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At least 91 records · Page 5Linked to original sources
PubMed1987

Oxygen conservation and oxygen-conserving devices in chronic lung disease. A review.

The efficacy of long-term oxygen therapy for hypoxemic COPD patients is well established. However, oxygen is expensive and the portability of home oxygen is limited by the weight and bulk of the oxygen source. As a result, there has been a recent surge of interest in creating oxygen-conserving devices and methods. The efficiency of oxygen therapy can be improved over steady flow delivery by focusing oxygen delivery to early inspiration. Three methods for improving oxygen delivery efficiency--transtracheal catheter, reservoir cannula and demand-pulse oxygen delivery--are currently available for patient use. Each has its own set of advantages and disadvantages. By using oxygen conservation methods, the oxygen required to achieve adequate blood oxygenation can be reduced by a factor of 2:1 to 7:1 compared to steady flow. Thus, the cost of oxygen can be substantially reduced while increasing the portability and range of home oxygen therapy.

Costs and Cost Analysis↗
PubMed2004

Conservation and non-conservation of genetic pathways in eye specification.

In this review we highlight two genetic pathways important for eye morphogenesis that are partially conserved between flies and vertebrates. Initially we focus on the ey paradigm and establish which aspects of this genetic hierarchy are conserved in vertebrates. We discuss experiments that evaluate the non-linear relationship amongst the genes of the hierarchy with a concentration on vertebrate functional genetics. We specifically consider the Six genes and their relationship to sine oculis, as tremendous amounts of new data have emerged on this topic. Finally, we highlight similarities between Shh/Hh directed morphogenesis mediated by basic Helix-Loop-Helix factors in vertebrate retinal cell specification and in specification of fly photoreceptors.

Animals↗
PubMed2000

[A case of emphysematous pyelonephritis improved with conservative therapy--indication for conservative therapy].

A 51-year-old female patient was hospitalized in our department with high fever and left flank pain. Laboratory examination showed leukocytosis, increase of C-reactive protein (CRP), hyperglycemia and renal insufficiency. Enterobacter aerogenes grew out of the cultured urine. The radiograph and computerized tomographic (CT) scan revealed streaky gas in the destroyed left renal parenchyma with perirenal gas. She was diagnosed with left emphysematous pyelonephritis. Antibiotics therapy, treatment for sepsis and disseminated intravesicular coagulation was initiated resulting in mitigation of inflammation. High blood glucose initially required insulin therapy, but finally returned to normal levels through administration of oral antidiabetics. Although leukocytosis and low grade fever continued, the patient was discharged on day 53 with a negative CRP. CT scan indicated that the emphysematous change was localized after three months and almost resolved after four months. Renal scintigram indicated the residual function of the affected kidney. Because of the possibility of residual renal function and the cure by conservative therapy alone, the conservative therapy is preferred when the initial treatment is effective.

Anti-Bacterial Agents↗
PubMed1994

[A randomized clinical trial of adjuvant endocrine therapy after breast conserving surgery for early breast cancer. Cooperative Study Group for Breast Conserving Therapy].

To evaluate the clinical efficacy of adjuvant endocrine therapy after breast conserving surgery for early breast cancer, we have conducted a randomized controlled study since 1989. One hundred twelve-patients having a small breast tumor, less than 2 cm in diameter, and no palpable axillary lymph node, were the subjects of this study. All these patients underwent partial mastectomy with axillary lymph node dissection and were randomly divided into two groups according to the type of postoperative adjuvant endocrine therapy: Group I, tamoxifen (20 mg/day) for 2 years; Group II, no tamoxifen administration. The median follow-up period was 32.2 months. The incidence of local recurrence in the ipsilateral breast was 1.9% in Group I, which was lower than in Group II (6.8%). Three-year disease-free survival rates were also more favorable in Group I (94.2%) than in Group II (88.9%). This difference in prognosis was evident in patients with ER-positive tumors but not related to the menopausal status. These results suggest that adjuvant endocrine therapy with tamoxifen may be recommended for patients who underwent breast conserving surgery for early breast cancer, especially in those with ER-positive tumors.

