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Biomedical subjects

G D'Alessandro

Publications and source records attributed to G D'Alessandro.

At least 19 recordsLinked to original sources

Peripheral neuropathy caused by antiepileptic drugs. Neurophysiological study of the A delta and C fibers.

The risk that antiepileptic drugs may cause damage to the peripheral nervous system led us to investigate 12 patients on carbamazepine and 12 patients on phenobarbital with the thermal threshold test. The heat and cold thresholds were measured at the ankle and wrist and, compared with those in 30 healthy subjects, they proved to be significantly higher. When the two groups of epileptics were compared separately with the controls, their thresholds were always higher. These findings are consistent with a toxic effect of both drugs on fine peripheral nerve fibers.

Adolescent

Clinical and neuroradiological findings in a case of pure word deafness.

Pure Word Deafness is a clinical syndrome included among the aphasias and is marked by complete deafness of sudden onset with conserved ability to understand and read the written word and with no speech disorders. We report the case of 61 year old man in whom pure word deafness developed after two episodes of acute cerebral ischemia in quick succession. Neuroimaging procedures, that is: computed tomography scan, single photon emission computed tomography and magnetic resonance imaging, revealed the presence of two ischemic lesions in the temporal cortex bilaterally. Neurophysiological investigations (electroencephalogram, brainstem auditory evoked potentials and stapedial reflex) were also studied. We discuss the outcome of all these investigations in the light of the relevant published work.

Brain

Incidence and prognosis of stroke in the Valle d'Aosta, Italy. First-year results of a community-based study.

BACKGROUND AND PURPOSE: We sought to determine the incidence rate, risk factors, and prognosis of stroke in Valle d'Aosta, Italy, to provide information for planning regional health-care facilities. METHODS: We undertook a prospective study of all new cases of stroke in the geographically defined population of 114,325 residents of Valle d'Aosta in northern Italy. RESULTS: In the first year of the study (January 1-December 31, 1989), 254 cases of first stroke were registered. The crude annual incidence rate was 2.23/1,000, 1.98/1,000 for men and 2.46/1,000 for women. After adjustment to the 1988 Italian population, the incidence rate for first stroke was 2.15/1,000 per year, 2.48/1,000 per year for men and 1.99/1,000 per year for women. The pathological diagnosis was cerebral infarction in 67%, intracranial hemorrhage in 15%, and unknown in 18%. The overall 30-day case-fatality rate was 31%. In survivors, Barthel Index Score recorded at 30 days from stroke onset showed that 100 patients (62%) were dependent in activities of daily living. CONCLUSIONS: Our results do not differ significantly from those reported in Umbria, the only similar study performed in Italy, and support non-Italian data as to risk factors in stroke.

Aged

Frequency of multiple sclerosis in Valle d'Aosta, 1971-1985.

According to studies done before 1980, the multiple sclerosis (MS) prevalence rate in Italy ranged from 7.2 to 27.1 cases per 100,000 inhabitants. More recent work has consistently put the MS prevalence rate to over 30 cases per 100,000 inhabitants. If these recent data are confirmed in the future, Italy can no longer be regarded as a country at low risk for MS, but must be included among the medium-high risk countries of continental Europe. We report the results of a prevalence and incidence survey conducted in Valle d'Aosta, a region whose special features make it an excellent epidemiological model. The mean annual incidence was 2.1 and on December 31, 1985, the prevalence was 39 cases per 100,000 inhabitants. These results confirm that the incidence and prevalence rate of MS in Valle d'Aosta is close to that of areas at high-risk for MS.

Adolescent

Posttranscriptional control of human homeobox gene expression in induced NTERA-2 embryonal carcinoma cells.

