PubMed Health⌕ Search

Biomedical subjects

A Semeraro

Publications and source records attributed to A Semeraro.

16 recordsLinked to original sources
PubMed2001

Efficacy and safety of haemodialysis treatment with the Hemocontrol biofeedback system: a prospective medium-term study.

BACKGROUND: Hypovolaemia has been implicated as a major causal factor of morbidity during haemodialysis (HD). A model biofeedback control system for intra-HD blood volume (BV) changes modelling has been developed (Hemocontrol), Hospal Italy) to prevent destabilizing hypovolaemia. It is based on an adaptive controller incorporated in a HD machine (Integra), Hospal Italy). The Hemocontrol biofeedback system (HBS) monitors BV contraction during HD with an optical device. HBS modulates BV contraction rates by adjusting the ultrafiltration rate (UFR) and the refilling rate by adjusting dialysate conductivity (DC) in order to obtain the desired pre-determined BV trajectories. METHODS: Nineteen hypotension-prone uraemic patients (seven males, 12 females; mean age 64.5+/-3.0 SEM years; on maintenance HD for 80.5+/-13.2 months) volunteered for the present prospective study that compared the efficacy and safety of bicarbonate HD treatment equipped with HBS, as a whole, with the gold-standard bicarbonate treatment equipped with a constant UFR and DC (BD). The study included three phases: Medium-term studies started with one period of 6 months of BD and always had a follow-up period of HBS treatment ranging from 14 to 30 months (mean 24.0+/-1.6); short-term studies started in September 1999, when all patients went back to BD treatment for a wash-out period of 4 weeks and a short-term study period of a further 3 weeks (phase A). Afterwards, they once again started HBS treatment for a wash-out period of 4 weeks and a short-term study period of a further 3 weeks (phase B). Every patient underwent acute studies during a single HD run, once during phase A and once in phase B. Resistance (R) and reactance (Xc) measurements were obtained utilizing a single-frequency (50 kHz) tetrapolar bioimpedance analysis (BIA). Extracellular fluid volume (ECV) was calculated from R, Xc, and height and body weight measurements using the conventional BIA regression equations. RESULTS: The overall occurrence of symptomatic hypotension and muscle cramps was significantly less in HBS treatment in both medium- and short-term studies. Self-evaluation of intra- and inter-HD symptoms (worst score=0, best score=10) revealed a statistically significant difference, as far as post-HD asthenia was concerned (6.2+/-0.2 in HBS treatment vs 4.3+/-0.1 in BD treatment, P<0.0001). No difference was observed between the two treatments when comparing pre- and post-HD lying blood pressure, heart rate, body weights and body weight changes in medium- and short-term studies. The residual BV%/ Delta ECV% ratio, expression of the vascular refilling, was significantly higher during HBS treatment in acute studies. CONCLUSIONS: HBS treatment is effective in lowering hypovolaemia-associated morbidity compared with BD treatment; this could be related to a greater ECV stability. Furthermore, HBS is a safe treatment in the medium-term because these results are not achieved through potentially harmful changes in blood pressure, body weight, and serum sodium concentration.

Aged↗
PubMed2001

Effect of acetate-free biofiltration on the anaemia of haemodialysis patients: a prospective cross-over study.

BACKGROUND: The discussion about the pathogenesis of renal anaemia, whether it is primarily due to relative erythropoietin (Epo) deficiency or to uraemic inhibition of erythropoiesis, is still open. Although it has so far not been possible to identify or isolate a substance retained in uraemia with a suppressive action directed specifically against red-cell production, dialysis therapy can improve the effect of both residual endogenous Epo and exogenous rHuEpo. To what extent the mode and/or the dose of dialysis influence Epo efficacy is as yet poorly understood. METHODS: This study was performed as a single-centre trial. The protocol included a run-in period of 4 months followed by a prospective cross-over study including 6 months each of acetate-free biofiltration (AFB) with a high-flux biocompatible membrane and standard bicarbonate dialysis (BD) with a low-flux cellulosic membrane in a random sequence. AFB is a haemodiafiltration technique based on a continuous post-dilution infusion of a sterile isotonic bicarbonate solution. At the start of the run-in period (and for the entire length of the study), rHuEpo administration was withdrawn; patients whose haemoglobin (Hb) levels dropped at a level <8.0 g/dl at one single monthly check, had to be withdrawn from the study. A blood sample was collected every month for the blood gas analysis and for the determination of blood urea nitrogen, serum creatinine, sodium, potassium, calcium, phosphorus, Hb, erythrocyte, reticulocyte, leukocyte and thrombocyte cell counts, mean globular volume and haematocrit. An equilibrated single pool Kt/V(urea)>1.2 was mandatory in both treatment modalities. Serum iron, total iron-binding capacity, and ferritin were checked every 3 months. RESULTS: Twenty-three of 137 haemodialysis patients were considered eligible for the trial on the basis of the entry criteria. Of these, 15 volunteered and only 10 completed the study. No significant differences in the haematological indices, in the biochemical parameters assessing body iron stores, or in i.v. iron dosage was observed when comparing AFB with BD treatments. The equilibrated single pool Kt/V(urea) was always >1.2 and in no case was a significant difference observed when comparing AFB with BD treatments. Treatment time was significantly different between the two treatments (262+/-2 min in BD and 249+/-1 in AFB, P<0.0001). Neither pre- nor post-dialysis systolic and diastolic blood pressures, pre-dialysis serum bicarbonate and pH, pre-dialysis serum sodium, potassium, calcium, or phosphorus were significantly different when comparing the two treatment modalities. All 10 patients completed the 1-year follow-up without any major side-effects. CONCLUSIONS: Our study did not show any improvement of anaemia when treating a highly selected patient group, in the absence of any Epo therapy, with AFB compared with standard BD. Even though these conclusions cannot be extended in toto to the entire dialysis population, in which there is a large proportion of Epo-treated patients with Hb levels around 11 g/dl, we may nevertheless conclude that when patients are well selected, adequately dialysed, and not iron- and/or vitamin-depleted, the effect of a haemodiafiltration technique with a high-flux biocompatible membrane is less than might be expected from the results of uncontrolled studies.

