Production of isoamyl acetate in ackA-pta and/or ldh mutants of Escherichia coli with overexpression of yeast ATF2.

The gene coding for alcohol acetyltransferase ( ATF2), which catalyzes the esterification of isoamyl alcohol and acetyl coenzyme A (acetyl-CoA), was cloned from Saccharomyces cerevisiae and expressed in Escherichia coli. This genetically engineered strain of E. coli produced the ester isoamyl acetate when isoamyl alcohol was added externally to the cell culture medium. Various competing pathways at the acetyl-CoA node were inactivated to increase the intracellular acetyl-CoA pool and divert more carbon flux to the ester synthesis pathway. Several strains with deletions in the ackA-pta and/or ldh pathways and bearing the ATF2 on a high-copy-number plasmid were constructed and studied. Compared to the wild-type, ackA-pta and nuo mutants produced higher amounts of ester and an ackA-pta-ldh-nuo mutant lower amounts. Isoamyl acetate production correlated well with intracellular coenzyme A (CoA) and acetyl-CoA levels. The ackA-pta-nuo mutant had the highest intracellular CoA/acetyl-CoA level and hence produced the highest amount of ester (1.75 mM) during the growth phase under oxic conditions and during the production phase under anoxic conditions.

Circumferential torsoplasty.

The abdominal deformities remaining after massive weight loss of 30% or more body weight often are not satisfactorily corrected by standard abdominoplasty techniques. Redundant lateral flank and hip rolls may in fact be accentuated by the operation. Accordingly, a circumferential torso excision was designed by the senior author and utilized for 7 patients during the past two years. This technique dramatically reduces the lateral flank and posterior tissue rolls to improve the operative results. Contour improvement of the buttocks and lateral thighs is produced as well. We employ a four blade propeller pattern of fascial plication centered on the umbilicus which tightens the abdominal fascia in both vertical and horizontal dimensions. Details of patient selection, operative technique, post-operative management and results are presented. Complications have been minimal and satisfaction of both patients and surgeons significantly enhanced.

Renal duplication anomalies in the fetus: clues for prenatal diagnosis.

Duplex kidneys are one of the most common major congenital abnormalities of the urinary tract. The antenatal diagnosis of duplex kidney and its associated ureterocele is infrequent. We report on our experience with the prenatal diagnosis of duplex kidneys in seven fetuses over the past 24 months. In all fetuses, the sagittal length of the duplex kidney was above the 95th centile for gestational age. A 'cyst-like' structure in the upper pole of the duplex kidney and a ureterocele in the urinary bladder were present in all of the seven fetuses. An ipsilateral dilated ureter was seen in six of seven fetuses. Postnatal confirmation of renal duplication anomalies was obtained in all neonates. Increased familiarity of the prenatal sonographer with duplex kidney will allow for its antenatal diagnosis and thus early postnatal treatment.

Penile prosthesis implantation in total phalloplasty.

A series is presented of 8 patients who had undergone either total phalloplasty or free flap penile reconstruction. Our experience with prosthetic implantation is reviewed as is a brief history of phallic construction, including previously reported efforts at achieving rigidity with prosthetic implantation, autologous material implantation and so forth. We present in detail our current technique of implantation in these 8 patients, who underwent 10 attempts at implantation. In 4 patients infection necessitated removal of the prosthesis (2 have since undergone successful reimplantation). Of the 8 patients in whom implantation was attempted 6 (60%) currently have prostheses in place.

Buried penis as a contraindication for circumcision.

Neonatal circumcision is a frequently performed procedure with rare complications. Buried penis is an infrequent congenital penile deformity. If unrecognized, circumcision of these infants may have serious consequences. Buried penis refers to a penile shaft that is buried below the surface of the prepubic skin because of an abnormally prominent suprapubic fat pad and dense fascial bands retracting and tethering the penis. Description of the entity and operative repair are discussed. Avoidance of neonatal circumcision in patients with buried penis is imperative to prevent worsening of the condition.

A fetal lamb model of partial urethral obstruction: experimental protocol and results.

The functional effects of bladder outlet obstruction in the developing urinary tract are well recognized in patients born with posterior urethral valves, in whom a spectrum of bladder dysfunction has been described. To better understand the changes occurring in the partially obstructed developing lower urinary tract, a fetal lamb model of partial urethral obstruction was developed. Fetal lambs at 90 days' gestation underwent surgical placement of a silver ring (ex utero) at the level of the proximal bladder neck, with concomitant ligation of the urachus. Control animals underwent urethral ligation only. The lambs were then allowed to go through normal gestation, and ewes were delivered spontaneously. The animals were studied between 2 and 7 days after birth. The postmortem examination showed that the ring was just distal to the bladder neck, around the proximal urethra. This resulted in gradual, partial occlusion of the urethra. Bladder weights, bladder wall thickness, and bladder capacity were significantly increased in the partially obstructed animals as compared with the controls. There was little or no upper tract dilatation in the obstructed group. This animal model, the first to produce gradual outflow obstruction in the fetus, provides a reproducible model of partial urethral obstruction. The model can be used to assay the biochemical and physiological changes found in the developing urinary tract of fetal lambs submitted to intravesical obstruction.

