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M Farina

Publications and source records attributed to M Farina.

At least 55 records · Page 3Linked to original sources

In vivo and in vitro effects of lysine clonixinate on nitric oxide synthase in LPS-treated and untreated rat lung preparations.

Recent studies have shown that some nonsteroidal antiinflammatory drugs (NSAIDS) inhibited the inducible NO synthase (iNOS) without direct effect on the catalytic activity of this enzyme. This study was conducted to investigate the in vitro and in vivo effects of lysine clonixinate (LC) and indomethacin (INDO) on NOS activity in rat lung preparation. LC is a drug with antiinflammatory, antipyretic, and analgesic action. In the in vitro experiments, rats were injected with saline or lipopolysaccharide (LPS) and killed 6 h after treatment. Lung preparations were incubated with LC at 2.3 x 10(-5) M or 3.8 x 10(-5) M. The minimum concentration did not modify NOS activity in control or LPS-treated rats but the maximum dose inhibited increased NO production induced by LPS. Furthermore, INDO at 10(-6) M had no effect on enzymatic activity in control or LPS-treated rats. In the in vivo experiments, 40 mg/kg of LC were injected ip. Such a dose did not affect basal production of NO. When LC and LPS were injected simultaneously 6 h before sacrifice, a significant decrease in LPS-induced NOS activity was observed. INDO 10 mg/kg injected in control animals had no effect on NOS activity and did not block LPS induced stimulation of NO production when injected simultaneously. Finally, when LC (40 mg/kg) was injected 3 h after LPS, the enzymatic activity remained unchanged. Expression of iNOS was detected by Western blotting in rats treated with LPS plus 4, 10, 20, and 40 mg/kg of LC. The lowest dose was the only one showing no effect on LPS-induced increase of iNOS. In short, LC is a NSAID with inhibitory action on the expression of LPS-induced NOS, effect that was not seen with INDO in our experimental conditions.

Animals↗

Amorphous mineral phases in magnetotactic multicellular aggregates.

Magnetotactic multicellular aggregates consist of several bacteria that produce iron sulfide magnetosomes through a complex and poorly understood process. We observed new amorphous mineral particles within the cytoplasm of magnetotactic multicellular aggregates. Elemental mapping and electron energy loss spectroscopy detected iron and oxygen, but not sulfur, in these particles. These amorphous particles were about the same size as mature magnetosomes, around 50-70 nm in diameter. No membranes were observed surrounding the amorphous minerals. Partially crystalline inclusions composed of a crystalline core and an amorphous region around them similar in texture to the amorphous particles were also present. The shape of these amorphous regions followed the shape of the crystalline cores they enveloped. These regions also contained oxygen and iron. The crystalline phase, as previously reported, contained sulfur and iron. The presence of independent amorphous particles has not been reported before in magnetotactic multicellular aggregates.

Bacterial Physiological Phenomena↗

Determining the best catheter for sonohysterography.

OBJECTIVE: To compare the characteristics of six different catheters for performing sonohysterography (SHG) to identify those that offer the best compromise between reliability, tolerability, and cost. DESIGN: Prospective study. SETTING: University hospital. PATIENT(S): Six hundred ten women undergoing SHG. INTERVENTION(S): We performed SHG with six different types of catheters: Foleycath (Wembley Rubber Products, Sepang, Malaysia), Hysca Hysterosalpingography Catheter (GTA International Medical Devices S.A., La Caleta D.N., Dominican Republic), H/S Catheter Set (Ackrad Laboratories, Cranford, NJ), PBN Balloon Hystero-Salpingography Catheter (PBN Medicals, Stenloese, Denmark), ZUI-2.0 Catheter (Zinnanti Uterine Injection; BEI Medical System International, Gembloux, Belgium), and Goldstein Catheter (Cook, Spencer, IN). MAIN OUTCOME MEASURE(S): We assessed the reliability, the physician's ease of use, the time requested for the insertion of the catheter, the volume of contrast medium used, the tolerability for the patients, and the cost of the catheters. RESULT(S): In 568 (93%) correctly performed procedures, no statistically significant differences were found among the catheters. The Foleycath was the most difficult for the physician to use and required significantly more time to position correctly. The Goldstein catheter was the best tolerated by the patients. The Foleycath was the cheapest whereas the PBN Balloon was the most expensive. CONCLUSION(S): The choice of the catheter must be targeted to achieving a good balance between tolerability for the patients, efficacy, cost, and the personal preference of the operator.

