Tailoring the synthesis of tantalum-based thin films for biomedical application: Characterization and biological response.

The aim of this study was to tailor the deposition parameters of magnetron sputtering to synthetize tantalum oxide (TaxOy) films onto commercially pure titanium (cpTi) surface. The structural and optical properties, morphology, roughness, elemental chemical composition and surface energy were assessed. The impact of TaxOy films on initial Streptococcus sanguinis adhesion was investigated. The morphology and spreading of pre-osteoblastic (MC3T3-E1) cells on a crystalline tantalum oxide film were evaluated. TaxOy films with estimated thickness of 600 nm and different structures (amorphous or crystalline) were produced depending on the various oxygen flow rates and parameters used. X-ray diffraction analysis revealed that the 8 O2 sccm (600 °C/400 W) group showed crystallization corresponding to the ß-Ta2O5 phase. Optical analysis showed that the 4 O2 sccm (200 °C 300 W) to 8 O2 sccm (600 °C 300 W) groups and 10 O2 sccm (200 °C 300 W) group presented regular and large-amplitude interference oscillations, suggesting high optical homogeneity of the films. The crystalline ß-Ta2O5 coating showed higher roughness and surface energy values than the other groups (P < .05) and was biocompatible. Compared with cpTi, the amorphous and crystalline tantalum oxide films did not increase bacterial adhesion (P > .05). By tailoring the deposition parameters, we synthetized a crystalline ß-Ta2O5 coating that improved titanium surface properties and positively affected cell spreading and morphology, making it a promising surface treatment for titanium-based implants.

Minimally invasive surgery in trauma: technology looking for an application.

BACKGROUND: Minimally invasive surgery has achieved pre-eminence for certain operations in general surgery over the last two decades, as the reduction in surgical insult has produced faster recovery with enhanced patient satisfaction and favourable health economics. Minimally invasive techniques have been less enthusiastically adopted by the trauma surgical community, despite some evidence of efficacy for nearly 40 years. METHODS: The literature on minimally invasive techniques in trauma was reviewed. RESULTS AND CONCLUSIONS: To date, minimally invasive surgery has played only a small role in trauma surgery. As clearer indications emerge and technology improves, surgeons should be encouraged to incorporate laparoscopy and video-assisted thoracoscopy (VATS) into their protocols and gain familiarity and expertise with their use.

Appendico-cutaneous fistula in cystic fibrosis.

Appendico-cutaneous fistulae are rare. We describe a 12-year-old girl with cystic fibrosis (CF) and a chronically draining sinus in the right iliac fossa, found to be a primary appendico-cutaneous fistula. Misdiagnosis of right iliac fossa pain in patients with CF and the preponderance of complicated disease frequently lead to manifestations of appendicitis rarely seen in usual clinical practice.

Intubated, ventilating patients with complete tracheal transection: a diagnostic challenge.

Tracheal transection is a rare injury after blunt trauma. The presence of complete tracheal transection in the intubated, ventilating patient is even more rare and constitutes a major diagnostic challenge. The liberal use of computed tomography (CT) scans as an adjunct to endoscopy is paramount.

Dispositional pessimism predicts delayed return to normal activities after inguinal hernia operation.

BACKGROUND: The traditional outcome measure to assess effectiveness of inguinal hernia operation was recurrence. Open mesh repair has reduced recurrence rates and attention is now turning to outcomes other than recurrence. The factors influencing the large variation in reported times of resumption of normal activities after inguinal hernia repair are many and diverse. The human factors influencing resumption of normal activity are rarely reported. METHODS: We undertook a prospective study of 206 patients undergoing primary inguinal hernia repair in an ambulatory setting in a public hospital to ascertain whether dispositional outlook on life affected resumption of normal activity after hernia repair. Outlook on life was assessed using the life orientation test. An independent observer assessed the patients preoperatively and determined timing of resumption of normal activities. RESULTS: Regression analysis showed a highly significant relationship between delayed return to normal activity and dispositional pessimism (P =.0004). DISCUSSION: Dispositional pessimism correlates strongly with delayed return to normal activities. Further studies of this kind will help to elucidate the human factors that affect recovery after operation. Studies which use return to normal activities as a measure of the outcome of a surgical technique should include an assessment of the patient's preoperative outlook on life. Surgeons should consider the personality of the patient presenting for groin hernia repair and may wish to tailor their counseling accordingly.

The malignant epidemic--changing patterns of trauma.

OBJECTIVES AND SETTING: The worldwide burden of trauma is increasing, but is unequally distributed between nations. Trauma in South Africa targets the young and productive in society and imposes a major burden on the health infrastructure. We undertook a review of injury trends among patients attending the Johannesburg Hospital Trauma Unit (JHTU) and the Johannesburg Medicolegal Laboratory (JMLL) in order to document the evolution in patterns of trauma over a 17-year period of great social and political change. DESIGN, SUBJECTS AND OUTCOME MEASURES: This was a retrospective review of all priority-one patients attending the JHTU from January 1985 to December 2001. The JHTU trauma database was used to retrieve information on patient demographics, wound mechanism and injury severity. The database at the JMLL, maintained since 1996, was examined and the manner and place of death were analysed. RESULTS: The JHTU has seen an unprecedented increase in the number of trauma patients over the last 17 years. The patients' demographic profiles have altered and injury is now predominantly due to interpersonal violence. Unnatural deaths examined at the JMLL have declined by 19% since 1996; however, the proportion of those deaths due to gunshot wounds has risen. CONCLUSIONS: The social and political changes in South Africa in recent years have led to changes in the injury profiles seen at the JHTU. Part of the increase can be explained by desegregation and a reduction in the provision of local hospital services; however, the impact of urbanisation within South Africa, cross-border migration and the high incidence of substance abuse are recognised. Evidence supports the implementation of legislative, environmental, social and behavioural interventions to contain and reduce the incidence and impact of violence and injury. Concerted efforts must be made at all levels to curb South Africa's trauma epidemic.

