Liposome-mediated transfer of vascular endothelial growth factor cDNA augments survival of random-pattern skin flaps in the rat.

Tissue engineering is an application for gene therapy that is in its infancy. We show that simple liposomal-mediated gene transfer could result in a potentially useful biological effect in the field of wound healing. cDNA encoding the 165 amino acid form of vascular endothelial growth factor complexed to commercially available liposomes was injected into rat skin 1 week before raising a random pattern 3 x 10 cm flap. The flap survival was enhanced by 14 percent, and was accomplished without accessing the arterial inflow of the territory. These results were statistically significant (p<0.002) and reproducible. No adverse effects were seen. Histological analysis of the angiogenesis localized much of the new vessel formation to the area around the hair follicles. Polymerase chain reaction amplification of extracted flap tissue confirmed the presence of the transgene.     

Karzinomassoziierte Retinopathie (CAR) bei Mammakarzinom und Karzinoid

Fragestellung: Die Karzinomassoziierte Retinopathie (CAR) stellt ein seltenes paraneoplastisches Syndrom dar, das bislang am h?ufigsten bei kleinzelligen Bronchialkarzinomen beschrieben wurde. Wir berichten über 3 Patientinnen mit CAR in Gegenwart eines Mammakarzinoms bzw. eines Karzinoids der Cervix uteri. Patienten und Methode: Es wurden biomikroskopische, perimetrische, angiographische und elektrophysiologische Befunde erhoben. Au?erdem erfolgte eine Testung der Immunreaktivit?t der Seren an humaner Retina. Ergebnisse: Die Befunde umfa?ten ringf?rmige Gesichtsfelddefekte mit statokinetischer Dissoziation und eine pathologische St?bchen- und Zapfenantwort im ERG. Bei 1 Patientin wurde immunhistochemisch eine Reaktion im Bereich der Photorezeptorinnensegmente, der ?u?eren K?rnerschicht sowie der ?u?eren plexiformen Schicht bei fehlendem Nachweis von Antik?rpern gegen Recoverin gefunden. Diskussion: Neben dem kleinzelligen Bronchialkarzinom k?nnen auch andere Prim?rtumoren mit einer CAR vergesellschaftet sein. Der Nachweis von retinalen Autoantik?rpern unterstützt die Annahme einer tumorinduzierten Immunantwort aufgrund der Expression identischer Epitope durch die Tumorzellen. Dabei kommen offensichtlich verschiedene retinale Proteine als Autoantigene in Betracht.      

Early use of intrapleural fibrinolytics in the management of postpneumonic empyema. A prospective study.

OBJECTIVE: A prospective randomized study was conducted in order to analyze the role of fibrinolytics in the treatment of complicated parapneumonic effusion. METHODS: From 2001 to 2004, 127 consecutive patients were managed for thoracic empyema. In all cases the cause was bacterial pneumonia. Seventy patients were managed with sole tube thoracostomy (group A) and 57 with combination of tube thoracostomy and streptokinase instillation (group B). Groups were statistically compared for the age, gender, duration of symptoms, quality of pleural fluid, chest imaging, complete drainage, length of hospital stay and mortality. Multivariate analysis was used in order to define the factors that affect outcome. RESULTS: Tube thoracostomy was successful in 47 (67.1%) cases (group A), while fibrinolysis led to a favorable outcome in 50 cases (87.7%) (P<0.05). The length of stay in thoracic surgical department was significantly longer for group A (P<0.001). Mortality rate in group A was significantly higher (P<0.001). Multiple regression analysis disclosed as sole independent favorable factor for pleural drainage, the use of fibrinolysis during the course of chest tube drainage (P=0.006, odds ratio 4.29, 95% CI 1.51-12.14). CONCLUSIONS: Fibrinolytic agents are a useful adjunct in the management of complicated parapneumonic effusions. Intrapleural fibrinolytics, if used early in the fibrinopurulent stage of a parapneumonic effusion, decrease the rate of surgical interventions (VATS or open decortcation) and the length of hospital stay with minor associated morbidity.     

