Functional Characterization of the Left Ventrolateral Premotor Cortex in Humans: A Direct Electrophysiological Approach.

In monkeys, motor outputs from premotor cortex (PM) involve cortico-cortical connections with primary motor cortex (M1). However, in humans, the functional organization of PM and its relationship with the corticospinal tract (CST) is still uncertain. This study was carried out in 21 patients undergoing intraoperative brain mapping prior to tumor resection. The left ventrolateral premotor cortex (vlPM-BA6) was identified preoperatively by functional magnetic resonance imaging, and then investigated intraoperatively using high frequency direct electrical stimulation (HF-DES) of the convexity of M1 and vlPM-BA6, with simultaneous recording of motor-evoked potentials (MEPs) from oro-facial, hand and arm muscles. The somatotopy, organization of evoked responses, latency of MEPs, and cortical excitability of vlPM-BA6 were compared with reference data from M1. vlPM-BA6 was found to be less excitable, with significantly longer MEP latencies than M1. In addition to the pure oro-facial and hand-arm muscle representation, a "transition oro-hand zone" was identified in vlPM-BA6. The longer latency of vlPM-BA6 MEPs suggests that human vlPM could act on spinal motoneurons either directly through more slowly conducting CST fibers or via less direct pathways through M1, brainstem, or spinal mechanisms. The results help in disclosing the very different roles of vlPM and M1 in motor control.

[Consequence of hypertensive disorders during pregnancy (THE) on women's cardiovascular health]. / Consecuencia de los trastornos hipertensivos durante el embarazo (THE) sobre la salud cardiovascular de la mujer.

Patients with hypertensive disorders of pregnancy (HDP) are at increased risk of maternal-fetal complications and represent the third leading cause of maternal mortality. To date, it is known that women experiencing this condition during pregnancy have a higher future risk of cardiovascular events (CVD). Our objective was to report the incidence of new-onset hypertension in the postpartum period. We conducted a cohort study in high-risk pregnant patients who underwent ambulatory blood pressure monitoring (ABPM) between weeks 20-30. Patients were categorized as normotensive (NT) or gestational hypertensive (GH), excluding those with chronic hypertension, and were followed until the end of pregnancy with a postpartum assessment after 3months. Patients with HDP (39%) had a higher incidence of preeclampsia and newborns with low birth weight and preterm birth. A total of 177 pregnant women were analyzed for the primary outcome. Among those with GH, 33.3% vs 17.2% of NT (P=.014) reported new-onset hypertension. The odds ratio for developing new-onset hypertension was 2.3 (95%CI: 1.20-4.77), for those with GH. In conclusion, pregnant patients with GH assessed by ABPM between 20-30weeks are at higher risk of developing new-onset hypertension in the postpartum period, emphasizing the need for closer monitoring and control to prevent future cardiovascular complications.

[Prevalence, knowledge and control of arterial hypertension in vulnerable neighborhoods of Argentina: A Cross-sectional Study]. / Estudio de prevalencia, conocimiento y control de la hipertensión arterial en barrios vulnerables de Argentina.

INTRODUCTION: Hypertension (HTN) represents the primary individual risk factor, contributing significantly to the global burden of cardiovascular diseases (CVD). In our country, epidemiological research has highlighted substantial variations in the prevalence of these risk factors across different populations. However, there is a lack of epidemiological studies assessing exclusive cardiovascular risk factors within vulnerable neighborhoods characterized by extremely limited economic resources, sociocultural challenges, and inadequate healthcare access. METHODS: A multicenter cross-sectional observational study was conducted among individuals residing in economically deprived and marginalized communities, including informal settlements and underprivileged neighborhoods. Simple random sampling of households was employed. Blood pressure measurements, anthropometric assessments, and epidemiological, economic, and sociocultural questionnaires were administered. Results encompass prevalence rates, awareness levels, and blood pressure control across diverse regions. Logistic regression was utilized to identify independent variables influencing primary outcomes. RESULTS: A total of 989 participants were analyzed. The overall prevalence of hypertension was 48.2%. About 82% had a body mass index (BMI) >25. Approximately 45.3% had less than 6 years of formal education. Independent association was established between education levels below 6 years and higher hypertension prevalence. Among hypertensive individuals, 44% were unaware of their condition, with only 17.2% achieving control, correlated with having health insurance and a higher educational background. Merely 24% were receiving combined therapy. CONCLUSION: The prevalence of hypertension within vulnerable neighborhoods is alarmingly high, surpassing rates in other social strata. Knowledge, treatment, and control levels of hypertension are suboptimal, comparable to other populations. Inadequate use of combination therapy was observed. This study underscores the urgent need for targeted interventions addressing cardiovascular risk factors in poor areas to mitigate the burden of CVD.

