The death rate of Ostertagia circumcincta and Trichostrongylus colubriformis in lactating ewes: implications for anthelmintic resistance

Lactating adult Romney ewes were infected, 4 weeks post-lambing, with benzimidazole (bz) resistant strains of Ostertagia circumcincta and Trichostrongylus colubriformis. Commencing 4 weeks after the initial infection the ewes were subjected to challenge 3 times weekly with 5000 L3 of bz-susceptible strains of both parasite species. At weekly intervals over the following 6 weeks, groups of ewes were drenched with a bz anthelmintic (oxfendazole) to remove bz-susceptible parasites and slaughtered to determine adult worm burdens of the bz-resistant parasites. The O. circumcincta infection declined exponentially with a mean daily death rate of 10.6% day-1 and no worms were recovered after 4 weeks or more of challenge. The T. colubriformis infection did not decline significantly over the 6 weeks of continuous challenge, indicating that the death rate could not be distinguished from zero. The upper 95% confidence limit for the death rate of T. colubriformis was 4.9%. The implications of these death rates on selection for drug resistance following ewe drenching during the post-partum period are discussed with selection pressure likely to be greater for T. colubriformis than for O. circumcincta.

Correlation of clinical, magnetic resonance imaging, and cerebrospinal fluid findings in optic neuritis

We found 42 of 74 patients (57%) with isolated monosymptomatic optic neuritis to have 1 to 20 brain lesions, by magnetic resonance imaging (MRI). All of the brain lesions were clinically silent and had characteristics consistent with multiple sclerosis (MS). None of the patients had ever experienced neurologic symptoms prior to the episode of optic neuritis. During 5.6 years of follow-up, 21 patients (28%) developed definite MS on clinical grounds. Sixteen of the 21 converting patients (76%) had abnormal MRIs; the other 5 (24%) had MRIs that were normal initially (when they had optic neuritis only) and when repeated after they had developed clinical MS in 4 of the 5. Of the 53 patients who have not developed clinically definite MS, 26 (49%) have abnormal MRIs and 27 (51%) have normal MRIs. The finding of an abnormal MRI at the time of optic neuritis was significantly related to the subsequent development of MS on clinical grounds, but interpretation of the strength of that relationship must be tempered by the fact that some of the converting patients had normal MRIs and approximately half of the patients who did not develop clinical MS had abnormal MRIs. We found that abnormal IgG levels in the cerebrospinal fluid correlated more strongly than abnormal MRIs with the subsequent development of clinically definite MS.

Retransplantation for recurrent hepatitis C

Recurrence of hepatitis C virus (HCV) after orthotopic liver transplant (OLT) may be mild or may lead to progressive liver disease requiring retransplantation (re-OLT). Results of re-OLT for hepatitis C are not well known. We analyzed outcomes in 14 patients retransplanted for recurrent hepatitis C. All had evidence of recurrent hepatitis on multiple biopsies. Polymerase chain reaction (PCR) was performed in blood or tissue samples from 12 patients when recurrence was suspected; all 12 were positive for HCV-RNA. Explants showed chronic hepatitis with bridging necrosis in 3 patients, hepatitis with transition to cirrhosis in 2, hepatitis and cirrhosis in 3, and cirrhosis alone in 2. In 2 patients, in whom immunosuppression had been withheld for 4 to 6 weeks, there was also evidence of chronic rejection. Four died of sepsis perioperatively (median, 32.5 days; range, 9-59); pre-OLT, 3 of 4 had renal failure, and 1 had fever with no obvious source of infection. Ten patients did well early after OLT and were discharged. One patient was readmitted 6 weeks after discharge and died of cytomegalovirus (CMV) infection 127 days after re-OLT. One patient with concomitant vanishing bile duct syndrome, probably due to chronic rejection, developed recurrent hepatitis and died of progressive liver failure 161 days after re-OLT. Eight patients are well at a median of 926 days (range, 315-1930) after re-OLT. Three have evidence of mild recurrent hepatitis on liver biopsy, one is overweight with severe steatosis on biopsy, and four have no evidence of recurrent hepatitis. Retransplantation for hepatitis C should be considered a viable option for patients who develop end-stage hepatic dysfunction secondary to recurrent disease and should be performed before development of infectious complications and renal insufficiency.

