Modulation of Leishmania major aquaglyceroporin activity by a mitogen-activated protein kinase

Leishmania major aquaglyceroporin (LmjAQP1) adventitiously facilitates the uptake of antimonite [Sb(III)], an active form of Pentostam® or Glucantime®, which are the first line of defence against all forms of leishmaniasis. The present paper shows that LmjAQP1 activity is modulated by the mitogen-activated protein kinase, LmjMPK2. Leishmania parasites coexpressing LmjAQP1 and LmjMPK2 show increased Sb(III) uptake and increased Sb(III) sensitivity. When subjected to a hypo-osmotic stress, these cells show faster volume recovery than cells expressing LmjAQP1 alone. LmjAQP1 is phosphorylated in vivo at Thr-197 and this phosphorylation requires LmjMPK2 activity. Lys-42 of LmjMPK2 is critical for its kinase activity. Cells expressing altered T197A LmjAQP1 or K42A LmjMPK2 showed decreased Sb(III) influx and a slower volume recovery than cells expressing wild-type proteins. Phosphorylation of LmjAQP1 led to a decrease in its turnover rate affecting LmjAQP1 activity. Although LmjAQP1 is localized to the flagellum of promastigotes, upon phosphorylation, it is relocalized to the entire surface of the parasite. Leishmania mexicana promastigotes with an MPK2 deletion showed reduced Sb(III) uptake and slower volume recovery than wild-type cells. This is the first report where a parasite aquaglyceroporin activity is post-translationally modulated by a mitogen-activated protein kinase.

Immunomodulatory effects of Lactobacillous plantarum and Helicobacter pylori CagA⁺ on the expression of selected superficial molecules on monocyte and lymphocyte and the synthesis of cytokines in whole blood culture

Helicobacter pylori (H. pylori) infections are usually superficial and clinically asymptomatic, but in approximately 10-20% cases it can be more aggressive and associated with other pathologies. The reason for weak or strong pro-inflammatory responses in gastric mucosa that occur during H. pylori infection is not understood. Combined treatment, including antibiotic therapy with administration of probiotic bacteria along, considerably improves the effectiveness of H. pylori eradication and reduces the relapse rate. Thus, the aim of this study was to analyze the effect of Lactobacillus plantarum (L. plantarum) and/or H. pylori CagA(+) on leucocytes in whole blood cultures. This study revealed how selected strains of H. pylori and L. plantarum modulate expression of chosen membrane markers of monocytes and lymphocytes, and the cytokine synthesis of in vitro cultures. The level of IFN-γ was higher in cultures stimulated with L. plantarum than in combination of this two examinated strains. We also observe the tendency to increase the level of IFN-γ by L. planatrum in relation to cells stimulated by H. pylori. In contrast, both H. pylori alone and in combination with L. plantarum had a strong modulatory effect on the synthesis of interleukin-10. Moreover lymphocytes with higher expression of CD25 and CD58 receptors was observed only in those cultures that were stimulated with L. plantarum strain alone or in combination with H. pylori. Effects exerted on the immune system, both in terms of natural and adaptive response, constitute the only functional criterion of probiotic bacteria. The immunostimulant effects documented in this study suggest that Lactobacillus spp. can restore immune function of mucosal membrane during symptomatic infection with H. pylori.

Management of proximal femoral fractures 2011: Association of Anaesthetists of Great Britain and Ireland

There should be protocol-driven, fast-track admission of patients with hip fractures through the emergency department. Patients with hip fractures require multidisciplinary care, led by orthogeriatricians. Surgery is the best analgesic for hip fractures. Surgical repair of hip fractures should occur within 48 hours of hospital admission. Surgery and anaesthesia must be undertaken by appropriately experienced surgeons and anaesthetists. There must be high-quality communication between clinicians and allied health professionals. Early mobilisation is a key part of the management of patients with hip fractures. Pre-operative management should include consideration of planning for discharge from hospital. Measures should be taken to prevent secondary falls. 10. Continuous audit and targeted research is required in order to inform and improve the management of patients with hip fracture.

