Libido, sexuality and the levonorgestrel IUS in Malaysia.
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Adolescent↗
Biomedical subjects
C Y Wong
Publications and source records attributed to C Y Wong.
Pulmonary haemorrhage in a patient with Kikuchi disease.
Kikuchi disease is an immunologic disease and most commonly presents with cervical lymphadenopathy. It is usually self-limiting [1]. It is sometimes associated with systemic lupus erythematosus (SLE) [2], and can be associated with many complications including aseptic meningitis, neuropathy, brachial neuritis. It can also be associated with lymphoma, and may sometimes be misdiagnosed as such [3]. The following is the first reported case of Kikuchi disease associated with pulmonary haemorrhage. The patient died and no other cause of the pulmonary haemorrhage could be identified at post mortem.
Adult↗
Treating pulmonary TB. Revisiting an old problem.
BACKGROUND: There is a resurgence of pulmonary tuberculosis worldwide, due to increase in air travel, decrease in resources in health control, as well as the AIDS pandemic. As pulmonary tuberculosis was not common in Australia, family physicians are facing a new challenge. The following is to highlight some principles in tuberculosis treatment. OBJECTIVE: This article revisits some of the basic principles of treatment of tuberculosis in order to maximise management. DISCUSSION: The tubercle bacillus has been capable of developing resistance to antituberculosis drugs for some time, making multiple drug therapy mandatory. Antituberculosis drugs on the other hand can be toxic and commonly cause gastro-intestinal upset. The patient has to take many tablets a day for many months. By informing patients of the side effects, compliance, which is the key issue to successful therapy, is enhanced.
Antitubercular Agents↗
Impact of inadequate fine-needle aspiration cytology on outcome of patients with palpable breast lesions.
BACKGROUND: The purpose of the present study was to assess the impact of inadequate fine-needle aspiration cytology (FNAC) breast specimens on the outcome of patients with a palpable breast lesion. METHODS: A retrospective review was carried out of inadequate FNAC specimens from the Department of General Surgery, Singapore General Hospital in 1997. RESULTS: One hundred and thirty-eight (16.6%) of 831 FNAC specimens were reported inadequate, and these form the study group. Outcome analysis was divided into benign on excision biopsy (n = 38; 29.4%); benign on repeat FNAC or trucut biopsy (n = 6; 4.7%); benign on follow up (n = 46; 35.7%); malignant on histology (n = 11; 8.5%); and lost to follow up (n = 28; 21.7%). The 11 cases with breast cancer were further analysed. The mean time to treatment was 88.3 days for three patients whose tumours were not clinically suspicious of malignancy versus 20 days for six patients who were diagnosed with cancer clinically from the onset. One patient with cancer refused treatment and one absconded from treatment only to return 7 months later. CONCLUSION: Breast cancer was present in 8.5% of the inadequate FNAC specimens. When clinical suspicion of malignancy is high, an excision biopsy is advised in patients with inadequate FNAC specimens. If properly managed with triple tests and good clinical judgement, the inadequate FNAC specimens do not delay treatment in patients with breast cancer.
Adult↗
Microdochectomy for single-duct nipple discharge.
INTRODUCTION: Isolated single-duct nipple discharge is worrying and poses a surgical dilemma. Factors predicting malignancy are controversial. MATERIALS AND METHODS: Retrospective review of 92 consecutive microdochectomies for single-duct nipple discharge in a tertiary referral centre over 8 years. RESULTS: The commonest causes were ductal papilloma (52%) and fibrocystic diseases of the breast (21%). Five (5%) patients had breast carcinoma, of whom only 1 had an invasive component. The median age of these patients was 43 years (range 26 to 72 years) which was similar to median age of the whole cohort. Sixty-seven (73%) patients presented with blood-stained nipple discharge. The 5 patients with breast carcinoma had blood-stained discharge. Mammography was abnormal in 1 out of 4 patients in the carcinoma group. CONCLUSIONS: The incidence of breast carcinoma in patients presenting with isolated single-duct nipple discharge was low (5%) among Singaporean women. There was no reliable predictors of malignancy, though all patients with carcinoma presented with blood-stained discharge. Microdochectomy still remains an effective treatment for nipple discharge both for cure and diagnosis.
