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Biomedical subjects

R Mansour

Publications and source records attributed to R Mansour.

36 records · Page 2Linked to original sources
PubMed1987

A new technique for placement of tunneled subclavian right atrial catheters: experience with 130 cases.

We have developed a new single step technique for placement of indwelling silastic subclavian right atrial catheters through a short subcutaneous tunnel that is simple, relatively inexpensive, and can be done in the outpatient clinic. Between December 1984 and July 1986, 130 catheters were inserted in 122 patients using this approach for a cumulative total of 8,900 catheter days. Major complications have included five catheter infections with bacteremia, two procedure-related pneumothoraces, one internal jugular vein thrombosis, and one catheter fragment embolization to the right heart (total major complication rate, 6.9%). Minor complications have included five catheter migrations, seven catheter or catheter hub leaks, and two irreversible lumen occlusions (total minor complication rate 10.8%). Damaged or malpositioned catheters can be replaced through the same subcutaneous tract using a guidewire exchange technique. When this has not been possible, we have not encountered technical difficulties (due to subclavian thrombosis or stenosis) prohibiting insertion of a new catheter, even on the same side. These catheters provide reliable venous access for patients requiring frequent blood sampling, intravenous (IV) fluid or blood product administration, chemotherapy, IV narcotics for pain control, long-term antibiotic therapy, or hyperalimentation. They are ideal for infusion of vesicant chemotherapeutic agents and for patients undergoing ambulatory outpatient infusion chemotherapy. They have a low overall morbidity rate and excellent patient acceptance. Catheter maintenance procedures are simple and non-time-consuming. The same technique can be used to place multichannel catheters in patients requiring greater venous access. We now recommend early placement of these catheters in patients who will require frequent phlebotomy or drug administration during the course of their treatment.

Adolescent↗
PubMed1986

The effects of enclomiphene and zuclomiphene citrates on mouse embryos fertilized in vitro and in vivo.

The ovulatory agent clomiphene citrate, a racemic mixture of the estrogenic zuclomiphene and antiestrogenic enclomiphene isomers, has been associated with gamete/embryo toxicity in various animal models. To assess the potential effects of these isomers on fertilization and early embryogenesis, 3200 embryos were obtained from mouse oocytes fertilized in vivo and in vitro and exposed to increasing concentrations of zuclomiphene, enclomiphene, and clomiphene citrate in culture. Fertilization rates (p less than 0.01), blastocyst formation rates (p less than 0.02), and degeneration rates (p less than 0.005) were all adversely affected in a dose-dependent fashion. There were no statistically significant differences between the two isomers. Preincubation with 17 beta-estradiol did decrease the degenerative changes induced by clomiphene citrate but did not improve the decreased rate of blastocyst formation. These findings suggest adverse effects of a high concentration of clomiphene citrate and its isomers on fertilization and early mouse embryo growth that may have implications in the clinical use of this drug.

Animals↗
PubMed1986

T-piece injector assembly for continuous positive airway pressure.

A T-piece injector assembly delivers a blended oxygen/air mixture proximally via the side-arm of the T-piece, while continuous positive airway pressure (CPAP) is independently regulated by an injector adapted distally to the open end of the reservoir tubing. The system can provide different CPAP levels without significant fluctuations in the airway pressure and/or the inspired oxygen concentrations, and it maintains the original simplicity and safety of the T-piece.

Positive-Pressure Respiration↗
PubMed1985

Embryo toxicity of clomiphene citrate on mouse embryos fertilized in vitro and in vivo.

The effect of the ovulatory agent clomiphene citrate on fertilization and early embryogenesis was investigated with the use of in vitro fertilized mouse oocytes. Alterations in early embryogenesis with clomiphene citrate exposure were further studied with the use of embryos obtained from mouse oocytes fertilized in vivo. In the nontreated group, the fertilization rate was 81%, and 61% of the oocytes reached the blastocyst stage by 96 hours. Both fertilization and blastocyst formation declined in a dose-dependent fashion when clomiphene citrate was added to the culture media in concentrations greater than or equal to 10 micrograms/ml (p less than 0.001). The rate of progressive embryo cleavage was also slower at 48 and 72 hours after drug exposure. Mouse embryos fertilized in vivo demonstrated similar findings, with decreased blastocyst formation and increased degeneration rates, again at clomiphene citrate concentrations greater than or equal to 10 micrograms/ml (p less than 0.01). Exposure to the drug beyond 24 hours had no additional effect. It appears that clomiphene citrate-exposed embryos may undergo subtle changes that later manifest themselves in the form of decreased embryo growth rates and increased embryo degeneration rates.

