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Multiple-country comparison of dairy sires.

A multiple-trait sire model was described in which yields of daughters in different countries were considered to be different traits. Such a model required estimates of genetic correlations among sire genetic effects in different countries. Observations were average daughter yield deviations, which were yields adjusted for all fixed effects within a country and for mate and animal permanent environmental effects. The methodology was described through a small example. Methods for estimating genetic covariances between countries as well as the advantages and disadvantages of the multiple-country approach to international comparisons were discussed. The proposed method appears to be better theoretically than methods in which the genetic correlations among countries are assumed to be 1. The relationships of estimated transmitting abilities of sires from the multiple-country analysis with international conversion formulas were discussed.

Animals↗

Isoprenylation is required for the processing of the lamin A precursor.

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic for mevalonate. Moreover, inhibition of prelamin A processing by mevinolin treatment is rapidly reversed by the addition of exogenous mevalonate. Processing of prelamin A is, therefore, dependent on isoprenoid metabolism. Analysis of the conversion of prelamin A to lamin A by two independent methods, immunoprecipitation and two-dimensional nonequilibrium pH gel electrophoresis, demonstrates that a precursor-product relationship exists between prelamin A and lamin A. Analysis of R,S-[5-3H(N)]mevalonate-labeled cells shows that the rate of turnover of the isoprenoid group from prelamin A is comparable to the rate of conversion of prelamin A to lamin A. These results suggest that during the proteolytic maturation of prelamin A, the isoprenylated moiety is lost. A significant difference between prelamin A processing, and that of p21ras and the B-type lamins that undergo isoprenylation-dependent proteolytic maturation, is that the mature form of lamin A is no longer isoprenylated.

Amino Acid Sequence↗

Deposition of C3b and iC3b onto particulate activators of the human complement system. Quantitation with monoclonal antibodies to human C3.

Monoclonal antibodies were used to determine the number and molecular form of C3 bound to particulate activators of the complement (C) system by human serum. Sheep erythrocytes (E) coated with IgM (EIgM) and IgG (EIgG) were used to study activation of the classical pathway (CP). Yeast (Y), rabbit erythrocytes (ER), and five species of bacteria (Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae type 3, Streptococcus pyogenes, and Hemophilus influenzae type b) were used to study activation of the alternative pathway (AP). The deposition of C3b onto EIgM and EIgG incubated in C7-deficient human serum was dependent on the serum concentration. At all serum concentrations tested, there was complete conversion of C3b to iC3b. Kinetic analysis of C3b deposition and conversion to iC3b indicated that these events occurred almost simultaneously; the reaction was completed by 15 min. The deposition of C3 onto the AP activators ER and Y was also dependent on serum concentration, and ER, but not Y, required the presence of Mg-EGTA and thus the activation of only the AP. C3b deposition and conversion to iC3b on Y was complete in 15 min, with 82% of bound C3 converted to iC3b. For ER, maximum C3 deposition required 30 min in both the presence and absence of Mg-EGTA. However, after 1 h of incubation, 74% of bound C2 was iC3b in the absence of Mg-EGTA, compared with only 52% in the presence of Mg-EGTA. Thus, even on AP activators, a large portion of C3b may be converted to iC3b, and this conversion is probably controlled by elements on the particle's surface. Studies with the five species of bacteria yielded similar results. Approximately 3-5 X 10(4) molecules of C3 were bound per microorganism, with opsonization being completed in 30 min. Remarkably, only 16-28% of bound C3 was in the form of iC3b, even after 2 h of incubation. The presence or absence of Mg-EGTA, or the addition of purified CR1 to the reaction mixture, did not significantly effect the ratio of C3b to iC3b. Finally, SDS-PAGE and autoradiography of particle-bound 125I-C3 fragments confirmed that there was no conversion of iC3b to C3d,g or C3d. The data obtained about the opsonization of bacteria suggest that the predominant form of C3 that is encountered by inflammatory phagocytes may be C3b.

Animals↗

Serum HER-2/neu conversion to positive at the time of disease progression in patients with breast carcinoma on hormone therapy.

