Surgical management of villous and tubulovillous adenomas of the rectum]

One hundred four cases of middle and low rectal villous and tubulovillous adenomas have been operated on with transanal polypectomy (8), transanal endoscopic microsurgery--TEM (80), anterior rectum resection with double stapled straight sigmoideorectosomy (7), and deep rectum resection, bi-directional mucosectomy and hand sutured straight sigmoideoanostomy (9). The option of the authors to remove the tumours in 5 cm to the dentate line are the transanal polypectomy or transanal mucosectomy corresponding to their size. The transanal endoscopic microsurgical technic is recommended to manage the polyps smaller than 4 to 5 cm in the middle rectum. The best radicallity in removal of the circular, extended villous adenomas could be achieved with deep rectum resection, bi-directional mucosectomy and transanal straight, hand sewn sigmoideoanostomy.     

Three ventriculoplasty techniques applied to three left-ventricular pseudoaneurysms in the same patient

A 59-year-old male patient underwent surgery for triple-vessel coronary artery disease and left-ventricular aneurysm in 1994. Four months after coronary artery bypass grafting and classical left-ventricular aneurysmectomy (with Teflon felt strips), a left-ventricular pseudoaneurysm developed due to infection, and this was treated surgically with an autologous glutaraldehyde-treated pericardium patch over which an omental pedicle graft was placed. Two months later, under emergent conditions, re-repair was performed with a diaphragmatic pericardial pedicle graft due to pseudoaneurysm reformation and rupture. A 3rd repair was required in a 3rd episode 8 months later. Sternocostal resection enabled implantation of the left pectoralis major muscle into the ventricular defect. Six months after the last surgical intervention, the patient died of cerebral malignancy. Pseudoaneurysm reformation, however, had not been observed. To our knowledge, our case is the 1st reported in the literature in which there have been 3 or more different operative techniques applied to 3 or more distinct episodes of pseudoaneurysm formation secondary to post-aneurysmectomy infection. We propose that pectoral muscle flaps be strongly considered as a material for re-repair of left-ventricular aneurysms.     

Serum concentration of immunoglobulin G‐type antibodies against the whole Epstein–Barr nuclear antigen 1 and its aa35–58 or aa398–404 fragments in the sera of patients with systemic lupus erythematosus and multiple sclerosis

Several studies suggest that infection by Epstein–Barr virus (EBV) might be one of the environmental factors which facilitates the development of autoimmune disorders in genetically susceptible individuals. Recent data indicate that high anti‐Epstein–Barr nuclear antigen 1 (EBNA)‐1 immunoglobulin (Ig)G titre is a strong risk factor for multiple sclerosis (MS) in patients both with and without the main genetic predisposing trait, human leucocyte antigen (HLA)‐DRB1*15:01. Because no similar studies have been published in systemic lupus erythematosus (SLE) patients, we determined the HLA‐DRB1*15:01 carrier state and the serum titres against the whole EBNA‐1 and its small fragments aa35–58 and aa398–404 in 301 SLE patients, 135 MS patients and in 345 healthy controls. The carrier state of the HLA‐DRB1*15:01 allele was deduced from genotyping of a tagSNP (rs3135388) by applying a Taqman‐based assay. The serum concentrations of antibodies to EBNA‐1 and its aa35–58 or aa398–404 fragments were determined using a commercial assay (ETI‐EBNA‐G) and home‐made enzyme‐linked immunosorbent assays, respectively. The serum concentration of anti‐EBNA‐1 antibodies was significantly (P < 0·001) higher both in MS and SLE patients than in controls. Similar significant differences were found both in HLA‐DRB1*15:01 carriers and non‐carriers. Furthermore, titres of antibodies against the aa35–58 EBNA‐1 fragment were elevated both in MS and SLE patients. By contrast, the levels of aa398–404 EBNA‐1 antibodies were elevated significantly only in the SLE patients. These findings indicate that high anti‐EBNA‐1 IgG titres are HLA‐DRB1*15:01‐independent risk factors not only for MS, but also for SLE, while high antibody titres against the aa398–404 fragment are characteristic for SLE.     

Antagonist of growth hormone-releasing hormone induces apoptosis in LNCaP human prostate cancer cells through a Ca2+-dependent pathway

Antagonists of growth hormone-releasing hormone (GHRH) exert antiproliferative effects directly on cancer cells, which are mediated by the tumoral GHRH receptors. However, the signal transduction pathways involved in antiproliferative effect of GHRH antagonists have not yet been elucidated. We used flow cytometry to investigate whether GHRH antagonist JV-1-38 can induce changes in the cytosolic free Ca2+ concentration leading to apoptosis in LNCaP human prostate cancer cells. JV-1-38 evoked prompt Ca2+ signal in a dose-dependent way (1-10 microM) and induced early stage of apoptosis in LNCaP human prostate cancer cells at a concentration effective in suppression of cell proliferation (10 microM) peaking after 3 h. Unexpectedly, agonist GHRH(1-29)NH2, which elevates cytosolic free Ca2+ concentration in pituitary somatotrophs at nanomolar concentrations, failed to induce Ca2+ signal or apoptosis even at a 10-fold higher concentration (100 microM). However, agonist GHRH(1-29)NH2 inhibited JV-1-38-induced Ca2+ signals in a dose-dependent way without affecting the antagonist-induced apoptosis. Peptides unrelated to GHRH did not induce Ca2+ signals in LNCaP human prostate cancer cells. EDTA (10 mM) or nifedipine (10 microM) significantly reduced the Ca2+ signal and early stage of apoptosis induced by JV-1-38, supporting the view that the increase in intracellular Ca2+ in response to JV-1-38 occurs primarily through extracellular Ca2+ entry through voltage-operated Ca2+ channels. In conclusion, GHRH antagonists activate tumoral GHRH receptors and are able to induce apoptosis in LNCaP human prostate cancer cells through a Ca2+-dependent pathway. Treatment with GHRH antagonists may offer a new approach to the therapy of prostate and other hormone-sensitive cancers.     

