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Biomedical subjects

M Ip

Publications and source records attributed to M Ip.

At least 37 records · Page 2Linked to original sources
PubMed1999

Differentiation of degenerative retinoschisis from retinal detachment using optical coherence tomography.

OBJECTIVE: To assess the potential of optical coherence tomography (OCT) to differentiate retinoschisis from retinal detachment. Optical coherence tomography is a noninvasive, noncontact imaging method that produces high-resolution, cross-sectional images of ocular tissue. DESIGN: Retrospective case series. PARTICIPANTS: Thirteen eyes of 12 patients with the differential diagnosis of retinoschisis versus retinal detachment. METHODS: Differentiation between retinoschisis and retinal detachment was established from both ophthalmoscopic and OCT examinations. MAIN OUTCOME MEASURE: Ability of OCT to differentiate retinoschisis from retinal detachment was measured. RESULTS: Thirteen eyes of 12 patients with retinal elevation were examined with OCT. The cross-sectional view produced by OCT was effective in distinguishing retinoschisis from retinal detachment. Optical coherence tomography images of retinoschisis show a splitting of the neurosensory retina. The OCT images of retinal detachment show separation of full-thickness neurosensory retina from the retinal pigment epithelium band. The OCT images correlated with the clinical impression in all 13 cases. CONCLUSIONS: Based on this series of cases, OCT is a potentially useful new test that may be used to distinguish retinoschisis from rhegmatogenous retinal detachment.

Adult↗
PubMed1999

Transpupillary thermotherapy of occult subfoveal choroidal neovascularization in patients with age-related macular degeneration.

OBJECTIVE: To evaluate the efficacy of transpupillary thermotherapy for the treatment of occult subfoveal choroidal neovascularization (CNV) in patients with age-related macular degeneration. DESIGN: A retrospective, noncomparative case series. PARTICIPANTS: Sixteen eyes of 15 consecutive patients who presented with occult subfoveal choroidal neovascularization secondary to age-related macular degeneration. INTERVENTION: After informed consent was obtained, 16 eyes of 15 patients were treated with transpupillary thermotherapy. All patients underwent pretreatment fluorescein angiography and were deemed untreatable by the Macular Photocoagulation Study standard. Transpupillary thermotherapy was delivered using a diode laser at 810 nm. A variable spot size of 1.2 mm, 2.0 mm, or 3.0 mm was used depending on the size of CNV. The diode laser was delivered through a contact lens, and treatment was initiated in one spot for 60 seconds' duration at a power range between 360 and 1000 mW. The end point was an area of no visible color change to a light-gray appearance. MAIN OUTCOME MEASURES: In all eyes, outcome was assessed by Snellen chart visual acuity and clinical examination. In 10 of 16 eyes, preoperative and postoperative fluorescein angiography and optical coherence tomography were available. In the remaining 6 of 16 eyes, exudation was measured by postoperative clinical examination alone. RESULTS: Three eyes (19%) showed a two-or-more-line improvement in visual acuity over a period of 6 to 25 months. Mean follow-up was 13 months. Visual acuity remained stable (no change or one-line improvement) in nine treated eyes (56%). The remaining four eyes (25%) showed a decline (equal to one-line worsening or greater) in visual acuity. Fifteen eyes (94%) demonstrated decreased exudation on fluorescein angiography, optical coherence tomography, and/or clinical examination. CONCLUSIONS: Transpupillary thermotherapy shows no deleterious side effects in treating occult subfoveal choroidal neovascularization. A randomized, prospective study is necessary to evaluate treatment efficacy.

Aged↗
PubMed1999

Evidence of clonal dissemination of multidrug-resistant Streptococcus pneumoniae in Hong Kong.

The relationship between the phenotypic and genotypic characteristics of 105 penicillin-intermediate or -resistant Streptococcus pneumoniae isolates saved during 1994 to 1997 at the Prince of Wales Hospital and Pamela Youde Nethersole Eastern Hospital, Hong Kong, was studied. The pbp genes for penicillin-binding proteins 1a, 2b, and 2x for each isolate were amplified by PCR, and the products were digested with restriction enzymes HinfI and AluI. A combination of the pulsed-field gel electrophoresis (PFGE) profiles, pbp fingerprints, and phenotypic characteristics of capsular types and antibiograms enabled these isolates to be divided into four major groups. Seventy-four percent (78 of 105) of the strains, belonging to serotypes 23F, 19F, and 14, showed indistinguishable pbp fingerprint patterns (group A1, 1-1-1, 1-1-1), with PFGE patterns belonging to group A and its subtypes, suggesting that these strains were closely related. Eighty-three percent (65 of 78) of these isolates were also resistant to tetracycline, erythromycin, chloramphenicol, and trimethoprim. The type 23F isolates were indistinguishable from representative strains of the Spanish 23F clone by these molecular methods, indicating that these strains may be variants of the Spanish 23F clone. Serotype 6B accounted for 19% (20 of 105) of the isolates with reduced penicillin susceptibility and was made up of variants belonging to four different pbp fingerprint groups with the PFGE pattern group B, the predominant group being indistinguishable from that of the Spanish 6B clone. Other PFGE and fingerprint groups were mainly obtained from penicillin-susceptible strains of various serotypes. The results suggest that the rapid emergence of drug-resistant S. pneumoniae in Hong Kong has been due to the rapid dissemination of several successful clones.

