Central venous catheter infection due to Ustilago species.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to R Patel.
Explore the source record for details and available documents.
Forty-one consecutive liver transplant recipients were studied by polymerase chain reaction (PCR) of serum and peripheral blood mononuclear cells, reverse transcription (RT)-PCR of peripheral blood mononuclear cells, and viral blood culture for symptomatic cytomegalovirus (CMV) infection. The techniques were also used to predict the occurrence of CMV infection. For diagnosis of symptomatic CMV infection, the sensitivity and specificity of the different techniques were as follows: PCR of serum, 100% and 45%; RT-PCR, 25% and 97%; PCR of peripheral blood mononuclear cells, 83% and 35%; and blood culture, 83% and 86%, respectively. PCR of serum was positive in 83% of subjects with symptomatic infection before onset compared with 17% positive by blood culture. While viral blood culture was the best technique for the diagnosis of symptomatic CMV infection, PCR of serum was best at predicting the development of symptomatic CMV infection.
The role of OKT3 monoclonal antibody administration was studied as a risk factor for symptomatic cytomegalovirus (CMV) infection in 229 consecutive liver transplant recipients not receiving specific CMV prophylaxis. Twenty-six patients (11.4%) received OKT3 and 17 of them developed CMV infection, 11 (4.8%) being symptomatic. OKT3 use was a significant risk factor for symptomatic CMV infection by both univariate (relative risk [RR], 2.9; 95% confidence interval [CI], 1.5-5.8; P = .002) and multivariate time-dependent (RR, 3.4; 95% CI, 1.7-7.1; P = .001) analyses. A subgroup analysis revealed that OKT3 use was a significant risk factor for symptomatic CMV infection in CMV-seropositive but not seronegative recipients. OKT3 therapy for steroid-resistant rejection is a risk factor for symptomatic CMV infection in liver transplant recipients who are seropositive for CMV before transplantation. This group should be targeted for antiviral prophylaxis when OKT3 antirejection therapy is used.
Haemophilus influenzae can acquire heme from hemopexin for use as a source of both essential porphyrin and iron. In classical ligand-binding studies, we observed time-dependent, saturable, and displaceable binding of human 125I-labelled hemopexin to intact cells of H. influenzae type b (Hib) strain 760705 grown in an iron-restricted medium. From these experiments, which demonstrate that hemopexin associates with a single class of binding site, the affinities (Kds) and receptor numbers were calculated for heme-hemopexin (Kd, 205 nM; 3,200 receptors per cell) and apohemopexin (Kd, 392 nM; 4,400 receptors per cell). Thus, Hib expresses a specific hemopexin receptor which shows some preference for the heme-protein complex. Affinity chromatography on hemopexin-Sepharose 4B of detergent-solubilized membranes from Hib strain 760705 results in the copurification of three proteins with molecular masses of 57, 38, and 29 kDa. Trypsinization of whole cells of Hib 760705 abolishes hemopexin binding and correlates with the disappearance of the 57-kDa hemopexin-binding protein and appearance of a 52-kDa species which does not bind either hemopexin in ligand blot assays or a monoclonal antibody (MAbT11-30) raised against the 57-kDa protein. From immunoblotting assays and NH2-terminal amino acid sequence analysis, the 38-kDa protein isolated following hemopexin affinity chromatography was identified as the porin protein P2. These data, taken together with the receptor-binding studies which support a single class of hemopexin-binding site, suggest that P2 and the 29-kDa protein function as accessory proteins to the 57-kDa hemopexin-binding protein to facilitate the uptake of heme from receptor-bound hemopexin. To determine whether hemopexin binding and the 57-kDa protein are conserved in Haemophilus strains, whole-cell dot blots and immunoblots of the outer membrane proteins prepared from strains belonging to each of 21 different Hib outer membrane protein subtypes, six nontypeable strains, and five Haemophilus parainfluenzae strains were probed with either hemopexin or MAbT11-30. Only the H. parainfluenzae strains which lack the 57-kDa protein do not bind hemopexin. Since H. influenzae has also been shown to produce a soluble 100-kDa hemopexin-binding protein, cell-free culture supernatants were also examined for the presence of this protein. Apart from Hib 760705 and H. parainfluenzae, the 100-kDa hemopexin-binding protein was detected in all the other Haemophilus strains. The abilities of Hib 760705 to both bind and acquire heme from hemopexin without expressing a 100-kDa soluble hemopexin-binding protein show that in strain 760705, this 100-kDa protein is not essential for the utilization of heme from hemopexin.
