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Biomedical subjects

S Khalil

Publications and source records attributed to S Khalil.

At least 19 recordsLinked to original sources

Indirect atomic absorption spectrometric determination of pindolol, propranolol and levamisole hydrochlorides based on formation of ion associates with manganese thiocyanate and potassium ferricyanide.

A new simple, accurate, precise and sensitive indirect method for the determination of pindolol HCl (1), propranolol HCl (2) and levamisole HCl (3) using atomic absorption spectrometry has been developed. The method is based on precipitation of the ion associates formed from the reaction of (1), (2) or (3) with manganese thiocyanate and/or potassium ferricyanide. The solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. Saturated solutions of each ion-associate were prepared under the optimum conditions and the metal ion content in the supernatant was determined. The method has been used for the determination of 1.14-17.07, 1.18-17.75 and 1.08-16.24 microg/ml of (1), (2) and (3), respectively using manganese thiocyanate and 1.71-25.60, 1.77-26.62 and 1.62-24.36 microg/ml of (1), (2) and (3), respectively using potassium ferricyanide. The method developed applied for analysis of bulk drugs and some of their pharmaceutical preparations.

Adjuvants, Immunologic↗

Indirect atomic absorption spectrometric determination of pindolol, propranolol and levamisole hydrochlorides based on formation of ion-associates with ammonium reineckate and sodium cobaltinitrite.

A new simple, accurate, precise and sensitive indirect method for the determination of pindolol HCl (1), propranolol HCl (2) and levamisole HCl (3) using atomic absorption spectrometry has been developed. The method is based on precipitation of the ion-associates formed from the reaction of (1), (2) or (3) with ammonium reineckate and/or sodium cobaltinitrite. The solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. Saturated solutions of each ion-associate were prepared under the optimum conditions and the metal ion content in the supernatant was determined. The method has been used for the determination of 1.14-17.07, 1.18-17.75 and 1.08-16.24 microg/ml of (1), (2) and (3), respectively, using ammonium reineckate, and 1.71-25.60, 1.77-26.62 and 1.62-24.36 microg/ml of (1), (2) and (3), respectively, using sodium cobaltinitrite. The method developed was applied for analysis of bulk drugs and some of their pharmaceutical preparations.

Cobalt↗

Atomic emission spectrometric determination of ephedrine, cinchonine, chlorpheniramine, atropine and diphenhydramine based on formation of ion associates with ammonium reineckate.

Ion-associate complexes of ephedrine HCl (I), cinchonine HCl (II), chlorpheniramine maleate (III), atropine sulphate (IV) and diphenhydramine HCl (V) with ammonium reineckate were precipitated and their solubilities were studied as a function of pH, ionic strength and temperature. Saturated solutions of each ion-associate under the optimum precipitation conditions were prepared and the Cr ion content in the supernatant was determined. The solubility products were thus elucidated at different temperatures. A new accurate and precise method using direct current plasma-atomic emission spectrometry for the determination of the investigated drugs in pure solutions and in pharmaceutical preparations is described. The drugs can determined by the present method in the ranges 1.6-52,2.64-85.8,3.12-101.4,5.52-180.4 and 2.72-75.85 microg/ml solutions of I, II, III, IV and V, respectively.

Atropine↗

Ondansetron/promethazine combination or promethazine alone reduces nausea and vomiting after middle ear surgery.

