Airborne fungi and their secondary metabolites in working places in a compost facility

The present study investigates in detail the exposure to airborne fungal spores in working places in compost facilities. The fungal species composition in the air is compared with the spectrum of microbial metabolites with regard to the physiological properties of different fungal species. The results indicate that the spectrum of microbial volatile organic compounds (MVOCs) and the production of mycotoxins can be specific for certain species. In addition to the pathogenic and allergological relevance, the fungi may have different toxicological health impacts.

Conserved sequence motifs of CDR3 loops of TCR specific for two major epitopes of the grass pollen allergen PhI p 1

We analyzed the cDNA sequence data of complementarity determining regions (CDR3) of epitope mapped alphabeta TCR of T cell clones (TCC). The TCC were specific for the major timothy grass (Phleum pratense) pollen allergen Phl p 1 and were derived from the peripheral blood of seven unrelated grass pollen-allergic individuals. Each TCR recognized one of two immunodominant T cell epitopes, PP73 or PP103, of Phl p 1. Although a diversity of recombined V and J segments was observed, amino acid motifs as long as five residues were conserved among CDR3 loops of TCR from TCC of different atopic individuals specific for the same peptide. The conserved sequences could comprise as much as 60% of the CDR3. All amino acid residues of the motifs of the CDR3beta and most of the CDR3alpha of all TCR used in this study were encoded by randomly added nucleotides. This indicates that they were specifically selected for by the peptide bound to the MHC class II molecule. For one selected patient, a larger number of TCC, specific for PP103, was analyzed. The TCR repertoire was limited to three different TCR. The same MHC class II molecule, DRB1*1301, was identified to present PP103 to each of the three TCR.

Improved investigation of portal-hepatic veins by echo-enhanced Doppler sonography

Microbubbles of air released from a galactose vehicle (Levovist) amplify the intensity of Doppler signals. They survive both pulmonary and systemic capillary passage, leading to echo enhancement in the entire vascular system. The aim of this study was to investigate this agent in patients with liver disease and insufficient Doppler signals. A total of 275 Doppler examinations were performed in 176 patients; 20 of these patients could not be studied conventionally due to bowel gas, obesity or noncompliance. They received Levovist to examine portal or hepatic veins or TIPS patency. Angiography, computed tomography (CT) scan or magnetic resonance tomographic angiography (MRTA) was performed subsequently as a control. After administration of Levovist, portal or hepatic veins and TIPS patency could be unequivocally assessed in 18 of the 20 patients. In two patients, suspected occlusion of the portal vein was disproved because the diagnosis was not confirmed later. Only minor adverse effects were encountered. Echo-enhanced Doppler sonography with Levovist is well tolerated. Further study of the value of Levovist for the assessment of portal-hepatic vessels not amenable to conventional Doppler sonography is justified.

[Psychotherapy research--how it should (not) be done. An expert reanalysis of comparative studies by Grawe et al. (1994)]

22 psychotherapy outcome studies used in the Bernese meta-analysis by Grawe, Donati and Bernauer (1994) for a treatment comparison between behavioural and psychoanalytic-psychodynamic treatment concepts were reanalysed by 12 expert psychotherapy researchers independent of each other. Three clinical criteria served as basic criteria for the assessment of the methodological quality of the 22 comparative studies: treatment dosage, therapists' competence or expertise, and an adequate realisation of the intended treatment concept. The expert ratings were then compared with an evaluation of an assessment of a research team from the University of Ulm and with the one from the Bernese research team. Contrary to the Bernese meta-analysis, both the experts and the Ulm research group conclude that only 5 or 8 of the 22 studies, respectively, could be accepted for a relatively fair comparison between the treatments under study. Out of the 5/8 studies, none could be considered fully suitable for a treatment comparison, at the most only moderately suitable. These remaining 5 or 8 studies, respectively, do not prove superiority of one treatment over the other. Hence, the "Dodo Bird Verdict" stands up under scrutiny.

