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Biomedical subjects

C Ferro

Publications and source records attributed to C Ferro.

At least 37 records · Page 2Linked to original sources
PubMed1995

Nocturnal activity patterns of Lutzomyia longipalpis (Diptera: Psychodidae) at an endemic focus of visceral leishmaniasis in Colombia.

Nocturnal activity of the sand fly Lutzomyia longipalpis (Lutz & Neiva) was studied from August 1991 to July 1992 in a small rural community in Colombia where American visceral leishmaniasis is endemic. During 2 or 3 nights each month, sand flies were collected with hand-held aspirators each hour between 1730 and 0630 hours, from a pigpen and a cattle corral located 30 m apart. Host-seeking activity of L. longipalpis adults was characterized by 2 general patterns: (1) adult sand fly activity increased shortly after sunset and continued until just after sunrise, and (2) peak sand fly activity was greatest early in the evening (1830-2330 hours) and then declined steadily toward morning. Female L. longipalpis activity generally increased after 2030 hours, whereas that of males remained constant or declined as the evening progressed. There were seasonal differences in sand fly abundance between the 2 sites: peak abundance in the cattle corral occurred during hot, dry periods, whereas maximum abundance in the pigpen occurred when relative humidity was higher. Influence of relative humidity on activity varied with season. Sand fly activity tended to decrease at temperatures below 24 degrees C and increase in the presence of moonlight.

Animals↗
PubMed1995

Age structure, blood-feeding behavior, and Leishmania chagasi infection in Lutzomyia longipalpis (Diptera: Psychodidae) at an endemic focus of visceral leishmaniasis in Colombia.

Ecological studies on the sand fly Lutzomyia longipalpis (Lutz & Neiva) were conducted during 1990-1992 in a small rural community in Colombia where American visceral leishmaniasis (AVL) is endemic. Subsamples of sand flies collected weekly from pigpens, the interior of houses, and natural outdoor resting sites were dissected to determine physiological age and Leishmania chagasi Cunha & Chagas infection rates. Eleven female L. longipalpis had flagellates in their gut, 2 of which were successfully cultured and identified as Leishmania chagasi. The reproductive status, stage of ovarian development, and trophic history of female sand flies varied among sites, habitats, and time of collection. The percentage of parous females ranged from about one-third to two-thirds overall and varied seasonally. Of most relevance to AVL transmission was the finding that 8% of L. longipalpis females were multiparous. In addition, our data suggest that L. longipalpis rest inside houses after blood-feeding outdoors, and that this species can blood-feed more than once during a single gonotrophic cycle.

Aging↗
PubMed1995

[Follow-up with Doppler color ultrasonography of patients treated with transjugular intrahepatic portosystemic diversion].

We investigated both reliability and limitations of color flow duplex US (CFDU) during the preoperative period and in the follow-up of the patients submitted to transjugular intrahepatic portosystemic shunt (TIPS). MATERIAL AND METHODS. Sixty-six patients suffering from cirrhosis underwent TIPS. Twenty-seven patients were excluded from the trial, as they were treated in other hospitals and submitted to different follow-up. Twenty-four hours before and 48 hours after TIPS, and at 3, 6 and 12 months' intervals during the follow-up, the mean flow rate was measured in the main portal vein and in the stent; the reappearance of ascitis was monitored by the same operator with CFDU. Six and 12 months after TIPS, all patients underwent venography and endoscopy. RESULTS. In 25 cases (64%), both CFDU and venography confirmed shunt patency. In these patients, the flow rate in the main portal vein and stent remained constantly high. In 9 patients (23%), CFDU diagnosed a stenosis on the basis of a marked reduction in the mean flow rate in the main portal vein (p < 0.001), which in 2 patients returned to pre-TIPS values, and in the stent proximal to the portal vein (p < 0.001). In 2 patients (5%), the obstruction was characterized by a return to pre-TIPS values in the portal vein and by the absence of any flow in the stent. Velocimetric sampling in the stent proximal to the vena cava had poor statistical significance. Venography confirmed the flowmetric results in all but 3 patients (7%). CONCLUSIONS. On the basis of our data, CFDU exhibited about 100% sensitivity, 89% specificity and 92% accuracy in the diagnosis of TIPS stenosis/obstruction. We therefore consider CFDU a useful tool in the follow-up of the patients submitted to TIPS, angiography being suggested only when needed on the basis of CFDU and/or endoscopic findings.

