[Supraventricular arrhythmia after pneumonectomy. Apropos of 100 cases and review of the literature]

Supraventricular arrhythmias are frequently observed in pneumonectomy surgery. We retrospectively studied a series of 100 consecutive patients undergoing pneumonectomy for cancer between 1994 and 1996. We found 24% of significant supraventricular arrhythmias, corresponding to atrial fibrillation in 75% of cases, occurring in 80% of cases until the third postoperative day. The only risk factor significantly associated with these arrhythmias was the patient's age. These arrhythmias are easily reduced, spontaneously in 25% of cases, and usually by amiodarone, alone or associated with digitalis alkaloids. While the mortality of the overall group was 12%, 8% of patients with arrythmia died. These deaths concerned patients whose arrythmias occurred after the fourth postoperative day in a context of a pulmonary infection.

[Halicephalobus (Syn. Micronema) deletrix as a cause of granulomatous gingivitis and osteomyelitis in a horse]

Therapy resistant swellings of the maxillary region and unilateral nasal discharge in older horses are mainly thought to be consequences of neoplasias of the oral cavity, especially of the gingiva and the teeth, or to develop from tumours of the nasal cavity. We report an unilateral swelling of the left nasal and buccal region in a 13-year-old gelding, which was accompanied by an aggressive destruction of involved osseous tissue due to a severe proliferative granulomatous inflammation. The granuloma was caused by the nematode Halicephalobus (syn. Micronema) deletrix. This nematode infection is known for over 30 years, even though the here reported form is uncommon and rarely diagnosed. However, this report shows that even in cases of unilateral maxillary swellings in horses a granulomatous inflammation due to nematodiasis should be considered as an additional differential diagnosis.

High-resolution emboli detection and differentiation by characteristic postembolic spectral patterns

BACKGROUND AND PURPOSE

High-intensity transient signals (HITS) detected by transcranial Doppler ultrasonography correspond to microemboli in intracranial arteries. The purpose of this study was to develop new diagnostic criteria for the differentiation of these microembolic signals from artifact, based on a high-resolution analysis of Doppler power spectra in an in vitro model.

METHODS

Two hundred seventy-six formed emboli, consisting of different biological and nonbiological materials and as air bubbles, were injected into a flow phantom with artificial blood vessels and perfused in a steady or a pulsatile way. Embolic passage was assessed with a modified 2.5-MHz pulsed Duplex machine and a commercial 2-MHz Doppler system. Embolic HITS were analyzed using internationally accepted criteria for the audiovisual characteristics of HITS. Doppler spectra changes associated with HITS were evaluated by means of a specially developed high-resolution analysis of Doppler raw data.

RESULTS

Seventy-seven percent of all embolic events could be identified using conventional audiovisual criteria for embolic HITS. Analysis of Doppler spectra showed that all injected emboli generated high-amplitude signals with a minimum of at least 3 dB above background level. In addition, using high-resolution processing, specific changes in Doppler spectral patterns could be identified after all embolic HITS caused by solid particles. These postembolic spectral patterns were always characterized by a Doppler frequency shift decreasing in time and resembling the letter lambda (lambda). Duration and appearance of the postembolic spectral patterns were mainly influenced by the size and velocity of the embolus. Similar phenomena could not be found in case of embolism by either small air bubbles or in case of provoked artifact registration. Using a commercial Doppler system specific, we documented postembolic spectral patterns in 47% of injected emboli.

CONCLUSIONS

In this study, highly specific changes in Doppler spectral patterns associated with microembolic HITS could be characterized, resulting in further criteria for the differentiation between microembolic signals and artifact in Doppler emboli detection. The sensitivity of the detection of these signals can be increased by high-resolution analysis of raw Doppler data.

