Immunologic monitoring in lung allograft recipients

To identify patients with increased risk of chronic lung allograft rejection, we assessed the utility of an in vitro biopsy-derived lymphocyte growth assay and serum anti-HLA antibody screening as a complement to currently available methods of monitoring lung allograft recipients. Lymphocyte growth assay was performed on bronchoscopic fragments of tissue cultured in medium with rIL-2. Seventy-nine biopsies from 31 lung transplant recipients were tested by lymphocyte growth assay, and results were correlated with histopathology findings. Positive lymphocyte growth was found in 12/26 (46%) episodes of acute rejection, 5/44 biopsies without rejection (11%), and 0/9 episodes of bronchitis. Positive lymphocyte growth was seen in 7/16 (44%) grade A1 rejections and in 5/10 (50%) grade A2 rejections, as opposed to only 5/44 (11%) grade A0 (no rejection) biopsies (P < 0.01 for both A1 and A2 with respect to A0). Actuarial probability of remaining free from obliterative bronchiolitis (OB)* tended to be higher in patients who did not exhibit lymphocyte growth in biopsies. Sequential samples of sera obtained at the time of the biopsy were screened for lymphocytotoxic anti-HLA antibodies. Twenty-two of 44 recipients (50%) developed anti-HLA antibodies during the first postoperative year, exhibiting greater than 10% reactivity to an HLA reference panel of lymphocytes in four or more consecutive serum samples. Actuarial survival of lung allograft recipients with anti-HLA antibodies (n = 22) was lower than in those without anti-HLA antibodies (n = 22; P = 0.03). Of the 22 antibody producers, 7/12 died as a consequence of OB. Of the 22 non-antibody-producers, 1/2 deaths occurred as a consequence of OB. Anti-HLA antibodies were present in 9/11 instances of OB (82% sensitivity) and in 13/33 patients without OB (61% specificity; P = 0.03). These data indicate that lung transplant recipients with positive lymphocyte growth and anti-HLA antibodies are at an increased risk of chronic allograft rejection.     

Clinical presentation of experimentally induced rabies in horses

Twelve naive and nine test-vaccinated horses which developed clinical signs of rabies as a result of the required protocol of a vaccine trial were prospectively observed. Nineteen of the 21 cases were confirmed positive for rabies infection of the brain by fluorescent antibody test. The two horses with negative results had ganglioneuritis of the trigeminal ganglion or lymphocytic perivascular cuffing in the brain stem in addition to clinical signs. Average incubation period was 12.3 days and average morbidity was 5.5 days. Naive animals had significantly shorter incubation and morbidity periods (P < 0.05). Muzzle tremors were the most frequently observed (81%) and most common initial sign. Other common signs were pharyngeal spasm or pharyngeal paresis (71%), ataxia or paresis (71%), lethargy or somnolence (71%). The furious form was manifested in 43% of rabid horses and some of these furious animals initially manifested the dumb form. The paralytic form was not observed. Histopathology was characteristics for rabies. The results of this trial do not reflect on the efficacy of commercially licensed equine rabies vaccines.     

Endometritis in cattle experimentally induced by Chlamydia psittaci

On the day of estrus, eight virgin heifers received intrauterine inoculations of yolk sac propagated Chlamydia psittaci strain BovEnd 11/88 isolated from the uterus of a slaughter cow. All heifers developed purulent vaginal discharge which persisted for 3 to 7 weeks. Chlamydiae or chlamydial antigen were detected in vaginal and uterine discharges of infected animals by culture or Capture ELISA, while other bacterial pathogens were not found. In sera of the chlamydia-infected heifers marked increases in antibody titres against the chlamydial genus-specific LPS-antigen were found by ELISA and complement fixation test. Six heifers were artificially inseminated in 5 successive cycles beginning at the first estrus following intrauterine inoculation. In two of the infected heifers spontaneous healing of endometritis occurred after 5 estrus cycles. Only these animals conceived after the 5th breeding, whereas in the remaining four animals a chlamydia-associated chronic endometritis was recognized as the cause of infertility in the 19th and 26th week p.i. at slaughter. Two control heifers which remained clinically normal after intrauterine exposure to sterile yolk sac-suspensions conceived at the 1st and 2nd service, respectively.     

