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Biomedical subjects

F Pons

Publications and source records attributed to F Pons.

At least 91 records · Page 5Linked to original sources
PubMed2000

[Thoracoscopic treatment of pulmonary hydatidosis: a case report].

Hydatidosis is a ubiquitous parasitic condition observed in a pulmonary localization in 30 to 40% of cases. The hydatid cyst develops slowly and is well tolerated by the host who presents no signs for a long period. Complications include compression, fissuration, rupture, anaphylactic shock or infection after a latency phase of variable duration. Treatment of pulmonary hydatidosis is classically surgical with enucleation of the cyst by cleavage between the adventice and the anhistic membrane via thorachotomy using the Ugon and Barret procedure. Needle aspiration is also possible via thorachotomy or thoracoscopy. Finally resection of the pulmonary parenchyma can be used to excise the hydatic cyst. We describe a thoracoscopic treatment using specific material, in a man with complications due to a voluminous pulmonary hydatid cyst.

Adult↗
PubMed2000

[New attitudes to the treatment of recurrent idiopathic pneumothorax].

We examine the classical indications for thoracoscopy in case of pneumothorax and recall the therapeutic modalities of thoracoscopic treatment. We then discuss the long-term incidence of this approach, examining outcome in terms of post-operative pain, respiratory function, cost and complications. A comparison of these parameters after thoracoscopy with those observed after classical surgery would favor thoracoscopic management.

Adult↗
PubMed2000

Effects of 14-day spaceflight on myosin heavy chain expression in biceps and triceps muscles of the rhesus monkey.

In rats, changes in myosin expression are induced by the chronic elimination of weight-bearing activity, particularly in the postural muscles. This occurs during spaceflight and hindlimb suspension. Myosin heavy chain (MHC) changes affect fast and slow fiber types differently depending on muscle function. An increase in co-expression of different MHC within the same fiber will signal early changes in muscle fibers. In the rat soleus muscles, the spaceflight-induced increase in fast MHC expression appears to be essentially due to the enhanced or de novo synthesis of IID or IIX MHC. In response to microgravity, the expression of slow-type myosin decreases, while that of fast-type increases. There is scarce information concerning the effect of microgravity on rhesus monkeys (Macaca mulatta), especially on their upper limbs. We investigated the expression of MHC using an immunocytochemical approach to determine the nature and magnitude of the changes in biceps and triceps muscles of rhesus monkeys during the Bion 11 14-day mission.

Adaptation, Physiological↗
PubMed1999

[Sentinel lymph node detection with lymphoscintigraphy and intraoperative probe in malignant melanoma patients].

BACKGROUND: The sentinel lymph node is the first node in a lymphatic basin to receive lymphatic drainage from a tumor site. If this node is free of tumor, then radical lymphadenectomy may be avoided. The goal of this study was to assess the usefulness of lymphoscintigraphy and intraoperative gamma probe in the sentinel node detection in patients with malignant melanoma. METHOD: We prospectively studied 40 patients with malignant melanoma (24 in I/II stages and 16 in III stage). The day before surgery a lymphoscintigraphy with 99mTc-nanocolloid was performed and the first lymph node identified was considered as sentinel node. For intra-operative mapping a hand-held gamma probe was used. RESULTS: Sentinel nodes were identified in 39/40 (97.5%) patients. In 24 patients with I/II stages 34 sentinel nodes were demonstrated (six positive and 28 negative for malignant melanoma). A total amount of 161 regional lymph nodes was harvested, all of them being negative for malignant melanoma. In 16 patients with III stage, 22 sentinel nodes were located (14 positive and eight negative for malignant melanoma). A total of 89 regional lymph nodes were excised in sentinel nodes positive patients (44 positive and 45 negative for malignant melanoma) and 36 lymph nodes in sentinel node negative, all of them negative for malignant melanoma. CONCLUSIONS: In patients with malignant melanoma, lymphoscintigraphy with 99Tc-nanocolloid is useful for the detection of sentinel lymph node. Biopsy of this node is useful for the selection of patients to undertake a lymphadenectomy.

Adult↗
PubMed1999

Significant loss of bone mass in patients with early, active ankylosing spondylitis: a followup study.

