Microvascular changes in the lower extremities of paraplegics with heterotopic ossification.

OBJECTIVES: To investigate the morphological aspects of blood microvasculature of the skin and subcutaneous tissues in subjects with paraplegia with heterotopic ossification (HO). METHODS: In two patients with traumatic spinal cord injury and HO, punch biopsies of skin and hypodermic soft tissue in the region of HO near the hip were studied with histological and ultrastructural methods. RESULTS: Alterations of endothelial cell and basement membrane of capillaries and small vessels were observed. Hyperactive endothelium, thickening and reduplication of the basement membrane, changes of the perivascular connective tissues and microcalcifications in the subcutaneous fat tissue were also seen. CONCLUSIONS: This present study indicates microvascular changes in the skin and subcutaneous tissue in the region of HO near the hip of two subjects with paraplegia. In our opinion the described vascular changes may induce hypoxiemic alterations of the soft para-articular tissues leading metabolic changes which may contribute to the development of HO. Therefore, it cannot be concluded whether these changes are directly responsible for HO induction.

The Cycloxygenase-2 inhibitor SC58236 is neuroprotective in an in vivo model of focal ischemia in the rat.

Focal ischemia was induced in the fronto-parietal region of rat brain, by injection of Rose Bengal, followed by light activation. Focal ischemia was accompanied by formation of PGD(2) peaking 60-90 min post irradiation and declining thereafter. Increased Cycloxygenase-2 (COX-2) expression was also observed. Control ischemic rats showed distinct morphological alterations with necrosis of neurons, glial cells and blood vessels, surrounded by a halo with pyknotic cells with cytoplasm swelling and vacuolization. Compound SC58236, a selective COX-2 inhibitor, dose-dependently prevented, ischemia-induced eicosanoid formation (area under the curve (AUC) of controls: 3.11 +/- 0.87; AUC of 20 mg/kg SC58236: 0.39 +/- 0.24), and caused significant reduction of damaged area (30.7 and 18.9% at SC58236 20 and 6.6 mg/kg), suggesting that selective inhibitors of COX-2 are neuroprotective.

Effect of acute alcohol on ischemia-induced glutamate release and brain damage.

Epidemiological studies show that chronic ethanol consumption at high doses enhances the risk of cerebral stroke. The mechanisms responsible for the greater vulnerability of alcoholics' brains to stroke have to be completely understood, but a role for excitatory amino acids has been suggested. In order to study the interaction between alcohol and ischemia, we investigated the effect of acute alcohol administration in a model of focal cerebral ischemia. In particular, we evaluated the release of glutamate and aspartate from the cerebral frontal cortex by a transdialysis technique. Alcohol was acutely administered at 1.5 and 3.0 g/kg ip. During the period of maximal alcoholemia, ethanol almost abolished the ischemia-induced release of glutamate leading to glutamate values around or below the basal. Aspartate levels were unaltered both following ischemia and alcohol+ischemia. The decrease in glutamate release, however, was not accompanied by a significant reduction of the extension of the damaged area assessed by histological analysis.

Inhibition of prostanoid synthesis protects against neuronal damage induced by focal ischemia in rat brain.

Changes in prostanoids concentration and effects of the non-specific COX inhibitor indomethacin on prostanoids levels and extension of tissue damage were studied following focal ischemia induction in the fronto-parietal region of rat brain. Ischemia was induced in animals bearing a transcerebral microdialysis probe by injection of Rose Bengal, a photosensitive dye, followed by light activation. Prostanoid levels were determined in the dialysate using immunoenzymatic techniques. PGD2 levels rose significantly up to 237+/-22 pg/ml compared to a basal level measured before ischemia induction which was below the detection limit. TXB2 changes were smaller and had a different time course. Treatment with indomethacin abolished the ischemia-induced PGD2 release and reduced the extent of injury to the area by 43+/-3.7%. These results suggest that prostanoid release may play an important role in neurodegenerative processes and that cyclooxygenase inhibitors may contribute to protect against cerebral tissue damage.

