Postoperative tracheal extubation after orthotopic liver transplantation

BACKGROUND

The duration of postoperative mechanical ventilation and its influence on pulmonary function in liver transplant recipients is still debated controversially.

METHODS

We retrospectively analyzed the incidence of immediate tracheal extubation, prolonged mechanical ventilation (>24 h following surgery), and episodes of reintubation in 546 patients who underwent orthotopic liver transplantation (OLT) at our institution.

RESULTS

Immediate tracheal extubation in the operating theater was achieved in 18.7% of patients, and prolonged mechanical ventilation was required by 11.2% of patients. In these, median time of extubation was 49.5 h, whereas the remaining 70.1% of patients required ventilation support for a median 5 h after OLT. As risk factors for prolonged mechanical ventilation we identified the indications of acute liver failure and retransplantation, as well as factors such as mechanical ventilation prior to OLT, massive intraoperative bleeding, and severe reperfusion injury of the liver graft. The incidence of reintubation was 8.8% in patients who were immediately extubated following surgery, and 13.1% in patients who underwent extubation within 24 h. The incidence was significantly increased in patients requiring prolonged mechanical ventilation (36.1%).

CONCLUSIONS

Immediate tracheal extubation was safe and well tolerated. The incidence of reintubation was not increased when compared to patients in whom extubation succeeded later. However, special attention should be given to transplant recipients presenting in reduced clinical condition at the time of OLT, undergoing complicated surgery, or receiving liver allografts with severe reperfusion injury because of an increased risk for prolonged mechanical ventilation.

[Perforation of the cecum by a toothpick--a rare differential acute appendicitis diagnosis. Case report and review of the literature]

We report the case of a 46-year-old man who was admitted to the medical department of the hospital Reichenbach with a 2-day history of central and upper abdominal pain. The pain was displaced in the right lower abdominal quadrant, which is why the patient was transferred to our department. At laparoscopy a toothpick was found perforating the cecum. Laparoscopic management, therapeutic possibilities and problems of diagnosis are discussed. The patient does not recall having ingested a toothpick. The laparoscopic treatment of perforation of the cecum by a toothpick might be among the rarest operations ever conducted. In the literature no such publication could be found up to now.

[Importance of computer tomography in preoperative diagnostics of polyposis nasi]

Computed tomography (CT) is a very important diagnostic tool prior to endoscopic nasal or paranasal sinus surgery. However, it is frequently notice during endonsal surgery of the paranasal sinuses, that the intraoperative results do not completely agree with the radiological ones. The objective of the present study was to compare clinical and operative findings with those of CT investigations. We collected 200 cases treated during the past 2 years and studied their CT reports. Paranasal sinuses were separated into six regions, and the pathological changes due to sinusitis found by CT were classified into four groups. Altogether, we found a highly significant relationship between CT and intraoperative findings (r = 0.44; P < 0.0001), but differences were found in several regions. The highest correlation was found in the anterior ethmoid bone area (r = 0.98), posterior ethmoid bone area (r = 0.53), maxillary sinus (r = 0.36) and sphenoid sinus (r = 0.35). There was only a low agreement in the case of frontal sinus and recessus frontalis. Possible factors such as time between CT and operation or inflammation are discussed. While CT is the image modality of choice in evaluating patients with chronic paranasal sinusitis, agreement to intraoperative findings is not perfect. This should be taken into consideration when planning functional endoscopic sinus surgery.

Quadruple tacrolimus-based induction therapy including azathioprine and ALG does not significantly improve outcome after liver transplantation when compared with standard induction with tacrolimus and steroids: results of a prospective, randomized trial

BACKGROUND

Tacrolimus in combination with prednisolone has been proven to be a safe and effective immunosuppressive induction therapy in solid organ transplantation. However, it remains unclear whether a tacrolimus-based quadruple induction regimen with azathioprine and an antilymphocytic preparation could further improve the results after orthotopic liver transplantation. Therefore, we designed a prospective, randomized study to compare the immunosuppressive efficacy of dual (tacrolimus and prednisolone) and quadruple (tacrolimus, azathioprine, ALG Merieux and prednisolone) induction after liver transplantation.

METHODS

After randomization, 120 consecutive patients of primary liver transplants were divided into the dual group (n=59) and the quadruple group (n=61) and followed for a minimum of 3 years.

RESULTS

Patient survival at 3 years was 88.2% in the dual versus 94.9% in the quadruple group. Overall 25 patients in each group (41 and 42%, respectively) developed acute rejection. There was no difference in the number and severity of rejections. In each group only four patients required OKT3-therapy, however, although three of four patients in the quadruple group responded to OKT3 and cleared rejection, none of the four patients in the dual group were treated successfully with OKT3 (P<0.02). Rejection in these patients resolved only after additional treatment with mycophenolate mofetil. Adverse events and infections were equally distributed in both groups. Asymptomatic Cytomegalovirus infections were more common in the quadruple group (P<0.02). As of today, only one patient developed posttransplant lymphoproliferative disease (dual group).

