Biomedical subjects

M Galante

Publications and source records attributed to M Galante.

At least 19 recordsLinked to original sources

PubMed2003

Factors influencing hospital infection control policies in Italian hospitals.

A study was undertaken to determine the resources available in Italian hospitals for the control of nosocomial infections and the factors favouring a successful approach. During January-May 2000 a questionnaire about infection control was sent to the hospital health director of all Italian National Health System hospitals treating acute patients and with more than 3500 admissions in 1999. An active programme was defined as a hospital infection control committee (HICC) meeting at least four times in 1999, the presence of a doctor with infection control responsibilities, a nurse employed in infection control and at least one surveillance activity and one infection control guideline issued or updated in the past two years. There was a response rate of 87.5% (463/529). Almost fifteen percent (69/463) of hospitals had an active programme for Infection Control and 76.2% (353/463) had a HICC. Seventy-one percent (330/463) of the hospitals had a hospital infection control physician and 53% (250/463) had infection control nurses. Fifty-two percent (242/463) reported at least one surveillance activity and 70.8% (328/463) had issued or updated at least one guidance document in the last two years. The presence of regional policies [odds ratio (OR) 8.7], operative groups (OR 4.2), at least one full-time nurse (OR 4.6) and a hospital annual plan which specified infection control (OR 2.1) were statistically associated with an active programme in the multivariate analysis.

Cross Infection↗

PubMed2001

Homeostatic plasticity induced by chronic block of AMPA/kainate receptors modulates the generation of rhythmic bursting in rat spinal cord organotypic cultures.

Generation of spontaneous rhythmic activity is a distinct feature of developing spinal networks. We report that rat embryo organotypic spinal cultures contain the basic circuits responsible for pattern generation. In this preparation rhythmic activity can be recorded from ventral interneurons and is developmentally regulated. When chronically grown in the presence of an AMPA/kainate receptor blocker, this circuit expresses long-term plasticity consisting largely of increased frequency of fast synaptic activity and reduction in slow GABAergic events. We examined whether, once this form of homeostatic plasticity is established, the network could still exhibit rhythmicity with properties similar to controls. Control or chronically treated ventral interneurons spontaneously generated (with similar probability) irregular, network-driven bursts over a background of ongoing synaptic activity. In control cultures increasing network excitability by strychnine plus bicuculline, or by raising [K(+)](o), induced rapid-onset, regular rhythmic bursts. In treated cultures the same pharmacological block of Cl(-)-mediated transmission or high-K(+) application also induced regular patterned activity, although significantly faster and, in the case of high K(+), characterized by slow onset due to postsynaptic current summation. Enhancing GABAergic transmission by pentobarbital surprisingly accelerated the high-K(+) rhythm of control cells (though depressing background activity), whereas it slowed it down in chronically treated cells. This contrasting effect of pentobarbital suggests that, to preserve bursting ability, chronic slices developed a distinct GABAergic inhibitory control on over-expressed bursting circuits. Conversely, in control slices GABAergic transmission depressed spontaneous activity but it facilitated bursting frequency. Thus, even after homeostatic rearrangement, developing mammalian spinal networks still generate rhythmic activity.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed2001

Stance control is not affected by paresis and reflex hyperexcitability: the case of spastic patients.

