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Biomedical subjects

I Mora

Publications and source records attributed to I Mora.

At least 19 recordsLinked to original sources
PubMed2006

Prevalence of human papilloma virus infection of the uterine cervix in women with abnormal cervical cytology.

PURPOSE OF INVESTIGATION: To determine the prevalence of human papillomavirus (HPV) using polymerase chain reaction (PCR) in women with abnormal cytology results. METHODS: A prospective study of 215 women with abnormal cytology results referred consecutively to the cervical pathology clinic was carried out. A second cervical cytology using the Bethesda System was performed on all the patients to confirm the initial diagnosis, as well as to test for the presence of HPV by PCR and a colposcopy and punch biopsy in cases presenting with an abnormal pattern on colposcopy. The sensivitiy, specificity, and positive and negative predictive value (PPV and NPV) were calculated using 2 x 2 tables. RESULTS: The women aged 35 years or younger presented a higher percentage of HPV infection (85.6%) than the women over 35 years of age (54%). The highest percentage of women with a positive result for HPV was found in those with a cytological high-grade squamous intraepithelial lesion (HSIL) (85.5%), as compared with 47.4% of the women with a cytological low-grade squamous intraepithelial lesion (LSIL). HPV infection has a high negative predictive value (93.2% of cases) and a high sensitivity (93.5%) for the detection of HSIL by biopsy, although the specificity and positive predictive value were low, 51.5% and 52.1%, respectively. CONCLUSION: Patients with cytological HSIL have a high prevalence of HPV infection.

Adult↗
PubMed1993

H reflexes in close muscles: cross-talk or genuine responses?

At rest, common peroneal nerve stimulation induced weak H responses in the peroneus longus (PL) and/or in the tibialis anterior (TA) muscles in half the subjects. The genuine H response of each muscle had to be proved since cross-talk could be suspected. PL and TA H responses were identified since (i) the reflex was often observed in only one muscle; (ii) H and M recruitment curves of each muscle were not systematically correlated; (iii) weak voluntary contractions induced opposite reflex changes in the antagonist PL and TA; (iv) direct stimulation of one of the muscles did not induce any cross-talk in the other provided that the EMG was of low voltage. It is concluded that H reflexes of close muscles can be studied independently.

Adolescent↗
PubMed1991

Quantification of T- and H-responses before and after a period of endurance training.

Tendon (T-) and Hoffmann (H-) responses in the soleus muscle were quantified either separately or in association to compare the mononeurons activated and to study their changes after a period of endurance training. In a first experiment T- and H-responses of the same amplitude were compared: the electrical stimulus (inducing the H-response) and the Achilles tendon tap (inducing the T-response) were associated so that the T-response firstly was concomitant with the H-response, and secondly shifted 10 ms forward or back compared to the H-response. From the study of these combined reflexes we would suggest that the same motoneurons are involved in T- or H-responses of the same amplitude. In a second experiment the maximal H-responses, the T-responses and maximal aerobic power (Waer,max) were measured on 20 subjects before and after a period of endurance training. For 75% of the subjects the Waer,max and the reflex parameters (T or H) varied in the same direction: most of them exhibited higher values of both Waer,max and reflex amplitudes while the others had Waer,max and reflex values hardly modified or decreased. The different effects of the training period could reflect the heterogeneity of the subject's status and involvement in sport. In most cases the T:Hmax ratios were also influenced, reflecting the fact that T- and H-responses were not identically affected by training. Thus it is suggested that an endurance training programme can influence not only the excitability of the motoneurons but also the response of the muscle receptors to stretch. An interpretation in terms of a change of spindle receptivity and/or a change in their recruitment due to a greater stiffness of the trained muscles is suggested.

Adult↗
PubMed1989

Detection of hepatitis delta virus RNA in chronic liver disease.

A series of 120 patients with chronic delta hepatitis virus (HDV) were investigated using a newly developed assay for the detection of serum delta RNA and this marker was correlated with other markers of HDV infection. The assay was shown to be both specific and sensitive and provides a direct non-invasive measurement of HDV infectivity. Serum HDV RNA was detected in 51.2% of all patients and in about 64% of those who were liver HDV antigen positive. Its presence was particularly associated with the early stages of the disease where it was found in 83% of cases with chronic active hepatitis (CAH) and progressively less common in CAH associated with cirrhosis and in inactive cirrhosis. The presence of both HBeAg (and HBV DNA) and high levels of HDV RNA in the sera of 5 of the patients analysed, clearly demonstrates simultaneous replication of both HBV and HDV. The serum HDV RNA 'slot blot' assay described in this study should prove invaluable in elucidating further the natural history of delta hepatitis and in monitoring antiviral therapy.

