Biomedical subjects

S Sadek

Publications and source records attributed to S Sadek.

At least 55 records · Page 3Linked to original sources

PubMed1987

Efficacy of ceruletide controlled saline infusion for retained ductal stones after cholecystectomy and exploration of the common bile duct.

The synthetic peptide ceruletide induces maximal relaxation of the sphincter of Oddi. In a preliminary communication, ceruletide controlled saline infusion of the common bile duct (CBD) was found to be effective in promoting the passage of retained ductal calculi after cholecystectomy and exploration of the common bile duct. This paper reports on the further experience with this simple treatment which was administered to 27 patients with retained ductal calculi in 16 different hospitals within the U.K. The success of the procedure was documented by repeat T-tube cholangiography. Passage of stones into the duodenum was documented in 13 patients (48%) with complete clearance in 9 (33%) following one saline infusion/ceruletide treatment. The radiological stone size ranged from 3 to 15 mm. Within this range, there was no correlation between a successful outcome and size of retained stones. The duration of the saline T-tube infusion during ceruletide treatment averaged 54.7/min (SD 14.3). There was no correlation between flow rate of saline through the T-tube and a successful outcome. A significant inverse correlation was observed between the CBD pressure during ceruletide controlled saline T-tube infusion and successful stone passage (chi 2 = 9.9, P less than 0.01). Ampullary impaction by a stone was encountered in one patient. These results are encouraging and indicate that pharmacological dilatation of the sphincter of Oddi together with saline infusion is effective in the management of retained stones after exploration of the common bile duct. This treatment, which does not require any special expertise, should be tried in the first instance before more invasive procedures are used.

Adult↗

PubMed1987

99Tcm hydroxyethyl starch: a potential radiopharmaceutical for lymphoscintigraphy.

The usefulness of 99Tcm hydroxyethyl starch (99Tcm HES) has been evaluated for visualization of lymphatic channels and lymph nodes. 99Tcm HES was prepared with a labelling efficiency higher than 95%. Its usefulness for imaging lymphatic channels and lymph nodes were compared to 99Tcm human serum albumin (99Tcm HSA), 99Tcm dextran (99Tcm DXT) and 99Tcm sulphur micro colloid (99Tcm SMC) in rabbits. 99Tcm HES showed a good visualization of lymphatic channels and lymph nodes and it had the highest clearance rate from the injection site (P less than 0.01). 99Tcm HES showed higher uptake by the nodes than 99Tcm DXT (P less than 0.001) at 90 min post injection. The concentration of 99Tcm HES in the lymphatic channels was higher than that of 99Tcm SMC at 90 min post injection (P less than 0.001). Preliminary studies of 99Tcm HES in humans provided high-quality lymphoscintigrams of the leg, and the pelvic and para aortic lymph nodes in less than 10 min post injection. In addition, partially and completely obstructed lymphatics could be differentiated from the normal one. Hence 99Tcm HES is a potential radiopharmaceutical for visualization of lymphatic channels and nodes.

Animals↗

PubMed1987

Splenic implants: evaluation with radionuclide methods.

The viability of omental splenic implants placed in 16 patients who had undergone splenectomy was assessed with 37 technetium-99m tin colloid studies and five studies with Tc-99m-labeled denatured red blood cells (RBCs). Indications for splenectomy included trauma in eight patients, schistosomal (Bilharzial) portal hypertension in six, splenic artery aneurysm in one, and Wiskott-Aldrich syndrome in one. Studies were done within the 1st month and at various intervals up to 13 months after surgery. Implants in five of eight trauma patients were seen during the 1st month, and implants in seven of seven were seen after 6 months (one patient could not be followed up). Three of six implants in cases of portal hypertension were seen in the 1st month and four of four at 6 months (two patients were not followed up). In two of the five studies with denatured RBCs, Tc-99m tin colloid study was also done 48 hours later; in these cases denatured RBCs were more successful in showing the implants. The authors conclude that radioisotopic procedures are valuable in following up the viability of splenic implants. The "take" of splenic implants in patients with schistosomiasis is equally successful to that in trauma patients.

Adolescent↗

PubMed1987

Development of an animal model using a closed system to study the sensitivity of a radiopharmaceutical for the detection of gastrointestinal bleeding.