Cancer chemoprevention: some complications and limitations

Chemopreventive strategies are very attractive and have earned serious consideration as a potential means of controlling cancer incidence. However, the use of some anti-initiating entities (enzyme inducers or inhibitors) devised to reduce tumor initiation is controversial. Indeed, considering the double-edged-sword (activating or detoxifying) nature of drug metabolizing enzymes, any attempt to modulate such catalysts by dietary components (including drugs) may lead to cancer risk.

From differentiation to proliferation: the secretory amyloid precursor protein as a local mediator of growth in thyroid epithelial cells

In various species, thyrotropin (TSH) is known to stimulate both differentiation and proliferation of thyroid follicle cells. This cell type has also been shown to express members of the Alzheimer amyloid precursor (APP) protein family and to release the secretory N-terminal domain of APP (sAPP) in a TSH-dependent fashion. In this study on binding to the cell surfaces, exogenously added recombinant sAPP stimulated phosphorylation mediated by mitogen-activated protein kinase and effectively evoked proliferation in the rat thyroid epithelial cell line FRTL-5. To see whether this proliverative effect of sAPP is of physiological relevance, we used antisense techniques to selectively inhibit the expression of APP and the proteolytic release of sAPP by cells grown in the presence of TSH. The antisense-induced inhibition was detected by immunoblot, immunoprecipitation, and immunocytochemical analyses. After the reduced APP expression and sAPP secretion, we observed a strong suppression of the TSH-induced cell proliferation down to 35%. Recombinant sAPP but not TSH was able to overcome this antisense effect and to completely restore cell proliferation, indicating that sAPP acts downstream of TSH, in that it is released from thyroid epithelial cells during TSH-induced differentiation. We propose that sAPP operates as an autocrine growth factor mediating the proliferative effect of TSH on neighboring thyroid epithelial cells.

Intraoperative high dose rate brachytherapy in recurrent or metastatic colorectal carcinoma

BACKGROUND

The survival of patients with recurrent or metastatic colorectal cancer usually is less than 12 months. In an attempt to improve this dismal prognosis, we investigated the role of intraoperative high dose rate brachytherapy (IOHDR) in the management of these patients.

METHODS

From April 1992 to December 1996, 26 patients with locally recurrent or metastatic colorectal carcinoma were treated with maximal surgical resection and IOHDR. Intraoperative radiation dose ranged from 10 to 20 Gy, prescribed at 0.5 cm depth. The residual tumor irradiated was microscopic in 16 patients (62%) and gross residual in 10 patients (38%). Six patients received postoperative external beam radiation therapy.

RESULTS

After a median follow-up of 28 months (range 6 to 54 months), seven of 15 evaluable patients (47%) failed in the area treated with IOHDR. The median time to local failure was 21 months (range 4 to 52 months). The median survival was 23 months (microscopic 24 months; gross 17 months), with a 4-year actuarial survival rate of 36%. Major morbidity was observed in 7 patients (47%) and usually was surgery-related.

CONCLUSION

The use of IOHDR in association with radical resection increases local control in patients with recurrent or metastatic colorectal cancer. Patients with microscopic residual disease achieved a better result than do those with gross residual disease. Future strategies include the addition of limited EBRT dose to IOHDR, even for previously irradiated patients.

Adenosine kinase inhibitor GP515 attenuates hepatic leukocyte adhesion after hemorrhagic hypotension

