NADPH-d activity in rat thymus after the application of retinoid acid.

The aim of this work was to determine the localization of nicotinamide-adenine dinucleotide phosphate-diaphorase (NADPH-d) activity as the marker for synthesis of nitric oxide synthase (NOS) in the rat thymus after the application of retinoid acid (RA) on 1st, 7th, 14th and 21st days of gestation. The given results can build the basis for understanding of the role of NOS in rat thymus. NADPH-d positive cells were represented with dark-blue color and were localized on corticomedullar junction of the thymus. These cells were of different intensity of coloring and were shaped in oval, circle or irregular forms. NADPH-d positive nerve fibers were observed in perivascular topography. They were marked more strongly in the case of control group. The result of application of RA to gravid rats was that the birth weights of newborn rats and their thymuses were smaller, but without statistically significance.

Influence of surgical and chemical orchidectomy on weight and distribution of AChE-nerve fibres in thymuses of adult rats.

The thymus is a crossroad between the immune and neuroendocrine systems. As such, it is innervated by acetylcholinesterase (AChE)-positive fibres of the vagus, the recurrent laryngeal and the phrenic nerves. It is well know, that the innervations density of the thymus increases with age. In our study, adult rats were orchidectomized (surgically and chemically by the application of a luteinizing hormone-releasing hormone). The density of AChE-positive nerve fibres in thymuses, as well as the weight of thymuses was examined. The authors found that both surgical and chemical orchidectomy result in macroscopic and microscopic regeneration of the atrophied thymuses. In regenerated rat's thymuses after orchidectomy the density of AChE-positive nerve fibres was markedly higher in comparison with the control animals. The distribution, as well as the density of AChE-positive nerve fibres in regenerated thymuses after orchidectomy evokes the images of its innervations like in young animals before age-related involution. The authors also found a markedly higher weight of thymuses of orchidectomized rats in comparison with the control groups. In recent study the authors proved that after 8 weeks surgical orchidectomy leads to the regeneration of thymic AChE-positive innervation and chemical orchidectomy by administration of luteinizing hormone-releasing hormone after 4 weeks of adult rats.

Effect of pesticide bendiocarbamate on distribution of acetylcholine- and butyrylcholine-positive nerves in rabbit's thymus.

Many pesticides used in agriculture have a negative effect on organisms. The group of hazardous pesticides includes the cholinesterase inhibitor bendiocarbamate. According to literature, bendiocarbamate has relatively low toxicity in mammals and vertebrates in general, since it does accumulate in their tissues and the cholinesterase activity returns to norm within 24 h after acute exposure. The present study focused on the influence of bendiocarbamate on rabbit thymus after its administration at a dose of 5 mg/kg body weight (BW) for the period of 3 months. The thymus was observed for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)-positive nerve fibers visualized by histochemical methods. Microscopic findings of BuChE-positive nerve fibers show the same density and the topography by the experimental and the control animals. On the other hand, AChE-positive nerve fibers in experimental animals after administration of bendiocarbamate is only poorly identified, suggesting that bendiocarbamate inhibits AChE but not BuChE.

Distribution of NADPH-diaphorase and AChE activity in the anterior leaflet of rat mitral valve.

The mitral valve, as an active flap, forms the major part of the left ventricular inflow tract and therefore plays an important function in many aspects of left ventricular performance. The anterior leaflet of this valve is the largest and most ventrally placed of two leaflets that come together during ventricular systole to close the left atrioventricular orifice. Various neurotransmitters are responsible for different functions including controlling valve movement, inhibiting or causing the failure of impulse conduction in the valve and the sensation of pain. Nitric oxide acts as a gaseous free radical neurotransmitter, neuromediator and effective cardiovascular modulator. Acetyl-choline is known to function as a typical neurotransmitter. Histochemical methods for detection of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), as an indirect nitric oxide-synthase marker, and method for detection of acetylcholinesterase (AChE) were used. Both methods were performed on the same valve sample. A widespread distribution of nerve fibres was observed in the anterior leaflet of the mitral valve. The fine NADPH-d positive (nitrergic) nerve fibres were identified in all zones of valve leaflet. AChE positive (cholinergic) nerve fibres were identified forming dense network and fibres organized in stripes. Endocardial cells and vessels manifested heavy NADPH-d activity. Our observations suggest a different arrangement of nitrergic and cholinergic nerve fibres in the anterior leaflet of the mitral valve. The presence of nitrergic and cholinergic activity confirms the involvement of both neurotransmitters in nerve plexuses and other structures of mitral valve.

Comparative study of the topographic localization of NADPH diaphorase positive cells in the rabbit and pheasant thymuses.