OBJECTIVE: To analyze whether inflammatory disease activity plays a substantial role in the loss of bone mass observed in ankylosing spondylitis (AS) patients who have not yet developed ankylosis. METHODS: A longitudinal cohort study of 34 patients with early AS (duration <10 years) without ankylosis was conducted. The mean followup was 19 months. Loss of bone mass in defined regions of the lumbar spine and femoral neck was analyzed by dual x-ray absorptiometry. Patients were grouped according to biologic parameters of disease activity (erythrocyte sedimentation rate or C-reactive protein level). Group 1 consisted of 14 patients with active disease; group 2 comprised 20 patients with inactive disease. Serum levels of interleukin-6 (IL-6) and of hormones (sex, thyroid, and calciotropic), vertebral mobility (Schober test), daily physical activity, and treatment administered were recorded every 6 months for all patients. RESULTS: At the end of the followup period, patients with active AS showed a significant reduction in bone mass in the lumbar spine (mean 1.01 gm/cm2 at study entry versus 0.961 gm/cm2 at followup [P = 0.005]) and femoral neck (0.849 gm/cm2 versus 0.821 gm/cm2 [P = 0.015]), which represented losses of 5% and 3%, respectively. In contrast, no significant reduction in bone mass was observed in patients with inactive AS. As expected, serum IL-6 levels were significantly higher in patients with active AS than in those with inactive disease (mean +/- SD 8.3 +/- 9 pg/ml versus 2.8 +/- 5 pg/ml [P = 0.008]). No significant differences were observed between the 2 groups in any of the other variables analyzed. CONCLUSION: The observation that loss of bone mass in AS occurred only in patients with persistent active disease strongly suggests that inflammatory activity of the disease itself plays a major role in the pathophysiology of the early bone mineral disorders observed in these patients.

Adult↗
PubMed1999

Long-term postmenopausal hormone replacement therapy effects on bone mass: differences between surgical and spontaneous patients.

BACKGROUND: Hormone Replacement Therapy (HRT) begun soon after spontaneous menopause or oophorectomy minimizes or even reverses the loss of bone that occurs normally during those years. The persistence of this HRT protective effect at long-term on bone density, however, is not well documented. AIM: to evaluate the effects of 5 years of HRT in postmenopausal women on bone mineral density of the lumbar spine. SUBJECTS AND METHODS: The 5-year prospective study enrolled 154 postmenopausal women, of them 136 completed the first year and were considered electible to continue the follow-up. These 136 postmenopausal women were allocated to two groups according their origin: surgical (n=68) and spontaneous (n=68). HRT was prescribed and bone mineral density (BMD) was measured at the lumbar spine prior to commencement of therapy, and then yearly for the duration of the study. All patients received a continuous therapy with standard dose (0.625 mg/day) of conjugated equine estrogen (CEE) or 50 microg/day of 17-beta-Estradiol in transdermal therapeutic systems (TTS). Subjects who experienced natural menopause also received 5 mg/day of medroxyprogesterone acetate sequentially added to the last 12 days of estrogen therapy. Treated groups were compared with two non-treated control groups (surgical n=77; spontaneous n=53). RESULTS: Our data showed that HRT increased the BMD of women who had experienced spontaneous menopause. Comparison with a control group revealed that HRT also protected against bone loss in women who had undergone surgical menopause. CONCLUSION: Long term hormone replacement therapy increases bone mineral density in women who have experienced natural menopause, and protects against bone loss in surgically postmenopausal women.

Absorptiometry, Photon↗
PubMed1999

Exclusion of muscle specific actinin-associated LIM protein (ALP) gene from 4q35 facioscapulohumeral muscular dystrophy (FSHD) candidate genes.

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder for which no candidate gene has yet been identified. The gene corresponding to one of the novel human cDNAs that we cloned on the basis of a muscle restricted expression pattern [Piétu G, Alibert O, Guichard B, et al. Genome Res 1996;6:492-503] was mapped in the region of the FSHD1A genetic locus, i.e. one of the loci involved in this muscular dystrophy. The corresponding encoded protein contains a PDZ and a LIM domain, two protein-protein interaction domains, and was very recently shown to bind alpha-actinin-2 and was named ALP (actinin-associated LIM protein) [Xia H, Winokur S, Kuo W, Altherr M, Bredt D. J Cell Biol 1997;139:507-515]. We raised a specific polyclonal anti-ALP serum against an ALP recombinant polypeptide to evaluate the size, level of expression and subcellular localization of ALP in three patients, clearly diagnosed with FSHD disease. Quantitative or qualitative alterations of ALP expression have not been detected in any of them, thus prompting us to exclude ALP as a FSHD gene candidate.

