Electron Microscopic Abnormalities Research Articles

A Case of MIRAGE Syndrome with SAMD9 Mutation and Refractory Infantile Diarrhea: Endoscopic Biopsy Evaluation via Light and Electron Microscopy.

An infant with intrauterine growth restriction, suspected of having MIRAGE syndrome based on prenatal ultrasound, presented with genital ambiguity, adrenal insufficiency, intractable diarrhea from birth, and a pathogenic SAMD9 mutation (c.1376G>A, p.R459Q). Endoscopic biopsies of the duodenum revealed complex light and electron microscopic abnormalities. Hypoplastic villi without signs of enteritis suggests a disorder of mucosal growth with reduced absorptive surface area contributes to intractable diarrhea. Ultrastructural study showed prominent dilated endoplasmic reticulum, abnormalities of Golgi morphology, specialized granule, and mucin processing. We hypothesize that the SAMD9 mutation alters mucosal growth, and the processing of mucin, Paneth and neurosecretory granules, with premature degradation of specific granules in enterocyte lysosomes. These distinctive morphological findings support the idea that multisystem manifestations of MIRAGE syndrome are due to a primary disorder of microsomal trafficking.

End stage of arrhythmogenic cardiomyopathy with severe involvement of the interventricular septum

Detailed histopathologic, immunohistochemical, and ultrastructural analysis of the heart of a 56-year-old woman with end-stage arrhythmogenic cardiomyopathy with a pathogenic plakophilin-2 mutation is described. The explanted heart revealed severe fibrofatty replacement of nearly the entire right ventricular free wall. The left ventricle was severely affected, and, most remarkable, there was massive involvement of the interventricular septum. Immunohistochemical and electron microscopic findings of intercalated disks revealed areas with a heterogeneous distribution of connexin43 and focal electron microscopic abnormalities among these regions. This case illustrates that arrhythmogenic cardiomyopathy is not limited to the right ventricle but involves the entire myocardium, including the interventricular septum.

Enfermedades de la cadena respiratoria mitocondrial. Evaluación y variabilidad en 52 pacientes

Clinical, electrophysiological, genetic and biochemical deficiencies variability were evaluated in 52 patients diagnosed of mitochondrial respiratory chain diseases (MRCD). 26 men and 26 women, aged 19 to 79 years, were tested by clinical examination, electrophysiological techniques, muscle biopsy and genetic and biochemical studies. The patients were classified into seven phenotypes: myopathy, chronic progressive external ophthalmoplegia, progressive ophthalmoplegia plus ataxia, Kearns-Sayre syndrome, mitochondrial encephalomyopathy with lactic acidosis and stroke episodes (MELAS), myoclonic encephalopathy with ragged-red fibers (MERRF), and encephalopathies. Each phenotype may begin by different ways. The electromiography showed myopathy in 39 cases and various types of neuropathy in 10. Ragged-red COX negative fibers or widespread electron microscopic abnormalities were found in 47 cases. Simple deletions, multiple deletions and three different point mutations were observed. Deficiency of complexes I, II, III and IV were found alone or in different associations. MRCD shows wide variations in clinical, genetic and biochemical studies. Some patients with nonspecific manifestations, mainly of central nervous system, need careful attention and to be on account of diagnostic suspicion.

Electron microscopic abnormalities of skeletal muscle in patients with collagen VI deficiency in Ullrich's disease.

By electron microscopy, we examined the skeletal muscle from two patients with Ullrich's disease. One patient had a deletion in the collagen VI alpha 2 gene. The muscle biopsy specimens showed no collagen VI immunoreaction, while the expression of collagen IV was increased. Collagen VI is a microfibrillar protein in the extracellular matrix with cell adhesive properties, and collagen IV is a principal component of the basal lamina. Electron microscopy revealed unevenness, extension, and folding of the muscle plasma membrane, and showed thickening and overproduction of the basal lamina. The data show that type VI collagen is certainly one of the important extracellular matrix components maintaining the structural integrity of skeletal muscle, and a defect of the collagen VI protein causes abnormalities of the muscle plasma membrane, dystrophic muscle changes, and up-regulation of collagen IV.