OBJECTIVES: Spastic patients were studied to understand whether stance unsteadiness is associated with changes in the control of voluntary force, muscle tone, or reflex excitability, rather than to abnormal posture connected to the motor deficit itself. METHODS: Twenty four normal subjects, 12 patients affected by amyotrophic lateral sclerosis (ALS), seven by spastic paraparesis, and 14 by hemiparesis were studied. All patients featured various degrees of spasticity and paresis but were free from clinically evident sensory deficits. Body sway during quiet upright stance was assessed through a stabilometric platform under both eyes open (EO) and eyes closed (EC) conditions. The sudden rotation of a supporting platform, in a toe up and toe down direction respectively, evoked short (SLR) and medium latency (MLR) reflex responses to stretch of the soleus or the tibialis anterior (TA) muscle. RESULTS: No relation was found between clinical findings (tone, muscle strength, tendon reflexes, plantar response, and duration of disease) and body sway. On average, all patient groups exhibited a forward shift of the centre of foot pressure (CFP) with respect to normal subjects; in addition, paraparetic and to a much larger extent hemiparetic patients showed a lateral shift of CFP. Body sway area was significantly increased only in the hemiparetic patients. No relation was found between position of the CFP and sway within any patient group. Soleus SLR was increased in all patients with respect to normal subjects. TA SLR was often seen in both patients with ALS and paraparetic patients, but only rarely in normal subjects and hemiparetic patients. However, no relation was found between amplitude of soleus or TA SLRs and stabilometric variables. The frequency and size of soleus MLR and TA MLR were decreased in all patients. These responses were decreased in size and not modulated by background EMG in the affected leg of hemiparetic patients, suggesting a disturbed control of spinal reflexes fed by spindle group II afferent fibres. CONCLUSIONS: It is proposed that body posture, paresis, or monosynaptic reflex hyperexcitability do not affect the control of equilibrium during quiet upright stance. In hemiparetic patients, the decreased amplitude of MLRs might be the main cause of the large postural instability. The results are congruent with the hypothesis of a role for group II afferent input in the reflex control of equilibrium.

Adult↗

PubMed2000

Opposite changes in synaptic activity of organotypic rat spinal cord cultures after chronic block of AMPA/kainate or glycine and GABAA receptors.

1. The well-developed cytoarchitecture of rat organotypic spinal cord culture makes it a suitable model to explore how persistent suppression of certain synaptic inputs might be compensated by increased synaptic efficacy (homeostatic plasticity). 2. Spontaneous or electrically evoked synaptic transmission of patch-clamped ventral horn interneurons was studied in control solution after blocking, for the second week in culture, AMPA/kainate receptors with CNQX or glycine and GABAA receptors with strychnine and bicuculline, or indiscriminately removing inputs with tetrodotoxin (TTX). 3. In untreated cells, spontaneous postsynaptic currents (PSCs) had fast (tau < 5 ms) or slow (tau > 10 ms) decay. A similar separation was observed when recording miniature currents (mPSCs). Slow decay PSCs were suppressed by strychnine plus bicuculline while fast decay events were eliminated by CNQX. 4. After chronic CNQX treatment the frequency of spontaneous, fast PSCs (of larger amplitude) or mPSCs was almost doubled with respect to control. These events were blocked by acutely applied CNQX, which unmasked slow PSCs. 5. After chronic TTX treatment neither the frequency nor the amplitude of spontaneous events was changed. 6. After chronic strychnine and bicuculline treatment the frequency and amplitude of all PSCs was decreased in most cells. mPSCs were also decreased in frequency. Spontaneous or electrically evoked currents acquired a larger component mediated by NMDA receptor activity. 7. The developing spinal network thus operated distinct homeostatic processes which led to strong enhancement in glutamatergic transmission after CNQX block or to broad downregulation of synaptic activity following chronic exposure to strychnine and bicuculline.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1999

Generation of rhythmic patterns of activity by ventral interneurones in rat organotypic spinal slice culture.

1. In the presence of certain excitatory substances the rat isolated spinal cord generates rhythmic oscillations believed to be an in-built locomotor programme (fictive locomotion). However, it is unknown whether a long-term culture of the same tissue can express rhythmic activity. Such a simplified model system would provide useful data on the minimal circuitry involved and the cellular mechanisms mediating this phenomenon. For this purpose we performed patch clamp recording (under whole-cell voltage or current clamp conditions) from visually identified ventral horn interneurones of an organotypic slice culture of the rat spinal cord. 2. Ventral horn interneurones expressed rhythmic bursting when the extracellular [K+] was raised from 4 to 6-7 mM. Under voltage clamp this activity consisted of composite synaptic currents grouped into bursts lasting 0.9 +/- 0.5 s (2.8 +/- 1.5 s period) and was generated at network level as it was blocked by tetrodotoxin or low-Ca2+-high-Mg2+ solution and its periodicity was unchanged at different potential levels. 3. In current clamp mode bursting was usually observed as episodes comprising early depolarizing potentials followed by hyperpolarizing events with tight temporal patterning. Bursting was fully suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and reduced in amplitude and duration by N-methyl-D-aspartate (NMDA) receptor antagonism without change in periodicity. Extracellular field recording showed bursting activity over a wide area of the ventral horn. 4. Regular, rhythmic activity similar to that induced by K+ also appeared spontaneously in Mg2+-free solution. The much slower rhythmic pattern induced by strychnine and bicuculline was also accelerated by high-K+ solution. 5. The fast and regular rhythmic activity of interneurones in the spinal organotypic culture is a novel observation which suggests that the oversimplified circuit present in this culture is a useful model for investigating spinal rhythmic activity.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1999