A numerical coefficient for evaluation of the environmental impact of electromagnetic fields radiated by base stations for mobile communications.

The aim of this study is the development of an Electromagnetic Environmental Impact Factor (EEIF). This is a global parameter that represents the level of electromagnetic impact on a specific area due to the presence of radiating systems, such as base station (BS) antennas for mobile communications. The numerical value of the EEIF depends only on the electromagnetic field intensity, a well-defined physical quantity that can easily be measured or computed. The paper describes the significant parameters of the field distribution adopted to evaluate the EEIF, and the assumptions used to develop a proper scale of values. Finally, some examples of application of the EEIF method are analyzed for real situations in a typical urban area.

Bioimpedance measurements in dentistry to detect inflammation: numerical modelling and experimental results.

Bioimpedance measurements represent an advantageous method to evaluate the physio-pathological conditions of biological tissues and their use is spreading in different application fields, from the evaluation of body composition to the vital signs monitoring, passing through the individuation of cancer tissues and the detection of different substances (e.g. glucose measurements in people affected by diabetes). In fact, tissues electric properties vary with their conditions; for example, electrical conductivity increases when there is an inflammatory process, because of the presence of oedema, hyperaemia and infiltration. Inflammatory phenomena are frequent in dentistry, in diseases like periodontitis and peri-implantitis; however, at present the diagnosis is mainly done with the naked eye, by observing the gingiva redness and swelling. OBJECTIVE: The aim of this work is to prove the feasibility of the inflammation detection by means of bioimpedance measurements. APPROACH: Both numerical simulations and preliminary experimental measurements provide significant outcomes in differentiating between healthy and inflamed tissues. MAIN RESULTS: Percentage differences in the impedance modulus equal to 4-20% (numerical simulations) and 35-56% (experimental measurements), respectively, depending on the considered conditions (e.g. electrodes characteristics and inflammation severity), were found. SIGNIFICANCE: Such a measure could be integrated in electromedical devices designed, for example, for the therapy of peri-implantitis, in order to personalise the therapeutic dose in terms of intensity and duration and focusing it on the impaired area, minimising the effects on the surrounding tissues.

An innovative therapy for peri-implantitis based on radio frequency electric current: numerical simulation results and clinical evidence.

Peri-implantitis is a severe inflammatory pathology that affects soit and hard tissues surrounding dental implants. Nowadays, only prevention is effective to contrast peri-implantitis, but, in recent years, there is the clinical evidence of the efficiency of a therapy based on the application of radio frequency electric current, reporting that 81% of the cases (66 implants, 46 patients) were successfully treated. The aim of this paper is to present the therapy mechanism, exploring the distribution of the electric currents in normal and pathologic tissues. A 3D numerical FEM model of tooth root with a dental implant screwed in the alveolar bone has been realized and the therapy has been simulated in COMSOL Multiphysics® environment. Results show that the electric current is focused in the inflamed zone around the implant, due to the fact that its conductivity is higher than the healthy tissue one. Moreover, by means of a movable return electrode, the electric current and field lines can be guided in the most inflamed area, limiting the interference on healthy tissues and improving the therapy in the area of interest. In conclusion, it can be stated that this innovative therapy would make a personalized therapy for peri-implantitis possible, also through impedance measurements, allowing the clinician to evaluate the tissue inflammation state.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in colorectal liver metastasis: the radiologist's perspective.

