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Biomedical subjects

I Mavromatis

Publications and source records attributed to I Mavromatis.

9 recordsLinked to original sources

Polymyositis in a patient with recurring ovarian cancer and history of unrelated breast cancer.

BACKGROUND: Polymyositis (PM) is an idiopathic inflammatory myopathy. Occasionally, it may present as a paraneoplastic syndrome and it is strongly associated with ovarian and weakly with breast cancer. We present here a case of a 60-year-old patient with sequential breast and ovarian (second primary) carcinomas followed by PM as a paraneoplastic disorder. CASE REPORT: The patient had been diagnosed with stage I breast carcinoma 3 years ago and had been treated with conservative surgery followed by radiotherapy and six cycles of chemotherapy (CMF). One and a half year later an ovarian carcinoma was diagnosed for which the patient underwent abdominal hysterectomy oophorectomy and omentectomy. The pathological report characterized it as second primary. Adjuvant chemotherapy with carboplatin and taxol was administered. Fourteen months after the initial laparotomy, the patient was re-operated due to ovarian carcinoma recurrence which was involving all lesser pelvis organs. After a successful radical removal of the recurrence the patient developed a fully expressed PM. This case serves to remind that this disease can occur as a paraneoplastic disorder.

Adenocarcinoma↗

Fracture callus engulfing a peripheral nerve does not affect its function: an experimental study in rabbits.

The fate of a peripheral nerve engulfed in fracture callus is not known. We investigated the impact of envelopment of the sciatic nerve by fracture callus using a New Zealand rabbit femoral fracture model. The sciatic nerve was mobilized and coiled around the ipsilateral femur, which was surgically fractured, shortened, and osteosynthesized. Bony union was achieved, and callus engulfed the sciatic nerve in all animals. Nerve function was evaluated clinically and by conduction studies preoperatively and postoperatively. Although the nerve function in terms of clinical evaluation, amplitude, motor latency, and spontaneous activity deteriorated immediately postoperatively, recovery was evident in the following weeks indicating that the detected nerve dysfunction was attributable to the surgical mobilization. In addition, histologic and quantitative histomorphometric analyses proved that in none of the animals did the callus compress the sciatic nerve whereas an impressive process of axonal regeneration took place despite callus maturation. Results of our study suggest that callus, engulfing a peripheral nerve, does not compress it and the nerve appears to be intact in an osseous canal. This results in preservation of the integrity and function of the nerve, which may have significant clinical applications.

Analysis of Variance↗

Chromosome 17p-linked myasthenias stem from defects in the acetylcholine receptor epsilon-subunit gene.

OBJECTIVE: To identify and to characterize functionally the mutational basis of congenital myasthenic syndromes (CMS) linked to chromosome 17p. BACKGROUND: A total of 37 patients belonging to 13 CMS families, 9 of them consanguineous, were investigated. All patients were linked previously to the telomeric region of chromosome 17p. Two candidate genes in this region encode synaptobrevin 2, a presynaptic protein, and the epsilon-subunit of the acetylcholine receptor (AChR). Direct sequencing of the synaptobrevin 2 gene revealed no mutations. The authors thus searched for mutations in the epsilon-subunit gene of AChR. METHODS: Direct sequencing of the AChR epsilon-subunit, restriction analysis, allele-specific PCR, and expression studies in human embryonic kidney cells were performed. RESULTS: The authors identified two previously characterized and five novel epsilon-subunit gene mutations, all homozygous, in the 13 kinships. Two of the novel mutations are truncating (epsilon723delC and epsilon760ins8), one is a missense mutation in the signal peptide region (epsilonV-13D), one is a missense mutation in the N-terminal extracellular domain (epsilonT51P), and one is a splice donor site mutation in intron 10 (epsilonIVS10+2T-->G). Unaffected family members have no mutations or are heterozygous. Expression studies indicate that the four novel mutations in the coding region of the gene and the most likely transcript of the splice-site mutation, which skips exon 10, are low-expressor or null mutations. CONCLUSIONS: Chromosome 17p-linked congenital myasthenic syndromes are caused by low-expressor/null mutations in the AChR epsilon-subunit gene. Mutations in this gene are a common cause of CMS in eastern Mediterranean countries.

