Cathodic adsorptive stripping voltammetric determination of nalidixic acid in pharmaceuticals, human urine and serum.

The quinolone antibacterial agent nalidixic acid (NAL) was studied by cyclic voltammetry (CV) and cathodic adsorptive stripping voltammetry (CASV). A sensitive method is described for the determination of NAL in its pure form, dosage forms and biological fluids. Controlled adsorptive accumulation of NAL on a hanging mercury drop electrode provides the basis for the direct stripping measurement of that compound in the nanomolar concentration level. Different variables were studied and optimized. The proposed method depends upon the voltammetric activity of NAL in Britton-Robinson buffer, whereby a well-defined cathodic peak is produced at pH 5.0 in presence of NO(3)(-). The calibration graph to determine NAL was linear in the range 7.4x10(-8)-2.5x10(-5) M by CASV. CAS voltammetry has been proved to be advantageous over a liquid chromatographic (LC) technique, allowing to detection limit signal to noise ratio, (s/n=3) of 0.766 ng ml(-1) (3.3x10(-9) M) NAL to be reached. The relative standard deviation (n=5) was 5.2% at concentration level of 1.0x10(-7) M NAL. The degree of interference from coexisting metal ions on the CASV signal for NAL was evaluated. The method was applied to two different commercial pharmaceutical products (Negram tablets and suspension) with very good recoveries. It was also shown that the method was successfully applied to the determination of NAL in human urine and blood serum. Mean recoveries were 98.8+/-0.3 and 98.9+/-0.41%, respectively.

The forkhead protein Fkh2 is a component of the yeast cell cycle transcription factor SFF.

In the yeast Saccharomyces cerevisiae, the MADS-box protein Mcm1, which is highly related to mammalian SRF (serum response factor), forms a ternary complex with SFF (Swi five factor) to regulate the cell cycle expression of genes such as SWI5, CLB2 and ACE2. Here we show that the forkhead protein Fkh2 is a component of SFF and is essential for ternary complex formation on the SWI5 and ACE2 promoters. Fkh2 is essential for the correct cell cycle periodicity of SWI5 and CLB2 gene expression and is phosphorylated with a timing that is consistent with a role in this expression. Furthermore, investigation of the relationship between Fkh2 and a related forkhead protein Fkh1 demonstrates that these proteins act in overlapping pathways to regulate cell morphology and cell separation. This is the first example of a eukaryotic transcription factor complex containing both a MADS-box and a forkhead protein, and it has important implications for the regulation of mammalian gene expression.

Immediate breast reconstruction in patients with locally advanced disease.

Immediate breast reconstruction for patients with early-stage disease is well established. This study evaluates a consecutive series of 22 patients with locally advanced disease (stage IIB or III) who underwent mastectomy and immediate breast reconstruction. All patients received several cycles of neoadjuvant chemotherapy (average, 3.5 cycles) followed by completion of chemotherapy beginning approximately 3 weeks following surgery. The perioperative morbidity was 14% and no patient suffered a delay in the resumption of chemotherapy. Patients have been particularly grateful about being offered reconstruction in this setting. Our preliminary results with this technique have been encouraging and further study is warranted.

The frontonasal flap for increased exposure in posttraumatic nasal deformity: a technical overview.

Nasal reconstruction continues to be a surgical challenge. The prominent location of the nose, the unique quality and texture of its skin, and the intricacies of its cartilaginous and bony infrastructure demand careful attention to fine detail. Attempts to refine reconstructive techniques have resulted in a myriad of local flaps. The frontonasal flap is well-described and reliable, but it is infrequently used. A brief review of the literature is presented. The authors describe a unique case of a 64-year-old woman with posttraumatic nasal tip and dorsal deformity. The frontonasal flap provided soft tissue coverage for the nasal tip and allowed excellent exposure for reconstruction of the hard nasal framework with cartilage and bone grafts. It provides local tissue with excellent contour, color, and texture match, and can be performed in one stage.

Single-stage treatment of sternal wound complications in heart transplant recipients in whom pectoralis major myocutaneous advancement flaps were used.