Quantification of HBsAg and HBV-DNA during therapy with peginterferon alpha-2b plus lamivudine and peginterferon alpha-2b alone in a German chronic hepatitis B cohort

BACKGROUND

Peginterferon alpha-2b (PEG-IFNa2b) and lamivudine are efficient treatment options for chronic hepatitis B virus (HBV) infection. We assumed that a combination therapy of PEG-IFNα-2b plus lamivudine will be more effective than PEG-IFNα-2b alone concerning loss of HBV-DNA, HBeAg seroconversion, and HBsAg reduction.

PATIENTS AND METHODS

Patients with chronic hepatitis B were randomised to nine months treatment with PEG-IFNα-2b 1.5 µg/kg o. i. w. or PEG- IFNα-2b plus lamivudine 100 mg/d. The study was designed with 60 patients per treatment arm. The primary endpoint was defined as loss of HBV-DNA (< 400 copies/mL) 24 weeks after the end of therapy. HBV-DNA (PCR), HBsAg (Architect, Abbott), and HBeAg (Axsym, Abbott) were determined prior to and at the end of treatment as well as at follow-up. HBV-genotypes were determined by Innolipa (Innogenetics).

RESULTS

Only 32 patients were randomised to combination therapy and 27 individuals to monotherapy due to low recruitment rates. On treatment reduction of HBV-DNA was significantly higher during combination therapy compared to PEG-IFNa-2b monotherapy (- 4.60 ± 2.71 vs. - 2.41 ± 2.17 log; p = 0.003). However, there was no difference in the number of cases achieving HBV-DNA < 400 copies/mL, ALT normalisation, or HBeAg seroconversion at follow-up. None of the parameters was significantly related to HBV-genotypes. In a post-hoc analysis serum HBsAg levels were analysed as an additional prognostic parameter for treatment response (n = 29). Combination therapy showed a stronger, but not significant HBsAg decline during (- 0.7 ± 1.17 log IU/mL vs. - 0.26 ± 0.61 log IU/mL; p = 0.35) and after therapy (- 0.68 ± 1.29 log IU/mL vs. - 0.24 ± 0.56 log IU/mL; p = 0.82). Two of three cases with a 2-log HBsAg decline to HBsAg levels < 100 IU/mL eliminated HBsAg during long-term follow-up.

CONCLUSION

The study was underpowered with respect to the primary endpoint due to low recruitment rates. However, in the post-hoc analysis HBsAg decline was over two-fold stronger at the end of treatment and follow-up after combination therapy and did not rebound after lamivudine withdrawal. These results may indicate the usefulness of future combination therapies without discontinuation of nucleos(t)ide analogues.

Quality of life in patients with various liver diseases: patients with HCV show greater mental impairment, while patients with PBC have greater physical impairment

Little is known comparing and contrasting quality of life (QoL) in patients with hepatitis C, compared to patients with other liver diseases. We performed two independent prospective cross-sectional studies including 511 and 284 patients with different forms of liver diseases. SF-36 was used in both studies. Fatigue Impact Score, WHO-BREF and Hospital Anxiety and Depression Scale (HADS) were used in either study only. In both studies, HCV-positive patients scored worse in the mental aspects of health-related QoL compared to other liver diseases, except for HBV in one study. Surprisingly, in both studies, quality of life was also significantly impaired in patients with viral clearance after interferon therapy but not after spontaneous clearance. Furthermore, patients with primary biliary cirrhosis showed significantly better mental health but significantly worse physical well-being. Liver diseases differ in their form of impaired QoL. In HCV, this impairment might not always return to normal after treatment-induced viral clearance. This may suggest that HCV either may not be involved in QoL impairment or may induce a process which persists after viral clearance in some patients.

