Morphological changes in the digestive system of 93 human immunodeficiency virus positive patients: an autopsy study

Involvement of the digestive system in patients with acquired immunodeficiency syndrome (AIDS) is frequent and many changes in these patients are diagnosed only at autopsy. There are few studies of autopsy with detailed analysis of this system and only one was conducted in Brazil. We evaluated each segment of the digestive system in 93 consecutive autopsies of patients infected with human immunodeficiency virus (HIV) and the importance of these lesions to death. Of these, 90 (96.8%) patients had AIDS. We reviewed medical records, autopsy reports and histological sections from tongue to rectum stained with hematoxylin-eosin. When necessary, we analyzed special stains and immunohistochemistry to investigate infections. There was damage to the digestive system in 73 (78.5%) cases. The most common infections were candidiasis (42%), cytomegalovirus (29%), histoplasmosis (11.8%), toxoplasmosis (9.7%) and mycobacterial infection (9.7%). Malignancies were rare, present in four (4.3%) cases (two Kaposi's sarcoma, one adenocarcinoma and one metastatic embryonal carcinoma). All segments showed lesions: tongue (48.6%), esophagus (44.8%), stomach (44.7%), colon (43.2%) and small intestine (28.9%). The lesions found were immediate cause of death in five (5.4%) cases. In another 36 (38.7%) cases the basic disease was systemic and also compromised the digestive system.

Age related changes in the elastic fiber system of the interfoveolar ligament

In order to evaluate age related changes of the elastic fiber system in the interfoveolar ligament, we studied the deep inguinal ring from 33 male cadavers aged from stillborn to 76 years. Selective and alternated staining methods for elastic fibers were performed to differentiate oxytalan, elaunin, and mature elastic fibers. We confirmed quantitative changes of the elastic fiber system with aging. There was a significant and progressive reduction of the oxytalan fibers (responsible for tissue resistance) and a significant increment in the mature elastic and elaunin fibers (responsible for tissue elasticity). Furthermore, there were structural changes in the thickness, shortness and curling of these mature elastic fibers. These changes induced loss of the elastic fiber function and loss of the interfoveolar ligament compliance. These factors predispose individuals to the development of indirect inguinal hernias that frequently emerge in adults and aged individuals, especially above the fifth decade.

Anatomic study of the dorsal arterial system of the hand

Historically, the dorsal arterial system of the hand received less attention than the palmar system. The studies concerning dorsal arterial anatomy present some controversies regarding the origin and presence of the dorsal metacarpal artery branches. Knowledge of the anatomy of dorsal metacarpal arteries is especially applied in the surgical planning for flaps taken from the dorsum of the hand. The purpose of this study is to analyze the arterial anatomy of the dorsum of the hand, compare our observations with those of previous studies from the literature, and therefore to define parameters for surgical planning for flaps supplied by the dorsal metacarpal arteries. METHOD: Twenty-six dissections were performed at the dorsum of the right hand of 26 cadavers by making a distal-based U-shaped incision. After catheterization of the radial artery at the wrist level, a plastic dye solution with low viscosity and quick solidification was injected to allow adequate exposure of even small vessels. The radial artery and its branches, the dorsal arterial arch, the dorsal metacarpal arteries, the distal and proximal communicating branches of the palmar system, and the distal cutaneous branches were carefully dissected and identified. RESULTS: The distal cutaneous branches originating from the dorsal metacarpal arteries were observed in all cases; these were located an average of 1.2 cm proximal from the metacarpophalangeal joint. The first dorsal metacarpal artery presented in 3 different patterns regarding its course: fascial, subfascial, and mixed. The branching pattern of the radial artery at the first intermetacarpal space was its division into 3 branches. We observed the presence of the dorsal arterial arch arising from the radial artery in 100% of the cases. The distance between the dorsal arterial arch and the branching point of the radial artery was an average of 2 cm. The first and second dorsal metacarpal arteries were visualized in all cases. The third and fourth dorsal metacarpal arteries were visualized in 96.2% and 92.3% of cases, respectively. There was proximal and distal communication between the dorsal arterial arch and the palmar system through the communicating branches contributing to the dorsal metacarpal artery formation. CONCLUSION: At the dorsum of the hand there is a rich arterial net that anastomoses with the palmar arterial system. This anatomical characteristic allows the utilization of the dorsal aspect of the hand as potential donor site for cutaneous flaps.