Acetates↗
PubMed2000

Familial mastocytosis associated with neurosensory deafness.

Mastocytosis is a disease characterized by excessive accumulation of mast cells in different tissues and symptoms caused by the release of mast cell mediators. The skin is frequently directly involved in mastocytosis. The disease is rarely seen in other members of the subjects' family; only 49 cases of familial mastocytosis have been reported. Familial mastocytosis associated with hearing loss may represent a newly described inherited entity. We describe a brother and sister exhibiting skin mastocytosis and neurosensory deafness, associated with a history of hearing loss in their father's family. The appearance of the mast cell disease in two siblings, who presented with similar clinical features represents a familial form of mastocytosis; the association with an inherited form of deafness may constitute a new syndrome. Our patients show several features similar to some previously reported cases but different insofar that additional congenital defects and mental retardation are absent.

Adolescent↗
PubMed1999

Liver cancer is induced by a subnecrogenic dose of DENA when associated with fasting/refeeding: role of glutathione-transferase and lipid peroxidation.

In previous studies, we reported that fasting/refeeding has a role in sustaining the initiation of liver cancer by a subnecrogenic (noninitiating) dose of diethylnitrosamine (DENA). This research investigated whether the metabolic alterations imposed by fasting/refeeding provide an imbalance between the generation of carcinogenic molecules and the scavenger defense mechanisms in rat liver. Metabolism of DENA, levels of reduced glutathione (GSH) and GSH transferase (GST) activity, as well as basal and stimulated malondialdehyde (MDA) production, were examined. Rats fasted for 4 days showed a decrease in the liver levels of GSH, GST activity, monounsaturated fatty acids and % of labeled nuclei. After 1 day of refeeding, at which point DENA was administered, the levels of GSH recovered, GST activity remained below control values, basal and stimulated MDA production and content of total polyunsaturated fatty acids in liver phospholipids decreased. One day after DENA treatment, MDA production further decreased, although the % of labeled nuclei increased. No significant changes in the content of arachidonic acid, the main target of peroxidation, were observed at any time. The results indicated that the induction of the hepatocellular carcinoma was associated with a depression of GST activity and lipid peroxidation when rats were given 20 mg/kg of DENA after 1 day of refeeding after 4-day fasting.

Animals↗
PubMed1997

Fatal Streptococcus viridans descending mediastinitis: case report and review of the literature.

Mediastinitis is a life-threatening complication of cardiac, neck and oesophageal surgery. It has also been reported following upper digestive and respiratory procedures and as a consequence of oesophageal perforation following the ingestion of foreign bodies. Much more infrequently, mediastinitis can occur in association with oropharyngeal or cervical infections. We describe the case of a patient with fatal mediastinitis and septic shock. The onset of mediastinitis was preceded by a 2-day course of sore throat and other flu-like symptoms.

Aged↗
PubMed1995

Leber's hereditary optic neuropathy (LHON)-related mitochondrial DNA sequence changes in italian patients presenting with sporadic bilateral optic neuritis.

