Synthetic biomaterials for soft-tissue augmentation and replacement in the head and neck.

Within the next 10 to 15 years, synthetic biomaterials will probably become available that may make many of the polymeric implants discussed in this article obsolete. These new, genetically engineered biomaterials will contain morphogenic proteins capable of directing new tissue growth. We may be able to engage in true "tissue engineering" that allows us to grow a number of tissue types at will, as opposed to implanting bioinert compounds that only mimic the shape of living tissue.

Soft-tissue augmentation and replacement in the head and neck. General considerations.

It is clear that many of the factors that affect wound healing when natural biomaterials are used also affect the long-term success of semisynthetic and synthetic alloplasts. The development of a new generation of biomaterials that combine synthetic components with bioactive proteins are just now beginning to move from the laboratory into clinical testing. Within the next decade, biologically active growth proteins, in combination with resorbable synthetic alloplasts, may allow missing tissues to be regenerated rather than just "filled in" by permanent implants.

Hydroxyapatite cement: a new method for achieving watertight closure in transtemporal surgery.

Transtemporal approaches to the petrous apex and CP angle are standard procedures in the armamentarium of the neurotologist. In the majority of these cases, it is not possible to achieve a watertight suture closure of the dura following the procedure. Subsequently, cerebrospinal fluid leakage and potential meningitis are among the most troublesome complications for both patient and surgeon.

Bacterial plant oncogenes: the rol genes' saga.

The rol genes are part of the T-DNA which is transferred by Agrobacterium rhizogenes in plant cells, causing neoplastic growth and differentiation. Each of these bacterial oncogenes deeply influences plant development and is finely regulated once transferred into the plant host. Both from the study of the effects and biochemical function of the rol genes and from the analysis of their regulation, important insight in plant development can be derived.

An anatomic study of the effects of dural puncture with different spinal needles.

Background And Objectives: The purpose of this study is to evaluate the effects of puncture of lumbar dura mater with needles of different sizes and with bevels of different shapes.

Methods: After removal, the dura was punctured with different needles (22-, 25-, 27-, and 29-gauge Quincke, 24-gauge Sprotte, 22-gauge Whitacre, and 18-gauge Tuohy needles) and observed by stereomicroscope to examine the gross morphology. Histologic features were observed by light microscope using frozen and fixed samples stained with hematoxylin and eosin or specific methods (Masson and Weigert) to evidence elastic or collagen fibers.

Which induction drug for cesarean section? A comparison of thiopental sodium, propofol, and midazolam.

Study Objective: To determine maternal and neonatal effects of three different induction drugs (thiopental sodium, propofol, and midazolam) for cesarean section.

Design: Randomized, double-blind study.

Setting: Inpatient obstetric department at a general hospital.

Experimental mandibular regrowth by distraction osteogenesis. Long-term results.

The use of gradual distraction to grow bone (distraction osteogenesis) has gained widespread orthopedic acceptance, but has only recently been applied to craniofacial skeletal defects. The use of bifocal distraction osteogenesis to fill experimental segmental mandibular defects with regenerate bone was recently reported. Though all canines in that study demonstrated normal oromandibular function, they were observed for only 4 weeks following defect closure.

Alkalinization improves the quality of lidocaine-fentanyl epidural anaesthesia for caesarean section.

This double-blind randomized study of 116 healthy women was undertaken to evaluate whether alkalinization potentiated the analgesic effects of epidural fentanyl-lidocaine for elective Caesarean section. After a test-dose of 3 ml, lidocaine 2% with adrenaline 1:200,000, all patients received 100 micrograms, fentanyl in 5 ml saline and they were then divided into two groups, to receive incremental doses of 5 ml lidocaine 2% with adrenaline 1:200,000 with or without 0.1 mEq.

Priming to heat shock proteins in infants vaccinated against pertussis.

To investigate whether and in which proportion normal individuals experience a priming to microbial heat shock proteins (hsp), the presence of antibodies to two mycobacterial hsp was tested in serum sample from 2- to 4-mo-old children before and at different times after vaccination with the trivalent vaccine against tetanus, diphtheria, and pertussis (DTP). We show that 88.9% of infants vaccinated with DTP developed antibody responses to mycobacterial hsp.

Facial skeletal augmentation using hydroxyapatite cement.

This study investigates the use of a new calcium phosphate cement, which sets to solid, microporous hydroxyapatite, for facial bone augmentation. In six dogs, the supraorbital ridges were augmented bilaterally with this hydroxyapatite cement. On one side, the hydroxyapatite cement was placed directly onto the bone within a subperiosteal pocket.

Experimental tracheal replacement using a revascularized jejunal autograft with an implantable Dacron mesh tube.

Defects comprising more than 50% of the trachea cannot be reliably reconstructed by any current technique or prosthesis. A composite tracheal replacement implant consisting of a Dacron-urethane mesh tube and revascularized jejunal autograft was applied to this problem. This composite implant was used to replace 7 to 10 cm of trachea in eight dogs.

