Interaction between bovine collagen and glycolic acid peeling: A proposal of a new protocol

For the past 10 years the alfa-hydroxyacids and the bovine collagen injection have been used for peeling and the correction of multiple skin diseases. Until now, such progressive achievement has occurred in separate parallels just like the indications that have been held distinct. However, the studies carried out in order to clarify the mechanical action of the two substances have shown a common and fundamental denominator: the stimulation of synthesis of the new collagen in the patient's skin. On the basis of these results and the existence of common clinical indications of the use of glycolic acid and collagen, the authors have worked out a protocol involving a combined and contemporary application in progressive steps. They developed the rationales of such protocol and analyzed the results of its application on a number of carefully selected patients for a clinical comparison and on a sample of rats for a histological comparison. They have concluded that the contemporary use of glycolic acid and bovine collagen is a simple and safe method whose synergy action leads to more intense and long-lasting effects than the ones observed in the isolated application of the two substances. The authors have also obtained interesting and significant histological results.     

Phosphatidylcholine does not affect peritoneal transport of intact rabbits

Ultrafiltration and solute transport during 60-min peritoneal dialyses of normal rabbits with intraperitoneal administration of phosphatidylcholine were compared to control values. The ultrafiltration rate of 0.27 mL/Kg/min did not increase when phosphatidylcholine was added. This agent had no effect on the ultrafiltration coefficient, sodium mass transport or solute clearances. Previously reported beneficial results with this agent could be due to repletion of a deficiency or an effect of the organic solvent. More studies of safety and efficacy of phosphatidylcholine are warranted before widespread clinical use.     

Stopping a medical research project for financial reasons

Sir, We are writing to provide some clarifications on the EditorialComment by Drüeke et al. [1]. We would have been happyto provide these very same clarifications had we been fairlyinvited to do so before the publication of the article. First of all, we would like to     

Lack of evidence for an impairment of tuberoinfundibolar dopaminergic neurons in aged male rats of the Sprague-Dawley strain

Circulating prolactin (PRL) levels, dopamine (DA) content, in vitro basal and stimulus-evoked endogenous DA release from arcuate-periventricular nuclei median-eminence fragments were studied in young (4 months) and old (24-25 months) male rats of Sprague-Dawley strain. Serum PRL levels did not differ in young and aged animals. In addition DA tissue content, basal and K+- or d-amphetamine evoked endogenous DA release did not show age-related differences. These results suggest that in male rats of the Sprague-Dawley strain the activity of tuberoinfundibular dopaminergic (TIDA) neurons does not change during senescence, unlike what happens in other strains of rats.     

Clinical trial comparing plasma arc and conventional halogen curing lights for orthodontic bonding.

The purpose of this clinical trial was to evaluate the reliability and time saved with a plasma arc curing unit (Apollo 95E, Dental/Medical Diagnostic Systems, Woodland Hills, Calif) compared with a conventional curing unit (Ortholux XL 3000, 3M Unitek, St Paul, Minn) for direct bracket bonding with resin adhesive. Forty-five patients were involved in the study, and 608 brackets were bonded in a contralateral quadrant pattern. The patients were followed for a mean (+/- standard deviation) period of 11 +/- 3.2 months. Survival analysis was carried out to compare the failure rate for the 2 techniques. The time required for bonding with each technique was also recorded. The mean survival time was 399 days, and there were no significant differences in survival time between the 2 bonding methods. Twelve bonding failures were reported with each technique. The curing time per bracket was significantly reduced with the plasma curing light compared with a conventional curing unit (65 +/- 19 vs 82 +/- 31 seconds). The plasma arc curing light can save chair-time without affecting the bonding failure rate.     

Soft tissue facial volumes and shape in skeletal Class III patients before and after orthognathic surgery treatment.

BACKGROUND: To obtain the best surgical results in orthognathic surgery, treatment planning and the evaluation of results should be performed on measurable three-dimensional reproductions of the face of the patients, and compared to reference subjects. METHODS: Seven women aged 18-35 years, all with a skeletal Class III and mandibular asymmetry, were assessed both before (on average, 2 months) and after (on average, 10.7 months) surgical intervention (mandibular reduction by sagittal split osteotomy and LeFort I maxillary advancement). The three-dimensional coordinates of 50 soft tissue facial landmarks (face, eyes, nose, mouth and lips, ears) were collected with a noninvasive, electromagnetic digitizer; facial volumes were estimated, and compared to reference values collected in 87 healthy women of the same age and ethnic group. Inter-individual modifications in facial shape were also assessed. RESULTS: Before surgery the patients had smaller faces than the reference women, with larger lower lips and noses. A large within-group variability was found. Surgical treatment significantly reduced total facial volume and mandibular volume, increased total and upper lip volumes (Student's t test, p<0.05), and made all values more homogenous within the group. Shape differences were significantly larger before than after surgery. On average, right side gonion was the landmark that moved the most, closely followed by menton, while the tragi and ala nasi moved the least. The three-dimensional approach used in this study enabled quantitative evaluation of the final soft tissue results of surgery, without submitting the patients to invasive procedures.     

Arthroscopic Latissimus Dorsi Transfer

The patient is placed in lateral decubitus. A 6-cm incision made in the axilla allows access to the latissimus dorsi tendon and its neurovascular pedicle. Holding the arm in internal rotation, the surgeon detaches sharply the tendon off the humeral shaft and then reinforces it with wrapping sutures. Pulling the free limbs of the sutures exposes the under surface of the muscle and helps to identify the neurovascular pedicle. Special lighting retractors suited for a large diameter scope are helpful. Mobilization is completed when 2 cm of the tendon crosses the posterior edge of the acromion. The standard lateral portal is used for visualization. A silicon drain tube stiffened by a Wissinger rod is advanced from the posterior portal under direct visualization in the space between teres minor and deltoid, exiting in the auxiliary incision. A suture loop passed down the tube retrieves the tendon sutures out the posterior portal. These are then moved out the anterior portal, thus pulling the tendon over the tuberosity. The first anchor is inserted at the anterior aspect of the greater tuberosity, close to the articular cartilage and long head of the biceps tendon. Two to 3 anchors are inserted fixing the tendon to the tuberosity until it is stable.