Pretransplant Exposure to Donor HLA-DR Antigen in Random Transfusion Units and the Development of Donor Antigen-Specific Hyporeactivity

Our previous studies have shown that the in vitro assay of donor antigen-specific hyporeactivity is a useful marker for identifying solid organ transplant recipients (kidney, lung and heart) at low risk for immunologic complications (i.e., late acute rejection episodes and chronic rejection). Donor antigen-specific hyporeactivity is defined as a significantly decreased post- vs. pretransplant proliferative response to donor antigens while response to third-party controls remains unchanged. We analyzed whether exposure to the same HLA-DR antigen pretransplant via random blood transfusion and posttransplant via the transplanted organ influenced the development of hyporeactivity. Thirty previously nontransfused recipients, each receiving two 150 ml pretransplant random blood transfusions, were assessed for hyporeactivity at 1 year posttransplant. Of the 12 recipients with pretransplant exposure to kidney HLA-DR via transfusions, 6 (50%) developed hyporesponsiveness; in contrast, of the 18 recipients who were not preexposed, only 3 (15%) exhibited this form of immunomodulation. Of interest, 2 of the 3 hyporesponsive recipients who were not preexposed, received units containing HLA-DR antigens previously shown to share crossreactive epitopes with the kidney HLA-DR. In conclusion, these results suggest a increased incidence in the development of hyporeactivity in patients receiving pretransplant transfusions which share an HLA-DR antigen with the transplanted kidney.     

Punctal occlusion and blepharoplasty in patients with dry eye syndrome

Blepharoplasty and inferior punctal occlusion were performed on 24 consecutive patients with dry eye syndrome. Fifteen patients (62.5%) had symptomatic dry eye syndrome preoperatively and nine patients (37.5%) had asymptomatic dry eye syndrome diagnosed during the preoperative workup (subclinical dry eye syndrome). After surgery, nine patients (37.5%) had improvement of their dry eye syndrome, 10 patients (42%) were unchanged, and two patients (8%) had worsening of their dry eye syndrome. A third patient had worsening of the dry eye syndrome 6 months postoperatively when her puncta reopened. Two patients (8%) had increased irritation only when wearing contact lenses, but in one patient this resolved 6 months after surgery. Thus, although a significant number are improved, a few patients will have worsening of dry eye syndrome after blepharoplasty and inferior punctal occlusion.     

What is the HACCP (hazard analysis critical control point) approach and how can it be applied to enteral tube feeding?

The HACCP (hazard analysis critical control point) concept is now widely applied in the food industry and provides a structured and critical approach to the identification and control of hazards that may affect food safety. It has shifted the emphasis for control from retrospective end-product testing to the effective control of raw materials and key processing operations.
This paper discusses how the HACCP approach can be applied to enteral feeding. This involves each unit assembling a multidisciplinary team of personnel involved in enteral feeding. This team will then carry out a detailed analysis of the process from selection of ingredients and feeding systems through to consumption of the feed by the patient by constructing a flow chart that relates specifically to each unit. They can then identify and assess the hazards associated with the handling of the product at each stage in the process. This will enable them to identify the points where control over an identified hazard can be achieved (critical control points, CCP) such as quality of ingredients, design of administration systems, preparation and distribution of the feeds and the procedures involved in the assembly and manipulation of the systems. Control and monitoring procedures can then be specified and implemented at relevant stages in the process. The major strengths of the HACCP procedure are that it entails a team effort from key personnel involved in the full range of activities associated with the product and each detailed analysis is specific to each unit's practices and resources and can be continually reviewed and modified in response to changing circumstances.     

Intra-operative support via augmented reality techniques in endoscopic surgery.

Computer assisted operation planning systems are gaining increasing recognition in the field of surgery. These systems offer new possibilities for preparing an intervention, with the goal of reducing the amount of expensive operating-room time required for the intervention. The safest and most effective surgical approach should always be selected, but it is often difficult to transfer the output of the planning system to the intra-operative situation so that the planning results can be considered during the actual intervention. At the Fraunhofer Institute for Computer Graphics (IGD) in Darmstadt and the Centre for Advanced Media Technology (CAMTech) in Singapore methods are being developed to bridge the gap between the external planning session and the intra-operative case: Augmented Reality (AR) techniques are used to overlay preoperative scanned image data, as well as results of the planning session, on the operation field.     

Supratentorial ischemic stroke: more than an upper motor neuron disorder.

