Teacher candidates' mastery of phoneme-grapheme correspondence: massed versus distributed practice in teacher education.

Matching phonemes (speech sounds) to graphemes (letters and letter combinations) is an important aspect of decoding (translating print to speech) and encoding (translating speech to print). Yet, many teacher candidates do not receive explicit training in phoneme-grapheme correspondence. Difficulty with accurate phoneme production and/or lack of understanding of sound-symbol correspondence can make it challenging for teachers to (a) identify student errors on common assessments and (b) serve as a model for students when teaching beginning reading or providing remedial reading instruction. For students with dyslexia, lack of teacher proficiency in this area is particularly problematic. This study examined differences between two learning conditions (massed and distributed practice) on teacher candidates' development of phoneme-grapheme correspondence knowledge and skills. An experimental, pretest-posttest-delayed test design was employed with teacher candidates (n = 52) to compare a massed practice condition (one, 60-min session) to a distributed practice condition (four, 15-min sessions distributed over 4 weeks) for learning phonemes associated with letters and letter combinations. Participants in the distributed practice condition significantly outperformed participants in the massed practice condition on their ability to correctly produce phonemes associated with different letters and letter combinations. Implications for teacher preparation are discussed.

Post marketing surveillance on the use of zonisamide for epilepsy in the Philippines: A preliminary report

The objective of the study is to monitor on a wide population base the safety and efficacy of zonisamide in patients with partial, generalized, and combined seizures. This is an open label, descriptive, post-marketing surveillance preliminary report that includes the data obtained from October 2008 to May 2010 of a four-year study. The study included 516 patients allocated to either zonisamide monotherapy or zonisamide add-on therapy, with efficacy and safety assessed monthly for three months. For adult patients, a maximum oral dose of 600 mg per day was allowed while a maximum dose of 12 mg/kg/day of zonisamide was allowed for pediatric patients. Efficacy measures were the proportion of responders and percentage change in seizure frequency from baseline. 321 of the 516 patients were included in the efficacy analysis. The responder rates were 53.27%, 80.37%, and 92.52% after the 1st month, 2nd month, and 3rd month of treatment respectively. The use of zonisamide led to seizure-reduction rates of 45.74%, 68.43%, & 82.85% during the 1st, 2nd, & 3rd month of use respectively. Safety analysis was done on all the 516 subjects. Adverse events were mostly mild and observed in 6.78% of patients. No serious adverse events were encountered. 7 subjects (1.4%) discontinued taking zonisamide because of increased seizure frequency in 4 patients, and 1 patient each due to absence of effect on seizure-control, rashes, and thrombocytopenia. All the rest continued taking zonisamide.

The utility of flexible sigmoidoscopy after a computerized tomographic colonography revealing only rectosigmoid lesions.

BACKGROUND: Identifying polyps by computerized tomographic colonography typically prompts colonoscopy, increasing its cost, risk and inconvenience. Many polyps are confined to the rectosigmoid and theoretically amenable to resection via flexible sigmoidoscopy. AIM: To determine the prevalence of advanced proximal colonic neoplasia when computerized tomographic colonography reveals only rectosigmoid polyps, and characterize the yield of polypectomy via flexible sigmoidoscopy in such patients. METHODS: Subjects underwent computerized tomographic colonography and colonoscopy with segmental unblinding. Patients with only rectosigmoid findings by computerized tomographic colonography were identified retrospectively. Flexible sigmoidoscopy findings were estimated by including lesions distal to the descending/sigmoid colon junction during colonoscopy. Proximal lesions were also reviewed. Advanced lesions were defined as: adenocarcinoma, tubular adenoma >1 cm, > or =3 tubular adenomas, tubulovillous histology or high-grade dysplasia. RESULTS: By computerized tomographic colonography, 15% (203 of 1372) had only rectosigmoid polyps. Concomitant lesions in the proximal colon were seen in 32% (64 of 203) during colonoscopy. Advanced proximal neoplasia occurred in 2% (three of 203) with only rectosigmoid polyps on computerized tomographic colonography. CONCLUSIONS: Using flexible sigmoidoscopy to follow-up computerized tomographic colonography demonstrating only rectosigmoid polyps would eliminate 15% of subsequent colonoscopies. This strategy carries a small risk of missed proximal advanced neoplasia. This miss rate appears comparable to that of colonoscopy alone. Further study on the cost-effectiveness of this approach is warranted.