Pathogenesis of experimentally induced rabies in domestic ferrets

Isl-1 is a member of a family of Homeodomains containing proteins that possess an N-terminal pair of zinc binding LIM domains. The Isl-1 gene in rat codes for a protein that binds to the insulin gene enhancer and is also involved in regulation of amylin and proglucagon genes. A DNA sequence coding for 66 amino acid residues containing the C-terminal homeodomain fragment of Isl-1 was expressed as a soluble protein in Escherichia coli. Here, we describe a procedure which allows the rapid native purification of recombinant homeodomain protein fused to an N-terminal tag of six histidines. The purified homeodomain showed DNA-binding activity to its cognate DNA sequence. An enhanced binding activity is observed in the presence of a reducing agent in electrophoretic mobility shift assays. The DNA binding was further characterized by circular dichroism spectroscopy. Addition of DNA to the homeodomain did not change the overall secondary structure content, but the thermal and chemical denaturing profiles were altered. A stabilization of the secondary structure was observed upon DNA binding. The free energy of unfolding at 23 degrees C was 7 kJ mol(-1) in absence of DNA and 29 kJ mol(-1) in the presence of DNA.     

Vascular complication disclosing lung cancer in children

Stroke are not as rare in pediatric patients as once suspected. Exhaustive diagnostic evaluation must be performed, to identify a cause, evaluate risk factors of recurrence and propose preventive treatment. We report a case in a teen-ager secondary to cerebral embolism. These embols have an exceptional origin: pulmonary venous thrombosis, secondary to undifferentiated sarcoma located in the lung and extended to pulmonary vein. Stroke by cerebral embolism are not always originated from heart disease, and may be misdiagnosed only transthoracic echocardiography is realised.     

The pathology of the pulmonary arteries in lung tumors

A study was undertaken to analyse the type and extent of pathological changes in the pulmonary arteries in non-small cell malignant tumours of the lung. Large-section histological preparations were made from 33 squamous cell carcinomas and 30 adenocarcinomas (T1 and T2 tumours) and classified according to tumour margin area (zone 1), intermediate area (zone 2) and tumour centre (zone 3). Transmural tumour growth with intraluminal cell formations in the pulmonary artery branches were found in the centre of all adenocarcinomas and 86% of squamous cell carcinomas, involving subsegment, prelobular and lobular arteries. Obstructive and obliterative changes in the pulmonary arteries as the result of tumour compression and secondary fibrosing changes predominantly occurred in the centre of all tumours. They were less common and less marked in zones 1 and 2. -Pulmonary artery branches in lung tumours of stages T1 and T2 showed marked infiltrating, obliterative and secondary inflammatory changes as far as complete vascular occlusions. These observations indicate that cytotoxic drugs, introduced via the systemic circulation, cannot reach and therefore not exert their effects in extensive areas of tumour.     

The anti-inflammatory effect of fusafungine during experimentally induced rhinosinusitis in the rabbit

