RESUMO
An anal fissure is a small cut or tears in the skin or mucosal lining of anal passage or at the opening of anus. It affects the quality of life due to severe pain and sometimes causes bleeding also while passing the stool. It can affect people of any age. In recent time, laser treatment creates a new era for management of anal fissure. It is easier, safer, faster for the treatment of chronic anal fissure. The aim of the study was to evaluate short term and long term clinical and surgical outcome of laser treatment. In this prospective study total 82 patients with chronic anal fissure underwent laser treatment from July 2019 to June 2020 at Anower Khan Modern Medical College Hospital and Care Medical College Hospital, Bangladesh. All the patients who completed their 1.5 months and 6 months follow up were included for the study and their data was analyzed. Out of 82 patients, 71 were females and 11 were male. The mean age 40.31±9.23, mean operative time was 15.0±10.0 minutes. Mean hospital stay 24.35±1.23 hours (1 day). Mean healing time was 14.03±12.04 days. All patients were followed upto at outpatient clinic 1.5 and 6.0 months postoperatively. This study shows that laser treatment is a simple, safe, and effective procedure to treat the anal fissure with a low rate of complications. It can be treated as an effective treatment for patients with chronic anal fissure. However, this procedure has some limitations.
Assuntos
Fissura Anal , Terapia a Laser , Humanos , Fissura Anal/cirurgia , Fissura Anal/terapia , Feminino , Masculino , Adulto , Doença Crônica , Estudos Prospectivos , Terapia a Laser/métodos , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
There are several surgical options described for the treatment of anorectal fistulas, specially in complex cases where recurrence rates and the possibility of postoperative complications are still high. Laser- FiLaC™ has been described in this study as an option in the management of anorectal fistula. The aim of this study was to assess the novel radial laser probe treatment in complex fistula in-ano and report the success rate and recurrence rate. We studied retrospectively 56 patients who, according to our hospital patient records, underwent radial laser probe surgery between March 2019 and August 2020. In a mean follow-up time of 6 months, the success rate at 2 months was 86.0%. Most operations were done under spinal anesthesia. The recovery time was rapid and median sick leave was 7 days. Of those initially successfully treated, 3.0% developed a recurrence. Altogether 4.0% of the patients underwent a re-operation. There is a good success rate using FiLaC™ treatment. FiLaC™ is very effective in treatment of complex fistula and as well as recurrence of fistula. It has a short hospital stay and as well as it is painless surgical technique that should be largely used in our country.
Assuntos
Canal Anal , Fístula Retal , Humanos , Estudos Retrospectivos , Canal Anal/cirurgia , Fístula Retal/cirurgia , Lasers , Resultado do TratamentoRESUMO
Mastectomy is very common surgical procedure for breast cancer. The closure of transverse elliptical mastectomy incisions has been represented with numerous modifications since 1915. The technical challenge is to avoid a fold of skin dogging laterally ("dog-ear"). This might lead to off future discomfort and poor cosmetic result. However, various surgical techniques are reported to tackle this lateral dog ear, there is no standardized technique. We therefore conduct a systematic review of the surgical techniques with the aim of comparing the merits and limitations of every technique. The comparative study among 72 patients was performed in Bangabandhu Sheikh Mujib Medical University, Anower Khan Modern Medical College & Hospital and Care Medical College & Hospital, Bangladesh from July 2017 to January 2020. Patients were divided randomly into two groups: Group I underwent fishtail technique group (36 patients), Group II underwent modified suturing technique group (36 patients). The follow up periods were 1 month and 3 months post-operatively for determination of the presence of dog ear and patient's satisfaction regarding cosmetic outcome and comfortability. Incidence of dog ear in fish-tail plasty group patients was less than that for Group II yet the difference is not significant less (p value 0.001). In consideration of patient satisfaction, doctor satisfaction and patient comfortability were significantly higher in Group I than Group II (p value 0.476 and 0.001 respectively). Fish-tail plasty was significantly better in patient satisfaction, comfortability and doctor satisfaction than modified suturing techniques and it might be recommended following mastectomy in obese patients for improving cosmesis and avoiding discomfort due to redundant skin.