Housing quality among North Carolina farmworker families.

Substandard housing poses risks for health and safety. Few studies have documented the housing conditions experienced by Latino farmworker families in the U.S. The purpose of this analysis is to assess the quality of housing occupied by farmworker families in eastern North Carolina and determine how individual and family characteristics are associated with housing quality. Interviews were completed in six North Carolina counties with 186 Latino farmworker households that included a child under the age of 18 to document respondent, household, and dwelling characteristics. Most households were crowded, with 69.4% having more than one person per room (excluding bathrooms and kitchens). Dwellings were often located adjacent to fields (46.0%), suffered from structural problems (e.g., 18.3% had roof leaks), and lacked facilities and appliances (e.g., 26.9% did not have a working oven). Most farmworker family dwellings did not meet the U.S. Department of Housing and Urban Development's minimum criteria for health and safety. Respondents in their thirties, who lived in North Carolina for less than five years, moved two or more times in the past year to follow crops, and lived in grower-provided housing had the poorest housing quality. These results demonstrate that North Carolina Latino farmworker families lack adequate housing. Further research is needed to evaluate farmworker housing conditions in all areas of the U.S., and to document the relationship of these housing conditions to health outcomes. The collaboration of researchers, advocates, policy makers, housing developers, health care providers, and educators is needed to improve the housing conditions of farmworker families.

The extent of bisexual behaviour in HIV-infected men and implications for transmission to their female sex partners.

Heterosexual transmission of HIV is a growing problem for women, but many women do not know how their partners acquired HIV. We described a group of HIV-infected men and women, and focused on: (1) sexual identity and bisexual behaviour in men, and (2) the proportion of women who acknowledged having a bisexual male partner. This study examined HIV-infected persons who participated in a cross-sectional interview project from January 1995 through July 2000; 5,156 men who have sex with men (MSM), and 3,139 women. The proportion of MSM who reported having sex with women (MSM/MSW) varied by race: 34% of black MSM, 26% of Hispanic MSM, and 13% of white MSM. While 14% of white women acknowledged having a bisexual partner, only 6% of black and 6% of Hispanic women reported having a bisexual partner. Most behaviourally bisexual men identified as either bisexual (59%) or homosexual (26%). Among MSM/MSW, 30% had more female partners than male partners, while only 10% had more male partners than female partners. These data suggest that bisexual activity is relatively common among black and Hispanic HIV-infected MSM, few identify as heterosexual, and their female partners may not know of their bisexual activity.

Effects of hypoxia on plasma amino acids of fetal sheep.

Secondary amino acid disturbances from circulatory responses during hypoxia may cause problems in interpreting plasma amino acid profiles of sick babies investigated for possible inherited defects. Systematic studies to characterise them are difficult in man. We investigated the effects of hypoxia on plasma amino acids by studying 9 late gestation fetal sheep in utero during 11 one hour episodes of moderately severe isocapnic hypoxia. In 6 experiments, maternal plasma amino acids were also monitored. Fourteen fetal plasma amino acids increased significantly, with the largest proportionate changes in alanine, valine, leucine, isoleucine, phenylalanine, tyrosine, ornithine and lysine. Maternal amino acids did not increase. Probable explanations were reflex peripheral vasoconstriction in skeletal muscle beds and decreased hepatic blood flow. The findings extend our knowledge of the fetal response to hypoxic stress, demonstrate the importance of skeletal muscle in branched-chain amino acid metabolism, and should help with interpretation of postnatal plasma amino acid disturbances.

Inhibition of chondrocyte differentiation in vitro by constitutive and inducible overexpression of the c-fos proto-oncogene.