Prognostic value of morphological classifications and clinical variables in elderly and young patients with multiple myeloma.

The prognostic value of morphological classifications and clinical variables was compared between 31 elderly (> or = 65 years) and 43 young (< 65 years) patients with myeloma. Prognostic factors were divided into three groups: factors useful in elderly patients, e.g., calcium, albumin; factors useful in young patients, e.g., platelet, creatinine, light-chain type; and factors useful in both patients, e.g., clinical stage, hemoglobin, LDH, CRP, bone marrow plasma cell and plasmablast percentages, light- and electron-microscopic classifications. The 5-year survival rates of elderly patients with calcium < 12 and > or = 12 mg/dl were 66.2 and < 11.1%, respectively (p<0.01). Those of the young patients were 64.1 and 33.3%, respectively. The 5-year survival rates of elderly patients with platelets > or = 200 x 10(9)/l and < 100 x 10(9)/l were 59.7 and 50.0%, respectively. Those of the young patients were 68.9 and 33.3%, respectively (p<0.05). The 5-year survival rates of elderly patients with few and numerous electron-microscopic abnormalities were 90 and 0%, respectively (p<0.01), those of young patients were 92.9 and < 14.3%, respectively (p<0.01). These findings suggest that individual clinical variables may differ in prognostic importance in elderly and young patients.

Gastroduodenal manifestations in patients with skeletal fluorosis.

A prospective case-controlled study was performed to evaluate the gastrointestinal symptoms and mucosal abnormalities occurring in patients with osteofluorosis. Ten patients with documented osteofluorosis and ten age- and sex-matched healthy volunteers were included in the study. Clinical evaluation, real-time ultrasound, and upper gastrointestinal endoscopy and biopsy from the gastric antrum and duodenum were performed in all subjects. The biopsies were subjected to a rapid urease test and light and electron microscopic examinations. Ionic fluoride levels were estimated in the drinking water, serum, and urine using an ION 85 ion analyzer. All patients with osteofluorosis had gastrointestinal symptoms, the most common being abdominal pain. Endoscopic abnormalities were found in seven patients with osteofluorosis. In all 7 of these patients, chronic atrophic gastritis was seen on histology. Electron microscopic abnormalities were observed in all 10 patients with osteofluorosis. These included loss of microvilli, cracked-clay appearance, and the presence of surface abrasions on the mucosal cells. None of the control subjects had any clinical symptoms or mucosal abnormalities. It was concluded that gastrointestinal symptoms as well as mucosal abnormalities are common in patients with osteofluorosis.

Toxic effects of chronic fluoride ingestion on the upper gastrointestinal tract.

In a prospective case controlled study, we evaluated the adverse effects of long-term fluoride ingestion on the gastrointestinal tract. Ten patients with otosclerosis who were receiving sodium fluoride 30 mg/day for a period of 3-12 months, and 10 age- and sex-matched healthy volunteers were included. They were all evaluated clinically and subjected to a real time ultrasound examination, upper gastrointestinal endoscopy, and biopsies from the gastric antrum and duodenum. The biopsies were subjected to a rapid urease test as well as light and electron microscopic examinations. Ionic fluoride was estimated in the serum, urine, and drinking water using an ION 85 Ion Analyzer. Seven subjects (70%) ingesting fluoride had abdominal pain, vomiting, and nausea. Petechiae, erosions, and erythema were seen on endoscopy in all the subjects, but not in the controls. Histological examination of the gastric antral biopsy showed chronic atrophic gastritis in all the subjects but in only one (10%) healthy volunteer. Scanning electron microscopic examination showed "cracked-clay" appearance, scanty microvilli, surface abrasions, and desquamated epithelium in the subjects ingesting fluoride, but not in the controls. We conclude that long-term fluoride ingestion is associated with a high incidence of dyspeptic symptoms as well as histological and electron microscopic abnormalities.

