Search PubMed⌕ Search

Biomedical subjects

J P Figueroa

Publications and source records attributed to J P Figueroa.

At least 19 recordsLinked to original sources
PubMed2006

Seroprevalence of sexually transmitted infections among accepted and deferred blood donors in Jamaica.

Critical donor selection and testing increases the safety of blood transfusion by excluding donors at risk of transmitting infections. This study investigated the seroprevalence of and risk factors for sexually transmitted infections (STIs) among accepted and deferred blood donors in Jamaica. A total of 1015 blood donors consisting of 794 (78%) accepted donors and 221 (22%) deferred donors presenting at the Central Blood Bank, Jamaica, over a six-month period, were recruited for this study. A standardized questionnaire was administered to each participant and a sample of blood obtained for detection of hepatitis B surface antigen, antibodies to Treponema pallidum, human immunodeficiency virus (HIV) and human T-cell lymphotrophic virus type-1 (HTLV-1). Deferred donors were three times more likely to be seropositive for STI than accepted donors (16.3% vs 5.2%, OR 3.57, 95% CI 2.16 - 5.90, p < 0.0001). Males had significant association between STI seropositivity and having fathered children with two or more women (p = 0.0085), unprotected sexual intercourse with several persons (p = 0.0326), and history of genital herpes (p = 0.0121). Significant risk factors identified among females were unprotected sex with several partners (p = 0.0385); having more than ten lifetime partners (p = 0.0105); and use of depoprovera (p = 0.0028). This study confirms higher rates of STI among deferred blood donors and supports the donor deferral system in Jamaica.

Adolescent↗
PubMed2005

Increased cervical electrical activity during oestrus in progestagen treated ewes: Possible role in sperm transport.

The aim of this investigation was to characterize the pattern of cervical myoelectrical activity (EMG) in the sheep, during the periovulatory period, after synchronization of oestrus with progestagen and eCG. EMG was measured with a computerised modular system in five ewes previously fitted with a pair of monopolar Teflon needle electrodes in the muscle layers of the cervix. Each ewe was submitted to oestrus synchronization treatment with intravaginal progestagen sponge during 12 days, and the administration of 500 IU of eCG at the withdrawal of sponge. EMG was recorded in each animal during 19 h, starting 44 h after withdrawal of sponge. The number and duration of events were determined every hour during the experiment. Two distinct event durations were identified: one lasting less than 200 s and another lasting between 300 and 500 s. The two types of events analysed (less than 200 s and lasting between 300 and 500 s) had a similar pattern during the period of observation although they were not in synchrony. For events lasting less than 200 s, activity increased between 48 and 50 h after sponge withdrawal, with the peak of activity being observed between 51 and 53 h. For events of 300-500 s duration, the peak of activity was observed between 48 and 50h after sponge withdrawal and activity was maintained until 51-53 h. The increase in cervical motility observed in progestagen-eCG treated ewes is in keeping with the increase in cervical activity observed by others in natural cycling animals, and suggests that exogenous hormones used in synchronization protocols had no deleterious action on cervical motility during periovulatory period. The enhanced activity of cervical muscle layer found around the time of mating and/or AI suggests it may play an important role as a regulatory mechanism of sperm transport. Taking advantage of the cervical responsiveness to various drugs, experimental modulation of cervical activity could be used to facilitate cervical sperm transport and consequent improve of fertility after cervical AI.

Animals↗
PubMed2005

High risk health behaviours among adult Jamaicans.

The purpose of this study was to assess the prevalence of high risk health behaviours among adult Jamaicans aged 15-49 years in 2000, and to compare the results with the 1993 survey. A nationally representative sample of 2013 persons aged 15-74 years was surveyed in 2000 using cluster sampling in the Jamaica Healthy Lifestyle Survey (Wilks et al, unpublished). Interviewer administered questionnaires and anthropometrical measurements were done. Data for a sub-sample of adults aged 15-49 years were analyzed The sub-sample included 1401 persons (473 men and 928 women). Significantly more men (18.6%) than women (4.3%) reported never having had a blood pressure check (p = 0.0001). Approximately one-third of the women reported that they had never had a Pap smear (36.0%) or a breast examination (31.2%). Current cigarette smoking was reported in 28.6% of men and 7.7% of women (OR 3.73 CI 2.71, 5.15), while 49.0% of men and 15.0% of women ever smoked marijuana (OR 3.28 CI 2.56, 4.20). Significantly more men (28.0%) than women (11.7%) reported ever having a sexually transmitted disease (OR 2.93 CI 2.16, 3.97); having more than one sexual partner in the past year (49.1% vs 11.4%, OR 4.31 CI 3.22, 5.76) and usually using a condom during sexual intercourse (55.3% vs 40.5%, OR 1.3 CI 1.11, 1.68). Between 1993 and 2000, significant trends include: more persons reported having a blood pressure check, a reduction in multiple sexual partners, increased condom use at last sex (women), reduced crack/cocaine use (males) and increased marijuana smoking. Although there were some significant positive lifestyle trends between 1993 and 2000, high risk behaviours remain common among Jamaican adults. Comprehensive health promotion programmes are needed to address these risk behaviours.

