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1.
Soc Work Health Care ; 63(4-5): 370-384, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38453172

RESUMO

Very few literatures have focused on transition of older adults from hospitals to nursing homes in African region. As a first step, this study explored the experience of medical social worker when transiting older adult from the hospital to nursing home in southwestern region of Nigeria. A descriptive qualitative approach collected through a semi-structured interview among 16 medical social workers showed that there is limited availability of nursing home facilities in Nigeria. Additionally, bureaucratic and administrative hurdles often added to the complexities of facilitating seamless transitions into nursing care homes. Cultural beliefs and family dynamics exert a substantial influence on the decision-making process, making the task of medical social workers even more intricate. There is a need for a greater support from policymakers and healthcare authorities to address the challenges facing Nigerian medical social workers. Hence, to better understand and address these experiences, the healthcare system can better equip medical social workers to navigate the transitions effectively and ensure the well-being of older adults during this crucial phase of their lives is adequately supported.


Assuntos
Casas de Saúde , Assistentes Sociais , Humanos , Idoso , Nigéria , Atenção à Saúde , Hospitais , Pesquisa Qualitativa
2.
Prev Vet Med ; 225: 106155, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38394961

RESUMO

Besides its translational value, an improved understanding of dog longevity and mortality is necessary to guide health management decisions, breed selection, and improve dog welfare. In order to analyse the lifespan of dogs in Italy, identify the most common causes of death, and evaluate possible risk factors, anonymised medical records were collected from 9 veterinary teaching hospitals and 2 public health institutions. Data regarding breed, sex, neuter status, age, diagnosis, and mechanism of death were retrieved. Cause of death (COD) was classified by pathophysiologic process (PP) and organ system (OS). Of the 4957 dogs that died between 2004 and 2020 included in the study, 2920 (59.0%) were purebred, 2293 (46.2%) were female, 3005 (60.6%) were intact, 2883 (58.2%) were euthanised. Overall median longevity was 10.0 years. Median longevity was significantly longer for crossbreds, females, neutered dogs, and small-sized breeds. The breeds with the highest median age at death were the Yorkshire terrier, English cocker spaniel, West Highland white terrier, Italian volpino, and Shih Tzu, whilst the American bulldog, English bulldog, American pit bull terrier, Bernese mountain dog and the Maremma and the Abruzzes sheepdog had the lowest median age at death. The most frequent COD by PP was neoplasia (34.0%), which occurred more frequently in large breeds, namely German shepherd, Labrador retriever and Boxer. Degenerative diseases mostly affected small-sized dogs like Miniature pinscher and Dachshund. Regarding the OS involved, diseases of the renal/urinary system were most frequently responsible for COD (15.0%), prevalently degenerative and inflammatory/infectious. Substantial variation in median longevity according to causes of death by PP and OS was observed. These data are relevant for breeders, veterinary practitioners, and owners, to assist breed selection, facilitate early diagnosis, guide choice when purchasing a purebred dog and making health management decisions, and ultimately improve dog welfare.


Assuntos
Doenças do Cão , Longevidade , Cães , Feminino , Animais , Masculino , Doenças do Cão/etiologia , Causas de Morte , Fatores de Risco , Itália/epidemiologia
3.
Res Vet Sci ; 170: 105187, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38422840

