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Biomedical subjects

K M Chan

Publications and source records attributed to K M Chan.

At least 145 records · Page 8Linked to original sources
PubMed1997

Zinc toxicity following massive coin ingestion.

This is the first reported case of human fatality associated with zinc intoxication following a massive ingestion of coins. Four hundred and sixty-one coins were removed form the gastrointestinal tract of a schizophrenic patient during the course of hospitalization. Many of the post-1981 pennies, which consist primarily of zinc, showed severe corrosion due to their prolonged contact with acidic gastric juice. The patient presented with clinical manifestations consistent with the local corrosive as well as systemic effects of zinc intoxication and died 40 days after admission with multi-system organ failure. Tissue samples of the kidneys, pancreas, and liver obtained at autopsy revealed acute tubular necrosis, mild fibrosis, and acute massive necrosis, respectively, and contained high levels of zinc. The overall effects of zinc intoxication on the various organ systems, possible hematological derangement, and the impairment of copper absorption as well as the outcome with treatment are discussed.

Bilirubin↗
PubMed1997

Ender nailing for ipsilateral femoral shaft fractures after Austin-Moore hemiarthroplasty.

BACKGROUND: The management of ipsilateral femoral shaft fractures after hemiarthroplasty is controversial. METHODS: Fifteen patients (average age 82.4 +/- 8 years) with ipsilateral femoral shaft fractures after uncemented hemiarthroplasty were treated by closed reduction and Ender nailing. Under radiographic control, closed reduction was attempted. If not possible, cerclage of the shaft fracture was accomplished through a limited lateral approach. Ender nails were then inserted well past the tip of the stem of the prosthesis. RESULTS: There were a superficial wound infection and a deep vein thrombosis. At 6 months, five patients had died, and backing out of the nails necessitated removal in one patient. At 1 year, nine patients were still alive. Of these, seven were able to walk with aids. At 2 years, seven patients were still alive and were walking with aids. Two patients presented shortening of more than 1.5 cm of the operated femur. After an average of 5 years, 11 patients were dead, two were still walking, and two were bedridden. CONCLUSIONS: The technique described is an option in the treatment of fractures of the ipsilateral femoral shaft after uncemented hemiarthroplasty.

Aged↗
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↗
PubMed1997

Relationship between isokinetic concentric and eccentric contraction modes in the knee flexor and extensor muscle groups.

We investigated whether in normal subjects isokinetic concentric and eccentric strength variables were related in order to have a better picture in relation to rehabilitation and possible injury prevention. We studied the relationship between isokinetic concentric and eccentric peak torque, total work, and average power of knee extension and knee flexion at 60 degrees/sec and 120 degrees/sec in 42 young Chinese adults (22 males, age = 27 +/- 6.9 years; 20 females, age = 24.9 +/- 5.05 years) using the Cybex 6000 isokinetic dynamometer. Repeated analysis of covariance was used to compare the means between concentric and eccentric variables adjusted by limb dominance, speed of testing, and the muscle groups tested. A highly significant correlation was found between all concentric and eccentric variables, with correlation coefficients (r) ranging from 0.67 to 0.93. All but two of the eccentric variables were significantly greater than the concentric variables. Concentric and eccentric knee flexion to knee extension (H:Q) ratios were poorly correlated, with r ranging from 0.359 to 0.645. Although there is an acceptably high correlation between isokinetic concentric and eccentric strength variables of knee flexion and extension in young healthy individuals, we recommend measuring concentric and eccentric strength to plan a proper rehabilitation program and to assess muscle groups in a given contraction mode.

Adult↗
PubMed1997

Effect of basic fibroblast growth factor. An in vitro study of tendon healing.

The effect of basic fibroblast growth factor on the proliferative and chemotactic response of cultured rat patellar tendon fibroblasts was studied in an in vitro wound closure model. In quiescent confluent fibroblast culture, a uniform cell free zone, or wound, was generated mechanically as an in vitro wound. The width of the cell free zone was measured at 0, 6, 12, and 24 hours after the injury, in the presence of 0, 2, 10, or 50 mg/mL of basic fibroblast growth factor. Basic fibroblast growth factor, at a concentration of 10 ng/mL, significantly accelerated wound closure, resulting in almost complete closure by 24 hours after the injury. Basic fibroblast growth factor, at a concentration of 2 ng/mL, significantly enhanced cell proliferation as estimated by 5-Bromo-2'-deoxyuridine incorporation, but increasing the concentration of the growth factor to 50 ng/mL did not show additional improvement. Thus, the enhancement of wound closure by basic fibroblast growth factor may be caused by the cell proliferative response, rather than by chemotaxis.

Animals↗
PubMed1997

The enzymic potential of tissue kallikrein (rK1) in rat submandibular saliva depends on whether it was secreted via constitutive or regulated pathways.

