[Relationship between physicians and HIV patients: influence on adherence and quality of life]

OBJECTIVE

To assess the influence of the relationship between people living with HIV/AIDS and health care providers on treatment adherence and quality of life.

METHODS

Qualitative study conducted in Mexico, in 2003, with informants recruited from HIV/AIDS support groups, non-governmental organizations, and infectious disease clinics in public hospitals. A total of 40 people living with HIV/AIDS and five support group leaders were interviewed. Data were collected using sociodemographic questionnaires and in-depth interviews exploring the experience of living with HIV/AIDS, including treatment, disease perception, quality of life, physical and emotional health, and relationship with physicians. Responses were recorded, transcribed and organized thematically based on codes using an inductive analysis.

RESULTS

Most respondents aged between 26 and 45 years. The main obstacles to care were related to lack of risk awareness and information among people living with HIV/AIDS and physicians. Physicians proved not to be well trained on HIV/AIDS care. During the follow-up care, most problems were related to inadequate treatment adherence mainly caused by poor communication with physicians and discrimination in public services.

CONCLUSIONS

Overall the problems identified were related to information deficiencies, physicians' lack of training and paternalism, and social stigmatization of people living with HIV/AIDS associated with the epidemic.

[Migraine with aura and patent foramen ovale. A different clinical entity]

INTRODUCTION

This work has aimed to evaluate the prevalence of patent foramen ovale in subjects with migraine with aura by transcranial contrast doppler and to describe the clinical and risk profile of these patients.

METHOD

We performed a transcranial contrast doppler in 94 consecutive out-patients with migraine with aura (MWA) in a neurology outpatient clinic. They were divided into two groups according to the presence of patent foramen ovale: MWA_RLsh (with right-to-left shunt) and MWA_RLNsh (without right-to-left shunt). Differences between the groups were analyzed according to endpoints of age, gender, clinical severity, aura type and attacks frequency, comorbility, cardiovascular risk factors (CVRFs), neuroimaging findings, severity of shunt and treatment.

RESULTS

n=94; MWA_RLsh: 47 (54%). MWA_RLNsh: 40 (46%). Age: 33.13; standard desviation (SD): 10.8 vs 33.496; SD: 11.2; p=0.728. Female: 66 vs 72.5%; p=0.511. Visual aura: 73.9% vs 78.9%; p=0.921. There were no significant differences in regards to the risk factors studied or to the comorbid diseases that are associated to migraine. The patients with patent foramen ovale have an odds ratio (OR) of ischemic stroke: 1.189 (95% confidence interval [CI]: 0.226 to 6.248; p=0.840), OR for subclinical brain lesions in cranial magnetic resonance imaging (MRI): 0.589 (95% CI: 0.193 to 1.799; p=0.35) and OR for combined previous ischemic stroke and subclinical brain lesions: 0.745 (95% CI: 0.261 to 2.129; p=0.58). Migraine attack frequency >1 per month: 27.9 vs 36.4; p=0.464. Need for prophylaxis therapy: 44.7 vs 57.7%; p=0.284.

CONCLUSIONS

Both groups are similar regarding their clinical profile. We did not find a greater prevalence of stroke or silent brain lesions in the group with positive shunt..

[Women who are left behind: the impact of international migration on the process of seeking health care]

OBJECTIVE

To analyze how women who are left behind seek care in communities with a high migration index.

MATERIAL AND METHODS

This is a cross-sectional study which used a qualitative approach. Sixty in-depth interviews were conducted between October 2004 and May 2005 with female partners of migrants in two communities (urban / rural) from a region in central Mexico with high migration to the United States.

RESULTS

Migration determines two forms of familial reorganization: one in which female partners of migrants reintegrate with their families; and one in which they remain on their own. Women who reintegrate with their families receive more support, but are also subjected to more control, rendering them with less capability to seek care, particularly related to sexual and reproductive health. Women who remain on their own have less support but have more control and capacity to seek care, with privacy and independence.

CONCLUSIONS

The familial reorganization influences timely health care-seeking behaviour of female partners of migrants. The situations identified can function as obstacles or facilitators to mobilize healthcare resources.

[Stroke in the very old. Care in neurology units versus others general medical ward]

INTRODUCTION

The aim of this study is to compare the diagnosis, management, clinical course and outcome of the very major patients with acute stroke in our sanitary area.

METHOD

Retrospective collection of data from a hospital-based registry, between January 2002 and March 2004, 130 stroke patients aged 84 and older admitted consecutively. We compared the patients admitted to the neurology unit (NU) to those admitted to other services (GWs). Demographic analysis, risk factors, morbidity to hospital admission (dementia, cancer, previous stroke and laboratory variables), neurological deficit measured for Canadian Neurological Scale (CNS) score, diagnostic studies, length of stay, outcomes variables (in-hospital mortality, complications developed during hospitalization and Rankin scale at hospital discharge) and need for institutionalization were analyzed.

