-/- oocytes frequently resembles mitotic cleavage or produces an abnormally large polar body. In these oocytes, the spindle shape is altered and the spindle fails to translocate to the cortex, leading to the establishment of an altered cleavage plane. Moreover, the first polar body persists instead of degrading and sometimes undergoes an additional cleavage, thereby providing conditions for parthenogenesis. These studies identify meiotic spindle formation and programmed degradation of the first polar body as new and important roles for the Mos/MAPK pathway.

Mos/mitogen-activated protein kinase can induce early meiotic phenotypes in the absence of maturation-promoting factor: a novel system for analyzing spindle formation during meiosis I

Mitogen-activated protein kinase (MAPK) is selectively activated by injecting either mos or MAPK kinase (mek) RNA into immature mouse oocytes maintained in the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX). IBMX arrests oocyte maturation, but Mos (or MEK) overexpression overrides this block. Under these conditions, meiosis I is significantly prolonged, and MAPK becomes fully activated in the absence of p34cdc2 kinase or maturation-promoting factor. In these oocytes, large openings form in the germinal vesicle adjacent to condensing chromatin, and microtubule arrays, which stain for both MAPK and centrosomal proteins, nucleate from these regions. Maturation-promoting factor activation occurs later, concomitant with germinal vesicle breakdown, the contraction of the microtubule arrays into a precursor of the spindle, and the redistribution of the centrosomal proteins into the newly forming spindle poles. These studies define important new functions for the Mos/MAPK cascade in mouse oocyte maturation and, under these conditions, reveal novel detail of the early stages of oocyte meiosis I.

Abnormal centrosome amplification in the absence of p53

The centrosome plays a vital role in mitotic fidelity, ensuring establishment of bipolar spindles and balanced chromosome segregation. Centrosome duplication occurs only once during the cell cycle and is therefore highly regulated. Here, it is shown that in mouse embryonic fibroblasts (MEFs) lacking the p53 tumor suppressor protein, multiple copies of functionally competent centrosomes are generated during a single cell cycle. In contrast, MEFs prepared from normal mice or mice deficient in the retinoblastoma tumor suppressor gene product do not display these abnormalities. The abnormally amplified centrosomes profoundly affect mitotic fidelity, resulting in unequal segregation of chromosomes. These observations implicate p53 in the regulation of centrosome duplication and suggest one possible mechanism by which the loss of p53 may cause genetic instability.

Notational analysis on game strategy used by the world's top male squash players in international competition

The purpose of this study was to provide a profile of the competition strategy used by the world's top squash players at the international level and provide recommendations for other players to improve their playing strategy. A total of 10 matches including three in round one, the four quarter finals, the two semi-finals, and the final of the 1993 Hong Kong Squash Open were filmed using a 3-CDD video camera. The tournament was played under the North American scoring system. Notational analysis which is based on frame by frame video analysis was used to categorize a player's motion. The frequency of each stroke, and the success or failure rate of each stroke were recorded. Shots were classified as "effective", "ineffective", "winning" and "losing" shots and the analysis demonstrated that 70.28% were "effective", 19.86% were "ineffective", 5.37% were "winning" and 4.48% were "losing" shots. The mean number of shots per game was 252.09. The order of priority using different kinds of strokes in matches were as follows: drive (length) (60.79%), drop (17.91%), volley (11.79%), boast (4.80%), and lob (4.72%). The results of this study show that the "pressure and attack game" was the most important strategy for the world's top squash players in producing winning performances. Also identified are the strokes and the strategies which should be practiced to improve performance. This method of notational analysis can be utilized to evaluate the strengths and weaknesses of players at all levels of competition.

Caregivers of frail elderly and medically fragile children: perceptions of ability to continue to provide home health care

The purposes of this study were to compare the characteristics and support systems of caregivers of frail elderly and medically fragile children and to determine what factors discriminated between caregivers who could (and could not) continue to provide home health care. Caregivers of children were significantly more likely (chi 2 = 52.30)2), p = < .0000) to report that they were managing OK than caregivers of frail elderly. They also reported receiving more support and assistance from formal and informal sources, although in general, less than 30% of the caregivers received any help. Five variables (Mental impairment of the elder, poor physical and mental health of the caregiver, high monthly caregiving-related expenses, and use of paid in-home assistance) explained 35% of the variance between caregivers of frail elderly who were managing OK and those who were unable to continue to manage. Six variables (physical and mental impairment of the child, physical health of the caregiver, feeling like there were no alternative providers, time demand and lack of assistance from others) explained 26.57% of the variance between caregivers of children who were managing OK and those who were unable to continue to manage. The findings suggest that a strong objective stressor, combined with a lack of personal and social resources are associated with caregivers' perceptions that they cannot continue to manage home health care.

