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Biomedical subjects

M Franco

Publications and source records attributed to M Franco.

At least 109 records · Page 6Linked to original sources
PubMed1997

Fibrosing colonopathy in children with cystic fibrosis.

PURPOSE: Fibrosing colonopathy is a newly described entity seen in children with cystic fibrosis. The radiological hallmarks are foreshortening of the right colon with varying degrees of stricture formation. High-dose enzyme therapy has been implicated as the cause of this process. The purpose of this study is to review the author's experience with evaluation and treatment of these patients. METHODS: There are currently 380 patients being treated at our CF center. Fifty-five of these patients have been treated with high-dose enzyme therapy (> 5,000 units of lipase/kg). The medical records of these patients, who are at risk for developing fibrosing colonopathy, were reviewed for the presence of recurrent abdominal complaints, and the work-up and treatment of these symptoms. RESULTS: Chronic complaints of abdominal pain, distension, change in bowel habits, or failure to thrive were present in 24 of the 55 patients treated with high-dose enzymes. So far, 18 of these 24 patients have been evaluated by contrast enema. Thirteen of eighteen have been found to have fibrosing colonopathy characterized by foreshortening and strictures of the colon. Additional findings included focal strictures of the right colon (7 of 13), long segment strictures (5 of 13), and total colonic involvement (1 of 13). Nine patients with the most severe symptoms have undergone colon resection, including five segmental right colectomies, three extended colectomies (ileo-sigmoid anastomosis), and one subtotal colectomy with end-ileostomy. Pathological evaluation has shown submucosal fibrosis, destruction of the muscularis mucosa, and eosinophilia. No postoperative complications or deaths occurred. All nine postoperative patients have noted marked symptomatic improvement. Contrast enema follow-up results are available for six patients, and have documented no recurrent strictures to date. Three of four nonoperative patients have less severe symptoms and are currently being treated conservatively. The other family has refused surgery and the patient is being treated symptomatically. CONCLUSION: High-dose lipase replacement has been implicated as the etiology for FC and was present in all of our patients. Our cystic fibrosis center now routinely limits lipase to 2,500 U/kg per dose. We recommend the use of the contrast enemas to evaluate at-risk patients who have chronic abdominal complaints or who present with recurrent bowel obstruction. Colon resection should be performed in those with clinically and radiographically significant strictures with the expectation of a good outcome.

Child↗
PubMed1997

Resorption of composite polymer-hydroxyapatite membranes: a time-course study in rabbit.

The histological findings in rabbit, concerning the resorption of a new composite hydroxyapatite-polymer membrane used in guided tissue regeneration are reported. The polymer appeared to be completely resorbed in about 4-6 months, while the inorganic component, hydroxyapatite, appeared to begin to resorb after the tenth month. The integrity of the membrane appeared to be unchanged after a 10-month period. No inflammatory cell infiltrate was present. This new type of membrane appeared to be relatively well tolerated by the host, had no significant adverse soft and hard tissue reaction, appeared to be easy to handle and had good space-maintaining capabilities. More research is certainly needed before clinical use in man.

Absorption↗
PubMed1997

Vascular reactivity and effect of serum in a rat model of hypertriglyceridemia and hypertension.

It has not been definitely established whether elevated circulating triglyceride-rich lipoproteins constitute an independent risk factor for hypertension, atherosclerosis, myocardial infarction, and coronary heart disease. To investigate some aspects of the physiopathology of this lipid metabolism abnormality, a model of experimental hypertriglyceridemia and hypertension in rats was studied. The animals received commercially refined sugar (30%) in their drinking water during a period of 12 to 17 weeks. Monthly measurements of blood pressure and serum triglycerides were taken during and at the end of the treatment period; the levels of glucose and insulin were also determined. The blood, the aorta, and mesenteric artery were removed. Age- and weight-matched controls were used. The reactivity of the isolated vessels to norepinephrine and acetylcholine and the effect of control and hypertriglyceridemic serum on the same preparations were investigated. In hypertriglyceridemic rats, the response to acetylcholine in the tissues was reduced compared to the control arteries; the hypertriglyceridemic serum elicited contractions that were greater than those induced by control serum. The impaired response of hypertriglyceridemic tissue to the vasodilator and the effect of the hypertriglyceridemic serum on artery contraction suggest that the overall dyslipidemia could contribute to a chronic increase in vascular tone and, consequently, to hypertension.