RESULTS

from a total of 130 patients, 44 (34,1 %) admitted to NU and 85 (65,9 %) to GWs. No difference was seen in demographic analysis, risk factors, morbidity to hospital admission, neurological deficit and outcomes variables. Length of stay was 8,4 days; 5,5 in the NU and 12,87 days among patients in the GWs (p=0,0001). There are significant differences in diagnostic studies in favor to NU (p < 0,05). Among the patients admitted into GWs the percentage of institutionalization to the discharge was of 28,8 % opposite to 5,6 % in the NU (p=0,006).

CONCLUSIONS

There are not evidences of age discrimination for access to neurological units for demographic, risk factors, morbidity or neurological deficit. The diagnostic process is more rigorous and less costly in the NU than in the GWs.

HIV prevention and men who have sex with women and men in México: findings from a qualitative study with HIV-positive men

Unprotected sex between men is the major risk factor for HIV infection in México and many other Latin American countries. There is a substantial body of literature demonstrating that the relationship between sexual identity and sexual practice is not binary or causal -- men who have sex with other men do not necessarily perceive themselves as gay -- and there is increasing interest in HIV prevention with men who have sex with both men and women. In México, HIV prevention with men who have sex with women and men and who are not socially affiliated or identified with gay men is lacking. This paper explores the sexual histories and HIV-risk perception of HIV-positive Mexican men who indicated that they have sex with women in a screening interview and then in the context of an in-depth interview also reported having had sex with men. We consider the sexual practices and sexual and social identities of these men, examining their explanations for having sex with other men, the strategies used to affirm their masculinity, the management of their sexual identity in their social networks, HIV-risk perception before diagnosis and sexual practices after diagnosis. Recommendations are made to improve HIV prevention for men who have sex with men as well as women and who do not assume a gay or bisexual identity.

Prognostic significance of surgical margins in transoral CO2 laser microsurgery for T1–T4 pharyngo-laryngeal cancers

Histological affected or close margin is an adverse factor in conventional surgery of larynx-hypopharynx cancer. Our objective was to analyze the relevance of the margins in transoral laser microsurgery (TLM). A retrospective study of 357 consecutive patients with cancer of the larynx and hypopharynx (T1-T4) treated with TLM. Three possible margins were considered: tumor free, affected, and uncertain. An affected margin showed marked tumor infiltration. An uncertain margin was defined when the sample was insufficient, when it showed carbonization impeding accurate evaluation, or when tumor cells were less than 2 mm. Margins were free in 254 (71.1%) patients, affected in 64 (17.9%) and uncertain in 39 (10.9%). One hundred and three patients (28.9%) presented tumor relapse. The margins were associated with tumor relapse (P < 0.001), but were not significantly related to the tumor site (P = 0.307), the pT classification (P = 0.183), or the difficulty of surgical exposure (P = 0.427). Distant metastases were found in 4.7% of the patients with free margins, in 7.7% of those with uncertain margins, and in 14.1% with affected margins. These differences were statistically significant (P = 0.028). Tumor involvement of the surgical margin was associated with higher rates of local relapse, distant metastasis and the necessity of salvage surgery, together with a lower specific actuarial survival rate.

Bridging the gap between antiretroviral access and adherence in Mexico

The goal in this article is to examine social problems associated with highly active antiretroviral therapy (HAART) adherence in Mexico and the related challenges for Mexican persons living with HIV/AIDS (PLWHAs). The study was conducted from the perspective of infected and affected individuals. The authors completed 64 in-depth interviews with heterosexual male and female PLWHAs, as well as with some key individuals from their social network. Following the principles of grounded theory, they carried out inductive analysis to create codes and organize central themes. The authors identified problems related to accessing HAART and found that conditions for implementing recommendations made in the international literature to improve adherence are poor. The findings highlight the importance of social factors, such as health care system irregularities, ineffective physician-patient communication, and availability of family and other sources of social support such as self-help groups for PLWHAs' access and adherence to antiretroviral therapy in Mexico.

[HIV/AIDS-related stigma and discrimination: the case of health care providers in México]

OBJECTIVE

To analyze the social construction of stigma and discrimination processes associated with HIV/AIDS and people living with HIV/AIDS (PLHA), based on the perceptions of health care providers in three states of the Mexican Republic.

MATERIAL AND METHODS

Qualitative and quantitative description. Observation at nine institutions; in-depth interviews (14) and surveys (373) directed to providers of health services.

RESULTS

Seventy-five percent of providers reported having received training related to HIV/AIDS; however, notions persist as to patients being hopeless; discrimination due to the idea of risk groups; the immediate identification of living with the virus, having the syndrome and death; and specific lack of knowledge of forms of transmission. Twenty-three percent would not buy food from a PLHA and 16% think they should be banned from public services. With respect to confidentiality: 89% believe it should be maintained and 38% think that employers and administrators have the right to know about their employees' condition. Isolation, notes in clinical histories pointing to HIV, obligatory testing and delays in surgeries for PLHA were constant practices. The perception that men who have sexual relations with men and sexual workers decide their sexual practices marks the division between innocent victims and guilty ones, which determines the stigmatization and discrimination processes in health services.

CONCLUSIONS

The design of strategies to decrease stigma and discrimination associated with HIV/AIDS demands the inclusion of an ethical debate about human rights and a structural focus regarding social conditions that go beyond the notion of risk behaviors.

