Biological activity of amoebicin m4-A from Bacillus licheniformis M-4.

Amoebicin m4-A from Bacillus licheniformis M-4 exerts a bactericidal and bacteriolytic action on Bacillus megaterium GR10. Protein, DNA, and RNA synthesis are inhibited, and the membrane electrical potential of this bacterium is depleted by amoebicin. Synthesis of DNA and RNA by Naegleria fowleri HB-1 is also inhibited. Liposomes constructed from L-alpha-phosphatidylcholine become permeable to ions, low-molecular-weight solutes, and high-molecular-weight polymers after treatment with amoebicin.     

Alterations in the pattern of collagen deposition may contribute to the deterioration of systolic function in hypertensive patients with heart failure.

OBJECTIVES: We sought to assess the distribution of collagen deposits and collagen degradation in hypertensive patients with either systolic heart failure (SHF) or diastolic heart failure (DHF). BACKGROUND: Increased collagen synthesis and deposition have been described in the myocardium of heart failure (HF) hypertensive patients. METHODS: We studied 39 HF hypertensive patients subdivided into two groups: 16 with SHF and 23 with DHF. Endomyocardial biopsies were performed to quantify mysial (i.e., perimysial plus endomysial) and perivascular and scar-related collagen volume fraction (CVF). Matrix metalloproteinase (MMP)-1 and its tissue inhibitor matrix metalloproteinase (TIMP)-1 were analyzed in cardiac samples by Western blot and immunohistochemistry, and in blood samples by enzyme-linked immunosorbent assay. RESULTS: Mysial CVF was lower in SHF hypertensive patients than in normotensive (p < 0.05) and DHF hypertensive patients (p < 0.01). Perivascular and scar-related CVF was higher (p < 0.05) in the two groups of hypertensive patients than in normotensive subjects, and in SHF hypertensive compared with DHF hypertensive patients. The MMP-1:TIMP-1 ratio was increased (p < 0.05) in tissue and serum samples from the SHF hypertensive group compared with the other two groups of subjects. The MMP-1 expression was increased (p < 0.01) in the interstitium and cardiomyocytes of SHF hypertensive patients compared with DHF hypertensive and normotensive subjects. The serum MMP-1:TIMP-1 ratio was inversely correlated with ejection fraction (r = -0.510, p < 0.001) and directly correlated with left ventricular end-diastolic diameter (r = 0.549, p < 0.001) in all subjects. CONCLUSIONS: These findings show that the pattern of collagen deposits and the balance of the MMP-1/TIMP-1 system are different in the myocardium of SHF and DHF hypertensive patients. It is proposed that excessive degradation of mysial collagen may be related to the compromise of systolic function in HF hypertensive patients.     

Impact of an anti-hepatitis B virus (HBV) immunization program in patients undergoing dialysis in Havana, Cuba

The follow-up of HBV markers in selected high infection risk populations, in patients from the hemodialysis and peritoneal dialysis services was used to assess the effectiveness of a special vaccination program. Viral infection markers were studied in prevalence cross sections of the whole population of patients, and also by recording the reports of clinical cases of hepatitis B occurred during that period in those groups of patients. The prevention program consisted of the vaccination of all patients negative to the viral markers and the indication of vaccination for the new cases during the period of the kidney disease, just before the start of the treatment at the hemodialysis unit; besides all the persons susceptible to infection that had already been included in the program, regardless of the stage of the disease. The results show the benefit of the vaccination in these patients, but it is more effective in the period before the treatment with dialysis where there is a lower possibility of being exposed to the virus and the immune system is still competent. Once the program was established, after a follow up o 6 years, there have been no reports of new cases of hepatitis B and the incidence of the disease has been declining.     

Postmortem molecular analysis of SCN5A defects in sudden infant death syndrome.

