Hydroxychavicol, a novel betel leaf component, inhibits platelet aggregation by suppression of cyclooxygenase, thromboxane production and calcium mobilization

BACKGROUND AND PURPOSE

Platelet hyperactivity is important in the pathogenesis of cardiovascular diseases. Betel leaf (PBL) is consumed by 200-600 million betel quid chewers in the world. Hydroxychavicol (HC), a betel leaf component, was tested for its antiplatelet effect.

EXPERIMENTAL APPROACH

We tested the effect of HC on platelet aggregation, thromboxane B(2) (TXB(2)) and reactive oxygen species (ROS) production, cyclooxygenase (COX) activity, ex vivo platelet aggregation and mouse bleeding time and platelet plug formation in vivo. The pharmacokinetics of HC in rats was also assessed.

KEY RESULTS

HC inhibited arachidonic acid (AA) and collagen-induced platelet aggregation and TXB(2) production. HC inhibited the thrombin-induced TXB(2) production, but not platelet aggregation. SQ29548, suppressed collagen- and thrombin-induced TXB(2) production, but not thrombin-induced platelet aggregation. HC also suppressed COX-1/COX-2 enzyme activity and the AA-induced ROS production and Ca(2+) mobilization. HC further inhibited the ex vivo platelet aggregation of platelet-rich plasma (>100 nmole/mouse) and prolonged platelet plug formation (>300 nmole/mouse) in mesenteric microvessels, but showed little effect on bleeding time in mouse tail. Moreover, pharmacokinetics analysis found that more than 99% of HC was metabolized within 3 min of administration in Sprague-Dawley rats in vivo.

CONCLUSIONS AND IMPLICATIONS

HC is a potent COX-1/COX-2 inhibitor, ROS scavenger and inhibits platelet calcium signaling, TXB(2) production and aggregation. HC could be a potential therapeutic agent for prevention and treatment of atherosclerosis and other cardiovascular diseases through its anti-inflammatory and antiplatelet effects, without effects on haemostatic functions.

The potential role of phagocytic capacity in the osteolytic process induced by polyethylene wear particles

Osteolysis induced by ultra-high molecular weight polyethylene wear particles is the major cause of long-term failure of artificial joints. We examined the effects of wear particles on bioactivity by analysing the biophysical aspects of particle phagocytosis. We estimated the maximum number of internalized particles (the phagocytic capacity) for particles of various sizes and shapes. We demonstrated that elongated particles had a smaller phagocytic capacity than spherical particles of the same volume. A review of the literature showed that the ratio of particle concentration (number of particles/number of cells) to phagocytic capacity is critical for particle-induced biological responses. When this ratio was < 1, the biological response was approximately proportional to the ratio itself. When this ratio was > 1, limited changes in the biological response were observed. The saturation level of the phagocytic capacity for a particle population appears to reflect the degree of polyethylene particle-induced biological response.

Development and validation of the revised Cedars-Sinai health-related quality of life for rheumatoid arthritis instrument

OBJECTIVE

To improve accuracy and content coverage of the original 33-item Cedars-Sinai Health-Related Quality of Life for Rheumatoid Arthritis Instrument (CSHQ-RA).

METHODS

A total of 312 RA patients from 55 sites were screened in a 24-week trial. Patients completed an expanded 48-item version of the CSHQ-RA, Medical Outcomes Study Short Form 36 (MOS SF-36), and Stanford Health Assessment Questionnaire (HAQ) Disability Index at 5 visits. The revised CSHQ-RA was created based on response frequencies and distributions, item-to-item correlation, factor and Rasch analysis, and input from experts. Psychometric evaluation included internal consistency, test-retest reliability, convergent and discriminant validity, and responsiveness. Minimum clinically important difference (MCID) was also measured.

RESULTS

Response rates were 93% at baseline and 71% at 12 weeks. Eighty-one percent of respondents at baseline were women, mean +/- SD age was 52 +/- 12 years, and mean +/- SD duration of RA was 10.8 +/- 10.4 years. The revised CSHQ-RA included 36 items measuring 7 domains (4 original and 3 new). All Cronbach's alpha coefficients were >0.8, indicating good internal consistency. Test-retest reliability measured intraclass correlation coefficients, which ranged from 0.86 to 0.95. All 7 domains correlated significantly with the MOS SF-36 and HAQ, indicating good convergent validity. Analysis of variance of disability group scores showed good discriminant validity (P < 0.0001). The MCIDs ranged from 6.2 for social well-being to 14.8 for pain/discomfort.

