Febrile lady with acute renal failure and desquamating erythema

A 63-year-old woman developed acute renal failure and streptococcal toxic shock syndrome caused by streptococcus group G. Initially, an erythema resembling vasculitis was misleading. The subsequent clinical course, however, was typical for streptococcal toxic shock syndrome and met the criteria put forward by The Working Group on Severe Streptococcal Infections. In patients infected with streptococcus group G, toxic shock syndrome is rare. The streptococcus group G strains isolated from this patient did not produce pyrogenic exotoxins. Instead they produced an M-like protein related to group C and G streptococci that do not act as superantigens.

The purine nucleoside adenosine in retinal ischemia-reperfusion injury

Adenosine, an intercellular messenger that is a product of the metabolism of ATP, plays a major role in neuronal and vascular responses of the retina to alterations in oxygen delivery. Significant changes in adenosine concentration have been measured in the retina during both ischemia and during the subsequent reperfusion period which result in important, but complex, functional effects. Adenosine A1 receptor stimulation produces a protective effect during ischemia, whereas overstimulation of the A2a receptor has deleterious effects. The mechanisms underlying these findings have not been completely determined, but most likely are the result of alterations in excitotoxicity, gene expression, and blood flow. Paradoxically, prolonged increases in adenosine concentration may be injurious to the retina, a consequence of superoxide radical formation secondary to adenosine catabolism. Adenosine is a critical mediator of blood flow changes in response to ischemia. It is a significant component of the retina's compensatory hyperemic response to ischemia, hypoxia, and hypoglycemia. Increasing endogenous adenosine concentrations may be useful in ameliorating post-ischemic hypoperfusion. Overall, current evidence suggests that adenosine is a vital component of the endogenous retinal response to substrate deprivation. Additionally, in vitro studies provide strong evidence that adenosine is a mediator of the formation and effects of vascular endothelial growth factor, which in turn promotes neovascularization. Finally, the ability of the retina to develop an ischemia-tolerant state by ischemic preconditioning is an intriguing phenomenon that reveals yet another essential role for adenosine in the retina's endogenous response to ischemia. The experimental results described in this review suggest that continued investigation into the role of adenosine in the retina may lead to important clinical applications for adenosine-based therapies that could decrease the incidence of retinal damage in ischemic vasculopathies such as diabetes, glaucoma, and retinal vascular occlusion.

Carbon nanotube actuators

Electromechanical actuators based on sheets of single-walled carbon nanotubes were shown to generate higher stresses than natural muscle and higher strains than high-modulus ferroelectrics. Like natural muscles, the macroscopic actuators are assemblies of billions of individual nanoscale actuators. The actuation mechanism (quantum chemical-based expansion due to electrochemical double-layer charging) does not require ion intercalation, which limits the life and rate of faradaic conducting polymer actuators. Unlike conventional ferroelectric actuators, low operating voltages of a few volts generate large actuator strains. Predictions based on measurements suggest that actuators using optimized nanotube sheets may eventually provide substantially higher work densities per cycle than any previously known technology.

The neurodevelopmental outcome of term infants with different intrauterine growth characteristics

The objective of this study was to test the hypothesis that neurodevelopmental outcome would differ between two groups of small-for-gestational age infants born at term showing different in utero growth characteristics during the third trimester. The design was a prospective cohort study done at a tertiary referral centre. The 76 subjects who fulfilled the inclusion criteria had an estimated fetal weight below the 10th centile for their gestation. Subsequent to enrolment, repeat ultrasound scans were performed weekly to determine growth velocity. Twenty-three infants whose change in fetal abdominal circumference between first and last scan was greater than -1.5 standard deviation scores (SDS) were assigned to the intrauterine growth retardation group (IUGR) while 53 infants whose fetal abdominal circumference changed less than 1.5 SDS were assigned to the small-for-gestational-age (SGA) group. Ten infants with normal intrauterine growth were enrolled as controls. Following delivery all infants had a neurological examination and a cranial ultrasound scan. At 1 year, 75 infants (87%) were traced and reassessed (49 SGA, 18 IUGR and eight controls) with a neurological examination and a developmental assessment. At birth, impairments were found in 27 (51%) of the SGA, 13 (57%) of the IUGR groups and one (10%) of the controls. At 1 year, 18 (37%) of the SGA subjects, six (33%) of the IUGR subjects and one (13%) of the control infant were impaired, including three (6%) of the SGA subjects and one (6%) of the IUGR subjects who were disabled. We conclude that in term fetuses with an estimated birthweight below the 10th centile for their gestation, the pattern of growth in the third trimester does not affect outcome at 1 year. In spite of optimum obstetric management, nearly one-third of the combined SGA and IUGR term fetuses had suffered some, albeit minor, neurological damage.