STUDY OBJECTIVES: To determine the incidence of postoperative nausea and vomiting when a combination of ondansetron and promethazine is given prophylactically, and to ascertain the effect of postoperative nausea and vomiting on recovery room duration and patient satisfaction. DESIGN: Prospective, randomized, placebo-controlled, double-blind study. SETTING: University-affiliated tertiary-care hospital. PATIENTS: 87 ASA physical status I and II adult patients scheduled for middle ear surgery. INTERVENTIONS: Patients were randomly assigned to receive one of the following interventions intravenously: ondansetron 4 mg (Group 1), promethazine 25 mg (Group 2), ondansetron 2 mg plus promethazine 12.5 mg (Group 3, combination), or placebo (Group 4). MEASUREMENTS AND MAIN RESULTS: Independent, study blinded observers recorded complaints of nausea and number of episodes of vomiting for 24 hours following the patient's first response to commands. All patients were contacted the day after discharge to inquire about nausea and vomiting. The awakening time, postanesthesia care unit and day surgery unit durations, opioid use, and side effects were recorded. At the end of the 24-hour period, the study blinded observers asked patients for an overall assessment of their global anesthesia experience using an 11-point scale. During the 24-hour period, the incidence of postoperative nausea and vomiting was reduced from 74% (placebo) to 39% (promethazine; p = 0.03) and 29% (combination; p = 0.003). Compared with placebo, the severity of vomiting was significantly less in the combination group (p = 0.04). The number of very satisfied patients correlated negatively with the incidence of postoperative nausea and vomiting (p < 0.0001) and with the severity of vomiting (p = 0.003). CONCLUSION: The prophylactic use of an antiemetic with middle ear surgery may reduce postoperative nausea and vomiting over 24 hours, and the ondansetron/promethazine combination or promethazine alone are cost-effective choices. Finally, the combination reduced significantly the severity of vomiting.

Adolescent↗

Ion-selective electrode for the determination of trazodone in tablets.

A coated wire trazodone-selective electrode based on incorporation of trazodone-tetraphenylborate ion pair in a poly(vinylchloride) coating membrane was constructed. The influences of membrane composition, temperature, pH of the test solution, and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a trazodone concentration range from 1.41 x 10(-5) to 0.89 x 10(-2) M, at 25 degrees C, and was found to be very selective, precise, and usable within the pH range 2.4-9.0. The standard electrode potentials, E degree, were determined at 20, 25, 30, 35, 40 and 45 degrees C and used to calculate the isothermal temperature coefficient (dE degree/dT) of the electrode. Temperatures higher than 45 degrees C seriously affected the electrode performance. The electrode was successfully used for potentiometric determination of trazodone hydrochloride both in pure solutions and in pharmaceutical preparations.

Antidepressive Agents, Second-Generation↗

Caudal block in children: ropivacaine compared with bupivacaine.

BACKGROUND: Bupivacaine provides reliable, long-lasting anesthesia and analgesia when given via the caudal route. Ropivacaine is a newer, long-acting local anesthetic that (at a concentration providing similar pain relief) has less motor nerve blockade and may have less cardiotoxicity than bupivacaine. METHODS: In a double-blind trial, 81 healthy children, undergoing ambulatory surgical procedures, were randomly allocated to receive caudal analgesia with either bupivacaine or ropivacaine, 0.25%, 1 mVkg. All blocks were placed by an attending anesthesiologist or an anesthesia fellow after induction of general anesthesia. RESULTS: Data were available for 75 children. There were no significant differences between the two groups in baseline characteristics or in anesthesia, surgery, recovery room, or day surgery unit durations. The quality and duration of postoperative pain relief did not differ. Motor and sensory effects were similar. Time to first micturition did not differ. CONCLUSION: Ropivacaine (0.25%, 1 ml/kg) provided adequate postoperative analgesia with no difference from bupivacaine (0.25%, 1 ml/kg) in quality and duration of pain relief, motor and sensory effects, or time to first micturition in our study children.

Amides↗

Postoperative respiratory complications in ex-premature infants after inguinal herniorrhaphy.