Adult↗
PubMed1996

[Role of conservative therapy and medical treatment in ectopic pregnancy: literature review and clinical trial comparing medical treatment and conservative laparoscopic treatment].

OBJECTIVE: to compare methotrexate (MTX) to laparoscopic salpingotomy for conservative management of ectopic pregnancy (EP). DESIGN: prospective randomized study. PATIENTS: eighty-nine patients were randomized into 2 groups using a random number table. Inclusion criteria were an EP visualized by ultrasound with a pretherapeutic score < or = 13 as assessed by 6 criteria graded from 1 to 3: gestational age, hCG level, P level, abdominal pain, volume of the hemoperitoneum, and diameter of the hematosalpinx. INTERVENTIONS: 1 mg/kg of MTX injected transvaginally into the ectopic pregnancy without anaesthesia or IM administration (1.5 mg/kg) when EP cannot be safely or easily punctured (group 1) versus laparoscopic salpingotomy (group 2). RESULTS: the success rates defined by hCG levels returned to normal (< 10 mlU/mL) were 43 out of 46 in group 1 and 40 out of 43 in group 2. Medical treatment was significantly associated with shorter post-operative stay (24 vs 46 hours). hCG return to normal was quicker after laparoscopic treatment (13 vs 29 days). Reproductive performances were similar in both groups. CONCLUSIONS: in selected cases of EP with a pretherapeutic score < or = 13, MTX treatment appeared to be as safe and efficient as was conservative treatment by laparoscopy, an expectant management should be offered as a treatment option only in women fulfilling the criteria for a good prognostic.

Adolescent↗
PubMed1995

[Studies on theory and models of systemic conservation of animal and poultry genetic resources. II. Simulation experiment of systemic conservation of animal and poultry genetic resources].

Tribolium castaneum simulation and computer simulation proved the feasibility and rationality of Systemic Conservation of Animal and Poultry Genetic Resources (SCAPGR) theory and the biological meaning of the SCAPGR mathematical models. It also demonstrated that the right effective population size should be maintained and gene flow among populations should be controlled and adequate selecting method and mating system should determined according to population genetic characters of gene conserved in the SCAPGR population.

Animals↗
PubMed1997

[Conservative surgical treatment of a spontaneous splenic rupture during infectious mononucleosis. Report of a case and review of the [Conservative surgical treatment of a spontaneous splenic rupture during infectious mononucleosis. Case report and literature review].

A spontaneous splenic rupture occurred in a 31 year old patient suffering from infectious mononucleosis. An echography and an abdominal CT Scan revealed a rupture of the inferior pole of the spleen with a hemoperitoneum. A conservative surgical treatment was performed. Postoperative course was uneventful. This case-report draws the attention to the possibility of a conservative surgical treatment of a splenic rupture in the course of infectious mononucleosis. This attitude avoids the complications of splenectomy.

Adult↗
PubMed2002

Ferric hydroxamate binding protein FhuD from Escherichia coli: mutants in conserved and non-conserved regions.

Uptake of iron complexes into the gram-negative bacterial cell requires highly specific outer membrane receptors and specific ATP-dependent (ATP-Binding-Cassette (ABC)) transport systems located in the inner membrane. The latter type of import system is characterized by a periplasmic binding protein (BP), integral membrane proteins, and membrane-associated ATP-hydrolyzing proteins. In gram-positive bacteria lacking the periplasmic space, the binding proteins are lipoproteins tethered to the cytoplasmic membrane. To date, there is little structural information about the components of ABC transport systems involved in iron complex transport. The recently determined structure of the Escherichia coli periplasmic ferric siderophore binding protein FhuD is unique for an ABC transport system (Clarke et al. 2000). Unlike other BP's, FhuD has two domains connected by a long alpha-helix. The ligand binds in a shallow pocket between the two domains. In vivo and in vitro analysis of single amino acid mutants of FhuD identified several residues that are important for proper functioning of the protein. In this study, the mutated residues were mapped to the protein structure to define special areas and specific amino acid residues in E. coli FhuD that are vital for correct protein function. A number of these important residues were localized in conserved regions according to a multiple sequence alignment of E. coli FhuD with other BP's that transport siderophores, heme, and vitamin B12. The alignment and structure prediction of these polypeptides indicate that they form a distinct family of periplasmic binding proteins.