Hepatic angiomyolipoma: two case reports of caudate-based lesions and review of the literature

Two case reports of hepatic angiomyolipoma, both originating in the caudate lobe, are reported with a review of the literature. The liver is the second most common site of angiomyolipoma, an uncommon benign tumor of mixed mesenchymal origin. It is commonly diagnosed following abdominal pain or as an asymptomatic mass discovered on abdominal ultrasound or computed tomography scan. Of 74 cases reported, the lesions ranged from 0.3 to 36 cm in diameter and are noted between the first and eighth decade, with predominant female predilection. The right lobe is the most common site, with lesions arising in the caudate lobe comprising only five cases. The natural history of the hepatic lesion is unknown. Malignant invasion or metastatic disease has not been documented. Hepatic and renal angiomyolipoma can occur concurrently (13 of 60 cases), although the majority are not biopsy proven. Multicentric hepatic disease occurs. The correlation between tuberous sclerosis and hepatic angiomyolipoma is not confirmed histologically and occurs rarely. These lesions have a characteristic radiographic appearance due to high fat content. Histologically, angiomyolipoma are characterized by an admixture of adipose tissue, blood vessels, and smooth muscle cells. These lesions cannot reliably be differentiated from a malignant lesion based on clinical history, radiologic examination, and/or pathologic interpretation. If clinical suspicion for malignancy is low, then careful observation with serial radiologic follow-up is performed. The treatment for a symptomatic or suspicious lesion is resection, if feasible. Liver transplantation may be considered for large or centrally located lesions not amenable to resection.

Assessment of damage and recovery of sinusoidal endothelial cell function by in vivo hyaluronic acid uptake in cold-preserved and transplanted rat livers

We sought to evaluate the significance of endogenous hyaluronic acid levels and in vivo uptake of exogenous hyaluronic acid as markers of liver endothelial cell damage and correlate these findings to graft survival/function in a rat orthotopic liver transplant model. Endogenous hyaluronic acid levels were measured after orthotopic liver transplantation performed with freshly explanted livers, with livers preserved for 30 hr, and after sham operation. Exogenous hyaluronic acid uptake was evaluated in six study groups: fresh liver grafts, livers preserved for 12 hr, 24 hr, 30 hr and 48 hr, and sham-operated livers. Endogenous hyaluronic acid levels fell after orthotopic liver transplantation with freshly harvested livers and after sham operation, but rose in animals transplanted with livers preserved for 30 hr (P<0.01 vs. sham operation). In the preserved group, there was no difference in endogenous hyaluronic acid levels between survivors and nonsurvivors. Uptake of exogenous hyaluronic acid was significantly lower after orthotopic liver transplant with grafts preserved for 12 hr than after sham operation or orthotopic liver transplant with nonpreserved livers (P<0.05). Hyaluronic acid uptake further deteriorated in the 24-, 30-, and 48-hr groups. No significant difference in hyaluronic acid elimination rate was found when results obtained from livers preserved for extended periods (>12 hr) were compared in survivors and nonsurvivors. Hyaluronic acid uptake was reevaluated in surviving animals after 2 weeks. Completely restored function was observed in all survivors, indicating recovery of endothelial cells. We conclude that endogenous hyaluronic acid levels and exogenous hyaluronic acid uptake are reliable markers of liver sinusoidal endothelial cell function and that normal or moderately compromised hyaluronic acid uptake is associated with good graft function. On the other hand, endothelial cell dysfunction suggested by poor hyaluronic acid elimination is not a completely reliable predictor of subsequent deterioration of graft function in rat liver transplantation.