CONCLUSIONS

The data from our single-center study indicate that both tacrolimus-based dual and quadruple immunosuppressive induction regimens yield similar safety and effectiveness after liver transplantation.

Co-occurrence of non-toxic (cyanopeptolin) and toxic (microcystin) peptides in a bloom of Microcystis sp. from a Chilean lake

A cyanobacterial bloom occurring in 1998 in lake Tres Pascualas (Concepción/Chile) was found to be dominated by Microcystis sp. The bloom contained both non-toxic (cyanopeptolin-type) and hepatotoxic (microcystin-type) peptides. Cyanopeptolin structure of the non-toxic peptides (called cyanopeptolin VW-1 and VW-2, respectively) was revealed by matrix assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS) of whole cells, showing dominant molecular ions at m/z = 975 and m/z 995, respectively. On post source decay (PSD), both cyanopeptolins showed fragments deriving from Ahp-Phe-MTyr (3-amino-6-hydroxy-2-piperidone), the characteristic partial structure of cyanopeptolins. The amounts of each of the two cyanopeptolins could only roughly be estimated to be >0.1% of bloom material dry weight. In addition the blooms contained microcystins (20 microg/g bloom dry weight as determined by RP-HPLC, 13 microg/g according to ELISA determination). MALDI-TOF-MS revealed several structural variants of microcystin: MCYST-RR (microcystin with Arg and Arg, indicated by m/z 1,038 and confirmed by PSD revealing a m/z = 135 fragment deriving from the Adda side chain, MCYST-FR (microcystin with Phe and Arg, indicated by m/z = 1,015). The presence of [Asp(3)]-MCYST-LR (microcystin with Leu and Arg, Asp non-methylated, indicated by m/z 981), and [Asp(3)]-MCYST-YR (microcystin with Tyr and Arg, Asp non-methylated, indicated by m/z 1,031) were likely. The relative amounts of the peptides varied between February, April, and May. Whole cell extracts from the bloom material revealed specific enzyme inhibitory activities. The serin-proteases trypsin, plasmin, elastase were inhibited, assumable due to the cyanopeptolins found. Elastase and the cysteine-protease papain were not inhibited, inhibitions of protein kinase and glutathione S-transferase (GST) were low. Strong inhibition was observed with protein-phosphatase-1, likely due to the microcystins present in the samples.

[EMG mapping--applications and results in assessment of muscle coordination disorders in patients with a knee endoprosthesis (knee TEP)]

QUESTION

Disorders of coordination, strength and proprioception are frequently described after surgery of the knee joint. These muscular coordination disorders have not yet been studied sufficiently. The purpose of this study was the objective-quantitative characterization of muscular coordination disorders of the M. quadriceps femoris by means of EMG mapping in the arthrotic knee joint and their progress after the implantation of a total knee arthroplasty and after in-patient rehabilitation.

METHODS

The extent and pattern of activation (EMG mapping) of the M. quadriceps femoris were investigated by means of a 16-channel EMG technique in 38 patients before and after the implantation of a total knee arthroplasty (type LCS).

RESULTS

EMG mapping permitted an objective-quantitative characterization of the extent and pattern of activation in the M. quadriceps femoris before and after the implantation of a total knee arthroplasty and therefore the objectivation of muscular coordination disorders. Muscular coordination disorders were present already before surgery and were also caused by the implantation of a total knee arthroplasty. These coordination disorders can be improved by an inpatient rehabilitation.

CONCLUSIONS

The development of exercise programs adequate for everyday life is necessary to remove quickly and actually the demonstrated coordination disorders.

Generation of antibodies directed against the low-immunogenic peptide-toxins microcystin-LR/RR and nodularin

The preparation of antibodies against the liver toxin microcystin, as described here, is of major importance for its detection and purification in food and water, and for a therapeutic approach to neutralize the toxin by passive immunization. Microcystin-LR (MLR) and microcystin-RR (MRR) were purified from cyanobacterial cell materials by extraction, Sephadex LH-20-, ODS silica gel-, ionic exchange and RP-HPLC-chromatography. In order to reduce the toxicity for parenteral administration, microcystins were coupled by the carbodiimide method to poly-L-lysine (PLL(50.000)). Mice and rabbits were immunized with the conjugates in the presence of two lipopeptide immunoadjuvants (P(3)CSK(4) and P(3)CS-T(h)). High MLR-specific antibody levels were observed after parenteral coadministration of antigen and lipopeptides, whereas no anti-MLR antibodies were obtained with free microcystin or the microcystin-PLL(50.000)-conjugate in the absence of lipopeptide. In oral immunization, coadministration of antigen and adjuvants resulted in an accelerated development of anti MLR-specific antibodies and high antibody levels. Using the antisera, we could detect different microcystins and nodularin down to a concentration range of 10-50 ng/ml by a competitive inhibition ELISA; detection of microcystins in crude cell preparations was also possible. Furthermore, microcystins from different sources could be detected and discriminated from cyclic cyanopeptolines.

