[Preliminary study on automatic quantification and grading of leopard spots fundus based on deep learning technology].

Objective: To achieve automatic segmentation, quantification, and grading of different regions of leopard spots fundus (FT) using deep learning technology. The analysis includes exploring the correlation between novel quantitative indicators, leopard spot fundus grades, and various systemic and ocular parameters. Methods: This was a cross-sectional study. The data were sourced from the Beijing Eye Study, a population-based longitudinal study. In 2001, a group of individuals aged 40 and above were surveyed in five urban communities in Haidian District and three rural communities in Daxing District of Beijing. A follow-up was conducted in 2011. This study included individuals aged 50 and above who participated in the second 5-year follow-up in 2011, considering only the data from the right eye. Color fundus images centered on the macula of the right eye were input into the leopard spot segmentation model and macular detection network. Using the macular center as the origin, with inner circle diameters of 1 mm, 3 mm, and outer circle diameter of 6 mm, fine segmentation of the fundus was achieved. This allowed the calculation of the leopard spot density (FTD) and leopard spot grade for each region. Further analyses of the differences in ocular and systemic parameters among different regions' FTD and leopard spot grades were conducted. The participants were categorized into three refractive types based on equivalent spherical power (SE): myopia (SE<-0.25 D), emmetropia (-0.25 D≤SE≤0.25 D), and hyperopia (SE>0.25 D). Based on axial length, the participants were divided into groups with axial length<24 mm, 24-26 mm, and>26 mm for the analysis of different types of FTD. Statistical analyses were performed using one-way analysis of variance, Kruskal-Wallis test, Bonferroni test, and Spearman correlation analysis. Results: The study included 3 369 participants (3 369 eyes) with an average age of (63.9±10.6) years; among them, 1 886 were female (56.0%) and 1, 483 were male (64.0%). The overall FTD for all eyes was 0.060 (0.016, 0.163); inner circle FTD was 0.000 (0.000, 0.025); middle circle FTD was 0.030 (0.000, 0.130); outer circle FTD was 0.055 (0.009, 0.171). The results of the univariate analysis indicated that FTD in various regions was correlated with axial length (overall: r=0.38, P<0.001; inner circle: r=0.31, P<0.001; middle circle: r=0.36, P<0.001; outer circle: r=0.39, P<0.001), subfoveal choroidal thickness (SFCT) (overall: r=-0.69, P<0.001; inner circle: r=-0.57, P<0.001; middle circle: r=-0.68, P<0.001; outer circle: r=-0.72, P<0.001), age (overall: r=0.34, P<0.001; inner circle: r=0.30, P<0.001; middle circle: r=0.31, P<0.001; outer circle: r=0.35, P<0.001), gender (overall: r=-0.11, P<0.001; inner circle: r=-0.04, P<0.001; middle circle: r=-0.07, P<0.001; outer circle: r=-0.11, P<0.001), SE (overall: r=-0.20; P<0.001; inner circle: r=-0.19, P<0.001; middle circle: r=-0.20, P<0.001; outer circle: r=-0.20, P<0.001), uncorrected visual acuity (overall: r=-0.18, P<0.001; inner circle: r=-0.26, P<0.001; middle circle: r=-0.24, P<0.001; outer circle: r=-0.22, P<0.001), and body mass index (BMI) (overall: r=-0.11, P<0.001; inner circle: r=-0.13, P<0.001; middle circle: r=-0.14, P<0.001; outer circle: r=-0.13, P<0.001). Further multivariate analysis results indicated that different region FTD was correlated with axial length (overall: ß=0.020, P<0.001; inner circle: ß=-0.022, P<0.001; middle circle: ß=0.027, P<0.001; outer circle: ß=0.022, P<0.001), SFCT (overall: ß=-0.001, P<0.001; inner circle: ß=-0.001, P<0.001; middle circle: ß=-0.001, P<0.001; outer circle: ß=-0.001, P<0.001), and age (overall: ß=0.002, P<0.001; inner circle: ß=0.001, P<0.001; middle circle: ß=0.002, P<0.001; outer circle: ß=0.002, P<0.001). The distribution of overall (H=56.76, P<0.001), inner circle (H=72.22, P<0.001), middle circle (H=75.83, P<0.001), and outer circle (H=70.34, P<0.001) FTD differed significantly among different refractive types. The distribution of overall (H=373.15, P<0.001), inner circle (H=367.67, P<0.001), middle circle (H=389.14, P<0.001), and outer circle (H=386.89, P<0.001) FTD differed significantly among different axial length groups. Furthermore, comparing various levels of FTD with systemic and ocular parameters, significant differences were found in axial length (F=142.85, P<0.001) and SFCT (F=530.46, P<0.001). Conclusions: The use of deep learning technology enables automatic segmentation and quantification of different regions of theFT, as well as preliminary grading. Different region FTD is significantly correlated with axial length, SFCT, and age. Individuals with older age, myopia, and longer axial length tend to have higher FTD and more advanced FT grades.