Adult↗

Placing the newborn on the maternal abdomen increases the volume of umbilical cord blood collected.

Haematopoietic stem cell transplantation is an important therapy for certain haematological and malignant disorders. Umbilical cord blood contains a high proportion of potentially transplantable haematopoietic progenitor cells. However, the use of cord blood stem cell transplantation is limited by the low number of stem cells obtainable from a single cord blood donor. The aim of our study was to investigate the possibility that procedures during delivery might influence the number of umbilical cord blood haematopoietic progenitor cells available for transplantation. We assessed the effects of upper and lower positions of the newborn infant on the yield of cord blood stem cells in 51 vaginal deliveries. Neonates in the upper position group were placed by the midwife on the maternal abdomen immediately after birth, while those in the lower position group were placed on the delivery table, below the maternal introitus. The total volume of cord blood and the total number of CD34+ cells collected from babies in the upper position group were significantly higher than those from babies in the lower position group. There were no significant differences in cord blood haemoglobin levels and white blood cell counts between the two groups, nor were there any adverse effects in the newborn infants. The simple manoeuvre of placing the newborn on the maternal abdomen after delivery may thus increase the yield of transplantable haematopoietic progenitor cells in cord blood.

Abdomen↗

Effect of hydrostatic pressure on the morphology and ultrastructure of wild-type and trehalose synthase mutant cells of Saccharomyces cerevisiae.

AIMS: Saccharomyces cerevisiae was used for studying the physiological effects of hydrostatic pressure. METHODS AND RESULTS: The effects of hydrostatic pressure on the ultrastructure of wild-type and trehalose-6-phosphate synthase (tps1) mutant cells were investigated by transmission electron microscopy. Pressure induced several morphological changes in wild-type and tps1 cells, the latter showing greater structural alterations. When the cells were submitted to a preheat treatment they both acquired resistance to the pressure treatment. CONCLUSION: As the tps1 mutant was 1000-fold more barosensitive than its parental strain, it showed greater structural alterations compared with the wild-type. Microscopic images of the yeast cells suggested that hydrostatic pressure induced changes in the cytoskeleton and therefore, on the cell wall and in the dynamics of the organelles. SIGNIFICANCE AND IMPACT OF THE STUDY: This work presents the effects of hydrostatic pressure on the morphology of yeast cells and confirms the importance of several different factors in the protection of cells against stress.

Glucosyltransferases↗

Early clamping of umbilical cord blood and foetal CD34 enrichment.

We describe the relation between clamping time and blood volume collected, and two enrichment systems of CD34+ stem cells from umbilical cord blood, in order to determine the criteria for an excellent recovery with high proliferative ability and bone marrow reconstitution. After an obstetrician-based cord blood collection, the purification of stem cells was performed either with a combination of monoclonal antibodies, negative selections, using the Stem Sep method, or with a positive cells selection owing to their surface CD34 antigens, using the Mini Macs system. An excellent recovery of haematopoietic progenitors--burst forming unit erythroid; colony-forming unit granulocyte and macrophage; and colony-forming unit granulocyte, erythroid, monocyte, and macrophage--inversely related to an increase in clamping time, was achieved using the Mini Macs system (54% of colonies with a 90% purity), while the recovery of haematopoietic progenitors was 35% (with a 80% purity) using the Stem Sep method. By clamping umbilical cord blood at an early stage, we obtained a greater number of CD34+ cells, and their clonogenic activity increased with enrichment. This is particularly useful considering that the number of CD34+ stem cells contained in a unit of placental blood is sufficient for transplanting into a child but not for an adult engraftment. Thus, using these methods, we obtain a larger number of CD34+ stem cells. This increases the possibility of reducing graft versus host disease in adult patients and produces survival rates similar to the ones we observed in transplantation of bone marrow from unrelated donors.

Antigens, CD↗

Clinical, endocrine and metabolic effects of acarbose, an alpha-glucosidase inhibitor, in PCOS patients with increased insulin response and normal glucose tolerance.