CONCLUSION

The revised CSHQ-RA was validated using a broader RA patient population. It captures 3 additional domains (social well-being, pain/discomfort, and fatigue), which allow for measuring all important aspects of health-related quality of life.

Extension splint for trigger thumb in children

Sixty-two reducible trigger thumbs in 50 children with age from 0 to 4 years (mean, 1 year 11 months) were reviewed to study the effect of splinting. Thirty-one thumbs in 24 children received splinting for a mean of 11.7 weeks. The other 31 thumbs in 26 children were only observed. The results were categorized as cured, improved, or nonimproved. Follow-up was conducted after a mean of 20 months (age, 43 months). Result in the splinted group showed cured in 12 thumbs, improved in 10 thumbs, and nonimproved in 9 thumbs, whereas in the observed group, result showed 4, 3, and 24, respectively. Splinting results in 71% trigger thumbs cured or improved that is better than observation alone. The subsequent surgical release for the nonimproved trigger thumbs after splinting still had excellent results. Because surgical release for trigger thumb is not urgent, we suggest extension splinting to be a treatment option before the elective surgery.

Association of obesity and chronic diseases in Taiwan

Two systems were used to classify weight status based on body mass index (BMI) of 3,178 Taiwanese adults who participated in the 1993-1996 Nutrition and Health Survey and to explore associations of BMI categories and disease. In the system proposed by the International Association for the Study of Obesity and the International Obesity Taskforce for Asian adults, overweight was associated with one disease (hypertension) and obesity was associated with four diseases: diabetes (OR = 2.66; 95% CI = 1.39-5.09; p < 0.01); gout (OR = 4.33; 95% CI = 1.92-9.75; p < 0.01); hypertension (OR = 4.92; 95% CI = 2.87-8.42; p < 0.01); thyroid disease (OR = 2.29; 95% CI = 1.12-4.67; p < 0.05). In the system devised by Taiwan Health Department for Taiwanese adults, overweight was associated with four diseases (arthritis, diabetes, gout, hypertension), and obesity was associated with three diseases: diabetes (OR = 2.11; 95% CI = 1.07-4.19; p < 0.05); gout (OR = 4.06; 95% CI = 1.77-9.28; p < 0.01); hypertension (OR = 5.28; 95% CI = 3.23-8.63; p < 0.01). The Obesity Taskforce may underestimate the association of excess weight and disease in Taiwan.

Single-center experience of pediatric heart transplantation in taiwan

Heart transplantation (HTx) is a treatment for end-stage heart failure or a complex or inoperable congenital defect. The long-term survival and the adequate donor to recipient body weight (D/R BW) ratio remain to be determined. From March 1995 to May 2004, 14 children (6 months-16 years of age) underwent HTx due to underlying diseases of idiopathic dilated cardiomyopathy (n = 10; 71.4%), congenital heart disease (n = 3; 21.4%), and Kawasaki disease (n = 1; 7.1%). Donor-recipient body weight ratio ranged from 0.89 to 3.9. Big heart syndrome was present in one patient when D/R BW ratio was more than 3. Actuarial survival was 92.9% at 5 years after transplantation. Only the one patient who had Kawasaki disease died due to early primary graft failure. HTx is a feasible method with good long-term survival rates for end-stage heart failure or for complex or inoperable congenital defects. After careful pretransplant evaluation, a high D/R BW ratio (more than 3) is acceptable.

Modulation of HER2 expression by ferulic acid on human breast cancer MCF7 cells

BACKGROUND

The molecular mechanisms underlying the mitogenic effect of ferulic acid (FA), an active compound derived from Angelica sinensis, have never been elucidated. It was the aim of this study to investigate the proliferative effect of FA on human breast cancer cell lines and to elucidate its modulation mechanism on HER2 expression in MCF7 line.

