Interictal spike localization using a standard realistic head model: simulations and analysis of clinical data

OBJECTIVES

In this paper realistic and standard realistic head models were applied to neural source localization.

METHODS

Three different triangulated head structures; the brain, the skull and the scalp were constructed from MRI information of each patient. For each subject the exact positions of the electrodes were digitized.

RESULTS

The influence of the number of triangles and of the skull conductivity on the accuracy of the method was tested. The use of a standard realistic head model instead of spherical models is proposed in cases where detailed MRI information is not available, and the accuracy of this procedure is tested with dipole simulations. These techniques were applied also to EEG signals from 3 patients with focal epilepsy. In all cases the neural activity was assumed to be confined to a small portion of cortical tissue, so that the neural generator was approximated to a current dipole. The realistic head model localization is discussed on the basis of neuroimaging information.

CONCLUSIONS

We show that the standard realistic head model is two or 3 times better than the spherical model for dipole localization and we propose it as a good alternative to the spherical model for EEG data processing, in cases where full MRI information is not available.

Correlation dimension maps of EEG from epileptic absences

PURPOSE

The understanding of brain activity, and in particular events such as epileptic seizures, lies on the characterisation of the dynamics of the neural networks. The theory of non-linear dynamics provides signal analysis techniques which may give new information on the behaviour of such networks.

METHODS

We calculated correlation dimension maps for 19-channel EEG data from 3 patients with a total of 7 absence seizures. The signals were analysed before, during and after the seizures. Phase randomised surrogate data was used to test chaos.

RESULTS

In the seizures of two patients we could distinguish two dynamical regions on the cerebral cortex, one that seemed to exhibit chaos whereas the other seemed to exhibit noise. The pattern shown is essentially the same for seizures triggered by hyperventilation, but differ for seizures triggered by light flashes. The chaotic dynamics that one seems to observe is determined by a small number of variables and has low complexity. On the other hand, in the seizures of another patient no chaotic region was found. Before and during the seizures no chaos was found either, in all cases.

CONCLUSIONS

The application of non-linear signal analysis revealed the existence of differences in the spatial dynamics associated to absence seizures. This may contribute to the understanding of those seizures and be of assistance in clinical diagnosis.

Extra-adrenal phechromocytoma and renal cell carcinoma--an unusual case of tumour synchronism

We report an unusual case of tumour synchronism combining an extra-adrenal pheochromocytoma and a renal cell carcinoma in a 48-year-old male. The most usual forms of presentation are described in accordance with their clinical significance. We emphasize the diagnostic importance of specific biochemical studies and the accurate anatomical localization of extra-adrenal chromaffin tissue by magnetic resonance imaging (MRI) and scintigraphy with 131 Iodine-methyliodobenzylguanidine (131I-MIBG). Surgical excision was the treatment of choice after the institution of adequate preoperative cardiovascular management. Pertinent features of the natural history of these tumours are described in accordance with their different embryological origin.

Severity of abuse before and during pregnancy for African American, Hispanic, and Anglo women

OBJECTIVE

To describe timing and severity of abuse before and during pregnancy for African American, Hispanic, and white Anglo American women.

FINDINGS

Among 199 abused women, 18.1% of the women were abused during pregnancy but not the year before, 30.2% were abused the year before but not during pregnancy, and 51.8% were abused both the year before and during pregnancy. The timing of abuse did not vary by ethnicity. The three (ethnicity) by three (timing) factorial analysis of variance showed severity of abuse to vary by timing of abuse. Women reporting abuse both before and during pregnancy reported greater severity of abuse on each of the five measures than did women abused only before pregnancy or only during pregnancy.

CONCLUSIONS

Over half (51.8%) of the women reported abuse before and during pregnancy with these women reporting greater severity of abuse on all five severity scores. Timing and severity of abuse did not vary by ethnic group. The majority of women abused during pregnancy were also abused prior to pregnancy, indicating the need for universal screening of all women during each health encounter.

Physiological variability of fluid-regulation hormones in young women

We tested the physiological reliability of plasma renin activity (PRA) and plasma concentrations of arginine vasopressin (P[AVP]), aldosterone (P[ALD]), and atrial natriuretic peptide (P[ANP]) in the early follicular phase and midluteal phases over the course of two menstrual cycles (n = 9 women, ages 25 +/- 1 yr). The reliability (Cronbach's alpha >/=0.80) of these hormones within a given phase of the cycle was tested 1) at rest, 2) after 2.5 h of dehydrating exercise, and 3) during a rehydration period. The mean hormone concentrations were similar within both the early follicular and midluteal phase tests; and the mean concentrations of P[ALD] and PRA for the three test conditions were significantly greater during the midluteal compared with the early follicular phase. Although Cronbach's alpha for resting and recovery P[ANP] were high (0.80 and 0.87, respectively), the resting and rehydration values for P[AVP], P[ALD], and PRA were variable between trials for the follicular (alpha from 0.49 to 0.55) and the luteal phase (alpha from 0.25 to 0. 66). Physiological reliability was better after dehydration for P[AVP] and PRA but remained low for P[ALD]. Although resting and recovery P[AVP], P[ALD], and PRA were not consistent within a given menstrual phase, the differences in the concentrations of these hormones between the different menstrual phases far exceeded the variability within the phases, indicating that the low within-phase reliability does not prevent the detection of menstrual phase-related differences in these hormonal variables.