Deletion of UDP-glucose pyrophosphorylase reveals a UDP-glucose independent UDP-galactose salvage pathway in Leishmania major

The nucleotide sugar UDP-galactose (UDP-Gal) is essential for the biosynthesis of several abundant glycoconjugates forming the surface glycocalyx of the protozoan parasite Leishmania major. Current data suggest that UDP-Gal could arise de novo by epimerization of UDP-glucose (UDP-Glc) or by a salvage pathway involving phosphorylation of Gal and the action of UDP-glucose:alpha-D-galactose-1-phosphate uridylyltransferase as described by Leloir. Since both pathways require UDP-Glc, inactivation of the UDP-glucose pyrophosphorylase (UGP) catalyzing activation of glucose-1 phosphate to UDP-Glc was expected to deprive parasites of UDP-Gal required for Leishmania glycocalyx formation. Targeted deletion of the gene encoding UGP, however, only partially affected the synthesis of the Gal-rich phosphoglycans. Moreover, no alteration in the abundant Gal-containing glycoinositolphospholipids was found in the deletion mutant. Consistent with these findings, the virulence of the UGP-deficient mutant was only modestly affected. These data suggest that Leishmania elaborates a UDP-Glc independent salvage pathway for UDP-Gal biosynthesis.

LmxMPK4, an essential mitogen-activated protein kinase of Leishmania mexicana is phosphorylated and activated by the STE7-like protein kinase LmxMKK5

The essential mitogen-activated protein kinase (MAP kinase), LmxMPK4, of Leishmania mexicana is minimally active when purified following recombinant expression in Escherichia coli and was therefore unsuitable for drug screening until now. Using an E. coli protein co-expression system we identified LmxMKK5, a STE7-like protein kinase from L. mexicana, which phosphorylates and activates recombinant LmxMPK4 in vitro. LmxMKK5 is comprised of 525 amino acids and has a calculated molecular mass of 55.9kDa. The co-expressed, purified LmxMPK4 showed strong phosphotransferase activity in radiometric kinase assays and was confirmed by immunoblot and tandem mass spectrometry analyses to be phosphorylated on threonine 190 and tyrosine 192 of the typical TXY MAP kinase activation motif. The universal protein kinase inhibitor staurosporine reduced the phosphotransferase activity of co-expressed and activated LmxMPK4 in a dose-dependent manner. To our knowledge this is the first time that an in vitro activator of an essential Leishmania MAP kinase was identified and our findings form the basis for the development of drug screening assays to identify small molecule inhibitors of LmxMPK4 in the search for new therapeutic drugs against leishmaniasis.

[Angle of needle position for the epidural-perineural injection at the lumbar spine]

AIM

The aim of this study was to find the correct angle of the needle position for the epidural perineural injection at the lumbar spine without any help by imaging.

METHODS

In 11 human cadaver lumbar spines besides dura, nerve roots and bones all soft tissue had been removed to allow us to look into the anterior lateral epidural spaces between L3 and S1 in different angles with an operation microscope. The area between the dura (medial), facet joint (lateral) and the laminae (cranial and caudal) were photographed and planimetrically measured. This area is called the width of the injection canal.

RESULTS

Degenerative lumbar spines show a width of the injection canal of 29.61 mm(2) in L5/S1 with an angle of the needle position of 15 degrees to the midline. The optimal angle position of the needle brought a width of the injection canal in L4/5 only for 7.3 mm(2) and in L3/4 for 3.5 mm(2). In non-degenerative spines the injections canals were much wider.

DISCUSSION

The epidural-perineural injection into the anterolateral epidural space only makes sense in the segment L5/S1. Here the L5 nerve root is reached as well as the S1 root - the main causes of sciatica. In upper segments the injection canal is far smaller even at optimal injection angles. In case of nerve root compression at L4 and upwards other epidural injection techniques should be used such as the epidural dorsal loss of resistance technique or the transforaminal technique.

CONCLUSION

With some training it is possible to perform epidural-perineural injection for sciatica without the help of imaging.

Leishmania MAP kinases – Familiar proteins in an unusual context

Mitogen-activated protein kinases are well-known mediators of signal transduction of higher eukaryotes regulating important processes like proliferation, differentiation, stress response and apoptosis. In Leishmania, the typical three-tiered module of MAP kinase signal transduction pathways is present. However, typical activators like cell surface receptors and substrates such as RNA polymerase II transcription factors are missing. Here, I describe the set of 15 putative mitogen-activated protein kinases encoded in the Leishmania genome and discuss their potential function.