Nicotinamide adenine dinucleotide hydrogen phosphatediaphorase (NADPHd) histochemistry was used as a marker for nitric oxide synthase (NOS). In the rabbit thymus, NADPHd staining was observed between the capsule and corticomedullary junction in radially oriented blood vessels in the cortex. The outer surface of the thymic lobule and interlobular septa showed adipocytes clumped together. There was a high density of NADPHd positive cells in the medulla, without a sharp boundary in corticomedullary space. In addition to radially oriented blood vessels in the cortex, they were also found as solitary profiles with well stained walls in the medulla. Neuronal plexuses were localized in perivascular topography. In the pheasant thymus, NADPHd positive cells were present as clusters which were distributed in the medulla and the corticomedullar area. NADPHd positive nerve fibres were localized in perivascular topography.

Yeast-like microorganisms in eye infections.

The proportion of yeast species involved in eye infections in 11 patients was examined. The presence of yeast organisms as causative agents of endophthalmitis was found in corneal smears (n = 4), conjunctival swabs (4), and vitreous fluid (3). Altogether 5 strains of Candida albicans, 2 strains of C. krusei and one strain each of C. guilliermondii, C. parapsilosis, C. tropicalis and Cryptococcus neoformans were isolated from the clinical material. The hematogenic origin of endophthalmitis was proved in 7 cases on the basis of positive blood samples and in 2 cases by the isolation of yeasts from the tip of an intravenous catheter. Endophthalmitis-supporting risk factors such as indwelling intravenous catheters, prolonged use of broad-spectrum antibiotics and chemotherapy, surgical intervention, diabetes mellitus, and malignancy were observed in the patients.

Comparative analysis of NADPH-diaphorase positive neurons in the rat, rabbit and pheasant thoracic spinal cord. A histochemical study.

The distribution of NADPH-diaphorase (NADPH-d) activity was investigated and compared in the rat, rabbit and pheasant thoracic spinal cord. The investigation of all spinal cord regions (laminae) in three experimental species revealed marked differences in the distribution of NADPH-d activity. Cross sectional analysis of the spinal cord of the rat, rabbit and pheasant confirmed differences in the shape of the gray matter in all examined species. More detailed investigation of Rexed's laminas showed similar distribution of NADPH-d activity in the spinal cord of the rat and rabbit, which were different when compared with the spinal cord of the pheasant. Ventral horn of the rat and rabbit showed no labelling whereas in pheasant this area possessed a number of scattered, intensively stained neurons. In the location of autonomic preganglionic neurons, differences were found as well. In the rat there was seen a number of densely packed, clearly dark blue coloured neurons. Similarly, these neurons were present in the rabbit spinal cord but they were less numerous. No staining was found in this region of pheasant. Pericentral area (lamina X) and intermediate zone (laminaVII) revealed the presence of NADPH-d positive neurons in all examined species although they differed in number and shape of their bodies. The dorsal horn showed the presence of NADPH-d staining in all three animals but its distribution was different in medio-lateral direction. It can be suggested that observed differencies in the presence and distribution of NADPH-d activity across the examined species may reflect different fylogenetic development.

[Laminar distribution of NADPH-diaphorase in the thoracic spinal cord in pheasants]. / Laminárna distribúcia NADPH-diaforázy v hrudníkovej mieche bazanta.

BACKGROUND: The distribution of NADPH-diaphorase (NADPH-d) activity was investigated in the spinal cord of pheasants. MATERIAL AND METHODS: Histochemical method for visualization of NADPH-d was used in this study. This method is considered to be a good marker for NO synthase. RESULTS: The investigation of NADPH-d activity in laminae of the thoracic spinal cord of pheasants revealed the presence of scattered intensively stained neurons in laminae VIII and IX of the ventral horn. In the location of autonomic preganglionic neurons, no presence of NADPH-d positivity was noticed. The pericentral area (lamina X) and intermediate zone (lamina VII) showed NADPH-d positive neurons located more dorsally with larger distance from the central canal. In superficial layers of the dorsal horn (lamina I and II) marked differences were seen in the distribution of NADPH-d activity through the medio-lateral direction. CONCLUSION: In summary, it can be suggested that the observed presence of NADPH-d activity may reflect the utilization of NO in the thoracic part of the spinal cord in pheasants. (Fig. 5, Ref. 20.)

[Variation in the localization of NADPH-d positive neurons in the gray matter of the spinal cord in different species]. / Odlisnosti v lokalizácii NADPH-d pozitívnych neurónov v sivej hmote miechy jednotlivých druhov.

