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Biomedical subjects

B Lam

Publications and source records attributed to B Lam.

36 records · Page 2Linked to original sources
PubMed2000

Endobronchial actinomycosis associated with a foreign body.

Primary endobronchial actinomycosis is an exceedingly rare condition which closely mimics bronchial carcinoma both clinically and radiologically. We report the case of a middle-aged Chinese man who had right lower lobe endobronchial actinomycosis associated with inhalation of a presumed chicken bone. The patient made a complete clinical and radiological recovery after a 2 month combined course of amoxycillin and clavulanate, after removal of the foreign body, which was only detected after using contiguous computed tomography. Our experience in the management of this patient should help clinicians in the investigation and management of this rare but treatable condition.

Actinomycosis↗
PubMed2000

Chemoradiotherapy for advanced lymphoepithelioma-like carcinoma of the lung.

Lymphoepithelioma-like carcinoma (LELC) of the lung, an Epstein-Barr virus-associated undifferentiated carcinoma, is a rare entity of pulmonary malignancy. It tends to affect young non-smoking Asians and is often resectable. However, little is known of the treatment of the even rarer locally advanced or metastatic cases. We report our experience of three Chinese patients with advanced LELC of the lung who were treated with combination-chemotherapy (5-fluorouracil, leucovorin, and cisplatin) and radiotherapy. The encouraging response of these patients supports the use of this regime in other patients.

Adult↗
PubMed2000

Severe bronchiectasis in patients with "cystlike" structures within the ciliary shafts.

Cilia are minute hairlike structures which sweep the respiratory tract clean by continuous beating. Ciliary dysfunction can occur which leads to development of bronchiectasis. We describe the clinical and investigation profiles of four patients who had early-onset severe and otherwise idiopathic bronchiectasis associated with a previously undescribed ciliary defect in which numerous cystlike structures are present within the ciliary shafts. The patients had otherwise normal ciliary microtubular ultrastructure and central microtubular orientation. Our newly described ciliary abnormality appears to be a primary defect and more systematic studies should be performed to evaluate this further.

Adult↗
PubMed2000

Circulating nitric oxide is suppressed in obstructive sleep apnea and is reversed by nasal continuous positive airway pressure.

Epidemiological studies have implicated obstructive sleep apnea (OSA) as an independent comorbid factor in cardiovascular and cerebrovascular diseases. The recurrent episodes of occlusion of upper airways during sleep result in pathophysiological changes that may predispose to vascular diseases, and we postulate that nitric oxide may be one of the mediators involved. This study investigates the levels of circulating nitric oxide (NO), measured as serum nitrites and nitrates, in the early morning in OSA subjects compared with control subjects, and the effect of overnight nasal continuous positive airway pressure (nCPAP) in OSA subjects. Thirty men with moderate to severe OSA (age = 41.9 +/- 9.0; apnea-hypopnea index, AHI = 48.0 +/- 18.1) were compared with 40 healthy men (age = 40.6 +/- 5.4; AHI = 1.4 +/- 1.2). Serum nitrite/nitrate levels were significantly lower in OSA subjects (OSA = 38.9 +/- 22.9 microM, control subjects = 63.1 +/- 47.5 microM, p = 0.015). There was significant negative correlation between serum nitrites/nitrates and the following parameters: AHI (r = -0.389, p = 0.001), oxygen desaturation time (r = -0.346, p = 0.004), and systolic blood pressure (BP) (r = -0.335, p = 0.005). Stepwise multiple linear regression with systolic or diastolic BP as the dependent variable identified serum nitrites/nitrates as the only significant correlate. Twenty-two OSA subjects had measurements of serum NO at baseline and after an overnight application nCPAP. There was significant increase in serum NO after nCPAP (baseline = 30.5 +/- 14.4 microM, after nCPAP = 81.0 +/- 82.1 microM, p = 0.01). This study demonstrates, for the first time, that circulating NO is suppressed in OSA, and this is promptly reversible with the use of nCPAP. The findings offer support for nitric oxide being one of the mediators involved in the acute hemodynamic regulation and long-term vascular remodeling in OSA.

Adult↗
PubMed1998

Obstructive sleep apnea syndrome: an experience in Chinese adults in Hong Kong.

OBJECTIVE: Epidemiologic studies in Caucasian populations suggested that symptomatic obstructive sleep apnea (OSA) occurred at a prevalence of 1-10%. The condition has been increasingly recognised among the Chinese in Hong Kong. We therefore, summarize our experience with OSA at the Department of Medicine, The University of Hong Kong at Queen Mary Hospital from 1985-1996. METHODS: All clinic records concerning demographic data, anthropometric data, clinical features, polysomnographic findings and treatment were reviewed. RESULTS: One hundred and twenty-two patients were diagnosed to have OSA. Demographic and clinical features were similar to Caucasian data with a male predominance of 84%, a mean age of about 50 years, and obesity as a risk factor at a mean body mass index of 30.4, which was higher than that of the average local population, although lower than that of OSA patients in Caucasian series. About 27% of the patients have a body mass index (BMI) similar to or below the population average. Nearly all were habitual snorers, and the majority had excessive daytime sleepiness. On polysomnography, the mean apnea-hypopnea index was 38. Common associated medical conditions were hypertension (34%), diabetes mellitus (10%), ischemic heart disease (9%), hyperlipidemia (6%). Most patients were managed successfully with nasal continuous positive airway pressure. Treatment with oral appliances for milder cases is being explored. CONCLUSIONS: OSA has been increasingly recognised among Chinese adults in Hong Kong in the past decade. Demographic features were similar to Caucasian data. The majority of patients were overweight, although 27% were not, and further investigation on the contribution of faciomaxillary morphology to OSA in this group is warranted.

