Biomedical subjects

M W Wong

Publications and source records attributed to M W Wong.

At least 19 recordsLinked to original sources

PubMed2005

A work study of the CAD/CAM method and conventional manual method in the fabrication of spinal orthoses for patients with adolescent idiopathic scoliosis.

A study was conducted to compare the CAD/CAM method with the conventional manual method in fabrication of spinal orthoses for patients with adolescent idiopathic scoliosis. Ten subjects were recruited for this study. Efficiency analyses of the two methods were performed from cast filling/ digitization process to completion of cast/image rectification. The dimensional changes of the casts/ models rectified by the two cast rectification methods were also investigated. The results demonstrated that the CAD/CAM method was faster than the conventional manual method in the studied processes. The mean rectification time of the CAD/CAM method was shorter than that of the conventional manual method by 108.3 min (63.5%). This indicated that the CAD/CAM method took about 1/3 of the time of the conventional manual to finish cast rectification. In the comparison of cast/image dimensional differences between the conventional manual method and the CAD/CAM method, five major dimensions in each of the five rectified regions namely the axilla, thoracic, lumbar, abdominal and pelvic regions were involved. There were no significant dimensional differences (p < 0.05) in 19 out of the 25 studied dimensions. This study demonstrated that the CAD/CAM system could save the time in the rectification process and offer a relatively high resemblance in cast rectification as compared with the conventional manual method.

Adolescent↗

PubMed2001

Snapping during manual stretching in congenital muscular torticollis.

Manual stretching frequently is used in the treatment of congenital muscular torticollis in infants. During manipulation, it is not uncommon for the sternocleidomastoid muscle to snap or suddenly give way. The main objective of this study was to evaluate the predisposing causes and clinical significance of such snapping. Four hundred fifty-five patients younger than 1 year of age with congenital muscular torticollis treated with a standardized gentle manual stretching program during a 13-year period were studied. Using prospective standardized assessment parameters, the pretreatment, treatment, and followup results of a group of 41 patients with snapping detected during treatment were compared with the results of a group of 404 patients without snapping during treatment. The group with snapping was associated with a more severe sternomastoid tumor, higher incidence of hip dysplasia, earlier clinical presentation, and shorter duration of treatment. With a mean followup of 3.5 years, the group with snapping was not different from the group that had no snapping in the final assessment score and percentage requiring surgery. From this study, unintentional snapping during the gentle manipulation treatment of congenital muscular torticollis has clinical and ultrasonographic evidence of partial or complete rupture of the sternocleidomastoid muscle. No long-term deleterious effect on the outcome was observed after the snapping.

Female↗

PubMed2001

Clinical determinants of the outcome of manual stretching in the treatment of congenital muscular torticollis in infants. A prospective study of eight hundred and twenty-one cases.

BACKGROUND: The natural history of congenital muscular torticollis and the outcome of different treatment modalities have been poorly investigated, and the results of treatment have varied considerably. METHODS: The main objective of this prospective study was to evaluate the outcomes of 821 consecutive patients with congenital muscular torticollis who were first seen when they were less than one year old, were treated with a standardized program of manual stretching, and were followed for a mean of 4.5 years. Before treatment, the patients were classified into one of three clinical groups: (1) palpable sternomastoid tumor, (2) muscular torticollis (thickening and tightness of the sternocleidomastoid muscle), and (3) postural torticollis (torticollis but no tightness or tumor). RESULTS: Of the 821 patients, 452 (55%) had a sternomastoid tumor; 276 (34%), muscular torticollis; and ninety-three (11%), postural torticollis. Multivariate analysis of the outcomes showed that (1) the duration of treatment was significantly associated with the clinical group (p < 0.0001), a passive rotation deficit of the neck (p < 0.0001), involvement of the right side (p < 0.0001), difficulties with the birth (p < 0.009), and age at presentation (p < 0.0001); (2) the overall final assessment score was associated with the rotation deficit (p = 0.02), age at presentation (p = 0.014), and duration of treatment (p < 0.0001); and (3) subsequent surgical treatment was required by 8% (thirty-four) of the 452 patients in the sternomastoid tumor group compared with 3% (eight) of the 276 patients in the muscular torticollis group and 0% (none) of the ninety-three patients in the postural torticollis group. CONCLUSIONS: This large prospective study demonstrated that controlled manual stretching is safe and effective in the treatment of congenital muscular torticollis when a patient is seen before the age of one year. The most important factors that predict the outcome of manual stretching are the clinical group, the initial deficit in rotation of the neck, and the age of the patient at presentation. Surgical treatment is indicated when a patient has undergone at least six months of controlled manual stretching and has residual head tilt, deficits of passive rotation and lateral bending of the neck of >15 degrees, a tight muscular band or tumor, and a poor outcome according to our special assessment chart.