The presence of NADPH-diaphorase (NADPH-d) activity was investigated in the thoracic part of rat, rabbit and pheasant spinal cords. Histochemical method for visualization of NADPH-d was used in this study. The comparison between all spinal cord regions (laminae) in three experimental species revealed marked differences. Especially in the ventral horn, the presence of NADPH-d activity was different. While the pheasant ventral horn possessed number of scattered intensively stained neurons, the rat and rabbit showed no NADPH-d activity in this region. Pericentral area (lamina X), intermediate zone (lamina VII) and dorsal horn revealed the presence of NADPH-d positive neurons in all examinated species although they differed in the distribution of NADPH-d activity. In summary, it can be suggested that the observed differences in the presence and distribution of NADPH-d activity among species may reflect their different phylogenetic development. As a consequence, different NO function in spinal cord of various species can be presumed. (Fig. 10, Ref. 28.)

Rare non-albicans Candida species detected in different clinical diagnoses.

In working on the incidence of yeasts we excluded from the tested set C. albicans, C. krusei, C. parapsilosis and C. tropicalis on the basis of morphological and biochemical properties. We found 16 rare species of yeasts: C. claussenii (16), C. guilliermondii (10), C. robusta (9), C. pulcherrima (8), C. zeylanoides (4), C. glabrata (3), C. lusitaniae (3), C. catenulata (2), C. mesenterica (2), C. utilis (2), C. freyschussii, C. intermedia, C. kefyr, C. lipolytica, C. mogii, C. pseudotropicalis (1 for each). These yeasts were detected mainly in cases of premature babies (22) from the nasopharynx (13), from the rectum (4), from the skin (23), from wound drains and from blood (1 for each), with gynaecological diagnoses (15) and rarely other diagnoses, such as malignancy (5), hypertension and respiratory infections (4 for each), kidney transplantation (3), dialysis, haemolytic-uremic syndrome (2 for each), perforation of gastric ulcus, otitis, prostatitis, ulcus cruris, coma, spina bifida, peritonitis and hepatic failure from different clinical material.

Prevalence of Cryptococcus neoformans in clinical specimens.

Cryptococcus neoformans isolated from various clinical materials in 14 cases, was identified by (1) cultivation on Sabouraud glucose agar and CHROMagar Candida, (2) microscopic examination of Indian-ink-stained preparations and (3) determination of biochemical properties (assimilation and fermentation of saccharides, assimilation of KNO3, production of urease and phenol monooxygenase). C. neoformans was determined in five specimens from paediatric patients in the intensive care unit and in nine specimens from adult patients, most frequently from liquor at meningitis (n = 3).

Relative pathogenicity of Candida tropicalis in rat tongue mucosa.

The potential of C. tropicalis to colonize and infect rat tongue mucosa was demonstrated. Thirty female Sprague-Dawley rats were infected orally with three different strains of C. tropicalis. The animals were killed one and three weeks following the inoculation and sections of their tongue were stained with hematoxylin-eosin and Grocott stain. Histological changes were observed in the group of animals killed one week after inoculation and infected with C. tropicalis strain isolated from the crural ulcer of a diabetic patient. The most important finding was acute purulent myositis with the formation of abscesses. The myositis was local without signs of spreading to the surrounding tissue. Epithelium-penetrating hyphae observed in the Grocott-stained sections were relatively fewer and more sparsely distributed.

Non-albicans Candida species isolated from plastic devices.

In this work we point out an occurrence of non-albicans Candida species isolated from catheters, cannulas and drains. We detected eight non-albicans Candida species in 49 examined samples: C. parapsilosis (n = 26), C. tropicalis (n = 12), C. krusei (n = 4), C. claussenii, C. mesenterica (n = 2 for each), C. guilliermondii, C. kefyr and C. lusitaniae (n = 1 for each). Material examined from children hospitalized in intensive care units was the most frequent. Eight samples were from the oncology department, seven from the surgery department, six from the anaesthesiology department, four from the dialysis unit, two from the hematology department, one from the internal medicine department and one from the stomatology department. We examined cannula scraping 26 times (53%), catheter scraping 14 times (28.6%) and drain scraping nine times (18.4%).

[Acetylcholinesterase-positive innervation in the regenerated thymus in old rats after surgical and chemical castration]. / Acetylcholínesterázovo-pozitívna inervácia regenerovaného týmusu starých potkanov po chirurgickej a chemickej kastrácii.

