Testing of alkaline and enzymatic hydrolysis pretreatments for fat particles in slaughterhouse wastewater

Four pretreatments to hydrolyse and/or reduce the size of fat particles in slaughterhouse wastewater (SHW) were tested: sodium hydroxide and three lipases of plant, bacterial and animal (pancreatic) origin. Hydrolysing agents and SHW containing between 2.5 and 3 g/l of fat particles were mixed at room temperature for 4 h. Additions of 5-400 meq NaOH/l did not increase soluble COD (SCOD) in SHW, but the average particle size was reduced to 73% +/- 7% of the initial average particle size (D(in)) at NaOH concentrations ranging from 150 to 300 meq/l. Pretreatment with pancreatic lipase PL-250 reduced the average particle size to a maximum of 60% +/- 3% of D(in). As D(in) was decreased from 359 to 68 microns, the enzyme concentration required to obtain the maximum particle size reduction increased from 200 to 1000 mg/l. A 4-h pretreatment with PL-250 also increased the free long-chain fatty acid (LCFA) concentration to a maximum of 15.5 mg/l, indicating some solubilization of the pork fat particles in SHW. SCOD was not significantly increased by the pretreatment, but SCOD was not found to be a good indicator of enzymatic lipolysis because of enzyme adsorption on the fat particle surface. Pancreatic lipase appeared more efficient with beef fat than pork fat, possibly because beef fat contains less polyunsaturated fatty acids than pork fat. The bacterial lipase LG-1000 was also efficient in reducing average fat particle size, but high doses (> 1000 mg/l) were required to obtain a significant reduction after 4 h of pretreatment. SCOD was not increased by pretreatment with LG-1000. No particle size reduction or changes in SCOD were noted after 4 h of pretreatment with the plant lipase EcoSystem Plus. It was concluded that PL-250 was the best pretreatment to hydrolyse fat particles in SHW. However, its impact on the efficiency of a downstream anaerobic digestion process remains to be tested.

Heterogenous and homogenous catalytic oxidation by supported gamma-FeOOH in a fluidized-bed reactor: kinetic approach

Oxidation of benzoic acid (BA) by H2O2 was performed with a novel supported gamma-FeOOH catalyst in a circulating fluidized-bed reactor (CFBR). This study focused mainly on determining the proportions of homogeneous catalysis and heterogeneous catalysis in this CFBR. Also studied herein was how pH, H2O2 concentration, and BA concentration affect the oxidation of BA. Experimental results indicate that the decomposition rate of H2O2 was proportional to its concentration and that the oxidation rate of BA depended on both H2O2 and BA concentrations. The change in the rate constant of heterogeneous catalysis by pH was described in terms of ionization fractions of surface hydroxyl group. From the mathematical deduction, we can infer thatthe reaction rate associated with ...Fe(III)OH2+ is markedly higher than that with ...Fe(III)OH. Conclusively, although heterogeneous catalysis contributes primarily to the oxidation of BA at pH 4.4-7.0, the homogeneous catalysis is of increasing importance below pH 4.4 because of the reductive dissolution of gamma-FeOOH.

Treatment of progressive hepatitis C recurrence after liver transplantation with combination interferon plus ribavirin

