Lifestyle factors and comorbidities in gout patients compared to the general population in Western Sweden: results from a questionnaire study

OBJECTIVE

This study aimed to identify lifestyle factors associated with gout in patients with prevalent gout compared to the general population.

METHOD

Adult patients with gout identified in primary and secondary care in Western Sweden between 2015 and 2017 were sent a questionnaire asking about demographics, lifestyle, and comorbidities. Five age- and gender-matched controls were identified in a random sample of 52 348 individuals aged 16-84 years who participated in the National Public Health survey in Sweden, year 2015. Logistic regression models were used to compare cases and controls with regard to lifestyle factors and comorbidities.

RESULTS

Of the 1589 invited gout patients, 868 (55%) responded. After matching for age and gender, 728 were included in the analysis (82.4% male; mean ± sd age 69.3 ± 10.5 years for men and 71.8 ± 9.9 years for women with gout). Male and female gout patients were significantly more likely to be overweight or obese (men 79% vs 66%; women 78.5% vs 65.3%), to have binge-drinking behaviour (men 29.9% vs 11%; women 13.7% vs 2.9%), and to be ex-smokers, compared to controls. Moreover, male gout patients reported lower levels of physical activity, while diabetes and hypertension were more common in both genders with gout than in controls.

CONCLUSION

In this questionnaire study, gout patients reported significantly more obesity and binge-drinking behaviour and less physical activity than controls. This suggests that there are great unmet needs for the management of lifestyle factors, particularly regarding overweight/obesity and binge drinking, in patients with gout.

Single cell analysis of lymph node tissue from HIV-1 infected patients reveals that the majority of CD4+ T-cells contain one HIV-1 DNA molecule

Genetic recombination contributes to the diversity of human immunodeficiency virus (HIV-1). Productive HIV-1 recombination is, however, dependent on both the number of HIV-1 genomes per infected cell and the genetic relationship between these viral genomes. A detailed analysis of the number of proviruses and their genetic relationship in infected cells isolated from peripheral blood and tissue compartments is therefore important for understanding HIV-1 recombination, genetic diversity and the dynamics of HIV-1 infection. To address these issues, we used a previously developed single-cell sequencing technique to quantify and genetically characterize individual HIV-1 DNA molecules from single cells in lymph node tissue and peripheral blood. Analysis of memory and naïve CD4(+) T cells from paired lymph node and peripheral blood samples from five untreated chronically infected patients revealed that the majority of these HIV-1-infected cells (>90%) contain only one copy of HIV-1 DNA, implying a limited potential for productive recombination in virus produced by these cells in these two compartments. Phylogenetic analysis revealed genetic similarity of HIV-1 DNA in memory and naïve CD4(+) T-cells from lymph node, peripheral blood and HIV-1 RNA from plasma, implying exchange of virus and/or infected cells between these compartments in untreated chronic infection.

Hematopoietic precursor cells isolated from patients on long-term suppressive HIV therapy did not contain HIV-1 DNA

BACKGROUND

We address the key emerging question of whether Lin(-)/CD34(+) hematopoietic precursor cells (HPCs) represent an important latent reservoir of human immunodeficiency virus type 1 (HIV-1) during long-term suppressive therapy.

METHODS

To estimate the frequency of HIV-1 infection in bone marrow, we sorted Lin(-)/CD34(+) HPCs and 3 other cell types (Lin(-)/CD34(-), Lin(-)/CD4(+), and Lin(+)/CD4(+)) from 8 patients who had undetectable viral loads for 3-12 years. Using a single-proviral sequencing method, we extracted, amplified, and sequenced multiple single HIV-1 DNA molecules from these cells and memory CD4(+) T cells from contemporaneous peripheral blood samples.

RESULTS

We analyzed 100,000-870,000 bone marrow Lin(-)/CD34(+) HPCs from the 8 patients and found no HIV-1 DNA. We did isolate HIV-1 DNA from their bone marrow Lin(+)/CD4(+) cells that was genetically similar to HIV-1 DNA from lymphoid cells located in the peripheral blood, indicating an exchange of infected cells between these compartments.

