Biomedical subjects

R Marin

Publications and source records attributed to R Marin.

At least 19 recordsLinked to original sources

PubMed2004

[Nonpenetrating deep trabeculectomy treated with mitomycin C, without implant. A prospective evaluation of 55 cases].

PURPOSE: Since 1998 we have been conducting a prospective study of nonpenetrating deep trabeculectomy with chronic open-angle glaucoma to evaluate the efficiency of the technique. MATERIAL AND METHODS: The study was carried out in 55 eyes of 41 patients who suffered from open-angle glaucoma. After performing a superior scleral flap, mitomycin diluted to 0.01% was applied for 3 minutes, then the 4 x 4-mm superficial scleral flap was dissected at two-thirds deepness until reaching the cornea. The Schlemm canal and the external trabecula were surgically removed and the two points of the Schlemm canal were catheterized with a trabeculotome to ensure that the ablation was well done. If it was not, it was completed by using a trabeculotome as a guide. Postoperatively, if the filtering bleb tended to decrease or ocular pressure began to increase, the operated trabecular region was reopened with Yag laser. The filtering bleb characteristics were correlated with the normalization of intraocular pressure in the first 30 cases. RESULTS: Preoperative pressure without treatment was 32 mmHg. Postoperative intraocular pressure without treatment was 20 mmHg or less in 79% of the eyes after 4 months, 77.5% after 6 months, 75% after 8 months and 61% after 12 months. By adding a local hypotension treatment in monotherapy, a pressure of 20 mmHg or less was obtained in 79% of the cases after 12 months. No severe complications were observed. The presence of a filtering bleb is an important factor in the normalization of postoperative pressure (p=0.0048). CONCLUSIONS: This surgical technique provides a substantial decrease in intraocular pressure and very few complications after 12 months of follow-up.

Adolescent↗

PubMed2003

Estradiol prevents amyloid-beta peptide-induced cell death in a cholinergic cell line via modulation of a classical estrogen receptor.

The pathology of Alzheimer's disease includes amyloid-beta peptide aggregation that contributes to degeneration of cholinergic neurons. Even though the underlying molecular mechanisms remain unclear, recent in vitro evidence supports a protective role for estrogens against several neurotoxic agents. Here we report that, in a murine cholinergic cell line (SN56), the massive cell death induced by 1-40 fragment of amyloid-beta peptide was prevented by 17beta-estradiol through a mechanism that may involve estrogen receptor activation. The protective effect of estradiol was observed in a dose-dependent manner, and was completely blocked by the pure antiestrogen ICI 182,780. In contrast, the inactive isomer 17alpha-estradiol consistently showed weaker neuroprotection than the native hormone that was unaffected by ICI 182,780 treatment. In addition, equivalent concentrations of 17beta-estradiol enhanced luciferase activity in cells transfected with a luciferase reporter gene driven by tandem estrogen response elements. Estrogen-induced luciferase activity was blocked by ICI 182,780, indicating estrogen receptor-dependent transcriptional activity. We also observed by reverse transcription-polymerase chain reaction, Western blot and immunocytochemistry that increasing concentrations of 17beta-estradiol enhanced the expression of estrogen receptor alpha mRNA and protein during amyloid-beta-induced toxicity. Under these conditions, it was found by confocal microscopy that the localization of estrogen receptor alpha in the absence of hormone was mainly extranuclear. However, the receptor was consistently observed also at the nuclear region after estrogen exposure. Overall, these data suggest that estrogen may exert neuroprotective effects against amyloid-beta-induced toxicity by activation of estrogen receptor-mediated pathways. In addition, intracellular estrogen receptors are up-regulated by their cognate hormone even during exposure to neurotoxic agents.

Acetylcholine↗

PubMed2003

An ICI 182,780-sensitive, membrane-related estrogen receptor contributes to estrogenic neuroprotective actions against amyloid-beta toxicity.

Although estrogen (E2)-related neuroprotection has been repeatedly demonstrated in different models, the involvement of non-classical estrogen receptors (ERs) in this activity remains unclear. Using SN56 murine cholinergic cell line from the basal forebrain, we present evidence indicating that an ER associated with the plasma membrane participates in estrogen-dependent reduction of neuronal death induced by amyloid-beta peptide (Abeta) toxicity. Exposure to either E2 or estradiol-horseradish peroxidase (E-HRP) for 15 min significantly reduced Abeta-induced cell death. This effect was decreased by the ER antagonist ICI 182,780 as well as by MC-20 antibody directed to a region neighboring the ligand-binding domain of ERa. Using MC-20 antibody in unpermeabilized SN56 cells, we detected a protein at the plasma membrane region. The binding of impermeant forms of E2, E-HRP, and E-BSA-FITC to specific sites of SN56 plasma membrane was blocked by pre-incubation with E2, ICI 182,780, and MC-20 antibody in a concentration-dependent manner. Thus, a membrane-related ER that shares some structural homologies with ERalpha may participate in estrogen-mediated neuroprotection.

