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J Morales

Publications and source records attributed to J Morales.

At least 55 records · Page 3Linked to original sources
PubMed2001

Immunological evaluation of Escherichia coli-derived hepatitis C virus second envelope protein (E2) variants.

Two variants of the hepatitis C virus (HCV) E2 envelope protein, lacking the C-terminal domain and comprising amino acids 458-650 (E2A) and 382-605 (E2C), respectively, were efficiently produced in BL21 (DE3) Escherichia coli cells. E2A and E2C were used to immunize mice. The E2C variant induced the maximal mean antibody titer. Anti-E2C mouse sera reacted mainly with E2 synthetic peptides covering the 70 amino acid N-terminal region of the E2 protein. Moreover, a panel of anti-HCV positive human sera recognized only the E2C protein (28.2%) and the synthetic peptide covering the HVR-1 of the E2 protein (23.1%). These data indicate the existence of an immunologically relevant region in the HVR-1 of the HCV E2 protein.

Animals↗
PubMed2001

Repeated administration of hepatitis C virus core-encoding plasmid to mice does not necessarily increase the immune response generated against this antigen.

DNA immunization is a promising approach in generating immune responses to infectious pathogens in many different animal models. In an effort to augment the anti-[hepatitis C virus (HCV) core] immune response, generated after DNA immunization, the importance of vaccination regimen regarding dose and boosting was investigated in the present study. Balb/c mice were intramuscularly injected with an expression plasmid encoding a truncated variant comprising amino acids 1-176 of the HCV core protein. The highest anti-core antibody titres (1:3700) were detected in mice inoculated with 50-100 microg of core-encoding plasmid. Additionally, we demonstrated that antibody levels induced by a single injection of DNA could be further increased by boosting with a second injection of DNA three weeks after primary immunization. However, administration of additional doses or lengthening of the resting period between inoculations resulted in similar or even weaker anti-core antibody responses. A similar anti-(HCV core) lymphoproliferative response was also detected in animals that had the highest level of anti-core antibodies. These results indicate that, in clinical trials, vaccination regimen might be a critical factor in generating optimal anti-(HCV core) immune responses after genetic immunization.

Animals↗
PubMed2001

Effects of blood volume restitution following a portal hypertensive-related bleeding in anesthetized cirrhotic rats.

The aim of this study was to investigate the influence of different strategies of blood volume restitution in the outcome of portal hypertension-related bleeding in anesthetized cirrhotic rats. Gastrointestinal hemorrhage was induced by sectioning a first order branch of the ileocolic vein in 38 cirrhotic rats (common bile duct ligation and occlusion). The subsequent hypovolemic shock was treated with no transfusion (n = 17), moderate transfusion (50% of expected blood loss, 5 mL, n = 11), and total transfusion (100% of expected blood loss, 10 mL, n = 10). At the end of the blood transfusion period (minute 15), mean arterial pressure (MAP) partially recovered in rats receiving moderate transfusion or no transfusion but decreased in the 10-mL transfusion group ( downward arrow 12 +/- 43%, P < .05 vs. no transfusion and 5 mL transfusion). After transfusion, groups given no or 5 mL transfusion remained hemodynamically stable. However, rats receiving 10 mL transfusion continued to deteriorate with persistent bleeding and progressive fall in MAP ( downward arrow 65 +/- 12%; P < .05 vs. no transfusion and 5 mL transfusion). Collected blood loss was significantly greater in the 10-mL group (20.0 +/- 1.5 g) than in groups given 5 mL (15.9 +/- 2.8 g; P < .05) or no transfusion (13.2 +/- 2.1 g; P < .05 vs. 10 mL and 5 mL transfusion). Survival in the no transfusion group was 47%. Rats given 5-mL transfusion had 64% survival. The worst survival was observed in the 10-mL transfusion group (0% survival; P < .05). We concluded that a transfusion policy aimed at completely replacing blood loss worsens the magnitude of bleeding and mortality from portal hypertensive-related bleeding in cirrhotic rats. On the contrary, moderate blood transfusion allowed hemodynamic stabilization and increased survival.

Animals↗
PubMed2001

Carpal collapse in rheumatoid arthritis--prevalence and clinical significance: a preliminary study.

