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Biomedical subjects

K K Lo

Publications and source records attributed to K K Lo.

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

Evaluation on the antipruritic role of transcutaneous electrical nerve stimulation in the treatment of pruritic dermatoses.

BACKGROUND: Pruritus is a common and sometimes distressing symptom in many dermatological conditions. Response to conventional pharmaceutical agents may not be satisfactory, and adverse effects are real problems. OBJECTIVE: To evaluate the short-term efficacy and adverse effects of transcutaneous electrical nerve stimulation (TENS) for ameliorating pruritus in patients with dermatoses. METHODS: A prospective 1-week study using TENS given once daily for treating pruritic dermatoses in 5 patients. RESULTS: Significant amelioration of pruritus was obtained without adverse effect referable to TENS treatment, and a subjective reduced use of conventional topical drugs was also reported by all patients. CONCLUSIONS: TENS is a useful aramentarium for short-term amelioration of pruritus in pruritic dermatoses. Long-term efficacy and safety await further studies.

Adolescent↗
PubMed1999

Multiresolution browsing of pathology images using wavelets.

Digitized pathology images typically have very high resolution, making it difficult to display in their entirety on the computer screen and inefficient to transmit over the network for educational purposes. Progressive zooming of pathology images is desirable despite the availability of inexpensive networking bandwidth. An efficient progressive image resolution refining system for on-line distribution of pathology image using wavelets has been developed and is discussed in this paper. The system is practical for real-world applications, pre-processing and coding each 24-bit image of size 2400 x 3600 within 40 seconds on a Pentium II PC. The transmission process is in real-time. Besides its exceptional speed, the algorithm has high flexibility. The server encodes the original pathology images without loss. Based on the image request from a client, the server dynamically generates and sends out the part of the image at the requested scale and quality requirement. The algorithm is expandable for medical image databases such as PACS.

Algorithms↗
PubMed1998

Colonic diverticulosis in Hong Kong: distribution pattern and clinical significance.

This is a retrospective study on the prevalence of diverticulosis in Hong Kong Chinese adults. Eight-hundred and fifty-eight consecutive barium enema examinations over a period of 18 months (January 1995-June 1996) were analysed. Results show that the prevalence of diverticulosis in our community is 25.1% with no significant difference between male and female adults. The prevalence is lower than Western countries but higher than in Asia. Moreover, the peak prevalence is at the 50-79 years age group with lower prevalence in the older age groups. This may be explained by the rapid rise in prevalence in the younger age groups so that the age-related increase in prevalence become obscured. We postulate that this may be due to Western cultural influence in our diet and lifestyle. There is no significant difference in the symptomatology of patients with and without diverticulosis, supporting the idea that diverticulosis alone is usually asymptomatic. There is predominance of right hemicolon involvement in our subjects, in contrast to the left hemicolon predominance in the Caucasian population. Of patients with diverticulosis, 55.3% have only right-sided involvement and 32.6% have bilateral involvement. Only 12.1% of patients with diverticulosis have exclusively left hemicolon involvement. Caecal and ascending colon diverticula are found in 6.4% and 17.6% of all the adults under study, respectively. Clinicians caring for patients from our community should take note of this high frequency of caecal and ascending colon diverticulosis as caecal and ascending colon diverticulitis is notoriously difficult to diagnose clinically.

Adult↗
PubMed1998

Porokeratotic eccrine ostial and dermal duct naevus with dermatomal trunk involvement: literature review and report on the efficacy of laser treatment.

Porokeratotic eccrine ostial and dermal duct naevus (PEODDN) is a rare, benign hamartomatous malformation involving the eccrine sweat duct. The existence of filiform keratinous plugs that represent cornoid lamellae overlying dilated infundibula of eccrine ducts is a distinctive feature and the presence of associated abnormal dermal ducts is frequent. We report a patient with PEODDN who exhibited lesions on the left side of her chest. Cases of PEODDN reported in the literature are reviewed. Our experience in treating this patient with ultrapulsed carbon dioxide laser is also presented.

Eccrine Glands↗
PubMed1998

The evolution of stigmata of hemorrhage in bleeding peptic ulcers: a sequential endoscopic study.