Adenosquamous carcinoma of the head and neck: criteria for diagnosis in a study of 12 cases

AIMS

Adenosquamous carcinoma (ASC) of the head and neck is an unusual neoplasm in which a general consensus with regard to diagnostic criteria has not yet been reached. In this study we report the clinicopathological results of 12 ASCs, with special attention to their histological and immunohistochemical characteristics in order to define this neoplasm more precisely.

METHODS AND RESULTS

All the patients were male with a peak incidence in the sixth decade of life. The tumours were located most frequently in the larynx and oral cavity, followed by the nasal cavity and pharynx. ASCs had two distinct histological components. The most extensive one was an usual keratinizing squamous cell carcinoma, arising from the surface epithelium, where characteristically severe dysplasia or carcinoma in situ was found in all cases. The second component was an adenocarcinoma, usually displayed in the deepest areas of the tumour. Evidence of origin from salivary or seromucinous glands was not found. Immunohistochemical studies demonstrated in most cases positivity of glandular differentiated areas for carcinoembryonic antigen (CEA) (11/12), CK7 (9/12) and CAM5.2 (7/12), whereas the squamous cell component was unreactive or reacted only focally for these markers. High-molecular-weight cytokeratin 34BE12 was positive in both components and CK20 was always negative. All cases showed high expression of Ki67 antigen. Most of them had overexpression of p53 (8/12) and DNA aneuploidy (10/12). Fifty percent of patients with ASC died of disease after a mean period of 23 months (range 12-35 months).

CONCLUSIONS

ASC of the head and neck is an aggressive neoplasm that originates in the surface epithelium of the upper respiratory tract. Severe dysplasia or carcinoma in situ is usually found and its recognition helps to make the diagnosis. In addition to mucin stains, positive immunoreactivity for CEA, CK7 and CAM5.2 helps to identify the glandular component.

Axial gain resolution in optical sectioning fluorescence microscopy by shaded-ring filters

We present a new family of pupil masks to control the axial component of the intensity distribution in the focal region of tightly focused light fields. The filters, which consist of a circular clear pupil with a single shaded ring, allow to control the width of the central lobe of the axial spot together with the residual sidelobes energy. The filters can be applied to improve the optical sectioning capacity of different scanning microscopes.

[Analysis of cerebrospinal fluid related complications (hydrocephalus, fistula, pseudomeningocele and infection) following surgery for posterior fossa tumors]

INTRODUCTION

Hydrocephalus, cerebrospinal fluid (CSF) leak, pseudomeningocele and CSF infection are potential complications related to surgical treatment of posterior fossa tumors. The objectives of this study were to review the incidence of such complications and to identify contributing factors related to them.

MATERIAL AND METHODS

This study is based on a retrospective review of the medical records of 71 consecutive patients who underwent posterior fossa surgery for a tumor between the period January 1997 and December 2001. Postoperative hydrocephalus was defined as enlargement of the ventricles and the subsequent clinical worsening requiring surgical treatment. Criteria for CSF leakage were:observed leak of CSF through the wound, rhinorrhea or otorrhea. Pseudomeningocele was determined when there was a large epidural CSF collection diagnosed in the postoperative period or by magnetic resonance imaging performed at least three months after posterior fossa surgery. Finally, CSF infection was defined on clinical ground and positive biochemical examination, but not necessarily positive cultures.

RESULTS

The series included 84 operations for resection of posterior fossa tumors on 71 patients. There were CSF related complications in 31% (26/84)with the following detailed incidence: 9.5% (8/84) postoperative hydrocephalus; 14.3% (12/84) CSF leak, 7.1% (6/84) pseudomeningocele; 8.3% (7/84) CSF infection. The mortality rate is 5.9% (5/84). The tumor size was the only statistically significant factor associated with the occurrence of CSF related complications (mean 39.43 mm, SD 18.51 mm vs.29.80 mm, SD 14.12 mm, p=0.015). In the subgroup of patients, in which hydrocephalus was managed preoperatively, the election of an external ventricular drain vs.other strategies (subcutaneous reservoir, definite shunt or endoscopic third ventriculostomy) was associated with a higher occurrence of CSF related complications (p=0.006). The mortality rate was associated with age (mean 63.60 years, SD 5.86 years vs.49.18 years, SD 16.39 years; p=0.002). The occurrence of CSF related complications also influenced mortality (p=0.030), particularly postoperative hydrocephalus (p< 0.001). Inpatient hospital stay was longer in the subgroup of patients who developed CSF related complications (p=0.002).

CONCLUSIONS

Tumor size was the only factor associated with the development of CSF related complications after surgery for posterior fossa tumors. In the subgroup of patients in which hydrocephalus was surgically treated preoperatively, the election of an external ventricular drain compared to other surgical modalities was associated with a higher rate of CSF related complications. The development of such complications, particularly hydrocephalus, was related with mortality.

[Evaluation of microsurgical treatment in a series of 121 intracranial aneurysms]

OBJECTIVE

The results obtained with therapy of intracranial aneurysms, in terms of morbidity and mortality, are very important when the patient has to choose between microsurgical techniques or endovascular management. The aim of this paper is to review the information regarding current microsurgical treatment of intracranial aneurysms, and presenting our experience over the last five years.