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) is common, although the majority of cases are mild. A subset of transplant recipients develops progressive allograft injury, including cirrhosis and allograft failure. Minimal data are available on the safety and efficacy of antiviral treatment in this group of patients. The aim of this study is to review our experience in the treatment of moderate to severe HCV recurrence with combination interferon-alpha2b and ribavirin (IFN/RIB). Between October 1993 and October 1999, a total of 197 patients underwent OLT for HCV-related liver failure. This study describes 12 transplant recipients with moderate to severe recurrence treated with IFN/RIB. All patients met at least 1 of the following inclusion criteria: (1) moderate to severe inflammation (grade III to IV) on allograft biopsy, (2) bridging fibrosis on allograft biopsy, or (3) severe cholestasis attributable solely to HCV recurrence. Two patients had undergone re-OLT for allograft cirrhosis secondary to HCV recurrence and now had evidence of progressive HCV in their second allografts. Appropriate dose reductions of both IFN and RIB, as well as initiation of granulocyte colony-stimulating factor (G-CSF), for marked leukopenia were recorded. IFN/RIB therapy was started 60 to 647 days post-OLT, and duration of therapy ranged from 39 to 515 days. Seven patients were administered G-CSF to successfully treat leukopenia. Six of the 12 patients (50%) became HCV RNA negative by polymerase chain reaction. One of these 6 patients (no. 1) was HCV RNA negative at 6 months but chose to discontinue therapy because of intolerable side effects, experienced a relapse, and was HCV RNA positive at 12 months. Two of the remaining 5 patients were HCV RNA negative at 2 and 9 months off therapy. For the entire group, there was a statistically significant decrease in serum biochemical indices assessed at initiation of therapy and 1, 3, and 6 months into therapy. Most patients required dose reductions of both IFN and RIB. Five patients died; 3 patients died of liver-related complications that included severe intrahepatic biliary cholestasis, severe HCV recurrence, and chronic rejection with profound cholestasis. In the subset of HCV-positive liver transplant recipients with moderate to severe recurrence, combination IFN/RIB therapy resulted in complete virological response (serum RNA negative) in 6 of 12 patients ( approximately 50%). However, only 1 of 12 patients (8.3%) had sustained virological clearance after cessation of IFN/RIB therapy. Dose reductions of both IFN and RIB were required in most patients. The use of G-CSF (sometimes preemptively) allowed correction of leukopenia and full-dose antiviral therapy. Multicenter trials using combination therapy to identify factors predictive of response are needed in the subset of patients with progressive allograft injury.

A deletion mutation in region V of the cytomegalovirus DNA polymerase sequence confers multidrug resistance

A patient with AIDS and cytomegalovirus (CMV) retinitis received ganciclovir and foscarnet for 20 and 5 months, respectively, with evidence of periodic disease progression. After this therapy, a CMV isolate from the patient was resistant to ganciclovir, foscarnet, and cidofovir. Sequence analysis showed a known ganciclovir resistance mutation in the viral UL97 phosphotransferase (L595F) and a new mutation in conserved region V of the DNA polymerase gene (pol) sequence (codons 981-982 deleted). The pol mutation was transferred to a laboratory CMV strain (Towne) by homologous recombination and selection with either ganciclovir or foscarnet. Recombinant viruses containing this deletion showed a 6-8-fold increased ganciclovir resistance and a 3-5-fold increased resistance to both foscarnet and cidofovir, compared with the wild-type CMV. A single mutation in region V of CMV pol can, therefore, confer multiple drug resistance in a clinical isolate.

Preferential accessibility of the yeast his3 promoter is determined by a general property of the DNA sequence, not by specific elements

Yeast promoter regions are often more accessible to nuclear proteins than are nonpromoter regions. As assayed by HinfI endonuclease cleavage in living yeast cells, HinfI sites located in the promoters of all seven genes tested were 5- to 20-fold more accessible than sites in adjacent nonpromoter regions. HinfI hypersensitivity within the his3 promoter region is locally determined, since it was observed when this region was translocated to the middle of the ade2 structural gene. Detailed analysis of the his3 promoter indicated that preferential accessibility is not determined by specific elements such as the Gcn4 binding site, poly(dA-dT) sequences, TATA elements, or initiator elements or by transcriptional activity. However, progressive deletion of the promoter region in either direction resulted in a progressive loss of HinfI accessibility. Preferential accessibility is independent of the Swi-Snf chromatin remodeling complex, Gcn5 histone acetylase complexes Ada and SAGA, and Rad6, which ubiquitinates histone H2B. These results suggest that preferential accessibility of the his3 (and presumably other) promoter regions is determined by a general property of the DNA sequence (e.g., base composition or a related feature) rather than by defined sequence elements. The organization of the compact yeast genome into inherently distinct promoter and nonpromoter regions may ensure that transcription factors bind preferentially to appropriate sites in promoters rather than to the excess of irrelevant but equally high-affinity sites in nonpromoter regions.

Detection of unsuspected colonic abnormalities using the pneumocolon technique during small bowel meal examination

AIMS

The pneumocolon technique in small bowel meal examination is used to obtain double-contrast views of the distal ileum. The purpose of this study was to determine the proportion of cases in which an overhead pneumocolon radiograph demonstrated clinically relevant findings in the colon.