Light and electron microscopic abnormalities in diastrophic dysplasia growth cartilage.

Light and electron microscopic studies of diastrophic dysplasia iliac crest growth cartilage performed on five occasions in two patients from 1 to 10 years of age reveal extensive cell and matrix abnormalities at each time period. Light microscopy shows atypical chondrocytes with extreme variation in size and shape, and premature cytoplasmic degeneration, and formation of target ghost cells. Prominent, densely staining fibrotic foci are present throughout the cartilage. Ultrastructure reveals some structurally intact chondrocytes with a single large fat inclusion, slightly dilated rough endoplasmic reticulum, and abundant glycogen. As early as 1 year of age cystic degeneration of chondrocyte cytoplasm is evident with indistinct organelles seen. The cartilage matrix demonstrates a general increase in fibrous tissue as well as the fibrotic foci. The collagen in these foci is remarkably abnormal. It is composed of short, extremely broad fibrils ranging from 150 to 950 nm in width which are separated at their terminal ends but fused to each other centrally in random fashion. On cross-section there are very few round fibrils but rather a marked irregularity in shape giving the appearance of having fibrils randomly added to others to form enlarged nonuniform fibril aggregates. On longitudinal sectioning, regular cross-banding across the entire fibril width is seen but fibril splitting and aggregation are highly irregular.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluoride as a possible aetiological factor in non-ulcer dyspepsia.

A prospective case controlled study was conducted to evaluate the role of fluoride as a possible aetiological factor for non-ulcer dyspepsia (NUD). Twenty patients with NUD and 10 age and sex matched healthy controls were subjected to clinical evaluation, upper gastrointestinal endoscopy and biopsies from the gastric antrum and duodenum. The antral and duodenal mucosa was subjected to a rapid urease test for Helicobacter pylori and histological and electron microscopic examinations. Fluoride levels in the drinking water, serum and urine were estimated using a ION 85 ion-analyser. These levels were significantly higher in patients with NUD than in controls (P less than 0.05). Histological abnormalities in the antral and duodenal mucosa were seen in 14 patients (70%) with NUD and 1 control subject (10%) (P less than 0.05). Electron microscopic abnormalities in the mucosal cells were seen in all patients with NUD but in none of the controls (P less than 0.01). The fluoride levels in serum and urine correlated with the symptoms, histological and electron microscopic abnormalities (P less than 0.05). It was concluded that chronic exposure to fluoride may result in NUD and should be considered in patients where other known cause of dyspepsia have been excluded.

Retinal Tolerance of an Implantable Light Source for Use During Vitrectomy Surgery

To assess for the possible development of a phototoxic lesion, we exposed five Dutch belted rabbit retinas to constant illumination with an implantable "chandelier" light source at maximal intensity for 1 hour. No clinically apparent lesion developed in any of the experimentally treated eyes by 48 to 72 hours posttreatment. Light and electron microscopic examination failed to reveal any of the characteristic changes of retinal phototoxicity. A control eye treated with a 20-minute exposure to a standard endoiluminator probe at maximal intensity held 2 mm from the retinal surface demonstrated typical light and electron microscopic phototoxic abnormalities, whereas a retina similarly treated with a 5-minute exposure was normal. We have confirmed that a standard endoilluminator probe can create a phototoxic lesion in the experimental setting. Furthermore, no phototoxicity from the sustained retinal exposure to a fixed, implantable light source for a clinically relevant duration could be demonstrated.