Adhesion of leukocytes to the vascular endothelium hallmarks a key event in neutrophil-mediated organ injury after ischemia-reperfusion. The autacoid adenosine has been shown to inhibit activated neutrophil function and to interfere with leukocyte-endothelial adherence. Its therapeutic use in ischemia-reperfusion, however, has been limited by severe cardiovascular side effects. We therefore investigated the effects of the adenosine kinase inhibitor GP515 in vivo on hepatic leukocyte-endothelial interactions in a rat model of hemorrhagic hypotension and resuscitation, using intravital microscopy. Rats were pretreated with either GP515 (0.25 mg/kg) or saline in a randomized and blinded manner and subjected to pressure-controlled hemorrhagic hypotension at a mean arterial pressure of 40 mmHg for 60 min followed by 5 h of resuscitation. Five hours after resuscitation in saline-treated animals, firm leukocyte-sinusoidal adhesion was strongly enhanced in the periportal and midzonal sublobular regions, and sinusoidal diameters were also markedly reduced. Compared with saline treatment, GP515 significantly attenuated shock and resuscitation-induced leukocyte adhesion in both sublobular regions. Moreover, although GP515 did not significantly affect macrohemodynamical and hematological parameters, it enlarged narrowed sinusoidal diameters and tended to improve sinusoidal blood flow. We propose that the adenosine-regulating agent GP515 has a therapeutic potential to attenuate ischemia-reperfusion-induced inflammation by capitalizing on the beneficial anti-inflammatory effects of endogenous adenosine.

Role of nitric oxide in the regulation of the hepatic microcirculation in vivo

BACKGROUND/AIMS

Nitric oxide (NO) is an important mediator in the regulation of vascular tone. However, no data exist on the physiological role of NO in the regulation of the hepatic microcirculation. This study was designed to evaluate the role of NO in the hepatic microcirculation in vivo under physiological conditions.

METHODS

The hepatic microcirculation was investigated in anesthetized rats by intravital fluorescence microscopy after injection of fluorescein-isothiocyanate-labeled erythrocytes. Following assessment of baseline sinusoidal perfusion, animals were randomly treated with L-NMMA (n=6), L-arginine (n=6), nitroprusside sodium (NPS, n=5) or a comparable volume of NaCl (n=4). Drugs were given through a portal vein catheter at three doses (Dx), each followed by intravital microscopy. L-NMMA was given: 5 mg/kg (D1), 25 mg/kg (D2), 50 mg/kg (D3); L-arginine 30 mg/kg (D1), 150 mg/kg (D2), 300 mg/kg (D3); and NPS continuously 80 microg x kg(-1) x h(-1).

RESULTS

L-NMMA induced a significant increase of mean arterial blood pressure (MAP) (114 vs. 129 mm Hg; p<0.05). In contrast, MAP of NPS-treated animals decreased (107 vs. 91 mm Hg; p<0.01) whereas MAP of animals receiving L-arginine did not significantly differ. Sinusoidal blood flow revealed dose-dependent changes: L-NMMA significantly decreased perfusion of sinusoids (D1: 65%, D2: 57%, D3: 50% of baseline, p<0.05). Injection of L-arginine increased the sinusoidal flow even with the lowest dose (D1: 137%, D2: 133%, D3: 123%, p<0.05). Continuous infusion of NPS had little effect on sinusoidal blood flow at the first and second times of microscopy but sinusoidal blood flow was significantly increased at the third time (D1: 103%, D2: 106%, D3: 122%).

CONCLUSIONS

Inhibition of NOS results in a dose-dependent disturbance of the hepatic microcirculation despite significantly increased MAP, whereas L-arginine increases the sinusoidal blood flow. The results indicate an important role for NO in the regulatory mechanisms of hepatic sinusoidal perfusion under physiological conditions.

Pathways of Fos expression in locus ceruleus, dorsal vagal complex, and PVN in response to intestinal lipid

Exogenous cholecystokinin (CCK) injected peripherally mimics effects of lipid entering the intestine on food intake and gastric motility via vagal afferents and induces c-fos expression in the locus ceruleus complex (LCC), nucleus of the solitary tract (NTS), area postrema (AP), and paraventricular nucleus (PVN). However, the role of peripheral endogenous CCK in induction of c-fos expression in the brain at ingestion of nutrients is controversial. In awake rats, intraduodenal lipid infusion markedly increased Fos protein-like immunoreactivity (FLI) in these brain nuclei. Perivagal capsaicin pretreatment reduced the increase of FLI in the LCC, NTS, and PVN by 66-86% and in the AP by 46%. The CCK-A receptor antagonist MK-329 (0.1 mg/kg i.p.) diminished the FLI increase in LC, NTS, AP, and PVN by 39-100%; the CCK-B receptor antagonist L-365,260 reduced the increased FLI in the AP by 54%. After capsaicin pretreatment, both CCK antagonists had additional inhibitory effects only on FLI in the AP. These findings suggest that entry of lipid into the intestine activates c-fos in the LCC, NTS, and PVN predominantly via CCK-A receptors on vagal afferents and in the AP via vagal and nonvagal pathways, as well as CCK-B and CCK-A receptors.

