Biomedical subjects

F Giannini

Publications and source records attributed to F Giannini.

At least 37 records · Page 2Linked to original sources

PubMed1999

Usefulness of segmental and comparative tests in the electrodiagnosis of carpal tunnel syndrome: the Italian multicenter study. Italian CTS Study Group.

The Italian CTS Study Group performed a wide multicentric and multiparametric study to quantify the increase of electrodiagnostic sensitivity using an extended neurophysiological protocol and particularly segmental and comparative tests. The study also evaluated the clinical features of carpal tunnel syndrome (CTS) diagnosed by these tests, using validated physician- and patient-oriented measurements. The study group was composed of 740 patients for a total of 1123 idiopathic CTS hands. Overall, the sensitivity of standard tests (median digit-wrist sensory conduction velocity and wrist-thenar distal motor latency) was 83.5%. Comparative/segmental tests disclosed abnormal findings in a further 11.4% of cases, providing CTS electrodiagnosis in about 7 of 10 "standard negative" cases. The overall sensitivity of the electrodiagnostic protocol was 94.9%. The CTS population diagnosed by segmental/comparative tests had a clinical picture characterized by a high percentage of pain, and severe discomfort but no limitation in functional daily activity. Our data confirm the usefulness of a complete neurophysiological assessment by using segmental/comparative tests when standard tests yield normal results.

Adult↗

PubMed1999

Multifocal neural conduction impairment in forestry workers exposed and not exposed to vibration.

OBJECTIVE: The aim of the study was to assess peripheral neural involvement induced by exposure to hand-arm vibration. METHODS: Twenty lumberjacks, working regularly with chain-saws and exposed to hand-arm vibration (group E) and 20 forestry workers performing heavy manual work and not exposed to vibration (group NE) were matched with a control group of 20 healthy non-manual workers (group C). The subjects of groups E and NE, all symptomatic, and of group C underwent extensive bilateral neurophysiological examination consisting of: sensory conduction (velocity and amplitude) of radial, median and ulnar nerves in digit-wrist segments; sensory conduction (velocity) of median nerve in wrist-elbow segment; mixed conduction (velocity and amplitude) of median and ulnar nerves in palm-wrist segments; motor conduction velocity, including distal motor latencies, and amplitude of median (elbow-wrist) and ulnar (elbow-wrist and across the elbow) nerves. RESULTS: Electrophysiological abnormalities were found in 85% of group E's limbs, versus 62.5% of group NE's limbs. The most frequent pathological pattern in group E was a 'multifocal' impairment (multiple sites of several nerve segments), with a prevalent involvement of sensory rather than motor fibres in the hand, seldom extending to the forearm. Multivariate analysis showed that the neurographic parameters which better characterized workers exposed to hand-arm vibration had a pattern different from that usually found in idiopathic carpal tunnel syndrome (CTS). CONCLUSION: These results suggest that vibration-induced neural involvement can be considered neither pure digital neuropathy, nor definite CTS, as previously described.

Action Potentials↗

PubMed1998

Role of folate receptor and reduced folate carrier in the transport of 5-methyltetrahydrofolic acid in human ovarian carcinoma cells.

