A novel mutation (K317M) in the MAPT gene causes FTDP and motor neuron disease

BACKGROUND

Frontotemporal dementia with parkinsonism is often linked to chromosome 17 and is related to mutations in the MAPT gene. In some families the genetic basis is still unknown. The authors report two pedigrees with FTDP-17 harboring a novel mutation (K317M) in exon 11 in the MAPT gene.

METHODS

The authors identified two apparently unrelated pedigrees with an autosomal dominant neurodegenerative condition. Thirteen patients were examined and eight autopsies were performed.

RESULTS

Mean age at onset was 48 years. Mean disease duration was 6 years. Dysarthria often heralded the disease. All cases had parkinsonism and pyramidalism and half of them had amyotrophy. Behavioral or personality changes were not a prominent feature. Cognitive decline appeared late in the evolution. Neuropathologically, a massive degeneration of the substantia nigra without Lewy bodies was a constant finding. A variable degree of frontotemporal atrophy was found. Corticospinal tract degeneration and anterior horn neuron loss were present in six of seven autopsies in which the spinal cord was examined. An extensive deposition of abnormal tau protein in a mixed pattern (neuronal, glial) was observed. Pick's bodies were not seen. Biochemical analysis of tau revealed two bands of 64 and 68 kDa.

CONCLUSION

Genetic analysis revealed the same novel mutation (K317M) in exon 11 of the MAPT gene in both pedigrees. A common haplotype between members of the two pedigrees suggests that they belong to the same family.

[Bilateral subthalamic nucleus deep-brain stimulation (STN-DBS) in Parkinson's disease: initial experience in Cruces Hospital]

INTRODUCTION

Clinical outcomes of Parkinson's disease patients treated for 12 months with STN-DBS were analyzed. PATIENTS ADN METHODS: Twelve patients were selected using the CAPSIT protocol criteria and placement of electrodes in the appropriate target was performed according to results of fusion image techniques and intraoperative microrecording.

RESULTS

A reduction in motor UPDRS (44 %) and activities of daily living (58 %) scores during <<off>> phases were observed. <<On>> time with dyskinesias was reduced (86 %), while severe dyskinesias disappeared. Levodopa dosage was also lowered (44 %). Patients and caregivers showed a clear-cut benefit on quality of life (58 % and 61 % respectively). No cognitive deterioration was observed and morbidity was in the same range as that published by other teams.

CONCLUSION

Bilateral STN-DBS is an effective symptomatic therapy for complicated Parkinsońs disease patients. It improves the quality of life of patients and their caregivers and allows a reduction of levodopa dosage.

[Twiddler's syndrome in a patient with implantable cardioverter defibrillator: an avoidable complication?]

The Twiddler's syndrome is an uncommon, but potentially life-threatening complication in patients with an implantable cardioverter-defibrillator. Early identification of repetitive vicious attitudes and a periodic radiological follow-up in predisposed patients, may be useful in the primary prevention of this syndrome.

Maxillary undifferentiated carcinoma with rhabdoid features

The rhabdoid malignant tumor was individualized by Haas et al. as an independent entity within the kidney malignant neoplasms in 1981. From its histopathological characteristics, different cases of rhabdoid extra-renal tumor were documented. This aspect has been also recognized in a wide heterogeneous group of tumors (carcinoma, melanoma, mesothelioma and mesenchymal tumors). The diagnosis of extrarenal rhabdoid tumor is based on the presence of a proliferation of epithelioid cells with large nuclei, prominent nucleoli, abundant eosinophilic cytoplasm, and conspicuous cytoplasmic intermediate filaments, which compress the nuclei. In this article we present the case of a 50-year-old male patient with a malignant maxillary tumor with characteristic rhabdoid features. Its differential diagnosis will be discussed. The literature will also be reviewed.

[Diagnostic clinical trial in children using an allergenic extract of Blomia tropicalis]

BACKGROUND

Blomia tropicalis is a mite that is one of the most important causes of allergic sensitization in studies of tropical and subtropical regions. Nonetheless, there are no published studies of the sensitivity and specificity of B. tropicalis extracts.

METHOD

An open, non-randomized study was carried out in 205 asthmatic children and in 205 non-asthmatic children, both groups with an age range of 1 to 14 years. Duplicate skin prick tests were made using allergen extracts standardized by biological units and positive and negative controls. The test was considered positive when the average diameter of the wheal was > or = 3 mm and negative when it was < 3 mm. The validity of the test was estimated by calculating sensitivity, specificity, and the positive and negative predictive values.

RESULTS

The skin prick test was positive in 82.92% of the asthmatic children and in 10.7% of the non-asthmatic children, yielding a sensitivity of 82.9%, 95% CI 76.9; 87.7 and a specificity of 89.3%, 95% IC 84.0; 93.0. The positive predictive value was 88.5%, 95% IC 83.0; 92.5 and the negative predictive value was 83.9%, 95% IC 78.2; 88.4.

CONCLUSIONS

Blomia tropicalis is an important cause of bronchial asthma among the children of the northern Camagüey region.