MATERIAL AND METHODS

We studied 101 consecutive patients with 121 intracranial aneurysms admitted between 1996 and 2000 with the initial diagnosis of subarachnoid hemorrhage. We paid special attention to the day of admission from the onset of the symptomatic hemorrhage to the grade of Hunt&Hess scale and the possibility of early or delayed microsurgical treatment. The diagnosis was based on four vessels cerebral angiography and in a few cases with CT-angiography. All patients were treated by microsurgical technique and such treatment was completed by nimodipine, intensive care unit management and in some cases of postoperative suspected vasospasm, induced arterial hypertension was applied. Post surgical angiography was carried out in all patients to confirm the clipping of the cerebral aneurysm. The 12 months assessment was based on the Glasgow Outcome Scale (GOS).

RESULTS

The 92.1% of the patients were admitted with a grade equal or below III in the Hunt&Hess scale. A 80% were operated within the 72 hours of admission and in the remaining cases, the surgical treatment was delayed due to a grade IV or V or to a medical contraindication. Four patients died (3.9%). At 12 months follow up, 88.9% presented a score I or II in the GOS.

CONCLUSION

According to our results, there are a substantial improvements in the microsurgical treatment of cerebral aneurysms, specially in patients admitted early after the onset of the symptoms of their hemorrhage, who have a grade I to III in the Hunt&Hess scale and showed a good level of consciousness. We think that the improvement of our results are due to: l. the high percentage of patients admitted with grades I to III. 2. the high percentage of patients operated within the first 72 hours from the onset of their symptomatic hemorrhage. 3. surgery was always carried out by the same two experienced vascular neurosurgeons. 4. intraoperative measures taken to prevent the rupture of the aneurysm. 5. early administration of nimodipine, ICU management, doppler studies and in seldom cases, induced hypertension therapy to treat the vasospasm and postoperative hypotension.

Hipoacusia neurosensorial por hiperbilirrubinemia neonatal

In this article, the sensorineural hearing loss is presented as a possible sequelae of neonatal hyperbilirubinemia. In our program of early hipoacusia detection, 241 babies were examined from January 1996 until November 1999; 7 cases had a history of hyperbilirubinemia in the neonatal period and 2 of them were diagnosed of sensorineural hearing loss. We discuss how the bilirubin or any other associated factor might have been the cause and this could explain the selective affectation of some children.

Health physics technician injury reduction

As part of a safety summit sponsored by Fluor Hanford Occupational Health and Safety, it was noted that Health Physics Technicians (HPTs) have one of the highest injury rates at Hanford. A multi-disciplined team made up of HPTs, health physics professionals, health physics management, indostrial hygienists, and medical personnel was established to determine causes and corrective actions. Committee activities included reviewing and characterizing occupational injuries and illnesses, assessing areas affecting the health of HPTs, soliciting field input, performing field evaluations of tasks, and making recommendations for improvements to senior management. Five areas showed a need for immediate improvement: manmachine interface (human factors and ergonomics), work environment, procedures, people, and communications. A key area of risk identified is the lack of ergonomic design considerations of the survey instruments currently used. There are several cases of cumulative trauma disorder requiring surgery. These cases are directly related to use of health physics instrumentation and/or survey techniques. The committee has made ergonomics and instrument redesign/modification its key initiative for 2001. The committee is encouraging vendor support and is seeking feedback from other health physics organizations regarding their experience and any recommendations they would like to make. Some success has already been achieved through an ergonomics-training program aimed at all HPTs and their supervisors. In addition, there have been several changes made to the way surveys are conducted, survey frequencies have been reduced, and the way modifications have been made to existing instrumentation. This is a long-term initiative with broad support within the Hanford HPT community. This document reports the progress made thus far on the initiative.

Tailoring the axial shape of the point spread function using the Toraldo concept

A novel procedure for shaping the axial component of the point spread function of nonparaxial focusing systems by use of phase-only pupil filters is presented. The procedure is based on the Toraldo technique for tailoring focused fields. The resulting pupil filters consist of a number of concentric annular zones with constant real transmittance. The number of zones and their widths can be adapted according to the shape requirements. Our method is applied to design filters that produce axial superresolution in confocal scanning systems.

Confirmation of the mapping of a 12-O-tetradecanoylphorbol-13-acetate promotion susceptibility locus, Psl1, to distal mouse chromosome 9

Susceptibility to two-stage skin carcinogenesis in the mouse is affected by several genes. In addition, studies suggest that genes that modify the response of mice to skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) also may influence histologic changes in the skin as the result of TPA treatment. One TPA susceptibility locus, Psl1, previously was mapped to distal chromosome 9. The mapping of this locus was confirmed by marker-based genotypic selection. Furthermore, Psl1 or a gene closely linked to Psl1 influenced epidermal hyperplasia and epidermal labeling index of mice treated with TPA.

