[Clinical Neurophysiology: past, present, future]

Clinical Neurophysiology is a medical speciality whose aim is the study of the nervous and muscular system for diagnostic, prognostic and therapeutic purposes. This article analyses the basic objective pursued by this discipline, the techniques it employs and its recognition as a medical speciality. The article briefly reviews its definition and scope, how it is structured at present and the future possibilities it offers.

[Transcranial magnetic stimulation]

Transcranial magnetic stimulation is a non-invasive tool for the electrical stimulation of the cerebral cortex, and for evaluation of the excitability of the motor cortex and pathways. Transcranial magnetic stimulation can be applied as single pulses of stimulation, pairs of stimuli separated by variable intervals to the same or different brain areas, or as trains of repetitive stimuli at various frequencies. Single stimuli can depolarize neurons and evoke measurable effects. Series of stimuli (repetitive transcranial magnetic stimulation) can modify the excitability of the cerebral cortex at the stimulated site and also at remote areas along functional anatomical connections. TMS might provide novel insights into the pathophysiology of the neural circuitry underlying neurological and psychiatric disorders, but more work is needed to establish the role of transcranial magnetic stimulation in clinical neurology.

Descriptive spatial and spatio-temporal analysis of the 2000-2005 canine rabies endemic in Santa Cruz de la Sierra, Bolivia

The authors analysed laboratory samples testing positive for rabies virus collected between 2000 and 2005 from Santa Cruz de la Sierra, Bolivia, to assess the spatial and spatio-temporal distribution of the endemic of canine rabies. According to the results of the spatial analysis, canine rabies was not evenly distributed in the city. Significant spatio-temporal clustering of canine rabies cases showed a trend towards clusters with high incidence rates in two particular areas compared with surrounding areas in the city. Benefits obtained from each of the analytical techniques utilised are described and practical difficulties in conducting and interpreting the results are discussed.

Surgical repair of the anomalous origin of the right pulmonary artery from the ascending aorta

The anomalous origin of the right pulmonary artery (AORPA) from the ascending aorta is a rare congenital malformation. We describe an infant who underwent a surgical correction with direct anastomosis between the right pulmonary artery and the pulmonary trunk. Eighteen months later, the patient remains asymptomatic, and no significant residual stenosis was detected on angioresonance.

Open vs laparoscopic repair of secondary lumbar hernias: a prospective nonrandomized study

BACKGROUND

Lumbar hernias are uncommon defects of the posterior abdominal wall. Surgical treatment is still controversial in these cases. The aim of this study was to compare outcome and costs of the laparoscopic approach vs the open method.

METHODS

We conducted a prospective nonrandomized study of 16 patients who underwent operation for secondary lumbar hernia between January 1997 and January 2003. Nine were treated via the laparoscopic approach and seven with an open technique. The following variables were analyzed: clinical data, hospital data (operating time and length of stay), patient comfort (consumption of analgesics and time to return to normal activities), and recurrences. Hospital costs were also analyzed.

RESULTS

There were no differences between the two groups in terms of age and history, although the defects of the patients in the laparoscopic group were smaller. Mean operating time, postoperative morbidity, mean hospital stay, consumption of analgesics, and time to return to normal activities were significantly lower in the laparoscopic group (p < 0. 01). No were there any statistical differences between the two types of surgical procedure in terms of hospital costs. However, the final cost did show differences when expenses for readmissions and recurrences were taken into account (p < 0.01).

CONCLUSION

The laparoscopic approach to secondary lumbar hernia repair is more efficient and more profitable than the traditional open technique.

Impacto de una vía clínica para el pie diabético en un hospital general

OBJECTIVE

The ulcers, infections and isquemia of the foot are the main causes of hospitalisation of the diabetic patient and, very frequently, they are reason for the amputation of the limb. The objective of this investigation consists of evaluating the results of a multidisciplinary clinical pathway designed by the set of specialists of different departments from our hospital, as well as of the associated personnel of infirmary, implied in the management of this pathology.