Penetrating vascular trauma in Johannesburg, South Africa.

An awareness that time crucially affects outcome underpins the principles of management of vascular injury. Patients with hard signs of vascular injury should undergo urgent exploration. Soft signs mandate investigation, and arteriography is still the standard of care. Noninvasive vascular imaging may prove its worth in the future. All patients with penetrating arterial injury should receive broad-spectrum antibiotic prophylaxis. Early repair of carotid artery injury provides the best likelihood of a neurologically intact survivor. There is a definite and emerging role of endovascular therapy both for difficult access injuries and for the later complications of vascular injury, such as false aneurysm and arteriovenous fistulas. The experimental and clinical evidence for the use of intraluminal shunts in peripheral vascular injury is compelling, and experience in their use is accumulating. Vascular trauma is complex and ideally is carried out by experts in a multidisciplinary environment; resuscitation and prompt revascularization are likely to lead to satisfactory outcomes. The major trauma load in South Africa represents an unparalleled experience in management of vascular injury, which seems likely to continue for the foreseeable future.

Off-pump cardiac revascularization after a complex stab wound.

Penetrating cardiac injuries are among the most dramatic and lethal of all injuries. High survival rates in selected reports have given the erroneous impression that the lethality of cardiac injuries has diminished in recent years. In a review of 1,198 cases of penetrating cardiac trauma from South Africa, only 6% of patients arrived at hospital alive. Many patients with proximal coronary artery injuries present without signs of life. Cardiopulmonary bypass is advocated as a means of salvage, but mortality rates are high. We present a case of arterial revascularization using off-pump technology.

Biogenesis of porin of the outer mitochondrial membrane involves an import pathway via receptors and the general import pore of the TOM complex.

Porin, also termed the voltage-dependent anion channel, is the most abundant protein of the mitochondrial outer membrane. The process of import and assembly of the protein is known to be dependent on the surface receptor Tom20, but the requirement for other mitochondrial proteins remains controversial. We have used mitochondria from Neurospora crassa and Saccharomyces cerevisiae to analyze the import pathway of porin. Import of porin into isolated mitochondria in which the outer membrane has been opened is inhibited despite similar levels of Tom20 as in intact mitochondria. A matrix-destined precursor and the porin precursor compete for the same translocation sites in both normal mitochondria and mitochondria whose surface receptors have been removed, suggesting that both precursors utilize the general import pore. Using an assay established to monitor the assembly of in vitro-imported porin into preexisting porin complexes we have shown that besides Tom20, the biogenesis of porin depends on the central receptor Tom22, as well as Tom5 and Tom7 of the general import pore complex (translocase of the outer mitochondrial membrane [TOM] core complex). The characterization of two new mutant alleles of the essential pore protein Tom40 demonstrates that the import of porin also requires a functional Tom40. Moreover, the porin precursor can be cross-linked to Tom20, Tom22, and Tom40 on its import pathway. We conclude that import of porin does not proceed through the action of Tom20 alone, but requires an intact outer membrane and involves at least four more subunits of the TOM machinery, including the general import pore.

ASC1/RAS2 suppresses the growth defect on glycerol caused by the atp1-2 mutation in the yeast Saccharomyces cerevisiae.

To better define the regulatory role of the F(1)-ATPase alpha-subunit in the catalytic cycle of the ATP synthase complex, we isolated suppressors of mutations occurring in ATP1, the gene for the alpha-subunit in Saccharomyces cerevisiae. First, two atp1 mutations (atp1-1 and atp1-2) were characterized that prevent the growth of yeast on non-fermentable carbon sources. Both mutants contained full-length F(1)alpha-subunit proteins in mitochondria, but in lower amounts than that in the parental strain. Both mutants exhibited barely measurable F(1)-ATPase activity. The primary mutations in atp1-1 and atp1-2 were identified as Thr(383) --> Ile and Gly(291) --> Asp, respectively. From recent structural data, position 383 lies within the catalytic site. Position 291 is located near the region affecting subunit-subunit interaction with the F(1)beta-subunit. An unlinked suppressor gene, ASC1 (alpha-subunit complementing) of the atp1-2 mutation (Gly(291) --> Asp) restored the growth defect phenotype on glycerol, but did not suppress either atp1-1 or the deletion mutant Deltaatp1. Sequence analysis revealed that ASC1 was allelic with RAS2, a G-protein growth regulator. The introduction of ASC1/RAS2 into the atp1-2 mutant increased the F(1)-ATPase enzyme activity in this mutant when the transformant was grown on glycerol. The possible mechanisms of ASC1/RAS2 suppression of atp1-2 are discussed; we suggest that RAS2 is part of the regulatory circuit involved in the control of F(1)-ATPase subunit levels in mitochondria.

Molecular interactions of cancer and age.

The authors believe that the aging process--the loss of youthful resilience--is caused by the decline of many hormones. By restoring these hormone levels, the decay associated with old age can be eliminated and in some cases, perhaps reversed. The hormones that naturally occur in the body should be replenished through a medically sound regimen. The hormones must work together. The data indicate that aging occurs at two levels: systemically and cellularly. Systemic controls regulate the rates of intracellular enzymatic processes that accelerate to protect against aging.