Age Factors↗

PubMed2001

Limb salvage in extensive diabetic foot ulceration-a preliminary clinical study using simple debridement and herbal drinks.

Diabetic patients frequently suffer from foot ulcer. In spite of the advances in treating many complicated diseases, amputation is usually the 'cure' for diabetic foot ulcer. Diabetic foot ulcer was treated in this study using Chinese herbal medicine and simple debridement as an alternative to amputation. Limb salvage was successful in 35 of 40 legs. These results encourage continuing research into the treatment of diabetic ulcer using Chinese herbal medicine.

Aged↗

PubMed2000

The clinical presentation and outcome of treatment of congenital muscular torticollis in infants--a study of 1,086 cases.

BACKGROUND/PURPOSE: The main objectives of this study were to define the clinical patterns and characteristics of congenital muscular torticollis (CMT) presented in the first year of life and to study the outcome of different treatment methods. METHODS: This is a prospective study of all CMT patients seen in 1 center over a 12-year period with uniform recording system, assessment methods, and treatment protocol. RESULTS: From a total of 1,086 CMT infants, 3 clinical subgroups of sternomastoid tumor (SMT; 42.7%), muscular torticollis (MT; 30.6%), and postural torticollis (POST; 22.1%) were identified. The SMT group was found to present earlier within the first 3 months and was associated with higher incidence of breech presentation (19.5%), difficult labor (56%), and hip dysplasia (6.81%). Severity of limitation of passive neck rotation range (ROTGp) was found to correlate significantly with the presence of SMT, bigger tumor size, hip dysplasia, degree of head tilt, and craniofacial asymmetry. CONCLUSIONS: A total of 24.5% of the patients with initial deficits of passive rotation of less than 10 degrees showed excellent and good outcome with active home positioning and stimulation program. The remaining cases with rotation deficits of over 10 degrees and treated with manual stretching program showed an overall excellent to good results in 91.1% with 5.1% requiring subsequent surgical treatment. The most important prognostic factors for the necessity of surgical treatment were the clinical subgroup, the ROTGp, and the age at presentation (P < .001).

Age Factors↗

PubMed2000

The relationship of physical trauma and surgical stress to menstrual dysfunction.

To evaluate the incidence and pattern of menstrual dysfunction in reproductive age group women suffering acute musculoskeletal trauma, 198 women between 15 and 50 years of age admitted consecutively into an acute orthopaedic unit were recruited over a 6-month period. The patients were then followed up for 6 months with menstrual diaries to compare their menstrual pattern with their preadmission status. Excluding those with significant menstrual problems before admission, the menstrual pattern remained normal in 135 (68%) (EM), while 12 (6%) developed polymenorrhoea (PM), and 51 (25%) had oligomenorrhoea or amenorrhoea (OAM) within the 6-month observation. The three groups did not differ in their mean age, body mass index, parity or age of menarche, but previous cycle lengths were shortest in the PM group (25.4 days, SD 7.64) (p<0.05) and history of amenorrhoea in the previous one year was most common in the OAM group (p<0.025). Univariate analysis showed the incidence of moderate to major trauma,operative treatment, longer operative time, general anaesthesia, blood transfusion and immobilisation were significantly higher in the PM and OAM groups compared to the unchanged group (p<0.05). A logistic regression model showed that general anaesthesia and longer surgical operations remained significantly related to the development of menstrual dysfunction. We conclude that the pattern of menstrual dysfunction after acute orthopaedic trauma appeared to be dictated by the woman's pre-existing menstrual characteristics and the stress of surgical treatment.