RESUMO

To assess the effects of the acute inflammatory response (AIR) induced by Escherichia coli lipopolysaccharide (LPS) on plasma and tissue disposition of florfenicol (FFC) and its metabolite florfenicol amine (FFC-a), after its intramuscular (IM) administration, twenty-two New Zealand rabbits were randomly distributed in two experimental groups: Group 1 (LPS) was treated with three intravenous doses of 2 µg LPS/kg bw, before an intramuscular dose of 20 mg/kg FFC twenty-four h after the first LPS or SS injection; Group 2 (Control) was treated with saline solution (SS) in equivalent volumes as LPS-treated group. Blood samples were collected before (T0) and at different times after FFC administration. Acute inflammatory response was assessed in a parallel study where significant increases in body temperature, C-reactive protein concentrations and leukopenia were observed in the group treated with LPS. In another two groups of rabbits, 4 h after FFC treatment, rabbits were euthanized and tissue samples were collected for analysis of FFC and FFC-a concentrations. Pharmacokinetic parameters of FFC that showed significantly higher values in LPS-treated rabbits compared with control rabbits were absorption half-life, area under the curve, mean residence time and clearance /F (Cl/F). Elimination half-life and mean residence time of FFC-a were significantly higher in LPS-treated rabbits, whereas the metabolite ratio of FFC-a decreased significantly. Significant differences in tissue distribution of FFC and FFC-a were observed in rabbits treated with LPS. Modifications in plasma and tissue disposition of FFC and FFC-a were attributed mainly to haemodynamic modifications induced by the AIR through LPS administration.


Assuntos
Endotoxemia , Tianfenicol , Tianfenicol/análogos & derivados , Coelhos , Animais , Lipopolissacarídeos , Antibacterianos , Endotoxemia/induzido quimicamente , Endotoxemia/tratamento farmacológico , Endotoxemia/veterinária , Escherichia coli/metabolismo , Tianfenicol/farmacocinética , Inflamação/veterinária , Meia-Vida , Injeções Intramusculares/veterinária
4.
PLoS One ; 18(11): e0289259, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37943815

RESUMO

INTRODUCTION: The goal of preoperative planning techniques for advancement of the tibial tuberosity is to determine the amount of advancement required to achieve a postoperative patellar tendon angle of 90° and to select the optimal wedge size to achieve this target. MATERIAL AND METHODS: Three radiographic methods for determining the advancement distance for the tibial tuberosity were evaluated for comparability and interobserver reliability. Among the methods developed, we decided to include the common tangent method, the tibial anatomy-based method, and the Bielecki method. For all techniques, radiographs were taken in mediolateral projection with the knee joint flexed at 135°. Three observers with different levels of experience independently evaluated and scored the degree of osteoarthritis for each stifle, as previously described, and performed measurements of the amount of advancement of the tibial tuberosity on 33 stifles using common tangent method, tibial anatomy-based method, and Bielecki method. RESULTS: According to the results, the overall score for osteoarthritis in the mediolateral view was influenced by the experience of the observers, which contradicts the results from a previous study. Regarding the measurement methods used to assess advancement, poor interobserver reliability was found for common tangent method and Bielecki method, while only a slightly moderate interobserver agreement was found for tibial anatomy-based method. DISCUSSION: These results are inconsistent with data collected by Bielecki and colleagues. Moreover, measurements from common tangent method and tibial anatomy-based method were overlapping, as confirmed previously. Conversely, Bielecki method showed no agreement with the other methods included in the present study, with a significantly higher mean rank, probably due to its correction formula. Based on the results of the present study, tibial anatomy-based method has better interobserver reliability and is easier to perform according to the observers.


Assuntos
Osteoartrite , Ligamento Patelar , Animais , Humanos , Reprodutibilidade dos Testes , Ligamento Patelar/cirurgia , Joelho de Quadrúpedes , Osteoartrite/diagnóstico por imagem , Osteoartrite/cirurgia , Osteotomia/métodos , Tíbia/diagnóstico por imagem , Tíbia/cirurgia
5.
Vet Sci ; 10(7)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37505878

RESUMO

Bilateral cataracts were diagnosed in two rescued juvenile, immature loggerhead sea turtles (Caretta caretta), weighing 1.65 and 1.7 kg. Both animals showed vision impairment and difficulty in feeding without assistance. In fact, they did not notice the presence of the food in the tank unless it was brought close to touching the mouth. Ocular ultrasonography and electroretinography showed no lesions of the vitreal body and retinal layer, therefore, both animals were candidates for bilateral cataract surgery. Topical administration of tropicamide + phenylephrine alternating with rocuronium resulted in only minimal mydriasis. Administration of intracameral rocuronium did not improve mydriasis. Phacoemulsification using a one-handed technique was performed bilaterally with a phacoemulsification device (Sovereign, AMO (Abbott Medical Optics®). After surgery, the systemic anti-inflammatory drug (dexamethasone 0.2 mg/kg, IM daily for one week) and antibiotics (enrofloxacin 10 mg/kg IM q 72 h, for 4 weeks; ceftazidime 20 mg/kg IM q 72 h for 3 weeks) were administered. Topical ofloxacin, flurbiprofen and tobramycin/dexamethasone were instilled TID for 4 weeks. Both turtles regained vision in both eyes. Results at a 10-month follow-up were satisfactory. This is the first report of cataracts in turtles rescued in the Mediterranean Sea and the first description of surgical treatment of cataracts in loggerhead turtles so young.