Increased in vitro uptake of the complement C3b in the serum of patients with Guillain-Barré syndrome, myasthenia gravis and dermatomyositis

To examine the role of complement in certain autoimmune neuromuscular diseases, we used an in-vitro quantitative complement uptake assay that allows measurement of the capacity of patients' sera to deposit fragments of the third complement component onto sensitized targets. C3 uptake was significantly higher in patients with active dermatomyositis, Guillain-Barré syndrome and myasthenia gravis, compared to inclusion body myositis and controls. The in-vitro C3 uptake assay supports the role of C3b neoantigen and Membranolytic Attack Complex deposition in the target tissues and may be a useful tool to monitor disease activity in patients with complement-mediated neurological disorders.     

A flow visualization study of an anatomic coronary artery anastomosis model with an implant.

Flow Streamlining Devices is a new tool in Coronary Artery Bypass Grafting (CABG). They aim in: a) Performing a sutureless anastomosis to reduce thrombosis at the veno-arterial junction, and b) Providing a hemodynamically efficient scaffolding to reduce secondary flow disturbances. Thrombosis and flow disturbances are factors that have been reported as contributing factors to the development of intimal hyperplasia (IH) and failure of the graft. By reducing thrombosis and flow disturbances, it is expected that IH will be inhibited and the lifetime of the graft extended. To evaluate the hemodynamic benefits of such an implant, two models were designed and fabricated. One simulated the geometry of the conventional anastomosis without an implant, and the other simulated an anastomosis with a flow streamlining implant. Identical flow conditions relevant to a coronary anastomosis were imposed on both models and flow visualization was performed with dye injection and a digital camera. Results showed reduction of disturbances in the presence of the implant. This reduction seems to be favorable to hemodynamic streamlining which may create conditions that may inhibit the initialization of IH. However, the compliance and geometric mismatch between the anastomosis and the implant created a disturbance at the rigid compliant wall interface, which should be eliminated prior to clinical applications.     

Experimental quantiles of epidemiological indices in case-control studies with non-differential misclassification

The formulae for some typical epidemiological indices in case-control studies with non-differential misclassification are expressed in terms of two groups (α, β) and (γ, δ) of misclassification probabilities of exposure E and confounder C, respectively, and the initially estimated frequencies. The parameters α and β denote the probability that subjects exposed to E are classified as non-exposed and the probability that non-exposed ones will be classified as exposed, respectively. Similarly, δ and γ stand for the probability that those who have been exposed to C will be classified as non-exposed and the probability that non-exposed subjects are classified as exposed, respectively. The non-negativeness of the expressions for the ‘true’ frequencies in terms of the measured ones and the misclassification probabilities leads to the construction of feasibility regions for α, β, γ and δ. For a number of ‘acceptable’ 4-tuples (α, β, γ, δ), all of which lie inside these feasibility regions, a sequence of feasible values for an epidemiological index is determined, after employing a systematic procedure by means of a ‘searching net’ with increments Δα, Δβ, Δγ, Δδ. The procedure serves to determine the characteristics of the (experimental) cumulative distribution function for any selected epidemiological index. The final stage in exploiting the structure of feasibility regions for α, β, γ and δ is to use the cumulative distribution function to calculate quantiles for the index associated with prescribed probabilities.     

Prevalence of Hepatitis A, B, and C markers in school children of a rural area of Crete, Greece

Objective: To determine the prevalence of hepatitis A, B, and C markers in children who were attending junior and senior high schools in a high risk area in rural Crete, Greece. Methods: Three-hundred and thirty-four children who attended the three junior schools and one senior high school in the Agios Vassilios province of Southern Crete were invited to participate in the study. Three hundred and four of them were tested for hepatitis A, B, and C markers. Hepatitis B (HBV) markers (HBsAg and anti-HBc) as well as hepatitis A (anti-HAV) and hepatitis (anti-HCV) antibodies were tested with commercial enzyme-linked immunosorbent assay kits. Results: Six of the 304 children (1.97%) were found to be positive for anti-HAV, 1 (0.33%) to HBsAg, 7 (2.30%) to anti-HBc and none were found positive for anti-HCV. No significant differences were seen between the prevalence of anti-HAV antibodies in males (2%) and females (1.95%), and of anti-HBc antibodies in males (3.33%) and females (1.30%). Conclusions: The very low prevalence of anti-HAV is obviously due to the improved conditions of hygiene and it raises the question of the possible emergence of this disease at an older age and therefore appropriate preventative strategies should be considered. The low endemicity of hepatitis B in Crete in contrast to other areas of Greece also calls for a vaccination policy probably during adolescence. The absence of hepatitis C markers in the children in contrast to the observed higher prevalence of HCV-infected people in the adult population in the same rural area raises questions regarding possible sources of transmission of hepatitis C during the preceding years.     

