Biomedical subjects

D Marquez

Publications and source records attributed to D Marquez.

9 recordsLinked to original sources

PubMed1997

Cloning of rat and human inducible penile nitric oxide synthase. Application for gene therapy of erectile dysfunction.

Erectile dysfunction is mainly due to the inability of the cavernosal smooth muscle of the penis to undergo complete relaxation. In the aging rat model, erectile dysfunction is accompanied by a reduction of penile smooth muscle compliance and, in very old animals, by a decrease in penile nitric oxide synthase (NOS), which is responsible for the synthesis of the mediator of penile erection, nitric oxide (NO). We have investigated whether the stimulation of penile NOS expression by local induction or gene therapy can mitigate erectile dysfunction in the aged rat. A mix of iNOS (inducible NOS) inducers was continuously delivered to the penises of 5- ("adult"), 20- ("old"), and 30- ("very old") mo-old rats for 3-6 days, and the erectile response to electrical field stimulation of the cavernosal nerve was measured. The erectile dysfunction observed in old and very old rats as compared to adult animals was ameliorated by treatment with iNOS inducers. Penile iNOS was detectable in the penis of these rats by Western blot, NADPH diaphorase, and NOS activity assays. Inducible NOS was inducible in vitro in both rat and human corpora cavernosal tissue and in rat penile smooth muscle cells (RPSMC), as shown by Western blots. However, NO synthesis in cavernosal tissue upon iNOS protein induction remained low, indicating that the increased NOS levels were under physiological control. The iNOS cDNA was cloned from induced RPSMC mRNA and generated by reverse transcriptase polymerase chain reaction (RT-PCR) from induced human penile smooth muscle cells and corporal tissue. The coding regions from both the rat (RPiNOS) and human (HPiNOS) penile iNOS showed several amino acid differences from their analogous isoform in nonpenile tissues. RPiNOS cDNA injected into the penis mitigated the aging-associated erectile dysfunction. The iNOS construct was detected in cavernosal tissue by PCR, and its expression by RT-PCR and Western blots. These results open the way for the possible use of NOS isoforms in the management of erectile dysfunction.

Aging↗

PubMed1996

Cloning of a novel neuronal nitric oxide synthase expressed in penis and lower urinary tract.

The neuronal nitric oxide synthase (nNOS) is the main NOS isoform in the urogenital tract catalyzing the synthesis of nitric oxide, the mediator of penile erection and presumably an important factor in the control of urinary voiding. We have cloned from the rat penile corpora cavernosa a cDNA coding for a novel nNOS differing from the cerebellar nNOS by the presence of a 102 nucleotides stretch and other features. This new species is the only nNOS mRNA expressed in the rat penis, urethra, prostate, and skeletal muscle, coexists with the cerebellar nNOS in the pelvic plexus and bladder, and is detectable in the cerebellum. The novel insert is present in human penile RNA and is transcribed from intron 16. The features and distribution of the penile nNOS suggest that it is may be regulated differentially from the cerebellar nNOS.

Amino Acid Sequence↗

PubMed1995

Restoration of normal adult penile erectile response in aged rats by long-term treatment with androgens.

In order to determine whether the aging-related impairment of penile erection can be corrected by exogenous androgens, 20-mo-old ("old") rats received implants of Silastic tubing containing either testosterone (T) or dihydrotestosterone (DHT). Untreated aged-matched rats were used as reference controls, and values were compared with those obtained previously for 5-mo old ("adult") rats. After 45 days, groups of six rats were submitted to electrical field stimulation of the cavernosal nerve (EFS), and the intracavernosal pressure and mean arterial pressure (MAP) were recorded. Compared to the untreated old rats, the old animals receiving either T or DHT showed a similar and significant (p < 0.01) increase (56%) in the maximal intracavernosal pressure (MIP) to a level slightly above that of the untreated adult rats. The response was sensitive to the nitric oxide synthase (NOS) inhibitor Nw-nitro-L-arginine methyl ester (L-NAME). The MIP:MAP ratio in the treated animals was nearly double that found in the old untreated controls. Penile NOS activity was measured by the [3H]L-arginine-citrulline conversion, and neuronal NOS (nNOS) levels were estimated by a semiquantitative Western blot assay with antibodies against human nNOS. No significant variations were observed in either NOS levels or NOS activity between the treated and untreated old rats. These results suggest that aging-related erectile dysfunction in the intact rat may be responsive to androgen therapy and that this correction is not associated with an increase in the basal levels of penile NOS, in contrast to what occurs in castrated rats.

Aging↗

PubMed1988

Salvage of infected total knee arthroplasty.