Adult↗
PubMed1989

Detection of proteins encoded by the pre-S region of hepatitis B virus in the sera of HBsAg carriers: relation to viral replication.

In order to determine the relationship between the presence of pre-S1 and pre-S2 proteins and the level of hepatitis B virus (HBV) replication, a study of 94 HBsAg chronic carriers, 15 anti-HBe positive patients who suffered a viral reactivation and 12 HBeAg, HBV-DNA positive cases under antiviral therapy, has been carried out. Pre-S1 and pre-S2 antigens were detected by RIA using polystyrene beads coated with anti-preS1 or anti-preS2 (Dr W. Gerlich, Göttingen) and 125I-anti-HBs as tracer. The presence of pre-S1 and pre-S2 antigens was detected in 74 (79%) and 85 (90%), respectively, out of the 94 HBsAg chronic carriers included. The level of these antigens was significantly higher in HBeAg, HBV-DNA positive patients than in the other patients (p less than 0.05). Among anti-HBe positive patients suffering a reactivation, a significant increase of pre-S1 and pre-S2 levels was observed, concurring with ALT exacerbation and HBV-DNA positivity. After reactivation, the level of pre-S antigens returned to the basal values. A significant decrease in pre-S antigen levels (p less than 0.05) among patients who respond to recombinant interferon therapy was observed, while no changes were detected among non-responder cases. The detection of pre-S1 and pre-S2 antigens in serum is more frequent in those patients with high viral replication. Furthermore, among anti-HBe carriers with a viral reactivation, synthesis of pre-S antigens takes place again.

Adult↗
PubMed1989

Virus-like particles associated with reverse transcriptase activity in acute sporadic non-A,non-B hepatitis.

Reverse transcriptase activity was tested in 65 patients with non-A,non-B hepatitis, with positive results in 2 acute sporadic cases with favorable outcome. Virus-like particles were observed in ultra-thin sections of successive serum samples from one of the reverse transcriptase activity-positive patients by electron microscopy. These results suggest that some non-A,non-B hepatitis types could be related to a virus-like agent associated with a reverse transcriptase activity.

Adult↗
PubMed1988

Assessment of hepatitis B virus DNA levels in chronic HBsAg carriers with or without hepatitis delta virus superinfection.

In order to document the incidence of hepatitis delta virus (HDV) replication markers and their relationship to HBV replication, 91 HBsAg chronic carriers were studied. Of these, 51 were anti-HD-positive (19 HBeAg-positive and 32 anti-HBe-positive). Liver HDAg was found in 75% of anti-HD-positive patients. Of the 19 patients who had anti-HD and HBeAg, 13 were HBV-DNA-positive. None of the anti-HBe patients were HBV-DNA-positive. No differences with respect to HBV-DNA concentration were observed between anti-HD-positive and -negative patients. Liver HDAg was detected with similar frequency in patients who were HBeAg- and HBV-DNA-positive (63.6%) and in those who were anti-HBe-positive (78.5%), with no statistically significant difference. HBcAg and HDAg were simultaneously detected in 36% of the anti-HD cases. Patients with anti-HD and HBV-DNA had the highest levels of transaminases (SGPT). Our results suggest that in certain patients HDV and HBV replication coexists without mutual inhibition.

Adult↗
PubMed1988

Elevation of 2',5'-oligoadenylate synthetase activity and HLA-I associated beta 2-microglobulin in response to recombinant interferon-gamma administration in chronic HBeAg-positive hepatitis.

We have analyzed the immunomodulatory effect of 5 and 2 MU of recombinant interferon-gamma (rIFN-gamma) administered to 8 carriers of HBsAg with histologically proven chronic active liver disease. After the rIFN-gamma administration, T8 lymphocyte subsets showed a significant decrease (basal vs. 4 weeks, p less than 0.05) and T4/T8 ratios were higher than the basal values in 6/8 patients. Serum levels of the HLA class I-associated beta 2-microglobulin increased significantly in all patients within the first week of treatment, both with the high (p less than 0.01) and the low (p less than 0.05) rIFN-gamma dose. Then, differences between the two doses reached statistical significance (p less than 0.03). Similar results (p less than 0.05) were obtained by measuring the 2',5'-oligoadenylate (2-5A) synthetase activity, co-occurring with the decreases in HBV-DNA polymerase and HBV-DNA, although no differences were found between the two doses. In addition, levels of 2-5A synthetase correlated significantly with those of beta 2-microglobulin (r = 0.743, p less than 0.01). On the other hand, after the rIFN-gamma administration, all the patients had liver membrane antibodies (LMA) in their serum (p less than 0.05); only two patients (who were anti-HD positive) showed LMA at the end of the follow-up. rIFN-gamma has both antiviral and immunomodulatory effects in HBeAg carriers with chronic liver disease.