BACKGROUND: Prolonged exposure of breast carcinoma cells in vitro to tamoxifen results in tamoxifen resistance. Tamoxifen-resistant cells express increased HER-2/neu mRNA and protein. The objective of this study was to determine whether patients with metastatic or locally advanced breast carcinoma who have negative serum HER-2/neu status at the initiation of first-line hormone therapy with letrozole or tamoxifen convert to positive serum HER-2/neu status at the time of disease progression and to determine whether serum HER-2/neu conversion to positive status is associated with response to therapy and overall survival. METHODS: Serum samples were obtained at baseline and at the time of disease progression from 240 patients who initially had negative serum HER-2/neu status (< 15 ng/mL). A manual microtiter, enzyme-linked immunosorbent assay that was specific for the extracellular domain of the HER-2/neu (c-erbB-2) oncoprotein product was used to quantitate serum levels. RESULTS: Among 240 patients, 61 patients (26%) converted from serum HER-2/neu negative to positive (> 15 ng/mL) at the time of disease progression. Thirty-two of 129 patients (25%) who were treated with tamoxifen and 29 of 111 patients (26%) who were treated with letrozole became converted to positive serum HER-2/neu status at the time of disease progression. The response rate and the time to disease progression on first-line hormone therapy were not affected by serum HER-2/neu conversion. The survival of patients who converted to positive serum HER-2/neu status was significantly shorter compared with the survival of patients who remained negative for serum HER-2/neu. A multivariate analysis revealed that conversion to positive serum HER-2/neu status was an independent prognostic variable for survival. CONCLUSIONS: Conversion to positive serum HER-2/neu status occurred in approximately 25% of patients who received first-line hormone therapy. Conversion to serum HER-2/neu-positive status occurred with equal frequency in antiestrogen and aromatase-inhibitor therapy. The current results showed that serum conversion to HER-2/neu-positive status was an independent risk factor for decreased survival in patients with breast carcinoma.

Antineoplastic Agents, Hormonal↗

Results of the betaxolol versus placebo treatment trial in ocular hypertension.

PURPOSE: To determine whether treatment with betaxolol can delay or prevent the conversion from ocular hypertension to early glaucoma on the basis of visual field criteria, by means of a prospective, randomised, placebo-controlled trial. METHODS: Three hundred and fifty-six ocular hypertensives were randomized to treatment with either betaxolol drops or placebo drops during the period 1992-1996. Each patient was followed prospectively with 4-monthly visits. Examination at each visit included visual field testing, intra-ocular pressure (IOP) measurement and optic disc imaging. Conversion to early glaucoma was defined on the basis of visual field change by AGIS criteria. An intent-to-treat analysis compared visual field conversion after 3 years in the treatment and placebo arms. Normal visual field survival analysis was also performed. The IOP characteristics of the two treatment groups were compared. RESULTS: Two hundred and fifty-five patients completed the study, which ended in 1998, with a range of follow-up of 2-6 years. Sixteen (13.2%) of 121 patients in the placebo group converted to glaucoma, compared with 12 (9.0%) of 134 patients in the betaxolol group. The intent-to-treat analysis demonstrated no evidence of any difference in conversion rates between the betaxolol and placebo groups after 3 years. Visual field survival analysis demonstrated no significant difference between the betaxolol and placebo groups. The betaxolol-treated group had significantly lower post-treatment IOP values. Converters had significantly higher pre- and post-treatment IOP values than non-converters. CONCLUSIONS: Betaxolol significantly lowered the IOP level compared with placebo. Conversion to glaucoma was found to be related to both the baseline and post-treatment IOP levels. However the intent-to-treat analysis did not demonstrate a statistically significant reduction in the conversion rate in the betaxolol-treated group.

Adrenergic beta-Antagonists↗

Hand use by tufted capuchins (Cebus apella) to extract a small food item from a tube: digit movements, hand preference, and performance.

The aim of this study was to analyze the manual patterns used by tufted capuchin monkeys (Cebus apella) to retrieve a small food item from a narrow tube, with special attention focused on the independent use of single fingers, fine digit movements, hand preference, and intermanual differences in the time it took the monkeys to obtain the food. The capuchins (n = 20) mainly used their forefinger to extract the food from the tube. The simultaneous use of the index and middle fingers occurred less frequently, and the use of the forefinger in combination with other digits occurred rarely. The capuchins demonstrated a capacity to move single digits independently when the fingers were locating the food inside the tube, and displayed a high mobility of the distal phalanx joints. However, they possessed only a limited capacity to coordinate single fingers in space, and displayed only a slight degree of manual preshaping when they approached the tube. A hand-preference analysis failed to reveal any significant lateral bias for the group, since both adults (> or = 5 years) and immature individuals (<5 years) of both sexes used either hand with the same frequency. Conversely, a latency analysis showed a significant interaction between the subject's age and performance difference between hands: in adults, but not in immature individuals, the left hand was faster than the right hand in retrieving food.

Animals↗

In vivo setting behaviour of fast-setting calcium phosphate cement.