Amyloid beta-Peptides↗

PubMed2001

Characterization of basal nitric oxide production in living cells.

Nitric oxide (NO) is an important modulator of immune, endocrine and neuronal functions; however, measuring physiological levels of NO in cell cultures is generally difficult because of the lack of suitable methodologies. We have selected three cell lines from different origins: the neuroblastoma-derived Neuro2A (N2A), the cholinergic SN56 and the non-neuronal COS-1. We first demonstrated the presence of NADPH-diaphoretic activity, a potential marker of the NO-synthesizing (NOS) enzyme. By immunocytochemistry, using specific antibodies for each NOS subtype, we observed that subtype I was present in all cell lines and that subtype II was present in COS-1 and N2A cell lines. The presence of these NOS subtypes was further verified by Western blot analysis. Control cells treated with DAF-2 DA exhibited significant fluorescent levels corresponding to basal NO production. The subcellular distribution of the synthesizing enzyme was consistent with the NO-fluorescence signal; whereas, fixation affected the subcellular pattern of NO fluorescence signal. Addition of NOS inhibitors or NO scavengers to the incubation medium reduced the intensity of the NO fluorescence signal in a concentration-dependent manner. Conversely, increasing concentrations of a NO donor, or incident light, increased the fluorescence intensity. Our observation of NO production and distribution using the DAF-2 method has a direct impact on studies using these cell lines.

Animals↗

PubMed2001

The amount of estrogen receptor alpha increases after heat shock in a cholinergic cell line from the basal forebrain.

Estrogen exerts a neuroprotective action in response to a variety of cell stresses. However, to what extent intracellular estrogen receptors are involved in these functions remains to be determined. We have found that SN56 cells, a neuronal-derived cholinergic cell line which produces luteinizing hormone-releasing hormone and contains the mRNAs encoding estrogen and progesterone receptors, also express estrogen receptor alpha, as well as the heat shock protein 90. Exposure of these cells to drastic temperature elevation for 1 h immediately increased the intracellular levels of these two proteins, whereas it rapidly reduced the content of estrogen receptor alpha mRNA. In addition, the amount of estrogen receptor alpha-heat shock protein 90 complexes was increased in response to thermal stress. Pre-treatment with geldanamycin, a potent inhibitor of heat shock protein 90, decreased the amount of estrogen receptor alpha, suggesting that its elevation after the heat insult may be related to its association with heat shock protein 90. In contrast, exposure of heat-shocked cells to 17beta-estradiol reduced the number of estrogen receptor alpha-heat shock protein 90 complexes, suggesting that the receptor conserves the affinity for its cognate ligand under these conditions. Therefore, the interaction of the estrogen receptor with heat shock protein 90 may serve to prevent its degradation during the thermal insult, as well as to maintain it in a high-affinity hormone-binding conformation. Since neuroprotective estrogen effects have been described in a variety of cytotoxic situations, these findings may be suggestive of an integrated neuronal response to injury, which includes the protection of available estrogen receptors through their association with heat shock protein 90.

Benzoquinones↗

PubMed2001

Prevalence of intestinal metaplasia in the distal oesophagus, oesophagogastric junction and gastric cardia in symptomatic patients in north-east Italy: a prospective, descriptive survey. The Italian Ulcer Study Group "GISU".