Color change using HSB color system of dental resin composites immersed in different common Amazon region beverages

The purpose of this study is to evaluate in vitro the color stability of composite resins when exposed to beverages with high coloring contents from the Amazon region. 240 samples from four different composite brands (Natural Look, Z350, 4Seasons and Opallis) of hue A3 were fabricated using an acrylic matrix. The samples were stored in distilled water at 37ºC for 24 hours. The initial color (T0) was registered using a Canon EOS Rebel XTi 10 mp camera, and then the samples were divided into four groups (n=15): G1 (coffee), G2 (açaí juice), G3 (energetic guaraná) and G4 (control - distilled water). The samples were exposed to solutions of DES (6hs) and RE (18hs) and placed in a double boiler under constant agitation, at 37ºC for 30 days. The samples were immersed in the coloring solutions for 15 minutes daily. After 7, 15 and 30 days, new photographic registers were made (T1, T2 and T3). The images were analyzed using Corel PHOTO-PAINT 12 software to identify the colors through the HSB system. The Kruskal-Wallis and t tests (p<0.05) demonstrated significant differences in color (hue, saturation and brightness). The results revealed that none of the tested composites showed color stability when exposed to coloring solutions, and that the Amazon region beverages (açaí juice and energetic guaraná) showed to be less coloring than coffee.

Lankesterella alencari n. sp., a toxoplasma-like organism in the central nervous system of Amphibia (Protozoa, Sporozoa)

Lankesterella alencari n. sp. a Sporozoa that occur in the blood and CNS of the South American frog Leptodactylus acellatus is described. Since the tissue forms of this parasite have been previously reported as belonging to the genus Toxoplasma, we attempted in fection of 2 species of amphibia (Bufo marinus an dLeptodactylus ocellatus) with a Toxoplasma strain of human origen; inoculation was by intraperitoneal injection of parasite-containing ascitic fluid from infected mice. Attempt of experimental inoculation of the parasite found in the CNS of L. ocellatus in a highly susceptible host (mice) was unsuccessful. These results suggest that Toxoplasma does not occur naturally in the amphibia; be related to Toxoplasma is excluded. The following genera of haematozoa found in brazilian amphibia have been considered briedfly: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon and Trypanosoma.

The conduction system of the heart in mice chronically infected with Trypanosoma cruzi: histopathological lesions and electrocardiographic correlations

Chronic focal and diffuse myiocarditis with interstitial fibrosis developed in Swiss outbred mice and in the inbred AKR and A/J strains of mice which were chronically infected with several Trypanosoma cruzi strains belonging to three biological types (Type I, II and III). High incidence of electrocardiographic changes with predominance of intraventricular conduction disturbances, 1st. and 2nd. degree AV block, arrhythmias, comparable with those found in human Chagas' disease, were also present. Morphological study of the conduction tissue of the heart revealed inflammatory and fibrotic changes. The presence of inflammation in the inter-atrial septum almost always coincided with the inflammatory involvement of the ventricular conduction system. Focal inflammation was associated with vacuolization and focal necrosis of the specific fibers. Most of the lesions were seen affecting the His bundel (76.3% of the cases), the right bundle branch (73.3%), AV node (43.9%) and left bundle branch (37.5%). Correlation between morphological changes in the conduction tissue and electrocardiographic alteration occured in 53.0 to 62.5% of the cases, according to the experimental groups.

A new species of culex (Melanoconion) from atlantic tropical system of Souther Brazil (Diptera: Culicidae)

The male adult of Culex (Melanoconion) anoplicitus, a new species from Southern Tropical Atlantic System of Brazil, South America, is described and illustrated. Identification may be made by characteristic morphological aspects of genitalia which are peculiar to this species.

Prof. Hugo de Souza Lopes and the modern system of Sarcophagidae (Diptera)

Prof. Dr. Hugo de Souza Lopes is one of the authors of the phylogenetic classification of Sarcophagidae, especially Sarcophaginae. In this paper I present the taxonomic key of the tribes of Sarcophaginae according to his opinion; a list of the 48 genera and subgenera and the 356 species described by Prof. Lopes; and a review of subtribal construction of tribe Sarcophagini with a key of the subtribes. One new subtribe Boettcheriiscina Verves, subtr. nov. and two new monotypic genera (Mufindia Verves, gen. nov., and Sabiella Verves, gen. nov.) are described. The role of Prof. Lopes in the knowledge of taxonomy and ecology of American, Oriental, Australian and Oceanic Sarcophagidae is illumined.

Morphology and Histology of the Female Reproductive System of Abedus ovatus Stal (Belostomatidae: Hemiptera: Insecta)

In Abedus ovatus Stal, the female reproductive system consists of a pair of ovaries leading to oviduct and opens out by genital aperture. Each ovary is composed of five telotrophic ovarioles, with four different regions, terminal filament, germarium, vitellarium and pedicel. Germarium and vitellarium are the germ tubes in which the development of oocyte occurs. In the germarium, the differentiation of trophocytes into young oocytes was observed in three zones, ZI, ZII and ZIII. Further development of oocytes in the vitellarium could be divided into seven stages, STI STVII. The developed eggs are lodged in the pedicel

The postembryonic development of the ocellar system of Triatoma infestans Klug (Heteroptera: Reduviidae)

Simple eyes or ocelli coexist with compound eyes in many adult insects. The change in the morphology of the ocelli along the five larval instars of Triatoma infestans was studied by light and scanning electron microscopy. Our analysis showed that the development of the ocelli of these bugs occurs gradually along the larval life. The photoreceptor layer is present from the second-instar onwards. The cornea appears first at the imaginal stage and grows up to the 18-20th day after the last ecdysis, associated to an increase in the retinal mass. Findings are discussed in a comparative fashion and in relation to the functionality of the ocellar system in T. infestans.