6.
Animals (Basel) ; 13(13)2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37443898

RESUMO

In Chile, studies of parasites from the family Sarcocystidae (Apicomplexa) have mostly been related to domestic animals. We aimed to assess the presence of Sarcocystidae taxa in cricetid rodents from Central and Southern Chile. We studied 207 rodents, encompassing six species, from 13 localities. We isolated DNA from tissue samples, amplified the Sarcocystidae 18S rRNA gene with polymerase chain reaction, and performed phylogenetic analyses using maximum likelihood and Bayesian inferences. In addition, we examined blood smears and performed histological studies in organs from Sarcocystidae DNA-positive animals. Three specimens were DNA-positive and three genotypes were retrieved and named: Sarcocystis sp. P61, related to Sarcocystis strixi, was detected in two Abrothrix olivacea. Toxoplasmatinae gen. sp. P99 was retrieved from those same two specimens, and was related to Toxoplasma and other genera, although it branched independently. Besnoitia sp. R34 was detected in one Abrothrix hirta, and was clustered with congeneric species associated with rodents. No protozoa were found during microscopic studies; thus, it was not possible to confirm parasitic interactions rather than accidental encounters. However, the close relatedness of the retrieved genotypes to parasites of rodents supports the hypothesis of host-parasite associations. All three genotypes are suggested as potential new taxa, including a putative new genus.

7.
Animals (Basel) ; 13(13)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37443903

RESUMO

In human ophthalmology, the benefits of using high-frequency radiowave (HFR) electrocautery for surgical procedures were demonstrated and include effective haemostasis, shorter surgery times, and rapid recovery. In canine eyelid surgery, intraoperative bleeding is a common feature that may obscure the surgical field view and lead to the increased swelling of adjacent tissues, bruising, and pain. To evaluate the efficacy and benefits of HFR electrocautery in canine eyelid and third eyelid surgery, the medical records of 48 surgical excisions of eyelid tumours (involving up to one-third of the eyelid length) and 4 third eyelid excisions were reviewed. The information was collected including the breed, age, clinical signs, HFR power setting and mode of the surgical unit, electrode used for the surgery, intraoperative complications, histopathological diagnosis, and postoperative outcomes. Surgical techniques were performed using the Surgitron Dual 3.8 MHz Frequency RF device (Ellman International, Oceanside, NY, USA). Intraoperative bleeding was recorded as absent or very mild, and the surgical procedures were very fast. No complications occurred during the procedures. Healing within 10 days was observed in all the dogs. No tumour recurrences were recorded at the 12-month follow-up. HFR electrosurgery proved to be a safe, effective, and easy-to-perform technique for the removal of eyelid and third eyelid tumours in dogs.