Interactions of new and conventional H3-antagonists with non-histaminergic receptors involved in neurogenic and myogenic contractile responses of guinea-pig ileum

1. Possible effects of new and conventional H3-receptor antagonists towards various non-histaminergic receptors (alpha2-adrenergic, 5-HT3-serotonin, mu-opiate, A1-adenosine, M1-and M3-muscarinic) involved in neurogenic and myogenic contractile responses of guinea-pig ileum are investigated. 2. When the isolated ileum was contracted by the 5-HT3 receptor agonist, 2-methyl-5-HT (5 x 10(-7)-8 x 10(-6) M), acetylcholine (1 x 10(-9)-1 x 10(-7) M), KCl (3 x 10(-2) M) or electrical stimulation some of the drugs, included thioperamide and clobenpropit, reduced the contractile response when tested at micromolar concentrations (1-3 x 10(-5) M) (only compound IV exhibited an M3 competitive antagonism with a pK(B) = 5.49 +/- 0.18). 3. Ileal twitch responses to electrical stimulation were dose-dependently inhibited by the selective agonists clonidine (3 x 10(-10)-1 x 10(-7) M), dermorphin (1 x 10(-11)-1 x 10(-8) M), R-N6-(2-phenylisopropyl)-adenosine (1 x 10(-9)-3 x 10(-8) M) and McN-A-343 (1 x 10(-7)-1 x 10(-5) M) with different potencies and comparable efficacy (spike amplitude reduction > 85%). All the H3 antagonists under study (up to 1 x 10(-5) M) showed no or minor interactions at the neuronal sites except the compound V which behaved as a weak competitive antagonist at alpha2-adrenoreceptors (pK(B) = 5.96 +/- 0.06). 4. In conclusion, both new and conventional H3-blockers interacted at the enteric neuronal sites here studied with a 1000-30,000 fold lower antagonistic potency than that previously reported for the ileal H3 histamine receptors. Their spasmolytic activity precludes firm conclusions about the non-competitive interaction with 5-HT3 ileal receptor which requires further investigations.

Testing an intervention to prevent further abuse to pregnant women

Although violence against women is recognized as a major public health problem, few interventions have been developed to reduce abuse. In this study, 132 pregnant women received three counseling sessions that were designed to reduce further abuse. A comparison group of 67 abused women were offered wallet-sized cards listing community resources for abuse. Women in both groups were followed at 6 months and 12 months post-delivery. Using repeated measures MANCOVA with entry scores as a covariate, we found significantly less violence reported by women in the intervention group than by women in the comparison group.

Bone mineral density and depression: a community study in women

In a community sample of 102 Portuguese white women we evaluated the relationship between osteoporosis and indexes of psychopathology and well-being. Depressive symptoms were assessed by the Beck Depression Inventory (BDI), psychopathology by the Hopkins Symptom Checklist-90 Revised (SCL-90-R), and quality of life using the Psychological General Well-Being Index. A questionnaire comprising social, demographic, clinical, and behavioral characteristics was also used. The sample prevalence of osteoporosis was 47.1%. Women with osteoporosis presented significantly higher scores on the total BDI (16+/-9 vs. 13+/-10, p=0.045) and lower scores in the hostility (0.8+/-0.6 vs. 1.2+/-0.7, p=0.012) and phobic anxiety (1.1+/-0.8 vs. 1.5+/-0.9, p=0.041) subscales of the SCL-90-R. No differences were found regarding mean general well-being scores (62+/-17 vs. 64+/-19, p=0.665). This study showed that women with osteoporosis have significantly higher levels of depressive symptoms and a corresponding higher prevalence of depression, independent of other factors strongly associated with osteoporosis, such as age or body mass index.

The first clinical and epidemiological programme on renal disease in Bolivia: a model for prevention and early diagnosis of renal diseases in the developing countries

BACKGROUND

The prevalence and incidence of renal diseases in developing countries are not known. This lack of knowledge is an obstacle to the adoption of preventive measures which may be of great value in a social and economic environment where treatment options for end-stage renal failure are simply not available to the vast majority of the population. Urinalysis, a simple and inexpensive test, remains a cornerstone in the evaluation of the kidney and may also be easily employed in mass screening for renal abnormalities in a developing country.

METHODS

An educational campaign on renal diseases was conducted in three selected areas of Bolivia. Urine samples were collected and sent to one of 21 participating clinical centers. Fresh urine specimens were screened using a dipstick for chemical analysis and by microscopic urinalysis after centrifugation. In those patients in whom urinary abnormalities were found, further investigations were carried out in order to define the diagnosis; these patients were enrolled in a 3-year follow-up program.

RESULTS

Apparently healthy subjects (n = 14,082) were referred to the First Clinical and Epidemiological Program of Renal Diseases from rural and metropolitan areas in Bolivia. Urinary abnormalities were detected in 4261 subjects at first screening. The most common form of urinary abnormality was hematuria, which was found in 2010 (47% of positively screened subjects). Other renal abnormalities were leukocyturia (41%) and proteinuria (11%). Confirmatory tests and further clinical studies were then carried out in 1019 people. On a second screening 35% of the subjects had no urinary abnormalities; in the remaining people the following diagnosis were made: asymptomatic urinary-tract infection (48.4%), isolated benign hematuria (43.9%), chronic renal failure (1.6%), renal tuberculosis (1.6%). Other diagnosis were: renal stones 1.3%, diabetic nephropathy 1% and polycystic kidney diseases 1.9%.

CONCLUSIONS

This study helped define for the first time the frequency of asymptomatic renal diseases in Bolivia. It shows that it is possible to screen a large population of patients at relatively low cost, providing the framework for further action that may help in the prevention and timely diagnosis of renal diseases.

[Urinary tract malformations in newborns at the Clinical Maternity Hospital of the University of Chile]

BACKGROUND

The prevalence of urinary malformations at birth is steadily increasing, probably due to the availability of better diagnostic techniques.

AIM

To assess the prevalence of renal agenesis, hidroureteronephrosis and polycystic kidney at birth in the obstetric wards of the University of Chile Clinical Hospital.

PATIENTS AND METHODS

As a part of the Latin American Collaborative Study of Congenital Malformations, 54.039 consecutive births at the Maternity, between January 1982 and December 1997, were studied.