The in vivo setting behaviour of fast-setting calcium phosphate cement (FSCPC) between femoral muscles of the rat was investigated to evaluate the possible value of FSCPC for medical and dental application. Conventional CPC (c-CPC) and FSCPC were implanted between femoral muscles, and various aspects of the setting behaviour such as setting time, mechanical strength and conversion ratio of cement into hydroxyapatite (HAP: Ca10(PO4)6(OH)2) were measured by the Vicat needle method, diametral tensile strength (DTS) measurement, and quantitative powder X-ray diffraction (XRD) analysis, respectively. The setting time of FSCPC in vivo was 5-7 min, in contrast to 48 min for c-CPC. As a result of its fast setting, set specimens of FSCPC showed higher mechanical strength from the initial stage than c-CPC. Higher DTS values were observed in FSCPC than c-CPC implanted after 24 h. Powder XRD analysis revealed faster conversion of FSCPC than c-CPC into HAP, which was responsible both for the faster setting and higher mechanical strength from the initial stage. We concluded, therefore, that FSCPC may be used for a wide range of clinical applications, i.e. fields where fast setting is required such as orthopaedic, plastic and reconstructive, and oral and maxillofacial surgery.

Animals↗

The caring relationship in hospice care: an analysis based on the ethics of the caring conversation.

Good nursing is more than exercising a specific set of skills. It involves the personal identity of the nurse. The aim of this article is to answer two questions: (1) what kind of person should the hospice nurse be? and (2) how should the hospice nurse engage in caring conversations? To answer these questions we analyse a nurse's story that is intended to be a profile of an exemplary hospice nurse. This story was constructed from an analysis of five semistructured interviews with hospice nurses, based on the 'ethics of the caring conversation', which is inspired by the ethical perspective of Paul Ricoeur. The research questions concentrate on the norms of respect, responsibility and reciprocity, which are integral parts of the 'ethics of the caring conversation'.

Communication↗

An RBRVS approach to financial analysis in health care organizations.

Resource-based relative value scales (RBRVS) have altered the outpatient reimbursement system of America's health care system and established a method of standardization whereby the efficiency of medical practices of varying size and complexity can be compared using a standard (the cost conversion factor) for analysis. This article compares the utility of RBRVS with earlier systems of reimbursement and concludes with a brief speculative assertion regarding the emergence of the next stage of ambulatory care reimbursements through ambulatory payment classifications.

Costs and Cost Analysis↗

Reaction coordinate analysis of the S2-S1 internal conversion of phenylacetylene.

The reaction coordinate of the S(2)-S(1) internal conversion (IC) of phenylacetylene (PA) was analyzed using the ab initio complete active space self-consistent field (CASSCF) method. In the first process after electronic excitation into S(2), the aromatic benzene ring is transformed into a nonaromatic quinoid structure. The ethynyl part (-C[triple bond]CH) takes an incomplete allenoid structure in which the CC bond elongates to an intermediate value between typical C[triple bond]C triple and C=C double bonds, but the bend angle of -CCH is 180 degrees . In the second process, PA takes a complete allenoid structure with an out-of-plane location of the beta-H atom (i.e., the H atom of the ethynyl part) and a further elongation of the CC bond so that PA is most stable in S(2) (S(2)-bent). The conical intersection between S(2) and S(1) (S(2)/S(1)-CIX) is located near the S(2)-bent geometry and is slightly unstable energetically. After transition at S(2)/S(1)-CIX, PA quickly loses both quinoid and allenoid structures and recovers the aromaticity of the benzene ring in S(1). Analysis of the dipole moment along the reaction coordinate shows that the weak electron-withdrawing group of the ethynyl part in S(0) suddenly changes into an electron-donating group in S(2) after the main transition of S(0)-S(2). The photoinduced change of the dipole moment is a driving force to the formation of a quinoid structure in S(2). Regarding the benefit of the reaction coordinate analysis of the multidimensional potential energy surfaces of PA, the present picture of the IC process is much more elaborate than our previous representation (Amatatsu, Y.; Hasebe, Y. J. Phys. Chem. A 2003 107, 11169-11173). Vibrational analyses along the reaction coordinate were also performed to support a time-resolved spectroscopic experiment on the S(2)-S(1) IC process of PA.

Journal Article↗

The in vitro conversion of chorismate to isochorismate catalyzed by the Escherichia coli entC gene product. Evidence that EntA does not contribute to isochorismate synthase activity.

