Evidence that Wra and Wrb are antithetical

Studies on 24 Wr(a+b+) and 23 Wr(a-b+) blood samples, using anti-Wrb in the enzyme-linked antiglobulin test (ELAT), have shown that Wr(a+b+) red cells bind, on average, a little over half the amount of anti-Wrb bound by Wr(a-b+) red cells. Similarly, ELAT studies using six different anti-Wra and 10 Wr(a+b+) samples, as well as red cells from the original Wr(a+b-) proposita, have shown that Wr(a+b+) red cells bind about half the amount of anti-Wra bound by Wr(a+b-) red cells. Various pitfalls that can arise when the ELAT is used to measure antigen ratios on red cells have been avoided but are described. This conclusive evidence that Wra and Wrb have an antithetical relationship is discussed in light of the knowledge that a ficin-resistant portion of MN sialoglycoprotein (SGP), when carried in liposomes, can inhibit anti-Wrb. It is possible that Wra, Wrb, or both may encode a post-translational change in MN SGP, or production of transferases that glycosylate membrane lipids that affect in situ orientation of MN SGP, or production of protein band 3 that then forms a complex with MN SGP at the red cell membrane surface.     

Yersinia-related Arthritis in the United Kingdom. A Report of 12 Cases and review of the Literature

Reactive arthritis following infection with Yersinia is endemicin Scandanavian countries; the prevalence is low in the UK,however. We have reviewed the literature pertaining to Yersinia-relatedreactive arthritis in the UK and describe 12 patients who presentedover a 3-year period with an asymmetrical seronegative polyarthropathyand serological evidence of recent Yersinia infection. Fivepatients recalled having a diarrhoeal illness prior to the onsetof the arthropathy. None had a prior history of psoriasis, inflammatorybowel disease or ankylosing spondylitis. A history of urethraldischarge was elicited from one patient. Extra-articular manifestationswere seen in three patients (iritis in two, erythema nodosumin another). Four patients developed chronic joint disease afterperiods of 4, 6, 8, and 18 months, respectively. The prevalenceof Yersinia-related arthritis in the UK may be higher than previouslythought.     

Guidelines for the laboratory diagnosis and susceptibility testing of methicillin-resistant Staphylococcus aureus (MRSA)

These evidence-based guidelines have been produced after a literature review of the laboratory diagnosis and susceptibility testing of methicillin-resistant Staphylococcus aureus (MRSA). We have considered the detection of MRSA in screening samples and the detection of reduced susceptibility to glycopeptides in S. aureus. Recommendations are given for the identification of S. aureus and for suitable methods of susceptibility testing and screening for MRSA and for S. aureus with reduced susceptibility to glycopeptides. These guidelines indicate what tests should be used but not when the tests are applicable, as aspects of this are dealt with in guidelines on control of MRSA. There are currently several developments in screening media and molecular methods. It is likely that some of our recommendations will require modification as the new methods become available.     

Change in neoadjuvant chemotherapy could alter the prognosis of patients with pancreatic adenocarcinoma: A case report

BACKGROUNDNeoadjuvant treatment has become a standard of care for borderline or locally advanced pancreatic cancer and is increasingly considered even for up-front resectable disease. The aim of this article is to present the case of a 62-year-old patient with locally advanced pancreatic adenocarcinoma who was successfully treated with gemcitabine plus nab-paclitaxel after the failure of the first line treatment.CASE SUMMARYComputerized tomography scan and magnetic resonance imaging demonstrated a nodular lesion of ill-defined limits in the body of the pancreas, measuring approximately 4.2 cm × 2.7 cm, with an infiltrative aspect. The tumor had contact with the superior mesenteric vein, splenomesenteric junction and the proximal segment of the splenic artery, causing focal reduction of its lumens. Due to vascular involvement, neoadjuvant chemotherapy treatment with eight cycles of “folinic acid, 5-fluorouracil, irinotecan and oxaliplatine” (FOLFIRINOX) were performed. At the end of the cycles, surgery was performed, but the procedure was interrupted due to finding of lesions suspected of metastasis. Gemcitabine plus nab-paclitaxel was then successfully used for neoadjuvant treatment with subsequent R0 surgical resection.CONCLUSIONGemcitabine plus nab-paclitaxel may be effective as an alternative regimen when FOLFIRINOX fails as the first line of treatment, suggesting the need for further studies to identify which patients would benefit from each type of therapeutic approach.     

