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Biomedical subjects

L Parisi

Publications and source records attributed to L Parisi.

At least 19 recordsLinked to original sources

Pre-symptomatic neurological involvement in Behcet's disease: the diagnostic role of magnetic transcranial stimulation.

Twenty Behcet's disease (BD) patients with or without neurologic signs and symptoms were studied by means of magnetic transcranial stimulation. The most frequent abnormalities were an increase of motor evoked potential latency and a delay of central motor conduction time (CMCT). In 5 out of 9 BD patients with pyramidal signs central motor conduction changes were present. Furthermore, 2 out of 7 patients without neurologic signs and symptoms showed an increased threshold and a prolonged CMCT. The data obtained suggest that this technique is useful not only to confirm the neurologic impairment but also to reveal subclinical or pre-symptomatic central motor involvement in BD subjects.

Adolescent

Protective activity of a murine monoclonal antibody against acute and chronic experimental infection with type IV group B streptococcus.

A murine IgM monoclonal antibody (MAb H11) was developed against the type polysaccharide capsular antigen of group B streptococcus (GBS), serotype IV, after intraperitoneal immunisation of BALB/c mice with heat-killed bacteria. MAb H11 reacted in immunodiffusion with the purified polysaccharide in both its sialylated and desialylated form, giving a line of identity, and opsonised type IV GBS strains in an in vitro assay. When administered at the time of intraperitoneal lethal challenge with homologous GBS, or 4 h earlier, MAb H11 protected 90% of the mice. Protection was still observed when MAb H11 was given 4 h after the challenge. This MAb was strongly effective in preventing septic arthritis induced by type IV GBS.

Acute Disease

Multimodal evoked potentials in HIV-1-seropositive patients: relationship between the immune impairment and the neurophysiological function.

Multimodal evoked potentials (PRVEP, BAEP, mSEP) were recorded in 56 HIV-1 seropositive outpatients free from opportunistic CNS pathologies and/or overt HIV-1 encephalopathy. EPs were altered in 17 of 39 (43.6%) seropositive subjects without AIDS (group A) and in 13 of 17 (76.5%) patients with AIDS (group B). A high incidence of subclinical alterations (30.8%) were found in group A patients. Significant BAEP (I-III, III-V, I-V) interpeak latency and mSEP (N9-N13, N9-N20) conduction time prolongations were found in group A and B patients. PRVEP P100 was significantly prolonged only in group B. An inverse relationship between BAEP interpeak latencies and CD4 count was found. Our findings support the hypothesis of an important role of immunodepression in the development of neurophysiologic abnormalities, together with a preferential involvement of acoustic pathways, in the course of HIV-1 infection.

AIDS Dementia Complex

Purification and biochemical characterization of a 65-kilodalton mannoprotein (MP65), a main target of anti-Candida cell-mediated immune responses in humans.

A 65 kDa-constituent (MP65) of a whole-cell mannoprotein (MP) fraction of Candida albicans was purified by immunoaffinity chromatography with monoclonal antibodies directed against periodate-insensitive, protease-sensitive MP epitopes, putatively polypeptide in nature. These antibodies were obtained by immunization of mice with concanavalin A bead-coupled, low-glycosylated MP from hyphal cells of C. albicans grown in the presence of a subinhibitory dose of tunicamycin. The immunoaffinity-purified MP65 molecule had a pI of 4.1 and a protein/polysaccharide ratio of 1.8:1. It was resistant to hydrolysis by endoglycosidase H, endoglycosidase F, or N-glycoffanases but still reactive with concanavalin A. The polysaccharide moiety of MP65 was composed exclusively of mannose and glucose at a ratio of 12.7 to 1. The protein moiety showed numerous potential O-glycosidic linkage sites as suggested by the high proportion of serine and threonine (together accounting for more than 20% of the total amino acid composition) and susceptibility to diluted alkali. This treatment and digestion with alpha-mannosidase caused a reduction in the MP65 molecular mass to around 54 kDa. The N-terminal sequence of MP65 protein moiety was rich in alanine and valine (7 of 13 amino acids) and did not show any significant homology with deposited sequences in data banks. Purified MP65, at doses of a few nanograms, induced extensive T-cell proliferation of human peripheral blood mononuclear cells. This proliferation was specifically inhibited, in a dose-response fashion, by the antigen-binding fragment of the monoclonal antibody used for immunoaffinity purification. Overall, these results highlight biochemical and molecular details of MP65, a main target of human T-cell response to C.albicans.

Amino Acid Sequence

Postural rearrangement in IDDM patients with peripheral neuropathy.