Adolescent↗
Levonorgestrel IUS use in Islamic Malaysia.
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Contraceptive Agents, Female↗
Distribution of two hemolytic toxin genes in clinical and environmental isolates of Aeromonas spp.: correlation with virulence in a suckling mouse model.
Previous studies have shown that two hemolytic toxins, HlyA and AerA, contribute to the virulence of Aeromonas hydrophila. A survey was performed to gauge the distribution of hlyA and aerA genes in clinical and environmental Aeromonas isolates. For A. hydrophila, A. veronii biotype sobria and A caviae, 96%, 12% and 35% of strains, respectively, were hlyA positive, whereas, 78%, 97%, 41%, respectively, were aerA positive. All virulent A. hydrophila isolates were hlyA+ aerA+. This genotype was most common in A. hydrophila (75.4%) followed by A. caviae (29.4%) and A. veronii biotype sobria (9.6%). For A. hydrophila, a two-hemolytic toxin model of virulence provides the best prediction of virulence in an animal model.
Aeromonas↗
Percutaneous transport of diclofenac sodium from mixtures of fatty alcohol (or fatty acid) and propylene glycol through the rabbit abdominal skin.
Diclofenac sodium is a nonsteroidal anti-inflammatory drug with analgesic, antipyretic, and anti-inflammatory activity. When used in a topical application, diclofenac can diffuse through the skin and into the subcutaneous tissue to effect the anti-inflammatory action. In this study, in vitro evaluations of the percutaneous transport of diclofenac sodium in various bases containing fatty alcohols/propylene glycol or fatty acid/propylene glycol mixtures through the abdominal skin of the rabbit were investigated. Results show that the transdermal flux of diclofenac sodium in the fatty alcohol/propylene glycol bases of the same ratio is affected by the chain length of the fatty alcohol, and its effect is in the order of C10 > C12 > C14 > C18. However, the transdermal flux of diclofenac sodium in the fatty acid/propylene glycol bases of the same ratio is also affected by the chain length of the fatty acid, but no absolute relationship was found. For the same chain length of fatty acid and fatty alcohol used in the formulation base that was otherwise the same, the transdermal flux of diclofenac sodium is higher in the formula containing fatty alcohol than that containing fatty acid.
Abdomen↗
A comparison of trucut biopsy with fine needle aspiration cytology in the diagnosis of breast cancer.
INTRODUCTION: Carcinoma of the breast is common in Singapore and many patients may present with just a suspicious breast lump. AIM: To determine the accuracy of fine needle aspiration cytology (FNAC) and trucut biopsy in the diagnosis of suspicious breast lumps in an outpatient setting. METHODS: A total of 39 women, from May 1995 to November 1995, who had a suspicious breast lump were subjected to concurrent FNAC and trucut biopsy. RESULTS: The accuracy of FNAC is 90% whereas trucut biopsy is 67%, the difference being statistically significant with a p < 0.02. CONCLUSION: FNAC is recommended for the diagnosis of suspicious breast lumps.
Adenocarcinoma, Mucinous↗
Focused abdominal sonography for trauma (FAST).
This study aims to examine the feasibility of applying the focused ultrasound examination (FAST) in the initial assessment of the trauma patient. Its advantage over diagnostic peritoneal lavage lies in the speed in which it can be performed, its non-invasiveness and repeatability. Over the period January 1997 to July 1998, the FAST examination (Acuson 128XP/10, 3.5 MHz probe) was used to assess the presence of haemopericardium or haemoperitoneum in 38 multi-trauma patients admitted to the Singapore General Hospital. The sample comprises mainly males (82%) with a mean age of 34 years (range 17 to 77 years). The mechanism of injury was predominantly blunt (95%). Mean Injury Severity Score (ISS) was 22. Eleven patients presented in shock and 16 patients had abdominal tenderness on examination. A single surgeon did the examination, which was performed during the secondary survey phase of resuscitation. Time taken for the FAST examination averaged 2.3 +/- 1.3 minutes. The results of the examination were compared to diagnostic peritoneal lavage, CT scan, operative findings, serial examination and/or post-mortem findings. Overall sensitivity was 67% and specificity 97%. Although the FAST examination missed the small amount of free fluid seen in the CT scan of 2 patients, these patients did not have to undergo laparotomy as their abdominal examination was normal. We conclude that the FAST examination is feasible and should be part of a general surgeon's armamentarium in the initial assessment of trauma.
