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排序方式: 共有1044条查询结果,搜索用时 15 毫秒
1.
Marouni MJ Barzilai A Keller N Rubinstein E Sela S 《International journal of medical microbiology : IJMM》2004,294(1):27-33
Group A streptococcus (GAS) is the principle etiologic agent of bacterial pharyngotonsillitis and a wide range of other diseases. Failure to eradicate GAS from patients has been documented in 5-30% of patients with pharyngotonsillitis, in spite of the continued sensitivity of GAS to penicillin and other beta-lactams. It was recently proposed that eradication failure might be attributed to the ability of GAS to maintain an intracellular reservoir during antibiotic treatment. We have previously shown that strains derived from patients with bacterial eradication failure, despite antibiotic treatment (persistent strains), adhered to and were internalized by cultured epithelial cells more efficiently than strains that were successfully eradicated. Since, penicillin and other beta-lactams do not penetrate well into mammalian cells, intracellular survival of GAS is crucial in order to persist during prolonged antibiotic treatment. In this study, we compared the survival of GAS strains from cases of eradication failure and eradication success, using an epithelial cell culture model. We found that persistent strains show significantly increased intracellular survival, compared to the 'eradication success' strains. This finding supports the idea that an intracellular reservoir of GAS plays a role in the etiology of antibiotic eradication failure. 相似文献
2.
Alexander Pushkin Natalia Abuladze Eitan Gross Debra Newman Sergei Tatishchev Ivan Lee Olga Fedotoff Galyna Bondar Rustam Azimov Matt Ngyuen Ira Kurtz 《The Journal of physiology》2004,559(1):55-65
We have recently shown that carbonic anhydrase II (CAII) binds in vitro to the C-terminus of the electrogenic sodium bicarbonate cotransporter kNBC1 (kNBC1-ct). In the present study we determined the molecular mechanisms for the interaction between the two proteins and whether kNBC1 and CAII form a transport metabolon in vivo wherein bicarbonate is transferred from CAII directly to the cotransporter. Various residues in the C-terminus of kNBC1 were mutated and the effect of these mutations on both the magnitude of CAII binding and the function of kNBC1 expressed in mPCT cells was determined. Two clusters of acidic amino acids, L958 DDV and D986 NDD in the wild-type kNBC1-ct involved in CAII binding were identified. In both acidic clusters, the first aspartate residue played a more important role in CAII binding than others. A significant correlation between the magnitude of CAII binding and kNBC1-mediated flux was shown. The results indicated that CAII activity enhances flux through the cotransporter when the enzyme is bound to kNBC1. These data are the first direct evidence that a complex of an electrogenic sodium bicarbonate cotransporter with CAII functions as a transport metabolon. 相似文献
3.
Pedro Guimarães de Azevedo Luana Reis Miranda Eduardo Souza Nicolau Rayane Benfica Alves Maria Aparecida Camargos Bicalho Patrícia Pereira Couto Adauto Versiani Ramos Renan Pedra de Souza Rafael Longhi Eitan Friedman Luiz De Marco Luciana Bastos-Rodrigues 《Obesity research & clinical practice》2021,15(4):334-338
BackgroundObesity has reached epidemic proportions worldwide, affecting life quality and span. Susceptibility to obesity is partly mediated by genetic differences. Indeed, several genes from the clock gene family have already been shown to be intimately associated with obesity in diverse ethnic groups. In the present study, an association between BMI and the rs707467, rs228697 and rs228729 PER3 (Period Circadian Clock 3) polymorphisms in subjects with class II (BMI ≥ 35.0–39.9 kg/m2) and class III obesity (>40 kg/m2, extreme obesity) were carried out using TaqMan real-time PCR. Overall, 259 Brazilian adults were genotyped, of whom 122 had class II or III obesity (BMI ≥ 35.0 kg/m2) and 137 were controls having normal weight (BMI > 18.5 and <24.9 kg/m2).ResultsPER3 tag SNP (rs228729) shows a significant association with extreme obesity (1000 permutation p = 0.03 and p = 0.04), for genotype and allele frequency respectively) and a haplotype among the three assessed SNPs (alleles G/T/A, rs228697, rs228729, and rs707467, respectively, 1000 permutation p = 0.03) was significantly more prevalent in the group with obesity.ConclusionThis exploratory association study suggests that PER3 rs228729 may be associated with extreme obesity in Brazilian adults, however, replication is needed. 相似文献
4.
