Cyclosporin-A(CyA) is a very potent immunosuppressive agent which is widely used in transplantations and autoimmune diseases. The aim of this study was to investigate (i) the vascular changes after long term and low dose CyA treatment, (ii)if Cremophor-EL(the vehicle in the intravenous form of CyA) is responsible from these changes, and (iii) the structural effect of combined therapy with prednisolone on light and electrone microscope level.

Twenty-four female Sprague-Dawley rats were divided into four groups: First group was control. The other three group had daily intraperitoneal injection of 4mg/kg/day CyA for 2.5 months. Second group had oral, third group had intravenous form of this drug while the fourth group had intravenous form with 1 mg/kg/day prednisolone. Biopsy specimens from renal cortex were embedded in paraffin and Araldite for light and electron microscopic examinations.

Light microscopic changes were quite similar in all three experimental groups and confined to arterioles and small arteries: Endothelial cells protruded into the lumen,even seperating from the intimal layer; while some of them were undergoing pyknosis.

Centrosome abnormalities and abnormal mitotic formations have been shown in human breast cancer tissue and in LNCaP and DU145 prostate cancer cells in culture. Here we report on abnormal centrosome and centriole organization in the transgenic adenocarcinoma mouse prostate (TRAMP) model and on the implications for abnormal cell divisions, genomic instability, and apoptosis. Centrosomes are microtubule organizing centers which assemble bipolar spindles in normal cells. In cancer, centrosomes cause the formation of mono-, tri-, and multipolar mitoses which will separate chromosomes unequally during cell division.

We investigated the occurence of abnormal mitoses in TRAMP tissue in different stages of cancer progression using transmission electron microscopy (TEM). Advanced stages of prostate cancer are characterized by multiple abnormal mitoses ranging from tripolar to unusual multipolar formations. In addition, apoptotic bodies are abundant which may indicate that multipolar mitoses will lead to cell death or apoptosis.

Barban and chlorpropham are common carbamate herbicides that disrupt mitosis by destabilizing plant microtubules. Tubulins, protein subunits of microtubules, in plant and animal cells are highly conserved through evolution. Plant and animal cells have been shown to possess similar microtubule structural proteins, microtubule binding proteins, and organizational proteins. These similarities suggest that herbicides targeting plant microtubules might also affect animal microtubules. Previous tubulin immunofluorescence microscopic studies of HeLa cells, a human cervical cancer cell line, have shown that barban is strongly cytoskeletotoxic and chlorpropham is weakly cytoskeletotoxic. Both barban and chlorpropham have been shown to disrupt mitosis and disorganize spindle apparatus formation in numerous types of mammalian cancer cells.

This investigation was undertaken to examine the effect of barban and chlorpropham on MRC-5 cells, a normal human fibroblast cell line, as well as on HeLa cells. A monoclonal antibody to α-tubulin, a microtubule specific protein, was used to probe the formation of spindle apparatuses in dividing cells.

Canine hepatozoonosis, an emerging tick-transmitted protozoal disease of dogs in the United States, was first recognized in Texas in 1978. Since 1978, the geographic distribution of the disease has expanded to include Louisiana, Alabama, Georgia, and Oklahoma. The expansion of hepatozoonosis maybe associated with spread of the tick vector, Amblyomma maculatumThe causative agent of North American hepatozoonosis was initially thought to be a particularly virulent strain of Hepatozoon canis,the parasite that causes hepatozoonosis in the Old World. However, because of notable differences between the disease and the morphologic features of asexual and sexual stages of the parasites in the USA and the Old World, the organism responsible for canine hepatozoonosis in North America was designated a new species, Hepatozoon americanumThe clinical course of canine hepatozoonosis in the USA is chronic, progressive, and generally fatal. The disease manifests with intermittent fever, gait abnormalities, marked lethargy, weight loss, muscle wasting, and pain.

Ultrastructural examination is sometimes necessary for diagnosis of surgical pathology material. Not uncommonly, tissue is not fixed in 3% glutaraldehyde prior to realizing that electron microscopy would be valuable or even necessary to render a diagnosis. It is well known that formalin can be an adequate fixative for ultrastructural evaluation of tissue. Increasingly, non-formalin based fixatives have become more popular with routine surgical pathology practice. Prefer™, a glyoxal-based fixative, has become a popular substitute for formalin in many institutions. We are not aware of any study that has compared ultrastructural morphology of tissue fixed in formalin to tissue fixed in a glyoxal-based fixative.