The Ehlers-Danlos syndrome: Recognition, characterization, and importance of a milder variant of the classic form: A preliminary study

The diagnosis of Ehlers-Danlos syndrome is based on the clinical criteria of joint hypermobility, increased skin extensibility, abnormal scarring, and easy bruisibuity. The literature reports this syndrome as rare, yet our experience dictated to the contrary. The present study of the prevalence of Ehlers-Danlos syndrome in a general dermatology population revealed (1) a milder variant of the classic mitis form of Ehlers-Danlos syndrome was common and present in 9% of the population studied, (2) these patients could be easily identified by the use of a denned clinical scoring system, and (3) a statistically significant association existed between clinical findings in Ehlers-Danlos syndrome and electron microscopic collagen abnormalities. The identification of this syndrome may be important prognostically in patients with diseases or conditions in which collagen plays a major role, such as joint disease (dislocations), bruising disease (pigmented purpura), and potentially scarring diseases (acne, patients undergoing cutaneous surgery).

Chronic progressive external ophthalmoplegia. II. A qualitative and quantitative electronmicroscopy study of skeletal muscles.

This study quantifies the major electron microscopic changes in limb muscle biopsies from 31 out of 34 patients with the syndrome of chronic progressive external ophthalmoplegia. Patients were divided into three clinical groups -- A) 10 sporadic cases with muscle weakness only; B) 9 familial cases with muscle weakness only; C) 15 cases with muscle weakness and one or more of the following features: pigmentary retinopathy, cerebellar ataxia, pyramidal signs and peripheral neuropathy. Electron microscopic mitochondrial abnormalities were found in all groups (8 patients from group A, 3 from group B, 14 from group C). Quantitative measurements of certain muscle fibre constituents, using a point-counting technique, revealed decreased myofibril volume-fractions and increased volume-fractions of mitochondria, glycogen and lipid in some biopsies from each group. Mitochondrial volume-fractions correlated positively with lipid content, the proportion of type 1 fibres, and the percentage of fibres with increased oxidative enzyme activity. The three groups defined clinically showed no significant differences in terms of the relative proportions of these measured constituents.

On the Pathogenesis of Hepatic Dysfunction and Necrosis Following Acute Circulatory Failure

To clarify whether diminished hepatic blood flow and portal endotoxaemia interact in the pathogenesis of hepatic dysfunction secondary to acute circulatory failure, such as shock, prolonged hypotension, or left-sided heart failure, the present study was undertaken in rats. Reduced hepatic perfusion, which was produced by partial obstruction of the portal vein, caused elevation of serum transaminase activities and electron microscopic abnormalities of hepatocytic structure, namely, disruption of plasma membrane, swelling of mitochondria, vesiculation and disruption of endoplasmic reticulum, etc. Portal endotoxaemia, which was induced by infusion of endotoxin into the portal vein, led to a rise of serum transaminase activities and random, focal coagulative hepatocellular necrosis. In contrast, massive hepatic necrosis and excessive elevation of serum transaminase activities, which are similar to those seen in patients with shock, etc., were produced when portal endotoxaemia was superimposed upon poor hepatic perfusion. These experimental results suggest that acute hepatic failure and massive hepatic necrosis secondary to acute circulatory failure may be induced by the coexistence of reduced hepatic blood flow and portal endotoxaemia.

On the Pathogenesis of Hepatic Dysfunction and Necrosis Following Acute Circulatory Failure

To clarify whether diminished hepatic blood flow and portal endotoxaemia interact in the pathogenesis of hepatic dysfunction secondary to acute circulatory failure, such as shock, prolonged hypotension, or left-sided heart failure, the present study was undertaken in rats. Reduced hepatic perfusion, which was produced by partial obstruction of the portal vein, caused elevation ofserum tramsaminase activities and electron microscopic abnormalities of hepatocytic structure, namely, disruption of plasma membrane, swelling of mitochondria, vesiculation and disruption of endoplasmic reticulum, etc. Portal endotoxaemia, which was, induced by infusion of endotoxin into the portal vein, led to a rise of serum transaminase activities and random, focal coagulative hepatocellular necrosis. In contrast, massive hepatic necrosis and excessive elevation of serum transaminase activities, which are similar to those seen in patients with shock, etc., were produced when portal endotoxaemia was superimposed upon poor hepatic perfusion. These experimental results suggest that acute hepatic failure mvdmassive hepatic necrosis secondary to acute circulatory failure may be induced by the coexistence of reduced hepatic blood flow and portal and endotoxaemia.

