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Biomedical subjects

J Gonzales

Publications and source records attributed to J Gonzales.

At least 19 recordsLinked to original sources

A short-term study of the safety, pharmacokinetics, and efficacy of ritonavir, an inhibitor of HIV-1 protease. European-Australian Collaborative Ritonavir Study Group.

BACKGROUND: Reverse-transcriptase inhibitors have only moderate clinical efficacy against the human immunodeficiency virus type 1 (HIV-1). Ritonavir is an inhibitor of HIV-1 protease with potent in vitro anti-HIV properties and good oral bioavailability. METHODS: We evaluated the antiviral activity and safety of ritonavir in a double-blind, randomized, placebo-controlled phase 1 and 2 study of 84 HIV-positive patients with 50 or more CD4+ lymphocytes per cubic millimeter. The patients were randomly assigned to one of four regimens of ritonavir therapy, or to placebo for four weeks and then (by random assignment) to one of the ritonavir regimens. RESULTS: During the first 4 weeks, increases in CD4+ lymphocyte counts and reductions in the log number of copies of HIV-1 RNA per milliliter of plasma were similar among the four dosage groups, but in the three lower-dosage groups there was a return to base-line levels by 16 weeks. After 32 weeks, in the seven patients in the highest-dosage group (600 mg of ritonavir every 12 hours), the median increase from base line in the CD4+ lymphocyte count was 230 cells per cubic millimeter, and the mean decrease in the plasma concentration of HIV-1 RNA (as measured by a branched-DNA assay) was 0.81 log (95 percent confidence interval, 0.40 to 1.22). In a subgroup of 17 patients in the two higher-dosage groups, RNA was also measured with an assay based on the polymerase chain reaction, and after eight weeks of treatment there was a mean maximal decrease in viral RNA of 1.94 log (95 percent confidence interval, 1.37 to 2.51). Adverse events included nausea, circumoral paresthesia, elevated hepatic aminotransferase levels, and elevated triglyceride levels. Ten withdrawals from the study were judged to be related to ritonavir treatment. CONCLUSIONS: In this short-term study, ritonavir was well tolerated and had potent activity against HIV-1, but its clinical benefits remain to be established.

Adult

Lack of deleterious effect of slow-release sodium fluoride treatment on cortical bone histology and quality in osteoporotic patients.

We evaluated the effects of intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate therapy on cortical bone histology, reflection ultrasound velocity (material strength) and back-scattered electron image analysis (BEI) in 26 osteoporotic patients before and following therapy. All measurements were made on transiliac crest bone biopsies obtained before and following 2 years of therapy in each patient. For all 26 patients there were no significant changes in cortical bone histomorphometric parameters. In 15 patients in whom bone material quality was assessed by reflection ultrasound, there was no change in velocity (4000 +/- 227 SD to 4013 +/- 240 m/s). BEI disclosed no mineralization defects or the presence of woven bone. Mean atomic number (density) of bone increased slightly, but significantly (9.261 +/- 0.311 to 9.457 +/- 0.223, P = 0.031). While these changes are less marked than those observed for cancellous bone, they indicate that this form of therapy does not adversely affect cortical bone remodelling.

Adult

Variable effects of human and canine polymorphonuclear leucocytes on vascular smooth muscle tone.

