Evaluation of highly sensitive diagnostic tools for the detection of P. falciparum in pregnant women attending antenatal care visits in Colombia.

BACKGROUND: In low transmission settings early diagnosis is the main strategy to reduce adverse outcomes of malaria in pregnancy; however, microscopy and rapid diagnostic tests (RDTs) are inadequate for detecting low-density infections. We studied the performance of the highly sensitive-RDT (hsRDT) and the loop mediated isothermal DNA amplification (LAMP) for the detection of P. falciparum in pregnant women. METHODS: A cross-sectional study was conducted in two malaria-endemic municipalities in Colombia. We screened pregnant women in the context of an antenatal care program in health facilities and evaluated five tests (microscopy, conventional RDT, hsRDT, LAMP and nested polymerase chain reaction-PCR) for the detection of P. falciparum in peripheral blood, using a quantitative reverse transcription PCR (qRT-PCR) as the reference standard. Diagnostic performance of hsRDT and LAMP were compared with routine testing. RESULTS: The prevalence of P. falciparum was 4.5% by qRT-PCR, half of those infections were subpatent. The sensitivity of the hsRDT (64.1%) was slightly better compared to microscopy and cRDT (59 and 53.8% respectively). LAMP had the highest sensitivity (89.7%) for detecting P. falciparum and the ability to detect very low-density infections (minimum parasite density detected 0.08 p/µL). CONCLUSIONS: There is an underestimation of Plasmodium spp. infections by tests routinely used in pregnant women attending antenatal care visits. LAMP methodology can be successfully implemented at local hospitals in malaria-endemic areas. The relevance of detecting and treating this sub-patent P. falciparum infections in pregnant women should be evaluated. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT03172221 , Date of registration: May 29, 2017.

Diverticulitis in HIV-infected patients within the United States.

OBJECTIVES: Diverticulitis in patients on immunosuppressant therapy has been associated with increased mortality, but there are no data for HIV-infected patients. Our aim was to compare the outcomes of hospitalizations for diverticulitis in patients with and without HIV infection. METHODS: Cross-sectional study of hospitalizations in the United States accessed through the Nationwide Inpatient Sample, Healthcare Cost and Utilization Project. Patients hospitalized for diverticulitis in 2007-2011 were included in the analysis. The primary outcomes of interest were mortality and surgical therapy rates. Patients from 2003 to 2011 were utilized to analyse trends in prevalence. RESULTS: There were 2375 patients with HIV infection hospitalized for diverticulitis and 1 160 391 patients without HIV infection hospitalized for diverticulitis from 2007 to 2011. The patients with HIV infection were younger and more likely to be male and nonwhite (P < 0.001 for all). There were also differences in insurance types (P < 0.001) and hospitals [size (P = 0.008), type (P < 0.001) and location (P < 0.001)]. After multivariate analysis, patients with diverticulitis and HIV infection had a significantly increased in-hospital mortality rate [odds ratio (OR) 3.94 (95% confidence interval, CI, 1.52-10.20)] and a lower rate of surgical intervention [OR 0.74 (95% CI 0.57-0.95)]. From 2003 to 2011, there was a linear increasing trend in the prevalence of HIV infection among patients hospitalized for diverticulitis (P < 0.001). CONCLUSIONS: HIV-infected patients with diverticulitis had increased mortality and received less surgical treatment in comparison to the general population. Diverticulitis in HIV-infected patients increased in prevalence over the study period.

Alterations in the optic nerve and retina in patients with COVID-19. A theoretical review.

The objective of this research is to identify and systematize the medical conditions generated by SARS-CoV-2 on the optic nerve and retina of young, adult, and elderly adults who suffered from COVID-19 in the period 2019-2022. A theoretical documentary review (TDR) was conducted within the framework of an investigation to determine the current state of knowledge of the subject under study. The TDR includes the analysis of publications in the scientific databases PubMed/Medline, Ebsco, Scielo and Google. A total of 167 articles were found, of which 56 were studied in depth, and these evidence the impact of COVID-19 infection on the retina and optic nerve of infected patients, both during the acute phase and in subsequent recovery. Among the reported findings, the following stand out: anterior and posterior non-arteritic ischemic optic neuropathy, optic neuritis, central or branch vascular occlusion, paracentral acute medial maculopathy, neuroretinitis, as well as concomitant diagnoses such as possible Vogt-Koyanagi-Harada disease, multiple evanescent white dot syndrome (MEWDS), Purtscher-like retinopathy, among others.

Study of the properties of ZnO:Zn thin films obtained from ZnO/Zn/ZnO structure deposited by DC sputtering.

