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1.
Drug Dev Ind Pharm ; : 1-13, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38718267

RESUMEN

OBJECTIVES: This research aimed to overcome challenges posed by cefepime excessive elimination rate and poor patient compliance by developing transdermal delivery system using nano-transfersomes based chitosan gel. METHODS: Rotary evaporation-sonication method and the Box-Behnken model were used to prepare cefepime loaded nano-transfersomes (CPE-NTFs). The physiochemical characterization of CPE-NTFs were analyzed including DLS, deformability index, DSC and antimicrobial study. Optimized CPE-NTFs loaded into chitosan gel and appropriately characterized. In vitro release, ex vivo and in vivo studies were performed. RESULTS: The CPE-NTFs were physically stable with particle size 222.6 ± 1.8 nm, polydispersity index 0.163 ± 0.02, zeta potential -20.8 ± 0.1 mv, entrapment efficiency 81.4 ± 1.1% and deformability index 71 ± 0.2. DSC analysis confirmed successful drug loading and thermal stability. FTIR analysis showed no chemical interaction among the excipients of CPE-NTFs gel. The antibacterial activity demonstrated a remarkable reduction in the minimum inhibitory concentration of cefepime when incorporated into nano-transfersomes. CPE-NTFs based chitosan gel (CPE-NTFs gel) showed significant physicochemical properties. In vitro release studies exhibited sustained release behavior over 24 h, and ex vivo studies indicated enhanced permeation and retention compared to conventional cefepime gel. In vivo skin irritation studies confirmed CPE-NTFs gel was nonirritating and biocompatible for transdermal delivery. CONCLUSION: This research showed nano-transfersomes based chitosan gel is a promising approach for cefepime transdermal delivery and provides sustained release of cefepime.

2.
Molecules ; 29(7)2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38611831

RESUMEN

In addition to traditional use in fermented dairy products, S. thermophilus also exhibits anti-inflammatory properties both in live and heat-inactivated form. Recent studies have highlighted that some hydrolysates from surface proteins of S. thermophilus could be responsible partially for overall anti-inflammatory activity of this bacterium. It was hypothesized that anti-inflammatory activity could also be attributed to peptides resulting from the digestion of intracellular proteins of S. thermophilus. Therefore, total intracellular proteins (TIP) from two phenotypically different strains, LMD-9 and CNRZ-21N, were recovered by sonication followed by ammonium sulphate precipitation. The molecular masses of the TIP of both strains were very close to each other as observed by SDS-PAGE. The TIP were fractionated by size exclusion fast protein liquid chromatography to obtain a 3-10 kDa intracellular protein (IP) fraction, which was then hydrolysed with pancreatic enzyme preparation, Corolase PP. The hydrolysed IP fraction from each strain exhibited anti-inflammatory activity by modulating pro-inflammatory mediators, particularly IL-1ß in LPS-stimulated THP-1 macrophages. However, a decrease in IL-8 secretion was only observed with hydrolysed IP fraction from CNRZ-21N, indicating that strain could be an important parameter in obtaining active hydrolysates. Results showed that peptides from the 3-10 kDa IP fraction of S. thermophilus could therefore be considered as postbiotics with potential beneficial effects on human health. Thus, it can be used as a promising bioactive ingredient for the development of functional foods to prevent low-grade inflammation.


Asunto(s)
Proteínas de la Membrana , Streptococcus thermophilus , Humanos , Sulfato de Amonio , Interleucina-1beta , Macrófagos
3.
Interv Neuroradiol ; 29(4): 363-370, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35354315