A deficiency in the mechanism for p34cdc2 protein kinase activation in mouse embryos arrested at 2-cell stage

Mouse embryos of the ddY strain fertilized in vitro undergo the first cleavage to the 2-cell stage but not the second cleavage even 45 hr after insemination (2-cell block). We examined the phosphorylation state of p34cdc2 and histone H1 kinase activity in mouse 2-cell embryos to investigate the relationship of p34cdc2 with 2-cell block. In the first mitotic cell cycle, the amount of phosphorylated forms of p34cdc2, which were detected as the bands of retarded mobility on SDS-PAGE followed by immunoblotting with anti-p34cdc2 antibody, increased during interphase and abruptly decreased at M phase. Concomitant with this dephosphorylation, histone H1 kinase activity was increased. After the embryos cleaved to the 2-cell stage, the amounts of phosphorylated forms of p34cdc2 increased up to 33 hr after insemination. However, the activation of histone H1 kinase did not occur and the states of phosphorylation of p34cdc2 did not show any significant changes until 45 hr. In contrast, 2-cell embryos of B6C3F1 mice, which do not show a 2-cell block and develop normally to blastocysts in vitro, exhibit the dephosphorylation of p34cdc2 and an increase in histone H1 kinase activity between 31 and 45 hr after insemination. When the ddY mouse embryos arrested at the 2-cell stage were treated with okadaic acid, an inhibitor of protein phosphatases 1 and 2A, the dephosphorylation of p34cdc2 occurred and histone H1 kinase activity increased. The chromosomes of these embryos stained with 4',6'-diamidino-2-phenylindole revealed the initiation of condensation. These results suggest that 2-cell-blocked embryos contain enough p34cdc2 to induce mitotic events but the protein remains in a latent form.

Activation of p34cdc2 protein kinase activity in meiotic and mitotic cell cycles in mouse oocytes and embryos

p34cdc2 protein kinase is a universal regulator of M-phase in eukaryotic cell cycle. To investigate the regulation of meiotic and mitotic cell cycle in mammals, we examined the changes in phosphorylation states of p34cdc2 and its histone H1 kinase activity in mouse oocytes and embryos. We showed that p34cdc2 has three different migrating bands (referred to as upper, middle and lower bands) on SDS-PAGE followed by immunoblotting with anti-PSTAIR antibody, and that the upper and middle bands are phosphorylated forms since these two bands shifted to the lower one by alkaline phosphatase treatment. In meiotic cell cycle, only germinal vesicle (GV) stage oocytes had the three forms. The phosphorylated forms decreased gradually in oocytes up to 2 h after isolation from follicles, and thereafter the phosphorylation states did not change significantly until metaphase II. However, the histone H1 kinase activity oscillated, being activated at the first and second metaphase in meiosis and inactivated at the time of the first polar body extrusion. These results suggest that changes in phosphorylation states of p34cdc2 triggered its activation at the first metaphase, but not inactivation and reactivation at the first and second metaphase, respectively. In mitotic cell cycle, phosphorylated forms appeared at 4 h after insemination, increased greatly just before metaphase, and were dephosphorylated in metaphase. Histone H1 kinase activity was high only at metaphase. This kinase activation is probably triggered by dephosphorylation of p34cdc2.

A generic intron increases gene expression in transgenic mice

To investigate the role of splicing in the regulation of gene expression, we have generated transgenic mice carrying the human histone H4 promoter linked to the bacterial gene for chloramphenicol acetyltransferase (CAT), with or without a heterologous intron in the transcription unit. We found that CAT activity is 5- to 300-fold higher when the transgene incorporates a hybrid intron than with an analogous transgene precisely deleted for the intervening sequences. This hybrid intron, consisting of an adenovirus splice donor and an immunoglobulin G splice acceptor, stimulated expression in a broad range of tissues in the animal. Although the presence of the hybrid intron increased the frequency of transgenics with significant CAT activity, it did not affect the integration site-dependent variation commonly seen in transgene expression. To determine whether the enhancement is a general outcome of splicing or is dependent on the particular intron, we also produced equivalent transgenics carrying the widely used simian virus 40 small-t intron. We found that the hybrid intron is significantly more effective in elevating transgene expression. Our results suggest that inclusion of the generic intron in cDNA constructs may be valuable in achieving high levels of expression in transgenic mice.

