Replication of the broad host range plasmid RSF1010: requirement for three plasmid-encoded proteins.

Cloning of specific regions of plasmid RSF1010, in conjunction with in vitro replication studies, has revealed three novel genes: repA, repB, and repC. They are clustered in one region of the plasmid, separated from the origin of replication by regions that are not essential for plasmid viability in an Escherichia coli host. In vivo, a 2.1-kilobase segment of the plasmid, bearing the replication origin, can establish itself as an autonomous replicon if the DNA region carrying the three rep genes is present in the same cell on an independent plasmid. In vitro, RSF1010 DNA is efficiently replicated by an ammonium sulfate fraction from the E. coli extract, provided the extracts are prepared from cells that can supply the required rep gene products. Using cells containing the cloned rep gene region as a source of elevated levels of the rep proteins, we have partially purified these proteins in functional form. When added to an enzyme fraction derived from plasmid-free cells, they specifically promote the replication of plasmid DNA bearing the RSF1010 origin.     

Steep learning curve of laparoscopic splenectomy

BACKGROUND AND PURPOSE: In 1992, Ochsner Foundation Hospital was among the first institutions in which laparoscopic splenectomy was performed. The aim of this study is to review our experience and discuss the lessons learned. METHODS: A retrospective review of 33 cases of laparoscopic splenectomy for idiopathic thrombocytopenic purpura (ITP) (N = 22), autoimmune hemolytic anemia (AIHA) (5), thrombocytopenic purpura (TTP) (2), and other disorders (4) at Ochsner Foundation Hospital between 1992 and 1999 was conducted. Several measures, including rates of conversion to open splenectomy, were recorded and analyzed. RESULTS: Of the 33 cases, 26 (79%) were completed laparoscopically. Four were converted to an open procedure secondary to bleeding and three secondary to difficulty in dissection. Six conversions to open surgery were necessary during the first eight laparoscopic splenectomies and only one during our last 25 cases. Two patients required reoperations for bleeding. The average hospital stay after laparoscopic splenectomy was 2.3 days; eight patients stayed only 1 day. All of the TTP patients, 86% of the patients with ITP, and 40% of those with AIHA responded well to splenectomy. CONCLUSION: Laparoscopic splenectomy is a safe although complex procedure. Bleeding is the major complication but has been less common with experience. Even with today's technology, very large spleens are still extremely difficult to remove. With the short recovery and ready acceptance of patients and physicians, this technique is being used with increasing frequency. A significant learning curve exists for the safe completion of this challenging procedure.     

Airway management in adult patients with deep neck infections: a case series and review of the literature

Patients with deep neck infections, especially those with Ludwig's angina, may die as a result of airway management mishaps. Skillful airway management is critical, but a safe method of airway control in these patients is yet to be established. We subjected patients with deep neck infections to fiberoptic tracheal intubation by using topical anesthesia to provide general anesthesia for surgical interventions. Patient characteristics and techniques for intubations were recorded on a special data-collection form. Of the 26 patients, 17 had Ludwig's angina, and 9 had other types of deep neck infections. Three patients were tracheally intubated while in the sitting position, 2 in Fowler's position, and 21 in the supine position with the head up 10 degrees-15 degrees. Tracheal intubations were successful in 25 patients: 19 nasally and 6 orally. After surgery, seven patients were kept tracheally intubated, and five patients had tracheostomies. Complications were limited to three cases of mild epistaxis and four oversedations with transient hypoxemia. Twelve patients remembered part of the procedure, and two considered it unpleasant. Tracheal intubation with a flexible bronchoscope by using topical anesthesia is highly successful in adult patients with deep neck infections. Tracheostomy using local anesthesia is recommended if fiberoptic intubation is not feasible, if the clinician is not skillful in the use of awake fiberoptic intubation, or if intubation attempts have failed.     

Use of the Intubating LMA-Fastrach™ in 254 Patients with Difficult-to-manage Airways

Background : The laryngeal mask airway (LMA(TM); LMA North America, Inc., San Diego, CA) has a well-established role in the emergency and elective treatment of patients with difficult-to-manage airways (DA). In this study, the authors report their clinical experience with the intubating LMA (LMA-Fastrach(TM); LMA North America, Inc., San Diego, CA) in 254 patients with different types of DA.

Methods : The authors reviewed the anesthetic and medical records of patients with DA in whom the LMA-Fastrach(TM) was used electively or emergently at four institutions from October 1997 through October 2000. In each case, the number of insertion and intubation attempts was recorded. Success rates for blind and fiberoptically guided intubation through the LMA-Fastrach(TM) were calculated, up to a maximum of five attempts per patient.

Results : The LMA-Fastrach(TM) was used in 257 procedures performed in 254 patients with DA, including patients with Cormack-Lehane grade 4 views; patients with immobilized cervical spines; patients with airways distorted by tumors, surgery, or radiation therapy; and patients wearing stereotactic frames. Insertion of the LMA-Fastrach(TM) was accomplished in three attempts or fewer in all patients. The overall success rates for blind and fiberoptically guided intubations through the LMA-Fastrach(TM) were 96.5% and 100.0%, respectively.     

A renoprotective effect of enalapril in chronic transplantation nephropathy

AIM: To study safety and efficacy of ACE inhibitor enalapril in chronic transplantation nephropathy (CTN) as well as nephroprotective efficacy of this drug in various clinical variants of CTN. MATERIAL AND METHODS: A retrospective study covered 220 recipients with CRF. The patients were divided into the study group (n = 103) and the control group (n = 117). The study group was given ACE inhibitor enalapril the efficacy of which was assessed by arterial pressure (systolic, diastolic, mean) dynamics, 24 h proteinuria and the rate of CTN progression. This rate was suggested by probability of plasm creatinin doubling (Kaplan-Meier technique). RESULTS: Enalapril significantly inhibited CTN progression running with minimal or marked proteinuria, had a pronounced hypotensive effect, promoted stabilization of minimal proteinuria (in CTN with minimal proteinuria) or reduction of protein excretion (in a proteinuric variant of CTN). CONCLUSION: Use of enalapril in CTN in a daily dose 10 mg maximum is safe and can be used for inhibition of CTN progression.     

Carbon dioxide absorber as a cause of high airway pressures

We investigate an incident in which a carbon dioxide absorber caused difficulty with ventilation. The problem as it developed throughout the anesthetic, and clues that led to the determination that the carbon dioxide canister was the problem, is discussed.