Phenotypic analysis of lymphocyte subpopulations in lymph nodes draining the ear following exposure to contact allergens and irritants

The murine local lymph node assay (LLNA) measures in vivo proliferation in draining lymph nodes (DLN) following topical exposure to chemicals to assess contact sensitization potential. However, proliferation has also been observed with some irritants. To further characterize events in the DLN during the LLNA and distinguish allergens from irritants, phenotypic analysis of lymphocyte subsets was made following topical exposure. In preliminary studies, mice were treated on the ears for 3 consecutive days, and 48 hr following the final application, analysis of CD3, CD4, CD8, and B220 expression was evaluated by flow cytometry. The allergens oxazolone (OXAZ) and picryl chloride (TNCB) and the irritant benzalkonium chloride (BC) increased cell number compared to vehicle. The increase in lymph node cellularity for these materials was due to an increase in the total number of T and B lymphocytes. Interestingly, even though contact sensitization is a cell-mediated immune response (Th1), mice exposed to the contact allergens showed a preferential increase in B lymphocytes in the DLN as seen by an increase in the percentage of B220+ cells. The percentage of B220+ cells was 13.1 and 36.1% for OXA and TNCB, respectively, compared to percentages of 7.4 and 9.3% for irritant and vehicle, respectively. With some allergens, a concomitant decrease in the percentage of CD3+ cells was seen. Time course studies demonstrated the increase in the percentage of B220+ cells was seen in allergen treated mice by 24 hr after the final application of material, plateaued by 48 hr, and was still elevated by 96 hr. In allergen-treated mice, percentages of B220+ cells increased dose dependently. Further studies were performed to evaluate additional contact allergens and irritants and determine if evaluation of flow cytometric parameters could potentially identify contact allergens and differentiate them from irritants. Analysis of data from these studies, which examined a total of five contact allergens and six irritants, showed that the modifications to the LLNA improved the identification of irritants and allergens in individual experiments by including both phenotypic analysis of the DLN and cell number per node as endpoints rather than either endpoint alone.

Resection of benign hepatic lesions with selective use of total vascular isolation

BACKGROUND

The main morbidity associated with hepatic resection is related to excessive blood loss. Total vascular isolation (TVI) may be used to minimize blood loss in difficult hepatic resection cases.

STUDY DESIGN

We reviewed our criteria for use of TVI and our experience in 43 patients who underwent hepatic resection for benign lesions between January 1990 and January 1995. Total vascular isolation was used in 23 patients; 20 resections were performed without TVI.

RESULTS

We found TVI particularly useful for resection of highly vascular lesions, and lesions located centrally or adjacent to major vessels. The use of TVI reduced blood loss in difficult hepatic resections; transfusion requirements for these patients were similar to requirements for the resection of peripheral lesions. Fewer complications directly related to hepatic resection were encountered in the TVI group.

CONCLUSIONS

Appropriate use of TVI will improve results after difficult hepatic resections and allow maximal sparing of normal hepatic tissue when operating on benign lesions.

Safe use of hepatic allografts from donors older than 70 years

Between March 1991 and August 1995, 36 livers from donors >/=70 years old were transplanted. In donors, we recorded the following risk factors: alanine aminotransferase > 120 and rising, dopamine dose > 15 microg/kg/min, hypotension (systolic blood pressure <80) >1 hr, stay in the intensive care unit >5 days and body mass index >/=27. In 35 recipients, we recorded pretransplant United Network for Organ Sharing (UNOS) status, cold/warm ischemia time, intraoperative blood loss, and occurrence of poor early graft function or primary nonfunction. Mean recipient age was 55 years (range, 25-75 years). Four recipients were UNOS status 1, 19 were UNOS 2, and 12 were UNOS 3. Two livers were used as second grafts for primary graft nonfunction. Mean donor age was 73 years (range, 70-84 years). Intracranial bleeding was the cause of death in the majority of donors. The 36 donors had 40 risk factors; 10 donors had >1 risk factor. Mean cold and warm ischemia times were 9:08 +/- 2:57 hr and 51 +/- 9 min. Mean total operative time was 7.5 hr. Posttransplant mean peak alanine aminotransferase and aspartate aminotransferase levels were 937.3 +/- 703.1 IU/L and 923.3 +/- 708.5 IU/L, respectively. Mean prothrombin time on postoperative day 2 was 14.9 +/- 1.6 sec. Average total bilirubin on postoperative day 5 was 4.9 mg/dl. Median length of stay in the intensive care unit was 4 days. One recipient had poor early graft function; two recipients had primary nonfunction. Mean follow-up was 503 days (range, 110-1714 days). Three-month actual graft and patient survival rates were 85% and 91%, respectively. One-year actuarial graft and patient survival rates were also 85% and 91%, respectively. We conclude that older livers can be used safely. Advanced donor age should not be a contraindication to liver procurement.