Surgical and chemical castrations in old rats result in the regeneration of the involuted thymus. The distribution of ACHE-positive nerves did not differ in the regenerated thymi after surgical and chemical castrations. A number of ACHE-positive nerves were detected not only in perivascular topography but also in the functioning thymus parenchyma. A marked difference in thymus density of ACHE-positive nerves was found in rats without castration. We assume that our findings represent an indirect evidence that cholinergic nerves stimulate lymphopoiesis in the thymus. (Fig. 6, Ref. 16.)

[NADPH-diaphorase activity in autonomic preganglionic neurons in the rabbit]. / Aktivita NADPH-diaforázy v autonómnych pregangliových neurónoch králika.

BACKGROUND: In order to provide a morphological basis for the understanding of the role of nitric oxide (NO) in autonomic preganglionic neurons, the present study was designed to clarify the localization and distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity, a marker of NO synthase, in the rabbit spinal cord. METHODS: 11 Chinchilla rabbits of both sexes were used in this study. Animals were kept under conditions of controlled light and heat regimens. NADPH-d activity was examined by histochemical methods. RESULTS: The presence of NADPH-d activity in the spinal cord was detected in the dorsal horn, around the central canal (lamina X) and in autonomic preganglionic neurons. Focused on the latter, there was a prominent NADPH-d activity between T1 and L5 segments in the intermediate zone and less intensive NADPH-d staining between S1 and S3 segments. Differences between the two parts of the autonomic system were seen in the arrangement (periodical in sympathetic, and continuous in parasympathetic), in the length of neuronal processes length (shorter in sacral preganglionic neurons) and in their localization (both are seen in the intermediolateral nucleus, but neurons of the sympathetic autonomic system can be found also medially towards the central canal, whilst those of the parasympathetic system were not). CONCLUSIONS: The present results suggest that NO can be used as a transmitter in preganglionic neurons and can be involved in autonomic and sensory processes. (Fig. 10, Ref. 37.)

[Co-localization of substance P and NADPH-d in the thoracic spinal cord of rabbits]. / Kolokalizácia SP a NADPH-d v hrudníkovej mieche králika.

In this study we have demonstrated the localization of substance P (SP) and nitric oxide (NO), in the thoracic spinal cord of rabbit. SP was concentrated in the dorsal horn of the spinal cord, mostly in the superficial layers (LI, LII), around the central canal (LX), and in the region of intermedia-lateral nucleus (IML nc.). NADPH-d (nicotinamide adenine dinucleotide phosphate diaphorase) is an enzyme, which proves the presence of NO. The highest concentration of NADPH-d positive structures were found in the same regions as the SP-positivity. SP is suggested to play a role in the nociceptive transmission. Localization of NADPH-d revealed also the fact that NO may be involved in nociceptive transmission in the spinal cord. Close association of sympathetic preganglionic neurons and fibers with SP and NADPH-d positive structures suggest a role of these neurotransmitters in the modulation of sympathetic activity. (Fig. 11, Ref. 18.)

[Localization of NADPH-d positive cells in the thymus of pheasants and mice]. / Lokalizácia NADPH-d pozitívnych buniek v týmusoch bazanta a mysi.

The presented study was designed to clarify the localization and distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity, a marker of NO synthase, in pheasant and mouse thymuses. To provide a morphological basis for understanding the role of nitric oxide (NO) in the thymus. The NADPH-d histochemistry revealed dark blue stained cell structures. In the pheasant thymus, NADPH-d positive cells were present as clusters which were distributed in the medulla and the corticomedullar area. NADPH-d positive cells were observed mostly in the medulla of the mouse thymus. They were round, oval or irregular in shape, with various intensity of staining. There were found NADPH-d positive nerve fibres in the perivascular location in both groups of experimental animals. (Fig. 4, Ref. 14.)

[Localization of NADPH-d positive structures in the thymus of rabbits and rats]. / Lokalizácia NADPH-d pozitívnych struktúr v týmuse zajaca a potkana.

In order to provide a morphological basis for understanding the role of nitric oxide (NO) in the thymus, present study was designed to clarify the localization and distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADP-d) activity, a marker of NO synthase in rabbit and rat thymuses. The NADPH-d histochemistry revealed a different distribution of diaphorase positive reactivity in both animal species, visible as dark blue structures. The rabbit thymus displayed lightly stained cortex, whereas medulla was seen as a rounded complex of intensively stained cells, without sharp demarcation between them. However, unlike the rat thymus, the NADPH-d positive cells appeared to be arranged in an irregular line of dense staining at the corticomedullary junction. In the rat thymus, the NADPH-d positive nerve fibres were not evident, whereas neuronal-like plexuses were seen in the perivascular topography of the rabbit thymus. These results suggest that NO may participate in the regulation of thymic function. (Fig. 6, Ref. 30.)