Biomedical subjects
Publications and source records attributed to S M Gaini.
A case of cervical vertebral erosion due to tortuous vertebral artery is presented. This entity is rare and only 11 cases have been reported in the literature. The present case is the first to be demonstrated by magnetic resonance imaging. The importance of considering this vascular anomaly in the differential diagnosis of cervical spinal tumors is discussed.
Changes in membrane lipid content and composition have been repeatedly detected in experimentally induced as well as spontaneous tumors. Previous data on ganglioside analysis in human astrocytomas suggested a possible correlation between their content and pattern and the histological grading of these tumors. In our study we could definitely prove this correlation: in fact the level of malignancy, passing from grade I to grade IV, is associated with a statistically significant increase of a ganglioside identified as ganglioside GD3. Another important modification in the ganglioside pattern of human astrocytomas is the decrease in polysialylated species with increasing level of malignancy.
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The properties of [3H]-gamma-aminobutyric acid [( 3H]GABA) binding were studied in biopsied specimens from normal human brain and from 18 cases of human brain gliomas, made up of 6 astrocytomas, 6 glioblastomas, 3 oligodendrogliomas, and 3 medulloblastomas. In fresh membranes obtained from normal gray and white matter one population of Na+-dependent GABA receptors was observed, while in the frozen Triton X-100-treated membranes two distinct populations of Na+-independent binding sites were detected. Specific GABA binding sites in brain gliomas were shown only in frozen Triton X-100-treated membranes. As in normal tissue, these receptors are Na+-independent and bind [3H]GABA with two distinct affinity components. The biochemical profiles of [3H]GABA binding to membranes obtained from different tumors of glial origin are quite similar and cannot be related to the degree of malignancy of the neoplasia.
The content and distribution of phospholipids, as well as their fatty acid composition, were studied in 16 human meningiomas in comparison with normal leptomeninges. The total phospholipid content of tumors (expressed as organic phosphorus/mg DNA) was similar to that of the tissue from which they originated. The same phospholipid classes were present in both tissues, but with a different pattern: an increase of phosphatidylinositol and phosphatidylcholine and a decrease of sphingomyelin and alkenyl-acyl phosphatidylethanolamine were detected in meningiomas. Stearic, palmitic, and oleic acids were the major phospholipid fatty acids in both leptomeninges and meningiomas. However, remarkable differences between the fatty acid composition of the two tissues were shown. The most striking difference is a marked increase of unsaturated fatty acids in tumors associated with a decrease of saturated forms. This feature is common to all major phospholipid classes. The possible significance and role of phospholipid modifications in the functional properties of meningioma plasma membrane is discussed.
The ganglioside pattern from normal human temporal cortex and cerebellum has been studied in fresh specimens obtained at surgery. The analyses have been performed by two-dimensional thin layer chromatography with an intermediate ammonia treatment which is a methodology particularly suitable for resolving alkali labile gangliosides. Alkali labile gangliosides were detected in all the analyzed specimens and their content contributed to 23% and 11% of total lipid bound sialic acid, in temporal cortex and cerebellum, respectively.
The specific activities of five glycohydrolases of lysosomal origin (beta-N-acetylglucosaminidase, beta-glucuronidase, beta-galactosidase, alpha-mannosidase and alpha-fucosidase) were measured in different types of primary and metastatic tumors of the human nervous system. The activities of these hydrolytic enzymes in samples of tumor tissue were compared with those in the white matter of 'control' tissue. The specific activities of beta-glucuronidase and beta-N-acetylglucosaminidase were significantly higher (P less than 0.001) in each group of tumors than in normal cerebral matter. The activities of the other hydrolases were sometimes significantly increased in primary tumors, but not always. In metastatic tumors, they were also significantly higher (P less than 0.01).
Ganglioside content and distribution were determined in control meninges and in 30 human meningiomas belonging to four different histological types. Irrespective of the histological classification all meningiomas showed a ganglioside content significantly higher than that of control meninges. The analysis of ganglioside distribution in each meningioma showed that in the majority of the cases the increase of ganglioside content was primarily the result of selective accumulation of ganglioside GM3; in the remaining cases ganglioside GM1 was present in a significantly higher amount than in the control dura mater and leptomeninges. A common feature of both types of meningiomas is a simplification of ganglioside pattern, with a shift from the polysialylated to the monosialylated forms. A tentative classification of meningiomas into "GM3-rich" and "GM1-rich" types, together with an explanation for the selective accumulation of these two types of ganglioside, is proposed.