The enzymic activity and immunoreactivity of rat tissue kallikrein (rK1) secreted at rest by granular duct cells of unstimulated submandibular glands has been compared with that secreted on autonomic nerve stimulation. Although a direct vesicular, constitutive secretory pathway operates for rK1 secretion from granular duct cells of unstimulated and parasympathetically stimulated glands the rK1 was not present in a pro-form and actually showed a greater enzymic activity per unit immunoreactive protein than the granule-derived rK1 in sympathetically evoked saliva. Constitutively secreted rK1 was found to be in a single chain molecular form by reducing SDS gel electrophoresis. In contrast rK1 secreted from the storage granule pool of granular duct cells on sympathetic nerve stimulation was present in much higher amounts and occurred in both one-chain and two-chain forms as revealed by SDS gel electrophoresis under reducing conditions. The lower enzymic potential of rK1 in sympathetically evoked saliva might be accounted for by its conversion to a two-chain form.

Animals↗
PubMed1997

Epidemiology of falls among the elderly community dwellers in Singapore.

AIM: Falling is a serious medical problem for elderly persons. This study was done to look at prevalence and risk factors for falls in community dwelling elderly in Singapore. METHOD: A random sample of 3,000 persons aged 60 years and above was chosen from a database based on the 1990 population census. Letters were sent out to 2,582 subjects who had local and complete addresses. In the letter, they were informed about the purpose of the survey, and invited to participate in a questionnaire and clinical health screening at an appointed date at a polyclinic. Participants were reminded the day before their appointment by telephone, and a new appointment could be given at the subject's convenience. RESULTS: We found a prevalence rate of falls of 17.2%. Two-thirds of these had single falls, while one-third had recurrent falls, defined as having more than one fall within the previous one year. The following factors were found to be significantly associated with increase falling in the elderly: age > or = 75 years (O.R. = 1.82, 95% C.I. 0.95-3.50), female sex (O.R. = 2.5, 95% C.I. 1.40-4.48), Malay race (O.R. = 2.66, 95% C.I. 1.21-5.86), poor vision (O.R. = 1.7, 95% C.I. 0.99-2.90), Barthel's score of less than 20 (O.R. = 1.76, 95% C.I. 0.94-3.28), those taking 2 or more drugs daily (O.R. = 2.1, 95% C.I. 1.22-3.72) and the presence of hypertension (O.R. = 1.78, 95% C.I. 1.06-3.01). Fall rate is also twice as high in women as in men. At the same time, we found that women in the group we studied also tend to exercise less than the men. Fallers also had significantly more mobility and activities of daily living (ADL) disabilities (reflected by a lower Barthel's score) and this is consistent with other results. The only factor that reduced the risk of falling was regular exercise (O.R. = 1.64, 95% C.I. 0.93-2.93). CONCLUSION: In our study, we found differences between the group with single and recurrent falls. In the group with single falls, the fall tend to occur outdoors (O.R. = 2.97, 95% C.I. 1.03-8.60) and during the day (O.R. = 3.47, 95% C.I. 1.20-10.0), tend to be accidental (O.R. = 3.16, 95% C.I. 1.05-9.50) and tend to seek medical attention (O.R. = 3.68, 95% C.I. 1.23-11.0). Overall, 32 persons (46.4%) seek medical treatment after their falls, and of these, 65.6% were women. Risk factors for falls should be screened for all elderly.

Accidental Falls↗
PubMed1996

Identification of two prolactin cDNA sequences from a goldfish pituitary cDNA library.

We have identified two different cDNA clones encoding for goldfish prolactin (gfPRL) from a pituitary cDNA library. The coding regions of these clones are predicted to encode for an identical amino acid (aa) sequence with four silent mutations. The 3'-untranslated regions (UTRs) of these clones show only 72% nucleotide (nt) sequence identity. The two genes each encoding gfPRL might have derived from recent gene duplication before the divergence of goldfish from other Cypriniforms. Genomic Southern blot analysis of goldfish DNA also demonstrated that there is a small family of two genes for prolactin in the genome of goldfish.

Amino Acid Sequence↗
PubMed1996

Isolation and characterization of two distinct growth hormone cDNAs from the goldfish, Carassius auratus.

As a first step toward the development of a ribonuclease protection assay for studying the regulation of growth hormone (GH) gene expression in pituitary cells of the goldfish, Carassius auratus, we report the isolation of two cDNA clones encoding goldfish GH from a cDNA library prepared from pituitary poly(A)+ RNA. The complete nucleotide sequences of these two GH cDNA clones have been determined and both of them were predicted to encode a polypeptide of 210 amino acids (aa) including a putative signal peptide of 22 aa. One of the GH cDNAs encodes a polypeptide (gfGHI) with five cysteine residues (similar to other carp Ms), whereas another encodes a polypeptide (gfGHII) with four cysteine residues (similar to most teleostean GHs). Because these two GH cDNAs have distinct nucleotide sequences at their coding and 3' untranslated regions, they are likely to be encoded by two different genes.

Amino Acid Sequence↗
PubMed1996

Iliopsoas haematoma in an adolescent Taekwondo player.