[Circulating Haemophilus influenzae in Cuba. Characterization of strains isolated from meningitis]

Haemophilus influenzae B(Hib) is often associated with serious systemic infections in children under 5 years of age. Since 1993, it is the most frequent agent isolated in meningoencephalitis. All the strains isolated in the country have been characterized in the National Reference Laboratory at the "Pedro Kourí" Tropical Medicine Institute. Results revealed that 97% of strains isolated from bacterial meningoencephalitis in Cuba during the period 1993-1995 corresponded to serotype B, 0.6% to serotype A and 2.4 not belong to any serotype. The classification of serotype B-strains into biotypes proved that 76% was biotype I and 21% biotype II, 8 to biotype III and 1.2% was biotype V. This study found the following resistance to ampicillin 40%, to chloranphenicol 43.3%, sulpha metoxazol 36%, trimetroprim 37.3% and tetracycline 31%.

[The determination of antibodies to the human immunodeficiency virus type 1 (HIV-1) in samples of dried blood on filter paper]

The possibility of detecting HIV-1 antibodies by an immunoblotting kit is studied in a panel of 125 known specimens of dried blood spotted on filter paper and their corresponding serum samples. No differences were observed in the patterns of bands with both types of samples or in the sensitivity and specificity, where 100% figures were attained, allowing to conclude that the blood specimen taken on filter paper may be used for the detection of HIV-1 antibodies by the DAVIH-BLOT system and may be kept at 4 degrees C during 30 weeks.

Technetium-99m-labeled anti-EGF-receptor antibody in patients with tumor of epithelial origin: I. Biodistribution and dosimetry for radioimmunotherapy

Accurate estimation of biodistribution and absorbed dose to normal organs and tumors is important for immunoscintigraphic studies and radioimmunotherapy treatment planning.

METHODS

Four patients (3 men, 1 woman; mean age 54.8 +/- 9.2 yr; range 42-64 yr) were administered 3 mg of anti-human epidermal growth factor receptor (anti-hEGF-r) antibody (ior egf/r3), radiolabeled with 99mTc activity of 39.5 +/- 1.1 mCi (range 38.5 mCi-40.7 mCi) by intravenous bolus infusion. After administration, blood and urine samples were collected from three patients up to 24 hr after injection. Whole-body anterior and posterior scans were obtained at 5 min and 1, 3, 5 and 24 hr after injection. Using a computer program, regions of interest were drawn over the heart, liver, spleen, bladder and tumor to measure the activity in the source organs at each scanning time. Time-activity curves for each source organ were then fitted to monoexponential or biexponential functions by nonlinear least squares regression using the flexible polyhedrals method, which adequately fit our data with the correlation coefficient of 0.985 +/- 0.013, and were integrated to determine organ residence times. The mean absorbed doses to the whole body and various normal organs were then estimated from residence times and from blood and urine samples using the methods developed by the Medical Internal Radiation Dose Committee. The effective dose equivalent and effective dose were calculated as prescribed in ICRP Publication Nos. 30 and 60.

RESULTS

Plasma disappearance curves of 99mTc-labeled anti-hEGF-r antibody were best-fit by a two-compartment model in all patients with a distribution half-life (t(1/2alpha)) of 0.207 hr +/- 0.059 hr (mean +/- s.d., n = 3) and an elimination half-life (t(1/2beta)) of 13.9 hr +/- 2.2 hr. Among the various organs, significant accumulation of the radiolabeled antibody was found in the liver (48.5% +/- 4.4%, mean +/- s.d.), heart (3.50% +/- 0.17%) and spleen (3.1% +/- 1.8%) at 5 min postadministration. These values were reduced to 3.2% +/- 0.4%, 0.1% +/- 0.01% and 0.1% +/- 0.1%, respectively, at 24 hr. Mean cumulative urinary excretion of 99mTc-labeled anti-hEGF-r antibody was 4.6% +/- 0.6% at 24 hr postinjection. Estimates of radiation absorbed dose to normal organs in rad/mCi administered (mean +/- s.d., n = 4) were: whole body 0.017 +/- 0.002; gallbladder wall 0.074 +/- 0.007; spleen 0.136 +/- 0.076; and liver 0.267 +/- 0.036. The effective dose equivalent and effective dose estimates for adults were 0.041 +/- 0.008 rem/mCi and 0.027 +/- 0.004 rem/mCi administered.

CONCLUSION

This feasibility study indicates that 99mTc-labeled anti-hEGF-r antibody (ior egf/r3) can be used safely; this analysis provides a dosimetric framework for future studies. This monoclonal antibody, labeled with 188Re, could possibly permit a successful regional radioimmunotherapy of tumors of epithelial origin.

