Transforming growth factor-bate (TGF-β) is a growth-relating peptide that has been shown to enhance collagen production in vivo and in vitro. TGF-β isoforms include TGF-β 1, β2 and β3. TGF-β receptors subtypes include type I (TGFβRI) and type II (TGFβRII) receptors. Overproduction of TGF-β can lead to real damage.

Renal graft rejection is major problem after kidney transplantation with severe renal damage. We hypothesized that renal tissue level of TGF-β may increase in renal rejection after kidney transplantation. Therefore, the current study was designed to determine the TGF-β 1 isoform and its receptor TGFβRI in human renal tissue with rejection by immunohistochemical staining (IHCS) and compared with normal human renal tissue. The results of IHCS was evaluated by IHCS staining density scores (0, no staining; 1, minimal staining; 2, mild staining; 3, moderate staining; and 4, strong staining). The positive staining area (+%) in entire section was also determined. The sections treated with preabsorbed blocking peptide or nonimmune rabbit serum demonstrated no immunoperoxidase activity.

Nitric oxide (NO) is a potent endothelial-drived vasorelaxing factor and may involved in salt sensitive hypertension and renal damage. Nitric oxide is produced from L-arginine by activation of nitric oxide synthase (NOS). Three NOS has been identified which are brain NOS (bNOS), inducible NOS (iNOS) and endothelial NOS (eNOS). On the other hand, renal graft rejection is major problem after kidney transplantation with severe renal damage and renal vasoconstriction. While NOS has been reported localized in human and animal kidney, the status of three NOS in human renal tissue with rejection remains poorly defined. Therefore, the present study was designed to determine the expression of bNOS, iNOS and eNOS by immunohistochemical staining (IHCS) in human renal tissue with rejection and compared with that in normal human renal tissue.

Human renal biopsy (n=5) were obtained after kidney transplantation with mild and moderate renal rejection. Normal kidney biopsy was obtained during nephrectomy.

Angiotensin II (AH) is a potent vasoconstrictor and mitogenic factor. AH receptors include type 1 (ATI) and type 2 (AT2) receptors. Recent studies demonstrated that both ATI and AT2 receptors expressed in human myocardium. Circulating and local tissue level of AH was increased in severe congestive heart failure (CHF). However, the expression of ATI and AT2 in cardiac tissue with CHF remains controversial. Therefore, the present study was designed to investigate the protein expression of ATI and AT2 receptors in normal human myocardium and in human cardiac tissue with mild and severe CHF.

Human atrial tissues from normal subjects and CHF patients with ischemic cardiomyopathy and dilated cardiomyopathy were obtained from open-heart surgery and cardiac transplantation. ATI and AT2 receptor expression was investigated by immunohistochemical staining (IHCS). The results of IHCS was evaluated by IHCS staining density scores (0, no staining; 1, minimal staining; 2, mild staining; 3, moderate staining; and 4, strong staining).

Cardiac myocytes maintained in cell culture develop hypertrophy both in response to mechanical loading as well as to receptor-mediated signaling mechanisms. However, it has been shown that the hypertrophic response to these stimuli may be modulated through effects of intercellular contact achieved by maintaining cells at different plating densities. We recently developed the new special tissue culture system to culture minced cardiac tissue and to evaluate the apoptotic effect of different agent in cardiomyocytes. After 24 hours culture period, different culture conditions and factors may damage the cardiomyocyte. Therefore, we performed different methods to evaluate the viability of cardiomyocyte in cardiac tissue with 24 hours culture period in our special culture system.

Human cardiac atrial tissue was obtained from open-heart surgery (n=6). After cardiac tissue excision, the samples were immediately placed in oxygenated, nominally Ca2+-free Tyrode solution for transport to the laboratory. The time between excision and the beginning of laboratory processing was five to fifteen minutes.

C-type natriuretic peptide (CNP) is endothelial cell origin and has potent vasodilatory and antimitogenic actions. We reported that CNP was markedly increased in human cardiac tissue with severe congestive heart failure. To date, the effects of CNP on cardiomyocyte growth and death remain unclear. Therefore, the present study was designed to investigate the actions of CNP on apoptosis and apoptosis-related gene p53 expression in human cardiomyocytes.

Human cardiac atrial tissue was obtained from open-heart surgery (n=6). The cardiac tissue was minced and incubated in the special tissue culture system in the absence or presence of CNP (10-7 M) for 24 hours. These studies were repeated with HS-142-1 (HS, 10-6 M), a natriuretic peptide biological receptor antagonist. To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) was performed. The p53 expression was determined by immunohistochemical staining (IHCS). An average of 1000 nuclei was analyzed for TUNEL and p53 staining studies.

