Biomedical subjects

D Kluchova

Publications and source records attributed to D Kluchova.

12 recordsLinked to original sources

PubMed2002

Alterations of the vessel wall innervation during diabetes mellitus.

Coronary and valvular heart disease during diabetes mellitus (DM) are major contributors of morbidity and mortality in the diabetic population. Relatively little atention has been given to the study of heart valve nerve structures in different pathological processes. In this study we have demonstrated the presence of possible morphological alterations in vessels of the anterior cusp of the rat mitral valve during 8-12 weeks DM. A histochemical method was used for the detection of NADPH-diaphorase (NADPH-d), which is the indirect NO-synthase marker. Arterioles and fine capillaries were localized in the attachment zone of the anterior cusp. Perivascular nerve fibres were identified running in the tunica adventitia. A marked dilatation of the vessels was seen in diabetes in comparison with control samples. No NADPH-d positive nerve fibres were observed in the tunica adventitia. It can be presumed that metabolic changes in the vessel walls during DM reflect modified neurotransmission of NO by means of their excessive overproduction of NOS (endothelial--eNOS) in endothelial cells. (Fig. 6, Ref. 32.).

Animals↗

PubMed2001

Immunohistochemical detection of LRP protein in the normal human lung.

In this study, we have determined the LRP (lung resistance-related protein) by immunohistochemical method. LRP belongs to proteins which cause the multidrug resistance (MDR). It has been found in various normal human tissues, where it plays a protective role against toxic compounds. Multidrug-resistant cells distribute the cytotoxic drug into the perinuclear region and then redistribute it back into the cytoplasm. It is just a hypothesis today that LRP can mediate drug resistance by regulating both the cytoplasmic redistribution and the nucleocytoplasmic transport of drugs. In order to detect LRP we have used the paraffin-embedded sections of the normal human lung tissue. LRP was predominantly located in two regions: 1) in bronchial epithelial cells and 2) in alveolar macrophages. Positive cells were coloured brown and showed strong reactivity. Negative control included the omitting of primary antibody and replacing it by buffer solution. Bronchial epithelial cells and alveolar macrophages stayed uncoloured, i.e. unreactive. (Fig. 5, Ref. 17.).

Bronchi↗

PubMed2000

[Coexistence of cholinergic and nitrergic neurotransmitters in the spinal cord of rabbits].

Nitric oxide (NO) plays a major role as a neuronal messenger molecule. NO has been assumed to act as a retrograde signalling molecule that modulates transmitter release. Acetylcholine (ACh) is known to function as a typical neurotransmitter. In the present work the presence of both transmitters (NO and ACh) and their possible relations in the rabbit spinal cord were examined. In our experiments histochemical methods for the visualisation of acetylcholinesterase (AChE) and NADPH diaphorase (NADPH-d) were used. Both histochemical methods were performed separately and together on the same sections of the thoracic spinal cord. NADPH-d positive dark blue stained neurons were mainly detected in superficial and deep layers of dorsal horn, preganglionic autonomic neurons and pericentral area (1). The presence of AChE positive amber yellow neurons was confirmed mostly in motoneurons located in ventral horns and then in neurons of the intermediate zone. Except for the above mentioned also double-labeled neurons containing both yellow and dark blue histochemical product were noticed. Their presence was confirmed in the intermediate zone and in the pericentral area. Thus, the coexistence of NADPH-d and AChE was confirmed in the area of interneurons. These observations suggest that NO may play a role in the control of cholinergic neuronal activity and that NO can be involved in the modulation of synaptic transmission. (Fig. 9, Ref. 21.)

Acetylcholine↗

PubMed2000

[New pedagogic methods in anatomy: experience at Cambridge University].

The expansion of knowledge in basic medical sciences is not linked to the time assigned for the teaching of anatomy to medical undergraduates. The question of "basic knowledge" in teaching anatomy during medical training arises as a need for education of future clinical doctors. Nowadays, two extreme views in teaching anatomy can be recognized: one adopted some pure anatomists who feel their existence threatened even by the idea of any reduction in their field, and one by some morphologists exclusively interested in cellular biology, who consider that classical anatomy is of no interest, since it has been exhausted as a field for research. An intermediate position is taken by some clinicians, who maintain that anatomy is indispensable but seek a severe reduction in the content to what they consider to be necessary. The above mentioned need for clinicians was reflected in recommendations of Education Committee of the General Medical Council (GMC) which in short, could be characterized by: the substantial reduction of factual information, the increase of student learning and the emphasis of clinically applied anatomy with its integration to the general medical education. GMC delegated the Department of Anatomy at the University of Cambridge by the developing of the new anatomy course. This new course was for the first time introduced in school year 1998-1999. In this study are presented ways and methods of undergraduate anatomy teaching at the University of Cambridge. These educational principles could serve as a model for teaching anatomy during its transformation in other medical faculties.

Anatomy↗

PubMed2000

[Detection of peptidergic and nitrergic structures in the spinal ganglia of rabbits].

