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J M Polo

Publications and source records attributed to J M Polo.

At least 73 records · Page 4Linked to original sources
PubMed1989

The application of nerve conduction and clinical studies to genetic counseling in hereditary motor and sensory neuropathy type I.

One hundred and thirty two individuals at risk for hereditary motor and sensory neuropathy (HMSN) type I from 11 unrelated families were evaluated by physical examination. Motor conduction velocity (MCV) studies of median and/or peroneal nerves were performed on 99 of them. Seventy-three subjects were found to be affected. In all age categories including the first decade of life, the ratio of affected individuals at risk did not significantly differ from the expected 1:1 ratio; that is, penetrance of the gene was complete. The majority of affected members in the first decade had no clinical features considered diagnostic of peroneal muscular atrophy syndrome, and full clinical expression developed in the second decade. Marked slowing of MCV was already present in the early years of life, even as young as 6 months. Moreover serial MCV studies carried out throughout the first year of life in an affected girl showed no physiological increase in conduction velocity. For purposes of genetic counseling, our experience suggests that, starting from 6 months of age, a clinically and electrophysiologically normal subject has a zero risk of having inherited the HMSN type I gene. However given the limited numbers in this series, infants at risk with normal clinical evaluation and MCVs should be followed up yearly up to 5 years of age.

Adolescent↗
PubMed1989

The dose of propranolol for migraine prophylaxis. Efficacy of low doses.

Although propranolol is still the drug of first choice for migraine prophylaxis, the optimal antimigraine dose of this drug is still unknown. The main aim of our study is to clarify this point. Fifty-three patients suffering from severe migraine attacks were given propranolol at low doses, close to or up to 1 mg/kg body weight daily, for one month. If the patient responded, then treatment was maintained unchanged for a further two months. If the patient did not respond, propranolol was progressively increased until control was obtained. Thirty-nine (73.5%) patients responded to low doses, and 7 of the 17 patients whose dose had been increased, because of poor or absent response, showed improvement. Five patients did not finish the study because of intolerable side effects, which intensified as the dose was increased. Tolerance was not noticed. In addition to confirming the well-known utility of propranolol in migraine prophylaxis, our results show that low doses are effective in controlling serious migraine bouts in many patients. Fewer than a third of patients will need higher doses in controlling migraine attacks.

Adolescent↗
PubMed1989

[Occipital condyle syndrome: presentation of a case].

We present the clinical features and radiologic findings of a patient with the so-called occipital condyle syndrome (OCS). This clinical picture is originated by the selective metastasization of one of the condyles of the occipital bone. As it was shown in our case, this syndrome may be the presenting feature of a systemic neoplasm. The occipital condyle syndrome must be suspected in front of any patient with the binomial intense unilateral occipital pain that exacerbates with palpation and turning the neck and ipsilateral hemilingual paralysis. We briefly discuss the differential diagnosis of this condition. As conventional radiologic studies may show no abnormalities, plain X-ray examination and computed tomography must selectively study the region of the foramen magnum. The importance of the diagnosis is beyond academic interest; early radiotherapy, as it was the case of our patient, may lead to a substantial symptomatic improvement.

Aged↗
PubMed1988

Differences in virion stability among Sindbis virus pathogenesis mutants.

The structure of closely related Sindbis virus strains, which differ in their virulence for neonatal mice, has been probed by measuring the sensitivity of virions to heat, varying concentrations of dithiothreitol (DTT), phenylglyoxal or low pH. Attenuated mutants (SB-RL and SB-FP) were much more sensitive to loss of infectivity after heat or DTT treatment than either the prototype virulent strain (SB) or same-site virulent revertants of SB-RL. Incubation of SB-RL virions in the presence of DTT increased their density and exposed sulfhydryl groups on both E1 and E2 glycoproteins as determined by [14C]iodoacetamide labeling. Incubation of SB-RL at pH 6.1 for 1 h at 37 degrees C resulted in a 50% decrease in titer, whereas an equivalent decrease in SB titer was obtained at pH 6.0. Attenuated (SB-RL) and virulent (SB) strains could not be distinguished on the basis of phenylglyoxal sensitivity. Comparison of the nucleotide sequences of these strains and analysis of strains derived from recombinant full-length cDNA clones demonstrated that reduced virion stability under these conditions was a consequence of an arginine for serine substitution at position 114 of the surface glycoprotein E2. This same amino acid substitution is responsible for attenuation in neonatal mice. However, experiments with a second-site virulent revertant of SB-RL, which retained E2 arginine 114 and the reduced stability phenotype, indicated that virion instability in itself was not directly responsible for reduced virulence in vivo.

Animals↗
PubMed1988

Localized CNS brucellosis: report of 7 cases.