RESUMEN

BACKGROUND: Heparin induced thrombocytopenia Type II (HIT-II) is a dangerous thromboembolic complication of heparin therapy. The current literature on incidence and outcomes of HIT-II in aneurysmal subarachnoid hemorrhage (aSAH) patients remains sparse. OBJECTIVE: We report our institution's incidence and outcomes of HIT-II in aSAH patients. METHODS: We performed a retrospective cohort study at an academic medical center between June 2014 and July 2018. All patients had aSAH confirmed by digital subtraction angiography. Diagnosis of HIT-II was determined by positive results on both heparin PF4-platelet antibody ELISA (anti-PF4) and serotonin release assay (SRA). RESULTS: 204 patients met inclusion criteria. Seven patients (7/204, 3.5%) underwent laboratory testing, three of whom met clinical criteria. HIT-II incidence was confirmed in two of these seven patients (2/204, 0.98%), who had high BMI and T4 scores. CONCLUSION: Our institution's report of HIT-II incidence in aSAH patients is lower than previously reported in this population and more closely parallels HIT-II incidence in the general and surgical ICU setting. Widely-accepted American College of Chest Physicians (ACCP) clinical diagnostic criteria in conjunction with anti-PF4 and SRA testing is the gold standard of clinical diagnosis of HIT-II in aSAH patients.


Asunto(s)
Hemorragia Subaracnoidea , Trombocitopenia , Trombosis , Humanos , Hemorragia Subaracnoidea/diagnóstico por imagen , Hemorragia Subaracnoidea/tratamiento farmacológico , Estudios Retrospectivos , Trombocitopenia/inducido químicamente , Heparina/efectos adversos , Anticoagulantes/efectos adversos
4.
Nutrients ; 14(24)2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36558497

RESUMEN

Although arachidonic acid (ARA) is the precursor of the majority of eicosanoids, its influence as a food component on health is not well known. Therefore, we investigated its impact on the gut microbiota and gut-brain axis. Groups of male BALB/c mice were fed either a standard diet containing 5% lipids (Std-ARA) or 15%-lipid diets without ARA (HL-ARA) or with 1% ARA (HL + ARA) for 9 weeks. Fatty acid profiles of all three diets were the same. The HL-ARA diet favored the growth of Bifidobacterium pseudolongum contrary to the HL + ARA diet that favored the pro-inflammatory Escherichia-Shigella genus in fecal microbiota. Dietary ARA intake induced 4- and 15-fold colic overexpression of the pro-inflammatory markers IL-1ß and CD40, respectively, without affecting those of TNFα and adiponectin. In the brain, dietary ARA intake led to moderate overexpression of GFAP in the hippocampus and cortex. Both the hyperlipidic diets reduced IL-6 and IL-12 in the brain. For the first time, it was shown that dietary ARA altered the gut microbiota, led to low-grade colic inflammation, and induced astrogliosis in the brain. Further work is necessary to determine the involved mechanisms.


Asunto(s)
Cólico , Microbioma Gastrointestinal , Ratones , Animales , Masculino , Ácido Araquidónico/farmacología , Eje Cerebro-Intestino , Ratones Endogámicos BALB C , Dieta
5.
Nutrients ; 14(22)2022 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-36432464

RESUMEN

Streptococcus thermophilus, a food grade bacterium, is extensively used in the manufacture of fermented products such as yogurt and cheeses. It has been shown that S. thermophilus strains exhibited varying anti-inflammatory activities in vitro. Our previous study displayed that this activity could be partially due to peptide(s) generated by trypsin hydrolysis of the surface proteins of S. thermophilus LMD-9. Surface protease PrtS could be the source of these peptides during gastrointestinal digestion. Therefore, peptide hydrolysates were obtained by shaving two phenotypically distinct strains of S. thermophilus (LMD-9 PrtS+ and CNRZ-21N PrtS-) with pepsin, a gastric protease, followed or not by trypsinolysis. The peptide hydrolysates of both strains exhibited anti-inflammatory action through the modulation of pro-inflammatory mediators in LPS-stimulated THP-1 macrophages (COX-2, Pro-IL-1ß, IL-1ß, and IL-8) and LPS-stimulated HT-29 cells (IL-8). Therefore, peptides released from either PrtS+ or PrtS- strains in the gastrointestinal tract during digestion of a product containing this bacterium may display anti-inflammatory effects and reduce the risk of inflammation-related chronic diseases.