Toll homologue expression in the beetle tribolium suggests a different mode of dorsoventral patterning than in drosophila embryos

The gene Toll (Tl) encodes a maternally supplied interleukin 1 receptor-related transmembrane protein, a key component required to establish dorsoventral polarity in the Drosophila embryo. We have isolated Tl homologs of a primitive dipteran, Clogmia albipunctata, and of the beetle Tribolium castaneum. Tribolium Tl protein (Tl) lacks sequences in the C-terminal portion of the cytoplasmic domains that are conserved in the dipteran homologs. The Tl homolog of Tribolium mediates the ventralizing activity when expressed as a gain-of-function variant in transgenic Drosophila, indicating that the sequences conserved in the Diptera are not essential for Tl signaling. In contrast to Drosophila where Tl gene expression occurs maternally and supplies uniformly distributed Tl in the egg membrane, Tl transcripts form a ventral-to-dorsal gradient in the Tribolium blastoderm stage embryo. This localized expression pattern of Tl transcripts, as compared with the strong maternal and ubiquitous expression in Drosophila and Clogmia embryos, suggests that dorsoventral patterning in long-germ band and short-germ band insects involves the same components but different modes of their action.

Retinal ischemic preconditioning in the rat: requirement for adenosine and repetitive induction

PURPOSE

A brief period of ischemia can induce a remarkably complete state of ischemic tolerance in the retina, a phenomenon known as ischemic preconditioning (IPC). The mechanisms of IPC were studied in the rat retina by examining the role of adenosine as a possible mediator and determining whether IPC protection could be induced more than once in the same rat.

METHODS

Retinal ischemia was produced for 60 minutes in ketamine-xylazine-anesthetized Sprague-Dawley rats, and recovery was measured using electroretinography. Twenty-four hours earlier, the IPC stimulus of 5 minutes of ischemia was applied. To test the role of adenosine as a mediator of IPC, the selective adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 0.45 mg/kg, 2.25 mg/kg, or 4.5 mg/kg), the A2a antagonist 8-(3-chlorostyryl)caffeine (CSC; 0.1 mg/kg or 1.0 mg/kg), or their cyclodextrin vehicle were administered 15 minutes before IPC. To examine whether exogenous adenosine administration could mimic IPC, animals received intravitreal injections of the adenosine A1 receptor stimulant adenosine amine congener (ADAC) or the A2a stimulant CGS21680, followed by ischemia 24 hours later. To test the hypothesis that IPC could be induced repeatedly without loss of protection, rats were divided to receive IPC or sham IPC, followed 10 days later by IPC or a sham procedure, and 24 hours later by 60 minutes of ischemia.

RESULTS

Adenosine A1 receptor blockade with 4.5 mg/kg DPCPX administered intraperitoneally (IP) before or immediately after 5 minutes of ischemia completely blocked IPC protection, whereas lower doses resulted in partial blockade. CSC at the lowest dose (0.1 mg/kg) had no significant effect on IPC's protective effect, whereas partial blockade was found with 1.0 mg/kg CSC. A1 or A2a receptor stimulation produced partial but significant mimicking of IPC protection, effects that were antagonized by DPCPX or CSC. Ischemic preconditioning applied twice, separated by 10 days, and followed by 60 minutes of ischemia 24 hours after the second IPC stimulus, resulted in nearly identical recovery of function after ischemia compared with IPC performed one time.

CONCLUSIONS

Adenosine, acting through the A1 and A2a receptors, is a critical component in the induction of ischemic tolerance after preconditioning in the retina. The neuroprotective effects of IPC in the retina are lost over time but may be reinduced by subsequent application of the IPC stimulus.

[Pilot study on early diagnosis of renal cell carcinoma by sonography]

The goal of this study was to investigate the practicability and effectiveness of a systematic screening for renal cell carcinoma by ultrasound in the course of the established German Health Ministry screening programs.

METHODS

In two centers (Mainz and Wuppertal) a screening program for renal cell carcinoma for all citizens (age > 40 years) was established. The screening was divided into two phases (time period 1 year): (1) All citizens over 40 years could attend voluntarily a cost-free ultrasound investigation. (2) A follow-up investigation for the entire screening population was provided.

