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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
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1991

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↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1987

Central and peripheral involvement in hemodialysed subjects: neurophysiological and nephrological relationships.

Nerve conduction velocity and visual evoked potential studies were conducted in 31 patients with chronic renal failure undergoing periodic hemodialysis. The results indicate damage to the central nervous system, such as delayed P100 wave, even in the absence of clinical signs, and to the peripheral nervous system, such as distal sensorimotor neuropathy. The degree of peripheral involvement correlates with the duration of dialysis and with some blood chemistry values but not with the evoked potential parameters. There is no correlation between central and peripheral nervous damage, which presumably points to a difference in pathogenesis.

Adult↗
PubMed1987

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↗
PubMed1987

Parasympathetic assessment in Parkinson's disease.

There is little evidence of autonomic dysfunction in PD, although autonomic disturbance was included in the original description by J. Parkinson. In addition, there are no data for de novo PD patients. We selected 14 de novo parkinsonians (seven men and seven women), aged 62.7 +/- 8.2 years, with mild disease (stage 1 through 2 on the Hoehn and Yahr's scale), without history of diabetes, heart disease, or alcoholism, and without neuropathy or orthostatic hypotension. Fourteen age- and sex-matched normal persons were controls. We found a highly significant difference in the respiratory sinus arrhythmias during deep breathing (p less than 0.01); the basal heart rate, the respiratory sinus arrhythmias during quiet breathing, and the Valsalva ratios did not differ statistically, however. In the absence of neuropathy and orthostatic hypotension and in the presence of normal Valsalva ratios, we believe that the abnormality found by us may apply only to parasympathetic dysfunction, perhaps at a central level. In addition, the abnormality seems to be independent of stage and therapy.

Aged↗
PubMed1986

Phase II study of vaccinia melanoma cell lysates (VMCL) as adjuvant to surgical treatment of stage II melanoma. II. Effects on cell mediated cytotoxicity and leucocyte dependent antibody activity: immunological effects of VMCL in melanoma patients.

Patients with stage II melanoma were vaccinated with vaccinia virus-induced melanoma cell lysates (VMCL). The vaccine contained viable vaccinia virus, membranous fragments and no intact nuclei. A number of antigens defined by monoclonal antibodies were detected in the vaccine including the ganglioside GD3 and DR antigens. Administration of the vaccine was associated with depression of natural killer cell activity against melanoma and K562 target cells in the first 3-6 months of treatment. Leucocyte dependent antibody (LDA) activity against melanoma cells was induced or increased in titre in approximately half of the patients studied. Continued vaccination was associated in a number of patients with a decrease in LDA titres. Studies on a small sample of patients revealed that this was associated with the development of serum factors which inhibited LDA activity. LDA activity appeared directed to non-MHC antigens on melanoma cells which were of at least two specificities. One specificity which was shared with antigens on a number of non-melanoma carcinoma cells was removed by absorption on fetal brain and may be similar to oncofetal antigens described by other workers. Reactivity against melanocytes was induced in some patients and may underline the development of vitiligo in several patients. These results suggest that vaccines prepared from VMCL may be a favourable method for increasing immune responses against melanoma.

Antibodies, Neoplasm↗
PubMed1985

Occurrence of pituitary adenoma in craniofacial fibrous dysplasia: a neuroendocrine and neuroradiological case study.

An 18 year old man with fibrous dysplasia of bone and several endocrine abnormalities was investigated. Laboratory tests showed high levels of prolactin, TSH and GH and low levels of testosterone and LH. TRH and GnRH showed normal responsiveness of the pituitary in spite of the high hormonal levels. The circadian rhythms disclosed no abnormalities of hypothalamic control. The neuroradiological study revealed pathological tissue but no positive sign of a pituitary adenoma, although the sella turcica polytomograms did suggest erosion of the floor. Our data are compatible with the presence of a mixed adenoma or adenomas of the pituitary. We emphasize the importance of a correct study, including neuroradiological and neuroendocrine investigations, in patients with fibrous dysplasia of bone.

Adenoma↗
PubMed1982

An immuno-enzymatic assay for herpes simplex virus tumour associated antigen in gynecological oncology.

The authors studied the HSV-TAA (Herpes Simplex Virus Tumor Associated Antigen) in patients affected by female genitale tract tumors, using the immunoenzymatic assay (ELISA). They found a positive frequence of 65% in sera of patients affected by uterine cervical carcinoma and of the 80% in sera of patients affected by vulvar carcinoma. The authors suggest that this enzymatic method has a real value and propose its use in the early diagnosis of the female genital tract neoplasms.

Antigens, Neoplasm↗
PubMed1981

Perspectives and limits of an immunoenzymatic assay (ELISA) for herpes simplex virus (HSV) tumor-associated antigen (TAA).

An ELISA has been developed to detect specific antibodies for HSV-TAA in sera of patients with head, neck and urogenital tract carcinomas (Cancer, 45:1980). Further studies have shown that 64/800 controls (8.12%), i.e. healthy people, are positive against 312/425 patients with herpes associated tumors (73.41%). People with herpes recurrens show 18% positivity, precancerous lesions 44% and other cancers 6%. Immunodepression, chemo- and radio-therapy play an inhibitory role on the ELISA positivity for TAA. Radical surgery of the HSV-TAA positive cancers results in lack of specific antibody whereas relapse or metastasis of the tumor yields positive results. The reproducibility of the test is very good and the standard error is low (1.0655). The conclusions allow us to foresee the use of this ELISA for early detection of the HSV-TAA antibodies in certain human carcinomas.

Animals↗
PubMed1979

[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↗
PubMed1979

[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↗