We have investigated the role of c-Fos in chondrocyte differentiation in vitro using both constitutive and inducible overexpression approaches in ATDC5 chondrogenic cells, which undergo a well-defined sequence of differentiation from chondroprogenitors to fully differentiated hypertrophic chondrocytes. Initially, we constitutively overexpressed exogenous c-fos in ATDC5 cells. Several stable clones expressing high levels of exogenous c-fos were isolated and those also expressing the cartilage marker type II collagen showed a marked decrease in cartilage nodule formation. To investigate further whether c-Fos directly regulates cartilage differentiation independently of potential clonal variation, we generated additional clones in which exogenous c-fos expression was tightly controlled by a tetracycline-regulatable promoter. Two clones, DT7.1 and DT12.4 were capable of nodule formation in the absence of c-fos. However, upon induction of exogenous c-fos, differentiation was markedly reduced in DT7.1 cells and was virtually abolished in clone DT12.4. Pulse experiments indicated that induction of c-fos only at early stages of proliferation/differentiation inhibited nodule formation, and limiting dilution studies suggested that overexpression of c-fos decreased the frequency of chondroprogenitor cells within the clonal population. Interestingly, rates of proliferation and apoptosis were unaffected by c-fos overexpression under standard conditions, suggesting that these processes do not contribute to the observed inhibition of differentiation. Finally, gene expression analyses demonstrated that the expression of the cartilage markers type II collagen and PTH/PTHrP receptor were down-regulated in the presence of exogenous c-Fos and correlated well with the differentiation status. Moreover, induction of c-fos resulted in the concomitant increase in the expression of fra-1 and c-jun, further highlighting the importance of AP-1 transcription factors in chondrocyte differentiation. These data demonstrate that c-fos overexpression directly inhibits chondrocyte differentiation in vitro, and therefore these cell lines provide very useful tools for identifying novel c-Fos-responsive genes that regulate the differentiation and activity of chondrocytes.

Thymic alterations in feline GM1 gangliosidosis.

GM1 gangliosidosis is an inherited metabolic disease characterized by progressive neurological deterioration with premature death seen in children and numerous animals, including cats. We have observed that thymuses from affected cats greater than seven months of age (GM1 mutant cats) show marked thymic reduction compared to age-matched normal cats. The studies reported here were done to describe alterations in the thymus prior to (less then 90 days of age) and during the development of mild (90 to 210 days of age) to severe (greater than 210 days of age) progressive neurologic disease and to explore the pathogenesis of the thymic abnormality. Although histologic examination of the thymus from GM1 affected cats less than 210 days of age showed no significant differences from age-matched control cats, thymuses from GM1 mutant cats greater than 210 days of age were significantly reduced in size (approximately 3-fold). Histologic sections of lymph nodes, adrenal glands, and spleens from GM1 gangliosidosis-affected cats showed no significant differences. Flow cytometric analyses showed a marked decrease in the percentage of immature CD4+CD8+ thymocytes (p < 0.001) and significantly increased CD4-CD8+ cells (p < 0.01) in GM1 mutant cats greater than 210 days of age when compared to normal age matched cats. Co-labelling with CD4, CD8, and CD5 indicated an increase in the percentage of GM1 mutant cat thymocytes at this age which were CD5high, suggesting the presence of more mature cells. Cytometric analyses of subpopulations of peripheral lymphocytes indicated an increase in CD4-CD8+ cells (p < 0.05) with concurrent decreases in CD4+CD8- and CD4-CD8- cells (which were not significant). Similar analyses of thymocyte and lymphocyte subpopulations from cats < 210 days of age showed no significant differences between GM1 mutant and normal cells. GM1 mutant cats at all ages had increased surface binding of Cholera toxin B on thymocytes, indicating increased surface GM1 ganglioside expression. Increases were highly significant in GM1 mutant cats greater than 210 days of age. In situ labelling for apoptosis was increased in GM1 mutant cats between 90 to 200 days of age when thymic masses were within normal limits. In GM1 mutant cats over 200 days of age, decreased labelling was observed when thymic mass was reduced and the CD4+CD8+ subpopulation, known to be very susceptible to apoptosis, was significantly decreased. These data describe premature thymic involution in feline GM1 gangliosidosis and suggest that increased surface GM1 gangliosides alters thymocyte development in these cats.

Intrinsic tone of cerebral artery segments of human infants between 23 weeks of gestation and term.