RESULTS

Ten thousand volunteers attended the screening program. Mean age was 60 years. Thirteen renal cell carcinomas were detected. The incidence of other findings was 15%; none of those required further treatment.

CONCLUSION

Systematic screening for renal cell carcinoma by ultrasound is cost-effective and showed high acceptance and practicability in a German population. The rate of detection of renal cell carcinoma was higher than initially statistically calculated.

Self-administered medication packet for patients experiencing a vaginal birth

A patient satisfaction survey at Missouri Baptist Medical Center revealed that patients experiencing a vaginal delivery needed to wait for their medications and did not consistently receive adequate information about medications. Furthermore, a chart review noted that physicians ordered a wide variety of medications for their patients but that the patients did not always use all their medications. A review of patients' accounts determined that their medications were costly. A multidisciplinary team using the FOCUS-PDCA quality improvement model designed and implemented a self-administered medication packet. Outcomes included continued patient satisfaction with decreases in cost, narcotic use, and medication errors.

LKB1 somatic mutations in sporadic tumors

Germline mutations of LKB1/Peutz-Jeghers syndrome gene predispose carriers to hamartomatous polyposis of the gastrointestinal tract as well as to cancer of different organ systems. Although Peutz-Jeghers syndrome patients frequently present with neoplasms of the colon, stomach, small intestine, pancreas, breast, ovaries, and cervix, somatic mutations appear to be rare in the sporadic tumor types thus far studied (colorectal, gastric, testicular, and breast cancers). To evaluate whether somatic mutations of LKB1 contribute to the tumorigenesis of yet unstudied tumor types, we screened 14 cell lines and 129 tumor specimens from different cancers for a genetic defect in LKB1. Six melanoma and eight myeloma cell lines were scrutinized for LKB1 somatic mutations by genomic sequencing. No changes were found in the coding LKB1 sequence and exon/intron boundaries. Next, we analyzed 12 pancreatic, 8 gastric, 12 ovarian granulosa cell, 26 cervical, 28 lung, 24 soft tissue, and 19 renal tumors by single-strand conformational polymorphism analysis. Three changes in LKB1 coding nucleotide sequence were identified. One base pair deletion at A957 and G958 substitution by T occurred in a cervical adenocarcinoma sample, resulting in a frameshift and premature stop codon at position 335. Substitution of A581 by T occurred in a lung adenocarcinoma sample, resulting in the change of aspartic acid at position 194 to valine. A loss of another allele was detected in this sample. One silent change, C1257T, was found in a pancreatic carcinoma sample. The changes were not present in the matched normal tissue DNA samples. Our results suggest that mutational inactivation of LKB1 is a rare event in most sporadic tumor types.

Binuclear Drosophila oocytes: consequences and implications for dorsal-ventral patterning in oogenesis and embryogenesis

The position of the nucleus along the anterior rim of stage 8 Drosophila oocytes presages the dorsal side of the egg and the developing embryo. In this paper, we address the question of whether the oocyte has a previously determined dorsal side to which the nucleus is drawn, or whether nuclear position randomly determines the dorsal side. To do so, we have taken advantage of a genetic system in which Drosophila oocytes occasionally become binuclear. We find that (i) the two nuclei migrate independently to their respective positions on the anterior rim, sometimes selecting the same site, sometimes not, (ii) the two nuclei are equivalent in their ability to induce a dorsal-ventral pattern in the overlying follicular epithelium, and (iii) at any position around the anterior circumference of the egg chamber the follicle cell sheet is equally responsive to the Gurken signal associated with the oocyte nuclei. These results argue that the dorsal-ventral axis is determined arbitrarily by the randomly selected position of the nucleus on the anterior rim of the oocyte. Some of the binuclear eggs support embryonic development. However, despite the duplication of dorsal chorion structures, the majority of such embryos show normal dorsal-ventral patterning. Thus, processes exist in the ventral follicular epithelium or in the perivitelline space that compensate for the expansion of dorsal follicle cell fates and consequently allow the formation of a normal embryonic axis.