Between 1981 and 1986, 25 patients with 26 infected total knee arthroplasties (TKAs) were treated with complete debridement of the knee, prosthetic removal, and six weeks of intravenous antibiotics, followed by insertion of a new prosthesis. The patients were followed for 12-57 months (average, 29 months). There was no evidence of residual infection at follow-up examination in any case. Applying the Hospital for Special Surgery knee rating system, 12 patients (50%) were rated excellent, six patients (25%) good, two patients (9%) fair, and four patients (6%) poor. Of the six patients with fair and poor results, five had reduced scores due to joint problems unrelated to the infected TKA. Fourteen patients had no pain at follow-up examination, and four had only slight pain. Nine patients had no limp, ten had a slight limp, one had a moderate limp, and the remainder either had a severe limp or were bedridden due to other joint problems. Eight patients could walk an unlimited distance and four could walk at least one-half mile. Twenty-one knees had a range of flexion greater than 90 degrees. Three patients had extensor lags of 20 degrees or greater. Only one patient required bracing for ambulation.

Aged↗

PubMedDate not supplied

[Complications of laparoscopic cholecystectomy].

The laparoscopy cholecistectomy is a surgical procedure described in 1987, and it has had an important apogee and it's had substitute to open procedure. Between its advantages is notable, the postoperatory evolution without pain, paralytic ileus and the short time of hospitalization besides the patient can go away the same day in some cases. In Venezuela, the procedure has been received with enthusiasm by the surgeons with prefer this procedure however, there are complications derived in part for the lack of experience in the first cases, but occur non related of the experience. The quantization of the complications is not simple to realize for different reasons. We present twelve complications, two belong to patients intervened in the Hospital Universitario de Caracas and ten belong to patient transferred from other center. The complications were: pseudoaneurism of hepatic artery, hematoma of the wall, cutting of common bile duct, section the right bile duct, abscess of vesicular bed in two cases, retropneumoperitoneum, ascites by biliary fistula and four biloma. The treatment varied in every case and the utilization of radiologic technique with percutaneous drainage were useful in five cases. We conclude: first, this technique is not free of complications. Second, the percutaneous drainage (abscess, biloma), endoscopic procedure (biliary prosthesis) in fistulaes and arteriographics (arterial embolization), are useful in some cases, and could prevent the surgical reintervention.

Cholecystectomy, Laparoscopic↗

PubMedDate not supplied

[Endoscopic retrograde cholangiopancreatography in hepatic fascioliasis].

We present a 60 years old female with a history of upper right quadrant pain, fever and eosinophily. We made the diagnosis of fasciolasis on clinical, parasitology studies and radiological findings. In the endoscopic retrograde cholangiopancreatography (ERCP) we found the bile duct of normal caliber, but with many filling defects. Fasciola eggs were found in the bile. This is the first case with endoscopic retrograde cholanglopancreatography and the fourth case of fasciolasis in Venezuela.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMedDate not supplied

[Biliary cystadenoma. Report of a case].

Biliary Cystadenoma are rare benign neoplasms that occurs mainly in young women. Clinical features includes abdominal pain and biliary obstruction. The diagnosis is for clinical features and radiologic method, but require the pathological report. The treatment is surgical. We report a 30 years old woman, with biliary obstruction and radiological findings of a neoplasm located in the left hepatic duct, that was surgically removed. The pathological report was a biliary cystadenoma. We discuss the clinical radiological and pathological tindings.

Adult↗

PubMedDate not supplied

[Accessory spleen: compensating hypertrophy after of splenectomy. A case report].

The prevalence of accessory spleens has been reported to be about 7.1% in infants. When these patients undergo splenectomy without removal of the accessory spleen, the latter develop hypertrophy later in life and can reach the size of a normal spleen, with clinical manifestations similar to the ones before surgery. We report the case, of fourteen-old boy, who had splenectomy 7 year ago, for refractory and recurrent thrombocytopenia, who had splenectomy at age 7 years because of persistent thrombocytopaenia, resistant to non-surgical treatment, and who was found by conventional ultrasound study, doppler duplex color and selective angiography to have a hypertrophied spleen with sings of portal thrombosis and portal hypertension.

Adolescent↗

PubMedDate not supplied

[Intrahepatic lithiasis].

The intrahepactic lithisis is unusual in the Occidental hemisphere. The prevalence in Venezuela in unknown. We study all the edoscipic retrograde cholangiography carried for lithiasic pathology, in the Servicio de Gastroenterología, Hospital Universitario de Caracas, since January 1993 until April 1995. Over 342 patients, 9 were intrahepatic lithisis (1.16%). Seven cases of Caracas and two refered of the rest of the country. The sex was female in seven patients and males in two. The age range was 15 to 67 years old. The clinic feature much frequent was abdominal pain. The diagnosis was ultrasound and endoscopic retrograde cholangiography. The treatment was endoscopic with sphincterotomy and removal stones and surgical with resection in two cases, and choledocotomy in the other four cases.

Adolescent↗