Actinin↗
PubMed1999

Biochemical markers of bone turnover after surgical menopause and hormone replacement therapy.

The objective of this study was to evaluate the effect of surgical menopause and hormone replacement therapy (HRT) on the new biochemical markers of bone turnover. Fourteen women who had undergone surgical menopause and began HRT 3 months after surgery were recruited for a 1-year study. Results were compared with a control group of 31 healthy premenopausal women of similar age. Serum samples were obtained to determine total alkaline phosphatase, bone alkaline phosphatase, propeptides carboxy- and amino-terminal of type I procollagen (PICP, PINP), osteocalcin, tartrate-resistant acid phosphatase, and carboxy-terminal telopeptides of type I collagen (ICTP and serum CTX). Urine samples were analyzed for hydroxyproline, pyridinoline, deoxypyridinoline, alpha- and beta-carboxy-terminal telopeptides of type I collagen (alpha-CTX and beta-CTX), and amino-terminal telopeptide of type I collagen (NTX). Determinations were performed after 3 months of surgical menopause and after 3 and 9 months of HRT. All biochemical markers increased after menopause, and most of them normalized after 9 months of HRT. Serum PINP showed the highest proportion of increased values after surgery among bone formation markers (62%), as well as the highest mean percent increase (101%). Among bone resorption markers in postmenopausal women, urinary beta-CTX, alpha-CTX, NTX, and serum CTX showed the highest proportion of increased values (100%, 67%, 58%, 58%, respectively) as well as the greatest mean percent increase. They were also the markers with the most marked response to HRT. In conclusion, serum PINP is the most sensitive marker of bone formation, whereas beta-CTX is the most sensitive marker of bone resorption after surgical menopause. In addition, both markers showed the highest response after HRT.

Acid Phosphatase↗
PubMed1999

Effect of toluene diisocyanate and its corresponding amines on viability and growth of human lung fibroblasts in culture.

Toluene diisocyanate (TDI) is a highly volatile chemical known to cause occupational asthma in exposed workers. TDI-induced asthma is associated with airway epithelium injury and repair, and subepithelial fibrosis. We investigated the effect of TDI and its hydrolysis products, the 2,4- and 2,6-toluenediamines (TDA), on viability and growth of human lung fibroblasts (HLFs) in culture, using a tetrazolium-based cell viability assay. The effects of increasing concentrations of each of these chemicals were evaluated on quiescent cells seeded at two densities (2500 and 5000 cells/well) and treated for 24 or 48 h. TDI (10(-4)-10(-5) mol/L, as a mixture of 80% 2,4-TDI and 20% 2,6-TDI) exhibited a partial but significant cytotoxic effect (10-24%, p<0.05) on HLFs. This effect was observed at both cell densities, and was time- and concentration-dependent. 2,4-TDA, at lower concentrations (10(-8)-10(-6) mol/L) applied for 48 h, also partially reduced HLF viability (10-15%, p<0.05), whereas it tended to trigger cell growth at concentrations higher than 10(-5) mol/L. 2,6-TDA exhibited both a cytotoxic and a proliferative effect on HLFs that depended on concentration, time of exposure and cell culture density. Significant cytotoxicity was only observed after 24 h of treatment with 10(-7)-10(-6) mol/L 2,6-TDA, and reached greater intensity in cells cultured at the highest density. In contrast, 2,6-TDA stimulated HLF growth only after 48 h of incubation at 10(-4) mol/L on cells cultured at the lowest density. Taken together, our results showed that TDI and 2,4-TDA somewhat decreased HLF viability, whereas 2,6-TDA appeared to exhibit both a cytotoxic and a growth stimulatory effect on these cells. TDI and 2,4-TDA are thus suggested to contribute to airway epithelium damage associated with TDI-induced asthma, whereas 2,6-TDA might either trigger epithelial damage or induce cell proliferation that could contribute to epithelium repair or subepithelial fibrosis.