[Study of mechanisms and factors related to sexual abuse in female children and adolescents]

OBJECTIVE: To study the frequency of sexual abuse in children and adolescents and its related factors. METHODS: Retrospective analysis of 617 cases of sexual abuse, assisted between July 1994 and August 1999 at the Womeńs Health Reference Center, divided into two groups: 71 children (age <10 years), and 546 adolescents (age > or =10 and <20 years). The analyzed variables were: sexual crime; embarrassment; presumption of violence; characteristics and number of abusers; the victimacute;s situation at the moment of the crime; and occurrence of physical traumas. Epi Info 6 software was utilized to gather data, and the results were analyzed by the chi-square test. RESULTS: Significant statistic results were found. 90.8% of the adolescents were victims of rape, and 46.5% of the children suffered sexual assault. The presupposed violence (PV) was more frequent in the group of children (63.4%) and a serious threat in the group of adolescents (63.2%). Innocentia consilli was exclusive PV among 100% of children and 59.5% of adolescents. 84.5% of children were molested by identifiable abusers, most frequently family members. Perpetrators were unknown in 72.3% of the cases of adolescent abuse. 42.3% of sexual abuse of children occurred in their homes, and 28.2% at the abusers. Adolescents were approached during daily activities (34.8%) and on their way to work or school (28.4%). Most patients did not have genital or extragenital trauma. CONCLUSIONS: Children suffered sexual assault, perpetrated by a known abuser through presupposed violence in private places. Adolescents were raped by unknown individuals, under serious threat, in nondomestic places.

Lymphoid tissue viral burden and duration of viral suppression in plasma

OBJECTIVES

To assess virological response in lymphoid tissue and its impact on the durability of response in plasma in HIV-1-infected persons who achieved sustained suppression of plasma viraemia with different antiretroviral regimens.

METHODS

Consecutive patients on first-line antiretroviral therapy were included if they had a plasma HIV-1 RNA viraemia < 20 copies/ml within the last 6 months and tonsillar tissue accessible for biopsy. First-line therapy contained two nucleoside analogues: alone (2NRTI group, n = 3); plus a HIV-1 protease inhibitor (PI group, n = 11) or plus nevirapine (NVP group; n = 16). Patients were followed until virus was detectable in plasma, they changed therapy or were lost to follow-up.

RESULTS

Tonsillar HIV-1 RNA could be detected (> 100 copies/mg) in 10 patients: one in the PI group (9%), six (38%) in the NVP group and in all three patients in the 2NRTI group. Primary resistance mutations could be detected in only 2 of these 10 patients. After a median of 9 months after the biopsies, viral suppression in plasma had failed in 6 of these 10 patients whereas failure had only occurred in 1 out of 20 with initially undetectable viral load in lymphoid tissue (P = 0.01; log rank test).

CONCLUSIONS

In patients with sustained viral suppression in plasma, triple therapy including a HIV-1 protease inhibitor was more potent than triple therapy containing nevirapine or dual therapy with nucleoside analogues to reduce viral burden in lymphoid tissue. A worse response in lymphoid tissue could not be explained by local selection of resistance and was associated with a less durable virological response in plasma.

Inefficient processing of an olfactomedin-deficient myocilin mutant: potential physiological relevance to glaucoma

Mutations in TIGR/MYOC (myocilin), a secretory protein of unknown function, have been recently linked to glaucoma. Most known mutations map to the C-terminus, an olfactomedin-like domain. We have previously shown that, in contrast to the wild-type, a truncated form of myocilin lacking the olfactomedin domain is not secreted. In this study, we present evidence that the mutant protein is not correctly processed in the endoplasmic reticulum (ER) and accumulates into insoluble aggregates. In addition, we show that the presence of increasing amounts of mutant protein induces a fraction of the soluble, native myocilin to move to the insoluble fraction. Given the importance of such protein aggregates in the etiology of several aging-related diseases, we propose that olfactomedin-defective mutants might contribute to the pathology of glaucoma through a mechanism involving intracellular accumulation of misfolded proteins.

Altered secretion of a TIGR/MYOC mutant lacking the olfactomedin domain

TIGR/MYOC, a novel 504 amino acids (aa) protein of unknown function, has recently been linked to glaucoma. The protein is both intra- and extracellular and most known mutations map to its C-terminus, an olfactomedin-like domain. To investigate the properties of a TIGR/MYOC peptide lacking this important domain, we constructed a replication-deficient adenovirus with the first 344 aa and over-expressed the truncated protein in primary human trabecular meshwork cells and perfused human anterior segment cultures. The truncated mutant contains the entire N-terminus plus 98 aa of the olfactomedin-like domain. We found that the delivered truncated mutant accumulates inside the cell, reduces secretion of endogenous TIGR/MYOC and induces an increase in outflow facility at 48 h post-infection. Based on these findings, we hypothesize that TIGR/MYOC might have a dual role in trabecular meshwork function. This dual role might be that of an intracellular modulator of vesicular transport as well as that of a secreted protein involved in extracellular matrix conformation. Both functions could have a direct effect in maintaining aqueous humor outflow facility.

