Biomedical subjects

A Toscano

Publications and source records attributed to A Toscano.

At least 73 records · Page 4Linked to original sources

PubMed1995

Early-onset cerebellar ataxia, myoclonus and hypogonadism in a case of mitochondrial complex III deficiency treated with vitamins K3 and C.

A 16-year-old girl presented with early-onset cerebellar ataxia, myoclonus, elevated lactic acidosis and hypogonadotropic hypogonadism. Muscle biopsy specimens revealed fibres with a "ragged" appearance with increased mitochondria and lipid droplets. Biochemical investigation revealed a deficiency of complex bc1 (complex III) of the mitochondrial respiratory chain. Genetic analysis did not show either deletions or known mutations of mitochondrial DNA (mtDNA). Phosphorus magnetic resonance spectroscopy (31P-MRS) showed defective energy metabolism in brain and gastrocnemius muscle. A decreased phosphocreatine (PCr) content was found in the occipital lobes accompanied by normal inorganic phosphate (Pi) and cytosolic pH. These findings represented evidence of a high cytosolic adenosine diphosphate concentration and a relatively high rate of metabolism accompanied by a low phosphorylation potential. Muscle 31P-MRS showed a high Pi content at rest, abnormal exercise transfer pattern and a low rate of PCr post-exercise recovery. These findings suggested a deficit of mitochondrial function. Therapy with vitamins K3 and C normalized brain 31P-MRS indices, whereas it did not affect muscle bioenergetic metabolism. In this patient, the endocrinological disorder is putatively due to a mitochondrial cytopathy. Although an unknown mtDNA mutation cannot be ruled out, the genetic defect may lie in the nuclear genome.

Adolescent↗

PubMed1995

Duplication of dystrophin gene and dissimilar clinical phenotype in the same family.

We report here three related patients with a duplication of exons 19-41 of the dystrophin gene, having dissimilar clinical phenotype and dystrophin immunohistochemistry. Two brothers aged six and three years had myalgia, proximal muscular weakness and hypertrophic calves, with 10- 20-fold increase of serum creatine kinase. Muscle biopsy showed dystrophic changes and reduced, patchy binding of dystrophin. The clinical and laboratory findings were consistent with a diagnosis of Becker muscular dystrophy with early onset. Their 14-year-old cousin had only mild hyperCKemia. His muscle biopsy was normal with only mild reduction of dystrophin immunostaining. At follow-up, he is still without symptoms and signs at age 19. All three patients had the same gene duplication and an increased dystrophin size of 507 kDa. Expression of the dystrophin-associated glycoproteins adhalin, alpha-dystroglycan, and beta-dystroglycan were normal in the three patients. An intrafamilial variability in patients carrying a partial duplication of the dystrophin gene may be related to a quantitative difference in mRNA.

Blotting, Southern↗

PubMed1995

Intrafamilial phenotypic heterogeneity of the Poland complex: a case report.

Three cases of familial unilateral gluteal hypoplasia are reported. The index case in addition to having gluteal hypoplasia also has unilateral pectoral muscle hypoplasia. Another relative has unilateral symbrachydactyly of the distal phalanges of one foot. All four affected individuals in our pedigree were female. We propose that our cases are best classified as part of the Poland complex of anomalies. Our cases emphasize that intrafamilial phenotypic heterogeneity is possible within the Poland complex.

Buttocks↗

PubMed1995

Maternally inherited hearing loss, ataxia and myoclonus associated with a novel point mutation in mitochondrial tRNASer(UCN) gene.

We report on a new maternally-inherited syndrome characterized by a combination of sensorineural hearing loss, ataxia and myoclonus in a large kindred from Sicily. Hearing loss was the most widespread and sometimes the only symptom found in family members. Sequence analysis of the mitochondrial DNA regions encompassing the tRNA genes revealed the presence of a heteroplasmic insertion at nucleotide position 7472. The insertion adds a seventh cytosine to a six-cytosine run that is part of the mitochondrial tRNASer(UCN) gene. Conformational analysis showed that this mutation is likely to alter the structure of the T psi C loop in the tRNASer(UCN) clover leaf secondary structure. Moreover, the degree of heteroplasmy in blood and muscle was correlated with the clinical phenotype, and homoplasmic mutant hybrids showed decreased complex I activity, low oxygen consumption and high lactic acid output, indicating faulty oxidative phosphorylation. Finally, mutation was absent in 381 unrelated maternal lineages, suggesting specific segregation with the disease. We propose that the C7472 insertion-mutation is pathogenic, and etiologically related to hearing loss and other symptoms that define a novel maternally-inherited clinical entity.