OBJECTIVE: To evaluate the prevalence and clinical significance of carpal collapse in Mexican women with rheumatoid arthritis (RA). METHODS: We evaluated the carpal height ratio (CHR) of 97 women with RA and 90 healthy women. Using plain radiographs of both hands, measurements were performed by 2 radiologists in a single blind fashion. We analyzed functional class, characteristics and duration of the disease, and presence of rheumatoid factor (RF). RESULTS: CHR values of the controls were 0.49+/-0.02 (values reported in American Caucasian women are 0.54+/-0.04). Thirty-five patients had carpal collapse (defined as CHR < or = 0.43) in the right hand, 30 in the left hand, and 23 bilaterally. Carpal collapse was associated with RF seropositivity and roentgenographic degree of progression (p < 0.01), as well as with cumulative dose of steroids. As 95% of the patients were right-handed, dexterity was not apparently affected. We observed no differences in Health Assessment Questionnaire, functional class, or disease duration between patients with and those without carpal collapse. CONCLUSION: The definition of carpal collapse may have ethnic related differences. Carpal collapse is common in Mexican women with RA and it is not an indicator of functional limitations.

Adult↗
PubMed2001

An association of cervical inflammation with high-grade cervical neoplasia in women infected with oncogenic human papillomavirus (HPV).

Previous reports of genital conditions, such as nonspecific genital infection/sore or vaginal discharge associated with cervical cancer (L. A. Brinton et al., J. Natl. Cancer Inst. (Bethesda), 79: 23-30, 1987; C. J. Jones et al., Cancer Res., 50: 3657-3662, 1990), suggest a possible link between either genital tract inflammation or changes in bacteria flora consistent with bacterial vaginosis (BV) and cervical cancer. To test whether changes in vaginal bacterial flora or the degree of cervical inflammation are associated with women having a human papillomavirus (HPV) infection or with women infected with oncogenic HPV having high-grade cervical lesions (high-grade squamous intraepithelial lesions or cancer), we conducted a case-control study of women <50 years old enrolled in the Costa Rican natural history study of HPV and cervical neoplasia. To test whether BV and inflammation were associated with HPV DNA positivity, Analysis 1 was restricted to women with no or mild (low-grade or equivocal) cytological abnormalities, and the degree of inflammation and Nugent score (a measure of BV) were compared between women infected (n = 220) and not infected (n = 130) with HPV. To test whether BV and inflammation were associated with high-grade lesions, Analysis 2 was restricted to women infected with oncogenic HPV, and the degree of inflammation and Nugent score were compared between women with (n = 95) and without (n = 158) high-grade cervical lesions. In Analysis 1, BV and cervical inflammation were not associated with HPV infection. In Analysis 2, BV was not associated with high-grade lesions. However, we found a marginally significant positive trend of increasing cervical inflammation associated with high-grade lesions in oncogenic HPV-infected women, (P(trend) = 0.05). Overt cervicitis was associated with a 1.9-fold increase in risk of high-grade lesions (95% confidence interval, 0.90-4.1). The results of this study suggest that cervical inflammation may be associated with high-grade lesions and may be a cofactor for high-grade cervical lesions in women infected with oncogenic HPV.

Adult↗
PubMed2000

A truncated variant of the hepatitis C virus core induces a slow but potent immune response in mice following DNA immunization.

Vaccination of BALB/c mice with pIDKCo, a plasmid containing the coding sequence for the first 176 amino acids of the hepatitis C virus (HCV) core protein, induced both humoral and cellular specific immune responses. Particularly, the level of anti-core antibodies increased slowly with time up to a mean value above 1:8000 that was generally superior than that found in anti-HCV positive individuals. Six out of nine anti-HCV positive human sera were able to inhibit at different extent the binding of mouse anti-core sera to a recombinant capsid protein. Our results show that it is possible to elicit a potent humoral and cellular immune response against the HCV core antigen in mice following DNA immunization.

Animals↗
PubMed2000

Population-based study of human papillomavirus infection and cervical neoplasia in rural Costa Rica.