2',5'-Oligoadenylate Synthetase↗
PubMed1988

Antiviral effect of recombinant gamma interferon in chronic hepatitis B virus infection: a pilot study.

A pilot study has been designed in order to determine the tolerance and effectiveness of recombinant interferon gamma (rIFN-gamma) in chronic hepatitis B virus (HBV) infection. Eight HBsAg, HBeAg, HBV-DNAp and HBV-DNA-positive patients were randomly assigned to one of two groups. In group 1, 0.25 mg of rIFN-gamma/m2 body surface was administered daily for 28 days to 4 patients. In group 2, 0.10 mg of rIFN-gamma was administered to 4 patients under the same conditions. All the patients concluded the treatment and were observed over 11 more months. During treatment, 6 out of 8 patients showed decreased levels of HBV-DNA and HBV-DNAp. In addition, by the 8th month of follow-up, six patients became negative for HBV-DNAp and 2 for HBcAg; all patients remained positive for HBV-DNA. At the end of the study, only 2 patients remained negative for HBV-DNAp, 4 for HBcAg and one became negative for HBV-DNA. No differences in antiviral effect were observed between the two groups. Furthermore, the T4/T8 lymphocytes ratio increased during therapy. In conclusion, rIFN-gamma may play a role in the treatment of chronic HBV infection.

Adult↗
PubMed1988

Different levels of hepatitis B virus replication among hepatitis Be antigen-positive chronic carriers.

Detection of hepatitis B virus DNA polymerase (HBV DNA-pol) activity and of HBV DNA sequences in serum allowed to distinguish the different degrees of HBV replication in chronic HBsAg carriers. The amount of HBV DNA in the serum of 48 HBsAg and HBeAg positive patients in relation with the presence or absence of HBV DNA-pol was determined by dot-blot hybridization. The HBeAg positive cases with HBV DNA-pol activity had significantly higher HBV DNA levels than those which were DNA-pol negative (p less than 0.001). However, no significant differences with respect to liver function tests (transaminase, albumin, gammaglobulin) or to the histological diagnosis were found between both groups. Quantitative detection of serum HBV DNA in HBsAg chronic carriers may be helpful for learning the natural history of HBV infection and monitoring the antiviral therapy.

Carrier State↗
PubMed1988

Different doses of recombinant alpha interferon in the treatment of chronic hepatitis B patients without antibodies against the human immunodeficiency virus.

A total of 24 chronic carriers of HBsAg, HBeAg and hepatitis B virus (HBV)-DNA were included in a controlled trial. The patients were randomly assigned to four groups: Group I (n = 6): control; group II (n = 6): 2.5 MU; group III (n = 6): 5 MU and group IV (n = 6): 10 MU rIFN-alpha/m2 body surface 3 times weekly i.m. during 6 months. At the end of the treatment, all patients under therapy, as well as 4 belonging to the control group, lost HBV-DNA polymerase. HBV-DNA became negative in 3 (50%), 1 (17%), and 2 (33%) patients from groups II, III, and IV, respectively, while all patients from the control group maintained HBV-DNA. At 15 months of follow-up, 6 patients (33%) under therapy (2 from each group) and 1 from the control group remained HBV-DNA-negative. Knodell's index decreased significantly on comparing basal and final liver biopsies among patients in group IV (16.0 +/- 1.9 vs 7.0 +/- 1.9, p less than 0.01), while no changes were observed in the other groups. Five patients (27%) developed anti-IFN antibodies during treatment. In summary, although low doses of rIFN-alpha (2.5-5 MU) had an antiviral effect on HBV replication, only patients treated with 10 MU showed a significant decrease in liver histological activities. In addition, the effectiveness of rIFN-alpha therapy may be negatively influenced by the appearance of anti-IFN antibodies.

Adult↗
PubMed1987

A controlled study of treatment with recombinant interferon alpha in chronic hepatitis B virus infection: induction and maintenance schedules.

To determine the antiviral effect of recombinant-interferon (rIFN)-alpha in hepatitis B virus (HBV) chronic infection, a controlled study was carried out. A total of 20 HBsAg chronic carriers (18 chronic active hepatitis and 2 chronic persistent hepatitis) were included. All of them had remained HBeAg, HBV-DNA and HBV-DNA polymerase (HBV-DNAp) positive at least six months before treatment. The patients were randomly assigned to two groups: control (n = 10), and treatment (n = 10). A dose of 5.5 megaunits of rIFN-alpha/m2 body surface was administered every day for 21 days (induction) and twice a week for six months thereafter (maintenance). No basal differences were observed between the two groups. No case of intolerable toxicity was observed. One treated patient died in a car crash in the second month. At the end of the first week of therapy, 7/10 (70%) of the treated patients became HBV-DNAp negative. However, in the fifth month only 2 patients remained HBV-DNAp negative and also became HBV-DNA and HBeAg negative. In contrast, no changes in viral markers among control cases were observed. In conclusion, rIFN-alpha has an antiviral effect on chronic HBV infection; however, the induction plus maintenance schedule is not useful to obtain a permanent effect.