Cone beam CT and conventional tomography for the detection of morphological temporomandibular joint changes

OBJECTIVE

To compare the diagnostic accuracy of cone beam CT images with conventional tomographic images for the detection of morphological temporomandibular joint (TMJ) changes.

METHODS

80 dry human skulls were scanned using a NewTom 3G scanner and lateral and frontal reconstructions of the right and the left TMJs were performed. In addition, lateral and frontal cross-sectional tomograms of the skulls' TMJs were obtained in a Cranex Tome unit with Digora storage phosphor plates. Naked-eye inspection of the TMJs performed by three observers served as the gold standard for the true presence of morphological changes. The mandibular fossae were excluded from the study due to few changes in this joint component. The NewTom and the conventional tomographic images were examined by three independent observers using a binary scale for the presence of morphological changes in the condyle (flattening, defects and osteophytes) and the articular tubercle (flattening and defects). The accuracy for the different types of changes in relation to the condyles and the articular tubercles was expressed as sensitivity and specificity values, whereas the diagnostic accuracy for a general assessment including all changes in both joint components was expressed by the sum of cases where the gold standard and the radiographic scores were not identical (absolute difference). Differences between the two radiographic modalities were tested by paired t-test.

RESULTS

Detection of the various types of morphological changes in relation to the condyle and the articular tubercle assessed separately resulted in no significant differences between the two radiographic modalities, with the exception of bone defects in the articular tubercle examined on frontal views alone where the specificity with tomography was significantly higher than with cone beam CT. Detection of all morphological changes in relation to both the condyle and the articular tubercle showed a significantly higher accuracy with tomography than with cone beam CT using lateral views alone, but there was no significant difference between the two modalities using frontal views alone and lateral and frontal views in combination.

CONCLUSION

In general, no significant differences in diagnostic accuracy for the detection of bone changes in the condyle and in the articular tubercle were found between cone beam CT images and conventional tomograms.

Targeted gene deletion of Leishmania major UDP-galactopyranose mutase leads to attenuated virulence

Considering the high incidence of galactofuranose (Gal(f)) in pathogens and its absence from higher eukaryotes, the enzymes involved in the biosynthesis of this unusual monosaccharide appear as attractive drug targets. However, although the importance of Gal(f) in bacterial survival or pathogenesis is established, its role in eukaryotic pathogens is still undefined. Recently, we reported the identification and characterization of the first eukaryotic UDP-galactopyranose mutases. This enzyme holds a central role in Gal(f) metabolism by providing UDP-Gal(f) to all galactofuranosyltransferases. In this work, the therapeutical potential of Gal(f) metabolism in Leishmania major was hence evaluated by targeted replacement of the GLF gene encoding UDP-galactopyranose mutase. In L. major, Gal(f) is present in the membrane anchor of the lipophosphoglycan (LPG) and in glycoinositolphospholipids. Accordingly, the generated glf(-) mutant is deficient in LPG backbone and expresses truncated glycoinositolphospholipids. These structural changes do not influence the in vitro growth of the parasite but lead to an attenuation of virulence comparable with that observed with a mutant exclusively deficient in LPG.

Comparison of diagnostic accuracy of film and digital tomograms for assessment of morphological changes in the TMJ

OBJECTIVE

To compare diagnostic accuracy of tomograms obtained with film and three digital image receptor modalities for detection of morphological changes in the temporomandibular joint (TMJ).

METHODS

Lateral and frontal cross-sectional tomograms of 158 TMJs in 80 dry human skulls were obtained with four X-ray receptors: one conventional film (Agfa-Gevaert), two photostimulable phosphor (PSP) plates: VistaScan and Digora PCT and one charge-coupled device (CCD): ProMax. The film and the PSP plate tomograms were exposed in a Cranex Tome X-ray unit and the CCD tomograms in the ProMax X-ray unit. The tomograms were examined by three observers for the presence of morphological changes in the condyle, the mandibular fossa and the articular tubercle. Naked-eye inspection of the articular surfaces of the TMJs performed by the same three observers served as the gold standard for the true presence of morphological changes.

RESULTS

For examination of TMJ changes using lateral and frontal tomograms in combination and lateral tomograms separately, the ProMax modality obtained a significant lower diagnostic accuracy than the other three modalities, between which no significant differences were found. For morphological changes localized to the condyle in which the highest number of changes were present according to the gold standard, the same result was found.