Bridged cobalt amine complexes induce DNA conformational changes effectively

Cobalt(III) hexaamine ion [Co(NH3)6]3+ is known to facilitate the transition of B- to Z-DNA or B- to A-DNA depending on the DNA sequences. Specific interactions are found between the amines of [Co(NH3)6]3+ and DNA atoms of A-DNA or Z-DNA. Bridged Co(III)pentaamine complexes, with multiple amine groups arranged in a rigid framework, may enhance the effectiveness of the conformational transition by occupying simultaneously two of the Co(III) hexaamine binding sites. Therefore, the imidazole-bridged Co(III)pentaamine complexes have been synthesized and their interactions with DNA oligonucleotides investigated by circular dichroism (CD) and NMR spectroscopy. CD studies of the titrations of d(A2C15G15T2) with [(NH3)5Co(Im)Co(NH3)5]Br5 and [(NH3)5Co(Im)2Co(NH3)4]Br7 showed that the former metal compound indeed is more effective than [Co(NH3)6]3+ in inducing the transition from B- to A-DNA. The conversion of B- to A-DNA was also supported by one- and two-dimensional NMR studies. Similarly for the titrations of poly(dC-dG). poly(dC-dG) and d(m5C-G)15 with these two bridged Co(III) complexes, efficient induction of Z-DNA was observed. Our studies suggest that bridged Co(III)pentaamine complexes may be useful agents for studying nucleic acid structures.

Out of balance: consequences of a partial keratin 10 knockout

Recently we generated keratin 10 knockout mice which provided a valuable model for the dominantly inherited skin disorder epidermolytic hyperkeratosis. Here we investigated the molecular basis for their phenotype. Hetero- and homozygotes expressed a truncated keratin 10 peptide which has been identified directly by microsequencing. Epitope mapping of monoclonal antibodies to keratin 10T enabled us to study its distribution relative to keratin 6, which is highly expressed in keratin 10 knockout mice, by double-immunogold electron microscopy. This revealed that keratin 10T was restricted to complexes with keratin 1 but did not mix with keratin 6. The latter did not form extended filaments with keratins 16/17 but aggregates. Keratins 6/16 were unable to compensate for the lack of normal keratin 1/10 filaments. Remarkably keratin 6 aggregates strictly colocalized with keratohyalin granules. Residual keratin 1/10T clumps were located in the cell periphery and at desmosomes which maintained a normal architecture. Surprisingly keratin 2e, a keratin tailored to sustain mechanical stress, was completely lost in paw sole epidermis of homozygous keratin 10 knockout mice, pointing to keratin 10 as its partner. The selective pairing of keratin 10T and the loss of keratin 2e indicate that in vivo keratins are less promiscuous than in vitro. Skin fragility in keratin 10 knockout mice and in epidermolytic hyperkeratosis is probably the consequence of two complementing mechanisms namely a decrease of normal keratin 1/10 filaments and an increase in keratins 6/16 with a poor filament-forming capacity.

Innovation in the management of soft tissue sarcomas in infants and young children: high-dose-rate brachytherapy

PURPOSE

Conventional low-dose-rate (LDR) brachytherapy is effective in treating childhood sarcomas, but often not practical (due to the associated radiation hazards) in the young children who require continuous observation and sedation. Fractionated high-dose-rate brachytherapy (HDR) was used to deliver adequate tumoricidal radiation while preserving bone and organ growth in children.

