Scaling of Joint Motion and Muscle Activation for 3-Dimensional Control of Reach Extent.

This study investigated the scaling of upper arm kinematics, joint motion, and muscle activation for three-dimensional (3D) reaches to targets of increasing distance. Fifteen participants completed 108 total reaches to targets placed 7, 14, and 21 cm across midline. Peak velocity, acceleration, and time to peak velocity scaled to both target and movement distance. Shoulder and elbow excursion scaled to target distance and were highly coordinated. Anterior deltoid activation scaled to both target and movement distance in the early and late phases of reach control. Biceps and triceps activation scaled to movement distance primarily in the late phase. Scaling of these outcome variables provides a model for understanding the control of reach distance in a 3D environment.

Changes in Energy Expenditure, Dietary Intake, and Energy Availability Across an Entire Collegiate Women's Basketball Season.

ABSTRACT: Zanders, BR, Currier, BS, Harty, PS, Zabriskie, HA, Smith, CR, Stecker, RA, Richmond, SR, Jagim, AR, and Kerksick, CM. Changes in energy expenditure, dietary intake, and energy availability across an entire collegiate women's basketball season. J Strength Cond Res 35(3): 804-810, 2021-The purpose of this study was to identify changes in energy expenditure and dietary intake across an entire women's basketball season. On 5 different occasions across the competitive season, female collegiate basketball players (19.8 ± 1.3 years, 173.9 ± 13.6 cm, 74.6 ± 9.1 kg, 27.1 ± 3.2% fat, 53.9 ± 6.4 ml·kg-1·min-1, n = 13) were outfitted with heart rate and activity monitors over 4 consecutive days and completed 4-day food and fluid records to assess changes in energy expenditure and dietary status. Dual-energy x-ray absorptiometry was used to assess baseline body composition and resting energy expenditure (REE) was measured before and after the season. Data were analyzed using 1-factor repeated-measures analysis of variance. Total daily energy expenditure (TDEE, p = 0.059) and physical activity levels (TDEE/REE, p = 0.060) both tended to decrease throughout the season. Energy balance was negative at all time points throughout the season. Absolute and normalized daily protein intake at the end of the season was significantly (p < 0.05) lower than at the beginning of the season. Carbohydrate (3.7 ± 0.4 g·kg-1·d-1) and protein (1.17 ± 0.16 g·kg-1·d-1) intakes were lower than commonly recommended values based on previously published guidelines. These findings suggest that greater education and interventions for collegiate athletes and coaches regarding dietary intake and energy expenditure are warranted.

A Pilot Study to Examine the Impact of Beta-Alanine Supplementation on Anaerobic Exercise Performance in Collegiate Rugby Athletes.

Beta-alanine (BA) is a precursor to carnosine which functions as a buffer assisting in the maintenance of intracellular pH during high-intensity efforts. Rugby is a sport characterized by multiple intermittent periods of maximal or near maximal efforts with short periods of rest/active recovery. The purpose of this pilot study was to evaluate the impact of six weeks of beta-alanine supplementation on anaerobic performance measures in collegiate rugby players. Twenty-one male, collegiate rugby players were recruited, while fifteen completed post-testing (Mean ± SD; Age: 21.0 ± 1.8 years, Height: 179 ± 6.3 cm, Body Mass: 91.8 ± 13.3 kg, % Body Fat: 21.3 ± 4.4). Supplementation was randomized in a double-blind, placebo-controlled manner between 6.4 g/d of beta-alanine and 6.4 g/d of maltodextrin placebo. Body composition, upper and lower-body maximal strength and muscular endurance, intermittent sprint performance, and post-exercise lactate, heart rate, and rating of perceived exertion were assessed before and after supplementation. Data were analyzed using a 2 × 2 (group × time) mixed factorial analysis of variance (ANOVA) with repeated measures on time. No significant interaction effects were noted for body mass, fat mass, fat-free mass, and percent bodyfat (p > 0.05). No performance effects resulting from beta-alanine supplementation were detected. Results from this initial pilot investigation suggest that BA exerts little to no impact on body composition parameters, muscular strength, muscular endurance, or intermittent sprinting performance. With the limited research exploring the impact of BA in this sporting context, these initial findings offer little support for BA use, but more research is needed to fully understand the potential impact of BA on various aspects of resistance exercise performance.