Repair of the complications of hypospadias surgery.

In 1992 a retrospective review was conducted of 190 patients evaluated and treated for complications of hypospadias surgery during 1979 through 1990 at the Devine Center for Genitourinary Reconstructive Surgery of Sentara Norfolk General Hospital and Children's Hospital of the King's Daughters. We could not contact 13 patients and 8 are awaiting a second stage procedure. Of the 177 patients 167 (94.35%) have had a successful outcome, defined as a controllable urinary stream, functional erection and an acceptable cosmetic appearance, and 2 (1.13%) are considered failures. Details of presenting problems, surgical techniques and recent modifications of these procedures are presented.

Dermal grafts for correction of severe chordee associated with hypospadias.

We report on 24 patients with hypospadias and severe chordee that could not be straightened with conventional techniques. We used small dermal grafts to augment the ventral tunica albuginea, which resulted in a completely straight, normal appearing erection in all patients. Subsequent urethroplasty was not complicated by the presence of the dermal graft. This procedure is technically straightforward and consistently results in a completely straight penis. Although required only rarely in hypospadias surgery, we recommend the dermal graft technique of tunica albuginea augmentation for cases of refractory chordee.

Hemangioma of penis and scrotum.

Hemangiomas of the genitalia are extremely rare. A hemangioma is self-limited and usually resolves spontaneously, therefore conservative treatment is generally recommended. However, genital hemangiomas may require surgical treatment if they become symptomatic. Herein we report a case of hemangioma of the penis and scrotum requiring surgical excision. The natural history and alternative treatments of hemangiomas are described.

Nasal reconstruction with autologous rib cartilage: a 43-year follow-up.

Autogenous costal cartilage has long been a popular material for nasal augmentation. The history of autogenous cartilage transplantation is reviewed. Two patients are presented who underwent nasal augmentation with autologous costal cartilage with a 43-year follow-up on each patient.

Effects of dietary fish oil lipids on allergic and inflammatory diseases.

Fish oil is rich in the polyunsaturated N-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic acids (DCHA). EPA competes with arachidonic acid (AA) for metabolism by the cyclooxygenase and lipoxygenase pathways. Selective metabolites derived from EPA have reduced biological activities as compared with the AA-derived counterparts. Dietary supplementation with EPA led to incorporation of EPA into membrane phospholipids, an inhibition of 5-lipoxygenase pathway activity, and a reduction of the elaboration of platelet-activating factor. Neutrophil chemotaxis and the capacity of these cells to adhere to endothelial cells are substantially attenuated. This suggests that EPA has anti-inflammatory potential. Clinical trials in rheumatoid arthritis, psoriasis, atopic dermatitis, and bronchial asthma have shown beneficial effects. Whether the benefit obtained clinically is sufficient to replace or significantly reduce any clinical condition remains to be answered.

The surgical treatment of chordee without hypospadias in men.

During a 2-year period we treated 26 young men for chordee without hypospadias. Many of these patients had straight erections as children but a ventral curvature developed as they achieved puberty. We describe the anatomical findings and discuss the possible cause for the development of this anomaly. Surgical therapy begins with a circumcising incision and reflection of the skin to expose the shaft of the penis. The corpus spongiosum containing the urethra was mobilized by resecting the dysgenetic tissue in the dartos and Buck's fascia layers. In 1 patient this dissection was sufficient to straighten the penis but in the remaining 25 the penis was not straight. In those patients we mobilized the dorsal bundle of vessels and nerves, and removed 1 or several ellipses of tunica albuginea to equalize the lengths of the ventral and dorsal aspects of the corpora cavernosa. The corpus spongiosum usually is elastic and the curve almost never is caused by shortness of the urethra, which stretches to fit the straightened penis. In 24 of the 26 patients the curvature was resolved with 1 operation, while 2 needed a second procedure.

Diphallia and hindgut duplication.

Diphallia is a rare congenital condition that presents in many, varied ways. Associated anomalies are to be expected. These anomalies should be sought out and treated as early in the patient's life as possible because they are the principal cause of mortality in these individuals. Half the patients reviewed by Ravitch in 1953 with duplication of the colon and genital tracts died of intestinal complications. Definitive genital repair should be done at an age where the anatomy is of large enough caliber for eased surgical manipulation, but prior to the age of recall. From our experience with hypospadias repair, the optimal age seems to be 12 months of age. Each case must be treated individually in order to achieve the best functional and aesthetic result.

Reconstruction of traumatically acquired defects of the phallus.

Trauma to the male phallus may be treated in a systematic approach to achieve aesthetically and functionally pleasing results. Isolated burns should be treated early with excision and preputial flap or skin graft closure. Avulsion injuries are closed primarily or skin grafted. Subtotal loss can be treated with penile lengthening techniques. Total loss is treated with reimplantation or microvascular free tissue transfer phalloplasty. There are reconstructive surgical options, instead of penectomy, in patients with penile malignancies.