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PubMed1989

Rodent common fragile sites: are they conserved? Evidence from mouse and rat.

Nineteen fragile sites induced by aphidicolin in lymphocyte cultures from the laboratory mouse are documented. These sites are compared with previously described fragile sites induced in mouse fibroblast systems, and then with those reported on chromosomes which have been evolutionarily conserved between the mouse and the laboratory rat. Of a total of 38 fragile sites thus far identified in mouse fibroblasts and lymphocytes, only 4 sites are common to the two cell types; 34 sites show no correspondence of loci. The reason for this discrepancy is unclear, but it is possible that these data may indicate some degree of tissue specificity of fragile site expression in the mouse. Eight autosomes in the mouse and rat retain straightforward and nearly complete banding homology. To test the hypothesis that fragile sites are conserved between the two species, we compared these eight autosomes with regard to number and distribution of fragile site loci. A total of 30 fragile sites is distributed over the conserved chromosomes. Only 4 (possibly 5) are common to both species; 18 are found in the rat but not the mouse, and 4 are found in the mouse but not the rat. Of the 4 shared sites, notable differences in frequency of expression exist. Our comparisons show that: (1) a small number of fragile sites is conserved; (2) a large number of fragile sites is not conserved, and (3) some sites which are conserved are quite different in the frequency at which they are expressed in the two species, indicating that the sites themselves may have undergone evolutionary change.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2004

Examination of breast conserving therapy in lobular carcinoma.

BACKGROUND: Experience with conserving surgery for lobular carcinoma has grown as more breast conserving surgeries have been performed. We examined the results of breast conserving therapy in lobular carcinoma. PATIENTS AND METHODS: We examined the postoperative positive margin rate, presence or absence of additional surgery, presence or absence of local or systemic recurrence and role of breast helical CT in 25 cases of breast conserving surgery performed at this department from 1991 through June 2003. RESULTS: Among the 303 cases of all breast conserving surgeries, there were 63 case with positive margins (20.8%), but there were 15 of 25 positive margin cases (60.0%) among the lobular carcinoma cases. In 8 of the 15 positive margin cases the technique was changed to mastectomy. One case of recurrence in the breast has been observed thus far. Although the positive margin rate and positive margin rate in infiltrating carcinoma cases tended to decline after the introduction of breast helical CT, the rates remained high. CONCLUSIONS: Since the positive margin rate was significantly high at the time of breast conserving surgery for lobular carcinoma, careful selection of technique based on imaging studies such as breast helical CT and MRI along with careful follow-up is considered necessary.

Adult↗
PubMed1998

A comparison of conservative and delayed surgical treatment of anterior cruciate ligament ruptures. A matched pair analysis.

A series of 60 matched and paired patients with complete rupture of the anterior cruciate ligament (ACL) was studied; 30 were treated conservatively, even though operation was recommended, and 30 were operated on within 35 months (range 18 to 48 months) after the ACL rupture. The average age was 34 years in each group. They were assessed 39 months after arthroscopy or reconstruction. At follow up, no patient had flexion of less than 100 degrees, 13 of the reconstructed knees had an extension deficit, but in only one was this more than 10 degrees. Thirty-six percent of the reconstructed and 14% of the conservatively treated patients graded their sports activity as unlimited, while 13% of the ACL reconstructions and 21% of those treated conservatively were severely limited. The Lysholm, Cincinnati and OAK scores were significantly better in the reconstructions. The anterior drawer sign was positive in 24% of the ACL reconstructions and in 81% of the conservatively treated patients; 19% had a positive pivot shift after reconstruction compared to 75% of those treated conservatively. Even though there was a considerable number of patients with a decreased range of motion after ACL reconstruction because of the slow regime of postoperative mobilisation used, the results of operation are significantly better than after conservative treatment even when ACL reconstruction was carried out late after injury.

Adult↗
PubMed2002

Significance of bile leaks complicating conservative surgery for liver hydatidosis.