Somatosensory and motor evoked potentials at different stages of recovery from severe traumatic brain injury.

OBJECTIVE: To detect changes of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) at different stages of recovery from severe brain injury and to determine whether they can be used to predict late functional outcome. DESIGN: Correlational study on a prospective cohort. SETTING: Brain injury rehabilitation center. PATIENTS: Twenty-seven consecutively sampled patients with severe traumatic brain injury referred to the inpatient intensive rehabilitation unit of primary care in a university-based system. MAIN OUTCOME MEASURES: (1) Glasgow Outcome Scale, Disability Rating Scale, and Functional Independence Measure; (2) SEPs and MEPs from upper limbs (ULs) and lower limbs (LLs). Outcome was assessed at 6 and 12 months after trauma. Correlations were computed with the nonparametric test of Spearman-Rank. RESULTS: Both SEPs and MEPs showed dynamic changes (p < .02 for N20, p < .05 for N30, P40, and N45), with a trend toward a progressive normalization. N30 was more frequently abnormal than N20. SEPs from LLs were more frequently and more persistently abnormal than those from ULs. Clinical and functional outcome was strongly correlated with the degree of abnormality of SEPs from LLs (p < .002), whereas only mild relationships were found with SEPs from ULs. Both SEPs and MEPs showed a high negative predictive value (83% for N30 and 83% for P40), but only SEPs from LLs also had a high positive predictive value (72% for P40). Sensitivity was 88% both for N30 and P40. Specificity was 50% for N30 and 70% for P40). CONCLUSION: SEPs from LLs can be very useful in monitoring the postacute phase of traumatic brain injury and in identifying patients who require further intensive rehabilitation. MEPs may be of questionable value.

Adolescent↗

PubMed1998

Time course of stabilometric changes after a strenuous treadmill exercise.

OBJECTIVE: To detect the effect of a strenuous exercise on equilibrium and to quantify its time course. PARTICIPANTS AND METHODS: Body sway area, sway path, and center of foot pressure were recorded in eight young able-bodied subjects, standing quietly with feet together, with eyes open (EO) and eyes closed (EC), on a dynamometric platform, before and after treadmill walking for 25min, during which subjects approached the maximum heart rate. RESULTS: A significant increase in body sway was observed after exercise. It was present under both visual conditions and affected both sway area and sway path. Sway increased most in the initial few minutes (sway area EO=800.7mm2 [p < .005], EC=1,779.5mm2 [not significant]; sway path EO=545mm [p < .0001], EC=811.8mm [p < .05]) with respect to preexercise values (sway area EO=449.4mm2, EC=1,316.2mm2; sway path EO=369.5 mm, EC=652.5mm) and was followed by a plateau (sway area EO=609.9mm2, EC=1,567.9mm2; sway path EO=431.2mm, EC=710.9mm). Full recovery to basal values occurred within about 15min after the end of the exercise. CONCLUSIONS: Body sway is affected by prolonged fatiguing exercise, such as strenuous walking. This effect is of moderate extent and vanishes within a few minutes.

Adult↗

PubMed1998

Network bursting by organotypic spinal slice cultures in the presence of bicuculline and/or strychnine is developmentally regulated.