Characterization of human immunodeficiency virus type 1 vif gene in long-term asymptomatic individuals

We have determined the sequence of the human immunodeficiency virus type 1 (HIV-1) vif genes from a cohort of 42 long-term nonprogressors (LTNP) and compared these sequences to those of 8 late progressors. The coding potential of the vif open reading frame directly derived by nested PCR from uncultured peripheral blood mononuclear cell DNA was conserved in all 50 individuals. The nucleotide distances between vif sequences were not significantly different between LTNP and late progressors, indicating similar selections of viruses within both types of long-term HIV-1-infected subjects. However, a statistically significant correlation between an amino acid signature at position 132 of Vif and the viral load was found within LTNP. Namely, amino acid Ser was associated with low viral load and amino acid Arg with high viral load. This signature was also observed when LTNP with low viral load were compared to progressors. The Ser132 signature was introduced in place of Arg132 present in the HIV-1 YU-2 Vif prototype into chimeric viruses to assess the impact of Vif signature on the virus. While the replication properties in the SupT1 cell line were unmodified, the mutagenized virus revealed a fivefold decreased replication in activated PBMC, suggesting a possible role of this Vif signature for viral production in vivo.

Development of a microparticle-enhanced nephelometric immunoassay for quantitation of human lysozyme in pleural effusion and plasma

A microparticle-enhanced nephelometric immunoassay, based on polystyrene beads coated with antihuman lysozyme antibody, has been developed for lysozyme quantification in sera and pleural effusions. The standard curve extends from 0.58 mg/l to 18.75 mg/l and no antigen effect was observed. The results showed a good serial precision. The intra-assay precision (n = 20) expressed as CV was between 2.2 and 4.2 in three different concentrations. The inter-assay precision, with different calibration curves (n = 12) was between 6.4 and 7.1. The analytical assay showed a sufficient linearity (r > 0.999). There were no interferences either with haemoglobin (up to 4 g/l), lipids (up to 0.5%, expressed as 1% Lipofundina content), or bilirubin (up to 5 mg/dl). The analytical sensitivity was lower than 0.6 mg/l. The correlation with a Micrococcus lysodeikticus turbidimetric assay showed a correlation coefficient of 0.915. We have studied 92 patients with pleural effusion. In each case, pleural fluid adenosine deaminase activity and pleural fluid to plasma lysozyme ratio were determined. The lysozyme ratio showed similar clinical sensitivity and specificity as to adenosine deaminase.

Measles virus fusion protein is palmitoylated on transmembrane-intracytoplasmic cysteine residues which participate in cell fusion

[3H]palmitic acid was metabolically incorporated into the viral fusion protein (F) of Edmonston or freshly isolated measles virus (MV) during infection of human lymphoid or Vero cells. The uncleaved precursor F0 and the F1 subunit from infected cells and extracellular virus were both labeled, indicating that palmitoylation can take place prior to F0 cleavage and that palmitoylated F protein was incorporated into virus particles. [3H]palmitic acid was released from F protein upon hydroxylamine or dithiothreitol treatment, indicating a thioester linkage. In cells transfected with the cloned MV F gene, in which the cysteines located in the intracytoplasmic and transmembrane domains (Cys 506, 518, 519, 520, and 524) were replaced by serine, a major reduction of [3H]palmitic acid incorporation was observed for F mutated at Cys 506 and, to a lesser extent, at Cys 518 and Cys 524. We also observed incorporation of [3H]palmitic acid in the F1 subunit of canine distemper virus F protein. Cell fusion induced by cotransfection of cells with MV F and H (hemagglutinin) genes was significantly reduced after replacement of Cys 506 or Cys 519 with serine in the MV F gene. Transfection with the F gene with a mutation for Cys 518 abolished cell fusion, although less mutant protein was detected on the cell surface. These results suggest that the F protein transmembrane domain cysteines 506 and 518 participate in structures involved in cell fusion, possibly mediated by palmitoylation.

Evaluation of a hand-held electrical conductivity meter for detection of subclinical mastitis in cattle

OBJECTIVE

To assess, under field conditions, whether a hand-held electrical conductivity (EC) meter could be used to detect subclinical mastitis caused by pathogens most commonly associated with mastitis in dairy cows.

ANIMALS

425 lactating cows on 15 dairies in Costa Rica.

PROCEDURE

Immediately prior to milking, milk samples from each quarter were tested, using a hand-held EC meter. A milk sample from the quarter with the highest score was submitted for bacteriologic culture. Results of bacteriologic culture were compared with highest absolute EC score for each cow and with differential EC score (ie, difference between the highest and lowest absolute EC scores for the 4 quarters of each cow).

RESULTS

Absolute EC score for cows with subclinical mastitis was significantly higher than that for cows without subclinical mastitis, and absolute EC score was significantly associated with detection of subclinical mastitis. If absolute EC score > or = 7 was considered indicative of subclinical mastitis, sensitivity was 0.43, specificity was 0.83, predictive value of a positive result was 0.39, and predictive value of a negative result was 0.85. Differential EC score for cows with mastitis was significantly higher than that for cows without subclinical mastitis. If differential EC score > or = 2 was considered indicative of subclinical mastitis, sensitivity was 0.53, specificity was 0.77, predictive value of a positive result was 0.37, and predictive value of a negative result was 0.87.

CLINICAL IMPLICATIONS

A hand-held EC meter may be used to screen cows for subclinical mastitis.