Penile neurovascular structure revisited: immunohistochemical studies with three-dimensional reconstruction.

Penile erection is a neurovascular phenomenon that requires well coordinated and functional interaction between penile vascular and nervous systems. In order to provide a useful tool to examine pathologic changes in the erectile tissue, mainly focusing on penile neurovascular dysfunction, we established the technique to determine the differential distribution of endothelial cells, smooth muscle cells, pericytes, and nerve fibers in the mouse penis using immunohistochemical staining with three-dimensional reconstruction. Immunofluorescent staining of penile tissue was performed with antibodies against CD31 (an endothelial cell marker), smooth muscle α -actin (SMA, a smooth muscle cell marker), NG2 (a pericyte marker), or ßIII-tubulin (a neuronal marker). We reconstructed three-dimensional images of penile vascular or neurovascular system from stacks of two-dimensional images, which allows volume rendering and provides reliable anatomic information. CD31-positive endothelial cells, SMA-positive smooth muscle cells, and NG2-positive pericytes were evenly distributed and composed sinusoidal or venous wall. However, the endothelial layer of the cavernous artery or dorsal artery was mainly covered with smooth muscle cells and rarely associated with pericytes. The reconstructed three-dimensional images clearly visualized typical wavy appearance of nerve fibers that evenly innervate to cavernous sinusoids, cavernous artery, dorsal vein, and dorsal artery. We observed a significant decrease in CD31-positive endothelial cells, NG2-positive pericytes, and ßIII-tubulin-positive nerve fibers in the penis of diabetic mice compared with those in normal condition. Our protocol for immunofluorescent staining with three-dimensional reconstruction will allow a better understanding of the penile neurovascular anatomy and may constitute a standard technique to determine the efficacy of candidate therapeutics targeting therapeutic angiogenesis or neural regeneration.

Calorie restriction reverses age-related alteration of cavernous neurovascular structure in the rat.

Calorie restriction (CR) refers to a reduction of calorie intake without compromising essential nutrients to avoid malnutrition. CR has been established as a non-genetic method of altering longevity and attenuating biological changes associated with aging. Aging is also an important risk factor for erectile dysfunction. The aim of this study was to examine whether CR diet can reverse the age-related alterations of erectile tissue in the aged rat. Four groups of rats were used: young rats (7 months) + ad libitum, aged rats (22 months) + ad libitum, young rats + CR diet, and aged rats + CR diet. The ad libitum group had free access to both food and water, and CR groups were fed 60% of the food intake of their ad libitum littermates, starting from 6 weeks before sacrifice. The penis was harvested and stained with antibodies to von Willebrand factor, smooth muscle α-actin, platelet-derived growth factor receptor-ß, phospho-eNOS, nNOS, and neurofilament. We also performed Masson trichrome staining and TUNEL assay. The blood samples were collected for the measurement of serum total testosterone level. The contents of endothelial cells, smooth muscle cells, pericytes, and neuronal cells as well as serum testosterone levels were significantly lower in the penis of aged rats than in their young littermates. CR significantly restored cavernous endothelial cells, smooth muscle cells, pericytes, and neuronal cell contents and decreased cavernous endothelial cell apoptosis and fibrosis in both young and aged rats. CR also increased serum testosterone level in aged rats, but not in young rats. CR successfully improved age-related derangements in penile neurovascular structures and hormonal disturbance. Along with a variety of lifestyle modifications, our study gave us a scientific rationale for CR as a non-pharmaceutical strategy to reprogram damaged erectile tissue toward neurovascular repair in aged men.