The entC and entA genes, coding for the enzymes isochorismate synthase and 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase, respectively, were subcloned behind the T7 promoter in the expression plasmid pGEM3Z. Their protein products were overproduced and partially purified for in vitro analysis of the conversion of chorismate to isochorismate. Whereas previous genetic experiments suggested that the EntA enzyme has a role in this conversion, this study clearly indicates that EntC alone catalyzes the reaction. Addition of EntA had no effect on isochorismate synthase activity. As a result, the mutation (previously designated entC401) in strain AN191 was characterized by nucleotide sequence analysis. The lesion is a single base substitution in the entA gene, resulting in a glutamic acid-for-glycine substitution at the penultimate amino acid (residue 247) of the EntA enzyme. The mutant protein was partially purified and shown to be devoid of 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase activity, whereas the entC gene product from strain AN191 exhibited normal isochorismate synthase function. These results conflict with the earlier characterization of the entC401 mutation in a different genetic background. The data presented herein establish that the EntA protein does not contribute to isochorismate synthase activity and that the mutant strain that led to this suggestion harbors a defective allele of entA rather than entC.

Base Sequence↗

Analysis of aminoimidazole ribosides by capillary electrophoresis--diagnosing defects in second part of purine biosynthetic pathway.

BACKGROUND: Only three inherited metabolic defects have been identified in purine de novo synthesis (PDNS). We present here CE methods for diagnosing defects in the second half of PDNS (from sixth to tenth enzymatic conversion) based on analysis of aminoimidazole ribosides - dephosphorylated intermediates - in urine. METHODS: Assays were performed in an uncoated fused-silica capillary using two electrophoretic separation systems: 60 mmol/l borate - 2-amino-2-methyl-1-propanol-80 mmol/l sodium dodecylsulfate (pH 9.6) and 200 mmol/l phosphate - sodium (pH 1.8). RESULTS: The reported conditions allowed separation of all metabolites from major urinary constituents with analysis time less than 10 min and separation efficiency of 220 and 350 thousands theoretical plates per meter for borate and phosphate system, respectively. The intra- and interday imprecisions were less than 4.4% and 9.9% CV. Potential usefulness of the methods was demonstrated on samples from a patient with adenylosuccinate lyase deficiency and Chinese hamster ovary cell lines defective in PDNS. CONCLUSIONS: CE is a useful and effective tool in the analysis of aminoimidazole ribosides which enables diagnosis of known as well as not so far identified inherited defects of PDNS pathway.

Adenylosuccinate Lyase↗

[Proceedings in the implantation of a laparoscopic radical prostatectomy program].

OBJECTIVE: To describe our proceedings in the implatation of our laparoscopic radical prostatectomy program (LRP). METHODS: Our working agenda and step-oriented implementation of our LRP program are shown. RESULTS: Four main steps were scheduled to acomplish this goal. These were: Preparatory phase, programed open conversion, development and analysis. Overlapping of each of these phase occured although their major content run on a time-basis. After basic skills acquisition and updating of our equipment we moved into the fixed-time open conversion we allowed us to progresively improve our performance without putting our patients into risks. Operative time of this phase exceeds that of our open cases in 63 minutes and no major complications took place. A rapid decrease in the operative time was noted after the first 15 cases (197' vs 264'). CONCLUSION: Implantation of a program of LRP can be done safely with a pre-planned program tailored to the needs and characteristics of each group and institution.

Humans↗

E2F as a regulator of keratinocyte proliferation: implications for skin tumor development.

E2F and DP family members are established regulators of the cell cycle. In this study, we examined their activity/expression during keratinocyte growth arrest. Treating human epidermal keratinocytes with the growth inhibitors TPA or IFN-gamma or allowing the cells to reach confluence resulted in 90% inhibition of DNA synthesis, whereas a keratinocyte-derived squamous carcinoma cell line (SCC25) was resistant to growth inhibitors. Gel shift analysis of keratinocytes using an E2F response element indicated that growth arrest was associated with a decrease in all E2F binding complexes. This indicates that growth inhibition is not due to negative regulation by pocket proteins. Conversely, gel shift analysis of growth inhibitor-resistant SCC25 cells showed no decrease in E2F binding. If deregulated E2F expression/activity is involved in tumor development, then the deliberate deregulation of E2F activity may make keratinocytes resistant to growth inhibitors in much the same way as the SCC cells. The HPV16 E7 protein is known to activate E2F. Retroviral infection of keratinocytes with E7-expressing constructs resulted in growth inhibitor resistance, whereas infection with E6 constructs did not. E2F is a heterodimeric complex consisting of E2F family members (1-5) and DP proteins (1-3). Examination of the expression levels for E2F genes and other genes associated with the cell cycle indicated that E2F1 was profoundly decreased in growth-arrested keratinocytes (90%), whereas E2F3, E2F5, and DP1 were not. E2F2 and E2F4 were increased in IFN-gamma-treated keratinocytes but not in TPA-treated or confluent keratinocytes. In contrast, SCC25 cells did not undergo growth arrest and did not downregulate E2F1 mRNA expression in response to growth inhibitors. Our results indicate that E2F DNA binding and in particular E2F1 mRNA expression are associated with keratinocyte proliferation. Our results with the SCC25 cells and the E7-infected cells are consistent with the proposition that deregulated E2F expression/activity (in particular E2F1) may be involved in the unregulated proliferation of skin tumor cells.

