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Biomedical subjects

B K Ng

Publications and source records attributed to B K Ng.

15 recordsLinked to original sources
PubMed1995

Hypertension in disguise--a trap for the unwary.

A 36-year-old asymptomatic Chinese male with polycystic kidney disease (PKD) developed hypertension 1 year after the diagnosis of PKD. The patient was treated initially as for hypertension associated with PKD. However, over a 6-year period his hypertension became progressively difficult to control and he developed severe symptomatic hypokalemia. Subsequent investigations confirmed the presence of primary hyperaldosteronism. The initial computed tomographic scans of the adrenals did not reveal any definite adenomas. The patient subsequently underwent bilateral adrenal venous sampling, which suggested a left-sided source of aldosterone excess. A repeat computed tomography of the adrenals with fine cuts revealed a 6-mm diameter adenoma of the left adrenal gland. He underwent an uncomplicated left adrenalectomy. All antihypertensive and potassium supplements were stopped on the 5th postoperative day. Two and half years after the adrenalectomy he remains normotensive and normokalaemic without any medication. The case illustrates the importance of measuring serum potassium before initiation of any therapy and the need to consider secondary causes even if a primary association is known. It also reinforces the fact that when hypertension becomes difficult to control, a secondary cause has to be searched actively. The association between primary aldosteronism and renal cysts has been highlighted only recently. The association of polycystic kidneys and primary aldosteronism has been reported in the literature only once previously.

Adenoma↗
PubMed1994

An unusual presentation of carcinoma of the gallbladder--case report.

Unusual modes of presentation of carcinoma of the gallbladder have been described in the literature. However, this is probably the first reported case of carcinoma of the gallbladder presenting with acute large bowel obstruction. This paper also reviews the literature pertaining to the clinical features and current treatment of carcinoma of the gallbladder. It continues to be a discouraging disease characterised by late diagnosis and a poor outcome.

Adenocarcinoma↗
PubMed1994

Obturator hernia--case reports.

Two cases of obturator hernia are presented. Both patients presented with intestinal obstruction and the diagnosis was not made preoperatively. A review of recent articles showed 57 cases of obturator hernia in 53 patients reported in the period 1981 to 1990 which also showed no improvement in the management of these cases with a high mortality rate of 30%. A high index of suspicion must be maintained in order to diagnose this condition and reduce morbidity and mortality.

Aged↗
PubMed1994

Intrahernial tumour--a case report.

Intrahernial tumour is an uncommon entity. Up to 1980, there are 23 reported cases of primary intrahernial tumours. Suspicion should arise when a longstanding hernia has recently become incarcerated. This is the first reported case of primary tumour of the transverse colon found within a paraumbilical hernia presenting with obstruction.

Adenocarcinoma↗
PubMed1993

Selection of patients for surgery in the management of thyrotoxicosis.

There is at present no consensus as to what the best treatment for thyrotoxicosis is. If the patients are carefully selected, surgery offers a safe and effective cure for the disease over a short period of time. We reviewed the selection criteria of forty-one patients with thyrotoxicosis treated surgically in Alexandra Hospital. Over 90% of the patients were referred for surgery by physicians and general practitioners. The majority (95%) were young patients (under 40 years) and almost all were treated with antithyroid drugs before opting for surgery. The most common indication given for surgery was failure of conservative treatment (20/41). This was followed by patients who had difficulty adhering to the antithyroid drug regime (12/41) and patients who requested surgery for cosmetic reasons (5/41). Almost half of the patients had large glands (> 50g). One year after surgery, 84% of the patients remained euthyroid, 8% developed hypothyroidism and 8% had relapsed thyrotoxicosis. Three quarters of the patients tested positive for thyroid antibodies. This did not appear to increase the rate of hypofunction. There was no mortality from surgery.

Adolescent↗
PubMed1992

A successful peritoneovenous shunting of ascites using the great saphenous vein.

For the surgical palliation of massive ascites, a LeVeen or Denver shunt may be implanted to drain ascitic fluid from the peritoneal cavity into the circulation. But all commercial shunts are costly and depend on a synthetic valve to prevent blood refluxing into the peritoneal cavity. We report here the first patient with a malignant ascites that was successfully palliated by peritoneovenous shunting using the great saphenous vein as a biological valve.

Ascites↗
PubMed1990

Large bowel cancer in the young adult.

Within a month, we saw two young national servicemen with adenocarcinoma of the caecum. Both presented to use as emergencies and both had a right hemicolectomy performed. This literature review is to promote a greater awareness of the potential for colorectal cancer in young adults less than 40 years of age. The incidence ranged from 2% to 16.8% of all cases of large bowel cancer. About two-thirds of the tumours were Dukes' C and D at the time of presentation. There was a preponderance of poorly differentiated carcinoma and the mucinous type of carcinoma. Early diagnosis and attempts at curative resection are of utmost importance. Radical extirpation of advanced primary disease is well worthwhile and can be associated with long term survival in the young. Family history is important to identify a group of patients with cancer family syndrome.