Physiologic, Metabolic, and Nutritional Attributes of Collegiate Synchronized Swimmers.

Synchronized swimming is a sport that requires high levels of strength, power, and endurance, as well as artistic skill to perform in an aquatic environment. Purpose: The purpose of this study was to identify physiological characteristics and dietary habits of collegiate synchronized swimmers. Methods: A total of 21 female participants (mean [SD] age = 20.4 [1.6] y, height = 168.0 [4.9] cm, and weight = 64.4 [8.7] kg) performed resting metabolic rate test. Body composition was determined using skinfolds (4-site and 7-site) and dual-energy X-ray absorptiometry (DEXA). Dietary intake was assessed using 4-d dietary records. Results: Resting metabolic rate was 110.9 (10.5) kJ/kg normalized to body weight and calculated relative daily caloric intake was 121.4 (42.3) kJ/kg. Estimated energy availability ranged from 109.1 (52.1) to 126.7 (52.6) kJ/kg fat-free mass per day and was correlated (P = .045) to resting metabolic rate. Percentage body fat measured using DEXA (28.7% [4.8%] fat) was higher than both 4-site (25.7% [4.8%] fat, P = .001) and 7-site (25.3% [4.7%] fat, P = .001) skinfold values. No significant correlations were reported between bone mineral density, body composition, and dietary intake data. Conclusions: Synchronized swimmers have similar body composition and training habits as other competitive aquatic athletes. Dietary intake data revealed low energy availability and lower than recommended macronutrient levels.

Metabolic impact of protein feeding prior to moderate-intensity treadmill exercise in a fasted state: a pilot study.

BACKGROUND: Augmenting fat oxidation is a primary goal of fitness enthusiasts and individuals desiring to improve their body composition. Performing aerobic exercise while fasted continues to be a popular strategy to achieve this outcome, yet little research has examined how nutritional manipulations influence energy expenditure and/or fat oxidation during and after exercise. Initial research has indicated that pre-exercise protein feeding may facilitate fat oxidation while minimizing protein degradation during exercise, but more research is needed to determine if the source of protein further influences such outcomes. METHODS: Eleven healthy, college-aged males (23.5 ± 2.1 years, 86.0 ± 15.6 kg, 184 ± 10.3 cm, 19.7 ± 4.4%fat) completed four testing sessions in a randomized, counter-balanced, crossover fashion after observing an 8-10 h fast. During each visit, baseline substrate oxidation and resting energy expenditure (REE) were assessed via indirect calorimetry. Participants ingested isovolumetric, solutions containing 25 g of whey protein isolate (WPI), 25 g of casein protein (CAS), 25 g of maltodextrin (MAL), or non-caloric control (CON). After 30 min, participants performed 30 min of treadmill exercise at 55-60% heart rate reserve. Substrate oxidation and energy expenditure were re-assessed during exercise and 15 min after exercise. RESULTS: Delta scores comparing the change in REE were normalized to body mass and a significant group x time interaction (p = 0.002) was found. Post-hoc comparisons indicated the within-group changes in REE following consumption of WPI (3.41 ± 1.63 kcal/kg) and CAS (3.39 ± 0.82 kcal/kg) were significantly greater (p < 0.05) than following consumption of MAL (1.57 ± 0.99 kcal/kg) and tended to be greater than the non-caloric control group (2.00 ± 1.91 kcal/kg, p = 0.055 vs. WPI and p = 0.061 vs. CAS). Respiratory exchange ratio following consumption of WPI and CAS significantly decreased during the post exercise period while no change was observed for the other groups. Fat oxidation during exercise was calculated and increased in all groups throughout exercise. CAS was found to oxidize significantly more fat (p < 0.05) than WPI during minutes 10-15 (CAS: 2.28 ± 0.38 g; WPI: 1.7 ± 0.60 g) and 25-30 (CAS: 3.03 ± 0.55 g; WPI: 2.24 ± 0.50 g) of the exercise bout. CONCLUSIONS: Protein consumption before fasted moderate-intensity treadmill exercise significantly increased post-exercise energy expenditure compared to maltodextrin ingestion and tended to be greater than control. Post-exercise fat oxidation was improved following protein ingestion. Throughout exercise, fasting (control) did not yield more fat oxidation versus carbohydrate or protein, while casein protein allowed for more fat oxidation than whey. These results indicate rates of energy expenditure and fat oxidation can be modulated after CAS protein consumption prior to moderate-intensity cardiovascular exercise and that fasting did not lead to more fat oxidation during or after exercise.

