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Biomedical subjects

K L Cheung

Publications and source records attributed to K L Cheung.

At least 91 records · Page 5Linked to original sources

Current status of breast cancer in Hong Kong.

OBJECTIVE: To study the mode of presentation, the tumor, nodes, metastasis (TNM) staging and the efficacy of multimodal treatment of breast cancer among Chinese women treated in Queen Mary Hospital. METHODS: The available records of all breast cancer patients treated between January 1980 and December 1994 were reviewed. The mode of presentation, the TNM staging of the disease, estrogen receptor status and the mode of surgical and adjuvant treatment were studied. Statistical correlation was performed between the factors studied and the survival time. RESULTS: Seven hundred and one cases of breast cancer were identified. The mean age of the patients was 56.6 years (range, 20-98 years). The most common complaint was the presence of a mass which occurred in 635 (90.6%) patients and 454 (71.5%) of these patients were painless. The majority of patients had T2 tumours (51.8%) and stage II disease (59.6%), but only 86 (12.3%) patients underwent breast conservative therapy (BCT). Estrogen receptor was positive in 43% of patients. Two hundred and ninety (41.4%) patients were node positive and the mean number of involved nodes was 3.8 per patient. Adjuvant chemotherapy was given to 125 node positive patients, adjuvant tamoxifen to 188 patients and both to 63 patients. Univariate analyses of factors possibly affecting survival showed that advanced stage disease and nodal involvement were associated with a significantly lower survival time. Among the node positive patients, those with seven or more involved nodes had a shorter survival. The types of surgery and adjuvant treatment (for node positive patients) had no direct correlation with survival. CONCLUSION: Our results showed that the majority of our patients presented with a painless mass and the final outcome was determined by the tumour load at the time of presentation (TNM staging and nodal status).

Adult↗

Recurrent aortic valve prosthesis dehiscence secondary to aortoarteritis: three case reports and literature review.

We report three young Chinese male patients who underwent aortic valve replacement for severe aortic regurgitation of subacute onset, complicated by recurrent dehiscence of the aortic valve prosthesis, due to aortitis. One of the three patients underwent aortic valve replacement three times and progression of the prosthesis dehiscence was arrested with the use of corticosteroids. A review of the literature on the prognosis and treatment of aortoarteritis with particular reference to the management of recurrent valvular dehiscence is discussed.

Adult↗

Varicella exposure in a neonatal intensive care unit: emergency management and control measures.

We describe an exposure of varicella zoster virus in our neonatal intensive-care unit and the emergency procedures instituted to prevent an outbreak. Fifty-seven infants and 129 staff members were exposed but none developed chickenpox. The measures included rapid identification of varicella antibody status in all neonates and those staff members with uncertain history of varicella infection; cohorting of exposed infants according to immune status; and prompt administration of varicella zoster immunoglobulin to susceptible patients. The recommendation of the American Academy of Pediatrics did not accurately predict the immune status of preterm infants, as only one of the eight susceptible infants would have qualified for immunoglobulin prophylaxis if their guidelines had been followed. Mass screening of all exposed infants using the varicella zoster enzyme linked immunosorbent assay (ELISA) test was the only reliable means of determining the immune status. Of the four risk factors evaluated for the prediction of antibody status: gestational age, postnatal age, birthweight and episodes of blood transfusion, only postnatal age was found to independently predict the immune status of our patients. Because varicella zoster susceptible staff members are difficult to identify on the basis of history, we suggest that prospective screening of staff in high-risk units be undertaken and vaccination with live varicella vaccine be offered to susceptibles.

Antibodies, Viral↗

Inoue balloon pericardiotomy for patients with recurrent pericardial effusion.

The results and follow-up data for 11 patients with recurrent effusion due to various etiologies who underwent balloon pericardiotomy with the Inoue balloon catheter between May 1992 and July 1994 are described. Inoue balloon pericardiotomy was successful in 10 patients (91%), who remained free of pericardial effusion at a mean follow-up duration of 4.2 months. All patients tolerated the procedure well with minimal discomfort and with no complications. Despite good symptomatic relief, 9 patients (82%) eventually succumbed to disease dissemination, with a mean survival time of 1.4 months. It is concluded that Inoue balloon pericardiotomy is a safe and useful alternative to surgical pericardial windowing for the symptomatic treatment of recurrent pericardial effusion.

Catheterization↗

High dose rate intracavitary brachytherapy in the treatment of nasopharyngeal carcinoma.