C-type natriuretic peptide (CNP) of endothelial cell origin via NPR-B receptor mediates antimitogenic and vasodilatory actions. As a circulating endocrine system, CNP plays a fundamental role in cardiorenal regulation. However, the actions of CNP on renal mesangial cell apoptosis remain poorly defined. Apoptosis might plays an important role during development of renal glomerular mesangial cells pathophysiology. The mechanisms of apoptosis include p53-dependent pathway and p53-independent pathway.

The hypothesis of this study is that CNP induces apoptosis through the process involving p53 gene in human glomerular mesangial cells via natriuretic peptide biological receptor. Therefore, the current study was designed to investigate the effects of CNP on apoptosis and p53 expression in human mesangial cell in the absence or presence of CNP biological receptor antagonist.

Cultured human mesangial cells (Clontech Lab., San Diego, CA) was incubated for 24 hours in the absence or presence of CNP (10-7 M). These studies were repeated with HS 142-1 (HS, 10-5 M), a CNP biological receptor antagonist.

Apoptosis or programmed cell death is involved in many diseases include end-stage renal failure. Apoptosis-related genes include both stimulate genes and inhibitory gene of apoptosis. The genes which stimulate apoptosis include p53 and p21-WAF. The genes which inhibit apoptosis include bcl-2 gene family. The mechanisms of apoptosis include p53-dependend pathway and p53- independent pathway. We hypothesized that apoptosis-related genes may activate in renal graft rejection after kidney transplantation. Therefore, the present study was designed to investigate apoptosis-related gene expression and localization by immunohistochemical staining (IHCS) in human renal tissues with graft rejection and compare with that in normal human renal tissue.

Human renal biopsy (n=5) were obtained after kidney transplantation with mild and moderate renal rejection. Normal human kidney biopsy was obtained during nephrectomy. P53, p21-WAF and Bcl-2 levels in renal tissue were determined by IHCS. The results of IHCS was evaluated by IHCS staining density scores (0, no staining; 1, minimal staining; 2, mild staining; 3, moderate staining; and 4, strong staining).

Regulation of apoptosis involves a number of genes that can be classified into broad categories. These include genes that act as effectors of apoptosis, such as p53, c-myc, bax, p21- WAF, and genes that primarily suppress apoptosis, such as Bcl-2 gene family. These genes have been reported to be responsible for the modulation of certain stress induced apoptosis and cell cycle arrest.

It has also been reported that apoptosis involved in cardiovascular diseases such as myocardial infarction, reperfusion injury, left ventricular hypertrophy, and hypertension. However, the expression of apoptosis-related genes in human cardiomyocytes in normal subjects and in patients with congestive heart failure (CHF) remains unclear. Therefore, the present study was designed to determine the expression and localization of apoptosis-related genes in human heart.

Five normal subjects and five end-stage CHF human ventricular cardiac tissues were obtained from cardiac transplantation. The expression of p53, p21-WAF and Bcl-2 were determined by immunohistochemical staining (IHCS).

Angiotensin II (AII) is a potent vasoconstrictor and mitogenic factor. The biological actions of All through AII receptors which include AT-1 and AT-2 receptors. However, the effects of AII on cardiomyocyte apoptosis and caspase expression remain controversial. Therefore, the current study was designed to investigate the actions of AII on human cardiomyocyte apoptosis and caspase-1 expression.

Human cardiac tissue was obtained from open-heart surgery (n=6). The cardiac tissue was minced and incubated in the special tissue culture system for 24 hours in the absence or presence of AII (10-7 M). These studies were repeated with losartan (10-6 M, AT-1 receptor antagonist) and PD123319 (PD, 10-6 M, AT-2 receptor antagonist). To detect the DNA fragmentation, TUNEL staining and DNA gel analyses were performed. The caspase-1 expression was determined by immunohistochemical staining (IHCS). An average of 1000 nuclei was analyzed for both TUNEL and caspase-1 IHCS studies.

Cyclosporine A (CsA) is the most effective and widely used immunosuppressant drug in heart, lung and kidney transplantation. However, the effect of CsA is limited by the significant toxicity. The mechanism of CsA-induced toxicity is remaining controversial. Cellular apoptosis is being suggested as a possible mediator of CsA toxicity. To date, regarding the effects of CsA on apoptosis and apoptosis-related gene regulation in cardiomyocytes remain unclear. Therefore, the current study was designed to investigate the effect of CsA on apoptosis and apoptosis-related gene p53 expression in human cardiomyocytes. We hypothesized that CsA induces apoptosis in human cardiomyocytes through p53-dependent pathway.

