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Biomedical subjects

D Katz

Publications and source records attributed to D Katz.

At least 19 recordsLinked to original sources
PubMed2006

A cyclosporine-based immunosuppressive regimen may be better than tacrolimus for long-term liver allograft survival in recipients transplanted for hepatitis C.

UNLABELLED: Rapid recurrence of severe hepatitis C (HCV) after liver transplantation is a major barrier to survival of the transplanted liver. While cyclosporine (CsA) in vitro has been shown to suppress HCV replication, an effect is not seen with tacrolimus (Tac). Evidence is inconsistent whether or how this translates to clinical practice. To expand the evidence on this issue, we analyzed graft survival and histological outcomes after liver transplantation for HCV hepatitis. METHODS: Using our longitudinal database (1991 onward) graft outcomes for all liver transplant recipients with HCV were evaluated (105 grafts in 97 patients). Severe activity, severe fibrosis, and graft survival were analyzed. All liver biopsies were scored (blinded) according to the Ludwig scale. Immunosuppression was based on prednisone and a calcineurin inhibitor (Tac n = 89, 85%; CsA n = 15, 14%). Comparisons of outcomes using CsA versus Tac therapy were done using survival analysis via the log-rank test. RESULTS: Graft survival was significantly better in the CsA group. Although there was no apparent difference in severe activity (grade 2), there was a statistically significant difference in graft survival without fibrosing cholestatic hepatitis (P = .01) and a trend toward a difference in fibrosis-free survival (P = 0.1). The rate of sustained response to antiviral therapy was twice as high in the CsA group, 50% versus 22% (P = 0.16; NS). CONCLUSIONS: Graft survival in liver transplant recipients with HCV may be greater with CsA-based immunosuppression. There may also be a lower rate of fibrosing cholestatic hepatitis in this group.

Biopsy↗
PubMed2004

Bicarbonate is a native cofactor for assembly of the manganese cluster of the photosynthetic water oxidizing complex. Kinetics of reconstitution of O2 evolution by photoactivation.

Assembly of the inorganic core (Mn(4)O(x)Ca(1)Cl(y)) of the water oxidizing enzyme of oxygenic photosynthesis generates O(2) evolution capacity via the photodriven binding and photooxidation of the free inorganic cofactors within the cofactor-depleted enzyme (apo-WOC-PSII) by a process called photoactivation. Using in vitro photoactivation of spinach PSII membranes, we identify a new lower affinity site for bicarbonate interaction in the WOC. Bicarbonate addition causes a 300% stimulation of the rate and a 50% increase in yield of photoassembled PSII centers when using Mn(2+) and Ca(2+) concentrations that are 10-50-fold larger range than previously examined. Maintenance of a fixed Mn(2+)/Ca(2+) ratio (1:500) produces the fastest rates and highest yields of photoactivation, which has implications for intracellular cofactor homeostasis. A two-step (biexponential) model is shown to accurately fit the assembly kinetics over a 200-fold range of Mn(2+) concentrations. The first step, the binding and photooxidation of Mn(2+) to Mn(3+), is specifically stimulated via formation of a ternary complex between Mn(2+), bicarbonate, and apo-WOC-PSII, having a proposed stoichiometry of [Mn(2+)(HCO(3)(-))]. This low-affinity bicarbonate complex is thermodynamically easier to oxidize than the aqua precursor, [Mn(2+)(OH(2))]. The photooxidized intermediate, [Mn(3+)(HCO(3)(-))], is longer lived and increases the photoactivation yield by suppressing irreversible photodamage to the cofactor-free apo-WOC-PSII (photoinhibition). Bicarbonate does not affect the second (rate-limiting) dark step of photoactivation, attributed to a protein conformational change. Together with the previously characterized high-affinity site, these results reveal that bicarbonate is a multifunctional "native" cofactor important for photoactivation and photoprotection of the WOC-PSII complex.

Apoenzymes↗
PubMed2004

Wireless capsule video endoscopy compared to barium follow-through and computerised tomography in patients with suspected Crohn's disease--final report.