Adolescent↗

PubMed2000

The C282Y mutation of the HFE gene is not found in Chinese haemochromatotic patients: multicentre retrospective study.

OBJECTIVE: To detect two novel mutations (C282Y and H63D) of the HFE gene in Chinese patients with hepatic iron overload. DESIGN: Multicentre retrospective study. SETTING: Four public hospitals, Hong Kong. PARTICIPANTS: Fifty Chinese patients who presented from January 1987 through December 1999 with hepatic iron overload from various causes. MAIN OUTCOME MEASURES: The DNA from liver biopsy samples was tested for HFE mutations by restriction fragment length polymorphism analysis. RESULTS: The sample DNA quality was unsatisfactory for analysis of the C282Y mutation in one case and the H63D mutation in nine cases. The C282Y mutation was not detected in any of the 49 satisfactory samples. Three of the 41 samples were heterozygous for the H63D mutation and only one was homozygous, giving an allele frequency of 6.1%. Of the three H63D-heterozygotes, one had beta-thalassaemia major, one had beta-thalassaemia minor, and one had hereditary spherocytosis. None of the 12 patients who were presumed to have primary haemochromatosis were positive for either mutation. CONCLUSIONS: The classical form of human leukocyte antigen-linked hereditary haemochromatosis appears to be absent form this locality. The H63D mutation is found in a minority (9.8%) of the patients, in whom it may act synergistically with an erythropoietic factor.

Adolescent↗

PubMed2000

Hormonal predisposition to menstrual dysfunction in collegiate dance students.

OBJECTIVE: To evaluate the effect of dance training on menstrual function in teenage dance students and to identify risk factors associated with menstrual dysfunction. METHODS: Dance students from a collegiate school of performing arts were recruited when they were first admitted to the school. Basic epidemiological data and menstrual history were gathered using a structured questionnaire. The subjects' self image appraisal was scored utilizing the Offer Self Image Questionnaire. Anthropometric measurements, body fat percentages and hormonal profiles were measured. The subjects were followed up after 12 months of intensive dance training, and the menstrual pattern, self image scoring and fat composition assays were repeated. RESULTS: A total of 50 students completed the study. The mean age was 18.9 years (s.d. 1.86). While all were eumenorrheic at first assessment, eight were amenorrheic and eight were oligomenorrheic at the second assessment, giving an incidence of menstrual dysfunction of 32%. A general reduction in weight and body fat composition was observed after training. Those with menstrual dysfunction did not differ from those that remained eumenorrheic in their basic anthropometric parameters, nor was the serial change in these parameters in the second assessment different between the two groups. Psychological assessment scores also showed an identical trend. All hormonal values were within the normal range, but the group with menstrual dysfunction showed a significantly higher LH/FSH ratio (p=0.012) and DHEAS levels (p=0.036) at the pre-training assessment while other hormonal parameters did not differ. CONCLUSION: The incidence of menstrual dysfunction in adolescent dance students undergoing intensive training was high. Those with pre-existing hormonal predisposition prior to entering training appeared particularly at risk.

Adolescent↗

PubMed1998

The large subunit of basal transcription factor SNAPc is a Myb domain protein that interacts with Oct-1.