Amino Acid Sequence↗
PubMed1998

The MHC class II transactivator (CIITA) requires conserved leucine charged domains for interactions with the conserved W box promoter element.

The class II transactivator CIITA is required for transcriptional activation of the major histocompatibility complex (MHC) class II genes. Aside from an N-terminal acidic transcriptional activation domain, little is known about how this factor functions. Extensive mutagenesis of CIITA was undertaken to identify structural motifs required for function. The ability of mutants to activate a reporter gene under the control of MHC class II conserved W-X-Y or X-Y regulatory elements was determined. Two mutants displayed differential activity between the two promoters, activating transcription with the W-X-Y but not the X-Y elements. All mutants were tested for their ability to interfere with wild-type CIITA activity. Five CIITA mutant constructions were able to down-regulate wild-type CIITA activity. Three of these mutants contained targeted disruptions of potential functional motifs: the acidic activation domain, a putative GTP-binding motif and two leucine charged domains (LCD motifs). The other two contained mutations in regions that do not have homology to described proteins. The characterization of CIITA mutants that are able to discriminate between promoters with or without the W box strongly suggests that CIITA requires such interactions for function. The identification of LCD motifs required for CIITA function brings to light a previously undefined role of these motifs in CIITA function.

Amino Acid Substitution↗
PubMed1994

Complementary functions of E1a conserved region 1 cooperate with conserved region 3 to activate adenovirus serotype 5 early promoters.

The amino-terminal region of the adenovirus type 5 E1a protein including conserved regions (CRs) 1 and 2 binds the 105-kDa retinoblastoma protein and a second, 300-kDa, cellular protein. We show that mutant viruses with deletions of CR1 which release the binding of either p105 or p300 still activate early promoters and infect cells productively. However, mutations which disrupt binding of both proteins disrupt early promoter activity and block the viral life cycle. Ela CR3, which has an established role in early promoter activation, can act in trans to the amino-terminal functions. This suggests that the amino terminus provides distinct, redundant functions related to p300 and Rb binding that synergize with CR3 to transactivate early genes.

3T3 Cells↗
PubMed1986

Cytochrome b-559 genes from Oenothera hookeri and Nicotiana tabacum show a remarkably high degree of conservation as compared to spinach. The enigma of cytochrome b-559: highly conserved genes and proteins but no known function.

Recent data suggest that cytochrome b-559, an intrinsic membrane protein of the oxygen-evolving photosystem II in chloroplasts, is a heme cross-linked heteromeric polypeptide unit (Herrmann et al. 1984, FEBS Lett 176:239-244). The genes for this cytochrome, designated psbE and psbF, have been located on the chloroplast chromosome of Oenothera hookeri and Nicotiana tabacum by hybridization with fragments of the corresponding spinach genes, and characterized. In both cases, the nucleotide sequence discloses 2 uninterrupted reading frames of 83 and 39 codons separated by a few nucleotides, as in spinach. The amber translation stop codon of psbE overlaps the putative ribosome-binding site for psbF in all cases. The predicted molecular weights of the proteins are 9.2 and 4.3 kd, respectively. In each of the three plant species, and the direction of transcription is opposite to that of the gene for cytochrome f which is located distal to the b-559 genes. Comparison of the deduced amino acid sequences with those from the corresponding spinach genes shows 97% homology. The ubiquitous presence and remarkably high degree of structural and functional conservation of this gene cluster supports the hypothesis of a heteromeric assembly and an important functional role for cytochrome b-559.

Amino Acid Sequence↗
PubMed1986

Conservation among the immunoglobulins of carcharhine sharks and phylogenetic conservation of variable region determinants.