A method to manage the resistivity of n-type ZnO films is presented. It involves the controlled diffusion of Zn at low temperature in N2 atmosphere into the ZnO/Zn/ZnO structure. The structures were made by DC sputtering technique. The diffusion periods were varied from 5 to 30 min. This process allow us to obtain ZnO films with excess of Zn (ZnO:Zn). The electrical characterization showed that the resistivity of the films can be varied from 0.01 to 100 omega-cm, the electron concentration from 10(19) to 10(17) cm(-3) and the carrier mobility from 10 to 40 cm2N-s. The films are nanocrystalline with preferred (002) orientation and crystal size that varies from 13 to 20 nm depending on the diffusion period. The films have a band gap of 3.18 eV and 70% of transmittance in the visible region, these properties were obtained from the transmittance measurements of low-resistivity films. Films have good structural, optical and electrical properties, and could be used in the manufacture of light emitting diodes.

Prevalence, treatment, and outcomes of the hepatic artery stenosis after liver transplantation.

INTRODUCTION: Hepatic artery stenosis (HAS) after liver transplantation can lead to altered hepatic function and/or thrombosis, there by increasing morbidity and mortality. The prevalence of HAS in the literatures varies from 4% to 11%. OBJECTIVE: We sought to describe the prevalence and treatment of hepatic artery stenosis. METHODS: We performed a descriptive retrospective analysis of 253 liver transplantations from March 1998 to May 2007, including patients with suspected HAS owing to increased hepatic enzymes, altered Doppler ultrasound (us) and hepatic biopsy. The confirmation of HAS was achieved through areriography. RESULTS: Nine patients were identified to have HAS, a 3.5% prevalence. Among the HAS patients, seven were male and two female. Their average age was 35.5 years (range, 65 to 53). The average time between the diagnosis and transplantation was 14.2 months (range, 9 to 68). The increase in hepatic enzymes among this group averaged: aspartate aminotransferase 131 U/L (range, 26 to 412) and alanine aminotransferase 192 U/L (range, 35 to 511). Doppler US showed alteration in the resistance level index. All patients underwent areriography; only one could not be treated owing to severe hepatic artery spasm, which also occurred during another attempt weeks after the first one. Among the eight patients, six were treated with stents and two with angioplastis. All treated patients displayed improvements in parameters. Four patients treated with stents required retreatment: two underwent angioplasty and two, a thrombolytic. One graft rethrombosed but evolved in compensated fashion with recanalization by collaterals. There has been no graft loss or mortality in this population. The average time of posttreatment follow-up was 31.28 (range, 9 to 68) months. CONCLUSION: The prevalence of HAS in our unit was within that reported in the literature. Treatment with a stent or angioplasty proved to be efficient to control this complication, considering that hepatic function recovered and that there was neither graft nor patient loss.

Host feeding profiles of Rhodnius pallescens (Hemiptera: Reduviidae) in rural villages of Central Panama.

Rhodnius pallescens, reported to be the principal vector of Chagas' disease in central Panama, has been shown to feed on opossums, anteaters, sloths, rodents, birds and, rarely, lizards in sylvatic habitats in this country; however, the extent of its anthropophagic affinities in rural areas has never been determined. The host selections of 1,340 R. pallescens from domestic and peridomestic habitats of three Panamanian villages were determined by microcapillary precipitin tests. Slightly more than half of the triatomines collected in houses and nearby palm trees and bird nests had fed on humans. Opossums, which are important reservoirs of Trypanosoma cruzi in Panama, were the second most frequently selected host. The importance for the transmission of Chagas' disease to humans of the close relationship between the principal vector and reservoir in sylvatic and peridomestic environments and the anthropophagy of the former is discussed. Pigeons and chickens were the dominant bloodmeal sources of triatomines collected in their respective shelters. The roof rat, Rattus rattus, was the third most common mammalian host, and may represent an ancillary reservoir in the transmission of Chagas' diseases in rural areas of Panama.

Susceptibility of Aotus trivirgatus to Leishmania braziliensis and L. mexicana.

Two Aotus trivirgatus (owl monkeys) were infected experimentally with Leishmania braziliensis and two with L. mexicana strains of Panamanian origin in a pilot study to determine the susceptibility and the course of infection of cutaneous leishmaniasis in this primate species. Montenegro skin tests performed on all animals prior to parasite inoculation were negative. A standardized inoculum of promastigotes was injected intradermally on the nose of each monkey. All of the animals developed infections which lasted from 3.5 to 8.5 months. Depigmentation developed at the site of the inoculation in all of the subjects. The severity of the resulting lesions was greater in the animals infected with L. braziliensis. Positive skin tests developed in three A. trivirgatus at days 62, 76, and 139 postinoculation, respectively. An explanation for the negative skin test in the fourth animal is discussed.