Effects of Rest Interval Length on Acute Battling Rope Exercise Metabolism.

The purpose of this study was to quantify and compare the acute metabolic responses to battling rope (BR) exercise using 2 different rest intervals. Twelve men and 10 women (age = 20.8 ± 1.3 years) performed a control protocol and 2 BR exercise protocols on separate days (48-72 hours) in random order while connected to a metabolic system. The BR protocol consisted of 8 sets of 30-second intervals (15 seconds of single-arm waves and 15 seconds of double-arm waves) using either a 1-minute (1RI) or 2-minute (2RI) rest interval length. A metronome was used to standardize repetition number/frequency for each exercise, that is, 15 waves for each arm for single-arm waves and 15 repetitions of double-arm waves. The mean oxygen consumption (VO2) values for the entire protocol were significantly higher during the 1RI than 2RI protocol, and values in men were 11.1% (1RI) and 13.5% (2RI) higher than women, respectively, and equated to 52.8 ± 5.5% (men) and 50.0 ± 11.2% (women) of VO2max during 1RI and 40.5 ± 4.5% (men) and 37.7 ± 11.0% (women) of VO2max during 2RI. Energy expenditure values were significantly higher during the 1RI than the 2RI protocol in men (11.93 ± 1.4 vs. 8.78 ± 1.4 kcal·min) and women (7.69 ± 1.3 vs. 5.04 ± 1.7 kcal·min) with values in men statistically higher than women. Blood lactate, mean protocol minute ventilation, and heart rate were significantly higher during the 1RI protocol than the 2RI protocol, and these data were significantly higher in men compared with women. These data demonstrate that BR exercise poses a significant cardiovascular and metabolic stimulus with the mean effects augmented with the use of a short rest interval.

Comparison of the acute metabolic responses to traditional resistance, body-weight, and battling rope exercises.

The purpose of this study was to quantify and compare the acute metabolic responses to resistance exercise protocols comprising free-weight, body-weight, and battling rope (BR) exercises. Ten resistance-trained men (age = 20.6 ± 1.3 years) performed 13 resistance exercise protocols on separate days in random order consisting of only one exercise per session. For free-weight exercise protocols, subjects performed 3 sets of up to 10 repetitions with 75% of their 1 repetition maximum. For the push-up (PU) and push-up on a BOSU ball protocols, subjects performed 3 sets of 20 repetitions. For the burpee and PU with lateral crawl protocols, subjects performed 3 sets of 10 repetitions. For the plank and BR circuit protocols, subjects performed 3 sets of 30-second bouts. A standard 2-minute rest interval (RI) was used in between all sets for each exercise. Data were averaged for the entire protocol including work and RIs. Mean oxygen consumption was significantly greatest during the BR (24.6 ± 2.6 ml·kg·min) and burpee (22.9 ± 2.1 ml·kg·min) protocols. For the free-weight exercises, highest mean values were seen in the squat (19.6 ± 1.8 ml·kg·min), deadlift (18.9 ± 3.0 ml·kg·min), and lunge (17.3 ± 2.6 ml·kg·min). No differences were observed between PUs performed on the floor vs. on a BOSU ball. However, adding a lateral crawl to the PU significantly increased mean oxygen consumption (19.5 ± 2.9 ml·kg·min). The lowest mean value was seen during the plank exercise (7.9 ± 0.7 ml·kg·min). These data indicate performance of exercises with BRs and a body-weight burpee exercise elicit relatively higher acute metabolic demands than traditional resistance exercises performed with moderately heavy loading.

Tissue-engineered articular cartilage exhibits tension-compression nonlinearity reminiscent of the native cartilage.