RESULTS

Eighty three newborns had urinary tract malformations (15.3/10,000). Fourteen (2.6/10,000) had renal agenesis, 34 (6.3/10,000) had hidroureteronephrosis and 35 (6.5/10,000) had polycystic kidney. Eleven percent of these children were stillbirths and 35% died in the first days of life. Fifty six percent were male, 34% female and 10% had ambiguous sex. Mean birth weight was 2750 g, mean gestational age was 35.4 weeks and mean maternal age was 28 years old. Twenty three percent of mothers had a history of previous abortions, 8% had a history of stillbirths and 10% a history of metrorrhagia during the first trimester of pregnancy. Twenty five percent of children had a relative with a malformation and 48 children had other associated malformations such as pulmonary hypoplasia, external malformations caused by extreme oligoamnios or internal malformations such as utereral, urinary bladder; uretral or external genitalia agenesis.

CONCLUSIONS

The prevalence of urinary malformations in this hospital was higher than in other hospitals participating in the collaborative study. This difference could be due to an under registration of malformations in other hospitals.

Melatonin receptor ligands: synthesis of new melatonin derivatives and comprehensive comparative molecular field analysis (CoMFA) study

The CoMFA methodology was applied to melatonin receptor ligands in order to establish quantitative structure-affinity relationships. One hundred thirty-three compounds were considered: they were either collected from literature or newly synthesized in order to gain information about the less explored positions. To this end, various melatonin derivatives were prepared and their affinity for quail optic tecta melatonin receptor was tested. Compounds were aligned on the putative active conformation of melatonin proposed by our previously reported pharmacophore search, and their relative affinities were calculated from the displacement of 2-[125I]-iodomelatonin on different tissues expressing aMT receptors. Compounds were grouped into three sets according to their topology. Subset A: melatonin-like compounds; subset B: N-acyl-2-amino-8-methoxytetralins and related compounds; subset C:N-acyl-phenylalkylamines and related compounds. CoMFA models were derived for each set, using the steric, electrostatic, and lipophilic fields as structural descriptors; the PLS analyses were characterized by good statistical parameters, taking into account the heterogeneity of the binding data, obtained with different experimental protocols. From the CoMFA model for the melatonin-like compounds, besides the well-known positive effect of 2-substitution, a low steric tolerance for substituents in 1, 6, and 7, and a negative effect of electron-rich 4-substituents were observed; the information provided by the newly synthesized compounds was essential for these results. Moreover, a comprehensive model for the 133 compounds, accounting for a common alignment and a common mode of interaction at the melatonin receptor, was derived (Q2 = 0.769, R2 = 0.905). This model validates our previously reported pharmacophore search and offers a clear depiction of the structure-affinity relationships for the melatonin receptor ligands.

[Detection of HIV antibodies in pooled sera]

The use of sera mixtures for the detection of HIV antibodies was studied in a population of low prevalence (0.006%), using the diagnosis systems of national production: Recombinant HIV UMELISA and RECHIV 1 + 2. The systems were evaluated with individual samples and mixtures of 5 and 10 sera from healthy blood donors and from HIV-1 and/or HIV-2 positive and undetermined persons. It was observed that the utilization of mixtures of 10 sera is not feasible; however, the use of mixtures of 5 affects neither the specificity nor the sensitivity of the systems studied.

Severity of abuse to pregnant women and associated gun access of the perpetrator

To investigate the relationship between abuse to pregnant women and gun access by the abuser, an ethnically stratified cohort of 199 pregnant abused women (70 African-Americans, 63 non-Hispanic Anglo-American, and 66 Hispanic women were interviewed using: (1) The Index of Spouse Abuse, a measure of the severity of physical and nonphysical abuse; (2) The Danger Assessment Scale, a measure of potential danger of homicide; and (3) The Severity of Violence Against Women Scale, a measure of threats of violence and actual violence. There were no significant differences by ethnicity among the 41.2% of the abused women who reported that their male partner had access to a gun. Among these same women reporting gun access, 17% reported the abuser kept the gun on his body. Women reporting gun access by the abuser reported higher level of abuse on all scaled instruments (P = < 0.01). To protect women's safety and prevent further trauma and potential homicide, routine assessment for abuse and gun access is recommended. Additionally, policy initiatives to remove firearms from abuse perpetrators may reduce the severity of violence experienced by abused women.

[Mutations of the p53 suppressor gene in gastric adenocarcinoma]

BACKGROUND

We have shown numeric alterations such as hyperploidy and hypoploidy with loss of chromosome 17 in primary gastric cancer. This chromosome maps p53 suppressor gene that induces the transcription of genes related to cellular cycle control, DNA synthesis and repair, cellular differentiation and apoptosis.

AIM

To analyze, at a molecular level, the possible alterations of p53 suppressor gene in samples of gastric cancer and non tumoral mucosa.

MATERIAL AND METHODS

Tissue samples of gastric carcinoma and non tumoral gastric mucosa coming from 26 patients subjected to a total gastrectomy were analyzed. The mutation of p53 suppressor gene exons 7 to 9 were determined using a conformational polymorphism analysis in single strands of the gene and indirect sequencing in some cases.

RESULTS

Alterations in p53 gene were found in 77% of tumoral and 19% of non tumoral samples. T insertions in codons 260, 317 and 321, G insertion in codon 328 and G-T transvertion in codon 302 were found. Aminoacid sequence analysis of p53 protein obtained with sequencing data showed that T insertion in codon 260 could translate three erroneous aminoacids after the mutation and produce a truncated protein due to the creation of a stop codon. No associations between alterations of p53 gene and clinical or pathological variables such as age, sex, tumor localization, histological type and presence of lymph node metastases were observed.

CONCLUSIONS

Mutations of p53 suppressor gene are frequent in gastric carcinoma.

