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Biomedical subjects

C Ong

Publications and source records attributed to C Ong.

At least 19 recordsLinked to original sources
PubMed2006

Intrauterine lignocaine as an anaesthetic during endometrial sampling: a randomised double-blind controlled trial.

OBJECTIVE: To evaluate the effectiveness of intrauterine lignocaine as an anaesthetic during endometrial sampling. DESIGN: Prospective, randomised, double-blind, placebo-controlled trial. SETTING: Outpatient gynaecological minor operation unit in a public hospital. POPULATION: Two hundred premenopausal women scheduled for endometrial sampling because of abnormal uterine bleeding. METHODS: Transcervical intrauterine instillation of 5 mL of 2% lignocaine or 5 mL of normal saline before performing endometrial sampling with vacuum aspirator. MAIN OUTCOME MEASURES: Evaluation of pain associated with the procedure using a visual analogue scale. RESULTS: The use of intrauterine lignocaine reduced pain during suction curettage in endometrial sampling. CONCLUSIONS: Transcervical instillation of lignocaine reduced pain during endometrial sampling.

Adult↗
PubMed2005

Germ cell development in the descended and cryptorchid testis and the effects of hormonal manipulation.

Germ cell development is an active process in normal testes during the first 4 years after birth, with transformation of the neonatal gonocytes into adult dark spermatogonia and then primary spermatocytes. The hormonal regulation of these changes is not fully understood, with evidence both for and against a role for gonadotrophins and androgens. Early surgical intervention in infancy aims to prevent or reverse germ cell maldevelopment. Although hormonal treatment for maldescent has been shown to be ineffective, there is still controversy over whether it may be useful as an adjunct to surgery to stimulate germ cells. Current evidence suggests that hormonal therapy may not stimulate transformation of neonatal gonocytes but may trigger prepubertal mitosis of primary spermatocytes. Further studies are required to determine the role of hormone treatment on germ cell development.

Cell Transformation, Neoplastic↗
PubMed2005

Outbreak of cyclosporiasis in British Columbia associated with imported Thai basil.

Sporadic outbreaks of cyclosporiasis, a common cause of protracted diarrhoea in underdeveloped countries, are often undetected and undiagnosed in industrial countries. In May 2001, an outbreak of Cyclospora cayetanensis gastroenteritis was identified in British Columbia, Canada, with 17 reported cases. We conducted a case-control study involving 12 out of the 17 reported and confirmed case patients. Eleven (92%) of the patients had consumed Thai basil, an essential ingredient in Vietnamese cuisine, compared to 3 out of 16 (19%) of the control patients (P = 0.003). Trace-back investigations implicated Thai basil imported via the United States as the vehicle for this outbreak. This is the first documented sporadic outbreak of cyclosporiasis linked to Thai basil in Canada, and the first outbreak of cyclosporiasis identified in an ethnic immigrant population. This outbreak provides the opportunity to increase our understanding of this emerging pathogen and improve on our prevention and control for future outbreaks.

Adult↗
PubMed2004

LEKTI demonstrable by immunohistochemistry of the skin: a potential diagnostic skin test for Netherton syndrome.

BACKGROUND: Netherton syndrome (NS) is a rare autosomal recessive condition characterized by ichthyosiform erythroderma, trichorrhexis invaginata and atopic manifestations. Confirming the diagnosis may be difficult in the early stages. Mutations in the SPINK5 gene which encodes for the serine protease inhibitor LEKTI are associated with NS. These mutations create premature termination codons which result in absent or abnormal expression of LEKTI in patients with NS. OBJECTIVES: To investigate the expression of LEKTI in the skin of patients with NS in comparison with normal controls and patients with other skin conditions, namely atopic dermatitis, psoriasis and nonbullous ichthyosiform erythroderma. METHODS: Immunohistochemistry was performed on skin sections from four patients with NS, four normal controls, four with atopic dermatitis, two with psoriasis and two with nonbullous ichthyosiform erythroderma, using a primary rabbit polyclonal antibody against LEKTI. RESULTS: LEKTI was localized to the stratum granulosum in normal skin. All four skin sections from patients with NS showed absent or very reduced staining for LEKTI. Staining in the other disorders showed positive LEKTI expression in varying patterns. CONCLUSIONS: NS can be difficult to diagnose especially in the early stage, which can lead to inappropriate treatments particularly if it is misdiagnosed as atopic dermatitis. Immunohistochemistry of skin with an antibody against LEKTI is a potentially useful diagnostic test for NS.

Adolescent↗
PubMed2003

Blue fingers.

Explore the source record for details and available documents.

Aged↗
PubMed2002

The influence of timing and route of administration of intravenous ketorolac on analgesia after hand surgery.