CONTEXT: Fatal arrhythmias from occult long QT syndrome may be responsible for some cases of sudden infant death syndrome (SIDS). Because patients who have long QT syndrome with sodium channel gene (SCN5A) defects have an increased frequency of cardiac events during sleep, and a recent case is reported of a sporadic SCN5A mutation in an infant with near SIDS, SCN5A has emerged as the leading candidate ion channel gene for SIDS. OBJECTIVE: To determine the prevalence and functional properties of SCN5A mutations in SIDS. DESIGN, SETTING, AND SUBJECTS: Postmortem molecular analysis of 93 cases of SIDS or undetermined infant death identified by the Medical Examiner's Office of the Arkansas State Crime Laboratory between September 1997 and August 1999. Genomic DNA was extracted from frozen myocardium and subjected to SCN5A mutational analyses. Missense mutations were incorporated into the human heart sodium channel alpha subunit by mutagenesis, transiently transfected into human embryonic kidney cells, and characterized electrophysiologically. MAIN OUTCOME MEASURES: Molecular and functional characterization of SCN5A defects. RESULTS: Two of the 93 cases of SIDS possessed SCN5A mutations: a 6-week-old white male with an A997S missense mutation in exon 17 and a 1-month old white male with an R1826H mutation in exon 28. These 2 distinct mutations occurred in highly conserved regions of the sodium channel and were absent in 400 control patients (800 alleles). Functionally, the A997S and R1826H mutant channels expressed a sodium current characterized by slower decay and a 2- to 3-fold increase in late sodium current. CONCLUSION: Approximately 2% of this prospective, population-based cohort of SIDS cases had an identifiable SCN5A channel defect, suggesting that mutations in cardiac ion channels may provide a lethal arrhythmogenic substrate in some infants at risk for SIDS.     

Abordajes en cirugía tiroidea

Thyroidectomy is the most frequent procedure in endocrine surgery. The conventional approach through a collar incision, as described by Kocher in XIX^th century, has become the “gold standard”. It is continuously evolving in spite of, many years ago, it showed to be safe and efficient with quality standards difficult to beat.Endoscopic and robotic surgery have developed “new approaches” to thyroid in order to improve the cosmetic results, looking even for invisible scars.We have done a thoughtful review of most of them trying to understand their benefits and drawbacks.Currently none of these “new approaches” have been shown to be better than conventional open thyroidectomy beyond offering a better cosmetic result. Besides, only a small percentage of patients can benefit of them. However, most of these approaches will remain if they treat the diseased thyroid and also improve the quality of life of our patients.     

Achieving hospital operating objectives in the light of patient preferences

Patient satisfaction is becoming increasingly important for the successful operation of private and public hospitals. The quality of the service provided can be improved if internal and external customers' opinions are taken into account during the definition of hospital operating objectives. This research presents a new methodology, called the simulation service quality system (SSQS), developed to improve operating performance measures in the light of customer preferences. The motivation for the development of the SSQS methodology arose from the need to achieve timeliness standards at United States Veterans' Hospitals. The Harry S. Truman Memorial Veterans' Hospital in Columbia Missouri served as the validation and initial application site for the SSQS methodology. Details one such project: the objective of reducing customer waiting times to 30 minutes or less at an outpatient treatment clinic. Through the identification of relationships and interactions, discrete-event simulation techniques are applied to model and experiment with the system to ultimately arrive at recommended changes in hospital operating policies which achieve the objective.     

Economic study of neutropenia induced by myelotoxic chemotherapy

This article describes the economic and social impact of nutropenia induced by myelotoxic chemotherapy in patients with cancer during the period 1 January–31 December 1991. Neutropenia is a life-threatening complication of chemotherapy in patients with cancer. The episodes of (ever and infections originating from neutropenia require hospitalization of the patient until the granulocyte levels are restored. The calculation of the economic cost was based on the following parameters: length of stay in hospital, analytical tests performed on the patient, type and cost of drug therapy administered, blood transfusions performed, health assistance received, cost of isolation and absence from work. The overall economic cost of neutropenia in patients with cancer reached 329,775 pesetas ($2,893). Cost of the health-care staff was the largest budget item in relation to the total health resources estimated.     

An Atypical Presentation of Visual Hallucinatory Experiences Following Prolonged Blindness*

We report a patient with long-standing blindness experiencing both simple and complex visual hallucinations secondary to a cortical arteriovenous malformation (AVM). The hallucinations were located in the right visual field corresponding to the contra-lateral site of cortical damage. This case contributes to our understanding of neurophysiological mechanisms underlying visual hallucinations and ongoing research investigating the phenomenology of hallucinations with respect to the cause and localization of neural damage.