Cause of hoarseness in elderly patients

Hoarseness is a common symptom in older individuals and may reflect a wide variety of pathologic, medical, physiologic, and/or functional causes. Although vocal fold atrophy is one of the more common reported findings in the elderly, inconclusive information is known about the differential diagnosis and cause of dysphonia in older individuals. The purpose of this investigation was to review the cause of hoarseness in all patients older than 65 years and to determine any correlation with advancing age and other demographic factors. Additionally, we wanted to determine the effect vocal pathology has on objective voice measures with advancing age. The two most common causes of hoarseness found in 393 patients older than 65 years were vocal fold bowing and unilateral vocal fold paralysis, followed by benign vocal fold lesions, voice tremor, and spasmodic dysphonia. Although objective measures of vocal function were abnormal compared with reported normative data, they did not increase in severity with advancing age. Apparently, the compounding effect of age on underlying vocal pathology does not increase the severity of the vocal disturbance, at least as represented by objective voice measures. The high incidence of medical illnesses seen in this population also needs to be kept in mind because it may further affect the underlying voice disturbance. It might be interesting to compare data on the patients' perceptions of their vocal disturbance for each disorder as a function of age. It would also be helpful to know whether patients responded to treatment differentially based on age.

Combined effect of two different polymorphic sequences within the beta globin gene cluster on the level of HbF

Beta thalassemia and Hb Lepore heterozygotes included in this study exhibit fetal hemoglobin levels varying from trace quantities to 14% (1.74 g/dl) of total hemoglobin in the adult. In this work, we have examined the correlation of DNA sequence polymorphisms with the observed HbF level. The analysis of polymorphic markers within the beta globin cluster in 39 individuals heterozygous for beta thalassemia or Hb Lepore confirms the previous findings for homozygous beta thalassemia: the presence of both an (AT)9 T5 sequence configuration at position -540 of the beta globin gene and a (C --> T) variation at -158 of the Ggamma globin gene is associated with elevated expression of HbF. However, at least one defective beta globin gene is required to reveal this association. The best evidence is from the study of individuals heterozygous for Hb Lepore with various levels of HbF. In these individuals it was possible to explore the effect of a single (AT)x Ty motif (the other being absent from the rearranged Lepore chromosome) on HbF expression. The presence of the (AT)9 T5 configuration increases HbF level from a median of 0.515 g/dl observed in (AT)7 T7 subjects, to 1.39 g/dl. We confirm the existence of linkage disequilibrium between the (C --> T) variation at -158 of Ggamma gene and the (TG)13 configuration at the second intervening sequence (IVS-2) of Agamma gene and identify two new polymorphisms in this region: (TG)7 (CG)5 (TG)8 linked to haplotype V and (TG)8 (CG)5 (TG)10 linked to haplotype II. This study suggests that two distinct regions of the beta cluster, whether in cis or in trans to each other, can interact to enhance HbF expression when a beta thalassemic determinant is present in heterozigosity.

Violent pornography and abuse of women: theory to practice

To examine violent pornography use and associated violence against women, an ethnically stratified sample of 198 abused women were asked about their partners' use of pornographic materials, and if they had been asked or forced to look at, act out, or pose for pornographic scenes or pictures. Overall, 40.9% of the women reported the abuser used pornographic material, with the proportion significantly higher for Whites (58.7%), compared to Blacks (27.1%) or Hispanics (38.5%). When groups were formed according to the abuser's use of pornography and associated involvement of the woman, violence scores as measured on the Index of Spouse Abuse, Danger Assessment, and Severity of Violence Against Women scales were significantly higher (p = <.001) for women reporting the abuser requested or forced her to look at, act out, or pose for pornographic scenes. Severity of violence was not related simply to whether or not the abused used pornography. This analysis is a beginning step toward understanding how pornography influences woman abuse.

Safety behaviors of abused women after an intervention during pregnancy

OBJECTIVE

To evaluate an intervention protocol, administered during pregnancy, for increasing safety-seeking behaviors of abused women.

DESIGN

Prospective, ethnically stratified cohort analysis.

SETTING

Public prenatal clinics.

PARTICIPANTS

Pregnant women reporting physical or sexual abuse in the year before or during the present pregnancy. One hundred thirty-two women met study criteria, received the intervention, and were followed for 1 year after the completion of the pregnancy.

INTERVENTION

Three education, advocacy, and community referral sessions that included information on safety behaviors.

MAIN OUTCOME MEASURE

Adoption of safety behaviors by abused women. Safety behaviors were measured before the intervention, twice during pregnancy, and at 2, 6, and 12 months after completion of the pregnancy.

RESULTS

Repeated measures analysis of variance showed a significant increase in adoption of each safety behavior (p < .0001), with most behaviors showing a significant increase after the first intervention session.

CONCLUSIONS

Pregnant women who were abused and were offered an intervention protocol report a significant increase in safety behavior adoption during and after pregnancy. Abuse during pregnancy is common. Identification of abuse and immediate clinical intervention that includes information about safety behaviors can result in safety behavior adoption that may prevent future abuse and increase the safety and well-being of women and infants.

Symptoms of post-traumatic stress disorder in abused women in a primary care setting

Abuse is a major source of trauma to women, and post-traumatic stress disorder (PTSD) results from exposure to extreme trauma. To describe the relationship between symptoms of PTSD and severity of abuse, an ethnically stratified cohort of 131 abused women in a primary care setting was interviewed. Symptoms of PTSD, both intrusion (i.e., trouble falling asleep, strong waves of feelings about the abuse) and avoidance (i.e., trying not to think or talk about the abuse, staying away from reminders of the abuse), were significantly (p < 0.01) correlated to severity of abuse, regardless of ethnicity. When asked about childhood physical or sexual abuse, women reporting physical abuse had significantly (p < 0.05) higher intrusion scores, whereas those reporting sexual abuse had significantly (p < 0.004) higher avoidance scores. Sixty-five percent of the women reported dreams, flashbacks, or terror attacks and had significantly (p < 0.001) higher mean results on both intrusion and avoidance. The need to offer abused women information about the connection between severity of abuse and symptoms of PTSD is discussed. We recommend that clinicians ask all abused women about dreams, flashbacks, or terror attacks to assess for further symptoms of PTSD.