MATERIALS AND METHODS

By using MCF7 (oestrogen receptor-positive; ER+, HER2-low), BT474 (ER+, HER2-high), MDAMB231 (ER-, HER2-low) and SKBR3 (ER-, HER2-high) human breast cancer cell lines as in vitro models, the mitogenic effects of FA were assessed by trypan blue dye exclusion assay and DNA flow cytometry. Ferulic acid-modulated cell signalling and HER2 gene expression were evaluated in MCF7 line by Western blot and real-time RT-PCR analysis.

RESULTS

Ferulic acid ER-dependently stimulated cell proliferation on MCF7 cells in a concentration-dependent manner. The HER2 oncogene (one of the prognostic factors of breast cancer) and ESR1 gene (oestrogen receptor-alpha; ERalpha) transcription were markedly up-regulated by FA treatment. Besides, HER2 signalling and its downstream molecules such as AKT and ERK1/2 were involved in FA-modulated ERalpha and cyclin D1 synthesis. Addition of anti-HER2 antibody, trastuzumab, abrogated FA-enhanced proliferative effect on MCF7 cells, indicated a positive feedback control for the action of HER2 in this setting. The fact that the ER antagonist blocked most of the FA-up-regulated HER2 expression, and that trastuzumab down-regulated ERalpha gene expression, suggested a cross-talk between ERalpha and HER2 signalling on MCF7 cells.

CONCLUSION

The authors' conclude that FA causes human breast cancer cell proliferation by up-regulation of HER2 and ERalpha expression.

Progressive coxa vara by eccentric growth tethering in immature pigs

The present study tested progressive coxa vara by eccentric growth tethering that might be used to correct coxa valga in cerebral palsy. Eight young pigs received screw fixation at inferior portion of right femoral head at age 4 months and were killed at age 7.25 months for bilateral femurs for comparison. The neck-shaft angle at the tethered side was significantly less than that at the control side (129.8 vs. 138.3 degrees , P<0.05). Histological study showed bony bar formation. Eccentric growth tethering by one screw resulted in a reduction of neck-shaft angle by 8.5 degrees and shortening of femoral length by 4%.

Efficiency of a grazing-incidence off-plane grating in the soft-x-ray region

Efficiency measurements of a grazing-incidence diffraction grating in the off-plane mount were performed using polarized synchrotron radiation. The grating had 5000 grooves/mm, an effective blaze angle of 14 degrees, and was gold coated. The efficiencies in the two polarization orientations (TM and TE) were measured in the 1.5-5.0 nm wavelength range and were compared with the efficiencies calculated using the PCGrate-SX code. The TM and TE efficiencies differ, offering the possibility of performing unique science studies of astrophysical, solar, and laboratory sources by exploiting the polarization sensitivity of the off-plane grating.

Craniofacial morphometric analysis of mandibular prognathism

The purpose of this study was to provide more information about the morphological characteristics of the craniofacial complex in mandibular prognathism. Forty young adult males having mandibular prognathism were compared with 40 having normal occlusion. This was conducted to carry out geometric morphometric assessments to localize alterations, using Procrustes analysis and thin-plate spline analysis, in addition to conventional cephalometric techniques. Procrustes analysis indicated that the mean craniofacial, midfacial and mandibular morphology was significantly different in prognathic subjects compared with normal controls. This finding was corroborated by the multivariate Hotelling T(2)-test of cephalometric variables. Mandibular prognathism demonstrated a shorter and slightly retropositioned maxilla, a greater total length and anterior positioning of the mandible. Thin-plate spline analysis revealed a developmental diminution of the palatomaxillary region anteroposteriorly and a developmental elongation of the mandible anteroposteriorly, leading to the appearance of a prognathic mandibular profile. In conclusion, thin-plate spline analysis seems to provide a valuable supplement for conventional cephalometric analysis because the complex patterns of craniofacial shape change are visualized suggestive by means of grid deformations.