The tree-buttress biotope: a pathobiocenose of Leishmania braziliensis.

A total of 52,033 sandflies, comprising 33 species, was collected in tree buttresses in Panama. Of the 18,025 females collected, 1,592 (8.8%) engorged phlebotomines of 18 species contained sufficient blood for identification of their vertebrate hosts by the microcapillary precipitin method. Lutzomyia ylephiletor and Lu. trapidoi, vectors of Leishmania braziliensis, had fed predominantly on sloths (47.0% and 65.1%, respectively). Lutzomyia shannoni, a common non-anthropophilic sandfly in tree buttresses also fed most frequently on sloths (28.0%) and probably also contributes to the Leishmania transmission cycle among the edentates. Two-toed sloths (Choloepus hoffmanni), the principal reservoir of L. braziliensis in Panama, cohabit the same arboreal bioptope with these sandfly species. Leishmania braziliensis was isolated in culture from 14 of 68 (20.6%) C. hoffmanni captured in the study sites during the period of this investigation. The data illustrate that the butrresses of large trees in Panama represent potential pathobiocenose bioptopes of L. braziliensis. Other sandfly species tested for host-feeding sources included: Lu. trinidadensis, which fed preferentially on reptiles; Lu. triramula, Lu. ovallesi, and Lu. camposi fed most frequently on armadillos. The hosts of 11 additional sandfly species were identified; however, the numbers recorded were too small to discern distinct feeding patterns among the phlebotomines.

Host feeding profiles of Triatoma dimidiata in peridomestic habitats of western Panama.

Bloodmeal analysis of Triatoma dimidiata collected in peridomestic habitats of western Panama showed that avian feedings comprised 25% of this species' host selections; opossums, the principal reservoir of Chagas' disease in the republic, were not among mammalian feedings. These findings may account for the low infestation rates of Trypanosoma cruzi in the bugs and the hypoendemicity of Chagas' disease in western Panama.

Host-feeding patterns of mosquitoes (Diptera: Culicidae) from central Panama.

A 10-year study of blood meal identification in mosquitoes collected at numerous sites over several ecosystems in central Panama was conducted from 1977 to 1987. The hosts for 4,391 mosquito blood meals, representing 30 species, were identified to the family level of specificity in most instances. The degree that individual mosquitoes had fed on animals of different classes and families within these classes was determined. Multiple feeding among several mosquito species was documented. The relationship between reservoir hosts of endemic arboviruses and a number of known and potential mosquito vectors was demonstrated as a result of the blood meal identifications.

Short report epidemiologic studies on cutaneous leishmaniasis in eastern Panama.

The Panamanian Ministry of Health, through the Interamerican Development Bank, contracted the Gorgas Memorial Laboratory to conduct epidemiologic studies on leishmaniasis and malaria in eastern Panama from July 1984 through June 1985. Preliminary results of the biomedical and entomologic teams investigating the epidemiology of cutaneous leishmaniasis in the eastern part of the country are presented in this short report. The principal findings of the study revealed 1) a large disparity in the incidence and prevalence of the disease among the five communities investigated; 2) the appearance of self-cures without the benefit of effective treatment; 3) a relatively high percentage of subclinical cases; and 4) determination of the sandfly vector species for each community. Also reported here is a case of a double infection with two distinct species of Leishmania, L. mexicana and L. amazonensis, in a single individual.

Hosts of sandfly vectors of Leishmania braziliensis guyanensis in the central Amazon of Brazil.

The blood meals of 2,569 phlebotomine sandflies from areas endemic for cutaneous leishmaniasis in the central Amazon of Brazil were tested by the microcapillary precipitin method to determine their vertebrate hosts. The two-toed sloth, Choloepus didactylus, was the predominant host of two incriminated vectors of Leishmania braziliensis guyanensis in the region, Lutzomyia umbratilis and Lu. anduzei (64.0% and 63.6%, respectively). The Lu. "shannoni" group, a complex of several species in which females are indistinguishable, also fed predominantly on sloths (73.0%). Species comprising the Lu. "shannoni" group have not been implicated as vectors of leishmaniasis; however, their feeding patterns in the study area illustrate their potential involvement in the transmission of the parasites to two-toed sloths, which are the principal reservoir hosts of L. braziliensis in Panama. Rodents, and particularly porcupines, were the second most frequently fed-on mammal by Lu. umbratilis (11.6%) and the Lu. "shannoni" group (8.5%).

Leishmania mexicana complex: human infections in the Republic of Panama.