8.
Antibiotics (Basel) ; 12(4)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37107001

RESUMO

BACKGROUND: Experimental reports have demonstrated that florfenicol (FFC) exerts potent anti-inflammatory effects, improving survival in a murine endotoxemia model. Considering the anti-inflammatory and immunomodulatory properties of pentoxifylline (PTX) as an adjuvant to enhance the efficacy of antibiotics, the anti-inflammatory effects of the interaction FFC/PTX over the E. coli Lipopolysaccharide (LPS)-induced acute inflammatory response was evaluated in rabbits. METHODS: Twenty-five clinically healthy New Zealand rabbits (3.8 ± 0.2 kg body weight: bw), were distributed into five experimental groups. Group 1 (control): treated with 1 mL/4 kg bw of 0.9% saline solution (SS) intravenously (IV). Group 2 (LPS): treated with an IV dose of 5 µg/kg of LPS. Group 3 (pentoxifylline (PTX) + LPS): treated with an oral dose of 30 mg/kg PTX, followed by an IV dose of 5 µg/kg of LPS 45 min after PTX. Group 4 (Florfenicol (FFC) + LPS): treated with an IM dose of 20 mg/kg of FFC, followed by an IV dose of 5 µg/kg of LPS 45 min after FFC administration. Group 5 (PTX + FFC + LPS): treated with an oral dose of 30 mg/kg of PTX, followed by an IM dose of 20 mg/kg of FFC, and, 45 min after an IV dose of 5 µg/kg of LPS was administered. The anti-inflammatory response was evaluated through changes in plasma levels of interleukins (TNF-α, IL-1ß and IL-6), C-reactive protein (CRP), and body temperature. RESULTS: It has been shown that each drug produced a partial inhibition over the LPS-induced increase in TNF-α, IL-1ß, and CRP. When both drugs were co-administered, a synergistic inhibitory effect on the IL-1ß and CRP plasma concentrations was observed, associated with a synergic antipyretic effect. However, the co-administration of PTX/FFC failed to modify the LPS-induced increase in the TNF-α plasma concentrations. CONCLUSIONS: We concluded that the combination of FFC and PTX in our LPS sepsis models demonstrates immunomodulatory effects. An apparent synergistic effect was observed for the IL-1ß inhibition, which peaks at three hours and then decreases. At the same time, each drug alone was superior in reducing TNF-α levels, while the combination was inferior. However, the peak of TNF-α in this sepsis model was at 12 h. Therefore, in rabbits plasma IL-1ß and TNF-α could be regulated independently, thus, further research is needed to explore the effects of this combination over a more prolonged period.

9.
J Vet Pharmacol Ther ; 46(3): 195-199, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36789482

RESUMO

This work aimed to assess the effects of the coadministration of pentoxifylline (PTX) on the pharmacokinetic profile of florfenicol (FFC) after intramuscular administration in rabbits. Ten New Zealand white rabbits, 1 year of age and 3.9 ± 0.1 kg body weight, were assigned according to a randomized block design to Group 1 (FFC): treated with 30 mg/kg of FFC intramuscularly, and Group 2 (PTX + FFC) treated with an oral dose of 30 mg/kg PTX 45 min before the intramuscular injection of 30 mg/kg FFC. Blood samples were collected before and at different times between 0.5 and 12.0 h after drug administration. FFC plasma concentrations were determined by high-performance liquid chromatography. Results showed that IM injection of the long-acting formulation of FFC in rabbits resulted in a slow increase in mean plasma concentrations reaching a Cmax of 3.09 ± 0.52 ug/mL at 2.8 ± 0.45 h (Tmax ) after drug administration. While coadministration of PTX and FFC decreased the time to achieve the maximal concentration by modifying the absorption of FFC without changes in the other pharmacokinetic parameters.


Assuntos
Pentoxifilina , Tianfenicol , Coelhos , Animais , Antibacterianos/farmacocinética , Tianfenicol/farmacocinética , Injeções Intramusculares/veterinária , Administração Oral
10.
Endocrinol Diabetes Nutr (Engl Ed) ; 69(8): 629-645, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36369235

RESUMO

The risk of suffering from gonadal germ cell tumors (GCT) is increased in some patients with different sexual development (DSD), mainly in those with Y chromosome material. This risk, however, varies considerably depending on a multitude of factors that make the decision for prophylactic gonadectomy extremely difficult. In order to make informed recommendations on the convenience of this procedure in cases where there is potential for malignancy, this consensus guide evaluates the latest clinical evidence, which is generally low, and updates the existing knowledge in this field.