Asthma↗
PubMed1999

In-111 octreotide scan in a case of a neuroendocrine tumor of unknown origin.

Major neuroendocrine tumors contain many somatostatin receptors. This feature allows for the localization of primary tumors and tumor metastases by scintigraphy with the radiolabeled somatostatin analog octreotide. We describe a patient with nonspecific clinical data and ultrasonography and CT that showed an isolated focal lesion in the liver. In-111 octreotide scintigraphy was essential in establishing the diagnosis of liver metastasis from a neuroendocrine tumor confirmed by pathologic findings. Because clinical symptoms recurred, ultrasonography and CT were performed a few months after surgery. Both were negative. However, In-111 octreotide scintigraphy suggested multiple bone metastases and established the diagnosis of bone metastases from a neuroendocrine tumor, which was confirmed by Tc-99m MDP bone scans and MRI.

Bone Neoplasms↗
PubMed1999

Radioimmunoguided surgery of colorectal carcinoma with an 111In-labelled anti-TAG72 monoclonal antibody.

Radioimmunoscintigraphy (RIS) and radioimmunoguided surgery (RIGS) were assessed for their usefulness in patients with colorectal carcinoma. Twenty-nine patients (18 primary tumours, 10 with a suspicion of recurrence and one colonic diverticulitis) were studied. Radioimmunoscintigraphy was performed 48 and 72 h after the injection of an anti-TAG72 monoclonal antibody (CYT-103) labelled with 111In. Radioimmunoguided surgery was performed between 72 and 96 h post-injection. During surgery, a systematic screening was performed with a hand-held gamma detecting probe and a surgical index (tumour-to-normal tissue) was obtained. There were statistically significant differences between counts in normal tissue versus tumour (P < 0.001) and RIGS was considered positive for the detection of tumour if the ratio between the counts in the area suspicious of tumour and the counts in the normal tissue was greater than 1.5. The overall sensitivity for RIS and RIGS was 71.4% (55.6% in primary tumours and 100% in recurrences) and 82.1% (83.3% in primary tumours and 80% in recurrences), respectively. Radioimmunoguided surgery changed the surgical procedure in two cases with small tumour deposits. Occult regional lymph node involvement in primary tumours was not found; therefore, RIGS, as a complementary technique to RIS, is particularly useful in recurrences and can help the surgeon in the resection of small tumour deposits which are difficult to localize.

Adult↗
PubMed1999

Quantitative evaluation of bone scintigraphy in the assessment of Paget's disease activity.

Interest in the assessment of activity of Paget's disease has increased since the advent of effective therapies. The aim of this study was to develop a quantitative method for the scintigraphic assessment of Paget's disease activity in bone. Twenty patients with Paget's disease were studied prospectively. A scintigraphic visual activity index, together with a quantitative activity index that reflects both the extent and activity of the disease, was obtained for each patient. The quantitative activity index is calculated as the sum of the activity (geometric mean measured from the anterior and posterior views) for all affected bones divided by a reference obtained in non-affected bone. To evaluate the validity of the scintigraphic methods, several biochemical markers of bone turnover were assessed: serum total alkaline phosphatase and serum propeptide aminoterminal of type I procollagen (PINP) as markers of bone formation; urinary hydroxyproline and urinary N-terminal cross-linked telopeptide of type I collagen (NTx) as markers of bone resorption. The visual and quantitative scintigraphic indices were highly correlated (r = 0.78, P < 0.0001). The highest correlations between the biochemical markers and the quantitative activity index were found for PINP (r = 0.69, P < 0.001), which was the most sensitive marker of bone formation, and for urinary NTx (r = 0.63, P < 0.005), which was the most sensitive marker of bone resorption. In conclusion, quantitative evaluation of bone scintigraphy allows easy and objective assessment of Paget's disease activity and it may be useful in evaluating the effectiveness of therapies.

Adult↗
PubMed1999

Long-term compliance with estrogen replacement therapy in surgical postmenopausal women: benefits to bone and analysis of factors associated with discontinuation.