The hepatic sinusoid in hairy cell leukemia: An ultrastructural study of 12 cases

Ultrastructural lesions of the liver were studied in 12 cases of hairy cell leukemia, with the alterations of the sinusoidal barrier receiving special emphasis. Portal and sinusoidal tumoral infiltration was observed in all cases. It was associated with angiomatous lesions of the sinusoids in eight cases; these lesions consisted of randomly distributed cavities lined by hairy cells and containing hairy cells and erythrocytes. In addition to the attachment of hairy cells to the sinusoidal wall, other striking electron microscopic abnormalities of the sinusoids included 1) wide areas of communication between the sinusoidal lumen and Disse's space, allowing extravasation of blood cells; 2) focal disruption of the sinusoidal wall; and 3) replacement of the sinusoidal cell lining by tumor cells in close contact with hepatocytes. Most of these changes closely resembled those observed in peliosis hepatis. As in peliosis, sinusoidal alterations in hairy cell leukemia might be due to the destruction of the sinusoidal wall, and tumor cells could play a role in the pathogenesis of the lesions. The pattern of liver involvement in hairy cell leukemia, which is peculiar among hepatic localizations of blood malignancies, might reflect the unique phenotype of the tumor cells.

New aspects of parenteral nutrition with fat emulsions in injured patients.

AbstractAdequate nutrition is essential to recover from injury. There is a close correlation between the severity of injury and the catabolism in the flow phase. During the last few years, many contraindications against the intravenous infusion of fat emulsions have been discussed and determined to be invalid. The development of clinical applicable intravenous fat emulsions and the introduction of all‐in‐one (AIO) solutions for continuous intravenous nutrition have been a great success in the care of injured patients with and without major complications. Careful investigations of the stability of fat emulsions in AIO solutions by examination of visible changes, light and electron microscopic abnormalities, zeta potential, and coulter counting of the size distribution of liposomes revealed that fat emulsions are now safe for long‐term complete parenteral nutrition.The metabolic response to trauma and operation is characterized by the ebb and flow phase. While the patients in the ebb or shock phase should not receive nutrition, patients in the flow or catabolic phase resulting from the combination of decreased nutritional intake and increased nutritional requirement due to injury and its complication as sepsis and organ failure should receive sophisticated intravenous nutrition. The most probable means of achieving sufficient nutrition without metabolic derangement is the partitioning of the energy supply on carbohydrates and fat and the continuous intravenous administration of an AIO solution. Data that have been gathered reveal that the partial use of fat as energy source in injured patients with and without major complications (diabetes mellitus, acute pancreatitis, acute renal failure, liver insufficiency, and sepsis) diminishes the metabolic derangements and improves the standard of nutritional care. After many years of worldwide experimental and clinical investigations, fat is contraindicated only in the shock phase and in primary or secondary disturbances of fat metabolism that lead to a triglyceride level in serum above 4.5 mmol/l during continuous intravenous nutrition.

Clofibrate-induced myotoxicity in rats. Temporal profile of myopathology.

In this report, the temporal sequence of myopathology during a clofibrate-induced muscular syndrome and its recovery in rats is described using histopathologic, histochemical and electron microscopic technics. Two stages of myopathology are described: an early stage characterized by myopathic features, and a later stage characterized by neurogenic features. Although muscle histology returns to normal after 1 week of discontinuing the drug, electron microscopic abnormalities persist through the second week. It is proposed that clofibrate, in addition to its myotoxic effect, may be neurotoxic.