A retrospective study on 61 patients, with local persistent or recurrent nasopharyngeal carcinoma (NPC), treated during 1990-1992 with high dose rate intracavitary brachytherapy alone or combined with external irradiation, is presented. All 39 patients with persistent disease were treated solely with brachytherapy. The actuarial 3-year local failure-free survival (LFFS) rates of the persistent and recurrent groups were 82% and 45% respectively. The corresponding disease specific survival rates were 82% and 62%. Fifteen patients with recurrence received the combined modality treatment and their 3-year LFFS rate was 65%. Three out of 7 patients treated by brachytherapy could be controlled locally. The total dose given to the floor of sphenoid was an important predictor of local control. Of the 23 patients with persistent disease treated with < 17.5 Gy to this area, 6 failed locally as opposed to none of the 16 patients receiving a higher dose (p = 0.031). For those with recurrence treated by the combined modality, none of the 7 patients given >/= 57.5 Gy recurred while 5 local failures were observed among those receiving a smaller dose (p = 0.041). The general implications of these results for the treatment of NPC recurrence are discussed.

Actuarial Analysis↗

Paclitaxel-induced cardiotoxicity. An ultrastructural study.

The ultrastructural appearance of the myocardium in a fatal case of paclitaxel-induced cardiotoxicity is reported, which includes swelling of the sarcoplasmic reticulum, loss of myofibrils, and accumulation of lipofuscin as well as laminated myelinoid figures. Such changes are very similar to those seen in anthracycline-induced cardiotoxicity and may suggest a pathogenetic final common pathway. While endomyocardial biopsy is a recognized means of monitoring anthracycline-induced cardiotoxicity, whether more liberal use of endomyocardial biopsy can prevent fatal cases of paclitaxel-induced cardiotoxicity needs to be further assessed.

Antineoplastic Agents, Phytogenic↗

Endoscopic stenting for malignant biliary obstruction.

OBJECTIVE: To evaluate the results of endoscopic stenting in patients with malignant biliary obstruction. DESIGN: Retrospective review. SETTING: Surgical endoscopy unit at a tertiary referral center. PATIENTS AND INTERVENTION: Plastic endoprosthetic stents were inserted for the relief of biliary obstruction in 131 consecutive patients. Among the 104 patients with malignant biliary obstruction, 60 underwent stenting as definitive palliative treatment. MAIN OUTCOME MEASURES: Data on the type and size of stents employed, their effectiveness in relieving jaundice, their complications, and the quality of survival were analyzed. RESULTS: Median survival was 1.93 months. The majority of the stents (88.3%) were placed endoscopically, and single straight stents were most frequently used (96.7%). Jaundice was relieved in 35 patients. Early (< or = 14 days) and late acute cholangitis were found in four and 11 patients, respectively. Early and late stent migration was noticed in two and six patients, respectively. Pancreatitis occurred in one patient, and no papillotomy site bleeding was encountered. When compared with the 18 patients with proximal obstruction at or above the common hepatic duct, the 42 patients with distal ductal obstruction had longer median survival (P = .03) and more effective relief of jaundice (P = .005) and required less antibiotic treatment (P = .03). These 42 patients also enjoyed better quality of survival when it was analyzed with reference to six objective parameters (P = .0018). CONCLUSIONS: Stenting offers palliation of malignant biliary obstruction, and the results are particularly encouraging in distal obstruction.

Adult↗

Mitral valve prolapse causing severe mitral regurgitation in a patient with absent right pulmonary artery.

A 33-year-old man was investigated for dyspnea on exertion and the presence of a pansystolic murmur. Physical examination revealed dextrocardia confirmed by chest radiograph, which also showed oligemic right lung field. Subsequent cardiac catheterization revealed secundum atrial septal defect, persistent left sided superior vena cava, and severe mitral valve prolapse causing severe mitral regurgitation with pulmonary hypertension. The right pulmonary artery was absent. It is the first report of the association between severe mitral valve prolapse and absent right pulmonary artery.

Adult↗

Bacterial contaminated breast milk and necrotizing enterocolitis in preterm twins.

A pair of preterm twins developed fatal necrotizing enterocolitis (NEC) in association with Staphylococcus epidermidis septicaemia after receiving contaminated expressed breast milk (EBM). S. epidermidis NEC can be associated with severe bowel inflammation, high morbidity and mortality. Breast milk is the most suitable nutrient for preterm infants but EBM should undergo regular screening for bacterial overgrowth. We urge caution before administering EBM found to be heavily contaminated with S. epidermidis to preterm infants.