Use of an alkaline phosphatase-labelled probe for the detection of Mycoplasma synoviae in chickens

Short nucleotides directly labelled to alkaline phosphatase (SNAP probes) are an interesting alternative to digoxigenin-labelled probes (DIG probes), because they reduce the number of steps necessary in dot blots for the detection of DNA or amplificate. This study examined the questions whether a SNAP probe might not only save time, but also increase the sensitivity of another PCR-based DNA probe test using a digoxigenin probe. Amplificates obtained by multispecies polymerase chain reaction (PCR), with either purified genomic DNA or DNA extracted from tracheal swabs taken in chicken flocks, were detected by both methods. The results for the clinical specimens were compared to culture. Under stringent conditions, the specificity and sensitivity obtained with the SNAP probe were comparable to the results obtained with the DIG probe. The quantities 10 fg (SNAP probe) and 100 fg (DIG probe) of purified Mycoplasma synoviae DNA were detected after amplification, but more positive clinical specimens were detected with the DIG probe. Under non-stringent conditions sensitivity with purified DNA did no change, but the coloration of the dots improved markedly, and more positive specimens could be detected with the SNAP probe than with the DIG probe, truly positives as confirmed by culture. Because cross-reaction with Mycoplasma gallisepticum and Mycoplasma imitans, two species with DNA that was also recognized by the multispecies primers, occurred under non-stringent conditions, it was concluded that, to take the full advantage of SNAP probes, their use in combination with species-specific primer pairs is recommended. PCR as a method for mycoplasma detection is however, always accompanied with serological and cultural methods. When a M. synoviae mono-infection is likely by serological results, non-stringent dot blot conditions and use of the SNAP probe will ease and improve the detection of mycoplasma.

2-(diethylamino)thieno1,3ŏxazin-4-ones as stable inhibitors of human leukocyte elastase

A series of 2-(diethylamino)thieno1,3ŏxazin-4-ones was synthesized and evaluated in vitro for inhibitory activity toward human leukocyte elastase (HLE). The Gewald thiophene synthesis was utilized to obtain several ethyl 2-aminothiophene-3-carboxylates. These precursors were subjected to a five-step route to obtain thieno2,3-d1,3ŏxazin-4-ones bearing various substituents at positions 5 and 6. Both thieno2,3-d and thieno3,2-d fused oxazin-4-ones possess extraordinary chemical stability, which was expressed as rate constants of the alkaline hydrolysis. The kinetic parameters of the HLE inhibition were determined. The most potent compound, 2-(diethylamino)-4H-1benzothieno2,3-d1,3ŏxazin-4-one, exhibited a K(i) value of 5.8 nM. 2-(Diethylamino)thieno1, 3ŏxazin-4-ones act as acyl-enzyme inhibitors of HLE, similar to the inhibition of serine proteases by 4H-3,1-benzoxazin-4-ones. The isosteric benzene-thiophene replacement accounts for an enhanced stability of the acyl-enzyme intermediates.

[Laparoscopic therapy of diaphragmatic rupture on both sides]

The usual treatment for operative repair of diaphragmatic injuries is laparotomy or thoracotomy. We report on a 26-year-old patient, who was treated by laparoscopic surgery for a rupture on both sides of the diaphragm. The operation was without complications and the advantages of minimally invasive laparoscopic surgery were clearly evident. There was much less strain on the patient and the postoperative recovery period was short. In addition, for unclear findings there is a high diagnostic potential in laparoscopy. The rupture on the right side of the diaphragm was not diagnosed until laparoscopy, although our patient underwent extensive diagnostics prior to the intervention.

Isolation and structural characterization of glycosphingolipids of in vitro propagated human umbilical vein endothelial cells

To investigate in detail the expression of glycosphingolipids (GSLs) on endothelial cells, 4.85 x 10(9) human umbilical vein endothelial cells (HUVECs) were cultivated in a 2 l bioreactor using microcarriers as a support for anchorage dependent growing cells. Neutral GSLs and gangliosides were isolated and their structures were determined by TLC immunostaining, fast atom bombardment-mass spectrometry (FAB-MS) of the native GSLs, and gas chromatography-electron impact mass spectrometry (GC-EIMS) of partially methylated alditol acetates. GbOse4Cer, GbOse3Cer, and LacCer, all carrying mainly C24- and C16-fatty acid beside C18-sphingosine, were detected as the major neutral GSLs (36%, 23%, and 15% of the total orcinol stain, respectively); GlcCer, nLcOse4Cer, and nLcOse6Cer were expressed to substantial minor amounts (9%, 12%, and 5% of the total orcinol stain, respectively). TLC immunostaining revealed the presence of lipid bound Lewisx antigen, whereas the isomeric Lewisa structure was detectable only in very low quantities. GM3(Neu5Ac) with C18-sphingosine was the major ganglioside constituting about 90% of the whole ganglioside fraction. The fatty acid composition was determined by GC-MS of fatty acid methyl esters, indicating the predominance of C24- and C16-substituted GM3(Neu5Ac), followed by C18- and C22-substituted species. Terminally alpha2-3 sialylated neolacto-series ganglioside IV3Neu5Ac-nLcOse4Cer was the second most abundant ganglioside in HUVECs (8% of the total resorcinol stain), and IV6Neu5Ac-nLcOse4Cer and VI3Neu5Ac-nLcOse6Cer (together less than 2% of total resorcinol stain) were found in minor quantities. Lipid bound sialyl Lewisx antigen with poly-N-acetyllactosaminyl chains, and traces of gangliotetraose-type gangliosides GM1 and GD1a were identified by TLC immunostaining. The expression of dominant neutral GSLs LacCer, GbOse3Cer, and GbOse4Cer, and of ganglioside GM3(Neu5Ac) was assayed by indirect immunofluorescence microscopy of cell layers grown in chamber slides, each showing different plasma membrane and subcellular distribution patterns. The complete structural characterization of GSLs from HUVECs contributes to our understanding about their functional role, not only of the carbohydrate but also of the lipid moiety, as receptors for bacterial toxins, as cell surface antigens of cellular interaction and as receptors for blood components and macromolecules of the extracellular matrix.