An experimental animal model using a closed system to study the sensitivity of radiopharmaceuticals for the detection and localization of gastrointestinal (GI) bleeding site in a sheep was developed. This model was validated with 99mTc-DTPA. Radioactivity as low as 85.47 +/- 13.32 kBq in a volume of 2.1 +/- 0.14 ml at a bleeding rate of 0.07 ml/min was detected. Simulated intermittent bleeding experiments indicated that at 1 h after injection of 99mTc-DTPA there was still enough circulating radioactivity to bleed into the gut and that it was possible to perform repeat injection of 99mTc-DTPA as early as 2 h after the first injection.

Animals↗

PubMed1986

Dynamic lymph flow imaging in lymphedema. Normal and abnormal patterns.

Dynamic imaging of lymphatic flow was performed in 23 patients complaining of lymphedema of the lower extremities. All were injected intradermally with 1 mCi of Tc-99m human serum albumin (HSA) in the medial web on the dorsum of both feet. Image acquisition for the lower pelvis and both thighs was started within 5 minutes. An extra-large field-of-view gamma camera (General Electric 500A) with a low-energy, all-purpose collimator interfaced to a General Electric Star computer was used. Images were acquired in dynamic-byte mode, 128 X 128 matrix size, every one minute up to 40 minutes. Delayed images for the same region and for both legs were taken at 90 minutes. Time-activity curves from equal regions of interest over the inguinal regions on both sides were generated. Three patterns were recognized. Normal flow (12 patients) with symmetric or slightly increased or decreased flow on one side than the other and characterized by early appearance of medial bands, inguinal and pelvic lymph nodes in the early and the delayed images. Time-activity curves showed a stepladder rise in pulses every 3 to 4 minutes. Enhanced pattern (six patients), characterized by fast flow of lymph through the dilated lymphatics, and occasionally by subcutaneous pooling and increase in the number and size of inguinal and pelvic lymph nodes on the affected side.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1985

[125I]Aminobenzyladenosine, a new radioligand with improved specific binding to adenosine receptors in heart.

The density of adenosine receptors in membranes derived from rat hearts in 25 times lower than the density of receptors in rat brain membranes. Consequently, adenosine radioligands which are useful in brain such as l-[3H]phenylisopropyladenosine, [3H]cyclohexyladenosine, [3H]-2-chloroadenosine and l-[125I]hydroxyphenylisopropyladenosine are of limited usefulness in heart, due to a high ratio of nonspecific to specific binding. We have synthesized a new radioligand, [125I]-N6-4-aminobenzyladenosine, which binds to rat heart membranes with one-sixth the nonspecific binding of the other radioligands. [125I]-N6-4-aminobenzyladenosine bound to rat ventricle membranes with a KD equivalent to that of l-[125I]hydroxyphenylisopropyladenosine and a Bmax of 15.2 fmol/mg protein. [125I]-N6-4-aminobenzyladenosine bound with a higher affinity to brain (KD = 1.93 nM) than to heart membranes (KD = 11.6 nM). At the radioligand KD, 60% of the total [125I]-N6-4-aminobenzyladenosine bound to heart membranes was specifically bound. Iodination of aminobenzyladenosine increased its affinity for the adenosine receptor by 22-fold, possibly due to a steric or hydrophobic effect of iodine. The new ligand was found to be a full adenosine agonist based on its ability to inhibit cyclic adenosinemonophosphate accumulation in isolated embryonic chick heart cells and rat adipocytes. [125I]-N6-4-Aminobenzyladenosine bound to a single affinity site and was displaced from cardiac and brain adenosine receptors by other adenosine analogues with a potency order of l-phenylisopropyladenosine greater than 5'-N-ethylcarboxamide adenosine. These characteristics suggest that the radioligand binds to an Ri adenosine receptor.

Adenosine↗

PubMed1985

Lymphscintigraphy in peripheral lymphedema using technetium-labelled human serum albumin: normal and abnormal patterns.