In vitro activities of penciclovir and acyclovir against herpes simplex virus types 1 and 2.

Penciclovir (PCV) and acyclovir are acyclic guanine analogs which inhibit herpes simplex virus (HSV) DNA polymerase. Their 50% infective doses were 0.5 to 0.8 microgram/ml for clinical isolates of HSV-1 and 1.3 to 2.2 micrograms/ml for HSV-2. Furthermore, HSV-infected cultures receiving 2-h pulses of PCV had 2- to 50-fold less HSV than acyclovir-treated cultures, consistent with the prolonged intracellular half-life of PCV triphosphate.     

Heterogeneity of anti-U demonstrable by the use of papain-treated red cells

When red cells (RBCs) are treated with papain, one form of the U antigen, which we have named UPS (U papain-sensitive), is almost completely removed or denatured. A second form, UPR (U papain-resistant), remains unaltered on the treated RBCs. Tests on 42 examples of anti-U showed that two contained only anti-UPS, 19 contained only -UPR, and 21 contained separable -UPS and -UPR. In those sera containing both antibodies, anti-UPR was always the stronger of the two. These findings suggest 1) that UPS is located on the Ss sialoglycoprotein (glycophorin B) at a position distal to a papain-sensitive site or that the cleavage point is within the portion of the SGP that comprises UPS, and 2) that UPR is located between the papain-sensitive site and the RBC membrane. The UPS determinant was not denatured by neuraminidase, L-cysteine, trypsin, ficin, or alpha-chymotrypsin, and it was only partially denatured by pronase. The finding that RBCs treated with para-chloromercuribenzoic acid or para-chloromercuriphenyl sulfonic acid did not react with anti-UPR but did continue to react with anti-UPS suggests that the in situ configuration of UPR, but not UPS, is dependent on the presence of one or more disulfide bonds. RBCs of the S-s-U+(weak) phenotype were shown to carry markedly reduced amounts of both UPS and UPR.     

Detection of antibodies to Trypanosoma cruzi among blood donors in the southwestern and western United States. II. Evaluation of a supplemental enzyme immunoassay and radioimmunoprecipitation assay for confirmation of seroreactivity

BACKGROUND: Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, is endemic to Latin America and may be transmitted in the United States via blood donated by infected immigrants. Blood- borne pathogens such as T. cruzi require supplemental testing for confirmation of seroreactivity. STUDY DESIGN AND METHODS: A study was undertaken to determine an optimal scheme for confirmation of seroreactivity in repeatedly reactive samples identified by the Chagas antibody enzyme immunoassay (EIA). The procedure for initial confirmation involves three purified antigens coated onto three separate polystyrene beads and uses an EIA format. If the sample is reactive with two of three or three of three antigens, it is confirmed as seroreactive. If none or one of three beads is reactive, the sample is indeterminate and subjected to a radioimmunoprecipitation assay (RIPA). The RIPA must demonstrate characteristic bands at 32, 34, and 90 kDa. RESULTS: When tested with sera from persons with potentially cross-reactive diseases (n = 39) or against a presumed negative population from southeast Wisconsin (n = 289), the confirmatory EIA had a specificity of 100 percent. Sensitivity was 100 percent (28/28) with xenodiagnosis-positive sera and 97.6 percent (80/82) with chagasic sera from Latin America. The RIPA showed a specificity of 100 percent in EIA- nonreactive samples (n = 100) and a sensitivity of 100 percent with both xenodiagnosis-positive (28/28) and chagasic (82/82) sera. CONCLUSION: The confirmatory EIA and the RIPA together provide a highly specific and sensitive means of confirming seroreactivity for antibodies to T. cruzi.     

Linking Dissolution to Disintegration in Immediate Release Tablets Using Image Analysis and a Population Balance Modelling Approach

Purpose  

In order to achieve an improved understanding of disintegration and dissolution phenomena for an immediate release tablet formulation, a technique to monitor the number and size of particles entrained within the dissolution media was developed in combination with a population balancing model.