BACKGROUND: The aim of this study was to evaluate whether treatment with acarbose, an alpha-glucosidase inhibitor, improved hyperandrogenic symptoms, insulin and androgen serum concentrations in hyperinsulinaemic patients with polycystic ovary syndrome (PCOS). METHODS: 30 hyperinsulinaemic women with PCOS and 15 controls were evaluated. Patients were randomized, using a computer-generated randomization list, into two groups of 15 each and treated with placebo or 300 mg/day of acarbose for three months. Hirsutism and acne/seborrhoea scores, hormonal and sex hormone binding globulin serum concentrations, glycaemia and insulin responses to a standard oral glucose load (75g) were measured in all patients before and after three months of treatment. RESULTS: A significant reduction of the acne/seborrhoea score was observed in patients treated with acarbose and eight of them resumed a regular menstrual rhythm. These clinical improvements were associated with a significant reduction of the insulin response to glucose load, a significant decrease of LH, total testosterone and androstenedione and with a significant increase of sex hormone binding globulin serum concentrations. The serum concentrations of FSH, dehydroepiandrosterone sulphate, prolactin and 17alpha-hydroxyprogesterone did not change significantly. No clinical, metabolic and hormonal modifications were observed in PCOS patients treated with placebo. CONCLUSIONS: This is the first report showing a reduction of the acne/seborrhoea score in hyperinsulinaemic patients with PCOS treated with acarbose. This improvement was associated with a significant decrease of the insulin response to oral glucose load and of LH and androgen serum concentrations and with a significant rise of sex hormone binding globulin concentration.

Acarbose↗

Endocrine and metabolic effects of insulin sensitizers in the treatment of patients with polycystic ovary syndrome and hyperinsulinaemia.

We evaluated 16 women with polycystic ovary syndrome (PCOS) and 67 controls, aged 18-34 years. All subjects had an oral glucose tolerance test (OGTT), showing a normal response. They were subdivided into 2 groups (normoinsulinaemic, hyperinsulinaemic) undergoing 7 days of octreotide treatment. This caused modifications in body mass index, waist-hip ratio and blood pressure. No modifications were observed in basal luteinizing hormone (LH), follicle-stimulating hormone, androgens, 17alpha-hydroxyprogesterone, oestradiol, sex-hormone-binding globulin (SHBG), prolactin and cortisol serum concentrations in normoinsulinaemic patients. A significant decrease in the concentration of LH, androgens, and a significant increase in SHBG were observed in the hyperinsulinaemic patients. In hyperinsulinaemic patients, the treatment restored a regular insulinaemic response to an OGTT. No modifications of glycaemic response were detected in normoinsulinaemic ones. In hyperinsulinaemic patients, a decompensation of the glycaemic response was observed. Several agents (insulin sensitizers) decrease insulin secretion and androgen concentration. They could be considered an approachable long-term therapy for hyperinsulinaemic hyperandrogenic patients. In the next few years the pharmacotherapy for PCOS could be greatly expanded, allowing some patients, such as hyperinsulinaemic ones, to be treated with insulin sensitizers.

17-alpha-Hydroxyprogesterone↗

Nitric oxide synthases in pregnant rat uterus.

The conversion of [14C]arginine into [14C]citrulline as an indicator of nitric oxide synthesis was studied in uteri isolated from rats on different days of gestation, after labour and during dioestrus. Nitric oxide synthesis was present in uterine tissues isolated at each stage of gestation and also in tissues collected during dioestrus and after labour. Expression of neuronal nitric oxide synthase was not detectable at any of the stages studied. Endothelial nitric oxide synthase was present at all the stages studied, but there was a significant increase on day 13 of gestation and a decrease thereafter, with the lowest expression recorded on the day after labour. Inducible nitric oxide synthase expression in rat uteri increased substantially during pregnancy, with the highest expression on day 13 of gestation; expression decreased at term and after labour. The changes in expression of inducible nitric oxide synthase were coincident with the changes in nitric oxide synthase activity in uteri treated with aminoguanidine. Thus, these findings indicate that an increase in expression of inducible nitric oxide synthase in the uterus may be important for maintenance of uterine quiescence during pregnancy and its decrease near the time of labour could have an effect on the start of uterine contractility.

Animals↗

Regulation of lipid peroxidation by nitric oxide and PGF2alpha during luteal regression in rats.

