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Biomedical subjects

N Khoury

Publications and source records attributed to N Khoury.

At least 19 recordsLinked to original sources

Hypercalcemia in Langerhans' cell granulomatosis with elevated 1,25 dihydroxyvitamin D (calcitriol) level.

A 48-year-old woman presented with a history of premature menopause, polyuria, polydipsia, fever, and diffuse bony tenderness. Her evaluation revealed central diabetes insipidus, hypothalamic amenorrhea, an elevated free calcium on multiple occasions with an elevated 1,25 dihydroxyvitamin D level, and osteoporosis by densitometry. Skeletal series revealed multiple lytic lesions involving the long bones. The diagnosis of Langerhans' cell granulomatosis was made. She was treated with hormone replacement therapy, radiotherapy, and vinblastine, with a dramatic improvement in her pain and a near normalization of her free calcium. Whereas hypercalcemia has been described in several granulomatous disorders and is secondary to unregulated extrarenal production of 1,25 dihydroxyvitamin D, it is, however, extremely rare in Langerhans' cell granulomatosis. This is the first case report of Langerhans' cell granulomatosis with hypercalcemia and documented elevated increased 1,25 dihydroxyvitamin D level that responded to the treatment of her primary disease.

Antineoplastic Agents, Phytogenic↗

[Diffuse colitis associated with mycophenolate mofetil treatment: apropos of 1 case].

Mycophénolate mofétil (MMF) or Cellcept is a potent immunosuppressor that inhibits purin synthesis used to prevent human allograft rejection. The most important secondary effects include haematological and intestinal disorders. Among them, diarrhea is the most common. It is dose-dependant and appears commonly during the first 2 months of treatment. Its physiopathology remains unclear. We reported a case of colitis, 6 months after a kidney transplantation. The patient was treated since day 2 with 2 grams per day of MMF. Morphological analysis showed a diffuse colitis from the coecum to the rectum. Histological samples confirmed a colitis with atrophic crypts but with mucosal secretions and some cryptic abscesses. No granuloma or CMV inclusion was founded. Histochemical immunostaining for CMV was negative. Finally, symptoms regressed within 5 days after tapering down MMF dose in association with metronidazole treatment. The role of MMF in inducing colitis is discussed.

Aged↗

A randomized prospective controlled trial of laparoscopic extraperitoneal hernia repair and mesh-plug hernioplasty: a study of 315 cases.

Inguinal hernias can be repaired by traditional methods, tension-free, mesh-plug hernioplasty, and the less conventional laparoscopic techniques that have the added advantage of quicker recovery. Between September 1994 and September 1997, a prospective randomized controlled trial was performed on 292 patients with a total of 315 hernias. Of these, 150 patients with 169 hernias underwent the extraperitoneal laparoscopic repair (TEP) and 142 patients with 146 hernias were treated with mesh-plug hernioplasty. Patients were examined at 1 week after surgery and every 4 months thereafter for 3 years. Operative results, postoperative recovery, complications, and recurrences were recorded. Follow-up was complete for 89% of the patients. The average operative time was 31.5 minutes for the TEP and 30.5 minutes for the mesh-plug hernioplasty. The average operative time for the last 75 laparoscopic cases was 20 minutes, 10 minutes shorter than the open-surgery group. The overall recurrence rate was (2.5%) for the TEP and (3%) for the mesh-plug hernioplasty. Patients undergoing the laparoscopic repair consumed less narcotic analgesic and returned to their normal activity 1 week sooner than the open-surgery group. A median of 8 days vs. 15 days was required for patients to return to work, respectively, in the TEP and open-surgery group (p<0.01). Intraoperative complications occurred in two patients (1.3%) in the TEP repair. Both had peritoneal tear that mandated conversion to the TAPP repair. There were no major postoperative complications. A total of 20 (13%) minor postoperative complications occurred in the TEP. Thirty-three (23%) minor complications occurred in the open-surgery group (p<0.01). Ninety-eight percent of the patients were discharged the same day in the open-surgery group compared to 100% in the laparoscopy group. Patients with inguinal hernias who undergo extraperitoneal laparoscopic repair have the same recurrences and hospital stay but recover more rapidly, consume less analgesic, and have fewer minor complications than those who undergo the mesh-plug hernioplasty.