To address this question, we took sections of fresh tissue from three different tumors (metastatic melanoma involving a lymph node, squamous cell carcinoma of the lung, and mixed papillary serous and clear cell carcinoma of the ovary) and fixed a portion of each in 3% glutaraldehyde, 10% neutral buffered formalin, and Prefer™.

Primary cardiac tumors of any type in infancy and childhood are rare, with a prevalence of 0.03%reported in autopsy surveys carried out at children's hospitals. Within the pediatric population,the most common primary tumor involving the heart is rhabdomyoma. These tumors may bedivided into 3 groups: 1) arising in tuberous sclerosis; 2) arising sporadically; or 3) arising in congenital heart disease. Many cardiac rhabdomyomas are asymptomatic and regress early in life without clinically untoward effects. Only a small proportion of these tumors come to the attention of the pediatrician and pathologist when there is obstruction of blood flow, a murmur related to subaortic stenosis, or arrhythmias. Rhabdomyomas may be detected prenatally during ultrasound examination, with one case being diagnosed at 22 weeks gestation. Although it is possible to subdivide the tumors into 3 groups, the association of this entity with tuberous sclerosis is very strong with at least 60 to 85% of children with rhabdomyomas having tuberous sclerosis.

Two forms of muscular alterations have been described in alcoholic patients, one acute, the so called Hypokalemic alcoholic Myopathy; focal or diffuse pain, swelling, tenderness and weakness of skeletal muscle are the main clinical features, and the chronic one with proximal muscle weakness wich progresses slowly in a period of weeks or months Ultrastructurally myofibril disorganization and necrosis where described.

In this work we present a systematic study of skeletal muscle alterations in four alcoholic patients who attended the Department of Internal Medicine at Caracas University Hospital . The patients were males, ages between 56 and 62 years old, and presented chronic alcoholism with muscle weakness with a more distal distribution and polymyalgia. Biopsies were taken from quadriceps femorismuscle with a percutaneous neddle and processed for routine transmission electron microscopy.

Muscle fibers showed different degrees of atrophy with myofibril disorganization (Fig.l) and disappearence (Fig.2). Myonuclei were hyperchromatic and intermyofibrilar spaces were widened and exhibited abundant lipid droplets.

Several endocrine disorders with increase or deficiency of hormone production may present a skeletal muscle compromise. Those conditions have been considered as metabolic myopathies. Nevertheless, some pathological abnormalities, mainly microvascular changes and the existence of a cell infiltrate, found in endocrine disorders with an autoimmune origin (primary hipothyroidism, hyperthyroidism associated with Graves disease, diabetes mellitus) have permitted classifing them as inflammatory myopathies. Although muscle pathology in diseases with isolated hormone production alteration has been extensively studied, this investigation has not been realized in patients with abnormalities in several endocrine glands. In this work we report the skeletal muscle ultrastructural pathology in a patient with multihormonal disorder.

A 19 years old male patient presented dwarfism with lack of muscular and sexual development. Plasma levels of thyroxin, Cortisol, growth hormone, testosterone, LH and FSH were low . TSH plasma levels were high.

BK polyoma virus is a 40-45 nm DNA virus that was first identified in the urine of an immunosuppressed patient in 1971. BK virus infection often occurs in childhood and is subclinical. The majority of adults have antibodies to the virus. Asymptomatic viruria, ureteral ulceration, and ureteral stenosis have been described with infection in immunosuppressed patients. Renal graft dysfunction and interstitial nephritis have been associated with BK virus. Differentiation between rejection and infection is important. We report a case of a renal transplant patient with BK polyoma virus infection. This case illustrates the variety of methods that can be used for identification of BK polyoma virus.

The patient, a 52 year old female, presented with an asymptomatic rise in serum creatinine (1.4 to 2.1 mg/dl). Her past medical history was significant for a cadaver kidney transplant two years prior for polycystic kidney disease.

Renal function impairment can be found in severe or complicated P. falciparum malaria. Some studies report 2-5% incidence of acute renal failure associated with high mortality (1). Causes of acute renal damage are not clearly understood but massive hemoglobinuria seems unlikely in the majority of cases and different immunopathogenic mechanisms leading to tubulointerstitial nephritis are currently proposed (2). Ultrastructure of renal lesions in malaria have been performed in humans (3) and in some infections of rodents and monkeys (4). These studies report abnormalities mainly in the glomerular area and references to tubular cell pathologic changes are still limited. This work describes tubular and capillary alterations in P. berghei malaria.