Assuntos
Neoplasias da Mama , Cicatriz , Mastectomia , Feminino , Humanos , Bangladesh , Neoplasias da Mama/cirurgia , Cicatriz/prevenção & controle , Mastectomia/métodos , Obesidade/complicações , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Curative surgery remains the mainstay treatment of carcinoma stomach till to date. Preoperative accurate diagnosis of the depth of tumour invasion (T) and nodal involvement (N) in stomach cancer is important in determining the choice of an optimal therapeutic approach. Endoluminal ultrasonography (EUS) is considered as most reliable tools for assessing locoregional staging as it can overcome bones and air barrier on the other hand computed tomography (CT) has increased its' efficacy greatly after introduction of extreme multi-detector and phase-contrast CT. The objective of this study was to compare the accuracy of T and N staging with EUS and CT by comparing with postoperative histopathology in stomach carcinoma. This cross-sectional observational study was conducted in the department of General Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh from August 2019 to July 2020. Forty five (45) patients who underwent curative stomach resection surgery due to carcinoma of stomach were enrolled in this study. All patients were investigated by EUS and CT preoperatively to assess locoregional staging. Then patients underwent stomach resection surgery and specimen sent for histopathology. EUS had sensitivity 80.0% to predict T staging but specificity 60.0% and the overall accuracy was 68.89%. CT result showed sensitivity 59.38% to predict T staging but specificity 46.15%, and the overall accuracy was 55.56%. EUS had 65.63% sensitivity to predict nodal involvement but specificity 61.54% and the overall accuracy was 64.44%. CT had 83.33% sensitivity to predict nodal involvement but specificity 55.56% and the overall accuracy was 77.78%. EUS is more accurate than CT in T staging but CT is more accurate than EUS in the N staging of carcinoma stomach. So EUS and CT both should be used as a diagnostic tool for preoperative locoregional staging of carcinoma stomach.
Assuntos
Carcinoma , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia , Endossonografia/métodos , Estudos Transversais , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia , Carcinoma/patologia , Estadiamento de Neoplasias , Sensibilidade e EspecificidadeRESUMO
LASER Haemorrhoidoplasty (LH) is a novel procedure in modern medical science. It is a no cut, painless and bloodless clinical procedure with comparatively fewer complications in comparison to Stapler Haemorrhoidopexy (SH) for the treatment of grade III-IV haemorrhoids. It is very applicable surgical procedure at shrinking the terminal branches of haemorrhiodal arteries with fewer complications than Stapler Haemorrhoidopexy (SH). The aim of the study was to compare LASER Haemorrhoidoplasty (LH) with Stapler Haemorrhoidopexy (SH). The comparative study was performed in Bangabandhu Sheikh Mujib Medical University (BSMMU), Anower Khan Modern Medical College and Hospital and Care Medical College and Hospital, Dhaka, Bangladesh from August 2019 to July 2020. A total of 84 patients with grade III-IV haemorrhoids were allocated into two groups: LASER Haemorrhoidoplasty (LH) and Stapler Haemorrhoidopexy (SH) with 42 patients in each group prospectively. Comparative results and post-operative follow up periods were 4 months. The mean operative time was 28.6min (LH) and 36.2min (SH) (p=0.0006). The average blood loss was 6.42ml (LH) and 12.6ml (SH) (p<0.05). The mean hospital stay 18.36 hours (LH) and 28.40 hours (SH) (p<0.05). Mean postoperative pain score (VAS) at 12 hours was 3.8 (LH) and 6.81 (SH) (p<0.05), at 24 hours was 2.6 (LH) and 4.6 (SH) (p<0.05), at 1 week was 0.46 (LH) and 0.88 (SH) (p=0.05) and at 3 months 0.04 (LH) and 0.10 (SH) (p=0.401). Complications were found in (2.4%) patients ≤1 week in the (LH) group 7(16.7%) in the (SH) group which was statistically significant (p<0.05) between the two groups. Patients with haemorrhoids treated with LASER Haemorrhoidoplasty had a better outcome than stapler haemorrhoidopexy in terms of early postoperative pain as well as complications and was associated with a shorter hospital stay and early return to work. LASER Haemorrhoidoplasty was most effective and alternative to the popular stapler Haemorrhoidopexy for grade III-IV haemorrhoids.