METHODS

The overhead pneumocolon radiographs in 151 patients who underwent small bowel meals were evaluated retrospectively. A chart review was performed on those patients with positive colonic findings to determine if the suspected abnormalities affected patient management.

RESULTS

Colonic abnormalities were identified in 34 of the 151 patients. One patient had a previously undiagnosed ascending colonic cancer; 17 had evidence of acute or chronic colitis; 13 had diverticulosis; one had a caecal polyp; one had an ileosigmoid fistula; one had a filling defect in the ascending colon. In 25 cases the colonic abnormality was visible only on the pneumocolon radiograph and not on the preceding single-contrast images. Management was altered by the colonic findings in seven cases. False-positive findings occurred in two cases.

CONCLUSIONS

A routine overhead radiograph following use of the pneumocolon technique is a useful adjunct to small bowel meal examination as it can yield unsuspected and clinically significant colonic findings.Chou, S. (2000). Clinical Radiology55, 459-464.

Efficacy and safety of patient-controlled analgesia for morbidly obese patients following gastric bypass surgery

BACKGROUND

Adequate postoperative pain control is important to reduce potential cardiopulmonary complications. It is often difficult to determine dosages of narcotics for morbidly obese patients following Roux-en-Y gastric bypass (RYGBP) due to respiratory depression. Individualization of analgesic therapy, patient-controlled analgesia (PCA), can provide optimal dosage for pain control and minimize the side-effects.

METHOD

25 morbidly obese patients who received PCA with morphine sulfate following RYGBP. PCA settings we re as follows: morphine, 20 microg/kg of ideal body weight, 10-minute lock out interval and 80 % of a calculated amount for a 4-hour limit. W e measured arterial blood gas, heart rate, mean arterial pressure, arterial oxygen saturation, respiratory rate, opioid amount, patient satisfaction, visual analog pain scale (VAS), and the incidence of nausea, vomiting, pruritus and sedation.

RESULTS

Average morphine usage was 44.2+/-28.7 mg during the day of surgery (DOS); 49.1+/-27.4 mg during POD (postoperative day) #1; and 36.6+/-22.8 mg during POD#2 (p < 0.01). 24 patients were satisfied with their pain control on POD#1. VAS was 5.4+/-2.1 on the day of surgery, but remained below 4 thereafter. Arterial oxygen saturation and vital signs were maintained without significant changes. 5 patients experienced mild sedation on the day of surgery and 3 patients experienced mild sedation on POD#1. 1 patient experienced nausea and vomiting and 4 patients had pruritus; however, none required treatment.

CONCLUSION

PCA is safe and effective for morbidly obese patients following RYGBP.

A standardized plaque reduction assay for determination of drug susceptibilities of cytomegalovirus clinical isolates

Twelve laboratories collaborated in formulating and testing a standardized plaque reduction assay for cytomegalovirus (CMV) cell-associated clinical isolates. Four characterized and plaque-purified CMV strains, as well as six coded clinical isolates obtained after antiviral therapy, were distributed and tested. Good agreement was obtained for four of the clinical isolates, but a broad distribution of results was obtained for two isolates. Analysis of these results indicates the problems associated with clinical isolates, including the large genetic variability and the highly cell-associated phenotype. This collaborative effort, by addressing these problems, represents a significant step toward the development of a standardized assay.

Pitfalls in the interpretation of MIBG scans in cervical neuroblastoma

Cervical neuroblastoma (CNB) is relatively rare, accounting for less than 5% of these tumors. Because it arises from the cervical sympathetic chain, complete resection will leave the child with Horner's syndrome in a high proportion of cases. Advances in technology have allowed for the development of diagnostic and imaging modalities more specific to the disease. One of these has been the advent of radiolabeled meta-iodobenzylguanidine (MIBG) to assess the primary tumor and focal metastatic involvement. This nuclide is also taken up by normal salivary-gland tissue; this may be altered, however, in the presence of sympathetic denervation. We present a case of a primary CNB associated with Horner's syndrome, which led to confusion in interpretation of the subsequent MIBG scan. We alert the reader to potential pitfalls in the use of this examination in this disease entity.