Bacteremia↗

Retinoblastoma in association with the chromosome breakage syndromes Fanconi's anaemia and Bloom's syndrome: clinical and cytogenetic findings.

Two children presenting with sporadic unilateral retinoblastoma and exhibiting a high degree of chromosome breakage were noted to have unusual facies, microcephaly and abnormal skin pigmentation. In the first child the pattern of both spontaneous and mitomycin-C-induced chromosome breakage was characteristic of Fanconi's anaemia although the degree of breakage was extreme. She also exhibited a striking increase in X-ray-induced chromosomal damage in G0 lymphocytes as measured by dicentric formation and increase in chromatid-type aberrations. She had a number of typical clinical features, including cafe-au-lait patches and abnormalities involving the kidney; however, she demonstrated neither the hypoplasia of radius and thumb nor the typical aplastic phase of this disorder. At age 22 months the child became anaemic with trilineage myelodysplasia, which was rapidly followed by the development of acute myeloblastic leukaemia. The early onset (at age 4 months) of retinoblastoma may have been associated with the underlying genomic instability. The second child exhibited a pattern of chromosome breakage characteristic of Bloom's syndrome, in addition to a moderate increase in damage induced by mytomycin-C. She had the typical stunted growth and malar hypoplasia of Bloom's syndrome although she did not demonstrate the frequently described erythematous 'butterfly rash' Although patients with Fanconi's anaemia and Bloom's syndrome are recognised to be at an increased risk of cancer, retinoblastoma has not previously been described in patients with either condition. We suggest that underlying recessive chromosome breakage syndromes may be underdiagnosed in paediatric cancer patients, with important implications for prognosis and genetic counselling.

Bloom Syndrome↗

Isolated congenital tuberculosis otitis in a preterm infant.

We report an unusual case of localized congenital tuberculosis otitis in a preterm infant. Unlike disseminated congenital cases, the manifestations of localized otitis are associated with a triad of signs: (i) regional lymphadenopathy in the absence of typical systemic features of tuberculosis; (ii) delayed onset of presentation; and (iii) refractory otitis unresponsive to conventional antimicrobial agents. The need for greater diligence in looking for neonatal tuberculosis is emphasized, especially in an ethnic or socioeconomic environment where the disease is prevalent.

Antibiotics, Antitubercular↗

High frequency oscillatory ventilation in newborns with idiopathic persistent pulmonary hypertension.

Three consecutive term infants diagnosed as suffering from idiopathic persistent pulmonary hypertension of the newborn (PPHN) were tried on high frequency oscillatory ventilation (HFOV) after failure of conventional mechanical ventilation (CMV). All experienced a significant improvement in oxygenation. All three infants survived. HFOV was utilised in a fourth term infant initially diagnosed as having idiopathic PPHN with an immediate benefit. This infant subsequently died and was found at autopsy to have a lethal congenital maldevelopment of pulmonary microcirculation. No serious adverse effects were encountered with HFOV in contrast to the use of pharmacologic agents where hypotension was a serious problem. A therapeutic trial of HFOV is simple and efficient, and would not cause undue delay in the commencement of other rescue therapy should it prove unsuccessful. We predict HFOV will replace non-specific vasoactive agents as the standard first line alternative to CMV for the treatment of idiopathic PPHN.

Female↗

Fluorescence in situ hybridisation studies to characterise complete and partial monosomy 7 in myeloid disorders.

Eight patients with myeloid disorders characterised by a karyotype including apparent monosomy or partial monosomy 7, in the presence of a ring or marker chromosome, were investigated by fluorescence in situ hybridisation (FISH) with a chromosome 7 centromere-specific probe and an Alu-PCR derived chromosome 7 paint. In 4 of 5 cases a ring chromosome was shown to be of chromosome 7 origin; in one of these the apparent ring was shown to consist solely of chromosome 7 centromeric material, and in the fifth case the ring was derived from chromosome 18. In three cases monosomy 7 had arisen during the course of karyotype evolution and was clearly not the primary cytogenetic abnormality. One further case demonstrated fragmentation and cryptic translocation of chromosome 7 material. In the last case a chromosome described as der(l)t(1;7)(p11;p11) was redefined as dic(1;7)(p11;q11). The application of FISH has enabled a more accurate characterisation of chromosome abnormalities, and extended studies of this type may eventually lead to more precise prognostic groups defined by karyotype.

Adult↗