OBJECTIVE: Previous studies have shown variable effects of human and canine polymorphonuclear leucocytes (neutrophils) on vascular tone. The aim of this study was to identify whether these variations in neutrophil function are due to species differences. METHODS: Canine and human arterial rings (with and without endothelium) were contracted with the thromboxane A2 analogue U46619, and then exposed to isolated neutrophils. RESULTS: Human neutrophils caused a significant relaxation of the human mammary arterial rings, and the relaxation was unaffected by the cyclo-oxygenase inhibitor indomethacin, enhanced by superoxide dismutase (SOD), and inhibited by oxyhaemoglobin. The relaxant effect of human neutrophils was also diminished upon pretreatment with NG-monomethyl-l-arginine (L-NMMA), indicating that the vasorelaxant material released by the neutrophils was nitric oxide (NO). Human neutrophils also relaxed canine femoral arterial rings, and the relaxant effect was potentiated by SOD and inhibited by pretreatment with oxyhaemoglobin or L-NMMA, confirming that the vasorelaxation was via release of NO. Canine neutrophils, on the other hand, caused an endothelium dependent contraction of autologous femoral arterial rings. This vasoconstriction was not affected by indomethacin, SOD, oxyhaemoglobin, or L-NMMA. However, treatment of canine neutrophils with the 5-lipoxygenase inhibitor piriprost attenuated (p < 0.02) their contractile effect on vascular rings, suggesting that neutrophil generated 5-lipoxygenase products were probably responsible for smooth muscle contraction. Presence of the leukotriene C4 and D4 receptor antagonist FPL 55,712 totally blocked the contractile effects of canine neutrophils, indicating that femoral arterial ring contraction was mediated by peptido-leukotrienes. CONCLUSIONS: The endothelium dependent nature of the canine neutrophil induced contraction suggests that the 5-lipoxygenase product leukotriene A4 is taken up by endothelial cells for conversion to peptido-leukotrienes. Since SOD had no effect and FPL 55,712 totally blocked the vasoconstrictor effects of canine neutrophils, it appears that the vasoconstrictor effects of the latter are mediated primarily through peptido-leukotrienes. In contrast, the vasorelaxation by human neutrophils is mediated through release of NO.

Animals

Colposcopic and histologic findings and human papillomavirus (HPV) DNA test variability in young women positive for HPV DNA.

The purpose of this study was to determine the prevalence of human papillomavirus (HPV)-related disease in women positive for HPV DNA by using a commercially available DNA detection kit and to compare these results to HPV DNA variability observed in repeated sampling. Young women attending family planning clinics who were positive for HPV DNA on routine screening were asked to return for a repeat HPV DNA test, cytology, colposcopy, and biopsy if indicated. Of the 78 women examined, 35% had biopsy-verified low-grade dysplasia of the cervix, and 64% had evidence of HPV-related disease somewhere in the anogenital area. Fifty percent of the women had a negative test on repeat sampling, but there was no association between DNA persistence at the second visit and colposcopic/histologic findings. In conclusion, the minority of women positive for HPV DNA have latent infection. In addition, variability in detection is common and unrelated to the presence of HPV-related disease.

Adolescent

Natural history of anal cytologic abnormalities and papillomavirus infection among homosexual men with group IV HIV disease.

Previous studies have demonstrated a high prevalence of anal cytologic abnormalities as well as anal human papillomavirus (HPV) infection among homosexual men with group IV HIV disease. However, the natural history of these changes in this population has not yet been studied. To this end, 37 homosexual men with group IV HIV disease attending an outpatient HIV clinic were followed at approximately 9-month intervals for an average of 17 months, using anal cytology, anoscopy, anal biopsy, and anal HPV DNA hybridization. During the study, the proportion of the 37 subjects with anal cytologic abnormalities increased from 27 to 65%. The proportion of subjects with any grade of anal intraepithelial neoplasia rose from 8 to 32%, with high-grade anal intraepithelial neoplasia increasing from 0 to 16%. The proportion of subjects with anal HPV infection increased from 60 to 89%, and infection with multiple HPV types was noted in at least 48%. We conclude that a large proportion of homosexual men with group IV HIV disease develop anal cytologic abnormalities, including anal intraepithelial neoplasia, over a short period of time. Together with a rapidly increasing incidence of anal cancer among single, never-married men in the San Francisco Bay area, these results suggest that these men may be at significant risk of development of anal cancer.

Adult

Gamete and zygote intrafallopian transfers and related techniques.

Until recently, most authors reported superior results (ie, higher implantation and pregnancy rates) with gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) compared with results using in vitro fertilization-embryo transfer (IVF-ET). According to these investigators, the advantages of tubal over uterine transfer are related mainly to a stable tubal environment and a more appropriate arrival time of the embryo into the uterine cavity. However, more recently, the use of IVF-ET has been increasingly extended to etiologies other than tubal infertility. Indeed, the recent simplification of this technique and the achievement of pregnancy rates comparable to those obtained with tubal transfers have seriously questioned the value of ZIFT and any other type of tubal embryo transfer. As discussed in this review, the results obtained with various transfer procedures in nontubal infertility must still prove ZIFT to be a more effective procedure than IVF-ET. Efforts to develop transcervical methods of transfer to the tube have not translated into higher pregnancy rates than those with IVF-ET. On the other hand, laboratory conditions appear to affect embryos in ways not corrected by the tubal milieu. Negative effects of laboratory conditions on embryos are confirmed by differences in results between GIFT and ZIFT that are accentuated with age. The results obtained with GIFT in patients 40 years of age and older seem to emphasize not only the high compliance of the endometrial receptivity but also the relevance of the biologic potential of the embryos in the process of implantation at this age.