BACKGROUND/PURPOSE: The duration of postoperative cardiorespiratory monitoring of premature infants after inguinal herniorrhaphy is uncertain. Prolonged observation requiring hospital admission may be unnecessary and increases costs. METHODS: This study was a retrospective review of 191 inguinal herniorrhaphies performed between 1993 and 1996 at the Hermann Children's Hospital. The authors reviewed their experience to identify factors associated with postoperative apnea and bradycardia and determine a safe period of observation. RESULTS: Among 191 elective inguinal herniorrhaphies performed, 57 (29.8%) were in expremature infants (< or =60 weeks postconception). Five (8.8%) infants either failed extubation or were unable to extubate (group 1). The average age for this group was 41.0 +/- 1.2 weeks compared with 47.2 +/- 1.0 (P = .06) for those who were successfully extubated (group II). Preoperative apnea-bradycardia was found in four (80%) infants in group I compared with 32 (61.5%) in group II (P = 0.67). All group I and 21 (40.4%, P = .09) group II infants with a history of preoperative apnea required intubation for an average of 24.4 +/- 7.8 days and 8.2 +/- 2.4 days, respectively (P = .04). American Society of Anesthesia (ASA) scores were 2.6 +/- 0.4 for group I compared with 1.8 +/- 0.1 for group 11 (P = .01). The use of both intraoperative narcotics (three [60%] in group I v six [12%] in group II, P = .01]) and vecuronium (four [80%] in group I v 16 [31%] in group II, P = .03) were significantly more common in group I infants. Operating room time was 46.4 +/- 4.1 minutes for group I compared with 60.6 +/- 3.9 minutes for group II (P = .27). Postoperative apnea-bradycardia occurred in all five group I infants and two (3.8%, P = .001) group II infants. Group II infants were treated successfully with supplemental oxygen. CONCLUSIONS: All instances of postoperative apnea-bradycardia and laryngospasm occurred within 4 hours after operation without significant differences between groups. The risk of postoperative cardiorespiratory distress requiring reintubation in premature infants who undergo inguinal herniorrhaphy is not insignificant (8.8%). The judicious use of narcotics and vecuronium, and limiting patient selection to those with ASA score of less than 3 may lessen the need for reintubation. When present cardiorespiratory distress occurs early; therefore we recommend outpatient inguinal herniorrhaphy as a safe and cost-effective choice.

Anesthetics↗

Sublingual midazolam premedication in children: a dose response study.

The purpose of this study was to evaluate various doses of sublingual midazolam premedication in children. In our prospective, double-blind, placebo-controlled trial, children (n = 102, age range 12 to 129 months) scheduled for day surgery were randomized to receive either midazolam in one of three doses (0.25, 0.5, or 0.75 mg.kg-1) or placebo. Injectable midazolam was mixed with a thick grape syrup and placed under the tongue; the patient was asked to hold it as long as possible before swallowing. Children readily accepted the mixture. Analysing all patients randomized, none of the children receiving placebo vs 28% receiving 0.25 mg.kg-1 (P = 0.02), 52% receiving 0.5 mg.kg-1 (P < 0.001), and 64% receiving 0.75 mg.kg-1 (P < 0.001) of midazolam showed satisfactory sedation (drowsy) at 15 min after administration. Children receiving the two higher doses of midazolam (0.5 and 0.75 mg.kg-1) accepted mask induction willingly, while the group receiving 0.25 mg.kg-1 resembled the placebo group (P < 0.05).

Adjuvants, Anesthesia↗

Primary T-cell lymphoma of the urinary bladder.

Primary malignant lymphoma of the urinary bladder is very rare. Less than 100 cases have been reported; most are B-cell lymphomas. We report a case of primary T-cell lymphoma of the urinary bladder in a patient with a history of schistosomiasis. The patient is a 52-year-old man with suprapubic pain and hematuria. Examination revealed a large suprapubic mass. Computed tomography scan of the pelvis showed a large lobular mass occupying the urinary bladder. No pelvic or abdominal lymphadenopathy was noted, and results of metastatic workup were negative. The patient underwent a transurethral biopsy of the bladder mass that revealed a diffuse large cell lymphoma that was negative for the B-cell marker L-26 (CD 20) and positive for the T-cell marker CD-3. Polymerase chain reaction studies of the paraffin-embedded tissue revealed rearrangement of the T-cell receptor gamma gene. The patient was administered cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOPP) chemotherapy and currently is being treated. This case represents, to our knowledge, a very rare primary lymphoproliferative neoplasm of the urinary bladder that might represent an unusual immune response to schistosomiasis.