PATIENTS AND METHODS

We have analysed the evolution of a series of clinical and socio-economic indicators comparing, in the patients admitted with diagnose of complicated diabetic foot, the previous period to the implantation of the clinical pathway years 1998, 1999 and 2000) with the later period to this implantation (years 2001 and 2002). It is evaluated in each group: the percentage of greater and smaller amputations, mortality, the average stay, the percentage of readmitances in 30 days, the percentage of arteriographies, the percentage of patients controlled by rehabilitation, and the economic cost of the individual processes, as well as the global cost. In the group including in the clinical pathway it was carried out, in addition, a satisfaction survey. The statistical comparison was made by means of the Chi square test.

RESULTS

We did not find differences as far as the average stay, nor to intrahospitable mortality. If we found a clear increase in the percentage of arteriographies (of the 3.5% passage to 13%), and in the percentage of patients controlled by rehabilitation (of the 19.8% passage to the 84.3%). The rate of greater amputations of the patients not including in the clinical pathway change from 17.4% to 9.7% after the implantation of this route. The rate of readmitances to 30 days diminished from 9.3 to 6,5%. The global economic cost and the average cost by patient have been inferior after the implantation of the clinical route. The survey of satisfaction of this last group offered a global satisfaction of 95%.

CONCLUSIONS

The results suggest that the approach to the diagnose and treatment on the complicated diabetic foot by means of this multidisciplinary clinical pathway improves the evolution of the hospitalised patient, diminishing the number of greater amputations, without extending the average stay and maintaining, or even diminishing, the global economic cost.

Diversity and species composition of sand flies (Diptera: Psychodidae) in a Venezuelan urban focus of cutaneous leishmaniasis

The present study examined the spatial and temporal abundance and diversity of phlebotomine sand flies in an area of Venezuela that is an ancient focus of leishmaniasis. The study was conducted in 6 stations in urban localities in Trujillo City, located in northwestern Venezuela (9 degrees 22' 24" N, 70 degrees 26' 08" W), which is located in a mountain range in the Andean ecoregion (altitude = 600-1,010 m). During 1995-99, entomological surveys were conducted after and before the rainy season. Shannon light traps were operated from 1800 to 2000 h in peridomestic site trap locations. Twelve species were captured, and Lutzomyia youngi, L. ovallesi, L. scorzai, L. gomezi, L. lichyi, and L. shannoni occurred at all localities in each year. The abundance of these species showed low variation over time but high variation between localities. The Sørensen similarity index, used to compare diversity between years within each locality, ranged from 0.60 at Carmona to 0.84 at La Hacienda. Sand fly communities exhibited annual variation in species richness and diversity. Variations were affected more by changes in species abundance than by changes in species composition. Lutzomyia ovallesi, L. lichyi, and L. scorzai had the highest coefficient of variation between years (63, 38, and 23%, respectively).

Entomological aspects of Chagas' disease transmission in the domestic habitat, Argentina

OBJECTIVE: To study the risk of Trypanosoma cruzi domestic transmission using an entomological index and to explore its relationship with household's characteristics and cultural aspects. METHODS: There were studied 158 households in an endemic area in Argentina. Each household was classified according to an entomological risk indicator (number of risky bites/human). A questionnaire was administered to evaluate risk factors among householders. RESULTS: Infested households showed a wide range of risk values (0 to 5 risky bites/human) with skewed distribution, a high frequency of lower values and few very high risk households. Of all collected Triatoma infestans, 44% had had human blood meals whereas 27% had had dogs or chickens blood meals. Having dogs and birds sharing room with humans increased the risk values. Tidy clean households had contributed significantly to lower risk values as a result of low vector density. The infested households showed a 24.3% correlation between time after insecticide application and the number of vectors. But there was no correlation between the time after insecticide application and T. infestans' infectivity. The statistical analysis showed a high correlation between current values of the entomological risk indicator and Trypanosoma cruzi seroprevalence in children. CONCLUSIONS: The risk of T. cruzi domestic transmission assessed using an entomological index show a correlation with children seroprevalence for Chagas' disease and householders' habits.