BACKGROUND: Incidence of adenocarcinoma of distal oesophagus and gastric cardia, probably arising from areas of intestinal metaplasia, has been increasing rapidly. AIMS: To define prevalence of intestinal metaplasia of distal oesophagus, oesophagogastric junction and gastric cardia and to evaluate potential associated factors, by means of a prospective multicentre study including University and teaching hospitals, and primary and tertiary care centres. PATIENTS: Each of 24 institutions involved in study enrolled 10 consecutive patients undergoing first-time routine endoscopy for dyspeptic symptoms. METHODS: Patients answered symptom questionnaires and underwent gastroscopy Three biopsies were taken from distal oesophagus, oesophago-gastric junction and gastric cardia, and were stained with haematoxylin and eosin. Specimens were also evaluated for Helicobacter pylori infection. RESULTS: A total of 240 patients (124 male, 116 female; median age 56 years, range 20-90) were enrolled in study. Intestinal metaplasia affected distal oesophagus in 5, oesophago-gastric junction in 19 and gastric cardia in 10 patients. Low-grade dysplasia was found at distal oesophagus and/or oesophago-gastric junction of 3/24 patients with intestinal metaplasia vs 2/216 without intestinal metaplasia (p<0.05). A significant association was found between symptoms and presence of intestinal metaplasia, regardless of location, and between Helicobacter pylori infection and intestinal metaplasia at oesophago-gastric junction. CONCLUSIONS: Intestinal metaplasia of distal oesophagus, oesophagogastric-junction and gastric cardia is found in a significant proportion of symptomatic patients undergoing gastroscopy and is associated with dysplasia in many cases. Although prevalence of dysplasia seems to decrease when specialized columnar epithelium is found in short segment, or even focally in oesophago-gastric junction, these small foci of intestinal metaplastic cells may represent source of most adenocarcinomas of cardia.

Barrett Esophagus↗

PubMed2001

A random comparison of fosinopril and nifedipine GITS in patients with primary renal disease.

OBJECTIVE: To investigate in a random comparison the capacity of an angiotensin converting enzyme inhibitor (fosinopril), and that of a long-acting dihydropiridine (nifedipine GITS) to modify the decay in renal function in patients with primary renal disease, exhibiting a progressive increase in serum creatinine during the previous 2 years. METHODS: A randomized, open-label, multicenter study with a minimum follow-up of 3 years. A total of 241 patients were included in the study. All of them were hypertensive and had a 25% or at least 0.5 mg/dl increase in the value of serum creatinine during the 24 months prior to entering the study. Initial doses of fosinopril and nifedipine GITS were 10 and 30 mg respectively, and titration to 30 and 60 mg was performed if needed to obtain the expected blood pressure goal (< 140/90 mmHg). Furosemide, atenolol, and doxazosin were added as second, third, and fourth drugs if necessary, for blood pressure control. The primary end-point of the study was the appearance of double the serum creatinine values and/or the need to enter a dialysis programme. Secondary end-points were cardiovascular events, death, changes in 24 h proteinuria, and the evolution of serum creatinine. Data reflect the analysis performed by intention to treat. RESULTS: Mean age of the group was 54 +/- 14, and 59% were males. Primary glomerulonephritis (31%), nephrosclerosis (26%) and polycystic kidney disease (19%) were the three most frequent diagnostic findings. After 3 years of follow-up, 21% (27/127) of patients treated with fosinopril, and 36% (40/112) of those receiving nifedipine GITS presented a primary end-point, (OR 0.47, 95% confidence intervals 0.26-0.84, P = 0.01). Renal survival was significantly better when fosinopril constituted the first step therapy (P = 0.002). These results did not seem to be influenced by the type of primary renal disease. Proteinuria decreased at the end of the study by a mean of 57% in the fosinopril group and increased by 7% in the group receiving dihydropiridine. Blood pressure control did not differ among groups for diastolic values. During follow-up, however, the patients receiving ACEi showed systolic blood pressure values 4-6 mmHg lower. CONCLUSION: In patients with chronic renal failure and hypertension due to primary renal disease, fosinopril significantly differed from nifedipine GITS by its capacity to slow the progressive decay in renal function. The drugs also differed by their capacity to lower blood pressure. The better control, in particular of systolic blood pressure, in the fosinopril arm could have contributed in a relevant manner to the attainment of a better outcome when the ACEi was employed.

Adult↗

PubMed2001

Outcome of liver disease in a large cohort of histologically proven chronic hepatitis C: influence of HCV genotype.