Hepatic hydatidosis presents a challenge in liver surgery, and there is still controversy regarding the appropriate surgical technique. A high incidence of postoperative bile leaks is reported as a significant disadvantage of conservative surgical procedures. The purpose of this study was to examine the incidence and clinical importance of bile leakage in patients being treated exclusively by a conservative surgical technique. From January 1985 to November 2000 a total of 187 patients were operated on at our department for hepatic hydatidosis. They were subjected to the standard conservative surgical technique (wide unroofing and cyst drainage). A total of 18 complications were related to bile leakage (10%), 3 of them bile abscesses (1 drained surgically and 2 percutaneously), 1 case of bile peritonitis due to an accessory bile duct in the gallbladder bed (treated surgically), and 14 fistulas (1 bronchobiliary and 13 biliocutaneous). Five of the fistulas, including the bronchobiliary one, were treated successfully by endoscopy; and the remaining nine healed after conservative treatment. Bile leakage, representing a significant complication following conservative operations for hepatic hydatidosis, can be effectively treated conservatively or endoscopically, not justifying more aggressive surgical approaches.

Adolescent↗
PubMed2000

Comparative map alignment of BTA27 and HSA4 and 8 to identify conserved segments of genome containing fat deposition QTL.

Quantitative trait loci (QTL) associated with fat deposition have been identified on bovine Chromosome 27 (BTA27) in two different cattle populations. To generate more informative markers for verification and refinement of these QTL-containing intervals, we initiated construction of a BTA27 comparative map. Fourteen genes were selected for mapping based on previously identified regions of conservation between the cattle and human genomes. Markers were developed from the bovine orthologs of genes found on human Chromosomes 1 (HSA1), 4, 8, and 14. Twelve genes were mapped on the bovine linkage map by using markers associated with single nucleotide polymorphisms or microsatellites. Seven of these genes were also anchored to the physical map by assignment of fluorescence in situ hybridization probes. The remaining two genes not associated with an identifiable polymorphism were assigned only to the physical map. In all, seven genes were mapped to BTA27. Map information generated from the other seven genes not syntenic with BTA27 refined the breakpoint locations of conserved segments between species and revealed three areas of disagreement with the previous comparative map. Consequently, portions of HSA1 and 14 are not conserved on BTA27, and a previously undefined conserved segment corresponding to HSA8p22 was identified near the pericentromeric region of BTA8. These results show that BTA27 contains two conserved segments corresponding to HSA8p, which are separated by a segment corresponding to HSA4q. Comparative map alignment strongly suggests the conserved segment orthologous to HSA8p21-q11 contains QTL for fat deposition in cattle.

Adipose Tissue↗
PubMed1999

Sequence-ready physical map of the mouse chromosome 16 region with conserved synteny to the human velocardiofacial syndrome region on 22q11.2.

Proximal mouse Chromosome (Chr) 16 shows conserved synteny with human Chrs 16, 8, 22, and 3. The mouse Chr 16/human Chr 22 conserved synteny region includes the DiGeorge/Velocardiofacial syndrome region of human Chr 22q11.2. A physical map of the entire mouse Chr 16/human Chr 22 region of conserved synteny has been constructed to provide a substrate for gene discovery, genomic sequencing, and animal model development. A YAC contig was constructed that extends ca. 5.4 Mb from a region of conserved synteny with human Chr 8 at Prkdc through the region conserved with human Chr 3 at DVL3. Sixty-one markers including 37 genes are mapped with average marker spacing of 90 kb. Physical distance was determined across the 2.6-Mb region from D16Mit74 to Hira with YAC fragmentation. The central region from D16Jhu28 to Igl-C1 was converted into BAC and PAC clones, further refining the physical map and providing sequence-ready template. The gene content and borders of three blocks of conserved linkage between human Chr 22q11.2 mouse Chr 16 are refined.

Animals↗
PubMed2006

Conservative use of chest-tube insertion in children with pleural effusion.