Local Gurken signaling and dynamic MAPK activation during Drosophila oogenesis

During Drosophila melanogaster oogenesis Gurken, a TGF-alpha like protein localized close to the oocyte nucleus, activates the MAPK cascade via the Drosophila EGF receptor (DER). Activation of this pathway induces different cell fates in the overlying follicular epithelium, specifying the two dorsolaterally positioned respiratory appendages and the dorsalmost cells separating them. Signal-associated internalization of Gurken protein into follicle cells demonstrates that the Gurken signal is spatially restricted and of constant intensity during mid-oogenesis. At the same time MAPK activation evolves in a spatially and temporally dynamic way and resolves into a complex pattern that presages the position of the appendages. Therefore, different dorsal follicle cell fates are not determined by a Gurken morphogen gradient. Instead they are specified by secondary signal amplification and refinement processes that integrate the Gurken signal with positive and negative feedback mechanisms generated by target genes of the DER pathway.

The Drosophila gene brinker reveals a novel mechanism of Dpp target gene regulation

decapentaplegic (dpp), a Drosophila member of the TGFbeta family of secreted molecules, functions as a long-range morphogen in patterning of the embryo and the adult appendages. Dpp signals via the SMAD proteins Mad and Medea. Here we show that in the absence of brinker (brk), Mad is not required for the activation of Dpp target genes that depend on low levels of Dpp. brk encodes a novel protein with features of a transcriptional repressor. brk itself is negatively regulated by Dpp. Dpp signaling might relieve brk's repression of low-level target genes either by transcriptional repression of brk or by antagonizing a repressor function of brk at the target gene promoters.

Mutations and impaired function of LKB1 in familial and non-familial Peutz-Jeghers syndrome and a sporadic testicular cancer

Germline mutations in LKB1 have been reported to underlie familial Peutz-Jeghers syndrome (PJS) with intestinal hamartomatous polyps and an elevated risk of various neoplasms. To investigate the prevalence of LKB1 germline mutations in PJS more generally, we studied samples from 33 unrelated PJS patients including eight non-familial sporadic patients, 20 familial patients and five patients with unknown family history. Nineteen germline mutations were identified, 12 (60%) in familial and four (50%) in sporadic cases. LKB1 mutations were not detected in 14 (42%) patients, indicating that the existence of additional minor PJS loci cannot be excluded. LKB1 is predicted to encode a serine/threonine kinase. To demonstrate the putative Lkb1 kinase function and to study the consequences of LKB1 mutations in PJS and sporadic tumors, we have analyzed the kinase activity of wild-type and mutant Lkb1 proteins. Interestingly, while most of the small deletions or missense mutations resulted in loss-of-function alleles, one missense mutation (G163D) previously identified in a sporadic testicular tumor demonstrated severely impaired but detectable kinase activity.

Differing roles of adenosine receptor subtypes in retinal ischemia-reperfusion injury in the rat

Adenosine has been shown to be a major component of the retina's endogenous reaction to ischemia. In earlier studies, the significant changes in adenosine concentration that occur during ischemia and the ensuing reperfusion period were documented. While previous studies have shown that adenosine is a mediator of the changes in blood flow that occur in response to ischemia, hypoxia, and hypoglycemia in the retina, little is known about other functional effects that result from these changes in adenosine concentration. Accordingly, the influence of adenosine receptor blockade on the functional and histological outcome following ischemia in rats was examined. Specific antagonists of the adenosine A1 and A2a receptors were injected systemically, prior to ischemia of either 5, 30, or 60 min. The recovery of the electroretinogram a and b waves was followed for up to 7 days after ischemia, and retinal structure was examined by light microscopy. The adenosine A1 receptor antagonist DPCPX attenuated recovery after retinal ischemia of either 5 or 30 min, while the A2a receptor antagonist CSC dramatically protected retinal function and structure even with ischemia lasting up to 60 min. It was concluded that blockade of the A2a receptor, possibly combined with stimulation of the A1 receptor, may represent a potential new strategy for the prevention of ischemic damage in the retina.

[Regeneration of mouth mucosa in the buccal plane following graft procurement for reconstruction of bulbar urethral stenoses]

The use of free buccal mucosal grafts in the treatment of urethral strictures has become very popular. In 1996 and 1997 we harvested free buccal mucosal grafts up to 7 cm long and 4 cm wide from 12 patients who underwent urologic surgery for urethral strictures. In 2 patients the donor site was closed primarily by sutures. Four patients received Lyodura and another 4 patients received Syspurderm as temporary wound coverage. In 2 patients Ethisorp patches were used. Donor site pain was judged by the patients on a visual analogue scale during the first postoperative week. The 2 patients who received the Ethisorp patches complained of more intense pain, probably caused by the rigidity of the material. In all patients regeneration of the donor site mucosa was good. During the follow-up period of 4-18 months scar formation at the lower vestibulum was noticed as the only complication. Permanent limitation of mouth opening, stenosis of the parotid duct or hypesthesia did not occur.