A nine-codon deletion mutation in the cytomegalovirus UL97 phosphotransferase gene confers resistance to ganciclovir

A deletion mutation (codons 595 to 603) in the cytomegalovirus (CMV) UL97 gene was recently reported after sequence analysis of leukocyte DNA from a patient receiving ganciclovir. The corresponding viral phenotype was examined by transfer of this mutation to a laboratory CMV strain (strain Towne). The recombinant virus was resistant to ganciclovir (8.4-fold increase in the 50% inhibitory concentration), was sensitive to foscarnet, and replicated normally in cell culture.

Donor polymorphism of tumor necrosis factor gene: relationship with variable severity of hepatitis C recurrence after liver transplantation

BACKGROUND

Hepatitis C-related liver failure is the leading indication for liver transplantation worldwide. Although histologic recurrence is identified in the majority of patients, the spectrum of allograft injury is wide. To date, most studies have focused on the contribution of immunosuppression and viral factors. We hypothesized that the allograft plays a significant role in determining timing and severity of hepatitis C virus (HCV) recurrence. The purpose of this analysis was to determine if genetic polymorphisms of the tumor necrosis factor (TNF) locus were associated with the highly variable severity of HCV recurrence.

METHODS

Thirty-one HCV-seropositive liver transplant recipients with long-term follow-up were studied. Genomic DNA was extracted from archived donor spleens which corresponded to each patient. We performed polymerase chain reaction amplification, followed by sequencing for two promoter TNF-alpha variants (at positions -238 and -308), and restriction fragment length analysis for four polymorphic loci within the TNF-beta gene (NcoI, TNFc, aa13, and aa26).

RESULTS

The relative prevalence of polymorphisms corresponded to distributions previously reported in normal control populations. Twenty-two of 31 (71%) patients received a donor liver homozygous for the wild type allele (TNF1) at the -308 TNF-alpha promoter region. The interval to histologic recurrence was significantly shorter and severity of HCV allograft hepatitis was significantly greater in patients with one or two TNF308.2 alleles. At last follow-up biopsy, 5 of 9 (56%) patients with a TNF308.2 donor liver had evidence of severe histological activity index as compared to 2 of 22 (9%) of patients receiving a donor liver homozygous for the TNF1 allele (P = 0.01). There was no correlation between rejection rates and the presence of any TNF-alpha or TNF-beta alleles. TNF-beta polymorphisms within the donor liver did not correlate with severity of HCV recurrence.

CONCLUSIONS

The donor TNF-alpha promoter genotype may influence the inflammatory response to HCV reinfection of the graft and contribute to accelerated graft injury. If the association between this genetic marker (TNF308.2) and disease progression is confirmed, it could improve our understanding of HCV pathogenesis and influence donor selection and patient management.

Transcriptional activation in yeast cells lacking transcription factor IIA

The general transcription factor IIA (TFIIA) forms a complex with TFIID at the TATA promoter element, and it inhibits the function of several negative regulators of the TATA-binding protein (TBP) subunit of TFIID. Biochemical experiments suggest that TFIIA is important in the response to transcriptional activators because activation domains can interact with TFIIA, increase recruitment of TFIID and TFIIA to the promoter, and promote isomerization of the TFIID-TFIIA-TATA complex. Here, we describe a double-shut-off approach to deplete yeast cells of Toa1, the large subunit of TFIIA, to <1% of the wild-type level. Interestingly, such TFIIA-depleted cells are essentially unaffected for activation by heat shock factor, Ace1, and Gal4-VP16. However, depletion of TFIIA causes a general two- to threefold decrease of transcription from most yeast promoters and a specific cell-cycle arrest at the G2-M boundary. These results indicate that transcriptional activation in vivo can occur in the absence of TFIIA.

Association of multispecific CD4(+) response to hepatitis C and severity of recurrence after liver transplantation

BACKGROUND & AIMS

After liver transplantation for hepatitis C virus (HCV), reinfection of the allograft invariably occurs. Indirect evidence suggests that the cellular immune response may play a central role. The purpose of this analysis was to determine the correlation between HCV-specific peripheral CD4(+) T-cell responses and the severity of recurrence after liver transplantation.

