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D Nunez

Publications and source records attributed to D Nunez.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Effects of SIN-1, a metabolite of molsidomine, on paf-acether-blood platelets interactions].

The metabolite of molsidomine, 3-morpholino-syndnonimine (SIN-1) is a vasodilator and an inhibitor of platelet activation induced by adenosine-5'-diphosphate (ADP), arachidonic acid (AA) and thrombin. We present the results of SIN-1 on platelet aggregation induced by paf-acether and on the biosynthesis of this mediator by washed rabbit platelets. SIN-1 inhibits submaximal platelet aggregation induced by 50 pM paf-acether. This inhibition is dose-dependent (SIN-1 IC50: 37 +/- 10 nM, n = 3). SIN-1 also inhibits submaximal aggregations induced by ADP (IC50: 13 +/- 11 nM) and AA (IC50: 26 +/- 12 nM) (n = 3-5). Finally, SIN-1 inhibits dose-dependently the formation of lyso paf-acether (the precursor of paf-acether) and of thromboxane A2, and AA freeing by thrombin-stimulated platelets. Thus SIN-1 has a wide spectrum activity on platelets. He is both capable of inhibiting platelet aggregation induced by all used agonists and to inhibit the formation of paf-acether and thromboxane A2, two powerful mediators of platelet aggregation.

Animals↗
PubMed1986

Specific inhibition of PAF-acether-induced platelet activation by BN 52021 and comparison with the PAF-acether inhibitors kadsurenone and CV 3988.

BN 52021 is a chemically defined substance extracted from Ginkgo biloba leaves. Its inhibitory potency was tested on washed human platelets prepared so as to render them specifically sensitivity either to adenosine 5'-diphosphate (ADP), arachidonic acid (AA) or PAF-acether. Its activity and specificity were compared with those of two other reported inhibitors of PAF-acether effects: Kadsurenone and CV 3988. PAF-acether-induced aggregation of washed human platelets was concentration dependently inhibited by BN 52021 (IC50: 2.22 +/- 0.79 microM against 7.5 nM PAF-acether (n = 3)). Under the same experimental conditions the aggregation triggered by ADP was not modified and that induced by AA was marginally affected. The PAF-acether EC50 in platelet-rich plasma was increased 5- and 46-fold with 1 microM and 5 microM of BN 52021 respectively. This strongly suggested that the mechanism of action of BN 52021 is of the competitive type. Analysis of [3H]PAF-acether binding showed that BN 52021 as well as unlabelled PAF-acether prevented [3H]PAF-acether binding to intact washed platelets. In washed human platelets Kadsurenone affected only PAF-acether-induced aggregation (IC50: 0.8 +/- 0.4 microM (n = 3)), whereas CV 3988 inhibited the aggregation induced by ADP, AA and PAF-acether (IC50 were 10.2 +/- 2.3 microM; 2.2 +/- 0.1 microM; 1.0 +/- 0.1 microM respectively (n = 3). In contrast, up to 30 microM, CV 3988 was a specific antagonist of PAF-acether-induced platelet aggregation in plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗
PubMed1986

Percutaneous biliary drainage in acute suppurative cholangitis.

One hundred and sixteen percutaneous drainage procedures of the biliary system were performed in a 2-year period. Eight of 9 acutely ill patients with the diagnosis of acute suppurative cholangitis were successfully treated nonoperatively. They represented 26% of all patients with benign or postsurgical obstruction referred for biliary decompression. Conversely, acute suppurative cholangitis only occurred in 2.3% of patients with underlying malignant disease. These observations are considered most relevant in predicting the purulent nature of the disease, with further implications for patient management. Early recognition and prompt decompression of the biliary system are mandatory, along with the appropriate antibiotic coverage. Our experience compares favorably with surgical results and the procedure is proposed as the method of choice for the initial treatment of acute suppurative cholangitis.

Acute Disease↗
PubMed1986

Radiographic evaluation of the cocaine smuggler.