Midfacial and mandibular morphometry of children with Class II and Class III malocclusions

There is insufficient evidence in conventional cephalometric analysis of the actual sites of putative maxillofacial change in Class II and Class III malocclusions. The purpose of this study was to provide more information about the morphological characteristics of the midfacial complex and mandible in children with Class II or III malocclusions. Seventy children with Class II, division 1 malocclusion and 70 children with Class III malocclusion were compared with 70 children with normal occlusion. This study was conducted to carry out geometric morphometric assessments to localize alterations using Procrustes analysis and thin-plate spline analysis. Procrustes analysis indicated the midfacial and mandibular morphologies differed between normal occlusion subjects and subjects with Class II or Class III malocclusion (P<0.0001). The deformations in subjects with Class II malocclusion may represent a developmental elongation of the palatomaxillary complex and a shortening of the mandible anteroposteriorly, which leads to the appearance of a protruding midface and retruding mandibular profile. In contrast, the deformations in subjects with Class III malocclusion may represent a developmental shortening of the palatomaxillary complex and elongation of the mandible anteroposteriorly, which leads to the appearance of a retrognathic midface and prognathic mandibular profile.

Linking watershed and eutrophication modelling for the Shihmen Reservoir, Taiwan

The Shihmen Reservoir, located in northern Taiwan, features the second storage volume of impoundments on the island. The watershed of the Shihmen Reservoir has been subjected to serious pollutants due to anthropogenic interference. This study applies a watershed model, BASINS, to simulate the flow and nutrients loads from the watershed. BASINS then drives the CE-QUAL-W2 model for water quality predictions in the reservoir. The watershed modelling results are compared with field data. They reveal that significant nutrient loads were generated from the watershed during storms. The model calibration and verification were achieved with water surface elevation, temperature, and water quality constituents including nutrients, dissolved oxygen, and chlorophyll a in the reservoir using the eutrophication model.

Two Novel PHEX Mutations in Taiwanese Patients with X-Linked Hypophosphatemic Rickets

BACKGROUND

X-linked hypophosphatemic rickets (XLH) is an X-linked dominant disease characterized by renal phosphate wasting, hypophosphatemia, aberrant vitamin D metabolism, and defective bone mineralization. The disease is caused by mutations in the PHEX gene (phosphate-regulating gene with homologies to endopeptidases on the X-chromosome) located at Xp22.1. To date, a variety of PHEX mutations have been identified in these patients.

METHODS

PCR and direct sequencing was performed for all exons and intron-exon boundaries of the PHEX gene in two XLH families.

RESULTS

Two novel mutations, including a missense mutation (L206W) in exon 5 and a frameshift mutation (nucleotide 1826_1830delAAAAG, stop after codon 610) in exon 18 were discovered and the laboratory and radiographic findings for these patients analyzed.

CONCLUSIONS

We found that PHEX gene mutations were responsible for XLH in these Taiwanese patients. Additional studies are needed to enhance understanding of the role of PHEX in XLH pathogenesis.

Nodular glomerulosclerosis mimicking diabetic nephropathy without overt diabetes mellitus

The duration of diabetes mellitus and presence of hyperglycemia appear to be important in the development of diabetic nephropathy. Here, we present three patients with edema, heavy proteinuria, chronic renal failure, in whom no past or present symptomatic glucose intolerance or diabetic retinopathy were found. The kidney biopsy of these patients showed diffuse glomerular basement membrane thickening and nodular glomerulosclerosis, which resembled diabetic nephropathy. The renal function of these patients deteriorated rapidly and renal replacement therapy started later in the average of 11 months since the first visiting. These cases were diagnosed as diabetic nodular glomerulosclerosis, although there was no obvious evidence for diabetes. The absence of overt diabetes and diabetic retinopathy at presentation of nodular glomerulosclerosis in these cases does not refute the hypothesis that metabolic consequence of hyperglycemia is a prerequisite for the pathogenesis of diabetic microangiopathy, but some factors other than hyperglycemia may be responsible for renal damage in our patients. The modifiable risk factors in such a condition are postulated and discussed.