Follow-Up Studies↗
PubMed1995

[Treatment of superior vena cava syndrome by metal stents. Preliminary experience].

This study was aimed at verifying the feasibility of stent placement in superior vena cava syndrome (SVCS). From April, 1993, to February 1995, fifteen patients (12 men, 3 women, age range: 48-72 years, average age: 58 years), were treated for malignant stenoses involving superior vena cava in 9 cases, right innominate vein in 3, left innominate vein in 2 and subclavian veins in 1. All patients had been submitted to CT angiography and digital venography to assess side, length and type of the stenosis. In 6 patients locoregional fibrinolysis (with urokinase) was performed. The stenosis was successfully dilated by balloon catheter and the stent was finally removed. Subclavian and innominate veins stenoses were treated with Wallstent, using brachial approach, while stenoses of superior vena cava required transfemoral catheterization for Gianturco-Rosch "Z" stent placement. A control venogram was performed after stenting, with the evaluation of pre/post stent pressure gradient, and later at 1, 3 and 6 months. The stents were positioned in all patients with immediate technical success; no major complications occurred. Two recurrences were successfully resolved. Radiation and/or medical therapy without vascular disobstruction showed worse results in the treatment of superior vena cava syndrome. The percutaneous placement of self-expandable stents should be not only the therapeutic alternative to surgery but the method of choice in these pathologic conditions.

Aged↗
PubMed1994

[Transjugular intrahepatic portosystemic shunt (TIPS)].

Transjugular intrahepatic portosystemic (TIPS) is radiological technique that has opened up new therapeutic horizons in the treatment of portal hypertension. Technically, the procedure includes catheterizing of the suprahepatic veins, prevalently right or middle, by means of transjugular access, and the creation of an intrahepatic path with the main portal branch. Later dilatation of the path by angioplasty and the application of a metallic stent at the site of the shunt complete the operation. Personal experience of 43 TIPS in 42 patients with a follow-up of 24 months is reported.

Adult↗
PubMed1994

[Ultrasonography and retrograde transpapillary cholangiopancreatography combined with sphincterotomy in the diagnosis of choledochal lithiasis. Our experience with 87 patients].

We retrospectively reviewed the US findings of 87 patients to assess US sensitivity in the detection of choledochal (CBD) stones. Endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic sphincterotomy (ES) was used as the diagnostic standard, except for 1 patient who underwent surgical exploration. First, the distal CBD was studied with transverse and parasagittal US scans through the head and uncinate portions of the pancreas. CBD stones usually appeared as hyperechoic lesions, most of them with acoustic shadowing. In some cases, the stone moves during real-time scanning, which further confirms the diagnosis. Fifty-four of 87 patients had CBD stones and US detected them in 46 cases. The absence of a stone was diagnosed correctly in 28 of 33 patients. In our series, US sensitivity, specificity and accuracy were 85%, positive predictive value 88% and negative predictive value 78%. If the distal duct cannot be demonstrated adequately or if duct size is normal, US sensitivity in detecting stones decreases and other examinations, such as ERCP, should be performed. We conclude that US can be used as the diagnostic method of choice to examine the patients with suspected biliary tract disease. Although ERCP is the gold standard for diagnosis and therapeutic purposes in choledochal stones, it remains an invasive technique and must therefore be held in reserve.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1994

[The percutaneous treatment of purulent intrathoracic fluid collections in HIV+ patients].

Eighteen HIV+ patients with purulent fluid intrathoracic collections (16 pleural empyemas and 2 lung abscesses) and persistent sepsis were treated with percutaneous drainage; all patients had received antibiotics for 5-7 days at least. Empyemas and lung abscesses were cured (according to clinical and radiographic criteria) in all patients (100%). One major complication was successfully treated--i.e., a pneumothorax with a iatrogenic lesion of the internal mammary artery, requiring selective embolization. In our experience, CT is the method of choice to guide lesion puncture. Van Sonnenberg Sump catheters (12-16 F) have been inserted in the last six months with the Trocar technique. The maneuvers were successful in all cases, with good compliance and management of patients in a 9-25 days' period (mean: 14 days). In our experience, the percutaneous drainage of intrathoracic fluid collections in HIV+ patients should be considered the method of choice.