Adolescent↗

Field evaluation of a live vaccine against porcine reproductive and respiratory syndrome in fattening pigs.

A live vaccine based on a European isolate of porcine reproductive and respiratory syndrome virus (Porcilis PRRS) was tested in this study in order to determine the protection of fattening pigs against the respiratory form of the syndrome under field conditions. Ten thousand pigs in an infected farm were vaccinated against PRRS virus at the age of 6 weeks and were compared with non-vaccinated pigs with respect to their health status, mortality, performance parameters (average daily gain, average daily feed intake, feed conversion ratio) and the presence of certain pathogens in their lungs. The results showed that treated pigs became ill less frequently and demonstrated reduced mortality compared with untreated ones. As compared with non-vaccinated animals, PRRS-vaccinated pigs also performed in a better way with respect to the feed conversion ratio (P < 0.05) and average daily gain (P < 0.05), while feed intake was similar for both groups (P > 0.05). Bacteriological examinations of the lungs revealed increased incidence of respiratory bacterial infection in untreated pigs compared with treated ones. A tendency for a faster antibody response was also detected in the vaccinees. The results of the present study show that immunization with a live vaccine does protect fattening pigs against the respiratory manifestations of PRRS.

Animals↗

Mapping of the familial infantile myasthenia (congenital myasthenic syndrome type Ia) gene to chromosome 17p with evidence of genetic homogeneity.

Familial infantile myasthenia is an autosomal recessive disorder, recently classified as congenital myasthenic syndrome type Ia. Onset of symptoms is at birth to early childhood with significant myasthenic weakness and possible respiratory distress, followed later in life by symptoms of mild to moderate myasthenia. Thirty-six patients of 12 families, seven of them consanguineous, were used to map the familial infantile myasthenia gene. A combination of linkage search through the genome, DNA pooling and homozygosity mapping were employed resulting in the localisation of this disease locus to the telomeric region of chromosome 17p. A maximum lod score of 9.28 at theta = 0.034 was obtained between the disease locus and marker locus D17S1537. Haplotype analysis showed all families to be consistent with linkage to this region thus providing evidence for genetic homogeneity of familial infantile myasthenia. Multipoint linkage analysis mapped the disease gene in the approximately 4.0 cM interval between marker loci D17S1537 and D17S1298 with a maximum multipoint lod score of 12.07. Haplotype analysis and homozygosity by descent in affected individuals of the consanguineous families revealed results in agreement with the confinement of the familial infantile myasthenia region within the interval between marker loci D17S1537 and D17S1298.

Chromosome Mapping↗

Visual evoked potentials in hypothyroid and hyperthyroid patients before and after achievement of euthyroidism.

Thyroid hormone deficiency is frequently associated with central nervous system (CNS) disturbances such as mental retardation, convulsions, coma etc. Studies of quantitative changes in CNS in hypo- or hyperthyroidism are scarce. Evoked potentials is a good method of assessing the electrical response of the brain to different (visual, acoustic, somatosensory) stimuli and has been used extensively in the study of brain disturbances and to a lesser degree in metabolic diseases. We studied the visual evoked potentials (latency and amplitude) in 12 patients with hyperthyroidism and 15 patients with hypothyroidism, before treatment and after they became euthyroid. Four of the hyperthyroids (33%) had abnormally prolonged (> 104 msec) latencies before therapy. Two of them had clinical exophthalmos. No change was observed after euthyroidism was achieved. On the contrary 7 out of 15 (47%) hypothyroids had abnormally prolonged latencies which became normal in 4 when euthyroidism was achieved. Amplitude was lower than normal in 6 and became normal only in one of them after treatment. None of the hyperthyroid patients had amplitude changes. In conclusion, hypothyroid patients may have changes in the amplitude and/or the latency of visual evoked potentials which are reversible to a great extent with thyroxine. Evoked potentials is another method of studying in humans the metabolic effects of thyroxine deficiency in CNS.

Adult↗