Geometric morphometric assessment of treatment effects of maxillary protraction combined with chin cup appliance on the maxillofacial complex

The aim of this study was to investigate the treatment effects on the maxillofacial complex by maxillary protraction combined with chin cup therapy among growing children. An effective geometric morphometric assessment of cephalometric radiographs, using Procrustes analysis and thin-plate spline analysis, was applied to evaluate shape change in the craniofacial and midfacial configurations of a treated sample of 20 children with skeletal Class III malocclusion. This was compared with matched untreated skeletal Class III controls. Marked treatment induced change involved the maxilla and the mandible. Major deformation consisted of forward advancement of the maxillary complex with negligible rotation of the palatal plane and a forward direction of growth of the mandibular condyle associated with a restriction in sagittal advancement of the chin. Considerable dentoalveolar components contributed to the correction of anterior crossbite. Further detailed study of skeletofacial remodelling in response to maxillary protraction in other skeletal components, including the cranial base and the mandibular complex that contribute to Class III skeletal discrepancies, is warranted.

Relationship between arterial and end-tidal carbon dioxide pressures during anesthesia using a laryngeal tube

BACKGROUND

The Laryngeal Tube (LT), (VBM Medizintechnik, Sulz, Germany) is a relatively new supraglottic device for controlling the airway. Arterial carbon dioxide tension (PaCO(2)) can be estimated by monitoring the end-tidal tension of carbon dioxide (PETCO(2)). The relationship between PETCO(2) and PaCO(2) during controlled ventilation via the LT has not been reported.

METHODS

During general anesthesia, 45 patients were mechanically ventilated using an LT. PETCO(2) and PaCO(2) were measured once PETCO(2) had reached a steady state. The LT was then removed and the trachea intubated using an endotracheal tube (ETT), and the identical ventilatory variables were resumed. Following stabilization, PETCO(2) was again determined and PaCO(2) estimated.

RESULTS

The mean PETCO(2) and PaCO(2) values were 4.43 +/- 0.26 kPa and 4.67 +/- 0.32 kPa, respectively, during LT ventilation, and 4.36 +/- 0.23 kPa and 4.61 +/- 0.26 kPa, respectively, during ETT ventilation. Analysis of differences between the PETCO(2) and PaCO(2) values using the Bland and Altman method revealed a bias +/- precision of 0.24 +/- 0.15 kPa for LT and 0.27 +/- 0.15 kPa for ETT. The root mean square error was 0.28 for the LT and 0.30 for the ETT.

CONCLUSION

This study suggests that for healthy adult patients mechanically ventilated via the LT, the PETCO(2) value reflects the PaCO(2) value as closely as when patients are ETT ventilated, allowing capnometry to be used to evaluate the adequacy of ventilation.

Rush pin fixation versus traction and casting for femoral fracture in children older than seven years

BACKGROUND

The optimal treatment for femoral fractures in children is controversial. The purpose of this study was to compare the results of Rush pin fixation with those of conservative treatment, and to evaluate the sequels of growth plate injury by internal fixation.

METHODS

Eighteen femoral shaft fractures in 17 children who had concomitant head injury or multiple traumas were treated surgically. The mean age at operation was 9 years 3 months (range, 7 years 5 months to 11 years 1 month). One Rush pin was inserted from the tip of the greater trochanter, without reaming, to fix the fracture. Another 20 age-matched children treated by traction and casting were the control subjects.

RESULTS

All the fractures united without consequences. In addition to a decrease in hospital stay with the use of the Rush pin (10 days vs. 27 days, p<0.05), fewer leg length discrepancies (4.2 mm vs. 7.1 mm, p<0.05) were also noted, compared with conservative treatment. The growth of the proximal femur after Rush pin fixation was evaluated after an average of 59 months. No femur shortening, coxa valgus, or hip dysplasia was noted.

CONCLUSIONS

Intramedullary Rush pin fixation for femoral shaft fracture in children older than 7 years is a simple and reliable alternative. One narrow and non-reaming pin inserted from greater trochanter did not demonstrate femoral growth inhibition.

Effects of sucrose concentration on the developmental potential of human frozen–thawed oocytes at different stages of maturity

BACKGROUND

Success of human oocyte cryopreservation depends on multiple cryobiological factors that could influence the developmental potential of the oocytes. The objective of this study was to examine the effects of different sucrose concentrations on the developmental potential of human frozen-thawed oocytes at different maturity stages.

METHODS

A total of 355 oocytes collected from small follicles were randomly divided into three groups and two groups (B and C) were cryopreserved using slow-freezing method. Group A included 131 oocytes at different maturity stages without freezing. Another 119 oocytes in Group B were cryopreserved with 0.1 M sucrose and 105 oocytes in Group C with 0.2 M sucrose concentration.