Isochromosome 14q in refractory anemia

Trisomy 14 in hematologic disease is a rare finding and is almost exclusively associated with myeloid cell lineage. We present a case of refractory anemia (MDS-RA) with the uncommon features of marked elliptocytosis and schistocytosis in the peripheral blood and isochromosome 14q. The analysis of the clinical outcome of this case and of others of myelodysplastic (MDS)/myeloproliferative syndromes with trisomy 14 as the sole abnormality suggests that it does not confer an unfavorable prognosis.

Clinical correlates of interferon gamma production in patients with tuberculosis

To determine if the capacity to produce interferon (IFN) gamma is related to the clinical manifestations of tuberculosis, we correlated Mycobacterium tuberculosis-induced IFN-gamma production by peripheral blood mononuclear cells (PBMCs) with clinical, radiographic, and laboratory variables for 63 human immunodeficiency virus (HIV)-negative patients and 43 HIV-positive patients with tuberculosis. For HIV-negative patients whose chest radiographs showed moderately advanced disease, the mean IFN-gamma concentration +/- SD was 1,639 +/- 388 pg/mL, whereas that for patients with far-advanced disease was 327 +/- 100 pg/mL (P = .0001). For HIV-infected patients who had only pleuropulmonary disease, the mean IFN-gamma concentration was 1,002 +/- 257 pg/mL, whereas that for patients with disease outside the lungs and pleura was 149 +/- 55 pg/mL (P = .0004). Multivariate analysis confirmed that the radiographic extent of disease and the site of disease were the only independent predictors of IFN-gamma production in HIV-negative and HIV-infected patients (P < or = .001). We conclude that reduced IFN-gamma production by PBMCs is a marker of severe tuberculosis in both HIV-negative and HIV-infected patients with tuberculosis.

H3-receptor antagonists: synthesis and structure-activity relationships of para- and meta-substituted 4(5)-phenyl-2-[[2-[4(5)-imidazolyl]ethyl]thio]imidazoles

We report the synthesis, octanol/water partition coefficient (log P), dissociation constants (pKa), H3-receptor affinity (pKi in rat brain membranes, [3H]-N alpha-methylhistamine), and H3-antagonist potency (pA2 in guinea ileum, (R)-alpha-methylhistamine) of novel H3-receptor antagonists obtained by introducing a para or meta substituent on the phenyl ring of the lead compound 4(5)-phenyl-2-[[2-[4(5)-imidazolyl]ethyl]thio]imidazole (3a). The substituents were chosen to obtain broad and uncorrelated variation in their lipophilic, electronic, and steric properties. The log P values of the neutral species cover almost 3 orders of magnitude (from 1.40 to 4.11). The pKa,2 values (protonation of the 2-thioimidazole fragment) vary from 3.13 to 4.34, indicating that this fragment, which incorporates the so-called polar group common to many H3-receptor antagonists, is neutral at physiological pH. The compounds had pKi values in a range too narrow (from 7.28 to 8.03) to derive QSAR equations. In one case (3g), a biphasic displacement curve was observed (pKi,1 = 8.53; pKi,2 = 6.90). The pA2 values ranged 2 orders of magnitude (from 6.83 to 8.87) and yielded a QSAR model (PLS) indicating that antagonist potency depends parabolically on lipophilicity and is decreased by bulky para substituents. The compounds of this series, therefore, maintain a fair-to-good affinity for rat brain H3-receptor and a fair-to-good H3-antagonist potency on guinea pig ileum, although varying markedly in their lipophilicity. The series thus appears as a good candidate for pharmacokinetic optimization leading to brain-penetrating H3-receptor antagonists.

Resource use by abused women following an intervention program: associated severity of abuse and reports of abuse ending

Although violence against women is recognized as major public health problem, little is known about the effectiveness of interventions. To evaluate severity of abuse and use of community resources following an intervention program, 132 pregnant abused women received three counseling sessions in a prenatal setting. A comparison group of 67 abused women were offered a wallet-sized card listing community resources for violence. Resource use, severity of abuse, and reports of the abuse ending were measured for both groups at 6 and 12 months after delivery. Resource use was significantly (p < .001) related to severity of abuse, irrespective of whether the woman had received the intervention. Women using resources at 6 months were also users at 12 months. These findings indicate a "survivorship model" whereby abused women assertively and persistently seek a variety of community resources to end the abuse. The recommendation that primary care providers go beyond traditional identification and referral for abuse to coordination and evaluation of service delivery is discussed.

Plasma concentration and brain penetration of the H3-receptor antagonist thioperamide in rats

Thioperamide is a potent and selective H3-receptor antagonist, whose in vivo effects have been reported after systemic administration. Some questions have arisen about its ability to cross the blood-brain barrier, since different experimental conditions have given different results in rats, namely a low brain/blood ratio at low doses (10 mg/Kg) and a much higher one at higher doses (60 mg/Kg). In this work we demonstrate the dose-dependence of thioperamide pharmacokinetics, measuring its plasma and cerebral levels after i.p. administration of different doses to rats. Both the plasma half-life and brain penetration of thioperamide resulted as being dose-dependent: when administered to 80 g body weight Wistar rats at 10 mg/Kg i.p., the drug has a short half life (120') and a rather poor brain penetration, but increasing the dose (to 20, 40 and 60 mg/Kg) gives rise to a prolongation of its persistence in the blood (up to 600' at highest dose) and a higher brain penetration. Also, the profile of the plasma concentration curve varies from the dose of 10 to that of 20 mg/Kg, passing from a mono-exponential decrease to a more complex one characterized by an apparent distribution phase. The different distribution processes can be interpreted in the light of thioperamide protein binding and affinity for lipophilic tissues: protein binding can prevent brain penetration (but not distribution to other tissues) at lower doses, while at higher doses the free plasma fraction increases and it can allow passive distribution to lipophilic tissues such as brain tissues. A re-distribution from these tissues and plasma is probably responsible for the strong increase in half-life at high doses.