OBJECTIVE: To evaluate the influence of diabetic peripheral neuropathy on postural strategy. RESEARCH DESIGN AND METHODS: Static posturography and nerve conduction velocity were performed in the following age-matched subjects: 10 IDDM patients with peripheral neuropathy, 23 IDDM patients without peripheral neuropathy, and 21 control subjects. All subjects with signs or symptoms of postural instability were excluded from the study. The following posturographic parameters were drawn: 1) velocity of body sway, expressed as mean velocity and average of the SDs, 2) VFY, the parameter derived from the velocity variance and the anteroposterior mean position of the body (this parameter monitors the postural strategy pursued by the subject), and 3) fast Fourier transformation on the x (FFTX) and y (FFTY) planes, spectral analysis of the frequencies of body oscillation on frontal (x) and anteroposterior (y) planes. RESULTS: Mean velocity and its SD were higher in IDDM patients with peripheral neuropathy than in control subjects and IDDM patients without peripheral neuropathy (P < 0.001). VFY was increased in IDDM patients with peripheral neuropathy versus control subjects and IDDM patients without peripheral neuropathy (P < 0.01). A direct relationship was found between parameters of posturography and some parameters of nerve conduction tests. CONCLUSIONS: Diabetic patients with peripheral neuropathy demonstrate a shift from physiological ankle control to hip postural control as monitored by specific posturography analysis.

Adult

Electrophysiological assessment of visual function in newly-diagnosed IDDM patients.

Electrophysiological tests (electroretinogram, oscillatory potentials, visual evoked potentials, in the basal condition and after photostress) reveal an abnormal function of the visual system in insulin-dependent diabetic (IDDM) patients. The aim of our work was to assess whether electrophysiological abnormalities in visual function exist in newly-diagnosed diabetic patients free of any fluorangiographic signs of retinopathy. Ten control subjects (age 28.7 +/- 2.44 years) and then IDDM patients (age 25.2 +/- 6.78 years; disease duration 5.3 +/- 3.5 months) in stable metabolic control (HbA1C 7.5 +/- 1.1%) were evaluated. Flash-electroretinograms and oscillatory potentials were similar in both groups. Visual evoked potentials (VEP) recorded under basal conditions showed that P100 latency was significantly increased in the diabetic patients compared to control subjects (p < 0.01), while N75-P100 amplitude was similar in both groups. The recovery time of VEP after photostress was equivalent in diabetic patients and control subjects. The impaired basal VEPs suggest an early involvement of the nervous conduction in the optic nerve. However, the preserved flash-electroretinogram and the normal recovery time after photostress indicate that a short disease duration does not induce physiopathological changes in the outer retinal layers or in the macular function.

Adult

Body sway in diabetic neuropathy.

OBJECTIVE: To evaluate the influence of peripheral neuropathy on body sway assessed by posturography. RESEARCH DESIGN AND METHODS: The age-matched study subjects included 10 insulin-dependent diabetes mellitus (IDDM) patients with peripheral neuropathy (DN), 23 IDDM patients without peripheral neuropathy (D) according to the San Antonio Consensus Conference guidelines, and 21 control subjects (C). All subjects with symptoms and/or clinical signs of postural instability were excluded from the study. RESULTS: The trace surface was significantly larger in the DN than in the C and D groups (P < 0.05), and the trace length was longer in the DN than in the C and D groups (P < 0.01). Mean velocity was faster in the DN than in the other two groups (P < 0.001). A direct relationship was found between the parameters of posturography and some parameters of the nerve conduction velocity. CONCLUSIONS: Diabetic patients with peripheral neuropathy demonstrate a relative deficit in their ability to maintain posture. Posturography allows an early disclosure of the failure of postural control.

Adult

Visual evoked potentials after photostress in insulin-dependent diabetic patients with or without retinopathy.

Visual evoked potentials (VEPs) were assessed under basal conditions and after photostress in normal control subjects, in insulin-dependent diabetic patients with retinopathy (IDDPWR) and in insulin-dependent diabetic patients without retinopathy (IDDP). The VEPs recorded under basal conditions showed a P100 latency significantly higher in IDDP and IDDP-WR eyes than in control eyes and in IDDPWR than in IDDP eyes (P < 0.01). N75-P100 amplitude was significantly lower in IDDP and IDDPWR eyes than in control eyes (P < 0.01). No difference was recorded in the N75-P100 amplitudes between IDDP and IDDPWR eyes. In all eyes, the VEPs recorded after photostress showed an increase in latency and a decrease in amplitude. In both IDDPWR eyes and IDDP eyes VEPs recorded at 20, 40 and 60 s after photostress showed higher mean increments in P100 latency than in C control eyes, and IDDPWR eyes showed higher mean increments in P100 latency than IDDP eyes (IDDP vs control P < 0.01, IDDPWR vs control P < 0.01, IDDPWR vs IDDP P < 0.017). The mean reductions in amplitude observed at 20, 40 and 60 s after photostress in IDDP and IDDPWR eyes were lower than in control eyes (IDDP vs control P = 0.01, IDDPWR vs control P < 0.01, IDDPWR vs IDDP P < 0.01). VEPs were superimposable on the basal VEP (recovery time) at 73.9 s in control eyes, at 88.17 s in IDDP eyes and at 113.3 s in IDDPWR eyes. VEPs after photostress in IDDP patients with normal visual acuity and no fluorangiographic signs of retinopathy may show multiple modifications. This may indicate the presence of an early functional deficiency of the central retinal layers.