Adolescent↗
PubMed2005

Human immunodeficiency virus type-1 (HIV-1) subtypes in Jamaica.

The subtypes of 141 isolates of human immunodeficiency virus type-1 (HIV-1) from Jamaica were determined by a combination of env and gag heteroduplex mobility analysis (HMA) genotyping. The majority of HIV-1 isolates were subtype B (131/141, 93.0%); one (0.8%) isolate each of subtypes C, D and E was found and 7 (4.9%) were indeterminate. These results and the failure of the sets of primers used to amplify some of the HIV-1 isolates provide strong evidence of genetic diversity of the HIV/AIDS epidemic in Jamaica. Surveillance of the circulating HIV-1 genetic subtypes is a pre-requisite for developing regional vaccine strategies and understanding the transmission patterns of the virus. This is the first study of its kind in Jamaica and the findings complement data from other Caribbean countries. This work supports the view of colleagues from the French and Spanish-speaking Caribbean that an epidemiological network supported by regional laboratories will help track this epidemic accurately with positive outcomes for the public.

DNA, Viral↗
PubMed2004

Marginal validity of syndromic management for reproductive tract infections among pregnant women in Jamaica.

We assessed the validity of a syndromic case management approach for reproductive tract infections (RTIs) among 371 pregnant women attending antenatal care facilities in Kingston, Jamaica, using an algorithm previously validated in high-risk Jamaican women. For our antenatal attenders, the algorithm had low sensitivities for all RTIs (66.7% for cervicitis, 35.4% for trichomoniasis, 11.1% for bacterial vaginosis (BV) and 24% for candidiasis). Specificities for BV (88.9%) and candidiasis (81.1%) were higher than for cervicitis (62.8%) and trichomoniasis (68.5%). The positive predictive values were lower than 36% for all diagnoses, especially BV (6.9%). Syndromic management of RTIs in pregnant women was problematic using a clinical algorithm that had worked well for high-risk women. Syndromic management for RTIs in Jamaican antenatal clinics is only a temporary solution until more simple and affordable diagnostic tests for RTIs are developed and/or until laboratory support and clinical care can be upgraded at antenatal clinics.

Adolescent↗
PubMed2004

An overview of HIV/AIDS in Jamaica: strengthening the response.

The global HIV/AIDS epidemic continues to grow at an alarming rate. The Caribbean has the second highest HIV prevalence rates after sub-Saharan Africa. In Jamaica, annual AIDS case rates continue to increase, especially in St James. The epidemic is predominantly heterosexual with an estimated HIV prevalence of 1.5% among adults. A comprehensive HIV/STI control programme has resulted in a safe blood supply, high awareness of HIV/AIDS and how to prevent it, increased condom use and a significant decline in syphilis rates. However, a number of social factors, including the strong stigma associated with AIDS, facilitate continued HIV spread and impede effective control. The national response must be significantly strengthened by ensuring appropriate social policies, combating stigma, scaling up prevention, providing antiretroviral treatment and developing a timely multi-sectoral response.

Acquired Immunodeficiency Syndrome↗
PubMed2004

An assessment of mother-to-child HIV transmission prevention in 16 pilot antenatal clinics in Jamaica.