RESULTS

The post-thaw survival rate of the oocytes and the cleavage rate in Group C were significantly higher than that of Group B (P<0.05). For immature metaphase I (MI) stage oocytes, a significant difference was found in the maturation rate between Group C and Group B (P<0.05). The maturation rate for the GV oocytes in Groups A and C was significantly higher than Group B (P<0.01).

CONCLUSIONS

The results suggested that sucrose concentration of 0.2 M in the cryoprotectant solution is more suitable for human oocyte cryopreservation.

A CFD study of the deep bed filtration mechanism for submicron/nano-particle suspension

The mechanism of the deep bed filtration for submicron and nano particles suspension was conducted by means of a force analysis on the suspended particles flow path through order-packed granular filter beds. The flow fields through the filter beds were calculated by using the commercial available CFD software--Fluent. Various types of granular packing structures, such as the simple cubic packing, body-centered packing and face-centered packing structures were chosen for analysis. The motion of suspended particle of 2.967, 0.816, 0.460 and 0.050 microm in diameter, respectively, were tracked by considering the following forces including a net gravitational force, hydraulic drag force, lift force, Brownian force, van der Waals force and a double layer force. The effects of the granular bed packing structure, the porosity of these beds and the suspended particle diameter on the capture efficiency of a granular filter bed were examined. The force analysis depicts that the inertial effect and van der Waals force increased the capture probability of particles on the granular filter bed while the lift force and the Brownian force decreased the particle deposition. Simulated results show that among the chosen packing structures, the face-center packed granular bed gives the greatest pressure drop and capture efficiency of particles due to the lower packing porosity. The simple cubic packed filter bed showed the lowest pressure drop and capture efficiency of particles due to the greatest packing porosity among the chosen packing structures. It is mainly due to the simple cubic packing structure in which there exists the free vertical downward flowing path and thus exhibits a higher packing porosity. The comparisons of the simulated capture efficiency with experimental results depicted that the body-centre packed granular bed showed the best approximation of capture efficiency compared to that of the randomly packed granular bed.

Intervertebral disc herniation in adolescents

BACKGROUND

The purpose of this study was to review surgery-proven lumbar disc herniation in adolescents with an emphasis on the distinguishing features.

METHODS

Twenty-eight adolescents between 14 and 18 years old had lumbar discectomy after conservative treatment for 9 months. Indications for surgery were intractable pain and failure of conservative treatment for more than 6 weeks. Lumbar spine apophyseal ring fracture was found in 10 of the 24 patients (42%) who had computed tomography studies. Seven patients had piecemeal excision of the fractured apophysis together with the discectomy.

RESULTS

All but three patients could raise their leg more than 70 degrees after the operation. The latest follow-up was conducted an average of 6.1 years after surgery. Good or excellent results were noted in 93% of the patients. Two patients had follow-up operations for recurrent disc herniation and wound infection.

CONCLUSION

Apophyseal ring fracture was a feature in adolescent disc herniation that requires surgical intervention. Early computed tomography study is proposed to detect apophyseal ring lesion, which may lead to failure of conservative treatment. Excision of the fractured ring apophysis is suggested in addition to discectomy when the canal space is occupied.

Quality of life in multiple sclerosis patients in Spain

OBJECTIVE

The cross-sectional study evaluated the psychometric properties of the Functional Assessment of Multiple Sclerosis (FAMS) Spanish version and its use in measuring quality of life (QOL) of multiple sclerosis (MS) patients in Spain.

METHODS

The FAMS is a factorially derived self-report scale designed to assess six primary aspects of QOL of patients with MS: Mobility, Symptoms, Emotional Well-Being, General Contentment, Thinking and Fatigue, and Family/Social Well-Being. Its Spanish translated version was used to assess QOL of 625 MS patients recruited in an outpatient clinic setting from 58 hospitals in Spain. Internal consistency of the Spanish FAMS was evaluated Multiple regression analyses were performed to identify significant predictors from demographic, clinical and treatment characteristics, and Kurtzke Expanded Disability Status Scale (EDSS) scores in predicting FAMS scale scores.