Barriers and motivators to prenatal care among low-income women

Substantial evidence exists which links prenatal care to improved birth outcomes. However, low-income and nonwhite women in the United States, who are at greatest risk for poor birth outcomes, continue to receive the poorest prenatal care. The purpose of this study was to identify and compare barriers and motivators to prenatal care among women who lived in low-income census tracts. The stratified sample included recently delivered white, black and American Indian women who received adequate, intermediate, and inadequate prenatal care. Interviews were conducted which focused primarily on the women's perceptions of problems in obtaining prenatal care and getting to appointments. Results indicated that women with inadequate care identified a greater number of barriers and perceived them as more severe. Psychosocial, structural, and socio-demographic factors were the major barriers, while the mother's beliefs and support from others were important motivators. The predictive power of selected barrier variables was examined by a regression analysis. These variables accounted for 50% of the variance in prenatal care use. The results affirm the complexity of prenatal care participation behavior among low-income women and the dominant influence of psychosocial factors. Comprehensive, coordinated and multidisciplinary outreach and services which address psychosocial and structural barriers are needed to improve prenatal care for low-income women.

Providing access to home care for disabled children: Minnesota's Medicaid model waiver program

Home care programs for severely disabled, usually technology-dependent, children got a boost in 1981 when the Federal Government gave States permission to use Medicaid to fund home care under the Medicaid model home- and community-based waiver (2176). The model waiver program was unique because it eliminated the bias toward hospitalization by waiving parental income and assets when determining eligibility for children cared for at home and by allowing Medicaid to cover needed home care services. In 1985 Minnesota received Federal approval for the model waiver, and the results are detailed in this report. Although the waiver could provide funding for up to 50 children, after 2 years only 24 children had received approval. Stringent and complex eligibility criteria acted as barriers to accessing the model waiver. In addition, the interaction between the waiver and the State's health care system contributed to inconsistencies in eligibility. This interaction demonstrates the difficulty of administering publicly funded programs in the current health care environment. Recommendations are made for adjusting criteria for eligibility in the waiver program. Unresolved problems facing technology-dependent children on home care programs are discussed.

Perinatal lethal osteogenesis imperfecta in transgenic mice bearing an engineered mutant pro-alpha 1(I) collagen gene

Substitutions of single glycine residues of alpha 1(I) collagen have previously been associated with the inherited disease osteogenesis imperfecta type II. Transgenic mice bearing a mutant alpha 1(I) collagen gene into which specific glycine substitutions have been engineered show a dominant lethal phenotype characteristic of the human disease, and demonstrate that as little as 10% mutant gene expression can disrupt normal collagen function.

Effects on nurse retention. An experiment with scheduling

Four randomly selected nursing groups were assigned to three experimental groups and one control group to test the relative impact of three experimental nursing schedules, using a before-after design. The three experimental treatments were straight shifts; regular schedule but with unlimited requests for changes; and individual station-designed schedules. Before treatment, score differences between the experimental and control groups were limited to one of 36 highly reliable scales specifically constructed and pretested to gauge effects of scheduling. This single difference was judged not to be significantly related to experimental outcomes. Because of a poor job market situation, retention was not affected significantly by any of the three treatments, but root causes of turnover were. Results of the experiment showed that individual station-designed schedules triggered the most changes that favor retention. In contrast, the other two treatments unexpectedly increased nurses' own sense of marketability and reduced teamwork among nurses. Reasons accounting for the results are discussed in the text.

Hospital cost savings: resembling business

Hospitals, like other employers, offer health care benefits to their employees. Cost savings can be realized when hospitals offer packages that resemble those provided by business employers. Business packages explain variance in cost savings more than employee characteristics do.

Impact of environment on state university hospital performance. An explanatory model

This article, by means of a path model, shows the impact of environment on state university hospital performance. The state environment is shown to affect systematically the intensity of local competition, the reputation of the medical school, the financial independence of the parent university, the allocation of indigent care dollars, the nature of governance and management, and the performance of the hospital. Results show that while certain environments are predictably more supportive of universities and university hospitals, these environments tend also to attract health care competition. Competition is shown to pressure hospitals into greater efficiency, but competition is shown also to hurt viability. But a hospital management that pays attention to the hospital environment is shown to help both efficiency and viability. The model explains respectively 37% and 46% of the variance in hospital efficiency and viability.