In this study we have demonstrated the presence of neuropeptide substance P and non-peptide neurotransmitter NO (nitric oxide) in the dorsal root ganglia of rabbit. NADPH-diaphorase histochemical staining was used for the detection of NO and immunohistochemical method for the detection of substance P.A particular number of dorsal root ganglion (DRG) cells were stained by SP and NADPH-d reaction. The presence of SP and NADPH-diaphorase positive cells varied depending upon spinal level of DRGs. Positively stained neurons were only small or medium-sized. Cells of large diameter profiles showed no staining. Substance P immunoreactive cells were stained brown and dark brown, the intensity of NADPH-d staining varied from light to very dark blue. In some DRGs cells, there was a very significant neuronal co-localization of immunoreactivity for SP and reactivity for NADPH-d. In summary, DRG cells appear to express diaphorase and substance P activity, and some of them contain both neurotransmitters. Recent studies analysing the participation of NO in the regulation of SP release in the spinal cord suggest, that the DRGs neurons may display a close interaction between NO and SP. (Fig. 14, Ref. 39.)

Animals↗

PubMed2000

[Laminar distribution of NADPH-diaphorase in the thoracic spinal cord in pheasants].

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.)

Animals↗

PubMed2000

[Variation in the localization of NADPH-d positive neurons in the gray matter of the spinal cord in different species].

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.)

Animals↗

PubMed2000

Anatomy into the future.

The necessary increase in the clinical components of the medical curriculum has created pressure to reduce the amount of time spent on basic science, particularly the detailed learning of anatomy. Methods of learning must be re-evaluated, but departments will be constrained by resources available. The clinical aspects of anatomy should form the principles of a core course, with a limit to the wider anatomical knowledge required. Feedback from the students is recommended as an initial form of monitoring the course. (Ref. 13.)

Anatomy↗

PubMed1999

[Neurodegeneration and nitric oxide].

NO appears to play a significant role in the physiological processes of many of the body's systems. This review examines the present molecular, physiological and pathological knowledge related to NO and its clinical implications. The role of NO in pathophysiology of diseases is not yet fully elucidated. It is still unclear whether alterations in NO production, release and degradation are primary events in pathological processes. The presented work deals with neurodestructive and neuroprotective effects of NO. The hypothesis suggests that under physiological conditions NO acts as a neuronal messenger molecule. In pathological conditions, with excessive NO release, NO may function as a cytotoxic molecule being involved in several neurodegenerative processes. The most important issue associated with NO research will be to elucidate the cellular and molecular mechanisms of NO action. (Fig. 2, Ref. 32.)

Animals↗

PubMed1999

[Nitrergic structures in the spinal ganglia in rabbits].

Nitrergic structures in normal rabbit dorsal root ganglia (DRG) were demonstrated in this study. Histochemical reaction for detection of NADPH-d activity was used indicating, the presence of nitric oxide synthase (NOS). Diaphorase activity was found mostly in small ganglion cells. The cells defined as intermediate in size were stained less frequently, and no big cell expressed diaphorase activity. The intensity of staining varied from light blue and violet to very dark. The highest number of reactive cells was detected in the sacral DRG. Neurons expressed very low concentration of diaphorase activity in cervical, thoracic and lumbar DRGs. These findings suggest, that NADPH-diaphorase activity demonstrate a distinctive distribution depending upon spinal level.

Animals↗

PubMed1997

Spinal cord gray matter layers rich in NADPH diaphorase-positive neurons are refractory to ischemia-reperfusion-induced injury: a histochemical and silver impregnation study in rabbit.

Silver impregnation analysis of neuronal damage and concurrent histochemical characterization of NADPH diaphorase-positive neuronal pools in the rabbit lumbosacral segments was performed during and after transient spinal cord ischemia. Strongly enhanced staining of NADPH diaphorase-positive neurons and their processes appeared in the superficial dorsal horn (laminae I-III), the pericentral region (lamina X) of lower lumbar segments, the lateral collateral pathway, and mainly in neurons of the sacral parasympathetic nucleus in the S2 segment at the end of 40 min of abdominal aorta ligation or 1 day after reperfusion. Despite the development of extensive neuronal degeneration in the central gray matter (laminae IV-VII) between 1 and 4 days after ischemia, a number of nonnecrotizing neurons localized in the areas corresponding with the distribution of NADPH diaphorase-positive neurons was detected, suggesting a selective resistance of these classes of neurons against transient ischemic insult. While the precise mechanism of the observed resistance is not known, it is postulated that region-specific synthesis of nitric oxide and its vasodilatatory effect during the period of incomplete spinal ischemia may account for the observed selective resistance of these spinal cord neurons to transient ischemia.

Animals↗

PubMed1991

Blood flow and electrolytes in spinal cord ischemia.

The contribution of reoxygenation-reperfusion injury to ischemic brain damage has been clearly demonstrated but not in the spinal cord. To evaluate this phenomenon in spinal cord ischemia, we measured spinal cord blood flow (SCBF) by [14C]iodoantipyrine and electrolytes in rabbits after 10 or 40 min ischemia followed by 30 min or 4 days recirculation. Ischemia for 10 or 40 min reduced blood flow in the lower lumbar segments L5-L7 (30 ml/100 g/min) to 5 and 10% of control. After 30 min of recirculation moderate hyperemia (25-40% above control) was observed in segments L5-L7 which was not related to the degree of functional impairment. Na+, water, and Ca2+ increased and K+ decreased after 40 min ischemia, but were unchanged after 10 min ischemia. Recirculation for 30 min after 40 min of ischemia resulted in a progressive rise in Ca2+ which correlated with irreversible spinal cord injury.

Animals↗