BACKGROUND AND STUDY AIMS: Stigmata of hemorrhage in bleeding peptic ulcers have prognostic characteristics. In the present study, the evolution of these stigmata was studied prospectively using daily endoscopic examinations. PATIENTS AND METHODS: From January 1989 to October 1989, 778 consecutive patients with bleeding peptic ulcers underwent endoscopy within 24 hours of admission. The bleeding peptic ulcers were assigned by three endoscopists to five categories, those with: a) active bleeding, b) a nonbleeding visible vessel, c) adherent clot, d) dot, or e) a clean base. Actively bleeding ulcers were treated by epinephrine injection. Ulcers with nonbleeding visible vessels, adherent clots, or dots were left untreated. Daily endoscopic examinations were carried out for three subsequent days, or until the ulcer base became clean. RESULTS: On day 0, there were 56 actively bleeding ulcers (7%), 62 ulcers with visible vessels (8%), 104 with adherent clots (13%), 182 with flat dots (23%), and 374 with a white base (48%). On the subsequent three days, 24 of 62 ulcers with visible vessels (39%), 30 of 104 with adherent clots (29%), 24 of 182 with dots (13%), and 19 of 374 with a clean base (5%) on day 0 re-bled endoscopically or clinically, or both. The overall rebleeding risk was 9.9%, 4.9%, and 2.7% on days 1, 2, and 3, respectively. CONCLUSIONS: Stigmata of hemorrhage in bleeding peptic ulcers are predictive of rebleeding. They represent intermediate phases in the evolution of bleeding vessels into clean-based ulcers. The associated rebleeding risk diminishes as the vessel disappears from the ulcer base.

Endoscopy, Gastrointestinal↗
PubMed1998

Retroperitoneal ancient schwannoma: review of clinico-radiological features.

A case is reported here of an ancient schwannoma in the retroperitoneum. The findings of abdominal ultrasound and CT in a patient with a retroperitoneal ancient schwannoma are presented, and the clinical and radiological features of this unusual tumour are reviewed. The presence of a large, well-delineated complex cystic mass in the deep soft tissues should raise the possibility of an ancient schwannoma. It is important to recognize these tumours as benign with excellent prognosis so as to avoid unnecessary radical surgery.

Aged↗
PubMed1998

Treatment of vitiligo with autologous epidermal transplantation using the roofs of suction blisters.

We report our experience of autologous epidermal transplantation for three patients with vitiligo. The vitiligo in two patients was stable whereas that in the third was active. Autologous epidermal transplantation using suction blister roofs from normally pigmented skin was performed following the failure to repigment skin using topical steroid and/or psoralen-ultraviolet A treatment. Grafts were well taken in all three patients. Satisfactory repigmentation was noted in the two patients who had stable vitiligo; there were no complications except for mild hyperpigmentation at the donor areas. For the patient who had active vitiligo, depigmentation of the graft and concomitant Koebner's phenomenon at the donor site were observed 3 weeks after the procedure. We conclude that autologous epidermal transplantation using the roofs of suction blisters is an excellent and safe repigmenting procedure for stable, localised vitiligo and that active disease precludes transplantation.

Journal Article↗
PubMed1995

Cutaneous protothecosis: report of a case in Hong Kong.

We report a patient who presented with recalcitrant ulcerated papules and plaques on both legs. Histopathology revealed protothecosis, and subsequent culture of the lesions grew Prototheca wickerhamii. Gradual resolution of the ulcers occurred on treatment with itraconazole.

Aged↗
PubMed1995

Cutaneous tuberculosis in Hong Kong: a 10-year retrospective study.

BACKGROUND: Cutaneous tuberculosis was once a relatively common skin disease in Hong Kong. Tuberculosis verrucosa cutis was the commonest type. Because the last survey was carried out 25 years ago, it was thought necessary to find out the new incidence and pattern of this important disease in this locality. METHODS: A 10-year (1983-1992) retrospective survey on the epidemiologic and clinicobacteriologic aspects of cutaneous tuberculosis had been done in the public sector of Hong Kong. The records of the confirmed cases were retrieved for statistical analysis. RESULTS: A total of 176 cases are included in the final analysis. This represents 0.066% of all new skin cases seen during the 10-year period. Among these, 79.5% are erythema induratum, 6.3% lupus vulgaris, and 4.5% tuberculosis verrucosa cutis. They are further divided into true cutaneous tuberculosis (14.8%, n = 26) and the tuberculide (85.2%, n = 150). Among the patients with true tuberculosis, 42.3% had lupus vulgaris, 30.8% had tuberculosis verrucosa cutis, and 26.9% had scrofuloderma. Among the tuberculides, erythema induratum accounted for 93.3%. CONCLUSIONS: Cutaneous tuberculosis is now uncommon in Hong Kong. Tuberculosis verrucosa cutis is no longer the commonest type in Hong Kong as described in some textbooks. Erythema induratum is now the most common among the total cases and lupus vulgaris is the most common among the true cutaneous forms of tuberculosis.