Assuntos
Hemorroidas , Bangladesh , Hemorroidas/cirurgia , Humanos , Lasers , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Complicações Pós-Operatórias , Estudos Prospectivos , Grampeamento Cirúrgico , Resultado do TratamentoRESUMO
Bleeding per rectum is one of the most alarming conditions for any patient. Haemorrhoids are a common cause of bleeding in anorectal region. Conventional Haemorrhoidectomy is associated with significant pain & morbidity so much so that patient feared of and reluctant to undergo surgery. In 1998, introduction of stapled haemorroidopexy by Longo represented a radical change in the treatment of haemorrhoids. The aim of this prospective study was to evaluate short term & long term clinical & surgical outcome of stapled haemorrhoidopexy. A sample of 130 patients with symptomatic second-, third- & fourth- degree haemorrhoids underwent stapled haemorrhoidopexy from January 2013 to December 2016 at Care Medical college & Hospital & Fast care Hospital, Dhaka. Out of these 90 patients who completed their one year follow up was included for the study & their data was analyzed. Eighty percent of patient was females & the mean age 45 (25-75 years), Mean operative time was 35 minutes (25-70 minutes). Mean hospital stay 1 day (1-2 days). Intraoperative suture was 6 and incomplete doughnut 9. Use of analgesics 5 days. All patients were followed up to at outpatient clinic 12 months postoperatively. Stapled haemorrhoidopexy for haemorrhoids is an efficient procedure with less post operative pain, lower complication rates and better patient compliance & satisfaction.
Assuntos
Hemorroidectomia , Hemorroidas/cirurgia , Grampeamento Cirúrgico , Idoso , Bangladesh , Feminino , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Prospectivos , Resultado do TratamentoRESUMO
OBJECTIVE: To assess the impact of surgical management of endometrioma on the outcome of assisted reproduction treatment (ART). DESIGN: A systematic review and meta-analysis. SETTING: Department of reproductive medicine at teaching university hospital, UK. PATIENTS: Subfertile women with endometrioma undergoing ART. INTERVENTIONS: Surgical removal of endometrioma or expectant management. MAIN OUTCOME MEASURES: Clinical pregnancy rate, pregnancy rate, live birth rate, number of oocytes retrieved and number of embryos available and ovarian response to gonadotrophins. RESULTS: An extensive search of electronic databases for articles published from inception to September 2016 yielded 11 eligible studies for meta-analysis. Meta-analysis was conducted comparing surgery versus no treatment of endometrioma. There were no significant differences in pregnancy rate per cycle, clinical pregnancy rate and live birth rate between women who underwent surgery for endometrioma and those who did not. CONCLUSION: Current evidence suggests that women with endometriosis-related infertility have similar cycle outcomes to other patients going through ART. It is pertinent for clinicians to assess the risks of surgical intervention on ovarian reserve prior to initiating therapy.
Assuntos
Endometriose/complicações , Endometriose/cirurgia , Fertilização in vitro , Infertilidade Feminina/terapia , Injeções de Esperma Intracitoplásmicas , Coeficiente de Natalidade , Feminino , Humanos , Infertilidade Feminina/etiologia , Recuperação de Oócitos , Reserva Ovariana , Ovário , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Resultado do TratamentoRESUMO
This prospective study was done to find out the relative frequency of the malignancy in cold solitary thyroid nodules with other solitary thyroid nodules (hot and warm). This study was carried out in the Department of General Surgery and Otolaryngology-Head & Neck Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2011 to February 2012. One hundred (100) patients with clinically and ultrasonographically diagnosed as solitary thyroid nodules were included. Out of them, 52% of patients were in the third and fourth decades of life and 26% were in the second decade of life. In sex distribution, females were more affected than males and female: male ratio was 2.1:1. All patients presented with neck swelling, which moved with deglutition and 18% presented with palpitation. Solitary nodule was present in about 60% in the right lobe and 32% in the left lobe. In 72% patients, radioiodine uptake was low; in 25% patient's radioiodine uptake was normal. The thyroid scan revealed 72% cold nodule, in 25% patients radioiodine uptake was normal. On Ultrasonographic study, 60% were solid, 28% cystic and others mixed. Each and every patient of this series was treated surgically. Mostly (73%) lobectomy was done. Total thyroidectomy was done in 16% cases. On histopathology, 56% were colloid nodule, 28% were adenoma and 16% were carcinoma. Among the 16% malignant patients, majority of the patients had their age between 21-48 years. Histopathological types were mostly papillary (50%). Complications of surgery were mostly hoarseness of voice (5%), hematoma (4%), infection (2%) and hypoparathyroidism (3%). In this study, more malignant cases (20.83%) were found in cold solitary nodules.