The primary goal of this study was to identify secondary functional changes in the peripheral motor units of the paretic upper extremity (UE) in patients with severe ischemic stroke and to determine how these changes develop during the first weeks after stroke. An inception cohort of 27 consecutive patients with an acute ischemic supratentorial stroke and an initial UE paralysis was compared with 10 healthy control subjects. The ulnar nerve was electrically stimulated proximal to the wrist and electromyographic recordings were obtained from the abductor digiti minimi muscle. Hemiparetic side mean values of the compound muscle action potential (CMAP) 1 and 3 weeks after stroke were compared with the nonparetic side and with CMAP values obtained from healthy control subjects. The mean CMAP amplitude in patients was significantly lower on the paretic side compared with the nonparetic side and with control subjects. Decrease in CMAP amplitude was observed in more than half of the stroke patients, sometimes as early as 4 days after stroke, and persisted in most cases. Whenever present, it was accompanied by absence of motor recovery at that specific time after stroke. Decreased CMAP amplitude in the abductor digiti minimi muscle can be seen already in the very acute phases after stroke unrelated to peripheral neuropathy, radiculopathy, or plexopathy, and it is accompanied by absence of UMN recovery. This knowledge is important for interpreting electrophysiological data in stroke patients.     

Epitope analysis of the allergen ovalbumin (Gal d II) with monoclonal antibodies and patients' IgE.

Ovalbumin (OVA) is a major allergen (Gal d II) of hen egg white and is often the cause of hypersensitivity reactions to food. Further knowledge of the antigenic and allergenic epitopes of allergens will provide better treatment of this disease. To analyse these epitopes we produced a panel of monoclonal antibodies (mAbs) against native OVA. The initial information about the epitopes was obtained with the binding patterns of these mAbs in IEF-immunoprints and western blots of OVA under reducing and non-reducing conditions. It was possible to demonstrate that the different conformations of OVA exhibit different epitopes, and that there are other epitopes which are shared by each conformation. Seven different, although sometimes overlapping epitopes, could be determined on native OVA; four different epitopes on denaturated non-reduced OVA by means of immunoblots of the intact molecule. The number of epitopes which could be differentiated by the mAbs was increased by the use of peptide blots after CNBr fragmentation of the molecule. IgE binding to different OVA conformations and to CNBr-fragments of OVA was also detectable and appears in the same regions as the reactivity of some mAbs. Western blots of OVA and CNBr-peptides demonstrate that some antigenic/allergenic binding sites seem at least partly to be continuous epitopes. The identification of the CNBr-fragments was performed by a microsequence analysis of blotted CNBr-fragments after a 2-dimensional electrophoresis. IgE was found to bind the two largest CNBr-fragments (residues 41-172 and 301-385), but not the fragment corresponding to residues 173-196. A number of monoclonal antibodies also reacted with the two large fragments, especially with fragment 301-385, and some bind also to shorter peptides, such as fragment 173-196, which were not reactive to patients' IgE. Most of the monoclonal antibodies and patients' IgE bind to the fragments 41-172 and 301-385 in 2D-PAGE blots suggesting that these fragments are involved in an immunogenic structure.     

A technique for safe transanal passage of the circular end-to-end stapler for low anterior anastomosis of the colon

Two techniques are currently available for the creation of low anterior rectal stapled anastomoses. The first technique requires the placement of a pursestring suture at the superior margin of the rectal cuff, which is technically difficult. In the second technique, the rectal cuff is closed with a linear stapler. The circular end-to-end stapler, with the anvil removed, is then passed through an enterotomy in the rectal remnant. We describe an easy and safe method that obviates difficulties during the transanal passage of the stapler and minimizes the risk of injury to the rectum. This method uses an inexpensive and readily available rubber catheter and metal guide.     

Interventional radiology for restoration of vascular patency in the postoperative patient--case reports

The postoperative patient may present with one or more of a variety of problems amenable to management by interventional radiologic techniques, which may be curative by themselves or may, in addition, require or allow successful surgical intervention. To optimize patient care, a good working relationship between the vascular surgeon and the interventional radiologist is essential. Consideration should be given to the patient's presenting signs and symptoms, the surgical history with its alteration of anatomy, the results of available noninvasive studies, and knowledge of various therapeutic alternatives. Vascular radiologic interventions include angioplasty, thrombolytic therapy, a combination of both angioplasty and thrombolysis, and newer techniques such as percutaneous valvectomy. In this report, examples of some of the experience at Indiana University are presented. Emphasis is placed on the appropriate approach to the patient.