METHODS

Fifty-eight HCV-seropositive patients, including 43 liver transplant recipients with at least 1 year of histological follow-up, were studied. Peripheral blood mononuclear cells (PBMCs) were isolated from fresh heparinized blood and stimulated with either recombinant HCV antigens (core, E2, NS3, NS4, and NS5) or control antigens.

RESULTS

Fourteen (40%) of 35 patients with mild or no evidence of histological recurrence within their allografts responded to at least 1 of the HCV antigens. Eleven responded to NS3, 5 to all the nonstructural antigens, and 3 to the HCV core polypeptide alone. In contrast, in the 8 patients with severe HCV recurrence, no proliferation in response to any of the HCV antigens was seen (P = 0. 03) despite responses to the control antigens.

CONCLUSIONS

Despite immunosuppression, HCV-specific, major histocompatibility complex class II- restricted CD4(+) T-cell responses are detectable in patients with minimal histological recurrence after liver transplantation. In contrast, PBMCs from patients with severe HCV recurrence, despite being able to proliferate in response to non-HCV antigens, fail to respond to the HCV antigens. These findings suggest that the inability to generate virus-specific T-cell responses plays a contributory role in the pathogenesis of HCV-related graft injury after liver transplantation. It is hoped that further characterization of the immunoregulatory mechanisms related to recurrent HCV will provide the rationale for novel therapeutic strategies and diminish the incidence of inevitable graft loss.

Molecular epidemiology of hepatitis C infection in U.S. veteran liver transplant recipients: evidence for decreasing relative prevalence of genotype 1B

OBJECTIVE

The U.S. Veteran population represents a unique patient group to study different HCV genotypes because of geographically diverse exposures. The aim of this study was to characterize the distribution of HCV genotypes in U.S. veterans undergoing liver transplantation (OLT), trace genotypes to modes of acquisition (risk behavior and location), and evaluate the relative prevalence of HCV genotypes according to the time of acquisition.

METHODS

Between 10/88 and 12/95, 110 primary OLTs were performed in U.S. Veterans at our center. Forty-nine (45%) patients had detectable HCV-RNA by PCR at the time of OLT. Determination of HCV genotypes was performed by restriction fragment length polymorphism of the 5' noncoding region and classified according to Simmonds et al.

RESULTS

Twenty-three of 49 (47%) veterans had 1a, 17 (35%) 1b, two (4%) 2a, three (6%) 2b, two (4%) 3a, two (4%) mixed (1a/2a, 1b/2a). This distribution of HCV genotypes was comparable to the genotypic distribution of a contemporary cohort of nonveteran OLT recipients at the University of Washington. There was a statistically significant association between illicit injection drug use (IDU) and 1a, with 63% of 1a patients having IDU whereas only 14% of 1b patients admitted to IDU (p = 0.03). All patients in whom the mode of acquisition was unknown had genotype 1b (p = 0.04). Intranasal cocaine use was strongly correlated with IDU (p = 0.002). Patients who had tattoos but no history of blood transfusion (BT) or recreational drug use had genotype 1 (2 had 1a, 2 had 1b; p = NS). Twenty-two (45%) patients had serological evidence of prior hepatitis B (HBV) infection. Patients who had genotype 2a, 2b, 3a, or mixed were much more likely to have had HBV (seven of nine, 78%) than patients with genotype 1a or 1b (15 of 40, 37.5%) (p = 0.03). There was no significant correlation between BT, dates, or military branch of service, high risk behavior in Southeast Asia, level of education, ethnicity, and particular genotype(s). Whereas the proportion of 1b accounting for HCV infection in patients with a first exposure before 1968 was 50%, all patients with a first exposure post-1975 were non-1b (p = 0.04), suggesting a change in the epidemiology of HCV in our cohort.

CONCLUSIONS

In U.S. Veterans undergoing OLT: 1) 45% had PCR-confirmed HCV infection, 2) 1a was the predominant genotype and was associated with IDU, and 3) a significant decrease in the prevalence of genotype 1b from the pre-Vietnam era to post-1975 suggests a changing epidemiology of HCV genotypes.