BACKGROUND: Wireless capsule endoscopy is a superior diagnostic tool to barium small bowel follow-through and enteroscopy in diagnosing patients with occult blood loss. AIM: To compare capsule endoscopy with barium follow-through and entero-computerised tomography in patients with suspected Crohn's disease. SUBJECTS AND METHODS: Thirty-five patients with suspected Crohn's disease underwent the three examinations. The radiologist and gastroenterologist were blinded to each other's results. In cases of discrepancy, colonoscopy and ileoscopy were performed. RESULTS: Thirty-five patients (22 males), mean age 28.4 years, were included. Eighty-eight percent had abdominal pain, 83% had diarrhoea and 69% had weight loss. The diagnostic yield of capsule endoscopy was 77% versus 23% and 20% of barium and computerised tomography examinations, respectively (P < 0.05). The capsule detected all of the lesions diagnosed by barium follow-through and entero-computerised tomography. CONCLUSIONS: Capsule endoscopy is a superior and more sensitive diagnostic tool than barium follow-through and entero-computerised tomography in patients with suspected Crohn's disease.

Adult↗
PubMed2004

Selective endoscopic cholangiography for the detection of common bile duct stones in patients with cholelithiasis.

BACKGROUND AND STUDY AIMS: The detection and management of common bile duct (CBD) stones in patients undergoing laparoscopic cholecystectomy continues to be controversial. Several diagnostic and therapeutic strategies have been suggested. These include intraoperative cholangiography, selective endoscopic retrograde cholangiopancreatography (ERCP), magnetic resonance cholangiopancreatography, and endoscopic ultrasonography. The aim of this study was to evaluate the efficacy of selective ERCP in detecting CBD stones in patients with cholelithiasis before laparoscopic cholecystectomy. PATIENTS AND METHODS: In a prospective study, patients with cholelithiasis who presented during a 6-year period were assessed on a selective basis with ERCP for suspected CBD stones before laparoscopic cholecystectomy. ERCP was carried out if the patient had any of the following criteria: a dilated CBD on ultrasound, gallstone pancreatitis, or abnormal liver function tests. Intraoperative cholangiography was not performed in any of the patients. Long-term follow-up was undertaken. RESULTS: The study included 427 patients. On the basis of selective criteria, ERCP was carried out in 41 patients (9.6 %), with confirmed CBD stones in 22 cases (53.7 %). The most useful predictor of CBD stones on ERCP was the presence of a dilated CBD in association with abnormal liver function tests. In this situation, CBD stones were identified in 14 of 17 cases (82 %). Abnormal liver function tests alone had a sensitivity of 50 % (four of eight). All other parameters used in isolation had a lower detection rate. During a median follow-up period of 6 years (range 1-10 years), six of 386 patients (1.6 %) with initially normal imaging and biochemical tests presented again with retained stones. All were successfully managed by ERCP and sphincterotomy. There were no major complications. CONCLUSIONS: Preoperative selective ERCP is effective in detecting clinically significant CBD stones. However, there is a high false-negative rate when a single criterion is used to guide therapy. Multivariate analysis of preoperative parameters for risk stratification, in conjunction with other imaging modalities, may make it possible to minimize unnecessary ERCPs.

Adult↗
PubMed2004

The influence of age on quality of life outcome in women following a tension-free vaginal tape procedure.

PURPOSE: Tension-free vaginal tape (TVT) has been introduced and demonstrated to be an effective treatment for stress urinary incontinence. Improved general health in the elderly population has led to a greater number of patients seeking surgical treatment for incontinence. We evaluated the impact of TVT on quality of life in elderly patients, defined as age 70 and older. MATERIALS AND METHODS: We prospectively evaluated 67 patients with genuine stress incontinence differentiated by age into 2 groups, namely 21 who were 70 years and older, and a control group of 46 younger than 70 years, with a validated questionnaire. We assessed quality of life changes following TVT for incontinence treatment. RESULTS: At the most recent followup quality of life scores improved significantly in the 2 groups (p <0.05). Stress incontinence improved significantly in the 2 groups (p <0.05). CONCLUSIONS: TVT is effective in each group. It is a viable treatment option to improve quality of life in older women with stress urinary incontinence.