Establishment of in vitro model of erectile dysfunction for the study of high-glucose-induced angiopathy and neuropathy.

Penile erection requires complex interaction between vascular endothelial cells, smooth muscle cells, pericytes, and autonomic nerves. Diabetes mellitus is one of the most common causes of erectile dysfunction (ED) and multiple pathogenic factors, such as cavernous angiopathy and autonomic neuropathy, are associated with diabetic ED. Although a variety of animal models of diabetic ED play an important role in understanding pathophysiologic mechanisms of diabetes-induced ED, these animal models have limitations for addressing the exact cellular or molecular mechanisms involved in ED. Therefore, we established an in vitro model of ED for the study of high-glucose-induced angiopathy and neuropathy. We successfully isolated and cultivated mouse cavernous endothelial cells (MCECs) and mouse cavernous pericytes (MCPs). The cells were exposed to the normal-glucose (5 mmoL) or high-glucose (30 mmoL) condition for 48 h. In vitro matrigel assay revealed impairments in tube formation in primary cultured MCECs or MCPs exposed to high-glucose condition. To study cellular interaction between MCECs and MCPs, co-culture systems including indirect contact, indirect non-contact, and direct mixed co-culture system, were established. We observed impaired tube formation and increased permeability in MCECs-MCPs co-culture exposed to high-glucose condition. To evaluate the effect of high-glucose on neurite sprouting, the mouse major pelvic ganglion (MPG) tissue was harvested and cultivated in matrigel. Neurite outgrowth and nNOS-positive nerve fibers were significantly lower in MPG tissues exposed to the high-glucose condition than in the tissues exposed to the normal-glucose condition. We believe that in vitro model of ED will aid us to understand the role of each cellular component in the pathogenesis of diabetic ED, and also be a useful tool for determining the efficacy of candidate therapeutics targeting vascular or neuronal function. This model would present a new avenue for drug discovery and development of novel therapeutic modalities for erectile dysfunction.

Intracavernous delivery of clonal mesenchymal stem cells rescues erectile function in the streptozotocin-induced diabetic mouse.

The major hurdle for the clinical application of stem cell therapy is the heterogeneous nature of the isolated cells, which may cause different treatment outcomes. The aim of this study was to examine the effectiveness of mouse clonal bone marrow-derived stem cells (BMSCs) obtained from a single colony by using subfractionation culturing method for erectile function in diabetic animals. Twelve-week-old C57BL/6J mice were divided into four groups: controls, diabetic mice, and diabetic mice treated with a single intracavernous injection of PBS (20 µL) or clonal BMSCs (3 × 10(5) cells/20 µL). Clonal BMSCs were isolated from 5-week-old C3H mice. Two weeks after treatment, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was stained with antibodies to PECAM-1, smooth muscle α-actin, neuronal nitric oxide synthase (nNOS), neurofilament, and phosphorylated endothelial NOS (phospho-eNOS). We also performed Western blot for phospho-eNOS, and eNOS in the corpus cavernosum tissue. Local delivery of clonal BMSCs significantly restored cavernous endothelial and smooth muscle cell contents, and penile nNOS and neurofilament contents, and induced eNOS phosphorylation (Ser1177) in diabetic mice. Intracavernous injection of clonal BMSCs induced significant recovery of erectile function, which reached 80-90% of the control values. Clonal BMSCs successfully restored erectile function through dual angiogenic and neurotrophic effects in diabetic mice. The homogenous nature of clonal mesenchymal stem cells may allow their clinical applications and open a new avenue through which to treat diabetic erectile dysfunction.

A guanidinylated bioreducible polymer as a novel gene carrier to the corpus cavernosum of mice with high-cholesterol diet-induced erectile dysfunction.

