Search PubMed⌕ Search

Biomedical subjects

F Lopes

Publications and source records attributed to F Lopes.

13 recordsLinked to original sources

CK-19 expression by RT-PCR in the peripheral blood of breast cancer patients correlates with response to chemotherapy.

BACKGROUND: The recent introduction of sensitive RT-PCR-based techniques for the detection of epithelial antigen expression, such as CK-19, in the peripheral blood and bone marrow of breast cancer patients may provide an opportunity to evaluate tumor response at the molecular level, even in the absence of measurable disease while patients are still receiving chemotherapy. METHODS: We studied serially collected blood samples of 53 patients with breast cancer before, during, and after adjuvant, neoadjuvant, and palliative chemotherapy to evaluate its effects on the expression of CK-19 measured by RT-PCR. RESULTS: The percentage of CK-19 RT-PCR positivity decreased consistently from 43% (23/53) before chemotherapy to 14.3% (7/49), and to 18.9% (7/37) after 3 and 6 cycles, respectively (chi-square for linear trend = 7.948; p = 0.0048). Furthermore, there was a significant correlation between a negative CK-19 at three months and the response to chemotherapy (p = 0.024). CONCLUSION: We conclude that RT-PCR negativity for CK-19 expression at 3 months after the beginning of chemotherapy correlates with tumor response and, as treatment progresses, there is a significant trend for the occurrence of more negative RT-PCR results. Further studies are needed to confirm if this technique can be useful to assess response to chemotherapy in patients without measurable disease and if negativation of CK-19 expression while on chemotherapy is of prognostic significance.

Adult↗

Effects of presynchronization and bovine somatotropin on pregnancy rates to a timed artificial insemination protocol in lactating dairy cows.

The objective was to examine the effects of presynchronization and bovine somatotropin (bST) on pregnancy rates to a timed artificial insemination protocol in lactating dairy cows. Lactating Holstein cows (n = 543) were assigned randomly in a 2 x 3 factorial experiment in which cows received a presynchronization treatment or not, and were treated with bST (500 mg) at 63 +/- 3, 73 +/- 3, or 147 +/- 3 d postpartum. The latter group was used as a control. Presynchronization treatment consisted of two injections of PGF2alpha (25 mg) given 14 d apart, with the second injection of PGF2alpha being administered 12 d before initiation of the timed artificial insemination protocol. All cows received GnRH (100 microg) at 63 +/- 3 d postpartum, an injection of PGF2alpha (40 mg) 7 d later, a GnRH injection at 48 h after PGF2alpha and were inseminated 16 to 20 h later. Cows were resynchronized if determined to be nonpregnant at ultrasonography at 32 d after insemination with a GnRH injection (100 microg), an injection of PGF2alpha (40 mg) 7 d later, and a GnRH injection at 48 h after PGF2alpha and were inseminated 16 to 20 h later. Cows were examined for pregnancy at 32 d and reexamined at 74 d after insemination. No differences in pregnancy rates were observed between cows receiving bST treatment at 63 +/- 3 d postpartum or at 73 +/- 3 d postpartum. An interaction between presynchronization and bST treatment indicated that pregnancy rates were increased for cows treated with bST when cows were presynchronized. When anestrous cows were excluded from the analyses, both an effect of bST and of presynchronization were observed, indicating that bST increased pregnancy rates regardless of presynchronization treatment and that presynchronization also increased pregnancy rates independently of bST treatment. Presynchronization and bST treatment may be used to increase first-service pregnancy rates to a timed artificial insemination protocol.

Animals↗

Acyloxymethyl as a drug protecting group. Part 6: N-acyloxymethyl- and N-[(aminocarbonyloxy)methyl]sulfonamides as prodrugs of agents containing a secondary sulfonamide group.