Assuntos
Neoplasias Embrionárias de Células Germinativas , Desenvolvimento Sexual , Humanos , Consenso , Neoplasias Embrionárias de Células Germinativas/cirurgia , Castração
11.
Nucleic Acids Res ; 50(15): 8512-8528, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-35920318

RESUMO

Cold shock adaptability is a key survival skill of gut bacteria of warm-blooded animals. Escherichia coli cold shock responses are controlled by a complex multi-gene, timely-ordered transcriptional program. We investigated its underlying mechanisms. Having identified short-term, cold shock repressed genes, we show that their responsiveness is unrelated to their transcription factors or global regulators, while their single-cell protein numbers' variability increases after cold shock. We hypothesized that some cold shock repressed genes could be triggered by high propensity for transcription locking due to changes in DNA supercoiling (likely due to DNA relaxation caused by an overall reduction in negative supercoiling). Concomitantly, we found that nearly half of cold shock repressed genes are also highly responsive to gyrase inhibition (albeit most genes responsive to gyrase inhibition are not cold shock responsive). Further, their response strengths to cold shock and gyrase inhibition correlate. Meanwhile, under cold shock, nucleoid density increases, and gyrases and nucleoid become more colocalized. Moreover, the cellular energy decreases, which may hinder positive supercoils resolution. Overall, we conclude that sensitivity to diminished negative supercoiling is a core feature of E. coli's short-term, cold shock transcriptional program, and could be used to regulate the temperature sensitivity of synthetic circuits.


Assuntos
DNA Super-Helicoidal , Escherichia coli , Resposta ao Choque Frio/genética , DNA/metabolismo , DNA Girase/genética , DNA Girase/metabolismo , DNA Super-Helicoidal/genética , DNA Super-Helicoidal/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo
12.
Vet Sci ; 9(7)2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35878342

RESUMO

Force plate analysis assesses gait symmetry and limb loading. However, as previously described, individual and breed variability (body size and conformation) is related to breeding, body conformation, and size. This prospective study aimed to evaluate the influence of morphometric measures on the speed (V), peak of vertical force (PVF), vertical impulse (VI), and stance time (ST) in healthy dolichomorph and mesomorph dogs and their combined effect on and interactions with V, PVF, VI, and ST in the same morphological types. Fifty dogs were enrolled in the current study, and specific morphometric measurements were recorded for each dog. A force platform was used to record the ground reaction forces (GFRs), including PVF and VI. Multiple linear regression models were used for the study purposes. According to our results, GFRs are influenced by morphometric measures (body weight, withers height, and speed) not so much as a single contribution, but by the interaction between them. It is not possible to compare GFRs in dogs that do not belong to the same breed. However, the subjective variabilities make this comparison difficult and poorly reliable. According to the author, the comparison should be made between canine morphological types rather than breeds.

13.
Animals (Basel) ; 12(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35681840

RESUMO

In emergency veterinary practice, gastrointestinal foreign body (GFB) removal is a common procedure that is performed with different techniques, such as endoscopy or surgery. The aims of this retrospective, multicentre, clinical study were to report the common locations and types of objects recovered and to investigate clinical factors and outcomes in dogs after surgical or endoscopic treatment for GFB removal. Records of dogs with a GFB diagnosis referred to the Teaching Veterinary Hospital or treated in three different veterinary hospitals from September 2017 to September 2019 were examined. The data obtained from each case included breed, age, clinical signs at presentation, duration of clinical signs, type and location of the GFB, treatment, length of hospitalisation and outcome. Seventy-two dogs were enrolled in the study. There were 42 males (58%) and 30 females (42%). The median age was 36 months (range: 3 months to 8 years). Endoscopic retrieval was performed in 56% of GFBs (located in the stomach or duodenum), whereas 44% of dogs underwent surgery. The type of FB detected varied greatly: kid toy (14%), metallic object/coin (13%), cloth (13%), sock (8%), ball (8%), plastic material (8%), peach stone (7%), fishhook (6%), sewing needle (4%), hair tie (4%), pacifier (3%), plant materials (3%) and others (9%). Moreover, the FBs were classified as sharp (13%, n = 9), pointed (33%, n = 24), blunt (26%, n = 19), or linear (28%, n = 20). In this study, 68% of FBs were localised in the stomach, 25% in the intestinal tract (50% duodenum, 28% jejunum, and 22% ileum), and 7% in both the stomach and small intestine. The type of GFB was not significantly associated with age, site or breed. There was a significant association between the type of GFB and sex: if the dog was male, there was a 38% probability of ingesting linear GFBs. The dog survival rate was 100% in cases treated by gastric endoscopic or surgical removal, 94% in cases treated with enterotomy and 33% in cases in which enterectomy was necessary. Enterectomy and multiple surgical sites were associated with a poor outcome. The presence of vomiting for more than 24 h was significantly associated with death.