OBJECTIVES: This study aims to determine the number and age distribution of pregnant women testing positive for HIV at 16 selected clinics in Jamaica between 2001 and 2002; the utilization of therapeutic interventions to minimize the risk of mother-to-child transmission (MTCT) and the current status of the HIV-exposed infants and, finally, the number of children who received testing for detection of HIV and to calculate the incidence of MTCT in these children. METHODS: A retrospective study was carried out at sixteen pilot clinic sites by examining the patient records for all confirmed HIV-positive pregnant mothers and the resultant infants at these facilities for the period January 2001 to December 2002. RESULTS: One hundred and twenty-three of 8116 pregnant women newly tested positive during the period January 2001 to December 2002; however, 176 HIV+ women delivered. Fifty-three (30%) knew their HIV status prior to participating in the programme. Sixty-two (1.4%) and 61 (1.6%) tested positive in 2001 and 2002, respectively. One hundred and ten (77%) and 113 (83%) mothers and infants, respectively, received ARV therapy, (92% - nevirapine, 8% - zidovudine). Twenty-three per cent of pregnant women received no ARV Forty-four (25.0%) of the 176 infants had a documented ELISA HIV test before eighteen months of age, none had a PCR test. The health status of 40 (23%) of these children was known: 30 (75%) were alive and well, five of whom did not receive any ARV, one (2.5%) was alive and ill and nine (22.5%) were reported dead, five of whom received ARV; 28.6% of infants who did not receive ARV were reported as either dead or ill compared to 13.8% of those receiving ARV CONCLUSION: Though the majority of pregnant women discovered their HIV status during pregnancy, a significant number got pregnant knowing that they were HIV+. The majority of mothers and infants received ARV but the follow-up and testing of infants was limited. Nevirapine is clearly protective in the prevention of MTCT of HIV and should be made universally accessible. All infants delivered to HIV+ mothers should be identified and tested for HIV.

AIDS Serodiagnosis↗
PubMed2004

HIV seroprevalence, uptake of interventions to reduce mother-to-child transmission and birth outcomes in greater Kingston, Jamaica.

BACKGROUND: The seroprevalence of HIV among pregnant women in the Caribbean is 2-3% and increasing. The Kingston Paediatric and Perinatal HIV Programme is developing and implementing a unified programme to eliminate mother-to-child transmission (MTCT) of HIV in Kingston, Jamaica. METHODS: Pregnant women presenting to Kingston Metropolitan Antenatal Clinics, Victoria Jubilee Hospital, Spanish Town Hospital and the University Hospital of the West Indies had HIV serology performed by ELISA, or by the new Determine Rapid Test after receiving group counselling. HIV-positive women were referred to High Risk Antenatal Clinics. Antiretroviral prophylaxis with zidovudine (AZT), or nevirapine was given. Care was administered using a standard protocol by a multi-disciplinary team of public and academic healthcare personnel. RESULTS: In year one, 19,414 women delivered Among 14,054 women who started antenatal care for this period, 5,558 (40%) received group counselling and 7,383 (53%) received HIV-testing. During the fourth quarter of follow-up, these comparative rates were 66% (2049/3 118) and 72% (2260/3118) respectively. HIV seroprevalence overall was 2.1% (152/7 383). One hundred and seven HIV+ women at varying gestational ages were identified in the programme, 72 had so far received AZT and nine nevirapine (76%). 0f 84 deliveries, birth outcomes were 75 live births (89%), six neonatal deaths and four maternal deaths (all from HIV/AIDS). Major challenges include repeat pregnancies of 36% despite prior knowledge of HIV seropositivity and poor partner notification with only 30% (32) having a HIV-test. Although rates of HIV testing in pregnant women in Greater Kingston are increasing, rates of testing overall remain sub-optimal. On the labour ward, there was sub-optimal identification of the HIV+ pregnant woman and administration of AZT chemoprophylaxis, along with issues of patient confidentiality and stigma. CONCLUSION: This programme needs strengthening in order to reduce maternal-fetal transmission of HIV in Greater Kingston, Jamaica "pMTCT-PLUS, or comprehensive family-centred care, is the next step".

Adolescent↗
PubMed2004

Socio-demographic characteristics of HIV-exposed and HIV-infected Jamaican children.

