Ethnic differences in vitamin D status, bone and body composition in South Asian indian and caucasian men.

Background: High prevalence of metabolic abnormalities and poor bone health in ethnic minorties may stem from differences in body composition and alterations in endocrine milieu. South Asian Indians (SAIs) are at greater risk for metabolic syndrome (MetS) and poor bone health than Caucasians. Often these differences are reported later in life and/or in a resident immigrant population compared to a Caucasian population. In this study, we determined whether vitamin D status, bone, body composition differed in young SAIs and Caucasians. Notably we compared differences amongst recent SAI immigrants and Caucasians. Methods: We examined differences in bone density, body composition, serum 25-hydroxy vitamin D (s25(OH)D), parathyroid hormone (sPTH), vitamin D binding protein (sDBP), osteocalcin (sOC), and dietary intakes in young healthy SAI and Caucasian men. Results: Sixty men (N = 30 SAIs and N = 30 Caucasians) with a mean age of 27.8 ± 7.4 years completed the study. Compared to the Caucasians, SAIs had statistically significantly lower s25(OH)D and higher sPTH (p < 0.05). We also found that s25(OH)D was negatively associated with sPTH only among the SAIs (r = - 0.389, p = 0.037). Also, lean mass% (LM%) and fat-free mass% (FFM%) were lower in SAIs (p < 0.05) compared to caucasians. s25(OH)D correlated with nearly all body composition parameters, while sPTH correlated negatively with LM% and FFM%, and positively with FM% (all p < 0.05) in the Caucasian group. Bone mineral density at most sites were also significantly lower (p < 0.05) in the SAI's compared to caucasians. Conclusion: Young SAIs have a poor vitamin D status and less favorable bone and body composition parameters compared to Caucasians. These findings highlight the possible complex interplay between skeletal and metabolic health in different ethnicities which may be evident early on in life. Interventions to improve bone and metabolic health should therefore target younger ethnic minorities.

Early determinants of atherosclerosis in paediatric systemic lupus erythematosus.

OBJECTIVES: To assess traditional and non-traditional cardiovascular risk factors and to determine the prevalence and correlates of early vascular markers of atherosclerosis in paediatric systemic lupus erythematosus (pSLE). METHODS: Fifty-four adolescents with pSLE had cardiovascular risk factor assessment, disease activity and vascular testing including carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), arterial stiffness measures, and myocardial perfusion studies. RESULTS: The traditional risk factors of hypertension, elevated triglycerides, apolipoprotein B, haemoglobin A1c and insulin levels and non-traditional risk factors of elevated homocysteine and fibrinogen were present (all p<0.001). Some arterial stiffness measures, central pulse wave velocity and characteristic impedance were elevated (p<0.001), but CIMT, FMD and myocardial perfusion were normal. Cumulative prednisone dose correlated with total cholesterol (r=0.5790, p<0.001) and elevated LDL-C (r=0.4488, p=0.0012). Hydroxychloroquine treatment correlated negatively with total cholesterol (r=-0.4867, p=0.0002), LDL-C (r=-0.4805, p=0.0002) and apolipoprotein B (r=-0.4443, p=0.0011). In multivariate analysis LDL-C correlated with cumulative prednisone dose and negatively with hydroxychloroquine treatment (R2=0.40, p<0.001). CONCLUSIONS: An increased burden of traditional and non-traditional risk factors and early evidence of insulin resistance and increased central arterial stiffness were present in paediatric SLE. Disease-specific and therapy-related factors are likely modifying these cardiovascular risk profiles warranting prospective longitudinal studies.

Enteral feeding in duct-dependent congenital heart disease.

BACKGROUND: Infants with duct-dependent congenital heart lesions are treated with a prostaglandin E1 infusion. We aimed to describe the feeding strategies used at our institution in such infants, and to describe the incidence of necrotising enterocolitis (NEC) in this patient group, investigating whether enteral feeding is associated with a higher risk. METHODS: Patients diagnosed with hypoplastic left heart syndrome, coarctation of the aorta, pulmonary atresia, or transposition of the great arteries born over a defined period were identified. Premature infants, those with pre-existing gastrointestinal disease, and those who never received prostaglandin were excluded. Data were compared using univariable and multivariable logistic regression models. RESULTS: A total of 177 patients were identified, of them 18 received a diagnosis of suspected or confirmed NEC. There was no association between the diagnosis of NEC and enteral feeding (P = 0.9). CONCLUSIONS: Based on these data, there does not appear to be an association between enteral feeding and NEC in infants receiving prostaglandin.