A double-blind clinical trial was conducted on 47 patients scheduled for hand surgery under general anaesthesia to determine whether ketorolac given as part of an intravenous regional anaesthesia technique could provide better postoperative analgesia than ketorolac given intravenously either before or after surgery. Patients were randomly allocated to one of three groups to receive ketorolac 20 mg: intravenously in the non-operative arm before surgery (systemic presurgery group); intravenously to the operative arm after tourniquet inflation (regional presurgery group); intravenously in the non-operative arm after surgery (systemic postsurgery group). Postoperative pain scores were similar in the systemic presurgery and regional presurgery groups. The mean visual analogue summary pain score during the 24 h after surgery was 12.2 mm higher in the systemic postsurgery group than in the systemic presurgery group (95% CI: 0.8-23.7 mm, p = 0.037). There were no clinically important differences in mean postoperative visual analogue pain scores between the three study groups. There were no statistical differences in the mean postoperative morphine requirements between the three study groups. There is no benefit, in terms of improved postoperative analgesia, in giving ketorolac as an intravenous regional anaesthetic compared with systemic administration before surgery. The administration of ketorolac after surgery, rather then before, is not supported.

Analgesics↗
PubMed2001

Squamous cell carcinoma of the lip. Patterns of relapse and outcome: Reporting the Westmead Hospital experience, 1980-1997.

Australia has one of the highest rates of squamous cell carcinoma of the lip in the world. Despite a high cure rate, many studies report relapse rates of between 5% and 20% with an associated mortality of 5-10%. The aim of this study was to review the patterns of relapse and outcome for patients treated at Westmead Hospital, Sydney. Ninety-three eligible patients were identified in a retrospective review of all lip cancer patients referred to Westmead Hospital between 1980 and 1997. Relevant data were extracted from the treatment files and included contact with referring doctors and utilizing the Cancer Council Registry. Equal numbers of patients were treated with radiotherapy alone or surgery (+/- adjuvant radiotherapy). The majority of patients were male (78.5%) with T1N0 cancers (64.5%) of the lower lip. A minority (5.4%) had nodal disease at diagnosis. Following treatment, 31 (33.3%) patients relapsed, 11 at the primary site, 18 at the regional nodes and two at both sites simultaneously. Patients treated with a combined approach (RTx/Sx) experienced a better outcome. Overall cancer-specific survival at 5 years was 85%. These findings highlight a disturbing relapse rate and mortality for a subgroup of patients diagnosed with a more aggressive form of lip cancer. Treatment and follow up of these patients should accordingly be more aggressive.

Adult↗
PubMed2001

[The associations between concentration of selenium in semen and sperm parameters as well as oxidative DNA damage in human sperm].

OBJECTIVE: To explore the associations between concentrations of selenium (Se) in serum and semen and sperm parameters as well as oxidative DNA damage in human sperm. METHODS: Concentrations of selenium in serum and semen were determined using atomic absorption spectrophotometer (AAS). The sperm parameters were detected according to WHO laboratory manual for the examination of human sperm. The levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and deoxyguanosine (dG) in human sperm DNA were measured using HPLC-ECD and HPLC-UV. RESULTS: Mean semen concentration of selenium was significantly higher in fertile subjects (0.74 mumol/L) than that in infertile subjects (0.56 mumol/L), while there was no significant difference in serum concentrations of selenium between the two groups. Semen volume (3.91 ml vs. 2.79 ml), sperm density (46.4 x 10(9)/L vs. 36.5 x 10(9)/L) and sperm count (168.0 x 10(6) vs. 102.0 x 10(6)) were significantly higher in fertile subjects than those in infertile subjects. There was no significant difference in motility and viability of sperm, and proportion of deformity sperm between the two groups, Significantly positive correlation was observed between semen concentration of Se and sperm density (r = 0.48, P < 0.01 for fertile subjects and r = 0.32, P < 0.05 for infertile subjects) as well as sperm count (r = 0.32, P < 0.05 for fertile subjects and r = 0.26, P < 0.05 for infertile subjects), sperm motility (r = 0.46, P < 0.01 for fertile subjects and r = 0.65, P < 0.01 for infertile subjects) and viability (r = 0.33, P < 0.05 for fertile subjects and r = 0.64, P < 0.01 for infertile subjects). There was no correlation between serum Se concentrations and sperm parameters. Moreover, 8-OHdG levels in sperm DNA inversely correlated with semen Se concentrations in fertile (r = -0.21, P < 0.05) and infertile (r = -0.28, P < 0.05) subjects. However, no significant correlation was found between 8-OHdG levels in sperm DNA and serum Se concentrations in all subjects. CONCLUSIONS: Semen concentrations of Se were associated with sperm quality and 8-OHdG levels in human sperm. Serum concentrations of Se did not affect sperm quality and oxidative DNA damage in human sperm.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Dual role of glutathione in selenite-induced oxidative stress and apoptosis in human hepatoma cells.