Parasites of the genus Leishmania responsible for human cutaneous leishmaniasis in the New World form 2 major taxonomic divisions: the Leishmania braziliensis and the L. mexicana complexes. We report the isolation and characterization of the L. mexicana complex among humans in the Republic of Panama. Characterization was based on parasite morphology, pathogenesis in infected golden hamsters, cellulose acetate isoenzyme electrophoretic mobilities, and membrane-specific monoclonal antibodies using the radioimmune binding assay technique.

Direct administration of interleukin-1 and interferon-gamma to rat pancreas leads to the in vivo production of nitric oxide and expression of inducible nitric oxide synthase and inducible cyclooxygenase.

INTRODUCTION: Proinflammatory cytokines may play a pivotal role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). In vitro, the formation of nitric oxide (NO) catalyzed by inducible NO synthase (iNOS) has been shown to be involved in the cytotoxic effects of cytokines on pancreatic beta cells. Cytokines have also been shown to cause the expression of inducible cyclooxygenase (COX-2) in isolated islets. AIMS: To describe a novel in vivo model that allows investigation of the effects of direct cytokine administration to the pancreas. METHODOLOGY AND RESULTS: By using this method, we demonstrate that administration of interleukin-1beta and interferon-gamma to rat pancreas results in the generation of NO in the treated pancreata as detected by NO trapping and electron paramagnetic resonance spectroscopy. Beta cells were identified as the source of the formed NO. Reverse transcription and polymerase chain reaction analyses showed that administration of cytokines to the pancreas leads to the expression of iNOS and COX-2 mRNA in the pancreas tissue as well as the islets isolated from such tissues. The compound phenyl N-tert-butylnitrone, which protects mice against streptozotocin-induced IDDM, inhibits NO formation and downregulates both iNOS and COX-2 mRNA levels.

Inhibition of the cytokine-mediated inducible nitric oxide synthase expression in rat insulinoma cells by phenyl N-tert-butylnitrone.

Cytokines and nitric oxide (NO) have been implicated in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). We have shown that the spin-trapping agent phenyl N-tert-butylnitrone (PBN) protects against streptozotocin (STZ)-induced IDDM in mice. In order to gain more insights into the mechanism(s) of the protective action of PBN against IDDM, we have investigated the effect of this compound on the cytokine-induced NO generation (measured as nitrite) in rat insulinoma RIN-5F cells. Our results demonstrate that PBN cotreatment prevents the generation of nitrite by RIN-5F cells induced by treatment with tumor necrosis factor-alpha, interleukin 1beta, and interferon-gamma in a dose-dependent fashion. The generation of NO as a result of cytokine treatment and the inhibitory effect of PBN were further confirmed by electron paramagnetic resonance spectroscopy. Aminoguanidine, a selective inhibitor of inducible nitric oxide synthase (iNOS), abolished the cytokine-induced nitrite generation whereas N-nitro-l-arginine, an inhibitor more selective for other NOS isoforms, was significantly less effective. Western and Northern analyses demonstrated that PBN inhibits the cytokine-mediated expression of iNOS at the transcriptional level. Cytokine-induced nitrite formation was also inhibited by the two antioxidant agents alpha-lipoic acid and N-acetylcysteine. These results indicate that PBN protects against IDDM at least in part by prevention of cytokine-induced NO generation by pancreatic beta-cells.

[Mucocutaneous leishmaniasis in Panama. Etiologic agent, epidemiologic and clinical aspects]. / Leishmaniasis mucocutánea en Panamá. Agente etiológico, aspectos epidemiológicos y clínicos.

From November 1985 to December 1988, 33 patients were enrolled at Santo Tomas Hospital and Gorgas Memorial Laboratory to study the etiology, epidemiology and clinical characteristics of mucocutaneous leishmaniasis. Seventeen were males and 16 females, 14 to 80 years old from the endemic rural areas of the provinces of Panama, Colón, Coclé, Darién, Veraguas, Bocas del Toro and San Blas. In 8 patients the respiratory mucosa involvement occurred at the time of the primary infection and 25 had the involvement after an incubation period of 2 to 30 years. Twenty one of these 25 patients had a clear history of cutaneous leishmaniasis and the characteristic depressed and hyperpigmented scar of a previous leishmanial infection. The Montenegro skin test was positive in all the patients, serology in 84%, direct smear in 47%, histopathology in 37% and culture in 26%. The strains were characterized as L. braziliensis panamensis by electrophoresis of isoenzymes. Possible risk factors in development of MCL were found to be female sex and the lack of past treatment of CL. The mucosal involvement was mild in the majority of the patients, the infection was localized in the nasal mucosal (nasal septum and inferior turbinate) in 91% of the patients, and the most common symptoms were epistaxis, nasal obstruction and rhinorrhea.