BACKGROUND: In the face of the continuing pandemic of HIV/AIDS, the burden of the disease is now largest in the resource-poor developing world. The Joint United Nations Programme on HIV/AIDS (UNAIDS) has listed the adult prevalence rate for the Caribbean as second only to Sub-Saharan Africa. OBJECTIVE: To document the socio-demographic characteristics of paediatric and perinatal HIV/AIDS in Kingston, Jamaica. METHODS: A cohort of HIV-infected pregnant women were identified at the leading maternity centres in Kingston and St Catherine and were enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme. Infants born to mothers within the programme were prospectively enrolled. Infants and children identified after delivery, whether HIV-exposed or infected, were also enrolled (retrospective group). All were followed according to standardized protocols. RESULTS: We report on a total of 239 children, 78 (prospective group) and 161 (retrospective group). Among the retrospective group, 68% were classified as infected. For the prospective group, the patients were recruited within twenty-four hours of birth in 98.7% of cases, whereas in the retrospective group, the median age of recruitment was 2.6 years. The median age of the mother was 27 years and that of the father was 33 years. There were seven teenage mothers. Twenty-six per cent of the children were in institutional care. Family size ranged from one to nine children--the median was two children. For those parents where occupation was reported, the majority held semi-skilled or unskilled jobs. Patients attended their regional clinics. CONCLUSION: HIV/AIDS represents a significant human and financial burden on a developing country such as Jamaica and this underscores the need for urgent and sustained interventions to stem the epidemic.

Child, Preschool↗
PubMed2004

Uptake of interventions, outcomes and challenges in caring for HIV-exposed infants in Kingston, Jamaica.

BACKGROUND: In a few Caribbean islands, prevention of mother-to-child transmission (pMTCT) of HIV with zidovudine prophylaxis has reduced transmission rates from 27 - 44% to 5.5 - 9 %. OBJECTIVES: To highlight the uptake of interventions, preliminary outcomes and challenges in caring for HIV-exposed infants in a pMTCT HIVprogramme in a resource-limited setting. METHOD: A cohort of HIV-infected pregnant women were identified at the leading maternity centres in Greater Kingston through HIV counselling and testing and enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme. Antiretroviralprophylaxis with zidovudine or nevirapine was given to the HIV-positive women and their newborns along with formula feeding. Some infants were enrolled retrospectively and followed irrespective of whether they had or had not received antiretroviral prophylaxis. A multidisciplinary team at the paediatric centres supervised protocol-driven management of the infants. Infants were followed for clinical progress and definitive HIV-infection status was to be confirmed at 18 months of age by ELISA or the Determine Rapid Test. RESULTS: During September 1, 2002 through August 31, 2003, 132 HIV-exposed infants were identified. For those infants prospectively enrolled (78), 97% received antiretroviral prophylaxis and 90% were not breastfed For all HIV-exposed children, 90% received cotrimoxazole prophylaxis and 88% continued follow-up care. Ninety-two per cent of all the infants remained asymptomatic and five died; of these deaths one is possibly HIV-related (severe sepsis at 11 weeks). This infant was retrospectively identified, had received no antiretroviral prophylaxis and was breastfed The main programme challenges, which were overcome, included the impact of stigma, compliance with antiretroviral chemoprophylaxis, breast-milk substitution and follow-up care. Financial constraints and laboratory quality assurance issues limited early diagnosis of HIV infection. CONCLUSION: Despite the challenges, the expected outcome is to prevent 50 new cases of HIV/AIDS in children living in Greater Kingston per year (300 over six years).

Antibiotic Prophylaxis↗
PubMed2004

CDC-defined diseases and opportunistic infections in Jamaican children with HIV/AIDS.

OBJECTIVE: To document the frequency of Centers for Disease Control and Prevention (CDC)-defined clinical conditions, opportunistic and co-infections among children with HIV/AIDS. METHODS: This prospective, observational study reports the findings of 110 HIV-infected children followed in multicentre ambulatory clinics during September 1, 2002, to August 31, 2003, from the 239 children enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme, Jamaica. We describe the clinico-pathologic characteristics of these children with HIV/AIDS, using the CDC criteria. RESULTS: The client distribution by clinic site was as follows: the University Hospital of the West Indies, 71 (64.6%), Bustamante Hospital for Children, 23 (20.9%), Comprehensive Health Centre 13 (11.8/%) and Spanish Town Hospital, 3 (2.7%). The median age of the 110 children with HIV/AIDS was 6.0 years (range 0.9-17.5). Mode of transmission was primarily mother-to-child (88.0%) and only 4% maternal/infant pairs received antiretroviralprophylaxis. Grouped by CDC category: 17 (15.4%) were asymptomatic (N), 22 (20.0%) mildly symptomatic (A), 30 (27.3%) moderately symptomatic (B) and 41 (37.3%) severely symptomatic (C). The most common CDC-defining symptoms were lymphadenopathy (12, 42.8%) and asymptomatic (6, 21.4%) in category N; lymphadenopathy (30, 29.7%), dermatitis (20, 19.8%) and persistent or recurrent upper respiratory tract infections (20, 19.8%) in category A; bacterial sepsis (18, 34.6%) and recurrent diarrhoea (11, 21.2%) in category B; and wasting (28, 30.0%), encephalopathy (26, 27.9%), and serious bacterial infections (15, 16.1%) in category C; Pulmonary tuberculosis (7, 7.5%) and Pneumocystis (jiroveci) carinii pneumonia; (5, 5.4%) were the most frequent opportunistic infections. Streptococcus pneumoniae (10, 30.3%) was the most common invasive bacterial pathogen causing sepsis and Escherichia coli (14, 34.2%) was the most common bacterial pathogen causing urinary tract infections, among the cohort. Thirty-three per cent commenced antiretroviral drugs (ARVs). There were 57 hospitalizations and five deaths. CONCLUSIONS: The study is an important step toward documentation of the natural history of paediatric HIV/AIDS in a primarily ARV-naive population from a developing country. It promotes training in paediatric HIV management as we move toward affordable access to antiretroviral agents in the wider Caribbean and the implementation of clinical trials.