To study primitive vertebrate recognition molecules we have purified the immunoglobulins of three species of carcharhine sharks. The tiger (Galeocerdo cuvieri), the sandbar (Carcharhinus plumbeus) and the galapagos sharks (Carcharhinus galapagensis) possess 18S high molecular weight and 7S low molecular weight immunoglobulin forms. Both within and between species these forms closely resemble each other in polypeptide chain composition, heavy chain mass, carbohydrate content, amino acid composition, antigenic character and amino terminal sequence. These carcharhine species are separated by at least 30 million years of evolutionary time and it is remarkable that so little diversification of immunoglobulin structure has occurred during their evolution. By several criteria carcharhine immunoglobulins most closely resemble mammalian IgM. Studies of serological cross-reactions indicate that some immunoglobulin determinants have been conserved over a broad phylogenetic range of vertebrate classes; most notably JH and VHa-related markers are shared between forms as diverse as sharks and mammals.

Amino Acids↗
PubMed1989

Definition of mouse chromosome 1 and 3 gene linkage groups that are conserved on human chromosome 1: evidence that a conserved linkage group spans the centromere of human chromosome 1.

Comparative mapping between the human and the mouse genomes allows characterization of linkage groups that have been conserved over evolution. In this study, genes previously localized to adjacent regions of human chromosome 1 were mapped to discrete regions on distal mouse chromosomes 1 and 3 using an interspecific cross. Linkage analysis in mouse defined two groups in which the gene order appears to be the same as that in humans: 15 genes localized between human chromosome 1q21 and 1q32 were found to span 29.5 cM on distal mouse chromosome 1; 6 genes localized between human chromosome 1q21 and 1p22 spanned 15.6 cM on distal mouse chromosome 3. These data suggest that gene order within large chromosome segments may remain stable over long periods of evolution and that the position of the centromere may reflect a late event in the evolution of higher eukaryotic organisms. These studies provide a model for examination of specific evolutionary events.

Animals↗
PubMed1992

Factors influencing local relapse and survival and results of salvage treatment after breast-conserving therapy in operable breast cancer: EORTC trial 10801, breast conservation compared with mastectomy in TNM stage I and II breast cancer.

A (modified) radical mastectomy (RM) was compared with breast-conserving therapy (BCT) in stage I and stage II breast cancer patients. Treatment of the study arm comprised lumpectomy, axillary clearance and radiotherapy to the breast (50 Gy in 5 weeks external irradiation and a boost with iridium implant of 25 Gy). 902 patients were included. There were 734 TNM stage II patients. Patients with microscopically incomplete excision of the tumour were not excluded. After a median follow-up of 6 years, overall survival and local recurrence rates do not differ significantly between the two study arms. Actuarial survival at 8 years was 73% after RM and 71% after BCT; actuarial local recurrence at 8 years was 9% and 15%, respectively. In the mastectomy group tumour size did not affect local relapse, but after BCT the incidence of local recurrences was higher for tumours of 2-5 cm (16%) than for smaller tumours (7%) (at 8 years, P = 0.08). Results of salvage treatment for local recurrence so far were similar in both the BCT and the mastectomy group.

Aging↗
PubMed1993

Breast conserving therapy in patients with relatively large (T2, T3) breast cancers by preoperative irradiation and myocutaneous LD flap reconstruction. A new technique in breast conservation.

We investigated the feasibility of breast conserving treatment (BCT) in patients with large (T2, T3) breast cancers, by combining preoperative radiotherapy and tissue replacement after wide excision by a myosubcutaneous flap transposition. The treatment consisted of 50 Gy whole breast irradiation followed by a 15-25 Gy iridium implant to the primary tumour with 2 cm margins. Four weeks after completion of the radiotherapy, wide excision of the original tumour area with a 1 cm margin and an axillary dissection was performed. In the same session the breast was reconstructed with an ipsilateral latissimus dorsi transposition flap. The treatment results in the first 6 patients are encouraging with respect to treatment toxicity and cosmetic outcome. The clinical tumour response after radiotherapy was difficult to evaluate. However, microscopic evaluation showed residual tumour in all specimens with (focal) involvement of the surgical margins in two. With a minimum follow-up of over 2.5 years no tumour recurrences in the breast have occurred.

