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Biomedical subjects

C C Chow

Publications and source records attributed to C C Chow.

At least 109 records · Page 6Linked to original sources
PubMed1994

Complications after laparoscopic pelvic lymphadenectomy: CT diagnosis.

OBJECTIVE: Laparoscopic dissection of pelvic lymph nodes has become an accepted alternative to open lymphadenectomy for staging of genitourinary tumors. This study reviews the CT findings in patients with major complications detected after laparoscopic dissection. MATERIALS AND METHODS: Of 85 patients who had laparoscopic dissection of pelvic lymph nodes at our institutions during a 3-year period, complications developed in 12 patients (14%), and eight of these had abdominopelvic CT studies done. CT findings and initial interpretations were correlated with follow-up surgical, clinical, or interventional radiologic findings in all cases. RESULTS: Complications of laparoscopic dissection detected with CT included small-bowel obstruction due to herniation through the trocar site in the abdominal wall (n = 2), extensive hematoma of the abdominal wall or retroperitoneum (n = 2), urinary ascites or multiple urinomas due to ureteral laceration or transection (n = 2), and lymphocele compressing the bladder where the peritoneum was sealed after lymphadenectomy (n = 1). In one case, CT showed pneumoperitoneum but failed to show a perforation of the sigmoid colon. CONCLUSION: Major complications occurred after laparoscopic dissection of pelvic lymph nodes and were diagnosed on the basis of CT findings in seven of eight patients. Recognition of the CT appearances of hernia or hematoma at the insertion sites of the trocars or the laparoscope is important, as is detection of injury to bladder, ureter, bowel, or blood vessels. Symptomatic lymphoceles were infrequently detected, probably because of the use of free drainage into the peritoneal cavity after laparoscopic dissection.

Aged↗
PubMed1994

A Chinese lady with Carney's complex.

A young Chinese lady with ACTH-independent Cushing's Syndrome was reported. Her clinical features was compatible with the recently described Carney's complex. Bilateral adrenalectomy was then performed. The diagnosis of bilateral pigmented nodular adrenocortical dysplasia was microscopically confirmed.

Adrenal Cortex↗
PubMed1993

Adrenocortical function and involvement in high risk cases of pulmonary tuberculosis.

SETTING: A regional hospital in Hong Kong. OBJECTIVE: To evaluate adrenocortical function in older patients admitted to hospital with active pulmonary tuberculosis (TB) and to determine whether adrenal insufficiency contributes to mortality in this high risk group. DESIGN: Adrenocortical function was assessed in 39 consecutive patients aged over 50 admitted to hospital with active pulmonary TB. Short Synacthen stimulation tests were performed before treatment and repeated at 2 months. In patients who died during treatment, a post-mortem examination was performed. Particular attention was paid to TB involvement of the adrenal glands. RESULTS: None of the patients had a subnormal basal cortisol concentration before treatment. 7 (18%) had raised basal cortisol concentrations and 16 (41%) had suboptimal cortisol responses to Synacthen stimulation. 14 patients (36%) died during treatment. The basal cortisol concentrations were significantly higher in the non-survivors compared to the survivors (743.7 +/- 288.5 vs 460.5 +/- 123.2 nmol/L, P < 0.0001). Autopsies were performed in 9 patients who died during treatment. Tuberculous involvement of the adrenal glands was found in only 1 patient who had a high basal cortisol concentration. After 2 months of treatment, all patients had normal cortisol concentrations and only 4 had borderline suboptimal Synacthen responses. The basal cortisol concentrations were significantly higher at presentation compared to those at 2 months after treatment (570.4 +/- 243.8 vs 386.3 +/- 108.3 nmol/L, P = 0.0014). CONCLUSION: Adrenal insufficiency is uncommon in patients with pulmonary TB. Suboptimal cortisol responses to Synacthen usually reflect a hyperstimulated basal state secondary to stress. Treatment with anti-TB drugs causes reduction in basal cortisol with associated improvement in the Synacthen response.