Ataxia↗

PubMed1995

[Ketorolac for prevention of acute postoperative pain].

BACKGROUND: Since NSAIDs are competitive antagonists of cyclooxygenase, they prevent the biosynthesis of prostaglandins, responsible for enhanced nociceptive sensitization and primary hyperalgesia. If NSAIDs administration is performed after eicosanoids cascade activation by surgical trauma, already released prostaglandins can exert their hyperalgesic effects for a finite time. Therefore prophylactic administration of NSAIDs (pre-emptive analgesia) should improve their effectiveness on acute postoperative pain. AIM OF STUDY: To assess the analgesic effect of preoperatively administered ketorolac, compared with its administration after surgical trauma. MATERIALS AND METHODS: Thirty adult patients, ASA physical status I-II, undergoing elective septoplasty, were allocated randomly in two groups, depending on timing of i.v. administration of ketorolac 0.4 mg/kg: 10 min before induction (group I); or 5 min after décollement of nasal septum cartilaginoid plan (group II). No other analgesic drugs were given. Postoperative pain was assessed with objective (SAP, DAP, HR) and subjective (VAS, BS 11) methods at 60, 90, 120, 150, and 180 min after the end of surgery. Rate and severity of any side-effect were recorded. RESULTS: Both VAS and BS 11 showed significant better pain relief after preoperative ketorolac at all time, without any adverse effect. Same result was shown by SAP at 60 and 90 min postoperatively. CONCLUSIONS: Due to prevention of nociceptive sensitization of prostaglandins released by tissue trauma, prophylactic NSAIDs administration to surgical patients with mild to moderate postoperative pain can improve their antinociceptive effects.

Acute Disease↗

PubMed1994

Immunocytochemistry of muscle cytoskeletal proteins in acid maltase deficiency.

Immunocytochemistry of dystrophin, spectrin, vinculin (sarcolemma-specific proteins), and desmin (an intermediate filament protein) were investigated in 5 patients with acid maltase deficiency (AMD). One patient had infant onset, 2 had childhood onset, and 2 had adult onset. All had a vacuolar myopathy with autophagic vacuoles containing glycogen and cytoplasmic degradation products. Dystrophin, spectrin, and vinculin were localized at the sarcolemma as in normal muscle fibers. Within the cytoplasm of many fibers, immunoreactivity for the three proteins was seen as single or multiple spots or as circular structures, which most likely corresponded to the limiting membrane of vacuoles. Desmin was overexpressed at the periphery of some vacuoles. It is plausible that, before exocytosis occurs, sarcolemma-specific proteins appear within the vacuole membrane. Vacuole immunolabeling frequently occurred in the patients with childhood and adult onset AMD, but very rarely occurred in the case with infant onset. We hypothesize that a reduced exocytosis rate might explain the infrequent vacuole immunolabeling and the early onset of the infant form of the disease.

Adult↗

PubMed1994

Muscle phosphoglycerate mutase (PGAM) deficiency in the first Caucasian patient: biochemistry, muscle culture and 31P-MR spectroscopy.