MATERIALS AND METHODS

Twelve children with diverse sarcomas were treated with fractionated HDR. The median age at diagnosis was 18 months (range, 1 to 42). Nine patients had rhabdomyosarcoma and three had other soft tissue sarcoma (STS) variants. Ten patients had microscopic residual disease at the time of brachytherapy. All patients were treated with appropriate chemotherapy and surgery. HDR was delivered in 3-Gy fractions twice a day to a total dose of 36 Gy in 8 days. External-beam radiation therapy (EBRT) was avoided. Patients were monitored for a median of 61 months (range, 30 to 78).

RESULTS

One patient developed local recurrence and distant metastases to the lungs. The 6-year actuarial local control and overall survival rates were 91% and 81%, respectively. Brachytherapy-related morbidity occurred in 50% of patients. The morbidity was mild to moderate in 42% of patients and consisted primarily of acute skin and mucosal reaction. One patient experienced severe (grade III to IV) toxicity. Another child, treated to the tongue, had delayed dentition only in the teeth adjacent to the brachytherapy site. The other children have exhibited only minimal or none of the bone growth retardation expected with EBRT.

CONCLUSION

The combination of conservative surgery, chemotherapy, and exclusive HDR to postchemotherapy tumor volume with a modest margin, avoiding EBRT, provided disease control in carefully selected young children, while preserving bone growth and organ function. The short duration of therapy and small volume irradiated allowed chemotherapy to be resumed shortly after brachytherapy. The use of HDR challenges the present philosophy of radiotherapy treatment volume, which holds that the prechemotherapy tumor volume should be treated with an acceptable margin. Brachytherapy should be included in multicentric clinical trials in young children.

Modification of hypothalamic-pituitary-adrenocortical activity by serotonergic agents in the rat

The effects of tandospirone, enciprazine, gepirone, buspirone (5-HT1A agents) and carvotroline (5-HT2) on hypothalamic-pituitary-adrenocortical activity (HPA) activity were studied. These drugs increased the plasma corticosterone levels in a dose-dependent manner. Their ED50 values were 3.8, 31.8, 3.1, 3.4 and 7.0 mg/kg, respectively. Drug effects peaked between 30 min and 1 h, and plasma corticosterone levels returned to control levels after 2 h. When the drugs were given in conjunction with a rotatory stress, gepirone and enciprazine increased and carvotroline decreased plasma corticosterone levels. Dexamethasone (0.1 mg/kg) pretreatment reduced drug-activated HPA axis activity.

Recombinant N-terminal fragment of bactericidal/permeability increasing protein (rBPI21) prevents shock-induced microcirculatory alterations in the liver

OBJECTIVE

To investigate the effects of the recombinant 21-kilodalton N-terminal fragment of recombinant bactericidal and permeability increasing protein (rBPI21) on leukocyte adhesion and the hepatic microcirculation after hemorrhagic shock.

DESIGN

Prospective, randomized, blinded, and placebo-controlled experimental study.

SETTING

University research laboratory.

SUBJECTS

Anesthetized Sprague-Dawley rats, weighing 220 to 250 g.

INTERVENTIONS

Rats were subjected to 60 mins of hemorrhagic shock and subsequent resuscitation to sufficiently restore systemic circulation. The microcirculation of the liver was investigated by intravital fluorescence microscopy 5 hrs after hemorrhagic shock. Four shock groups were compared with a sham-control group. Shock groups received either rBPI21 (10 mg/kg) or placebo either before or after shock period.

