Risk factors and renal outcomes of low bone mineral density in patients with non-dialysis chronic kidney disease.

Bone disorder is a common complication of chronic kidney disease (CKD). The clinical usefulness of bone mineral density (BMD) in CKD is not well known. Our study shows that low BMD is associated with physical activity and dietary Na/K intake ratio and can predict poor renal outcome in non-dialysis CKD. PURPOSE: Despite evidence of a link between bone mineral disorders and chronic kidney disease (CKD), the clinical implications of bone mineral density (BMD) in CKD are not well established. We investigated risk factors and renal outcomes of low BMD in CKD. METHODS: We analyzed data from the KNOW-CKD. BMD measured by dual-energy x-ray absorptiometry was classified by T score: normal (T score ≥ - 1.0), osteopenia (- 1.0 > T score > - 2.5), and osteoporosis (T score ≤ - 2.5) of the lumbar spine, hip, or femoral neck. Logistic regression analysis to assess risk factors of low BMD (T score < - 1.0) and Cox proportional hazards models to estimate risk of incident end-stage renal disease (ESRD). RESULTS: Low BMD was prevalent (osteopenia 33%; osteoporosis 8%) in 2128 adults with CKD (age 54 ± 12 years; male 61%). Over a median follow-up of 4.3 years, there were 521 cases of incident ESRD. Lower BMD was associated with female sex, older age, low eGFR, low BMI, and lifestyle factors of physical activity (odds ratio (OR) = 0.62, 95% confidence interval (0.49-0.77)) and spot urine Na/K ratio (1.07 (1.00-1.15)). In adjusted Cox models, low BMD was associated with increased incident ESRD (hazard ratio (HR) = 1.14 (0.92-1.41) for osteopenia; 1.43 (1.01-2.04) for osteoporosis, P for trend < 0.05) compared with the reference of normal BMD. The association between low BMD and ESRD was similar according to T score discordance classification. CONCLUSIONS: Low BMD was associated with modifiable lifestyle factors including low physical activity and high dietary Na/K intake ratio. The presence of low BMD is associated with poor renal outcomes in non-dialysis CKD.

Development of novel microsatellite markers for conservation genetic studies of Vulpes vulpes (Canidae) by using next-generation sequencing method.

The red fox, Vulpes vulpes (Canidae), is the most widely distributed terrestrial carnivore worldwide, but this species is classified as endangered in Korea. In this study, we developed 25 polymorphic microsatellite markers that included 3-13 (mean = 6.32) alleles per locus using 22 red fox individuals. The most polymorphic locus was FR(59)TG (13 alleles) and the least polymorphic loci were FR(70)TG and FR(182)AG (3 alleles each). No significant deviation from Hardy-Weinberg equilibrium (P < 0.05) was observed for the 25 markers. Observed (HO) and expected (HE) heterozygosity varied from 0.182 to 1.000 and from 0.175 to 0.929, respectively. These newly developed microsatellite markers will be useful for investigating the genetic diversity and population genetic structure of V. vulpes and will aid in developing conservation strategies for this species.

Outbreak of enterotoxigenic Escherichia coli O169 enteritis in schoolchildren associated with consumption of kimchi, Republic of Korea, 2012.

Enterotoxigenic Escherichia coli (ETEC) is now recognized as a common cause of foodborne outbreaks. This study aimed to describe the first ETEC O169 outbreak identified in Korea. In this outbreak, we identified 1642 cases from seven schools. Retrospective cohort studies were performed in two schools; and case-control studies were conducted in five schools. In two schools, radish kimchi was associated with illness; and in five other schools, radish or cabbage kimchi was found to have a higher risk among food items. Adjusted relative risk of kimchi was 5·87-7·21 in schools that underwent cohort studies; and adjusted odds ratio was 4·52-12·37 in schools that underwent case-control studies. ETEC O169 was isolated from 230 affected students, and was indistinguishable from the isolates detected from the kimchi product distributed by company X, a food company that produced and distributed kimchi to all seven schools. In this outbreak, we found that the risk of a kimchi-borne outbreak of ETEC O169 infection is present in Korea. We recommend continued monitoring regarding food safety in Korea, and strengthening surveillance regarding ETEC O169 infection through implementation of active laboratory surveillance to confirm its infection.

Efficacy and safety of hepatitis A vaccination in kidney transplant recipients.