A prerequisite for the successful clinical application of gene therapy in erectile dysfunction (ED) is the availability of safe and efficient gene delivery systems. The aim of this study was to examine the effectiveness of guanidinylated bioreducible polymer (GBP) polyplexes for gene delivery systems, which take advantage of the biodegradability of reducible disulfide bonds and the cell-penetrating ability of guanidine groups. For in vitro transfection experiments, we used mouse cavernous endothelial cells and A7r5 rat vascular smooth muscle cells. For in vivo experiments, we used a mouse model of hypercholesterolaemic ED in which 2-month-old male C57BL/6 mice were fed a diet containing 4% cholesterol and 1% cholic acid for 3 months. Animals or cells were treated with pCMV-Luc, poly(ethyleneimine) (PEI)25k/pCMV-Luc polyplex (weight ratio: 1) and GBP/pCMV-Luc polyplexes (weight ratio: 20, 40, 60 and 80). Gene expression was evaluated by luciferase assay, and the gene expression area was evaluated by immunohistochemistry. GBP had greater transfection efficiency as the weight ratio increased. GBP had sevenfold higher gene delivery efficiency in A7r5 cells at a weight ratio of 80 than did PEI25k. Moreover, the gene expression was more profoundly induced by GBP/pCMV-Luc than by pCMV-Luc in both the corpus cavernosum tissue of hypercholesterolaemic mice and in mouse cavernous endothelial cells, although the expression levels induced by the GBP gene delivery system were lower than those induced by the PEI25k gene delivery system. GBP revealed no considerable cytotoxicity to A7r5 cells and mouse cavernous endothelial cells (relative cell viability: 95 and 88% respectively), whereas PEI25k resulted in high cytotoxicity. Interestingly, immunofluorescent double staining revealed that luciferase expression induced by the GBP polyplex mainly overlapped with cavernous endothelial cells, but rarely with smooth muscle cells. The GBP-based non-viral gene expression system may be useful for the development of gene therapy in vasculogenic ED.

Effects of lower limb torsion on ankle kinematic data during gait analysis.

VICON Clinical Manager software is widely used for gait analysis and has four methods for computing ankle plantarflexion-dorsiflexion motion and transverse plane ankle rotation profiles. The authors evaluated 14 subjects with a diagnosis of spastic cerebral palsy and tibial torsion ranging from 39 degrees internal torsion to 90 degrees external torsion, using the four different processing methods. It was found that clinically measured tibial torsion >20 degrees external or >15 degrees internal led to significant differences in the calculated ankle plantarflexion-dorsiflexion and transverse plane ankle rotation measurements between the four methods. Pearson correlations indicated that these differences increased with increasing external or internal tibial torsion. The variability was enough to affect conclusions of published articles and clinical decision making.

Acute hematogenous osteomyelitis in children.

Acute hematogenous osteomyelitis in children is a relatively uncommon but potentially serious disease. Improvements in radiologic imaging, most notably magnetic resonance imaging, and a heightened awareness of this condition have led to earlier detection and resultant marked decreases in morbidity and mortality. Staphylococcus aureus, which has the ability to bind to cartilage, produce a protective glycocalyx, and stimulate the release of endotoxins, accounts for 90% of infections in all age groups. Infections with Haemophilus influenzae have become rare in immunized children. A careful history and a thorough physical examination remain important. Positive cultures are obtained in only 50% to 80% of cases; the yield is improved by the use of blood cultures and evolving molecular techniques. Improvements in antibiotic treatment have lessened the role of surgery in managing these infections. Sequential intravenous and high-dose oral antibiotic therapy is now an accepted modality. Evaluation of response to treatment by monitoring C-reactive protein levels has decreased the average duration of therapy to 3 to 4 weeks with few relapses. The emergence of antibiotic resistance, particularly resistance to methicillin and vancomycin by S aureus organisms, is of increasing concern. Long-term sequelae and morbidity are primarily due to delays in diagnosis and inadequate treatment.

Changes in gait at 1 year post-selective dorsal rhizotomy: results of a prospective randomized study.

