The inferior alveolar artery in its bony course

Based on the dissection of 30 hemi-mandibles, the authors report a study of the inferior alveolar artery in its intraosseous course. On morphologic considerations they propose a classification of the collaterals into two groups: the principal collaterals destined for the teeth and the bony alveolar tissue and the secondary collaterals destined for the sheath and the nerve as well as the bony tissue around the canal. Loss of the teeth and absorption of the alveolar bone modify the caliber of the inferior alveolar arterial axis, the distribution of its collaterals and possibly its mode of termination. These facts suggest a consideration of the vascularization of the mandible in terms of four sectors. They arrive at practical conclusions that may be drawn from this study in stomatology.     

Dural infolding during C1-2 myelography

Inward buckling of the dura at C1-2 may occasionally occur with hyperextension of the neck and can result in a difficult or unsuccessful puncture when the posterior lateral C1-2 approach is used for cervical myelography. In this circumstance, placement of the head in a neutral or slightly flexed position may widen the posterior subarachnoid space and facilitate the needle puncture.     

Expression and purification of functional recombinant epitopes for the platelet antigens, PlA1 and PlA2

The platelet antigens, PlA1 and PlA2, are responsible for most cases of posttransfusion purpura (PTP) and neonatal alloimmune thrombocytopenia (NAIT) in the caucasian population and are determined by two allelic forms of the platelet glycoprotein GPIIIa gene. To study the interaction between these antigens and their respective antibodies, we inserted the sequence that encodes the signal peptide and the N- terminal 66 amino acids of the PlA1 form of GPIIIa into the expression vector pGEX1. To express the PlA2 antigen, nucleotide 196 of the PlA1 coding sequence was mutated to the PlA2 allelic form. When transformed and induced in Escherichia coli, the two constructs produce glutathione S-transferase (GST)/N-terminal GPIIIa fusion proteins, one containing leucine at position 33 (PlA1), the other proline (PlA2). These proteins are easily purified in milligram quantities using glutathione-Sepharose and react specifically with their respective antibodies by immunoblot and enzyme-linked immunosorbent assay. Antigenicity of the PlA1 fusion protein in reduced glutathione increases with time; moreover, the addition of oxidized glutathione accelerates this process, presumably because of formation of the native disulfide bonds. Neutralization assays indicate that the PlA1 fusion protein competes for all of the anti-PlA1 antibody in the serum of patients with PTP and NAIT that is capable of interacting with the surface of intact platelets. This study shows that the GST/N-terminal GPIIIa fusion proteins contain conformational epitopes that mimic those involved in alloimmunization, and that regions other than the amino terminal 66 amino acids of GPIIIa are not likely to contain or be required for the development of functional PlA1 epitopes. Furthermore, these recombinant proteins can be used for the affinity-purification of clinical anti-PlA1 antibodies and specific antibody identification by western blotting, making them useful in the diagnosis of patients alloimmunized to PlA1 alloantigens.     

Results of pyeloureterostomy after ureterovesical anastomosis complications in renal transplantation

OBJECTIVES: The most frequent urologic complications after renal transplantation involve the ureterovesical anastomosis (ie, leakage, stenosis, and reflux), with a frequency of 1% to 30% in different series. We present the results of pyeloureterostomy using the recipient's ureter. METHODS: From 1988 to 1996, 570 cadaveric renal grafts were performed at our institution. A Lich Gregoir ureterovesical anastomosis was used in every case. Complications involving the anastomosis occurred in 19 cases (3.3%), with 10 stenoses (1.7%), 6 cases of leakage (1.1%), and 3 of reflux (0.5%). The mean donor age was 36.2 years, and the mean duration of cold ischemia was 29.4 hours. The mean recipient age was 41.3 years. Corrective surgery was performed 0.09 years (range 0.01 to 0.22) after transplantation for leakage, 1.13 years (range 0.14 to 5.11) for stenosis, and 5.55 years (range 0.51 to 9.71) for reflux. The recipient's ureter was stented with a ureteral catheter before median laparotomy, except in 3 cases of early leakage (less than 3 days). The recipient's ureter was cut, without the need for ipsilateral nephrectomy, and sutured to the graft pelvis. A nephroureterostomia stent (Gil Vernet stent) (12 cases) or a double J ureteral stent (7 cases) was used for urinary drainage. RESULTS: One graft was lost on day 1 through renal vein thrombosis. Percutaneous nephrostomy was performed on day 2 to clear an obstruction of the double J ureteral stent in one case, and a double J ureteral stent was inserted on day 2 because the nephrouretrostomia stent was incorrectly positioned in another case. Pyelographic controls on day 15 were normal in every case. The mean follow-up was 2.25 years (range 0.24 to 6.1) (2.9 years for leakage, 2.08 years for stenosis, and 1.44 years for reflux). One patient died with a functional graft 3 years after surgery. One graft was lost 4 years after surgery through chronic rejection. There were no complications affecting the ipsilateral kidney. No further ureteral complications occurred after surgery. The mean creatinine level 3 years after surgery was 1.59 mg/dL. CONCLUSIONS: Pyeloureterostomy is a safe and permanent treatment for complications of ureterovesical anastomosis and gives excellent results. The technique requires stenting of the recipient's ureter and graft drainage with a nephroureterostomia stent or a double J ureteral stent.     

Iotrol versus metrizamide in lumbar myelography: a double-blind study

In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population.     

The double puncture: an effective percutaneous technique for removing complex, multiple renal calculi

Percutaneous nephrostolithotomy, which can require a double puncture, is presently the method of choice in our institution for the removal of renal stones. Patients that underwent this procedure were evaluated to identify the possible reasons for the double puncture. Of 200 patients evaluated, 14 needed a second tract. The three variables that determined whether a second puncture was needed, in order of importance, were number and size of the stones, with second tracts needed in patients with multiple stones and staghorn calculi; anatomical variations of the renal collecting system itself, with bifid systems the most significant anatomic variation; and the dexterity of the radiologist in performing the puncture and the ability of the urologist to extract the stone. Second tracts were needed more frequently in patients who presented with stones in both the lower and middle poles of the collecting systems.     

Experience with the Amplatz retrievable vena caval filter. Work in progress

The Amplatz retrievable vena caval filter was designed in an attempt to decrease complications associated with the placement of Mobin-Uddin or Kimray-Greenfield filters. The design allows percutaneous retrieval, thus expanding application of the filter to situations requiring temporary prophylaxis against pulmonary embolism. Filters have been placed in 16 patients, nine (56%) for prophylactic purposes. All filters were easily inserted percutaneously. Complications occurred in three patients; these included complete thrombosis of the inferior vena cava below the filter, misplacement of one filter into the pericaval retroperitoneal tissue, and development of thrombus cranial to the filter. With the current introduction system, the possibility of filter misplacement has been essentially eliminated. No patient experienced symptoms suggestive of pulmonary embolism after filter insertion. One filter retrieval has been performed, with no complications.