Corpus luteum regression is related to an increased generation of reactive oxygen species. Although several studies indicate that PGF(2alpha) is involved in regression of the corpus luteum in mammalian species through an increase in reactive oxygen species, the exact mechanism remains unknown. In the present study, the relationship between nitric oxide and PGF(2alpha) in regulation of lipid peroxidation was studied. Ovarian tissue from pseudopregnant rats at mid- (day 5) or late phase or at the time of regression (day 9 of pseudopregnancy) of corpus luteum development was used. Thiobarbituric acid reactants, used as a lipid peroxidation index, were higher on day 9 of pseudopregnancy than on day 5. In contrast, glutathione content (an antioxidant metabolite) was lower on day 9 than on day 5 of pseudopregnancy. These results indicate that there was an enhanced oxidative status in ovarian tissue during luteolysis. Administration of N(omega)-nitro-L-arginine methyl ester (L-NAME: 600 micromol l(-1)), a competitive nitric oxide synthase (NOS) inhibitor, led to a decrease in basal thiobarbituric acid reactant content in ovarian tissue from rats on day 9 of pseudopregnancy only, indicating that during regression of the corpus luteum, NO could act as intermediary in ovarian lipid peroxidation. Administration of a luteolytic dose (3 microg kg(-1) body weight i.p.) of a synthetic PGF(2alpha) increased thiobarbituric acid reactant content in ovaries from rats on day 9 of pseudopregnancy. As this effect was reversed partially by L-NAME, it is proposed that during regression of corpora lutea, PGF(2alpha) and NO are involved in regulation of lipid peroxidation. As this effect was only reversed partially, it is possible that there is another mechanism involving PGF(2alpha) (but not the NO-NOS pathway) in regulation of ovarian lipid peroxidation. Furthermore, the administration of PGF(2alpha) enhanced ovarian NOS activity, whereas cyclooxygenase inhibition (by indomethacin treatment in vivo) reduced it. As western blotting of ovarian homogenates obtained from PGF(2alpha)-injected rats increased inducible NOS (iNOS) content, it is concluded that PGF(2alpha) enhances both activity and synthesis of NO in rat ovarian tissues during luteolysis. Taken together, these results indicate that in ovaries with regressing corpora lutea, both NO and PGF(2alpha) are involved in part in regulation of lipid peroxidation.

Animals↗

Adenomyosis and uterus rupture during labor.

A spontaneous uterus rupture occurred during the labour of a 37-week-pregnant woman showing a precocious rupture of membranes. It appeared enlarged and the cut surface of the myometrium showed coarse trabeculations. The histological examination showed a hypertrophic gravidic myometrium with heterogeneous areas of fibrosis and adenomyosis, necrotic decidual foci and hyperplastic cervical canal glands. Our experience suggests that a silent and spontaneous uterine rupture, is possible even in the absence of the principal risk factors.

Adult↗

[Sentinel lymph node for breast cancer: remove less to know more].

BACKGROUND: Our aim was to study the value of sentinel lymph node (SLN) biopsy in patients with breast cancer seen at a community hospital. METHODS: Consecutive cases receiving primary treatment for unicentric breast cancer less than 3 cm in diameter were prospectively studied from January 1999 to July 2000. All patients signed a detailed informed consent. The majority of patients (89%) underwent a combined technique of intradermal injection of 0.3-1.2 mCi of (99)Tc and 1-3 cc of Patent Blue at the biopsy site. Intraoperative localization was performed with a hand-held gamma probe. The first 15 patients underwent routine back-up lymphadenectomy. Thereafter, only patients with positive SLN, suspicious findings, or personal preference underwent formal axillary dissection. RESULTS: One hundred eight cases were included in the study with a median age of 61 years and a median diameter of the breast tumor of 1.5 cm. Success rate for identification of SLN was 94% (101/108 cases). A total of 917 additional lymph nodes were removed after SLN biopsy (median 6.5 lymph nodes/patient). Correlation between SLN and the final axillary status was 98%. In 20/36 patients (61%) with positive axillary status the sentinel lymph node was the only positive one. Ten patients had only microscopic foci of cancer found in the SLN. Sixty-seven patients (62%) could have avoided axillary dissection becouse the SLN was found, it was negative, and there were no other intraoperative suspicious findings. CONCLUSIONS: SLN biopsy is accurate and easily reproduced. Our data confirms that the majority of breast cancer patients may no longer need routine axillary lymphadenectomy.

