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Biomedical subjects

M Cossu

Publications and source records attributed to M Cossu.

At least 73 records · Page 4Linked to original sources
PubMed1992

An immunohistochemical study of the distribution of ABH antigens in human submandibular glands at the light and electron microscopic levels.

The distribution of blood group antigens ABH in submandibular glands was studied at light and electron microscopy levels by applying ImmunoGold Silver Staining (IGSS) and post-embedding ImmunoGold (IGS) methods, respectively. In IGSS treated samples, a cytoplasmic and a surface form of antigen localization were discernible in the glandular parenchyma. The former was restricted to most mucous cells and to scattered serous cells: A and B antigens were demonstrated in mucous cells of A and B type glands, while H antigen appeared in most mucous and occasional serous elements regardless of the blood type of donors. The latter appeared as a strong H reactivity on cell surfaces of serous acini and ducts regardless of the patient blood type. The IGS method was applied both on non-osmicated samples embedded in LR White resin and on osmicated, Epon embedded samples. In non-osmicated tissues, antigen labelling was revealed in secretory granules and cell surfaces. Positive secretory granules were found in most mucous cells and occasional serous, intercalated, and striated duct cells. A and B antigens weakly reacted in mucous cells of A and B type glands, respectively, while strong H reactivity was seen in mucous, serous, intercalated and striated duct cells of glands of all types. Surfaces labelled with H antigen were found on both lumenal and basolateral membranes of striated ducts in glands of all types. IGS method applied on osmicated, Epon embedded samples, selectively revealed blood group antigens in secretory granules of serous cells but not in the apical vesicles of striated ductal cells. Cell surfaces were completely unreactive.

ABO Blood-Group System↗
PubMed1991

Spinal subarachnoid hematoma of unknown etiology. A case report.

A case of spinal subarachnoid hematoma at T3-T7 level is reported in a 60-year-old hunter, who developed progressive spinal cord impairment after receiving the recoil of his shotgun. Both clinical and neuroradiological investigations, including the selective spinal angiography, failed to demonstrate the origin of the bleeding. The combination of an apparently trivial spinal trauma with temporary increase of the intrathoracic pressure might be considered as possible etiologic factor.

Diagnosis, Differential↗
PubMed1991

Changes in infratentorial blood flow following experimental cerebellar haemorrhage. A preliminary report.

The temporal progression of changes in blood flow within the hemispheric cerebellar cortex, following an experimental cerebellar ipsilateral haemorrhage, was investigated in rats by using the hydrogen clearance technique. Stereotactical injection of 50 microliters of fresh autologous blood into the paramedian white matter was found to produce an early drop of cerebellar blood flow, with subsequent rise toward higher values. An increase of the intracranial pressure only occurred at the time of injection of blood. Arterial blood gases, mean arterial blood pressure and blood glucose levels did not exhibit significant changes. Histochemical evaluations of glycogen phosphorylase showed a posthaemorrhagic pattern of enzyme depletion, consistent with the occurrence of an ischaemic damage in both the cerebellum and the brain stem.

Animals↗
PubMed1990

Gas bubbles within acute intracranial epidural haematomas.

In order to assess the actual incidence of gas bubbles trapped within acute intracranial epidural haematomas, as revealed by computed tomography (CT) of the skull, a series of 204 patients with surgically verified epidural haematomas was retrospectively reviewed. Gas bubbles were observed on CT scan in 22.5% of the cases, with the incidence rising to 37% when CT scanners of the last generation were employed. The available data failed to demonstrate the actual source of intracranial gas. No correlation was found between the presence of gas bubbles and outcome. No patient in the whole series showed any sign of intracranial infection.

Acute Disease↗
PubMed1990

Regional cerebral blood flow after omental transposition to the ischaemic brain in man. A five year follow-up study.