[Conventional heart surgery with the fast-track-method: experiences from a pilot study]

Early release after cardiac surgery can be promoted by implementation of a standard protocol for accelerated perioperative and early postoperative care, with optimal education and support of the patient playing a key role. We report on our preliminary experience with 100 selected patients who underwent a "fast track" protocol following coronary artery bypass (n = 61), valve replacement or reconstruction (n = 34) or closure of an atrial septal defect (n = 5) between 1996 and 1998. Surgery was performed through a midline sternotomy using normothermic or mild hypothermic cardiopulmonary bypass. Patients undergoing cardiac surgery with less invasive techniques were excluded from this study. The following criteria had to be fulfilled for early hospital discharge: sinus rhythm, temperature below 37.5 degrees C, stable haematocrit around 0.30, uncomplicated wound healing and complete mobilisation including stair exercises. Mean duration of the operation was 137 +/- 24 minutes and mean intubation time was 4.5 +/- 3 hours. Mean duration of hospitalisation from the day of the operation was 4.9 +/- 2.1 days. There was no early or late mortality in this group of patients and only 2 patients had to be re-admitted on postoperative day 10 and 14 because of atrial fibrillation in one and a wound healing problem in the other. Accelerated recovery and early hospital discharge is highly attractive in selected patients; in helps to promote early cardiac rehabilitation and the costs of the procedure can be substantially reduced. According to our experience and the most recent literature, this approach does not expose patients to higher mortality or morbidity. In addition, fast-tracked patients have shown a higher level of satisfaction. Under optimal cooperation between surgery, anaesthesiology and intensive care unit, the fast-track protocol can be applied in approximately 30% of overall adult cardiac surgery patients.

[Extracranial cephalic schwannomas. Apropos of 13 cases]

The authors report a series of 13 extracranial cephalic schwannomas, treated between 1981 and 1998. Schwannomas are rare and benign tumors derived from Schwann cells. Cephalic sites represent 2.5% of all schwannomas. Their diagnosis is often delayed, because symptoms mainly consist of compression disorders. There is a female predominance. The age distribution is homogeneous. There are no risk factors. There is no predominant side. The orbit and jugular foramen are the most frequent sites. The trigeminal nerve is usually involved. CT scan and magnetic resonance imaging (MRI) specify the topography and characteristics of the tumor and can contribute to the diagnosis. Macroscopically, schwannoma is a well-demarcated, ovoid or spherical, brownish tumor, off-centered from the nerve. It is composed of soft, easily fragmented tissue. The diagnosis is often obvious on microscopic examination and rarely requires immunohistochemical confirmation. The only treatment is surgical. It consists enucleation after opening the epineurium, using on operating microscope, without disruption of the nerve. Total excision ensures recovery. The authors have observed only one recurrence (first patient operated without microscope). Compression disorders regress completely. Nerve injuries have a variable prognosis. Malignant transformation is exceptional. Type II neurofibromatosis must be excluded in young patients.

Transcatheter closure of atrial septal defects within the oval fossa: medium-term results in children using the 'ASDOS'-technique

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of the ASDOS-technique (Sulzer-Osypka GmbH, Germany) for transcatheter closure of atrial septal defects within the oval fossa.

BACKGROUND

Although several attempts have been made to occlude defects within the oval fossa by transcatheter techniques, none of these has gained general acceptance.

METHODS

Patients with a defect in the oval fossa measuring equal to or less than 20 mm diameter, with a residual septal rim of 5 mm or greater, body weight greater than 10 kg, with clinical indications for surgical closure were considered for transcatheter closure. Follow-up investigations were performed at discharge, after 1, 3, 6 and 9 months, as well as after 1 and 2 years.

RESULTS

Of 78 patients considered for closure, a device was inserted in 41 patients (53%), with success being achieved in 40 patients (98%). The ages ranged from 1.1 to 15 years (7.8 +/- 1.92 years), the 'stretched' diameter of the defect from 10 to 20 mm (14.7 +/- 2.60 mm), and the diameters of the inserted devices from 25 to 45 mm (33.2 +/- 5.43 mm). Transient impairment of atrioventricular conduction occured in 4 patients. During the follow-up of 23.0 +/- 5.6 months elective surgical closure of a residual shunt was performed 26 months after insertion of the device in one patient. None of the other patients required surgery, hospitalisation or medical treatment, and none is requiring further treatment of the defect within the oval fossa. Fracture of one arm of the device occurred in 4 patients, but the fractured arms are in an unchanged and stable position after a period of at least 19 months.