Adult↗

A comparative study of laparoscopic extraperitoneal and transabdominal preperitoneal herniorrhaphy.

Laparoscopic minimally invasive surgical procedures are gaining popularity. Laparoscopic hernia repair is now less controversial and more readily acceptable, with at present numerous technical modifications described in an attempt to define the best procedure. Between November 1992 and February 1995, a nonrandomized trial of laparoscopic inguinal herniorrhaphy was performed on 115 patients with a total of 120 hernias. Of these 58 patients with 60 hernias underwent the transabdominal preperitoneal patch repair (TAPP) without plug and 57 patients with a total of 60 hernias were offered the extraperitoneal (EXTRA) approach using a distension balloon. The average operative time was 55 min for the TAPP and 50 min for the EXTRA procedure. The overall recurrence rate was 1.7% with a follow up of 1-27 months. The recurrence rate was 3.4% for the TAPP and none for the EXTRA approach. All patients returned to their normal activity within 1 week of discharge. Patients undergoing the EXTRA repair consumed less amount of narcotic analgesic than did the group undergoing the TAPP repair. Of the EXTRA group 58% did not require any analgesic, compared to 22% of the TAPP group (p < 05). There were no intraoperative complications. A total of 8 (6.9%) postoperative complications occurred in 115 patients. Four complications (6.9%) occurred in the TAPP procedure: 2 transient urinary retentions, 1 pulmonary edema, and 1 Richter's type hernia. Four (6.9%) complications occurred in the EXTRA procedure: 1 urinary retention, 2 abdominal wall ecchymoses, and 1 thoracic pain. Hospital stay was shorter for the EXTRA group: 57% were discharged the same day and 98% were discharged within 24 h of their operations for the EXTRA group compared to 10 and 84%, respectively, for the TAPP (p < 0.05). Laparoscopic extraperitoneal hernia repair can be accomplished with shorter hospitalization and less analgesic requirement than the TAPP repair. The overall incidence of complications, the recurrence rate, and the return to normal activity were not different between the two types of repair.

Adult↗

Laparoscopic appendectomy versus open appendectomy: retrospective assessment of 200 patients.

OBJECTIVE: To compare laparoscopic appendectomy (LA) with traditional methods as the primary treatment for acute appendicitis. DESIGN: A retrospective case series. SETTING: A regional, nonuniversity hospital in northwestern Quebec. PATIENTS: Two hundred patients with a clinical diagnosis of acute appendicitis: 100 (43 men, 57 women; mean age 27 years) underwent laparoscopic appendectomy and 100 (67 men, 33 women; mean age 21 years) had an open appendectomy (OA). INTERVENTIONS: LA or OA. MAIN OUTCOME MEASURES: Operating time, rate of conversion to OA, need for analgesia, morbidity and outcome. RESULTS: LA was successful in 88% of patients. The mean operating time was 50 minutes for LA versus 24 minutes for OA. On average, patients of the LA group had a 1-day decrease in postoperative hospital stay (2.6 versus 3.6 days). The wound infection rate was lower in the LA group (2% versus 12%) as was the intra-abdominal abscess rate (2% versus 6.0%). There were no deaths in either group. The overall morbidity was 4.5% for the LA group and 18% for the OA group. A clear tendency toward a shorter convalescence was seen in the LA group. CONCLUSIONS: LA is a safe and viable treatment alternative for acute appendicitis. Prospective randomized studies are needed to confirm its potential advantages.

Acute Disease↗

[Survival ability of genetically engineered strains of Escherichia coli. 1. Physiological characterization and the effect of different physiochemical conditions].