Tertiary N-acyloxymethyl- and N-[(aminocarbonyloxy)methyl]sulfonamides were synthesised and evaluated as novel classes of potential prodrugs of agents containing a secondary sulfonamide group. The chemical and plasma hydrolyses of the title compounds were studied by HPLC. Tertiary N-acyloxymethylsulfonamides are slowly and quantitatively hydrolysed to the parent sulfonamide in pH 7.4 phosphate buffer, with half-lives ranging from 20 h, for 7d, to 30 days, for 7g. Quantitative formation of the parent sulfonamide also occurs in human plasma, the half-lives being within 0.2-2.0 min for some substrates. The rapid rate of hydrolysis can be ascribed to plasma cholinesterase, as indicated by the complete inhibition observed at [eserine] = 0.10 mM. These results suggest that tertiary N-acyloxymethylsulfonamides are potentially useful prodrugs for agents containing a secondary sulfonamide group, especially with pKa < 8, combining a high stability in aqueous media with a high rate of plasma activation. In contrast, N-[(aminocarbonyloxy)methyl]sulfonamides 7h-j do not liberate the parent sulfonamide either in aqueous buffers or in human plasma and thus appear to be unsuitable for development as sulfonamide prodrugs.

Biotransformation↗

Acyloxymethyl as a drug protecting group. Part 7: Tertiary sulfonamidomethyl ester prodrugs of benzylpenicillin: chemical hydrolysis and anti-bacterial activity.

Tertiary sulfonamidomethyl esters of benzylpenicillin (4) were synthesised and evaluated as a new class of potential prodrugs for beta-lactam antibiotics. Their hydrolysis in aqueous buffers was studied by HPLC and reveal a U-shaped pH rate profile with a pH-independent process extending from ca. pH 2 to ca. pH 10. This pathway is characterised by kinetic data that are consistent with a unimolecular mechanism involving rate-limiting iminium ion formation and penicillinoate expulsion. Benzylpenicillin and the corresponding sulfonamide are the ultimate products detected and isolated, indicating that beta-lactam ring opening is much slower than ester hydrolysis. As expected from the high reactivity, benzylpenicillin esters (4) displayed similar in vitro antibacterial activity to benzylpenicillin itself. Compared to the benzylpenicillin derivatives, sulfonamidomethyl esters of benzoic, clofibric and valproic acids display a much higher stability, giving rise to a Brønsted beta1g value of -0.96 and suggesting that tertiary sulfonamidomethyl esters may be useful prodrugs for carboxylic acid drugs with pKa > 4.

Anti-Bacterial Agents↗

Cold: a risk factor for stroke?

A retrospective study was performed to investigate seasonal variation in stroke incidence and to evaluate the hypothesis that cold might be a risk factor. Data were obtained from the central registry of the Hospital de S. João, Porto, Portugal, concerning 4048 patients consecutively admitted for cerebrovascular disease during a period of 33 months. Monthly admissions for stroke and its subtypes were related to mean values of ambient temperature using linear correlation. There was a strong inverse correlation between average temperature and total admissions for cerebrovascular disease (r = -0.72, P < 0.00005), intracerebral haemorrhage (r = -0.66, P < 0.00005), ischaemic stroke (r = -0.46, P = 0.007) and transient ischaemic attack (r = -0.41, P = 0.017). These correlations were independent of any seasonal variation in the number of hospital admissions due to all causes. No relation was found between temperature and subarachnoid haemorrhage. The rhythmometric analysis showed the presence of a statistically significant rhythm with an acrophase in the coldest months. These results support the hypothesis of stroke being a chronorisk disease to which cold might represent a triggering factor.

Cerebrovascular Disorders↗

Short-term memory and cognitive variability in adult fragile X females.

We investigated the possibility that adult fragile X [fra(X)] heterozygotes have a distinct or specific cognitive profile, with a particular focus on visuospatial and/or memory deficits. With a sample of 13 adult fra(X) female carriers (2 fra(X) positive) and age-matched control women, we performed 2 tests: Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Revised Visual Retention Test (RVRT). An identifiable cognitive profile was not evident in the study group, but significant differences were evident in RVRT performance in number correct and number of errors when compared to controls and normative data. The combination of the WAIS-R and RVRT data suggests that the short-term memory component of the tasks may be of more significance than visuospatial performance in the deficits observed.

Adult↗

Comparison of 3, 5 and 7 days' treatment with Quinimax for falciparum malaria in Guinea-Bissau.