Reliable nucleic acid extraction techniques for blood specimens are required for the sensitive detection of viral DNA. Standardized procedures for processing blood specimens for the molecular detection of herpesviruses (cytomegalovirus [CMV], herpes simplex virus, varicella-zoster virus, and Epstein-Barr virus [EBV]) have not been established. Three methods were used to extract DNA from blood specimens from healthy donors and asymptomatic immunocompromised patients: (i) IsoQuick treatment of whole blood, (ii) extraction of the peripheral blood leukocytes by lysis (lysis buffer and proteinase K), and (iii) extraction of peripheral blood leukocytes with phenol-chloroform (sodium docecyl sulfate solution and proteinase K). All blood specimens from 25 healthy blood donors were negative for CMV, herpes simplex virus and varicella-zoster virus nucleic acid sequences, regardless of the extraction method, while three samples (12%) extracted by the lysis technique were positive for EBV DNA. Of 25 blood samples from asymptomatic immunocompromised patients, CMV and EBV each were detected in nine specimens by lysis extraction, four each by IsoQuick and four (CMV) and six (EBV) by the phenol-chloroform method. Our results indicate that the lysis method is optimal for the detection of CMV and EBV DNA sequences by PCR from the leukocytic fraction of blood specimens. DNA of these viruses is frequently present in blood specimens from asymptomatic immunocompromised patients and occasionally from healthy donors.
Cytomegalovirus (CMV) viremia is a widely used laboratory marker of CMV disease following transplantation and is additionally used to trigger preemptive antiviral therapy. Despite this, the optimal method for diagnosing CMV viremia in transplantation recipients remains unknown. To determine the sampling frequency and blood volume required for the optimal diagnosis of viremia by shell vial assay, a prospective study of 46 viremic transplantation recipients was conducted. Blood specimens (2.5 and 5 ml) were collected twice, 3 h apart, at a median of 1.4 days (range, 1 to 3 days) after the triggering shell vial-positive blood had been collected. Considering a single 2.5-ml specimen, an average of only 40% of previously viremic patients had documented CMV in their blood: this increased to 50% when a second 2.5-ml sample of blood was collected 3 h later. The yields of two 2.5-ml versus two 5-ml samples were 50 versus 61%, respectively. Viremia as detected by shell vial assay is intermittent, and increasing the frequency and volume of blood sampling increases its diagnosis. These results have implications in diagnosis of CMV infection and its preemptive therapy.
Twenty-two men and 16 women with a mean age of 67 years were treated for rectal carcinoma by transanal excision. Patients presented with rectal bleeding (63%), change in bowel habits (11%), rectal pain (4%), or were asymptomatic and discovered on screening proctosigmoidoscopy (22%). The tumors were located from the anal verge to 8 cm proximally and ranged in size from 1 to 4 cm. Pathologic findings included adenocarcinoma (92%), squamous cell carcinoma (4%), and cloacogenic carcinoma (4%). Postoperative hospitalization averaged two days (0 to 29 days). One patient died of a perioperative myocardial infarction for an operative mortality of 3 per cent. Morbidity was 7 per cent and included urinary retention and pneumonia. Postoperative radiation therapy was administered to 11 patients with either undifferentiated tumors or invasion into the muscularis propria. Follow-up in these 38 patients averaged 30 months. One patient died of metastatic carcinoma, and two patients developed local recurrence that was treated successfully by a low anterior resection or abdominoperineal resection. Transanal excision of rectal carcinoma can be performed in properly selected patients with good overall survival and local control.
Jumping translocations are an unusual phenomenon and have been rarely reported in leukemia. We report three patients whose leukemic cells had multiple related clones resulting from unbalanced jumping translocations of 1q and 7q to chromosomes 1, 8, 15, 21 and 22. The chromosome findings, together with limited published reports, suggest that jumping translocations are new non-random rearrangements and may represent poor prognostic biological markers. Although their origin is unknown, circumstantial evidence suggests that telomeric ends of receptor chromosomes may play a role in stabilizing jumping translocations in dividing malignant cells.