Adult

Detection of human papillomavirus DNA in anal intraepithelial neoplasia and anal cancer.

Forty anal paraffin-embedded tissue specimens from 24 subjects were studied for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31, and 33, herpes simplex virus (HSV), Epstein-Barr virus, and cytomegalovirus DNA by using the polymerase chain reaction. These tissues ranged from histologically normal to invasive squamous cell carcinoma. HPV DNA was detected in the invasive anal cancer tissues of 11 of 13 subjects. HPV types were segregated by histopathological severity, with HPV 16 associated exclusively with high grade anal intraepithelial neoplasia and invasive cancer. HPV types 6 and 11 were associated with condyloma and low grade anal intraepithelial neoplasia. HPV DNA in situ hybridization studies confirmed the presence of HPV DNA in the invasive cancer tissues of 6 of 12 subjects. HPV DNA in these tissues was highly focal and primarily associated with invasive cell nests that demonstrated the greatest degree of squamous differentiation. HSV DNA was detected only in association with advanced disease, being found in the cancer tissues of 5 of 13 subjects, and in 3 of 4 subjects with high grade anal intraepithelial neoplasia, but was not detected by in situ hybridization. Epstein-Barr virus and cytomegalovirus DNA were not detected in the 40 tissue specimens. We conclude that HPV infection may play an important role in the pathogenesis of anal cancer. The association between HSV infection and high grade anal disease suggests that HSV infection may also play a role in disease progression.

Adult

Assessment by reflection ultrasound method of the effect of intermittent slow-release sodium fluoride-calcium citrate therapy on material strength of bone.

It has been suggested that fluoride therapy, while increasing bone mass, produces bone with inferior mechanical properties. In the present report this hypothesis was tested using a novel reflection ultrasound technique. Transiliac crest bone biopsies were obtained from 16 patients with osteoporosis and vertebral compression fractures (12 women and 4 men, mean age 56 years) before and after approximately 2 years of intermittent slow-release sodium fluoride therapy (25 mg twice a day) combined with continuous calcium citrate supplementation. Samples were analyzed by a reflection ultrasound method, which analyzes ultrasound velocity with a sample site resolution of 200 microns and thus provides a measure of the mechanical property of single trabeculae (material). For the group, mean fractional change in velocity increased 6.1 +/- 2.3% (SEM) from a mean value of 3303 +/- 80 to 3484 +/- 55 m/s (p = 0.028). A total of 13 patients (81%) demonstrated higher velocities after treatment. Thus reflection ultrasound analysis of bone appears to provide a sensitive means of assessing changes in the material property of bone. Furthermore, these results suggest that the treatment regimen utilized in these patients improves strength of bone at the material or trabecular level largely independently of change in bone mass. The combination therapy also increased spinal (L2-L4) bone density for the group as assessed by dual-photon absorptiometry (5.3 +/- 2.0%). There was no significant correlation between the change in ultrasound velocity and bone density (r = 0.0026, p = 0.996).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Measurement of mechanical properties of bone material in vitro by ultrasound reflection: methodology and comparison with ultrasound transmission.