A 16-year-old male Taekwondo player was admitted with a 1-day history of right groin pain and a palpable mass in the right lower abdominal quadrant following a Taekwondo training session. No history of direct trauma was given, but the pain followed a high inward-to-outward kick. The patient was not on any medication, and tumour and infection were excluded. A high-resolution real-time ultrasound scan identified a well-defined, hyperechoic, heterogeneous mass in the substance of the right iliopsoas muscle, compatible with a collection of partially clotted blood, confirming the clinical diagnosis of iliopsoas haematoma. After conservative treatment the patient resumed training and is now fully asymptomatic.

Adolescent↗
PubMed1996

Neurotrophin-4/5 treatment reduces infarct size in rats with middle cerebral artery occlusion.

The aim of this study was to determine whether neurotrophin-4/5 (NT-4/5) treatment alters infarction volume following permanent focal cerebral ischemia in the rat. Permanent focal cerebral ischemia was produced in adult male rats by intraluminal occlusion of the right middle cerebral artery. NT-4/5 was administered intraventricularly one day before and immediately following occlusion. Rats were sacrificed at 1, 4 and 7 days after occlusion. NT-4/5 treatment reduced infarction volume by 34% when compared to control rats 1 day after occlusion. Infarction volume was unaltered by treatment 4 to 7 days after occlusion. Middle cerebral artery occlusion led to a significant reduction in levels of mRNAs coding for catalytic and truncated TrkB receptors. This expression was unaffected by NT-4/5 treatment.

Animals↗
PubMed1996

Magnetic resonance imaging in coccidioidal arthritis.

OBJECTIVE: The authors assessed the MRI findings of appendicular coccidioidal arthritis. DESIGN: T1- and T2-weighted MR images of affected joints, both with and without intravenous gadopentetate dimeglumine, were performed in nine adult patients (ten studies) and evaluated by three masted readers, using a four-point certainty scale for: synovial abnormality, articular cartilage loss, subarticular bone loss, abnormal marrow signal, enhancement of osseous and articular structures, and assessment of disease activity. Findings were correlated with biopsy results or clinical course. RESULTS: Eight patients had active and one had inactive arthritis, involving the knee (five patients), ankle (two patients), and elbow (one patient). Synovial complex was the most common finding in active arthritis (P < 0.025). Cartilage and subarticular bone loss were seen 56% and 89% of patients with active disease, respectively. Abnormal marrow signal was uncommon (two patients). All cases showed synovial and/or osseus enhancement. CONCLUSIONS: MRI findings in coccidiodal arthritis are described. Enhancement of thickened synovium and erosions was seen after intravenous gadopentetate.

Adult↗
PubMed1996

Shoulder instability in athletes. The Asian perspective.

Recently, there has been an upsurge of interest among the orthopaedic sports medicine community in Asia on this subject of athletic shoulder instability. This is particularly prominent in countries such as Japan, Korea, Taiwan, and Hong Kong, where sports requiring throwing and overhead use of the upper limb are popular. In this review, the classification of the condition is analyzed with a specific account of the rotator interval injury. A systematic plan of clinical assessment is presented highlighting the specific regional considerations in clinical practice and cost-effectiveness of the health care systems in Asia. The management of athletic shoulder instability depends on patient attitude and cultural background. In Asia, the popular choice of Bankart repair with capsular shift procedure is presented with special reference to the unique experience of multidirectional and habitual posterior instability. Arthroscopic surgery is becoming popular in Asia, and the indications and limitations of the technique in the management of shoulder instability are discussed.

Arthroscopy↗
PubMed1996

Noninfectious pulmonary complications after organ transplantation.

Organ transplantation is a successful and recognized option for patients with end-stage pulmonary, cardiac, hepatic, renal, and hematologic disease. As with any new technology, however, a set of complications has developed in the form of lung injury after transplantation as a result of ischemic, chemotherapeutic, radiation-induced, and immunologic damage to the lungs. Interstitial changes soon after transplantation are typically due to pulmonary edema, the adult respiratory distress syndrome, and reperfusion injury or allograft rejection (in the case of lung transplantation). Late pulmonary injury presents as obliterative bronchiolitis and lymphoproliferative disease. Bone marrow transplant recipients are unique because they develop the idiopathic pneumonia syndrome, diffuse alveolar hemorrhage, pulmonary venoocclusive disease, and graft-versus-host disease. New insights about these interstitial syndromes are the subject of this review.

Adult↗
PubMed1996

Bilateral lobar transplantation utilizing living related donors.

As the recipient list for patients requiring lung transplantation continues to increase, cadaveric donor lung availability has remained static. Our experience with utilizing lobes from living related donors for bilateral pulmonary transplantation in 20 patients has yielded a 75% survival at 1 year follow-up. Morbidity and mortality have been predominately due to infection. Rejection episodes have been mild and unilateral and have responded to augmented corticosteroids. Pulmonary function tests in the recipients tend to improve steadily during the first year postoperatively, and the patients have excellent functional capacity. There have been no significant complications in the donors. On the basis of our clinical experience, we have found that bilateral lobar transplantation utilizing living related donors has resulted in organ availability that can be lifesaving in critically ill patients and can provide a good alternative in certain noncritical, deteriorating patients.

Adolescent↗