Assuntos
Adenoma/epidemiologia , Carcinoma/epidemiologia , Nódulo da Glândula Tireoide/epidemiologia , Adenoma/patologia , Adenoma/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bangladesh/epidemiologia , Carcinoma/patologia , Carcinoma/cirurgia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Radioisótopos do Iodo/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores Sexuais , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/cirurgia , Tireoidectomia , Adulto JovemRESUMO
This prospective study was done to observe the diversity of clinical presentation of carcinoma of tongue and to study the pathological variety of carcinoma of tongue and was conducted in the Department of General Surgery and Otolaryngology and Head Neck Surgery in Bangabandhu Sheikh Mujib Medical University, Dhaka Medical College Hospital on 50 patients from January 2011 to July 2013. In this series highest number of patients were middle aged (36%). Male female ratio was 2:1. Average socioeconomic conditions of the patient were poor (68%). Betel nut and leaves chewing (88%) and smoking (56%) habits were commonly practiced for more than 10 years among the patients. Depending on site of involvement, variation in presenting symptoms has been observed. Oral tongue carcinoma mostly was presented with tongue lesion, pain and dysphagia where as the carcinoma of base of tongue commonly was presented with dysphagia, lump in neck. Lateral border of tongue (60%) was seen commonly involved. Ulcerative lesion (56%) predominantly was found in tongue lesion. Eighty percent (80%) of cases had no palpable Lymph node. Only few patients were found with Lymph node metastasis and most of them had carcinoma in base of the tongue (75%). Most of the carcinoma was well differentiated Squamous cell carcinoma. Carcinoma of tongue in our study commonly found in middle aged male patients. Variation of symptoms has depended on anatomical site involved. Most of the carcinoma was well differentiated Squamous cell carcinoma. Carcinoma other than squamous cell was not found.
Assuntos
Neoplasias da Língua/patologia , Adulto , Idoso , Areca/efeitos adversos , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fumar/efeitos adversosRESUMO
PURPOSE: Multiple steps, at both scientific and clinical level, are involved in assisted reproduction technology (ART). Optimization of each of these steps contributes to maximize the success of ART. Embryo transfer is one of the vital steps in ART. An easy embryo transfer increases the success of ART. Adequate training is required to undertake embryo transfer, but anatomical difficulties in completing this procedure alter the success of treatment. Difficult embryo transfer is challenging for clinicians but has an overwhelming negative impact on patients. Difficult embryo transfer may cause cervical or endometrial trauma with uterine contractions which can lead to unsuccessful implantation and poor outcome after ART. METHODS: Literature review of published material looking at all interventions that were employed to overcome difficult embryo transfers during ART. RESULTS: We identified 5 methods (17 studies) were employed to overcome difficult embryo transfer which are: Hysteroscopic methods in 4 studies (2 case reports, 2 case series). Malecot catheters after hysteroscopic evaluation were used in 2 studies (1 case report, 1 case series). Dilators including hygroscopic dilators were used in 2 studies (1 case report, 1 case series) and mechanical dilators were used in 3 studies (2 case series, 1 RCT-patients 367). Intrafollopian transfer was reported in 1 case report. Transmyometrial embryo transfers were reported in 5 studies (2 case reports, 2 case series, 1 RCT). CONCLUSION: There were only two randomized controlled studies (RCTs) identified in the review. All other were either case series or case reports. We found that there was no uniform classification or grading of difficulty of embryo transfer in the literature. A grading system has been suggested in this review. We recommend that there should be a consensus guideline formulated for interventions to overcome difficult embryo transfer. A large multicenter randomized controlled study is required to compare different methods for women with difficult embryo transfer.
Assuntos
Transferência Embrionária/métodos , Técnicas de Reprodução Assistida , Adulto , Implantação do Embrião , Feminino , Humanos , Gravidez , Contração UterinaRESUMO
Pancreas transplants are now highly effective for patients with diabetes mellitus. Improvements in outcomes have primarily been due to significant reductions in technical failures and immunological graft loss. In this short review we discuss three areas of controversy in the field of pancreas transplantation. Notwithstanding the controversies we have highlighted, in line with the American Diabetic Association position statement, simultaneous pancreas-kidney transplants and pancreas after kidney transplants should be routine for diabetic kidney recipients, and a pancreas transplant alone is appropriate for non-uremic labile diabetic patients.
