Bone Marrow Mononuclear Stem Cells Transplanted in Rat Infarct Myocardium Improved the Electrical Conduction without Evidence of Proarrhythmic Effects

PURPOSE: The arrhythmogenic effect of stem cells transplantation (SCT) in an infarct myocardium is still unknown. We investigated arrhythmogenicity of SCT in rat cryo-infarct model. MATERIALS AND METHODS: In rat cryo-infarct model, bone marrow mononuclear stem cells (MNSC, 1 x 10(7) cells) were transplanted into the infarct border zone (BZ) of the LV epicardium. We compared the optical mapping and inducibility of ventricular tachycardia/fibrillation (VT/VF) among normal (n=5), cryo-infarct (n=6), and SCT rats (n=6). RESULTS: The VT/VF inducibility was higher in the cryo- infarct (47.2%, p=0.001) and SCT groups (34.6%, p=0.01) than in the normal group (12.8%). The induced VT/VF episodes persisted for more than 2 minutes in 4.3%, 26.4% and 17.3% in the normal, cryo-infarct and SCT group, respectively. In the SCT group, the action potential duration at 70% was shorter at the SCT site than the BZ during SR (75.2 +/- 8.1 vs. 145.6 +/- 4.4 ms, p=0.001) and VT (78.2 +/- 13.0 vs. 125.7 +/- 21.0 ms, p= 0.001). Conduction block was observed at the SCT site and BZ during VT. However, no reentry or ectopic foci were observed around the SCT sites. CONCLUSION: The electrical conduction was improved by SCT without evidence of augmentation of arrhythmia in the rat cryo-infarct model.

The Effects of Obstacles on the Dynamics of Ventricular Fibrillation

BACKGROUND AND OBJECTIVES: The effects of artificial obstacles on the dynamics of ventricular fibrillation have been extensively investigated with an electrical mapping system. This study was performed to assess the influence of transmural obstacles on the dynamics of wavefronts, and determine whether these can convert ventricular fibrillation to ventricular tachycardia by stabilizing the wavefronts in the fibrillating right ventricular tissues of pigs, using an optical mapping system. MATERIALS AND METHODS: The right ventricles of pigs (n=15) were excised and placed in a tissue perfusion system, with the epicardium facing up. Holes, with increasing sizes, from 2 to 8 mm in diameter, were created using a skin biopsy punch. Another 8 mm sized hole was then made adjacent to the first, and the changes in the wavefront dynamics and cycle length of the optical action potential waves investigated. RESULTS: In 14 of the 20 obstacles, in ten tissues, transient attachment of electrical activities along the rim of obstacles and transient rotation of the wavefronts were observed. During baseline ventricular fibrillation, the fibrillation cycle length was 118.5+/-24.7 msec, which was increased to 135.4+/-30.2 msec after creation of the first hole, and to 159.4+/-47.7 msec after the second (p=0.01). There was a positive correlation between the obstacle size and cycle length (r=0.43, p=0.007). In three tissues, conversion to ventricular tachycardia from ventricular fibrillation was observed after creation of the two holes. CONCLUSION: Obstacles of an appropriate size had anti-fibrillatory effects in tissues with ventricular fibrillation, which was partly explained by the temporary attachment of wavefronts to the obstacles.

The frequency of thiamine deficiency in chronic alcoholics and in patients at a long-term care facility / 대한내과학회지

BACKGROUND: As socioeconomic status has improved, malnutrition has become rare in Korea and generally it is no longer considered as a serious problem in medical practice. However, contrary to the above general belief we managed four patients with beriberi in 1999 and it became apparent that malnutrition might remain a problem in certain groups of patients. In this study, we assessed the nutritional state, especially with respect to thiamine deficiency, in chronic alcoholics and in patients residing at a long-term care facility (LTCF). METHODS: Fourteen chronic alcoholic patients and twenty patients being hospitalized in a long-term care facility were assigned as the study groups. The subjects' mean ages and standard deviations were 48.9+/-10.2 and 50.6+/-6.7, respectively. Medical records were reviewed to determine other aspects of their nutritional status and their dietary patterns. Ten peoples who visited the health promotion center at Inha University Hospital, for routine check-ups were allocated to the control group. Blood total thiamine levels were measured by high-performance liquid chromatography. RESULTS: Body mass indices were significantly lower in chronic alcoholics and in patients at the LTCF than in the control group (p=0.0065). Serum albumin levels were within the reference range in all three groups, but were significantly lower in patients at the LTCF than in the control group (p=0.0013). Moreover, no difference was detected between the alcoholic group and the control group in terms of thiamine levels. However, the mean thiamine level in patients at the LTCF was statistically lower than that of the control group and four (20%) patients in the LTCF group showed subnormal blood thiamine levels. The thiamine level tended to decrease with age in both alcoholics and patients at the LTCF. No correlation was found between thiamine level and the other variables examined, namely, hospital stay, body mass index, and serum albumin level. CONCLUSION: A considerable portion of patients in a long term care facility showed thiamine deficiency, however, no evidence of thiamine deficiency was found among alcoholics. This result suggests that thiamine deficiency in patients at long-term care facility may be more prevalent and that thiamine supplementation may be warranted, especially for those with other thiamine deficiency risk factors.