We performed a prospective randomized trial to compare the effects of selective dorsal rhizotomy with intensive physical therapy to intensive physical therapy alone in a group of children with mild spastic diplegic cerebral palsy. Instrumented gait analysis was carried out upon enrollment into the study and after 1 year. Changes in ambulatory status, time/distance parameters, and gait kinematics were observed for both groups. Considerable variability was present in both groups. Changes in ankle dorsiflexion, foot progression angle, and hip and knee extension in stance were significantly better in the selective dorsal rhizotomy group compared to the physical therapy group at 1 year (p < 0.05). These differences were not associated with significant improvements in functional gait as determined by changes in time/distance parameters or ambulatory status.

Relationship of peak height velocity to other maturity indicators in idiopathic scoliosis in girls.

BACKGROUND: Our aim was to compare height velocity data, obtained from clinical height measurements, for girls who had idiopathic scoliosis with the data for adolescents who did not have scoliosis. We also compared the growth data with chronological age, menarchal age, and Risser sign in terms of their accuracy in the prediction of growth and progression of the scoliosis. METHODS: One hundred and twenty of 371 patients in a database of girls managed with a brace for the treatment of idiopathic scoliosis had sufficient height data for us to quantify their growth peak. Height velocity data was generated from standing-height measurements obtained, in a scoliosis clinic, with a minimum six-month interval between measurements, and the timing of peak height velocity was calculated. The age at menarche was recorded from the patients' records. The Risser sign and Cobb angle were determined by a single observer. Progression of the scoliosis was defined as an increase in the Cobb angle of at least 10 degrees, compared with the curve magnitude at the time of the initial evaluation, after a minimum of six months. Progression to a magnitude requiring surgery was defined as progression of at least 10 degrees to a magnitude of 45 degrees or more. RESULTS: The height velocity plot grouped by peak height velocity showed a high peak and a sharp decline with values similar to those in normal populations. Extrapolating from percentile charts, 90 percent of our patients ceased growing by 3.6 years after peak height velocity. The growth peak was blunted (averaged over too long a period such that the data for the period of most rapid growth was averaged in with that for a period of slower growth) when chronological age, menarchal age, and Risser sign were used to predict growth; this indicated that these maturity scales grouped the patients poorly in terms of growth. The primary curve was progressive in eighty-eight of the 120 patients. Sixty of these patients had a curve of more than 30 degrees at peak height velocity, and in fifty (83 percent) of the sixty the curve progressed to 45 degrees or more. The remaining twenty-eight patients had a curve of 30 degrees or less at peak height velocity, with only one curve (4 percent) progressing to 45 degrees or more. Peak height velocity also grouped patients for maximal progression of the curve more accurately than did the other maturity scales, as most of the curves progressed maximally at peak height velocity. There was a wider spread of timing of maximal progression when chronological age, menarchal age, and Risser sign were used to predict progression. CONCLUSIONS: Height velocities generated from clinical height measurements for patients with idiopathic scoliosis document the growth peak and predict cessation of growth reliably. Knowing the timing of the growth peak provides valuable information on the likelihood of progression to a magnitude requiring spinal arthrodesis.

Peak height velocity as a maturity indicator for males with idiopathic scoliosis.

We retrospectively studied 43 adolescent boys treated with orthoses for idiopathic scoliosis to assess the usefulness of the timing of peak height velocity for predicting growth remaining and the likelihood of curve progression when compared with Risser sign, closure of the triradiate cartilage, and chronologic age. We compared the peak height velocity data in boys to our previous work for girls with adolescent idiopathic scoliosis. We found the median height velocity plots showed a similar high peak and sharp decline as is found in girls. All 13 patients with a curve magnitude > 30 degrees at the time of peak height velocity had progression of their scoliosis to > 45 degrees despite bracing. Four of 29 patients (14%) with curves < or = 30 degrees at peak height velocity progressed to 45 degrees. These values generate a sensitivity of 76%, specificity of 100% and accuracy of 91% in predicting progression to 45 degrees. Similar values have been found in female patients. The use of peak height velocity to predict the length of time for remaining growth was superior to Risser sign and chronologic age for boys with idiopathic scoliosis. Closure of the triradiate cartilage approximated the timing of peak height velocity in boys.