Eighteen Italian patients presenting with sporadic, bilateral, simultaneous, or sequential optic neuritis (ON) were evaluated for 14 base changes in mitochondrial DNA (mtDNA) previously found associated with Leber's hereditary optic neuropathy (LHON), aiming to identify at a molecular level LHON cases with nontypical phenotypes. During a 36-month follow-up, 11 ON patients developed clinical or laboratory features allowing diagnosis of clinically definite multiple sclerosis (MS). None was positive for any of the "primary" LHON-associated mutations. However, single or multiple "secondary" LHON-associated sequence changes at 4216/ND1, 4917/ND2, and 13708/ND5 were detected in ON and ON-MS patients. MS controls without visual failure as well as healthy control subjects harbored the same base changes at similar frequencies. In addition, coexistence of three sequence changes was found in two cases (1 ON-MS patient and 1 MS control patient). We also report finding two new neutral sequence base changes in the ND-4 gene which were identified by SSCP and confirmed by automated DNA sequence analysis. The results suggests that these secondary mutations do not contribute to MS susceptibility in these patients, but rather represent neutral mitochondrial DNA polymorphisms. In addition, whether there are biochemical abnormalities related to single and multiple secondary mtDNA sequence changes remain to be demonstrated.

Adult↗
PubMed1995

Fluorescence-based DNA minisequence analysis for detection of known single-base changes in genomic DNA.

We describe a rapid, automated method for direct detection of known single-base changes in genomic DNA. Fluorescence-based DNA minisequence analysis is employed in a template-dependent reaction which involves a single nucleotide extension of an oligonucleotide primer by the correct fluorescently-tagged dideoxynucleotide chain terminator. Detection following electrophoresis on denaturing acrylamide gels is facilitated by alkaline phosphatase treatment of reaction products after extension followed by isopropanol precipitation of the dye-tagged, single-base-extended primer to remove unincorporated deoxynucleotides. Fluorescence analysis of the incorporated dye tag reveals the identity of the template nucleotide immediately 3' to the primer site. This technique does not require radioactivity or biotinylated PCR product, relies on the incorporation of a single dideoxynucleotide terminator to extend the primer by one nucleotide and takes advantage of the sensitivity of fluorescent terminators developed for automated DNA sequence analysis. As a demonstration, we have applied the assay to human genomic DNA for detection of the sickle mutation in the beta-globin gene, and have also examined feasibility for simultaneous delineation using a multiplex-like strategy in a single gel-lane of some of the most common beta-thalassemia mutations in the Mediterranean basin.

Anemia, Sickle Cell↗
PubMed1994

Cytologically balanced t(2;20) in a two-generation family with alagille syndrome: cytogenetic and molecular studies.

Alagille syndrome is a clinically defined, dominantly inherited disorder affecting the liver, heart, face, eye, and vertebrae. Alagille syndrome has previously been localized to the short arm of chromosome 20, on the basis of reports of a small number of patients with chromosomal deletions of 20p. We undertook a cytogenetic study of patients with Alagille syndrome and identified a family in which a cytologically balanced translocation between chromosomes 2 and 20, 46,XX/XY, t(2;20)(q21.3;p12), is segregating concordantly with the disease. The breakpoint on chromosome 20p in this t(2;20) is consistent with the shortest region of overlap demonstrated in the reported deletion patients. This is the first report of a translocation associated with 20p and Alagille syndrome, and this rearrangement confirms the location of the Alagille disease gene at 20p12. We have established a somatic cell hybrid from a lymphoblastoid cell line from one of the affected individuals that contains the derivative chromosome 20 (20qter-->p12::2q21.3-->qter) but not the derivative chromosome 2, the normal chromosome 2, or the normal chromosome 20. Southern blot and PCR analysis of probes and sequences from 20p have been studied to define the location of the translocation breakpoint. Our results show that the breakpoint lies distal to D20S61 and D20S56 within band 20p12.

Alagille Syndrome↗
PubMedDate not supplied

Tympanic muscle reflex elicited by electric stimulation of the tongue in normal and pathological subjects.

A bilateral reflex contraction of the tensor tympani muscle has been obtained in man by electric stimulation of the tongue (1-2 mA). The stimulus is well tolerated and always effective. The advantage is stressed of eliciting a contraction of this muscle without involvement of the stapedius, as occurs with other methods. An analysis has been subsequently conducted in normal subjects and in patients affected by pathology of the tympano-ossicular system: tympanosclerosis, otosclerosis, suprastapedial facial paralysis; in cases of interruption of the afferent arch: section of the homo-lateral lingual nerve; in cases of involvement of its central portion: cerebello-pontine-angle tumours; and in cases of section of chorda tympani. A chiasm-like central nervous pattern is suggested.

Acoustic Stimulation↗
PubMedDate not supplied

Value of the isolated tensor tympani muscle reflex elicited by electric lingual stimulation.