Asunto(s)
Interleucina-8 , Streptococcus thermophilus , Streptococcus thermophilus/metabolismo , Interleucina-8/metabolismo , Lipopolisacáridos/metabolismo , Proteínas Bacterianas/metabolismo , Péptidos/farmacología , Péptidos/metabolismo , Endopeptidasas/metabolismo , Péptido Hidrolasas/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/metabolismo
6.
Nutrients ; 14(11)2022 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-35684011

RESUMEN

(1) Background: A tryptic hydrolysate of bovine αs1-casein (CH) exerts anxiolytic-like properties in many species, including humans. This is mainly related to the presence of α-casozepine (α-CZP), which yields these properties in rodents. This study evaluates, in a rat model, the roles of the vagus nerve and the benzodiazepine binding site of GABAA receptors in the mode of action of CH. (2) Methods: The conditioned defensive burying test was used to evaluate anxiety. (3) Results: Participation of the vagus nerve in the mode of action of CH was excluded, as the global anxiety score in vagotomised rats was not significantly different from that of non-vagotomised animals. The blocking of the binding sites of benzodiazepines with flumazenil antagonised CH anxiolytic-like properties. (4) Conclusions: The vagus nerve does not play a role in the anxiolytic-like properties of CH. On the other hand, this anxiolytic-like activity relies on the benzodiazepine binding site of the GABAA receptors. This result is consistent with previous in vitro studies and, more specifically with the discovery of α-CZP, the peptide responsible for the anxiolytic-like properties of CH.


Asunto(s)
Ansiolíticos , Animales , Ansiolíticos/farmacología , Ansiedad/tratamiento farmacológico , Benzodiazepinas/farmacología , Sitios de Unión , Caseínas/metabolismo , Bovinos , Fragmentos de Péptidos , Ratas , Receptores de GABA-A/metabolismo , Nervio Vago/metabolismo , Ácido gamma-Aminobutírico
7.
Foods ; 11(8)2022 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-35454744

RESUMEN

Streptococcus thermophilus, a lactic acid bacterium widely used in the dairy industry, is consumed regularly by a significant proportion of the population. Some strains show in vitro anti-inflammatory activity which is not fully understood. We hypothesized that peptides released from the surface proteins of this bacterium during digestion could be implied in this activity. Consequently, we prepared a peptide hydrolysate by shaving and hydrolysis of surface proteins using trypsin, and the origin of peptides was checked by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Most of the identified peptides originated from bacterial cell surface proteins. The anti-inflammatory activity of peptide hydrolysate was investigated under inflammatory conditions in two cell models. Peptide hydrolysate significantly decreased secretion of pro-inflammatory cytokine IL-8 in lipopolysaccharide (LPS)-stimulated human colon epithelial HT-29 cells. It also reduced the production of pro-inflammatory cytokines IL-8, IL-1ß and the protein expression levels of Pro-IL-1ß and COX-2 in LPS-stimulated THP-1 macrophages. The results showed that peptides released from bacterial surface proteins by a pancreatic protease could therefore participate in an anti-inflammatory activity of S. thermophilus LMD-9 and could prevent low-grade inflammation.

8.
Microorganisms ; 9(11)2021 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-34835505

RESUMEN

Growth of the lactic acid bacterium Streptococcus thermophilus in milk depends on its capacity to hydrolyze proteins of this medium through its surface proteolytic activity. Thus, strains exhibiting the cell envelope proteinase (CEP) PrtS are able to grow in milk at high cellular density. Due to its LPNTG motif, which is possibly the substrate of the sortase A (SrtA), PrtS is anchored to the cell wall in most S. thermophilus strains. Conversely, a soluble extracellular PrtS activity has been reported in the strain 4F44. It corresponds, in fact, to a certain proportion of PrtS that is not anchored to the cell wall but rather is released in the growth medium. The main difference between PrtS of strain 4F44 (PrtS4F44) and other PrtS concerns the absence of a 32-residue imperfect duplication in the prodomain of the CEP, postulated as being required for the maturation and correct subsequent anchoring of PrtS. In fact, both mature (without the prodomain at the N-terminal extremity) and immature (with the prodomain) forms are found in the soluble PrtS4F44 form along with an intact LPNTG at their C-terminal extremity. Investigations we present in this work show that (i) the imperfect duplication is not implied in PrtS maturation; (ii) the maturase PrtM is irrelevant in PrtS maturation which is probably automaturated; and (iii) SrtA allows for the PrtS anchoring in S. thermophilus but the SrtA of strain 4F44 (SrtA4F44) displays an altered activity.