Assuntos
Diabetes Mellitus/cirurgia , Transplante de Rim , Transplante de Pâncreas , Guias como Assunto , Humanos , Transplante de Rim/tendências , Transplante de Pâncreas/tendências , Medição de Risco , Fatores de Risco , Resultado do TratamentoRESUMO
OBJECTIVES: To determine, first, the prevalence and severity of various symptoms related to estrogen deficiency in women within a few years of receiving treatment for breast cancer, second, how women perceive the effects of these symptoms on their quality of life and, third, what measures have been taken to relieve vasomotor symptoms. METHODS: Two hundred women (aged 29-65 years) who had received treatment for breast cancer within the last 5 years were included in this cross-sectional survey. Information was collected about their breast cancer treatment, menopausal symptoms (Menopausal Rating Scale), the perceived effects of menopausal symptoms on their and their partner's quality of life and any treatments they were receiving for hot flushes. RESULTS: All but one woman reported at least one symptom related to the menopause (95.9% vasomotor; 83.3% psychological; 89.7% somatic). Current treatment with tamoxifen or previous chemotherapy did not influence the prevalence or the severity of hot flushes. Current antidepressant treatment was, however, significantly associated with a higher prevalence and severity of most menopausal symptoms, including hot flushes and sweats (p = 0.008). The severity of hot flushes and sweats was significantly correlated with self-assessed effects on overall quality of life (r(s) = 0.47); 56.4% of the respondents believed that menopausal symptoms had affected their partner's quality of life, the strongest correlations being with severity of sexual symptoms (r(s) = 0.56) and vaginal dryness (r(s) = 0.5). Only 21% of women experiencing hot flushes were receiving any treatment for hot flushes, with most women describing no knowledge or poor knowledge of treatment options. CONCLUSIONS: The majority of women receiving treatment for breast cancer report menopausal symptoms, which negatively correlate, not only with their own, but also with their partner's quality of life. Most women experiencing hot flushes are not receiving treatment due to lack of both awareness and confidence in the existing treatment options.
Assuntos
Neoplasias da Mama/psicologia , Menopausa/psicologia , Qualidade de Vida , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Estudos Transversais , Inglaterra/epidemiologia , Feminino , Fogachos/epidemiologia , Fogachos/fisiopatologia , Humanos , Pessoa de Meia-Idade , Prevalência , Índice de Gravidade de Doença , Inquéritos e QuestionáriosRESUMO
This work deals with multisensor data fusion to obtain landcover classification. The role of feature-level fusion using the Dempster-Shafer rule and that of data-level fusion in the MRF context is studied in this paper to obtain an optimally segmented image. Subsequently, segments are validated and classification accuracy for the test data is evaluated. Two examples of data fusion of optical images and a synthetic aperture radar image are presented, each set having been acquired on different dates. Classification accuracies of the technique proposed are compared with those of some recent techniques in literature for the same image data.
Assuntos
Algoritmos , Inteligência Artificial , Monitoramento Ambiental/métodos , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Técnica de Subtração , Aumento da Imagem/métodos , Armazenamento e Recuperação da Informação/métodos , Fotografação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , TransdutoresRESUMO
A novel extracellular matrix protein flectin (250 kD M(r)) shows specific left-right asymmetric expression before and throughout the looping process during heart development in avian embryos [Tsuda et al., 1996]. Flectin is a candidate molecule to provide directionality to the looping process in the avian model. In this study on mouse embryonic heart development, flectin is shown to be developmentally regulated and to be expressed in a specific asymmetric fashion, but in a different pattern from that observed in avian hearts. The molecules involved in development tend to be the same, but timing of expression, modulation, and asymmetry are different. In the mouse embryo, flectin is expressed symmetrically when the cardiogenic plate is formed. As looping progresses, flectin expression becomes asymmetric. There is right side predominance at the outflow tract and left side predominance at the ventricular portion of the tubular heart. The left side predominance of flectin develops in an anteroposterior direction, while right side predominance of the outflow tract remains relatively unchanged. These differential expression patterns of flectin decrease once the looping process is completed. After looping, flectin becomes restricted to the epicardium and subepicardial extracellular regions. In inv/inv mice, a known mouse model for human situs inversus, in which the directionality of heart looping is inverted, flectin expression pattern is mirror image of that of normal mouse embryos during looping stages. Our study indicates that, in the mouse, flectin shows a specific asymmetric expression pattern after initiation of heart looping and that this asymmetric expression pattern is related to the directionality of looping. The remodeling of the extracellular matrix (ECM) including specific flectin expression begins with the looping process. This morphogenetic change of the ECM coincides with the differentiation of each region of the tubular heart.