In vitro characterization of potency, affinity and selectivity of H3-antagonists: from thioperamide to thioperamide unrelated imidazole derivatives

This paper summarizes the findings obtained for three different series of original compounds designed as potential H3-antagonists starting from thioperamide structure. The compounds were tested in functional and binding assays to estimate their potency, affinity and selectivity for histamine H3 receptors. Among them, many non-thiourea/isothiourea derivatives acted as selective H3 competitive antagonists and, particularly, 4(5)-[2-[4(5)-cyclohexylimidazol-2-ylthio]ethyl] imidazole (dIII) proved to be the most potent H3 blocker vs (R)-alpha-methylhistamine in electrically-stimulated ileum. This imidazole derivative, devoid of thiourea dependent toxic effects, with high affinity displaced biphasically [3H]-N alpha-methylhistamine bound to rat brain H3 sites. Thus, such compound could be proposed as the prototype molecule for the development of new non-thiourea/isothiourea H3-antagonists and as experimental tool to explore the intriguing question of H3 receptor heterogeneity.

Ligands of the histamine H3-receptor: new potent antagonists of the 2-thioimidazole type

An overview of H3-receptor ligands is presented, with particular attention to antagonists. The protein binding of the classical H3-receptor antagonist thioperamide and its effect on in vivo distribution are discussed. A series of H3-receptor antagonists characterised by the presence of an imidazole ring, a spacer (ethylthio-, ethylamino-, propylthio- or propylamino-chain), a second heterocycle nucleus and a lipophilic group is described. Their H3-receptor antagonist potency has been measured on electrically stimulated guinea-pig intestine, and their affinity for central H3-receptor has been determined by competitive inhibition of [3H]N alpha-methylhistamine binding to rat cortex. Biphasic inhibition curves have been observed in some cases. Compounds endowed with interesting activity belong mostly to the class of 2-[[2-[4(5)-imidazolyl]ethyl]thio]imidazole, having a phenyl or a cyclohexyl group.

Gradients of HLA diversity in South American Indians

Information concerning the HLA-A and -B loci was considered in relation to 3796 Amerindians living in 39 places in South America, data related to HLA-C being based on a smaller subset of 2989 persons distributed among 33 localities. Synthetic gene frequency maps were then constructed using principal-components analysis. Clearly significant longitudinal (principal component 1) and latitudinal (principal components 1, 2, and 3) clines were observed, most probably indicating ancient migration routes.

Desensitization of bladder sensory fibers by intravesical capsaicin has long lasting clinical and urodynamic effects in patients with hyperactive or hypersensitive bladder dysfunction

PURPOSE

Capsaicin was used to treat symptomatic patients with hyperactive or hypersensitive bladders.

MATERIALS AND METHODS

Capsaicin solution (1 mM.) was instilled into the bladder of 16 patients with spinal hyperreflexia, bladder instability or hypersensibility.

RESULTS

Frequency decreased in 14 patients and continence was achieved in 10 of 14 incontinent cases. Mean first desire to void and maximal cystometric capacity increased significantly. These effects lasted for 6 to 12 months and were renewed following repeat treatment.

CONCLUSIONS

Bladder afferent desensitization with capsaicin is promising in patients with motor or sensory bladder dysfunction, although initial pungency might limit its use.

[Chronic inflammatory demyelinating polyneuropathy. Report of six cases]

Chronic inflammatory demyelinating polyneuropathy is a heterogeneous disease characterized by symmetrical motor and sensitive alterations, absence of tendon reflexes and increased cerebrospinal fluid protein levels. We report 6 patients with the disease, (three males) aged 41 to 70 years old. Four had the classical presentation and two had an asymmetrical paresis, that predominated in superior limbs. These patients had a proximal block with scarce prolongation of distal nerve conduction velocity. In all patients, underlying illnesses were discarded with a full diagnostic work up. Subjects were followed from 2 to 14 months after the diagnosis. In all, treatment with steroids improved muscle strength and sensitivity.

[Evaluation of the Cell-DYN 35))]

The Cell-Dyn 3500 is an automated haematology analyzer which quantitatively measures and computes haematological quantities including a full "five-part" white cell differential. It measures 22 parameters for erythrocytes, white blood cells and platelets, also giving the respective histograms. Evaluation of the Cell-Dyn 3500 was performed according to the International Committee for Standardization in Haematology (ICSH) norms, for a period of 5 weeks. A total of 1,235 samples were studied by comparison with the Coulter MaxM. The five-part white cell differential and the flagging system were estimated and compared with the smear examination of 506 samples, by four clinical pathologists trained in cytology. Good correlation was obtained within, between batches, and day-to-day, for the following parameters: red blood cells (RBC), haemoglobin (HGB), mean cell volume (MCV), white blood cells (WBC) and platelets (PLT). The accuracy was estimated (RBC, HGB, VGM, WBC and PLT) each day with three different levels of titrated controls with good results. The linearity was established for RBC, HGB, WBC and PLT. The results obtained were good. Carry-over studies were performed according to the Broughton method for the same parameters and the results were also good. Stability studies for the automatic parameters including the differential white blood cell count showed that these parameters were stable at 4 degrees C for 48 hours. At room temperature the stability was reduced to 7 hours. Agreement was good between the Cell-Dyn 3500 and the Coulter MaxM, for the automatic haemocytometric values. The comparative studies between the five-part white cell differential of the haematologic analyzer and the manual differential showed excellent results for neutrophils and lymphocytes, very good for monocytes and eosinophils. For the flag estimation two criteria were established, one based on the clinical significance and the other based on the alarm detection described in the analyzer manual. The specificity was good for both criteria. In general the sensibility was better for the second criteria. The Cell-Dyn 3500 has thus shown to be a good haematology analyser which greatly reduces the morphological examination of smears.