The exercise 201T1 imaging procedure in patients with left bundle branch block (LBBB) is associated with a relatively high frequency of false-positive septal perfusion defects. We therefore initiated a study designed to determine the frequency of false-positive septal defects seen with adenosine/thallium imaging. In total, 900 adenosine/thallium cases performed at our institution for assessment of coronary artery disease were reviewed. Sixty-eight patients had LBBB on resting electrocardiogram (ECG) and sucessfully completed the imaging procedure, of whom 25 had coronary angiography. Only 6 of the 68 patients demonstrated reversible septal defects on thallium imaging. Of these 6 patients, 3 underwent coronary angiography and all of them had significant (> 70%) LAD stenosis. Therefore, at most only 4% of the patients with LBBB had a false-positive reversible septal defect. Three additional patients had fixed septal defects. Of these three patients, one underwent cardiac catheterization and was found not to have significant LAD stenosis. The results from this study suggest that adenosine/thallium imaging is associated with an acceptably low frequency of false-positive septal defects and should be used as an alternative to exercise/thallium in patients with LBBB.
Evaluation of the iron status (haemoglobin and ferritin concentrations, and percentage transferrin saturation) in a prospective study of 65 pregnant women (55 white and 10 black) revealed that adequate maternal iron stores during pregnancy cannot be maintained with prevailing dietary patterns. Although 80.6% of the patients had normal indices in the first trimester, only 12.3% were normal in the third. Significant depletion of iron stores occurred in the second trimester, but significant iron-deficient erythropoiesis only occurred in the third trimester. Despite the decline in iron status, iron deficiency anaemia was only seen in 7-8% of the patients. Even after correction for the haemodilution and increased transferrin concentrations in pregnancy, over 70% of women had depleted iron stores in the third trimester. No beneficial effect on fetal birth weights was found on withholding of maternal iron supplementation. This study clearly demonstrated that white and urban black pregnant women require iron prophylaxis to maintain iron stores.
Chronic intestinal pseudo-obstruction (CIP), a syndrome of disordered intestinal motility, is characterized by failure of the intestine to propel its contents through an unobstructed lumen. The symptoms and signs of CIP can be very similar to those of mechanical bowel obstruction. The two disease states differ in management, however; therefore, clinicians must differentiate the two. Abnormal propulsion can result from many causes. Cases can be classified as primary or secondary, and identifiable causes can be subdivided into those affecting neuronal control of motility and those directly affecting intestinal muscle function. Careful history, physical examination, and investigations help identify causative factors. The secondary forms of CIP are more common than the primary, and many cases are reversible by correction of the causative factor (e.g., drugs, metabolic abnormalities, or infection). Management of CIP depends on the cause of the disorder, the extent and location of intestine involved, and the severity of symptoms; general measures include dietary changes, prokinetic agents, and, rarely, surgical interventions. Some children with severe, refractory CIP who are wholly dependent on parenteral nutrition are candidates for consideration of intestinal transplantation.
The mechanism of the antineoplastic effects of suramin may involve interference with signal transduction, but in general is not well understood. We examined several polyanions to determine their effects on the kinase activity of the protein kinase C (PKC) beta1 and other PKC isoforms. Similar to suramin, a phosphorothioate oligodeoxynucleotide 28-mer homopolymer of cytidine (SdC28) inhibited the phosphatidylserine and Ca2+-dependent phosphorylation of an epidermal growth factor receptor octapeptide substrate. The inhibition by suramin was mixed competitive/noncompetitive with respect to ATP, but uncompetitive with respect to substrate. In contrast, the inhibition by SdC28 was competitive with respect to substrate (Ki = 5.4 microM) and not competitive with respect to ATP. The PKC alpha and beta1 isoforms were inhibited to the same extent with SdC28, while PKC epsilon was not inhibited. SdC28, in the absence of lipid cofactor, stimulated substrate phosphorylation, and in the absence of substrate induced PKC beta1 autophosphorylation. Similar behavior was seen with another polyanion, the polysulfated carbohydrate pentosan polysulfate (polyxylyl hydrogen sulfate). H4, a bis-naphthalene disulfonate tetraanion structurally related to suramin, also inhibited kinase activity but was not competitive with respect to ATP. Dianions closely related to H4 failed to inhibit PKC beta1, suggesting that multiple (>2) negative charges are required. The interactions of polyanions with PKC are complex, and are dependent on the molecular structure of the polyanion, the presence of cofactors, and the PKC isoform.