Assuntos
Padronização Corporal/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Coração Fetal/embriologia , Coração Fetal/metabolismo , Fatores de Transcrição , Animais , Padronização Corporal/genética , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mutação , Gravidez , Proteínas/genética , Situs Inversus/embriologia , Situs Inversus/genéticaRESUMO
Mice with mutations at the downless (dl) locus have defects in hair follicle, tooth, sweat gland, preputial gland, Meibomian gland, and tail development. The dl phenotype is analogous to the human genetic disorder termed autosomal hypohidrotic (or anhidrotic) ectodermal dysplasia (HED). On the basis of the identification of two related transgenic insertional mutations in the downless gene, yeast artificial chromosomes (YACs) were identified that map to the critical region of mouse Chromosome (Chr) 10. To determine which of the YACs contain the dl gene, we generated YAC transgenic mice by mouse embryo microinjections. The 200-kb YAC B25.D9 was found to rescue all of the downless defects. In addition, the transgenic YAC rescued the dominant Sleek (Dlslk) allele. Since the sequences within the YAC are entirely deleted in one of the transgenic mutants, our results establish that Sleek encodes a dominant-negative protein whose effects can be reversed by expression of extra copies of the wild-type locus.
Assuntos
Cromossomos Artificiais de Levedura/metabolismo , Displasia Ectodérmica/genética , Mutagênese Insercional , Alelos , Animais , Modelos Animais de Doenças , Humanos , Hibridização in Situ Fluorescente , Camundongos , Camundongos Transgênicos , Linhagem , FenótipoRESUMO
Visceral left-right asymmetry occurs in all vertebrates, but the inversion of embryo turning (inv) mouse, which resulted following a random transgene insertion, is the only model in which these asymmetries are consistently reversed. We report positional cloning of the gene underlying this recessive phenotype. Although transgene insertion was accompanied by neighbouring deletion and duplication events, our YAC phenotype rescue studies indicate that the mutant phenotype results from the deletion. After extensively characterizing the 47-kb deleted region and flanking sequences from the wild-type mouse genome, we found evidence for only one gene sequence in the deleted region. We determined the full-length 5.5-kb cDNA sequence and identified 16 exons, of which exons 3-11 were eliminated by the deletion, causing a frameshift. The novel gene specifies a 1062-aa product with tandem ankyrin-like repeat sequences. Characterization of complementing and non-complementing YAC transgenic families revealed that correction of the inv mutant phenotype was concordant with integration and intact expression of this novel gene, which we have named inversin (Invs).
Assuntos
Proteínas/genética , Fatores de Transcrição , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromossomos Artificiais de Levedura , Hibridização in Situ Fluorescente , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Dados de Sequência Molecular , Fenótipo , Deleção de SequênciaRESUMO
The role of basic amino acid residues that are highly conserved in the N-terminal domain of 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPs) in the binding of the substrate, shikimate-3-phosphate, has been assessed. Lys 19 and Arg 24 in the Bacillus subtilis EPSPs were substituted by glutamic acid and aspartic acid residues respectively by site-directed mutagenesis. Native and the mutant proteins were expressed using a two-vector system and the expressed proteins were purified to near homogeniety. The replacement of either Lys 19 or Arg 24 with a negatively charged residue nearly completely abolished the enzyme activity. The kinetic characterization of the purified wild type and the mutant proteins revealed that the substitution of positively charged residues in the N-terminal domain (K19 and R24) results in reduced affinity for shikimate-3-phosphate (S3P). The results suggest the involvement of these residues in the binding of S3P during enzyme catalysis.
Assuntos
Alquil e Aril Transferases , Bacillus subtilis/enzimologia , Ácido Chiquímico/análogos & derivados , Transferases/metabolismo , 3-Fosfoshikimato 1-Carboxiviniltransferase , Sítios de Ligação , Sequência Conservada , Escherichia coli/genética , Mutagênese Sítio-Dirigida , Conformação Proteica , Dobramento de Proteína , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Ácido Chiquímico/metabolismo , Transferases/química , Transferases/genéticaRESUMO
The role of a conserved arginine (R104) in the putative phosphoenol pyruvate binding region of 5-enolpyruvyl shikimate-3-phosphate synthase of Bacillus subtilis has been investigated. Employing site directed mutagenesis arginine was substituted by lysine or glutamine. Native and mutant proteins were expressed and purified to near homogeneity. Estimation of Michaelis and inhibitor constants of the native and mutant proteins exhibited altered substrate-inhibitor binding mode and constants. Mutation R104K hypersensitized the enzyme reaction to inhibition by glyphosate. The role of R104 in discriminating between glyphosate and phosphoenol pyruvate is discussed.