Folate receptor-alpha (FR-alpha) is generally over-expressed in non-mucinous human ovarian carcinomas. The meaning of FR-alpha over-expression and its role in the 5-methyltetrahydrofolic acid (N5-CH3-H4PteGlu) transport in such tumors is not clear, especially compared with the reduced folate carrier (RFC), the other known folate transporter. In this study, we analyzed molecular FR-alpha and RFC expression in 16 ovarian carcinoma tissues and in 5 ovarian carcinoma cell lines using competitive PCR. Co-expression of the 2 transporters was found both in vivo and in vitro. FR-alpha mRNA expression in the cell lines was in good agreement with the corresponding protein expression evaluated by cellular folic acid binding and immunofluorescence analysis, using a specific monoclonal antibody (MAb) (MOv18). Moreover, RFC mRNA expression levels were consistent with the selective cellular binding of N-hydroxysuccinimide of [3H]-methotrexate (NHS-MTX). The 5 ovarian carcinoma cell lines (IGROV-1, SW-626, SKOV-3, OVCAR-3 and OAW-42), grown at physiological N5-CH3-H4PteGlu concentrations (20 nM) and expressing FR-alpha and RFC levels superimposable to those observed in vivo, were used as in vitro cellular model to evaluate the different contribution of FR-alpha and RFC to the transport of N5-CH3-H4PteGlu. The cytoplasmic N5-CH3-[3H]H4PteGlu accumulation observed in each cell line was approximately linear over 4 hr of incubation, but there was no correlation between the rate of folate internalization and FR-alpha and RFC expression levels. Furthermore, the selective inhibition of FR-alpha and RFC functionality allowed us to distinguish their differential role on the overall N5-CH3-[3H]H4PteGlu intracellular delivery. Treatment with the N-hydroxysuccinimide of folic acid, which blocks FR-alpha activity, showed only a partial inhibition (about 20%) of folate internalization in all the cell lines. In contrast, the inhibition of RFC by NHS-MTX, under conditions that did not affect FR-alpha functionality, generally reduced folate accumulation by more than 70%. Only one cell line (IGROV-1) showed a comparable contribution of the 2 transport systems. Our findings suggest that in ovarian carcinomas, in spite of its over-expression, FR-alpha generally plays a minor role in N5-CH3-H4PteGlu transport compared with RFC.

Biological Transport↗

PubMed1998

In vitro studies on mode of action of antifungal 8.O.4'-neolignans occurring in certain species of Virola and related genera of Myristicaceae.

Neutral racemic antifungal alcohols of 8.O.4'-neolignan type, were evaluated for inhibitory activity towards the fungal cell wall, using the whole cell Neurospora crassa hyphal growth inhibition assay. Results strongly suggested that these compounds could act by inhibiting cell wall polymer synthesis or assembly. Active compounds were tested for their inhibitory activities against (1,3)-beta-glucan synthase, an enzyme that catalyzes the synthesis of the major wall polymer (1,3)-beta-glucan. Although these compounds were found to be inhibitors of the enzyme (inhibition ranging between 2 and 72% at 250 micro/ml), comparison of these results with those from agar dilution assays, allow us to infer that these compounds do not act via the inhibition of glucan synthase. In addition, ketones with same pattern of substitution as alcohols, which have no antifungal properties in agar dilution assays, still displayed similar glucan synthase inhibition.

Antifungal Agents↗

PubMed1998

Clinical and electrophysiological findings and follow-up in tarsal tunnel syndrome.

The authors report clinical and electrophysiological findings in 59 patients with tarsal tunnel syndrome (TTS) and follow-up in 23 of them. The entrapment was prevalent in females; was bilateral in 6 patients and involved medial plantar in 7 and lateral plantar nerves in two cases. Eleven presented with other nerve entrapment syndromes or focal mononeuropathies, due to hereditary neuropathy with liability to pressure palsy or systemic diseases. The other 48 subjects had TTS without any other related entrapment syndromes: 23 were idiopathic cases, 13 had a history of local trauma, 3 had systemic diseases and the others had external or intrinsic compressions. The most frequent symptoms were paraesthesia or dysaesthesia (86% of feet) and pain (55%). Hypoaesthesia of the sole and weakness of toe flexion were evident in 74% and 22% of feet, respectively. Absence of sensory action potential or slowing of sensory conduction velocity (SCV) of the plantar nerves were present in 77% of feet; significant differences of SCV between affected and unaffected plantar nerves and/or between distal sural and plantar nerves were evident in 14%. Abnormalities of plantar SCV were therefore absent in only 9% of feet. Distal motor latency was delayed in 55% and electromyography showed neurogenic changes in 45% of sole muscles. Five cases (6 feet) underwent surgery with excellent or good results in 5, 4 of them also showing improvement in distal conduction of the plantar nerves. Nine were treated with local steroid injections, with good results shown in 6 patients. Nine other patients who did not receive any therapy showed a disappearance of symptoms or good outcome in 6 cases. The subjects with poor therapeutic results had S1 radiculopathy or systemic diseases. The authors underline that patients with connective tissue diseases should not be treated by surgical decompression because they may have subclinical neuropathy. Some subjects with idiopathic or trauma-induced TTS recover spontaneously. Surgical release should be limited to cases with space-occupying lesions and when conservative treatments fail.