The tensile modulus of articular cartilage is much larger than its compressive modulus. This tension-compression nonlinearity enhances interstitial fluid pressurization and decreases the frictional coefficient. The current set of studies examines the tensile and compressive properties of cylindrical chondrocyte-seeded agarose constructs over different developmental stages through a novel method that combines osmotic loading, video microscopy, and uniaxial unconfined compression testing. This method was previously used to examine tension-compression nonlinearity in native cartilage. Engineered cartilage, cultured under free-swelling (FS) or dynamically loaded (DL) conditions, was tested in unconfined compression in hypertonic and hypotonic salt solutions. The apparent equilibrium modulus decreased with increasing salt concentration, indicating that increasing the bath solution osmolarity shielded the fixed charges within the tissue, shifting the measured moduli along the tension-compression curve and revealing the intrinsic properties of the tissue. With this method, we were able to measure the tensile (401±83kPa for FS and 678±473kPa for DL) and compressive (161±33kPa for FS and 348±203kPa for DL) moduli of the same engineered cartilage specimens. These moduli are comparable to values obtained from traditional methods, validating this technique for measuring the tensile and compressive properties of hydrogel-based constructs. This study shows that engineered cartilage exhibits tension-compression nonlinearity reminiscent of the native tissue, and that dynamic deformational loading can yield significantly higher tensile properties.

Plague studies in California: a review of long-term disease activity, flea-host relationships and plague ecology in the coniferous forests of the Southern Cascades and northern Sierra Nevada mountains.

We review 28 years of long-term surveillance (1970-1997) for plague activity among wild rodents from ten locations within three coniferous forest habitat types in the northern Sierra Nevada and the Southern Cascade mountains of northeastern California. We identify rodent hosts and their fleas and document long-term plague activity in each habitat type. The highest seroprevalence for Yersinia pestis occurred in the chipmunks, Tamias senex and T. quadrimaculatus, and the pine squirrel, Tamiasciurus douglasii. The most commonly infected fleas were Ceratophyllus ciliatus and Eumolpianus eumolpi from chipmunks and Oropsylla montana and O. idahoensis from ground squirrels. Serological surveillance demonstrated that populations of T. senex, T. quadrimaculatus and T. douglasii are moderately resistant to plague, survive infection, and are, therefore, good sentinels for plague activity. Recaptured T. senex and T. quadrimaculatus showed persistence of plague antibodies and evidence of re-infection over a two year period. These rodent species, their fleas, and the ecological factors common to the coniferous forest habitats likely promote the maintenance of plague foci in northeastern California.

Texas National Coastal Assessment (2000-2004): challenges, solutions, lessons learned and future directions.

The Texas National Coastal Assessment (NCA) program began with the immediate challenge of integrating the NCA effort with Texas Parks and Wildlife Department's (TPWD) Coastal Fisheries Division and its existing probabilistic Fishery Independent Monitoring Program. Close coordination and detailed planning along with a novel two boat sampling operation helped to make this alliance work. Partnerships with National Estuary Programs and the Texas Commission on Environmental Quality (TCEQ) greatly improved coverage of the Texas coast over the initial fifty station design. Airboats, biobags, and polyvinyl chloride (PVC) corers were instrumental in overcoming numerous technical challenges. NCA data provide a more complete assessment of water and sediment quality than the traditional 305(b) report, with better spatial coverage and a measure of validity. There were differing patterns of PCBs, PAHs, DDTs and chlorinated pesticides, and metals such as mercury (Hg), arsenic (As), lead (Pb) and zinc (Zn) along the Texas coast. A confederation of Texas state agencies is considering ways to take advantage of probabilistic sampling designs to monitor the Texas coast. The TCEQ and TPWD are working on a joint project to redesign sediment and water quality monitoring that may serve as a springboard to a continuous monitoring program and opportunities for further improvement of ecosystem health assessment of the Texas coast.

Image-guided percutaneous biopsy of musculoskeletal lesions in children.