For treatment of malaria, the World Health Organization recommends 10 mg of quinine per kg body-weight 3 times a day for at least 7 d. In Guinea-Bissau, as in several other African countries, a 3 d treatment regimen (10 mg/kg twice daily) is currently used. We therefore compared the 3 d treatment period with periods of 5 and 7 d. A total of 145 children with clinical malaria due to monoinfection with Plasmodium falciparum, with > or = 20 parasites per 200 leucocytes, were treated with intramuscular Quinimax 10 mg per kg body-weight twice daily for 3, 5 or 7 d. The children were then examined once weekly for 4 weeks. Following the 3 d treatment regimen, 34 of 43 children (79%) had parasitaemia on day 28 or before; following the 5 d treatment regimen, 36 of 40 children (90%) did so; and following the 7 d treatment regimen, 7 of 62 children (11%) were parasitaemic at that time. This study thus suggests that the currently recommended 3 d Quinimax treatment regimen in Guinea-Bissau for moderate and severe malaria is not effective.

Adolescent↗

Low-dose quinine for treatment of Plasmodium falciparum malaria in Guinea-Bissau.

The recommended dose of 10 mg quinine/kg bodyweight 3 times a day for 7 days for treatment of malaria is so high that many patients experience cinchonism. We have earlier obtained good results with 7 days' treatment with 20 mg Quinimax/kg bodyweight divided into 2 daily doses. In order to identify the lowest effective dose, children with symptomatic malaria were treated with quinine twice a day for 7 days. They were assigned to 1 of 3 groups treated daily with 10 mg/kg, 15 mg/kg, or 20 mg/kg bodyweight, respectively; 42, 46, and 34 children, respectively, received treatment and completed 5 weeks of follow-up. The cumulative percentages of all children with parasitaemia during follow-up on day 28 or before were 33%, 13% and 12%, respectively. Treatment with 10 mg quinine salt/kg daily for 7 days gave a significantly higher rate of recrudescence than did treatment with 15 or 20 mg/kg daily. Thus at least 15 mg of quinine salt/kg bodyweight daily should be recommended for treatment of symptomatic Plasmodium falciparum malaria in Guinea-Bissau.

Adolescent↗

Efficacy of ivermectin against the bloodsucking insect, Rhodnius prolixus (Hemiptera, Triatominae).

Ivermectin (0.2 mg/kg body weight) caused a high mortality in nymphs and adults of Rhodnius prolixus following a single meal in mice sub-cutaneously injected with the drug. This effect was more evident in nymphs of 1st-and 2nd-instar than in older nymphs and adults. Third-instar nymphs presented a high mortality when fed on mice treated with ivermectin 24 and 48 hours previously, while mortality was significantly reduced in nymphs fed on mice treated 72 hours before. Surviving 3rd-instar nymphs did not molt. When adult females were fed once on mice treated for 24 hours with ivermectin there was a considerable reduction in egg production. This inhibition was not reversed by a second feeding on normal mice. We concluded that sub-lethal doses of ivermectin caused toxic effects interfering in the neuro-endocrine control of development and reproduction of this bloodsucking insect.

Animals↗

[HIV, HPV, and syphilis prevalence in a women's penitentiary in the city of São Paulo, 1997-1998].

Incarcerated women as a group are particularly vulnerable to infections. The lack of public programs for prevention, early diagnosis, and treatment contribute to the increase in the incidence and prevalence of diseases in general and especially sexually transmitted diseases. This article aims to estimate the prevalence of infection by the human immunodeficiency virus (HIV), human papillomavirus (HPV), and syphilis among inmates at the Women's Penitentiary in the State capital of São Paulo, Brazil. All inmates were invited to participate in the study, which was divided into two stages: 1. STD/AIDS preventive workshops including interviews and 2. laboratory tests. The interview covered knowledge of STD/AIDS, risk behavior, and individual reproductive health history. A total of 262 women, with a mean age of 32.4 years and limited schooling, participated in more than one stage of the study. Prevalence rates were 14.5% for HIV, 16.3% for high-oncogenic-risk HPV probes, 4.8% for low-oncogenic-risk HPV probes, and 5.7% for syphilis. The authors conclude that STD/HIV constitute a serious health problem in the prison system, requiring urgent preventive measures.