Two genetically engineered E. coli strains L+ and CAG+ possessing the ability to produce the enzyme Pro-urokinase and showing additionally ampicillin resistance, and wild-strains L- and CAG-, were characterized using 328 physiological tests. Their test profiles were compared with those of 30 clinical and nonclinical E. coli isolates. This biotyping made a differentiation and recognition of the genetically manipulated strains possible. It also allowed distinguishing them from the other tested isolates. The genetically engineered strains showed a narrower activity spectrum compared with their wild-strains. However, based on differentiating characteristics, all strains could be clearly biochemically identified as E. coli. Under different laboratory test conditions (organic load, pH, salt content, temperature), the E. coli strains showed no striking features or peculiarities with respect to their survival compared to data from literature. However, low pH (pH less than 5), high salt content (greater than 7%) as well as low (less than 8 degrees C) and high (greater than 37 degrees C) incubation temperatures clearly reduced their ability to survive. Apart from a few exceptions (e.g. survival of strain L+ at 44 degrees C and pH 7 with high cell densities), the survival of the genetically engineered strains corresponded to that of the control and wild-strains. Both CAG strains, especially the genetically manipulated strain CAG+, showed in many cases reduced viability compared with the other strains.

Bacterial Typing Techniques↗

[Survival capacity of genetically altered Escherichia coli strains. 2. Survival of pure cultures in different water and soil matrices].

The survival of two genetically engineered E. coli strains (L+, CAG+) compared to that of 4 control strains (N0, K12, L-, CAG-), was investigated in drinking water, surface water, sewage and soil under different conditions. Both genetically manipulated strains are able to produce Prourokinase, an anticoagulant. It was found, that all strains died off inspite of high inoculated bacterial densities. In drinking water, no bacteria could be recultivated immediately following inoculation. Upon inoculation in surface water, the genetically manipulated strains L+ and CAG+ were more sensitive than the other strains. The same was found for sewage under aerobic conditions, whereby, the control strains N0 and K12 as well as the wild-strains of the genetically manipulated organisms, L- and CAG- survived the whole experimental period and kept their numbers at a level between 100 and 1000 CFU/ml. Under anaerobic conditions, a die-off of all tested strains was similarly registered with time. The influence of the autochthonous microflora of sewage water could be documented in that, under these conditions, all test strains survived the whole experimental period of 31 days with the exception of the genetically manipulated strain CAG+. In soil experiments, it was found that the humus-rich garden soil was more effective in eliminating the E. coli strains than sand. The antagonistic effect of the autochthonous soil microflora was only clearly seen in experiments with garden soil. However, these results did not meet the expectations for the two CAG strains, for which a longer survival period had been previously established for in nutrient rich soil. In contrast to the E. coli control strains N0 and K12, the two L strains and the CAG+ strain survived the whole test period of 36 days. It can be concluded that under these simulated environmental conditions, all tested strains of E. coli die off more or less in a short period of time following inoculation with the autochthonous microflora of environmental samples.

Aerobiosis↗

A comparative immunohistochemical study of peritoneal and ovarian serous tumors, and mesotheliomas.

The distinction between serous neoplasms of the peritoneum in women and conventional mesothelioma can be difficult. In order to determine any significant immunohistochemical differences, formalin-fixed, paraffin-embedded sections of 10 peritoneal serous tumors (PST), 10 ovarian serous tumors (OST), and 10 epithelial mesotheliomas were evaluated with a panel of 10 antibodies directed against carcinoembryonic antigen (CEA: polyclonal, monoclonal), high molecular weight keratin (34 beta E12), low molecular weight keratin (35 beta H11), Leu-M1, TAG-72 (monoclonal antibody B72.3), human milk fat globulin (HMFG-2), vimentin, placental alkaline phosphatase (PLAP), and S-100 protein. The antibodies CEA, Leu-M1, and B72.3 had the most discriminatory value in differentiating serous tumors from mesothelioma. Eighty-five percent of PSTs and OSTs (17 of 20) were positive with CEA, Leu-M1, and/or B72.3. None of the mesotheliomas stained for CEA or Leu-M1; three mesotheliomas had very focal positivity with B72.3 (1% or less). Vimentin, PLAP, HMGF-2, keratin, and S-100 had no significant discriminatory value. Epithelial mucin was present in 80% of serous tumors, while the mesotheliomas lacked epithelial mucin. Leu-M1, CEA, and/or B72.3 positivity in a peritoneal tumor supports a diagnosis of serous tumor. However, since some PST do not stain for any of the three antibodies and the focal nature of positive reactions in some cases may be difficult to interpret, exclusion of mesotheliomas is enhanced by the use of mucin stains.

