Out of the boxes,out of the silos: The need of interdisciplinary collaboration to reduce poor-quality medical products in the supply chain

In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.     

晕可宁颗粒对急、慢性梅尼埃病模型的影响

目的　探讨晕可宁颗粒的主要药效学 ,为临床提供药效学资料及治疗学基础。方法　采用三氯甲烷破坏豚鼠一侧膜迷路感受器模型 ,探讨受试药对眼震颤、摆头及旋转的影响 ;采用内淋巴囊和内淋巴管阻塞手术复制豚鼠膜迷路实验性膜迷路积水模型 ,研究内耳组织平均中阶面积 (SMA)增加率及形态学的变化。结果　抑眩宁阳性对照组、晕可宁颗粒 (8、16g/kg)模型给药组豚鼠眼球震颤次数减少 ,差异有显著意义 (P <0 .0 5 )。成功复制了不同程度膜迷路积水豚鼠模型 ,表现为前庭膜重度膨出 ,前庭阶缩小 ,膜蜗管增大 ,SMA增加率变大 ,差异有显著意义 (P <0 .0 1) ;晕可宁颗粒灌胃后可减轻豚鼠实验性膜迷路积水的程度 ,差异有显著意义 (P <0 .0 1) ;但与空白对照组比较SMA增加率差异无显著意义 (P >0 .0 5 )。结论　晕可宁颗粒可以减轻内淋巴囊积水程度 ,对梅尼埃病症状有对抗治疗作用。     

慢性粒细胞白血病的核型及其预后意义

目的 :分析细胞遗传学在慢性粒细胞白血病 (CGL)的诊断、疗效及其预后中的临床意义。方法 :对 116例采用骨髓细胞直接法和 (或 )短期 ( 2 4h)培养法制备染色体标本 ,采用R显带技术进行核型分析。结果 :在 116例CGL中 ,发现 110例Ph( +) ,在病程各期 (慢性期、加速期、急变期 )均出现 ,占 94.8%。 6例Ph( -) ,占 5 .17%。其中 96例Ph( +)细胞为 10 0 % ,占 87.2 %。 14例Ph( +)细胞为 41.6%～ 93 .1% ,占 12 .7% ,核型呈嵌合状态。 12例除Ph( +)外 ,还出现额外染色体改变 ,占 10 .9%。分别为双Ph ,+8,-Y ,-7及超二倍体 ( >46条 )。绝大部分患者经干扰素、羟基脲治疗后Ph( +)阳性率不变。结论 :染色体核型分析不仅有助于CGL的诊断和鉴别诊断。还是监测病情缓解或复发的重要指标。     

Myokardiales Pumpversagen bei dilatativer Kardiomyopathie und Phäochromozytom

Zusammenfassung Bei einer 37 j?hrigen, bisher gesunden Patientin entwickelte sich eine über 2 Monate progrediente Dyspnoe. Radiologisch und echokardiographisch zeigte sich eine massive Dilatation s?mtlicher Herzh?hlen mit biventrikul?ren Thromben und eine stark herabgesetzte Kontraktilit?t. Die Endomyokardbiopsien wurden von 2 Instituten als Myokarditis eingestuft. Im weiteren Verlauf entwickelten sich thrombembolische Komplikationen und ein therapierefrakt?res Pumpversagen, in dem die Patientin schlie?lich verstarb. Bei der Obduktion fand sich au?er einem dilatierten 600 g schweren Herzen mit biventrikul?ren Thromben ein klinisch bisher unbekanntes Ph?ochromozytom der linken Nebenniere. Die eingehende histologische und immunhistologische Aufarbeitung des Herzmuskelgewebes einschlie?lich Reevaluierung der Endomyokardbiopsien führte zur Revision der ursprünglichen Diagnose: Das Krankheitsbild der 37 j?hrigen Patientin war durch eine katecholamininduzierte dilatative Kardiomyopathie verursacht worden.      