A retrospective analysis of the plain abdominal films of 53 "body packer" drug smugglers was performed to ascertain the importance of radiographic studies in the diagnosis and management of these patients. Eighty-nine percent had studies diagnostic for foreign body ingestion. Multiple, well-defined, homogeneous oval or oblong densities, especially if surrounded by a crescent of air (double-condom sign), are key findings. If these densities were found in the proximal ascending colon or upper gastrointestinal tract, the diagnosis was almost assured. Six percent of patients exhibited complications suggested on serial radiographs, proving the necessity for follow-up studies until complete expulsion or removal of the foreign body. Radiologic evaluation is essential in the diagnosis and management of the cocaine smuggler.

Adult↗
PubMed1986

Covalent binding of eicosanoids to platelet proteins.

Following an incubation of washed human platelets with 14C-arachidonic acid, a small fraction of the radioactivity became tightly bound to the protein pellet. Three criteria suggested that it was actually a covalent binding: it was not removed by exhaustive extractions with solvents of various polarities, it was not dialysable against SDS-buffer and it corresponded to the labeling of several protein bands after SDS-polyacrylamide gel electrophoresis. The use of several pharmacological agents (indomethacin, eicosatetraynoic acid, dazoxiben, diamide) has allowed us to divide this binding into three components: the first one, independent from both cyclooxygenase and lipoxygenase, the second one dependent on cyclooxygenase products and finally the third one, dependent on lipoxygenase products.

Arachidonic Acid↗
PubMed1986

Renal cell carcinoma complicating long-term dialysis: computed tomography-guided aspiration cytology.

The diagnosis of renal cell carcinoma was established by computed tomography-guided aspiration in two small solid lesions occurring in end-stage kidneys. This represents a safe means of providing more specific information about the various lesions that specific information about the various lesions that frequently develop in chronic hemodialysis patients: complex cysts, adenoma, and renal cell carcinoma. The proposed conservative approach of simple observation of these lesions may be altered if a precise diagnosis is obtained. Computed tomography is considered the most reliable imaging modality for evaluation and guided aspiration.

Adult↗
PubMed1986

Percutaneous transjejunal biliary dilatation: alternate management for benign strictures.

Since 1980, 23 patients with diffuse benign biliary strictures underwent percutaneous retrograde biliary dilatation through a surgically created jejunal access route. Bile ducts of 15 patients with sclerosing cholangitis, five with traumatic strictures, and three with strictures of diverse etiology were dilated with 25-atm balloons during 88 separate sessions. Individual dilatation intervals ranged between 2 and 36 months. Three patients with sclerosing cholangitis died. One uncomplicated bile duct rupture occurred in the trauma group because of balloon oversizing. Our 5-year experience indicates that bile duct patency can be safely maintained by repeated retrograde dilatations without the need for biliary catheters or stents.

Adolescent↗
PubMed1986

Nonsurgical drainage of appendiceal abscesses.

Five patients with abdominal abscesses complicating appendicitis were successfully treated by catheter drainage. In two patients, the percutaneous procedure was performed after incomplete surgical drainage; in three patients it was used as the only means of initial drainage. No interval appendectomy was required and no complications were associated with the procedure. Percutaneous management of appendiceal abscesses can be proposed as an alternative to surgical drainage.

Abscess↗
PubMed1985

Computed tomography demonstration of retroperitoneal contrast material extravasation complicating translumbar aortography.

The computed tomography appearance of contrast material extravasated in the right perirenal space is presented. The complication occurred during test injection prior to translumbar aortography. The computed tomography findings were those of a right prerenal collection with high attenuation numbers representing contrast extravasation. Concurrent displacement of the second portion of the duodenum and inferior vena cava was present. No other retroperitoneal abnormalities were noted. The importance of computed tomography for early recognition and follow-up are emphasized.

Aged↗
PubMed1985

Experimental candidiasis after thermal injury.