An ultrasound reflection technique was designed and implemented to study the mechanical properties of bone material. The technique uses the fact that an ultrasound beam produced in water undergoes total internal reflection off a bone sample at a critical angle formally related to the velocity of a pressure wave in bone. When the plane of scattering is rotated around the normal to the sample surface, the critical angle varies with a periodic dependence dictated by the intrinsic symmetry of the bone structure at the point being examined. Most current measurements of sound velocity are made using transmission techniques. A double-blind intercomparison between this technique and a transmission technique, which was previously validated against tensile mechanical testing, was performed for samples of isotropic materials and of human cortical bone. Strong correlations were found for both sets of samples. For the isotropic materials the velocities were approximately equal, but for bone they were on average 11% higher in reflection than in transmission. This was the result both of the higher frequency employed in reflection (3.5 rather than 2.25 MHz) and of the different effects of sample imperfections on the two measurements. In particular, the reflection technique used in this work studied the surface of the sample, but the ultrasound beam in the transmission method propagated through its interior. In assessing the mechanical properties of bone specimens by ultrasound, the reflection technique samples a discrete bone surface element and the transmission method analyzes the entire volume of the specimen. Thus the reflection technique may yield a measure of the mechanical property of bone trabeculae that is largely unaffected by the mass of the entire specimen, but mass and the structural density of the specimen affect the transmission method.

Biomechanical Phenomena

The association between human papillomavirus deoxyribonucleic acid status and the results of cytologic rescreening tests in young, sexually active women.

We examined the utility of cytologic rescreening tests in women who had positive test results for human papillomavirus deoxyribonucleic acid but who were diagnosed as having benign conditions at cytologic testing. One hundred twenty-five Papanicolaou smears from women who were screened for human papillomavirus deoxyribonucleic acid were sent routinely to a private laboratory for diagnoses. These slides were then reviewed independently by two pathologists who were blinded to the human papillomavirus deoxyribonucleic acid results. The effects of cytologic rescreening in cases of both positive and negative human papillomavirus deoxyribonucleic acid were assessed by calculating z scores. Cervical intraepithelial neoplasia was diagnosed in 40% by pathologist A and in 20% by pathologist B of the human papillomavirus-positive subjects compared with none diagnosed by the private cytology laboratory (z = 3.09, p less than 0.005 and z = 1.98, p less than 0.05, respectively). No significant differences were found in the human papillomavirus-negative group. We conclude that cytologic rescreening in human papillomavirus deoxyribonucleic acid-positive women who were initially diagnosed as having benign cytologic results will yield a significant proportion of cases of cervical intraepithelial neoplasia.

Adolescent

Immune status as a determinant of human papillomavirus detection and its association with anal epithelial abnormalities.

One hundred and twenty Danish homosexual men were enrolled to characterize risk factors for anal type-specific human papillomavirus (HPV) expression and to examine its association with anal epithelial atypia. Detection of HPV strongly correlated with immunosuppression measured by T-lymphocyte subset markers and rose nearly linearly from 7.3% among subjects with CD4/CD8 ratios above 1.0 to 35.3% among those with a ratio below 0.4 (p trend = 0.003). No association was found between presence of HPV and a wide range of lifestyle factors including number of sex partners/year, smoking, alcohol consumption and illegal drug intake. However, self-reported history of anal condyloma in the past year was correlated with HPV (p less than 0.001). Simultaneous testing for presence of HPV in the oral cavity showed evidence of HPV 16,18 and 31,33,35. Anal smears were abnormal in 19.5% of the men and correlated strongly with presence of HPV (OR = 6.1, p less than 0.001). Type-specific associations were found with HPV 31/33/35 (OR = 8.5) and HPV 16/18 (OR = 3.1) only. The association remained significant after adjusting for immune status. Overall, HPV was detected in 50% of the cases with abnormal smears. However, HPV was found in all subjects with abnormal smears and a CD4/CD8 ratio below 0.4, compared to only 3 of 14 subjects with abnormal smears and a ratio greater than or equal to 1.3. In conclusion, (1) HPV may be missed in a substantial number of infected subjects with a normal immune system. This may have an impact on studies trying to describe risk factors for HPV transmission and its correlation with cancer development. (2) The finding of HPV 16,18 and 31,33,35 in the oral cavity makes oral-genital sexual activity at least a hypothetical route of transmission for these HPV types. (3) HPV appears to play a central role in the development of anal epithelial abnormality.

Adult

Interaction of human immunodeficiency and papilloma viruses: association with anal epithelial abnormality in homosexual men.