P. berghei parasitized erythrocytes (strain from the Swiss Tropical Medicine Institute) were inoculated intraperitoneally in C57BL/6 male mice. Renal samples were obtained at 13th-14th days post-infection when severe illness was evident and parasitaemia reached 40-50%. Samples were processed by routine techniques for transmission electron microscopy and observed in Hitachi H-500 and H-7100 electron microscopes.

It has been shown that cavities or vacuoles are most evident in the posteroventral and antero ventral cochlear nucleus (PVCN & AVCN) of the gerbil. These vacuoles are reported as a neurodegenerative disorder or spongioform degeneration or a dynamic process related to the degree of auditory stimulation or microenvironmental homeostasis in the cochlear nucleus of the gerbil. Little information is avalable on the origin and formation of microcysts in the dorsal cochlear nucleus (DCN) of the gerbil. The aim of this study, was to investigate the possible formation of microcysts in the gerbil DCN after a surgical ligation of the external auditory canal by transmission electron microscopy.

The mongolian gerbil, Meriones unguiculatus,had been acoustically deprived on the right side by a surgical ligation of the external auditory canal at six months old.

Mice expressing the Epstein-Barr virus nuclear antigen-leader protein (EBNA-LP) develop congestive heart failure and atrial thrombosis as early as four months of age. Epstein-Barr virus (EBV) is a common human herpes virus with a complex life cycle involving chronic replication in epithelial tissues. The EBNA-LP, one of six EBV nuclear antigens, has an unknown biochemical function but is associated with EBV-induced growth transformation. This transgenic line was originally produced to investigate oncogenic consequences, but unexpectedly resulted in mice with progressive heart failure. Since the progression and development of the heart failure is highly predictable, this transgenic line may serve as a valuable model for studying the pathophysiologic changes associated with human dilated cardiomyopathy. We describe here the ultrastructural characteristics of the myocardium from EBNA-LP transgenic mice in order to better delineate the pathogenesis of the associated heart disease.

We are participating in a collaborative project at NIOSH on mechanisms of silicosis, in which rats were exposed to filtered air (control) or silica aerosol of 15 mg/m3 (6 hr/day, 5 days/week), with assays conducted at intervals over a 6 month period. We are especially interested in the role of nitric oxide (NO) in the pathophysiology of lung disease. One source of NO is the alveolar macrophage, known to express the inducible form of nitric oxide synthase (iNOS); we used immunohistochemical techniques to determine whether iNOS is upregulated in alveolar macrophages and other lung sources in response to silica.

Silica-exposed and air control animals were sacrificed after 10, 20, 41, 79, and 116 days of exposure. Formalin fixed, paraffin embedded tissues were cut at 5μm, deparaffinized in xylene and rehydrated. Slides were microwaved in citrate buffer, pH 6.0 for antigen retrieval.2 After blocking endogenous peroxidase in 3% H2O2:Methanol (1:1), slides were placed in 10% BSA for 30 min, then incubated overnight in the primary antibody (Monoclonal anti-iNOS, Transduction Laboratories, N32020, 1:50 dilution)

Inhalation injury is present in 32-38% of patients with severe burns and is associated with an increase of 20-84% above the mortality expected based on age and burn size alone. Most previous studies of smoke inhalation injury have utilized large animals such as the sheep and we have previously reported a TEM and SEM study of lung injury in the sheep. The present observations are part of a study to develop a small animal combined model of smoke inhalation and surface burn.

Adult, male Sprague-Dawley rats were used. Animals were anesthetized and randomly assigned to one of four groups. Groups 1 and 2 received a 20% total body area surface (TBSA) full thickness scald burns while groups 3 and 4 were sham treated. Five hours after burn injury, rats were placed in a nose only exposure device and half of each group was exposured to either room air alone or room temperature tree bark smoke for 16.25 minutes.

Whole body exposure to the chemical warfare agent, mustard gas, bis-(2-chloroethyl) sulfide, or its laboratory model compound, half mustard, 2-chloroethyl ethyl sulfide (CEES), induces cutaneous, respiratory and ocular impairments. Of these, ocular damage causes the most immediate incapacitation with initial symptoms evident within minutes. This incapacitation is a result of irritation and edema of eyelids, conjunctiva and especially cornea. Development of corneal epithelial lesions and edema leads to deterioration of corneal transmissive and refractive properties with untoward effects on visual acuity. Heretofore, there has been no specific pretreatment, or antidotal therapy for mustard gas-induced ocular impairment. In the present study, we describe morphological correlates of the apparent attenuation of such damage by a mixture compound developed by Varma et al. Varma mixture (VM) consists of compounds known to provide bio-energetic support, prevent oxidative stress, modulate membrane permeability and support tissue metabolism. The mustard agent used in this study was CEES.