Systemic haemodynamics in infants with vein of Galen malformation: assessment and basis for therapy.

Systemic haemodynamics in three infants with severe cardiac failure secondary to vein of Galen malformation (VGAM) were studied using two-dimensional and Doppler echocardiography. In all cases, ventricular outputs were over two times normal and superior vena caval flows up to 10 times normal reflecting high flow through the low-resistance fistula. Severe pulmonary hypertension, right heart dilatation and retrograde flow in the descending aorta were uniformly present. Systemic blood flow below the head and neck was reduced resulting in metabolic acidosis at presentation. Two infants had patent arterial ducts, in which flow was entirely right to left and on entering the aorta passed predominantly retrogradely towards the VGAM. These findings provide a basis for understanding the pathophysiology of cardiac failure in VGAM and support treatment with pulmonary and systemic vasodilating agents.

Primary non-Hodgkin's lymphoma of the nose and nasopharynx: clinical features, tumor immunophenotype, and treatment outcome in 113 patients.

PURPOSE: To study the clinical features and outcome for primary non-Hodgkin's lymphomas of the nose/nasopharynx (NNP-NHLs) according to immunophenotype. PATIENTS AND METHODS: One hundred thirteen Chinese patients with primary NNP-NHLs that belonged to the categories E, F, G, or H according to the Working Formulation (WF), with full immunophenotypic data and complete clinical follow-up data, were analyzed in this retrospective study. RESULTS: Ninety (79.6%) patients had localized (stage I or II) disease, while 23 (20.4%) had stage III or IV disease. The lymphomas in 51 (45.1%), 24 (21.3%), and 38 (33.6%) patients showed natural killer (NK)/T- (CD56-positive), T-cell, and B-cell immunophenotype, respectively. Seventy-three patients (65.8%) achieved a complete remission, of whom 34 (46.6%) subsequently relapsed. The median follow-up time for those alive was 88 months. The 5-year actuarial disease-free and overall survival rates were 34.4% and 37.9%, respectively. Multivariate analysis showed that only stage and immunophenotype were significant for survival. NK/T lymphomas were distinctive among the three immunophenotypes in the following aspects: the highest male-to-female ratio, more frequent involvement of the nasal cavity alone, higher risk of dissemination to the skin, more frequent development of hemophagocytic syndrome, and the worst prognosis (overall median survival, 12.5 months). CONCLUSION: The three immunophenotypes studied are shown to exhibit different clinical patterns. Since the NK/T phenotype carries the worst prognosis, patients who present with NNP-NHL should have their tumors analyzed for CD56 expression.

Molecular analysis of HLA DP and DQ genes associated with dermatitis herpetiformis.

HLA class II DQ and DP genes from dermatitis herpetiformis patients were amplified and analyzed using molecular probes and compared to those from celiac disease patients and to an HLA and ethnically matched control group. In dermatitis herpetiformis, as in celiac disease, the strongest association of disease was with the DQ subregion alleles DQB1*0201 and DQA1*0501 that are linked to the DRB1*0301 allele. DQB1*0201 determines the DQw2 serologic marker whereas DRB1*0301 determines the DRw17 serologic marker (formerly termed DR3). A DP subregion allele DPB1*0301 was increased and a constellation of DPB1 alleles that included DPB1*0202, *0901, and *1301 was decreased in dermatitis herpetiformis. DPB1*0101, an allele reported to be increased in celiac disease, was not increased in dermatitis herpetiformis. DP beta chains that lack a negatively charged amino acid residue at position 69 of the DP beta chain are significantly over-represented both in dermatitis herpetiformis and celiac disease patients with the DRw17, DQw2 haplotype, compared to healthy controls with that haplotype. These data favor a multigenic model for the contribution of HLA class II D region genes to dermatitis herpetiformis susceptibility. Further, they indicate that a specific DQ molecule, when present in combination with the product of one of several different DPB1 alleles, may contribute to susceptibility to the intestinal lesion, which is common to dermatitis herpetiformis and celiac disease.