Determination of hip position in the Pavlik harness.

Fourteen children treated for developmental dysplasia of the hip with a Pavlik harness were evaluated at the time of harness application with clinical examination, hip ultrasonography, and anteroposterior radiography. Ten orthopedic surgeons with experience levels varying from residents to experienced pediatric orthopedic surgeons evaluated the studies to determine hip position in the harness. Clinical examination agreed with hip ultrasonography for hip position in 100% of hips. Interpretation of radiographs agreed with ultrasonography in only 49% of cases in which the hip was judged to be dislocated and in 82% of cases in which the hip was judged to be reduced. When imaging is used to aid in assessing hip position during treatment with a Pavlik harness, ultrasonography appears to be superior to anteroposterior radiography for assessing hip position.

Chronic musculoskeletal pain in childhood.

We studied 73 children with chronic or recurrent musculoskeletal pain of > or = 6 weeks' duration. Thirty-six children had no identifiable organic etiology for their pain, with a minimum follow-up of 2 years for ongoing symptoms. Thirty-seven children had an organic etiology for their pain. Use of an Inappropriate Symptom Checklist was helpful in distinguishing between children with chronic pain who were found to have an organic disease and those without an identifiable organic disease. Seventy-seven percent of children with no inappropriate symptoms had an organic diagnosis ultimately made. Conversely, 79% of children with two or more inappropriate symptoms ultimately had no organic diagnosis to explain their pain. Behavioral self-report measures testing could not differentiate between children with chronic pain with or without organic disease. Intervention by a psychologist skilled in pain management was helpful.

Determining treatment of flatfeet in children.

Infants are born with flexible flatfeet, and the normal arch develops in the first decade of life. Flexible flatfeet rarely cause disability, and asymptomatic children should not be burdened with orthotics or corrective shoes. Flexible flatfeet with tight heelcords may become symptomatic and can be addressed with a stretching program. Surgical intervention for flexible flatfeet is reserved for patients who have persistent localized symptoms despite conservative care. Rigid or pathologic flatfeet have multiple etiologies and many will require treatment to alleviate symptoms or improve function.

Comparison of functional outcomes from orthopedic and neurosurgical interventions in spastic diplegia.

Selective dorsal rhizotomy (SDR) and orthopedic surgery, in the form of muscle-tendon (MT) lengthening surgery are commonly performed in ambulatory children with spastic diplegia to improve their level of motor function. This investigation is a post hoc comparison of the functional effects from each of these surgical options in 30 patients with spastic diplegia who underwent one of these interventions as their initial surgical procedure. Sixteen children underwent SDR and 14 underwent MT surgery in two separate prospective clinical trials. The same functional outcome measures preoperatively and approximately 1 year postoperatively were used in both studies including temporospatial parameters from three-dimensional gait analysis, the total score, and score on each of the five dimensions of the Gross Motor Function Measure (GMFM). Comparisons indicate that patients who underwent SDR had significant improvements in GMFM Dimensions 2, 4, and 5 as well as in total score, although 63% of those studied had a 10% or more reduction in gait velocity. Gait was more predictably improved in the MT group, with only 21% demonstrating reductions in velocity. Conversely, the change in GMFM scores in the MT group was not as pervasive and skewed toward higher skills with only GMFM Dimension 5 and total score improved significantly. Several important hypotheses are derived from these comparisons. Multicenter clinical trials are needed to define more clearly the indications for and to assess more comprehensively the outcomes from each intervention.

The effect of limb-length discrepancy on gait.

We evaluated the gait of thirty-five neurologically normal children who had a limb-length discrepancy of the lower extremities that ranged from 0.8 to 15.8 per cent of the length of the long extremity (0.6 to 11.1 centimeters). The twenty-two boys and thirteen girls had an average age of thirteen years (range, eight to seventeen years). No patient had a substantial angular or rotational deformity of the lower extremities. We found no correlation between the actual discrepancy or the per cent discrepancy and any of the dependent kinematic or kinetic variables, including pelvic obliquity. Discrepancies of less than 3 per cent of the length of the long extremity were not associated with compensatory strategies. When a discrepancy was 5.5 per cent or more, more mechanical work was performed by the long extremity and there was a greater vertical displacement of the center of body mass. Clinically, this degree of discrepancy was manifested by the use of toe-walking as a compensatory strategy. Children who had less of a discrepancy were able to use a combination of compensatory strategies to normalize the mechanical work performed by the lower extremities.