Seven patients with brucellar infection localized in the central nervous system (CNS) are reported. This series represent 3.5% of all brucellosis cases in our hospital. There was a conspicuous absence of systemic signs and symptoms. The clinical course was characteristically protracted. Meningitis (acute, chronic, transient and recurrent) and progressive myeloradiculopathy were the 2 clinical patterns. Cranial nerve neuropathy was frequent, eight nerve involvement being present in 4 cases; transitory ischemic attacks and subarachnoid haemorrhage occurred in 2. Routine laboratory determinations were negative or non-specific. Cerebrospinal fluid (CSF) findings included hypoglycorrhachia, lymphocytic pleocytosis and hyperproteinorrhachia. There was also a remarkable increase in the gamma-globulin and IgG values with morphology of oligoclonal bands in CSF electrophoresis. Brucella agglutination titers were low or absent in serum and/or CSF. By contrast, Coombs tests were always positive and higher titers were found in serum and CSF. After treatment a persistent CSF positive Coombs test at low titers together with an isolated increase in CSF gamma-globulin and IgG values were detected in cured patients. Brucella blood cultures were negative, but CSF cultures were positive in four cases. Rifampin and doxycycline seems to be the treatment of choice. These agents must be maintained at least for 4 months in order to avoid relapses. Corticosteroids may be helpful at the beginning of treatment. Outcome is generally favourable in this disorder. We conclude that clinical and biological characteristics of localized CNS brucellosis are in accordance with those already described in other types of localized brucellosis.

Anti-Bacterial Agents↗
PubMed1988

Motor neuron disease in Cantabria.

Sixty-two patients with motor neuron disease (MND), encompassing amyotrophic lateral sclerosis (ALS), progressive bulbar palsy (PBP) and progressive muscular atrophy (PMA), were selected from within a defined area (Cantabria) in northern Spain, from 1974 to 1985. The annual incidence of MND was 1.01 per 100,000 inhabitants and the prevalence rate was 3.52 per 100,000. The male to female ratio was 1.78:1. Age-specific incidence rates increased with advanced age, with a maximum between 60 and 69 years for males and over 70 years for females. The median age at onset was 60.5 years. The average interval between the onset symptoms and diagnosis was 11 months. Fifty-three per cent of the patients had conventional or pseudopolyneuritic ALS, 36% had PBP and 11% had PMA. There were three familial cases. Two PMA patients had had acute poliomyelitis. The mean duration of the disease was 26.6 months and was significantly longer in males aged under 60 years. The survival rates in 50 patients with adequate follow-up were 18% after 5 years from onset and 6% after 10 years.

Adult↗
PubMed1988

Molecular analysis of Sindbis virus pathogenesis in neonatal mice by using virus recombinants constructed in vitro.

Genetic loci affecting Sindbis virus pathogenesis in neonatal mice have been examined by using a full-length cDNA clone of the virus (Toto1101). The full-length cDNA is linked to a bacteriophage SP6 promoter to facilitate the synthesis of infectious RNA transcripts in vitro. Virus derived from Toto1101 showed reduced virulence (attenuation) in neonatal mice. Replacement of the E1 glycoprotein and 6K genes of Toto1101 with cloned E1 and 6K genes derived from a virulent Sindbis virus strain, AR339 (SB), resulted in a new construct, TR2000, that gave rise to virulent virus. Sequence determinations for the entire substituted regions of TR2000, Toto1101, and related virulent and attenuated strains identified three coding differences in E1 between Toto1101 and TR2000. These differences, individually or in combination, may be responsible for the attenuated phenotype. Previous studies in this laboratory identified another attenuating mutation at amino acid position 114 of the E2 glycoprotein (N.L. Davis, F.J. Fuller, W.G. Dougherty, R.A. Olmsted, and R.E. Johnston, Proc. Natl. Acad. Sci. USA 83:6771-6775, 1986). Substitution of Arg-114 in the mutant SB-RL for Ser-114 of SB appears to confer three distinguishing phenotypes: attenuation in neonatal mice, increased sensitivity to specific E2 monoclonal antibodies, and accelerated penetration of BHK cells. Replacement of TR2000 sequences containing the codon for amino acid 114 of E2 with corresponding fragments from cDNA clones of SB or SB-RL produced two strains of Sindbis virus (TR2100 and TR2200) which were isogenic except for the E2 114 codon (Ser and Arg, respectively). The three diagnostic phenotypes cosegregated according to the origin of the codon for amino acid 114 of E2, confirming the dramatic effect of this single amino acid substitution on these three phenotypes.

Amino Acid Sequence↗
PubMed1987

Prevalence of hereditary motor and sensory neuropathy in Cantabria.