Action Potentials↗

PubMed1998

Hepatitis C virus and immunoglobulin gene rearrangements: an early step in lymphomagenesis?

A clonal expansion of peripheral blood mononuclear cells committed to IgM cryoprecipitating rheumatoid factor production has been demonstrated in hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC). To determine the role of HCV in B cell gene rearrangements we studied a series of 57 HCV-infected patients with and without MC. Clonal Ig gene rearrangements of both RNA and DNA were detected in 10 of the 13 patients with type II MC, 1 patient had gene rearrangement of the DNA only, and 2 had polyclonal patterns. 2 of the 17 patients with type III MC showed clonal rearrangement of both RNA and DNA, in 6 only the DNA was rearranged clonally and in 9 the patterns were completely normal. 14 of 27 patients with cryocrit <1% or without cryoglobulins had clonal DNA rearrangements without any in the RNA. These results suggest that clonal lesions in the DNA are related to HCV infection and that these changes antedate the appearance of mixed cryoglobulinemia.

Cryoglobulinemia↗

PubMed1997

All-trans, 13-cis and 9-cis retinoic acids induce a fully reversible growth inhibition in HNSCC cell lines: implications for in vivo retinoic acid use.

Retinoids are a group of vitamin A analogues that have shown promise as chemopreventive and therapeutic agents in many types of malignancy and have been entered in clinical trials with some successful results. To better understand the mechanism that mediates retinoid action and the anti-proliferative effects, we treated 7 human oral squamous-cell carcinoma (SCC) cell lines (FADU, HEp-2, CCL-17, SCC-9, SCC-15, SCC-25 and HN-212) with 10(-6) M of all-trans retinoic acid (ATRA), 9-cis and 13-cis retinoic acid (RA) in continuous for different periods of time. We assessed the extent of growth inhibition, the stability of the anti-proliferative effect and the mRNA expression levels (by RT-PCR) of RA receptors (RARs), retinoid X receptors alpha (RXR alpha) and cytosolic RA-binding proteins (CRBP I and CRABP II) in treated cells compared with controls. The data obtained showed that all 3 RAs were able to inhibit the cellular growth of the tested cell lines, although to a different extent. The cis compounds were able to inhibit the proliferation of all cell lines, whereas ATRA was ineffective in inhibiting the proliferation of the CCL-17 cell line, which was naturally resistant to ATRA concentrations in the range between 10(-5) and 10(-6) M. All inhibitory effects were completely reversible since all cell lines restored their normal growth proliferation within few days after drug removal. RT-PCR analysis of the receptor and cell binding protein status of control and treated cells showed a good correlation between growth inhibition and induction of, or increase in, the expression levels of RAR beta in RA-treated cells. No differences were observed in RAR alpha and RXR alpha mRNA expression levels between control and treated cells. CRBP I, CRABP II and RAR gamma mRNA levels increased in some treated cell lines but not in all.

Alitretinoin↗

PubMed1997

Role of antepartum computerized fetal heart rate analysis in the prediction of fetal distress during labor.

