Relationship between oral bacteria and hemodialysis access infection

OBJECTIVE: Controversy exists concerning the association between oral bacteria and infection of hemodialysis (HD) shunts. The purpose of this study was to determine the extent to which oral bacteria are associated with vascular access site infections in a group of HD patients. STUDY DESIGN: Microbial blood culture data for 87 HD patients were collected: 53 via chart review (retrospective), and 34 with newly suspected vascular access infections (prospective). The primary outcome was the nature (i.e., species) of the bacteria recovered from blood cultures of subjects with vascular access infection, specifically those bacteria considered to be oral flora. RESULTS: The predominant bacteria reported to cause HD vascular access infections were Staphylococcus (48.6%) and Enterococcus (17.6%) species. Most infections occurred in hemodialysis catheters (89%) compared with AV grafts (11%) and AV fistulas (0%). The subclavian venous access (41%) and the internal jugular venous access (38.9%) were more commonly infected than other sites. None of the bacteria identified by blood cultures were considered to be oral flora. CONCLUSION: The results suggest that oral bacteria rarely, if ever, cause vascular access infections in hemodialysis patients.     

Modification of the peritoneoscopic technique of peritoneal dialysis catheter insertion: experience of an interventional nephrology program

Bowel perforation is a well-recognized complication of peritoneal dialysis catheter insertion and is associated with increased morbidity and cost of medical care. In this article we describe our 2-year experience (August 2001-October 2003) with a modified peritoneoscopic technique of peritoneal dialysis catheter insertion to minimize the incidence of bowel perforation. Seventy patients underwent 82 consecutive peritoneal dialysis catheter insertions using the innovative technique. The modified technique is very similar to the traditional peritoneoscopic procedure except for the following differences. To gain access to the peritoneal cavity, a Veress insufflation needle (Ethicon Endo-Surgery Inc., Cincinnati, OH) is utilized instead of the trocar. In contrast to the sharp tip of the trocar, the Veress needle has a blunt, self-retracting end. In addition, the Veress needle is only 14 gauge as opposed to the 2.2 mm diameter of the trocar. Upon introduction of the Veress needle into the abdominal cavity, two "pops" are discerned similar to the trocar. After introduction, 400-500 cc of air are infused and the needle is removed. The infusion of air creates a space between the peritoneal surface of the anterior abdominal wall and the bowel loops. At this point, the cannula with trocar is inserted into the space created. The rest of the steps of the procedure are the same as the traditional peritoneoscopic technique. Utilizing the innovative technique, all 82 catheter insertions were performed successfully without a single bowel perforation. No other complications except for catheter migration (n = 2) were noted. The extra cost of the needle (35 USD) should be viewed in the context of the costs associated with management of a bowel perforation. Large-scale studies are needed to confirm the superiority of this innovative technique over the traditional peritoneoscopic insertion found in our case series. In the interim, however, the increased morbidity and cost associated with bowel perforation calls for logical measures to be taken to avoid this dreaded complication.     

P53 gene mutations in pleuropulmonary blastomas

Pleuropulmonary blastoma (PPB) is rarechildhoodtumororiginating fromeitherlung orpleura. Although several cytogenetic changes, such as trisomy 2, trisomy 8, and loss of 17p material, have been reported, evidence of gene mutations is still lacking. Pathologically, PPB shares similarities with rhabdomyosarcoma in which p53 mutations are frequently detected. Possible implication of p53 mutations in PPB was investigated. PPBs of 3 patients were analyzed for occurrence of p53 mutations by using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method, and the nature of mutations was confirmed by direct sequencing. Two PPBs were confirmed to harbor p53 mutations. One was a Val to Leu substitution at codon 173, and another was a ArgArg to TrpCys substitution at codons 282 and 283. In each tumor, only the mutated allele was detected, suggesting inactivation of p53. Both patients with mutations had fatal outcome, while the remaining patient in whom no mutation was detected is disease free for 3 years after completion of treatment. The results raise the possibility that p53 inactivation can occur as a nonrandom genetic change involving the pathogenesis and outcome of PPB. Further studies in a larger series are necessary to clarify these matters.     