Adult↗

[Psychiatric manifestations of a new variant of Creutzfeldt-Jakob disease. Apropos of a case].

UNLABELLED: The new variant of Creutzfeldt-Jakob disease (nvCJD) was first described in the UK in 1996 (16). The nvCJD differs from sporadic, genetic and iatrogenic CJD. Creutzfeldt-Jakob disease is closely associated with an abnormal isoform PrPSc of a cell-surface glycoprotein, prion protein (14). Molecular analysis suggests that nvCJD is caused by the same prion strain as bovine spongiform encephalopathy (BSE) (4, 10). To the end of September 2000, there have been 82 cases of nvCJD in the UK. We report the second French case of nvCJD to our knowledge (5, 13). CASE REPORT: This 36 year old woman was referred by a local general practitioner with a 6 month history of psychiatric symptoms of major depressive disorder. According to her family, the patient had suffered from personality change for several months before the onset of depression including apathy, emotional lability, infantile affect. There was no history of health problems. As she was admitted to the psychiatric department of our hospital in Paris suburbs, she presented a major depressive disorder. There were no specific psychiatric features allowing distinction from common depressive disorders, except a marked emotional lability. The patient's condition progressed rapidly within the following days. She presented memory impairment and disorientation. Drug treatments, clomipramine (125 mg/day) and venlafaxine (200 mg/day), were used with no benefit. She presented subsequently transient delusions and auditory hallucinations, fleeting for some hours. The predominant delusional themes were somatic type and pregnancy. The delusions were concomitant with delusions of the onset of cognitive impairment. The patient tested negative for the P 14.3.3 protein in the CSF. Computed tomography scan of the brain did not show any relevant abnormality. The electroencephalogram showed non specific slow wave activity. The neurological symptoms developed 7 months after the onset of depressive symptoms including ataxia, myoclonus, excessive daytime drowsiness, headache. After the onset of neurological symptoms, the illness progressed rapidly over the next 2 months with cognitive impairment, particularly memory impairment, myoclonus, ataxia, incontinence of urine and progressive immobility leading to dependency. CSF tests were negative. She was referred to a neurology department where the diagnosis was confirmed by brain biopsy (detailed elsewhere). The patient died in a state of akinetic mutism. DISCUSSION: The clinical features of our patient were consistent with previous descriptions of nvCJD, mainly those of the National CJD Surveillance Unit studies (17): early psychiatric symptoms, prolonged duration of illness (median: 14 months), earlier age at death, compared with sporadic CJD. Psychiatric symptoms occur in the clinical course in about a third of cases of sporadic CJD (3). In contrast, of the 35 cases that have died of nvCJD identified in the study by Will et al. (17), 34 suffered from early and prominent psychiatric symptoms, mainly depression and anxiety. In most of the patients, the first symptoms were psychiatric. Drug treatment was used in most cases, some patients had a transient improvement (18). The patient without psychiatric symptoms reported by the NCJDSU (17) was emotionally labile. Infantile affect and emotional lability, found in our patient, are frequently reported in other studies (1, 18). Schizophreniform disorders have been described during the clinical course, with auditory and visual hallucinations and paranoid delusions (17, 18). The insomnia and excessive daytime drowsiness our patient presented have been described in similar cases (18). Investigations are important to rule out alternative diagnoses. EEG records do not show periodic triphasic complexes as in sporadic CJD. The P 14.3.3 protein in the CSF is positive in half the cases of nvCJD (17). First neurological symptoms developed 6 months after the onset of psychiatric symptoms including ataxia, myoclonus and persistent painful sensory symptoms (17, 18). In most of the cases, MRI brain scans show bilateral pulvinar high signal (17), found subsequently in our patient and detailed elsewhere (13). The terminal stages are progressive cognitive impairment, helplessness and akinetic mutism. CONCLUSION: The first symptoms of this patient were purely psychiatric and difficult to distinguish from common psychiatric disorders. Clinical surveillance of human prion disease is crucial in France, as in UK. The link with BSE has dramatically highlighted the need for neurological and neuropsychological precise investigations.

Adult↗