Detection of hepatocellular carcinoma in cirrhotic patients: sensitivity of CT and ultrasonography

Patients with cirrhosis are at increased risk for the development of hepatocellular carcinoma. The heterogeneous hepatic parenchyma produced by cirrhosis makes detection of hepatomas more difficult. The purpose of this study was to determine the sensitivities of CT and ultrasonography for detecting hepatomas in cirrhotic patients. A retrospective analysis was performed of 733 patients who underwent liver transplantation at our institution. A study population of 21 patients was selected who met our inclusion criteria. The inclusion criteria required a pathologic diagnosis of hepatocellular carcinoma, pathologic evidence of cirrhosis, and contrast-enhanced CT and sonographic examinations performed within 1 week of each other. The sensitivities of CT and ultrasonography were determined by comparing the imaging findings with pathology findings from serially sectioned total hepatectomy specimens. A total of 40 hepatomas were detected pathologically in the 21 patients in our study population. CT identified 12 of 21 patients with hepatomas and detected 18 of 40 individual lesions (patient detection sensitivity = 57%, lesion detection sensitivity = 45%). Ultrasonography identified 14 of 21 patients with hepatomas and detected 21 of 40 individual lesions (patient detection sensitivity = 67%, lesion detection sensitivity = 51%). Combining the findings of CT and ultrasonography allowed identification of 17 of 21 patients with hepatomas and detection of 24 of 40 individual lesions (patient detection sensitivity = 80%, lesion detection sensitivity = 60%). We conclude that CT and ultrasonography have a low sensitivity for the detection of hepatocellular carcinoma in patients with cirrhosis.

CWR22: the first human prostate cancer xenograft with strongly androgen-dependent and relapsed strains both in vivo and in soft agar

Most patients' prostate cancers respond to androgen deprivation but relapse after periods of several months to years. Only two prostate cancer xenografts, LNCaP and PC-346, have been reported to be responsive to androgen deprivation and to relapse subsequently. Both of these tumors shrink slightly, if at all, and relapse less than 5 weeks after androgen withdrawal. After androgen withdrawal, the human primary prostate cancer xenograft CWR22 regresses markedly, and prostate-specific antigen (PSA) falls up to 3000-fold in the blood of mice. PSA usually returns to normal. In some animals, the tumor relapses and is then designated CWR22R. In these animals, PSA starts to rise approximately 2-7 months, and tumor begins to grow 3-10 months after castration. Animals with CWR22 need to be euthanized because of large tumors 6-12 weeks after the transplantation of CWR22. Androgen withdrawal prolongs life approximately 3-4-fold.

Autoimmune hepatitis in a patient with sickle cell disease

In this report, we describe the case of a 28-yr-old woman with sickle cell anemia who presented with acute hepatic failure manifested by anorexia, malaise, painless jaundice, elevated aminotransferase activities, and severe coagulopathy. Liver biopsy revealed changes consistent with autoimmune hepatitis. Treatment with corticosteroids and azathioprine was followed by improvement in biochemical liver test results. The literature on sickle cell-associated liver diseases is reviewed.

Severe recurrent cholestatic hepatitis C following orthotopic liver transplantation

Recurrent infection with hepatitis C virus (HCV) is almost universal following orthotopic liver transplantation although clinical severity varies. Data on 135 patients who underwent transplantation for hepatitis C cirrhosis were reviewed. We describe a progressive, severe cholestatic form of hepatitis occurring in a subgroup of patients with recurrent hepatitis C. Ten patients with severe recurrent hepatitis C were identified; 1 has died, 1 awaits retransplantation, and 8 have undergone retransplantation. All 10 developed severe progressive cholestatic hepatitis, with a mean rise in bilirubin to 24.7 mg/dL at the time of retransplantation. Histology at initial recurrence was of mild hepatitis without evidence of rejection. The failed grafts showed either cirrhosis or confluent hepatic necrosis. The onset of cholestasis preceded retransplantation by less than 5 months. Our study suggests that a minority of patients with recurrent hepatitis C after undergoing liver transplantation develop a severe progressive cholestatic hepatitis and liver failure.