A bilateral reflex contraction of the isolated tensor tympani muscle has been obtained in man by bipolar electric stimulation of the edge of the tongue (DC generator). The avoidance of the elevated and variable body electric resistance and of the variable contact resistance from the hand to the ground plate, represents an appreciable improvement of this method in comparison with the unipolar method described in a earlier paper. A further improvement has also been achieved by applying the electric stimulus to one inferior aspect of the tongue near the floor of the mouth, nearer to the lingual nerve. An analysis has been subsequently conducted in normal subjects and in patients affected by pathologies of the tympano-ossicular system; otosclerosis, tympanosclerosis, unilateral complete suprastapedial facial paralysis, interrumption of the ossicular chain; in cases of interruption of the afferent arc: section of the unilateral lingual nerve; involvement of its central portion: cerebello-pontine angle tumour, brain stem tumour. A chiasma-like central nervous pattern is suggested.

Brain Neoplasms↗
PubMedDate not supplied

[Lymphectomy in differentiated thyroid cancers: our experience].

INTRODUCTION: At present we are still debating on which is the most adequate therapeutic strategy concerning the size of the thyroidectomy and the extension of the lymphectomy in differentiated thyroid tumors. PATIENTS AND METHODS: From January 2000 to December 2005, 334 operations for thyroid neoplasms have been performed; 304 (91%) for differentiated tumors. In 124 cases (37%) the latero-cervical and/or the central compartment lymphectomy have been associated with thyroidectomy: 79 monolateral and central compartment lymphectomies (ML and CCL) (64%), 11 bilateral and central compartment lymphectomies (BL and CCL) (8%), and 34 central compartment lymphectomies (CCL) (28%) have been performed. RESULTS: Out of the 124 lymphectomies, in 44 cases (35.5%) we found the presence of metastasis in the lymph nodes of latero-cervical and central compartments, in 10 cases (8%) absence of metastasis in the lymph nodes of the latero-cervical and central compartments, in 25 cases (20%) presence of metastasis in the latero-cervical lymph nodes and absence of metastasis in the lymph nodes of the central compartment. In 11 cases of bilateral and central compartment lymphectomies, 5 of them (4%) had positive lymph nodes of the latero-cervical and central compartments, while the other, only 6 (5%), had positive latero-cervical lymph nodes on the same side as the neoplasia. In 34 central compartment lymphectomies there was absence of metastasis. Mortality rate was zero. There was one case (0.8%) of recurrent laryngeal nerve temporary bilateral palsy (RTBP); 4 cases (3.2%) of recurrent temporary monolateral palsy (RTMP); 2 cases (1.6%) of definitive monolateral palsy (DMP); 29 cases (23.5%) of temporary hypoparathyroidism (TH); 7 cases (5.5%) of definitive hypoparathyroidism (DH). CONCLUSIONS: Latero-cervical lymphectomy should be performed by necessity when clinical tests or pre-diagnostic exams show suspect lymph nodes, whereas central compartment lymphectomy should be performed in any case of thyroid neoplasia.

Adult↗
PubMedDate not supplied

[Computerized rhinomanometry in legal medicine].

The medico-legal evaluation of the damage deriving from nasal respiratory function handicap is based on anamnestic data and rhinoscopic findings. These parameters can actually be integrated by means of functional parameters obtained by rhinomanometry. Today such a method is reliable and well standardized. The possibility of obtaining some nasal function parameters by objective methodology is highly useful in clinical and forensic medicine. In the present work the mean values obtained from total nasal resistance testing have been matched with those referring to the single nasal cavity by submitting two groups to automated rhinomanometry: one of subjects with normal rhinoscopy, the other of subjects showing nasal stenosis. Each test was performed by submitting the patient to thirty minutes of acclimatization. The patient was sitting with a mask suitably hooked up to the rhinomanometer which was, in turn, interfaced to a P.C. by means of an original acquisition system. The preliminary calibration was automatically made once a day. If calibration was incorrect the program impeded data recording. On the basis of the obtained data an attempt was made to identify a nasal resistance value which could be considered as a threshold; a dividing line between normal and stenosis values. Analyzing the obtained parameters it was rather found that a band of intermediate values lay between certain nasal perviousness and "heavy" stenosis. In this manner it was possible to define the total and unilateral nasal resistance values below which ventilatory function is always normal as well as a value above which the resistance values of stenosis are significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Bipolar electric stimulation to elicit and isolated tensor tympani reflex.

A bipolar electrode is described, designed to obtain improved reflex responses from the tensor tympani muscle by electric stimulation of the under surface of the tongue, d.c. generator, 7-9 V d.c. In comparison with the previous unipolar method of stimulation the responses under oscilloscopic analysis appear very constant and of greater size. The latency, in normal subjects, is 117 msec.

Electric Stimulation↗