Human cardiac atrial tissue was obtained from open-heart surgery (n=5). The cardiac tissue was minced and incubated in the special tissue culture system for 24 hours in the absence or presence of CsA (10-7 M). To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) was performed.

Cyclosporine-A is the one of the most effective immunosuppressant drug in organ transplantation. However, cyclosporine-A has a potent cytotoxic effect. Cellular apoptosis is being suggested may contribute to the cyclosporine A-mediated cytotoxic action. To date, regarding the effects of cyclosporine-A on apoptosis and apoptosis-related genes expression in vascular smooth muscle cells remain unclear. Therefore, the current study was designed to investigate the actions of cyclosporine-A on apoptosis and p53 expression in human vascular smooth muscle cells.

Human saphenous vein was obtained from coronary artery bypass surgery (n=5). After saphenous vein removed, the tissue was minced and incubated in the special tissue culture system for 24 hours in the absence or presence of cyclosporine-A (10-6M). To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) was performed. The p53 level in human vascular smooth muscle cells was determined by immunohistochemical staining (IHCS). An average of 1000 nuclei was analyzed for both TUNEL and p53 EHCS studies.

Angiotensin II is a potent vasoconstrictor and mitogenic factor. However, the effects of angiotensin II on human vascular smooth muscle cells apoptosis remain controversial. Therefore, the current study was designed to investigate the actions of angiotensin II on human vascular smooth muscle cells apoptosis.

Human saphenous vein was obtained from coronary artery bypass surgery (n=6) and was minced and incubated in the special tissue culture system in the absence or presence of angiotensin II (10-6 to 10-12M) for 1, 2, 4, 8, 16, & 24 hours. These studies were repeated with losartan (10-6M, AT- 1 receptor antagonist) and PD-123319 (10-6M, AT-2 receptor antagonist). To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) and DNA agarose gel analyses were performed. An average of 1000 nuclei was analyzed for TUNEL studies.

TUNEL staining and DNA gel analysis demonstrated that angiotensin II increased apoptosis in human vascular smooth muscle cells.

Organisms are generally designated as “extreme” when they possess adaptations that allow them to flourish when one or more environmental parameters (e.g., temperature, ionizing radiation, oxygen, water, nutrients, inorganic ions) are at unusually high or low levels. A trade-off for this extraordinary resilience is that such organisms often grow poorly (if at all) in more conventional milieus. As a result, few of them are mammalian pathogens. (Anaerobic bacteria, which frequently thrive in the hypoxic conditions afforded by devitalized tissue, are an exception to this rule.)

A broader definition of “extremity” encompasses all organisms that occupy narrow or unusual environmental niches. In this more inclusive scheme, a wealth of viruses, bacteria, fungi, and parasites with pathogenic potential in humans can be considered extreme. These organisms often pose formidable diagnostic challenges. Many have extremely narrow host ranges, rendering passage in animals and development of model systems for infection difficult or impossible.

Opportunistic viral infections in immunosurpressed patients may morphologically involve only a few cells. Identifying an optimal area by LM is most important before an attempt at detection of viral particles by EM. The purpose of this communication is to emphasize unusual and important structural findings for some viruses.

BKV - BK polyomavirus latently infects renal tubular epithelial cells. Immunosuppressed patients many develop reactivation with resultant tubular cell damage and acute interstitial nephritis. Ultrastructural examination shows spherical and tubular virus particles of typical polyomavirus. Cross sections of the tubular form of this virus may contain electron dense cores (fig.l). Cells may be coinfected with HIV on rare occasions (fig.2).

JCV - JC polyomavirus is the major cause of progressive multifocal leukoencephalopathy (PML). JCV are rarely seen in reactive bizarre astrocytes. Biopsy of the tissue at the periphery of lesions of PML is likely to include JC-infected oligodendrocytes; it is important to appreciate that astrocytes, regardless of appearance, are unlikely to contain the virus.

“Emergence” of infectious disease agents in humans, domestic animals and wildlife during the past 20 years has been widely described. Perception of emergence derives largely from the application of improved identification methods, including refinements in molecular, serologic, and microscopy technologies that enable researchers to monitor species migration with greater sensitivity. The reality of emergence comes from shifts in genetic profiles and from influences of ecological changes often brought about by human interventions designed for economic or quality-of-life gains, and ecologic management. CDC has frequent involvement with many outbreaks caused by various infectious disease agents, some of which may be considered emerging. Notable unusual agents include filoviruses (Fig. 1) and hantaviruses (Fig. 2). More typically encountered agents include caliciviruses (Fig. 3) and influenza viruses (Fig. 4). Recently, threats of national and international bioterrorism have added to CDC's responsibilities for prompt identification of infectious agents.