Regional cerebral blood flow, recorded by the 133Xenon inhalation method, was measured preoperatively and over a five years postoperative period in six patients with completed stroke and stabilized neurological deficits, who had undergone omental transposition for revascularization of the ischaemic brain. Comparisons of the preoperative blood flow values with those recorded following surgery demonstrate a postoperative increase of blood flow in five patients, with a high statistical degree of significance in four of them at the final examination. The flow increase was noted over the infarcted areas of the brain, upon which the omentum had been placed, as well as areas of the ischaemic hemisphere without omental placement and the contralateral hemisphere. Out of the five patients who demonstrated preoperative flow values below the expected norm for age, four showed final postoperative cerebral blood flow within the normal limits for their age. The results are consistent with the assumption that the transposed omentum played a role in postoperative blood flow increase, by adding collateral circulation to the ischaemic brain.

Adolescent↗
PubMed1990

Subcellular localization of blood group substances ABH in human salivary glands.

We investigated the subcellular localization of ABH antigens in human submandibular, sublingual, and buccal glands by applying a post-embedding immunogold method using monoclonal antibodies specific for A, B, and H antigens. In most glands the immunoreactivity was usually restricted to mucous cells, in which only secretory granules and sometimes Golgi cisternae were specifically labeled. A and B antigens were demonstrated only in the glands of type A, B, and AB subjects, while H antigen was visualized in glands from individuals of all blood types. Moreover, differences were observed in the relative distribution of ABH antigens, depending on the type of gland.

ABO Blood-Group System↗
PubMed1990

Ultrastructure of human bulbourethral glands and of their main excretory ducts.

The endpieces of human bulbourethral (BU) glands, studied with SEM after removal of the connective tissue, consist of short, coiled tubules often dilated into alveoli. Immunohistochemical studies at the EM level have shown that the mucous cells of these glands have mucous droplets, which react to blood group antigens, suggesting that BU glands participate in the secretion of these antigens into the seminal plasma. The main excretory duct is lined by a stratified columnar epithelium consisting of six-seven cellular layers. Cells of superficial layers, that are endowed with typical secretory granules, seem to contribute some unknown components to the secretions of these glands.

ABO Blood-Group System↗
PubMed1990

Human meibomian glands: a histochemical study for androgen metabolic enzymes.

Human meibomian glands were treated for the histochemical demonstration of several enzymatic activities. The 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD), 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) appeared intensely reactive in the differentiating excretory cells, and weakly reactive in the basal cells and in the epithelial cells of the proximal portion of the ducts. The results indicate that meibomian glands can metabolize androgens by the reductive pathway, characteristic of target tissues. The finding of an intense reactivity for the enzymes glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) is also discussed.

Adolescent↗
PubMed1990

Transient upper monoballism in the presence of contralateral chronic subdural hematoma.

A case of chronic subdural hematoma associated with contralateral upper monoballism is reported. Intracranial midline shift and transtentorial herniation of the ipsilateral temporal lobe were the only demonstrated CT abnormalities. Complete neurological recovery followed the evacuation of the hematoma. Direct mechanical injury caused by the marked brain compression and distortion, and transient ischemic changes within cerebral areas whose damages may result in ballism, may be considered important causative factors of such an unusual neurological complication.

Chronic Disease↗
PubMed1989

Parkinsonism in the presence of intracranial extracerebral haematomas.

Bilateral Parkinsonism has been observed in a 60-year-old female with a chronic subdural intracranial haematoma. Scattered, poorly marginated, hypodense areas within the ipsilateral pallidus and putamen were evident on the preoperative CT scans. The rapid neurological improvement following the surgical drainage of the subdural clot and the evolution of the densitometric features of the nuclear lesions, which became clear-cut, though smaller, in the following months, suggest a cause-and-effect relation between the haematoma and the clinical symptomatology. To the best of our knowledge this is the first case in which anatomical lesions within the basal ganglia could be detected neuroradiologically.

Basal Ganglia Diseases↗
PubMed1989

Evaluation of cerebral blood flow data in stroke patients using a mapping system.