The impact of patient delay and physician delay on the outcome of laparoscopic cholecystectomy for acute cholecystitis 总被引:6,自引:0,他引:6
Eldar S Eitan A Bickel A Sabo E Cohen A Abrahamson J Matter I 《American journal of surgery》1999,178(4):303-307
BACKGROUND: Laparoscopic cholecystectomy is now used in the management of acute cholecystitis. Under these circumstances unfavorable conditions may result in conversion and complications. Information about these conditions may help in planning the laparoscopic approach or in proceeding directly to open cholecystectomy. This study was initiated to evaluate perioperative factors associated with conversion and complications of laparoscopic cholecystectomy in acute cholecystitis. Special attention was paid to the duration of complaints until surgery, to the delay on the part of the patient, and to the delay on the part of the physician. METHODS: Between January 1994 and December 1997, we attempted to perform laparoscopic cholecystectomy on 348 patients with acute cholecystitis. All perioperative data were collected on standardized forms. RESULTS: There were 182 cases (52%) of acute uncomplicated cholecystitis, 90 (26%) of gangrenous cholecystitis, 33 of hydrops (9.5%), and 43 of empyema of the gallbladder (12.5%). Seventy six patients (22%) needed conversion to open cholecystectomy and complications occurred in 57 cases. Advanced cholecystitis was associated with significant patient delay (P = 0.01), and it had a significantly higher conversion rate (39%) compared with early cholecystitis (14.5%); (P <0.00001). Conversion rates were also associated with male gender (P = 0.0017), a history of biliary disease (P = 0.0085), and a patient delay of >48 hours (P = 0.028). The total and infectious complication rates were associated with an age older than 60 years (P = 0.023 and 0.007, respectively) and male gender (P = 0.026 and 0.014, respectively). CONCLUSIONS: In acute cholecystitis, patient delay is associated with a high conversion rate. Early timing of laparoscopic cholecystectomy tends to reduce the conversion rate, as well as the total and the infectious complication rates. Male gender, a history of biliary disease, and advanced cholecystitis are associated with conversion. Male and older patients are associated with a high total and infectious complication rates. 相似文献
5.
The use of a large synthetic mesh for laparoscopic repair of significant ventral abdominal wall defects may be accompanied
by technical difficulties resulting from improper orientation and positioning of the mesh over the defect. We suggest a technique
based on initial fixation of the mesh center to the central point of the defect, and subsequent centrifugal attachment of
the mesh to the abdominal wall. This technique is advantageous because it leads to precise orientation and positioning of
the synthetic patch and to significant reduction of the time needed for its reinforcement over and around the defect.
Received: 25 September 1998/Accepted: 27 November 1998 相似文献
6.
Screening for mutations in candidate genes for hypospadias 总被引:2,自引:0,他引:2
Nordenskjöld A Friedman E Tapper-Persson M Söderhäll C Leviav A Svensson J Anvret M 《Urological research》1999,27(1):49-55
Hypospadias, a condition with a frontally placed urethral orifice on the penis, is the most common malformation in males.
During fetal development several components are necessary for normal male genital development. Testosterone and dihydrotestosterone
act via the androgen receptor but a defective receptor function results in different degrees of genital malformations. Testosterone-5α-reductase
converts testosterone to dihydrotestosterone, which is crucial for normal differentiation, and a total lack of this enzyme
results, in syndromes with hypospadias. The Wilms' tumour 1 (WT1) gene is expressed in the fetal gonad and genital malformations
can occur due to WT1 gene mutations. These genes are therefore strong candidate genes for hypospadias. We have analysed 35
boys with hypopadias and one girl diagnosed as with complete androgen insensitivity syndrome, using exon by exon polymerace
chain reaction (PCR) amplification of the AR, WT1 and 5α-reductase genes and screened for point mutations and performed subsequent
DNA sequencing. No mutations in any of these genes were found in the 26 patients with isolated hypospadias. Two patients with
severe hypospadias with cryptorchidism were found to carry mutations in the androgen receptor gene. Also the girl with clinically
diagnosed complete androgen insensitivity was found to be homozygous for a splice mutation in the 5α-reductase gene. In summary,
mutations in the WT1, AR and 5α-reductase genes are not common causes of isolated hypospadias.
Received: 1 October 1997 / Accepted: 4 May 1998 相似文献
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10.
Eitan Prisman Marat Slessarev Takafumi Azami Dan Nayot Michael Milosevic 《International journal of radiation biology》2013,89(7):457-462
Purpose: Carbogen has long been under investigation as an adjuvant to radiotherapy of tumors. A major factor confounding its evaluation is its inconsistency in raising blood partial pressure of CO2 (pCO2). We investigated whether a new partial rebreathing method would provide better control of pCO2 than carbogen.Methods and materials: We compared the efficacy of each method in 10 healthy volunteers. Volunteers breathed 1.5, 3 and 5% carbogen in 5-min stages via the usual non-rebreathing circuit. All the volunteers then breathed 100% O2 through a commercial sequential gas delivery (SGD) circuit modified by attaching a reservoir to its exhalation port. Hypercarbia was induced by step reductions in oxygen flow to the SGD circuit. We monitored minute ventilation and end-tidal pCO2 (ETpCO2) as a surrogate for its arterial value.Results: Inhalation of 1.5 and 3% carbogen did not increase ETpCO2 from baseline (40 ± 1.5 mmHg); 5% carbogen increased ETpCO2 to 45 ± 1.6 mmHg (p < 0.001). With the SGD circuit, reducing O2 flow to 4.3 ± 0.7 l/min increased ETpCO2 in all subjects from 41 ± 2.0 mmHg (baseline) to 46 ± 2.1 mmHg (p < 0.001). Voluntary hyperventilation reduced ETpCO2 with 5% carbogen but not with SGD (p = 0.379).Conclusions: We confirm previous observations that carbogen inhalation does not result in a predictable rise in ETpCO2 and suggest that a precise and stable target ETpCO2 can instead be induced by simply controlling O2 flow into a modified SGD circuit. We hoped that the reliable control of pCO2 will enable studies that address first, the efficacy of raising ETpCO2 on specific tumor blood flow, and eventually, its benefit as an adjuvant to radiotherapy. 相似文献