CONCLUSIONS

Our medium-term data show that transcatheter closure in children of defects within the oval fossa can be performed with a high efficacy and safety using the ASDOS-device.

Cerebral CT findings in male opioid-dependent patients: stereological, planimetric and linear measurements

Cerebrospinal fluid (CSF) space enlargement has been demonstrated in substance-related disorders like alcohol and cocaine dependence. Experimental animal studies showed a reduction in shape and size of mesolimbic dopaminergic neurons after chronic morphine administration. Other studies indicated a change of neurofilament and glial fibrillary acid proteins after chronic opiate administration. Furthermore, frequent overdosing and toxicological effects of 'street'-heroin may lead to CSF space enlargement in opioid dependence. In our study the pericortical and ventricular CSF space of 21 male opioid-dependent patients was compared with an age- and sex-matched normal control group. Considering serious problems with ratio and proportion measures, we used a battery of linear (cella media index, Huckman number, frontal horn index), planimetric (cortical atrophy score) and stereological volumetric measures in order to detect differences in cranial computerized tomography scans. We found a significant ventricular and cortical volume loss of the brain in opioid-dependent patients. A higher degree of frontal lobe volume loss seemed to be associated with a shorter period of abstinence before relapse. However, the etiology of volume loss of the brain in opioid-dependent patients is still unclear, but experimental animal studies provide some evidence that long-term, chronic opiate exposure is associated with visible changes of specific structures in the brain.

A scientific relational database combined with a report generator for endoscopy in networks: EndoNet

BACKGROUND AND STUDY AIMS

The flexibility required in academic endoscopy units is not provided by the available database systems. In a project involving substantial cooperation between endoscopists and computer scientists, we have developed an adaptable database, combined with a report generator embedded in the hospital's intranet.

PATIENTS AND METHODS

Six workstations in different areas of the hospital were clustered with a UNIX operating system to implement multi-user capability and access control. A relational database was used to design an application appropriate to the specific needs of the endoscopy unit in a teaching hospital engaged in scientific research. Both the terminology used in standardized endoscopy nomenclature and a free text block facility were included. A graphical user interface was developed to assemble pertinent data, generate the reports, and supervise the database.

RESULTS

A total of 4936 examinations including 2988 patients were entered consecutively during continuous routine operation of the system. Complete report generation required five minutes (median; range 1-9 minutes). Both structured items and free text were used in all the reports. Querying of the database was possible, concerning matters such as the need for repeated endoscopic therapy in acute gastrointestinal bleeding (4%), the search for Helicobacter pylori in appropriate patients (64%), the rate of accidental pancreatic duct visualization in endoscopic retrograde cholangiography (24%), and links between examinations and active trials (2%). Indicating improved report quality, the number and the diameter of esophageal varices in patients with varices were more frequently reported with the new report system than with previous typed reports (P<0.001). An anonymous questionnaire revealed that the readability of the computer-generated reports was better than that of the previous typewritten reports (P=0.01).

CONCLUSIONS

This report describes the creation of a database application and a report generator meeting the needs of scientific and routine use, and the successful application of this system in an academic endoscopy unit.

[Airborne molds and their metabolites at workplaces in composting plants]

Airborne fungal contaminants in composting facilities gain more and more importance in regard to health hazards for workers and an emission of spores and microbial metabolites in the environment. Possible health impacts of bioaerosols are widely discussed from both an allergological and a toxicological point of view. The present study investigates in detail the exposure to airborne fungal spores at working places in compost plants. These fungal spores are compared to the spectrum of microbial volatile metabolites with regard to the physiological properties of each fungal species. The results indicate, that the spectrum of microbial volatile organic compounds (MVOC) as well as the production of mycotoxins can be specific for certain species. In addition to the pathogenic and allergological relevance, the fungi may have different toxicological health impacts. However, an evaluation of health effects caused by the great variety of volatile organic compounds remains difficult, since information on their toxicological impact is lacking.

