132 research outputs found
Comment on "Effect of biofilm formation by clinical isolates of Helicobacter pylori on the efflux-mediated resistance to commonly used antibiotics".
Attaran et al[1] have recently shown that decreased susceptibility of established Helicobacter pylori (H. pylori) biofilms to specific antibiotics, was associated with the overtly enhanced transcription of two efflux pump genes, hp1165 and hefA, involved in specific resistance to tetracycline and multiple antibiotics, respectively. Apart from antibiotic exposure, secretion of multiple antimicrobial peptides, such as human ?-defensins (h?Ds), by the gastric epithelium upon Hp challenge, may act as early triggering events that positively impact biofilm formation and thus, antibiotic resistance. In this regard, we undertook genomic transcriptional studies using Hp 26695 strain following exposure to sublethal, similar to those present in the gastric niche, concentrations of h?Ds in an attempt to provide preliminary data regarding possible mechanisms of immune evasion and selective sensitivity of Hp. Our preliminary results indicate that h?D exposure ignites a rapid response that is largely due to the activation of several, possibly interconnected transcriptional regulatory networks - origons - that ultimately coordinate cellular processes needed to maintain homeostasis and successful adaptation of the bacterium in the gastric environment. In addition, we have shown that both antibiotic and h?D resistance are mediated by dedicated periplasmic transporters, including the aforementioned efflux pump genes hp1165 and hefA, involved in active export of antibiotics from the cell membrane and/or, as recently suggested, substrate sensing and signalling. Furthermore, it appears that sublethal doses of h?Ds may enhance biofilm formation by the sustained expression of, mainly, quorum sensing-related genes. In conclusion, we provide additional data regarding the role of specific innate immune molecules in antibiotic cross-resistance mechanisms that may deepen our understanding in the context of the development of novel eradication regimens
Long-term treatment of osteoporosis: safety and efficacy appraisal of denosumab
Denosumab is a fully human monoclonal antibody to the receptor activator of nuclear factor-κB ligand (RANKL), a member of the tumor necrosis factor receptor superfamily essential for osteoclastogenesis. Denosumab treatment is associated with a rapid, sustained, and reversible reduction in bone turnover markers, a continuous marked increase in bone mineral density at all sites, and a marked decrease in the risk of vertebral, hip, and nonvertebral fractures in women with postmenopausal osteoporosis. Therefore, it could be considered as an effective alternative to previous bisphosphonate treatment as well as first-line treatment of severe osteoporosis. Cost-effectiveness studies support this suggestion. In addition, denosumab seems to be the safest treatment option in patients with impaired renal function. Denosumab is characterized by reversibility of its effect after treatment discontinuation, in contrast with bisphosphonates. Large-scale clinical trials, including the extension of FREEDOM trial for up to 5 years, are reassuring for its safety. However, given its brief post-market period, vigilance regarding adverse events related to putative RANKL inhibition in tissues other than bone, as well as those related to bone turnover oversuppression, is advised
Diagnostic approach to Helicobacter pylori-related gastric oncogenesis.
Helicobacter pylori (H. pylori) is a causative agent of peptic ulcer disease and plays an important role in the development of various other upper and lower gastrointestinal tract and systemic diseases; in addition to carcinogenesis and the development of mucosa-associated lymphoid tissue lymphoma, extragastric manifestations of H. pylori are increasingly being unraveled. Therefore, prompt and accurate diagnosis is essential. Within this narrative review we present an overview of the current trend in the diagnosis of H. pylori infection and its potential oncogenic sequelae, including gastric mucosa atrophy, intestinal metaplasia, dysplasia and gastric cancer. Signs of H. pylori-related gastric cancer risk can be assessed by endoscopy using the Kyoto classification score. New technology, such as optical or digital chromoendoscopy, improves diagnostic accuracy and provides information regarding H. pylori-related gastric preneoplastic and malignant lesions. In addition, a rapid urease test or histological examination should be performed, as these offer a high diagnostic sensitivity; both are also useful for the diagnosis of sequelae including gastric and colon neoplasms. Culture is necessary for resistance testing and detecting H. pylori-related gastric dysbiosis involved in gastric oncogenesis. Likewise, molecular methods can be utilized for resistance testing and detecting H. pylori-related gastric cancer development and progression. Noninvasive tests, such as the urea breath and stool antigen tests, can also be implemented; these are also suitable for monitoring eradication success and possibly for detecting H. pylori-related gastric malignancy. Serological tests may help to exclude infection in specific populations and detect gastric and colon cancers. Finally, there are emerging potential diagnostic biomarkers for H. pylori-related gastric cancer
Normal bone turnover markers in a patient with active Paget’s disease of bone: response to treatment with zoledronic acid
Celem leczenia choroby kości Pageta (PDB) jest zahamowanie zwiększonego obrotu kostnego. Obecnie lekami z wyboru są bisfosfoniany.