An increase in cases of acute febrile encephalitis occurred in Western Malaysia between September 1998 and May 1999, and a similar illness was reported in Singapore in March 1999. Most cases occurred in males who had been exposed to pigs, or among abattoir workers, and at least 100 deaths were reported. The illness was characterized by fever and headache, followed by drowsiness and disorientation; patients with severe cases developed seizures and coma within 24 to 48 hours. Concurrently, there were also illnesses and deaths among pigs in the same region, although the symptoms predominantly involved the respiratory system, and only a few pigs had signs of neurologic disease. From a cerebral spinal fluid specimen from a human patient, Dr. Chua and colleagues were successful in isolating a virus that was morphologically identified as belonging to the family Paramyxoviridae, and is now known as Nipah virus.

Transmissible encephalopathy of animals (scrapie and bovine spongiform encephalopathy) and of man (Creutzfeldt-Jacob disease, new variant Creutzfeldt-Jacob disease, Kuru, Gerstmann-Straussler-Scheinker disease and familial fatal insomnia) have been well characterized as progressive neurodegenerative diseases, often associated with spongiform degeneration, neuronal loss, reactive astrocytic gliosis and variable amyloid plaques, without any sign of an immune response or inflammatory infiltrates. Prion proteins are elements that propagate variability through multiple biologically active conformers of a host encoded sialoglycoprotein (PrPc). The agent responsible for transmissible encephalopathies is composed mainly, if not exclusively, of an isoform of PrP, designated PrPSc. Extensive information of post-mortem material has been described at the light microscopic level, where the emphasis has been on spongiform tissue and amyloid plaques. Our study provides ultrastructural observations of the central nervous system, specifically of degenerating neurons and their associated changes during the course of scrapie infection in a hamster model.

The protozoan parasite Toxoplasma gondii represents a large group of Apicomplexan parasites with a highly unusual motility system that is crucial for cell locomotion and host cell invasion. Studying the motility system and interactions with host cells will increase our knowledge on how to prevent infection. Apicomplexan parasites can cause considerable health problems to animals including sheep, goats, pigs, and chicken. Eimeria is known as a pathogen of coccidiosis in chicken, and Cryptosporidium causes cryptospiridiosis in cattle and other farm animals. Toxoplasma gondii can cause infection that results in abortion, central nervous disorders and death of stressed and immunocompromised farm animals. Common to all Apicomplexan parasites is an unconventional motility system that is thought to be actively involved in host-cell invasion. However, the structural and biochemical characterization of Apicomplexan parasites has proven more difficult than previously thought because of genetic and behavioral differences of the parasites’ cytoskeletal proteins that differ from those in well studied mammalian systems.

Hepatitis C virus (HCV) is an RNA virus of the family Flaviviridae. In the decade since its identification,1 it has emerged as a leading cause of chronic hepatitis and cirrhosis. Easily transmissible by parenteral and sexual routes, fastidious in culture, highly limited in host range, and difficult to detect by most microscopic and immunohistochemical methods, HCV qualifies as an extreme pathogen. Another form of extremity exhibited by HCV is the bewildering array of renal disorders that occur in the setting of HCV-induced hepatitis.

Several different mechanisms may underlie the development of renal disease in patients infected with HCV. Immune complexes of anti-HCV antibodies and viral components, frequently bound to anti-immunoglobulin rheumatoid factors, can form in the circulation and be deposited in the kidney. HCV has also been shown to induce immune responses to a variety of autoantigens, some of which are expressed in the kidney. Hepatic injury caused by HCV may produce downstream effects on other organs, including the kidney.

Biofilms are collections of microorganisms at interfaces. Because of the high proportion of interfacial regions in the natural environment, biofilms are likely to be the repository for most of the world's microbial biomass. The close proximity of organisms within the biofilm presents the opportunity for intra- and interspecies signaling on a physical level through direct contact of organisms with one another, and on a metabolic level through production/excretion of intermediary molecules of metabolism and of specific cell signaling molecules. One of the best studied biofilms is dental plaque, which has been investigated from a microscopy standpoint since the time of van Loewenhouk and from a classical bacteriological standpoint since the relatively recent (20th century) development of anaerobic culture techniques. Through the even more recent (the last decade) application of molecular methods, it has been shown that perhaps half of all bacteria present in plaque are culturable and, at present, this consists of some 500 species.