Brain glucose metabolism with [18F]-fluorodeoxyglucose and positron emission tomography before and after surgical resection of epileptogenic cavernous angiomas

Surgery of cavernous angiomas is often proposed due to the epileptogenic and hemorrhagic potential of this lesion. Little information is available on the impact of surgical resection on brain metabolism, locally or at a distance from the lesion. Fifteen patients presenting with a cavernoma and epileptic seizures underwent positron emission tomography examinations before and 1 year after surgical resection. We studied the quantitative cerebral metabolic rate of glucose (CMRGlu) with [18F]-fluorodeoxyglucose. The global brain CMRGlu remained unchanged after surgery. There was a significant decrease of metabolism in the lesion hemisphere, which remained unchanged after surgery. The perilesional regions were less metabolic than the contralateral ones and less metabolic than remote regions within the same hemisphere, before and after surgery. The absence of pre- to postsurgical variations suggests that the metabolic consequences of the lesion are maintained despite the surgical procedure during long-term follow-up studies.

Mapping the stereospecificity of peptidyl prolyl cis/trans isomerases

The stereospecificity of peptidyl prolyl cis/trans isomerases (PPIases) was studied using tetrapeptide substrate analogs in which one amino acid residue was replaced by the cognate D-amino acid in various positions of the peptide chain. Reversed stereocenters around proline markedly increased the rate of the spontaneous trans to cis isomerization of the prolyl bond whereas cis to trans isomerizations were less sensitive. PPIases like human cyclophilin18, human FKBP12, Escherichia coli parvulin10 and the PPIase domain of E. coli trigger factor exhibited stereoselectivity demanding at the P1 to P2' position of the substrate chain. The discriminating factor for stereoselectivity was the lack of formation of the Michaelis complexes of the diastereomeric substrates. However, D-alanine at the P1 position preserved considerable affinity to the active site, and largely prevented activation of the catalytic machinery for all PPIases investigated.

Side-chain effects on peptidyl-prolyl cis/trans isomerisation

Peptidyl-prolyl cis/trans isomerisation has been frequently found as a rate limiting step in the folding of proteins. In order to determine whether the nature of the amino acid preceding proline controls the probability of cis prolyl bonds in native proteins, systematic studies on the thermodynamics and kinetics of the prolyl isomerisation in the pentapeptide series Ac-Ala-Xaa-Pro-Ala-Lys-NH2 were performed. All proteinogenic amino acids were substituted in the position preceding proline. When measured by 1H-NMR and CD spectroscopy both isomers proved to be devoid of ordered structure in the whole series of the oligopeptides in aqueous solution. Thus, isomerization rates and cis/trans ratios calculated from solvent jump and 1H-NMR magnetisation transfer experiments exclusively reflect the side-chain effects of the Xaa position in the peptide series. There is a rough correlation between the cis content in the oligopeptides and the propensity of Xaa-Pro cis prolyl bonds in proteins. This correlation suggests that the prolyl bond conformation is mainly determined by local effects in proteins. The rate constants kc-->t of pentapeptides containing unionised amino acids preceding proline range from 3.2 x 10(-3) s-1 (Xaa = Ala) to 0.5 x 10(-3) s-1 (Xaa = Trp) at 4 degrees C. Proline clustering led to an isomerisation cycle indicating considerable influence on the isomerisation rates of the peptide bond conformations flanking the rotating bond. Both tyrosine and histidine specifically reduce isomerisation rates severalfold by deprotonation of their respective side-chains.