Adrenal Cortex↗
PubMed1993

Lithium-associated transient thyrotoxicosis in 4 Chinese women with autoimmune thyroiditis.

Four Chinese female patients who suffered from manic-depressive disorder and underlying autoimmune thyroiditis developed transient episodes of thyrotoxicosis during maintenance lithium therapy. Endocrinologically speaking, three of them had "Hashitoxicosis", while the other had silent lymphocytic thyroiditis. Albeit rare among Western patients, such lithium-associated thyroid dysfunctions appeared to be more likely to occur in Hong Kong Chinese. They seemed to involve multiple aetiological factors, such as autoimmune thyroid disease, the toxic and immunomodulatory roles of lithium and perhaps genetic and dietary factors. Because of their self-limiting nature, the importance of avoiding unnecessary and potentially deleterious antithyroid treatment is emphasised.

Adolescent↗
PubMed1992

Thyroid abnormalities during chronic lithium treatment in Hong Kong Chinese: a controlled study.

Fifty Chinese psychiatric patients on chronic lithium treatment and the same number of sex- and age-matched control outpatients were assessed by a thyroidologist and underwent laboratory investigations. Lithium patients had a higher rate of goitres (50% vs 10%, P < 0.0001) and a higher mean TSH level (P < 0.005) than controls. Thyroid antibodies were detected in 7 older manic-depressive patients as opposed to 1 control, but not in patients with recurrent unipolar mania. Five patients, but no controls, had single or multiple episodes of hyperthyroidism, which was followed in 2 of them by biochemical hypothyroidism. It is suggested that variations in iodine status, dietary goitrogens, immunogenetic makeup and their complex interactions with chronic lithium treatment may contribute to ethnically different patterns of thyroid abnormalities.

Adolescent↗
PubMed1992

Folate concentration in Chinese psychiatric outpatients on long-term lithium treatment.

Among 46 Chinese and mostly manic-depressive (85%) outpatients attending a lithium clinic in Hong Kong, virtually no patients had low serum (0%) or erythrocyte (2%) folate. Their mean folate levels did not differ from lithium-free outpatients. Although serum folate correlated negatively with lithium dose (P less than 0.002) and serum level (P less than 0.01), lithium treatment probably did not by itself cause low folate. Folate level was not related to diagnosis, duration of mental illness, other drug usage or spot affective morbidity. Patients with a good response to lithium in the previous one year had a higher mean serum folate level than those with unsatisfactory response (P less than 0.05). These data suggest that folate deficiency is uncommon among Chinese psychiatric outpatients, but support recent evidence that folate at high concentrations enhances lithium prophylaxis.

Ambulatory Care↗
PubMed1992

Ga-67 citrate in diagnosing tracheoesophageal fistula in a patient with AIDS. Case report.

Increased radiopharmaceutical uptake in the mediastinum and/or hilum on Ga-67 citrate scan in patients with AIDS has been attributed, to date, mostly to infectious etiologies. Because other complications are being reported in these patients, awareness of their presentation in diagnostic imaging is important. Tracheoesophageal fistula can also be accompanied by a focal area of increased uptake in the mediastinum. In this patient, a Ga-67 citrate scan was the first modality of diagnostic imaging to raise suspicion of such a diagnosis.

Acquired Immunodeficiency Syndrome↗
PubMed1991

In vivo and in vitro sodium pump activity in subjects with thyrotoxic periodic paralysis.