OBJECTIVE: To ascertain the diagnostic ability of a computerized fetal heart rate (FHR) analysis system in the identification of patients at risk of fetal distress in labor. STUDY DESIGN: Five-hundred and seventy-seven healthy term pregnancies were enrolled in a prospective, cross-sectional study and subdivided into two groups, with (n = 90) or without (n = 487) fetal distress in labor. Computerized FHR recordings were performed periodically and regression analysis was performed in a univariate and multivariate way to assess the ability of the last FHR recordings in the prediction of subsequent fetal distress. RESULTS: The two groups showed a significant difference in almost all of the FHR parameters studied. The multivariate analysis showed that only the FHR baseline and the percentage of small acceleration were independently and significantly related to the labor outcome. The combination of these two parameters reaches a sensitivity of 45%, specificity of 91%, positive predictive value of 48% and negative predictive value of 90%, with an overall accuracy of 84%. CONCLUSIONS: The increase in FHR baseline and in small FHR accelerations can be major factors in the prediction of subsequent fetal distress in healthy term fetuses.

Computers↗

PubMed1995

Cervical and scalp recorded short latency somatosensory evoked potentials in response to epidural spinal cord stimulation in patients with peripheral vascular disease.

Somatosensory evoked potential (SEP) studies were performed in 14 patients with peripheral vascular disease who received epidural spinal cord stimulation (SCS) for chronic pain relief of the lower limbs. Signals were amplified and filtered between 20-2000 Hz and 200-2000 Hz to better identify activities in the high frequency range. In 7 patients bit-colour maps were also computed. In all the patients a homogeneous short-latency scalp evoked potential with a prevalent diphasic shape (P1-N1) was recorded. In all our scalp records, even with the wide bandpass, small short-latency positive deflections were observed on the descending front of the first major positive wave and they were better defined as a series of up to 6 wavelets, preceding the major negative scalp wave in the tracings filtered through the narrow bandpass. They appeared in an interval ranging from 5.5 to 15.6 msec. Bit-colour maps showed consistent positive fields, with a maximum at the vertex, starting mainly at about 5.5 msec; in 3 patients, a prominent positivity between 8.5 and 10.5 msec was recorded followed by smaller components preceding the major positive-negative (P1-N1) complex. More synchronous volleys during direct SCS produced clear short-latency SEPs. Although they were of larger amplitude, we regarded them as corresponding to those described by previous authors obtained by stimulation of nerves of the lower limbs, and probably arising from subcortical structures.

Adult↗

PubMed1994

Molecular mechanisms possibly affecting WT1 function in human ovarian tumors.

The frequent allelic deletions observed on the short arm of chromosome 11 in ovarian tumors suggest that the WT1 gene, a proposed tumor-suppressor gene located on chromosome 11p13 and expressed in the human fetal genitourinary system, may contribute to the development of ovarian neoplasms. Structural and sequence analysis of the entire coding portions of the WT1 gene did not reveal any abnormalities in the 20 ovarian tumor specimens (13 of which showed 11p13 allelic deletions) and 5 cell lines which we analyzed. These findings invalidate the hypothesis that the WT1 gene functions as a classical tumor-suppressor gene in ovarian tumorigenesis and suggest that a different recessive oncogene may be "exposed" by the observed 11p13 allelic deletions. Expression analysis showed that the WT1 gene was transcriptionally active in all the tumors tested, but considerable variations in the mRNA levels were found. This apparent variability, which should be confirmed at the cellular level in the tumor specimens, was also observed in the ovarian tumor-cell lines. Finally, WT1 expression data were evaluated in conjunction with immunohistochemical data on p53. The possible functional effects of altered WT1 mRNA expression in ovarian tumors are discussed, taking into account the potential WT1/p53 protein interaction.

Adenocarcinoma↗

PubMed1994

Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome.