Adult↗

Dissolution rate studies from a stationary disk/rotating fluid system.

The dissolution rates for hydrocortisone alcohol and acetate were determined using a stationary disk/rotating fluid system. The hydrocortisone was compressed in a tablet die, and the die placed in a vessel above a rotating magnetic bar. Dissolution rates were evaluated in aqueous media under conditions involving the following independent variables: solubility (Cs), diffusion coefficient (D), viscosity (v), rotational speed (omega), and tablet radius (r). A design equation which relates dissolution rate (R) to these variables was formulated for the system R alpha Cs D2/3 (v) -1/6(omega)1/2(r)3/2 This design equation adequately represents the system, which is related to fluid mechanics and convective diffusion models. The fluid mechanics model assumes that the fluid ideally rotates as solid-body rotation and the momentum layer is initiated at the outside radius of the tablet die. The convective diffusion model is based on the formation of a diffusion layer at the outside radius of the dissolving surface and a predictable relationship between the momentum and the mass transport quantities of bulk viscosity and diffusion coefficient. This configuration, like the rotating disk in a stationary fluid, offers the attractive attribute of being useful to study drug release mechanisms for systems of pharmaceutical interest.

Chemistry, Pharmaceutical↗

Evaluation of a tube method for determining diffusion coefficients for sparingly soluble drugs.

Evaluation of a non-steady state method using glass tubes for the determination of diffusion coefficients is the purpose of this study. Unlike capillaries, glass tubes accommodate a larger volume of solution, facilitating assay procedures. Tubes are more susceptible to convection than are capillaries, but this effect is anticipated and accounted for in experimental design and data treatment. Glass tubes, 66 or 90 mm in length and 2 mm outer diameter, were siliconized and then filled with aqueous drug solution and placed in a jacketed flask containing gently stirred solvent at 25 degrees C. Diffusion experiments were run from 140 to 168 hours. At the end of this time period, the tubes were removed from the flask, placed in an ultrasonic vibrator for one minute, and their contents assayed spectrophotometrically. Data collected using potassium chloride as the diffusant showed little tube-to-tube variability, demonstrating the precision of the tube method, while diffusion coefficients determined for benzoic acid and p-aminobenzoic acid using the tube method tested the accuracy of the method by comparing reasonably well with values obtained using standard methods such as the rotating disk, free boundary, and membrane cell. Experiments done with either hydrocortisone or sulfisoxazole as the diffusant demonstrated the appropriateness of the tube method for the study of the diffusion of sparingly soluble pharmaceutical solutes.

4-Aminobenzoic Acid↗

Renal extraction of glutamine from plasma and whole blood: studies in dogs and rats.

The change in plasma and blood cell pools of L-glutamine during a single pass through the kidney was studied in dogs and rats. It was shown that the glutamine content of blood cells does not change following one passage through the renal vascular bed in normal or acidotic dogs. Furthermore, an infusion of L-glutamine elevating by 10-fold the plasma concentration of this amino acid only minimally changed the blood cells' glutamine content. Therefore within the time frame of acute experiments, the dog blood cells can be assumed to be impermeable to glutamine in vivo. Accordingly, renal glutamine extraction can be measured using either whole blood or plasma arteriovenous difference in this species. However, the latter value is larger and therefore can be measured more accurately. In normal rats, no net renal glutamine extraction is measured. In contrast, a considerable renal glutamine uptake occurs in acidotic rats, 23% of the extracted glutamine coming from the blood cell pool. A load of glutamine in vivo significantly elevates both the plasma and the blood cell concentration. It is concluded (i) that the renal extraction of glutamine is best estimated using plasma arteriovenous difference in the dog, especially when the renal extraction is small; (ii) that whole blood measurements should be obtained in the rat.

Acidosis↗