9.
Microorganisms ; 9(6)2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-34064045

RESUMEN

Despite promising health effects, the probiotic status of Streptococcus thermophilus, a lactic acid bacterium widely used in dairy industry, requires further documentation of its physiological status during human gastrointestinal passage. This study aimed to apply recombinant-based in vivo technology (R-IVET) to identify genes triggered in a S. thermophilus LMD-9 reference strain under simulated digestive conditions. First, the R-IVET chromosomal cassette and plasmid genomic library were designed to positively select activated genes. Second, recombinant clones were introduced into complementary models mimicking the human gut, the Netherlands Organization for Applied Scientific Research (TNO) gastrointestinal model imitating the human stomach and small intestine, the Caco-2 TC7 cell line as a model of intestinal epithelium, and anaerobic batch cultures of human feces as a colon model. All inserts of activated clones displayed a promoter activity that differed from one digestive condition to another. Our results also showed that S. thermophilus adapted its metabolism to stressful conditions found in the gastric and colonic competitive environment and modified its surface proteins during adhesion to Caco-2 TC7 cells. Activated genes were investigated in a collection of S. thermophilus strains showing various resistance levels to gastrointestinal stresses, a first stage in the identification of gut resistance markers and a key step in probiotic selection.

10.
Food Funct ; 12(4): 1415-1431, 2021 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-33527945

RESUMEN

About one in three people are affected by anxiety disorders during their lifetime. Anxiety episodes can be brief due to a stressful event, but anxiety disorders can last at least 6 months. A wide variety of therapeutic drugs are available for the treatment of anxiety disorders, but due to the associated side effects of these anxiolytics, it is interesting to find alternatives. Some food protein hydrolysates or active peptide fragments present in such hydrolysates provide a natural and promising mean for preventing certain forms of anxiety. To date, only a small number of hydrolysates or peptides from food proteins with anxiolytic-like activity have been characterized. Most of these hydrolysates or peptides have displayed potent anxiolytic profiles in animal or clinical studies. The results suggest that these molecules may exert their effects at different levels. This paper reviews the data of the structure/activity relationship, physiological effects displayed in in vitro and in vivo assays, bioavailability, and safety profiles of anxiolytic peptides.


Asunto(s)
Ansiedad/tratamiento farmacológico , Proteínas en la Dieta/análisis , Hidrolisados de Proteína/uso terapéutico , Animales , Ansiolíticos/farmacología , Trastornos de Ansiedad/tratamiento farmacológico , Caseínas/química , Caseínas/uso terapéutico , Proteínas de Peces/química , Humanos , Proteínas de la Leche/química , Oligopéptidos/uso terapéutico , Fragmentos de Péptidos/química , Fragmentos de Péptidos/uso terapéutico , Ribulosa-Bifosfato Carboxilasa/uso terapéutico , Proteínas de Soja/química
11.
Adv Respir Med ; 89(2): 207-210, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33559117

RESUMEN

The discovery of a malignant pleural effusion indicates metastatic disease and thus invariably results in the highest possible cancer stage. Although the female reproductive tract overall is a common primary tumor site giving rise to malignant pleural effusion, vulvar carcinoma stands out for its propensity for locoregional spread rather than distant metastasis. Our case contributes to the extremely limited number of published descriptions of thoracic involvement by vulvar carcinoma, with malignant pleural effusion being a particularly unusual pattern.


Asunto(s)
Carcinoma de Células Escamosas/secundario , Derrame Pleural Maligno/diagnóstico , Derrame Pleural Maligno/etiología , Neoplasias de la Vulva/patología , Carcinoma de Células Escamosas/patología , Femenino , Humanos , Vulva/patología , Neoplasias de la Vulva/diagnóstico
12.
Cureus ; 12(4): e7719, 2020 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-32431997