CD56 (NKH1)-positive hematolymphoid malignancies: an aggressive neoplasm featuring frequent cutaneous/mucosal involvement, cytoplasmic azurophilic granules, and angiocentricity.

CD56 (NKH1) expression is a rare phenomenon in malignant lymphomas, mostly confined to those occurring in the nasal or nasopharyngeal region. In this study we provide a detailed clinicopathologic analysis of nine patients with CD56-positive hematolymphoid malignancies occurring in sites other than the upper aerodigestive tract. The disease occurred predominantly in young and middle-aged men (mean age, 40 years) who often presented with swinging fever, skin rash, and/or hepatosplenomegaly, usually in the absence of peripheral lymphadenopathy. There was frequent involvement of the skin and mucosal sites, such as the salivary gland, lungs, and small intestine. The disease pursued a highly aggressive course, with most patients dying within weeks despite cytotoxic therapy. Although the cytologic appearances and immunophenotypic profile varied from case to case, the group of tumors could be unified by two morphologic features, namely, the presence of azurophilic granules in the cytoplasm of the neoplastic cells and the frequent occurrence of angiocentric and angiodestructive infiltrates. Since CD56 reactivity appears to confer a poor prognosis in hematolymphoid malignancies, we recommended inclusion of CD56 antibody in the routine panel for immunophenotypic analysis.

Bone marrow involvement by nasal NK cell lymphoma at diagnosis is uncommon.

To look for subtle evidence of marrow involvement in nasal NK cell lymphoma at diagnosis, we retrospectively studied trephine biopsy specimens from 25 consecutive patients by 2 sensitive techniques: CD56 immunohistochemistry and Epstein-Barr virus-encoded RNA in situ hybridization (EBER ISH). Only 2 patients had marrow involvement by NK cell lymphoma at diagnosis. In 3 additional patients, marrow involvement developed during or after systemic recurrence. All 5 positive cases were revealed by EBER ISH, but only 3 cases showed CD56 immunoreactivity. Among the 5 cases, only 2 were recognized by morphologic assessment. All 5 patients died, often within a short period, compared with a mortality of 50% for patients without demonstrable marrow involvement. Marrow involvement is distinctly uncommon in nasal NK cell lymphoma at diagnosis, and EBER ISH is the most sensitive technique for the demonstration of occult NK cell lymphoma. Despite the low frequency of marrow involvement in nasal NK cell lymphoma, EBER ISH is worthwhile to identify the minor subgroup of patients with a high likelihood of early death due to disease and when autologous bone marrow or peripheral blood stem cell transplantation is contemplated.

Remote ischaemic preconditioning protects against cardiopulmonary bypass-induced tissue injury: a preclinical study.

OBJECTIVES: To test the hypothesis that remote ischaemic preconditioning (rIPC) reduces injury after cardiopulmonary bypass (CPB). DESIGN: Randomised study with an experimental model of CPB (3 h CPB with 2 h of cardioplegic arrest). Twelve 15 kg pigs were randomly assigned to control or rIPC before CPB and followed up for 6 h. INTERVENTION: rIPC was induced by four 5 min cycles of lower limb ischaemia before CPB. MAIN OUTCOME MEASURES: Troponin I, glial protein S-100B, lactate concentrations, load-independent indices (conductance catheter) of systolic and diastolic function, and pulmonary resistance and compliance were measured before and for 6 h after CPB. RESULTS: Troponin I increased after CPB in both groups but during reperfusion the rIPC group had lower concentrations than controls (mean area under the curve -57.3 (SEM 7.3) v 89.0 (11.6) ng.h/ml, p = 0.02). Lactate increased after CPB in both groups but during reperfusion the control group had significantly more prolonged hyperlactataemia (p = 0.04). S-100B did not differ between groups. Indices of ventricular function did not differ. There was a tendency to improved lung compliance (p = 0.07), and pulmonary resistance changed less in the rIPC than in the control group during reperfusion (p = 0.02). Subsequently, peak inspiratory pressure was lower (p = 0.001). CONCLUSION: rIPC significantly attenuated clinically relevant markers of myocardial and pulmonary injury after CPB. Transient limb ischaemia as an rIPC stimulus has potentially important clinical applications.