A non-randomized prospective study of 38 patients, 32 with ulcerative colitis and six with familial adenomatous polyposis (FAP), who underwent high or low anal transection during stapled restorative proctocolectomy was undertaken. The median (range) height of the staple line 6 months after operation was 5.2 (3.2-6.0) cm after high transection compared with 2.9 (1.8-3.6) cm after low transection. Nineteen of 20 patients after high anal transection had columnar epithelium in the distal 'doughnut' versus 16 of 18 after low transection. Active colitis was present in 12 of 19 'doughnuts' in patients with high anal transection and columnar mucosa and in seven of 16 after low transection. Nine patients (high transection two, low transection seven; P < 0.05) had striated muscle in the stapled distal 'doughnut'. Dysplasia was found in the resected colon in one patient with ulcerative colitis and adenocarcinoma in two colectomy specimens (ulcerative colitis, one; FAP, one). No dysplasia or carcinoma was seen in any of the 'doughnuts' from patients with ulcerative colitis. Four patients with FAP (high transection, two; low transection, two) had microadenoma in the distal 'doughnut'. Despite attempts to place a stapled pouch-anal anastomosis below the anal transition zone, it was not possible to remove columnar mucosa completely from the remaining anal canal in most patients (16 of 18). High anal transection and pouch-anal anastomosis should be the preferred option in restorative proctocolectomy, as a dentate-line anastomosis may not fully eliminate columnar epithelium and may involve resection of some of the external sphincter.
Explore the source record for details and available documents.
Most patients undergoing general anaesthesia are apnoeic during laryngoscopy and tracheal intubation. This study determined the time until the onset of desaturation following pre-oxygenation in apnoeic infants, children, and adolescents. Fifty ASA physical status I patients, 2 days to 18 yr of age, were studied. The patients were stratified into one of five groups according to age: Group I, 0-6 mo; Group II, 7-23 mo; Group III, 2-5 yr; Group IV, 6-10 yr; and Group V, 11-18 yr. Following induction of anaesthesia with halothane via mask or intravenous barbiturates, the ability of the anaesthetist to ventilate the lungs via the mask was ascertained and paralysis was accomplished with vecuronium 0.1 mg.kg-1. Manual mask ventilation was maintained with oxygen and halothane. When end-tidal N2 decreased below 3% (minimum time two minutes), the face mask was removed. The time between the removal of the face mask and a decrease in oxygen saturation (SpO2) from 99-100% to 90% was measured. Manual ventilation was then resumed and the trachea intubated. Desaturation started earlier in infants than in two- to five-year-old children (96.5 +/- 12.7 sec vs 160.4 +/- 30.7 sec, P < 0.0001). Children became desaturated faster than adolescents (160.4 +/- 30.7 vs 382.4 +/- 79.9 sec, P < 0.0001). The time required to reach 90% saturation correlated well with age by linear regression analysis (r2 = 0.88, P < 0.0001). We conclude that the time to onset of desaturation following pre-oxygenation with mask ventilation increases with age in healthy apnoeic children.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.
Lactobacillemia is rare and, to our knowledge, previously undescribed in liver transplant patients. We reviewed the clinical records of all patients who had undergone orthotopic liver transplantation between January 1985 and August 1992 for whom a blood culture after transplantation yielded Lactobacillus species. A case-control study for determination of risk factors for lactobacillemia in this patient population was also performed. Eight cases of lactobacillus bacteremia were identified. All patients received nonabsorbable oral antibiotics for selective bowel decontamination. In addition, six of eight case patients received intravenous vancomycin prior to the development of lactobacillemia. The biliary anastomosis in each case patient was a Roux-en-Y choledochojejunostomy. Analysis of the case-control study revealed that the presence of a Roux-en-Y choledochojejunostomy at the time of lactobacillemia is a statistically significant risk factor (odds ratio [OR] = infinity, 95% confidence interval [CI] = 1.8-infinity, P < or = .05) but that prior administration of intravenous vancomycin is not a statistically significant risk factor (OR = 2.6, 95% CI = 0.38-30.0, P value not significant) for lactobacillemia. The use of selective bowel decontamination and of intravenous vancomycin in liver transplant patients may select for Lactobacillus species. Furthermore, a Roux-en-Y choledochojejunostomy may allow colonization of the intrahepatic biliary tract with enteric flora.
Explore the source record for details and available documents.