Spinal cord ependymomas

Ependymomas are the most frequent spinal cord tumors in adult patients. Although magnetic resonance imaging can be a highly accurate diagnostic tool, it does not always provide accurate differentiation between ependymomas and astrocytomas. This is why the authors recommend surgical resection and histological evaluation in all intraspinal cord tumors. It cannot be said that a tumor is unresectable without first attempting to remove it. Complete removal should be accomplished whenever possible, and patients should undergo operation before they become neurologically impaired. Quality of life depends on preoperative neurological status. Postoperative radiotherapy should be avoided in all low-grade ependymomas even after partial removal. Radiotherapy may be used to treat anaplastic ependymomas, which are quite rare in the spinal cord. Patients with low-grade ependymomas must be followed for years and undergo reoperation if necessary. In our experience treating 93 spinal cord ependymomas, complete removal was achieved in 86 patients and only one patient underwent reoperation 18 years later for tumor recurrence. The gold standard in treatment protocol is gross-total resection without adjunctive radiation therapy. Good long-term outcomes have been achieved by using this strategy.

Experiences with novel techniques for reduction of stent flow in transjugular intrahepatic portosystemic shunts

The transjugular intrahepatic portosystemic shunt (TIPS) may deteriorate liver function and can cause encephalopathy in patients with cirrhosis of the liver. Then reduction of TIPS flow may be required. We here report several attempts to reduce shunt flow in TIPS-induced encephalopathy or liver function impairment with novel techniques. Three patients with cirrhosis of the liver were investigated: Two with severe recurrent encephalopathy and one with impaired liver function following TIPS insertion. Insertion of a reducing stent was ineffective to decrease shunt flow velocity in one patient with severe coagulopathy. Sufficient reduction of shunt flow was achieved by embolizing the space around the hourglass waist of the reducing stent with an occlusion emulsion. Insertion of a conventional stent within the preexisting TIPS with or without additional embolization reduced TIPS flow in the other patients. After reduction of shunt flow encephalopathy improved and liver function returned to the level before TIPS, respectively. During follow-up no occlusion of TIPS was observed. Thus, reduction of shunt flow velocity can be achieved by insertion of an additional stent into a curve-shaped TIPS. Embolization can be helpful to decrease TIPS flow, particularly in patients with severe coagulopathy. Reduction of TIPS flow can correct TIPS-induced complications.

Selective inactivation of parvulin-like peptidyl-prolyl cis/trans isomerases by juglone

In contrast to FK506 binding proteins and cyclophilins, the parvulin family of peptidyl-prolyl cis/trans isomerases (PPIases; E.C. 5.2.1.8) cannot be inhibited by either FK506 or cyclosporin A. We have found that juglone, 5-hydroxy-1,4-naphthoquinone, irreversibly inhibits the enzymatic activity of several parvulins, like the E. coli parvulin, the yeast Ess1/Ptf1, and human Pin1, in a specific manner, thus allowing selective inactivation of these enzymes in the presence of other PPIases. The mode of action was studied by analyzing the inactivation kinetics and the nature of products of the reaction of E. coli parvulin and its Cys69Ala variant with juglone. For all parvulins investigated, complete inactivation was obtained by a slow process that is characterized by pseudo-first-order rate constants in the range of 5.3 x 10(-)4 to 4. 5 x 10(-)3 s-1. The inactivated parvulin contains two juglone molecules that are covalently bound to the side chains of Cys41 and Cys69 because of a Michael addition of the thiol groups to juglone. Redox reactions did not contribute to the inactivation process. Because thiol group modification was shown to proceed 5-fold faster than the rate of enzyme inactivation, it was considered as a necessary but not sufficient condition for inactivation. When measured by far-UV circular dichroism (CD), the rate of structural alterations following thiol group modification parallels exactly the rate of inactivation. Thus, partial unfolding of the active site of the parvulins was thought to be the cause of the deterioration of PPIase activity.

Room-temperature vibrational difference spectrum for S2QB-/S1QB of photosystem II determined by time-resolved Fourier transform infrared spectroscopy

