Tissue response to polyanionic collagen: elastin matrices implanted in rat calvaria

The tissue response to polyanionic collagen matrices, prepared from bovine pericardium and implanted subperiosteally in rat calvaria, was studied. The materials were implanted in 72 male rats (Rattus norvegicus, albinus, Holtzman), randomly divided into four groups: GI-MBP hydrolyzed for 24 h; GII-MBP hydrolyzed for 36 h; GIII-MBP hydrolyzed for 48 h; GIV-native M BP. The materials were explanted after 15, 30 and 60 days and analyzed by routine histological procedures. Except for group IV (native bovine pericardium), polyanionic collagen from groups GI, GII and GIII showed low inflammatory reaction associated with bone formation, partially or completely integrated to the cranial bone; group GIV was characterized by an intense inflammatory reaction with occasional dystrophic mineralization and with occasional bone formation at 60 days when there was a decrease in the inflammatory reaction. Thus, the MBP from groups I, II and III were biologically compatible, enhancing bone formation with a slight delay at 60 days in GII. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Inside-out vein graft and inside-out artery graft in rat sciatic nerve repair

Although veins and arteries present similar wall structures, there are differences which may be relevant in peripheral nerve reconstruction. Inside-out vein grafts (IOVG) have been satisfactorily used to repair both motor and sensitive nerves. However, the inside-out artery graft (IOAG) is a new technique and not fully investigated. Our study presents comparative morphological data on nerve regeneration achieved with IOVG and IOAG in the repair of Wistar rat sciatic nerves. Jugular veins and aorta arteries were harvested from donor animals and used inside-out to bridge a 10-mm gap. Animals were sacrificed at 10 weeks to evaluate nerve regeneration. Both techniques presented great variability in nervous tissue, though some animals showed satisfactory results. Different intensities of scarring processes might have interfered with nerve regeneration. Although IOVG and IOAG techniques showed similar morphometric results, in general, IOVG presented a closer-to-normal nerve organization than IOAG.

Anatomical study of the diaphragm of the opossum (Didelphis albiventris)

The anatomical characteristics of the South American opossum diaphragm were described. Five male and seven female adult opossums, weighing between 700 and 1110 g, were used. Animals were killed by ether inhalation saturation. The abdominal and thoracic walls were dissected and opened, the viscerae were removed and the diaphragm anatomy was described and photographed in situ . After diaphragm removal, some dimensional data were taken and tabled. Primary branches of the phrenic nerves were dissected under a surgical microscope. The secondary branches were studied and described by transillumination after clarification in acetic acid. The opossum diaphragm is domed and has a mean area of 54.33 +/- 3.8 cm(2) . Well-identified costal, sternal and lumbar parts form the peripheral muscular region. The central tendinous region presents with a V-like form. Three folioles comprise the phrenic centre and present different dimensions. The caudal vena cava passes through its foramen between the ventral and right dorsal folioles. Both right and left phrenic nerves present one ventral branch and one dorsolateral trunk in 50.0% and 66.67% of the cases, respectively.

Testicular interstitial cells, and steroidogenic detection in the protogynous fish, Synbranchus marmoratus (Teleostei, Synbranchidae)

The swamp eel, Synbranchus marmoratus, is a freshwater protogynic diandric species. Primary males develop directly as males while secondary males arise from the sex reversal of females. Fishes from Argentine and Brazil inland waters were collected, examined and compared for this study. In order to characterize the interstitial testicular compartment, light and electron microscopy techniques and an enzyme histochemical examination for steroidogenic cells detection were used. The interstitial compartment of S. marmoratus is composed of Leydig and myoid cells, collagen fibers, blood cells, macrophages,and amyelinic nerves. At the ultrastructural level, no differences were observed in the interstitial tissue, either between specimens from the different sampling sites or between primary and secondary males. Leydig cells are present in all testes examined throughout the year. A cytoplasmatic reaction of 3beta-HSD was detected only in Leydig cells during sex reversal and in both type of males, mainly during the regressed and early maturation classes (autumn and winter). Leydig cells possess the typical fine structural characteristics associated with steroidogenesis. Furthermore, in both type of males, during sex reversal and after the spawning period, the number of granulocytes and macrophages present in the testes increased, suggesting that they could be involved in phagocytosis and resorption of damaged cells. (C) 2004 Elsevier Ltd. All rights reserved.

Fertility of rat epididymal sperm after chemically and surgically induced sympathectomy

Guanethidine, a chemical that selectively blocks sympathetic noradrenergic neurons, was used to investigate the role of sympathetic innervation in the fertility of rat epididymal sperm, using both natural mating and in utero insemination protocols. This animal model correlates, at least in part, with spinal cord injury (SCI) in men. Adult male rats were treated daily by i.p. injections, for 21 or 42 days, with 0 or 6.25 mg/kg guanethidine. To compare the effects of guanethidine-induced sympathectomy with those following surgically induced sympathectomy, the inferior mesenteric ganglion and the proximal hypogastric nerves were removed in another group of rats. Both chemically and surgically induced sympathectomy increased the weight of the epididymis and seminal vesicles/coagulating glands as well as the number and the transit time of cauda epididymal sperm. Neither serum testosterone levels nor LH was affected by treatment with guanethidine. Using natural mating, no litters were produced by guanethidine-treated rats. Chemically denervated rats failed to produce copulatory plugs or ejaculate into the uterus. However, distal cauda epididymal sperm from chemically or surgically denervated rats displayed normal fertilization ability (80%) using in utero inseminations. In addition, the sperm of denervated rats did not show abnormal sperm chromatin structure using an assay that detects DNA damage. We conclude that sympathectomy delays the transit of sperm through the cauda epididymidis and produces ejaculatory dysfunction but does not compromise sperm quality in the distal cauda epididymidis. Moreover, these data provide compelling evidence that there is no association between the prolonged transit time of sperm within the epididymis, i.e., pre-ejaculatory sperm aging, and the fertility of those sperm, which has important implications for artificial insemination using sperm from men with SCI.