Antineoplastic Combined Chemotherapy Protocols↗

A comparison of the efficacy, safety, and patient satisfaction of ondansetron versus droperidol as antiemetics for elective outpatient surgical procedures. S3A-409 and S3A-410 Study Groups.

UNLABELLED: Two identical, randomized, double-blind, placebo-controlled studies enrolled 2061 adult surgical outpatients at high risk of postoperative nausea and vomiting (PONV) to compare i.v. ondansetron 4 mg with droperidol 0.625 mg and droperidol 1.25 mg for the prevention of PONV. The antiemetic drugs or placebo were administered i.v. 20 min before the induction of anesthesia with a barbiturate compound, followed by maintenance with N2O/isoflurane/enflurane. Nausea, emetic episodes, adverse events, and patient satisfaction were analyzed for the 0 to 2 h and 0 to 24 h postoperative periods. In the 0 to 2 h postoperative period, there was a complete response (no emesis or rescue antiemetic) in 46% of subjects given placebo (P < 0.05 versus antiemetic groups), in 62% given ondansetron, in 63% given droperidol 0.625 mg, and in 69% given droperidol 1.25 mg (P < 0.05 versus ondansetron). In the 0 to 24-h postoperative period, there were no significant differences in complete response between the ondansetron and droperidol 0.625 or 1.25 mg groups; all groups remained superior to placebo. The proportion of patients without nausea during the 0 to 24 h postoperative period was greater in the antiemetic groups compared with the placebo group; however, droperidol 1.25 mg was more effective than ondansetron 4 mg or droperidol 0.625 mg (43% vs 29% or 29%, respectively). Headache incidence was higher in the ondansetron group compared with either droperidol group. Patient satisfaction scores did not differ significantly among antiemetic treatment groups, although all were superior to placebo. In conclusion, all antiemetic treatment regimens were superior to placebo for the prevention of PONV in the immediate postoperative period; however, droperidol 1.25 mg was more efficacious than ondansetron during the early recovery period (0-2 h). There were no significant differences between ondansetron and either droperidol dose for emesis prevention during the 0 to 24 h postoperative period. IMPLICATIONS: More than 2000 patients at high risk of postoperative nausea and vomiting were given either placebo, ondansetron 4 mg, or droperidol 0.625 mg or 1.25 mg i.v. before the administration of general anesthesia. After surgery, the incidence of nausea, vomiting, medication side effects, and patient satisfaction were evaluated for 24 h. Droperidol 0.625 or 1.25 mg i.v. compared favorably with ondansetron 4 mg i.v. for the prevention of postoperative nausea and vomiting after ambulatory surgery.

Adolescent↗

Human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus in organ transplant patients with immunosuppression.

Several recent studies have demonstrated Kaposi's sarcoma-associated herpes virus (KSHV), also known as putative human herpes virus-8 (HHV-8), DNA in various epidemiologic forms of Kaposi's sarcoma (KS), including AIDS-associated, classic, and endemic types. Risk of developing KS in non-HIV-infected immunosuppressed hosts, such as patients following solid organ transplantation, is also significantly higher compared to normal individuals. We have retrospectively evaluated 28 organ transplant patients with KS (23 cutaneous and five visceral) for the presence of KSHV genome by polymerase chain reaction (PCR) amplification of DNA isolated from formalin-fixed, paraffin-embedded archival tissue samples. 27/28 KS patients were positive for the presence of KSHV. In four KS patients, tissue samples with no histologic evidence of KS were also analysed for KSHV. No evidence of positivity in three samples was noted, but one patient had weak positive amplification products on DNA samples isolated from a gastric biopsy with chronic gastritis and lymph node with sinus histiocytosis. These data support the association of KSHV with KS developing in non-HIV-infected immunosuppressed patients, similar to other forms of KS, and suggest that KSHV may play a significant role in the development of all forms of KS.