BACKGROUND: Percutaneous core needle biopsy (PCNB) of musculoskeletal lesions can provide early and definitive diagnosis and guide decisions on management. The technique is less invasive than open biopsy and has a low complication rate. OBJECTIVES: The purpose of this study was to assess the diagnostic accuracy and safety of image-guided PCNB of musculoskeletal lesions in children. MATERIALS AND METHODS: Retrospective review of the medical records of patients referred for PCNB of musculoskeletal lesions was performed. Data collected included tumor type and complication rates. Lesion "hit" or "missed", and core adequacy and ability to reach a definitive pathological diagnosis were reviewed and used to determine whether the biopsy was overall successful or unsuccessful. RESULTS: A total of 127 biopsies were performed in 111 patients. Of the 127 PCNB procedures, 114 "hit" the lesion and 13 "missed," and 120 of the cores provided for analysis were deemed adequate for pathological interpretation and 7 were deemed inadequate. A definitive pathological diagnosis was possible in 97 of the 127 PCNB preocedures and not possible in 30. Overall 76% of the PCNB procedures were successful. The diagnostic success of biopsy in primary malignant tumors was significantly higher (92%) than in primary benign tumors (65%; P=0.008). Six minor complications resulted from PCNB. CONCLUSION: This study showed that PCNB is accurate and safe for the diagnosis of musculoskeletal lesions in pediatric patients, and its results are comparable to those in adult studies.

High-frequency sonographic patterns of the spleen in children.

PURPOSE: To retrospectively evaluate the normal sonographic appearance of splenic parenchyma in children of various ages with high-frequency transducer sonography. MATERIALS AND METHODS: Research ethics committee board approval was obtained, with waiver of informed consent. We evaluated in vivo sagittal and transverse sonograms of spleens obtained with 13-MHz linear-array transducers in 100 children (age range, 1 day to 17 years) with clinically diagnosed disease that did not affect the lymphoid system. Three radiologists working in consensus defined the grading system for the splenic parenchyma. Thereafter, these same radiologists graded the sonographic reticulonodular pattern independently as granular, mild, or marked. These grades were cross correlated with clinical data by using logistic regression analysis and chi(2) tests. Sonographic measurements of the splenic parenchyma in nine pediatric cadavers separate from the in vivo cohort of the study were compared with those of corresponding histologic slices by means of linear correlation. RESULTS: Both grade 2 and grade 3 patterns occurred more frequently in children older than 1 year but no older than 5 years, whereas grade 1 pattern occurred most frequently in neonates (P < .001). As patients' age (odds ratio, 1.6; P < .001) and splenic dimensions (odds ratio, 3.1; P < .001) increased, the frequency with which the reticulonodular pattern was classified as either grade 2 or grade 3 increased. No association was noted between sonographic patterns and body mass index (P = .85) or sex (P = .07). The parenchymal nodules graded as 2 or 3 on sonograms correlated well with the presence of lymphoid follicles (white pulp) at histologic analysis (r = .71, P = .03). CONCLUSION: High-frequency transducer sonography of the spleen in children can demonstrate normal echo patterns that should not be misinterpreted as indicative of disease.

Pediatric drowning: a 20-year review of autopsied cases: III. Bathtub drownings.

Bathtub drownings are a significant cause of mortality in the pediatric population. Infants and preambulatory children are disproportionately affected, and several studies have suggested that preventative campaigns have been ineffective in the prevention of such deaths. To obtain a better understanding of the factors associated with bathtub drownings, a retrospective review of autopsy records over a 20-year period (1984-2003) was performed. Eighteen consecutive cases of bathtub drownings were identified in 8 males and 10 females (ratio, 0.8; P = 0.6374). The age ranged from 6 months to 70 months (mean, 17 months; median, 11 months), and most cases occurred in infants aged 12 months or less (72%). Males tended to be older than females (mean, 23 months versus 11 months; P = 0.1889). Associated factors included inadequate adult supervision (89%), cobathing (39%), the use of infant bath seats (17%), and coexistent medical disorders predisposing the infant or child to the drowning episode (17%). The pathologic findings included a frothy exudate (28%), pleural effusion (28%), and increased lung weight (61%). All toxicologic samples submitted for analysis were negative. The present study highlights the factors associated with bathtub drownings and may aid in the prevention of such deaths in the pediatric population.

Pediatric drowning: a 20-year review of autopsied cases: II. Pathologic features.