Interstrain variation in the human cytomegalovirus DNA polymerase sequence and its effect on genotypic diagnosis of antiviral drug resistance. Adult AIDS Clinical Trials Group CMV Laboratories

The polymerase (pol) coding sequence was determined for 40 independent clinical cytomegalovirus isolates sensitive to ganciclovir and foscarnet. Sequence alignments showed >98% interstrain homology and amino acid variation in only 4% of the 1, 237 codons. Almost all variation occurred outside of conserved functional domains where resistance mutations have been identified.

Antiviral drug resistance in human cytomegalovirus

Drug-resistant cytomegalovirus (CMV) should be considered when viral shedding persists after several weeks of therapy. The problem is most likely to arise in the setting of a severely immunosuppressed host with continuing or relapsing disease. Not all treatment failure can be attributed to drug resistance. The testing of CMV isolates for drug resistance in cell culture is time-consuming and labor-intensive, but recent advances in understanding of the genetics of resistance have resulted in rapid genotypic assays for specific mutations in the viral UL97 phosphotransferase or UL54 DNA polymerase genes that can predict resistance and cross-resistance to specific drugs. This information may help in the selection of alternative therapy.

Seat belt fracture with late development of an enterocolic fistula in a child. A case report

STUDY DESIGN

A case report of a 9-year-old boy treated at a pediatric trauma center for a flexion-extension spiral fracture with late development of an enterocolic fistula subsequent to a high-velocity motor vehicle accident.

OBJECTIVES

To increase the awareness of possible delayed bowel complications associated with flexion-distraction injuries of the spine in children.

SUMMARY OF BACKGROUND DATA

Flexion-distraction fractures of the spine in children wearing lap seat belts, so-called "Chance" fractures, are an increasingly common result of high-velocity collisions. This type of fracture, referred to as a seat-belt fracture, is often associated with duodenal or jejunal tears. Although such intra-abdominal injuries are common in such fractures secondary to this type of trauma, the occurrence of an enterocolic fistula has never been reported.

METHODS

A review of all pediatric Chance fractures managed at the Children's Hospital of Eastern Ontario, as well as a literature review of all reported series of flexion-distraction injuries to the spine in children, were performed.

RESULTS

The subtle and prolonged symptomatology of this lesion and its similarity to a cast syndrome is emphasized.

CONCLUSION

Because the orthopedic surgeon is usually the primary care-giver for children with this type of seat-belt trauma, an appreciation of the possibility of a delayed onset enterocolic fistula with its symptomatology is essential to avoid prolonged morbidity.

Novel mutation in the CMV UL97 gene associated with resistance to ganciclovir therapy

Cytomegalovirus (CMV) strains resistant to ganciclovir have been associated with specific mutations in the UL97 and UL54 genes. The UL97 gene of a CMV strain isolated from a renal transplant recipient before and after 438 days of ganciclovir treatment was amplified by polymerase chain reaction and sequenced. A novel mutation resulting in deletion of codons 595 to 603 was identified in the viral DNA from specimens obtained after, but not before, prolonged ganciclovir therapy. Clinical and virological resolution of CMV disease occurred after switching to foscarnet therapy. Although many ganciclovir resistance mutations have been mapped to the UL97 codon range 591-607, this one is unusual in that it involves deletion of half these codons. Because UL97 seems to be necessary for effective CMV replication, this deletion suggests that much of codons 591-607 can be removed without destroying the biological function of UL97, and that this codon range can be altered in various ways to affect ganciclovir susceptibility. Rapid, flexible genotypic assays directed at this part of UL97 may facilitate the early recognition of ganciclovir resistance.

Association of cytomegalovirus genotype with graft rejection after liver transplantation

BACKGROUND

The envelope glycoprotein gB of human cytomegalovirus (CMV) occurs as one of four main genotypes. Some previous studies have proposed a relationship of CMV gB genotype to the frequency of symptomatic infection and to clinical outcomes in both transplant and human immunodeficiency virus-infected populations. Our aim was to define the distribution of CMV gB genotypes and the impact on acute cellular rejection and graft/patient survival after orthotopic liver transplantation (OLT).