Abdomen↗
Incorporation of tryptophan analogues into staphylococcal nuclease, its V66W mutant, and Delta 137-149 fragment: spectroscopic studies.
We have biosynthetically incorporated several tryptophan analogues into three forms of Staphylococcal nuclease to investigate the spectroscopic characteristics of these "intrinsic" probes and their effect on the structure of the proteins. The set of tryptophan analogues includes 5-hydroxytryptophan, 7-azatryptophan, 4-fluorotryptophan, 5-fluorotryptophan, and 6-fluorotryptophan. 5-Hydroxytryptophan and 7-azatryptophan have red-shifted absorbance spectra, and the latter has a red-shifted fluorescence, which is very sensitive to its environment (being heavily quenched in water). The fluorotryptophans can serve as 19F NMR probes, and 4-fluorotryptophan has a very low fluorescence quantum yield, thus making it a "knock-out" fluorescence analogue. The set of proteins studied includes wild-type nuclease, which has a single tryptophan site at position 140; its V66W mutant, which has a second tryptophan at position 66; and the Delta 137-149 fragment, V66W', which only has a tryptophan at position 66. The environments of positions 66 and 140 are significantly different; position 140 is near the end of the long C-terminal alpha-helix and is moderately solvent-exposed, whereas position 66 is in the beta-barrel core region of the protein and is surrounded by apolar side chains. Absorbance and 19F NMR spectra are used to estimate the extent of analogue incorporation for each protein. Steady-state and time-resolved fluorescence data are reported to characterize the emission of the analogues in these positions in the three proteins and to develop the use of the analogues as probes of protein structure and dynamics. Circular dichroism spectra are reported to show that, in all but a couple of cases, the secondary structure of the proteins containing the analogues is not significantly perturbed by the probes. Additionally, fluorescence anisotropy decay data show the variants of wild-type nuclease to have a rotational correlation time similar to that of tryptophan-containing nuclease.
Amino Acid Substitution↗
Incorporation of tryptophan analogues into staphylococcal nuclease: stability toward thermal and guanidine-HCl induced unfolding.
The tryptophan analogues, 5-hydroxytryptophan, 7-azatryptophan, 4-fluorotryptophan, 5-fluorotryptophan, and 6-fluorotryptophan, have been biosynthetically incorporated into Staphylococcal nuclease, its V66W mutant, and the Delta 137-149 fragment of the latter mutant. The guanidine-HCl induced unfolding and thermal unfolding of these proteins were studied to characterize the effect of incorporation of these tryptophan analogues on the thermodynamic stability of the proteins. The three proteins have tryptophan residues at positions 140 (in wild type) and 66 (in the Delta 137-149 fragment of V66W) and at both positions (in V66W). The unfolding data show that 5-hydroxytryptophan does not perturb the stability of wild-type nuclease, but it destabilizes the fragment and causes the V66W mutant to unfold in a more cooperative manner. 7-Azatryptophan is found to destabilize all three proteins. 4-Fluorotryptophan is slightly stabilizing of the three proteins, but the other two fluorotryptophans do not alter the stability of the proteins.
Amino Acid Substitution↗
Phosphorescence and optically detected magnetic resonance characterization of the environments of tryptophan analogues in staphylococcal nuclease, its V66W mutant, and Delta 137-149 fragment.