RESUMEN

Background With the recent advancement in medicine there has been a great emphasis on the management of chronic pain which remains as one of the major contributing factors for functional limitation in patients as well as a financial burden on healthcare. Newer treatment modalities are aimed at terminating the vicious pain cycles and in this regard peripheral nerve blocks have proven to be very effective. Objectives The aim of this study is to evaluate the effectiveness of interventions for both cancer and non-cancer patients by objective assessment of the patients before and after the procedure. Materials and methods The study included 252 patients who underwent nerve block procedures in Shaukat Khanum Memorial Cancer Hospital from December 2016 to December 2018. The patients were evaluated using numerical rating scale (NRS) for pain, reduction in analgesic doses and patient satisfaction after one and four weeks post procedure. The data was analyzed using mean values and calculating percentages. Results In cancer group, 168 patients were included; mean age 50.49 ± 15.39 with 46.43% females and 53.57% males, the average pain score was 2.62 ± 1.87 post procedure compared with 6.30 ± 1.87 post procedure. 48.21% of the patients reported a reduction in analgesia while 51.79% of the patients kept on using the same analgesics doses. 74.40% of the patients were satisfied and 25.60% patients remained unsatisfied after one week whereas 66.07% were satisfied, 23.81% were not satisfied and 10.12% loss to follow up after four weeks. In non-cancer group 84 patients were included; mean age 56.49 ± 15.79 with 41.67% females and 58.33% males, the average pain score before intervention was 5.99 ± 1.21 and after intervention it was 2.43 ± 1.62. In 73.81% non-cancer patients the analgesics doses were reduced and 70.24% patients were satisfied while 29.76% were unsatisfied after one week. After four weeks 55.95% were satisfied, 22.62% were not satisfied and 21.43% loss to follow up. Conclusion The study showed decrease in pain scores in both group of patients and the importance of nerve blocks as an effective method for chronic pain management. The reduction in the use of other analgesics was also commendable in both the groups.

13.
Food Res Int ; 131: 108906, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32247482

RESUMEN

The mucus, mainly composed of the glycoproteins mucins, is a rheological substance that covers the intestinal epithelium and acts as a protective barrier against a variety of harmful molecules, microbial infection and varying lumen environment conditions. Alterations in the composition or structure of the mucus could lead to various diseases such as inflammatory bowel disease or colorectal cancer. Recent studies revealed that an exogenous intake of probiotic bacteria or other dietary components (such as bioactive peptides and probiotics) derived from food influence mucus layer properties as well as modulate gene expression and secretion of mucins. Therefore, the use of such components for designing new functional ingredients and then foods, could constitute a novel approach to preserve the properties of mucus. After presenting some aspects of the mucus and mucins in the gastrointestinal tract as well as mucus role in the gut health, this review will address role of dietary ingredients in improving mucus/mucin production and provides new suggestions for further investigations of how dietary ingredients/probiotics based functional foods can be developed to maintain or improve the gut health.


Asunto(s)
Digestión/fisiología , Alimentos Funcionales , Mucinas , Probióticos , Animales , Humanos
14.
J Dairy Sci ; 102(1): 113-123, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30391182

RESUMEN

This study addresses the hypothesis that the extracellular cell-associated X-prolyl dipeptidyl-peptidase activity initially described in Streptococcus thermophilus could be attributable to the intracellular X-prolyl dipeptidyl-peptidase PepX. For this purpose, a PepX-negative mutant of S. thermophilus LMD-9 was constructed by interrupting the pepX gene and named LMD-9-ΔpepX. When cultivated, the S. thermophilus LMD-9 wild type strain grew more rapidly than its ΔpepX mutant counterpart. Thus, the growth rate of the LMD-9-ΔpepX strain was reduced by a factor of 1.5 and 1.6 in milk and LM17 medium (M17 medium supplemented with 2% lactose), respectively. The negative effect of the PepX inactivation on the hydrolysis of ß-casomorphin-7 was also observed. Indeed, when incubated with this peptide, the LMD-9-ΔpepX mutant cells were unable to hydrolyze it, whereas this peptide was completely degraded by the S. thermophilus LMD-9 wild type cells. This hydrolysis was not due to leakage of intracellular PepX, as no peptide hydrolysis was highlighted in cell-free filtrate of wild type strain. Therefore, based on these results, it can be presumed that though lacking an export signal, the intracellular PepX might have accessed the ß-casomorphin-7 externally, perhaps via its galactose-binding domain-like fold, this domain being known to help enzymes bind to several proteins and substrates. Therefore, the identification of novel distinctive features of the proteolytic system of S. thermophilus will further enhance its credibility as a starter in milk fermentation.