OBJECTIVE: To assess the influence of hepatitis C virus (HCV) genotypes on the clinical outcome of liver disease, we analysed 2,307 patients. RESULTS: The most frequently represented genotypes were 1b (40%) and 2 (28.1%). Patients with these genotypes had a median age higher than patients with other genotypes (P< 0.01). The overall survival of subjects with genotype 1b was poorer than the survival of patients with other genotypes (P< 0.01). Liver cirrhosis was found in 280 patients (12.1%), and type 1b was the most represented isolate among them (P< 0.01). Sixty-two patients (22%) developed hepatocellular carcinoma (HCC) during a follow-up of 1481.8 cumulative years (estimated crude incidence rate, 4.1 cases per 100 person-years for all cirrhotics; 5.9 cases for genotype 1a; 4.5 cases for genotype 1b; and 2.8 cases for genotypes non-1). Considering the whole population of 2,307 patients, only genotype 1b was associated significantly with both cirrhosis and the development of HCC. One hundred and nineteen cirrhotic patients underwent treatment with interferon in uncontrolled studies. Interferon therapy was associated with both better survival (P< 0.01) and a lower cumulative hazard for HCC (P< 0.01). CONCLUSIONS: Genotype 1b was associated with a poorer prognosis, probably because it leads to cirrhosis and consequently to HCC development. However, our data did not confirm genotype 1b as an independent risk factor for HCC in liver cirrhosis, which plays a major role in carcinogenesis. Interferon should be considered as a useful strategy in cirrhosis for improvement of survival and reduction of HCC risk.

Adolescent↗

PubMed2001

Physical medicine and rehabilitation in the military: the Bosnian mass casualty experience.

On February 5, 1994, a 120-mm mortar shell crashed into the main Market Square of Sarajevo, Bosnia. The explosion killed 66 and injured 206. The United States evacuated 71 of the injured to Landstuhl Regional Medical Center, where the Physical Medicine and Rehabilitation Service evaluated 28 victims. This mass casualty evacuation underscores the role of Army physiatrists in humanitarian assistance and wartime casualty management. The author collected data regarding demographic factors, injury types, complications, and functional limitations. Seventeen of the 28 patients evaluated were injured during the market bombing, with the rest being injured before the bombing. Of 132 diagnoses in these 28 patients, 31 were fractures, 14 were amputations, 8 were peripheral neuropathies, 3 were spinal cord injuries, and 1 was a traumatic brain injury. Contractures and decubitus ulcers, both complications of immobility, accounted for 18 of the diagnoses. Ambulatory impairments were present in all of the patients, and 4 patients had major impairments in activities of daily living.

Adolescent↗

PubMed2000

Mortality of sea lions along the central California coast linked to a toxic diatom bloom.

Over 400 California sea lions (Zalophus californianus) died and many others displayed signs of neurological dysfunction along the central California coast during May and June 1998. A bloom of Pseudo-nitzschia australis (diatom) was observed in the Monterey Bay region during the same period. This bloom was associated with production of domoic acid (DA), a neurotoxin that was also detected in planktivorous fish, including the northern anchovy (Engraulis mordax), and in sea lion body fluids. These and other concurrent observations demonstrate the trophic transfer of DA resulting in marine mammal mortality. In contrast to fish, blue mussels (Mytilus edulus) collected during the DA outbreak contained no DA or only trace amounts. Such findings reveal that monitoring of mussel toxicity alone does not necessarily provide adequate warning of DA entering the food web at levels sufficient to harm marine wildlife and perhaps humans.

Animals↗

PubMed2000

Long-term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis.

It is clearly established that beta-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (log rank test, P =.02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (log rank test, P =.20). Thirty and 25 patients, respectively, died during follow-up (log rank test, P =.13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (log rank test, P =.29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

Adolescent↗

PubMed2000

Cure of Helicobacter pylori-positive active duodenal ulcer patients: a double-blind, multicentre, 12-month study comparing a two-week dual vs a one-week triple therapy. GISU (Interdisciplinary Group for Ulcer Study).