Bacterial Capsules↗
PubMed1999

Transpupillary thermotherapy.

Hyperthermia has long been recognized as potentially useful in the treatment of human neoplasms. Only recently has technology allowed hyperthermic treatment to be delivered to ocular structures in the form of ultrasound, microwave, or ferromagnetic energy. A novel technique, transpupillary thermotherapy, allows the direct application of hyperthermic energy to posterior segment ocular structures. The treatment of two posterior segment diseases, choroidal melanoma and choroidal neovascularization attributable to age related macular degeneration, are reviewed in this article.

Choroid Neoplasms↗
PubMed1998

Critical care ethics in Hong Kong: cross-cultural conflicts as east meets west.

The practice of critical care medicine has long been a difficult task for most critical care physicians in the densely populated city of Hong Kong, where we face limited resources and a limited number of intensive care beds. Our triage decisions are largely based on the potential of functional reversibility of the patients. Provision of graded care beds may help to relieve some of the demands on the intensive care beds. Decisions to forego futile medical treatment are frequently physician-guided family-based decisions, which is quite contrary to the Western focus on patient autonomy. However, as people acquire knowledge about health care and they become more aware of individual rights, our critical care doctors will be able to narrow the gaps between the different concepts of medical ethics among our professionals as well as in our society. An open and caring attitude from our intensivists will be important in minimizing the cross-cultural conflict on the complex issue of medical futility.

Aged↗
PubMed1998

Ethical decision-making in critical care in Hong Kong.

OBJECTIVES: Biomedical ethics has assumed an increasingly important role in medicine over the past 30 yrs, and its development has served the important goal of protecting patients' rights and interests. However, medical ethics has evolved within a Western tradition, and conflict often arises when trying to apply Western medical ethics to patients from other cultures. Using Hong Kong as an example, this article reviews the nature and sources of cross-cultural conflict in the intensive care unit setting that often arises between physicians trained in Western medicine and patients from a Chinese cultural background. DATA SOURCES: This article draws on the first author's experience as a critical care physician in Hong Kong, and on a review of the literature on cross-cultural interactions in medicine. STUDY SELECTION: Studies were selected that contrasted the approaches of different cultures to common ethical dilemmas in medicine. Review articles examining the relationship between culture and ethics were also selected. CONCLUSIONS: Hong Kong presents an interesting case study because of the coexistence of Western and Chinese medicine in a predominantly Chinese population that practices many Chinese cultural traditions. Whereas contemporary Western medical ethics focuses on individual rights, autonomy, and self-determination, traditional Chinese societies place greater emphasis on such community values as harmony, responsibility, and respect for parents and ancestors. Specific areas of cross-cultural conflict include: the role of the patient and family in medical decision-making; the disclosure of unfavorable medical information to critically ill patients; the discussion of advance directives or code status with patients; and the withholding or withdrawal of life support.

China↗
PubMed1998

Kartagener's syndrome: a re-visit with Chinese perspectives.

The objective of this study was to evaluate the clinical, radiological investigation profiles, and ciliary function and ultrastructure in Chinese patients with Kartagener's syndrome (presence of dextrocardia, sinusitis and bronchiectasis). All patients with dextrocardia were assessed for the presence of sinusitis and bronchiectasis in our hospital network. Patients identified with Kartagener's were assessed when they were at steady state for their bronchiectasis. Seven cases (4 males; mean age 34.9 years) were identified and systematically reviewed. The mean 24 h sputum volume was 26.6 +/- 32.77 mL/day and the patients suffered from a mean of 2.9 exacerbations/year. Nasal symptoms (anosmia in one, obstruction in six and persistent discharge in three patients) were common. Only two cases (1 M) were married and both had normal fertility. Lung function assessment showed a mean FEV1/FVC of 83.3 +/- 38.78/86.5 +/- 36.72 (% predicted) with little reversibility. High resolution computerized tomography (HRCT) revealed bronchiectactic involvement of the lower lobes in seven and middle lobe/lingula in four cases. Assessment of alpha-1-anti-trypsin, aspergillus precipitins, auto-antibodies and serology for Pseudomonas pseudomallei was normal. Sputum culture yielded Pseudomonas aeruginosa in three, Haemophilus influenzae in three and commensals in one case. Phase contrast microscopy assessment of respiratory cilia, obtained by brushing the inferior turbinate, revealed that most of the mucosa was unciliated. The mean ciliary beat frequency was 5.2 +/- 6.76 Hz (range 0-13.7; normal range 12-18 Hz). Four patients had immotile cilia whilst the rest had normal ciliary movement. Transmission electron microscopy showed the absence of dynein arms in four patients. The results of this study show that patients with Kartagener's syndrome may have normal ciliary ultrastructure and the absence of dynein arms is not necessarily associated with ciliary immotility. The presence of ciliary immotility might have prognostic value as these patients appear to have more active bronchiectasis. Our experience on this series should help clinicians in the investigation and management of these patients.