The median sensory nerve conduction between ring finger and wrist is a suitable parameter for early detection of carpal tunnel syndrome (CTS), although shorter segments of median nerve have also been proposed for the same goal. In order to assess the relative diagnostic value of the sensory nerve conduction velocity (SNCV) of the third palmar branch versus the SNCV of the second palmar branch, generally performed until now, we studied 62 patients with typical signs and symptoms of CTS. The following parameters were evaluated by surface recording: orthodromic SNCVs in digit-wrist segments for median (index = M2, third = M3 and ring = M4 fingers), ulnar (fourth = U4 finger) and radial (thumb = R1) nerves; SNCVs in palm-wrist segments by surface bipolar stimulation at each metacarpo-phalangeal interspace (second = P2 and third = P3 for the median nerve and fourth = P4 for the ulnar nerve); and distal motor latencies of the median and ulnar nerves. No responses at the wrist were recorded in 22.6% of patients after digital stimulation of M4, whereas the SNCV of P3, the palmar nerve branch arising from digital nerves of the medial side of M3 and the lateral side of M4, was measurable in 93.5% of patients. As significantly expressed (P < 0.001) by the increased ratio of the mean values of P2 and P3 in CTS patients, the SNCV of P3 decreased more frequently and to a greater extent than the SNCV of P2.

Action Potentials↗

PubMed1994

Diagnosis of thoracic outlet syndrome. Relative value of electrophysiological studies.

The diagnostic utility of various electrophysiological techniques was evaluated in patients with thoracic outlet compression syndrome (TOCS). Our results suggest that in true neurogenic TOCS, there is no standard electrophysiological picture, but that this evolves with the severity of the syndrome. The first changes observed are electromyographic, followed by changes in F-wave and SEPs, followed finally by changes in nerve conduction parameters. EMG study was certainly more informative, showing neurogenic damage not only in limbs with neurological signs but also in about 1/4 of limbs with only subjective symptoms. The study of F-wave and SEPs does not seem to be particularly helpful, however, in view of the peculiar changes found in these patients, SEPs may be a useful complement to EMG. Nerve conduction studies were of little utility since changes in these parameters are only found in patients with long-standing anomalies and severe atrophy.

Adult↗

PubMed1994

Sex differences in surface EMG interference pattern power spectrum.

Sex differences in the spectral parameters of the surface electromyogram (EMG) power spectrum were studied during voluntary muscle contractions of different strength with rest in between. The influence of two different types of leads (unipolar and bipolar) on the values of the spectral parameters was also investigated under the same experimental conditions. The subjects were 15 healthy female and 15 healthy male volunteers. The relationship between the amplitude (root mean square) of the EMG and the force developed was not linear. The mean values of the median power frequency were lower in women than in men. With both types of lead, the increase in force was accompanied by a progressive increase in median power frequency in male and female subjects. The significant differences in spectral parameters observed in the two sexes are probably correlated with anatomic differences.

Adult↗

PubMed1994

Effects of Braxton-Hicks contractions on fetal heart rate variations in normal and growth-retarded fetuses.

The objective of this study was to evaluate whether Braxton-Hicks contractions induce changes in fetal heart rate variation in normal and growth-retarded fetuses. 110 uncomplicated singleton pregnancies were cross-sectionally studied as well as 16 pregnancies complicated by fetal growth retardation secondary to uteroplacental insufficiency. Fetal heart rate variability was analyzed by a commercially available computerized system (2CTG Hewlett Packard, Italy) 10 min before and 10 min after the Braxton-Hicks contraction. All the included fetal heart rate tracings fulfilled the following criteria: (1) presence of a single Braxton-Hicks contraction in the 20 min considered; (2) absence of fetal heart rate decelerations after the contraction, and (3) stable fetal heart rate behavioral pattern in the period analyzed. 82 tracings of normal fetuses were analyzed during an active fetal heart rate pattern (type B) and the remaining 28 during a quiet pattern (type A). In both patterns no significant differences in delta value, long-term irregularity, short-term variability and interval index were found before and after the contraction. All the tracings of growth-retarded fetuses were analyzed during the fetal heart rate pattern A. Short-term variation and interval index significantly decreased during the first 5 min after the contraction while no significant differences were found in the other indices investigated. The decrease in these indices was significantly more marked in those fetuses developing fetal distress within 7 days. In conclusion, Braxton-Hicks contractions induce a significant decrease of short-term variation and interval index only in growth-retarded fetuses. This can be useful in the early identification of fetal compromise in such fetuses.