Animals↗
PubMed1984

A micrometric and cytophotometric study of the simultaneous development of the cerebellar cortex and dental function in the rat during the early post-natal period.

A study was made of the growth of two cerebellar lobules receiving trigeminal afferents, crus 1 (C1) and uvula (U) and another lobule which receives only vestibular afferents, nodulus (N). Growth factors were determined using micrometry and histophotometry. Times of growth end were compared with first masticatory movements. The end of the maturation period of U and the beginning of absorption of tough diet appeared on the 15th post-natal day (PND). The end of growth of C1 on the 18th PND coincided with functional appearance of molars. It was suggested that, in the rat, maturity of the cerebellar cortex in certain lobules could be related to the early stage of weaning.

Aging↗
PubMed1984

Hemodynamic effects of diazepam-vecuronium-fentanyl sequence for induction of anesthesia for coronary artery surgery.

The hemodynamic effects of diazepam (0.2 mg/kg)--vecuronium (0.2 mg/kg)--fentanyl (10 micrograms/kg) sequence was investigated when used for induction of anesthesia and tracheal intubation in eleven patients undergoing CABG. The parameters monitored included HR, SBP, PAP and PCWP. Also, EKG was monitored via a modified V5 lead and C.O was measured by thermodilution. SVR, PVR and SV were computed from the measured parameters. Following induction of anesthesia by diazepam-vecuronium-fentanyl sequence, there was a decrease in SBP by 20.0% (P less than 0.05), in HR by 15.7% (P less than 0.001) in C.O by 13.3% (P less than 0.01) and in SVR by 13.6% (P less than 0.05) of control value. There were no changes in PAP, PCWP, PVR and SV. Coronary perfusion pressure and heart rate product were both decreased following this induction sequence. However, the percentage decrease in PR was higher than that of CPP, affecting favorably the myocardial oxygen supply-demand balance. Orotracheal intubation was followed by an increase of HR by 10.7% (P less than 0.05), SVR by 13% (P less than 0.05) and PCWP by 26% (P less than 0.05) of preceding value. However, all these values did not reach the control awake values. It was concluded that diazepam (0.2 mg/kg)--vecuronium (0.2 mg/kg)--fentanyl (10 micrograms/kg) sequence does not produce serious hemodynamic changes when used for induction of anesthesia and tracheal intubation in patients undergoing coronary artery bypass surgery.

Anesthesia↗
PubMed1981

Effect of neostigmine and pyridostigmine on the plasma cholinesterase activity.

The effect of neostigmine 0.05 mg kg-1 or pyridostigmine 0.25 mg kg-1 on serum cholinesterase activity was investigated in 20 adult patients undergoing elective surgery. Both drugs produced marked depression of enzymatic activity. The maximal depression was observed in samples taken 5 min after injection. The maximal percentage depression of enzymatic activity was not significantly different in the two drug groups. However, at 30-60 min after injection, the degree of depression was less in the neostigmine group. This may be attributed to the different plasma clearances of neostigmine and pyridostigmine.

Adolescent↗
PubMed1979

Hypersynchronisation and sedation produced by GABA-transaminase inhibitors and picrotoxin: does GABA participate in sleep control?

Systemic administration of GABA-transaminase inhibitors, gamma-acetylenic GABA (100 mg/kg) or gamma-vanylic GABA (1200 mg/kg) produces behavioral picture of somnolence accompanied by EEG hypersynchronisation reminiscent of electrographic signs of petit mal epilepsy. Similarly, systemic administration of GABA antagonist, Picrotoxin (3--4 mg/kg) produces a short lasting period of sedation preceding the development of myoclonic jerks which is also accompanied by Wave-spike discharges. The role of GABA in sleep control is discussed. Although the area is not ready for firm conclusions, the results suggest that hyperactivity of GABA-ergic system as well as its hypoactivity could mediate pathological somnolence associated with different forms of epilepsy.

4-Aminobutyrate Transaminase↗
PubMedDate not supplied

Intracytoplasmic sperm injection: a state of the art technique.

Of the micromanipulation techniques developed in the twentieth century, intracytoplasmic sperm injection (ICSI) has been the major breakthrough in the field of assisted fertilization. This article reviews the indications for the use of ICSI, its clinical application, the establishment of an ICSI programme including protocol and the results obtained since the introduction of ICSI and the potential risks. In addition, intracytoplasmic spermatid injection is briefly discussed.

Female↗