Infectious agents associated with diarrhoea of calves in the canton of Tilarán, Costa Rica

A case-control study of calves under 3 months of age was carried out by weekly visits to 15 farms in the canton of Tilarán, Costa Rica. Most farms were dedicated to beef or dual-purpose (DP) production. Faecal samples were collected over a 6-month period from a total of 194 calves with clinical signs and from 186 animals without clinical signs of diarrhoea as assessed by a scoring system. The samples were investigated for the presence of viruses, bacteria and parasites. Torovirus was detected for the first time in Costa Rica and was present in 14% of calves with diarrhoea and in 6% of the controls. Coronavirus and Rotavirus were less frequently encountered in either one of the groups (in 9 and 7% of scouring calves and in 1 and 2% of controls, respectively). Escherichia coli was detected in 94% of all the faecal samples, but isolates from only three samples from calves with diarrhoea contained the K99 antigen. Similarly, Salmonella was found only in scouring calves. Cryptosporidium oocysts were detected in animals with signs of diarrhoea, while other coccidia oocysts, Strongylida and Strongyloides eggs were frequently found in animals both with and without diarrhoea. A conditional logistic regression (CLR) analysis to compare healthy and scouring calves showed a significant difference with regard to the presence of Torovirus, Rotavirus and Coronavirus.

Sequence divergence of measles virus haemagglutinin during natural evolution and adaptation to cell culture

Phylogenetic analysis of the sequence of the H gene of 75 measles virus (MV) strains (32 published and 43 new sequences) was carried out. The lineage groups described from comparison of the nucleotide sequences encoding the C-terminal regions of the N protein of MV were the same as those derived from the H gene sequences in almost all cases. The databases document a number of distinct genotype switches that have occurred in Madrid (Spain). Well-documented is the complete replacement of lineage group C2, the common European genotype at that time, with that of group D3 around the autumn of 1993. No further isolations of group C2 took place in Madrid after this time. The rate of mutation of the H gene sequences of MV genotype D3 circulating in Madrid from 1993 to 1996 was very low (5 x 10(-4) per annum for a given nucleotide position). This is an order of magnitude lower than the rates of mutation observed in the HN genes of human influenza A viruses. The ratio of expressed over silent mutations indicated that the divergence was not driven by immune selection in this gene. Variations in amino acid 117 of the H protein (F or L) may be related to the ability of some strains to haemagglutinate only in the presence of salt. Adaptation of MV to different primate cell types was associated with very small numbers of mutations in the H gene. The changes could not be predicted when virus previously grown in human B cell lines was adapted to monkey Vero cells. In contrast, rodent brain-adapted viruses displayed a lot of amino acid sequence variation from normal MV strains. There was no convincing evidence for recombination between MV genotypes.

Two novel mutations in the Norrie disease gene associated with the classical ocular phenotype

Norrie disease (ND) is a rare X-linked recessive disorder characterized by congenital blindness due to a degenerative and proliferative dysplasia of the neuroretina and, occasionally, by deafness and mental handicap. Here, we report two novel mutations detected in patients with the classical eye features of ND. Both the one-base pair insertion in exon II (544/545 insA) and the two-base pair deletion in the start codon (418delTG) of the ND gene predict a functional 'null allele', i.e. the complete absence of the corresponding gene product.

Isolation and identification of bacteria associated with the screwworm fly Cochliomyia hominivorax, coquerel and its myiasis

We studied eight different myiasis of sheep caused by screwworm flies under laboratory conditions. Swabs were taken from the wound, before, during, and after the myiasis. Seven hundred and thirty-one samples were streaked on different bacteriological media. All samples were identified by Api System (bioMerieuex). We found thirty-eight different bacterial species in the exudates from the myiasis (before, during, and after the parasitic cycle). The analysis of bacterial flora of the screwworm showed, on larvae stage 1, 10 different bacterial species, on larvae 2, 12 bacterial species; larvae 3, 15 bacterial species; crawl off, 15 bacteria species, pupa, 9 bacterial species; and adults, 2 bacterial species and on the pioneer fly, 14 different bacterial species were isolated and identified.

Identification of two amino acids in the hemagglutinin glycoprotein of measles virus (MV) that govern hemadsorption, HeLa cell fusion, and CD46 downregulation: phenotypic markers that differentiate vaccine and wild-type MV strains

We have used site-directed mutagenesis of the hemagglutinin (H) glycoprotein of measles virus (MV) to investigate the molecular basis for the phenotypic differences observed between MV vaccine strains and recently isolated wild-type MV strains. The former downregulate CD46, the putative cellular receptor of MV, are positive for hemadsorption, and are fusogenic in HeLa cells, whereas the latter are negative for these phenotypic markers. CD46 downregulation in particular, could have profound consequences for the immunopathology of MV infection, as this molecule protects the cell from complement lysis. Mutagenesis of two amino acids, valine and tyrosine at positions 451 and 481, respectively, in the H protein from the vaccine-like Hallé MV strain to their counterparts, glutamate and asparagine, in the H protein from the wild-type Ma93F MV strain (creating the V451E/Y481N double mutation) abrogated CD46 downregulation, HeLa cell fusion, and hemadsorption. The converse double mutagenesis of the Ma93F H protein (E451V/N481Y) transferred the CD46-downregulating, fusogenic, and hemadsorption functions to this protein. The data provide the first mapping study of the functional domains of MV H. The consequences of these results for MV vaccine design and the role of CD46 in MV infection are discussed.