Acetylcholine↗
PubMed1997

Antigenic similarities to Paracoccidioides brasiliensis in thermo-dependent dimorphic fungi isolated from soil in Botucatu, SP, Brazil.

We compared the antigenic characteristics of two thermo-dependent dimorphic fungi isolated from soil in Botucatu, an endemic area of paracoccidioidomycosis (PCM) and Paracoccidioides brasiliensis. The soil isolates grew as cerebriform colonies at 37 degrees C (yeast form) and as cottonous colonies at 25 degrees C (mycelial form). No pathogenicity for ddY mice or hamsters were observed. In immunodiffusion test, there were precipitation bands between the 2 soil isolates and pooled PCM patient sera. There were also common precipitation bands at 21, 50 and 58 kDa between the soil isolates antigens and PCM patient sera by Western-blotting, but no gp43 kDa band. No gene for gp 43 kDa protein was detected in the soil isolates by PCR. The fact that these isolates were obtained from an endemic area of PCM and there were some antigenic similarities between the soil isolates and P. brasiliensis in immunodiffusion test and Western-blotting may have some importance in epidemiological surveys done with paracoccidioidin as well interfering with the immune response of the exposed population.

Animals↗
PubMed1997

SSRI-induced sexual dysfunction: fluoxetine, paroxetine, sertraline, and fluvoxamine in a prospective, multicenter, and descriptive clinical study of 344 patients.

The authors analyzed the incidence of sexual dysfunction (SD) with different selective serotonin reuptake inhibitors (SSRIs; fluoxetine, fluvoxamine, paroxetine, and sertraline) and hence the qualitative and quantitative changes in SD throughout time in a prospective and multicenter study. Outpatients (192 women and 152 men; age = 39.6 +/- 11.4 years) under treatment with SSRIs were interviewed with an SD questionnaire designed for this purpose by the authors and that included questions about the following: decreased libido, delayed orgasm or anorgasmia, delayed ejaculation, inability to ejaculate, impotence, and general sexual satisfaction. Patients with the following criteria were included: normal sexual function before SSRI intake, exclusive treatment with SSRIs or treatment associated with benzodiazepines, previous heterosexual or self-erotic current sexual practices. Excluded were patients with previous sexual dysfunction, association of SSRIs with neuroleptics, recent hormone intake, and significant medical illnesses. There was a significant increase in the incidence of SD when physicians asked the patients direct questions (58%) versus when SD was spontaneously reported (14%). There were some significant differences among different SSRIs: paroxetine provoked more delay of orgasm or ejaculation and more impotence than fluvoxamine, fluoxetine and sertraline (chi 2, p < .05). Only 24.5% of the patients had a good tolerance of their sexual dysfunction. Twelve male patients who suffered from premature ejaculation before the treatment preferred to maintain delayed ejaculation, and their sexual satisfaction, and that of their partners, clearly improved. Sexual dysfunction was positively correlated with dose. Patients experienced substantial improvement in sexual function when the dose was diminished or the drug was withdrawn. Men showed more incidence of sexual dysfunction than women, but women's sexual dysfunction was more intense than men's. In only 5.8% of patients, the dysfunction disappeared completely within 6 months, but 81.4% showed no improvement at all by the end of this period. Twelve of 15 patients experienced total improvement when the treatment was changed to moclobemide (450-600 mg/day), and 3 of 5 patients improved when treatment was changed to amineptine (200 mg/day).

1-Naphthylamine↗
PubMed1997

Differences in sleep variables, blood adenosine, and body temperature between hypothyroid and euthyroid rats before and after REM sleep deprivation.