Brachytherapy↗
PubMed1999

Family history of breast cancer and local recurrence after breast-conserving therapy. The Dutch Study Group on Local Recurrence after Breast Conservation (BORST).

The impact of a family history of breast cancer on the local recurrence (LR) risk after breast-conserving therapy (BCT) was performed within the framework of a large, multicentre matched case-control study of risk factors for LR after BCT (BORST study). Family history was assessed for 218 breast cancer patients with LR (cases) and 480 patients without LR (controls). Detailed histological tumour features were determined by review of the primary tumour. The risk of LR for patients with a positive family history was similar to or less than that of non-familial patients (unadjusted odds ratio (ORunadj) 0.66 (95% confidence interval (CI) 0.40-1.08)). Familial patients were older than non-familial patients (P = 0.07) and their tumours had a lower histological grade (P = 0.07). A second primary tumour occurred significantly more often in familial patients (P = 0.02). Adjustment for these factors did not essentially alter the results (ORadj 0.71 (0.38-1.32)). Separate analyses according to age at onset (younger and older than 50 years) and time to LR/site of LR produced similar results. The sole presence of a positive family history of breast cancer does not appear to be a risk factor for local recurrence after BCT. Whilst this might be different for genetically predisposed patients, a positive family history does not appear to be a contra-indication for BCT.

Breast Neoplasms↗
PubMed1993

Genetic conservation of hlyA determinants and serological conservation of HlyA: basis for developing a broadly cross-reactive subunit Escherichia coli alpha-hemolysin vaccine.

The HlyA determinant among Escherichia coli isolates from patients with symptomatic urinary tract infection was compared in this report with a prototype HlyA encoded by pSF4000 by DNA-DNA hybridization tests with 20-base synthetic oligonucleotides and monoclonal antibody binding and neutralization assays. Hybridization results demonstrated that 349 (98%) of 357 definitive reactions among 54 hemolytic strains shared homology with seven DNA probes spanning many HlyA regions corresponding to residues (R) 41 to 47, 55 to 61, 248 to 254, 306 to 312, 336 to 343, 402 to 408, and 929 to 935. Genetic divergence was identified by lack of hybridization signals among 17 to 76% of the hemolytic strains within the distal portion of a predicted hydrophobic region corresponding to R491 to 319 and within a predicted hydrophilic region corresponding to R491 to 497 and R532 to 538. Serological studies demonstrated that 26 (81%) culture supernatants of 32 hemolytic strains were bound by all 12 monoclonal anti-HlyA antibodies. Among five of six remaining strains, the culture supernatants were bound by 3 to 11 monoclonal antibody preparations. There was only one hemolytic culture supernatant that failed to be bound by any monoclonal antibody, although the strain hybridized with nine hemolysin DNA probes. In addition, hemolytic activity of all 24 different culture supernatants tested was reduced by at least twofold by one monoclonal antibody specific for R2-161. These data extend and support previous views that the HlyA determinant is conserved among E. coli strains and suggest that a broadly cross-reactive HlyA subunit vaccine can be developed.

Amino Acid Sequence↗
PubMedDate not supplied

Combined laryngeal conservation surgery and irradiation: can we expand the indications for conservation therapy?

Thirty-nine patients (median age of 60 years) with carcinoma of the supraglottic larynx (N = 16), vocal cord (N = 4), and hypopharyngeal wall and pyriform sinus (N = 19) were treated by combined conservation surgery and radiation therapy. Thirty-three patients had postoperative treatment, and the remaining six were given preoperative irradiation. The plan was chosen because of clinical and pathologic features known to be fraught with a high incidence of recurrence above the clavicles. Long-term complications occurred in six patients, two of whom died of aspiration pneumonia. Thirty-eight patients completed their treatment and have been followed for a median of 48 months (1 1/2 to six years). Survival rates are 56% and 63% for absolute and determinant cases, respectively.

Adult↗