Age Factors↗
PubMed2003

Early endothelial dysfunction following renal mass reduction in rats.

BACKGROUND: Endothelial dysfunction has been previously described in severely hypertensive rats with renal mass reduction (RMR) receiving large dietary Na loads. Because hypertension and Na loading reduce endothelium-dependent vasodilation, the effect of renal failure per se is unclear. METHODS: Responses to acetylcholine in noradrenaline-contracted isolated perfused mesenteric arteries were studied. Vessels were obtained from RMR rats kept on a normal diet, 3 and 10 days after surgery, and the results were compared with those from sham-operated rats (SN). The role of three putative mediators of endothelium-dependent vasodilation was assessed using: L-NAME (10(-4) mol L(-1)); indomethacin (INDO, 10(-5) mol L(-1)); and a mixture of charybdotoxin and apamin (C/A, both 10(-7) mol L(-1)), inhibitors of Ca-activated K-channels to mediate the effects of endothelium-derived hyperpolarizing factor (EDHF). RESULTS: Response to acetylcholine but not that to nitroprusside (endothelium-independent) was decreased in RMR. L-NAME reduced further acetylcholine relaxations in SN but not in RMR. By contrary, INDO decreased acetylcholine vasodilation in RMR but had no effect in SN. C/A had similar effects in the SN and RMR rats. The levels of 6-keto prostaglandin F1alpha were elevated in the urine of the RMR rats and were perfusate from the RMR vessels. CONCLUSION: Endothelial dysfunction occurs early after RMR, even when systolic blood pressure is only minimally elevated and Na intake is normal. This alteration may be because of decreased availability of nitric oxide, partially compensated by increased prostacyclin production.

6-Ketoprostaglandin F1 alpha↗
PubMed2002

Antibody cross-reactivity of alphaherpesviruses as mirrored in naturally infected primates.

The extent of antibody cross-reactivity of pooled antisera from rhesus monkeys, baboons, African green monkeys, langurs, sooty mangabeys and humans to 6 alphaherpesviruses (herpes B virus, herpes papio 2, simian agent 8, langur herpes virus and herpes simplex 1 & 2) was examined by two types of enzyme linked immunosorbent assays, an antibody capture assay (tELISA) and an antigen capture assay (dELISA). Percent cross-reactivity was calculated for each serum by comparison of the homologous reaction (100%) to the reaction with heterologous viruses. Comparison of the immunological reactivity of the mangabey antiserum pool to the panel of alphaherpesviruses indicated that these antibodies were induced by a yet unidentified alphaherpesvirus. In general, monkey sera were more cross-reactive to monkey herpesviruses than to human herpesviruses.However, the extent of cross-reactivity of monkey sera to human herpesviruses was relatively lower than the cross-reactivity of human sera to monkey herpes-viruses. Because of this phenomenon of "one-way" cross-reactivity that was also observed within the group of simian herpesviruses, it was difficult to rank the immunologic distances between the viruses in absolute terms.

Alphaherpesvirinae↗
PubMed2002

Serological evidence of alpha herpesvirus infection in sooty mangabeys.

Contact between sooty mangabeys (SMs) and a pigtailed macaque prompted the serological screening of SMs for evidence of infection with B virus. Serological tests detected SM antibodies that reacted with B virus polypeptides. Additional testing was performed with sera from SMs with no previous contact with macaques. Results from these tests indicated that 56% (33/59) of the SMs had antibodies that reacted with B virus and SA8. SM antibodies also reacted with herpesvirus papio 2 and to a lesser extent with human alpha herpesviruses (HSV-1 and HSV-2). There was an age-related increase in the presence of these antibodies in SMs that was consistent with the serological pattern of reactivity observed in other nonhuman primate species infected with alpha herpesviruses. These data suggest that SMs may be a host for a herpesvirus that is antigenically similar to those viruses present in other Old World nonhuman primates.