The human RNA polymerase II and III snRNA promoters have similar enhancers, the distal sequence elements (DSEs), and similar basal promoter elements, the proximal sequence elements (PSEs). The DSE, which contains an octamer motif, binds broadly expressed activator Oct-1. The PSE binds a multiprotein complex referred to as SNAPc or PTF. On DNAs containing both an octamer site and a PSE, Oct-1 and SNAPc bind cooperatively. SNAPc consists of at least four stably associated subunits, SNAP43, SNAP45, SNAP50, and SNAP190. None of the three small subunits, which have all been cloned, can bind to the PSE on their own. Here we report the isolation of cDNAs corresponding to the largest subunit of SNAPc, SNAP190. SNAP190 contains an unusual Myb DNA binding domain consisting of four complete repeats (Ra to Rd) and a half repeat (Rh). A truncated protein consisting of the last two SNAP190 Myb repeats, Rc and Rd, can bind to the PSE, suggesting that the SNAP190 Myb domain contributes to recognition of the PSE by the SNAP complex. SNAP190 is required for snRNA gene transcription by both RNA polymerases II and III and interacts with SNAP45. In addition, SNAP190 interacts with Oct-1. Together, these results suggest that the largest subunit of the SNAP complex is involved in direct recognition of the PSE and is a target for the Oct-1 activator. They also provide an example of a basal transcription factor containing a Myb DNA binding domain.

Amino Acid Sequence↗

PubMed1997

Association between body composition and menstrual dysfunction in collegiate dance students.

OBJECTIVE: To evaluate the relationship between body mass index, body fat composition and fat distribution and menstrual dysfunction in collegiate dancing students. METHOD: A total of 64 dancing students from a collegiate school of dancing were studied through interview by a structured questionnaire to elicit details of menstrual history, and these were correlated to anthropometric measurements obtained by physical examination. RESULTS: There were 22 ballerinas, 16 classic Chinese dancers, and 26 modern or theatrical dancers. Ten (15.6%) had oligomenorrhoea and 12 (18.7%) had amenorrhoea, with a slight, but statistically non-significant preponderance of ballerinas in the amenorrhoeic group. There was no difference in the body mass index among the eumenorrhoeic, oligomenorrhoeic or amenorrhoeic group, but amenorrhoeic dancers had a significantly lower percentage of total body fat as calculated by a 4 site skinfold thickness formula when compared to eumenorrhoeic ones (15.72% vs 17.95%, p < 0.05). Amenorrhoeic dancers also had lower waist to hip (p < 0.001) and waist to thigh circumference ratios (p < 0.001), indicating that they had more feminine figures favoured aesthetically for dancers. CONCLUSION: The data suggests that estimation of percentage of body fat gave a better correlation to menstrual status than either weight or body mass index. Thus, proper nutritional advice based on such evaluation should be an essential component in treating menstrual dysfunction in these dancers.

Adipose Tissue↗

PubMed1996

Kyphoscoliosis complicating pregnancy.

OBJECTIVE: To assess whether the outcome of pregnancies complicated by kyphoscoliosis has improved with modern obstetric and orthopedic care. METHODS: A total of 17 patients with 27 pregnancies complicated by kyphoscoliosis were identified from 91,498 pregnancies between 1980 and 1994 from the obstetric audit database. Their obstetric records and associated orthopedic records were carefully studied. RESULTS: The incidence of kyphoscoliosis complicating pregnancy in the study period was 0.029%. The mean age of these patients in their index pregnancy was 32.7 years (range 23-40), mean height 140.7 cm (range 126-163). The cause of the kyphoscoliosis included traumatic injury, spinal tuberculosis, infantile poliomyelitis and idiopathic kyphoscoliosis. Eight of the patients had previous spinal surgery. The vaginal delivery rate was high and none suffered any cardiorespiratory embarrassment. There was no maternal or perinatal mortality. CONCLUSIONS: The high maternal and perinatal risks associated with kyphoscoliosis reported in earlier literature is no longer valid. The high proportion of patients who had previous spinal surgery before pregnancy might be conducive to the avoidance of harassment and thus a favorable pregnancy outcome.

Adult↗

PubMed1995

The effect of dance training on menstrual function in collegiate dancing students.