Muscle phosphoglycerate mutase (PGAM) deficiency has been so far identified in only six patients, five of these being African Americans. We report the results of clinical, morphological, biochemical, muscle culture and 31P-MR spectroscopy studies in the first Caucasian patient with muscle PGAM deficiency. A 23-year-old man had a 10-year history of cramps after physical exertion with one episode of pigmenturia. Neurological examination and EMG study were normal. ECG and echocardiography revealed hypertrophy of the interventricular septum and slight dilation of the left chambers of the heart. Muscle biopsy revealed increased glycogen content and some accumulation of mitochondria. Muscle PGAM activity was markedly decreased (6.5% and 9.7% of control value in two different biopsies). Citrate synthase and other mitochondrial respiratory chain enzyme activities were much higher than normal. In contrast to the marked decrease of PGAM activity observed in muscle biopsy, total enzyme activity in the patient's aneural muscle culture was normal, being represented exclusively by BB isoenzyme. The deficiency of PGAM-MM isoenzyme was reproduced in the patient's innervated muscle culture. Muscle 31P-MR spectroscopy showed accumulation of phosphomonoesters only on fast "glycolytic" exercise. On "aerobic" exercise, Vmax, calculated from the work-energy cost transfer function, showed an increase consistent with the morphological and biochemical evidence of mitochondrial proliferation. This might represent a sort of compensatory aerobic effort in an attempt to restore muscle power.

Adult↗

PubMed1994

Clinical variability in Becker muscular dystrophy. Genetic, biochemical and immunohistochemical correlates.

We have investigated 59 Becker muscular dystrophy patients, representing 56 independent mutations, to test the hypothesis of predictability of muscle dystrophin expression and clinical phenotype based on location of dystrophin gene mutations. Partial intragenic deletions and duplications account for 82% of the independent mutations, of which 76.7% were deletions and 5.3% duplications. Mutations in which boundaries could be defined, were of in-frame type (35 out of 37, 94.6%, with two exceptions. Eighty-two percent of mutations were located at the distal part of the rod domain (exons 45-60), 9% at domain I (promoter through exon 9) and 9% at proximal and central parts of domain II. Domain I deleted patients tended to have a worse clinical phenotype, with earlier presentation, faster progression rate and lower dystrophin expression, while distal rod domain deleted patients showed a more classic Becker muscular dystrophy phenotype. Between these two groups, only the differences in the immunohistochemical patterns of dystrophin expression and disease progression rate were statistically significant. Partial clinical and biochemical heterogeneity was observed in the distal domain II patient group, due to the presence of few patients covering the extremities of clinical severity. Two asymptomatic patients had deletions located in the central (exons 41-44) and distal parts (exons 50-53) of the rod domain. Severe myalgia and cramps were often reported as early onset symptoms (18 out of 59): no correlation was found between this symptomatology and the location of the mutation. Relative levels of muscle dystrophin correlated with immunohistochemical patterns of subsarcolemma staining. Dystrophin levels (as estimated by 30 kDa antibody immuno-reactivity) correlated with age of reaching a moderate degree of muscle involvement as well as with delay in reaching that stage, a parameter of disease progression rate. Our data confirm that different Becker muscular dystrophy gene in-frame mutations have different effects on dystrophin expression and clinical severity, indicating several functional roles of the dystrophin domains.

Adolescent↗

PubMed1994

New approach for in vivo detection of insulitis in type I diabetes: activated lymphocyte targeting with 123I-labelled interleukin 2.

Insulitis is considered the histopathological hallmark of type I (insulin-dependent) diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, we have labelled recombinant interleukin 2 with 123I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. We studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled alpha-lactalbumin was used as the control protein. In the first set of experiments we studied the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving labelled alpha-lactalbumin (p < 0.003 at 20 min: p < 0.001 at 40 min; p < 0.001 at 60 min) or Balb/c mice injected with labelled interleukin 2 (p < 0.05 at 40 min; p < 0.001 at 60 min). In another set of experiments, gamma camera images have been acquired after injection of 123I-labelled interleukin 2. Radioactivity in the pancreatic region of prediabetic NOD and Balb/c mice showed similar kinetics to those observed by single organ counting, with higher accumulation in the pancreatic region of NOD mice (p < 0.04 after 22-45 min in NOD mice vs Balb/c mice).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

[Removal of a swallowed endotracheal tube in a neonate].