Gastric stromal tumour: a rare neoplasm presenting with gastrointestinal bleeding.

We report the case of a 67-year-old male patient who presented with melaena and acute anaemia. Upper digestive tract endoscopy and computed tomography of the abdomen showed a centrally ulcerated, broad-based, polypoid projection of 4 cm in the gastric antral wall. Although endoscopic biopsies were negative for neoplastic changes, the patient underwent distal gastrectomy with Billroth-I reconstruction. Histological and immunohistochemical studies on the surgical resection specimen revealed a gastrointestinal stromal tumour (GIST) of combined smooth muscle and neural type, with no evidence of mitotic activity but of uncertain biological behaviour. After serological detection, Helicobacter pylori eradication was recommended to prevent bacterial damage of the gastric remnant.

Structure of the initial lymphatics of the human urinary bladder with invasive urothelial tumors.

The ability of urothelial tumors of the urinary bladder to metastasize via the lymphatic circulation and the extent of metastatic involvement of regional lymph nodes is an important parameter in the staging and prognosis of these neoplasms. Accordingly, we examined the site and morphology of initial lymphatic vessels in the mucosa of the human urinary bladder in patients with invasive transitional cell carcinoma. Lymphatics in the papillary tumoral mass was also examined. Endoscopic transurethral biopsies from the urinary bladder of 120 patients with invasive transitional cell papillary carcinoma were utilized for this study. Biopsy from the uninvolved lateral wall of the same patient was utilized as a control. On histopathology of biopsies of neoplastic tissues, initial lymph vessels were seen in the deeper region of the mucosa but not in the subepithelial layer nor in the stroma of the tumoral papillae. The latter were often associated with arteriolar and venular vessels. When edema and inflammation occurred in peritumoral regions, lymphatics showed a dilated lumen, non-indented wall with dissociated perivascular collagen and elastic fibers. Tumoral permeation or embolization of lymphatics was seen in 12% of patients with invasive tumors, and these lymphatic vessels did not display significant morphologic changes. The absence of initial lymphatics in the stroma of tumoral papillae and in infiltrated subepithelial regions of the urinary bladder may explain the absence of lymph node metastasis in early-stage invasive urothelial tumors.

Structure of the lymphatic microcirculation in the human urinary bladder with different intraluminal pressure and distension.

The localization, morphology and fine structure of initial lymphatic vessels in the mucosa of the empty and distended urinary bladder were studied. Endoscopic transurethral biopsies of the empty (collapsed) bladder showed under light and electron microscopy numerous intramural lymphatics with a dilated lumen and thin profile. Contacts between endothelial cells were single, overlapping, interlocking, and open while the perivascular connective tissue was filled by fascicles of collagen fibers. In the most superficial layer (subepithelial mucosa), lymphatics were not seen. Biopsies obtained under elevated intraluminal pressure and distension showed on light and electron microscopy lymphatic vessels with small lumens characteristically reduced to irregular slits. Endothelial cell contacts were simple or overlapping; open junctions were rare. The perivascular connective tissue was dense and collagen and elastic fibers often abutted one another. These findings support that with a distended or expanded urinary bladder, the effect of increased intraluminal pressure on the superficial (mucosal) layer radially pulls on the connective tissue that in turn compresses the initial lymphatics thereby restricting lymph transport.

Langerhans' cell granulomatosis and Hodgkin's lymphoma. Report of a case.

A 48-year-old female with a history of accentuated dyspnea, pleural thickening in anteromedial portion with left patchy parenchymal shadowing invading adjoining parasternal structure of the rib cage, presented 13 months later marked superclavicular, anterior mediastinic and parahilar left lymphadenopathy. Open surgical biopsies on the pleural lesion invading the hypodermic tissues of parasternal region showed morphological and immunocytochemical patterns of Langerhans' cell histiocytosis (LCH). 13 months later the superclavicular lymph node biopsy diagnosed Hodgkin's lymphoma (HD), mixed cellularity type II, stage AE. On a total of 29 cases with association of LCH and HD, the described case in the second case that shows morphologically demonstrated LCh with subsequent development of HD. It is postulated that the development of HD in a patient with LCH, might represent malignant evolution of this hyperplastic process.