Blotting, Southern↗

A pyrazoline derivative of eunicin acetate.

The present crystal structure determination established spiro [¿3a,4,5,6,7,8,11,12,13,14,15,15a-dodecahydro-6,10,14-trimet hyl-2-oxo-5, 15-epoxy-3H-cyclotetradeca-[b]furan¿-3,3'-1'-pyrazoline]-6-yl acetate, C23H34N2O5, as a pyrazoline derivative of eunicin acetate. The spiro substitution of the pyrazoline ring causes elongation of the bonds within the lactone ring and also shortening of the carbonyl bond. The cembranolide skeleton is slightly more bent than that observed in the parent eunicin molecule.

Animals↗

Intravenous ondansetron in established postoperative emesis in children. S3A-381 Study Group.

BACKGROUND: In pediatric postsurgical patients, postoperative vomiting is a common occurrence that can delay recovery and result in unplanned hospital admissions after outpatient surgery. This randomized, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of ondansetron in the control of established postoperative emesis in outpatients aged 2-12 yr. METHODS: Screened for the study were 2,720 ASA physical status 1-3 children undergoing outpatient surgery during general anesthesia, which included nitrous oxide. Children experiencing two emetic episodes within 2 h of discontinuation of nitrous oxide were given intravenous ondansetron (n = 192; 0.1 mg/kg for children weighing < or = 40 kg; 4 mg for children weighing > 40 kg) or placebo (n = 183). RESULTS: The proportion of children with no emetic episodes and no use of rescue medication was significantly greater (P < 0.001) in the ondansetron group compared with placebo for both 2- and 24-h periods after study drug administration (78% of the ondansetron group and 34% of the placebo group for 2 h; 53% of the ondansetron group and 17% of the placebo group for 24 h). Among patients with at least one emetic episode or with rescue medication use, the median time to onset of emesis or rescue was 127 min in the ondansetron group compared with 58 min in the placebo group (P < 0.001). The median time from study drug administration until discharge was significantly shorter (P < 0.01) in the ondansetron group (153 min, range 44-593 min) compared with the placebo group (173 min, range 82-622 min). The incidence of potentially drug-related adverse events was similar in the ondansetron (3% of patients) and the placebo (4% of patients) groups. CONCLUSION: A single dose of ondansetron (0.1 mg/kg up to 4 mg) is effective and well tolerated in the prevention of further episodes of postoperative emesis in children after outpatient surgery. Administration of ondansetron also may result in a shorter time to discharge.

Antiemetics↗

Case report: autoimmune polyglandular syndrome.

The authors present a case of autoimmune polyglandular syndrome, a rare inherited condition. Early recognition allows prevention of significant morbidity and mortality. A review of the literature of this multiple endocrine end organ disease is presented.

Adult↗

Inhibition of plasma kallikrein. Kininase and kinin-like activities of preparations from the medicinal leeches.

The medicinal leech salivary gland secretion deprived of hirudin antithrombin activity inhibits amidolytic (substrate S-2302) and kininogenase (substrate kininogen) activities of plasma kallikrein, the main component of the intrinsic mechanism of blood coagulation. It therefore possesses high anticoagulant properties. Kininase (substrate bradykinin) activity of leech saliva and extracts from the medicinal leeches, as well as kinin-like effects of extracts heated at 100 degrees C have been detected. The last one is correlated with the hyperalgetic property of the heated extract. An analgetic effect was observed with the unheated extract but not with leech saliva after intranasal administration to rats.

Amino Acid Sequence↗