PURPOSE: Hepatic resection is the only potentially curative treatment for patients with colorectal liver metastasis (CRLM). Many multidisciplinary approaches, including the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure, have been proposed to increase the resectability rate in these patients. ALPPS is the most recently described staged liver resection technique, representing an advantageous strategy to induce a rapid and marked increase in the future liver remnant (FLR) volume. The aim of this article is to describe the radiological evaluation of this procedure and its variation. METHODS: This retrospective study included 9 patients with CRLM who underwent the ALPPS procedure. Abdominal imaging studies were reviewed, with an emphasis on a rational radiological approach. The number of liver metastases, the FLR volume (pre- and postportal vein ligation), anatomical variations, potential pitfalls related to disease progression, and postoperative complications were evaluated. RESULTS: The types of hepatic resection included 4 classical ALPPS cases, 3 right ALPPS variations, and 2 left ALPPS variations. The mean FLR volume calculated in the initial evaluation was 453 mL (213-790 mL). Following the first surgery, the mean FLR volume increased to 634 mL (410-957 mL), which indicated a mean volume increase of 181.1 mL (95% CI 149.7-212.5 mL; p < 0.001) and a mean absolute volume increase of 48% (19%-88%). CONCLUSION: The ALPPS procedure is an emerging form of two-stage hepatectomy. In this context, radiologists should provide crucial preoperative and perioperative information that may change surgical planning and contribute to an improvement in the oncologic outcome.

Macaque ventral premotor cortex exerts powerful facilitation of motor cortex outputs to upper limb motoneurons.

The ventral premotor area (F5) is part of the cortical circuit controlling visuomotor grasp. F5 could influence hand motor function through at least two pathways: corticospinal projections and corticocortical projections to primary motor cortex (M1). We found that stimulation of macaque F5, which by itself evoked little or no detectable corticospinal output, could produce a robust modulation of motor outputs from M1. Arrays of fine microwires were implanted in F5 and M1. During terminal experiments under chloralose anesthesia, single stimuli delivered to M1 electrodes evoked direct (D) and indirect (I1,I2, and I3) corticospinal volleys. In contrast, single F5 shocks were ineffective; double shocks (3 msec separation) evoked small I waves but no D wave. However, when the test (T) M1 shock was conditioned (C) by single or double F5 shocks, there was strong facilitation of I2 and I3 waves from M1, with C-T intervals of <1 msec. Intracellular recordings from 79 arm and hand motoneurons (MNs) revealed no postsynaptic effects from single F5 shocks. In contrast, these stimuli produced a robust facilitation of I2 and I3 EPSPs evoked from M1 (60% of MNs); this was particularly marked in hand muscle MNs (92%). Muscimol injection in M1 reduced I waves from F5 and abolished the F5-induced facilitation of late I waves from M1, and of EPSPs associated with them. Thus, some motor effects evoked from F5 may be mediated by corticocortical inputs to M1 impinging on interneurons generating late corticospinal I waves. Similar mechanisms may allow F5 to modulate grasp-related outputs from M1.

Normal high energy phosphate ratios in "stunned" human myocardium.

OBJECTIVES: We sought to investigate whether alterations in cardiac high energy phosphates occur in postischemic "stunned" human myocardium. BACKGROUND: Transient postischemic myocardial dysfunction is a common phenomenon that occurs in a variety of clinical settings in the absence of necrosis, and its pathogenesis is still unclear. Cardiac high energy phosphates are reduced during ischemia, and persistently altered myocardial high energy phosphate metabolism has been suggested as a mechanism contributing to stunning. METHODS: We studied 29 patients with a first anterior myocardial infarction (MI) who underwent successful reperfusion within 6 h of the onset of chest pain. These patients underwent 31P magnetic resonance spectroscopy (MRS) a mean of 4 days after MI for measurement of left ventricular contractility and relative high energy phosphate metabolites. Twenty-one patients underwent a second 31P MRS study a mean of 39 days after MI. Eight volunteers served as control subjects. RESULTS: Global and infarct area wall motion scores improved significantly between the early and late studies. No difference was found between early cardiac phosphocreatine (PCr)/beta-adenosine triphosphate (beta-ATP) ratios in patients and control subjects ([mean +/- SD] 1.51 +/- 0.17 vs. 1.61 +/- 0.18, respectively, p = 0.17) or between early and late study results in patients (1.51 +/- 0.17 vs. 1.53 +/- 0.17, respectively, p = 0.6). For alpha of 0.05, the study had a 90% power to detect a 9% difference. CONCLUSIONS: The results of this study demonstrate normal myocardial PCr/ATP ratios in patients with myocardial stunning after reperfusion and suggest that relative cardiac high energy phosphates are not depleted in stunned human myocardium.

