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Biomedical subjects

M Nouri

Publications and source records attributed to M Nouri.

72 records · Page 4Linked to original sources
PubMed1997

[An unusual complication of anterograde endopyelotomy: ureteral intussusception (a case report)].

Endopyelotomy has recently found a new place in the treatment of stenosis of the pyeloureteral junction, and it can represent a treatment of choice. We report an unusual case of antegrade ureteral intussusception after antegrade endopyelotomy in a 30 year-old young woman with a solitary kidney, which caused proximal ureteral obstruction. These intussusceptions were probably caused by double CH endoprosthesis. These iatrogenic injuries required surgical resection with calicoureterostomy.

Adult↗
PubMed1997

[Fournier's gangrene. Analysis of 32 cases].

A series of 32 treated cases of Fournier's gangrene is analysed. All patients were male, their age ranged from 19 to 89 years. In 16 cases (50%) the aetiology of gangrene was urethral (37.5%), anorectal (12.5%) and in the 16 remaining cases (50%) there was no identifiable cause. Mortality was high (28%) despite broad spectrum antibiotics and aggressive surgical debridement. This mortality was essentially associated to advanced age, debilitated state, delay in diagnosis and toxi infectious context. The average hospital stay was 26.5 days.

Abscess↗
PubMed1995

Acetylcholine and central respiratory control: perturbations of acetylcholine synthesis in the isolated brainstem of the neonatal rat.

The brainstem neurochemical processes which support spontaneous ventilation are not known. Cholinergic transmission may play an important role. If this is true, perturbations in acetylcholine (ACh) turnover should alter ventilatory output in a predictable manner. Using the isolated superfused brainstem-spinal axis from the neonatal rat, the effects of modifiers of ACh synthesis on spontaneous C-4 (phrenic) output were determined. 3-Bromopyruvate and hydroxycitrate, inhibitors of acetyl-CoA (substrate for ACh synthesis) formation, caused depression of the C-4 output in a dose-dependent manner when added to the superfusate. Triethylcholine, a false-transmitter generating choline analog, caused a similar depression. Citrate, a cytosolic precursor to acetyl-CoA formation, caused stimulation of C-4 (phrenic) output. The stimulatory effects of citrate were blocked by the muscarinic cholinergic blocker, atropine. These findings are consistent with the view that the ACh synthetic pathway provides a continuous and important input to the normal brainstem elements that support ventilation.

Acetylcholine↗
PubMed1995

Efficacy of intravenous delta-aminolaevulinic acid photodynamic therapy on rabbit papillomas.

Endogenously induced protoporphyrin IX (PPIX), a metabolite of delta-aminolaevulinic acid (ALA), has been evaluated as a photosensitising agent for destruction of papillomas in cottontail rabbit papillomavirus-infected Dutch belted and New Zealand rabbits. Three factors were evaluated: (1) relative retention ratio of drug in normal tissue, papilloma and plasma over time; (2) tissue tolerance to treatment factors; and (3) efficacy of treatment protocol. Three drug doses of ALA were examined: 50, 100 and 200 mg kg-1. Actual PPIX concentrations in tissue and plasma were determined spectrophotofluorometrically. The optimal treatment time occurred 3-6 h post ALA injection. The highest PPIX concentration ratio between papilloma and normal skin was 6:1. Different light doses were investigated, using an injection to exposure interval of 3 h and an irradiance of 100 mW cm-2 at a wavelength of 630 nm. Efficacy without risk of significant damage to normal skin was obtained using 100-200 mg kg-1 ALA and 40-60 J cm-2. A long-term (3 months) cure rate of 82% was obtained with a single treatment, provided that papilloma depth did not exceed 8 mm, volume was not more than 1000 mm3 and the plasma concentration of PPIX immediately before exposure was above 500 micrograms ml-1. The short time between injection and treatment and high efficacy, together with PPIX disappearance from plasma and tissue within 24 h, make injected ALA a highly attractive drug for photodynamic therapy.

Aminolevulinic Acid↗
PubMed1995

Treatment of the intraoperative penile erection with intracavernous phenylephrine.

A total of 23 patients who had an intraoperative penile erection during endoscopic or penile surgery underwent intracavernous injection of 200 micrograms phenylephrine. Detumescence occurred rapidly in all patients with a single injection. Hemodynamic changes consisted of a transient increase in systolic and diastolic blood pressures (+9%, p < 0.05) without significant change in pulse rate (-5%, p > 0.05). No marked side effect was reported even in elderly patients. Intraoperative penile erection, which seems to be more frequent in patients younger than 50 years, during general anesthesia with propofol or epidural anesthesia, can be treated safely with intracavernous injection of phenylephrine.