Age Factors↗
PubMed2002

[Deltoid muscle flap for massive rotator cuff tears: 41 cases with a mean 7-year (minimum 5 year) follow-up].

PURPOSE OF THE STUDY: The aim of this study was to assess outcome after deltoid muscle flap repair of massive rotator cuff tears. We examined functional and radiological results at least five years after surgery. MATERIAL AND METHODS: We reviewed 41 shoulders operated by three senior surgeons (MC, DK, HT). None of the patients were lost to follow-up. The global Constant score was used for pre- and postoperative functional assessment. Three groups were distinguished by preoperative active flexion (group I<90 degrees, group II 90 degrees -120 degrees, group III > 120 degrees ). AP, double oblique (3 rotation views to measure the subacromial space), and Lamy lateral radiographs were obtained in all patients. Shoulder anatomy was evaluated at last follow-up in eight patients: magnetic resonance imaging (MRI) because of persistent pain in one patient and ultrasonography performed by one radiologist (NC) in seven patients. RESULTS: The study population included 26 men and 15 women, mean age at surgery 59 years (42-78, 8). Mean follow-up was 7 years (5-8.5, 0.9). In the coronal plane, there were no distal tears, the stump was in an intermediate position in 7 cases (17%) and retracted to the glenoid in 34 (83%). In the sagittal plane, the supraspinatus exhibited a full thickness tear in all cases. The tear extended anteriorly or posteriorly in all cases. Thirty-eight patients (92%) were satisfied at last follow-up; their global Constant score had improved from 37 to 62 points. Mean anterior flexion improved from 113 degrees to 148 degrees and flexion force from 1.3 kg to 2.9 kg. When preoperative flexion was less than 90 degrees (11 cases), mean gain was + 89 degrees. Inversely, 7 of the 18 patients with flexion > 120 degrees lost a mean 40 degrees at last follow-up. Twenty-seven patient were reviewed at 12 and 89 months: pain relief and force were maintained. The subacromial space, measured in 88% of the cases, was 7.3 mm preoperatively and 5.5 mm at last follow-up. The subacromial space narrowed in 20 patients (56%); none of the patients exhibited an improvement. The flap was explored by ultrasonography in seven patients and by MRI in one: the flap was continuous in 50% and measured more than 4 mm in thickness. Reviews at 12 then 89 months demonstrated good maintenance of pain relief and progression of active flexion and force. DISCUSSION AND CONCLUSION: This long-term study confirms the usefulness of the deltoid flap for the treatment of full thickness massive tears of the rotator cuff. The flap provides persistent pain relief and good function and force. This technique should be discussed for young patients in good physical condition when preoperative imaging demonstrates and irreparable alteration of the tendinomuscular structures (supraspinatus retraction, fatty degeneration, severe amyotrophy). The technique is particularly useful when preoperative flexion is less than 90 degrees. Although the population size is too small for statistical analysis, indications for deltoid flap repair should probably be limited to tears involving at most two tendons and sparing the subscapularis.

Adult↗
PubMed2001

Suprahepatic venacavaplasty (cavaplasty) with retrohepatic cava extension in liver transplantation: experience with first 115 cases.

BACKGROUND: We first introduced the orthotopic liver transplantation utilizing cavaplasty technique in 1994. This paper describes the surgical technique and assesses the outcome of the cavaplasty OLT. METHODS: The cavaplasty procedure was used in 115 consecutive orthotopic liver transplantations, including six left lateral and two right lobe transplantations, between November 1994 and September 2000. Fifty-three (66.3%) transplantations required femoro-axillary veno-venous bypass in the initial 4 years, whereas only eight (22.9%) needed VB in the subsequent 2 years. Conversion to piggyback or standard technique was not necessary in any patient. RESULTS: Median results are as follows: operative time 4.5 hr, warm ischemia time 25 min, and blood transfused (packed red blood cells) 6 units. These findings did not differ between first transplantation and retransplantation. There were no perioperative deaths related to the cavaplasty technique. No hepatic venous outflow obstruction was observed, including living-related OLTs. No patient required postoperative hemodialysis for acute renal failure. The median intensive care and hospital stays were 2 days and 10 days, respectively. CONCLUSIONS: The cavaplasty technique requires no retrocaval, hepatic vein, or short hepatic vein dissection, and the inferior vena cava can be preserved, which provides advantages for hepatectomy and easy hemostasis, especially during retransplantation. The wide-open triangular caval anastomosis is easy to perform, allowing short implantation time and size matching and avoiding outflow obstruction. The short implantation time reduces the need for veno-venous bypass. Our experience indicates that the cavaplasty technique can be applied to all patients and is justified by minimal technical complications.