Rat epididymal sperm quantity, quality, and transit time after guanethidine-induced sympathectomy

Guanethidine, a chemical that selectively abolishes peripheral noradrenergic nerves, was used to investigate the role of sympathetic innervation in the maintenance of epididymal sperm quantity and quality. Four groups of 10 adult male rats each were treated daily for 21 days, by i.p. injections, with either 0 (saline vehicle), 6.25, 12.5, or 25 mg/kg guanethidine. Norepinephrine content was reduced to undetectable levels in the cauda epididymidis in all guanethidine groups after 3 wk of treatment and was reduced to 7.4% of the control values after 1 wk of 6.25 mg/kg treatment. While body weight gain was significantly decreased at 12.5 and 25 mg/kg compared to that in controls, there was a significant increase in the weights of the seminal vesicles/coagulating glands in all treated groups. The number of homogenization-resistant spermatids per testis and the daily sperm production per testis remained unchanged. The weight of the epididymis was significantly increased at 6.25 and 12.5 mg/kg. Moreover, the number of cauda epididymal sperm and the transit time were increased significantly at 6.25 mg/kg (10.2 days) compared to values in the control cauda (6.3 days). Neither serum testosterone levels nor LH was affected in a dosage-related manner. There were no effects of guanethidine treatment on cauda epididymal sperm motility or morphology. A quantitative analysis of detergent-extracted cauda epididymal sperm proteins by SDS-PAGE revealed no differences, but there were diminutions in seven proteins in homogenates of caput/ corpus tissue. Histologic analysis of testis and epididymis sections revealed no differences between control and denervated animals. In a subsequent experiment the lowest effective dosage (6.25 mg/kg) was given to rats for 1 wk, and an increased number of cauda epididymal sperm and a delay in sperm transit were observed. Our results indicate that low-dosage guanethidine exposure denervates the epididymis within 1 wk, thereby delaying epididymal transit; however, neither 1- nor 3-wk exposure produces qualitative changes in the sperm.

Unique Derived Features in Spermiogenesis and Sperm Morphology Supporting a Close Relationship between the Species of Hollandichthys and Rachoviscus (Characiformes: Characidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

S-100 dendritic cells in normal and Dermatobia hominis infested cattle skin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Central nervous system of Rhipicephalus sanguineus ticks (Acari: Ixodidae): an ultrastructural study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biological shape analysis by digital curvature

This paper reports the novel application of digital curvature as a feature for morphological characterization and classification of landmark shapes. By inheriting several unique features of the continuous curvature, the digital curvature provides invariance to translations, rotations, local shape deformations, and is easily made tolerant to scaling. In addition, the bending energy, a global shape feature, can be directly estimated from the curvature values. The application of these features to analyse patterns of cranial morphological geographic differentiation in the rodent species Thrichomys apereoides has led to encouraging results, indicating a close correspondence between the geographical and morphological distributions. (C) 2003 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.

Two new species of Brachycephalus (Anura : Brachycephalidae) from the Atlantic Forest in Parana State, Southern Brazil

Two new species of brachycephalid frogs are described from Pico Marumbi, municipality of Morretes, and Pico da Igreja, municipality of Guaratuba, Parana State, southern Brazil. The new species share the following attributes: body bufoniform; skin on top of the head, and central part of the back body smooth with no dermal co-ossification; outer metatarsal tubercle distinct; dermal roofing bones of skull unornamented; all paired cranial bones distinct and not fused; quadratojugals, and maxillary odontoids present. The new species from Pico Marumbi is characterized by male SVL = 11.6-12.5 and female SVL = 13.0-14.5 turn; and general color orange with dorsal reddish-brown irregular markings, lateral surfaces with small dark brown spots, and belly with brownish spots and small dots. The new species from Pico da Igreja is characterized by male SVL = 12.6-13.9 and female SVL = 14.6-15.3 mm; and general color orange, lateral surfaces with small dark brown spots, and belly with brownish coalescent spots and small dots. Comparisons with other brachycephalid species and osteological data are provided.

Morphological Changes of the Epididymis and Description of the Excurrent Ducts of Phrynops geoffroanus (Testudines: Chelidae) During the Reproductive Cycle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morfometria testicular durante o ciclo reprodutivo de Dendropsophus minutus (Peters) (Anura, Hylidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variações anatômicas no aparelho reprodutor masculino de Chaunus ornatus (Wied-Neuwied, 1821) (Anura, Bufonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

When decisions on homologous structures cause ambiguous taxa relationships: the Neomorphinae (Aves, Cuculidae) example

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)