Segments of basilar and middle cerebral arteries of eight human preterm and early postnatal infants have been examined using the resistance artery myograph technique for wire-mounted segments and the pressure perfusion arteriograph. Myograph-mounted segments spontaneously developed tone of varying duration and time course. Perfused segments showed maintained tone levels of approximately 40% of maximum possible constriction when the intraluminal pressure was 60 mm Hg. This level is not different from that found in adult human pial arteries of similar lumen diameter. Indomethacin (10[-5] M) either initiated tone increase or potentiated existing tone in the isometrically mounted segments. After washout of vasoconstrictors norepinephrine (10[-6] M) and angiotensin II (10[-8] M), indomethacin caused a pronounced, long lasting increase in basal tone. Spontaneous tone was reversed by acetylcholine (10[-6] M), isoproterenol (10[-8] to 10[-5] M), histamine (10[-8] to 10[-5] M), and papaverine (10[-5] M). Low levels of tone were increased and higher levels decreased by intraluminal flow. The pressure/diameter curves of these vessels were of similar shape as those of the equivalent size in the adult. It is concluded that intrinsic tone is a prominent feature of these large cerebral arteries, and it is modified by an endogenous indomethacin-sensitive process.

Motivational factors in the choice of postdoctoral general dentistry programs.

This study explored the importance of various personal and professional factors that may influence choices concerning postdoctoral training in general dentistry. We sent an eighty-one-question survey to all individuals (N = 1,995) who were registered to participate in the Postdoctoral Dental Matching Program (MATCH) and analyzed 599 returned surveys from those applying to GPR and/or AEGD programs. Approximately twenty questions addressed each of four time periods in the application process. Over half of respondents felt that learning more medicine, increasing their speed with dental procedures, gaining confidence in clinical skills, and treating compromised patients were very important. Over one-third of respondents felt that program location, salary and benefits, program philosophy and faculty, and nondental training experiences were very important. Females felt that thirty-five items were more important than did their male counterparts, whereas males indicated that two items were more important. While there were some differences between applicants to AEGD versus GPR programs, there were far more areas where the applicants to each of these programs shared common concerns. The data suggest that the majority of individuals who consider postgraduate general dentistry programs perceive a lack of experience at the predoctoral level relating to clinical dentistry in general and specifically to their understanding of medical principles and managing compromised patients.

Pilot study of controlled-release pilocarpine in normal subjects.

OBJECTIVES: Current systemic treatments with sialogogues for patients with xerostomia are limited because of minimal efficacy, short duration of activity, or problems with side effects. The purpose of this pilot study was an initial assessment of safety, efficacy, duration of action, multiple dose tolerance, and side effects of a controlled-release formulation of pilocarpine hydrochloride. STUDY DESIGN: Eight healthy hospitalized subjects were given 15 mg of a controlled-release pilocarpine formulation every 12 hours for three doses. Saliva and blood samples were collected at assigned intervals. Repeated measures analysis and paired t tests were used for statistical analyses. RESULTS: A significant (p < 0.05) increase in both parotid and whole saliva output followed all three doses beginning within 1 hour of dosing and lasting over 10 hours. Mean plasma pilocarpine concentration reached a maximum of 8.2 ng/ml at approximately 1 hour after the first dose, 11.5 ng/ml after the third dose, and declined to near baseline (0.06 ng/ml) 24 hours after the final dose. None of the participants showed evidence of adverse effects including complaints of sweating or gastrointestinal discomfort. CONCLUSIONS: A controlled-release formulation of pilocarpine may overcome the therapeutic weaknesses of current pilocarpine preparations by prolonging salivary secretion and reducing undesirable side effects.

Dynamics and species richness of tropical rain forests.

We present a worldwide analysis of humid tropical forest dynamics and tree species richness. New tree mortality, recruitment, and species richness data include the most dynamic and diverse mature tropical forests known. Twenty-five sites show a strong tendency for the most species-rich forests to be dynamic and aseasonal. Mean annual tree mortality and recruitment-turnover-is the most predictive factor of species richness, implying that small-scale disturbance helps regulate tropical forest diversity. Turnover rates are also closely related to the amount of basal area turnover in mature tropical forests. Therefore the contribution of small-scale disturbance to maintaining tropical forest diversity may ultimately be driven by ecosystem productivity.

Increasing turnover through time in tropical forests.

Tree turnover rates were assessed at 40 tropical forest sites. Averaged across inventoried forests, turnover, as measured by tree mortality and recruitment, has increased since the 1950s, with an apparent pantropical acceleration since 1980. Among 22 mature forest sites with two or more inventory periods, forest turnover also increased. The trend in forest dynamics may have profound effects on biological diversity.