Immediately following delivery a newborn infant was severely depressed. Because no respiratory effort was made and copious mucus was present, a Cole endotracheal tube was easily inserted into the trachea. Because of a mistaken manoeuvre for fastening the tube, the plastic adapter connection became dislodged from the tube, and the tube slipped out of trachea. The physician's gloved fingers could not maintain traction on the tube because of the excessive amount of mucus, and face mask ventilation made easier the slipping into the distal oesophagus. A second endotracheal tube was then properly placed in the trachea and the infant responded. The misplaced tube was removed from the oesophagus using a small, flexible biopsy forceps closed, advanced into the lumen of the swallowed tube under fluoroscopic vision. By opening the forceps, gripping the tube tightly from within, it was easily withdrawn. No adverse effects were observed.

Deglutition↗

PubMed1993

Muscle rearrangement in patients with hemiparesis after stroke: an electrophysiological and morphological study.

Skeletal muscle changes were evaluated in patients suffering from hemiparesis after stroke. Concentric needle EMG and single fiber EMG of the paretic gastrocnemius medialis muscle were performed. Maximal amplitude of H, T and M responses in calf muscles of both the affected and the unaffected sides were determined by usual electrophysiological techniques. Muscle biopsy of the lateral gastrocnemius muscle of the affected side was performed to determine the distribution of fiber types and fiber sizes. Fibrillation activity and positive sharp waves occurred in paretic muscles in patients with more recent hemiparesis while the duration of motor unit potentials was prolonged in patients with long-lasting disease. The H/M ratio was increased on the paretic side. The percentage of type 1 fibers was augmented in most patients with normal mean diameter and low atrophy factor. The percentage of type 2 fibers was reduced with decreased mean diameters and with a high atrophy factor. Such changes may be related to inactivity or transsynaptic degeneration of type 2 motoneurons as a consequence of the interruption of the corticospinal tract. Increased percentage of type 1 fibers may be due to a collateral reinnervation process or a motor unit type transformation.

Aged↗

PubMed1993

Bezafibrate-induced myopathy: no evidence for defects in muscle metabolism.

A 58-year-old man with chronic renal failure developed severe muscle pain and tenderness 1 week after starting bezafibrate 400 mg daily. Serum creatine kinase was 32,280 U/l. Muscle biopsy revealed scattered necrotic fibers and mild type 2b atrophy. Muscle total and free carnitine were at the upper limits of the normal range. Biochemical investigations of muscle homogenate showed normal carnitine pelmityl transferase (CPT) as well as normal individual glycolytic and mitochondrial enzyme activities. Withdrawal of the drug was followed by rapid clinical improvement. Our study casts doubt on the hypothesis that bezafibrate is able to affect muscle metabolic pathways. It is likely that the drug acts on cholesterol constituents of the muscle membrane, producing discontinuities of the sarcolemma and initiating cell necrosis.

Bezafibrate↗

PubMed1993

Muscle mitochondria investigation in myotonic dystrophy.

Mitochondrial abnormalities have been previously reported in some patients with myotonic dystrophy (DM). The aim of the present paper was to study muscle mitochondria in 32 DM patients by morphological, biochemical (when suggested by morphology) and genetic analysis. A single ragged red fiber, but no cytochrome c oxidase-negative fibers were found in the muscle specimen of 1 patient. However, mitochondrial enzyme activities resulted within the normal range. An electron microscopy study showed no significant mitochondrial changes. Southern blot analysis did not reveal any mitochondrial DNA heteroplasmy in all 32 patients. An explanation for the discordant results between this study and some previous reports of mitochondrial alterations in DM might be that their occasional presence is not related to the disease but to ageing. Another possibility is that among patients with a myotonic dystrophy phenotype, a small subgroup of subjects with a mitochondrial disease may exist and be differentiated.

Adolescent↗

PubMed1992

Evidence for intramitochondrial complementation between deleted and normal mitochondrial DNA in some patients with mitochondrial myopathy.

Twenty-three patients with mitochondrial myopathies and mitochondrial DNA deletions in muscle were studied by means of deletion mapping and sequencing, histochemistry and polarography. Histochemistry showed significantly less focal cytochrome oxidase deficiency relative to number of ragged red fibres when the deletion did not involve reading frames for cytochrome oxidase subunits. Polarography in such patients showed defects exclusively involving complex I, in contrast to the others with larger deletions who generally had more diffuse respiratory chain defects. Analysis of other published histochemical data showed similar findings to our own. It is concluded that translation of a proportion of deleted mitochondrial DNAs occurs in at least some patients with mitochondrial DNA deletions, implying that deleted and normal mitochondrial genomes share transfer RNAs within mitochondria in such cases.