Serum leptin, soluble leptin receptor, free leptin index and bone mineral density in patients with primary biliary cirrhosis

BACKGROUND/AIM: The pathophysiology of osteoporosis in chronic liver diseases is unknown. Recent data suggest that serum leptin is associated with bone mineral density (BMD). In animal studies leptin was found to be a potent inhibitor of bone formation. We investigated the relationship between serum leptin levels, soluble leptin receptor (sOB-R), free leptin index (FLI) and BMD in patients with primary biliary cirrhosis (PBC). PATIENTS AND METHODS: Ninety-four female patients with PBC were included in this study; 122 healthy women served as controls. Serum leptin levels were measured by radioimmunoassay, sOB-R by enzyme-linked immunosorbent assay. BMD was measured by dual energy X-ray absorptiometry in the lumbar spine and femoral neck. RESULTS: Serum leptin was significantly lower in patients with PBC compared with healthy controls. No difference was found between the body mass index (BMI) of patients and controls. There was a strong positive correlation between leptin and BMI. In PBC no association was found between leptin, sOB-R and liver function tests, histological stages or the presence of osteoporosis. Osteoporosis was present in 38 patients. A positive correlation was found between serum leptin and femoral neck z-score even after adjustment for BMI, whereas serum sOB-R correlated inversely with the serum leptin level. There was no difference in FLI between the subgroups of PBC patients according to the stages of the disease. CONCLUSIONS: We found a lower serum leptin level and a higher sOB-R in patients with PBC, which could not be explained by the difference in BMI. As leptin was associated with BMD, it may be hypothesized that leptin is involved in the complex regulation of bone metabolism in PBC.     

Ultrastructural features of the spermatozoon and its differentiation in Brandesia turgida (Brandes, 1888) (Digenea,Microphalloidea, Pleurogenidae)

Spermatological characters of the digenean Brandesia turgida (Brandes, 1888), an intestinal parasite of the frog Pelophylax ridibundus (Pallas, 1771), have been investigated by means of transmission electron microscopy for the first time. The process of the spermatozoon formation begins with the appearance of the differentiation zone bordered by cortical microtubules and containing two centrioles associated with striated rootlets and with an intercentriolar body. The intercentriolar body is made up of seven distinct electron-dense plates, two less electron-dense, and four electron-lucent zones. The orthogonal development of the two flagella is followed by a flagellar rotation and their proximodistal fusion with the median cytoplasmic process. This process is accompanied by an extension of both the mitochondrion and nucleus into the median cytoplasmic process. The mature spermatozoon of B. turgida contains two parallel axonemes of unequal lengths with the 9?+?“1” trepaxonematan pattern, mitochondrion, nucleus, parallel cortical microtubules, four electron-dense attachment zones, an external ornamentation of the plasma membrane, and electron-dense glycogen granules. The anterior extremity of the male gamete contains one complete centriole, a small component of the central element of the second centriole, and peripheral cortical microtubules (up to 45). The posterior extremity of the mature spematozoon exhibits tubular elements of the disorganized axoneme. The present study provides the first data on spermiogenesis within the family Pleurogenidae. Variations of the spermatozoa ultrastructural characters within Digenea, in particular, between different families of the superfamily Microphalloidea, are discussed.     

Development and characterisation of a monoclonal antibody family against aquaporin 1 (AQP1) and aquaporin 4 (AQP4)

Recent studies have discovered the existence of water-channel molecules, the so called aquaporins (AQP) presumably involved in active, ATP dependent water transport between the intracellular and extracellular compartments. Both genetic and protein sequences and structures of the AQPs are known and crystallographic analyses of some members of the AQP family have been performed. Specific antibodies are required to examine their histological locations and analyse their roles in physiological and pathological pathways of water transportation and osmotic regulation. Until recently some polyclonal antibodies have been developed against certain members of the AQP family. However, to date highly specific monoclonal antibodies against aquaporins do not exist. We have developed a monoclonal antibody family against the aquaporin 1 (AQP1) and aquaporin 4 (AQP4) molecules. Well-conserved epitop sequences of AQP1 and AQP4 proteins were selected by computer analysis and their synthetic peptide fragments were used as the antigens of immunisation and the following screening. Antibodies were characterised by immunoserological methods (ELISA, dot-blot and immunoblot), flow cytometry and immunohistochemistry of formaldehyde-fixed and paraffin-embedded tissue samples. RT-PCR tests controlled the specificity of the immune reactions. Our monoclonal antibodies recognised AQP1 and AQP4 in all the techniques mentioned above and apparently they are useful both in various quantitative and qualitative measurements of the expressions of AQP1 and AQP4 in several species (human, rat, mouse, invertebrates, even plants). According to preliminary immunohistochemical studies our monoclonal anti-AQP1 and anti-AQP4 antibodies are appropriate tools of patho-morphological examinations on routine formol-paraffin tissue samples.