Apoptosis↗

Converted laparoscopic colorectal surgery.

BACKGROUND: Conversion rates following laparoscopic colorectal surgery vary widely between studies, and the outcome of converted patients remains controversial. METHODS: A comprehensive search of the English-language literature was updated until May 1999. RESULTS: Twenty-eight studies on 3232 patients were considered for analysis. The overall conversion rate was 15.38%. Seventy nine percent of the studies did not include a definition for conversion; in these studies, the conversion rate was significantly lower than in the series where a specific definition was considered (13.7% vs 18.9%, chi-square test, p < 0.001). Converted patients had a prolonged hospital stay (11.38 vs 7.41 days) and operative time (209 vs 189 min) in comparison with laparoscopically completed patients (95% confidence interval (CI), 1.70-4.00 and 35.90-37.10, respectively). The factors associated with an increased rate for conversion were left colectomy (Odds Ratio [OR] = 1.061), anterior resection of the rectum (OR = 1.088), diverticulitis (OR = 1.302), and cancer (OR = 2.944) (for each parameter, Wald chi-square value, p < 0.001). CONCLUSIONS: In nonrandomized studies, the rate of laparoscopically completed colorectal resections is close to 85%. Because converted patients have a distinct outcome, a clear definition of conversion is required to compare the results of randomized trials. Such trials should also consider a 20% rate of conversion when estimating the sample size for the desired power level. It is likely that converted patients will have a significant impact on the results of future clinical research in laparoscopic colorectal surgery.

Aged↗

Human T cell receptor V beta gene polymorphism.

Southern blot hybridizations with human T cell receptor V beta gene probes were used to determine the sizes of the various V beta gene subfamilies. An analysis of DNA samples from 100 unrelated individuals identified a single individual who lacked one V beta gene segment. A second individual had an apparently different repertoire of V beta gene segments in one subfamily, as assayed by hybridization, possibly due to a gene conversion event. An analysis with four restriction enzymes of DNA from 30 consanguineous donors detected restriction fragment length polymorphisms associated with 12 of 14 V beta gene segment subfamilies examined. In an analysis of DNAs from a large panel of unrelated individuals, some alleles at these loci were found to be in linkage disequilibrium, indicating a potentially close physical linkage. The segregation of three polymorphisms, two associated with V beta gene segment loci and one associated with the C beta genes, was compatible with Mendelian inheritance, and demonstrated that highly informative haplotypes could be generated. The high degree of polymorphism observed in the human T cell receptor beta chain complex should allow exploration of possible associations between T cell receptor genes and inherited diseases involving the immune system.

Consanguinity↗

Analysis of leukotrienes by liquid chromatography/electrochemistry after conversion to dinitrobenzoate derivatives.

A sensitive liquid chromatography method has been developed using electrochemistry for the determination of leukotrienes in biological fluids. Biological specimens are treated with 3,5-dinitrobenzoyl chloride in acetonitrile which undergoes rapid reaction with hydroxyl groups of non-peptidic leukotrienes in the presence of pyridine and with amino groups of peptidic leukotrienes in the presence of potassium tetraborate buffer. The resulting dinitrobenzoate derivatives of leukotrienes are highly electroactive, suitable for reduction or oxidation at moderate potentials by an electrochemical detector. In reductive mode at -0.7 V or oxidative mode at +1.15 V potentials, the lower limits of detection for leukotriene derivatives were approximately 8 +/- 3 pg and 70 +/- 16 pg respectively, with a signal-to-noise ratio of 5 to 1. This method was applied to the detection of leukotrienes in plasma, nasal and bronchial fluids of patients with asthma.

Asthma↗

Conversational SAAM--an interactive program for kinetic analysis of biological systems.

CONSAM is a conventional version of the kinetic modelling program SAAM. Adjoined to the model processing capability of SAAM, CONSAM additionally affords the user creation, inspection, and alteration capabilities in model manipulation, assessment, and development. To achieve this flexibility CONSAM incorporates a text editor, a solution-saving facility, a model image-saving facility and a graphics package. Command syntax and command logic checking together with command argument defaulting help make CONSAM easy to use. The use of CONSAM in modelling a non-linear drug response to a moderately complicated dosing strategy is presented.

Computers↗