The aim of this work was to evaluate the effect of a more conservative use of chest-tube insertion on the short-term and long-term outcome of pleural infection. Sixty-five patients with pleural infection, aged 1 month to 16 years were each treated according to one of the two protocols: classical management with chest-tube insertion (classical group, n = 33), or conservative use of chest-tube insertion (conservative group, n = 32), with drainage indicated only in the case of voluminous pleural effusion defined by a mediastinal shift and respiratory distress and/or an uncontrolled septic situation. The two groups were comparable with regard to age, baseline C-reactive protein (CRP) value and white blood cell counts, pleural thickness, identified bacteria, and antibiotic treatment. Chest-tube insertion was performed in 17 patients (52%) of the classical group compared to eight patients (25%) of the conservative group (P = 0.03). Duration of temperature above 39 degrees C was shorter in the conservative group (10 +/- 1 vs. 14 +/- 1 days, P = 0.01), as was the normalization of CRP (13 +/- 1 vs. 17 +/- 1 days, P = 0.03). Duration of hospitalization and intravenous (IV) antibiotherapy as well as the delay of chest-radiograph normalization was not significantly different between the two groups. A more conservative use of chest-tube insertion did not change short- and long-term outcome of the pleural infection in children. Drainage could be restricted to the most severely affected patients with pleural empyema causing a mediastinal shift and respiratory distress and/or presenting with an uncontrolled septic situation.

Adolescent↗
PubMed2001

Surgical or conservative treatment for chronic rotator cuff calcifying tendinitis--a matched-pair analysis of 100 patients.

Conservative or operative treatment for rotator cuff calcifying tendinitis was investigated in 100 patients in a matched-pair analysis. They were examined clinically and ultrasonographically 35-60 months after the initial visit. The mean Patte score was 91.8 for the patients who underwent surgical treatment and 81 for the ones who received conservative therapy (p < 0.004), while the age-related Constant-score was 103.4 and 95, respectively. Ultrasonography showed 28% calcifications in the surgical group, 18% newly formed and 10% that did not resolve after surgery. In the conservatively treated group, 33% calcifications were seen, of which 67% resolved. The number of rotator cuff ruptures was significantly higher in the conservative group. In the surgical group, 2% of partial tears and in the conservative group 5% of partial and 4% of complete cuff ruptures were found. Conservative treatment for calcifying tendinitis leads to less favourable pain results in the long term than surgical treatment. Surgery shortens the painful period and may reduce the number of future rotator cuff ruptures. Finally, the subjective functional outcome is significantly better after surgery.

Activities of Daily Living↗
PubMed2005

Small bowel obstruction: conservative vs. surgical management.

PURPOSE: The aim of this study was to assess incidence, risk factors, and recurrence rates for conservative and surgical management of small bowel obstruction. METHODS: Retrospective chart review was conducted of 329 patients accounting for 487 admissions with small bowel obstruction. Data were obtained from the institutional database and patient charts. Patients with early recurrent small bowel obstruction had prior operations or hospitalization with conservative therapy for small bowel obstruction, then had a hospital stay >10 days following abdominal surgery because of obstruction or required readmission for small bowel obstruction within 30 days. Patients treated for prior small bowel obstruction and then readmitted after 30 days for a recurrent small bowel obstruction were classified as having late recurrent small bowel obstruction. RESULTS: A total of 329 patients with a diagnosis of small bowel obstruction were identified. At index admission, 43 percent (142) were successfully treated conservatively, whereas 57 percent (187) failed conservative treatment and underwent surgery. Overall, there were eight early deaths, four in each group (2.8 percent conservative vs. 2.1 percent surgical; no significant difference). The frequency of recurrence for those treated nonoperatively was 40.5 percent compared with 26.8 percent for patients treated operatively (P < 0.009). Patients treated without operation had a significantly shorter time to recurrence (mean, 153 vs. 411 days; P < 0.004) and had fewer hospital days for their index small bowel obstruction (4.9 vs. 12.0 days; P < 0.0001). Two hundred one (63 percent) patients had abdominal surgery and 119 (37 percent) patients had no prior abdominal surgery before developing a small bowel obstruction. Previous abdominal operations by procedure type were colorectal surgery (34 percent), gynecologic surgery (28 percent), exploratory laparotomy (20 percent), appendectomy (14 percent), cholecystectomy (12 percent), herniorraphy (8 percent), and gastric bypass (5 percent). The mean time interval between initial procedure and index small bowel obstruction was 1.3 years for gastric bypass, 6.1 years for herniorraphy, 7.8 years for exploratory laparotomy, 8 years for cholecystectomy, 8.4 years for colorectal surgery, 11.8 years for gynecologic surgery, and 22.5 years for appendectomy. There was no significant difference between early and late recurrent small bowel obstruction in patients treated nonoperatively or operatively, regardless of prior history of abdominal surgery. Logistic regression analysis failed to identify any specific risk factors that were predictors of the success of conservative or surgical management. CONCLUSIONS: Operatively treated patients had a lower frequency of recurrence and a longer time interval to recurrence; however, they also had a longer hospital stay than that of patients treated nonoperatively. There was no significant difference in treatment type or in incidence or type of prior surgery among patients with early and late small bowel obstruction. None of the variables analyzed in this study were significant predictors of the success of a particular treatment.