The effects of drugs, ions, and poly-l-lysine on the excretory system of Schistosoma mansoni

We have been able to label the excretory system of cercariae and all forms of schistosomula, immature and adult worms with the highly fluorescent dye resorufin. We have shown that the accumulation of the resorufin into the excretory tubules and collecting ducts of the male adult worm depends on the presence of extracellular calcium and phosphate ions. In the adult male worms, praziquantel (PZQ) prevents this accumulation in RPMI medium and disperses resorufin from tubules which have been prelabelled. Female worms and all other developmental stages are much less affected either by the presence of calcium and phosphate ions, or the disruption caused by PZQ. The male can inhibit the excretory system in paired female. Fluorescent PZQ localises in the posterior gut (intestine) region of the male adult worm, but not in the excretory system, except for the anionic carboxy fluorescein derivative of PZQ, which may be excreted by this route. All stages of the parasite can recover from damage by PZQ treatment in vitro. The excretory system is highly sensitive to damage to the surface membrane and may be involved in vesicle movement and damage repair processes. In vivo the adult parasite does not recover from PZQ treatment, but what is inhibiting recovery is unknown, but likely to be related to immune effector molecules.

Interaction between primary and secondary sporocysts of Schistosoma mansoni and the internal defence system of Biomphalaria resistant and susceptible to the parasite

The outcome of the interaction between Biomphalaria and Schistosoma mansoni depends on the response of the host internal defence system (IDS) and the escape mechanisms of the parasite. The aim of this study was to evaluate the responsiveness of the IDS (haemocytes and soluble haemolymph factors) of resistant and susceptible Biomphalaria tenagophila lineages and Biomphalaria glabrata lineages in the presence of in vitro-transformed primary sporocysts and secondary sporocysts obtained from infected B. glabrata. To do this, we assayed the cellular adhesion index (CAI), analysed viability/mortality, used fluorescent markers to evaluate the tegumental damage and transplanted secondary sporocysts. B. tenagophila Taim was more effective against primary and secondary sporocystes than the susceptible lineage and B. glabrata. Compared with secondary sporocysts exposed to B. tenagophila, primary sporocysts showed a higher CAI, a greater percentage of dead sporocysts and were labelled by lectin from Glycine max and Alexa-Fluor 488 fluorescent probes at a higher rate than the secondary sporocysts. However, the two B. tenagophila lineages showed no cercarial shedding after inoculation with secondary sporocysts. Our hypothesis that secondary sporocysts can escape the B. tenagophila IDS cannot be confirmed by the transplantation experiments. These data suggest that there are additional mechanisms involved in the lower susceptibilty of B. tenagophila to S. mansoni infection.

Standardisation of Western blotting to detect HTLV-1 antibodies synthesised in the central nervous system of HAM/TSP patients

Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1) antibodies (Abs) represents conclusive evidence of a specific immune response in the central nervous system of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Western blotting (WB) for HTLV Abs in serum is a confirmatory test for HTLV-1 infection. The aim of this study was to standardise the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1 proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF) and serum samples were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative patients and two HTLV-1 patients without definite HAM/TSP. The presence of reactive bands of greater intensity in the CSF compared to serum (or bands in only the CSF) indicated the intrathecal synthesis of anti-HTLV-1 Abs. All definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1 Abs; these Abs were not detected in the control patients. The most frequent intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal immune response against env (GD21 and rgp46-I) and gag (p24) proteins represents the most important humoral pattern in HAM/TSP. This response may be used as a diagnostic marker, considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis with HAM/TSP and the pathogenesis of this neurological disease.

Construction and characterisation of a complete reverse genetics system of dengue virus type 3

Dengue virulence and fitness are important factors that determine disease outcome. However, dengue virus (DENV) molecular biology and pathogenesis are not completely elucidated. New insights on those mechanisms have been facilitated by the development of reverse genetic systems in the past decades. Unfortunately, instability of flavivirus genomes cloned in Escherichia coli has been a major problem in these systems. Here, we describe the development of a complete reverse genetics system, based on the construction of an infectious clone and replicon for a low passage DENV-3 genotype III of a clinical isolate. Both constructs were assembled into a newly designed yeast- E. coli shuttle vector by homologous recombination technique and propagated in yeast to prevent any possible genome instability in E. coli . RNA transcripts derived from the infectious clone are infectious upon transfection into BHK-21 cells even after repeated passages of the plasmid in yeast. Transcript-derived DENV-3 exhibited growth kinetics, focus formation size comparable to original DENV-3 in mosquito C6/36 cell culture. In vitro characterisation of DENV-3 replicon confirmed its identity and ability to replicate transiently in BHK-21 cells. The reverse genetics system reported here is a valuable tool that will facilitate further molecular studies in DENV replication, virus attenuation and pathogenesis.