AIDS-Related Opportunistic Infections↗
PubMed1993

Dispersal of the sand fly Lutzomyia longipalpis (Diptera: Psychodidae) at an endemic focus of visceral leishmaniasis in Colombia.

Mark-release-recapture studies were carried out during 1990-1991 in El Callejón, Colombia, an endemic focus of American visceral leishmaniasis, to study the longevity, dispersal, and flight range of the principal vector, Lutzomyia longipalpis Lutz & Neiva. Several groups of wild-caught (n = 1,539) and laboratory-reared F1 (n = 2,208) sand flies were marked with fluorescent dusts and released. Recaptures at daytime resting sites, on animal bait, and in CDC light traps were made for 20 d following each release. From 2 to 9% of L. longipalpis were recaptured, a rate which differed between the sexes (7.7% male, 1.5% female). Overall, 49% of the L. longipalpis were recaptured between 0 and 50 m, 48% within 100 and 300 m, and nearly 3% at > or = 0.5 km from the release site. Sex differences in recapture site, distance flown, and direction were observed. Our results indicate that the dispersal behavior of peridomestic populations of L. longipalpis compares more closely with that of Old World sand fly species from similar habitats than to the sylvan Neotropical phlebotomines.

Animals↗
PubMed1993

Host preferences of the sand fly Lutzomyia longipalpis at an endemic focus of American visceral leishmaniasis in Colombia.

Blood meals from 579 Lutzomyia longipalpis (Diptera:Psychodidae), collected in an endemic focus of American visceral leishmaniasis in Colombia, were identified by precipitin test. Sand fly collections were made during a 16-month period from the inside walls of two houses, a pigpen, and rock crevices in a small community (El Callejon) within the endemic area. Feeding patterns of the sand flies varied with locality and date of collection. Overall, bovine feedings predominated, but feedings were also recorded on pigs, equines, humans, dogs, opossums, birds, and reptiles. Calculation of the forage ratios for each host species indicated that cows and pigs were the preferred hosts of Lu. longipalpis in El Callejon. Results of this study suggest that Lu. longipalpis is an opportunistic feeder and is not highly anthropophilic nor strongly attracted to dogs.

Animals↗
PubMed1993

[Malignant occlusion of the bile ducts. Treatment with metallic endoprosthesis: Wallstent vs Strecker's stent].

Stenting is the method of choice to relieve jaundice in the patients with inoperable malignant obstructions of the biliary tree. Over the last fifteen years, thousands of patients have been treated, if endoscopy failed or was unfeasible, with percutaneous transhepatic procedures: despite this wide experience, the role of conventional plastic endoprostheses is still debated, because these devices exhibit major limitations. The main objection to the use of Carey-Coons endoprostheses is the fact that a high rate of early occlusions has always been observed with plastic stents with a wide outer diameter (12-16 F). Metallic stents (self-expandable, Wallstent balloon-expandable Strecker stents) might solve these problems, especially in high-risk patients. The authors report their experience in 50 patients with midterm follow-up, a comparison of the two types of stents and their technical features.

Aged↗
PubMed1993

[Technical and methodologic considerations on a new approach to the transjugular intrahepatic portosystemic shunt].

The authors report their experience with 10 transjugular intrahepatic portosystemic shunts (TIPS) in nine patients with severe portal hypertension; indications were rebleeding after sclerosing treatment in 8 cases and unmanageable ascitis in one case. The passage of the needle from the hepatic venous system into the portal venous system during the procedure may be technically difficult with both skin markers and US guidance, and several passages through liver parenchyma may be needed: this step is certainly the most critical one, for maneuver duration--and therefore risks--depend on it. Thus, in the last 6 patients a new method was used to easily identify portal bifurcation: a thin stainless platinum-tip guide-wire (0.018-inch diameter) was inserted, by epigastric approach under US guidance, through a fine Chiba needle (22 G) in the left main portal branch, dramatically reducing the number of failed punctures and maneuver duration. Both the above goals are to be reached to make TIPS easier and therefore advantage both patients and interventional radiologists.

Equipment Design↗