14.
Vet Sci ; 9(6)2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35737333

RESUMO

Adhesions involving the bulbar and the palpebral conjunctiva (Symblepharon) may interfere with tear drainage, cause chronic conjunctivitis, and reduce ocular motility. This condition may be associated with adhesion of the edges of the upper and lower eyelids (ankyloblepharon). The present case describes bilateral symblepharon, ankyloblepharon and salt gland dysfunction in a juvenile Caretta caretta. The loggerhead presented both eyelids swollen, ulcerated, and not separable when rescued. Eye examination was not possible, but ultrasonography showed right bulbar integrity, while the left eye was smaller, with a thicker cornea that had lost its normal doubled lined structure. Surgical dissection of the fibrous adhesions between the palpebral and bulbar conjunctiva, cornea, and third eyelid was performed, and large dacryoliths were removed. The microscopic findings were consistent with chronic keratoconjunctivitis. Ultrastructurally, no virus-like particles were observed. In addition, tissue samples were negative for herpesvirus by qualitative PCR. The eyelids of both eyes and the corneal epithelium of the right eye healed; moreover, the vision was restored in the right eye. There were no recurrences after 12 months of follow-up, and the turtle was released 16 months after the end of treatments on the southern Tyrrhenian coast in the western Mediterranean Sea. To the authors' knowledge, this is the first report of symblepharon with ankyloblepharon and salt gland dysfunction in Caretta caretta turtle. Ocular ultrasonography was helpful in the preliminary diagnostic work-up.

15.
An Pediatr (Engl Ed) ; 96(4): 349.e1-349.e11, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35534418

RESUMO

Some people, including minors, have a gender identity that does not correspond to the sex assigned at birth. They are known as trans* people, which is an umbrella term that encompasses transgender, transsexual, and other identities not conforming to the assigned gender. Healthcare units for trans* minors require multidisciplinary working, undertaken by personnel expert in gender identity, enabling, when requested, interventions for the minor and their social-familial environment, in an individualized and flexible way during the gender affirmation path. This service model also includes hormonal treatments tailored as much as possible to the individual's needs, beyond the dichotomic goals of a traditional binary model. This guide addresses the general aspects of professional care of trans* minors and presents the current evidence-based protocol of hormonal treatments for trans* and non-binary adolescents. In addition, it details key aspects related to expected body changes and their possible side effects, as well as prior counselling about fertility preservation.


Assuntos
Disforia de Gênero , Guias de Prática Clínica como Assunto , Pessoas Transgênero , Transexualidade , Adolescente , Feminino , Disforia de Gênero/tratamento farmacológico , Identidade de Gênero , Humanos , Masculino , Menores de Idade , Transexualidade/terapia
16.
Biochim Biophys Acta Gene Regul Mech ; 1865(3): 194812, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35338024

RESUMO

Escherichia coli uses σ factors to quickly control large gene cohorts during stress conditions. While most of its genes respond to a single σ factor, approximately 5% of them have dual σ factor preference. The most common are those responsive to both σ70, which controls housekeeping genes, and σ38, which activates genes during stationary growth and stresses. Using RNA-seq and flow-cytometry measurements, we show that 'σ70+38 genes' are nearly as upregulated in stationary growth as 'σ38 genes'. Moreover, we find a clear quantitative relationship between their promoter sequence and their response strength to changes in σ38 levels. We then propose and validate a sequence dependent model of σ70+38 genes, with dual sensitivity to σ38 and σ70, that is applicable in the exponential and stationary growth phases, as well in the transient period in between. We further propose a general model, applicable to other stresses and σ factor combinations. Given this, promoters controlling σ70+38 genes (and variants) could become important building blocks of synthetic circuits with predictable, sequence-dependent sensitivity to transitions between the exponential and stationary growth phases.