Drosophila development: the secrets of delayed induction

Dorsoventral axis formation in Drosophila relies on extracellular signals which are generated only at the ventral side of the egg. This asymmetry, in turn, depends on the expression specifically in ventral follicle cells of pipe, the product of which seems likely to be a glycosaminoglycan-modifying enzyme.

Expression of different isoforms of TGF-beta and the latent TGF-beta binding protein (LTBP) by rat Kupffer cells

BACKGROUND/AIMS

Kupffer cells (liver resident macrophages) make an important contribution to the perpetuation of liver diseases by synthesis and secretion of TGF-beta. In some cell types TGF-beta, is expressed as a large latent complex containing the latent TGF-beta binding protein (LTBP) in addition to the N-terminal TGF-beta precursor (latency associated peptide). This study aimed to identify LTBP expression in rat Kupffer cells.

METHODS

Cells were isolated from rat liver by collagenase-pronase reperfusion, purified and cultured under standard conditions. TGF-beta and LTBP expression were characterized using alkaline phosphatase-anti-alkaline phosphatase immunostainings, reverse transcription-polymerase chain reaction and immunoprecipitation of metabolically labeled proteins.

RESULTS

Immunostainings of Kupffer cells with anti-sera against LTBP-1 (ab 39) and LTBP-2 indicated the expression of both LTBP isoforms in addition to the expression of latency associated peptide and TGF-beta. Transcripts of three LTBP isoforms (LTBP-1,-2,-3) and TGF-beta isoforms (TGF-beta-1,-2,-3) were detectable by reverse transcription-polymerase chain reaction. The LTBP-1D splice variant missing a part of the proteinase sensitive hinge region which has recently been described in hepatic stellate cells is expressed in Kupffer cells, too. Metabolic labeling of Kupffer cells with [35S]-Met/Cys followed by immunoprecipitation of the conditioned media using antisera against LTBP-1 and LTBP-2 indicated the secretion of high molecular mass TGF-beta complexes containing LTBP proteins of 230 and 170 kDa (LTBP-1) or 230 kDa (LTBP-2).

CONCLUSION

The results show that Kupffer cells partly synthesize and release TGF-beta as large latent complexes. This requires the extracellular activation of TGF-beta as a prerequisite for receptor binding and cellular signaling.

A surgical technique combining continent cutaneous urinary diversion and complete ileal ureteral replacement

PURPOSE

Defects of the entire urinary tract are sometimes so extensive that a colonic conduit appears to be the only viable therapeutic option. However, if an incontinent diversion is unacceptable, an alternative must be found.

MATERIALS AND METHODS

We report on a new technique for achieving a continent diversion in which ileocecal intestinal segments are used as a continent reservoir and substitute for both ureters.

RESULTS

At 2-year followup excellent results were achieved in terms of renal function, continence and quality of life as confirmed by symptomatic evaluation and radiographic investigations.

CONCLUSIONS

We demonstrate the feasibility of reconstruction of the entire urinary tract with a continent reservoir using intestinal segments with a pure colonic pouch and prevalvular ileal segment as a substitute for both ureters.

Simultaneous continuous measurement of pO2, pCO2, pH and temperature in brain tissue and sagittal sinus in a porcine model

INTRODUCTION

The clinical use of brain tissue oxygen measurement in patients with severe head injury is increasing. It is important to compare the findings in brain tissue with cerebrovenous blood oximetry, to obtain normal values and to find out limitations of the method. We evaluated a newly available multisensor probe simultaneously in the brain tissue and in the sagittal sinus in a porcine animal model.

METHODS

We placed the Paratrend 7-probe (BSL, High Wycombe, UK) in the left frontoparietal white matter and measured pO2 (PtiO2), pCO2 (ptiCO2), pH and temperature while simultaneously measuring these parameters (pcvO2, pcvCO2) in the sagittal sinus in 7 pigs under general anaesthesia during oxygen enhancement.

RESULTS

The relation between oxygen increase in brain tissue and in the sagittal sinus showed a coefficient of correlation (CCmean) rmean = 0.96. The quantitative response in brain tissue was much more sensitive than in the sinus. A close correlation between pCO2 in brain tissue and sagittal sinus and the increase of the inspired oxygen was seen: CC ptiCO2 to arterial oxygen pressure (paO2) - rmean = 0.67, CC pcvCO2 to paO2 - rmean = 0.88.