We have studied the expression of four human homeobox genes representative of four different clusters (i.e., HOX-1, HOX-2, HOX-3 and HOX-5) in the embryonal carcinoma (EC) cell line NT2/D1. Following treatment with retinoic acid (RA), these cells differentiate into several cell types, including neurons, and steadily accumulate polyadenylated transcripts derived from the genes in a period ranging from 18 hr to 14 days of RA treatment. The sizes of major transcripts in differentiated EC cells coincide with those previously detected by the same probes in human embryos. Nuclear run-on transcriptional analysis showed no difference in the transcription rate of the four homeobox genes in differentiated vs. undifferentiated EC cells. Inhibition of protein synthesis by 5-18 hr of treatment of undifferentiated cells with cycloeximide causes accumulation of some homeobox transcripts at levels comparable to those observed after 18 hr of RA induction, although it does not cause superinduction in fully differentiated cells. These data suggest that the activation of homeobox gene expression in RA-induced EC cells is controlled, at least in part, by posttranscriptional mechanisms.

Amino Acid Sequence

Expression of the gangliosides GM3, GD3 and GD2 in tissue sections of normal skin, naevi, primary and metastatic melanoma.

Expression of the gangliosides GM3, GD3 and GD2 was studied in tissue sections from 19 naevi, 29 primary and 83 metastatic melanoma using the ABC immunoperoxidase technique. GM3 was not detected in normal skin whereas GD2 was detected on the basal and stratum spinosum of the epidermis and on peripheral nerves in the dermis. GD3 was expressed on melanocytes but not on most other components of normal skin. However, GD3 was strongly expressed on epidermis adjacent to naevi and primary melanoma whereas GD2, in contrast to that in normal skin, was not expressed on the epidermis adjacent to 26/29 primary melanoma. All naevi were positive for GM3 and GD3 except that GM3 was not detected on junctional components of naevi. GD2 was not expressed on naevi except in areas showing neuroid differentiation. Studies on melanoma revealed that approximately 60% of primary and 75% of metastatic melanoma expressed GM3 to a varying extent. With 2 exceptions, all primary and metastatic melanomas expressed GD3 although there was variable expression within most of the individual tumours. GD2 was detected in only approximately 25% of primary and 50% of metastatic melanomas. Both GD2 and GD3 were detected on lymphocytes surrounding melanoma. The higher expression of GD2 on metastases compared to primary melanomas was consistent with the view that GD2 expression was associated with increased metastatic potential. However, the low proportion of metastases expressing GD2 and the absence of any correlation with thickness of the primary tumour suggested that GD2 expression was not a reliable marker of metastatic potential. No differences could be detected in ganglioside expression on metastases in skin or lymph nodes. These results appear to have implications for the use of MAbs against gangliosides in therapy of melanoma and in the study of melanocytic differentiation.

Antigens

Suppression of natural killer cell activity in humans by radiation from solarium lamps depleted of UVB.

Previous studies have shown that ultraviolet radiation (UVR) from solarium lamps suppressed natural killer (NK) cell activity in the blood and that sunscreen lotions offered no protection against this effect. In the present study we tried to determine whether the effects on NK cell activity were caused by the UVB or the UVA components of radiation from solarium lamps by filtering out UVB with Mylar sheeting. Groups of 10 normal subjects were either left untreated or exposed for 30 min on 12 consecutive days to radiation that was filtered or not filtered through a 0.1 mm thick Mylar sheeting. NK cell activity was depressed in the group exposed to solarium radiation and this was not prevented by filtration through Mylar. The latter procedure, however, appeared to prevent changes in blood lymphocyte subsets that are induced by solarium radiation as well as the reduction in Langerhans cell numbers in skin biopsies taken after exposure to solarium radiation. Suppression of NK cell activity was evident up to 14 days after cessation of UVR exposure. This would be consistent with the replacement of NK cells from bone marrow that had been damaged as a result of direct effects of UVA on NK cells in the microcirculation of the skin or else indicate functional suppression of NK cells by suppressor cells induced by UVR as postulated for UVR-induced suppression of delayed hypersensitivity responses in murine models. These studies suggest that UVA may be important in the induction of certain effects on the immune system in human subjects. Further studies are required to assess the implications of these findings with respect to induction of neoplasia and the design of sunscreens effective against UVA.