MEASUREMENTS AND MAIN RESULTS

No differences were observed in hemodynamic, respiratory, or metabolic parameters between the shock groups. However, the hepatic microcirculation showed severe deterioration 5 hrs after shock, indicated by significantly narrowed sinusoids in all shock groups compared with controls (8.5 +/- 0.3 microm vs. 10.0 +/- 0.4 pm). Leukocyte adhesion was markedly increased to comparable values in both placebo groups (619 cells/mm2 and 644 cells/mm2; sham, 168 cells/mm2). Neutralization of endotoxin by administration of rBPI21 before or after shock resulted in plain reduction of pathologic leukocyte-endothelial interaction (138 cells/mm2 and 85 cells/mm2).

CONCLUSION

The results support the hypothesis that endotoxin induces microcirculatory alterations after shock, and further suggest a potentially beneficial role of rBPI21 in the treatment of posttraumatic endotoxin-induced inflammatory reactions.

In vivo effects of halothane, enflurane, and isoflurane on hepatic sinusoidal microcirculation

BACKGROUND

It has been proposed that halogenated anaesthetics interfere with the endothelium-dependent circulatory control by attenuating the effects of endothelium-derived relaxing factor (EDRF/NO). This study was designed to determine whether or not volatile anaesthetics in vivo influence the microvascular tone in hepatic sinusoids.

METHODS

Using epifluorescence videomicroscopy, we compared the effects of the volatile anaesthetics halothane, enflurane, and isoflurane on hepatic microcirculation halothane, enflurane, and Animals were initially anaesthetized with pentobarbitone (50 mg.kg-1 i.p.) to allow instrumentation and laparotomy and were randomly allocated to one of 4 groups (n = 5-6 each) to receive either a supplementary dose of i.v. pentobarbitone (25 mg.kg-1; control group) or 0.75 MAC halothane, enflurane or isoflurane (1.5 MAC.h).

RESULTS

Halothane decreased significantly the volumetric blood flow as compared with isoflurane (P < 0.05) or pentobarbitone controls (P < 0.05). The decrease in sinusoidal blood flow caused by halothane was largely attributable to a decrease in sinusoidal diameter (P < 0.05), while red blood cells velocity remained unchanged. Isoflurane led to a significant decrease in sinusoidal width compared with controls (P < 0.05) but an increase in red cell velocity offset the effect of sinusoidal narrowing of volumetric blood flow, while enflurane had no significant effect on any of the measured parameters.

CONCLUSION

This study provides the first direct evidence that the volatile anaesthetics halothane and isoflurane in vivo shift the hepatic microvascular tone toward a more constricted state; however, flow velocity is enhanced with isoflurane, offsetting this effect. As a result the volumetric flow is at least affected by isoflurane, then enflurane and most significantly by halothane. Furthermore, our data are consistent with the concept that volatile anaesthetics in clinically relevant concentrations may influence the balance between endothelium-derived vasoactive factors which control microvascular tone.

1H NMR analysis of novel sialylated and fucosylated lactose-based oligosaccharides having linear GlcNAc(beta 1-6) Gal and Neu5Ac(alpha 2-6) GlcNAc sequences

Three novel oligosaccharides of human infant faeces have been fully characterised by methylation analysis and 500/600 MHz 1H NMR spectroscopy including DQF-COSY, TQF-COSY, TOCSY and ROESY experiments. The oligosaccharides were shown to be lactose-based structures two of which were substituted at C-6 of Gal with either the Le(x) trisaccharide, Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-, or Neu5Ac(alpha 2-6)Gal(beta 1-4)GlcNAc(beta 1-. They differ from other free oligosaccharides previously isolated from the human by having the (1-->6) linkage to Gal in the absence of a (1-->3) branch. The third oligosaccharide has Neu5Ac(alpha 2-6) linked to GlcNAc of the trisaccharide GlcNAc(beta 1-3)Gal(beta 1-4)Glc. This is a linear fragment of the disialylated tetrasaccharide sequence Neu5Ac(alpha 2-3)Gal(beta 1-3)[Neu5Ac(alpha 2-6)]GlcNAc(beta 1-found in the milk oligosaccharide disialyl LNT (the GlcNAc residue of the tetrasaccharide linked to lactose) and also of N-linked chains (GlcNAc linked to Man).