Do wskazań do stosowania leków antyresorpcyjnych u pacjentów z objawowa postacią PDB należą: bóle kostne i stawowe, powikłania
neurologiczne, planowany zabieg chirurgiczny w rejonie aktywnych zmian chorobowych i hiperkalcemia spowodowana unieruchomieniem.
Celem terapii antyresorpcyjnej jest uzyskanie poprawy stanu klinicznego i remisji biochemicznej, ocenianej na podstawie
normalizacji stężeń biomarkerów obrotu kostnego. Przed podjęciem decyzji o wdrożeniu terapii u chorych w późnej, sklerotycznej fazie
choroby (burned out) należy wziąć pod uwagę pogorszenie stanu klinicznego, a zwłaszcza występowanie bólów kostnych. U tych chorych
duże znaczenie ma badanie scyntygraficzne kości, ponieważ może ono uwidocznić zwiększoną aktywność osteoblastyczną, której mogą
nie wykazać markery obrotu kostnego. W niniejszej pracy przedstawiono przypadek chorego w późnym, sklerotycznym stadium PDB,
u którego występowały nasilone objawy kliniczne, lecz stężenia markerów obrotu kostnego były prawidłowe. Po leczeniu kwasem zoledronowym
nastąpiła istotna poprawa kliniczna.The treatment of Paget’s disease of bone (PDB) aims at the suppression of abnormal bone turnover; bisphosphonates are currently the
treatment of choice. Indications for antiresorptive treatment in symptomatic patients with PDB include bone or joint pain, neurological
complications, surgery planned at an active pagetic site and hypercalcaemia from immobilisation. The goals of antiresorptive treatment
are clinical improvement and biochemical remission, as assessed by the normalisation of bone turnover markers. Clinical deterioration,
especially bone pain, should be considered before deciding to treat patients with late sclerotic (burned-out) PDB. Bone scintigraphy may
be of importance in these patients, because it depicts increased osteoblastic activity, when bone markers may not. We present a case of
late sclerotic PDB with clinical deterioration but normal bone turnover markers, who experienced significant clinical improvement after
treatment with zoledronic acid
Association between Helicobacter pylori Infection and Nasal Polyps: A Systematic Review and Meta-Analysis.
BACKGROUND
Helicobacter pylori (H. pylori) has definite or possible associations with multiple local and distant manifestations. H. pylori has been isolated from multiple sites throughout the body, including the nose. Clinical non-randomized studies with H. pylori report discrepant data regarding the association between H. pylori infection and nasal polyps. The aim of this first systematic review and meta-analysis was the assessment of the strength of the association between H. pylori infection and incidence of nasal polyps.
METHODS
We performed an electronic search in the three major medical databases, namely PubMed, EMBASE and Cochrane, to extract and analyze data as per PRISMA guidelines.
RESULTS
Out of 57 articles, 12 studies were graded as good quality for analysis. Male-to-female ratio was 2:1, and age ranged between 17-78 years. The cumulative pooled rate of H. pylori infection in the nasal polyp group was 32.3% (controls 17.8%). The comparison between the two groups revealed a more significant incidence of H. pylori infection among the nasal polyp group (OR 4.12), though with high heterogeneity I = 66%. Subgroup analysis demonstrated that in European studies, the prevalence of H. pylori infection among the nasal polyp group was significantly higher than in controls, yielding null heterogeneity. Subgroup analysis based on immunohistochemistry resulted in null heterogeneity with preserving a statistically significant difference in H. pylori infection prevalence between the groups.
CONCLUSION
The present study revealed a positive association between H. pylori infection and nasal polyps
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