BACKGROUND: In recent years, symptomatic hepatitis A virus (HAV) infection has been reported with increasing frequency in Korea. Therefore, HAV vaccination should be considered in kidney transplant recipients (KTRs). The study investigated the efficacy and safety of HAV vaccination in KTRs under modern triple immunosuppressive agents. METHODS: We evaluated the seroprevalence of anti-HAV immunoglobulin-G (IgG) in KTRs who had visited the Seoul National University Hospital from March 2011 to August 2012. Seronegative patients were immunized with 2 doses of HAV vaccine at a 6-month interval. Seroconversion of anti-HAV IgG was determined 1 month after the second vaccine dose, and adverse effects were monitored after each vaccination. RESULTS: Among a total 416 KTRs who were screened, 338 (81.2%) patients were seropositive for anti-HAV IgG. However, among patients who were under 40 years of age, only 31.8% were seropositive. Fifty-two seronegative recipients (mean age 34.1 years, 71.2% male) had received 2 doses of vaccine, and only 14 of these patients (26.9%) showed seroconversion. Vaccine responders had lower serum creatinine (1.19 ± 0.24 vs. 1.45 ± 0.49 mg/dL, P = 0.013), higher plasma hemoglobin levels (14.4 ± 1.9 vs. 12.8 ± 1.8 g/dL, P = 0.006), and had lower tacrolimus use than cyclosporine use (57.1% vs. 84.2%, P = 0.040) compared with non-responders. Responders had a tendency of taking lower dose of prednisolone (3.5 ± 1.6 vs. 4.3 ± 1.2 mg/day, P = 0.076), and having fewer infection events (14.3 vs. 40.5%, P = 0.076). Multivariate analysis indicated that higher hemoglobin levels and lower serum creatinine levels were significant prognostic factors for seroconversion. Overall, the vaccine was well tolerated in all patients. CONCLUSION: HAV IgG screening is necessary for KTRs, especially young recipients. HAV vaccination was safe in KTRs; however, poor response to HAV vaccination makes it important to identify seronegative patients as early as possible and vaccinate them before end-stage renal disease occurs.

The effects of cyclophosphamide and mycophenolate on end-stage renal disease and death of lupus nephritis.

Debate continues about the optimal treatment modality of lupus nephritis (LN). We compared the efficacy and safety of intravenous cyclophosphamide (CYC) and mycophenolate mofetil (MMF) for LN treatment in Korea. After searching for systemic lupus erythematosus (SLE) patients diagnosed between 1998 and 2007 with the diagnostic code of ICD10, we selected the 71 patients who were treated with CYC or MMF without any other immunosuppressant except systemic steroid. Composite outcome was defined as progression to end-stage renal disease (ESRD) and/or all-cause mortality. The initial manifestations of the CYC group were more severe than those of the MMF group. The mean daily MMF dose was 980 ± 100 mg for 21.67 ± 18.25 months. The mean monthly dose per CYC pulse therapy was 850 ± 30 mg for 17.04 ± 13.15 months. The incidence of composite outcome was 5/20 (25%) in the MMF group and 4/51 (7.8%) in the CYC group. The relative risk (RR) for composite outcome in the CYC group was 0.249 (95% CI for RR: 0.067-0.934, p = 0.039) compared with the MMF group with Cox's hazard proportional analysis. In Kaplan-Meier analysis, the probability of composite outcome was lower in the CYC group than in the MMF group (Log rank test p-value = 0.026). The results of this retrospective study suggest that intravenous CYC therapy may be more efficacious in averting ESRD and death than MMF. These results need to be confirmed in a larger randomized controlled trial.

Clinical features of acute renal failure associated with hepatitis A virus infection.