AIDS-Related Opportunistic Infections↗
PubMed2004

Antiretroviral drug therapy in HIV-infected Jamaican children.

BACKGROUND: The study describes a cohort of HIV-infected Jamaican children receiving antiretroviral therapy (ART) and reports the outcome. METHOD: An observational prospective study was conducted on HIV-infected Jamaican children receiving anti retroviral drug therapy (ART). The outcome measures, weight, height, hospital admissions and length of stay were compared at initiation and within six months of commencing ART. RESULTS: There were 37 (33.6%) of 110 HIV-infected children receiving ART during 2001 to 2003. The median age at commencement was six years (age range 1-16 years) with 54.1% (20) males and 48% AIDS orphans. Care was home-based for 68 % of all cases with the University Hospital of the West Indies managing 27 (73%) and the Bustamante Hospital for Children 10 (27%). The distribution by Centers for Disease Control and Prevention (CDC) clinical class was C (severely symptomatic), 22 (59.5%); B (moderately symptomatic), 8 (21.6%); A (mildly symptomatic), 6 (16.2%) and N (asymptomatic), one (2.7%). Among 14 (36%) children with CD4 counts, 8 (57%) were CDC immune class 2 (moderate immunodeficiency) and 6 (43%) were class 3 (severe immunodeficiency). After commencing ART the mean difference in admissions was--1.5+/-2.55 admissions (95% CI -2.3, -0.6; p < 0.001) and in length of stay was -12.9+/-21 day (95% CI -19.9, -0.5.9; p < 0.001). Antiretroviral therapy resulted in a mean weight gain of 2.8 kg+/-4.9 kg (95% CI 1.0, 4.5; p < 0.003) and a mean gain in height of 1.7 cm+/-2.6 cm (95% CI 0.6, 2.8; p < 0.003). Five children required second line therapy. CONCLUSION: The introduction of antiretroviral therapy has resulted in improved outcomes and is being initiated in older children cared for mainly at home. Limitations in accessing affordable second line agents underscore the need for compliance with first line therapy.

Adolescent↗
PubMed2003

Connexin 43 ontogeny in fetal sheep adrenal glands.

We examined fetal sheep adrenal glands from 99 to 130 days of gestational age (dGA) to see how connexin 43 (Cx43), the major if not the only adult adrenal gap junction protein, changes expression as the adrenal cortex emerges from the well-documented refractory period to participate in labor and delivery. Immunocytochemical technique and Western blot were used to examine changes in the quantity and quality of Cx43. In addition, adrenal glands of ACTH infused fetuses or of fetuses from dexamethasone injected ewes underwent image analysis quantification after Cx43 immunostaining. Finally, fetal adrenal glands, from fetuses splanchnic nerve sectioned (SPLX) at 125 dGA, were examined for the pattern of Cx43 immunostaining at 131 days of gestation. From 100 to 130 dGA, the amount of Cx43 in cells of the adrenal cortex increased steadily while the pattern of immunoreactivity changed from predominantly cytoplasmic to membrane bound. At 100-103 dGA, ACTH infusion increased the size of the cortex, but decreased the expression of Cx43 per unit area while dexamethasone had no effect on either parameter. Lastly, the expression of Cx43 as a membrane bound protein was not delayed or reversed by SPLX. We conclude that the described changes in Cx43 are most intriguing given their temporal relationship to the described preparturient increases in ACTH and cortisol in peripheral fetal plasma as term approaches and deserve further investigation.