OBJECTIVE: To determine the increased cancer detection rate, if any, of programmes in the UK National Health Service breast screening programme (NHSBSP) using more than single reading of mammograms. DESIGN: Information on the detection of cancers by individual screening programmes from annual (KC62) returns, supplemented by questionnaire information about the number of readers. SETTING: The 87 NHSBSP programmes from England and Wales for the screening year 1 April 1996 to 31 March 1997. The study includes all programmes for prevalent screens where two views are mandatory, but excludes the four programmes using two view mammography for incident screening. MAIN OUTCOME MEASURES: Cancer detection, invasive cancer detection, and small (< 15 mm) invasive cancer detection by mammographic reading protocol using single reading as the reference level. RESULTS: Programmes collectively using single reading detected the lowest rate of cancers at both prevalent (first) and incident (subsequent) screening. The highest rate of age standardised cancer detection was achieved by programmes using double reading with arbitration. At prevalent screens, where all programmes used two views, those programmes using double reading with arbitration detected 32% (95% confidence interval (CI) 3% to 69%) more small (< 15 mm) invasive cancers than programmes using single reading. At incident screens, where all programmes analysed used one view this increased to 73% (95% CI 40% to 113%). Recall rates showed no obvious difference between single reading and the double reading protocols, being around 7% for prevalent screens and 3.5% for incident screens. DISCUSSION: The results suggest that the increase in cancer detection resulting from increasing the number of readers depends on the number of views, and is higher for one view than two views. Single reading of one view results in a low detection rate of small invasive cancers for most individual programmes. It is, however, recognised that a small number of individual readers may achieve high detection rates with such a protocol. All groups of programmes using different reader/view protocols are on average close to or above target cancer detection rates, except those using single reading of one view (mediolateral oblique) at incident screens.     

Surfactant improves lung function and mitigates bacterial growth in immature ventilated rabbits with experimentally induced neonatal group B streptococcal pneumonia

AIMS: To study the influence of surfactant on lung function and bacterial proliferation in immature newborn rabbits with experimental group B streptococcal (GBS) pneumonia. METHODS: Preterm rabbit fetuses (gestational age 28 days) underwent tracheotomy and were mechanically ventilated in a warmed body plethysmograph that permitted measurement of lung-thorax compliance. Fifteen minutes after the onset of ventilation the animals received either GBS or saline intratracheally; at 30 minutes, a bolus of saline or 200 mg/kg of a porcine surfactant (Curosurf) was administered via the airway. Bacterial proliferation was evaluated in lung homogenate at the end of the experiments and the results expressed as mean log10 cfu/g lung (SD). Animals receiving only saline (n = 20) or saline and surfactant (n = 20) served as controls. RESULTS: The average survival time was about three hours in all groups. Infected animals receiving surfactant (n = 22) had significantly less bacterial growth (9.09 (0.45) vs 9.76 (0.91)) and improved lung function (compliance: 0.61 (0.14) vs 0.34 (0.19) ml/kg. cm H2O) than infected rabbits receiving saline at 30 minutes (n = 22). CONCLUSION: Surfactant improves lung function and mitigates bacterial growth in preterm rabbits infected with group B streptococci.     

Bursting pressure in anastomotic healing in experimentally induced colitis in rats

BACKGROUND: Experimental studies on healing of colonic anastomosis have been thoroughly investigated. However, clinical parameters of the healing process of anastomosis in the inflamed colon has not yet been reported. METHODS: In the present study, healing of anastomosis in trinitrobenzene-sulfonic acid-induced colitis in rats was assessed by measuring the bursting pressure and bursting wall tension. RESULTS: On postoperative day 4, bursting pressure and bursting wall tension were significantly lower (P < 0.001) in rats with colitis with or without anastomosis and normal colon with anastomosis, compared with normal colon without anastomosis. On postoperative day 7, bursting pressure and bursting wall tension of normal colon with anastomosis approached that of normal colon without anastomosis. However, bursting pressure and bursting wall tension of rats with colitis with or without anastomosis remained significantly lower (P < 0.001) than the latter. Furthermore, unlike rats without colitis in which perforation occurred mostly at the anastomotic line, the bursting site in colitic rats was predominantly away from the anastomotic line. CONCLUSIONS: These results suggest that in surgery for inflammatory bowel disease, it is the adjoining inflamed bowel wall that is vulnerable to be perforated in response to increasing intraluminal pressure rather than the anastomosis that is braced by the sutures.     

Elevation of plasma angiotensinogen in rats with experimentally induced nephrosis

Oxidant injury contributes to myocardial stunning, and cardiac ischemic and reperfusion injury. Vitamin E is the major--and perhaps the only--lipid soluble, chain-breaking antioxidant in the heart. Vitamin E and its analogues potentially offer significant advantages for the prevention of ischemic and reperfusion injury. Recent investigations have suggested that modified vitamin E analogues may be more efficacious than vitamin E and may permit myocardial salvage from acute myocardial ischemic injury.     