Adult

Immunohistological evaluation of MHC class I and II antigen expression on nevi and melanoma: relation to biology of melanoma.

MHC antigen expression on 20 nevi, and 35 primary and 95 metastatic melanomas was studied by immunoperoxidase techniques using monoclonal antibodies to identify the antigens on frozen tissue sections. DR antigens were not detected on nevi but were detected on 71% of primary melanomas and 56% of metastases, suggesting that this antigen may be a useful marker of malignant transformation of nevi. Expression of class II antigen could not be related to other prognostic histological features of primary melanoma such as tumour thickness, but comparison of the common phenotypes of primary and metastatic melanoma suggested that expression of DR antigens alone in the absence of DP, DQ and ABC antigens may be an indicator of metastatic potential. Class I (HLA-A,B,C) antigens were also expressed infrequently on nevi but were detected on 43% of primary melanomas and 34% of metastases. HLA-A,B,C expression was inversely related to thickness of the primary melanoma. This as well as the lower expression of class I antigens on metastases, may indicate that growth and spread of melanoma may be inhibited by MHC (class I) dependent cytotoxic T cell responses. Expression of class I MHC antigens was unrelated to class II antigens. Expression of DR was more common than DP or DQ, but the latter with one exception, were not expressed in the absence of DR antigens. Significant differences were not found in MHC antigen expression on metastases in lymph nodes compared to those in subcutaneous sites, but further studies are needed to determine whether such differences may exist between metastases in other visceral sites.

Antibodies, Monoclonal

[Primary tumors of the spleen].

Four cases of so-called primary tumour of the spleen are discussed, stress being laid on their rarity and clinical course. The importance of splenectomy for precise histological diagnosis and assessment of the stage of the disease, factors which are indispensable for the oncologist when planning therapy, is also emphasized.

Adult

[Vascularization of the jejunal loop].

Vascularization of the first 60 cm of the jejunum is considered on the basis of a necroptic study of 100 cases. Attention is called to the possibility that surgical failure in ansa transposition techniques may be due to anatomical variations in the first jejunal branches of the superior mesenteric.

Humans

[Mastalgia].

A series of 624 cases of breast pain examined over a period of 5 years is reviewed in the light of age, fecundity, side affected, and occupation. The gynaecological evidence made it clear that most cases where attributable to hormone disorders. In particular, there were no instances in which initial cancer was detected as a result of the pain symptom. The findings are discussed in the light of the literature.

Adolescent

[Cryosurgery for hemorrhoids].

The new cryosurgical method of treating haemorrhoids is examined. Stress is laid on the importance of proper operation technique and correct evaluation of candidates. Infection, fistulae, abscesses, and stenosis are absolute contraindications.

Adult

[Anastomoses of the lower 3d of the esophagus].

In view of the larger number of operations on the bottom third of the oesophagus recently necessary in the destructive surgical therapy for tumours, the Authors re-examine 50 cases of oesophago-gastric and oesophago-jejunal anastomoses and stress the importance of accurate anastomoses, preferably single-layer in order to avoid early and delayed complications.

Adult

[Physiopathology of the gastrectomized patient].

The Authors re-examined 50 cases of various ages and both sexes subjected to total gastrectomy for neoplasia, without any other chemotherapic or radiant collateral treatmente, and analyse the sequelae following total removal of the stomach. On the basis of the data collected, they conclude on the importance of an adequate reconstructive technique, in particular stressing the utility of preservation of the duodenal transit and the need for suitable dietetic-pharmacological conduct in the years following the operation.

Female

[Intestinal occlusion caused by jejunal leiomyosarcoma].

A case of intestinal occlusion due to jejunal leiomyosarcoma is reported. Attention is drawn to the unusualness of the picture and the absence of an indicative symptomatology. Early diagnosis is desirable if surgery is to be successful.

Adult