METHODS

Between October 1988 and December 1996, 325 patients underwent cyclosporine-based OLT at our center. CMV infection was surveyed prospectively and defined as viral isolation from blood or urine; 53 (16%) patients had detectable CMV. Isolates were genotyped by polymerase chain reaction amplification and restriction digest analysis.

RESULTS

The distribution of CMV genotypes was: gB1, 19 (36%) patients; gB2, 15 (28%) patients; gB3, 13 (24%) patients; and gB4, 4 (8%) patients. Two patients (4%) had mixed infection (1 + 3, 1 + 4). Age, preOLT diagnosis, use of ganciclovir prophylaxis, basal immunosuppression, mean number of HLA donor/recipient mismatches, and United Network of Organ Sharing status were comparable among patients with different genotypes. Patients with gBl had a significantly higher mean number of acute rejection episodes (1.52+0.30 vs. 0.67+0.22; P=0.027). However, there was no difference in rejection severity, including OKT3 usage or FK506 conversion, or development of chronic rejection among patients with different genotypes. The gB genotype did not affect the development of symptomatic or tissue-invasive CMV disease, detected in 15 patients. Actuarial rates of patient (odds ratio [OR] 3.0; confidence interval [CI] 1.49-6.0) and graft (OR 2.57; CI 1.25-5.22) survival were significantly diminished in the group with CMV infection versus those without CMV (P<0.0001 for both), but there was no association with CMV genotype.

CONCLUSIONS

(1) Patients with CMV infection had significantly reduced patient and graft survival rates at 1 and 5 years after OLT as compared with OLT recipients without CMV infection. (2) CMV genotype gB1 was associated with a higher mean number of acute rejection episodes.

The capacity of a combined liposomal hepatitis B and C vaccine to stimulate humoral and cellular responses in mice

Combined hepatitis B surface antigen and hepatitis C antigen were encapsulated into 1, 2, and 5 microm discrete liposomes and then lyophilized. Groups of adolescent CD-1 mice were given a single 0.3 mL oral dose of these liposomes containing 50 microg/mL hepatitis B surface antigen and hepatitis C antigen, 50 microg/mL of the same antigens or liposomes alone. Animals in each group were sacrificed every 2 weeks for 10 weeks and the humoral response investigated by enzyme-linked immunosorbent assay (ELISA) and the cellular response by splenic lymphocyte proliferation to 10 microg of either antigen. Seroconversion to both antigens in the mice receiving liposomal antigens occurred in 87.5% of animals sacrificed at 4 weeks and later. One animal (12.5%) receiving antigen alone seroconverted to hepatitis B virus at 6 weeks, but all animals receiving liposomes alone remained negative. Proliferation indexes (PI) greater than 3 were observed in all animals receiving liposomal antigens, with the greatest response seen at 10 weeks. PI was less than 2 for all animals in the other two groups. Thus, a single oral dose of liposomes of three sizes containing both hepatitis B and C antigens given to mice resulted in rapid seroconversion and a progressive robust cellular immune response, whereas the antigens alone or liposomes without antigen did not.

Mutation in region III of the DNA polymerase gene conferring foscarnet resistance in cytomegalovirus isolates from 3 subjects receiving prolonged antiviral therapy

Three human immunodeficiency virus-infected subjects with progressive cytomegalovirus (CMV) retinitis despite prolonged antiviral therapy had buffy coat CMV isolates that were resistant to both ganciclovir and foscarnet. Genetic analysis of the resistant isolates showed that each contained a well-known ganciclovir resistance mutation in the viral UL97 phosphotransferase sequence, as well as a mutation (Ala to Val at codon 809, V809) in conserved region III of the DNA polymerase (Pol) sequence. A segment of the Pol sequence from one of the clinical isolates was transferred to CMV laboratory strain AD169 by homologous recombination. The recombinant virus containing V809 showed 6.3-fold increased foscarnet resistance and 2.6-fold increased ganciclovir resistance. Occurrence of the V809 mutation in 3 unrelated cases suggests that it is a clinically significant viral genetic marker for foscarnet resistance and decreased susceptibility to ganciclovir.