[Sport activity in children and adolescents: temperament and emotional traits]

AIM

Aim of this study is to evaluate anxiety and temperament characteristics in developmental age subjects who practised agonistic sport (individual or team sports) in comparison with a sample group of subjects who practice no agonistic sports.

METHODS

Sixty subjects aged from 10 to 16 years were enrolled in the study and divided into 3 groups: 20 subjects practised individual agonistic sport (Group A), 20 subjects practised team agonistic sports (Group B) and 20 subjects who practised non agonistic sport as control group, (Group C). The following tests were used: multidimensional anxiety scale for children (MASC) to evaluate anxiety, EAS scale (Buss e Plomin) to evaluate temperament (emotionability, activity, sociability and shyness for younger children).

RESULTS

MASC scale scores underline generalized anxiety with higher significantly score in subjects who practised agonistic sports (Group A and B) compared with Group C. Anxiety symptoms were more evident in subjects who practised individual discipline compared with those who practised team sports. EAS scale indicated that temperament of subjects who practised agonistic sport was characterised by a considerable aptitude for sociability with low emotionability/activity levels in comparison to control group.

CONCLUSION

None of the 3 groups showed a psychopathologic profile.

Isolation and characterization of a novel insect defensin from Rhodnius prolixus, a vector of Chagas disease

An antimicrobial peptide belonging to the defensin family of small cationic peptides associated with innate immunity in insects was isolated from the hemolymph of Rhodnius prolixus, a vector of Chagas disease. This peptide, designated R. prolixus defensin A, was purified and sequenced. The active peptide contains 43 residues and aligns well with other insect defensins. However the pre-pro region of the sequence has little shared identity with other insect defensins. We have identified 3 isoforms of R. prolixus defensin from cDNA clones obtained from RNA isolated from the whole bodies of immune activated insects. Northern analysis and Real-Time Quantitative PCR indicate that there is a very low baseline transcription of this peptide in naïve insects, and that transcription increases significantly in the fat body of immune activated insects. In addition there is a delayed induction of transcription of this peptide in the intestine 24 h post activation suggesting that the midgut/intestine of this species is active in the immune response against pathogens.

Effects of dietary lipids on cell proliferation of murine oral mucosa

BACKGROUND

The lack of certain essential polyunsaturated fatty acids (PUFAs) induces perturbation in cell proliferation, apoptosis and dedifferentiation that could be linked to an increased protumorigenic trend. Contrarily, n-3 essential fatty acids (EFAs) arrest cell proliferation in several tumor models. According to the concept of field cancerization, multiple patches of abnormal epithelial proliferation may coexist in the vicinity of oropharyngeal neoplasms. The purpose of the present study is to determine whether certain dietary PUFAs differentially modulate the patterns of cell proliferation and apoptosis at non-tumoral sites of the oral mucosa in mice bearing DMBA induced salivary tumors. After weaning, BALB/c mice were assigned to four diets: Control (C), Corn Oil (CO), Fish (FO) and Olein (O). Two weeks later, DMBA was injected into the submandibular area. The animals were sacrificed between 94 and 184 days at 4-6 PM. Fixed samples of lip, tongue and palate were stained using H-E and a silver technique. A quantification of AgNORs in the basal (BS) and suprabasal stratum (SBS) of the covering squamous epithelia as well as of mitosis and apoptosis was performed.

RESULTS

Analysis of Variance showed greater proliferation in tongue than in palate or lip. According to the diet, a significant difference was found in the Fish Oil, in which palate exhibited fewer AgNOR particles than that of the control group, both for BS and SBS (p < 0.05 and 0.152, respectively), indicating a reduced cell proliferation.