Phosphorescence and optically detected magnetic resonance (ODMR) measurements are reported on the triplet states of the tryptophan analogues, 7-azatryptophan (7AW), 5-hydroxytryptophan (5HW), and 4-, 5-, and 6-fluorotryptophan (4FW, 5FW, 6FW), when incorporated at position 140 of wild-type Staphylococcal nuclease (7AW-nuclease, etc. ), positions 66 and 140 of its V66W mutant (7AW-V66W, etc.), and the deletion fragment of the latter, Delta 137-149 (7AW-V66W', etc.). These measurements point to the retention of protein structure at position 140 in each of the wild-type nuclease analogues. Substitution of the analogue at both tryptophan sites of V66W leads to structured sites with differentiated triplet-state properties for all analogues except 7AW-V66W, whose structure is destabilized. 5HW-V66W' is the only fragment that apparently lacks structure at position 66. All other V66W' analogues exhibit a structured environment at position 66 (4FW-V66W' was not studied), but in each case this site can be differentiated readily from the corresponding site in intact V66W. 7AW-V66W' is resolved by ODMR into two discrete structures with slightly differing zero field splittings (ZFS). Interaction of the protein with 5HW at position 66 of 5HW-V66W induces a 2-fold increase in the ZFS E parameter, which is reduced to its normal value upon formation of the fragment, 5HW-V66W'. Analogous effects occur for 5FW, but on a smaller scale.
5-Hydroxytryptophan↗
The effect of a pressure garment on post-surgical drainage and seroma formation in breast cancer patients.
BACKGROUND: The treatment of choice for cancer of the breast are mastectomy and axillary clearance or wide excision with axillary clearance. The most common complication following such a procedure is seroma formation. Various methods have been used to prevent it. However, the use of a pressure garment in this context has not been fully evaluated in the current literature. RESULTS: In a randomised trial comparing patients with a pressure garment with those without one, we have found no improvement in post-operative drainage with the use of a pressure garment. There were more complications in the group without the pressure garment (19%) compared with those with the garment (15.7%). The only seroma occurred in those patients not using the garment. The use of the pressure garment appeared to increase the duration of use of the drain (6.8 vs 6.1 days), these differences in the two groups was not significant. One of the patients in the pressure garment group was unable to tolerate the warmth and discontinued wearing the garment in the third post-operative day. This gave a rejection rate of 5%. CONCLUSION: The use of a pressure garment does not reduce the post-operative drainage, however, the complication rate appears to be higher when the pressure garment is not being used.
Breast Neoplasms↗
Desmoid tumor (fibromatosis) of the breast. A clinician's dilemma--a case report and review.
Desmoid tumor of the breast is a clinician's dilemma as it is difficult to differentiate it from carcinoma clinically, mammographically, and cytologically. Histologically, it must be distinguished from fibrosarcoma. Current management favors wide excision with clear margins. Recurrence is relatively common and usually occurs within 3 years of excision. Adjuvant hormonal therapy does not reduce local recurrence rates; evidence indicates that postoperative radiotherapy can improve the 10-year recurrence-free survival rate.
Adult↗
Biosynthetic incorporation of tryptophan analogues into staphylococcal nuclease: effect of 5-hydroxytryptophan and 7-azatryptophan on structure and stability.