Open fractures of the tibia in children.

We treated 38 patients from 4 to 15 years old and with open growth plates for open fractures of the tibia. The average follow-up was 33 months (range, 9-122). All patients had repeated operative debridement, parenteral antibiotics, and immobilization by cast or fixation. Outcomes were analyzed with respect to age at the time of injury, grade of injury, and type of immobilization. The time to union was prolonged and averaged 21 weeks (range, 6-82). No patients younger than 11 years required bone grafting for union. The deep infection and nonunion rate was 8%, with all of these occurring in patients older than 11 years. Clinically significant leg-length discrepancy or functional limitation was encountered only in patients with an ipsilateral femur fracture or with deep infection requiring osseous debridement. Our data suggest that open tibia fractures in children older than 11 years have nonunion and infection rates that parallel those of adult patients, but that younger children have a more benign course. With aggressive wound care and adequate stabilization, few complications or sequelae should occur in open tibial shaft fractures in younger patients.

The prevalence of nonmuscular causes of torticollis in children.

Torticollis in children may result from a wide variety of pathologic processes. We retrospectively analyzed 288 patients seen in a tertiary care pediatric orthopedic facility for the evaluation of torticollis over a 10-year period to ascertain the frequency of nonmuscular causes of this condition. Fifty-three of these children (18.4% of the study population) had a nonmuscular etiology for their torticollis. Of these 53 patients, Klippel-Feil anomalies were present in 16 (30%), and an underlying neurologic disorder was present in 27 (51%). These neurologic conditions included ocular disorders in 12 (23%) patients, brachial plexus palsies in nine (17%) patients, and lesions involving the central nervous system in six (11%) patients. We conclude that nonmuscular causes of torticollis are collectively not rare. In a child without an identifiable muscular etiology for torticollis, Klippel-Feil anomalies or an underlying neurologic disorder is likely to be the cause of the deformity in the majority of patients.

[Inhibitory effects of calcium channel antagonist on the proliferation of vascular smooth muscle cells induced by adrenoceptor activators].

In cultured vascular smooth muscle cells (VSMC) of SD rat, it was demonstrated that 10(-6) - 10(-5) mol/L NE and 10(-7) - 10(-5) mol/L isoproterenol stimulated proliferation and 3H-TdR incorporation of the cells in a dose dependent manner. These effects might be significantly inhibited by co-incubation with either alpha-receptor blocker phentolamine (10(-6) mol/L) or beta-receptor blocker propranolol (10(-5) mol/L). It was also found that cell counting and 3H-TdR incorporation were markedly decreased after incubation nifedipine (10(-6) mol/L) or verapamil (10(-6) mol/L) with NE (P < 0.01 as compared to that of NE group). It was further observed that nifedipine and verapamil inhibited DNA synthesis and proliferation of VSMC induced by isoproterenol.

Removal of water produced from lipase-catalyzed esterification in organic solvent by pervaporation.

Esterification of oleic acid with n-butanol in the presence of Lipozyme(R) was carried out at 25 degrees C in isooctane with various initial water activities. Initial reaction rate as well as equilibrium conversion decreased at high initial water activity. Therefore, removal of water present in the reaction mixtures was essential. A pervaporation process was applied to the lipase-catalyzed synthesis of n-butyloleate to remove water. Pervaporation selectively separated water from the reaction mixture using a nonporous polymeric membrane, cellulose acetate. Therefore, pervaporation is potentially applicable to remove the water produced from various enzymatic processes, such as synthesis of various esters, peptides, and glycosides in a solvent system as well as in a solvent-free system. (c) 1995 John Wiley & Sons, Inc.