Helicobacter pylori serology in chronic gastritis with antral atrophy and negative histology for Helicobacter-like organisms.

It has been suggested that there may be a correlation between Helicobacter pylori (Hp) infection and precancerous lesions of the stomach. However, histological evaluation of bacterial colonization in chronic atrophic gastritis shows a relatively low prevalence of the microorganism, which does not support the hypothesis. The aim of our study was to investigate the Hp serology in 95 patients with chronic gastritis with antral atrophy, with (27 cases) and without (68 cases) intestinal metaplasia, and without Helicobacter-like organisms in antral and corpus biopsy specimens. For all subjects, serum anti-Hp immunoglobulin IgG was identified by a fluorescent immunoenzymatic method (Helori-test; Eurospital), and mucosal atrophy and activity were graded histologically (Sydney System score). The serum Hp-antibody status documented the presence of current bacterial infections in 64 of 95 (67.4%) patients and previous infections in another 17 subjects. In only 14.7% of cases was there no evidence of current or previous infection. These subjects had less severe mucosal atrophy and lower inflammatory scores. In addition, there were no cases of intestinal metaplasia in such subjects. The high prevalence of Hp infection confirms the primary role of the microorganism in the pathogenesis of chronic gastritis with antral atrophy, although the bacterium is no longer present in the advanced stages of such disease. The histological evaluation of Hp colonization following the criteria of the Sydney System appears from our study to underestimate the true prevalence of the infection in the stomach when there is mucosal atrophy.

p53 overexpression and human papillomavirus infection in transitional cell carcinoma of the urinary bladder: correlation with histological parameters.

Seventy-nine transitional cell carcinomas (TCCs) of the urinary bladder (25 grade 1, 22 grade 2, and 32 grade 3 tumours) were examined for p53 overexpression by immunohistochemistry with a monoclonal antibody and for human papillomavirus (HPV) infection by the polymerase chain reaction (PCR). Positive immunostaining for p53 was detected in 40.5 per cent of the cases; the percentage of positive cases was significantly lower in low-grade (G1 and G2) TCCs than in high-grade (G3) tumours (10.6 per cent vs. 84.4 per cent; P < 0.0001). The overall rate of HPV infection was 32.9 per cent; 20.3 per cent of the cases were positive for HPV 16, 3.8 per cent for HPV 18, and 8.9 per cent for both. Consensus primers as well as type-specific primers for HPV types 6, 11, and 33 failed to detect any additional case with HPV infection. The prevalence of HPV 16 and/or HPV 18 infection was significantly higher in low-grade than in high-grade tumours (44.7 per cent vs. 15.6 per cent; P = 0.0061). p53-positive cases were more common among papillary, deeply infiltrating tumours, and HPV-positive cases among papillary, non-infiltrating lesions. According to these data, p53 overexpression and HPV 16/18 infection are common findings in bladder TCC and there appears to be an inverse correlation of p53 overexpression and of HPV infection with tumour aggressiveness. The possibility of different molecular pathways in superficial low-grade and in invasive high-grade tumours is suggested.

Detection and morphology of thymic remnants after video-assisted thoracoscopic extended thymectomy (VATET) in patients with myasthenia gravis.

Thymectomy is often an extremely useful therapeutic procedure in myasthenia gravis (MG) and is usually indicated for adult patients with generalized disease. Because remnants of thymus may remain in extrathymic fat, an extended thymectomy is recommended. A new surgical approach without sternotomy: video-assisted thoracoscopic extended thymectomy (VATET) was performed in 30 MG patients. The weight of removed thymus ranged from 10.8 to 113 grams. The weight of fatty tissue removed from pretracheal, anterior mediastinal and costophrenic areas ranged from 6.3 to 74.8 grams. Histological examination revealed thymic remnants in 14.8% of pretracheal fat samples and in 33.3% of samples from anterior mediastinal plus costophrenic areas. These findings indicate that VATET is a radical procedure and may be the first choice surgery for young female MG patients, since aesthetic sequelae are reduced compared to procedures involving sternotomy.