5-Hydroxytryptophan (5HW) and 7-azatryptophan (7AW) are analogue of tryptophan that potentially can be incorporated biosynthetically into proteins and used as spectroscopic probes for studying protein-DNA and protein-protein complexes. The utility of these probes will depend on the extent to which they can be incorporated and the demonstration that they cause minimal perturbation of a protein's structure and stability. To investigate these factors in a model protein, we have incorporated 5HW and 7AW biosynthetically into staphylococcal nuclease A, using a trp auxotroph Escherichia coli expression system containing the temperature-sensitive lambda cI repressor, Both tryptophan analogues are incorporated into the protein with good efficiency. From analysis of absorption spectra, we estimate approximately 95% incorporation of 5HW into position 140 of nuclease, and we estimate approximately 98% incorporation of 7AW, CD spectra of the nuclease variants are similar to that of the tryptophan-containing protein, indicating that the degree of secondary structure is not changed by the tryptophan analogues. Steady-state fluorescence data show emission maxima of 338 nm for 5HW-containing nuclease and 355 nm for 7AW-containing nuclease. Time-resolved fluorescence intensity and anisotropy measurements indicate that the incorporated 5HW residue, like tryptophan at position 140, has a dominant rotational correlation time that is approximately the value expected for global rotation of the protein. Guanidine-hydrochloride-induced unfolding studies show the unfolding transition to be two-state for 5HW-containing protein, with a free energy change for unfolding that is equal to that of the tryptophan-containing protein. In contrast, the guanidine-hydrochloride-induced unfolding of 7AW-containing nuclease appears to show a non-two-state transition, with the apparent stability of the protein being less than that of the tryptophan form.
5-Hydroxytryptophan↗
Recurrence of accessory pathway conduction after successful radiofrequency ablation: histological findings.
The histological findings from a patient with Wolff-Parkinson-White syndrome (right superior paraseptal accessory pathway) who underwent successful radiofrequency ablation and had recurrence of tachycardia one month later in the absence of overt pre-excitation are reported. Histology revealed three small, oval to circular shaped, whitish, smooth areas on the right endocardial surface, the one being situated at the atrial free wall, and the other two being at the ventricular aspect. A very small hole was present in the interventricular component of the membranus septum. The accessory pathway band passed to either side of the small hole albeit disrupted by fibrous tissue in places. These findings indicate that multiple applications may cause penetration of the myocardium, and to achieve success, complete disruption of the pathway at some point along its course is required. Recurrence of retrograde accessory pathway conduction can be explained with the impedance mismatch hypothesis.
Adult↗
Cloning and characterization of two immunophilin-like genes, ilpA and fkpA, on a single 3.9-kilobase fragment of Aeromonas hydrophila genomic DNA.
Antiserum to Aeromonas hydrophila A6 cell envelopes was shown in a previous study (C. Y. F. Wong, G. Mayrhofer, M. W. Heuzenroeder, H. M. Atkinson, D. M. Quinn, and R. L. P. Flower, FEMS Immunol. Med. Microbiol. 15:233-241, 1996) to protect mice against lethal infection by this organism. In this study, colony blot analysis of an A. hydrophila genomic library using antiserum to A. hydrophila A6 cell envelopes revealed a cosmid clone expressing a 30-kDa protein which has not been described previously in aeromonads. The nucleotide sequence of a 3.9-kb fragment derived from this cosmid which expressed the 30-kDa protein revealed two potential open reading frames (ORFs) with homology to known immunophilin proteins. ORF1 encoded a 212-amino-acid protein (molecular mass, 22.4 kDa) with 56% identity to the immunophilin SlyD protein of Escherichia coli. ORF1 was subsequently designated ilpA (immunophilin-like protein). ORF3 encoded a potential gene product of 268 amino acids with a typical signal sequence and a predicted molecular size of 28.7 kDa. The inferred amino acid sequence showed 46% identity with the sequence of the FkpA protein of E. coli and 40% identity with the sequence of the macrophage infectivity potentiator (Mip) protein of Legionella pneumophila. ORF3 was designated fkpA (FK506 binding protein) by analogy with the E. coli FkpA protein. Expression of the FkpA protein was confirmed by Western blot (immunoblot) analysis, which detected a 30-kDa protein, with antiserum to the Mip protein of Legionella longbeachae and a specific antiserum to anA. hydrophila 30-kDa membrane protein. PCR and Southern analysis showed that a DNA sequence encoding FkpA was found in all 178 aeromonads of diverse origins tested. A nonpolar insertion mutation in the fkpA gene did not attenuate virulence in a suckling mouse model nor did it affect the expression of hemolysins or DNase. This suggests that either the fkpA gene is not essential in the virulence of A. hydrophila under these conditions or there are other genes in A. hydrophila coding for proteins with similar functions.
Aeromonas hydrophila↗