Periodontal status of HIV-seropositive and AIDS patients.

Few reported studies have evaluated the periodontal status of individuals infected by human immunodeficiency virus (HIV). The majority of these reports have evaluated the periodontal status of individuals presenting to dental care facilities due to oral problems. These reports suggest that severe gingival inflammation and attachment loss are often associated with HIV seropositive patients. The purpose of this study was to evaluate the periodontal status of HIV seropositive patients without biasing the data towards those presenting to dentists with oral problems. Sixty-three consenting male patients presenting to the infectious disease clinic at the Medical College of Virginia Hospitals were examined to determine the status of their periodontal health. Gingival index, plaque index, pocket depths, and attachment loss were determined using standard indices. Participants were first grouped according to the modified CDC Classification System for HIV infection and then categorized according to HIV risk factors for purposes of statistical analysis. No significant differences could be found in the gingival or periodontal status of subjects who were HIV seropositive versus those with AIDS. Periodontal status was also not significantly different for individuals based upon risk group. Periodontal health of the participants was similar to the general population (HIV status unknown). This would indicate that, although HIV gingivitis and HIV periodontitis have been documented in a number of HIV-infected patients, the frequency of affected individuals is less than previous reports would suggest.

A novel comprehensive DUE program--five years of experience.

A comprehensive program has been developed to evaluate prescribing practices in diverse drug therapy categories and in all areas of the institution. Input for topic selection comes not only from the pharmacy department, but also from QA, medical staff, and nursing. The development of monitoring criteria and review of the results by the P&T Committee, Medical Executive Committee, and other key medical staff members, promotes ownership of the program by the medical staff. The benefit of this ownership is active support for the program and participation in peer review. Overall, the results of this cost-effective program include limited use of broad spectrum antibiotics, select prescribing of high-risk drugs, and focused educational efforts to improve quality of patient care. The primary goal for the future of the program is to develop criteria and documentation mechanisms for reporting measurable clinical outcomes. In making the transition, it is important to use the success and impact of the current program as the foundation. This is particularly true for the concurrent monitoring program and its immediate feedback mechanism. The major challenge will be evaluating negative clinical outcomes and developing corrective actions as well as documenting the positive outcomes and the avoidance of negative outcomes of the current program. To meet this challenge, the DUE program must be integrated with all other institutional QA programs. Although a difficult task, this is a significant yet necessary step in the right direction for assuring optimal patient care.

Use and Misuse of Forest-harvested Fruits in the Iquitos Area.

Of 193 fruit species observed to be regularly consumed in the region surrounding Iquitos, Peru, 120 species are exclusively wild-harvested and 19 more originate from both wild and cultivated sources. The wild-harvested fruits of 57 species belonging to 24 different plant families are sold in the Iquitos market and are very important in the economy and diets of the area Nearly half of the Iquitos fruit vendors sell wild-harvested fruits (if fruits used as vegetables or starch sources are excluded), and over half of the fruit species sold are wild-harvested Many fruit species consumed at Iquitos differ from those consumed in other parts of Amazonia Although some native fruit species are beginning to be grown as crops, the wild populations of these high-potential species are being rapidly depleted by destructive harvesting techniques as market pressure begins to build In the last few years, the availability of several of the most popular fruit species has decreased markedly. If nondestructive sustained yield harvesting of resources such as wild-harvested fruits is to play its suggested important role in tropical forest conservation, much stronger efforts will be needed to prevent destructive overharvesting of these potentially significant resources.

Tree species richness of upper Amazonian forests.

Upper Amazonian data for tree species richness in 1-hectare plots are reported. All plants >/=10 cm diameter were censused and identified in six plots in Amazonian Peru and one on the Venezuela-Brazil border. The two plots from the everwet forests near Iquitos, Peru, are the most species-rich in the world, with approximately 300 species >/=10 cm diameter in single hectares; all of the Peruvian plots are among the most species-rich ever reported. Contrary to accepted opinion, upper Amazonian forest, and perhaps Central African ones, have as many or more tree species as comparable Asian forests. Very high tree species richness seems to be a general property of mature lowland evergreen forests on fertile to moderately infertile soils on all three continents.