Microcystin in cyanobacterial blooms in a Chilean lake

Cyanobacterial blooms dominated by Microcystis sp. occurred in lake Rocuant ("marisma", near Concepción/Chile) in February 1995 and 1996. In the bloom samples collected in both years the hepatotoxin microcystin was detected by RP-HPLC in both samples and in the sample of 1995 also by a toxicity assay using primary rat hepatocytes. In the bloom of 1995, the microcystin content of the dry bloom biomass was determined to be 130 micrograms/g on the basis of the RP-HPLC peak area and 800 micrograms/g on the basis of the rat hepatotoxicity assay, respectively. In the bloom of 1996, RP-HPLC analysis revealed a microcystin content of 8.13 micrograms/g bloom material dry weight. In this year no hepatotoxicity was measured using a concentration range up to 0.8 mg (d. w.) of bloom material per ml in the rat hepatotoxicity assay. This is the first report on the detection of microcystins in Chilean water bodies.

Evidence for Marek's disease in turkeys in Germany: detection of MDV-1 using the polymerase chain reaction

Since 1994 tumorous lesions have been monitored in turkeys on three farms in Germany. On one of these farms, chickens also had tumorous lesions. Affected turkeys were retarded in growth, apathic, pale and almost unable to move. The older the animals got, the more indistinct the clinical signs became. Mortality started at an age of 5 weeks and reached between 20% and 60% by the end of the fattening period of about 20 weeks. The aetiological differential diagnosis includes reticuloendotheliosis (RE), lymphoproliferative disease (LPD), lymphoid leukosis (LL) and Marek's disease (MD). Repeated serological examinations did not establish the presence of antibodies against REV, LLV or MDV-1. Cloacal swabs were negative for LL P27 antigen in ELISA. Solid tumors of various sizes as well as diffuse infiltrations were predominantly seen in the liver, spleen and kidney. Pleomorphic cell infiltration was rarely noted in the plexus brachialis and nervus ischiaticus. Herpesvirus of turkeys (HVT) was the only virus isolated from buffy coat cells derived from affected turkeys in chicken embryo kidney cell (CEK) and chicken embryo fibroblast (CEF) cultures. Use of polymerase chain reaction (PCR) for the amplification of the 132 bp repeat region provided evidence for the presence of MDV-1 DNA in tumor tissue from several diseased turkeys. No evidence was found for the presence of REV.

[The effect of erythropoietin (rh-EPO) om in vitro proliferation of granulocyte/monocyte-determined stem cells in bone marrow and peripheral blood]

AIM

The aim of the investigation was to determine the effect of recombinant human erythropoietin (rh-EPO) therapy on in-vitro proliferation of granulocyte/monocyte(gm)-determined stem cells in bone marrow and peripheral blood.

PATIENTS AND METHODS

The study comprised 28 dialysis patients (15 female, 13 male, aged between 22 and 78 years, dialysis sessions 3 times weekly 4 to 5 hours, mean duration time of dialysis treatment 4 to 99 months). Stem cell parameters were estimated before and after reaching the target hematocrit and the absolute number of leukocytes in peripheral blood was measured.

RESULTS

No alteration in total leukocyte number (PMN, monocytes, lymphocytes) of peripheral blood was found. Dialysis patients had a diminished proliferation capacity of colony forming unit-granulocyte/monocyte (CFU-GM) in bone marrow and an increased one in peripheral blood. The CFU-GM proliferation capacity in bone marrow improved during rh-EPO (34.3 +/- 5.8 x 10(5)/ml vs 120.5 +/- 37.8 x 10(5)/ml), whereas no changes in peripheral blood could be observed (46.7 +/- 7.15 x 10(5)/ml vs 37.6 +/- 12.05 x 10(5)/ml).