RESULTS

Most of the patients are females (66%), and 74% were of the relapsing-remitting (RR) clinical subtype. Cronbach's alpha coefficients were high (range=0.78-0.96), indicating subscale homogeneity comparable to that of the original English version. Linear multivariate regression analyses revealed that the EDSS is a dominant variable in predicting all the FAMS subscales, especially mobility (R2=0.51) and the total scores.

CONCLUSIONS

The Spanish FAMS is a psychometrically valid instrument that allows clinicians and clinical researchers the ability to measure the QOL concerns of MS patients in Spain.

Longitudinal followup study of ultrasonography in congenital muscular torticollis

High-resolution ultrasonography was used to examine affected sternocleidomastoid muscles in patients with congenital muscular torticollis at different times. Thirty-one female and 42 male patients were recruited and classified as having one of four types of fibrosis based on the sonograms. Compared with initial assessment, 22 (95.6%) patients with Type I fibrosis and 22 (57.9%) patients with Type II fibrosis had a change in classification at the end of the study. Among the patients with Type I fibrosis, the classification of one patient was changed to Type III fibrosis, the classifications of two patients were changed to normal muscle, and the classifications of the other patients were changed to Type II fibrosis. For patients with Type II fibrosis, the classifications of two patients were changed to Type III fibrosis, the classifications of three patients were changed to Type IV fibrosis, and the classifications of the other patients were changed to normal muscle. No changes in classification of patients with Types III and IV fibrosis occurred during followup. Patients with Type IV fibrosis had a significantly high incidence of surgical intervention. Congenital muscular torticollis is a dynamic disease. Ultrasonography can be valuable in observing the alteration. Aggressive management may be necessary for patients with Type IV fibrosis.

Meta-analysis: ribavirin-induced haemolytic anaemia in patients with chronic hepatitis C

AIM

To use meta-analysis to study the risk of anaemiarelated to ribavirin therapy for chronic hepatitisC.

METHODS

The MEDLINE database up to January 2001 was searched for randomized controlled trials of ribavirin (monotherapy or combined with interferon) for chronic hepatitis C. The outcomes evaluated were withdrawal from the study due to anaemia, ribavirin dosage reduction due to a decrease in haemoglobin and haemoglobin levels below 10 g/dL.

RESULTS

Based on 17 studies, the overall risk difference (ribavirin vs. no ribavirin) for anaemia was 0.09 [95% confidence interval (CI), 0.04-0.13]. Two Asian studies reported risk differences of 0.29 and 0.22, greater than the pooled risk difference of 0.07 (95% CI, 0.03-0.12) for 15 non-Asian studies. The risk associated with 1 g or more of ribavirin per day was higher (risk difference, 0.09; 95% CI, 0.04-0.14) than that for 0.8 g of ribavirin per day (risk difference, 0.01; 95% CI, - 0.04-0.06).

CONCLUSIONS

Chronic hepatitis C patients treated with 1 g or more of ribavirin per day were at a higher risk of developing anaemia. Reported risks were higher among Asian studies, which may be due to differences in study entrance criteria, dosage titration strategy or ethnic vulnerability.

Stresses at the cervical lesion of maxillary premolar--a finite element investigation

OBJECTIVES

The objective of this study was to use a three-dimensional (3-D) finite element model to investigate normal stress distribution to substantiate the tooth flexure mechanism. The study also compared the changes in the stresses by different occlusal loading sites and directions.

METHODS

The 3-D finite element analysis was used. A maxillary premolar was selected to construct the simulation model. The model was constructed step-by-step for convergence and validity. Seven load conditions for various load sites and different directions were simulated to the model.

RESULTS

The maximal principal stress and minimal principal stress distributions developed within the structures of seven load conditions were output and their stress distributions on z-plane at the vertical midline were shown. The peak tensile stress of the cervical area for various load conditions were compared and listed.

CONCLUSIONS

This study has shown that the presence of tensile stresses in the cervical region of a maxillary premolar by various loading sites and different directions. The results coincided with the stress-induced theory, hence sustaining it. The relationship of the affected factors of leverage to the development of cervical abfraction lesions, was explored.