CONCLUSIONS

The absence of infected HPCs provides strong evidence that the HIV-1 infection frequency of Lin(-)/CD34(+) HPCs from bone marrow, if it occurred, was <.003% (highest upper 95% confidence interval) in all 8 patients. These results strongly suggest that Lin(-)/CD34(+) HPCs in bone marrow are not a source of persistent HIV-1 in patients on long-term suppressive therapy.

HIV reservoirs and the possibility of a cure for HIV infection

Recent studies demonstrate that suppressive therapy can drive HIV-1 RNA levels to less than 50 copies mL(-1) in patient plasma. Yet, ultrasensitive assays show that most patients continue to harbour low-level persistent viremia. Treatment intensification studies indicate that low-level viremia could arise from several different sources. These sources include: (i) long-lived HIV-infected cells that replicate and produce virus; (ii) ongoing replication cycles in cells located in sanctuary sites where drug levels are suboptimal; and/or (iii) proliferation of latently infected cells with regeneration of a stable reservoir of slowly dividing infected cells. A well-defined latent reservoir of HIV is memory CD4+ T-cells where latency is established when an activated CD4+ T-cell becomes infected by HIV, but transitions to a terminally differentiated memory cell before it is eliminated. This review examines the dynamics and possible reservoirs of persistent HIV in patients on suppressive therapy, the mechanisms promoting viral latency and strategies to purge latent viral reservoirs. The promising research described here takes a number of steps forward to seriously address HIV remission and/or eradication.

Uropathogenic Escherichia coli P and Type 1 fimbriae act in synergy in a living host to facilitate renal colonization leading to nephron obstruction

The progression of a natural bacterial infection is a dynamic process influenced by the physiological characteristics of the target organ. Recent developments in live animal imaging allow for the study of the dynamic microbe-host interplay in real-time as the infection progresses within an organ of a live host. Here we used multiphoton microscopy-based live animal imaging, combined with advanced surgical procedures, to investigate the role of uropathogenic Escherichia coli (UPEC) attachment organelles P and Type 1 fimbriae in renal bacterial infection. A GFP⁺ expressing variant of UPEC strain CFT073 and genetically well-defined isogenic mutants were microinfused into rat glomerulus or proximal tubules. Within 2 h bacteria colonized along the flat squamous epithelium of the Bowman's capsule despite being exposed to the primary filtrate. When facing the challenge of the filtrate flow in the proximal tubule, the P and Type 1 fimbriae appeared to act in synergy to promote colonization. P fimbriae enhanced early colonization of the tubular epithelium, while Type 1 fimbriae mediated colonization of the center of the tubule via a mechanism believed to involve inter-bacterial binding and biofilm formation. The heterogeneous bacterial community within the tubule subsequently affected renal filtration leading to total obstruction of the nephron within 8 h. Our results reveal the importance of physiological factors such as filtration in determining bacterial colonization patterns, and demonstrate that the spatial resolution of an infectious niche can be as small as the center, or periphery, of a tubule lumen. Furthermore, our data show how secondary physiological injuries such as obstruction contribute to the full pathophysiology of pyelonephritis.

When bacteria such as uropathogenic Escherichia coli (UPEC) infect a living kidney, they face numerous physiological challenges such as the flow of urine. Bacteria need to attach themselves to the epithelial linings of the kidney to withstand this flow. In this work we use a live animal imaging model to study how UPEC colonize a living kidney despite the physiological challenges they face. We show that P and Type 1 fimbriae, two of the most well described UPEC adhesion factors, work together to promote successful bacterial colonization. P fimbriae mediate binding between the bacteria and the epithelial cells lining the tubules, while Type 1 appears to play a role in inter-bacterial binding and biofilm formation in the center parts of the lumen. The heterogeneous bacterial community which filled the tubule was subsequently shown to effect nephron filtration and resulted in a total loss of filtrate flow i.e. obstruction. This work demonstrates the interplay between the bacterial and host aspects, indicating how factors such as filtration may affect bacterial adhesion and vice versa. It also highlights the multifactorial basis of kidney infection, demonstrating how physiological injuries such as obstruction may contribute towards the full pathophysiology of pyelonephritis.