Nutrition counseling in private practice: attitudes and activities of family physicians

A community approach to cardiovascular disease control is advocated for the United States because of the high disease incidence and prevalence relative to other countries. The goal of this approach is to change nutrition behavior of all members of the community. As part of a program to identify barriers to physician participation, a survey of a random sample of family practice clinical faculty in a midwestern state was made to determine (a) if physicians agree that it is appropriate to give nutritional advice to a patient who came to the clinic for another reason, (b) the proportion of patients given nutritional advice, and (c) the barriers to giving nutritional advice. Most physicians report that giving nutritional advice to patients visiting them for other reasons is considered appropriate, but almost half the physicians give advice about dietary fat, dietary sodium, or dietary fiber to fewer than 20% of their patients. Only about 10% of physicians give advice to more than 80% of their patients. Absence of elevated risk factor levels or nutritional disease is the most common reason for not giving advice. Perceived lack of patient interest and expectation of patient nonadherence are also barriers. Unpalatability of the diet is occasionally a barrier. Cost of the diet is not a consideration. From these data it is concluded that family physicians consider it appropriate to give nutritional advice to patients who are not necessarily seeking it, but the perception that patients do not need or want, and would not follow, the advice inhibits physicians from delivering nutrition messages in private practice.

Feasibility of simulating physicians' judgments of patient severity

This article reports on adopting Gustafson's multiattribute utility method to develop a specific momentary severity index (vis-à-vis severity over time) for nontraumatic chest pain patients. A panel of physicians identified an appropriate set of indicators for the index. Three mathematic models were generated on the basis of these indicators with each model predicting no less than 81% of the variance in overall scores of 96 simulated patients with chest pain. High interrater reliability (0.94) was demonstrated. Congruent validity coefficients between the three model scores and the overall scores vary between 0.71 and 0.92 depending on how the panel physicians are grouped. Results indicate the feasibility of simulating physician judgments regarding patient severity in chest-pain-related cases.

Systematic impact of the state on CEO tenure

Using information from the literature on both for-profit industrial corporations and nonprofit community hospitals, a path model is constructed to show the effect of the state on CEO tenure at state-owned university hospitals. Results indicate that CEOs' lack of managerial influence and control over competition adversely affects their tenure at these institutions, even when the financial viability of the university hospital is not at stake.

Health-specific family coping index for noninstitutional care

We report on attempts to improve the Richmond/Hopkins Family Coping Index. Factor analysis showed that revised operational guidelines for using the index probably contributed to a significantly higher per cent of variance explained by the index (83 per cent versus 59 per cent). Interrater reliability was high (greater than or equal to .97). Correlation between this index and another coping index was also high (.94). Results support the continued use of the Family Coping Index--with new instructions--to assess patient/family coping.

Perceived palatability of the prudent diet: results of a dietary demonstration for physicians

"Product sampling" is an effective marketing strategy which lowers consumer buying resistance by providing a free sample of the product for the consumer to test. We used this strategy to demonstrate the palatability of the prudent diet (30-35% of calories from total fats, less than 10% from saturated fats, less than 3 g sodium, and increased fiber) to physicians attending a 5-day family practice continuing medical education conference. The effect of the intervention was evaluated with pre- and postintervention questionnaires and a 20% random sample of participants was surveyed 1 year later. The proportion of physicians who reported that they considered the diet to be "very palatable" rose from 26% before the demonstration to 64% after the demonstration. Only 5% of the physicians did not report a favorable response to the demonstration. Sixty-two percent of the physicians reported that the diet was better than expected, and 82% reported that the demonstration encouraged them to recommend the diet to their patients. One year after the intervention 60% considered the diet "very palatable" and 55% reported that the demonstration stimulated them to increase their dietary intervention activities. These data suggest that serving the prudent diet at continuing medical education programs helps to remove prejudices about the diet and encourages physicians to recommend the diet to their patients.

Primary nursing in an organizational context

This article analyzes primary nursing critically and comprehensively. Synthesizing past and present data, the authors suggest a new definition for primary nursing that takes the organizational context into consideration. They illustrate how organizations influence the effectiveness of primary nursing care. The documented information presented here will save nursing administrators hours of reading and analyzing, and will help them make informed decisions about primary nursing.