[Bilobar liver hematoma and spontaneous rupture after cesarean section]

A 25-year-old woman delivered a healthy baby in the 34th week of gestation by caesarean section due to placental abruption and fetal bradycardia. On the following day she developed dyspnea, tachycardia, hypotension and rising serum transaminase levels. After exclusion of a pulmonary embolism, the abdominal CT scan and cavography revealed a subcapsular hematoma of the entire dorsal liver surface and compression of the retrohepatic vena cava. During laparotomy a spontaneous rupture of the liver capsule with intraperitoneal hemorrhage was found. The dorsal liver was decapsulated and the subcapsular hematoma completely removed. The postoperative course was uneventful.

Popliteal entrapment syndrome: non-invasive diagnosis and complete recovery after surgery in an 11-year-old boy

We present an unusual case of popliteal entrapment syndrome type I in an 11-year-old boy. Presenting symptoms were exercise-related pain and pallor in his left lower leg. The diagnosis of popliteal entrapment syndrome was established by acral plethysmography, colour-coded Doppler sonography and MRI. After myotomy of the gastrocnemius muscle the symptoms resolved completely. Post-operative duplex scan showed normal blood flow, even in plantar flexion of the foot.

[Laparoscopic appendectomy as routine operation for treatment of inflammatory diseases of the appendix. Analysis of 733 laparoscopic appendectomies 6/1992 to 8/1997 in the Reichenbach district hospital]

All laparoscopic appendectomies were analysed retrospectively during 6/1992 and 8/1997 in our hospital. Operation time was 33.6 +/- 12.9 min. In 9 patients the operation had to be converted. Complications occurred in 1.77% (13 patients). 7 complications could be treated laparoscopically and 6 required a laparotomy. The hospital time was 6.4 +/- 2.2 days. The patients needed 1.3 +/- 1.7 days oral analgetics. We believe the laparoscopic appendectomy a reliable operation to treat all inflammatory diseases of the appendix.

[Treatment of advanced Budd-Chiari syndrome by liver transplantation]

Budd-Chiari syndrome (BCS) with hepatic vein occlusion is a rare disorder that can effectively be treated in advanced stages with orthotopic liver transplantation. We report on 16 patients who received 18 liver grafts and were followed up for at least 2 years. In 7 patients a hematological disorder was confirmed by bone marrow biopsy. One patient died after 4 months due to cytomegalovirus pneumonia; another patient died after 2 years due to progressive liver failure after portal vein thrombosis. The actuarial 5-year survival rate is 87.5% compared to 85.3% in all other 710 orthotopic liver transplantations performed from September 1988 to December 1995 at our institution. Anticoagulation consisted of intravenous heparin and overlapping continuation with dicoumarin. Three patients received hydroxyurea for thrombocytosis, one patient for 1 week only early after the transplantation. Two postoperative abdominal hemorrhages required laparotomy. Two patients had to be retransplanted, one for thrombosis of the hepatic artery and portal vein after discontinuation of dicoumarin due to GI bleeding and one for hepatic vein thrombosis after insufficient dicoumarin intake. Terminal BCS represents a good indication for orthotopic liver transplantation; however, life-long, closely monitored anticoagulation is essential.

Comparative pathogenesis of haemorrhagic enteritis virus (HEV) infection in turkeys and chickens

The pathogenesis of haemorrhagic enteritis virus (HEV) infection in chickens 3-4 days post-infection was compared with that in turkeys. As expected, infected turkeys showed HEV-specific lesions that included enlargement and mottling of the spleen, as well as haemorrhagic enteritis. In infected chickens, only splenomegaly was observed. The number of HEV-infected cells in the spleen was significantly (P < 0.05) higher in the turkey than in the chicken. In both species, the immunohistochemical labelling of B-cell surface determinants was diminished and the splenic B-cell areas were undetectable after HEV infection. Infection with HEV resulted in an increase in nitric oxide production by macrophages in chickens but not in turkeys.

Equine CRISP-3: primary structure and expression in the male genital tract

Although originally described in the male rodent genital tract, cysteine-rich secretory proteins (CRISPs) are expressed in a variety of mammalian tissue and cell types. The proteins of the male genital tract have been observed associated to spermatozoa and are believed to play a role in mammalian fertilization. Here we describe the identification and primary structure of the first equine member of the CRISP family. Equine CRISP-3 is transcribed and expressed in the stallion salivary gland, in the ampulla and the seminal vesicle. It displays all 16 conserved cysteine residues and shows 82% homology to human and 78% to guinea pig CRISP-2 (AA1, TPX 1) and 77% to human CRISP-3. In contrast to other mammalia, in the horse CRISP-3 is synthesized in great amounts in the accessory sexual glands, ampulla and seminal vesicle, thus allowing the isolation of equine CRISP-3 in amounts suitable for biochemical, physiological and structural studies from stallion seminal plasma.

