Localized 1H NMR spectra of glutamate in the human brain.

Localized 1H NMR spectra at TE = 12 ms were obtained from cerebral cortex of human subjects using ISIS with surface suppression. The 2.29-ppm resonance was assigned to C4 glutamate with contributions from C4 glutamine and GABA using in vivo spectral editing and comparison of chemical shift with pure compounds. The measured intensity ratio between the 2.29 resonance and the creatine resonance at 3.03 ppm was in good agreement with the ratio predicted from previously reported measurements of glutamate, glutamine, and GABA concentrations in biopsied human brain tissue.     

Identification and characterization of aquaporin-2 water channel mutations causing nephrogenic diabetes insipidus with partial vasopressin response

Congenital nephrogenic diabetes insipidus (NDI) is a rare disease caused most often by mutations in the vasopressin V2 receptor (AVPR2). We studied a family which included a female patient with NDI with symptoms dating from infancy. The patient responded to large doses of desmopressin (dDAVP) which decreased urine volume from 10 to 4 I/day. Neither the parents nor the three sisters were polyuric. The patient was found to be a compound heterozygote for two novel recessive point mutations in the aquaporin-2 (AQP2) gene: L22V in exon 1 and C181W in exon 3. Residue Cys181 in AQP2 is the site for inhibition of water permeation by mercurial compounds and is located near to the NPA motif conserved in all aquaporins. Osmotic water permeability (Pf) in Xenopus oocytes injected with cRNA encoding C181W-AQP2 was not increased over water control, while expression of L22V cRNA increased the Pf to approximately 60% of that for wild-type AQP2. Co-injection of the mutant cRNAs with the wild-type cRNA did not affect the function of the wild-type AQP2. Immunolocalization of AQP2-transfected CHO cells showed that the C181W mutant had an endoplasmic reticulum-like intracellular distribution, whereas L22V and wild-type AQP2 showed endosome and plasma membrane staining. Water permeability assays showed a high Pf in cells expressing wild-type and L22V AQP2. This study indicates that AQP2 mutations can confer partially responsive NDI.      

Clinical and radiologic outcome of humeral implants in shoulder arthroplasty

The clinical and radiological evolution of the glenoid socket in total shoulder arthroplasty is well documented, whereas evaluation of the humeral component has received much less attention. The outcome of 40 humeral replacements performed in 39 patients was studied with a minimum follow-up of one year. There were 26 Neer prostheses, 9 Modular Shoulder prostheses and 5 Aequalis prostheses. Twenty-nine prostheses were implanted with cement and 11 were cementless. The clinical and radiological results were assessed according to the scoring system used for the 1994 symposium of SO.F.C.O.T. X rays in the coronal plane were used to assess the position of the stem, radiolucencies around the humeral component and the percentage of the cross-section of the diaphysis filled by the humeral stem. The average follow-up period was respectively 55.6 months for the Neer prostheses, 17.9 months for the Modular Shoulder prostheses and 12.4 months for the Aequalis prostheses. Radiolucent lines were noted in 20 cases, all with uncemented humeral components. Two prostheses were loose; however, none required revision. The underlying pathology, surgical approach, position of the humeral component, implant design or association with glenoid resurfacing were not correlated with the presence of radiolucent lines or with a loose implant. Cementless fixation was the only parameter statistically related with the presence of radiolucent lines. This report confirms the good results obtained with cemented humeral prostheses. Radiological evaluation of the smooth cementless humeral implant showed many progressive radiolucent lines, without clinical expression. The authors analyze the various studies in the literature and discuss the interest of cementless implants with ingrowth surface.     

Turnaround time and barriers to treatment of newly diagnosed cancer in Uganda: a mixed-methods longitudinal study

IntroductionCancer represents a growing public health concern. Late-stage at diagnosis, limited access to effective treatment, and loss to follow-up are responsible for dismal outcomes.ObjectiveTo describe care pathways, turnaround times, and identify barriers to timely initiation of cancer treatmentMethodsUsing a sequential mixed-methods design involving focus group discussions, we followed up 50 participants between January, and June 2018. We computed the median observed turnaround time to treatment (TTT) at each care step and reported delay as deviations from the proposed ideal turnaround times.ResultsThe ideal TTT with either chemotherapy, or radiotherapy, or surgery was 8, 14, and 21 days respectively. At a median follow-up time of 35.5 days (IQR 17–66), only 29 of the 50 study participants had completed all steps between registration and initiation of treatment, and the observed median TTT was 16 days (9 – 22 days) for chemotherapy, and 30 days (17 – 49 days) for radiotherapy, reflecting a significant delay (p-value = 0.017). Reported barriers were; shortage of specialists, patients required visits to outside facilities for staging investigations, prohibitive costs, poor navigation system and time wastage.ConclusionsWhen compared to the recommended ideal turnaround time, there was significant institutional delay in access to chemotherapy and radiotherapy attributed to multiple external and internal healthcare system barriers.     