HIV reservoirs, latency, and reactivation: prospects for eradication

Current antiretroviral therapy effectively suppresses but does not eradicate HIV-1 infection. During therapy patients maintain a persistent low-level viremia requiring lifelong adherence to antiretroviral therapies. This viremia may arise from latently infected reservoirs such as resting memory CD4+ T-cells or sanctuary sites where drug penetration is suboptimal. Understanding the mechanisms of HIV latency will help efforts to eradicate the infection. This review examines the dynamics of persistent viremia, viral reservoirs, the mechanisms behind viral latency, and methods to purge the viral reservoirs. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, vol. 85, issue 1, 2010.

Intracellular hydrolysis of peptides

Purification of the first dipeptidases, glycylleucine dipeptidase (EC 3.4.13.2) and proline dipeptidase (EC 3.4.13.9), from intestine, have shown them to be true dipeptidases, hydrolysing only dipeptides in their laevo form. Although they have quite different specificities they show great similarities in their chemical and physicochemical properties. Specific antibodies against the two dipeptidases have been raised and used in combination with the double-layer immunofluorescent staining technique to study their histological localization in the small intestine. The results conclusively demonstrated that both glycylleucine dipeptidase and proline dipeptidase are exclusively located in the cytosol of the enterocytes. This location fits well with the current idea of transport and hydrolysis of dipeptides in the intestine where the dipeptides are taken by a specific transport mechanism and are hydrolysed intracellularly. Although it is tempting to add a specific role for the dipeptidases of the enterocytes in the final digestion of exogenous proteins, studies so far have shown their identity with the corresponding dipeptidases of other tissues. It is therefore suggested that their role in the digestion process may be based entirely on their abundance in the intestine.

Cellular signalling of PCH-induced pigment aggregation in the crustacean Macrobrachium potiuna erythrophores

The cellular system responsible for the transduction of the pigment-concentrating hormone (PCH) signal was investigated in erythrophores of the freshwater shrimp, Macrobrachium potiuna. Dose-response curves to the hormone were determined in the absence and in the presence of several drugs that affect sequential steps of the Ca(2+)-dependent signalling pathway. Additionally, the ability of forskolin to induce pigment dispersion was evaluated. Neomycin sulphate (10(-4) and 10(-3) mol.l-1), trifluoperazine (10(-5) and 10(-4) mol.l-1), 1-(5-isoquinolinesulfonlyl)-2-methylpiperazine (10(-7) and 10(-5) mol.l-1) and okadaic acid (10(-7) mol.l-1) significantly (P < 0.05) decreased the responses to PCH. However, okadaic acid at low concentration (10(-9) mol.l-1) and cyclosporin A (10(-6) and 10(-5) mol.l-1) did not significantly (P > 0.05) affect PCH activity. Forskolin (10(-4) mol.l-1) was able to half-maximally reverse the hormone-induced aggregation. Our results suggest that the pigment-concentrating hormone induces pigment aggregation through a Ca(2+)-dependent pathway with a posteriori phosphatase activation, probably the serine/threonine phosphatase 1.

Cytoskeleton and PCH-induced pigment aggregation in Macrobrachium potiuna erythrophores

Herein we report the effects of microtubule- and actin-like filament disrupting drugs, as well as the microtubule stabilizer taxol, on PCH-induced pigment granule aggregation within erythrophores of the freshwater crustacean Macrobrachium potiuna. Dose-response curves (DRCs) to the pigment-concentrating hormone PCH were determined under control and experimental conditions to evaluate the effects elicited by the cytoskeleton-affecting drugs. Colchicine, at temperatures 22 degrees C and 4 degrees C, and vinblastine significantly inhibited the aggregating response to PCH and affected the dynamics of the process, as shown by the change in the slope of the regression curve calculated from the DRCs. Lumicolchicine, a colchicine analogue with no affinity for tubulin, also inhibited pigment migration, though no change in the slope of the regression curve was observed. The inhibitory effects of lumicolchicine demonstrate that changes in sites other than cytoskeleton, such as membrane permeability, may also cause a decrease in the PCH-induced aggregating responses and that the colchicine effects may result from its action on cellular sites additional to the cytoskeleton. Taxol, a microtubule stabilizer, did not affect the DRC to PCH, and DMSO improved the PCH-evoked responses, pointing out to the maintenance of tubulin in the polymerized state as the appropriate condition for aggregation. Cytochalasin B, an actin-like filament disrupter, diminished the aggregating responses to the hormone, with no change in the slope of the regression curve, indicating that these elements take part in the process and that cytosolic calcium rise, sol/gel transformations and endoplasmic reticulum motility may well play an important role in granule migration. It is suggested that microtubules are steadily polymerized as a requirement for pigment aggregation and that process is biphasic, the initial phase being dependent on the microtubule integrity.