Adult↗

[Effect of nonsteroidal antiinflammatory drugs on colonic lipoxygenase and cyclooxygenase activities from patients with colonic neoplasia].

Lysine clonixinate (LC) is a nonsteroidal anti-inflammatory drug (NSAID) with good gastrointestinal tolerance. Treatment with LC at levels equivalent to those found in plasma following therapeutic doses resulted in significant inhibition of both cyclooxygenase 2 (COX-2) and production of 5 hydroxy-eicosatetraeonic acid (5-HETE) and slightly affected levels of cyclooxygenase 1 (COX-1) in in vitro studies carried out on human tissues. This study deals with the in vivo effect of the drug on human colon segments. Experiment 1: Five patients about to undergo hemicholectomy due to colon neoplasia were treated preoperatively with a continuous infusion of LC, to achieve a steady-state concentration between 4 and 6 mg/ml. Human colon segments from the five patients and from another five control patients receiving no treatment with [14C]-arachidonic acid were incubated. Human colon segments treated with LC showed significant inhibition of PGE2, the only prostaglandin (PG) synthesised by the tissue, as well as of 5-HETE. Experiment 2: Fifteen patients received an i.v. bolus of LC 100 mg (n1 = 5); LC 200 mg (n2 = 5) or indomethacin (INDO) 50 mg (n3 = 5). Both doses of LC showed greater inhibition of PGE2 synthesis than the INDO bolus. Both NSAIDs studied proved to have different effects on the production of 5-HETE; while treatment with LC elicited significant inhibition, levels with INDO remained unchanged. Western blotting analysis showed expression of both COX isoforms in colon segments, COX-2 levels being 20% higher. Both types of in vivo studies conducted continuous infusion and i.v. bolus, revealed that LC exerted significant inhibition of basal synthesis of PGE2 and 5-HETE.

Anti-Inflammatory Agents, Non-Steroidal↗

Two enrichment methods to obtain CD34+ stem cells from umbilical cord blood.

We describe the relation between umbilical cord clamping time and two different enrichment system of CD34+ stem cells from umbilical cord blood with the proliferative ability and bone marrow reconstitution of the stem cells obtained. After an obstetrician performed the cord blood collection, the purification of stem cells was performed either with a combination of monoclonal antibodies (negative selections) using the Stem Sep method, or with a positive cells selection based on their surface CD34 antigens using the Mini Macs system. An excellent recovery of haematopoietic progenitors (Burst Forming Unit Erythroids (BFUE); Colony Forming Unit Granulocytes and Macrophages (CFU-GM); and Colony Forming Unit Granulocytes, Erythroids, Monocytes and Macrophages (CFU-GME)), inversely related to the increase in clamping time, was performed with the Mini Macs system (54% of colonies, with a 90% purity). With Stem Sep method, haematopoietic progenitors recovery was 35% (with a 80% purity). By applying early clamping of umbilical cord blood we obtained a greater number of CD34+ cells and their clonogenic activity was increased with enrichment. This is a useful technique considering that the number of CD34+ stem cells usually contained from a unit of placental blood is enough for the transplant to a child, but not for an adult. Thus, using these methods, we can get a larger number of CD34+ stem cells which reduces the risk of Graft versus Host Disease also in adult patients, producing survival rates similar to the those obtained with transplantation of bone marrow from unrelated donors.

Antibodies, Monoclonal↗

Elemental analysis of uncultured magnetotactic bacteria exposed to heavy metals.

Natural enrichments of magnetotactic bacteria were used to study the sites where heavy metals accumulate in uncultured bacteria. Most bacteria obtained by magnetic concentration from these enrichments contained, in addition to the magnetosomes, large phosphorus-rich granules in the cytoplasm. Metal (Zn, Mn, Sr, Cd, Al, Cr, and Pb) chlorides were added independently to the enrichments, and after 24 h, the elemental composition of the phosphorus-rich granules, magnetosomes, and "soft parts" (cytoplasm plus cell envelope) of whole bacteria was analyzed by energy-dispersive X-ray analysis on a transmission electron microscope. All bacteria contained Mn and Sr in the phosphorus-rich granules; some of them presented Mn peaks also in the soft parts. Zinc accumulation was variable and was found mainly in the phosphorus-rich granules, but also in the soft part of some bacteria. Some analyzed bacteria presented Zn peaks only in the soft parts, and some of them did not present Zn in any structure. Cadmium and Al were found only in the granules of some bacteria. Chromium was found in the soft parts of some bacteria. Lead was not detected in any bacteria. We concluded that the phosphorus-rich granules are major sites for metal accumulation by these bacteria. No conclusive results for magnetosomes were obtained because of the limitations of the analytical techniques particularly when used for whole cell analysis.