Adult↗
PubMed1994

Photodynamic therapy using m-tetra(hydroxyphenyl) chlorin. An animal model.

OBJECTIVE: To evaluate the potent photosensitizer m-tetra (hydroxyphenyl) chlorin (m-THPC) by using rabbits with cottontail rabbit papillomavirus-induced tumors and the canine larynx as model systems. DESIGN: Nonrandomized control trial. SETTING: Division of ear, nose, and throat research at a tertiary care teaching hospital. MATERIALS: Rabbits were used for relative retention ratio studies and tissue tolerance tests. Studies on the swelling of normal tissues in the larynx after photoactivation were done with canines. INTERVENTION: Animals were injected with 0.3 mg/kg of m-THPC. At varying intervals, tissues were exposed to 652 nm of light. OUTCOME MEASURES: Outcome measures consisted of four elements: (1) decay of plasma concentration over time, (2) interval to and duration of maximal ratio between drug concentration in normal tissue and tumor, (3) maximal permissible light exposure to normal tissue (skin and laryngeal mucosa) at an optimal interval, and (4) efficacy--number of tumors with partial and complete response. RESULTS: The largest papilloma to skin ratio (10:1) occurred 4 to 8 days after drug injection. The rabbit skin damage threshold was 40 to 60 J/cm2 at 6 days. The canine laryngeal edema and erythema thresholds were 50 to 70 J. A 75% cure rate of papillomas was achieved with tumors that were less than 100 mm2 in area at light doses that ranged from 25 to 75 J/cm2. CONCLUSIONS: m-THPC shows efficacy in treating papilloma virus-induced tumors. We present a protocol for rapid optimization of the factors required for tumor destruction with minimal normal tissue damage, thus permitting determination of an optimal therapeutic protocol for any photosensitizer.

Animals↗
PubMed1994

Heat shock protein expression in human conjunctiva.

PURPOSE: To examine the distribution of human heat shock proteins (HSPs) HSP90, inducible HSP70 (iHSP70), constitutive and inducible HSP70 (cHSP70), HSP65, and human HSP27 in conjunctival biopsy specimens of ocular cicatricial pemphigoid (OCP), atopic keratoconjunctivitis, and healthy persons with cataract. METHODS: Using an immunoperoxidase technique, conjunctival biopsy specimens from ten patients with ocular cicatricial pemphigoid, ten patients with atopic keratoconjunctivitis and ten healthy persons undergoing cataract surgery were analyzed with a panel of monoclonal antibodies directed against human HSPs. RESULTS: Large amounts of HSP90 and HSP27, and lesser amounts of cHSP70, iHSP70, and HSP65 were present in atopic keratoconjunctivitis and normal epithelium; less of these proteins were seen in OCP conjunctival epithelium. In atopic keratoconjunctivitis and normal tissue the substantia propria contained a few HSP-positive cells, and the vascular endothelium was consistently negative for all of the HSPs. In sharp contrast, OCP stroma contained large numbers of cells staining for HSP27, HSP90, and iHSP70, and the vasculature was strongly positive, particularly for HSP90, cHSP70, and HSP27. CONCLUSION: These results indicate that normal and atopic keratoconjunctivitis epithelia express HSP90 and HSP27 and some form of HSP65 and HSP70. The differences between normal, atopic keratoconjunctivitis, and OCP stromal staining suggest an upregulated expression of HSP90, cHSP70, and HSP27 at the site of inflammation in OCP, the stroma, from cytokine release. The striking presence of HSP in the conjunctival vascular endothelium from OCP patients suggests a previously unappreciated role of the vasculature in OCP.

Aged↗
PubMed1994

Latent infection induced with cottontail rabbit papillomavirus. A model for human papillomavirus latency.

Latent human papillomavirus infection, a very common event, is most likely the source of primary and recurrent papillomas of the respiratory and genital tracts and might also be the source of neoplastic lesions of the female genital tract and the penis. We have developed a simple model for papillomavirus latency using cottontail rabbit papillomavirus. Skin of domestic rabbits was minimally scarified and inoculated with dilutions of a crude virus suspension ranging from 200 ng to 20 pg viral DNA per inoculated site. Dilution of virus to less than 10 ng/site resulted in delayed and reduced efficiency of inducing warts. After follow-up of 1 to 6 months, sites immediately adjacent to papillomas and inoculated sites where papillomas did not form were biopsied and analyzed by Southern blot and polymerase chain reaction. Inoculated tissues that were clinically and histologically normal contained viral DNA at low levels, detectable by polymerase chain reaction. Ability of the latent virus to induce warts was confirmed by activation with mild skin irritation causing wart formation. This simple model system for latent papillomavirus can be used to study mechanisms of viral activation, therapies to prevent activation, and therapies to eliminate latent virus and thus cure the infection.