Asunto(s)
Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/metabolismo , Péptido Hidrolasas/metabolismo , Streptococcus thermophilus/enzimología , Animales , Cromatografía Líquida de Alta Presión , Cromatografía de Fase Inversa , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/química , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/genética , Endorfinas/metabolismo , Hidrólisis , Leche/química , Leche/microbiología , Fragmentos de Péptidos/metabolismo , Péptidos/análisis , Péptidos/metabolismo , Proteolisis , Streptococcus thermophilus/genética , Streptococcus thermophilus/crecimiento & desarrollo
15.
Curr Drug Targets ; 18(11): 1269-1280, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27400970

RESUMEN

BACKGROUND: Global death rate due to cardiovascular diseases (CVDs) is highest as compared to other ailments. Principal risk factor associated with CVDs is hypertension. Major classes of current antihypertensive (AHT) therapies include angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARBs) and calcium channel blockers (CCBs). All these antihypertensive therapeutic drugs have low oral bioavailability and can induce upper respiratory tract abstraction, angioedema, reflex tachycardia and extreme hypotensive effect after oral administration which can cause lethal effects in patients with heart diseases. OBJECTIVE: Controlled and targeted release by using antihypertensive nano-medicines can provide better solution to overcome above-mentioned side effects. RESULTS: Scientific evolution towards the development of biopolymer based nano-carrier systems has unlocked new horizons for safe and/or edible nano drug delivery systems. In this article, we have reviewed in detail various mechanisms of AHT drugs, major draw backs associated with current therapeutic strategies, and the advantages of AHT nano-medicines over conventional drugs. Furthermore, recent reports of bio-based nano/micro -carrier systems with different AHT drugs have been analyzed with their key features. In depth review has been presented for chitosan as a potential carrier of AHT drugs due to its distinctive properties comprising muco-adhesive attribute, permeation enhancement as well as its biocompatible and biodegradable nature. CONCLUSION: Chitosan based novel AHT nano-ceuticals can improve oral bioavailability, reduce hydrophobicity and increase the plasma half-life of AHT drugs by their sustained release in lower part of the GIT.


Asunto(s)
Antihipertensivos/administración & dosificación , Hipertensión/tratamiento farmacológico , Nanomedicina/métodos , Antihipertensivos/farmacocinética , Disponibilidad Biológica , Quitosano/farmacocinética , Portadores de Fármacos , Semivida , Humanos
16.
J Agric Food Chem ; 63(34): 7522-31, 2015 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-26193375

RESUMEN

The influence on the hydrolysis of isracidin of cell-associated extracellular aminopeptidase and X-prolyl dipeptidyl peptidase activities in addition to protease PrtS of Streptococcus thermophilus strains was investigated. S. thermophilus LMD-9 (PrtS(+) phenotype) efficiently hydrolyzed the isracidin mainly through the PrtS activity, whereas strain CNRZ1066 (PrtS(-) phenotype) and two mutant strains LMD-9-ΔprtS and LMD-9-ΔprtS-ΔhtrA also displayed substrate hydrolysis, but different from that of the wild type strain LMD-9. Identification by mass spectrometry of breakdown products of isracidin revealed the existence of novel cell-associated extracellular carboxypeptidase and peptidyl dipeptidase activities in all PrtS(-) strains, besides known cell-associated extracellular aminopeptidase and X-prolyl dipeptidyl peptidase activities. Both aminopeptidase and peptidyl dipeptidase activities were not able to cleave the isracidin at peptide bonds with proline residues. No hydrolysis of isracidin was detected in cell free filtrate for all the strains studied, indicating that no cell lysis had occurred. Taken together, these results suggested the presence of cell-associated extracellular peptidase activities in S. thermophilus strains that could be vital for the growth of PrtS(-) strains.