CONCLUSION

The ProMax modality was significantly less accurate than the film, VistaScan and Digora PCT modalities for the detection of overall TMJ morphological bone changes as well as condylar bone changes.

[Influence of the x-ray technique on evaluation of cup anteversion after total hip arthroplasty]

AIM

Total hip arthroplasty (THA) is a standard procedure in orthopaedic surgery. Planar radiography of the implant is routinely performed to ensure that the operation has achieved the desired result. This study investigates the influence of varying the X-ray beam on the analysis of the radiograph.

METHOD

Twenty-three patients were analysed after implantation of a total hip replacement. Besides a CT scan of the pelvis, symphysis- and hip-centred radiographs were available. The cup anteversion was calculated using two published algorithms. The CT-based data were the gold standard.

RESULTS

Our study revealed a significant major error in the analysis of the symphysis-centred radiographs when compared with the hip-centered radiographs. Widmer's algorithm showed a significant superiority over Pradhan's formula.

CONCLUSION

The best approximation of the anteversion angle was achieved using Widmer's technique by centering the X-ray beam onto the hip.

Validity of HoNOS in identifying frequently hospitalized patients with ICD-10 mental disorders

OBJECTIVE

To identify frequently hospitalized patients by using the outcome and severity measure Health of the Nation Outcome Scales (HoNOS) in combination with the International Classification of Diseases (ICD)-10 in patients consecutively admitted to a psychiatric hospital.

METHOD

All full-time in-patients and all day-hospital patients were considered. Frequently hospitalized patients were defined as those with 10 or more hospitalizations.

RESULTS

The total HoNOS score at admission was found valid to discriminate between frequently and non-frequently hospitalized patients as well as in ranking the ICD-10 diagnosis by severity of symptoms and social problems. Frequently hospitalized patients were predominantly found within the diagnoses of schizophrenia and bipolar affective disorders. In these groups, high HoNOS scores were significantly associated with a longer stay in hospital. Improvement during hospitalization as measured by the HoNOS was significantly better for bipolar than for schizophrenic patients.

CONCLUSION

HoNOS was found to be a clinically relevant supplement to ICD-10 in identifying frequently hospitalized patients.

Synovial osteochondromatosis in a 9-year-old girl: clinical and histopathological appearance

This article reports the clinical and histopathological appearance of synovial osteochondromatosis in the right knee joint of a 9-year-old girl. Initial symptoms such as monoarticular joint swelling led to further diagnostic procedures with the aid of different imaging techniques including X-ray examination and MRI. The definitive diagnosis was based on histopathological findings after performing arthroscopy of the affected joint and the intraoperative appearance of the synovial lesions. Besides antiphlogistical drug-therapy, the treatment of choice is synovectomy.

Interacting protein kinases involved in the regulation of flagellar length

A striking difference of the life stages of the protozoan parasite Leishmania is a long flagellum in the insect stage promastigotes and a rudimentary organelle in the mammalian amastigotes. LmxMKK, a mitogen-activated protein (MAP) kinase kinase from Leishmania mexicana, is required for growth of a full-length flagellum. We identified LmxMPK3, a MAP kinase homologue, with a similar expression pattern as LmxMKK being not detectable in amastigotes, up-regulated during the differentiation to promastigotes, constantly expressed in promastigotes, and shut down during the differentiation to amastigotes. LmxMPK3 null mutants resemble the LmxMKK knockouts with flagella reduced to one-fifth of the wild-type length, stumpy cell bodies, and vesicles and membrane fragments in the flagellar pocket. A constitutively activated recombinant LmxMKK activates LmxMPK3 in vitro. Moreover, LmxMKK is likely to be directly involved in the phosphorylation of LmxMPK3 in vivo. Finally, LmxMPK3 is able to phosphorylate LmxMKK, indicating a possible feedback regulation. This is the first time that two interacting components of a signaling cascade have been described in the genus Leishmania. Moreover, we set the stage for the analysis of reversible phosphorylation in flagellar morphogenesis.