A total of 98 dancing students from a collegiate school of dancing were studied through interview using a highly structured questionnaire to elicit details of the duration and intensity of dance training, menstrual patterns and musculoskeletal injuries sustained during training; 70 (72%) of these dancing students were eumenorrhoeic, while 15 (15.4%) had oligomenorrhoea. Thirteen (13.4%) either had amenorrhoea for over 90 days at the time of the study, or were on hormonal treatment because of amenorrhoea for over 3 months in the past 1 year. Those who were amenorrhoeic had longer training hours per week when compared with eumenorrhoeic and oligomenorrhoeic students. Both oligomenorrhoeic and amenorrhoeic students had a lower body mass index (18.25 kg/m2 and 18.26 kg/m2 versus 19.45 kg/m2, p < 0.01), and a higher incidence of musculoskeletal injuries and chronic orthopaedic problems compared to eumenorrhoeic ones. Ballet students had a higher incidence of menstrual dysfunction and musculoskeletal injuries as compared to classic Chinese dance, modern dance and musical theatre dance students as well as a significantly lower average body mass index. These data suggest a proportional correlation between menstrual dysfunction and proneness to musculoskeletal injuries in training, which could be explained by a hormonal mechanism.

Adult↗

PubMed1994

Activation of Xenopus MyoD transcription by members of the MEF2 protein family.

Members of the MEF2 family of DNA binding proteins interact with a set of AT-rich sequences commonly found in the promoters and enhancers of muscle-specific genes. We have shown that a MEF2 binding site precisely overlaps the TFIID binding site (TATA box) in the Xenopus MyoDa (XMyoDa) promoter and appears to play an important role in muscle-specific activity of this promoter. To further investigate the potential role of MEF2 in the regulation of XMyoDa transcription, we have analyzed the appearance of factors that interact with the XMyoDa TATA/MEF2 site during early amphibian development. Proteins that bind specifically to this site were present at low levels during early development and increased in abundance during gastrulation and neurulation. Two related cDNAs were isolated that encode proteins that recognize the XMyoDa TATA motif. Both proteins are highly homologous to each other, belong to the MADS (MCM1 agamous deficiens SRF) protein family, and are most highly related to the mammalian MEF2A gene products. Xenopus MEF2A (XMEF2A) transcripts accumulated preferentially in forming somites after the appearance of XMyoD transcripts. Ectopic expression of XMEF2A and other members of the MEF2 gene family activated transcription of a reporter gene controlled by the XMyoDa promoter. Transcriptional activation of the XMyoDa promoter required only the conserved DNA binding domain of XMEF2A and was independent of a domain necessary for activity when this factor was bound to multiple upstream sites. These results suggest that the XMyoDa promoter can be activated by binding of MEF2 to the XMyoDa TATA motif and indicate that MEF2-dependent transcriptional activation occurs by different mechanisms depending on the location of the MEF2 binding site. We suggest that XMEF2 expression in myogenic cells contributes to the activation and stabilization of XMyoDa transcription during muscle cell differentiation.

Amino Acid Sequence↗

PubMed1994

Binding of TFIID and MEF2 to the TATA element activates transcription of the Xenopus MyoDa promoter.

Members of the MyoD family of helix-loop-helix proteins control expression of the muscle phenotype by regulating the activity of subordinate genes. To investigate processes that control the expression of myogenic factors and regulate the establishment and maintenance of the skeletal muscle phenotype, we have analyzed sequences necessary for transcription of the maternally expressed Xenopus MyoD (XMyoD) gene. A 3.5-kb DNA fragment containing the XMyoDa promoter was expressed in a somite-specific manner in injected frog embryos. The XMyoDa promoter was active in oocytes and cultured muscle cells but not in fibroblasts or nonmuscle cell lines. A 58-bp fragment containing the transcription initiation site, a GC-rich region, and overlapping binding sites for the general transcription factor TFIID and the muscle-specific factor MEF2 was sufficient for muscle-specific transcription. Transcription of the minimal XMyoDa promoter in nonmuscle cells was activated by expression of Xenopus MEF2 (XMEF2) and required binding of both MEF2 and TFIID to the TATA motif. These results demonstrate that the XMyoDa TATA motif is a target for a cell-type-specific regulatory factor and suggests that MEF2 stabilizes and amplifies XMyoDa transcription in mesodermal cells committed to the muscle phenotype.

Animals↗

PubMed1993

The Johnson antishear device and standard shin pad in the isokinetic assessment of the knee.