Sleep deprivation causes an increase in energy expenditure in animals. Thyroid gland function has been related to metabolic function, and this may be compromised in sleep manipulations. The objectives of the present study were the following: 1) to develop a model of hypothyroid rats by surgical removal of thyroid glands without extirpation of the parathyroid; 2) to observe the sleep architecture in euthyroid (Etx) and hypothyroid (Htx) rats, both before and after rapid eye movement (REM) sleep deprivation (96 hours); 3) to challenge both groups (i.e. Etx and Htx) with REM sleep deprivation (96 hours) and then evaluate the effects on temperature; and 4) to measure the levels of adenosine and thyroid hormones in blood. One-month-old Wistar male rats (weight 90-100 g) were studied. The thyroid gland was removed, and the parathyroid glands were reimplanted within the neck muscle (Htx) under halothane anesthesia. A sham-operated group was also included (Etx). Four months later, the animals were studied according to the following protocols. Protocol 1: Animals of both groups (i.e. Etx and Htx) were implanted for sleep recordings. After a baseline polysomnography, these animals were REM sleep deprived by the platform method (96 hours). Protocol 2. An intraperitoneal temperature transducer was placed into animals of both groups under deep halothane anesthesia. They were studied at baseline, during 96 hours of REM sleep deprivation, and on the rebound period. Protocol 3: Plasma thyroid hormones [T3, T4, and thyroid-stimulating hormone (TSH)] and plasma adenosine were determined in both groups. Results of protocol 1 indicated that the main difference observed in Htx rats during the baseline sleep was an increase in delta sleep (slow-wave sleep 2) and a reduction in waking time compared with Etx animals. REM sleep rebound after 96 hours of REM sleep deprivation was similar in both groups. In protocol 2, the main finding was that Htx animals had reduced body temperature. A significant difference in body temperature between Etx and Htx animals was found mainly during lights-on period. REM sleep deprivation in the Etx group produced an increase in body temperature. Htx animals showed the opposite effect, with a reduction in body temperature during and after REM sleep deprivation. In protocol 3, the main findings were that Htx animals exhibited a significant reduction in blood thyroid hormones (T3, T4), and that they also had high levels of plasma adenosine. REM sleep deprivation produces changes in temperature regulation. The increase in body temperature during REM sleep deprivation may require thyroid integrity. Absence of the thyroid gland does not seem to influence REM sleep recovery after its deprivation. The high plasma adenosine levels found in the Htx group may explain the increase in delta sleep in this group.

Adenosine↗
PubMed1997

Myocyte necrosis is the basis for fibrosis in renovascular hypertensive rats.

The pathogenesis of fibrosis and the functional features of pressure overload myocardial hypertrophy are still controversial. The objectives of the present study were to evaluate the function and morphology of the hypertrophied myocardium in renovascular hypertensive (RHT) rats. Male Wistar rats were sacrificed at week 4 (RHT4) and 8 (RHT8) after unilateral renal ischemia (Goldblatt II hypertension model). Normotensive rats were used as controls. Myocardial function was analyzed in isolated papillary muscle preparations, morphological features were defined by light microscopy, and myocardial hydroxyproline concentration (HOP) was determined by spectrophotometry. Renal artery clipping resulted in elevated systolic arterial pressure (RHT4: 178 +/- 19 mmHg and RHT8: 194 +/- 24 mmHg, P < 0.05 vs control: 123 +/- 7 mmHg). Myocardial hypertrophy was observed in both renovascular hypertensive groups. The myocardial HOP concentration was increased in the RHT8 group (control: 2.93 +/- 0.38 micrograms/mg; RHT4: 3.02 +/- 0.40 micrograms/mg; RHT8: 3.44 +/- 0.45 micrograms/mg of dry tissue, P < 0.05 vs control and RHT4 groups). The morphological study demonstrated myocyte necrosis, vascular damage and cellular inflammatory response throughout the experimental period. The increased cellularity was more intense in the adventitia of the arterioles. As a consequence of myocyte necrosis, there was an early, local, conjunctive stroma collapse with disarray and thickening of the argyrophilic interstitial fibers, followed by scarring. The functional data showed an increased passive myocardial stiffness in the RHT4 group. We conclude that renovascular hypertension induces myocyte and arteriole necrosis. Reparative fibrosis occurred as a consequence of the inflammatory response to necrosis. The mechanical behavior of the isolated papillary muscle was normal, except for an early increased myocardial passive stiffness.

Animals↗
PubMed1997

Tumoral calcinosis in hemodialysis patients. A review of three cases.

Soft tissue calcification are common in chronic hemodialysis patients and often affect the periarticular tissues, where they occasionally form tumoral masses. In a retrospective study of 254 hemodialysis patients we identified three such cases. Affected sites were the wrist, shoulder, and chest wall. None of the patients had secondary hyperparathyroidism. A discussion is provided of the roentgenographic and clinical features of tumoral calcinosis, of current pathogenic hypotheses, and of available treatments.

Adult↗
PubMed1997

Video-assisted thoracoscopic closure of postpneumonectomy bronchopleural fistulas.