Quantitative in vitro assay for crustacean chromatophorotropins and other pigment cell agonists

An in vitro crustacean (freshwater shrimp, Macrobrachium potiuna) erythrophore bioassay for chromatophorotropins and other pigment cell agonists is described. The present assay is a quantitative method that determines the pigment responses with the aid of an ocular micrometer. The pigment granules within the erythrophores are dispersed out into the dendritic processes of the cells when the isolated carapace is placed in physiological solution. This bioassay provides, therefore, a method for measuring the response of the pigment cells to aggregating agents such as pigment concentrating hormone (PCH). This bioassay is sensitive to PCH at a concentration as low as 3 x 10(-12) M. Calcium ionophore A23187 mimics the actions of PCH, but, unlike the hormone, the ionophore-induced pigment aggregation is irreversible after physiological solution rinses. Therefore, chromatophorotropic activities of pigment dispersing agents, such as pigment dispersing hormones (PDH), can be determined on ionophore-treated erythrophores. The potencies of alpha-PDH and beta-PDH show a threefold difference (not significant). Because of its convenience and its ability to make an objective determination of the bidirectional pigment movements within erythrophores, this bioassay is a suitable method for further structure-activity studies of the various chromatophorotropins and their analogs.

Guidelines (1988) for training in clinical laboratory management. International Federation of Clinical Chemistry (IFCC) Education Division and International Union of Pure and Applied Chemistry (IUPAC) Clinical Chemistry Division Commission on Teaching of Clinical Chemistry

Trainees in laboratory medicine must develop skills in laboratory management. Guidelines are detailed for laboratory staff in training, directors responsible for staff development and professional bodies wishing to generate material appropriate to their needs. The syllabus delineates the knowledge base required and includes laboratory planning and organisation, control of operations, methodology and instrumentation, data management and statistics, financial management, clinical use of tests, communication, personnel management and training, and research and development. Methods for achievement of the skills required are suggested. A bibliography of IFCC publications and other material is provided to assist in training in laboratory management.

International Federation of Clinical Chemistry (IFCC), Education Division. Guidelines (1988) for training in clinical laboratory management

Trainees in laboratory medicine must develop skills in laboratory management. Guidelines are detailed for laboratory staff in training, directors responsible for staff development and professional bodies wishing to generate material appropriate to their needs. The syllabus delineates the knowledge base required and includes laboratory planning and organisation, control of operations, methodology and instrumentation, data management and statistics, financial management, clinical use of tests, communication, personnel management and training, and research and development. Methods for achievement of the skills required are suggested. A bibliography of IFCC publications and other material is provided to assist in training in laboratory management.

Invertebrate neuropeptide hormones

The development of a long-term research program on the neurosecretory hormones of arthropods is described. The purification and full characterization of the first invertebrate neurohormones, the red pigment-concentrating hormone (RPCH) and the distal retinal pigment hormone (DRPH) demonstrated that they are peptides, an octapeptide and an octadecapeptide, respectively. Physiological function studies with the pure hormones and their synthetic preparations showed that the RPCH acts as a general pigment-concentrating hormone (PCH), and that the DRPH, in addition to its light-adaptive function, also constitutes a general pigment-dispersing hormone (PDH). In the regulation of the color-adaptation of the animals, the two hormones act as antagonists. The chromatophorotropic activities are widely distributed within the arthropod neuroendocrine systems. Purification of the pigment-concentrating activities from the locust corpora cardiaca lead to the isolation and characterization of the first insect neurohormones, the adipokinetic hormones (AKH I and AKH II). These two hormones, AKH I being a decapeptide and AKH II being an octapeptide, are close structural analogs to the crustacean PCH, demonstrating a common evolution of arthropod neurohormones. The hormones of this PCH-family all cross-react, but structure-function studies of the hormones show that quite different parts of their structure are involved in their binding to the various receptors.