Aged↗
PubMed1997

Inability of physicians to use metered-dose inhalers.

The effectiveness of antiasthmatic therapy with metered-dose inhalers (MDIs) is usually limited by defective inhalational technique. This study surveyed the MDI inhalation performance and knowledge of 100 physicians whose performance (demarcated into six stages) and knowledge scores correlated (r = 0.33, p < 0.001). Inhalation performance scores for shaking the canister, full expiration prior to using the MDI, breath holding thereafter, and positioning of the mouth-piece correlated with their corresponding knowledge scores (p < or = 0.02). Training of physicians entailing actual instruction and supervision of inhalational maneuvers may enhance the ability of doctors to use MDIs and facilitate better patient supervision.

Administration, Inhalation↗
PubMed1995

Incomplete catch-up growth in low birthweight Chinese infants in Hong Kong.

OBJECTIVE: To describe the early catch-up growth in length in Chinese low birthweight (< 2500 g) infants. METHODOLOGY: The infants (n = 181) were delivered between 1988 and 1993 and followed up at Queen Mary and Tsan Yuk Hospitals, Hong Kong. One third had a birthweight below -2SDS, most of whom were term or close-to-term babies small-for-gestational-age (SGA). The remaining babies were appropriate-for-gestational-age (AGA) in birthweight, but frequently born prematurely. RESULTS: The SGA group did not show a catch-up growth in height comparable to that reported on other recent studies, as 33-35% of the patients were still short at 6 and 12 months (7-12% for the AGA group). When comparing the postnatal mean growth curve of the SGA group with the mean curve of the AGA group there was little sign of catch-up growth. CONCLUSIONS: The results showed that Hong Kong SGA infants have an incomplete catch-up growth and for successful intervention the causative mechanisms have to be identified.

Body Height↗
PubMed1992

Response of preterm infants to hepatitis B vaccine.

Ninety-nine preterm infants with birth weights < 1750 gm had three doses of hepatitis B vaccine. Fifty-seven received the first dose when they weighed > or = 1000 gm (group 1) and 42 when they weighed > or = 2000 gm (group 2). The final seropositive rates and geometric mean titers of group 1 infants (79%, 61 mIU/ml) and group 2 infants (91%, 262 mIU/ml) were less than that of 43 normal term infants (100%, 679 mIU/ml).

Analysis of Variance↗
PubMed1986

Molecular epidemiology of human rotavirus infection in children in Hong Kong.

Rotavirus was identified in 256 (28.5%) of 899 hospitalized children with diarrhea during a 12-month period in Hong Kong. Fourteen electropherotypes were identified, and the appearance of each occurred in a sequential manner during the study period. One patient was shown to be mixedly infected with two prevalent electropherotypes. Sequential stool specimens from another case showed the appearance of an extra RNA band during the course of the diarrheal episode.

Child, Preschool↗
PubMed1985

Lipoxene: a new group of trihydroxy pentaenes of eicosapentaenoic acid derived from porcine leukocytes.

Incubation of porcine leukocytes with [1-14C]-15-hydroperoxyeicosapentaenoic acid (15-HPEPE) results in the formation of a group of polar metabolites which after separation and purification by RP-HPLC and SP-HPLC were found to be a series of new compounds containing three hydroxy groups and four conjugated double bonds. The structures of these new metabolites were established by U. V. spectrophotometry and GC/MS to be trihydroxy pentaenes of EPA, i.e., 5,6,15-trihydroxy-7,9,11,13,17-eicosapentaenoic acid and 5,14,15-trihydroxy-6,8,10,12,17-eicosapentaenoic acid. Because of the additional double bond at C17-18, these two new metabolites of EPA were proposed to be lipoxene A and lipoxene B, respectively.

Animals↗
PubMed1979

Identification of the C. coli dnaK (groPC756) gene product.

The E. coli dnaK (groPC756) gene product is essential for bacteriophage lambda DNA replication. Bacterial DNA segments carrying this gene have been cloned onto a bacteriophage lambda vector. The product of the dnaK gene has been identified on SDS polyacrylamide gels after infection of UV-irradiated E. coli cells. The dnaK gene codes for a polypeptide with an apparent molecular weight of 93,000-Mr. Transducing phages carrying amber mutations in the dnaK gene fail to induce the synthesis of the 93,000-Mr polypeptide chain upon infection of sup+ bacteria, but do so upon infection of supF bacteria. E coli carrying the dnaK756 mutation are, in addition, temperature sensitive for growth at 43 degrees C. It is shown that the dnaK756 mutation results in an overproduction of the dnaK gene product at that temperature.

Bacterial Proteins↗