Morphological changes in the skin microlymphatics in recently injured paraplegic patients with ilio-femoral venous thrombosis.

Based on morphological features of the lymphatic microcirculation of the skin from healthy subjects, and from paraplegic patients who had no evidence of ilio-femoral venous thrombosis (thromboembolic disease: TED), the leg terminal lymphatic vessels from skin biopsies of five male paraplegic patients with acute traumatic spinal cord lesions and with documented TED were studied. Paraplegic patients with TED had lymph vessels with a dilated lumen surrounded by a rarefacted perivascular connective tissue characterized by dissociation and disruption of collagen and elastic fibres. The lymphatic wall was generally attenuated and some open junctions and channels delimited by endothelial protrusions were observed. The venous outflow obstruction caused by deep venous thrombosis accompanied by the absence of ambulatory venous pressure in the paretic leg determines skin microlymphatic dilatation, lymph stasis and changes in the interstitial connective tissues. These alterations may be considered to be the morphological aspect of the dystrophic alterations seen in the skin of legs from paraplegic patients with TED. The results are discussed in view of the correct rehabilitative medical treatment necessary, and adequate prophylaxis of TED.

Tissue staining for Helicobacter pylori in intestinal metaplasia: correlation with its extension and histochemical subtypes.

The role played by Helicobacter pylori (Hp) infection in the occurrence of non-cardial gastric adenocarcinoma is suggestive but still debated. This study aimed to evaluate: a) the prevalence of Helicobacter-like organisms in antral bioptic specimens of 291 patients with chronic gastritis with antral atrophy and different subtypes of intestinal metaplasia (IM); b) the presence of a possible different positive tissue staining for the bacteria in the complete and incomplete intestinal metaplasia. Of the 291 patients, 222 cases (76.3%) showed type I IM, 28 cases (9.6%) type II IM and 41 cases (14.1%) type III IM. Helicobacter-like organisms were found in 42.9% of cases and positive tissue staining rate appeared to be inversely related to the extension of IM (58.7% in IM extended in less than 30% of specimens, 30.2% in IM extended between 30% and 60%, 2.7% in IM exceeding 60% of the biopsed area). The inverse correlation between lower positive tissue staining for Helicobacter-like organisms and greater extension of IM was statistically significant (p < 0.001). Incomplete metaplasia appeared to be unrelated to age and associated with a lower positive tissue staining for Helicobacter-like organisms; among patients with type I metaplasia, 118/222 showed Hp-positive bioptic specimens, vs 7/69 of types II and III (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aminoacid recovery via microdialysis and photoinduced focal cerebral ischemia in brain cortex of rats.

A photochemical method using the Rose Bengal dye as thrombogenic agent was employed to induce focal cerebral ischemia in frontoparietal cortex of rats. A transcerebral microdialysis probe was used to collect samples from ischemic cortical area. An increase in glutamate (6-fold) and in taurine (4-fold) within the first hour occurred. Neuropathological investigations demonstrate a reproducible damaged area surrounded by a thin peripheral area showing neuronal apoptotic phenomena. The method represents a reproducible model of focal cerebral ischemia with neuropathological aspects superimposable to those characteristic of thrombogenic stroke in man. This method could also be relevant in the study of neurotransmitters during the evolution of ischemia. Furthermore, the presence of apoptotic phenomena in the perilesional halo confirms an ischemic penumbra suggesting the significance of preclinical pharmacological trials.

The lymphatic vessels and their relationship to lymph formation in the human urinary bladder.

After endoscopic transurethral biopsies of normal human urinary bladder, an extensive network of small initial lymphatic vessels was depicted by means of light and electron microscopy. Using light microscopy, lymphatic vessels were seen in the mucosa and submucosa and formed a complex network in the detrusor muscular coat. These lymphatics were characterized by an irregular and attenuated wall and increased in number and size from the superficial to the deeper region of the bladder. Ultrastructurally, the lymphatic wall was characterized by endothelial cells joined together end-to-end or by complicated interdigitations. Often intercellular channels and gaps between two contiguous endothelial cells were present. A broad network of elastic and collagen fibers joined the lymphatic endothelial wall to the neighboring connective tissue. Nevertheless, as far as the fibrillar component was concerned, the vesical intramuscular lymphatic endothelial wall lacked elastic fibers. These anatomic variations were examined in reference to lymph formation in an organ (the urinary bladder) which undergoes continual changes in volume and pressure.