It is well known that glutathione, the major intracellular antioxidant, is closely involved in the metabolism and bioactivity of selenium. In the present study, glutathione was demonstrated to play a dual role on selenite (Se)-induced oxidative stress and apoptosis in human hepatoma HepG(2) cells. The experiment was carried out in two different modes to modulate intracellular reduced glutathione (GSH) content. In Mode A (pretreatment), cells were pretreated with N-acetylcysteine (NAC), buthionine sulfoximine (BSO), or GSH prior to Se exposure. In Mode B (simultaneous treatment), cells were treated with Se and NAC, BSO, or GSH simultaneously. It was found that Se-induced oxidative stress and apoptosis are closely related to the intracellular level of GSH. Both the increase and depletion of GSH content significantly enhanced Se-induced oxidative stress and apoptosis in HepG(2) cells. Results from this study clearly demonstrated that GSH has a dual role in the effects of Se on cancer cells: (i) GSH acts as a pro-oxidant, facilitating Se-induced oxidative stress, and (ii) GSH acts as an antioxidant, protecting against Se-induced oxidative stress and apoptosis. Understanding such a unique association between GSH and Se may help to explain the controversy in the literature over the complex relationship between selenium and glutathione, and ultimately the capability of selenium to prevent cancer.

Acetylcysteine↗
PubMed2000

Detection of oxidative DNA damage in human sperm and its association with sperm function and male infertility.

The expanding research interest in the last two decades on reactive oxygen species (ROS), oxidative stress, and male infertility has led to the development of various techniques for evaluating oxidative DNA damage in human spermatozoa. Measurement of 8-hydroxydeoxyguanosine (8-OHdG) offers a specific and quantitative biomarker on the extent of oxidative DNA damage caused by ROS in human sperm. The close correlations of 8-OHdG level with male fertility, sperm function and routine seminal parameters indicate the potential diagnostic value of this technique in clinical applications. On the other hand, single cell gel electrophoresis (SCGE or comet assay) and terminal deoxynucleotidyl transferase (TdT) mediated dUTP nick end labeling (TUNEL) assay have also been demonstrated to be sensitive, and reliable methods for measuring DNA strand breaks in human spermatozoa. As certain technical limitations were inherent in each of these tests, it is believed that a combination of these assays will offer more comprehensive information for a better understanding of oxidative DNA damage and its biological significance in sperm function and male infertility.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

First trimester maternal serum AFP and total hCG in aneuploidies other than trisomy 21.

Total human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) were measured in maternal serum at 10-14 weeks of gestation from 53 pregnancies affected by trisomy 18, 42 cases with trisomy 13, 46 with Turner's syndrome and 13 with other sex aneuploides. The only significant association was the finding of reduced levels of total hCG in cases of trisomy 18 and 13. The association of increased levels of AFP in cases of trisomy 18 with ventral wall defects and the slight increase in AFP in cases of sex chromosomal anomalies other than Turner's syndrome was found. AFP and total hCG are not likely to replace the markers free beta-hCG and PAPP-A in first trimester screening for chromosomal anomalies.

Adult↗
PubMed2000

Serum CA125 at 11-14 weeks of gestation in women with morphologically normal ovaries.

In a number of pregnant women ovarian cysts are found incidentally during the routine first trimester scan. These cysts may pose diagnostic difficulties, and the measurement of serum CA125 levels can be used to aid management. In this study we measured maternal serum CA125 levels in 188 women with uncomplicated pregnancies between 11-14 weeks of gestation. All women had morphologically normal ovaries observed on ultrasound examination. The median serum CA125 levels were 23.4 U/mL (range 2.2-166.3 U/mL, 95% reference interval 5.28-70.15) and did not change significantly with gestation. We conclude that CA125 levels are increased at 11-14 weeks of gestation and cut off values which are used to assess the nature of ovarian cysts in nonpregnant women cannot be applied to pregnant women at this gestation.

Adolescent↗
PubMed2000

Screening for trisomy 13 by fetal nuchal translucency and maternal serum free beta-hCG and PAPP-A at 10-14 weeks of gestation.

In 42 cases of trisomy 13 at 10-14 weeks of gestation, compared with 947 controls, the median multiple of the median (MoM) of maternal serum free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy associated plasma protein A (PAPP-A) was significantly decreased (0.506 MoM and 0.248 MoM respectively), whilst fetal nuchal translucency was increased (2.872 MoM). In 38% and 71% of cases of trisomy 13 maternal serum free beta-hCG and PAPP-A was below the 5th centile of the appropriate normal range for gestation and in 62% of cases the nuchal translucency was above the 95th centile. When combined together in a multivariate algorithm with maternal age, 90% of cases of trisomy 13 could be detected at a 0.5% false positive rate or 84% at a 0.1% false positive rate. We conclude that specific trisomy 13 risks should be part of developing risk algorithms combining maternal serum biochemistry and nuchal translucency for use in first trimester screening alongside those for trisomy 21 and trisomy 18.