Asunto(s)
Proteínas Bacterianas/metabolismo , Caseínas/metabolismo , Endopeptidasas/metabolismo , Fragmentos de Péptidos/metabolismo , Streptococcus thermophilus/enzimología , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Caseínas/química , Caseínas/genética , Endopeptidasas/química , Endopeptidasas/genética , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Proteolisis , Streptococcus thermophilus/química , Streptococcus thermophilus/genética
17.
Appl Microbiol Biotechnol ; 97(22): 9787-99, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24077683

RESUMEN

The trend to confer new functional properties to fermented dairy products by supplementation with bioactive peptides is growing in order to encounter the challenge of health-promoting foods. But these functional ingredients have not to be hydrolysed by proteases of bacteria used in the manufacture of these products. One of the two yoghurt bacteria, Streptococcus thermophilus, has long been considered as weakly proteolytic since its only cell wall-associated subtilisin-like protease, called PrtS, is not always present. Nevertheless, a recent study pointed out a possible peptidase activity in certain strains. In this present study, the stability of milk-derived bioactive peptides, e.g. the anxiolytic peptide, αs1-CN-(f91-97), in the presence of two different S. thermophilus strains with PrtS+ or PrtS− phenotype was studied. Both strains appeared to be capable of hydrolysing the αs1-CN-(f91-97) and other bioactive peptides by recurrent removal of N-terminal residues. The hydrolysis was neither due to intracellular peptidases nor to HtrA protease. Results obtained showed that the observed activity originates from the presence at the surface of both strains of an extracellular aminopeptidase activity. Moreover, a cell wall-associated X-prolyl dipeptidyl peptidase activity was also highlighted when ß-casomorphin-7 was used as substrate. All of these findings suggest that, in order to use fermented milks as vector of bioactive peptides, the stability of these bioactive peptides in this kind of products implies to carefully characterize the potential action of the surface proteolytic enzymes of S. thermophilus.


Asunto(s)
Enzimas Inmovilizadas/metabolismo , Leche/química , Péptido Hidrolasas/metabolismo , Péptidos/metabolismo , Streptococcus thermophilus/enzimología , Animales , Hidrólisis
18.
Br J Haematol ; 160(2): 237-43, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23157319

RESUMEN

Predictive biomarkers are needed in immune thrombocytopenia (ITP). Single nucleotide polymorphisms (SNPs) in beta 1 tubulin are potential candidates, as beta 1 tubulin is integral for platelet production and function, and SNPs in beta 1 tubulin have been associated with distinct phenotypes in platelets. We investigated the most prevalent beta 1 tubulin SNP (R307H) as a biomarker in patients with ITP via a retrospective chart review. Allelic frequencies between a group of 191 ITP patients and a healthy control group showed no difference, suggesting no direct aetiological role for the SNP in ITP. However, over similar periods of follow-up, both heterozygote and homozygote minor allele ITP patients were treated with significantly more treatment modalities and had significantly higher risk of failure to immune-modulatory therapies [relative risk (RR) = 1·5, 95% confidence interval (CI) = 1·1-2·1; P = 0·01]; with rituximab, in particular, ITP patients with the SNP experienced a 58% failure rate (RR = 1·6, 95%CI = 1·03-2·5; P = 0·04). Analysis of the absolute immature platelet fraction (A-IPF) as a marker of platelet production showed that SNP patients had significantly higher median A-IPFs compared to non-SNP patients when complete responses were achieved using immune modulatory therapies. The data suggest that the beta 1 tubulin R307H SNP has potential for use as a biomarker in ITP and may affect platelet turnover.


Asunto(s)
Factores Inmunológicos/uso terapéutico , Polimorfismo de Nucleótido Simple , Púrpura Trombocitopénica Idiopática/genética , Receptores de Trombopoyetina/agonistas , Tubulina (Proteína)/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Benzoatos/uso terapéutico , Biomarcadores , Niño , Preescolar , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Hidrazinas/uso terapéutico , Lactante , Masculino , Persona de Mediana Edad , Fenotipo , Recuento de Plaquetas , Púrpura Trombocitopénica Idiopática/sangre , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Pirazoles/uso terapéutico , Receptores Fc/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Estudios Retrospectivos , Rituximab , Tiazoles/uso terapéutico , Tiofenos/uso terapéutico , Trombopoyesis/genética , Trombopoyetina/uso terapéutico , Insuficiencia del Tratamiento
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