Ultrasonographic abnormalities of the pancreas in IDDM and NIDDM patients.

OBJECTIVE: To evaluate the relationship between the type and duration of diabetes and pancreas size by ultrasonography. RESEARCH DESIGN AND METHODS: Pancreas images of 40 IDDM and 36 NIDDM patients with 0.3-34 yr of disease were compared with those of 60 normal healthy control subjects. RESULTS: The diameters +/- SD of the head, body, and tail of the pancreas in IDDM patients (1.9 +/- 0.3; 0.9 +/- 0.2; and 1.4 +/- 0.2 cm, respectively) were smaller than in NIDDM patients (2.7 +/- 0.4; 1.2 +/- 0.3; and 1.8 +/- 0.4 cm, respectively) and control group subjects (2.4 +/- 0.4; 1.1 +/- 0.3; and 1.8 +/- 0.4 cm, respectively). The pancreatic shrinkage in IDDM patients was clearly evident after 10 yr of the disease. NIDDM patients and control subjects had similar pancreatic dimensions, except for a greater body thickness in NIDDM patients with > 10 yr of disease (1.2 +/- 0.4 vs. 1.1 +/- 0.3 cm). These results were not related to differences in age, sex, and body size. Pancreas image was hypoechogenic in 72.5% of IDDM patients and hyperechogenic in 83.3% of NIDDM patients. CONCLUSIONS: Smaller pancreases in IDDM patients in comparison with NIDDM patients and control subjects were clearly demonstrated only after 10 yr of disease. Patients with NIDDM were not affected by pancreatic dimensions, except for a greater body thickness after 10 yr of disease. Pancreatic echogenicity increased with age.

Diagnosis of herpes simplex encephalitis by magnetic resonance imaging and polymerase chain reaction assay of cerebrospinal fluid.

The early diagnosis of herpes simplex encephalitis (HSE) is essential because early introduction of antiviral therapy can significantly reduce the mortality of this disease. Herpes simplex virus (HSV) DNA detection in cerebrospinal fluid (CSF) samples is a rapid, noninvasive, specific, and highly sensitive method for HSE diagnosis. Neurodiagnostic methods have also been studied for noninvasive diagnosis of HSE. Magnetic resonance imaging (MRI) seems to be the most sensitive of them but it has not been compared to PCR in terms of efficacy for HSE diagnosis. In this study, 17 patients with focal encephalitis were prospectively evaluated by PCR analysis of CSF samples and MRI examination. MRI lesions involving the inferomedial region of one or both temporal lobes were observed in all PCR-positive patients but one. No PCR-negative patient presented with the same pattern of MRI lesions. MRI was also important for the establishment of an alternative diagnosis in three of eight PCR-negative patients. Both methods should be routinely applied in the evaluation of presumed HSE cases.

CT scans of cranial tuberculosis.

Tuberculosis of the central nervous system is still an important cause of death or significant neurologic disability. Prompt diagnosis and early treatment are extremely important to reduce its morbidity and mortality. The main forms of intracranial tuberculosis are represented by tuberculous meningitis, meningeal or parenchymal tuberculomas, and tuberculous abscess formation. Sequelae consist of hydrocephalus, calcifications, and areas of encephalomalacia. Less frequent manifestations include tuberculous osteitis of the skull and tuberculous otomastoiditis. Although MR imaging is in general somewhat more sensitive to the detection of cranial tuberculosis, CT is the diagnostic imaging mainstay in many clinical settings to demonstrate the various aspects of cranial tuberculosis on initial presentation and to monitor the evolution of the disease and response to therapy.