Bacteria↗

The otoconia of the guinea pig utricle: internal structure, surface exposure, and interactions with the filament matrix.

A unique feature of the vertebrate gravity receptor organs, the saccule and utricle, is the mass of biomineral structures, the otoconia, overlying a gelatinous matrix also called "otoconial membrane" on the surface of the sensory epithelium. In mammals, otoconia are deposits of calcium carbonate in the form of composite calcite crystals. We used quick-freezing, deep etching to examine the otoconial mass of the guinea pig utricle. The deep-etching step exposed large expanses of intact and fractured otoconia, showing the fine structure and relationship between their internal crystal structure, their surface components, and the filament matrix in which they are embedded. Each otoconium has a compact central core meshwork of filaments and a composite outer shell of ordered crystallites and macromolecular aggregates. A distinct network of 20-nm beaded filaments covers the surface of the otoconia. The otoconia are interconnected and secured to the gelatinous matrix by surface adhesion and by confinement within a loose interotoconial filament matrix. The gelatinous matrix is a dense network made of yet another type of filament, 22 nm in diameter, which are cross-linked by shorter filaments, characteristically 11 nm in diameter. Our freeze-etching data provide a structural framework for considering the molecular nature of the components of the otoconial complex, their mechanical properties, and the degree of biological versus chemical control of otoconia biosynthesis.

Animals↗

Pregnancy outcome of a transfusion-dependent thalassemic woman.

A clinical case concerning a normal pregnancy outcome in a transfusion-dependent woman affected by homozygous beta thalassemia, whose partner was negative with regard to the "thalassemic trait", was reported. The patient showed no iron deposit problems, viral diseases that could have made the pregnancy management difficult or any complications during the gestation. Blood transfusion was not necessary during the following caesarean delivery. The outcome was a healthy female child, born at a gestational age of 38 weeks, showing neither malformations nor problems. This was possible due to a detailed preconceptual guidance and a pre-pregnancy assessment. The patient normally would have had a blood transfusion every 20 days and a strict desferrioxamine chelating therapy; however, this treatment was suspended during her pregnancy because of the well-recognised teratogenic effects of the drug. The average values of ferritin were just a little higher than before being pregnant. The foetus, due to her particular chelating activity, probably maintained these ferritin levels. A sample of 95 ml umbilical cord blood was taken during the delivery. It is well known that umbilical cord blood contains a good quantity of CD34+ stem cells, the haematopoietic progenitors. It was therefore collected for transplanting to the mother and for bone marrow reconstitution. Moreover, our experience suggests that desferrioxamine therapy during lactation does not alter iron excretion in breast milk. Therefore, women now affected by Cooley disease may possibly have a normal pregnancy without ovulation induction, intrauterine growth retardation, foetal loss and preterm labour.

Blood Transfusion↗

Electron Spectroscopic Imaging of Magnetotactic Bacteria: Magnetosome Morphology and Diversity.

Magnetotactic bacteria from aquatic environments were analyzed with the electron spectroscopic imaging technique. Rod-shaped bacteria and cocci were present in most of the samples observed. Magnetotactic multicellular aggregates were also observed at some of the sampling sites. The use of electron spectroscopic imaging allowed the observation of magnetosomes inside magnetotactic microorganisms with exceptional clarity. The number, size, and morphology of magnetosomes, as well as their ultrastructural spatial disposition inside the bacterial cell, could be directly observed and associated with the disposition of flagella of the respective cells.This allowed us to examine the structural relationships between magnetosomes and flagella, which are important components in the mechanisms of magnetotaxis. In disrupted magnetotactic multicellular aggregates, connections between cells were also visualized. We believe this technique will be useful in studying not only magnetotactic bacteria but also other uncultured microorganisms from natural environments.

Journal Article↗