Rat protein binding and cerebral phospholipid affinity of the H3-receptor antagonist thioperamide

The binding of thioperamide, a known H3-receptor antagonist, to rat plasma and proteins and its affinity for rat cerebral phospholipids are investigated. Thioperamide is strongly bound to plasma proteins (95-80% at plasma concentrations of 3.5-400 micrograms mL-1), and its binding can be resolved into two components a high-affinity, saturable component and a non-specific component. The drug has a high affinity for cerebral phospholipids, with a partition coefficient of approximately 100 (log K = 2.06 +/- 0.14), which should promote brain penetration and accumulation. Protein binding and cerebral phospholipid affinity can suggest the explanation of some differences reported in the literature on thioperamide distribution data: at low plasma concentrations of the drug, its protein binding (95% at 3.5 micrograms mL-1) can prevent brain accumulation, while at higher concentrations the free plasma fraction suddenly increases (> 10% at 18 micrograms mL-1) and it allows passive distribution to lipophilic tissues such as brain tissue.

[Localization of brain electric sources in patients with focal epilepsy]

In this paper we discuss a non-invasive method to localize neural electrical sources using EEG data. In this method, the human head is modelled by a set of four concentric spheres with different conductivities which represent the scalp, the skull, the CSF and the brain or by three triangulated surfaces which approximate the exact head shape (in this model we do not consider the CSF layer) using NMR images. In this case the computer effort is very high, since the calculations imply thousands of equations. Therefore, the number of research groups working with this improved model, in the world, is very small. In both models, we assume that the neural source is a current dipole. This makes the model suitable for cases where the active brain areas are limited and localized. We discuss some error factors associated with the method, as the geometry of the head, the conductivity of the different layers and the number of electrodes used in the EEG measurements. Comparing the more realistic head model, with the spherical one we often have differences of 1-2 cm. However, we can reach even more pronounced differences in the frontal areas. Concerning the skull conductivity, we realized that it could introduce errors of 1-2 cm. We observed that at least 50 electrodes should be used only since 21 electrodes could imply errors of about 0.5 cm. The method was applied, both in the spherical version and the realistic one, to clinical cases of focal epileptic patients. The results are discussed in terms of the other clinical information available and they are coherent with the remaining clinical data.

Biological studies on 1,2-benzisothiazole derivatives V. Antimicrobial properties of N-alkanoic, N-arylalkanoic and N-aryloxyalkanoic derivatives of 1,2-benzisothiazolin-3-one: QSAR study and genotoxicity evaluation

N-alkanoic, N-arylalkanoic and N-aryloxyalkanoic acids of 1,2-benzisothiazolin-3-one, esters and amides of N-arylalkanoic and N-aryloxyalkanoic acids and 1,1-dioxide derivatives of N-arylalkanoic acids and esters were investigated in vitro antimicrobial activity. N-arylalkanoic and N-aryloxyalkanoic acids (compounds 4-12) and their esters and amides (compounds 13-26) exhibited a good antimicrobial activity against Gram positive bacteria, with several compounds showing potencies 10-20 times higher than 1,2-benzisothiazolin-3-one. None of the chemicals tested inhibited the growth of E. coli. Yeasts and moulds possess a considerable susceptibility to compounds 12-23. The logP (octanol-water) of esters and amides of N-arylalkanoic and N-aryloxyalkanoic acids were measured by the shake-flask technique and the potencies against Gram positive bacteria of the compounds tested was related to their lipophilicity. QSAR analysis showed a bilinear relation, with a logD0 around 3 for the activity on B. subtilis. The phenoxyacetic and phenoxybutyric acid derivatives are positive outliers, showing a potency higher than that predicted from their lipohilicity. The most active compounds were further tested against different Gram positive bacteria and moulds, including Bacilli, Sarcina lutea, Staphylococcus epidermidis, Candida spp. and dermatophytes. The antibacterial and antifungal activity was specific for 1,2-benzisothiazolin-3-ones, the corresponding 1,1-dioxide derivatives being inactive. The genotoxic properties of the compounds studied were evaluated by the Bacillus subtilis rec-assay and Salmonella-microsome test. None of the compounds showed DNA-damaging or mutagenic activity.

On-site storage of high level nuclear waste: attitudes and perceptions of local residents

No public policy issue has been as difficult as high-level nuclear waste. Debates continue regarding Yucca Mountain as a disposal site, and-more generally-the appropriateness of geologic disposal and the need to act quickly. Previous research has focused on possible social, political, and economic consequences of a facility in Nevada. Impacts have been predicted to be potentially large and to emanate mainly from stigmatization of the region due to increased perceptions of risk. Analogous impacts from leaving waste at power plants have been either ignored or assumed to be negligible. This paper presents survey results on attitudes of residents in three counties where nuclear waste is currently stored. Topics include perceived risk, knowledge of nuclear waste and radiation, and impacts on jobs, tourism, and housing values from leaving waste on site. Results are similar to what has been reported for Nevada; the public is concerned about possible adverse effects from on-site storage of waste.

Testing for human immunodeficiency virus infection in patients with tuberculosis

To investigate the utility of testing all tuberculosis patients for HIV infection in Los Angeles, we prospectively evaluated 183 hospitalized patients with acid-fast smear-positive tuberculosis who gave no history of HIV infection. HIV serologic testing was performed, and the presence of risk factors for HIV infection was assessed by interview and review of the medical record. Thirty-three patients (18%) were infected with HIV. Based on data obtained by interview, 124 (68%) of 183 patients had at least one risk factor for HIV infection. The most common risk factors were related to heterosexual transmission of HIV (prostitute contact, multiple sex partners, and a history of sexually transmitted disease). These risk factors were frequently not documented in the medical record. Among the 33 patients who were infected with HIV, 30 were identified by interviewing as having significant risk factors. We concluded that most tuberculosis patients in Los Angeles have risk factors for HIV infection and that systematic questioning does not identify risk factors in all HIV-infected tuberculosis patients. These data support current recommendations to screen all tuberculosis patients for HIV infection.

Inhibition of small intestinal motility by casein: a role of beta casomorphins?