Non-invasive assessment of ventricular force-frequency relations in the univentricular circulation by tissue Doppler echocardiography: a novel method of assessing myocardial performance in congenital heart disease.

OBJECTIVE: To describe the first clinical application of a novel tissue Doppler derived index of contractility, isovolumic acceleration (IVA), in the assessment of the ventricular myocardial force-frequency relation (FFR) in the univentricular heart (UVH). DESIGN: Prospective study. SETTING: Tertiary referral centre. INTERVENTIONS: Non-invasive assessment of the myocardial FFR by tissue Doppler echocardiography during atrial pacing. RESULTS: IVA was used to measure the FFR of the systemic ventricle in patients with structurally normal hearts and in patients with UVHs. Basal IVA of the normal hearts (mean (SD) 1.9 (0.3) m/s2) was significantly greater than that of UVHs in patients with a dominant right ventricle (RV) (1.0 (0.3) m/s2) or left ventricle (LV) (0.8 (0.7) m/s2; p < 0.05 for both). Neither the absolute nor percentage change from basal to peak values of IVA with pacing differed between the three groups. Peak force developed by the normal LV was significantly greater than that of the UVH, dominant LV group but not different from that of the UVH, dominant RV group. CONCLUSION: Contractility at basal heart rate is depressed in patients with UVH compared with the normal LV. Analysis of ventricular FFRs exposes further differences in myocardial contractility. There is no evidence that contractile function of the dominant RV is inferior to that of the dominant LV over a physiological range of heart rates.

Optical bistability and self-oscillation of a nonlinear Fabry-Perot interferometer filled with a nematic-liquid-crystal film.

A Fabry-Perot interferometer filled with an 83-microm-thick nematic-liquid-crystal film exhibits multiple-order optical bistability and self-oscillation. The oscillation is shown to be due to two competing mechanisms with different response times contributing to the laser-induced refractive-index change.

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.

Long term somatic growth after repair of tetralogy of Fallot: evidence for restoration of genetic growth potential.

OBJECTIVE: To compare actual with predicted long term growth after early repair of tetralogy of Fallot (TOF). DESIGN: Serial preoperative and postoperative anthropometric data were converted with z scores. The presence of restrictive physiology was assessed by echocardiography. PATIENTS: 45 otherwise healthy patients who underwent repair at median age 1.6 years (range 0.2-4.9) were studied. Predicted height was determined from mid-parental height corrected for sex. RESULTS: Mean (SD) weight and height z scores at the time of surgery were significantly depressed (-1.04 (0.82) and -0.93 (0.95), respectively; p < 0.0001 for both). At latest follow up at a median age of 14.2 years (range 11-20.5), mean weight and height z scores were 0.16 (1.1) and -0.05 (0.81) (p = 0.32 and p = 0.41, respectively). The improvement between surgical and late weight and height z scores was significant (p < 0.0001 for each comparison). Catch up growth was largely complete within two years. Age at correction, duration of follow up, and prior surgical procedures were unrelated to growth. Mean current height z scores were similar to those predicted by mid-parental height. Patients with restrictive right ventricular physiology (n = 24) had a significantly greater late z score for weight (0.49 v -0.34; p = 0.01), with a similar trend for height. Low birth weight patients experienced comparable catch up growth but remained shorter than patients with normal birth weight (mean height z score -0.64 v 0.06; p = 0.03). CONCLUSIONS: Early repair of TOF results in significant acceleration of weight and height, with normalisation of long term growth and fulfilment of genetic growth potential.

T wave alternans threshold in normal children.

INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) during exercise is a predictor of ventricular arrhythmia propensity in adult populations. TWA occurs in normal adults, but it is rare at < 70% of predicted maximum heart rate. An onset heart rate < or = 110 is believed to be significant. The aim of this study was to examine the feasibility of performing the test in children and to determine the normal heart rate threshold for sustained TWA in children. METHODS AND RESULTS: Alternans was evaluated during bicycle exercise in 100 normal volunteers aged 8 to 17 years. Adequate resting data were obtained in 76 of 100 children and was negative in all. Exercise data from 16 of 100 was excluded due to excessive noise. Median maximum heart rate was 192 (range 140 to 214). Sustained alternans was absent in 75 (89%) of 84. In the nine children with sustained alternans, median onset heart rate was 138 (range 120 to 158), and 7 of 9 had an onset heart rate > or = 135. Median heart rate threshold as a percentage of predicted maximum heart rate (220 - age) was 67% (range 58% to 76%). Only 1 subject (1.2%) had an onset heart rate < 60% of predicted maximum. There was no significant difference between age, gender, endurance, maximum heart rate, QRS duration, QT interval, or QTc in those with and those without sustained TWA. CONCLUSION: Noninvasive assessment of TWA is feasible at > or = 8 years of age. Sustained TWA was present in 11% of normal children, but was absent at heart rates below 120 and rare (1.2%) below 60% of predicted maximum heart rate.

Detection of quinolone-resistant Neisseria gonorrhoeae.

The present National Committee for Clinical Laboratory Standards (NCCLS) guideline for testing Neisseria gonorrhoeae quinolone susceptibility defines only a susceptible category for ciprofloxacin, enoxacin, lomefloxacin, and ofloxacin, while susceptible, intermediate, and resistant categories are defined for fleroxacin. To further define the criteria for detection of quinolone resistance in gonococci, by standard disk diffusion and agar dilution methodologies recommended by the NCCLS, we tested 29 strains of quinolone-resistant N. gonorrhoeae (QRNG) recently isolated from ofloxacin-treated patients who were considered clinical failures. Regression analyses were performed on these results together with those of another 20 strains showing reduced susceptibility and 13 fully susceptible strains (ofloxacin MICs of < or = 0.25 microgram/ml). With 5-micrograms ofloxacin disks, resistance in 27 (93.1%) of the QRNG strains (MICs of > 1 microgram/ml) was detected by the criterion of a zone diameter of < 22 mm, while in the remaining 2 (6.9%), the disks failed to detect resistance. A cluster of 15 highly resistant strains showed ofloxacin MICs of > 4 micrograms/ml and zone diameters of < 13 mm. When tested with 5-micrograms ciprofloxacin disks, the corresponding values for resistance and high-level resistance of these QRNG strains were < 25 mm (MICs of > 0.5 micrograms/ml) and < 15 mm (MICs of > 2 micrograms /ml), respectively. Six strains for which ofloxacin MICs were > or = 8 micrograms/ml showed no zones at all with both 5-micrograms ofloxacin and 5-micrograms ciprofloxacin disks. These QRNG strains are now firmly established in the Southeast Asia region, and it is important for clinical laboratories to recognize these clinically resistant strains and to monitor their spread.

Onychomycosis in Hong Kong.

BACKGROUND: Onychomycosis in temperate countries has been studied extensively, but few data are available on its epidemiology in tropical countries. We performed a survey of patients seen in Hong Kong for the 8-year period from January 1987 to December 1994. METHODS: A retrospective study of the mycology laboratory records of patients attending the Government Dermatology Clinics was carried out. Nail samples examined included clippings, scrapings, and drillings. Microscopy was performed on all specimens. Sabouraud dextrose agar was used for culture. RESULTS: Out of a total of 2382 nail samples (1024 (43.0%) toe, 1148 (48.2%) finger, and 210 (8.8%) unspecified site) examined, 340 (14.3%) were microscopy positive; 165 (48.5%) of these were culture positive, including 160 (97%) with dermatophyte and/or yeast, and 5 (3%) with molds. Men were affected more in the < 19 and > 50 years age groups, whereas women were affected more in the 20-50 years age group. Women were affected significantly more than men with yeasts, dermatophytes occurred more during adolescence. Dermatophytes showed a high peak in late spring, although both dermatophyte and yeast cases peaked in the summer months. Dermatophytes (29.1%) occurred more commonly than yeasts (19.4%) in microscopy-positive onychomycosis cases in Hong Kong. Trichophyton rubrum was the commonest dermatophyte, and Candida spp, other than C. albicans, were the commonest yeasts. Mixed infections (5%) were uncommon. CONCLUSIONS: Dermatophytes are more important than yeasts as a cause of onychomycosis in Hong Kong. Changes in climatic conditions affect the prevalence of dermatophytes more than yeasts.