Experimental hydroxyapatite cement cranioplasty.

Hydroxyapatite cement is a calcium phosphate-based material that when mixed with water forms a dense paste that sets within 15 minutes and isothermically converts in vivo to a microporous hydroxyapatite implant. This cement was used to reconstruct bilateral 2.5-cm-diameter full-thickness critical-sized parietal skull defects in six cats.

The pectoralis major myofascial flap for intraoral and pharyngeal reconstruction.

The pectoralis myocutaneous flap has been widely used for reconstruction of oral cavity and pharyngeal defects. However, it has several disadvantages, such as chest distortion, hair growth at the reconstructed site, and excessive bulk, all of which can be avoided by the use of the pectoralis myofascial flap. Oral cavities and pharyngeal defects, ranging in size from 4 to 9 cm in largest' dimension, in 26 patients were reconstructed with the pectoralis myofascial flap.

Ventilatory effects of subarachnoid fentanyl in the elderly.

Twenty-eight elderly patients scheduled for urological surgery were randomly assigned to receive, in a double-blind study, subarachnoid hyperbaric bupivacaine 15 mg with 50 micrograms (group A, n = 7), 25 micrograms (group B, n = 7), or 12.5 micrograms (group C, n = 7) of fentanyl or 1 ml of saline (group D, n = 7) in a total volume of 4 ml. The pattern of breathing and the ventilatory response to CO2 were studied before and 90, 150 and 480 min after the subarachnoid injection.

Mycobacterial heat-shock proteins as carrier molecules. II: The use of the 70-kDa mycobacterial heat-shock protein as carrier for conjugated vaccines can circumvent the need for adjuvants and Bacillus Calmette Guérin priming.

In a recent work, we have shown that mycobacterial heat-shock proteins (hsp) of 65-kDa (GroEL-type) and 70-kDa (DnaK-type) acted as carrier molecules in mice, previously primed with Mycobacterium tuberculosis var. bovis (bacillus Calmette-Guérin, BCG), for the induction of high and long-lasting titers of IgG against the repetitive malaria synthetic peptide (NANP)40. Anti-peptide antibodies were induced when the malaria peptide, conjugated to the mycobacterial hsp, was given in the absence of any adjuvants (Lussow et al.

Development and phase 1 clinical testing of a conjugate vaccine against meningococcus A and C.

A conjugate vaccine against meningococcus A and C was prepared using the non-toxic mutant of diphtheria toxin CRM 197 as a carrier protein. Capsular polysaccharides of Neisseria meningitidis group A and C were hydrolysed and the resulting oligosaccharides were then coupled to CRM 197 in order to obtain conjugates with a carbohydrate content of 25-30%. The final vaccine that contained 11 micrograms of each oligosaccharide and 88 micrograms of CRM 197 was used to immunize mice and rabbits.

Immunity to Haemophilus influenzae type b on sample population from central Italy.

A study on natural immunity to Haemophilus influenzae type b (Hib) was carried out in the province of Siena on 474 subjects ranging in age from 3 days to 70 years. The titration of antibody to capsular polysaccharide (PRP) was performed by the radioantigen-binding assay (RABA) method. A total of 66.

Distraction osteogenesis. Applications for mandibular regrowth.

One experimental surgical technique of bone replacement demonstrates the greatest potential for clinical applicability in the near future: the regrowth of bone by distraction (stretching). Distraction osteogenesis defines the technique of growing new bone by stretching existing bones. Although this technique does not represent the ultimate method of mandibular reconstruction, it shows sufficient promise that its eventual use for specific types of mandibular defects probably will occur in the near future.

Propofol and thiopentone for caesarean section revisited: maternal effects and neonatal outcome.

In 56 women undergoing elective caesarean section, general anaesthesia was induced with either propofol 1% or thiopentone 2.5% followed by 50% nitrous oxide in oxygen and isoflurane 0.75% until delivery.

Ruptured petrous carotid aneurysm presenting with otorrhagia and epistaxis.

Aneurysm formation and rupture within the petrous internal carotid artery (ICA) is an extremely rare occurrence with approximately 10 such cases in the literature. Etiologies of petrous ICA aneurysms include atherosclerosis, closed head trauma, iatrogenic injury during mastoid surgery, chronic middle ear infections, and congenital causes. Therapeutic options include carotid artery ligation, aneurysm resection with or without reconstruction, and radiographically controlled vessel occlusion.

Hydroxyapatite cement. II. Obliteration and reconstruction of the cat frontal sinus.

Frontal sinus obliteration and reconstruction can be performed with autogenous grafts or synthetic implants, each of which has significant limitations. Hydroxyapatite cement, which can be shaped intraoperatively and sets to a microporous hydroxyapatite implant, was applied to this problem. Nine cats had the anterior table of their frontal sinus unilaterally removed and the sinus cavity stripped of its mucosa.