In vitro oxidations of low-density lipoprotein and RAW 264.7 cells with lipophilic O(3P)-precursors

A beneficial property of photogenerated reactive oxygen species (ROS) is the capability of oxidant generation within a specific location or organelle inside a cell. Dibenzothiophene S-oxide (DBTO), which is known to undergo a photodeoxygenation reaction to generate ground state atomic oxygen [O(³P)] upon irradiation, was functionalized to afford localization within the plasma membrane of cells. The photochemistry, as it relates to oxidant generation, was studied and demonstrated that the functionalized DBTO derivatives generated O(³P). Irradiation of these lipophilic O(³P)-precursors in the presence of LDL and within RAW 264.7 cells afforded several oxidized lipid products (oxLP) in the form of aldehydes. The generation of a 2-hexadecenal (2-HDEA) was markedly increased in irradiations where O(³P) was putatively produced. The substantial generation of 2-HDEA is not known to accompany the production of other ROS. These cellular irradiation experiments demonstrate the potential of inducing oxidation with O(³P) in cells.

Lipophilic O(³P)-precursors generate 2-hexadecenal upon UV-irradiation.     

ATG16L1 and NOD2 polymorphisms enhance phagocytosis in monocytes of Crohn’s disease patients

AIM:To investigate if the presence of relevant genetic polymorphisms has effect on the effectual clearance of bacteria by monocytes and granulocytes in patients with Crohn’s disease(CD).METHODS:In this study,we assessed the differential responses in phagocytosis by measuring the phagocytic activity and the percentage of active phagocytic monocytes and granulocytes in inflammatory bowel disease patients as well as healthy controls.As both autophagy related like 1(ATG16L1)and immunityrelated guanosine triphosphatase gene are autophagy genes associated with CD and more recently nucleo-tide-binding ligomerization domain-containing protein2(NOD2)has been identified as a potent inducer of autophagy we genotyped the patients for these variants and correlated this to the phagocytic reaction.The genotyping was done with restriction fragment length polymorphisms analysis and the phagocytosis was determined with the pHrodo?Escherichia coli Bioparticles Phagocytosis kit for flowcytometry.RESULTS:In this study,we demonstrate that analysis of the monocyte and granulocyte populations of patients with CD and ulcerative colitis showed a comparable phagocytic activity(ratio of mean fluorescence intensity)between the patient groups and the healthy controls.CD patients show a significantly higher phagocytic capacity(ratio mean percentage of phagocytic cells)compared to healthy controls(51.91%±2.85%vs 37.67%±7.06%,P=0.05).The extend of disease was not of influence.However,variants of ATG16L1(WT:2.03±0.19 vs homozygoot variant:4.38±0.37,P<0.009)as well as NOD2(C-ins)(heterozygous variant:42.08±2.94 vs homozygous variant:75.58±4.34(P=0.05)are associated with the phagocytic activity in patients with CD.CONCLUSION:Monocytes of CD patients show enhanced phagocytosis associated with the presence of ATG16L1 and NOD2 variants.This could be part of the pathophysiological mechanism resulting in the disease.     

Lactate rise detected by 1H NMR in human visual cortex during physiologic stimulation.

Brain lactate concentration is usually assumed to be stable except when pathologic conditions cause a mismatch between glycolysis and respiration. Using newly developed 1H NMR spectroscopic techniques that allow measurement of lactate in vivo, we detected lactate elevations of 0.3-0.9 mM in human visual cortex during physiologic photic stimulation. The maximum rise appeared in the first few minutes; thereafter lactate concentration declined while stimulation continued. The results are consistent with a transient excess of glycolysis over respiration in the visual cortex, occurring as a normal response to stimulation in the physiologic range.