A randomized, placebo-controlled trial with anti-interleukin-2 receptor antibody for immunosuppressive induction therapy after liver transplantation

The introduction of quadruple induction therapy after liver transplantation with the murine anti-interleukin-2 receptor (IL-2R) antibody (BT563) has decreased the incidence of serious side effects, such as tachycardia, hypertension, rash, fever and nausea since it does not lyse its target cell. To investigate the immunosuppressive efficacy of BT563, a placebo-controlled trial was performed and BT563 was added to the standard triple induction after liver transplantation. Forty consecutive recipients of primary orthotopic liver transplants (OLT) (median age 47 yr [range 18-65]) were randomized. All patients received triple immunosuppression with cyclosporine A (CyA), prednisolone (PRED) and azathioprine (AZA). In addition, 19 patients received BT563 (Biotest, Dreieich, Germany) at a dose of 10 mg/d from day 0 until day 12. The remaining 21 patients received a placebo infusion at the same days after transplantation. Minimal follow-up for all patients was 3 yr. Patient survival at 3 yr was 74% in the BT563 group and 90% in placebo group. Similar results were observed for graft survival. Two acute rejection episodes were detected in the BT563 group and 9 acute rejections (5 steroid-resistant) were observed in the placebo group (p < 0.034). The incidences of sepsis, pneumonia, cholangitis, urinary tract infections as well as cytomegalo-virus (CMV) infections were similar in both groups. Side effects of the BT563 therapy and/or post-transplant lymphoproliferative disease (PTLD) were not detected. Quadruple induction therapy with BT563 significantly reduces the incidence of rejection episodes after liver transplantation, while infectious complications and/or PTLD is not increased. Therefore, the anti-IL2 receptor antibody BT563 constitutes a safe and efficient addition to the immunosuppressive induction regimen following OLT.

[Fatal course of measles infection in a patient with a low-grade malignant non-Hodgkin lymphoma]

HISTORY AND CLINICAL FINDINGS

A 35-year-old man, for 6 years known to have non-Hodgkin lymphoma (NHL) was admitted because of deteriorating general condition, drowsiness and 11 days of flu-like symptoms. A generalized rash had been noted 5 days after onset of symptoms. His 2-year-old son had fallen ill with measles a few days earlier. The patient had reportedly had measles as a child. On admission a generalized rash was found, he had a fever of 40.5 degrees C, tachypnoea, conjunctivitis and possible meningismus.

INVESTIGATIONS

Lactate dehydrogenase activity was raised to 458 U/ml, and C-reactive protein to 240 mg/ml. Cerebrospinal fluid contained 8/3 cells and protein of 269 mg/l. The chest radiogram revealed opacification in the left upper lobe. Computed tomography of the skull demonstrated a pansinusitis.

DIAGNOSIS, TREATMENT AND COURSE

As measles encephalitis seemed unlikely he was treated for the measles superinfection of bacterial pneumonitis (measles RNA in the bronchoalveolar lavage) and the sinusitis with broad-spectrum antibiotics. After initial improvement artificial ventilation had to be be gun on day 3 because of an acute respiratory distress syndrome, diagnosed both clinically and radiologically. Despite additional antiviral and intensive medical treatment he died on day 11.

CONCLUSION

Patients with impaired immunocompetence due to NHL may lose their immunological "memory" for a previous measles infection. Prevention of exposure may therefore be necessary, in addition to early hyperimmunoglobulin administration.

Combined liver-kidney transplantation: long-term follow up in 18 patients

Since August 1992, 18 patients underwent combined liver and kidney transplantation. Eight patients had lymphocytotoxic antibodies pretransplant and 5 of these patients (27.7%) had a positive crossmatch. Fifteen patients received cyclosporine-based immunosuppression and 3 patients were treated with a tacrolimus-based immunosuppressive protocol. One patient died in the postoperative course due to intractable bleeding episodes after 96 days and one kidney graft was lost due to technical complications. The 1 year survival rate of patients with combined transplantation was 95% vs 87% in patients with liver transplantation alone. None of the patients with a positive crossmatch experienced a hyperacute rejection of the kidney. The long-term patient and graft survival was not impaired in patients with a positive crossmatch. These results suggest that combined liver-kidney transplantation is a safe treatment for end-stage liver and renal disease. A positive crossmatch or positive lymphocytotoxic antibodies are not contraindications for a combined transplantation.

Studies on 2-benzyloxy-4H-3,1-benzoxazin-4-ones as serine protease inhibitors

The class of 3,1-benzoxazin-4-ones includes potent inhibitors of various serine proteases. Structural investigation on three 2-benzyloxy-4H-3,1-benzoxazin-4-ones (1-3) are described with respect to their reactivity to alkaline hydrolysis. The 13C NMR data of 2-benzyloxy-5-methyl-4H-3,1-benzoxazin-4-one 3 are discussed. This peri substituted compound was subjected to a crystal structure analysis. The heterocyclic skeleton together with the carbonyl oxygen and the methyl carbon is planar, and only small angle distortions occurred. The inhibition of neutrophil serine proteases by 1-3 is reported. The different reactivity of the 5-methyl derivative 3 towards serine proteases is mainly influenced by specific interactions within the active sites. Thus, 3 was found to rapidly acylate human leukocyte proteinase 3 and exhibited a Ki value of 1.8 nM.