Adolescent↗
PubMed1998

High-resolution computed tomography of bronchiolitis obliterans syndrome after bone marrow transplantation.

High-resolution computed tomography (HRCT) has been described to be useful in assessing bronchiolitis obliterans (BO) syndrome in the transplanted lung. Currently, BO syndrome is diagnosed if lung function deterioration shows persistent or progressive irreversible airflow obstruction, with FEV1 of less than 80% of baseline values, without clinical evidence of infection. The aim of this study is to assess the value of HRCT in evaluating BO syndrome after allogenic bone marrow transplantation (BMT). Fourteen HRCT scans were performed in 6 women and 3 men with moderately severe irreversible airflow obstruction and a clinical diagnosis of BO syndrome after BMT. Two patients had normal HRCT scans. In the remaining 7 patients, 7 of 11 HRCT scans were abnormal, with non-specific findings of bronchial dilatation (1), consolidation (2), hypoattenuated areas (4) and vascular attenuation (4). In comparison with the consistency of positive HRCT findings of BO syndrome in transplanted lungs, HRCT surveillance for BO syndrome in post-BMT patients with clinically established disease is of limited value, unless other pulmonary complications such as opportunistic infections are to be excluded.

Adult↗
PubMed1998

Rhodococcus equi lung abscess complicating Evan's syndrome treated with corticosteroid.

We report a case of Rhodococcus equi, an unusual pathogen, causing a right upper lobe lung abscess in a patient with Evan's syndrome (auto-immune haemolytic anaemia and thrombocytopenia) who was treated with high-dose corticosteroid therapy. The patient was treated successfully with clarithromycin, vancomycin, ciprofloxacin and imipenen which appear to be effective in combination for this unusual condition in which the treatment regimen has been controversial.

Actinomycetales Infections↗
PubMed1997

Systemic inflammatory response syndrome in intravascular lymphomatosis.

Intravascular lymphomatosis (IVL) is characterized by an intravascular proliferation of atypical mononuclear cells of haematopoietic origin occluding small blood vessels including venules, capillaries and small arteries, and can affect virtually any organ in the body. Clinically, the most common manifestations are involvement of the skin and central nervous system, although various organ involvement has been described. We report a patient who presented with fever and rash, and succumbed with acute neurological symptoms and systemic inflammatory response syndrome (SIRS) with no evidence of infection. The postmortem revealed disseminated involvement of virtually every organ with IVL, the malignant cells being of T-cell origin, which may secrete cytokines including tumour necrosis factor and interleukin-1, that are believed to be mediators in SIRS. In the absence of evidence of infection on microbiology and pathology, we postulate that the features of SIRS in this patient was due to the disseminated malignancy itself.

Adult↗
PubMed1997

Systemic lupus erythematosus patients with respiratory symptoms: the value of HRCT.

Ten Chinese patients with systemic lupus erythematosus (SLE) and with persistent respiratory symptoms were evaluated with high resolution computed tomography (HRCT), chest radiographs and lung function tests. Fourteen of 15 HRCT scans performed were abnormal. The predominant disease pattern, seen in 60% of patients, was one of chronic interstitial lung disease with honeycombing, architectural distortion, parenchymal bands, pleural irregularity, and a lower zone predominance. Three of 10 patients had histological evidence of either lung fibrosis or interstitial pneumonitis. Airways disease and pleural thickening were seen in 20% and 87% of scans, respectively. Pleural thickening and honeycombing were present in 53% and 20% of chest radiographs, respectively. All concurrent lung function tests were abnormal. Reduced diffusion capacity of carbon monoxide (DLCO/VA) was observed in 60% of lung function tests. There was no correlation between duration of disease and DLCO/VA. However, pathological reduction of DLCO/VA was seen in 71% of patients with honeycombing, and 88% of patients with ground glass opacity. Our study has documented a high incidence of HRCT features of chronic lung destruction and a lower zone predominance in SLE patients with persistent respiratory symptoms.

Adult↗
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↗