Treatment of sternal wound complications is controversial, particularly in immunosuppressed heart transplant recipients. Regardless of the severity of infection, we combine immediate, aggressive débridement with bilateral pectoralis major myocutaneous advancement flaps in a single procedure. Compared with management with pectoralis major turnover flaps or distant pedicled muscle flaps, treatment of these sternal wounds with pectoralis major myocutaneous advancement flaps is simpler and quicker and provides better aesthetic results. Furthermore, because pectoralis major myocutaneous flaps are based on the thoracoacromial arteries, whether or not the internal mammary arteries have previously been harvested for coronary grafts is irrelevant. Twenty consecutive heart transplant recipients with sternal wound complications were treated with this technique. No intraoperative or perioperative deaths occurred. The morbidity rate was 30%, with seroma treated by needle aspiration in four patients (20%) being the most common complication. Only one patient had a postoperative wound infection. All patients had excellent functional and aesthetic results.

Laparoscopic harvesting of jejunal free flaps.

We studied the safety and efficacy of laparoscopic jejunal free flap harvesting with total intracorporeal small-bowel anastomosis in an animal model. Eight dogs underwent laparoscopic resection of 8 to 15 cm of jejunum with endoscopic GIA anastomoses and jejunal segment harvesting through the periumbilical laparoscopic port. In six animals, the harvested jejunum was implanted subcutaneously and revascularized by anastomosis of the mesenteric artery and vein to the femoral vessels. Both the microvascular and intracorporeal jejunal anastomoses were studied at 10 days. Mean laparoscopic operative time was 2.9 hours, with the last five procedures all completed in fewer than 2 hours. Mean ischemic time was 1.9 hours. The laparoscopically performed small-bowel anastomoses were all successful. All dogs took regular diets within 1 day, with normal bowel function returning by the second day. Both clinically and histologically, the bowel wall and mesenteric vessels of all the segments harvested demonstrated no injury despite their laparoscopic harvest. Five of the free flaps remained fully viable at 10 days. One flap failed after prolapse of the flap resulting from inadequate fixation. Laparoscopic harvesting of the jejunal free flap is safe and efficacious and offers all of the potential advantages of laparoscopic abdominal surgery.

Frey's syndrome: prevention with temporoparietal fascial flap interposition.

The recent trend in management of Frey's syndrome has been the use of prophylactic procedures performed at the time of parotidectomy to prevent its symptoms postoperatively. An additional benefit of this approach is the prevention of the typical cheek contour deformity after parotidectomy. We reviewed our experience with interposition of a vascularized temporoparietal fascial flap between the parotid bed and overlying skin immediately after complete superficial parotidectomies to prevent Frey's syndrome and contour defects. The results of seven consecutive attempts revealed it to be an effective technique, achieving both goals in all patients with minimal morbidity.

Single-stage management of 74 consecutive sternal wound complications with pectoralis major myocutaneous advancement flaps.

The optimal management of sternal wound complications remains controversial. Since 1985, we have utilized a combination of immediate, aggressive debridement with simultaneous repair using bilateral pectoralis major myocutaneous advancement flaps, regardless of the degree of infection. As compared with the use of distant pedicled muscle flaps or pectoralis major turnover flaps, the management of complicated sternal wounds with immediate pectoralis major myocutaneous advancement flaps provides an effective yet simpler, quicker method of management with improved aesthetic results. In addition, basing the pectoralis major myocutaneous flaps on the thoracoacromial arteries eliminates the need for intact internal mammary arteries, valuable since the latter are increasingly used for coronary grafts. Seventy-four consecutive patients, 17 (23 percent) of whom were immunosuppressed heart transplant recipients, have been managed with this procedure. There were no intraoperative deaths. The 30-day perioperative mortality rate was 9 percent (7 of 74), with only 1 death related to persistent sepsis. The morbidity rate was 39 percent, with the most common complication being seroma managed by needle aspiration (18 of 74, 24 percent). The aesthetic and functional results have been uniformly excellent.

Unhooking the hook: sculpting the nasal tip by replanting the medial crura.