CONCLUSIONS

These results corroborate and reaffirm that the patterns of cell proliferation, apoptosis and differentiation of the oral stratified squamous epithelium may be differentially modulated by dietary lipids, and arrested by n-3 fatty acids, as shown in several other cell populations.

Mechanism of CIT-6 and VPI-8 crystallization from zincosilicate gels

The crystallisation of CIT-6, a large-pore zincosilicate with the framework topology of zeolite Beta and synthesised from clear hydrogels that contain, tetraethylammonium (TEA+), Li+ and Zn2+ cations, proceeds initially through the formation of an amorphous solid that incorporates all the initial Zn species. Nucleation of the *BEA phase is effected by reorganisation of the amorphous phase, whereas crystal growth involves the incorporation of soluble species also. A highly crystalline CIT-6 material is obtained after 164 h of synthesis at 140 degrees C. Scanning electron microscopy (SEM) shows that this sample exhibits two different types of crystals: well-defined pseudo-cubic crystals and rounded crystals. The latter has a broad crystal-size distribution. If crystallisation is continued with longer synthesis times, the VPI-8 crystalline phase appears, and a new population of needle-shaped crystals is detected in the SEM images. This new crystalline phase is nucleated on the surface of the rounded CIT-6 crystals, which disappear as the crystallisation progresses, while no changes are observed in the population of pseudo-cubic CIT-6 crystals. At higher crystallisation temperatures these phase transformations are accelerated, and the formation of VPI-8 is favoured over that of CIT-6.

An epidemiological study of Taenia solium cysticercosis in a rural population in the Bolivian Chaco

A survey of 100 rural households in a village in the Chaco region of Bolivia revealed a serious problem of Taenia solium cysticercosis, with a seroprevalence of 99/447 (22%) in humans and 102/273 (37%) in pigs. Risk factors for humans were being in older age groups, absence of sanitary facilities, poor formal education and inability to recognise infected pork. Significant risk indicators were a history of seizures and the reported elimination of worms in the faeces. Risk factors for pigs were being in older age groups and absence of sanitary facilities in the owner's house. The proportion of households with evidence of human cysticercosis was similar for those who owned pigs (48%) and those that did not (55%). This unexpected finding was attributed to the high overall prevalence of cysticercosis in pigs and the probability that everyone, regardless of pig-ownership, had ample opportunity to become infected in such communities. The main recommendation for reducing the prevalence of human cysticercosis was to provide more effective education campaigns, aimed at preventing both T. solium infection and cysticercosis.

Thrombocytopenia in HIV-infected drug users in the HAART era

The present case-control study compared 26 HIV+ drug users having persistent thrombocytopenia (TCP<150 000/mm(3)) with 54 available age, gender and HIV CDC classification matched controls with normal platelet counts. Participants were followed longitudinally over a 2-year period (1998-2000), and hematological alterations evaluated in relationship to antiretroviral treatment, drug use and nutritional (selenium) status. Demographic information and medical history, including antiretroviral treatment were obtained. Blood was drawn for complete cell blood count, T lymphocytes and viral load. Sixty-nine percent of the individuals with persistent TCP and 49% of the controls were receiving antiretrovirals. At baseline, no significant differences in CD4 existed between the two groups. Over time, CD4 cell count declined in the cases (P = 0.05) and a significantly higher proportion of the cases (38%) developed AIDS (CD4<200 cell/mm(3)), as compared to the controls (18%, P = 0.004). A high risk for development of thrombocytopenia was observed with specific drug use (heroin 2.96 times, P = 0.0007), selenium levels below 145 microg/l (6 times, P = 0.008), and abnormal liver enzyme (SGOT) levels (2 times, P = 0.002). Together, these results indicate a number of factors that may be sensitive predictors of thrombocytopenia, which, despite antiretroviral treatment, appears to be related to more rapid disease progression in drug users.