AIMS: To compare a two-week dual therapy to a one-week triple therapy for the healing of duodenal ulcer and the eradication of the Helicobacter pylori infection. PATIENTS AND METHODS: A total of 165 patients with active duodenal ulcer were enrolled in the study. At entry, endoscopy, clinical examination and laboratory tests were performed. Histology and the rapid urease test were used to diagnose Helicobacter pylori infection. Patients received either lansoprazole 30 mg plus amoxycillin 1 g bid for two weeks (two-week, dual therapy) or lansoprazole 30 mg plus amoxycillin 1 g plus tinidazole 500 mg bid for one week plus lansoprazole qd for an additional week (one-week, triple therapy). Two and twelve months after cessation of therapy, endoscopy and clinical assessments were repeated. RESULTS: Duodenal ulcer healing and Helicobacter pylori eradication were both significantly greater (p<0.0001) in the triple therapy group (healing: 98.6%; Helicobacter pylori cure rate: 72.6%) than in the dual therapy group (healing: 77.3%; Helicobacter pylori cure rate: 33.3%). Ulcers healed more frequently in Helicobacter pyloricured than in Helicobacter pylori-not cured patients (94.9% vs. 77.2%; p<0.0022). After one year, Helicobacter pylori eradication was re-confirmed in 46/58 patients previously treated with the triple therapy and in 10/40 patients treated with the dual therapy [p<0.0001]. Only three duodenal ulcer relapses were observed throughout follow-up: all were in Helicobacter pylori-not cured patients. CONCLUSIONS: Triple therapy was more effective than dual both in curing Helicobacter pylori infection and healing active duodenal ulcers. The speed of ulcer healing obtained after only 7 days of antibiotics and 14 days of proton pump inhibitors confirmed that longer periods of anti ulcer therapy were not necessary. Helicobacter pylori -not cured patients had more slowly healing ulcers which were more apt to relapse when left untreated.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2000

Pantoprazole versus one-week Helicobacter pylori eradication therapy for the prevention of acute NSAID-related gastroduodenal damage in elderly subjects.

AIM: To compare the efficacy of pantoprazole vs. a one-week Helicobacter pylori eradication therapy for the prevention of NSAID-related gastroduodenal damage. METHODS: Patients over 60 years old with symptoms and/or a history of ulcer who needed NSAID treatment were evaluated by endoscopy. H. pylori positive subjects who had no severe gastroduodenal lesions were randomized to take, concomitantly with NSAID therapy, either: (i) pantoprazole 40 mg daily plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. for 1 week (35 subjects, Group PAC) or (ii) pantoprazole 40 mg daily for 1 month (34 subjects, Group P). Endoscopy was repeated after 1 month. RESULTS: A significantly higher incidence of severe gastroduodenal damage was found in Group PAC than in Group P (29% vs. 9%, P<0.05). The percentages of patients worsened, unchanged and improved after 1 month were, respectively: Group PAC: 46%, 46%, and 9% and Group P: 7%, 65%, and 29% (P<0.0008). The percentage of H. pylori-negative subjects was 89% in Group PAC and 52% in Group P (P=0.0009). The incidence of gastroduodenal damage was higher in Group PAC treatment failures than in cured patients (50% vs. 25.8%, P=ns). CONCLUSION: One month of pantoprazole was more effective than a proton pump inhibitor-based triple therapy in the prevention of gastroduodenal damage in elderly H. pylori-positive NSAID users.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1999

[Home self-monitoring of arterial pressure: identification of the white coat reaction].

OBJECTIVES: To validate the reliability of a standard protocol for self-measurement at home of blood pressure (SMBP) in terms of its sensitivity and specificity for the diagnosis of the white-coat phenomenon (WCP), by comparing it with out-clinic monitoring of blood pressure (OMBP) and examining the effect on the two methods' concordance of blood pressure (BP) levels, the intensity of the WCP, age and the body mass index. DESIGN: Crossover descriptive study. SETTING: Two health centres in Asturias. PARTICIPANTS: 58 patients with hypertension, whose BP was not monitored in the clinic, were taught to take 30 SMBP readings in 10 days with a previously calibrated digital sphygmanometer. In the 15 days immediately following, a 24-hour OMBP session took place. Sensitivity, specificity, predictive values and the analysis of individual differences between the variables were assessed. MEASUREMENTS AND MAIN RESULTS: SMBP sensitivity was 84.21%. Specificity was 82.05%. For the estimated prevalence of white-coat hypertension in our area (22.7%), positive predictive value was 58%, and negative 95%. The graphic analysis of individual differences did not show that the consistency between the two methods was affected in a relevant way by any variable analysed. CONCLUSIONS: The SMBP protocol presented is a valid instrument, especially for confirming sustained hypertension. It enables the WCP to be suspected, though, if possible, this should be confirmed by means of OMBP.

Adult↗

PubMed1999

Repeated PGE1 treatment enhances nitric oxide and erection responses to nerve stimulation in the rat penis by upregulating constitutive NOS isoforms.