Adolescent↗
PubMed1995

Rapid decline in penicillinase-producing Neisseria gonorrhoeae in Hong Kong associated with emerging 4-fluoroquinolone resistance.

OBJECTIVE--To study the changes in penicillinase-producing (PPNG) and high-level tetracycline resistant (TRNG) Neisseria gonorrhoeae isolated in Hong Kong associated with emerging quinolone resistance (QRNG) over a two year period from November 1992 to October 1994. MATERIALS AND METHODS--Four thousand and eighty-six strains of Neisseria gonorrhoeae isolated, of which 432 were PPNG, were examined for susceptibilities to penicillin and tetracycline by an agar dilution method using the breakpoint minimum inhibitory concentrations (MICs) of 1 and 10 mg/1 respectively. Ofloxacin susceptibility was done using 0.1 and 1 mg/l. Penicillinase production was detected by performing the chromogenic cephalosporin nitrocefin test on all penicillin resistant (MIC > 1 mg/l) strains. RESULTS--Three thousand and eighty (75.4%) and 79 (1.9%) strains were found to be penicillin resistant and TRNG (MIC > 10 mg/l) respectively. Sixty-nine strains (1.7%) were resistant to both, of which 54 (1.3%) were PPNG. Three strains were multiply-resistant to penicillin, tetracycline and ofloxacin; however, none was PPNG. While the percentage of penicillin resistant strains remained stable (mean 75.5%, SD 7.0), TRNG decreased from 4.5% to 2.1%. The most dramatic change was the sharp decline of PPNG from 25.5% in January 1993 to 4.3% in October 1994, concurrent with a linear increase in strains with ofloxacin MIC > 0.1 mg/l. Significant clinical failure was seen in strains having ofloxacin MIC > 1 mg/l (QRNG), which increased drastically from 0.5% to 10.4% during the study period. Selection against PPNG and TRNG strains appeared to occur only when fully quinolone-susceptible strains first become less susceptible (MIC > 0.1 mg/l), but not when these less susceptible strains become fully resistant (MIC > 1 mg/l). CONCLUSION--PPNG is now no longer hyperendemic in Hong Kong. Emergence of QRNG is associated with rapid decline of both PPNG and TRNG. This is the first report of plasmid-curing effect of the 4-fluoroquinolones occurring on an ecological scale.

Drug Resistance, Microbial↗
PubMed1995

An open non-comparative pilot study with azithromycin in the treatment of non-gonococcal urethritis in the sexually transmitted disease clinics in Hong Kong.

The aim of this study is to find out the efficacy and safety of azithromycin in the treatment of males with uncomplicated non-gonococcal urethritis. It is an open, non-comparative study carried out in the major sexually transmitted disease clinics in Hong Kong. The subjects were 45 male outpatients with clinical symptoms and signs of acute non-gonococcal urethritis. Patients presenting with acute urethritis were examined and non-gonococcal urethritis were examined and non-gonococcal urethritis was daignosed by the positive urethral smear for white blood cells but negative for gonococcus. They were given a single 1 gram oral dose of azithromycin at the clinic. Follow-ups after one and two weeks to examine for cure and adverse events were made. The result showed that 35 out of 42 evaluable patients were cleared of urethritis. Only 2 out of 22 chlamydial antigen positive patients still remained positive at the last visit. Adverse events were not uncommon but all were only mild. We concluded that 1 gram single dose of azithromycin was effective and well tolerated in the treatment of non-gonococcal urethritis in male patients.

Acute Disease↗
PubMed1993

Ofloxacin susceptibilities of 5,667 Neisseria gonorrhoeae strains isolated in Hong Kong.