Lymphscintigraphy using Tc-99m human serum albumin (HSA) was examined in 23 patients with peripheral leg lymphedema. Each was injected intradermally with one mCi in the medial web space bilaterally. Images of the lower pelvis and both thighs were obtained within five minutes after injection using an extralarge field view camera GE 500A with low energy all purpose collimator interfaced with G.E. Star computer. These images were acquired in dynamic byte mode, 128 X 128 matrix size, every minute for 40 minutes. Delayed images for this region and of both legs were also taken at 90 minutes and time activity curves from comparable regions of interest over the inguinal area bilaterally were generated. Three patterns emerged: 1--normal lymph flow (12 patients) characterized by symmetrical or nearly symmetrical early appearance of lymphatics (medial bands) with visualization of inguinal and pelvic lymph nodes in both early and delayed images. Time activity curves showed step ladder rise, in "pulses" every three to four minutes. 2--enhanced lymph flow pattern (6 patients) was characterized by rapid movement of radiolabelled albumin through dilated lymphatics, occasionally with subcutaneous pooling, and both larger and more numerous inguinal and pelvic nodes on the lymphedematous side. 3--obstructed lymph flow (5 patients) was characterized by subcutaneous pooling, absent lymphatics, (medial bands) and flat, time activity curve on the lymphedematous side (only background activity) and absent inguinal and pelvic nodes. On delayed images, where lymphatic obstruction was incomplete there was delayed appearance of inguinal pelvic nodes which were fewer and smaller compared to the nonedematous side.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1985

Computerized 24-hour esophageal pH monitoring: a new ambulatory technique using radiotelemetry.

A computerized telemetric system using a portable microprocessor receiving unit has been designed for clinical use in ambulatory 24-hour esophageal pH monitoring. The receiving unit can be used with either a pH-sensitive radiotelemetry pill or a standard intraesophageal pH probe. Esophageal pH data is collected under microprocessor control while the patient is in the usual home or work environment. Computerized plotting and analysis of the compiled pH data is performed at the conclusion of the ambulatory testing. The system has been successfully used in patients with symptoms of esophageal reflux and healthy volunteers with no symptoms. The development of a computer-based radiotelemetry system for prolonged monitoring of esophageal pH represents a substantial advance in existing investigational technology. It allows the use of new radiotelemetric techniques of esophageal pH recording with increased patient comfort and acceptance over a 24-hour ambulatory testing period. Microprocessor control of both data collection and analysis allows rapid interpretation of complex 24-hour esophageal pH tracings and greatly facilitates the performance of esophageal pH monitoring as a routine clinical investigation.

Adult↗

PubMed1984

Computerized 24-hour ambulatory esophageal pH monitoring and esophagogastroduodenoscopy in the reflux patient. A comparative study.

Ambulatory 24-hour esophageal pH monitoring and esophagogastroduodenoscopy were performed in 72 patients with symptoms suggestive of gastroesophageal reflux. Additionally, 22 asymptomatic healthy volunteers underwent pH monitoring. In patients with classic reflux symptoms and endoscopic esophagitis, a mean of 5.41 minutes/hour of reflux below pH 4 was found compared to 0.70 minutes/hour in controls (p less than 0.0001). The mean number and duration of reflux events in this group were 1.51 events/hour and 4.0 minutes/event, compared with 0.31 events/hour and 2.26 minutes/event in volunteers (p less than 0.001, p less than 0.01). A new system for ambulatory esophageal pH monitoring is presented using a pH-sensitive radiotelemetry pill or a pH probe and computerized methods for ambulatory data collection, analysis, and storage. An overall sensitivity of 76% was obtained with a 91% selectivity for detection of acid reflux in 51 patients having classic symptoms of gastroesophageal reflux. Ambulatory pH monitoring was positive for acid reflux in seven of 11 patients with normal endoscopic findings. Conversely, eight of 12 patients with normal pH monitoring had endoscopic esophagitis. In 19 patients presenting with atypical symptoms or previous gastric surgery, endoscopic findings were normal in 15. Nine of these 15 were identified as acid refluxers by pH monitoring. A combined approach using both pH monitoring and endoscopy is warranted for maximal detection and quantification of disease. A clear clinical role for pH monitoring is seen in the early diagnosis of acid reflux, particularly in patients having normal endoscopic findings with nonspecific gastrointestinal complaints or previous gastric operations.

Adult↗

PubMed1984