Comparison of VivaSight double‐lumen tube with a conventional double‐lumen tube in adult patients undergoing video‐assisted thoracoscopic surgery

The efficiency of a double‐lumen tube depends on its position in the airways, which can be verified by fibreoptic bronchoscopy. The VivaSight DL is a single‐use double‐lumen tube with a camera embedded in the tube's right side. The view from the camera appears continuously on a monitor. In this prospective study of 71 adult patients, we compared intubation times using either the VivaSight DL or a conventional double‐lumen tube. Median (IQR [range]) duration of intubation with visual confirmation of tube position was significantly reduced using the VivaSight DL compared with the conventional double‐lumen tube (51 (42–60 [35–118]) s vs 264 (233–325 [160–490]) s, respectively, p < 0.0001). None of the patients allocated to the VivaSight DL required fibreoptic bronchoscopy during intubation or surgery. The VivaSight DL enables significantly more rapid intubation compared with the conventional double‐lumen tube.     

An alternative extrinsic pathway of human blood coagulation

To study the interrelationships of the major human coagulation pathways, factor X activation in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin were added to plasma samples containing 3H-labeled factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin the rate of factor X activation in factor VIII or factor IX deficient plasma was only 10% of the activation rate seen for normal or factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, restored normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these experiments, it is inferred that normal activation of factor X in plasma due to dilute thromboplastin requires factors VII, IX and VIII. An alternative extrinsic pathway that involves factors VII, IX, and VIII may be a major physiologic extrinsic pathway, and this pathway may help to explain the clinical observations of bleeding diatheses in patients deficient in factors IX or VIII.     

Cyp7b, a novel brain cytochrome P450, catalyzes the synthesis of neurosteroids 7α-hydroxy dehydroepiandrosterone and 7α-hydroxy pregnenolone

Steroids produced locally in brain (neurosteroids), including dehydroepiandrosterone (DHEA), influence cognition and behavior. We previously described a novel cytochrome P450, Cyp7b, strongly expressed in rat and mouse brain, particularly in hippocampus. Cyp7b is most similar to steroidogenic P450s and potentially could play a role in neurosteroid metabolism. To examine the catalytic activity of the enzyme mouse Cyp7b cDNA was introduced into a vaccinia virus vector. Extracts from cells infected with the recombinant showed NADPH-dependent conversion of DHEA (K_m, 13.6 μM) and pregnenolone (K_m, 4.0 μM) to slower migrating forms on thin layer chromatography. The expressed enzyme was less active against 25-hydroxycholesterol, 17β-estradiol and 5α-androstane-3β,17β-diol, with low to undetectable activity against progesterone, corticosterone, and testosterone. On gas chromatography and mass spectrometry of the Cyp7b metabolite of DHEA the retention time and fragmentation patterns were identical to those obtained with authentic 7α-hydroxy DHEA. The reaction product also comigrated on thin layer chromatography with 7α-hydroxy DHEA but not with 7β-hydroxy DHEA; when [7α-³H]pregnenolone was incubated with Cyp7b extracts the extent of release of radioactivity into the medium suggested that hydroxylation was preferentially at the 7α position. Brain extracts also efficiently liberated tritium from [7α-³H]pregnenolone and converted DHEA to a product with a chromatographic mobility indistinguishable from 7α-hydroxy DHEA. We conclude that Cyp7b is a 7α-hydroxylase participating in the synthesis, in brain, of neurosteroids 7α-hydroxy DHEA, and 7α-hydroxy pregnenolone.     

Minor histocompatibility antigens HA-1-, -2-, and -4-, and HY-specific cytotoxic T-cell clones inhibit human hematopoietic progenitor cell growth by a mechanism that is dependent on direct cell-cell contact

HLA-identical bone marrow transplantation (BMT) may be complicated by graft-versus-host disease or graft rejection. Both complications are thought to be initiated by recognition of minor histocompatibility (mH) antigens by HLA-restricted mH-antigen-specific T lymphocytes. Using HLA- A2-restricted mH antigens HA-1-, -2-, and -4-, and HY-specific cytotoxic T lymphocyte (CTL) clones, we studied the recognition by these CTL clones of interleukin-2 (IL-2)-stimulated T cells (IL-2 blasts), BM mononuclear cells (BMMNCs), and hematopoietic progenitor cells (HPCs). We showed that, when IL-2 blasts from the BM donors who were investigated were recognized by the HA-1-, -2-, and -4-, and HY- specific CTL clones, their BMMNCs and HPCs were recognized as well by these CTL clones, resulting in antigen-specific growth inhibition of erythrocyte burst-forming units (BFU-E), colony-forming units- granulocyte (CFU-G), and CFU-macrophage (CFU-M). the HA-2-specific CTL clone, however, inhibited BFU-E and CFU-G growth from four donors to a lesser extent than from two other donors. We further investigated whether inhibitory cytokines released into the culture medium by the antigen-specific stimulated CTLs or by stimulated BMMNCs were responsible for suppression of HPC growth or whether this effect was caused by direct cell-cell contact between CTLs and HPCs. HPC growth inhibition was only observed after preincubation of BMMNCs and CTLs together for 4 hours before plating the cells in semisolid HPC culture medium. When no cell-cell contact was permitted before plating, neither antigen-stimulated CTL nor antigen-nonstimulated CTLs provoked HPC growth inhibition. Culturing BMMNCs in the presence of supernatants harvested after incubation of BMMNCs and CTL clones together for 4 or 72 hours did also not result in HPC growth inhibition. Both suppression of HPC growth and lysis of IL-2 blasts and BMMNCs in the 51Cr-release assay appeared to be dependent on direct cell-cell contact between target cells and CTLs and were not caused by the release of inhibitory cytokines into the culture medium by antigen-specific stimulated CTLs or by stimulated BMMNCs. Our results show that mH-antigen-specific CTLs can inhibit HPC growth by a direct cytolytic effect and may therefore be responsible for BM graft rejection after HLA-identical BMT.     