A review of the literature on the use of ultrasonography in schistosomiasis with special reference to its use in field studies. 2. Schistosoma mansoni.

This review presents an outline of the pathology resulting from Schistosoma mansoni infections, and the ways in which it can be investigated. The use of ultrasonography is covered in detail. Ultrasonography can provide direct information about lesions in internal organs, and thus provide information about patterns of morbidity and about the regression of pathological changes after treatment. The method is non-invasive, and can be used under field conditions. Ultrasonography is valuable for the study of hepatosplenic pathology, to detect lesions such as the development of periportal fibrosis and the enlargement of the portal vein, which can indicate the development of portal hypertension. This may lead to a severe outcome, including bleeding from oesophageal varices, which is a principal cause of death from S. mansoni infection. A problem with the use of ultrasonography is that the mild lesions likely to be observed in population surveys are not always easy to assess. Ultrasonography has already been used in a number of epidemiological studies of S. mansoni infection, and has proved to be feasible and useful. However, the methodology used for ultrasound studies has varied considerably, so that it is difficult to make valid comparisons between results obtained in different places or at different times. A standardized methodology for making observations and recording the results is needed if the full potential benefit of using ultrasound in the monitoring of schistosomiasis control projects is to be realised.

Absorbed power distributions from single or multiple waveguide applicators during microwave hyperthermia.

A theoretical model has been developed to calculate the power distributions in biological-like tissues in direct contact with waveguide applicators. A numerical solution of the coupled integral equations is performed by means of their transformation into matrix equations by using the method of moments, where the biological tissue and the applicator are described by two independent matrices. The model permits an accurate evaluation of the electric field at the aperture. The application of this method for the evaluation of arrays is also discussed. Power contour plots produced by applicators routinely used in clinics have been computed and compared with experimental results obtained with tissue-equivalent phantoms for three typical bodies: homogeneous, stratified and inhomogeneous.

Ophthalmic artery aneurysms: an investigation by duplex scan.

With the objective of analyzing the postaneurysmal peak systolic velocity (PSV) in ophthalmic arteries, duplex scanning was analyzed in 28 carotid-ophthalmic artery segments after exclusion of ipsilateral carotid stenosis. For comparison, the angiographic study of the extracranial and intracranial carotid system was utilized as the "gold standard." A subgroup of 7 subjects with 8 ophthalmic arteries with aneurysms identified where the artery leaves the internal carotid artery presented with PSVs significantly reduced (mean PSVs 17.95 +/- 7.99 cm/s) compared to the mean PSVs in the healthy group (27.95 +/- 5.54 cm/s) (p = 0.006). A PSV of less than 19 cm/s offered a sensitivity of 80% and a specificity of 100% in diagnosing ophthalmic artery aneurysms. We conclude that duplex scan is diagnostically useful in the identification of patients with ophthalmic artery aneurysms when severe ipsilateral carotid stenosis is excluded.

Doppler mapping of direct carotid-cavernous fistulae (DCCF).

The aims of this study were to establish Doppler criteria for identifying direct carotid-cavernous fistulae (DCCF), as well as the level of agreement between results obtained by Doppler mapping vs. angiography. Doppler mapping and angiography were used to assess the direction of flow in the superior ophthalmic veins and the resistivity index in the internal carotid arteries of 30 patients with DCCF. Both methods independently demonstrated reverse flow in superior ophthalmic vein ipsilateral to the DCCF in 22 patients and normal flow in another four. The mean resistivity index for internal carotid arteries with ipsilateral DCCF was significantly reduced (p = 0.0001) compared with that for contralateral internal carotid arteries without DCCF. A resistivity index value of 0.495 offered a sensitivity and specificity of 86.6% in diagnosing ipsilateral DCCF. These findings suggest that a resistivity index < 0.495 in the ipsilateral internal carotid artery, with or without reverse flow in the superior ophthalmic vein, is associated with a reasonable probability of diagnosing DCCF.