Acute hepatitis A (AHA) is one of the most common infectious diseases; it is usually a self-limiting disease affecting the liver. Although extrahepatic manifestations are not common, some cases have been reported associated with acute renal failure. We reviewed the clinical features of patients with AHA complicated by acute renal failure (ARF group) and compared them with patients with noncomplicated AHA (non-ARF group). The medical records of 208 consecutive patients with AHA who were diagnosed between January 2003 and October 2008 were reviewed. We identified 15 patients (7.2%) with ARF associated with AHA. There were no differences between the ARF and non-ARF group with regard to gender and age. The peak value of alanine aminotransferase (ALT) (median: 6060 IU/L vs 1792 IU/L, P < 0.001), prothrombin time (PT) (International normalized ratio, median 1.72 vs 1.10, P < 0.001), and total bilirubin level (median: 9.6 mg/dL vs 6.3 mg/dL, P = 0.04) were significantly higher in the ARF than in the non-ARF group. Twelve patients (80%) recovered completely with haemodialysis (seven patients, 46.7%) or only conservative management (five patients, 33.3%), while one patient underwent liver transplantation because of fulminant hepatic failure, and two patients died because of fulminant hepatic failure. There were no deaths among patients with noncomplicated AHA in the non-ARF group. Five patients underwent kidney biopsy; two patients were diagnosed with acute tubular necrosis, two patients with acute interstitial nephritis with IgA nephropathy and one patient with acute tubulointerstitial nephritis. All patients in the ARF group had microscopic haematuria and proteinuria (100%vs 31.1%, P < 0.001). Urine sodium levels were more than 10 mEq/L in 10 patients. The findings of high urinary sodium concentrations, microscopic haematuria and proteinuria did not support the diagnosis of hepatorenal syndrome (HRS). Patients with AHA with ARF had higher ALT levels, more prolonged PTs, and higher total bilirubin levels. The prognosis for these patients was poorer than for those without ARF. However, the patients with ARF and nonfulminant AHA had recovered with proper treatment and should not be confused with patients that have HRS.

Tacrolimus is an alternative therapeutic option for the treatment of refractory lupus nephritis.

We conducted an open-labeled, prospective study to determine the efficacy and safety of tacrolimus as an alternative therapeutic option for those patients with refractory lupus nephritis. The study population comprised one male and eight female patients with diffuse proliferative lupus nephritis. All patients had failed to respond to sufficient intravenous cyclophosphamide therapy with proteinuria of >or=1 g/day and active urinary sediments. Tacrolimus (0.1 mg/kg/day) was administered for 1 year with adjusting drug level (4-10 microg/l). The mean serum creatinine level and spot urine protein creatinine ratio (UPCR) at baseline were 1.39 mg/dl and 2.27, respectively. After the treatment, proteinuria reduced significantly from median UPCR value of 2.19 (range, 1.19-3.34) to 0.44 (range, 0.12-2.13) (p < 0.05). Seven (78%) of the nine patients showed a complete clinical response, which was defined as stabilization in the disease-activity markers and serum creatinine level with reduction of >or=50% in UPCR; two patients showed complete remission with UPCR <0.2. One patient showed treatment failure because of the disease progression. No serious adverse effects were observed during the study. This study demonstrates that tacrolimus can show a significant therapeutic response in cases that are refractory to the standard regimen for diffuse proliferative lupus nephritis.

Core shell structure for solid gas synthesis of LiBD(4).

The formation of LiBD(4) by the reaction of LiD in a diborane/hydrogen atmosphere was analysed by in situ neutron diffraction and subsequent microstructural and chemical analysis of the final product. The neutron diffraction shows that nucleation of LiBD(4) already starts at temperatures of 100 degrees C, i.e. in its low temperature phase (orthorhombic structure). However, even at higher temperatures the reaction is incomplete. We observe a yield of approximately 50% at a temperature of 185 degrees C. A core shell structure of the grains, in which LiBD(4) forms a passivation layer on the surface of the LiD grains, was found in the subsequent microstructural (electron microscopy) and chemical (electron energy loss spectrometry) analysis.

Depression and health-related quality of life in maintenance hemodialysis patients.

BACKGROUND: This study was designed to determine the prevalence of depression among hemodialysis (HD) patients from urban hospitals in Korea, to illustrate demographic factors and biomarkers associated with depression and health-related quality of life (HRQOL), and to demonstrate association between depression and HRQOL. PATIENTS AND METHODS: For this multicenter, cross-sectional study, 160 HD patients from 3 university teaching hospitals and 3 local dialysis units in Korea were enrolled. Korean Beck's depression inventory and Korean version of Kidney Disease Quality of Life short form, version 1.3 (KDQOL-SFTM 1.3) were used to evaluate depression and quality of life, respectively. RESULTS: Depression was found in 51 out of 160 (31.9%) patients. Old age (> 60 years old), low hemoglobin level (< 10 g/dl), and low economic status were associated with depression, and old age (OR 6.138, p = 0.001) was the most important risk factor among them. Old age, female gender, presence of diabetes mellitus, high comorbidity index score (modified Charlson comorbidity index > or = 6), hypoalbuminemia (< 4.0 g/dl), and high CRP (> 0.5 mg/dl) were common factors associated with decreased HRQOL. Depression and HRQOL showed inverse linear relationship. CONCLUSIONS: Moderate to severe depression was common in maintenance HD patients in Korea. Among factors associated with depression and decreased HRQOL, some characteristics are potentially modifiable by social and medical intervention. Further prospective studies are warranted to see whether depression and HRQOL can be improved by modifying these factors.