Time-resolved FTIR spectroscopy has been used to kinetically characterize the vibrational properties of intact photosystem II-enriched membrane samples undergoing the S1QB-to-S2QB- transition at room temperature. To optimize the experimental conditions for the FTIR measurements, oxygen polarographic and variable chlorophyll a fluorescence measurements were used to define the decay of S2 and QA-, respectively. The flash-induced S2QB-/S1QB difference spectra were measured at a temporal resolution of 4.44 s and a spectral resolution of 4 cm-1. An intense positive band is observed at 1480 cm-1 in the difference spectrum and shows a slow decay with a half time of approximately 13 s. Based on its decay kinetics and analogy to the infrared absorption of QA- of photosystem II and QB- in bacterial reaction centers, we conclude that the 1480 cm-1 band arises from QB- of PSII and tentatively assign it to the upsilon(CO) mode of the semiquinone anion QB-. The infrared spectral features attributed to the S1-to-S2 transition of the Mn cluster at room temperature show striking similarity to the S2/S1 difference spectrum measured at cryogenic temperatures (Noguchi, T., Ono, T.-A., and Inoue, Y. (1995) Biochim. Biophys. Acta 1228, 189-200).

Role of phosphorylation in determining the backbone dynamics of the serine/threonine-proline motif and Pin1 substrate recognition

Proline residues provide a backbone switch in a polypeptide chain, which is controlled by the cis/trans isomerization about the peptidyl-prolyl bond. Phosphorylation of serine- and threonine-proline motifs has been shown to be a critical regulatory event for many proteins. The biological significance of these motifs has been further highlighted by the discovery of a novel and essential peptidyl-prolyl cis/trans isomerase Pin1. Pin1 is required for progression through mitosis via catalyzing the isomerization of phosphorylated Ser/Thr-Pro motifs specifically present in mitosis-specific phosphoproteins. However, little is known whether the phosphorylation regulates the conformational switch of the Ser/Thr-Pro bonds. Here, we report the synthesis and conformational characterization of a series of peptides that contain the phosphorylated or nonphosphorylated Ser/Thr-Pro motifs. Phosphorylation affected the rate of the cis to trans isomerization of the Thr/Ser-Pro bonds. As determined by a protease-coupled assay, the isomerization rate of phosphorylated Thr-Pro bond was found to be 8-fold slower than that of the nonphosphorylated analogue. Furthermore, studies of the pH dependence of the isomerization of the phosphopeptides reveal that both cis content and the rate constant of prolyl cis to trans isomerization are lower for the dianionic state of the phosphothreonine-containing peptides. These effects of phosphorylation are specific for phosphorylated Ser/Thr since neither phosphorylated Tyr nor glutamic acid was able to affect the prolyl isomerization. Finally, our experiments provide evidence that effective catalysis of cis/trans isomerization of phosphorylated Ser/Thr-Pro bonds by Pin1 is specific to the dianionic form of the substrate. Thus, our results demonstrate that protein phosphorylation specifically regulates the backbone dynamics of the Ser/Thr-Pro motifs and that Pin1 specifically isomerizes the certain conformation of the phosphorylated Ser/Thr-Pro motifs.

Effects of FK506-binding protein 12 and FK506 on autophosphorylation of epidermal growth factor receptor

FK506-binding proteins and cyclophilins are intracellular proteins that express peptidylproline cis-trans-isomerase (PPIase) activity. The effects of FK506-binding protein 12 (FKBP12) and the cyclophilins 18 and 23 on autophosphorylation of the epidermal growth factor (EGF) receptor prepared from plasma membranes of the human epidermoid cell line A431 have been investigated. Whereas FKBP12 inhibited EGF receptor tyrosine kinase activity in a concentration-dependent manner, the cyclophilins did not affect autophosphorylation. In contrast to the wild-type enzyme, several variants of FKBP12 with greatly reduced PPIase activity were unable to suppress EGF receptor tyrosine kinase significantly. Pervanadate an inhibitor of protein tyrosine phosphatases, abolished the effect of FKBP12 on EGF receptor autophosphorylation. Finally, FK506 and rapamycin, which are known to block the PPIase activity of FKBP12, induced a significant stimulation of EGF receptor autophosphorylation in intact A431 cells suggesting suppression of EGF receptor autophosphorylation by intracellular FKBP12 in vivo. Taken together the data point to an inhibitory function of FKBP12 in EGF receptor signaling, possibly induced by stimulation of a protein tyrosine phosphatase coupled to the EGF receptor. Both PPIase activity and substrate specificity of FKBP12 seem to be indispensable for this effect.