A single amino acid substitution changes ribonuclease 4 from a uridine-specific to a cytidine-specific enzyme

The structural features underlying the strong uridine specificity of ribonuclease 4 (RNase 4) are largely unknown. It has been hypothesized that the negatively charged alpha-carboxylate is close to the pyrimidine binding pocket, due to a unique C-terminal deletion. This would suppress the cleavage of cytidine-containing substrates [Zhou, H.-M., and Strydom, D. J. (1993) Eur. J. Biochem. 217, 401-410]. Replacement of the alpha-carboxylate by an alpha-carboxamide in a fragment complementation system decreased both (kcat/Km)CpA and (kcat/Km)UpA , thus refuting the hypothesis. However, model building showed that the deletion allowed the side chain of Arg-101 to reach the pyrimidine binding pocket. From the 386-fold reduction in (kcat/Km)UpA in RNase 4;R101N, it is concluded that this residue functions in uridine binding, analogous to Ser-123 in RNase A. In addition, it may have an effect on Asp-80. The 2-fold increase in (kcat/Km)CpA in the mutant R101N and the close proximity of the side chains of Arg-101 and Asp-80 suggested that the latter could be involved in suppressing CpA catalysis. The substrate specificity of RNase 4;D80A was completely reversed: (kcat/Km)UpA decreased 159-fold, whereas (kcat/Km)CpA increased 233-fold. The effect on CpA was unexpected, because the corresponding residue in bovine pancreatic RNase A (Asp-83) hardly affects cytidine-containing substrates. Furthermore, the residue is conserved in nearly all sequences of mammalian RNase 1. Thus, an evolutionary highly conserved residue does not necessarily function in the same way in homologous enzymes. A model, which proposes that the structure of RNase 4 has been optimized to permanently fix the position of Asp-80 and impede its movement away from the pyrimidine binding pocket, is presented.

Novel thieno[2,3-d][1,3]oxazin-4-ones as inhibitors of human leukocyte elastase

A series of thieno[2,3-d][1,3]oxazin-4-ones was synthesized and evaluated in vitro for inhibitory activity toward human leukocyte elastase. New synthetic routes to 2-alkoxy-, 2-alkylthio-, and 2-sec-amino-substituted derivatives are reported. This study demonstrates the versatility of 2-aminothiophenes prepared by Gewald reaction as a synthetic entry to serine protease-inhibiting, fused 1,3-oxazin-4-ones. Introduction of ethoxy, n-propoxy, and ethylthio groups at C-2 delivered the most potent inhibitors of this series with Ki values lower than 11 nM. Kinetic studies and product analyses revealed the formation of acyl-enzymes as a result of the attack of the active site serine at the carbon C-4 and subsequent deacylation. This mode of action is similar to the inhibition of serine proteases by 4H-3,1-benzoxazin-4-ones. Replacement of the benzene ring in benzoxazinones by a (substituted) thiophene led to improved hydrolytic stability and retained inhibitory potency.

The impact of donor organ quality on postoperative liver function after orthotopic rat liver transplantation

The impact of donor factors for posttransplant liver function was evaluated in the model of orthotopic rearterialized liver transplantation in the rat. The effect of donor fasting, parenteral hyperalimentation, hypotension, warm ischemia and endotoxins on histology, clinical chemistry and MEGX test was analyzed in syngeneic and allogeneic recipients of livers stored for 4 hrs on ice. In syngeneic animals, 20 min of warm ischemia led to significantly elevated serum transaminase levels and degree 2 histological damage on POD 2. Endotoxins produced a grade 1 histological damage. All groups had a lower MEGX formation rate compared to controls. In allogeneic animals, warm ischemia was the single most detrimental parameter. The strength of the rejection response on POD 8 did not depend on the type of donor pretreatment. The major finding of this non-survival study is the deleterious effect of warm ischemia and endotoxin on the functional and structural integrity of liver grafts after 4 hrs of cold ischemia.

Glycosphingolipids of skeletal muscle: I. Subcellular distribution of neutral glycosphingolipids and gangliosides in rabbit skeletal muscle