Despite improved surgical techniques and advances in medical-surgical treatment, postpneumonectomy bronchopleural fistulas remain an important cause of morbidity and a therapeutic challenge. Video-assisted thoracoscopic closure of these fistulas reinforced by transposition of bulky chest wall muscles or omentum to obliterate the residual space may lessen risks and complications of repeated thoracotomy in these often frail, debilitated, and compromised patients. We report our initial experience with video-assisted thoracoscopic debridement of the empyema cavity and closure of the postpneumonectomy bronchopleural fistula by transposing an entire pectoralis major muscle in one patient and by transposing a pedicled omentum in another patient.

Aged↗
PubMed1997

Surgical treatment of carotid kinking.

The authors take in exam 34 anatomical variation in the extracranial internal carotid artery (compared with more than 450 operated carotid artery), 15 of which involved kinking in patients with overt neurological symptoms, underwent corrective surgical treatment, and test the most useful and appropriate techniques in any case.

Adolescent↗
PubMed1997

[Surgery of the descending thoracic and thoraco-abdominal arteries. Report of 105 cases].

The Authors show their casistic of about 105 cases of thoracic descending and thoraco-abdominal aorta pathologies between 1.1.1993 and 30.12.1995. After a short introduction about the improvements in anesthesia and reanimation of these pathologies as well as the good reliability of diagnostic and currently available instruments, mortality and mobility parameters are taken into account, the last one referring to paraplegia and ARF. The casistic is evaluated splitting the cases into 2 groups, urgent surgery and election surgery, and differentiating the aneurysm type from the dissection type. Besides, the mortality and mobility are reported for any pathology, with a discussion of the parameters which drove the choice of the most suitable methodology to be adopted (ECC femoro-subclavian shunt, simple clamping). The results achieved show a mortality of 40% in urgency, between 5 and 15% in election, with a rate of paraplegia around 8-10% and a ARF between 5 and 15%. These data match the literature statistics and support the quality of the adopted methodologies.

Adult↗
PubMed1997

Myocardial fibrosis rather than hypertrophy induces diastolic dysfunction in renovascular hypertensive rats.

The aim of the present study was to evaluate the effect of interstitial fibrosis alone or associated with hypertrophy on diastolic myocardial function in renovascular hypertensive rats. Myocardial function was evaluated in isolated papillary muscle from renovascular hypertensive Wistar rats (RHT, n = 14), renovascular hypertensive rats treated with the angiotensin converting enzyme inhibitor (ACEI) ramipril, 20 mg.kg-1.day-1 (RHT RAM, n =14), and age-matched unoperated and untreated Wistar rats (CONT, n = 12). The ACEI treatment for 3 weeks allowed the regression of myocyte mass and the maintenance of interstitial fibrosis. Myocardial passive stiffness was analyzed by the resting tension-length relationship. The myocardial fibrosis was evaluated by measuring myocardial hydroxyproline (Hyp) concentration and by histological studies of the myocardium stained with hematoxylin and eosin or picrosirus red. Left ventricular weight was significantly higher in RHT (0.97 +/- 0.12 g) compared with CONT (0.66 +/- 0.06 g) and RHT RAM (0.69 +/- 0.14 g). The Hyp levels were 2.9 +/- 0.4, 3.4 +/- 0.3, and 3.8 +/- 0.4 micrograms/mg of dry tissue for the CONT, RHT, and RHT RAM, respectively. Perivascular and interstitial fibrosis were observed in RHT and RHT RAM groups. There were lymphononuclear inflammatory exudate and edema around arteries, involving adjacent myocytes in the RHT group. There was an increased passive stiffness in RHT and RHT RAM groups compared with the CONT group. In conclusion, our results indicate that the impaired diastolic function in the renovascular hypertensive rats is related to interstitial fibrosis rather than to myocardial hypertrophy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Myristoylation-facilitated binding of the G protein ARF1GDP to membrane phospholipids is required for its activation by a soluble nucleotide exchange factor.