Of 5,667 strains of Neisseria gonorrhoeae isolated from the Government Social Hygiene (sexually transmitted disease) Clinics in Hong Kong from 1990 to 1992, there was a trend toward an increase in the percentage of strains resistant in vitro to 0.01 and 0.1 microgram of ofloxacin per ml, with 54.3 and 5.5% resistant strains, respectively, in January 1990, rising to 95.3 and 41.5%, respectively, in December 1992. The percentage of strains for which the MIC is > 1 microgram/ml remains stable, and no clinical failure has yet been seen. This trend of decreasing susceptibility warrants close monitoring when ofloxacin is used as first-line treatment for gonorrhea.

Gonorrhea↗
PubMed1993

Exclusion of candidate genes from a role in cleft lip with or without cleft palate: linkage and association studies.

Candidate genes and marker loci for cleft lip/palate (CL/P) were tested using linkage analyses and association studies. Eight British families with apparent autosomal dominant inheritance of non-syndromic CL/P participated in the linkage analyses while the association analyses involved 61 unrelated British white people with CL/P and 60 controls. The report of an association between RARA (17q21) and unrelated Australian persons with CL/P (p = 0.016) was not confirmed in British CL/P persons (chi 2 = 0.954, p > 0.1). There was also no evidence of linkage between RARA and the eight CL/P families (Z = -3.211, theta = 0.001). Linkage was excluded between familial CL/P and F13A1 (map position 6p24-25) with an observed maximum lod score of Z = -2.052 at theta = 0.05. No association was found between alleles at VIM (10p13) and the British CL/P subjects (chi 2 = 0.110, p > 0.5). Multipoint analysis excluded linkage between familial CL/P and the markers D1S65 and D1S58 which flank the Van der Woude syndrome locus with a maximum lod score of Z = -4.0. This suggests that the genetic defect underlying VWS is not the same as in non-syndromic CL/P. There was no evidence of linkage between CRTL1 (5q15) and the eight CL/P families (Z = -3.466, theta = 0.05).

Base Sequence↗
PubMed1991

Injection or heat probe for bleeding ulcer.

A prospective randomized trial was performed to compare the efficacy of endoscopic epinephrine injection and heat probe treatment in actively bleeding peptic ulcers. Emergency endoscopy in 1758 patients over an 18-month period identified 132 patients with active ulcer bleeding. They were randomized to receive either endoscopic epinephrine injection or heat probe treatment. After endoscopy, the patients were transferred to the surgical gastroenterology ward and were managed by surgeons unaware of the treatment option. Bleeding was initially controlled in 96% by epinephrine injection and in 83% by heat probe (P less than 0.05). There was no significant difference in outcome as measured by transfusion requirement (4.5 units vs. 3.8 units), emergency surgery (20% vs. 22%), hospital stay (8 days vs. 7 days), and mortality (2 vs. 4) between the injection group and the heat probe group. Two patients in the heat probe group experienced perforation. We conclude that both endoscopic epinephrine injection and heat probe treatment are effective in stopping bleeding from actively bleeding ulcers. Epinephrine injection is technically easier to perform and has a higher initial success rate.

Adolescent↗
PubMed1989

Construction of a calorimeter prototype with a high sensitivity pulsed signal detection circuit.

A calorimeter based on a Wheatstone bridge detector is considered to be an ideal absolute absorbed dose measuring device. One drawback of the calorimeter is that its output signals are extremely small. The signal size can be increased by increasing the bridge excitation voltage, which, however, may lead to excess self-heating of a temperature-sensing thermistor in the calorimeter detector and may require corrections. The use of pulsed excitation was investigated in this study in place of a conventional DC excitation to induce higher bridge output voltage while keeping the average self-heating of a thermistor to a reasonably low value. Performance evaluations of our prototype pulsed calorimeter are presented.

Calorimetry↗
PubMed1988

Heater-probe treatment of bleeding peptic ulcers.

Fifty-six patients with actively bleeding peptic ulcers were treated with the heater-probe unit. Initial haemostasis was achieved in 48 patients (85.7%). The mean number of heater-probe applications was 6.7 pulses at a setting of 25-30 J. Rebleeding occurred in 11 patients (19.6%). Five were successfully treated with repeat heater-probe treatment, 5 required emergency surgery, and 1 rebleeding was stopped by adrenaline injection. The complications included one perforation in a patient with duodenal ulcer. The overall mortality was 2/56 (3.6%). Heater-probe treatment is an effective and safe haemostatic method for controlling actively bleeding ulcers.

Adult↗