Organotypic cocultures of dorsal root ganglia and spinal cord from embryonic rats provides direct access to spinal interneurons in a culture system in which the cytoarchitectural organization of the spinal cord slice is maintained. This preparation was used to investigate the possible induction of rhythmic behaviour at different times of development in vitro. Spontaneous rhythmic bursts induced by coapplication of strychnine (1 microM) and bicuculline (20 microM) were observed with patch-clamp recordings from ventral interneurons. Ventral horn interneurons consistently developed a very regular pattern of activity which was superimposed on a background of sustained synaptic activity. The pattern of the spontaneous bursting following application of strychnine and bicuculline showed a developmentally regulated difference in frequency between two distinct stages of in vitro development.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1996

Unilateral displacement of lower limb evokes bilateral EMG responses in leg and foot muscles in standing humans.

During upright stance, foot dorsiflexion induced by the movement of a supporting platform elicits a short- (SLR) and a medium-latency response (MLR) in both the soleus and the flexor digitorum brevis muscles; foot plantarflexion elicits a MLR in the tibialis anterior. The SLR is the counterpart of the stretch reflex, but no general agreement exists about the origin of the MLR, though recent results suggest that it is transmitted through group II afferent fibres. Animal studies have shown that group II fibres impinge on interneurones projecting contralaterally as well as ipsilaterally, whereas group I fibres impinge on interneurones which project mainly ipsilaterally. Therefore, we compared the changes in amplitude and latency of the SLRs and MLRs in the right and left limb during postural perturbations induced while subjects maintained both feet on the platform (both-on condition) or while they maintained only one foot on the platform and the other on firm ground (one-on condition). Under the both-on condition, the pattern of EMG responses described above occurred bilaterally. Under the one-on condition, both SLRs and MLRs occurred in the displaced leg. However, whereas the SLRs did not change in amplitude compared with the both-on condition, the MLRs decreased in amplitude to about 50%. MLRs were also present in the non-displaced leg. They were not preceded by any SLR but showed a further decrease in size with respect to the corresponding responses in the perturbed leg. Latency of the MLRs of the perturbed leg increased by about 5 ms passing from the both-on to the one-on condition. In the latter condition, a further increase of 5 ms was observed in the nonperturbed leg with respect to the displaced one. The occurrence of the MLRs but not of the SLRs in the contralateral non-displaced leg is in keeping with the notion that crossed neural pathways fed by spindle group II afferent fibres subserve the MLRs. The changes in latency of the MLRs under the one-on condition compared with both-on give a cue about the synaptic delays along the neural circuit and the time taken by the afferent impulses to cross the spinal cord.

Adult↗

PubMed1995

Percutaneous endoscopic gastrostomy and enteral nutrition in amyotrophic lateral sclerosis.

Bulbar involvement in amyotrophic lateral sclerosis (ALS) is often related to a worse prognosis on account of the higher risk of pulmonary aspiration and undernutrition due to dysphagia. The aim of our study was to assess the effects of enteral feeding by percutaneous endoscopic gastrostomy (PEG) in a long-term follow-up of ALS patients. We report the results of PEG in 31 ALS patients with bulbar involvement. The patients were observed at 3-monthly intervals over a period of 2 years after PEG. All the data were compared with those obtained from a control group of 35 ALS patients who refused PEG. Mortality did not differ significantly between the two groups of patients during the first 6 months of observation, whereas after this period it was lower in the PEG group. In the patients who had had PEG, the body mass index showed a mild but statistically significant improvement after tube insertion while in the control group it decreased significantly. The findings of this study demonstrate that PEG can improve survival in elderly and young ALS patients with bulbar involvement; it enhances their quality of life and helps their integration in their social and family surroundings. We think that PEG should be included symptomatic treatment of all ALS patients with bulbar involvement from the onset of symptoms.

Adult↗

PubMed1995

Ochronotic arthropathy: rapid destructive hip osteoarthritis associated with metabolic disease.

Ochronosis is a musculoskeletal manifestation of alkaptonuria, an inherited metabolic disorder associated with various systemic abnormalities related to the deposition of homogentisic acid pigment in connective tissues. This report describes a 58-year-old woman with ochronotic arthropathy who, in addition to the typical clinical features of the disorder, presented with rapidly progressive hip osteoarthritis. The destruction of the joint architecture and the severe functional impairment necessitated a total hip replacement which resulted in a satisfactory outcome.

