Chatton-Lwoff silver impregnation: an improved technique for the study of oncomiracidia (Platyhelminthes: Monogenea) chaetotaxy

Summary Difficulty was experienced in using direct silver nitrate impregnation techniques in the study of the chaetotaxy of the oncomiracidia of several freshwater ancyrocephalines. Eventually the Chatton-Lwoff method of silver impregnation, which was devised to study the cilia and basal bodies of ciliated protozoa, was utilized successfully following certain modifications. The improved technique is described in detail and photomicrographs showing the pattern of the sensillae are presented. ac]19800820     

Bladder Cancer After Radiotherapy for Prostate Cancer

External beam radiotherapy (EBRT) is frequently used in the management of prostate cancer (PCa) as definitive, postoperative, or salvage local treatment. Although EBRT plays a central role in the management of PCa, complications remain a troubling by-product. Several studies have demonstrated an association between radiotherapy and elevated risk of acute and late toxicities. A secondary malignancy induced by initial therapy represents one of the most serious complications related to definitive cancer treatment. The radiation-related secondary primary malignancy risk increases with increasing survival time. Transitional cell carcinoma of the bladder is the most frequent secondary primary malignancy occurring after radiotherapy and is described as more aggressive; it may be diagnosed later because some radiation oncologists believe that the hematuria that occurs after prostate EBRT is normal. Some patients treated for localized PCa will subsequently develop invasive bladder cancer requiring surgical intervention. Patients with PCa treated with EBRT should be monitored closely for the presence of bladder cancer.Key words: Bladder cancer, Prostate cancer, Radiotherapy, External beam radiotherapyThe phenomenon of radiation-inducing the carcinogenesis has been well described in literature for decades. The correlation between ionizing radiation and DNA damage has been discussed in several studies.^1–4 Most of these studies evaluated the growth of solid tumors in a large population exposed to moderate to heavy doses of radiation, such as factory workers, patients exposed to a large number of diagnostic radiographic studies, and survivors of atomic and nuclear explosions. ¹ The casual effects of radiation exposure with subsequent mutagenesis are quite clear, shown both in vivo and in vitro.² Previous radiotherapy (RT) for prostate cancer (PCa) may play an important role in the development of secondary primary bladder cancer. This is a fairly uncommon event but a very real entity, of which both urologists and radiation oncologists need to be aware.     

Pilot study using SELDI-TOF-MS based proteomic profile for the identification of diagnostic biomarkers of thyroid proliferative diseases

Biomarkers for thyroid cancer (TCa) lack specificity. To develop TCa specific biomarkers, SELDI-TOF-MS was used to examine the proteomic profile of biopsies obtained from papillary TCa along with adjacent normal tissue. Sixty-three potential biomarkers were categorized by univariate analysis into single biomarker candidates and segregated by multivariate analysis into normal and cancerous groups. Our studies demonstrate the sensitivity and reproducibility of this approach to detect biomarkers for TCa.     

Biophysical and Biochemical Heterogeneity of Purified Hepatitis B Antigen

Hepatitis B antigen of the D (a+, d+, y-) subtype was purified from plasma of apparently healthy persons and from hepatitis patients. The original samples contained 20- and 42-nm particles and tubular forms (20-nm diameter). Ultracentrifugation during the purification procedure yielded pellets which were then treated at pH 2.4. Both the large, 42-nm Dane particles and the tubular forms were lost during the acid treatment of the pelleted particles, yielding a preparation containing a mixture of particles approximately 20 and 25 nm in diameter. This difference in size was substantiated in that two distinct molecular weights were calculated from high-speed equilibrium data, 3.6 x 10(6) and 4.5 x 10(6). Further heterogeneity was observed in that hepatitis B antigenic activity was present in purified particles with an isoelectric pH of 4.0 and also in those with a pH of 4.4. No significant differences were observed in the gross amino acid composition of purified antigen obtained from plasma of three different persons. (125)I-labeled, purified antigen was found to contain six distinct polypeptides with molecular weights ranging from 10,000 to 39,000.     