Isokinetic training and assessment of the knee joint has been the mainstay of rehabilitation, especially in patients with anterior cruciate ligament deficiency. Besides the original shin pad used, the antishear device was introduced by Johnson in 1982. This device has been shown biomechanically to prevent excessive anterior translation of force on the tibia during training. However, there is a need to compare the antishear device and the standard shin pad in the isokinetic assessment. Hence, the major objective of this study is to define, if any, the difference in patient assessment between the new double pad device and the old single shin pad. Ten subjects with no previous history of injury on either knee were tested with the Cybex Isokinetic Dynamometer. There were four men and six women and the mean age was 25.2 years. They were randomized into different test sequences with different shin pads at different speeds. Correlation and paired t tests (P) were performed to find out the correlation and difference between the two devices. There was significant difference in performance assessment between the two devices in knee extension (P < 0.05) but no significant difference in knee flexion (P > 0.05). There was also a high correlation (r > 0.75) between the two devices. It is concluded that because of the significant difference of data generated between the two devices, it is important to select one single device with each patient during a series of testings.

Adult↗

PubMed1991

Cloning and sequencing of the grass carp (Ctenopharyngodon idellus) growth hormone gene.

An enriched lambda gt11 library for screening the grass carp (Ctenopharyngodon idellus) growth hormone gene was constructed using HindIII digested genomic DNA extracted from the spleen of the fish. Probing this library with a homologous cDNA, a clone carrying the growth hormone gene was obtained. The gene is 2501 bp long and consists of five exons and four introns. The sequence of nucleotide in the exons is almost identical to that of the cDNA except for ten positions. Analysis of the 5' sequence up to 1220 bp from the +1 position reveals the presence of a TATA box as well as a number of consensus regulatory sequences. Comparison of the grass carp growth hormone gene with those of other fish indicates that there is a high degree of homology with the gene from the common carp but not with those from the rainbow trout and Atlantic salmon.

Animals↗

PubMed1988

Laboratory and field assessment of molluscicidal activity of B-2 against Oncomelania hupensis, the vector snail of schistosomiasis in China.

Molluscicidal activity of B-2 (sodium 2,5-dichloro-4-bromophenol; called as Phebrol and registered in WHO as OMS 3012) was evaluated in a laboratory and the field trials were performed in two different localities in Yueyang city, China, for control of Oncomelania hupensis. B-2 was effective against O. hupensis both in the laboratory and in the field. A dosage of 50 g/m2 in 10% granular form or 20 ml/m2 in 25% liquid form of B-2 would be recommendable as a standard mollusciciding dose for control of O. hupensis.

Animals↗

PubMed1986

Effect of protein on glomerular filtration rate and prostanoid synthesis in normal and uremic rats.

Normal and uremic conscious rats that had been maintained on a low-protein diet were given oral protein or carbohydrate loads, and clearance studies were performed. Both the normal and uremic animals demonstrated a approximately 30% increase in glomerular filtration rate (GFR) in response to the protein bolus, but no significant increase in GFR was seen following the carbohydrate bolus. Similar studies were performed in uremic rats on a standard protein diet. The changes in GFR that were seen after an albumin bolus were similar but not as pronounced as those noted in the animals on the low-protein diet. Pretreatment with either aspirin or meclofenamate, cyclooxygenase inhibitors, completely blocked the protein-induced rise in GFR. The rats of glomerular production of prostaglandin (PG) E2 and 6-keto-PGF1 alpha (a stable metabolite of prostacyclin, PGI2) were determined by radioimmunoassay in a similar group of normal rats. The synthetic rates of PGE2 and 6-keto-PGF1 alpha following the protein bolus were 40 and 52% greater, respectively, than those observed following the carbohydrate load (P less than 0.005). Aspirin decreased glomerular prostanoid production in protein-treated animals by greater than 60%. Thus it appears that in the setting of protein restriction, the percent increase in GFR following a protein load is similar in both the normal and uremic rats, the increase in GFR in uremic rats is attenuated when animals were allowed to ingest a normal protein diet prior to study, and the increase in GFR seen in response to a protein load may be related to an increase in the synthesis of one or more vasodilatory glomerular prostanoids.

Animals↗