Membrane vesicles were prepared from rabbit skeletal muscle, separated by sucrose density gradient centrifugation and characterized by their specific marker enzymes, ligand binding, and ion flux activities. The fractions obtained (in the order of increasing density) were sarcolemma (SL), T-tubules (TT), sarcoplasmic reticulum (SR1 and SR2) and triads/mitochondria (Tr/M). Their glycosphingolipid compositions were analyzed by biochemical and immunochemical methods with specific antibodies (TLC immunostaining) and characteristic patterns were obtained from respective membrane fractions, expressed on a protein basis. Glucosylceramide, the main neutral glycosphingolipid of rabbit muscle, was found in SL and TT fractions, whereas SR and Tr/M vesicles lack this compound. Lactosylceramide was selectively recovered in the SR1 fraction. GM3(Neu5Ac), the main ganglioside in rabbit muscle, was found to account for 64% in the SL, 13% in the TT, 7% in the SR1, 3% in the SR2 and 13% in the Tr/M fractions. IV3Neu5Ac-nLcOse4Cer was mostly abundant in SL and decreased in the order SL > TT, Tr/M > SR1, SR2. IV6Neu5Ac-nLcOse4Cer was only detected in the SL and Tr/M fractions in noteworthy quantities. Ganglioseries gangliosides GM1, GD1a, GD1b and GT1b displayed homogeneous distribution patterns in each membrane preparation. They were expressed only in small amounts but mainly in SL, TT and Tr/M vesicles and to less extent in SR1 and SR2 fractions. The presence of GM3(Neu5Ac) in the SL as well as on subcellular level was confirmed in transverse muscle cryosections by means of indirect immunofluorescence microscopy. The SL was brightly stained, but considerable intracellular fluorescence was observed as expected from the biochemical analyses. Thus, the neutral GSL and ganglioside expression of the SL and the intracellular membraneous network is different in skeletal muscle both in terms of quantitative and qualitative GSL composition as demonstrated in details by means of biochemical and immunochemical techniques. The modulatory functions of GM3 and gangliosides of the neolacto- and ganglio-series towards the voltage dependent Ca(2+)-channel, largely preponderant in the triads-containing Tr/M fraction, is the subject of the accompanying paper (J. Müthing, U. Maurer, and S. Weber-Schürholz, Carbohydr. Res., 307 (1998) 147-157).

Prophylactic use of low-dose urodilatin for prevention of renal impairment following liver transplantation: a randomized placebo-controlled study

Many therapeutic measures have been employed to prevent or at least ameliorate postoperative renal impairment following liver transplantation. Recent clinical phase II studies have demonstrated that the new natriuretic peptide urodilatin has beneficial effects on renal function following heart and liver transplantation. The present study reports the first prospective randomized placebo-controlled trial of prophylactic urodilatin administration following liver transplantation. Seventy consecutive recipients of primary liver transplants were included in the study following randomization, and 33 patients continuously received urodilatin at a dose of 20 ng/kg/min for 7 d. The remaining 37 patients received a placebo infusion for the same time period. The course of serum creatinine and urea did not differ between the two groups nor did the daily urine production. However, the urodilatin group showed a higher preoperative median serum creatinine and a significant reduction on days 1 and 2, whereas this observation was not made in the placebo group. Furthermore, less furosemide was administered to the patients in the urodilatin group during the first 2 d. The incidence of postoperative hemodialysis and the number of treatments did not differ between the groups either (urodilatin group 4, vs. placebo group 6 and 22 for both groups, respectively). Side effects of the urodilatin therapy were not detected. The prophylactic low-dose urodilatin administration resulted in a trend towards amelioration of the renal function, but did not result in significant differences between the two experimental groups. Further studies, using higher doses, will be required to define the value of urodilatin for prevention of renal impairment after liver transplantation.

De novo malignancies after liver transplantation using tacrolimus-based protocols or cyclosporine-based quadruple immunosuppression with an interleukin-2 receptor antibody or antithymocyte globulin

BACKGROUND

Although conventional immunosuppression after liver transplantation consists of cyclosporine A (CsA), steroids, and azathioprine, recently introduced protocols entail CsA-based quadruple induction protocols or tacrolimus-based combinations. These protocols aim to reduce the rejection rate and the considerable morbidity related to the side effects of additional immunosuppressive treatment, but have not yet been analyzed regarding their long term de novo neoplastic risk.

METHODS

From September 1988 to May 1994, 500 liver transplantations were performed in 458 patients. The median follow-up was 50 months (range, 0.3-97 months) for all patients. Conventional triple therapy was implemented in 25 patients, CsA-based quadruple induction therapy using an antilymphocyte globulin preparation (ATG) in 190 patients, an interleukin-2 receptor antibody (BT563) in 141 patients, and tacrolimus-based dual or triple immunosuppression in 102 patients. The different protocols were evaluated in four randomized and two nonrandomized prospective trials.

RESULTS

De novo neoplasias were detected in 33 patients (7.2%) and were comprised of lymphomas (n = 7), skin malignancies (n = 8 lesions in 7 patients), intraepithelial neoplasias of the cervix uteri (n = 7), breast carcinoma (n = 3), lung carcinoma (n = 3), and other malignancies (n = 6). The incidence of de novo neoplasias did not differ in the different trial arms. Only a positive T-crossmatch and a low CD4+/CD8+ ratio in patients receiving CsA-based immunosuppression demonstrated a significant correlation with the development of a de novo tumor in a multivariant logistic regression analysis.

CONCLUSIONS

The development of de novo neoplastic diseases after liver transplantation with the use of CsA-based quadruple induction protocols or tacrolimus-based regimens for immunosuppresion was assessed over the long term. Recently introduced immunosuppressive protocols did not alter the posttransplant de novo tumor rate. Patients with a low CD4+/CD8+ ratio during CsA-based therapy or a positive T-crossmatch were identified to be at an increased risk for the development of a de novo malignancy.