We retrospectively examined regional cerebral blood flow values in 78 patients in the stabilized phase of stroke to evaluate the consistency of lateralization compared with computed tomographic imaging. Examinations were performed using the xenon-133 inhalation technique, and the data were processed and displayed by a computer-assisted system of our own design that allows statistical analysis in real time and is suitable for clinical use. The consistency of lateralization correlated with computed tomographic findings was tested for absolute values, percent distribution, and asymmetries. The latter yielded the highest degree of sensitivity (in 83.3% of the patients the affected hemisphere was correctly identified). Absolute values showed at least one hypoperfused area in the affected hemisphere in 48.7% of the patients, and percent distribution did so in 57.7%. Furthermore, the combination of the three methods of data analysis yielded a sensitivity of 91%; the remaining 9% of the patients, however, exhibited some abnormalities of regional cerebral blood flow (bilateral or contralateral hypoperfusion). Although good agreement was found for lateralization by computed tomography and by the combined use of the three methods of analysis, a complete overlap between functional and structural examinations should not be expected. Problems concerning the sensitivity of the xenon-133 inhalation technique under conditions of low blood flow and the statistical analysis of regional cerebral blood flow data are discussed.

Administration, Inhalation↗
PubMed1989

Spinal cord dysfunction from lumbar disk herniation.

Two patients with a herniated disk respectively at the level of the L4-L5 and of the L5-S1 intervertebral spaces presented with pyramidal signs, bladder paralysis and radicular impairment. The symptoms subsided immediately following surgical removal of the prolapsed disk. The role of transient ischemia in the lower segments of the spinal cord as possible cause of this uncommon clinical picture is discussed, and the pertinent literature is reviewed.

Female↗
PubMed1988

Histochemistry of L-leucyl beta-naphtylamidase activity in genital tract of men.

The histochemical method to demonstrate L-leucyl-beta-naphtylamidase (LNAase) activity has been applied to biopsies of normal human ductus deferens, deferential ampulla, seminal vesicle, prostate, bulbourethral (Cowper's) gland, and cavernous urethra. An intensely positive reaction was observed in the secreting epithelia of prostate, Cowper's, and urethral (Littré's) glands. Not only the prostate but also the Cowper's and Littré's glands secrete some LNAase into the semen. A possible role of the seminal LNAase is discussed.

Adult↗
PubMed1987

Axonal elongation into peripheral nerve grafts between thalamus and somatosensory cortex of the rat. An experimental model.

After destruction of the thalamocortical projections of one side in 12 adult rats, the ipsilateral thalamic ventrobasal nucleus was connected with the contralateral somatosensory cortex through an autologous peripheral nerve graft. Three months after the implanting procedure, horseradish peroxidase was applied to the transected nerve. Retrograde labeling of cells occurred in all examined animals. Evidence of newly formed thalamocortical connections provides the experimental basis to a model suitable for functional evaluations.

Animals↗
PubMed1987

Quantitative ultrastructural approach to the study of the spatial relationships among cell organelles. I. Cytological organization of human exocrine epithelia.

Currently available morphometric methods provide useful information on the three-dimensional properties (such as volume, surface, etc.) of biological structures. These methods, however, do not reveal how the same structures are spatially organized within the cell. A sum of problems, which concern mainly the definition of shape and location of the sectioned structures, does not allow the three-dimensional representation of the organelle arrangement from a quantitative analysis of sections. Following a different approach, this study considers the topographic relationship between ten distinct subcellular structures: nucleus, Golgi, ribosomes, mitochondria, lysosomes, lipid droplets, secretory granules, and apical, lateral, and basal plasmalemma. The analysis of associations from 2 X 2 tables calculated for each pair of structures and the pattern of multiple associations obtained by clustering methods provide a useful description of the spatial relationship among different cell compartments. The results of the investigation carried out in parallel on seven human exocrine glands (pancreas, parotid gland, submandibular gland, lacrimal gland, ceruminous gland, ampulla of the vas deferens, and seminal vesicle) allow an immediate evaluation of the method and a comparative analysis of the cytologic organization of secreting cells of human exocrine glands.

Data Interpretation, Statistical↗