Bone density patterns after normal and premature menopause

Objectives: The investigation of the effect of time and type of menopause on bone mineral density (BMD) at different ages. Methods: Five hundred and fourteen women, who had never received any hormonal substitution were studied in a cross-sectional design: 177 with normal (NMP), 210 with surgical (SUMP) and 127 with premature natural (EMP) menopause. Age at menopause was 49.1±3.9, 38.3±4.7 and 38.1±4.2 years (mean±1 S.D.), respectively. BMD was measured at L2–L4 vertebrae and proximal femur by the DEXA method. Results: EMP women presented significantly lower vertebral BMD than NMP women in the 45–55-years segments (P<0.001), but did not differ from SUMP women. This group exhibited lower vertebral BMD than NMP between 45 and 50 years (P<0.001). Regarding femoral neck, EMP women exhibited lower values than SUMP in the 45–50 and 55–65 age segments (P<0.001) whereas SUMP women presented significantly higher BMD values than NMP women after 55 years of age (P<0.001). The percentages of women with vertebral BMD (T-score values) in the osteoporotic range were significantly greater in EMP compared with either NMP or SUMP groups (both P<0.001) whereas in femoral neck lower in SUMP than the other two categories. Conclusions: Women with either natural or surgical premature menopause exhibit lower BMD of trabecular bone compared with normal menopause women at the age segments 45–55 and 45–50, respectively. However, surgical menopause women exceed normal menopause women in their mixed bone BMD values after 60 years as well as premature natural menopause women at almost all age segments.     

Estimation of genetic risk for type 1 diabetes

The most important gene loci defining risk of type 1 diabetes mellitus (T1DM) are located within the HLA gene region. HLA-DQ molecules are of primary importance but HLA-DR gene products modify the risk conferred by HLA-DQ. The risk associated with an HLA genotype is defined by the particular combination of susceptible and protective alleles. The highest risk is associated with a combination of two different risk haplotypes (7% risk to develop T1DM in Finland) whereas protective genotypes covering 69% of population have a risk of less than 0.2%). The complicated analysis of HLA genotypes is simplified by strong linkage disequilibrium between HLA-DRB1, -DQA1 and -DQB1 loci. In many cases one can deduce the alleles of other loci based on determination of the alleles in one locus. Differences between various populations in the frequency of marker alleles and in the linkages between them has to be taken into account. We have developed PCR based typing methods that utilize blood spot samples, microtiter plate format and lanthanide labeled oligonucleotide probes to define HLA-DQ and -DR alleles relevant for T1DM risk. Typing is run stepwise so that after initial HLA-DQB1 typing only those samples will be further analyzed in which -DQA1 or -DRB1 typing is informative and expected to contribute to the risk estimation. This method has been used to screen more than 50,000 newborn infants in Finland over a time period of 6 years, and it has been able to identify most children who have developed T1D during the follow-up period. The efficiency of the procedure has also been tested in Finnish and Greek populations.     

Induction of murine thyroiditis by a non dominant E(k)-restricted peptide of human thyroglobulin

We have previously shown that the human thyroglobulin (hTg) 20-mer peptide p2340 (aa 2340-2359) contains an epitope recognized by Tg-reactive B cells in patients with Graves' disease. The presence of several Ek-binding motifs within p2340 prompted us to examine whether this peptide can stimulate a T-cell response and elicit experimental autoimmune thyroiditis (EAT) in AKR/J (H-2k) mice. The peptide was found to be immunogenic at the T-cell level since it induced specific proliferative responses as well as interleukin-2 and interferon-gamma secretion in secondary cultures of peptide-primed lymph node cells (LNC). The p2340-specific proliferation was blocked almost completely by an Ek-specific monoclonal antibody (mAb) but was unaffected by a control Ak-specific mAb. Peptide-primed LNC did not respond to intact hTg and conversely, LNC primed in vivo with hTg did not respond to p2340 in culture, suggesting that p2340 contains non-dominant T-cell epitope(s). Direct subcutanaeous challenge of AKR/J mice (n = 9) with p2340 in adjuvant, elicited mild to moderate EAT (infiltration index of 1-2) and strong p2340-specific immunoglobulin G responses in all mice tested. These data delineate a new thyroiditogenic sequence within the carboxyl terminal region of hTg.