A Case of Acute Renal Failure after Sodium Phosphate Administration / 대한신장학회잡지

Although oral sodium phosphate, a colonic cleasing agent for colonoscopy, had been usually known to be safe, several cases have been reported on the development of acute renal failure(ARF) after the administration of this agent. Many authors suggested that the pathogenesis of ARF developed after sodium phosphate administration is related with hyperphosphatemia, which caused ARF by the deposition of phosphate and/or calcium in renal tubule or interstitium, or by the direct toxicity to renal tubular cells. Elderly patients or the patients with dehydration, underlying cardiovascular, renal, or hepatic disease predispose the development of adverse effects of sodium phosphate, such as water and electrolyte imbalance, especially hyperphosphatemia which may ultimately lead to ARF. We described here a case of acute renal failure associated with hyperphosphatemia after the administration of sodium phosphate. A review of the literatures is presented.

The Prevalence of Bartonella henselae Infection in Korean Feral Cats / 감염

BACKGROUND: Cat scratch disease (CSD) is an emerging disease worldwide and is mainly caused by Bartonella henselae, a gram-negative bacterium. The most common clinical manifestation is regional lymphadenopathy, though clinical recognition may be difficult, as atypical manifestations occur. The condition can be complicated by neuroretinitis, endocarditis, and sometimes fatal encephalopathy. The reservoir of B. henselae is the cat, and the prevalence rates of B. henselae infection in cat populations range from 4 to 70%. The prevalence of Bartonella infection in Korea has not been studied, thus, in this study Bartonella infection was investigated in cats captured in the Inchon and Ansan areas. METHODS: Twenty wild cats were captured and their livers and spleens were examined by polymerase chain reaction (PCR), bacterial culture, and histopathologically. PCR used two primers: Cat (sense:5'-GAT TCA ATT GGT TTG AA(G/A) GAG GCT-3', antisense:5'-TCA CAT CAC CAG G(A/G)C GTA TTC- 3') and Barto (sense:5'-(C/T) CT TCG TTT CTC TTT CTT CA-3', antisense:5'-AAC CAA CTG AGC TAC AAG CC-3'). Culture was performed by inoculating sliced spleen and liver into the ECV304 cell line and bacterial growth was observed over a period of 3 weeks. If no visible bacterial growth was identified, the presence of bartonella was examined by DNA staining, indirect immunofluorescent staining, and PCR. Liver and spleen were stained with H&E and scrutinized under the light microscope. RESULTS: Nine pairs of culture cells inoculated with liver and spleen were examined by indirect immunofluorescent staining and PCR; no positive case was found. In addition, no positive case was identified by PCR in the liver and spleen specimens of eleven cats. Spleen and liver specimens of eleven cats were examined by light microscopy and none showed granuloma. CONCLUSION: This preliminary study suggests that the Bartonella infection is probably uncommon in the cat population of the Inchon and Ansan areas. Further studies should be undertaken to detail the prevalence of Bartonella infection in other areas and in human.

A Case of Dengue Hemorrhagic Fever Imported from Africa / 감염

Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) is an acute febrile illness characterized by hemorrhagic phenomenon and hypovolemic shock due to increased vascular permeability and plasma leakage in patients infected with any one of four serotypes of dengue virus. The disease is one of the principal causes of hospitalization and death among children in several south-east Asian, central and south American, and African countries. With increasing use of air or ship transport, more travelers and sailors to the tropics are returning within the incubation period of acute febrile infection. Herein we reported the first Korean case of dengue hemorrhagic fever imported from Africa. We experienced a Korean sailor who complains of fever, chill, nausea, and epistaxis after the return from Mombasa, Kenya. His fellows also showed the similar complains. His illness improved spontaneously and the indirect immunofluorescent antibody testing revealed antibody titer of 1:1024 or more.