Alkaptonuria↗

PubMed1994

The limits of equilibrium in young and elderly normal subjects and in parkinsonians.

Body sway was studied at various body inclinations, voluntarily maintained for about 1 min, in young and elderly normals and in idiopathic parkinsonians. They stood on a dynamometric platform, whose output gave the instantaneous centre of foot pressure (CFP), its mean value and body sway area, with eyes open (EO) or closed (EC). Subjects held the normal upright stance, or the maximum possible inclined posture (body straight, rotated at the ankle joints) in forward or backward direction, or intermediate postures. EMG was recorded from tibialis anterior (TA), soleus (Sol), extensor digitorum brevis (EDB) and flexor digitorum brevis (FDB). The cross-correlation function between the profile of the EMG envelope and the profile of the shift of CFP along the sagittal plane was calculated. In young subjects standing with EO, the maximum extent of antero-posterior (A-P) displacement of CFP was about 60% of foot length. EC reduced this value to about 50%. In the elderly normals, the maximum A-P displacement was about 40% (EO) and 30% (EC). In both groups, sway area was minimal during normal stance with EO and increased progressively when the subjects leant forward or backward. With EC, sway area further increased during normal stance and the rate of increase in relation to inclination augmented markedly. Sol was tonically active during normal stance. Forward leaning increased Sol EMG and induced activity in FDB. TA and EDB were active during backward leaning. The peak of the cross-correlation function between Sol EMG and instantaneous CFP was higher during normal stance than forward inclination, while the reverse was true for FDB. This suggests a role of FDB in the fine-tuning of postural adjustment during forward leaning, and a weight-supporting role of Sol. During backward inclination, TA but not EDB was cross-correlated with CFP. In the parkinsonians, maximum A-P displacement of CFP was just about 30% of foot length (EO; about 20% with EC); its extent was inversely correlated with the severity of the disease. The relationship between sway area and A-P displacement was similar to the elderly, both with EO and EC, within the common range of inclination. In the patients affected by the long-term syndrome, A-P displacement was further reduced while sway area increase at the critical postures was often absent. In all patients, the relationship between muscle activity and body inclination was comparable to normal.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1992

Methylbromide intoxication: a case report.

This work focuses on the neurophysiological features in a patient with action myoclonus and mental deterioration following methylbromide intoxication. The patient is a 28-year-old man, without respiratory distress or exposure to other toxics. Myoclonus improved with polytherapy (clonazepam, 5-HT, carbidopa, GABA). The neurophysiological and neuropsychological evidence in this patient suggests a possible double site of action of methylbromide at cortical and subcortical levels.

Adult↗

PubMed1989

Medullary thyroid carcinoma. The need for early diagnosis and total thyroidectomy.

Forty patients with medullary thyroid carcinoma and 3 patients with C-cell hyperplasia were studied. Seventeen (40%) cases were sporadic and 26 (60%) were hereditary. Eight patients had type lla multiple endocrine neoplasia, 7 patients had type llb multiple endocrine neoplasia, and 11 patients had familial nonmultiple endocrine neoplasia medullary thyroid carcinoma. Mean follow-up was 6.3 years, with actuarial survival of 88% and 78% at 5 and 10 years (22 and 13 patients), respectively. Seven patients died 1.5 to 10 years after the initial operation; all had advanced disease at presentation (6 with distant, 1 with lymph node metastasis). No deaths occurred in patients with familial nonmultiple endocrine neoplasia medullary thyroid carcinoma, C-cell hyperplasia, or medullary thyroid carcinoma limited to the thyroid gland. Nineteen (68%) of 28 patients diagnosed without screening had regional or distant metastases, whereas only 6 (40%) of 15 patients diagnosed by screening had metastases. Twenty-six patients treated initially with total thyroidectomy and central neck clearance required an average of one reoperation, whereas those with lesser initial procedures required an average of two reoperations. We concluded that (1) familial nonmultiple endocrine neoplasia medullary thyroid carcinoma, early medullary thyroid carcinoma or C-cell hyperplasia, and asymptomatic patients have a good prognosis; (2) screening for medullary thyroid carcinoma by measuring serum calcitonin levels results in earlier diagnosis; and (3) total thyroidectomy and central neck clearance is the procedure of choice for medullary thyroid carcinoma.