BACKGROUND: Human papillomavirus (HPV) is the main cause of cervical neoplasia. Because few population-based studies have investigated the prevalence of type-specific infection in relation to cervical disease, we studied a high-risk population, estimating the prevalence of HPV infection and the risk associated with various HPV types. METHODS: We screened 9175 women in Guanacaste, Costa Rica, to obtain a referent standard final diagnosis, and tested 3024 women for more than 40 types of HPV with a polymerase chain reaction-based system. RESULTS: Among women with normal cytology, HPV infections peaked first in women younger than 25 years, and they peaked again at age 55 years or older with predominantly non-cancer-associated types of HPV and uncharacterized HPV types. Low-grade squamous intraepithelial lesions (LSILs) (n = 189) decreased consistently with age. The prevalence of high-grade squamous intraepithelial lesions (HSILs) (n = 128) peaked first around age 30 years and again at age 65 years or older. Seventy-three percent of LSILs were HPV positive, with HPV16 being the predominant type (16% of positive subjects). HPV was found in 89% of HSILs and 88% of cancers, with HPV16 being strongly predominant (51% and 53% of positive subjects). Virtually all HSILs and cancers had cancer-associated HPV types, with high odds ratios (ORs) and attributable fractions around 80%. Risk for HPV16 was particularly high (OR for HSILs = 320, 95% confidence interval [CI] = 97-1000; OR for cancer = 710, 95% CI = 110-4500). CONCLUSIONS: We confirm the early decline of HPV infection with age but note increased prevalence after menopause, which could be related to a second peak of HSILs, an observation that warrants further investigation. At least 80% of HPVs involved in cervical carcinogenesis in this population have been characterized. Polyvalent vaccines including the main cancer-associated HPV types may be able to prevent most cases of cervical disease in this region.

Adult↗
PubMed2000

HPV DNA testing in cervical cancer screening: results from women in a high-risk province of Costa Rica.

CONTEXT: Human papillomaviruses (HPVs) are known to cause most cervical cancer worldwide, but the utility of HPV DNA testing in cervical cancer prevention has not been determined. OBJECTIVE: To provide comprehensive data on the screening performance of HPV testing for the most common carcinogenic types, at different levels of analytic sensitivity. DESIGN: Laboratory analysis conducted during 1993-1995, using 3 cytologic techniques and cervicography, followed by colposcopic examination of women with any abnormal cervical finding, to detect all high-grade intraepithelial lesions and cancer (reference standard of clinically significant disease). The HPV testing was performed subsequently with masking regarding clinical findings. SETTING: Guanacaste Province, Costa Rica, a region with a high age-adjusted incidence of cervical cancer. PARTICIPANTS: Of 11742 randomly selected women, 8554 nonpregnant, sexually active women without hysterectomies underwent initial HPV DNA testing using the original Hybrid Capture Tube test; a stratified subsample of 1119 specimens was retested using the more analytically sensitive second generation assay, the Hybrid Capture II test. MAIN OUTCOME MEASURES: Receiver operating characteristic analysis of detection of cervical high-grade intraepithelial lesions and cancer by HPV DNA testing based on different cut points of positivity. RESULTS: An analytic sensitivity of 1.0 pg/mL using the second generation assay would have permitted detection of 88.4% of 138 high-grade lesions and cancers (all 12 cancers were HPV-positive), with colposcopic referral of 12.3% of women. Papanicolaou testing using atypical squamous cells of undetermined significance as a cut point for referral resulted in 77.7% sensitivity and 94.2% specificity, with 6.9% referred. Specificity of the second generation assay for positivity for high-grade lesions and cancer was 89.0%, with 33.8% of remaining HPV DNA-positive subjects having low-grade or equivocal microscopically evident lesions. The higher detection threshold of 10 pg/mL used with the original assay had a sensitivity of 74.8% and a specificity of 93.4%. Lower levels of detection with the second generation assay (<1 pg/mL) proved clinically nonspecific without gains in diagnostic sensitivity. CONCLUSIONS: In this study population, a cut point of 1.0 pg/mL using the second generation assay permitted sensitive detection of cervical high-grade lesions and cancer, yielding an apparently optimal trade-off between high sensitivity and reasonable specificity for this test. The test will perform best in settings in which sensitive detection of high-grade lesions and cancer is paramount. Because HPV prevalence varies by population, HPV testing positive predictive value for detection of high-grade lesions and cancer will vary accordingly, with implications for utility relative to other cervical cancer screening methods.

Adult↗
PubMed2000

Comparison between Tendency-Oriented Perimetry (TOP) and octopus threshold perimetry.