Base Sequence↗

PubMed1992

[Systemic poisoning caused by percutaneous absorption of mineral spirit].

Owing to a car accident, the clothes of a injured joiner were permeated with a timber impregnating product containing 51.8% of mineral spirit (a mixture of naphthenes, aromatic and aliphatic hydrocarbons). Despite a short-lasting skin exposure (approximately 40 minutes), dermal contact has caused full thickness burns that, in their turn, have made easier the percutaneous absorption and the storage of organic solvents in subcutaneous tissue depots. Twenty-four hours later, clinical findings of neurologic involvement have arisen, that have got worse when the peripheral tissue perfusion has got better by the adequate replacement of lost blood.

Adult↗

PubMed1992

Evidence against an X-linked locus close to DXS7 determining visual loss susceptibility in British and Italian families with Leber hereditary optic neuropathy.

Leber hereditary optic neuropathy (LHON) is associated with mutations of mtDNA, but two features of LHON pedigrees are not explicable solely on the basis of mitochondrial inheritance. There is a large excess of affected males, and not all males at risk develop the disease. These observations could be explained by the existence of an X-linked visual loss susceptibility gene. This hypothesis was supported by linkage studies in Finland, placing the susceptibility locus at DXS7, with a maximum lod score of 2.48 at a recombination fraction of 0. Linkage studies in 1 Italian and 12 British families with LHON, analyzed either together or separately depending on the associated mtDNA mutation, have excluded the presence of such a locus from an interval of about 30 cM around DXS7 in these kindreds, with a total lod score of -26.51 at a recombination fraction of 0.

Base Sequence↗

PubMed1992

A radiopharmaceutical for imaging areas of lymphocytic infiltration: 123I-interleukin-2. Labelling procedure and animal studies.

The labelling of interleukin-2 (IL-2) with 123I and its in vivo application for imaging chronic pathological lymphocytic infiltrations are described. The lactoperoxidase/glucoseoxidase technique was the labelling method of choice leading to immunoreactive IL-2 with high specific activity. Labelled IL-2 was injected in diabetes-prone non-obese diabetic (NOD) mice with pancreatic lymphocytic infiltration. As control animals, Balb/c mice were used. As specificity control, monoclonal antibodies AMT13 and UCHT1, bovine serum albumin and alpha-lactalbumin were radioiodinated and injected in mice. Eighteen NOD mice and four control Balb/c mice were used for gamma camera imaging experiments. Fifty-four NOD and 20 Balb/c mice were used for time course single organ counting and autoradiography. Gamma camera images showed that radioactivity accumulated in the pancreatic region from the 10th minute onwards in NOD mice injected with 123I-IL-2 but not in Balb/c mice, or in NOD mice injected with control radiopharmaceuticals. These findings were confirmed by counting the radioactivity present in single organs. Autoradiography of NOD pancreas, after injection of labelled IL-2, showed that radioactivity was specifically associated with infiltrating lymphocytes. In conclusion, this technique is highly specific and easy to perform and we suggest its application in humans for in vivo detection of areas of lymphocytic infiltration.

Animals↗

PubMed1991

Rapid detection of the A----G(8344) mutation of mtDNA in Italian families with myoclonus epilepsy and ragged-red fibers (MERRF).

We devised a rapid PCR-based method to screen for an A----G transition at nucleotide 8344 of the human mitochondrial tRNA(Lys) gene, which was recently reported, by Shoffner and co-workers, to be associated with myoclonus epilepsy and ragged-red fibers (MERRF), a maternally transmitted mitochondrial encephalomyopathy (Shoffner et al. 1990). We confirmed this association in five of seven Italian MERRF pedigrees. The mutation was specific for the MERRF trait, because it was never found in mtDNA of non-MERRF individuals, including 14 normal and 110 diseased controls. Our study corroborates the idea that the A----G(8344) mutation is the most frequent and widespread genetic cause of MERRF.

Base Sequence↗