Effects of long term intravenous administration of ethanol on rat pancreas.

Pancreatic exocrine function and morphologic changes were investigated in groups of rats receiving solutions of ethanol by oral or intravenous route, or equicaloric doses of glucose solution by intravenous route daily for a period of 4 weeks. Comparable degrees of exocrine dysfunction and morphologic changes in the pancreas at the ultrastructural level were observed in the groups given ethanol orally and in those receiving i.v. injections of ethanol, suggesting that neither intragastric ingestion nor high blood levels of alcohol is required for alcohol to exert its pancreatotoxic effects. All groups of rats receiving ethanol or glucose showed signs and pathologic findings of nutritional disorder, and at 4 weeks of treatment, electron microscopic abnormalities of the pancreas were more pronounced and higher in incidence in the groups given ethanol p.o. or i.v. than in the groups given i.v. doses of glucose. There was no microscopic evidence of protein plug or other changes in the region of origin of the pancreatic duct system in rats after 18 months of oral administration of ethanol. The present findings indicate that the cytotoxic effect of alcohol on acinar cells and nutritional disorder associated with alcohol ingestion constitute important factors in the pathogenesis of chronic alcoholic pancreatitis.

Hypothyroid myopathy. A clinical and pathologaical study.

Ten patients with varying degrees of hypothroid myopathy were studied clinically and by serial percutaneous needle muscle biopsies before and during treatment with L-thyroxine. The biochemical evidence of hypothyroidism was related to the severity of the myopathic and signs before treatment. The severity of myopathic symptoms before and during treatment correlated with the biochemical evidence of hypothyrodism, a type II fibre atrophy and increased central nuclear counts. Likewise, the clinical evidence of a myopathy before and during treatment was correlated with both a type II fibre atrophy and loss and increased central nuclear counts but was not related to the biochemical parameters of hypothyroidism, except the level of thyroid stimulating hormone. In the muscle, before and during treatment, of the two most severely affected patients, intracellular glycogen inclusions were seen in scattered muscle fibres. On light microscopy and on electronmicroscopy, numerous mitochondria were seen responding to L-thyroxine with accumulations of subsarcolemmal honey-combing. Vesicular abnormalities, an electron dense matrix or occasional crystalline deposits were seen in muscle mitochondria from less severely azffected patients. Severely myopathic muscle contained excessive glycogen, membrane bound glycogen and excess lipid in a mainly perinuclear distribution. Occasional myelin and membranous bodies were seen and satellite cells during the recovery phase. A group of patients with hypothyroid myopathy who are likely to have a delayed recovery of full muscle strength on L-thyroxine may be recognised by the presence of severe proximal muscle weakness and characteristic changes on histochemical and electronmicroscopic examination of muscle. The spectrum of histochemical and electronmicroscopic abnormalities of muscle revealed with increasing degree of hypothyrodism, suggests that a generally reversible acquired glycogen storage and mictochondrial disorder is an important feature in the pathogenesis of this condition.

Echothiophate cataracts in monkeys. Electron microscopy and microradiography.

• Anterior and posterior subcapsular cataracts were induced in cynomolgus monkeys by topical treatment with echothiophate iodide. The lenses were then studied by light and electron microscopy and by quantitative microradiography. Microradiography revealed foci of swollen lens fibers and reduced protein concentration in the anterior-most and posterior-most 0.3 mm of cortex. By electron microscopy, focal areas of the lens epithelium and the anterior and posterior subcapsular cortex demonstrated enlarged intercellular spaces containing cell membrane fragments and amorphous material. The cortical abnormalities were most frequent at or near the lens sutures. The microradiographic and electron microscopic abnormalities in the cortex corresponded in location, distribution, and optical properties to the vacuoles and solid-appearing opacities seen biomicroscopically in vivo. The mechanism for the increased hydration of the lens caused by cholinesterase inhibitors remains unknown.