A description of manual wheelchair skills training curriculum in entry-to-practice occupational and physical therapy programs in Canada

Purpose: To describe the curriculum for manual wheelchair (MWC) skills training in entry-to-practice occupational (OT) and physical therapy (PT) programs in Canada. Methods: An online survey was sent to 28 directors of entry-to-practice OT and PT programs in Canadian universities. Responses were solicited from individuals who could report about wheelchair skills training. Fourteen survey questions asked about: (1) demographic information, (2) specific curriculum content for MWC skills training, (3) teaching methods used, (4) instructional methods and estimated time used to teach MWC skills and (5) whether validated wheelchair skills training programs were used in curriculum development. Results: Responses received from 21/28 programs, (OT-11/14; PT-10/14). About 16 of 21 programs included curriculum for MWC skills training. Informal hands-on instruction was the most common method used for teaching wheelchair skills (13/21), while multiple lectures were used the least (5/21). Only 8/21 used a validated wheelchair skills training program in curriculum development. Conclusion: Despite the public availability of a validated wheelchair skills program, there is little use of the program in entry-to-practice curriculum. Integrating online training programs into existing curricula or the development of post-professional training modules may help clinicians to better accommodate the mobility needs of the substantially increasing population with disabilities.

• Implications for Rehabilitation

• Current clinical curriculum includes basic wheelchair skills training, but not necessarily training in the advanced wheelchair skills that are needed for optimal wheelchair mobility.

• There is evidence for a standardized approach for providing wheelchair skills training, that may be administered through curriculum, online or through post-graduate training modules.

     

The effect of hospital infection control policy on the prevalence of surgical site infection in a tertiary hospital in South-South Nigeria

Background:

Surgical site infections (SSIs) are a significant cause of morbidity, emotional stress and financial cost to the affected patients and health care institutions; and infection control policy has been shown to reduce the burden of SSIs in several health care institutions. This study assessed the effects of the implementation of the policy on the prevalence of SSI in the University of Port Harcourt Teaching Hospital, Nigeria.

Patients and Methods:

A review of the records of all Caesarean sections carried out in the hospital, before and 2 years after the implementation of the infection control policy was conducted. Data collected include the number and characteristics of the patients that had Caesarean section in the hospital during the period and those that developed SSI while on admission.

Results:

The proportion of patients with SSI decreased from 13.33% to 10.34%, 2 years after the implementation of the policy (P-value = 0.18). The implementation of the policy did not also result in any statistically significant change in the nature of the wound infection (P-value = 0.230), in the schedule of the operations (P-value = 0.93) and in the other predisposing factors of the infections (P-value = 0.72); except for the significant decrease in the infection rate among the un-booked patients (P-value = 0.032).

Conclusion:

The implementation of the policy led to a small decrease in SSI, due to the non-implementation of some important aspects of the WHO policy. The introduction of surveillance activities, continuous practice reinforcing communications and environmental sanitation are recommended to further decrease the prevalence of SSI in the hospital.     

Activated protein C resistance: molecular mechanisms based on studies using purified Gln506-factor V

Gln506-factor V (FV) was purified from plasma of an individual homozygous for an Arg506Gln mutation in FV that is associated with activated protein C (APC) resistance. Purified Gln506-FV, as well as Gln506-FVa generated by either thrombin or FXa, conveyed APC resistance to FV-deficient plasma in coagulation assays. Clotting assay studies also suggested that APC resistance does not involve any abnormality in FV-APC-cofactor activity. In purified reaction mixtures, Gln506-FVa in comparison to normal FVa showed reduced susceptibility to APC, because it was inactivated approximately 10-fold slower than normal Arg506-FVa. It was previously reported that inactivation of normal FVa by APC involves an initial cleavage at Arg506 followed by phospholipid- dependent cleavage at Arg306. Immunoblot and amino acid sequence analyses showed that the 102-kD heavy chain of Gln506-FVa was cleaved at Arg306 during inactivation by APC in a phospholipid-dependent reaction. This reduced but measurable susceptibility of Gln506-FVa to APC inactivation may help explain why APC resistance is a mild risk factor for thrombosis because APC can inactivate both normal FVa and variant Gln506-FVa. In summary, this study shows that purified Gln506- FV can account for APC resistance of plasma because Gln506-FVa, whether generated by thrombin or FXa, is relatively resistant to APC.     

Unusual chest pain syndromes caused by implanted cardiac device leads: a case series

Chest pain can occur after cardiac device lead placement through various mechanisms. Commonly, this is secondary to perforation. We present four cases of unusual chest pain syndromes secondary to device leads with normal function and position without evidence of typical complications. The possible etiologies and management considerations for these cases are discussed.