Field evaluation of a fenbendazole slow release bolus in the control of nematode infections in first-season cattle

The efficacy of a fenbendazole slow release bolus in controlling nematode infections of first-season cattle was evaluated in a field study in northern Germany. Two groups, each of 11 male calves, were set-stocked on separate pastures from May until October 1989 (157 days). The animals of one group were given the bolus at turnout and the animals of the control group were treated with fenbendazole (7.5 mg/kg bodyweight) eight weeks after turnout. Clinical inspections and measurements of faecal egg and larval counts, herbage trichostrongyle larval counts, plasma pepsinogen concentrations and bodyweight were made throughout the study. All the animals were slaughtered for worm counts and the evaluation of carcase quality two weeks after housing. The pasture grazed by the control group showed a marked increase in trichostrongyle larvae from late August onwards and, as a result, the control calves had increasing faecal egg counts and increased plasma pepsinogen concentrations in the latter part of the grazing season, although no clinical signs of parasitic gastroenteritis were apparent. The fenbendazole slow release bolus suppressed the trichostrongyle infections during the grazing season, and larval counts on the pasture grazed by the bolus-treated group remained low throughout the study. Postmortem examination showed that the bolus-treated calves harboured significantly (P < 0.01) fewer trichostrongyle worms, including inhibited stages, than the controls. Because of an inadequate lungworm challenge during the grazing season it was not possible to evaluate the efficacy of the fenbendazole slow release bolus in preventing parasitic bronchitis. At slaughter, the bolus-treated animals weighed more than the controls and tended to have a better carcase quality.

[Organ specific expression pattern of a carbon monoxide generating stress protein (hemoxygenase-1/heatshock protein 32) following hemorrhagic shock]

OBJECTIVE

Recent evidence suggests a possible role for Haeme oxygenase (HO)-derived carbon monoxide (CO) in the regulation of vascular tone through elevation of cyclic 3'-5' guanosine monophosphate (cGMP). Previous work from our laboratory has shown that blockade of the HO pathway by tin-protoporphyrin-IX (SnPP) after resuscitation from hemorrhage leads to a specific and profound increase in portal resistance while neither systemic nor hepatic arterial resistance are affected. We therefore investigated the organ-specific expression pattern of the stress-inducible protein haeme oxygenase-1/heat shock protein 32 after haemorrhage and resuscitation.

MATERIALS AND METHODS

After approval of the protocol by the local review board, male Sprague-Dawley rats (n = 6/group) were anaesthetised with pentobarbitone, instrumented for assessment of central haemodynamics and subjected to haemorrhagic hypotension (40 mm Hg for 1 h) followed by resuscitation with 60% shed blood and Ringer's solution or a time-matched sham protocol. Samples of liver, spleen, kidney intestine, aorta, and lungs were harvested 5 h after the onset of resuscitation and subjected to Western-blot analysis using a specific anti-rat HO-1/hsp 32 antibody (StressGen, Sidney, Canada).

RESULTS

Resuscitation with shed blood/Ringer's solution restored central haemodynamics and acid-base status while significant haemodilution was observed. Haemorrhage and resuscitation led to strong induction of HO-1 in the liver and slight induction in aortic tissue, while no increase in steady-state protein levels was observed in the other organs studied.

CONCLUSION

These results suggest a specific contribution of the HO/CO pathway to maintenance of low hepatic portal resistance in vivo in a clinically relevant model of haemorrhagic shock and adequate resuscitation.