OBJECTIVE: To compare the results obtained by a new ultra-short automated perimetry test known as Tendency-Oriented Perimetry (TOP), which is an algorithm based on estimation of thresholds from information gathered from adjacent points with those obtained by a standard bracketing approach. TOP is designed to save up to 1/5 of the time taken by standard strategy by presenting each stimulus once on each location (instead of 4 to 6 times per location with the standard technique) and reaching a final threshold estimate by gathering information from responses to adjacent locations. DESIGN: Prospective, multicenter, observational comparative case series. PARTICIPANTS/METHODS: Four academic institutions provided data from testing 57 subjects, 15 with a normal ocular exam and 42 with a variety of visual field abnormalities. A total of 228 visual fields were analyzed. Two examinations of standard thresholding testing (Octopus program 32) and two examinations of the TOP program were obtained in each subject the same day. MAIN OUTCOME MEASURES: Comparison of global indices such as mean deviation (MD), square root of loss of variance (sLV), topographical defects, point by point differences, reproducibility, sensitivity/specificity, and time required to complete the test. RESULTS: Correlation coefficient of global indices between both tests was high, with mean deviation of r = 0.97 (SE[YX] +/- 1.65 decibels) and square root of loss variance of r = 0.93 (SE[YX] +/- 1.10 dB). Mean sensitivity tended to be 1 dB higher while MD tended to be 1 dB lower with TOP strategy. Reproducibility was equally good between both tests for threshold determination as well as for all global indices (MS, MD per quadrant, and LV). Cluster criteria for abnormality demonstrated TOP versus 32: sensitivity of 89/87; specificity of 90/77; positive predictive value of 96/91; negative predictive value of 75/68; and accuracy of 89/84. Mean time taken by this beta version of TOP was 4.05 minutes standard deviation +/- 0.55 versus the standard 32 version taking 14.65 minutes standard deviation +/- 3.75. CONCLUSIONS: TOP was four times faster than the traditional full-threshold technique and was successful in detecting visual field abnormalities. Defects with TOP tended to be smaller, shallower, and with softer edges than with standard approach. TOP could prove an alternative to traditional perimetric techniques.

Adult↗
PubMed2000

Isolation and partial characterization of two types of muscle collagen in some cephalopods.

Collagen from muscle of volador (Illex coindetii), pota (Toradopsis eblanae), and white octopus (Eledone cirrhosa) was characterized in terms of anatomical location, sex, and maturity. Collagen content was higher in arms than in mantle in all three species; there were also significant differences in octopus depending on the age of the individual. Concerning sex, the largest differences in the amount of collagen were found in relation to total protein content. In volador and pota, collagen solubility was higher in the mantle than in the arms, and in the case of pota there were also sex-related differences. In octopus males, solubility was higher in the arms. Two types of collagen, I and V, were identified as the principal constituents in all three species and at both anatomical locations (mantle and arms). The electrophoretic mobility of the alpha2 chain differed in the two types of collagen, but the amino acid compositions of the collagen were similar in the mantle and arms in all three species examined.

Amino Acids↗
PubMed2000

Expression and immunological evaluation of the Escherichia coli-derived hepatitis C virus envelope E1 protein.

Immunological response against envelope protein E1 is very important in natural hepatitis C virus (HCV) infection, although it is insufficient to clear the viraemia. The HCV genomic region encoding the first 149 amino acids of the envelope E1 protein (E1(340), amino acids 192-340) was expressed in Escherichia coli (to a level of 30% of the whole cellular proteins) and purified to 85%. We measured the immune response in rabbits and mice as well as the reactivity against 37 human sera raised against the whole recombinant protein and E1-encoding peptides. From this, 51.1% of human sera were found to react with E1(340). High-level antibodies against E1(340) were obtained in rabbits and mice when immunized. These antibodies had a similar peptide-recognition pattern to that described previously for human sera. The most reactive region was located at the N-terminus of the E1 protein. Cellular immunity in mice was evaluated by delayed-type hypersensitivity assay. It revealed the induction of a CD4+ T-cell-mediated response by this protein. This E1(340) protein and the animal-derived anti-E1 sera are immunological tools that could aid in the monitoring and development of anti-HCV therapies.

Amino Acid Sequence↗
PubMed2000

Measurement of radiotherapy x-ray skin dose on a chest wall phantom.