Adolescent↗
PubMed2001

Imaging and spectroscopy of artificial-atom states in core/shell nanocrystal quantum dots.

Current imaging scanning tunneling microscopy is used to observe the electronic wave functions in InAs/ZnSe core/shell nanocrystals. Images taken at a bias corresponding to the s conduction band state show that it is localized in the central core region, while images at higher bias probing the p state reveal that it extends to the shell. This is supported by optical and tunneling spectroscopy data demonstrating that the s-p gap closes upon shell growth. Shapes of the current images resemble atomlike envelope wave functions of the quantum dot calculated within a particle in a box model.

Journal Article↗
PubMed2001

Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow.

HYPOTHESIS: Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow. DESIGN: Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period. SETTING: University teaching hospital. PATIENTS: Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs). INTERVENTIONS: All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10). MAIN OUTCOME MEASURES: Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival. RESULTS: All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04). CONCLUSION: Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.

Aged↗
PubMed2001

Stroop performance in focal lesion patients: dissociation of processes and frontal lobe lesion location.

There were three primary objectives: to examine the usefulness of the Stroop interference effect as a measure of frontal lobe function; to investigate the possibility of distinct lesion effects for word reading or color naming; and to specifically determine the brain regions necessary for the performance of the incongruent condition. Fifty-one patients with single focal brain lesions in frontal and non-frontal regions and 26 normal control subjects (CTL) were administered the word reading, color naming and incongruent conditions of the Stroop task. Only frontal lesions produced significant impairment. Patients with posterior lesions were not significantly deficient in any condition. Damage to the left dorsolateral frontal lobe resulted in increased errors and slowness in response speed for color naming. Contrary to Perret (Neuropsychology, 1974; 12: 323-330), lesions of the left frontal lobe did not result in a selective interference deficit on the Stroop incongruent condition. Rather, bilateral superior medial frontal damage was associated with increased errors and slowness in response time for the incongruent condition. This result is interpreted as failure of maintenance of consistent activation of the intended response in the incongruent Stroop condition. The results and conclusion are compatible with the prevalent theories of both the Stroop effect and the role of the superior medial frontal regions. The role of the anterior cingulate cortex on performance of the Stroop task is likely related to task and patient context.

Adult↗
PubMed2001

Long-term results justify autogenous infrainguinal bypass grafting in patients with end-stage renal failure.

INTRODUCTION: Infrainguinal bypass grafting for limb-threatening ischemia in patients with end-stage renal disease is generally thought to be associated with increased operative risk and poor long-term outcome. This retrospective study was undertaken to examine the modern-era, long-term results of infrainguinal bypass grafting in dialysis-dependent patients. METHODS: Over the past 5 years in a single institution, 425 lower extremities (368 consecutive patients) were revascularized for the indication of limb salvage. Sixty-four patients (82 limbs) were dialysis-dependent at the time of revascularization, and this group was analyzed separately. They exhibited statistically significant higher incidences of diabetes (83% vs 56%; P <.001), hypertension (91% vs 74%; P <.001), and more distal vascular disease, which required a greater proportion of proximal anastomoses at the popliteal level (24% vs 11%; P <.01) and distal anastomoses at the infrapopliteal level (75% vs 65%; P <.05). RESULTS: Despite the higher prevalence of comorbid conditions and distal disease in patients with renal failure, their perioperative 30-day mortality rate remained low (4.9%) and was not significantly different from that in patients with functioning kidneys (2.9%; P = not significant). After a median follow-up of 11 months (range, 0-60 months), the 3-year autogenous conduit secondary graft patency in patients with renal failure was no different than in patients with functioning kidneys (67% +/- 9% vs 64% +/- 5%; P = not significant). Nonautogenous conduits in dialysis-dependent patients exhibited a significantly poorer outcome with only 27% +/- 12% remaining secondarily patent at 2 years. As expected, both limb salvage and patient survival were significantly less in patients with renal faiture, although both exceeded 50% at 3 years (limb salvage 59% +/- 8% vs 68% +/- 5%; P <.05; patient survival 60% +/- 8% vs 86% +/- 4%; P <.001). The often-quoted phenomenon of limb loss, despite a patent bypass graft, occurred infrequently in this study (n = 3 of 82 limbs). CONCLUSION: Infrainguinal revascularization can be performed in dialysis-dependent patients with acceptable perioperative and long-term results, especially in patients in whom adequate autologous conduit is available.