Postoperative intravenous infusion of alprostadil (PGE1) does not improve renal function in hepatic transplant recipients

BACKGROUND

Acute renal failure is a frequent complication following orthotopic hepatic transplantation. A reduction in the synthesis of intrarenal vasodilator prostaglandins has been proposed as having an important role in the pathogenesis of renal insufficiency associated with hepatic dysfunction, as well as in the nephrotoxicity associated with cyclosporine and FK506 immunosuppressive therapy. Therefore, administration of vasodilator prostaglandins may improve renal function following hepatic transplantation. This study was designed to determine the effect of continuous intravenous alprostadil (prostaglandin E1) on postoperative renal function in hepatic transplant patients.

STUDY DESIGN

In a randomized, double-blind, placebo-controlled trial, 21 patients who had undergone orthotopic hepatic transplantation and had a measured postoperative glomerular filtration rate (GFR) of less that 50 mL/minute received intravenous alprostadil at 0.6 microgram/kg/hour or placebo for five days. Glomerular filtration rate and effective renal plasma flow (ERPF) were measured by a single-injection clearance method using a radionuclide agent in 53 patients within 12 hours after admission to our surgical intensive care unit. Usual postoperative care was not modified. Radionuclide GFR and ERPF measurements were repeated on postoperative day 3. Serum creatinine was measured preoperatively and postoperatively on day 3 and on day 5. A 24-hour serum creatinine clearance was measured on days 1, 5, and 14. Urine output was recorded hourly during the infusion period.

RESULTS

Ten patients received alprostadil, and 11 patients received placebo. There was a significant increase in GFR and ERPF in both groups on post-operative day 3 as compared with baseline values. There was no difference in GFR and ERPF between the two groups on day 3 (48 +/- 18 and 246 +/- 68 mL/minute in the alprostadil group compared with 53 +/- 17 and 270 +/- 131 mL/minute in the placebo group). Serum creatinine levels increased on day 3 in both groups but returned to baseline by day 5.

CONCLUSIONS

These results indicate that a reversible decrease in GFR is common on hepatic transplant patients during the postoperative period. Administration of a continuous intravenous infusion of alprostadil in the immediate postoperative period had no effect on renal function when compared with placebo.

The impact of immunosuppressive regimens on the cost of liver transplantation--results from the U.S. FK506 multicenter trial

In an effort to determine the total one-year cost of liver transplantation, the underlying drivers of that cost, and any cost differences between alternative immunosuppressive regimens, an analysis was performed comparing the average one-year posttransplant charges of 322 patients participating in the "U.S. Multi-center Prospective Randomized Trial Comparing FK-506 to Cyclosporine in Liver Transplantation." Total one-year inpatient charges including all readmissions were examined. Professional fees and outpatient charges were excluded. Costs for tacrolimus drug and blood assays were assumed to be equal to those in the CsA group. For patients completing the study, the tacrolimus group had an average length of stay and average one-year cost seven days (P = .06) and $19,290 (P = .05) lower than the CsA group. The difference in rejection profiles between the two arms seems to largely account for the lower costs. The tacrolimus arm consistently had fewer patients in the more severe rejection groups. Increased incidence and severity of rejection were directly related to higher average lengths of stay and costs of transplantation (P < .001). Tacrolimus immunosuppression during the first year after liver transplantation is more cost-effective than CsA in achieving similar patient and graft survival rates. Differing incidence and severity of rejection can dramatically affect the first-year cost of liver transplantation.