The pathologic findings in autopsies of drowning victims are nonspecific and vary from case to case. However, most reported pathologic series of drowning cases exclude children and do not take into consideration the unique circumstances surrounding bathtub drownings. In addition, the effect of resuscitation on the autopsy findings has not been studied in children. A retrospective review of autopsy records of non-bathtub drownings from a 20-year period (1984-2003) was performed and 63 cases were identified in 45 males and 18 females (age range 9 months to 17 years). The incidence of frothy exudate, pleural effusion, and increased lung weight was 43%, 36%, and 80%, respectively. The incidence of frothy exudate and the combination of all 3 factors was significantly higher in cases with no resuscitation compared with those cases with attempted resuscitation with or without delayed death. As the interval between the drowning episode and autopsy increased, the incidence of frothy exudate decreased significantly. There was no relationship between these findings and the age and sex of the decedent. Other clinical conditions or occult pathologic findings that may have contributed to death were found in 8 cases (13%). The findings highlight the need for thorough clinicopathologic correlation in cases of drowning to accurately interpret the pathologic findings.

Sudden unexpected death in infancy and childhood due to undiagnosed neoplasia: an autopsy study.

Sudden unexpected death due to clinically undiagnosed neoplasia in infancy and childhood (SUDNIC) is a rare phenomenon, with only small numbers of cases reported in the literature. In the majority of instances, the tumors involve critical structures within the heart or central nervous system and include gliomas, medulloblastomas, rhabdomyomas, and neoplasms of stromal elements. A 20-year retrospective review of autopsy records from the Hospital for Sick Children, Toronto, was performed (1984-2003, n = 4926), and 7 cases of SUDNIC were identified (0.14%). In addition, 1 case was obtained from the files of the Children's and Women's Health Centre of British Columbia, Vancouver. Diagnoses included 2 cases of acute leukemia (1 myelogenous, 1 lymphoblastic), 2 cases of mediastinal lymphoblastic lymphoma (pre-T cell type), 1 papillary fibroelastoma of the mitral valve prolapsing into and totally occluding the left anterior descending coronary artery, 1 medulloblastoma, 1 Wilms tumor associated with fatal intraperitoneal hemorrhage, and 1 widely disseminated gastric carcinoma. These cases demonstrate that infants and children may have minimal or no symptoms in the presence of significant disease and highlight the need for a thorough autopsy examination in cases of sudden unexpected death in infancy and childhood.

Sudden unexpected death in children with heart disease.

OBJECTIVE: To review a mortality database, and identify all sudden unexpected deaths in patients followed by the cardiac program. DESIGN: Retrospective review of prospectively maintained database. RESULTS: Over 8 years, we identified 80 sudden unexpected deaths, among which there were sufficient data in 69 (24 females). Patients died at a median age of 17.2 months (28 days-18.8 years). Forty-six patients had 2 functional ventricles and 23 had received palliation for a single-functional ventricle. Patients with a single ventricle died at a younger age (median 120 days; 28 days-17.2 years) and sooner after last assessment (median 27 days; 1-146 days) than patients in the biventricular group (median age 2 years; 43 days-18.8 years; median time since last assessment 49 days, 1 days-1 year) (P < .01; P = .01). Thrombosis was the most common cause (61%) of death in the single-ventricle group. Arrhythmia or presumed arrhythmia was the most common cause (46%) of death in the biventricular group. Fifty-one patients had undergone surgery. Six patients had primary electrophysiological disease, and 5 had cardiomyopathy. Eight deaths occurred in patients with pulmonary vascular disease. CONCLUSION: Our study demonstrates that sudden unexpected death occurred at a frequency of at least 10 patients per year over an 8-year period with 55,730 patient encounters. We were able to determine a clinical cause of death in most patients. Arrhythmias (30%) and pulmonary vascular disease (13%) are important causes of sudden death. Simple aortic valve disease and hypertrophic cardiomyopathy are rare (4%) causes of sudden death in childhood. Infants and young children with surgical shunts comprise 23% of sudden unexpected deaths that occur within a month of the last evaluation. Close surveillance of these patients is warranted.

Pediatric drowning: a 20-year review of autopsied cases: I. Demographic features.