Adrenal Cortex↗
PubMed2002

A survey of essential national health research in nine developing countries.

A survey of Essential National Health Research (ENHR) was conducted between December 1997 and November 1998 in nine developing countries. A total of 27 respondents from seven South East Asian and two Caribbean countries completed questionnaires. Respondents included 14 men and 13 women with a median age of 48 years (range 25-69 years); 15 were researchers, seven were health providers, three policy makers and one a community representative (one no response). ENHR was formally adopted in five countries mainly through public policy statements. Seven countries had a mechanism in place for promotion of ENHR and national meetings were held in five countries in the year prior to the survey. A special activity was conducted in order to define health research priorities in eight countries and a list of these priorities was available in seven countries. The level of ENHR activity was ranked as low or moderate in most countries except India and Malaysia which were rated as moderate to high. Three countries reported that the process resulted in new or additional funds being made available for research, while India reported available funds being reallocated to meet the priorities defined. The respondents of six countries said that ENHR networking had led to tangible results, including improved collaboration among researchers and research institutions and the sharing of resources among different organizations (five countries). The ENHR process had resulted in research findings being used to formulate or change health policy in five countries. Most countries had not produced any new research protocols through the ENHR process. However, there were 250 new research protocols in India and 68 in Pakistan, of which 20 and between 25 and 35, respectively, were funded and 15 peer reviewed articles had been published from India. This survey does suggest that the ENHR process may be promoting health research on priority health problems and the use of results to formulate policy in selected countries. However, it is too early to assess the contribution of ENHR to health and development and a variety of different studies would be needed to conduct this assessment.

Developing Countries↗
PubMed2001

Mitochondrial nitric oxide synthase is constitutively active and is functionally upregulated in hypoxia.

Nitric oxide is a potent modulator of mitochondrial respiration, ATP synthesis, and K(ATP) channel activity. Recent studies show the presence of a potentionally new isoform of the nitric oxide synthase (NOS) enzyme in mitochondria, although doubts have emerged regarding the physiological relevance of mitochondrial NOS (mtNOS). The aim of the present study were to: (i) examine the existence and distribution of mtNOS in mouse tissues using three independent methods, (ii) characterize the cross-reaction of mtNOS with antibodies against the known isoforms of NOS, and (iii) investigate the effect of hypoxia on mtNOS activity. Nitric oxide synthase activity was measured in isolated brain and liver mitochondria using the arginine to citrulline conversion assay. Mitochondrial NOS activity in the brain was significantly higher than in the liver. The calmodulin inhibitor calmidazolium completely inhibited mtNOS activity. In animals previously subjected to hypoxia, mtNOS activity was significantly higher than in the normoxic controls. Antibodies against the endothelial (eNOS), but not the neuronal or inducible isoform of NOS, showed positive immunoblotting. Immunogold labeling of eNOS located the enzyme in the matrix and the inner membrane using electron microscopy. We conclude that mtNOS is a constitutively active eNOS-like isoform and is involved in altered mitochondrial regulation during hypoxia.

Animals↗
PubMed2001

Nitric oxide synthase activity in brain tissues from llama fetuses submitted to hypoxemia.

The fetal llama (Lama glama; a species adapted to live in chronic hypoxia in the highlands of the Andes) did not increase cerebral blood flow and reduce the brain oxygen uptake during hypoxemia. Although nitric oxide (NO) is a normal mediator in the regulation of vascular tone and synaptic transmission, NO overproduction by hypoxemia could produce neuronal damage. We hypothesized that nitric oxide synthase (NOS) activity is either maintained or reduced in the central nervous system of the llama fetuses submitted to chronic hypoxemia. Approximately 85% of the Ca(2+)-dependent NOS activity was soluble, at least 12% was associated with the mitochondrial fraction, and less than 5% remains associated with microsomes. To understand the role of NO in chronic hypoxemia, we determined the effect of 24-h hypoxemia on NOS activity in the central nervous system. No changes in activity or the subcellular distribution of NOS activity in brain tissues after hypoxemia were found. We proposed that the lack of changes in NOS activity in the llama under hypoxemia could be a cytoprotective mechanism inherent to the llama, against possible toxic effects of NO.

Animals↗