Blood Vessel Prosthesis Implantation↗
PubMed2001

Two-stage evaluation and intervention program for control of methicillin-resistant Staphylococcus aureus in the hospital setting.

The aim of this study was to develop a 2-stage evaluation and intervention program for control of methicillin-resistant Staphylococcus aureus (MRSA) in the hospital setting. The first stage included evaluation of MRSA prevalence throughout the entire hospital; the presence of MRSA was determined in patients or medical staff who had a high risk of carrying it (i.e. as a result of contact with surgical wounds). In the second stage, "contact isolation" (which included the use of gloves, hand washing before and after treatment of a patient and isolation of patients' personal belongings) was carried out in every patient from whom MRSA was isolated in 4 intervention departments-Surgery, Orthopaedics, General ICU and Neonatal ICU-while the same policy of attempting to isolate MRSA was maintained. Both stages lasted 7 months. A comparison between MRSA prevalence in the evaluation and intervention stages disclosed a decrease in MRSA isolates from 91 to 56 in the entire hospital (p = 0.2) and from 45 to 24 in the intervention departments (p = 0.05), respectively; while the number of patients with MRSA decreased from 87 to 55 in the entire hospital (p = 0.2) and from 45 to 18 in the intervention departments (p = 0.007). The number of patients treated with vancomycin decreased from 48 before intervention to 23 after "contact isolation" was started in the entire hospital (p = 0.02) and from 31 to 5 in the intervention departments (p = 0.001). These results provide additional evidence in favor of establishing a program to control MRSA spread.

Anti-Bacterial Agents↗
PubMed2001

Dendritic cell activation and cytokine production induced by group B Neisseria meningitidis: interleukin-12 production depends on lipopolysaccharide expression in intact bacteria.

Interactions between dendritic cells (DCs) and microbial pathogens are fundamental to the generation of innate and adaptive immune responses. Upon stimulation with bacteria or bacterial components such as lipopolysaccharide (LPS), immature DCs undergo a maturation process that involves expression of costimulatory molecules, HLA molecules, and cytokines and chemokines, thus providing critical signals for lymphocyte development and differentiation. In this study, we investigated the response of in vitro-generated human DCs to a serogroup B strain of Neisseria meningitidis compared to an isogenic mutant lpxA strain totally deficient in LPS and purified LPS from the same strain. We show that the parent strain, lpxA mutant, and meningococcal LPS all induce DC maturation as measured by increased surface expression of costimulatory molecules and HLA class I and II molecules. Both the parent and lpxA strains induced production of tumor necrosis factor alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), and IL-6 in DCs, although the parent was the more potent stimulus. In contrast, high-level IL-12 production was only seen with the parent strain. Compared to intact bacteria, purified LPS was a very poor inducer of IL-1alpha, IL-6, and TNF-alpha production and induced no detectable IL-12. Addition of exogenous LPS to the lpxA strain only partially restored cytokine production and did not restore IL-12 production. These data show that non-LPS components of N. meningitidis induce DC maturation, but that LPS in the context of the intact bacterium is required for high-level cytokine production, especially that of IL-12. These findings may be useful in assessing components of N. meningitidis as potential vaccine candidates.

Acyltransferases↗