Allergic bronchopulmonary aspergillosis: Reactivity of IgE and IgG antibodies with antigenic components of Aspergillus fumigatus (IgE/IgG antigen complexes)

Sera of patients with ABPA were tested by XRIE tests incorporating their own serum (self-XRIE) to detect the presence of IgG/IgE antigen complexes to a “reference” Aspergillus fumigatus preparation. Of the 32 sera studied, 29 (90%) had visible precipitin (IgG) peaks, and 27 of these 29 as well as the three apparently precipitin-negative sera, i.e., 30 (94%), showed binding of specific IgE by autoradiography. The two precipitin-positive sera that did not show IgE binding were also skin test negative and RAST negative to this A. fumigatus antigen. Specific IgG as determined in ELISA correlated well with the grading of the XIE precipitin peaks (p < 0.05). There was also a highly significant correlation between specific IgE by RAST and grading the radioactive uptake seen in the autoradiograph (p < 0.001) indicating, for each serum, the presence of IgG antibodies to most of the components to which there was specific IgE. In the self-XRIE tests there was considerable variation of reactivity from serum to serum, in numbers of antigen/antibody peaks observed, in relative peak heights, and in the intensity of the respective staining. By comparing each test to a “reference” pattern developed with the use of an ABPA serum pool, the antigenic components of A. fumigatus were found to be of two main types: (1) antigens that appeared to be poorly precipitating (possibly low-molecular-weight components) but showed strong IgE binding (these were apparently major allergenic components and with one exception proved to be the faster migrating components) and (2) antigens that produced the strongest precipitin reactions with only weak binding of specific IgE and therefore minor allergenic components.     

MicroRNA155 Plays a Critical Role in the Pathogenesis of Cutaneous Leishmania major Infection by Promoting a Th2 Response and Attenuating Dendritic Cell Activity

Interferon (IFN)-γ is indispensable in the resolution of cutaneous leishmaniasis (CL), while the Th2 cytokines IL-4, IL-10, and IL-13 mediate susceptibility. A recent study found that miR155, which promotes CD4⁺ Th1 response and IFN-γ production, is dispensable in the control of Leishmania donovani infection. Here, the role of miR155 in CL caused by L. major was investigated using miR155-deficient (miR155^−/−) mice. Infection was controlled significantly quicker in the miR155^−/− mice than in their wild-type (WT) counterparts, indicating that miR155 contributes to the pathogenesis of CL. Faster resolution of infection in miR155^−/− mice was associated with increased levels of Th1-associated IL-12 and IFN-γ and reduced production of Th2- associated IL-4, IL-10, and IL-13. Concentrations of IFN-γ⁺CD8⁺ T cells and natural killer cells in draining lymph nodes were significantly higher in the L. major−infected miR155^−/− mice than in the infected WT mice, as indicated by flow-cytometry. After in vitro IFN-γ stimulation, nitric oxide and IL-12 production were increased, IL-10 production was decreased, and parasite clearance was enhanced in L. major−infected miR155^−/− DCs compared to those in WT DCs. Furthermore, IFN-γ production from activated miR155^−/− T cells was significantly enhanced in L. major−infected miR155^−/− DCs. Together, these findings demonstrate that miR155 promotes susceptibility to CL caused by L. major by promoting Th2 response and inhibiting DC function.