PURPOSE: To assess whether intracavernosal injections of prostaglandin E1 (PGE1) can influence nitric oxide (NO) release in the corpora in a rat model of penile erection. MATERIALS AND METHODS: The extracellular levels of NO were monitored at 100 seconds intervals in the corpus cavernosum of anesthetized rats by using differential normal pulse voltammetry with porphyrin-Nafion coated carbon fiber microelectrodes. The intracavernosal pressure (ICP) was simultaneously recorded. PGE1 was given either as a single dose (ranging from 0.2 to 15 microg.) or as repeated 2 microg. injections in alternate days for two weeks. The NO and ICP responses to electrostimulation of the cavernosal nerve (SCN) was studied in the animals in the repeated treatment schedule at 1, 7, 15 and 30 days after its termination. The levels of the three NO synthase (NOS) isoforms in the cavernous tissue were measured by immunoblotting. RESULTS: Acute PGE1 treatment dose-relatedly increased NO levels in the corpora, with a concomitant ICP increase with the highest dose. Repeated 2 microg. PGE1 injections increased the NO and ICP responses to SCN as compared with intact or vehicle-injected animals. This treatment also increased the penile content of the neuronal and endothelial NOS proteins. The inducible NOS isoform remained unchanged after either vehicle or PGE1 injections. The effects of the repeated PGE1 treatment were greater in the group studied 24 hours after the last injection and decreased progressively thereafter. CONCLUSIONS: Stimulation of NO release can contribute to the erectogenic effect of intracavernous PGE1 injections. The increased levels of constitutive NOS isoforms in the corpora could contribute to the improvement of the erectile function reported by some patients following repeated treatment with vasorelaxant agents.

Alprostadil↗

PubMed1999

A problem-solving method for 'unprotocolised' therapy administration task in medicine.

This paper describes a problem-solving method for modelling the 'unprotocolised' treatment administration task in medicine. We argue that there are medical domains in which no well-established standard treatment protocols exist, and the physician has to decide on the therapy that is to be applied to each patient, in function of a set of therapeutic objectives to be fulfilled. For this reason, we propose the modelling of this type of task adapting the generic class of problem resolution methods for design task, labelled as Propose-Critique-Modify (PCM). In this paper, we are presenting a model of expertise which has been developed using the basic modelling components of the CommonKADS methodology.

Artificial Intelligence↗

PubMed1999

Androgen-dependent nitric oxide release in rat penis correlates with levels of constitutive nitric oxide synthase isoenzymes.

Androgens are known to influence penile erection and nitric oxide synthase (NOS) activity in cavernosal tissue homogenates. The present study was an assessment of the effects of castration and androgen replacement on the in vivo release of nitric oxide (NO), and of the simultaneously recorded intracavernosal pressure (ICP) changes elicited by electrostimulation of the cavernosal nerves (SCN) in the anesthetized rat. The extracellular levels of NO in the corpora were monitored electrochemically using porphyrin microsensors. The content of NOS isoenzymes in corporal homogenates was determined by immunoblotting. The responses of castrated rats with or without testosterone (T) implants were compared to those of intact animals. Castration virtually abolished both the NO and the ICP responses to SCN. There was a concomitant significant decrease in the content of both the neuronal (nNOS) and the endothelial (eNOS) isoenzymes in the cavernosal tissue. All these effects of castration were prevented by T replacement. The NO response to SCN was positively correlated with the levels of nNOS and eNOS, especially when the values of the two isoforms were added (r = 0.71, P < 0.001). These data suggest that the facilitatory action of androgens on penile erection involves the up-regulation of both constitutive NOS isoenzymes in the corpora cavernosa.

Animals↗

PubMed1998

Scapula winger's brace: a case series on the management of long thoracic nerve palsy.

OBJECTIVE: To evaluate the clinical utility of a new scapula winger's brace. DESIGN: A case series. SETTING: A tertiary military clinic serving a young population. PARTICIPANTS: Fourteen patients referred to the clinic for thoracic nerve palsy of a least 3 months' duration. OUTCOME MEASURES: Manual muscle tests with and without the brace and patients' compliance/satisfaction with brace as measured by personal interview during follow-up. RESULTS: Muscle strength increased by one grade with brace application; patients who maintained compliance (n = 6) recovered their brace-free shoulder flexion strength and/or had reduced pain at the last follow-up (1 to 7 months after brace). All patients reported a subjective feeling of increased shoulder flexion strength and decreased pain with brace application. CONCLUSION: The scapula winger's brace is a useful tool for physiatrists in the management of scapular winging secondary to long thoracic nerve palsy. Additional studies are needed to confirm the conclusion that the device's benefits derive from proprioceptive feedback that prevents muscle overuse or overstretch and from its transfer of contralateral shoulder protraction force to the affected scapula.

Adult↗