Indicators of glial activation and brain oxidative stress after intraventricular infusion of endotoxin

Glial activation and oxidative stress are both consequences of brain aging. To investigate whether glial activation causes oxidative stress or not, the immune activator, lipopolysaccharide (LPS), was intraventricularly injected into the rat brain. The expression of candidate genes were examined by in situ hybridization histochemistry (ISHH) combined with immunohistochemistry for glial markers over a period of time up to 24 h after the LPS injection. The mRNA for glial fibrillary acidic protein (GFAP) was elevated around the injection site by 2 h, and the volume of elevated expression spread to the entire brain after 6 h, with higher levels present in the injected hemisphere. The level of inducible isoform of nitric oxide synthase (i-NOS) mRNA increased in a punctate-like pattern in the region of the injection by 6 h and this response spread to the entire brain after 12 h. These results indicate that the glia are activated for at least 24 h after a single LPS injection. The mRNAs for a heat-shock protein (HSP70) and for the manganese-dependent superoxide dismutase (Mn-SOD) were elevated in the ipsilateral hemisphere as early as 2 h post-injection, but these responses subsided nearly to basal levels by 4 h. These levels of mRNAs for these genes increased again after 6 h of the LPS injection; thus, the earlier increases of the messages appeared to be associated with the survival surgery procedure. With microautoradiographic analysis, scattered OX-42 positive cells expressed i-NOS mRNA after 6 h post-injection, but elevation of Mn-SOD mRNA was not detected in either microglia or astrocytes at any time point examined. The level for Cu/Zn-SOD mRNA did not alter at any time point. The beta-amyloid precursor protein (betaAPP) mRNAs were elevated beginning at 6 h. These results indicate that chronic glial activation leads to a condition of oxidative stress in the brain. The data also suggest that LPS injection could be used to study the effects of chronic glial activation on the survival of neuronal populations that could be at risk from oxidative stress.

The in vitro immunomodulatory effects of glyconutrients on peripheral blood mononuclear cells of patients with chronic fatigue syndrome

In humans, eight monosaccharides are required for the synthesis of glycoproteins. Dietary supplements that supply these crucial sugars are known as glyconutrients. A glyconutrient compound was added to Peripheral Blood Mononuclear Cells (PBMC) isolated from normal controls and patients with the Chronic Fatigue Syndrome (CFS), a disease associated with immune dysregulation. The in vitro immunomodulatory effects were investigated. Cell surface expression of the glycoproteins CD5, CD8, and CD11a were significantly lower in patients with CFS compared to normal controls. Addition of glyconutrient homogenate to PBMC from patients with CFS stimulated with phytohemagglutinin significantly increased the expression of each glycoprotein. Furthermore, natural killer (NK) cell function was reduced in CFS patients. The glyconutrient preparation significantly enhanced NK cell activity versus human herpes virus 6 (HHV-6)-infected H9 cells in an 8 h 51Cr release assay compared to placebo for PBMC from patients with CFS (p< .01). Finally, apoptosis was significantly higher in patients with CFS. The percentage of apoptotic cells was significantly decreased in PBMC from patients with CFS that had been incubated for 48 h with glyconutrients. Thus, glyconutrients improved abnormal immune parameters in vitro in patients with CFS.

Recurrent thyroglossal duct cysts: a clinical and pathologic analysis

OBJECTIVE

To analyze, in detail, the clinical and pathological findings in a patient population that had undergone previous Sistrunk procedures for the removal of thyroglossal duct cysts, in order to identify any possible factors that could be related to recurrence after 'definitive' surgery.

SETTING

A large pediatric tertiary care center.

METHODS

A retrospective chart review was performed to include all patients treated at a single center for thyroglossal duct cysts with a Sistrunk procedure, between 1978 and 1992 inclusive.

RESULTS

A total of 108 consecutive patients were analyzed. We noted that the presence of recent preoperative infection of the cyst was the only statistically significant (P < 0.05) clinical difference noted between the successful and the unsuccessful surgical groups. However, pathological analysis revealed that there was a substantially greater number of multiple thyroglossal duct tracts (P < 0.05) noted in the group that failed a Sistrunk procedure.

CONCLUSIONS

We feel that multiple thyroglossal tracts may play an etiologic role in some recurrent cysts. Thus, a wide conservative excision, including the middle two thirds of the hyoid bone, is necessary in order to include any multiple tracts in the resection.