Morphological changes of dermal blood and lymphatic vessels in chronic venous insufficiency of the leg.

Morphological changes of dermal blood and lymphatic microcirculation in skin biopsies from patients affected by Chronic Venous Insufficiency (CVI) associated with stasis dermatitis of the lower limbs, are reported here. Blood vessels are characterized by an occluded lumen, thickening and reduplication of the basement membrane. The structural changes in dermal lymphatic vessels are: (i) collapsed lumen of lymphatics located in the papillar dermis; (ii) numerous and complex interdigitations between contiguous endothelial cells and lack of open junctions; (iii) derangement of the anchoring filaments that normally pull the lymphatic lumen open. The connective matrix is characterized by fibrosis with formation of dense bundles of collagen and elastic fibers. These results suggest that the dermal lymphatic and blood microcirculation in CVI are connected to a reduced fluid exchange capacity because of the structural changes occurred in the vascular and lymphatic wall and in the surrounding connective tissue.

Effect of preoperative training on latissimus dorsi muscle for cardiomyoplasty. A morphometric study.

Dynamic cardiomyoplasty is based upon the use of electrostimulated Latissimus Dorsi muscle (LDM) to reinforce the ventricular wall of heart in patients with end-stage heart failure. In the present study we induced a preoperative reinforcement of LDM in 3 male patients selected for cardiomyoplasty, by means of a physiokinesiologic training. The application of morphometric techniques was useful to analyze the modifications in fibre type diameter and composition, in number and distribution of mitochondria and in number of capillaries in LDM needle biopsies performed before and after training. The preoperative muscle training induces trophic modifications in muscle fibres with increase in fibre diameter, in capillarity and in number and size of mitochondria. These parameters indicate that a preoperative training of LDM before cardiomyoplasty may be useful for muscle reinforcement and for preparation to the electrostimulation program in the postoperative cardiac assistance.

Infantile mitochondria encephalomyopathies: report on 4 cases.

Four muscle biopsies from the quadriceps femoris muscle of children with symptoms suggesting mitochondrial encephalomyopathy were examined for morphological and biochemical differences. From a biochemical point of view, our patients showed a derangement of mitochondrial metabolism and in particular a marked deficit in the activity of cytochrome c oxidase. In all patients there was an abnormally high rise of lactate and pyruvic acid levels in blood before and after glucose loading. Results of morphological and enzyme histochemical studies showed smaller muscle fibre diameters than in normal children. Typical red ragged fibres and ultrastructural abnormalities in muscle mitochondria were present in 1 case only. Three patients showed focal changes in the distribution of some sarcoplasmic oxidative enzyme activities. The present findings suggest that the main metabolic disorder, pointed out by biochemical studies, is scarcely reflected by morphological and ultrastructural studies in the early stages of mitochondriopathies.

Dermal lymphatics in myotonic dystrophy.

Myotonic dystrophy is an hereditary disorder of several organ systems. Skeletal muscle is a principal target organ, but abnormalities also occur in the peripheral microcirculation. Because morphological and functional changes in the dermal blood microcirculation may affect interstitial fluid drainage of the skin, we examined dermal lymphatic morphology in adult patients with myotonic dystrophy. Skin biopsies were taken from the big toe from patients with myotonic dystrophy (age 18-50 years) and subjected to light and electron microscopy; five healthy subjects served as controls. The salient findings in myotonic dystrophy were ultrastructural changes of the lymphatic endothelial cells and the fibrillar elements that surround the lymphatic wall. These abnormal lymphatic findings are interpreted in light of changes in the blood microvasculature and loose connective tissue in this disorder.