Postoperative follow-up of pituitary adenomas after trans-sphenoidal resection: MRI and clinical correlation

Our purpose was to correlate the morphological changes seen on MRI studies of the sellar region after trans-sphenoidal resection of pituitary adenomas with clinical and hormonal studies. Between January 1993 and March 1994, 16 patients with a pituitary adenoma (9 macroadenomas and 7 microadenomas) were subjected to trans-sphenoidal resection and included in a prospective study. The protocol consisted of MRI, hormonal and visual studies at the following times: immediately postoperative (1st week), 1st month, 4th month and 1st year after surgery. The evolution of the contents of the sella turcica (tumour remnant, packing material and gland tissue), effects on the infundibulum, optic chiasm, cavernous sinus and sphenoid sinus were correlated with the clinical and hormonal studies. Stabilisation of the postsurgical changes occurred by the 4th month. Tumour remnants were noted in the immediate postoperative period in macroadenomas. Compression of the infundibulum was the only reliable indicator of possible involvement. Optic chiasm compression, defined as close contact between the chiasm and the tumour, was the only morphological finding that indicated visual impairment. There was no standard repneumatisation pattern in the sphenoid sinus, since mucosal changes resembling sinusitis were one of the postsurgical changes. We found MRI not to be useful for follow-up of microadenomas.

[Complications associated with nonfunctioning pacemaker electrodes retained within the cardiovascular system]

INTRODUCTION AND OBJECTIVE

The aim of the present study was to evaluate the complications in patients with functionless pacing leads retained in the cardiovascular system.

PATIENTS AND METHODS

We retrospectively studied 39 patients: 31 underwent surgery for electrical or mechanical failure (group I) and eight for cutaneous pocket infection (group II). The follow-up was 45 +/- 34 months.

RESULTS

Only one patient (3%) from group I presented infectious complications probably related to the retained pacing lead. Seven patients (87%) in group II presented recurrence of the infection with persistent fever and/or septicemia due to skin erosion and unnoticed pacing lead infection (p < 0.0005). Removal of the infected generator was performed in 8/39 (21%) of the patients. Thoracotomy to explant the infected retained leads was required in five of them (62%). No patient presented lead migration or venous thrombosis during the follow-up.

CONCLUSIONS

Retained pacing leads in the cardiovascular system are well tolerated. However, in spite of adequate antibiotic treatment, patients with local and pacemaker system infection may present recurrence of the infection with persistent fever and/or septicemia. Early surgical pacemaker system removal is recommended in these patients due to the high morbidity.

Comparative assessment of the leprosy antibody absorption test, Mycobacterium leprae extract enzyme-linked immunosorbent assay, and gelatin particle agglutination test for serodiagnosis of lepromatous leprosy

A comparative assessment of three serological methods for leprosy diagnosis (the fluorescent leprosy antibody absorption [FLA-ABS] test, the Mycobacterium leprae soluble-extract enzyme-linked immunosorbent assay [ELISA], and the M. leprae particle agglutination [MLPA] test) was carried out. The objective was to identify their performance in clinical and epidemiological diagnosis of leprosy. The study group included 45 lepromatous leprosy patients under treatment. Specificity was > 95% for all three assays, and sensitivity was 95, 58, and 74% for the FLA-ABS test, the MLPA test, and the ELISA, respectively. The only cross-reactivity for M. tuberculosis-infected patients was with the soluble-extract ELISA. Although the FLA-ABS test displayed the highest specificity and sensitivity values, it can only be used in well-developed laboratories, and the patient's clinical and epidemiological background must be considered when results are interpreted because the test remains positive after therapeutic success and could be positive for some household contacts. The MLPA test is easier to perform and interpret, and it is adequate for small laboratories and epidemiological studies intended to detect active untreated or irregularly treated leprosy cases. Therefore, the FLA-ABS and MLPA tests are complementary, and both should be used for serodiagnosis of leprosy.

Dietary fiber analysis of cassava using gravimetric methods

We report the application of a method which combines digestion with pancreatin and neutral detergent treatment in the analytical study of dietary fiber from cassava. The use of pancreatin previous to the detergent extraction enabled rapid filtration, thus giving more reproducible results for neutral detergent fiber (NDF). Acid detergent fiber (ADF), hemicellulose, lignin and pectin were also determined. The values obtained for NDF (4.65%) and pectin (1.17%) are very important, considering their role in the digestive process.

Translational pauses during a spider fibroin synthesis

The large ampullate glands of Nephila clavipes synthesize a tissue-specific fibroin for the web and dragline. Its secretory product migrates as one homogeneous band of approximately 320,000 daltons in denaturing electrophoresis. Similar analyses of the secretory epithelium reveal, in addition to the final product, a step ladder array of peptides in a highly reproducible and consistent pattern. We have correlated these peptide ladders with the process of fibroin synthesis. First, the peptides are very prominent in stimulated glands and quite dim in non stimulated ones. Secondly, by offering the cultured glands different amino acids in the incubating medium, we have linked the presence of the bands with those amino acids which abound in the fibroin. The evidence correlates the peptides with active fibroin synthesis, thus they are products of translation, and possibly reflect discontinuities in the translational process such as those demonstrated during the synthesis of Bombyx fibroin.

[Norwegian scabies caused by Sarcoptes scabiei variety hominis]

A rare case of Norwegian scabies in a 16 years old female patient is reported. There also was Silver Roussel's syndrome and cellular immunologic deficiency. The case was confirmed at the biopsy, direct examination and immunologic examinations. Clinically, by erythema and adherent, abundant, whitish desquamation. The treatment resulted in a full recovery.