Adult↗
PubMed1989

Reduction of demand characteristics in the measurement of certainty during modeled conservation.

The purpose of the present experiment was to document the cognitive processes mediating the observational learning of conservation. Two formats for measuring certainty were contrasted among nonconservers assigned to one of give groups. Under a public format, two groups used a certainty rating scale and showed the experimenter how sure they were about the correctness of a peer model's statements. Under a private format, two groups employed the same scale but were assured that their rating was not known by the experimenter. Within each format, one group was presented with the model's conservation answers and one group with the model's opinions on arbitrary matters. Conservation was demonstrated to the fifth group which did not perform the certainty assessment. All conservation groups were post-tested immediately after modeling and 6 weeks later and all groups displayed equivalent stable learning. Whereas public certainty was constantly high, private certainty increased as the model proceeded through conservation exemplification, in accordance with a hypothesis of sequential imitation and comprehension processes. Private certainty was also higher for conservation than for opinion, although not on the first two items. Public certainty was high regardless of modeled content, and public rating latency was always found to be shorter. These results strongly suggested the presence of demand characteristics for high undifferentiated ratings under the public format of certainty appraisal. This contamination prevented valid monitoring of the course of cognitive rule processing.

Attention↗
PubMed1989

Localization of conserved and variable antigenic domains of equine infectious anemia virus envelope glycoproteins using recombinant env-encoded protein fragments produced in Escherichia coli.

Previous characterizations of equine infectious anemia virus (EIAV) glycoprotein variation by DNA sequence analysis and epitope mapping using monoclonal antibodies (MAbs) have revealed the presence of conserved and variable regions within the EIAV env gene. To extend these studies, fragments of the EIAV envelope proteins gp90 and gp45 were expressed in Escherichia coli and used in Western blot analysis with a diverse panel of equine immune sera to identify antigenic segments. All sera from EIAV-infected animals reacted with the carboxyl terminal portion of gp90 and the amino terminal portion of gp45, indicating the highly conserved and immunodominant nature of these regions. Other gp90 segments, both from conserved and variable env sequences, displayed variable reactivities with the panel of equine sera. A panel of MAbs was also used in Western blot assays with the recombinant protein fragments for physical localization of previously identified MAb epitopes. The binding sites of two neutralizing MAbs were localized to a highly variable region of gp90, while nonneutralizing epitopes were localized to conserved and variable regions of the envelope glycoproteins. These results, in addition to localizing important antigenic sites on EIAV glycoproteins, indicate that previously defined conserved and variable env nucleotide sequences indeed encode protein sequences constituting conserved and variable immunogens during persistent infection by EIAV.

Animals↗
PubMed2003

[Modalities and limits of conservative treatment of adenocarcinoma in situ of the uterine cervix: analysis of nine cases and review of the literature].

OBJECTIVE: The aim of this study is to assess the results of conservative management of adenocarcinoma in situ (AIS) of the uterine cervix in young patients. PATIENTS AND METHODS: Data of 16 patients treated for AIS were reviewed: 10 were treated initially conservatively (cold knife conization in five patients, loop excision in three patients and cervical amputation in two patients) and six radically. One patient treated initially conservatively with loop excision and positive margins underwent a completion surgery (hysterectomy). RESULTS: None patient had recurrence whatever the type of surgery (radical or conservative) with a mean follow-up of 74 months. Two pregnancies were observed. DISCUSSION AND CONCLUSIONS: Conservative surgery for patients with AIS could be considered in young patients. But [for] reviewing literature several conditions should be respected: careful follow-up after conservative treatment; cold knife conization; length of cone specimen >25 mm and free margins. If those criteria are respected the risk of recurrent disease under the form of invasive carcinoma is low.

Adenocarcinoma↗
PubMed2004

Radical versus conservative surgery for vulvar carcinoma.