Adenocarcinoma↗
PubMed1989

Cystosarcoma phyllodes: a review of surgical options.

The unpredictable behavior of histologic types and the disputable results of particular surgical procedures have contributed to the controversies surrounding phyllode tumors. The therapeutic issue is further compounded by an imprecise preoperative diagnosis. This is illustrated in our series of 106 patients, in whom 71.7% were mistakenly operated on for fibroadenoma. Since only 15.8% of this group developed local recurrence, it may be acceptable to adopt a watchful policy, unless detailed microscopic assessment of tumor margins provides evidence of inadvertent transection. Reoperation would then be logical advice, as with one of our patients. In patients clinically suspected of having phyllode tumors, tissue diagnosis is preferable to investigative procedures, which are seldom definitive. Our experience has been with frozen-section diagnosis, although trucut core biopsy is certainly an attractive procedure. In 18 patients only 50% were positively identified as having phyllode tumors. The logistic and therapeutic issues related to use of frozen-section diagnosis are discussed. Wide excision has been recommended by many investigators as an appropriate measure, as long as it is technically possible to remove the lesion with an adequate rim of normal breast tissue. This applies especially to young female patients (less than 20 years), in whom conservation of the breast is particularly desirable and whose tumors behave in a more benign manner. On the other hand, mastectomy is necessary if the phyllode tumor is large compared with breast morphologic size,when histologic transformation has taken place, or when clinical behavior takes a more aggressive course. In this retrospective study, conservative surgery is generally practiced for both primary and recurrent tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Cystosarcoma phyllodes--Asian variations.

Cystosarcoma phyllodes afflicting 106 female patients in a multiracial Asian society is reviewed and some interesting variations are noted when compared with Western patients. The incidence of phyllodes tumour is 3.83% of surgically removed breast tumours compared with 0.5-2.5% in Western series. This lends weight to the belief that non-Caucasians are more prone to this enigmatic breast disease than the Caucasian population. The profile of the Asian phyllodes patient is that of a young female, aged 25-30 years, whereas her Western counterpart is in her 40s. As a result, she is liable to be mistaken clinically as having fibro-adenoma. The disease is notably rare among the females below 20 years of age but in the Asian context, as much as one-quarter-one-third may be in the adolescent group. There were only three malignant and six borderline phyllodes tumours out of 106 cases, and this incidence is far below that of many other studies in which the malignant cases are believed to constitute 23-27%. However, this may not be a racial variation but explicable by the fact that the present study is an unselected cohort from a general surgical unit. The presence of associated benign breast disease in 25.5% cases helps to reinforce the widely held belief that fibro-adenoma and phyllodes tumour are related to some degree.

Adult↗
PubMed1976

The anthelmintic efficacy of fenbendazole against thiabendazole-resistant strains of Haemonchus contortus and Trichostrongylus colubriformis in sheep.

The anthelmintic efficacy of fenbendazole (methyl 5-(phenylthio)-2-benzimidazole carbamate) was tested in sheep against standardised strains of Hcaemonchus contortus and Trichostrongylus colubriformis, known to be resistant to thiabendazole (LD90 for thiabendazole against H ontortus was 200 mg/kg bodyweight and against T colubriformis was 150 mg/kg). Fenbendazole at dose rates of 5, 10 and 20 mg/kg per os reduced total worm counts in H contortus infected sheep by 66, 90 and 100 per cent respectively, with similar reductions recorded for worm egg outputs. For the thiabendazole resistant strain of T colubriformis, fenbendazole reduced total worm counts in infected sheep by 4, 44 (40-48), 79 (75-83), 96 and 100 per cent at dose rates of 5, 10, 20, 40 and 80 mg/kg per os. Significant suppression of worm-egg production by thiabendazole resistant T colubriformis was obtained with fenbendazole at dose levels of 5 mg/kg and above. The implications of these results are discussed in the light of the increasing occurrence of strains of trichostrongylid nematodes resistant to currently available benzimidazole anthelmintics.

Animals↗
PubMed1975

Anthropozoonotic helminthiases in Australasia: Part 3: - studies on the prevalence and public health implications of helminth parasites of dogs and cats in urban environments.

Man has acquired helminth infections at different times during his evolutionary history and animals have and do serve an important role in supplementing these acquisitions. Helminth species are divided into those which accompanied man as he emerger as a species and those which he has since acquired from domestic, wild and domiciliated animals by breakdown of ecological, physiological and immunological barriers (Sprent 1969). With particular reference to helminth zoonoses transmitted through domesticated animals, the role played by dogs and cats in disease transmission to man (in urban environments) has been largely overlooked. In the Australasian region, the most important helminth zoonoses transmitted by dogs and cats in heavily urbanised areas as Toxocara sp., Ancylostoma sp. and Dirofilaria immitis. The prevalence, geographic distribution and major epidemiological considerations for each parasite are discussed with the view that future control and/or eradication programs should be based on a sound epidemiological understanding of the natural life history of the helminths concerned.

Ancylostomiasis↗