OBJECTIVE: To examine whether sodium pump activity plays a part in the pathogenesis of thyrotoxic periodic paralysis. DESIGN: Measurement of platelet sodium-potassium ATPase and in vivo sodium pump activities in healthy subjects and thyrotoxic subjects with and without paralysis. SETTING: University hospital in Hong Kong. SUBJECTS: 21 healthy subjects, 23 untreated thyrotoxic subjects, 13 untreated men with periodic paralysis, seven treated thyrotoxic subjects, and six treated men with periodic paralysis. MAIN OUTCOME MEASURES: Platelet Na+, K(+)-ATPase activity and plasma rubidium concentration after oral loading. RESULTS: Median (range) platelet Na+, K(+)-ATPase activity in thyrotoxic subjects was 253 (169-821) mumol inorganic phosphate/h/g protein--significantly higher than that in healthy subjects (134 (81-180) mumol/h/g protein; p less than 0.001). Na+, K(+)-ATPase activity in those with periodic paralysis was 374 (195-1196) mumol/h/g protein, again significantly higher than that in healthy subjects (p less than 0.001) and that in other thyrotoxic subjects (p less than 0.01) despite similar degrees of hyperthyroidism. Activities in treated thyrotoxic subjects with and without periodic paralysis were 148 (110-234) and 131 (86-173) mumol/h/g protein respectively. Mean (95% confidence interval) plasma rubidium concentration five hours after oral administration in thyrotoxic subjects (7.0 (6.6 to 7.5) mumol/l) was significantly lower than in healthy subjects (10.2 (9.5 to 10.9) mumol/l; p less than 0.001) and higher than in those with periodic paralysis (6.0 (5.7 to 6.3) mumol/l; p less than 0.01). CONCLUSIONS: Sodium pump activity in untreated subjects with periodic paralysis is higher than in other thyrotoxic subjects, and this may be responsible for the hypokalaemia.

Adult↗
PubMed1991

Effect of low dose iodide supplementation on thyroid function in potentially susceptible subjects: are dietary iodide levels in Britain acceptable?

OBJECTIVE The aim of the study was to evaluate the risk of exposure to an increase in dietary iodide intake amongst potentially susceptible population groups in Britain. DESIGN A randomized controlled trial was performed in healthy women and in women with underlying thyroid abnormalities due to subclinical Hashimoto's thyroiditis (diagnosed on the basis of antithyroid antibodies) or previous iodide deficiency of supplementation with 500 micrograms/day iodide (giving a total intake of approximately 750 micrograms/day) for 28 days versus placebo. PATIENTS Two hundred and twenty-five women aged 25-54, randomly selected from a general practice in Cardiff, were screened for thyroid microsomal antibody. Antibody positive women (n = 20), and antibody negative controls (n = 30) were recruited into the trial comparing iodide and placebo. In addition, groups of patients aged 60-75 randomly selected from the Cardiff practice (n = 29), an iodide sufficient area, and a practice in Dowlais (n = 35), a previously iodide deficient area, were also enrolled into the trial. MEASUREMENTS Changes in free thyroxine and thyrotrophin levels were measured after 14 and 28 days of iodide supplementation. RESULTS All the iodide supplemented groups responded in the same way with a small fall in free thyroxine and rise in thyrotrophin levels (combined fall in free thyroxine 14 days after the start of supplementation -1.22 (95% confidence interval -0.59 to -1.84) pmol/l and at 28 days -0.86 (-0.30 to -1.43) pmol/l and rise in thyrotrophin at 14 days 0.55 (0.19 to 0.92) mU/l and at 28 days 0.59 (0.12 to 1.07) mU/l). In two of the iodide supplemented subjects thyrotrophin levels rose above the laboratory reference range and in a further three subjects initially elevated thyrotrophin values increased further. In contrast, no changes in thyroid function were observed in the placebo treated controls and none developed biochemical hypothyroidism. CONCLUSIONS Dietary iodide intakes of 750 micrograms/day or more may adversely affect thyroid function, especially in individuals with borderline hypothyroidism.

Adult↗
PubMed1990

Ultrasound appearances of de Quervain's thyroiditis.

De Quervain's thyroiditis can be readily recognised by ultrasound. The sonographic features and previously unreported signs of two such cases are illustrated. One case had typical multiple hypoechogenic areas in the thyroid parenchyma. The other had multiple small areas giving a spotty appearance not previously reported in de Quervain's. Both patients demonstrated remarkable shrinkage of the gland (to 17.4% and 57% of the original presenting volume). We believe this is a useful diagnostic feature of de Quervain's thyroiditis.