Cross-Sectional Studies↗

PubMed1994

An electromyographic evaluation of motor complications in thoracic herpes zoster.

Motor complications in thoracic herpes zoster were evaluated in 52 patients by electromyographic examination of the paraspinal muscles. At the initial EMG examination, abnormal findings were observed in 18 patients (35%). In 8 patients the myomers involved coincided in location with affected dermatomes, while in 10 patients, in addition to the involvement of myomers corresponding to affected dermatomes, there also appeared an involvement of one or more contiguous myomers not corresponding to affected dermatomes. Our study demonstrated that motor involvement in thoracic HZ is much more common than previously suggested and its incidence (35%) appears to be greater than that reported in both cervical and lumbosacral HZ.

Adult↗

PubMed1992

P-glycoprotein but not topoisomerase II and glutathione-S-transferase-pi accounts for enhanced intracellular drug-resistance in LoVo MDR human cell lines.

The biochemical bases of the multidrug-resistant (MDR) phenotype were investigated in drug-resistant sublines derived from LoVo human colon carcinoma cell lines by doxorubicin (DOX) and teniposide (VM26) selection. In addition to P-glycoprotein-mediated drug extrusion through the plasma-membrane, LoVo MDR cells display a further drug-resistance mechanism. That is, to achieve equitoxic effects, LoVo MDR sublines require much higher intracellular drug concentrations than those required by LoVo drug-sensitive parent cell line. Involvement of mdr1, topoisomerase II and glutathione-S-transferase-pi (GST-pi) drug-resistance systems in intracellular drug resistance was investigated. Pharmacologic and biochemical data indicated that intracellular drug resistance in LoVo MDR sublines is uniquely consequent to the drug-transporting property of intracytoplasmic membrane-bound P-glycoprotein molecules which compartment drugs in vacuole-like structures.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1992

Expression of glutathione-S-transferase-pi in human tumours.

Expression of glutathione-S-transferase-pi (GST-pi) gene was quantitatively analysed on various human tumours (renal cell, colorectal, head and neck, ovarian carcinomas, soft tissue sarcomas; non-Hodgkin lymphomas) and on the corresponding normal tissues when available (kidney, colorectum and head and neck). GST-pi mRNA expression level was found to be significantly higher in tumours (P less than 0.01) than in the normal counterparts (mainly 7.3, 3.5- and 3.0-fold in colorectal, head and neck, and renal carcinomas, respectively). Most tumours displayed a significant relationship between higher GST-pi expression level and poor differentiation grade of tumour cells, thus suggesting a relationship between GST-pi activity, neoplastic transformation and cellular differentiation grade. The high requirement of GST-pi activity neoplastic cells displayed was not singularly related to cellular replication rate. Finally, GST-pi gene expression levels were not affected by chemotherapeutic treatments.

Adolescent↗

PubMed1992

Chromosomal localisation of two putative 11p oncosuppressor genes involved in human ovarian tumours.

In this study, 44 primary or metastatic human ovarian tumours were tested for allelic deletions on the short arm of chromosome 11. Analysis of 12 polymorphic loci by Southern blotting evidenced loss of heterozygosity (LOH) in at least one locus in 41% of cases. Moreover, two hot spots of deletions were tentatively mapped on 11p13 and 11p15.5. Our results demonstrated that LOH at 11p is a common event in ovarian carcinomas and were indicative of the possible existence in 11p of two oncosuppressor genes involved in ovarian carcinogenesis. The similarity observed with 11p allelic losses in Wilms tumours, clustered in 11p13 and 11p15.5 too, suggests that deletion and possibly inactivation of the same growth regulatory genes (WT genes) could also contribute to development of the malignant phenotype in ovarian carcinomas. Finally, a statistically significant association (P = 0.005) between 11p deletions and hepatic involvement was suggested by the analysis of distribution of 11p LOH relative to different clinical and pathological parameters of the tumour patients.

Adult↗