Early stent-induced thrombosis in the pelvic circulation: a complication in APC resistance

Two cases of actinic granuloma of the skin occurring in association with a giant cell arteritis are reported. This is the first time that this association has been documented.     

Glutathione depletion in epithelial lining fluid of lung allograft patients

The lower respiratory tract is protected against reactive oxygen species (ROS) by a complex antioxidant system. In the epithelial lining fluid (ELF), glutathione (L-alpha-glutamyl-L-cysteinylglycine, GSH) is essential for adequate protection of pneumocytes from potential toxicity mediated by extracellular hydrogen peroxide (H2O2). We assessed the concentration of total GSH in bronchoalveolar lavage fluid (BALF) in lung allograft patients in the absence and presence of acute rejection. Bronchoalveolar lavage (BAL) and biopsies were performed concurrently on 36 occasions in 17 patients who had undergone lung transplantation. BALF samples were divided into two groups on the basis of presence or absence of acute lung rejection on transbronchial biopsy. Seven BALF samples were obtained from control subjects for comparison. The BALF data demonstrated significantly lymphocyte recruitment and evidence of lung injury during acute rejection episodes. Transplant allografts without rejection showed significant depletion of total GSH in the ELF as compared with that of normal volunteers (94.0 +/- 9.7 microM versus 302.6 +/- 40.8 microM, p < 0.01). Transplant allografts with acute rejection had a slightly higher GSH concentration in their ELF (179.8 +/- 34.7), but this was still lower than control values. The deficiency of total GSH in the alveolar fluid may predispose lung allografts to extracellular H2O2-mediated toxicity.     

Excitability changes and glucose metabolism in experimentally induced focal cortical dysplasias

Malformations of cortical development are increasingly recognized in association with severe epileptic syndromes, neuropsychological disorders and mental retardation. Several clinical and experimental studies suggest that functional consequences of cortical dysplasias are not restricted to the area of the dysplastic lesion but also involve remote brain regions. In the present study cortical malformations were induced in newborn rats at day of birth by intracerebral injection of the glutamatergic agonist ibotenate. The resulting cytoarchitectonic lesion associates neuronal depopulation of deep cortical layers, ectopic neurons in superficial layers and sulcus formation, mimicking human polymicrogyria and migration disorders. Electrophysiological recordings of evoked field potentials in slice preparations of adult animals reveal hyperexcitability in widespread cortical regions surrounding the dysplasia. Low-intensity stimulation induced epileptiform activity consisting of long-lasting, multiphasic and N-methyl-D-aspartate-dependent field responses. They appeared with high variability as all-or-none events. These widespread changes in excitability were not observed in sham-operated animals with small superficial ectopias but intact deep cortical layers, indicating that focal loss of these layers induces extended alterations in cortical connectivity and imbalance of excitation and inhibition. Restricted zones of increased excitability were also found in the forelimb and hindlimb representation cortex in sham-operated and control animals, demonstrating that this activity has to be considered as an intrinsic property of specific cortical areas. Deoxyglucose autoradiography showed that the widespread hyperexcitability in ibotenate-injected animals was not accompanied by alterations in glucose metabolism, although in the area of structural abnormality a typical metabolic pattern was found, revealing an increased glucose uptake in layer I. Hypometabolism as described for many types of human dysplastic lesions was not observed. This difference between the experimental and clinical data may be due to the absence of behavioral seizures in this model. However, it can be hypothesized that in patients with developmental malformations, additional pathogenic factors contribute to the manifestation of seizure disorders.     