A great challenge of rhinoplasty is the tip with insufficient projection or the hooked nose. Tip grafting is the standard method used to correct this. The open rhinoplasty technique provides exposure of nasal structures not afforded by the closed approach. We have used this approach to sculpt the nasal tip. Successful "unhooking of the hooked nose" by gaining tip projection has been achieved by completely replanting the medial crura. In the operation, the medial crura are freed in their entirety. The lateral alae of the lower cartilages are trimmed. The medial crura are then advanced dorsally until adequate nasal tip projection is obtained. They are secured to each other and to the septum in their new position with interrupted sutures. More tip definition can be obtained, if needed, by suturing the medial crura together near the tip. The dome can be sculpted to an appropriate width in a similar manner. This technique is advantageous because exact symmetry and positioning of the cartilages can be obtained under direct vision. It contours the tip structures to achieve more nasal tip projection, obviating the need for tip grafting. The technique is particularly useful in the patient with a low dorsum and acute nasolabial angle who will benefit from tip augmentation and elevation. The technique simultaneously thins the tip, adds nasal tip projection of 4 to 6 mm, and corrects the nasolabial angle. We have used this technique with good results in 15 patients. The technique and results were illustrated.

Nipple-areola reconstruction with intradermal tattoo and double-opposing pennant flaps.

Reconstruction of the nipple-areolar complex is an important part of postmastectomy breast reconstruction. Intradermal tattooing is effective for creating areolar pigmentation and is simpler than skin grafting. However, a simple method for the construction of a normal nipple using local tissues remains a challenge. Several techniques achieve long-term nipple projection but at the expense of complicated flap design, multidirectional scars, and often a need for skin grafting to obtain a uniform-appearing areola. Our one-stage method of nipple-areola reconstruction uses intradermal tattooing for pigmentation and double-opposing pennant flaps for nipple reconstruction. The entire procedure is simple and fast, routinely performed in < 30 minutes under local anaesthesia in the office. From September 1989 to March 1992 we performed 102 reconstructions. The method produces a realistic appearing nipple. We have had no flap necrosis.

Salvage of successful mandibular advancement for obstructive sleep apnea using a bipedicle osteocutaneous scapular free flap.

An interesting case is presented of a woman with obstructive sleep apnea due to mandibular hypoplasia who was successfully treated with mandibular advancement. After a postoperative complication, the correction was salvaged by using a previously undescribed bipedicled osteocutaneous scapular free flap.

The bipedicled osteocutaneous scapula flap: a new subscapular system free flap.

Thirty-six adult dissections (14 cadaver and 22 operative) demonstrate the constant presence of the angular branch of the thoracodorsal artery as a vascular pedicle to the inferior pole of the scapula. This vessel originated in all cases just proximal or distal to the serratus branch of the thoracodorsal artery and arborized to the periosteum 6 to 9 cm from the bony branch of the circumflex scapular artery. In eight patients, scapular osteocutaneous flaps were raised preserving the angular branch and the circumflex scapular artery and dissecting up to the subscapular vessels. In all cases, bone was independently perfused by the angular branch. In all six cases where the angular branch was the sole supply to bone, technetium-99m scans demonstrated perfusion. Addition of this vascular pedicle to scapula bone allows two separate bone flaps with one microanastomosis and provides a longer arc of rotation between skin supplied by the circumflex scapular artery and bone. Donor-site morbidity was no greater than with the standard scapula flap.

Oncologic and functional considerations of total glossectomy.

The efficacy of total glossectomy for advanced carcinoma of the tongue remains controversial. A retrospective chart review was undertaken to evaluate the oncologic and functional results in 17 consecutive patients who underwent this procedure. There were two patients with stage III disease, eight with stage IV disease, and seven with recurrent disease. The larynx was preserved in seven patients. One patient required a secondary laryngectomy. All patients were reconstructed immediately, 11 with a pectoralis major myocutaneous flap and 6 with free-tissue transfer. The operative mortality was 6 percent; the morbidity was 59 percent. At last follow-up, 53 percent of the patients were alive without disease, with a mean disease-free survival period of 36 months. Ninety-three percent of the patients regained swallowing and independent oral alimentation; 80 percent of those with laryngeal preservation regained intelligible speech. We have concluded that total glossectomy should be considered as a primary modality for advanced carcinoma of the tongue and not solely reserved for salvage in hopeless situations. With or without laryngectomy, excellent survival and functional results can be obtained.