Leishmania are obligate intracellular protozoans that infect phagocytes and cause a spectrum of clinical diseases such as cutaneous leishmaniasis (CL) and visceral leishmaniasis. Common in the tropical and subtropical regions, leishmaniasis affects over 1 billion people worldwide, with an incidence of up to 1 million cases per year.¹ CL is the most common type of Leishmania infection, manifesting as localized skin lesions that can become chronic, leading to significant tissue destruction and disfigurement.^2,3 It is well documented that the induction of a Th1 response and interferon (IFN)-γ are indispensable in the resolution of CL caused by Leishmania major,⁴ whereas disease progression is associated with the induction of a Th2 response and the production of cytokines such as IL-4 and IL-10.⁵ Establishing a disease-resolving response in the host is largely dependent on the ability to mount an appropriate Th1 immune response.⁴ Crucial in this response is the stimulation and activation of DCs that direct T-cell proliferation and differentiation toward IFN-γ–producing Th1 cells.^6,7 In addition to activating of phagocytic cells, IFN-γ induces the production of reactive nitrogen species, specifically nitric oxide (NO), leading to enhanced parasite clearance.⁴miR155 is a recognized regulator of immune cell function and immune response. miR155 enhances macrophage and DC activation and induces inflammatory response,^8,9 and up-regulation of miR155 in CD4⁺ T cells promotes preferential Th1 differentiation and IFN-γ production¹⁰ by suppressing the expression of suppressor of cytokine signaling (SOCS)-1.11, 12, 13, 14 Conversely, miR155 gene–deficient mice exhibit diminished levels of Th1/Th17 cells, macrophages, and DCs.¹⁵ miR155 has also been shown to play a role in regulating effector Th2 response.16, 17, 18 Collectively, these findings suggest that miR155 regulates both Th1 and Th2 responses, which control the outcome of CL caused by L. major. Therefore, the role of miR155 in immunity to L. major using miR155^−/− mice was investigated in the present study. The findings show that miR155 is not required for the induction of a Th1 response and IFN-γ in L. major infection. Rather, miR155 plays a disease-exacerbating role in CL by attenuating DC function and Th1 response and promoting Th2 response.     

Lactobacillus acidophilus Induces a Strain-specific and Toll-Like Receptor 2–Dependent Enhancement of Intestinal Epithelial Tight Junction Barrier and Protection Against Intestinal Inflammation

Defective intestinal tight junction (TJ) barrier is an important pathogenic factor of inflammatory bowel disease. To date, no effective therapies that specifically target the intestinal TJ barrier are available. The purpose of this study was to identify probiotic bacterial species or strains that induce a rapid and sustained enhancement of intestinal TJ barrier and protect against the development of intestinal inflammation by targeting the TJ barrier. After high-throughput screening of >20 Lactobacillus and other probiotic bacterial species or strains, a specific strain of Lactobacillus acidophilus, referred to as LA1, uniquely produced a marked enhancement of the intestinal TJ barrier. LA1 attached to the apical membrane surface of intestinal epithelial cells in a Toll-like receptor (TLR)-2–dependent manner and caused a rapid increase in enterocyte TLR-2 membrane expression and TLR-2/TLR-1 and TLR-2/TLR-6 hetero-complex–dependent enhancement in intestinal TJ barrier function. Oral administration of LA1 caused a rapid enhancement in mouse intestinal TJ barrier, protected against a dextran sodium sulfate (DSS) increase in intestinal permeability, and prevented the DSS-induced colitis in a TLR-2– and intestinal TJ barrier–dependent manner. In conclusion, we report for the first time that a specific strain of LA causes a strain-specific enhancement of intestinal TJ barrier through a novel mechanism that involves the TLR-2 receptor complex and protects against the DSS-induced colitis by targeting the intestinal TJ barrier.