Adult↗
PubMed1999

Molecular cloning of the human gene, PNKP, encoding a polynucleotide kinase 3'-phosphatase and evidence for its role in repair of DNA strand breaks caused by oxidative damage.

Mammalian polynucleotide kinases catalyze the 5'-phosphorylation of nucleic acids and can have associated 3'-phosphatase activity, predictive of an important function in DNA repair following ionizing radiation or oxidative damage. The sequences of three tryptic peptides from a bovine 60-kDa polypeptide that correlated with 5'-DNA kinase and 3'-phosphatase activities identified human and murine dbEST clones. The 57.1-kDa conceptual translation product of this gene, polynucleotide kinase 3'-phosphatase (PNKP), contained a putative ATP binding site and a potential 3'-phosphatase domain with similarity to L-2-haloacid dehalogenases. BLAST searches identified possible homologs in Caenorhabditis elegans, Schizosaccharomyces pombe, and Drosophila melanogaster. The gene was localized to chromosome 19q13.3-13.4. Northern analysis indicated a 2-kilobase mRNA in eight human tissues. A glutathione S-transferase-PNKP fusion protein displayed 5'-DNA kinase and 3'-phosphatase activities. PNKP is the first gene for a DNA-specific kinase from any organism. PNKP expression partially rescued the sensitivity to oxidative damaging agents of the Escherichia coli DNA repair-deficient xth nfo double mutant. PNKP gene function restored termini suitable for DNA polymerase, consistent with in vivo removal of 3'-phosphate groups, facilitating DNA repair.

Amino Acid Sequence↗
PubMed1998

Anti-IL-4 treatment prevents dermal collagen deposition in the tight-skin mouse model of scleroderma.

The tight-skin (Tsk/+) mutant mouse, a putative murine model of scleroderma, is characterized primarily by the excessive deposition of collagen and other extracellular matrix molecules in the dermis, and also by a developmentally acquired defect in pulmonary architecture. Passive transfer experiments have suggested an etiologic role for the immune system in Tsk/+ dermal pathology. In addition, CD4+ T lymphocytes have been shown to be required for the excessive accumulation of dermal collagen in these mice. As IL-4, a product of differentiated CD4+ T cells, is capable of regulating the synthesis of various matrix molecules (including type I collagen) by fibroblasts in vitro, we investigated the potential role of IL-4 in mediating Tsk/+ dermal fibrosis. Confirming that Tsk/+ cells are capable of responding to IL-4, we found receptors for this cytokine on Tsk/+ embryonic fibroblasts and a dermal fibroblast cell line derived from these mice. Furthermore, IL-4 receptors on Tsk/+ fibroblasts were functional since IL-4 stimulation in vitro increased type I collagen secretion from these cells. These results demonstrated the potential for IL-4 to be directly involved in the excessive deposition of dermal collagen in Tsk/+ mice. Critical insight into the role played by IL-4 in mediating the dermal phenotype, however, was obtained following the administration of neutralizing anti-lL-4 antibodies to Tsk/+ mice. This treatment prevented the development of dermal fibrosis, leading to normalization of dermal collagen content. Given the requirement for CD4+ T cells in Tsk/+ dermal fibrosis, our results suggest that Th2 cells and/or factors elaborated by this T cell subset may play a key role in regulating dermal collagen content in this strain.

Animals↗
PubMed1998

Intra-abdominal and pelvic abscess in Crohn's disease: results of noninvasive and surgical management.

BACKGROUND: Intra-abdominal and pelvic abscesses occur in 10-30 per cent of patients with Crohn's disease. The aim of this study was to establish the clinical characteristics and outcome of patients admitted over a 4-year period with an abdominal or pelvic abscess secondary to Crohn's disease. METHODS: Patients with Crohn's disease-related intra-abdominal or pelvic abscess were identified from a prospectively collected database, comprising all admissions between 1991 and 1994. Medical records were reviewed retrospectively and data gathered regarding management and outcome. RESULTS: Thirty-six patients were identified with Crohn's disease-related abscess, of whom 15 were considered for initial percutaneous drainage. Drainage was technically possible in eight of these patients: it failed in four, gave good long-term results in two, and was followed by recurrence after 3 years in one and by later surgery unrelated to the abscess in one. Twenty-eight patients underwent surgery, with only four requiring a stoma. Complications occurred in 12 patients. At 3 months, 22 of the 36 patients were in remission. CONCLUSION: Crohn's intra-abdominal abscesses are associated with a high morbidity rate. Selected cases can be drained percutaneously, without adding to the morbidity, and sometimes resulting in abscess resolution.

Abdominal Abscess↗