Effect of methotrexate on the germination and growth of Aspergillus fumigatus and Aspergillus flavus strains.

Methotrexate at concentrations of greater than or equal to 10(-5) M caused a significant reduction in the rate of germ tube formation of spores of Aspergillus fumigatus, but not of Aspergillus flavus, after 7 h incubation. At 10(-3) M the drug caused a significant reduction in germ tube elongation of A. fumigatus and A. flavus strains during the first 7 h of germination. After 18 h incubation, drug concentrations of greater than or equal to 4 x 10(-4) M produced greater than 80% reduction in growth of all strains tested. Potentiation of the antifungal effect against A. fumigatus was detected in tests in which methotrexate at 10(-4) M was used in combination with amphotericin B at 5 x 10(-7) M.

Emergence of multiple-antibiotic-resistant Streptococcus pneumoniae in Hong Kong.

Two hundred four strains of Streptococcus pneumoniae isolated in Hong Kong from January 1993 to May 1995 were analyzed for their antibiotic susceptibilities and epidemiological patterns. The ages of the patients from whom the strains were isolated from 1 month to 93 years (median, 53 years); the male-to-female ratio was 2.8, with a predominance of males in the pediatric group. Fifty-nine (28.9%) strains showed reduced penicillin susceptibility, including 40 (19.6%) with frank penicillin resistance (MIC > 1 microgram/ml). Tetracycline resistance alone was found in 28.4% of strains. Isolates with reduced penicillin susceptibility were more common in children than adults (40 versus 23.9%, P = 0.02), and penicillin resistance rates were significantly higher in hospitalized patients than in outpatients (39.5 versus 12.5%; p < 0.001). Penicillin resistance was significantly associated with resistance to ceftriaxone, erythromycin, and tetracycline (P < 0.01) but not with ofloxacin or vancomycin (P = 0.5). Among eight different patterns of resistance to three or more antibiotics, the commonest one (14.2%) was multiple resistance to penicillin, chloramphenicol, ceftriaxone, erythromycin, and tetracycline. Emergence of multiple-antibiotic-resistant S. pneumoniae reflects changes in the pneumococcus itself and the general indiscriminate use of antibiotics in treatment of respiratory infections in Hong Kong.

Quinolone-resistant Neisseria gonorrhoeae in Hong Kong.

OBJECTIVE: To study the serologic characters and antibiotic susceptibilities of quinolone-resistant Neisseria gonorrhoeae in Hong Kong. STUDY DESIGN: Sixty-nine strains of Neisseria gonorrhoeae isolated from clinical failure cases after treatment with ofloxacin during the period January 1, 1992, to January 1, 1995, were studied. A panel of 14 monoclonal antibodies against protein I classified these strains into 21 serovars. The pattern of serovar distribution against varying minimum inhibitory concentrations of ofloxacin was compared with 143 strains isolated from a cohort of quinolone-susceptible, clinically responsive cases. Antibiotic susceptibilities tests were performed on quinolone-resistant strains to penicillin, tetracycline, ciprofloxacin, spectinomycin, and ceftriaxone. Epidemiologic information on location of contact was collected. RESULTS: Serologic characterization showed that Bop and Bpy were the dominant serovars among quinolone-resistant strains. Most IA and other IB serovars had declined in the selection process for quinolone resistance. Antibiotic susceptibility tests showed that 81.2%, 89.9%, and 78.3% of quinolone-resistant Neisseria gonorrhoeae strains were resistant to penicillin, tetracycline, and both, respectively, whereas 10 of 69 (14.5%) of such strains displayed high-level quinolone resistance (ofloxacin minimum inhibitory concentration > 8 micrograms/ml). The quinolone-resistant strains remained fully susceptible to spectinomycin and ceftriaxone. CONCLUSIONS: Quinolone-resistant strains have become firmly established in Hong Kong. Serovar determination has documented shifts in the gonococcal population during the selection process for quinolone resistance. Places that use quinolones in the treatment of sexually transmitted diseases should be alert to the emergence of high-level quinolone-resistant Neisseria gonorrhoeae.