Over the past 4 years 11 patients with Cushing's disease have been operated on by a transsphenoidal microsurgical technique. All patients had small intrahypophyseal adenomas found at operation. Eight of the 11 patients had a remission of the disease on the basis of clinical evaluation and hormonal studies. The endocrinological results revealed a transient state of hypocorticism in all successfully treated patients. Within 6-8 months after operation recovery of hypothalamic-pituitary-adrenal function and other tropin function took place. These findings, together with the absence of recurrence up to now, further confirm the efficacy of transsphenoidal surgery in the management of patients with Cushing's disease.
The authors describe an adult onset sensorimotor polyneuropathy in a woman with light chain K-type myeloma. Neurophysiological investigation showed a severe reduction of conduction velocity of the peripheral nerve to the four limbs. A muscle and sural nerve biopsy were performed. Sural nerve displayed a severe loss of myelinated and unmyelinated fibers. No amyloid deposit was observed in vessels, perineurium and endomysium by electron microscopy examination. No onion bulb formation was present in nerve tissue, but many demyelinated fibers were surrounded by circumferentially disposed Schwann cell processes without any interposition of collagen fibrils. Some fibers exhibit signs of active remyelination; axonal alterations were rarely seen. Collagen pockets were frequently observed among proliferated collagen fibrils. The mechanism of peripheral nerve lesions in various categories of multiple myeloma is till now an unsolved problem. In this case the unusual association with a light chain myeloma suggest that these immunoglobulins play a role in the pathogenesis of the polyneuropathy as supported by experimental studies.
75 children ranging in age from 3 months to 14 years, operated on for post-traumatic cerebral lacerations, within an 18-year period, have been analyzed. These represent 2.1% of 3,460 children sustaining head injury and hospitalized during this same period. Total mortality was 16%. The cases were divided into 2 groups: (A) cerebral lacerations underlying a depressed fracture (coup lesion) -- 68 cases. In 42 cases the lacerations were focal without edema and/or intracerebral hematoma. 1 child died and 41 survived. In 26 cases the laceration was diffuse and accompanied by cerebral edema and/or intracerebral hematoma. 6 children died and 20 survived. (B) Brain lacerations following a contrecoup lesion -- 7 cases, 5 of these children died and 2 survived. The follow-up of the surviving patients in the above two groups has been discussed.
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Of 600 patients submitted to radioisotope cisternography carried out with radioiodinated human serum albumin (I131-HSA) a group of 140 had head injuries. Our investigation was intended to study the modifications of CSF circulation and absorption which accompany cranio-cerebral trauma. Of 88 head injured patients who did not undergo operation 44 had transient loss of consciouness, and 44 were in prolonged coma. Fifty-two patients underwent operation. Of these 5 had skull fractures with dural lesions, 7 had extradural haematomas, 19 had subdural haematomas, and 21 had brain contusions. Cisternograms were performed at different time intervals after trauma, and in some instances the test was repeated in order to study the possible long tern alterations of CSF circulation and absorption. Abnormalities of cisternographic pictures are classified into the following groups: 1 degree asymmetric diffusion; 2 degree operative cavity stagnation; 3 degree ventricular reflux; 4 degree associated abnormalities. Cisternographic features are analysed in relation to the corresponding clinical and pneumoencephalographic patterns in the patients examined. These investigations may enable us to recognise possible indications for shunt procedures in the management of CSF absorption defects, which are so frequently apparent after head injury.
In a series of 180 patients affected by brain stem tumors, 70 cases of children up to 16 years are analyzed. Diagnosis was made with clinical examinations, neuroradiological tests and, in 20 cases, with surgical explorations. A description is made concerning the clinical status with regard to site, extension and features of the tumor. Then the authors analyze statistically the survival of such patients in connection with clinical symptomatology, the radiological picture, medical treatment, radiation and/or surgical therapy either in the few cases of subtotal removal of the tumors, or in the more numerous cases of palliative procedures such as intra- and extra-thecal CSF shunting.
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The levels of the cyclic adenosine 3',5'-monophosphate (cyclic AMP)-phosphodiesterase (PDE) and the biochemical properties of its endogenous protein activator (PDEA) obtained from the human brain cortex and from different types of human cerebral tumours have been evaluated. The effects of the various PDEAs were studied measuring the activation of an activator-depleted cyclic AMP-PDE prepared from a normal brain cortex. The PDEA, obtained from normal and pathological tissues, did not change the affinity of the purified PDE for cyclic AMP, while it increased the Vmax of the enzyme. On the other hand, a cross-activation study showed that the PDEA lacked tissue specificity and was present in the tissue in excess over the enzyme. The levels of cyclic AMP-PDE and PDEA were much higher in normal than in tumoural tissues. The enzyme activity decreased in cerebral tumours more markedly than the protein activator. This biochemical pattern was more evident in the tumours of glial origin which are the most malignant.
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