During the 7th annual follow-up of our cohort of homosexual men in 1989, we tested the hypotheses that infection with human immunodeficiency virus (HIV) may enhance the expression of human papilloma virus (HPV) and that the development of anal epithelial abnormality is related to a biologic interaction between these two viruses. Overall, 41 (39%) of the 105 men had anal swabs positive for one or more genotypes of HPV 6/11, 16/18 or 31/33/35. Twenty-three (53%) of the 43 HIV-positive subjects harbored HPV compared to 18 (29%) of the 64 HIV-negative subjects (p = 0.012), including higher prevalence rates for HPV genotypes 16/18 (p = 0.01), 6/11 (p = 0.007), and 31/33/35 (p = 0.07). Multivariate logistic regression analysis of the HIV-positive subjects showed low CD4+ cell counts to be an independent risk factor for detection of HPV (p = 0.04) and in particular for HPV genotypes 31/33/35 (p = 0.02) and 6/11 (p = 0.07). In contrast, similar analysis of the HIV-negative subset showed that a positive antibody test for syphilis was associated with HPV (p = 0.03). Anal epithelial abnormalities were found in 13 (14%) of 92 technically adequate cytologic smears and were strongly associated with detection of any HPV genotypes by the dot-blot method (p = 0.01), and in particular with HPV genotypes 6/11 (p = 0.001). None of 15 subjects with HPV detected only by PCR had anal epithelial abnormality. We propose a viral interaction model, in which HIV-related immune deficiency allows reactivation of HPV, with a subsequent or concomitant appearance of epithelial abnormality.

Anal Canal

Anal intraepithelial neoplasia and anal papillomavirus infection among homosexual males with group IV HIV disease.

Ninety-seven male homosexuals with the acquired immunodeficiency syndrome or other group IV human immunodeficiency virus disease were studied for anal human papillomavirus infection and intra-anal cytological abnormalities. Human papillomavirus DNA was detected in 52 subjects (54%), and 38 subjects (39%) were found to have abnormal anal cytological findings; anal intraepithelial neoplasia was detected in 15 specimens (15%). Abnormalities on anal cytological smear were significantly associated with the presence of human papillomavirus DNA, with a risk ratio of 4.6. Infection with multiple human papillomavirus types was common (12%) and was associated with a risk ratio for cytological abnormalities of 39.0. Median T4 counts of subjects with abnormal cytological findings were significantly lower than those with normal findings. These studies indicate that immunosuppressed male homosexuals have a high prevalence of anal human papillomavirus infection and anal intraepithelial neoplasia, and this population may be at significant risk for the development of anal cancer.

Acquired Immunodeficiency Syndrome

[Bacteriological studies of the problem "Epidemic losses in hares and deer in habitats with high cultivation of 00-rapeseed"].

Within the scope of the research work for possible reasons of the so-called "wildlife mortality" more than 900 specimens of 440 animals (183 hares, 153 deer, 14 rabbits found dead, and 98 hares and 6 deer shot by hunters) were checked for the presence of Clostridia in inner organs. The results show that in 40.3% of the animals found dead but only in 13.3% of the hunted hares Clostridia were to be found. Out of the isolated Clostridia strains 24.4% could not be identified; potentially pathogenic species were found in 78.3% of isolates of hares, 81.7% of those of deer and in 9.2% of those of hunted hares. 23.9% of the isolates were C. perfringens. Considering the known epizootiology of clostridioses it can be concluded that clostridia certainly play a role in losses of wildlife, as well in hares as in deer. Triggering factors could lie in the kind of feed which is available for animals in modern agrarian landscape. During the critical period in autumn and winter there are mainly crop plants like rapeseed, wheat and barley only available for wildlife.

Animals

Lamellar bodies of cultured human fetal lung: content of surfactant protein A (SP-A), surface film formation and structural transformation in vitro.