Adult↗

PubMed1989

The yeast ATP synthase subunit 4: structure and function.

The structure of ATP synthase subunit 4 was determined by using the oligonucleotide probe procedure. This subunit is the fourth polypeptide of the complex when classifying subunits in order of decreasing molecular mass. Its relative molecular mass is 25 kDa. The ATP4 gene was isolated and sequenced. The nucleotide sequence predicts that subunit 4 is probably derived from a precursor protein 244 amino acids long. Mature subunit 4 contains 209 amino acid residues and the predicted molecular mass is 23250 kDa. Subunit 4 shows homology with the b-subunit of Escherichia coli ATP synthase and the b-subunit of beef heart mitochondrial ATP synthase. By using homologous transformation, a mutant lacking wild subunit 4 was constructed. This mutant is devoid of oxidative phosphorylation and F1 is loosely bound to the membrane. Our data are in favor of a structural relationship between subunit 4 and the mitochondrially-translated subunit 6 during biogenesis of F0.

Amino Acid Sequence↗

PubMed1988

NH2-terminal sequence of the isolated yeast ATP synthase subunit 6 reveals post-translational cleavage.

The three mitochondrially translated ATP synthase subunits of Saccharomyces cerevisiae were extracted from the enzyme and from whole mitochondria using an organic solvent mixture and then purified by reverse-phase HPLC. The amino acid composition of subunit 6 is close to the one predicted from the oli2 gene. The partial amino terminal sequence of subunit 6 reveals a post-translational cleavage site between the Thr-10 and Ser-11 residues of the precursor. Thus, mature subunit 6 contains 249 amino acid residues and displays a molecular mass of 27943 Da.

Amino Acid Sequence↗

PubMed1988

Recurrent thyroid carcinoma: characteristics on MR images.

Magnetic resonance (MR) imaging was used in 32 patients, including eight with benign disease, after partial or total thyroidectomy to determine sensitivity and specificity of MR imaging in the detection of tumor recurrence, to compare signal intensities of scar versus recurrent tumor qualitatively and quantitatively, and to define the extent of recurrent tumor. Findings from surgery (n = 23), needle biopsy (n = 1), or clinical follow-up (n = 8) were used for verification. Of 24 patients with primary thyroid carcinoma, 15 had recurrence and nine had a normal postsurgical thyroid bed. Diagnosis from MR images was correct in 20 cases, but false positive in three and false negative in one. Local recurrence was characterized by low to medium intensity on short repetition time (TR)/short echo time (TE) images and medium to high intensity on long TR/long TE images. Scar in the normal postsurgical thyroid bed showed low intensity on both short and long TR/TE images. Local recurrence of thyroid carcinoma and lymph node metastasis produced positive contrast compared with muscle on short TR/short TE (31 + 19%) and long TR/long TE (85 + 30%) images; fibrosis produced negative contrast, particularly on long TR/long TE (-56, -80%) images. These results indicate the capability of MR imaging in the evaluation of recurrence of thyroid tumors and in the differentiation of abnormal tissue due to tumor recurrence from postoperative fibrosis by means of signal contrast relative to a reference tissue.

Adult↗

PubMed1987

Subunit 4 of ATP synthase (F0F1) from yeast mitochondria. Purification, amino-acid composition and partial N-terminal sequence.

One subunit of the membrane portion of yeast ATP synthase was purified. Structural data are reported. This subunit (subunit 4) is the fourth polypeptide of the complex when classifying subunits in order of decreasing molecular mass. Its apparent relative molecular mass is about 25,000. The polypeptide was extracted from the complex with a mixture of chloroform/methanol (1/1) and 0.5 M pyridinium acetate pH 6.0. Purification was performed with a combination of gel permeation chromatography on Sephadex G-75 and high-performance gel permeation chromatography with aqueous solvents containing 5% sodium dodecyl sulfate. The amino acid composition is reported here. The following sequence of the NH2-terminal ten residues was determined: Met-Ser-Ser-Thr-Pro-Glu-Lys-Gln-Thr-Asp.

Adenosine Triphosphatases↗