Adult↗
PubMed1990

Serum soluble interleukin 2 receptor in hyperthyroid Graves' disease and effect of carbimazole therapy.

To study the activation of T lymphocytes in hyperthyroid Graves' disease, the serum concentrations of soluble interleukin 2 receptors (sIL2R) were determined during active thyrotoxicosis and following the return to a euthyroid state with carbimazole therapy. Serum sIL2R was measured by an enzyme linked immunoassay. The mean +/- SD serum sIL2R concentration during untreated hyperthyroidism was elevated as compared with controls (919.1 +/- 523.4 vs 374.2 +/- 189.4 U/ml, P less than 0.005). However, after carbimazole therapy the serum sIL2R in euthyroid patients fell to 377.9 +/- 90.3 U/ml, which did not differ from healthy controls. Serum sIL2R correlated significantly with the serum free T3 only during hyperthyroidism (r = 0.678, P less than 0.01). Our study suggests that in vivo measurement of serum sIL2R released from activated T lymphocytes is a useful immunological indicator of disease activity.

Adult↗
PubMed1990

Inhibition of muscarinic-coupled phosphoinositide hydrolysis by N-methyl-D-aspartate is dependent on depolarization via channel activation.

The intent of this work was to elucidate the mechanism by which N-methyl-D-aspartate (NMDA) receptor agonists inhibit a second messenger system, namely, the stimulation of phosphoinositide (PI) hydrolysis activated by muscarinic cholinergic receptor agonists. NMDA inhibited cholinergic stimulation of PI hydrolysis in a dose- and time-dependent manner. NMDA exerts this effect indirectly through channel activation, because both MK-801 and N-[1-(2-thienyl)cyclohexyl]piperidine (TCP) prevented this action. Prevention of the NMDA effect by removal of sodium, but not calcium, from the incubation buffer suggested that depolarization may be the responsible mechanism. Depolarization alone proved sufficient to inhibit cholinergic activation of PI hydrolysis, because both veratridine and an elevated extracellular potassium level inhibited cholinergic stimulation of PI hydrolysis. The effect of NMDA appeared to require sodium flux through NMDA channels rather than through voltage-dependent sodium channels, because tetrodotoxin failed to inhibit the effect of NMDA. In correlative electrophysiologic experiments, NMDA profoundly inhibited evoked excitatory postsynaptic potentials and population action potentials of CA1 neurons, an effect almost certainly due to depolarization. The dose and time course of the electrophysiologic effects correlated well with the biochemical effects. Taken together, the data support the assertion that NMDA receptor activation inhibits PI hydrolysis by depolarization mediated by sodium flux through NMDA channels.

Animals↗
PubMed1990

Response to control of hyperthyroidism in patients with myasthenia gravis and thyrotoxicosis.

Three patients presenting with both myasthenia gravis and thyrotoxicosis were treated initially with pyridostigmine and carbimazole respectively. Control of the hyperthyroidism was achieved in all cases but was accompanied by deterioration of the myasthenic symptoms in two and persistence in one. Thymectomy was performed with subsequent improvement in all three patients. Histology showed thymic hyperplasia in each case. The relationship of myasthenia gravis, thyrotoxicosis and the thymus is discussed.

Adult↗
PubMed1990

Sleep apnoea presenting as severe hypertension and silent occipital haemorrhage.

A 39-year old Chinese man presented with an acute onset of severe headache, accelerated hypertension and subsequently an unexpected extensive right occipital haemorrhage. These were found to be related to a sleep apnoea syndrome which had been unrecognized for many years despite its typical symptoms of loud snoring and excessive daytime sleepiness. Weight reduction led to significant clinical but not polysomnographic improvement of the sleep apnoea syndrome.

Adult↗