One hundred and forty-four patients with hereditary motor and sensory neuropathy (HMSN) were selected from within a defined area (Cantabria) in Northern Spain, from 1974 to 1984. The series comprises 49 index cases and 95 affected relatives. The prevalence ratio was 28.2 cases per 100,000. The results of the study indicate that the majority of the cases were hereditary as a dominant trait. The prevalence for the Type I HMSN cases did not differ from that of Type II cases. Previous population-surveys of these disorders are compared.

Charcot-Marie-Tooth Disease↗
PubMed1982

Occipitoatlantal instability and vertebrobasilar ischemia: case report.

A 37-year-old woman had occipitoatlantal instability due to hypoplasia of the occipital condyles. Neck pain and transient ischemic attacks in the vertebrobasilar territory occurred with extension of the neck, which also caused convergence spasm. Angiography demonstrated that these manifestations were due to compression of the vertebral arteries during neck extension. Immobilization of the neck in a Minerva cast resulted in complete relief of symptoms.

Adult↗
PubMedDate not supplied

Intravenous lidocaine for status epilepticus.

Intravenous lidocaine successfully controlled convulsive status epilepticus in eight patients. Lidocaine was administered, as a diazepam substitute, to elderly patients with chronic obstructive lung disease and to those patients unresponsive to the stated doses of intravenous diazepam. Although transient disappearance of seizures was noted after an initial dose of 100 mg, infusion of 200 mg was necessary to effectively control status. Continuous lidocaine infusion (3.5 mg/kg/h) was used in one case with good results. Undesirable side effects were not seen. The basic mechanisms for possible anticonvulsant action are reviewed. Lidocaine seems to be an effective and safe drug in convulsive status epilepticus. We suggest that lidocaine may be used as a first-line drug, as a diazepam substitute, in the treatment of convulsive status epilepticus in patients in whom respiratory depression is undesirable and in those who do not respond to intravenous diazepam.

Adult↗
PubMedDate not supplied

[The history and classification of human prion diseases].

INTRODUCTION AND DEVELOPMENT: The history of prion diseases is one of the most exciting chapters of the story of medicine in the twentieth century. It began in the nineteen twenties when Creutzfeldt (in one patient) and Jakob (in five patients) described a clinically polymorphic cerebral syndrome with a subacute or chronic course and fatal outcome. Although later reviews of these pioneer studies have cast doubt on the nosology of some of these cases, the eponym has been maintained over the years. It is even possible that the miliary sclerosis described by Gowers in the nineteenth century was in fact a spongiform encephalopathy. Subsequently the nosological limits of Creutzfeldt-Jakob disease remained ill-defined. This explains the large number of names given to it whilst it continued to be included in the chapter on degenerative conditions of the nervous system. Perhaps the turning point was when, in the nineteen sixties, Carleton Gajdusek et al showed that it was transmissible. Previously Gajdusek and Zigas had (in 1957) described the disease kuru in a group of indigenous cannibals in Papua (New Guinea). The possibility of a parallel between this kuru and the scrapie of sheep (in which transmission had been proved twenty years before) led them to experiment and eventually prove its infectious nature. Over the following years, reports of iatrogenic cases with different routes of transmission gave further proof. The absence of conventional microorganisms responsible for this group of conditions led Prusiner (in 1982) to suggest the theory of the infecting proton or prion. CONCLUSION: This theory led to better understanding of several pathological and physiopathological aspects, however, we are aware that the full story of prion diseases is still being written at the present time.

History, 20th Century↗
PubMedDate not supplied

[Atypical Guillain-Barré syndrome: multiple cranial neuropathy].

INTRODUCTION: Multiple cranial neuropathy is a condition rarely seen in everyday clinical practice. It has many different causes, and in spite of careful clinical investigation many cases remain of unknown aetiology. It is also considered to be an atypical variant, topographically circumscribed, of the Guillan Barr syndrome (GBS). CASE REPORT: A 23 years old man developed a progressive illness over ten days. He complained of diplopia, facial diplegia and a nasal voice. Subsequently, he also developed weakness of the neck and tongue muscles, dysphagia, abolition of reflexes of the left arm and right triceps reflex but without involvement of the respiratory muscles or other limbs. CSF studies showed slightly raised protein with no cells. Neurophysiological studies showed a demyelinating disorder with secondary axonal damage. In spite of further studies, no aetiological agent was found. DISCUSSION AND CONCLUSION: These observations suggested this case is of a topographical variant of GBS. Such cases have also been classified as the Miller Fisher syndrome, pharyngo cervico brachial paralysis, are flexic paraparesia and bilateral lumbar polyradiculopathy. In view of the diversity of the clinical and biological characteristics of the cases reviewed, which may mean different aetiopathogeneses, we consider that a thorough search should be made for the aetiology before these conditions are labelled as atypical variants of GBS.

Adult↗