Adenovirus Proteins II. N-Terminal Amino Acid Analysis

Adenovirus types 2, 4, 5, 6, 18, 21 and 27, were analyzed for N-terminal amino acids by use of (35)S-labeled phenylisothiocyanate of high specific radioactivity. Two free N-terminal amino acids, alanine and glycine, were found in these viruses in the molar ratio (alanine-glycine) of 2.5:1, with the exception of type 2 where the ratio was 3.6:1 and type 5 where the ratio was 5.5:1 Adenovirus type 2 was disrupted by acetone treatment, and two protein fractions were obtained after sucrose gradient centrifugation. One of these fractions, which was associated with the viral deoxyribonucleic acid and comprised approximately 18% of the total protein of the virus, was greatly enriched with respect to N-terminal alanine and glycine.     

E-cadherin mutations and cell motility: A genotype-phenotype correlation

E-cadherin has a determinant role in tumour progression, acting as an invasion and metastasis suppressor. Germline mutations of E-cadherin gene (CDH1) occur in 30% of families with Hereditary Diffuse Gastric Cancer (HDGC); of these 23% are missense mutations. The CDH1 missense mutations described to date span the entire gene and some lead to significant functional consequences. In this study, we explored the hypothesis that mutations affecting different E-cadherin protein domains have distinct effects on cell motility. To accomplish our objective we characterized the effect of eleven HDGC CDH1 germline missense mutations (T118R, L214P, G239R, A298T, T340A, P373L, R749W, E757K, E781D, P799R and V832M) on cell motility. Further, we studied their effect on the activation of signalling pathways known to be relevant for cell motility such as the EGFR, Src kinase and MAPKs. CDH1 mutations localized on the extracellular and juxtamembrane domains, both affecting the integrity of the extracellular domain, led to increased cell motility accompanied by increased EGFR activation. Moreover, we observed that cells expressing extracellular mutants exhibit increased activation of Src kinase and p38 MAPK. Our results allowed the identification of the E-cadherin domains pivotal for cell motility, further demonstrated a genotype-phenotype correlation, and defined a subset of HDGC cases which may benefit from EGFR inhibitors.     

Organic and inorganic substrates as probes for comparing native bovine lactoperoxidase and recombinant human myeloperoxidase

The interaction of native bovine lactoperoxidase (nbLPO) with four substrates has been studied and compared with that of recombinant human myeloperoxidase (rhMPO). Kinetic, spectroscopic and binding parameters extrapolated for each enzyme-substrate adduct have been interpreted in the light of the structural data available for myeloperoxidase (X-ray structure) and lactoperoxidase (3D-model), respectively. The differences in the reactivity and affinity of nbLPO and rhMPO towards SCN(-), catechol, dopamine and 3,4-dihydroxyphenylpropionic acid are here discussed and related to a different structure of the organic substrate access channel as well as to a different accessibility of the heme pocket in the two enzymes.     

Anthobothrium galeorhini n. sp. (Eucestoda: Tetraphyllidea) a parasite of Galeorhinus galeus (Triakidae) from the Argentine coast

Anthobothrium galeorhini n. sp. (Eucestoda: Phyllobothriidae) collected from the spiral intestine of Galeorhinus galeus (Linnaeus, 1758) at the Puerto Madryn (Atlantic coastal region) is described. The new species differs from A. cornucopia as described by Euzet (1959) by the size of body, bothridia, gravid proglottids and eggs; by the neck length and by the different number of testes and proglottids. The size of bothridia and the gravid proglottids, the cirrus length and the number of testes allow differentiating the species here proposed from A. laciniatum Linton, 1890 as described by Euzel (1959). The body and cirrus sac size, the bothridia shape and the number of testes separate the species here described from A. parvum Stossich, 1895 as described by Yamaguti (1952). The anatomic differences between the cestode described by Arandas Rego (1977) and located laxonomycally under the name Anthobothrium laciniatum are listed and the systematic position of the cestode is discussed. Species parasitic of skates listed in scientific literature must be taxonomically reaccommodated, since their characteristics are not consistent with the diagnosis of Anthobothrium.