Animals↗
PubMed1991

Asymptomatic cryptosporidiosis in nomadic shepherds and their sheep.

The formed stool samples of 276 asymptomatic members of 36 households of a group of nomadic shepherds and 215 non-diarrhoeal faecal samples from their sheep were examined for cryptosporidial infection by a modified Ziehl-Nielsen technique. Thirty-six (13%) human samples and 37 (17.2%) samples from sheep were positive. A strong possibility of asymptomatic zoonotic transmission of cryptosporidiosis due to prolonged and constant association of shepherds and their sheep was an important finding.

Adolescent↗
PubMed1982

Differential effect of acid meals on abomasal emptying and secretion in the milk-fed calf.

Preruminant (milk-fed) calves were prepared with an abomasal and re-entrant duodenal cannulae to assess the effect of acid test meals on abomasal emptying and secretion. Isotonic saline meals acidified with hydrochloric acid to pH 2 instilled directly into the abomasum did not affect abomasal emptying or acid and pepsin secretion when compared with saline meals at pH 6. Isotonic saline meals at pH 1.2 significantly inhibited abomasal acid secretion, but had little effect on emptying or pepsinogen secretion. Abomasal emptying, acid secretion and pepsinogen secretion were significantly inhibited when acid was introduced into the duodenum, irrespective of the acidity of the test meal. It is concluded that in the calf acid meals inhibit gastric acid secretion alone without effect on pepsinogen secretion and abomasal emptying. All three abomasal functions, however, were inhibited by acidification of the duodenum.

Abomasum↗
PubMed1981

The interplay between hydrogen ions, bicarbonate ions and osmolality in the anterior duodenum modulating gastric function in the conscious calf.

1. Gastric emptying, gastric acid and pepsinogen secretion were assessed simultaneously in the conscious calf using the test meal and duodenal perfusion technique (Bell & Mostaghni, 1975).2. Duodenal infusion of NaCl at a constant osmolality of 300 m-osmole/kg, but with pH ranging from 2.0 to 12.0, did not alter the high level of gastric emptying and secretion already reported for isotonic NaCl or NaHCO(3) alone (Bell & Mostaghni, 1975; Bell & Webber, 1979). Gastric function, therefore, is either unaffected by gastric chyme at pH 2.0-12.0 entering the duodenum, or else isotonicity is dominant over pH in activating duodenal receptors which increase motor activity.3. When the pH of the isotonic NaCl was reduced by the addition of HCl to below pH 2.0, inhibition of gastric function occurred in direct proportion to the amount of titratable acid present in the infusate. The H(+) moiety of isotonic duodenal infusates of pH < 2.0 dominates activation of osmoreceptors and so inhibits motor activity.4. When the same amount of acid but at differing concentrations and infusion rates was introduced into the duodenum uniform inhibition of gastric function occurred. This result indicates that duodenal acid receptors respond to acid concentration and flow rate to produce an integrated response in proportion to the amount (concentration x volume) of acid present.5. Isotonic NaHCO(3) solutions adjusted to pH 8.1-12.0 by the addition of NaOH, like isotonic NaCl infusions, did not affect gastric function until pH 11.0-12.0, when significant inhibition occurred. This inhibitory effect of isotonic NaHCO(3) at high pH is probably due to CO(3) (2-), since Na(2)CO(3) and Li(2)CO(3), but not LiCl, produce a similar inhibitory effect on gastric function.6. The inhibitory effect of carbonate gives some support to the existence of a CO(2)-sensor as suggested by Hunt & Knox (1972), whereby increased P(CO2) produced by intracellular or intercellular neutralization of CO(3) (2-) by duodenal H(+) activates acid receptors. But other experiments reported here, where simultaneous perfusion of HCl and excess NaHCO(3) produced a rise in intraluminal P(CO2), did not inhibit gastric function, which is contrary to the idea of a direct intraluminal effect of CO(2) on duodenal receptors.7. The pH, P(O2), P(CO2), HCO(3) (-) and base excess of venous blood showed no detectable change during duodenal infusion of either acidic or alkaline solutions. Metabolic acidosis or alkalosis, therefore, cannot be considered to play any part in controlling gastric function. The results thus corroborate the notion that the receptors controlling gastric function are localized in the intestinal mucosa.8. Our results suggest that interplay between acid and osmolality of gastric chyme occurs in the rostral part of the duodenum to produce a graded inhibitory effect which by negative feedback modulates the gastric effectors that normally activate smooth muscle, parietal cells and zymogen cells.

Animals↗