Several aspects on the effect of nutrients on small intestinal motility are not completely understood. We have analyzed changes of motor activity of the canine small bowel following intragastric administration of casein and soy protein. Studies were performed by intraluminal manometry with external transducers and multiple infused catheters with closely spaced registrating sites. Casein was followed by a statistically significant decrease of amplitude and frequency of small intestinal contractions, compared to soy protein. Pretreatment with naloxone suppressed the inhibitory effect of casein, suggesting that stimulation of opioid receptors by beta casomorphins, a product of digestion of casein, might be involved in the motility changes observed.

[Major histocompatibility system as a risk factor for alcoholic liver disease]

Several associations between alleles of the major histocompatibility system and alcoholic liver disease have been described. However, these are weak and change from one population to another. The aim of this work was to search for a possible genetic risk factor for alcoholic liver disease among Chilean alcoholics. We studied blood groups, serum proteins and HLA antigens in 39 alcoholic cirrhotics, 104 asymptomatic alcoholics and 44 non alcoholic controls. Asymptomatic alcoholics were also subjected to a percutaneous liver biopsy that showed moderate to severe histological liver damage in 46 subjects (44%). No differences in the studied genetic markers, were found among the four groups. It is concluded that this study does not confirm previously reported associations between genetic markers and alcoholic liver disease.

Phase I clinical trial in cancer patients of a new monoclonal antibody FC-2.15 reacting with tumor proliferating cells

FC-2.15 is a new murine IgM monoclonal antibody (MAb) that recognizes previously undescribed antigens present in proliferating breast cancer cells and normal peripheral granulocytes. A phase I clinical trial was performed in 11 patients with advanced cancer (breast, 5; colon, 2; melanoma, 1; lung, 1; medullary thyroid, 1; skin squamous carcinoma, 1). FC-2.15 was administered by i.v. infusion every other day; eight patients received four infusions, two patients three infusions and one patient received two infusions. One patient received two cycles of treatment. Total doses of MAb ranged between 2.5 and 5 mg/kg. Maximal FC-2.15 serum concentrations for different patients ranged between 1.3 and 7.5 micrograms/ml, and the serum half-life (t1/2-alpha) was approximately 7-9 h. All patients developed human anti-murine antibody. The most consistent toxicity (10 of 11 patients) was a profound and selective neutropenia that occurred within 1 h after the start of each infusion and reversed within 1 h after its discontinuation. Other frequent side effects included fever and chills that were easily manageable. Only two patients needed dose reduction or treatment interruption. The patient who received two treatment cycles did not develop allergic reactions. An objective partial response, consisting of a sustained (4 months) > 50% reduction of breast carcinoma liver metastases, was observed.

[Neurosyphilis and human immunodeficiency virus (HIV-1)infection. Experience with 6 cases]

HIV infected population has a higher incidence of syphilis, being this an independent risk factor for HIV infection. We report 88 HIV infected patients seen during the last three years. Fourteen (16%) had reactive serum VDRL and FTA-ABS and neurosyphilis was diagnosed in six (6.8%). Three had a treponemal uveitis-retinitis, one a meningovascular syphilis and one a secondary syphilis with meningeal and otological involvement. Patients were treated with penicillin 20 million UI/day for 14 days with good clinical and laboratory response and CSF normalization in those subjected to a second lumbar puncture. It is concluded that neurosyphilis must be considered in the differential diagnosis of neurological complications of HIV infections.

QSAR study on H3-receptor affinity of benzothiazole derivatives of thioperamide

Starting from the structure of thioperamide, a known H3-antagonist, a new series of compounds with a benzothiazole nucleus instead of the cyclohexylcarbothioamide moiety was synthesized. Various substituents, selected by experimental design, were introduced in position 6 of the benzothiazole nucleus, in order to change its physico-chemical characteristics. The lipophilicity of the synthesized compounds was measured by means of RP-HPLC, and their H3-receptor affinity was evaluated by competitive binding assays on rat cortex synaptosomes, with the labelled ligand N alpha-[3H]methylhistamine. A QSAR analysis was performed on the experimental data, using also substituent constants taken from the literature. The newly synthesized compounds showed lower H3-affinities than thioperamide; quantitative structure-activity relationships, described by models obtained with PLS and MRA techniques, were observed among benzothiazole derivatives. According to these relationships, any attempt to improve the potency of these compounds should involve the substitution of the benzothiazole moiety with less bulky and/or more flexible structures, which should also be less lipophilic and allow better electronic interactions with the binding site. 1-(Benzothiazol-2-yl)-4-[(1H)-imidazol-4-yl]piperidine represents a limit structure for H3-activity, since it seems impossible to improve its affinity by means of substitution in the studied position of the benzothiazole nucleus, as shown by predictions performed by a PLS model.

[Temporal lobectomy in refractory partial epilepsy. Report of 4 cases]

Thirty, out of 1200 patients of North Santiago Adult Epilepsy Program, were admitted to J J Aguirre Hospital due to refractory epilepsy. Looking for candidates for functional epilepsy surgery, these patients were evaluated by neurologists, psychiatrists and psychologists and with standard EEG, video monitored EEG, CAT scan, magnetic resonance imaging and SPECT. So far, four patients with temporal partial complex epilepsy have been studied, operated (anterior temporal lobectomy and amygdalo-hippocampectomy) and followed for more than one year. Of these, two are free of seizures, one has sporadic episodes and one has an important reduction. One of these patients had a postoperative amnestic syndrome of 3 to 4 weeks duration. According to these results and those reported in the literature, the rigorous selection of patients that could be benefitted by surgery is emphasized.

Quality in obstetrics using a telematic system

A telematic based system for antenatal care has been developed to be used in service integration between primary and secondary health care units. The system is based on low cost platforms and has a user friendly human computer interface. This system will provide better integration and coordination between the health care providers involved, improving the quality of the services. This experiment is being funded in the framework of the EC.Project-A 2007-EPIC. Quality indicators, agreed in the "European concensus conference of quality indicators for perinatal care", organized in conjunction with OBSQID project (AIM.2125) were integrated in the system. Data collection has started and the outcome will be used to validate the indicators on a transeuropean basis under the framework of the OBSQID Project.