Evaluation of apoptosis and cell proliferation in experimentally induced renal cysts

Cell proliferation and apoptosis in renal cysts induced by streptozotocin, alloxan and ferric-nitrilotriacetate were investigated in rats. In the kidneys of all treated animals dilated tubules at the cortico-medullary region, large cysts, glomerular cysts and tubular dilation in the medullary area were found. Both cell proliferation and apoptosis were increased in the epithelium of the non-dilated tubules, in the mesangial and interstitial cells. Cells lining the dilated tubules or cysts demonstrated apoptosis but their proliferating activity was low. By calculating the proliferation-apoptosis ratio we found that alloxan did not change the balance between the two mechanisms. Meanwhile streptozotocin resulted in an increased apoptosis and ferric-nitrilotriacetate in an increased cell proliferation. p53 expression might be responsible for the uncontrolled proliferation in rats treated with ferric-nitrilotriacetate as this oncoprotein was diffusely present in tubular cell nuclei. The observed apoptosis seemed to be independent of bcl-2 oncoprotein expression. We assume that the initial factor in such cystogenesis should be a cellular injury due to direct toxic or to the diabetogenic effect of the drugs. The latter is more likely as all the animals were hyperglycemic and insulin treatment following administration of streptozotocin prevented the morphologic changes.     

Immunocytochemical demonstration of the synovial membrane in experimentally induced arthritis of the rat temporomandibular joint

The present study is first to report an experimental model of adjuvant-induced arthritis in the rat temporomandibular joint (TMJ). Arthritis was induced by simultaneous intradermal administrations of Freund's complete adjuvant, one at the parietal scalp and the other at the base of the tail. In this model, we demonstrated responses of the synovial membrane by immunocytochemistry using antibodies to OX6 and ED1 which recognize Ia antigen in MHC class II antigen-expressing cells and the macrophage/monocyte lineage, respectively. Three weeks after administration, no remarkable signs of inflammation were macroscopically recognizable in the TMJ, but microscopically the synovial membrane in the TMJ revealed marked changes such as enhanced vascularization and hemostasis in the sublining layer and a thickening in the synovial lining cell layer. Intense OX6-immuno-reactivity was found in the synovial lining cells at lesions in the experimental group but not in the control group. Immunoelectron microscopy revealed that these OX6-immunopositive synovial lining cells developed dense cytoplasmic processes and numerous vacuoles and vesicles, resembling type A cells. Part of the type A cells also showed ED1-immunoreactivity. The expression of OX6 or ED1 immunoreactivity in the synovial lining cells might be involved in the initial immune responses in this arthritis model because the synovial membranes are exposed to the synovial fluids which have been believed to contain antigenic substances.     

Early signs of renal pathology in small intensity chemical exposure

Occupational exposure to vapours, gases and aerosols promotes increase of renal diseases incidence. Wider use of anamnestic data is recommended during preliminary and regular check-ups of this population.     

Thermoregulatory responses of the newborn pig during experimentally induced hypothermia and rewarming

Eph family receptor tyrosine kinases (including EphA3, EphB4) direct pathfinding of neurons within migratory fields of cells expressing gradients of their membrane-bound ligands. Others (EphB1 and EphA2) direct vascular network assembly, affecting endothelial migration, capillary morphogenesis, and angiogenesis. To explore how ephrins could provide positional labels for cell targeting, we tested whether endogenous endothelial and P19 cell EphB1 (ELK) and EphB2 (Nuk) receptors discriminate between different oligomeric forms of an ephrin-B1/Fc fusion ligand. Receptor tyrosine phosphorylation was stimulated by both dimeric and clustered multimeric ephrin-B1, yet only ephrin-B1 multimers (tetramers) promoted endothelial capillary-like assembly, cell attachment, and the recruitment of low-molecular-weight phosphotyrosine phosphatase (LMW-PTP) to receptor complexes. Cell-cell contact among cells expressing both EphB1 and ephrin-B1 was required for EphB1 activation and recruitment of LMW-PTP to EphB1 complexes. The EphB1-binding site for LMW-PTP was mapped and shown to be required for tetrameric ephrin-B1 to recruit LMW-PTP and to promote attachment. Thus, distinct EphB1-signaling complexes are assembled and different cellular attachment responses are determined by a receptor switch mechanism responsive to distinct ephrin-B1 oligomers.