Intestinal epithelial tight junctions (TJs) are the apical-most junctional complexes and act as a functional and structural barrier against the paracellular permeation of harmful luminal antigens, which promote intestinal inflammation.¹ The increased intestinal permeability caused by defective intestinal epithelial TJ barrier or a leaky gut is an important pathogenic factor that contributes to the development of intestinal inflammation in inflammatory bowel disease (IBD) and other inflammatory conditions of the gut, including necrotizing enterocolitis and celiac disease.^2,3 Clinical studies in patients with IBD have found that a persistent increase in intestinal permeability after clinical remission is predictive of poor clinical outcome and early recurrence of the disease, whereas normalization of intestinal permeability correlates with a sustained long-term clinical remission.4, 5, 6 Accumulating evidence has found that a defective intestinal TJ barrier plays an important role in exacerbation and prolongation of intestinal inflammation in IBD. Currently, no effective therapies that specifically target the tightening of the intestinal TJ barrier are available.Intestinal microbiota play an important role in modulating the immune system and in the pathogenesis of intestinal inflammation.⁷ Patients with IBD have bacterial dysbiosis in the gut, characterized by a decrease in bacterial diversity and an aberrant increase in some commensal bacteria, which are an important factor in the pathogenesis of intestinal inflammation.^8,9 Normal microbial flora of the gastrointestinal tract consists both of bacteria that are known to have beneficial effects (probiotic bacteria) on intestinal homeostasis and bacteria that could potentially have detrimental effects on gut health (pathogenic bacteria).¹⁰ The modulation of intestinal microflora affects the physiologic and pathologic states in humans and animals. For example, fecal transplantation from healthy, unaffected individuals to patients with refractory Clostridium difficile colitis is curative in up to 94% of the treated patients, and transfer of stool microbiome from obese mice induces obesity in previous lean mice, whereas transfer of microbiome from lean mice preserves the lean phenotype.11, 12, 13 The beneficial effects of gut microbiota are host and bacterial species-specific.¹⁴ Although multiple studies indicate that some commensal bacteria play a beneficial role in gut homeostasis by preserving or promoting the intestinal barrier function, because of conflicting reports, it remains unclear which probiotic species cause a persistent predictable enhancement in the TJ barrier and could be used to treat intestinal inflammation by targeting the TJ barrier. For example, some studies suggest that Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, or Lactobacillus rhamnosus cause a modest enhancement in the intestinal epithelial TJ barrier, whereas others have found minimal or no effect of these probiotic species on the intestinal TJ barrier.15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 The major aim the current study was to perform a high-throughput screening of Lactobacillus and other bacterial species to identify probiotic species that induce a rapid, predictable, and marked increase in the intestinal epithelial TJ barrier and protect against the development of intestinal inflammation by preserving the intestinal TJ barrier.In the studies described herein, most of the probiotic species tested (>20 species or strains) had a modest or minimal effect on intestinal TJ barrier function. L. acidophilus uniquely caused a rapid and marked increase in intestinal TJ barrier function. Further analysis indicated that the effect of L. acidophilus was strain-specific, limited to a specific strain of L. acidophilus, and did not extend to other L. acidophilus strains. The L. acidophilus enhancement of the intestinal TJ barrier was mediated by live bacterial-enterocyte interaction that involved Toll-like receptor (TLR)-2 heterodimeric complexes on the apical membrane surface of intestinal epithelial cells. Our animal studies also found that L. acidophilus causes a marked enhancement in mouse intestinal barrier function and protects against the dextran sodium sulfate (DSS)–induced colitis by preserving and augmenting the mouse intestinal barrier function in a strain-specific manner.     

Dual β-Catenin and γ-Catenin Loss in Hepatocytes Impacts Their Polarity through Altered Transforming Growth Factor-β and Hepatocyte Nuclear Factor 4α Signaling

Hepatocytes are highly polarized epithelia. Loss of hepatocyte polarity is associated with various liver diseases, including cholestasis. However, the molecular underpinnings of hepatocyte polarization remain poorly understood. Loss of β-catenin at adherens junctions is compensated by γ-catenin and dual loss of both catenins in double knockouts (DKOs) in mice liver leads to progressive intrahepatic cholestasis. However, the clinical relevance of this observation, and further phenotypic characterization of the phenotype, is important. Herein, simultaneous loss of β-catenin and γ-catenin was identified in a subset of liver samples from patients of progressive familial intrahepatic cholestasis and primary sclerosing cholangitis. Hepatocytes in DKO mice exhibited defects in apical-basolateral localization of polarity proteins, impaired bile canaliculi formation, and loss of microvilli. Loss of polarity in DKO livers manifested as epithelial-mesenchymal transition, increased hepatocyte proliferation, and suppression of hepatocyte differentiation, which was associated with up-regulation of transforming growth factor-β signaling and repression of hepatocyte nuclear factor 4α expression and activity. In conclusion, concomitant loss of the two catenins in the liver may play a pathogenic role in subsets of cholangiopathies. The findings also support a previously unknown role of β-catenin and γ-catenin in the maintenance of hepatocyte polarity. Improved understanding of the regulation of hepatocyte polarization processes by β-catenin and γ-catenin may potentially benefit development of new therapies for cholestasis.