Drowning is a significant cause of childhood mortality in the developed world. Males and preschool-aged children are overrepresented in most series of pediatric drowning. To obtain a better understanding of age- and gender-related factors, a retrospective review of autopsy records over a 20-year period (1984-2003) for cases of drowning (exclusive of bathtub drownings) was performed. Sixty-three consecutive cases of drowning were identified in 45 males and 18 females (ratio 2.5; P = 0.0007). The ages ranged from 9 months to 17 years, and most cases occurred in the 0- to 4-year age group (57%). Boys tended to be older than girls (5 years 9 months versus 4 years 4 months; P = 0.2133). Sites of drowning were open water (48%) and pools (44%), with children drowning in open water being significantly older than those drowning in pools (6 years 6 months versus 4 years 6 months; P = 0.0462). Most boys drowned in open water (53%), whereas most girls drowned in pools (50%). Resuscitation was attempted after the drowning episode in 84% of cases, with children aged 4 years or less having significantly higher rates than older children (P = 0.0346). The present study highlights differences in the pattern of drowning according to age and sex and may aid in developing targeted educational and preventative campaigns.

Aerosol transfer of bladder urothelial and smooth muscle cells onto demucosalized colonic segments for porcine bladder augmentation in vivo: a 6-week experimental study.

PURPOSE: In a pilot study we developed a cell transfer technology for populating demucosalized colonic segments with bladder urothelium. This process was achieved through aerosol transfer of a single cell suspension consisting of bladder urothelial cells, smooth muscle cells and fibrin glue onto demucosalized colonic segments. We further evaluate this new concept in a controlled study. MATERIALS AND METHODS: The study was performed on 20 piglets (20 kg). In all animals 50% of the bladder with excised, and a 10 cm segment of the sigmoid was isolated. Animals were then equally divided into 5 groups of 1) colocystoplasty only, 2) demucosalized colocystoplasty, 3) demucosalized colocystoplasty plus covering of the demucosalized sigmoid with fibrin glue only, 4) aerosol application of fibrin glue with single cell suspension of urothelial cells only to the demucosalized colon, and 5) aerosol application of fibrin glue with urothelial and smooth muscle cells to the demucosalized colon. The 4 corners of the augmented segments were marked with 5-zero polypropylene sutures. Animals were sacrificed 6 weeks later and the surface area of the augmented segment was measured. Segments were submitted to histological and immunohistochemical analysis. RESULTS: The surface area of the augmented segments showed an increase in group 1 animals, stabilization in groups 4 and 5, and marked reduction in groups 2 and 3. On hematoxylin and eosin, and Masson trichrome staining all group 1 animals showed normal colonic epithelium of the augment. All animals in groups 2 and 3 showed excessive scarring with urothelial coverage only at the augment periphery, while the central augment area showed no epithelium. Segments from groups 4 and 5 showed confluent epithelial covering with no fibrosis. There was no evidence of colonic epithelial re-growth in any animal in groups 2 to 5. Cytokeratin 7 and uroplakin III staining demonstrated complete coverage of the augmented segment with urothelium only in groups 4 and 5. CONCLUSIONS: The addition of aerosolized cells of urological origin is a viable augmentation approach that appears to achieve the much sought after inhibition of intrinsic fibrosis and contraction of colonic segments when incorporated into the urinary tract without this cellular component. Moreover, this technique appears to provide a histologically normal, confluent urothelium, which sets the stage for prevention of the well-documented biochemical aberrations inherent in augments containing gastrointestinal epithelium. While successful in this model regardless of the incorporation of urological smooth muscle cells, chronic studies are now warranted to validate the short-term results as well as determine whether the urological mesenchymal population (smooth muscle) will be required to sustain the uroepithelial phenotype in the long term.

Clinical, epidemiologic, and environmental surveillance for ehrlichiosis and anaplasmosis in an endemic area of northern California.

Two forms of tick-borne leukocytotropic rickettsioses have been recognized in California since the mid-1990s: human monocytic ehrlichiosis (HME) caused by Ehrlichia chaffeensis and human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum. Between 1997 and 1999, two cases of HME and four cases of HGA were diagnosed in residents of southern Humboldt County, California. Environmental followup at case-patients' residences revealed dense populations of Ixodes pacificus ticks, particularly in grassy roadside areas. PCR evidence of A. phagocytophilum was detected in approximately 2.0% of I. pacificus; E. chaffeensis was not detected in any of 625 ticks tested. Serologic antibody to A. phagocytophilum was detected in two of 54 participants in a community epidemiologic study; one of these also had antibody to E. chaffeensis. Over 85% of study participants reported finding a tick on themselves in the preceding 12 mo. Residents of southern Humboldt County are at significant risk of tick bites and should take appropriate prevention measures to avoid infection with rickettsia and other tick-transmitted pathogens.