CONCLUSIONS

Measuring partial oxygen pressure in brain tissue is more responsive to physiological variations, and the absolute values are more sensitive than oxygen measurement in the cerebrovenous compartment. This is important for interpreting measured values and introducing new coefficients for patient monitoring.

The role of the p53 protein in the selective vulnerability of the inner retina to transient ischemia

PURPOSE

To determine whether the p53 protein plays a role in the selective vulnerability of the inner retina to transient ischemia.

METHODS

Transient retinal ischemia was induced using a high intraocular pressure (HIOP) model in the Sprague-Dawley rat for 60 minutes. Histopathologic outcome was determined 7 days after ischemia. In addition, analysis for evidence for apoptosis (TdT-dUTP terminal nick-end label [TUNEL] staining) and p53 protein expression (immunohistochemistry) was performed at several points during the reperfusion period. In a separate set of experiments, wild-type mice and two groups of transgenic mice, one homozygous and the other heterozygous for the p53 null gene, were also subjected to HIOP for 60 minutes, and histopathology was performed 7 days later.

RESULTS

At 7 days subsequent to 60 minutes of ischemia in the rat, there was marked thinning of the inner retinal layers. There were scattered TUNEL-positive cells within the inner retina, peaking at 24 to 48 hours and persisting for at least 7 days. p53 immunochemistry demonstrated elevated protein levels within the inner retina; this finding peaked at 24 to 48 hours but was no longer present at 4 days after ischemia. TUNEL staining of the inner retina of the mouse was most prominent 24 hours subsequent to ischemia but persisted at 48 hours. Seven days subsequent to 60 minutes of ischemia in the wild-type and transgenic mice, histopathologic evaluation demonstrated preservation of the retinal histoarchitecture in the heterozygous group compared with the wild-type or homozygous animals.

CONCLUSIONS

These data further support the hypothesis that the delayed cell death that occurs after transient retinal ischemia is, in part, apoptotic. In addition, they suggest a role for the p53 protein in the selective vulnerability of the inner retina to transient ischemia. p53 protein may be a target for future therapeutic agents in the treatment of disorders of the retina where ischemia plays a pathogenetic role.

Transformation-dependent susceptibility of rat hepatic stellate cells to apoptosis induced by soluble Fas ligand

Cytokine-driven activation of hepatic stellate cells (HSC) in tissue injury and inflammation is a key pathogenetic event in liver fibrogenesis leading to an expanded pool of matrix producing myofibroblasts (MFB) which represent the transformed counterpart of HSC. We hypothesize that expansion of the pool of MFB might also be accomplished by modulation of apoptosis, which plays an opposite and complementary role to mitosis in the cellular homeostasis. We characterized the susceptibility of HSC in primary culture and of MFB in secondary culture to apoptosis induced by the soluble Fas ligand (sFasL) and related the effects to the expression levels of Fas (APO-1/CD95) and some major proapoptotic and contra-apoptotic protooncogenes. MFB showed a dose-dependent apoptotic reaction upon exposure to sFasL as evidenced by a strong increase of nucleosomal DNA fragments, loss of cellular DNA, positive TUNEL reaction, and annexin staining. The effect was found only if protein synthesis (cycloheximide) or RNA synthesis (actinomycin D) were arrested. HSC maintained for various times in primary culture were completely resistant to sFasL in combination with cycloheximide, but in late primary cultures (day 7 onward) an increasing susceptibility to sFasL-mediated apoptosis was developed. By semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis and alkaline phosphatase-anti-alkaline phosphatase staining Fas receptor was identified both in HSC and MFB at comparable expression levels. The expression of the contra-apoptotic protooncogenes bcl-2 and bcl-xl was found to be much stronger in early HSC than in late HSC and MFB as shown by ribonuclease protection assay. The expression of bcl-2 was additionally confirmed by semiquantitative RT-PCR and immunoblotting. Proapoptotic bax was found in comparable quantities at the RNA level in HSC and MFB but at the protein level MFB showed increased bax expression. It is concluded that transformation of HSC to MFB is paralleled by an increasing sensitivity to sFasL-mediated apoptosis, which might be related to a strong decrease of bcl-2 and bcl-xl expression, leading to a preponderance of proapoptotic gene expression in MFB. Modulation of apoptotic susceptibility of transforming HSC could be an important complementary pathway in the pathogenesis of fibrosis.