A hallmark of epithelial cells is polarization, which is achieved by the orchestration of external cues, such as cellular contact, extracellular matrix, signal transduction, growth factors, and spatial organization.¹ Hepatocytes in the liver show a unique polarity by forming several apical and basolateral poles within a cell.² The apical poles of adjacent hepatocytes form a continuous network of bile canaliculi into which bile is secreted, whereas the basolateral membrane domain forms the sinusoidal pole, which secretes various components, such as proteins or drugs, into the blood circulation.³ Loss of hepatic polarity has been associated with several cholestatic and developmental disorders, including progressive familial intrahepatic cholestasis (PFIC) and primary sclerosing cholangitis (PSC).^4,5 Although the molecular mechanisms governing hepatocyte polarity have been extensively studied in the in vitro systems, there is still a significant gap in our understanding of how polarity is established within the context of tissue during development or maintained during homeostasis.^6,7 Similarly, the molecular pathways contributing to hepatic polarity are not entirely understood, and a better comprehension of hepatic polarity regulation is thus warranted.Previous studies have confirmed the role of hepatocellular junctions, such as tight and gap junctions, in the maintenance of hepatocyte polarity.^8,9 Studies done in vitro and in vivo have shown that loss of junctional proteins, such as zonula occludens protein (ZO)-1, junctional adhesion molecule-A, and claudins, lead to impairment of polarity and distorted bile canaliculi formation.10, 11, 12, 13 In addition, proteins involved in tight junction assembly, such as liver kinase B1, are also involved in polarity maintenance.¹⁴ Among adherens junction proteins, various in vitro cell culture models have confirmed the role of E-cadherin in the regulation of hepatocyte polarity, possibly through its interaction with β-catenin.^15,16 However, there is a lack of an in vivo model to study the role of adherens junction proteins in hepatocyte polarity and their misexpression contributing to various liver diseases.β-Catenin plays diverse functions in the liver during development, regeneration, zonation, and tumorigenesis.17, 18, 19 The relative contribution of β-catenin as part of the adherens junction is challenging to study because like in other tissues, γ-catenin compensates for the β-catenin loss in the liver.^20,21 To address this redundancy, we previously reported a hepatocyte-specific β-catenin and γ-catenin double-knockout (DKO) mouse model was reported.²² Simultaneous deletion of β-catenin and γ-catenin in mice livers led to cholestasis, partially through the breach of cell-cell junctions. However, more comprehensive understanding of the molecular underpinnings of the phenotype is needed.In the current study, prior preclinical findings of dual β-catenin and γ-catenin loss were extended to a subset of PFIC and PSC patients. In vivo studies using the murine model with hepatocyte-specific dual loss of β-catenin and γ-catenin showed complete loss of hepatocyte polarity compared to the wild-type controls (CONs). Loss of polarity in DKO liver was accompanied by epithelial-mesenchymal transition (EMT), activation of transforming growth factor (TGF)-β signaling, and reduced expression of hepatocyte nuclear factor 4α (HNF4α). Our findings suggest that β-catenin and γ-catenin and in turn adherens junction integrity, are critical for the maintenance of hepatocyte polarity, and any perturbations in this process can contribute to the pathogenesis of cholestatic liver disease.