The ability of Candida albicans to infect thermally injured mice was studied. Female mice were either left unburned or given a 20% total body surface area 2-s or 7-s scald burn. The wound or skin surface was then inoculated with a human burn wound isolate of C. albicans. At 4 h postburn, approximately 10(2) to 10(3) CFU/g of tissue could be recovered from the skin of burned and unburned animals. Unburned mice cleared the organisms from the skin by 72 h, whereas in 7-s-burned animals, the candida increased in numbers to approximately 10(7) CFU/g of tissue. The ability of the organisms to invade systemically after wound surface inoculation was examined in mice given either a 2-s or a 7-s scald burn. Each injury was histologically confirmed as a full-thickness (third degree) burn, with slightly deeper tissue damage observed with the 7-s burn. At each time period examined (1, 4, 7, and 10 days), there were significantly fewer organisms in the wounds of mice given the 2-s injury than in wounds of mice burned for 7 s (P less than 0.05). In 3 of 33 mice given a 7-s injury, organisms were recovered from the kidneys at the time of sacrifice, whereas no evidence of invasion into the kidneys was noted in mice given a 2-s thermal injury. This study demonstrated that thermal injury enhances the ability of C. albicans to infect mice and that the depth of burn appears to be an important factor in determining whether the organisms can invade the burn wound to cause systemic infection. This animal model should be valuable in elucidating the virulence factors of C. albicans that play a role in the pathogenesis of candidiasis after thermal injury.

Animals↗
PubMed1984

Further characterization of human platelet activation in the absence of aggregation: phosphorylations of specific proteins and relationship with platelet secretion.

Platelet aggregation and secretion have been described to be associated with phosphorylation reactions. Thrombasthenic and EDTA-treated control platelets undergo a normal serotonin release in the absence of aggregation. We now studied the phosphorylation of specific proteins associated with platelet secretion. In the presence of ionophore, significant increases occurred in the phosphorylation of two polypeptides of 43,000 and 20,000 molecular weight ( P43 and P20) in a concentration dependent manner, and this was accompanied by an increase in the 14C-5HT release. The 32P-labelling of P43 and P20 reaches a peak within 1 min of platelet activation and is followed by a rapid dephosphorylation over the next 2-10 min. While the P20 is identified as the myosin light chain, the identity and the function of the P43 remain unknown. Isoelectric focusing separates 4 proteins from P43 during two dimensional electrophoresis, but only one of them is phosphorylated by A 23187. Chlorpromazine (CPZ) and trifluoperazine (TFP) inhibit the P43 and P20 phosphorylation as well as the 14C-5HT release in a dose dependent manner. The inhibitory action of the drugs is more pronounced for P43 than for P20, especially when the reactions are carried out at 20 degrees C instead of at 37 degrees C, while the release reaction is still inhibited under these conditions. These results allow different hypotheses for the relationship of phosphorylation-secretion and indicate the importance of one of these proteins ( P43 ) for the release reaction.

Blood Platelets↗
PubMed1982

Impact of modern diagnostic methods on the management of active rectal bleeding. Ten year experience.

We analyzed 178 patients admitted with a diagnosis of lower gastrointestinal hemorrhage from 1970 to 1979. Fifty-four percent had a subsequent or previous episode of bleeding and 78 percent required transfusions. One hundred eighteen patients had rigid sigmoidoscopy, with positive findings in 10 (8.5 percent); 98 underwent angiography, with positive findings in 41 percent; and 58 underwent colonoscopy, with positive findings in 48 percent. Comparison of these tests when the patient had active bleeding revealed the rates of positive findings for angiography and colonoscopy to be 42 and 85 percent, respectively. Sixty-five patients underwent operation and 16 eventually died, for a mortality rate of 25 percent. There was a higher percentage of deaths among patients with nondirected than in those with directed operations (32 versus 22 percent). Patients with lower gastrointestinal bleeding should undergo aggressive diagnostic evaluation utilizing sigmoidoscopy, angiography, and colonoscopy to increase the number of directed operations and decrease mortality and operative morbidity.

Adolescent↗
PubMed1978

Portosystemic communications studied by transhepatic portography;.

The experience of collecting 120 transhepatic portograms, performed in patients with different degrees of portal hypertension, affords the opportunity for discussing the anatomical and hemodynamic features of portosystemic communications. Multiple pathways of decompression were found. The coronary-gastroesophageal collateral formed pathways in 108 cases, other major collaterals in 41, and minor collaterals in 2. This multiplicity of communications suggests that no one vessel is indispensable as a collateral pathway.

Collateral Circulation↗
PubMed1978

[Not Available].

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History, Modern 1601-↗