Assuntos
Proteínas de Escherichia coli , Fator sigma , Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Fator sigma/genética , Fator sigma/metabolismo
17.
PLoS Comput Biol ; 18(1): e1009824, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35100257

RESUMO

Closely spaced promoters in tandem formation are abundant in bacteria. We investigated the evolutionary conservation, biological functions, and the RNA and single-cell protein expression of genes regulated by tandem promoters in E. coli. We also studied the sequence (distance between transcription start sites 'dTSS', pause sequences, and distances from oriC) and potential influence of the input transcription factors of these promoters. From this, we propose an analytical model of gene expression based on measured expression dynamics, where RNAP-promoter occupancy times and dTSS are the key regulators of transcription interference due to TSS occlusion by RNAP at one of the promoters (when dTSS ≤ 35 bp) and RNAP occupancy of the downstream promoter (when dTSS > 35 bp). Occlusion and downstream promoter occupancy are modeled as linear functions of occupancy time, while the influence of dTSS is implemented by a continuous step function, fit to in vivo data on mean single-cell protein numbers of 30 natural genes controlled by tandem promoters. The best-fitting step is at 35 bp, matching the length of DNA occupied by RNAP in the open complex formation. This model accurately predicts the squared coefficient of variation and skewness of the natural single-cell protein numbers as a function of dTSS. Additional predictions suggest that promoters in tandem formation can cover a wide range of transcription dynamics within realistic intervals of parameter values. By accurately capturing the dynamics of these promoters, this model can be helpful to predict the dynamics of new promoters and contribute to the expansion of the repertoire of expression dynamics available to synthetic genetic constructs.


Assuntos
Escherichia coli/genética , Regiões Promotoras Genéticas , DNA Bacteriano/genética , Expressão Gênica , Cinética , Transcrição Gênica
18.
ACS Biomater Sci Eng ; 7(9): 4483-4493, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34382772

RESUMO

The traditional silicate bioactive glasses exhibit poor thermal processability, which inhibits fiber drawing or sintering into scaffolds. The composition of the silicate glasses has been modified to enable hot processing. However, the hot forming ability is generally at the expense of bioactivity. Metaphosphate glasses, on the other hand, possess excellent thermal processability, congruent dissolution, and a tailorable degradation rate. However, due to the layer-by-layer dissolution mechanism, cells do not attach to the material surface. Furthermore, the congruent dissolution leads to a low density of OH groups forming on the glass surface, limiting the adsorption of proteins. It is well regarded that the initial step of protein adsorption is critical as the cells interact with this protein layer, rather than the biomaterial itself. In this paper, we explore the possibility of improving protein adsorption on the surface of phosphate glasses through a variety of surface treatments, such as washing the glass surface in acidic (pH 5), neutral, and basic (pH 9) buffer solutions followed or not by a treatment with (3-aminopropyl)triethoxysilane (APTS). The impact of these surface treatments on the surface chemistry (contact angle, ζ-potential) and glass structure (FTIR) was assessed. In this manuscript, we demonstrate that understanding of the material surface chemistry enables to selectively improve the adsorption of albumin and fibronectin (used as model proteins). Furthermore, in this study, well-known silicate bioactive glasses (i.e., S53P4 and 13-93) were used as controls. While surface treatments clearly improved proteins adsorption on the surface of both silicate and phosphate glasses, it is of interest to note that protein adsorption on phosphate glasses was drastically improved to reach similar protein grafting ability to the silicate bioactive glasses. Overall, this study demonstrates that the limited cell/phosphate glass biological response can easily be overcome through deep understanding and control of the glass surface chemistry.