Sequential occurrence of life-threatening hypokalemia and rebound hyperkalemia associated with barbiturate coma therapy.

OBJECTIVE: To report a sequential occurrence of life-threatening hypokalemia and rebound hyperkalemia following barbiturate coma therapy. CASE HISTORY: A 53-year-old man was admitted to the division of nephrology due to sudden development of severe hypokalemia. The patient had been treated following a clinical diagnosis of traumatic subarachnoid hemorrhage and subdural hematoma. Barbiturate coma therapy had been performed on this patient. He developed fatal hypokalemia 10 hours after the start of thiopental administration which did not respond to potassium supplementation. The lowest potassium level following barbiturate coma therapy was 1.0 mmol/l. Severe bradycardia and cardiac arrest developed, which necessitated cardiac massage and treatment with epinephrine and atropine. He recovered from cardiac arrest. When thiopental infusion was suddenly stopped, the potassium level increased to 8.9 mmol/l, which required quick administration of calcium gluconate and infusion of glucose solution mixed with regular insulin. Despite such management, he developed asystole. After direct current cardioversion and emergency hemodialysis, he recovered from cardiac arrest and his serum potassium level was stabilized. CONCLUSION: We recommend that clinicians must be aware of the potential occurrence of severe hypokalemia, which is rare but fatal, following barbiturate coma therapy. Rebound hyperkalemia, which is fatal, may also occur following cessation of thiopental infusion. Clinicians should also be aware of this potential complication. Further studies are needed to elucidate the precise mechanism of this clinical event.

Effective removal of leptin via hemodiafiltration with on-line endogenous reinfusion therapy.

AIMS: Leptin is a middle-molecular weight uremic toxin. Hemodiafiltration with on-line endogenous reinfusion (HFR) is a novel dialytic method combining the processes of diffusion, convection and adsorption. We performed a prospective crossover study of patients with end-stage renal disease to investigate the effect of HFR therapy on the level of leptin as compared to conventional low flux hemodialysis (LHD). METHODS: Eleven stable hemodialysis patients were treated with LHD for 12 weeks and then treated with HFR (SG30 Plus; Sorin Group Italia S.r.1, Mirandola, Italy) for 12 weeks. RESULTS: After 12 weeks of HFR treatment, serum leptin levels significantly decreased (17.1 (2.66 - 39.5) at Week 12 vs. 12.3 (1.80 - 24.3) ng/ml at Week 24, p = 0.014). Although serum adiponectin levels also decreased (1.66 (1.44 - 1.86) at Week 12 vs. 1.12 (0.79 - 1.34) g/ml at Week 24, p = 0.001), the ratio of leptin to adiponectin did not increase after HFR treatment. Serum beta2-microglobulin (beta2M) levels significantly decreased (37.7 (29.8 - 42.6) at Week 12 vs. 28.3 (26.5 - 32.2) mg/dl at Week 24, p = 0.002). Dry weight, Kt/V(urea), normalized protein equivalent of nitrogen appearance, subjective global assessment, and serum albumin levels of the patients were not changed after HFR treatment. There was no difference in the serum levels of C-reactive protein or interleukin-6 between Week 12 and Week 24. CONCLUSIONS: The results of our study indicate that HFR may be a better therapy than LHD for removal of middle-molecular-weight uremic toxins such as leptin and b2M.

Analysis of efficacy and safety of core-needle biopsy versus fine-needle aspiration cytology in patients with cervical lymphadenopathy and salivary gland tumour.

In this study, we compared the diagnostic accuracy and safety of fine-needle aspiration cytology and core-needle biopsy in patients with cervical lymphadenopathy or salivary gland tumour, and provided a basis for selecting the appropriate diagnostic method in clinical situations. A total of 278 patients were included in this study. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 66.7% and 100%, respectively, and negative predictive values were 92.6% and 100%, respectively, for diagnosing malignancy. In diagnosing lymphoma, fine-needle aspiration cytology gave false-negative results in all patients. In diagnosing tuberculous lymphadenopathy, the sensitivities of fine-needle aspiration cytology and core-needle biopsy were 33.3% and 91.15%, respectively, and the negative predictive values were 90.0% and 95.1%, respectively. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 42.9% and 100% in diagnosing malignant salivary gland tumours, and the negative predictive values were 91% and 100%, respectively. The results of this study showed that core-needle biopsy was superior in diagnosing and distinguishing critical diseases such as malignant lymphadenopathy and tuberculosis in patients with cervical lymphadenopathy and salivary gland tumour.