We have investigated the role of N-myristoylation in the activation of bovine ADP-ribosylation factor 1 (ARF1). We previously showed that myristoylation allows some spontaneous GDP-to-GTP exchange to occur on ARF1 at physiological Mg2+ levels in the presence of phospholipid vesicles (Franco, M., Chardin, P., Chabre, M., and Paris, S. (1995) J. Biol. Chem. 270, 1337-1341). Here, we report that this basal nucleotide exchange can be accelerated (by up to 5-fold) by addition of a soluble fraction obtained from bovine retinas. This acceleration is totally abolished by brefeldin A (IC50 = 2 microM) and by trypsin treatment of the retinal extract, as expected for an ARF-specific guanine nucleotide exchange factor. To accelerate GDP release from ARF1, this soluble exchange factor absolutely requires myristoylation of ARF1 and the presence of phospholipid vesicles. The retinal extract also stimulates guanosine 5'-3-O-(thio)-triphosphate (GTP gamma S) release from ARF1 in the presence of phospholipids, but in this case myristoylation of ARF is not required. These observations, together with our previous findings that both myristoylated and non-myristoylated forms of ARF GTP-gamma S but only the myristoylated form of ARFGDP bind to membrane phospholipids, suggest that (i) the retinal exchange factor acts only on membrane-bound ARF, (ii) the myristate is not involved in the protein-protein interaction between ARF1 and the exchange factor, and (iii) N-myristoylation facilitates both spontaneous and catalyzed GDP-to-GTP exchange on ARF1 simply by facilitating the binding of ARFGDP to membrane phospholipids.

ADP-Ribosylation Factor 1↗
PubMed1996

Paracoccidioides brasiliensis antigen batches from the same isolate show immunological and biochemical differences.

We investigated the occurrence of antigenic and biochemical variability among Paracoccidioides brasiliensis antigen batches prepared according to the same protocol. Initially (experiment #1), we analyzed two antigen lots of two human isolates (Bt1 & Bt2), cultured in two media (PYG: bactopeptone, yeast extract, glucose; MMM: McVeigh & Morton medium) in SDS-PAGE and in two immunological tests (immunodiffusion-ID and footpad swelling test-FPT). Afterwards (experiment #2), we compared the antigenic profile of three antigen batches from three human isolates (Bt1, Bt2 & Bt3) by two-dimensional immunoelectrophoresis (2 D-IEP) against a reference system for P. brasiliensis antigens. In experiment #1, there were important intra- and inter-strain antigenic differences between batches of the fungal isolates cultured on both media. The block titration of the antigen batches for the immunological tests revealed correlation between protein concentration and biological activity in ID and no correlation in FPT. In experiment #2, the reference system for P. brasiliensis showed 26 antigen peaks. There were important differences between batches prepared from the same isolate and between batches from different isolates. Our data suggested the occurrence of instability in the synthesis of antigenic components by a same P. brasiliensis isolate, under controlled incubation conditions.

Antigens, Fungal↗
PubMed1996

Criteria for the diagnosis of diffuse uterine myohypertrophy.

OBJECTIVES: Diffuse uterine myohypertrophy (DUMH) is a condition clinically diagnosed by the presence of uterine bleeding, homogeneous and diffuse uterine enlargement, and absence of any myoendometrial cause of bleeding. Since the morphologic criteria for the diagnosis of this entity are still controversial, this study aimed to investigate the clinical presentation and the morphologic findings of the cases of DUMH presenting at the University Hospital of Botucatu, São Paulo, Brazil. METHODS: We retrospectively studied 43 consecutive patients with DUMH submitted to hysterectomy (test group) and compared the findings with those obtained from 28 patients submitted to hysterectomy due to a prolapsed uterus (control group). There were no significant differences in age, weight or height between the two groups. RESULTS: The uterine weight of the DUMH group (mean +/- S.D. 157.4 +/- 46.4 g) was significantly heavier than that of the control group (99.5 +/- 35.4 g) and myometrial thickness was significantly greater in the DUMH group (2.5 +/- 0.5 cm) than in the control group (1.9 +/- 0.4 cm). No positive correlation was observed between increased uterine weight and parity, but there was a positive correlation between uterine weight and myometrial thickness. On the basis of the present study, we suggest that the diagnosis of DUMH be made clinically and in cases of uterine weight > or = 120 g and myometrial thickness > or = 2.0 cm. In addition, 10 cases of each group were analyzed by morphometry to evaluate interstitial fibrosis and myometrial hypertrophy. The data showed that the increase in uterine weight in DUMH is caused by enlargement of individual myometrial fibers rather than accumulation of interstitial collagen. CONCLUSION: Discriminant analysis to estimate the diagnostic significance of a number of clinical and pathologic variables (age, parity, uterine weight and morphometric parameters) was able to differentiate cases of DUMH from controls in 100% of the patients.

Adult↗