Id proteins in cell growth and tumorigenesis

Since the gene encoding Id1 was cloned in 1990, Id proteins have been implicated in regulating a variety of cellular processes, including cellular growth, senescence, differentiation, apoptosis, angiogenesis, and neoplastic transformation. The development of knockout and transgenic animal models for many members of the Id gene family has been particularly useful in sorting out the biologic relevance of these genes and their expression during normal development, malignant transformation, and tumor progression. Here we review the current understanding of Id gene function, the biologic consequences of Id gene expression, and the implications for Id gene regulation of cell growth and tumorigenesis.     

AgNORs and their relationship to cell size,histological grade,lymph node involvement,metastases, and survival pattern in carcinoma of the breast: A study from south India

An AgNOR count using the Smith and Crocker [Histopathology 12:113–125, 1988] method of staining was performed on 200 cases of carcinoma of the breast. A count of coarse AgNORs per nucleus was made on 50 random cells and the mean of their number per nucleus calculated. The relationship of a single variable “AgNOR count” to other variables such as cell size, histological grade, number of positive ipsilateral axillary lymph nodes, and presence of metastasis in regions other than the ipsilateral axillary lymph nodes was found using a univariate method of analysis. Also, the effect of different independent variables, e.g., number of AgNORs, cell size, histological grade, number of positive axillary lymph nodes, and metastasis on a single variable, i.e., 4-year period of survival, was also assessed by a univariate method of statistical analysis. It was found that the AgNOR count was significantly related to the cell size, histological grade, and presence of metastasis. Large cells, grade III tumors, and neoplasms with evidence of metastasis showed larger numbers of AgNORs in their nuclei. It was observed that the number of AgNORs significantly affected the 4-year survival of patients. The higher the AgNOR counts, the poorer were the chances of surviving for 4 years. The other factors that influenced survival in the present study were the number of positive axillary lymph nodes and metastasis to sites other than axillary lymph nodes. © 1996 Wiley-Liss, Inc.     

Vitamin E suppresses increased lipid peroxidation in cigarette smokers

Cigarette smoke contains many xenobiotics, including oxidants and free radicals, which can increase lipid peroxidation. Recently, breath pentane output (BPO) has been recognized as a good indicator of lipid peroxidation. Vitamin E is known to be a potent free radical scavenger which can protect biological membranes against oxidative damage. We investigated the effect of vitamin E (dl-alpha-tocopherol) on lipid peroxidation in 13 healthy smokers. The results showed (1) smokers had increased BPO as compared with 19 healthy non-smokers (16.3 +/- 1.9 vs 5.8 +/- 0.5, pmol/kg body weight/min, p less than 0.001) although both groups had comparable plasma vitamin E and selenium concentrations, (2) supplementation with vitamin E (800 mg/day for 2 weeks) decreased BPO in smokers, and (3) the concentration of plasma selenium-dependent glutathione peroxidase was restored to normal in those smokers (five out of 13) in whom this was low initially. We conclude that a normal plasma concentration of vitamin E does not prevent this increase of lipid peroxidation in smokers but that substantial doses of vitamin E will significantly reduce this increased lipid peroxidation. If a major function of vitamin E is to protect lipids from peroxidation, then smokers have a conditioned insufficiency of vitamin E on a normal diet.     

Immune inhibition of virus release from human and nonhuman cells by antibody to viral and host cell determinants.

Immune inhibition of release of the DNA viruses, herpes simplex virus types 1 and 2 and pseudorabies virus by anti-viral and anti-host cell sera occurred while two RNA viruses, influenza and encephalomyocarditis, were inhibited only by anti-viral sera (not anti-host cell sera). Simian virus 40 and surprisingly two herpes viruses, bovine mamillitis and equine abortion, were not inhibited by either anti-viral or anti-host sera. Using the herpes simplex virus model, inhibition of virus release was detected in different cells of human and nonhuman origin with cross-inhibition between cell lines of different origin; thus, this form of immunotherapy may not require antibody to be tissue or organ specific. Evidence of inhibition of virus release from neoplastic and leukemic cell lines suggests possible application of this approach to control of virus-mediated leukoproliferative pathology (e.g. Burkitt's lymphoma or adult T cell leukemia).