Depression and risk of tuberculosis: a nationwide population-based cohort study.

BACKGROUND: Studies on the association between depression and risk of tuberculosis (TB) are lacking. OBJECTIVE: To determine the association between depression and risk of TB. METHODS: From a nationwide database, patients with depression were identified to form the exposure cohort between 2003 and 2013. The control cohort comprised an equivalent number of subjects without any mood disorders, with each subject age- and sex-matched to a patient in the exposure cohort. The incidence of TB was identified in the exposure cohort and control cohort between 2003 and 2013. A multivariable Cox proportional hazards model was used to estimate the association between depression and the subsequent risk of TB. RESULTS: A total of 32 372 patients with depression and the same number of controls were identified. The risk of TB in the depression cohort was 2.63-fold (95%CI 1.74-3.96) higher than in the control cohort. When the depression was classified as 'mild' and 'severe', the risk of TB was proportional to depression severity. CONCLUSIONS: Patients with depression are at a higher risk for TB, and a dose-response relationship exists between depression and the subsequent risk of TB.

Protein Network Interacting with BK Channels.

The large conductance, voltage- and calcium-dependent potassium BK channel, also termed BKCa, Maxi-K, KCa1.1, or SLO1, regulates a wide array of key biological processes that are mediated by calcium ions. This broad regulatory function of BK channels requires the interactions of BK channels with diverse sets of proteins that have different molecular or cellular functions. Proteins that interact with BK channels range from the auxiliary subunits of BK channels to cytoskeletal proteins responsible for BK channel trafficking and localization. Furthermore, depending on cellular contexts, BK channels interact with proteins modifying channel properties, and with proteins that allow cell-specific responses. In this chapter, we review some of the relevant studies investigating the protein interaction network of BK channels with a focus on the biological roles of the interaction.

Non-communicable diseases and risk of tuberculosis in Korea.

BACKGROUND: It is possible that the increasing burden of non-communicable diseases (NCDs) and their risk factors are an obstacle to the reduction of tuberculosis (TB) incidence in the Republic of Korea. OBJECTIVE: To estimate population-attributable fractions (PAF) of NCDs and their risk factors related to TB in Korea. DESIGN: The prevalence of diabetes mellitus (DM), current smoking, heavy drinking and undernutrition was estimated from the Korean National Health and Nutrition Examination Survey (KNHANES) conducted in 2013. Estimates of effect for risk factors were obtained from meta-analyses. The PAF was calculated based on these data. RESULTS: The PAF of DM, current smoking, heavy drinking and undernutrition was 20.0%, 18.8%, 18.4% and 9.6%, respectively. Current smoking has the highest PAF among men, while undernutrition was the highest among women. Current smoking and heavy drinking were significantly attributed to TB among the younger population, while DM was the most common responsible factor among the older population. Major risk factors such as current smoking and DM were more prevalent in the lower income level population. CONCLUSION: NCDs and their risk factors play an important role at the population level in TB epidemics in Korea. Collaborative TB and NCD activities in TB control should therefore be intensified.

Efficacy of ultrasound-guided core needle gun biopsy in diagnosing cervical lymphadenopathy.

OBJECTIVE: Ultrasound-guided fine needle aspiration cytology (US-FNA) is useful for diagnosing cervical lymphadenopathy. However, FNA, has a high false negative rate, especially in patients with lymphoma. Ultrasound-guided core needle gun biopsy (US-CNB) has recently become important for diagnosing cancers, but its value remains undetermined. This study evaluates the efficacy of US-CNB, performed in an outpatient setting, in diagnosing cervical lymphadenopathy and the spectrum of related diseases. MATERIALS AND METHODS: This retrospective study included 79 subjects who were not squamous cell carcinoma suspects and did not have a history of malignancy between January 2006 and July 2009. A US-CNB was performed on enlarged cervical lymph nodes (>1.0cm) in all subjects. Diagnostic sensitivity, specificity, and accuracy of US-CNB in differentiating between malignant and benign lymphadenopathy were evaluated. All enrolled subjects underwent a planned US-FNA before the study US-CNB was performed. Results of US-CNB and US-FNA were compared. RESULTS: The correct histopathological diagnoses were made in 73 of 79 subjects (91.1%) using US-CNB samples. Of these, the most common diagnoses were reactive hyperplasia (26 subjects), Kikuchi's disease (17 subjects), tuberculous lymphadenitis (15 subjects), lymphoma (8 subjects), and metastatic carcinoma (3 subjects). The US-CNB was very good at differentiating between malignant and benign lymphadenopathy, with a diagnostic sensitivity, specificity, and accuracy of 91.6%, 100%, and 98.6%, respectively. Additionally, US-CNB was more accurate than US-FNA in identifying lymphoma (88.8% vs. 11.1%) and Kikuchi's disease (89.4% vs. 29.4%). No US-CNB related-complications were observed. CONCLUSION: The US-CNB is safe, effective, and has a high diagnostic yield for cervical lymphadenopathy. The US-CNB may also be useful for diagnosing lymphoma and Kikuchi's disease.