The associated microflora to the larvae of human bot fly Dermatobia hominis L. Jr. (Diptera: Cuterebridae) and its furuncular lesions in cattle

The microflora associated to furuncular lesions, larvae and pupae of Dermatobia hominis, as well as the relationships between parasite, host and microflora associated, as a comprehensive microsystem, has been studied. One hundred and two furuncular myiasis due to D. hominis larvae in several breeds of cattle were studied and the following bacterial species were significant: Staphylococcus aureus, S. epidermidis, S. warneri, Bacillus subtilis and Escherichia coli. Closely related, the microflora associated to 141 samples from first, second, third instar larva and both external surface and larval cavities has been studied. The representative associated microflora to the larvae were: S. aureus, B. subtilis, S. hycus and Moraxella phenylpiruvica, Moerella wisconsiensis, Proteus mirabilis and P. vulgaris, M. phenylpiruvica, M. wisconsiensis, P. mirabilis and P. rettgeri were the representative microflora associated to 64 pupae of D. hominis.

[Presence of antibiotics in pasteurized milk distributed in Costa Rica hospital nutrition services]

Two hundred samples of pasteurized milk collected from nutrition services of ten hospitals in Costa Rica, were evaluated for the presence of antibiotics residues. Bacterial inhibitory growth test were used to detect inhibitory substances. It was found that 13% (N = 200) of the samples were contaminated, with variations from 0% to 35% (N = 20) in the different hospitals tested. The larger number of positive samples corresponds to lactic industries that supply 70% of the hospital's requirements of pasteurized milk.

Temporal and geographical distribution of measles virus genotypes

The nucleotide sequence encoding the C terminus of the nucleocapsid protein of measles virus (MV) is the most variable in the genome. The sequence of this region is reported for 21 new MV strains and for virus RNA obtained from cases of subacute panencephalitis (SSPE) tissue. The nucleotide sequence of a total of 65 MV strains has been analysed using the CLUSTAL program to determine the relationships between the strains. An unrooted tree shows that eight different genotypes can be discerned amongst the sequences analysed so far. The data show that the C-terminal coding sequence of the nucleocapsid gene, although highly variable between strains, is stable in a given strain and does not appear to diverge in tissue culture. It therefore provides a good 'signature' sequence for specific genotypes. The sequence of this region can be used to discriminate new imported viruses from old 'endemic' strains of MV in a geographical area. The different genotypes are not geographically restricted although some appear to be the mainly 'endemic' types in large areas of the world. In global terms there appears to be at least four cocirculating genotypes of MV. The low level of divergence in the Edmonston lineage group isolated before 1970 indicates that some isolates are probably laboratory contaminants. This applies to some SSPE isolates such as the Hallé, Mantooth and Horta-Barbosa strains as well as some wild-type isolates from that period.

[Risk factors for Ureaplasma diversum infections in cattle of a tropical environment]

A case-control study, determined the influence of breed, age and number of deliveries as risk factors for Ureaplasma genital infections in Costa Rica dairy cattle. The animals with none or one delivery had a risk of infection 2.99 times higher than those with several parturition, regardless of breed. The risk was 1.95 times higher in Jersey than in Holstein, and decreased progressively until three deliveries. In cows with four deliveries there was a significant increase in the amount of animals infected and also a significant difference in the rate of infection between Holstein (27%) and Jersey (64%). Ureaplasma isolation was rare in cows with more than six deliveries.

[Isolation of the bacteria Ureaplasma sp. in the reproductive tract of milking cows in Costa Rica]

This is the first report of Ureaplasma sp. from the reproductive tract of Costa Rican cows. Among 204 animals sampled from 11 dairy farms in the country's Central Plateau, the infection rate was 0-71%. Isolation was more frequent in vulvo-vestibular (38.7%) than in cervical swabs (23%). Ureaplasma was correlated with clinical granular vulvitis symptoms.

Epidemiology of inflammatory bowel disease in the Province of Granada, Spain: a retrospective study from 1979 to 1988

An epidemiological study of inflammatory bowel disease in the Province of Granada, Spain, was conducted between 1979 and 1988. Altogether, 257 cases were identified: 167 ulcerative colitis, 79 Crohn's disease, and 11 indeterminate colitis. The mean incidence of ulcerative colitis in the 10 year period was 2/10(5) and 0.9/10(5) for Crohn's disease. This is the first epidemiological study in Spain of the incidence of ulcerative colitis and corroborates the results of an earlier population based study on the incidence of Crohn's disease in Spain.

Plasmodium falciparum proteinases and red blood cell invasion

Malarial proteinases of the erythrocytic life-cycle are used to design new inhibitors capable of blocking the parasite's development. The Merozoite Proteinase for Erythrocytic Invasion (MPEI) of Plasmodium falciparum, a neutral proteinase, and the acidic Pf37 proteinase acting on spectrin as substrate, are good candidates for this kind of strategy.