OBJECTIVE: The comparison of the radical and conservative surgical approaches for vulvar carcinoma in relation to the rate of recurrence and complications. METHODS: The records of invasive vulvar carcinoma cases were retrospectively reviewed in Istanbul University, Cerrahpasa School of Medicine, Gynecologic Oncology Division and Social Insurance Institution, Ankara Maternity Hospital, Gynecologic Oncology Department. Surgically treated cases with squamous histology were divided into radical vulvectomy and conservative procedures groups and were compared with respect to recurrence, complications, and disease-free survival. RESULTS: One hundred thirteen cases of invasive vulvar carcinoma cases were of squamous histopathology and 92 of these were surgically treated. The rate of local recurrence was lower in the radical vulvectomy group (25%) compared to conservative procedures groups (42.5%; p>0.05). The complication rates were comparable between the radical vulvectomy and conservative procedures groups (32.7% versus 35%, respectively; p>0.05). At the end of five years of the follow-up, the disease-free survival rates were 51.5% in radical vulvectomy group versus 35.7% in conservative procedures group (p>0.05). CONCLUSION: The rate of recurrence, complication, and disease-free survival are similar for the radical vulvectomy and the conservative procedures. Deciding the surgical strategy for vulvar carcinoma should depend on the experience of the surgeon for the short-term adequate results.

Adult↗
PubMed2006

Impact of surgeon specialty on ovarian-conserving surgery in young females with an adnexal mass.

PURPOSE: To evaluate the patterns of surgical care among pediatric and adolescent females undergoing operative intervention for an adnexal mass with particular attention toward factors associated with ovarian-conserving surgery and access to gynecologic care. METHODS: All female patients aged < or = 18 years undergoing surgery for an adnexal mass between January 1, 1991 and December 31, 2002 were retrospectively identified and demographic, operative, and pathologic data abstracted. Logistic regression analyses were used to identify factors independently associated with ovarian-conserving surgery and access to gynecologic care. RESULTS: Eighty-two consecutive cases were identified. The median age at surgery was 15 years, and 91.7% of patients were > or = 12 years of age. A malignant ovarian neoplasm was present in 14.6% of cases. Oophorectomy was performed in 52.4% of cases, while 47.6% of patients underwent ovarian-conserving surgery. Multivariate regression analysis revealed that ovarian-conserving surgery was significantly less likely in the setting of malignancy, torsion, and an ovarian size of > or = 6 cm. The presence of a gynecologic surgeon, compared to other surgical specialties, was statistically significantly and independently associated with ovarian-conserving surgery (odds ratio [OR] 8.71, 95% confidence interval [CI] 2.12-41.41, p = .001). Post-menarchal status and age > or = 16 years were the characteristic most predictive of access to gynecologic surgical care. CONCLUSIONS: In pediatric and adolescent patients, operative intervention for an adnexal mass is significantly more likely to result in ovarian conservation when performed by a gynecologic surgeon. For such patients, improved access to gynecologic consultation prior to surgical intervention may reduce the number of patients subjected to oophorectomy for benign conditions.

Adnexal Diseases↗
PubMed2003

How well is enzyme function conserved as a function of pairwise sequence identity?

Enzyme function conservation has been used to derive the threshold of sequence identity necessary to transfer function from a protein of known function to an unknown protein. Using pairwise sequence comparison, several studies suggested that when the sequence identity is above 40%, enzyme function is well conserved. In contrast, Rost argued that because of database bias, the results from such simple pairwise comparisons might be misleading. Thus, by grouping enzyme sequences into families based on sequence similarity and selecting representative sequences for comparison, he showed that enzyme function starts to diverge quickly when the sequence identity is below 70%. Here, we employ a strategy similar to Rost's to reduce the database bias; however, we classify enzyme families based not only on sequence similarity, but also on functional similarity, i.e. sequences in each family must have the same four digits or the same first three digits of the enzyme commission (EC) number. Furthermore, instead of selecting representative sequences for comparison, we calculate the function conservation of each enzyme family and then average the degree of enzyme function conservation across all enzyme families. Our analysis suggests that for functional transferability, 40% sequence identity can still be used as a confident threshold to transfer the first three digits of an EC number; however, to transfer all four digits of an EC number, above 60% sequence identity is needed to have at least 90% accuracy. Moreover, when PSI-BLAST is used, the magnitude of the E-value is found to be weakly correlated with the extent of enzyme function conservation in the third iteration of PSI-BLAST. As a result, functional annotation based on the E-values from PSI-BLAST should be used with caution. We also show that by employing an enzyme family-specific sequence identity threshold above which 100% functional conservation is required, functional inference of unknown sequences can be accurately accomplished. However, this comes at a cost: those true positive sequences below this threshold cannot be uniquely identified.