Cytokines and growth factors involved in peritoneal fibrosis of peritoneal dialysis patients.

Peritoneal fibrosis is initiated by exposure of peritoneal tissues to numerous harmful agents encountered during peritoneal dialysis. These agents interact with cells within the peritoneum to induce growth factors and cytokines that are important in the initiation, progression and maintenance of fibrosis. Some of the mediators implicated in the pathogenesis of peritoneal fibrosis include transforming growth factor (TGF) beta, connective tissue growth factor (CTGF), fibroblast growth factors (FGF), and platelet derived growth factor (PDGF).

Protective role of quercetin against cisplatin-induced hair cell damage in zebrafish embryos.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the protective effects of quercetin on cisplatin-induced hair cell damage in transgenic zebrafish embryos. MATERIALS AND METHODS: Five days postfertilization zebrafish embryos were exposed to 1 mM cisplatin and quercetin at 10, 50, 100, or 200 µM for 4 h. Hair cells within neuromasts of the supraorbital, otic, and occipital lateral lines were analyzed by fluorescent microscopy (n = 10). Survival of hair cells was calculated as the average number of hair cells in the control group that were not exposed to cisplatin. Ultrastructural changes were evaluated using scanning electron microscopy. RESULTS: Hair cell damage in neuromasts was decreased by co-treatment of quercetin and cisplatin (quercetin 100 µM: 8.6 ± 1.1 cells; 1 mM cisplatin only: 5.0 ± 0.5 cells; n = 10, p < 0.05); apoptosis of hair cells examined by special stain was also decreased by quercetin. The ultrastructure of hair cells within neuromasts was preserved in zebrafish by the combination of quercetin (100 µM) and cisplatin (1 mM). CONCLUSION: In conclusion, quercetin showed protective effects against cisplatin-induced toxicity in a zebrafish model. The results of this study suggest the possibility of a protective role of quercetin against cisplatin-induced apoptotic cell death in zebrafish.

Quantitative enumeration of acanthamoeba for evaluation of cyst inactivation in contact lens care solutions.

A simple, quantitative plate assay has been developed for use in the enumeration of Acanthamoeba. The technique uses an agarose overlay and low-nutrient medium to support the growth of amoebae on a bacterial lawn. The authors found that in this assay, individual trophozoites or dormant cysts will cause plaques to form in an Enterobacter aerogenes lawn. With the assay, it is possible to quantitatively assess the effects of various disinfectant compounds on the viability of Acanthamoeba. The authors used this assay to enumerate Acanthamoeba cyst viability after chemical disinfection in contact lens care solutions. The inactivation data indicated major differences among the four test solutions evaluated.

A trial for a DNA diagnosis of Plasmodium vivax malaria recently reemerging in the Republic of Korea using microtiter plate hybridization assay.

The polymerase chain reaction-based microtiter plate hybridization (PCR-MPH) assay was utilized for a DNA diagnosis of Plasmodium vivax malaria, which has recently reemerged in the Republic of Korea. The subjects were 18 parasite-proven patients and 5 healthy controls. Follow-up blood samples were collected from 4 patients after a standard course of treatment. Polymerase chain reaction and electrophoresis of all the patients' blood showed a prominent band at the 138 base pair area, but not in the controls or after treating the patients. Hybridization of the PCR products with known species-specific probes of the 18S rRNA of various malaria species revealed strong positive reactions against the Plasmodium vivax-specific probe (absorbance 1.30-1.90 at 405 nm) in all of the patients. The absorbance was positively correlated with the degree of blood parasitemia, but with a borderline significance. Sequencing of the probe region of the Korean P. vivax revealed no significant variations from the typical P. vivax. The results show that the PCR-MPH is a highly useful technique for the DNA diagnosis of Korean vivax malaria.