Progressive multifocal leukoencephalopathy after orthotopic liver transplantation

Six weeks after liver transplantation, a 51-year-old man developed a slowly progressive hemiparesis with deteriorating mental status and seizures. Successive computed tomography (CT) scans of the brain revealed unilateral nonenhancing white matter lucencies that gradually coalesced and progressed to both hemispheres. Brain biopsy results were consistent with progressive multifocal leukoencephalopathy (PML). We believe this is the first antemortem description of PML after liver transplantation. Herein, we describe the case and review the literature on PML after solid organ transplantation. Early recognition of this central nervous system disease may be important with new advances in therapy of this viral infection of the immunocompromised patient.

A binding site for activation by the Bacillus subtilis AhrC protein, a repressor/activator of arginine metabolism

In Bacillus subtilis, the AhrC protein represses genes encoding enzymes of arginine biosynthesis and activates those mediating its catabolism. To determine how this repressor also functions as an activator, we attempted to clone catabolic genes by searching for insertions of the Tn917-lacZ transposon that express AhrC-dependent, arginine-inducible beta-galactosidase activity. One such isolate was obtained. The region upstream of lacZ was subcloned in Escherichia coli in such a way that it could be replaced in the B. subtilis chromosome after appropriate manipulation. Analysis of exonuclease III-derived deletions located an AhrC-dependent, arginine-inducible promoter to within a ca. 1.9 kb fragment. The sequence revealed: the 3' end of an ORF homologous to gdh genes encoding glutamate dehydrogenase, with highest homology to the homologue from Clostridium difficile; the 5' end of an ORF homologous to a Saccharomyces cerevisiae gene encoding delta 1-pyrroline 5-carboxylate dehydrogenase (P5CDH), an enzyme of arginine catabolism; and just upstream of the latter, a sequence with homology to known AhrC binding sites in the upstream part of the biosynthetic argCJBD-cpa-F cluster. The same region has also been sequenced by others as part of the B. subtilis genome sequencing project, revealing that the P5CDH gene is the first in a cluster termed rocABC. Restriction fragments containing the putative AhrC-binding sequence, but not those lacking it, showed retarded electrophoretic mobility in the presence of purified AhrC. A 277 bp AhrC-binding fragment also showed anomalous mobility in the absence of AhrC, consistent with its being intrinsically bent. DNAse I footprinting localized AhrC binding to bp -16/-22 to +1 (the transcription startpoint). Such a location for an activator binding site, i.e. overlapping the transcription start, is unusual.

A multidisciplinary approach to hepatocellular carcinoma in patients with cirrhosis

BACKGROUND

A multidisciplinary approach has been developed to evaluate and treat patients with cirrhosis and hepatocellular carcinoma (HCC).

STUDY DESIGN

We evaluated 153 patients with cirrhosis and HCC. Fourteen patients with Child's A cirrhosis underwent resection. Transplantation was performed in 40 patients with HCC less than 5 cm (32 incidental, eight recognized preoperatively), in six patients with HCC 5 cm or greater not recognized preoperatively, and in 11 patients with recognized HCC 5 cm or greater; the latter 11 underwent transplantation in a multimodality protocol using pretransplant chemoembolization and intraoperative and postoperative chemotherapy.

RESULTS

Among the 14 patients who underwent resection, the three-year survival rate was 39 percent. Among the 40 patients with HCC less than 5 cm who underwent transplantation, no tumor recurrence was observed. Among the six with HCC 5 cm or greater unrecognized preoperatively, three had tumor recurrence. Among the 11 with HCC 5 cm or greater enrolled in the protocol, there were no deaths and one recurrence at a mean of 433 days follow-up. The four-year survival rate for all patients who underwent transplantation with HCC was 56 percent (66 percent excluding the six patients with unrecognized HCC 5 cm or larger).

CONCLUSIONS

Hepatocellular carcinoma less than 5 cm in patients with cirrhosis (Child's B or C) is an indication for hepatic transplantation. Hepatocellular carcinoma less than 5 cm in patients with cirrhosis (Child's A), although resectable, may in some cases be better treated by hepatic transplantation. Transplantation for HCC 5 cm or greater within a multimodality protocol has yielded excellent results at two years.