Sufficient skin dose needs to be delivered by a radiotherapy chest wall treatment regimen to ensure the probability of a near surface tumor recurrence is minimized. To simulate a chest wall treatment a hemicylindrical solid water phantom of 7.5 cm radius was irradiated with 6 MV x-rays using 20x20 cm2 and 10x20 cm2 fields at 100 cm source surface distance (SSD) to the base of the phantom. A surface dose profile was obtained from 0 to 180 degrees, in 10 degrees increments around the circumference of the phantom. Dosimetry results obtained from radiochromic film (effective depth of 0.17 mm) were used in the investigation, the superficial doses were found to be 28% (of Dmax) at the 0 degrees beam entry position and 58% at the 90 degrees oblique beam position. Superficial dose results were also obtained using extra thin thermoluminescent dosimeters (TLD) (effective depth 0.14 mm) of 30% at 0 degrees, 57% at 90 degrees, and a metal oxide semiconductor field effect transistor (MOSFET) detector (effective depth 0.5 mm) of 43% at 0 degrees, 62% at 90 degrees. Because the differences in measured superficial doses were significant and beyond those related to experimental error, these differences are assumed to be mostly attributable to the effective depth of measurement of each detector. We numerically simulated a bolus on/bolus off technique and found we could increase the coverage to the skin. Using an alternate "bolus on," "bolus off" regimen, the skin would receive 36.8 Gy at 0 degrees incidence and 46.4 Gy at 90 degrees incidence for a prescribed midpoint dose of 50 Gy. From this work it is evident that, as the circumference of the phantom is traversed the SSD increases and hence there is an inverse square fluence fall-off, this is more than offset by the increase in skin dose due to surface curvature to a plateau at about 90 degrees. Beyond this angle it is assumed that beam attenuation through the phantom and inverse square fall-off is causing the surface dose to reduce.

Breast Neoplasms↗
PubMed2000

Developmental arrest and physical entrapment eliminates supernumerary Ganaspis xanthopoda parasitoids in Drosophila melanogaster.

Superparasitism is a common condition in which a single host is injected with more than 1 parasitoid egg, but only 1 parasite survives to adulthood, and the remaining animals are eliminated. Here, for the first time, we show that supernumerary Ganaspis xanthopoda, endoparasitoids that invade Drosophila melanogaster, are physiologically suppressed during embryonic development. Whereas the suppressed supernumerary embryos can develop to the first larval instar, their subsequent growth is blocked because they become physically trapped within a novel multicellular envelope that is formed during late embryogenesis. Supernumerary embryos can produce this envelope when cultured in vitro even if they are separated from dominant embryos. Our results suggest that physiological suppression programs supernumerary individuals for developmental arrest, starvation, and necrotic or apoptotic death.

Acridine Orange↗
PubMed2000

Ocular effects of apraclonidine in Horner syndrome.

OBJECTIVE: To determine the location of action of apraclonidine, an alpha-adrenergic receptor agonist that reduces aqueous production and lowers intraocular pressure (IOP). METHODS: The study cohort consisted of 6 patients with Horner syndrome (decreased or absent sympathetic innervation of 1 eye). We instilled 1% apraclonidine into the affected eye, and the changes in IOP and pupil diameter (PD) of both eyes were measured over 4 hours. In a separate session, apraclonidine was instilled into the normal eye and the measurements were repeated. RESULTS: The average baseline IOP was 16.3 mm Hg for affected eyes and 16.7 mm Hg for normal eyes. The average maximum ipsilateral reduction in IOP was 5.8 mm Hg in affected eyes and 5.2 mm Hg in normal eyes; this difference was not statistically significant. The average baseline PDs for affected and normal eyes were 3.2 mm and 4.2 mm, respectively. Instillation of apraclonidine into affected eyes produced mydriasis of 1.0 to 4.5 mm; baseline anisocoria reversed in all patients. There was no significant change in the PD of normal eyes after ipsilateral instillation of apraclonidine. CONCLUSIONS: Apraclonidine's major site of pharmacologic action for reduction of aqueous production is on postjunctional alpha(2) receptors in the ciliary body. The up-regulation of alpha receptors that occurs with sympathetic denervation unmasks apraclonidine's alpha(1) effect, which clinically causes pupil dilation. Apraclonidine may be a useful medication for the diagnosis of Horner syndrome. Arch Ophthalmol. 2000;118:951-954

Adrenergic alpha-Agonists↗