The mode of action of peptidyl prolyl cis/trans isomerases in vivo: binding vs. catalysis

Polypeptides often display proline-mediated conformational substates that are prone to isomer-specific recognition and function. Both possibilities can be of biological significance. Distinct families of peptidyl prolyl cis/trans isomerases (PPIases) evolved proved to be highly specific for proline moieties arranged in a special context of subsites. Structural and chemical features of molecules specifically bound to the active site of PPIases served to improve catalysis of prolyl isomerization rather than ground state binding. For example, results inferred from receptor Ser/Thr or Tyr phosphorylation in the presence of site-directed FKBP12 mutant proteins provided evidence for the crucial role of the enzymatic activity in downregulating function of FKBP12.

Leukemia-free survival and mortality in patients with refractory or relapsed acute leukemia given marrow transplants from sibling and unrelated donors

Between April 1982 and February 1997 39 patients (24 male, 15 female) with refractory acute leukemia and a median age of 31 years (19-51 years) received allogeneic marrow grafts from an HLA-identical sibling (n = 27), HLA-identical unrelated donor (MUD; n = 10) or 1-antigen mismatched unrelated donor (n = 2). Twenty-eight patients had acute myelogenous leukemia and 11 acute lymphoblastic leukemia. For conditioning most patients received total body irradiation combined with cyclophosphamide (n = 23) or etoposide (n = 7). For graft-versus-host disease prophylaxis patients received cyclosporin A (CsA) and methotrexate (MTX) (n = 20), MTX alone (n = 3), CsA and methylprednisone (n = 6), or CsA alone (n = 10), respectively. As of June 1997 probability of leukemia-free survival projected to 3 years after BMT was 14% for patients given sibling marrow grafts and 28% after MUD transplantation. Transplant-related mortality projected to 3 years was 32% after sibling and 37% after MUD marrow grafting. Although not significantly different, probability of relapse projected to 3 years after BMT was lower after MUD at 56% compared to 78% with sibling BMT. Thus, high-dose chemo/radiotherapy followed by allogeneic marrow infusion has a curative potential for patients with refractory leukemia and offers the chance of long-term disease-free survival for some patients.

Semiautomated microtiter plate assay for monitoring peptidylprolyl cis/trans isomerase activity in normal and pathological human sera

An UV/VIS spectrophotometric assay technique was developed that was able to routinely monitor peptidylprolyl cis/trans isomerase (PPIase) activity of biological fluids in 96-well microtiter plates. The assay, based on monitoring the cis-to-trans isomerization of succinyl-Phe-cisPro-Phe-4-nitroanilide as substrate in a chymotrypsin-coupled reaction, yields a throughput of 96 samples per 30 min. The assay's capacity was exemplified by dealing with the PPIase activity in several normal and pathological human sera. Reference values of 151 healthy subjects (83 females, 69 males, 17 to 60 years old) were found to possess significant sex-specific differences. PPIase activity factor K of the sera was significantly greater in males (5th, 50th, 95th percentiles: 17, 36, 55 K) than females (14, 30, 48 K). PPIase activities of sera from healthy donors (n = 151) were significantly higher (Mann-Whitney rank-sum test P < 0.0001) than those of patients (n = 47). PPIase activity in serum samples stored at 4 degrees C was stable for at least 20 h.

Prolyl isomerases do not catalyze isomerization of non-prolyl peptide bonds

Prolyl isomerases accelerate the cis <--> trans isomerization of prolyl peptide bonds during protein folding and probably also in folded proteins. We asked whether this catalytic function is in fact restricted to prolyl bonds or whether the isomerizations of 'normal' non-prolyl peptide bonds are catalyzed as well. By using the P39A variant of ribonuclease T1 as a substrate we find that the trans --> cis isomerization of the Tyr38-Ala39 bond in the refolding of this protein is not catalyzed by prolyl isomerases of the cyclophilin, FKBP and parvulin families. These enzymes are neither able to catalyze amide bond isomerizations in the proline-free model peptide Ala-Ala-Tyr-Ala-Ala.