Endothelin-1 transgenic mice develop glomerulosclerosis, interstitial fibrosis, and renal cysts but not hypertension

The human endothelin-1 (ET-1) gene under the control of its natural promoter was transferred into the germline of mice. The transgene was expressed predominantly in the brain, lung, and kidney. Transgene expression was associated with a pathological phenotype manifested by signs such as age-dependent development of renal cysts, interstitial fibrosis of the kidneys, and glomerulosclerosis leading to a progressive decrease in glomerular filtration rate. This pathology developed in spite of only slightly elevated plasma and tissue ET-1 concentrations. Blood pressure was not affected even after the development of an impaired glomerular filtration rate. Therefore, these transgenic lines provide a new blood pressure-independent animal model of ET-1-induced renal pathology leading to renal fibrosis and fatal kidney disease.

The paracrine endothelin system: pathophysiology and implications in clinical medicine

Apart from the initially described vasoconstriction, endothelins have been shown to cause a variety of biological activities in non-vascular tissues. A rapidly growing body of data supports the concept of endothelin as a paracrine acting hormone. In this review, we will discuss the impact of this local endothelin system for various cardiovascular pathophysiological states, especially atherosclerotic vascular disease, restenosis, myocardial infarction, congestive heart failure, and arterial hypertension. In addition, the endothelin system is a modulator of renal function via its binding to abundant receptors in renal tissue and by the ability of renal endothelial and epithelial cells to synthesize and release endothelin. In the kidney, endothelin may function as a paracrine/autocrine factor in the regulation of renal blood flow, glomerular haemodynamics, and sodium and water homeostasis. The renal endothelin system is involved in kidney diseases such as impaired renal function in liver cirrhosis, cyclosporin toxicity, acute renal failure and renal glomerular and interstitial fibrosis. Therapeutic approaches with new orally active endothelin receptor antagonists are also discussed.

Detection of erythropoietin in human liquor: intrinsic erythropoietin production in the brain

Until now, erythropoietin (EPO) was thought to be produced exclusively in fetal liver and adult kidney and to regulate mammalian erythropoiesis. However, we recently showed that steady state levels of EPO mRNA could be induced up to 100-fold in primary mouse astrocytes cultured under hypoxic conditions, and also reported the presence of mRNA for EPO and its receptor in the brain of mouse, monkey and human. In extending these studies on humans we now show that immunoreactive EPO is present in ventricular cerebrospinal fluid (CSF) of 5 patients with traumatic brain injuries: EPO was found in 15 out of 15 CSF samples. There was no correlation between the serum EPO concentration and the concentration in the CSF. However, EPO concentrations in CSF correlated with the degree of blood-brain-barrier dysfunction. This suggests that EPO does not cross the intact blood-brain-barrier, implying that EPO is produced in the brain itself, most probably by astrocytes in an oxygen-dependent manner. In view that neuronal cells carry the EPO receptor, we propose that EPO acts in a paracrine fashion in the central nervous system and might function as a protective factor against hypoxia-induced damage of neurons.

Intensified regimen for advanced head and neck squamous cell carcinomas

OBJECTIVE

To devise an intensified treatment regimen for patients with advanced, resectable head and neck squamous cell carcinomas.

DESIGN

Phase I/II clinical trial consisting of perioperative cisplatin chemoradiotherapy, surgical resection, intraoperative radiotherapy, and postoperative cisplatin chemoradiotherapy.

SETTING

The Ohio State University Comprehensive Cancer Center, Columbus.

PATIENTS

Thirty-seven patients (median age, 63 years) with advanced oral cavity, oropharyngeal, or hypopharyngeal carcinomas.

RESULTS

The range of time at risk was 1 to 30 months (median, 21 months). Thirty of the 37 registered patients were analyzable; 11 have died (5 with distant metastases; 1 of lung carcinoma; and 5 were cancer-free); 2 experienced second primary tumors in the oral cavity (out of or adjacent to the previous radiotherapy portals). Treatment compliance was excellent (92%), morbidity was low, and excellent locoregional control was achieved.

CONCLUSIONS

The initial results are encouraging; the future strategy will intensify the systemic component of therapy based on results from concurrent laboratory studies.