Structure-function studies on red pigment-concentrating hormone, II. The significance of the C-terminal tryptophan amide

The significance of the C-terminal tryptophan residue of the red pigment-concentrating hormone (RPCH: Glu-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH2) regulating the blanching of the crustacean chromatophores has been investigated. RPCH and a number of analogues that differ only in the C-terminal part of the hormone, have been synthesized and assayed for biological activity on the shrimp Leander adspersus. It has been shown that the indole skeleton of tryptophan is an absolute requirement for the biological activity of the hormone. To provide maximum response the tryptophan must be blocked as the amide. The activity of synthetic [Tyr4]RPCH and adipokinetic hormone (AKH) purified from Schistocerca gregaria has been compared with the activity of synthetic RPCH.

Structure-function studies on red pigment-concentrating hormone; the significance of the terminal residues

The significance of the terminal residues of the red pigment-concentrating hormone (RPCH: Glu-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH2) for its blanching effect on crustacean chromatophores has been investigated. The chemical synthesis of the following small analogues, starting from the C-terminal amino acid are described: Ac-Trp-NH2, Boc-Gly-Trp-NH2, Ac-Gly-Trp-NH2, Gly-Trp-NH2, Ac-Pro-Gly-Trp-NH2, Glu-Trp-NH2, Glu-Pro-Gly-Trp-NH2, Ac-Pro-Gly and Glu-Pro-Gly-NH2. Assay of the biological activity of the various synthetic compounds in the shrimp Leander adspersus has established that only the C-terminal tryptophan residue is indispensable for the blanching effect of the hormone, although elongation of the chain length improves its potency.

Histological localization of two dipeptidases in the pig small intestine and liver, using immunofluorescence

Antibodies were raised in rabbits against glycylleucine dipeptidase (EC 3.4.13.2) and proline dipeptidase (EC 3.4.13.9) purified from the pig. IgG fractions were isolated and purified by affinity chromatography on Sepharose (dipeptidase) columns and then used in histological studies on the small intestine and the liver from pig, using the double layer immunofluorescence-staining technique. In the small intestine the dipeptidases were predominantly localized in the cytoplasm of the enterocytes. A reaction was also seen in the leukocyte cytoplasm in the stroma of the small intestine. The dipeptidases were present in the villi but not in the crypts. In the liver the dipeptidases were localized in the cytoplasm of the hepatocyte, but strong fluorescence was also obtained in the epithelium of the bile ducts. Glycylleucine dipeptidase and proline dipeptidase have been isolated from liver tissue and they were shown to be immunologically identical with the purified intestinal dipeptidases.

Crustacean color-change hormone: amino acid sequence and chemical synthesis

The blanching hormone of the prawn, Pandalus borealis, is pGlu-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH(2). Its structure was settled by a combination of mass spectrometry and Edman-dansyl analysis of a thermolysin fragment. Confirmation of the structure was obtained by chemical synthesis from amino acids. This neurosecreted hormone is active in picogram amounts when tested in shrimps.

Quantitative determination of enzymes in different parts of the villi and crypts of rat small intestine. Comparison of alkaline phosphatase, disaccharidases and dipepeptidases

By horizontal sectioning of a fresh frozen piece of rat intestinal wall different parts of the villi and the crypts were isolated. Every third serial section was taken for histologic examination and the intermediate sections were combined in pairs, homogenized and used for enzyme analysis. A quantitative comparison of the distribution of alkaline phosphatase, EC 3.1.3.1, disaccharidase, EC 3.2.1 (maltase, invertase, isomaltase, trehalase, lactase and cellobiase), and dipeptidase, EC 3.4.3 (L-alanyl-L-proline dipeptidase, L-alanyl-L-glutamic acid dipeptidase and glycyl-L-leucine dipeptidase), activities was performed. All of the enzymes were present in the villi and absent from the crypts. The disaccharidase and dipeptidase activities showed a rather similar distribution. The highest activities were found in the apical halves of the villi. The alkaline phosphatase activity was more distinctly located in the tips of the villi.