Assuntos
Implantes Absorvíveis , Fosfatos , Adsorção , Vidro , Silicatos
19.
PLoS One ; 16(8): e0256011, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34379677

RESUMO

INTRODUCTION: Cranial cruciate ligament failure is one of the principal causes of canine lameness. Several surgical procedures were proposed to achieve joint stabilisation; among these, the Modified Maquet Procedure involves using a titanium foam wedge to achieve and maintain the tibial tuberosity advancement. The force-plate analysis provides to objectively assess normal and abnormal gait and the outcome of different surgical techniques. The study evaluates the outcome of limbs that underwent Modified Maquet Procedure using land-force plate analysis comparing the operated limb with its healthy contralateral one as a control. MATERIALS AND METHODS: Thirty-five dogs with unilateral cranial cruciate ligament rupture were evaluated. Outcome after surgery was assessed by orthopaedic and radiographic evaluations and force plate gait analysis performed before surgery, at 15, 30 and 90 days after surgery. For objective comparison of ground reaction forces, data of operated limb were compared to contralateral limb on each time control and Symmetry Index at 90 days was determined. Healing radiographic signs, minor and major complication were reported. RESULTS: A significant improvement in ground reaction forces was reached in all the treated limbs between set time intervals. The median percentage increase in ground reaction forces was constant from 15 to 90 days, with a Symmetry Index >9 in 54.2% of patients suggesting a normal gait symmetry. A complete bone healing was noticed at 90 days follow-up radiographic assessment. We experienced three major (8.5%) and one minor (2.8%) complications. CONCLUSIONS: To the Authors' knowledge, this is the first study in the veterinary literature that assessed outcomes of dogs undergoing Modified Maquet Procedure for the treatment of cranial cruciate ligament rupture using force plate gait analysis and healthy contralateral limb as a control group. Our results confirm that Modified Maquet Procedure is an effective method to stabilise the stifle joint.


Assuntos
Lesões do Ligamento Cruzado Anterior/veterinária , Ligamento Cruzado Anterior/cirurgia , Doenças do Cão/cirurgia , Marcha/fisiologia , Recuperação de Função Fisiológica , Ruptura/veterinária , Extremidade Superior/cirurgia , Animais , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior , Artroscopia , Placas Ósseas , Cães , Feminino , Análise da Marcha , Masculino , Ruptura/cirurgia , Extremidade Superior/fisiopatologia
20.
Biochim Biophys Acta Gene Regul Mech ; 1863(5): 194515, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32113983

RESUMO

Positive supercoiling buildup (PSB) is a pervasive phenomenon in the transcriptional programs of Escherichia coli. After finding a range of Gyrase concentrations where the inverse of the transcription rate of a chromosome-integrated gene changes linearly with the inverse of Gyrase concentration, we apply a LineWeaver-Burk plot to dissect the expected in vivo transcription rate in absence of PSB. We validate the estimation by time-lapse microscopy of single-RNA production kinetics of the same gene when single-copy plasmid-borne, shown to be impervious to Gyrase inhibition. Next, we estimate the fraction of time in locked states and number of transcription events prior to locking, which we validate by measurements under Gyrase inhibition. Replacing the gene of interest by one with slower transcription rate decreases the fraction of time in locked states due to PSB. Finally, we combine data from both constructs to infer a range of possible transcription initiation locking kinetics in a chromosomal location, obtainable by tuning the transcription rate. We validate with measurements of transcription activity at different induction levels. This strategy for dissecting transcription initiation locking kinetics due to PSB can contribute to resolve the transcriptional programs of E. coli and in the engineering of synthetic genetic circuits.


Assuntos
Simulação por Computador , DNA Girase/metabolismo , DNA Bacteriano/genética , DNA Super-Helicoidal/genética , Proteínas de Escherichia coli/metabolismo , Iniciação da Transcrição Genética , DNA Bacteriano/química , DNA Super-Helicoidal/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Cinética , Novobiocina/farmacologia , RNA/genética , RNA/metabolismo , Inibidores da Topoisomerase II/farmacologia
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