Chronic Disease↗
PubMed1987

Receptors for polymerized human serum albumin in plasma derived hepatitis B vaccines.

The presence of polymerized human serum albumin receptors (pHSA-R) in two hepatitis B virus (HBV) plasma derived vaccines (HB-Vax, Merck Sharp and Dohme; Hevac-B, Pasteur) was detected by three methods, using pHSA polystyrene coated beads and 125I-anti-HBs (method 1) and polyclonal (method 2) or monoclonal (method 3) peroxidase conjugated anti-HBs. Only a very weak reaction was found for pHSA-R in HB-Vax vaccine when the tests were performed in undiluted vaccine. No reactivity in 1/100 dilution (normally used to test pHSA-R in serum samples) was observed. In contrast, Hevac-B vaccine contained pHSA-R activity in 1/100 dilution as tested by any of the three methods. Furthermore, the level of pHSA-R detected in Hevac-B vaccine is similar to that observed in asymptomatic HBsAg carriers with the same HBsAg concentration. In summary, Hevac-B vaccine contains pHSA-R, whilst HB-Vax shows only weakly reacting pHSA-R, probably insufficient to develop anti-pHSA-R antibodies.

Hepatitis B↗
PubMed1987

Changes of hepatitis B virus (HBV) markers during prolonged recombinant interferon alpha-2A treatment of chronic HBV infection.

Eleven HBsAg chronic carriers were treated with recombinant-interferon (rIFN)-alpha-2A with either 20 X 10(6) (n = 6) or 10 X 10(6) IU/m2 body surface (n = 5), i.m. twice weekly for 6 months. HBV-markers were tested monthly for 15 months. Throughout the follow-up, 6 patients (54%) became HBeAg, HBV-DNAp and HBV-DNA negative (responders). In addition, 8 were HBcAg-negative, 10 anti-HBc-IgM-negative and 2 HBsAg/IgM complexes negative. All patients gave polymerized human serum albumin receptors and HBsAg-positive results. The low rIFN dose seems to be more efficient for clearing HBV-markers than the high dose. Responder patients already showed lower (P less than 0.05) HBsAg concentration and HBsAg/IgM complexes levels in their basal samples as compared to non-responders, and exhibited under rIFN treatment significant decreases (P less than 0.05) in all HBV-markers studied. In conclusion, the most reliable HBV-markers to be assayed in the evaluation of antiviral therapy are HBV-DNA, HBV-DNAp or HBcAg. The testing of pHSA-R, HBsAg/IgM complexes and anti-HBc-IgM does not seem to be very useful.

Adolescent↗
PubMed1987

Identification of different degrees of hepatitis B virus (HBV) replication by serological (HBV-DNAp, HBcAg and HBV-DNA) and histological (HBcAg) methods.

The incidence of HBV-DNA polymerase, HBV-DNA and serum and liver HBcAg in 104 chronic HBsAg carriers was studied. HBV-DNA was the most frequently detected marker, followed by HBcAg and HBV-DNAp. According to their individual or combined presence, four different serological patterns of viral replication were discerned: 53 patients had all these markers, 30 had HBV-DNA but lacked HBV-DNAp (15 with and 15 without HBcAg) and 21 had no such markers detectable. The simultaneous positivity for all of those markers was observed only in HBeAg-positive patients. HBV-DNA alone or along with HBcAg was found in a similar incidence irrespective of the HBe system. Liver HBcAg was found in all but four patients with and in four without HBV-DNA. Viral DNA concentration was significantly (p less than 0.001) higher when HBV-DNAp tested positive. Indeed, HBeAg rather than anti-HBe patients had higher (p less than 0.005) levels of HBV-DNA. In HBeAg-positive patients, the nuclear HBcAg staining was significantly (p less than 0.05) higher when HBV-DNAp tested positive. In DNA polymerase-negative patients, but positive for HBV-DNA, those with or without HBcAg had a similar percentage of core antigen staining. The same distribution was seen in anti-HBe, HBV-DNA-positive patients. However, the mean percentage of hepatocytes displaying cytoplasmic HBcAg did not differ significantly among patients with HBV-DNA, irrespective of the HBe system and the HBV-DNAp status. Such patients had significantly (p less than 0.001) higher ALT levels than those without viral DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