OBJECTIVE: To evaluate prospectively the effects of long-term estrogen replacement therapy (ERT) on bone density in surgical postmenopausal women treated for 5 years with two different modalities and to determine the factors associated with discontinuation of ERT. DESIGN: We included in the present study 165 women (mean age, 46.8 +/- 4.6 years) who had undergone surgical menopause. ERT was prescribed immediately after surgery, and bone mineral density was measured at the lumbar spine before the women entered the study and at 12, 24, 36, 48, and 60 months after being included. Treated patients were assigned at random to one of two groups. The first group received conjugated equine estrogens 0.625 mg/day continuously, and the second group received transdermal 17beta-estradiol 50 mg/day continuously. Treated groups were compared with a nontreated control group. RESULTS: Our data showed that although ERT clearly protected against bone loss in women who had experienced surgical menopause, only one third of the treated patients continued ERT at the end of follow-up. The main reason for discontinuation was fear of cancer (36.1 % of cases). In addition, no differences were observed between oral and transdermal groups of treatment. CONCLUSIONS: Long-term ERT may have a protective effect against bone loss in surgically postmenopausal women; however, two thirds of treated patients discontinued therapy after 5 years and 43% of them presented a negative balance on bone mass in one or more bone density assessments. For this reason, enhancing compliance and monitoring treatment are mandatory.

Absorptiometry, Photon↗
PubMed1999

[The bronchorelaxant effect of helicidine, a Helix pomatia extract, interferes with prostaglandin E2].

Helicidine is a biological extract prepared from the snail Helix pomatia L. and used in man as an anti-tussive agent. However, its mechanisms of action are not fully defined. In this study, we have investigated a possible relaxant effect of helicidine on guinea-pig airway smooth muscle and evaluated the role of prostanoids and airway epithelium in this relaxation. H. pomatia extract (0.001-1 mg/ml) induced a dose-dependent relaxation of guinea-pig trachea pre-contracted with histamine both in the presence and absence of tracheal epithelium. No significant difference in dose-dependency or magnitude of the relaxation was observed between tracheal segments with or without epithelium (maximal relaxant response of 35 +/- 7 and 25 +/- 7.5%, respectively). Relaxation of the trachea induced by H. pomatia extract (0.001-1 mg/ml) was inhibited by pre-treatment with the cyclooxygenase inhibitor, indomethacin, both in the presence or absence of tracheal epithelium. H. pomatia extract (1 mg/ml) induced a marked and significant increase in prostaglandin E2 release in tracheal segments with and without epithelium. These results indicate that helicidine possesses a broncho-relaxant activity which is independent of epithelium integrity and which is partly mediated by the release of the relaxant prostanoid, prostaglandin E2. The origin of prostaglandin E2 production in the airways remains to be defined.

Animals↗
PubMed1999

Ossein-hydroxyapatite compounds for preventing postmenopausal bone loss. Coadjuvant use with hormone replacement therapy.

OBJECTIVE: To evaluate whether the addition of an ossein-hydroxyapatite compound (OHC) may improve the effect of hormone replacement therapy (HRT) on postmenopausal bone loss. STUDY DESIGN: Of the 118 recent surgically postmenopausal women initially selected for this open study, 96 completed one-year follow-up. Patients were allocated into four groups. The first group received 50 micrograms/d of transdermal 17-beta estradiol continuously (group E, n = 23), the second received 3.32 g/d of an OHC every day (group OHC, n = 23), the third received 50 micrograms/d of transdermal 17-beta estradiol continuously plus 3.32 g/d of the OHC every day (group E-OHC, n = 26), and an additional 24 women were used as untreated controls (group C). Bone mass, assessed by dual x-ray absorptiometry, was measured prior to and at the end of treatment. Samples, including serum calcium, phosphate and osteocalcine level, were collected before therapy and during the 6th and 12th treatment months. RESULTS: All treatment groups showed an increase in bone mineral content. This increase was higher in the E-OHC group (4.7%, P < .01). Concomitant biochemical effects at 6 and 12 months were compatible with the observed effects on bone mineral. CONCLUSION: The combined regimen of OHC and HRT increased vertebral bone mass in postmenopausal women to a greater extent than did OHC or HRT alone, suggesting that this drug combination may be useful in the management of postmenopausal bone loss.

Administration, Cutaneous↗