Colour Doppler ultrasound: a new index improves the diagnosis of renal artery stenosis.

The description of a new index, the renal-segmental ratio (RSR), and the comparison of its performance with other conventional Doppler parameters for the detection of renal artery stenosis (RAS). A total of 96 renal units were studied with angiography and colour Doppler ultrasound (US) independently. The Doppler parameters applied were: 1. renal artery peak systolic velocity (RE-PSV), 2. renal-aortic ratio (RAR), 3. early systolic acceleration (ESA), and 4. renal-segmental ratio (RSR). The angiographic study was used as the "gold standard" for the identification of > or = 50% RAS. The results indicate that RSR (sensitivity: 93.33%, specificity: 89.47%) and RE-PSV (sensitivity: 83.33%, specificity: 89.47%) were the best criteria for RAS diagnosis (p values <0.05). The results show that colour Doppler US is a reliable diagnostic modality for RAS diagnosis. The new index (RSR) improves the effectiveness of the method.

MRI of head and neck paracoccidioidomycosis.

Paracoccidioidomycosis, caused by the dimorphic fungus Paracoccidioides brasiliensis, is the most important systemic mycosis in Latin America. Imported cases have been reported in North America, Asia and Europe, in individuals who lived in endemic areas, sometimes many years before the development of clinical manifestations. The disease causes cutaneous and/or respiratory tract mucosal lesions as well as lymph node enlargement. Involvement of the oropharynx and/or the larynx, either alone or in association with pulmonary involvement, is one of the commonest clinical presentations. On MRI, the major features are mucosal lesions, usually hypointense on T1 weighted images and hyperintense on T2 weighted or fat suppressed images, affecting the oral cavity, oropharynx and larynx, with head and neck lymph node enlargement. Differential diagnosis includes other granulomatous infectious diseases, especially tuberculosis, and cancers such as squamous cell carcinoma and lymphomas.

Ascariasis of the alimentary tract, liver, pancreas and biliary system: its diagnosis by ultrasonography.

BACKGROUND/AIMS: The purpose of this study was to describe the echographic features of Ascaris lumbricoides invasion of the alimentary tract, biliary system, liver and pancreas. METHODOLOGY: We studied 38 patients with roundworm heavy infection whose diagnosis were primarily supported by ultrasonographic examination. RESULTS: Thirty-seven patients were admitted with the following clinical complications: bowel obstruction, intra and extrahepatic dilatation, acute cholecystitis, intrahepatic abscess, acute appendicitis, subphrenic collection and acute pancreatitis. Ultrasound scanning was able to recognize in 30 cases the echogenic, nonshadowing images of the worms as single or multiple strips; in 8 cases, coiled structures and amorphous material were detected. The "inner tube" sign was considered as the most specific one. In two cases the roundworms were displayed within the stomach, a curious finding, up to now never reported in medical literature. CONCLUSIONS: Real-time sonography represents an efficient, reliable and non-invasive diagnostic approach for hepatobiliary, enteric and pancreatic ascariasis.

Management of cervical cancer and surgical-pathological staging (SPS). Report of our clinical case series.

FIGO staging is imprecise in a relevant number of cases of cervical cancer, especially in advanced stages, when the prognosis and the choice of the therapy are most delicate. The Authors examine their case series about the index of correction of FIGO staging after Surgical Pathological Staging (SPS). Surgical Pathological Staging was applied systematically in 788 cases and revealed errors in FIGO staging in 16% of cases at stage I; 77% at stage II; and 96% at stage III. SPS allows a more precise knowledge of neoplastic diffusion and consequently to the elimination of many false advanced stages and to adequate the treatment. Furthermore 5 year survival rate confirms the role of SPS and Surgical therapy alone or combined with Radiotherapy and Chemotherapy in every stages of diffusion of cervical cancer.