Adult

Myopathy in long-term AZT therapy: clinical, electrophysiological and biopsy study in 67 HIV+ subjects.

The occurrence of muscular pathologies in AZT treated subjects has been evaluated in 67 HIV seropositive outpatients (56 AZT-treated and 11 untreated controls) in a neurological clinical and paraclinical follow-up study. Standard electromyographic and electrodiagnostic examinations, together with muscle enzyme determination, were performed in every subject, and periodically repeated at fixed intervals; in 11 patients a muscle biopsy sample was also obtained. An AZT-related myopathy was diagnosed in 8 biopsied cases; 9 more patients were considered to have AZT myopathy on clinical, EMG and ex juvantibus criteria. Statistical analysis showed that treatment duration was more relevant to the development of the myopathy than AZT dosage, though an individual predisposition could not be excluded, at least in a small number of cases. The risk of developing a toxic myopathy will therefore have to be considered when evaluating long-term effects of AZT therapy.

Adult

Repetitive stimulation in myasthenia gravis: decrementing response revealed by anticholinesterase drugs.

In myasthenia gravis (MG) a typical decrementing response is frequently revealed with repetitive stimulation (RS) in clinically unaffected muscles. However, RS is unlikely to give normal results in weak muscles. In two of our patients we found a normal response in clinically affected muscles. However, a decrementing response surprisingly appeared after the administration of anticholinesterase drugs. A possible explanation for this apparently paradoxical effect is as follows: some junctions are already blocked at rest, whereas others function normally both at rest and during RS. As a consequence, the initial compound muscle action potential (CMAP) is reduced in amplitude and shows no further decrement on RS. Anticholinesterase drugs reverse some blocks, therefore causing the CMAP increase in amplitude. However, these labile junctions are more prone than normal to synaptic fatigue, so a decrementing response is produced on RS. This behavior, though not frequently encountered, can account for some negative results of RS in MG.

Action Potentials

On a case of early-onset post-traumatic facial hemispasm.

In a 49 year old woman an injury to the right frontotemporal region was quickly followed first by paresis and then by spasm of the right side of the face. The early onset of the spasm prompts a critical review of current views on the pathogenesis of facial spasm.

Brain Concussion

In vitro activity of alpha, beta, gamma human interferons and Aspergillus terreus mycotoxins on cell proliferation.

The in vitro effect of different doses of alpha, beta and gamma human interferons and their interaction on the proliferation rate of human erythroleukemic cell line (K-562) and other cell lines has been evaluated. The results show that the stronger activity is exerted by beta HIF in comparison with alpha HIF. The action is selective and species-specific. beta HIF never elicited an "enhancing" effect on cell proliferation; on the contrary this phenomenon has been observed to occur with alpha and gamma HIF. In our cell system, the interaction between beta and gamma HIF gave a synergistic effect; on the contrary, no interaction has been observed to take place when beta HIF and directly cytotoxic mycotoxins extracted from A. terreus are associated.

Cell Division

Polycystic ovarian disease: ultrasonic evaluation and correlations with clinical and hormonal data.

The size, shape, margins, and structure of the ovaries, as observed in 26 patients with polycystic ovarian disease were analyzed, and uterine/ovarian ratio (maximum antero-posterior diameter of uterine fundus divided for longitudinal diameter of ovary) was calculated. The maximum surface area of the organs ranged from 9.5 cm2 to 17.3 cm2 (average value 12.9 cm2). A "roundness index" (minimum diameter X 100/maximum diameter) was calculated in order to evaluate the shape: it ranged from a value of 100 in perfectly rounded ovaries to a value of 54 in ovaries of oval shape. The ovarian structure was characterized by many small cysts of the same dimensions in 19 cases; in two patients there was a predominant cyst; in five cases it appeared as many thick echoes arranged along parallel lines. The uterine/ovarian ratio was always equal to or less than 1. Correlation tests for size, shape of the ovaries, patient's age, and duration of symptoms were highly significant. This leads one to suppose that both of these ultrasonic findings are a function of the duration of the disease and that polycystic ovarian disease, once established, is the cause of progressive enlargement of these organs.

Adolescent

[Cystic dilatation of the bile ducts : value of various methods of diagnosis. Apropos of 3 cases].

Three cases of cystic dilatation of the biliary tract of 1st, 4th and 5th type are reported here according to the classification established by Longmire and Hadad amended. In two patients the diagnosis was carried out through ultrasound examination and confirmed, in one case, by intraveinous cholangiography associated to computed tomography (and by peroperatory cholangiogram in the other one). In the third patient suffering from Caroli's disease the diagnosis was carried out during peroperating cholangiography. The possibilities of the different methods in diagnosing cystic dilatations of the biliary tract are discussed and therapeutic problems are taken into consideration.

Adult