While sebum provides several functions in the integument, there is considerable interest in the control of excess sebum on the human skin. The primary function of sebum is to lubricate and waterproof the stratum cornenum layer, in addition to preventing hair from becoming brittle. In several cases, the secretion of sebum is inhibited as a result of blockage of the drainage pathway for the sebaceous glands which may result in abnormal skin conduction (1,2). Clinac™ OC (Oil Control) has been developed with a special oil adsorbing polymer, DVB/lsobornyl Methacrylate/Lautyl Methacrylate Copolymer (3). This particular copolymer posses the capacity to adsorb oils because of its high affinity for hydrophobic nonpolar substances. The purpose of this investigation is to show the adsorptive capacity of the acrylate copolymer in Clinac™ OC preparation and in buffer.

The acrylate polymer was incubated in artificial sebum for 4 hrs and 8 hrs at 37 C.

It has been reported that cryptorchidism caused disruption of spermatogenesis that become extensive with time (1). The process of spermatogenesis undergoes spontaneous degeneration in rats, the spermatids degenerate, the primary spermatocytes have been reported to degenerate more commonly (2). Apoptosis has been considered the route for removing sensitive germ cells after short-term experimental cryptorchidism (3). The abdominal heat stress causes cell loss by apoptotic pathway (4). The cellular damage of the experimentally induced cryptorchid adult rat is regulated by local testicular factors in pachytene spermatocyte (5). In this preliminary diagnostic study, we examined the role of the effect of the body temperature on the seminiferous tubule cells in surgically induced unilateral cryptorchid testis at various time periods in rats. This study is to document the extent of the cellular damage at various specified time periods of abdominal retention of the testis.

Despite significant advances in molecular biology and immunology, electron microscopy (EM) continues to be useful for morphologic identification of infectious microbes in body fluid and cultured specimens from humans and experimental animals. Morphologic identification using negative stain and/or thin-section EM is often a primary tool in public health investigations, followed by immunologic, molecular, or cultured isolation. Difficulties encountered are usually related to the length of time between specimen (e.g. stool) collection and preparation for EM and/or handling and shipping conditions. Another negative mitigating factor may be multi-lab interventions prior to arrival. Appropriate specimen collection, storage, and handling prior to attempts to identify the agent are important factors for successful identification.

Barrier-control guidelines called “Universal Precautions for Laboratories“ have for many years been recommended by U.S. and international health services organizations. The guidelines are based on the premise that safe work sites result from a combination of engineering controls, management policies, work practices, and, when required, prompt medical intervention.

Laboratory safety in a diagnostic electron microscopy (EM) laboratory that deals with potentially infectious specimens is a complex issue. The risk of infection of laboratory personnel is an obvious concern, particularly in laboratories, such as diagnostic virology laboratories, which handle infected tissues and body fluids on a routine basis. A second hazard is introduced by the multitude of toxic, corrosive, and irritating chemical reagents required for the preparation of samples for EM. Physical hazards inherent in the complex machinery necessary for EM and other forms of microscopy must also not be overlooked. Attention to each of these concerns must be orchestrated over the course of a multistep process that often lasts several days. Success in this endeavor is facilitated by a comprehensive quality control program encompassing personnel, specimens, chemicals, and equipment.

The foundation for safe handling of samples in the clinical laboratory is the principle of universal precautions, under which all blood, other body fluids, and tissues are considered potentially infectious and handled using appropriate protective measures.

During metamorphosis amphibian tadpoles regress gills, tail and other larval structures. Thus gills are a good model to study how a highly complex three-dimensional vascular network regresses and finally disappears. Presently, only the microvascularization of external gills of larvae of Hynobiusdunni(2) and Litoria ewingi(3) is examined. The present study analyzes the spatio-temporal changes which the gill 3D-vascular network undergoes during metamorphosis using SEM of microvascular corrosion castings and a newly developed 3D-morphometry system (4, 5).

Vascular casts of gills of tadpoles of the South African Clawed Toad, Xenopus laevis Daudin of stages 57 to 62 (6) were analyzed by SEM. Stereopaired images (tilting angle: 6 degrees) grabbed with a slow scan frame grabber (Orion 4.27) from the SEMs photo-display were imported into a 3Dmorphometry system (6) to measure vessel diameters, interbranching distances, branching angles and branching orders of filter row venules. This study reports the changes in the branching orders only.