Lamellar bodies were isolated from dexamethasone and T3-treated explant cultures of human fetal lung, using sucrose density-gradient centrifugation. We examined their content of surfactant apoprotein A (SP-A), and their ability to form surface films and to undergo structural transformation in vitro. SP-A measured by ELISA composed less than 2% of total protein within lamellar bodies; this represented, as a minimum estimate, a 2-12-fold enrichment over homogenate. One- and two-dimensional gel electrophoresis also suggested that SP-A was a minor protein component of lamellar bodies. Adsorption of lamellar bodies to an air/water interface was moderately rapid, but accelerated dramatically upon addition of exogenous SP-A in ratios of 1:2-16 (SP-A:phospholipid, w/w). Similar adsorption patterns were seen for lamellar bodies from fresh adult rat and rabbit lung. Lamellar bodies incubated under conditions that promote formation of tubular myelin underwent structural rearrangement only in the presence of exogenous SP-A, with extensive formation of multilamellate whorls of lipid bilayers (but no classical tubular myelin lattices). We conclude that lamellar bodies are enriched in SP-A, but have insufficient content of SP-A for structural transformation to tubular myelin and rapid surface film formation in vitro.

Cell Fractionation

Glucocorticoid stimulation of fatty acid synthesis in explants of human fetal lung.

We examined the effects of glucocorticoids and thyroid hormone (T3) on fatty acid synthesis, fatty acid composition and fatty acid synthetase activity in explants of human fetal lung (16-23 wk gestation). Explants were cultured 1-7 days in the absence (control) or presence of dexamethasone (10 nM) and/or T3 (2 nM). In control explants fatty acid synthesis and fatty acid synthetase activity increased 200% and 455%, respectively, between 1 and 5 days. Dexamethasone (10 nM) stimulated fatty acid synthesis (tritiated water incorporation) 155% and fatty acid synthetase activity 117% after 5 days in culture. T3 (2 nM) was not stimulatory, either alone or in the presence of dexamethasone. Dexamethasone increased the proportion of newly synthesized fatty acid recovered in phosphatidylcholine from 72% (control) to 90% (P less than 0.02) of total fatty acid. Dexamethasone stimulation of fatty acid synthetase activity was consistent with a receptor-mediated process: (1) stimulation was saturable and dose-dependent (Kd = 1.5 +/- 0.3 nM); (2) the potency of glucocorticoid analogs and other steroids reflected their glucocorticoid activity; (3) stimulation was reversible when cortisol was removed from the medium. Stimulation by dexamethasone was apparent within 24 h of hormone exposure, and increased to a maximum between 4 and 6 days. Fatty acid synthetase activity was higher in Type II cells (3.54 +/- 0.58 nmol malate/min per mg protein) than in fibroblasts from treated explants. Although both cell types responded to hormone treatment the stimulation was greater for Type II cells (200% vs. 75% increase). The fatty acid composition of PC showed increases in 14:0 and 16:1 with culture alone which were further stimulated by dexamethasone but not T3. These results indicate glucocorticoid stimulation of fatty acid synthesis and are consistent with a key role for fatty acid synthetase in the hormonal induction of pulmonary surfactant phosphatidylcholine synthesis in cultured fetal lung.

Adult

Evidence of mucin M1 antigens in seminal plasma and normal cells of human prostatic urethra in relation to embryonic development and tumors.

By employing immunoperoxidase methodology, using monoclonal antibodies against the peptide core of gastric mucins (M1 antigens), we demonstrate the presence of M1 mucin-producing cells that are associated with the prostatic urethral epithelium and located mainly in the veru montanum area near the prostatic ductal and utriculus junctions. The significance of these M1 cells is not yet clear. Using an immunoradiometric assay, these M1 mucins were found predominantly in the prostatic fraction obtained from seminal plasma. By chromatography on Sepharose 6B and 2B and cesium chloride gradient centrifugation, we demonstrate that high-molecular-weight components (greater than 10(7) Da) show a density of 1.45 g/ml, similar to mucins, and are immunochemically related to peptidic gastric M1 mucins. The particular location of these M1 antigens in prostatic adult urethra and their fetal expression in cloacal structures suggest that, in males, the prostatic urethral epithelium includes some remnant cells from the enteric cloaca. Finally, the presence of mucin-containing cells in the prostatic urethra could possibly explain the histogenesis of the rare benign villous tumors and primary mucinous adenocarcinomas arising from the prostatic urethral epithelium.

Adult

Assisted reproductive technology and superfetation: a case report.

This observation reports a case of human superfetation. Fertilizable oocytes and embryos were obtained after ovarian stimulation in a women already several weeks pregnant. Spontaneous monofetal pregnancy had normal development and the embryos obtained after in vitro fertilization were actually frozen.

Adult