Animals↗
PubMed2005

Long-term motility and fertility conservation of chilled canine semen using egg yolk added Tris-glucose extender: in vitro and in vivo studies.

The effects of medium exchange on motility parameters of chilled canine semen preserved in egg yolk Tris-glucose (EYTG) extender were analyzed over a 27-d period. Semen extender was exchanged at three time points (Days 11, 21 and 27) after collection, when motility parameters were demonstrated to significantly decrease from parameters observed at semen preparation (Day 0) or at day of previous extender exchange. In the absence of medium exchanges, motile spermatozoa were observed up to Day 16 (mean +/- S.D. 1.5 +/- 0.3% of motile spermatozoa). A stimulation of the different semen motility parameters was observed after extender exchange. Semen extender exchange at Day 11 allowed conservation of motility until Day 21, compared to 16 d in the absence of extender exchange. At Day 21, when spermatozoa appeared immobile or dead, a second extender exchange was performed, allowing the extension of motility conservation up to Day 27. The third extender exchange, performed at Day 27, was no longer associated with motility stimulation. Glucose content in the medium decreased slowly over time; a concomitant decrease in pH was also observed. No changes in osmolarity were observed over time. To verify the fertility of long-term conserved chilled semen, two groups of 10 bitches were inseminated either once (Group 1) or twice at 48-h intervals (Group 2) intra-vaginally with semen conserved chilled for a mean of 9 +/- 1.8 d. Out of the 10 bitches inseminated once, 5 became pregnant, versus 7 in the group of animals inseminated twice. The present study reports the possibility to extend the conservation of chilled canine semen up to 3 wk with conservation of good fertility for at least 10 d. The role of energetic substrate and pH alteration is postulated and the classically accepted relation of semen motility/viability is raised.

Animals↗
PubMed2004

Is community-based ecotourism a good use of biodiversity conservation funds?

Community-based ecotourism (CBET) has become a popular tool for biodiversity conservation, based on the principle that biodiversity must pay for itself by generating economic benefits, particularly for local people. There are many examples of projects that produce revenues for local communities and improve local attitudes towards conservation, but the contribution of CBET to conservation and local economic development is limited by factors such as the small areas and few people involved, limited earnings, weak linkages between biodiversity gains and commercial success, and the competitive and specialized nature of the tourism industry. Many CBET projects cited as success stories actually involve little change in existing local land and resource-use practices, provide only a modest supplement to local livelihoods, and remain dependent on external support for long periods, if not indefinitely. Investment in CBET might be justified in cases where such small changes and benefits can yield significant conservation and social benefits, although it must still be recognized as requiring a long term funding commitment. Here, I aim to identify conditions under which CBET is, and is not, likely to be effective, efficient and sustainable compared with alternative approaches for conserving biodiversity. I also highlight the need for better data and more rigorous analysis of both conservation and economic impacts.

Journal Article↗
PubMed2004

The comparative method in conservation biology.

The phylogenetic comparative approach is a statistical method for analyzing correlations between traits across species. Whilst it has revolutionized evolutionary biology, can it work for conservation biology? Although it is correlative, advocates of the comparative method hope that it will reveal general mechanisms in conservation, provide shortcuts for prioritizing conservation research, and enable us to predict which species will experience (or create) problems in the future. Here, we ask whether these stated management goals are being achieved. We conclude that comparative methods are stimulating research into the ecological mechanisms underlying conservation, and are providing information for preemptive screening of problem species. But comparative analyses of extinction risk to date have tended to be too broad in scope to provide shortcuts to conserving particular endangered species. Correlates of vulnerability to conservation problems are often taxon, region and threat specific, so models must be narrowly focused to be of maximum practical use.

Journal Article↗