Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CPD”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
PubMed1977

Maintenance of low screen filtration pressure in blood stored in a new liquid medium: BAGPM.

Formation of microaggregates in blood stored in conventional media is reflected by rapidly rising screen filtration pressure (SFP). We show that the BAGPM (bicarbonate, adenine, glucose, phosphate, and mannitol) blood preservation system maintains SFP at near normal levels throughout the storage period of 42 days. Whenever the SFP had a tendency to rise in BAGPM blood, filtration through a routine in-line blood filter reverted SFP back to baseline levels. Blood from the same donors stored in citrate-phosphate-dextrose (CPD) adenine had a rapidly rising SFP by 7 to 14 days of storage. Filtration through the routine blood filter had no effect on the SFP of blood stored in CPD-adenine, CPD, or ACD. BAGPM not only maintains adequate levels of ATP and 2,3-diphosphoglyceric acid (2,3-DPG) during full 42 days of storage but also offers a unique system in which microparticulate material is prevented from forming, with maintenance of low SFP, perhaps because of its low leukocyte, platelet, and fibrinogen content.

Blood Preservation↗
PubMed1993

Analysis of complications in a chronic peritoneal dialysis pediatric patient population. The Italian Registry of Pediatric Chronic Peritoneal Dialysis.

During the period 1986-1991, the Italian Registry of Pediatric Chronic Peritoneal Dialysis collected data from 140 patients younger than 15 years at the start of chronic peritoneal dialysis (CPD). In this study we review the Registry's complications and patient hospitalization data. A total of 395 complications directly related to CPD were registered during 2722 dialysis-months. There were 176 episodes of peritonitis (44.5%), 161 catheter-related complications (40.7%) (103 exit-site infections, 17 leakages, 15 obstructions, 15 cuff extrusions, 5 hemoperitoneum, and 6 other complications), and 58 technique-related complications (14.8%) (39 abdominal hernias, 10 hydroceles, 5 with abdominal pain, 4 hydrothorax complications). The patient hospitalization rate during the period 1989-1991 was evaluated; the analysis referred to 106 patients who underwent treatment for a total of 1520.5 dialysis-months. Patients starting CPD in the year and patients already on CAPD spent 5.8 and 2.1 days per patient-month in the hospital, respectively; the difference was not statistically significant. The evaluation of complications (both technical and systemic) causing patient hospitalization showed that peritonitis was responsible for 43.2% of patient admissions and 36.3% of days hospitalized, catheter-related complications for 22% and 19.8%, technique-related complications for 8.3% and 5.1%, and other clinical complications for 26.5% and 38.8%, respectively.

Catheters, Indwelling↗
PubMed1993

Dialysis therapy in the elderly patient.

It is clear that an increasing number of elderly patients will require ESRD care as the decade proceeds. Currently available data suggest that outcomes on HD and CPD are similar in this patient group, although the data in elderly diabetics are not all in. A number of questions remain to be answered, however: (1) Can severity indices be developed so that patients can be properly matched for co-morbid conditions? This is essential if firm conclusions about the outcome of one modality compared to another can be drawn. (2) Is survival of elderly diabetics worse on CPD compared to HD? If so, is this because of differences in patient selection or co-morbidity or in the effects of the modality? (3) Can a simple, easy to use modality selection algorithm be developed for the elderly ESRD patient? (4) What factors add to the risk of morbidity and mortality in elderly ESRD patients, and how they can be modified? (5) What is the incidence of malnutrition in elderly ESRD patients? How does it relate to morbidity and mortality? Does it differ from those on HD compared to CPD? (6) Are there elderly patients who should not be started on dialysis? How can they be identified?

Aged↗
PubMed1978

[State and development of liquid conservation of thrombocytes].

In the present investigation the storage effect of AcD-AG and CPD-AG-stabilizers on thrombocytes was tested. The platelets were stored in platelet-rich plasma (PRP) at 4 degrees C or room temperature for 3 days. The concentrates gained by it were marked with Na251CrO4 and reinjected. The thrombocytokinetic parameters were evaluated. The results show that storage with the help of the mentioned stabilizers can be made to a certain extent only. Platelets stored in AcD-AG stabilizerhad a survival time of 2.7 +/- 1.1 days towards 9.0 +/- 1.0 days of fresh whole blood concentrates. The survival time of CPD-AG thrombocytes stored at 4 degrees C for 3 days amounted to 2.0 +/- 0.5 days. Storage of CPD-AG platelets at room temperature showed favourable results. Their survival time amounted to 6.2 +/- 0.6 days. Measurements of surface activity above the spleen and the liver indicate that degradation of stored platelets is mainly performed in the spleen. Problems of liquids storing in view of the significance of therapeutic thrombocyte substitution for hospitals are referred to.

Blood Cell Count↗
PubMed1995

The formation of filopodia-like protrusions during preparation of cell suspensions for scanning electron microscopy.

The standard preparation of cell suspensions (e.g., blood cells, cell suspensions derived from monolayer cultures or from various tissues, etc.) for scanning electron microscopy (SEM) includes fixation of the cells in suspension and subsequent dehydration and critical point drying (CPD) of the cells after their preliminary attachment to the special substrata. In the course of the SEM examination of cell suspensions of various origins, unusual morphological cell surface structures, filopodia-like protrusions (FLP), were consistently detected in 3-20% of the cells in the populations. FLP can be effectively observed only by using a stage tilt angle of no less than 30 degrees. FLP were single or multiple thin threads extending from basal parts of a spherical cell and attaching to the substratum surface used. FLP strikingly resembled substratum-attached filopodia formed by a viable cell at its earliest stages of spreading. The percentages of the cells with FLP were not significantly affected by the character of cell fixation (primary aldehyde fixation alone or primary aldehyde with subsequent OsO4 post-fixation) or the raising of the temperature and pressure inside the CPD bomb. It seems that the protrusions imitating the natural cell surface structures can probably be formed at later stages of the preparation of cell suspensions for SEM, namely during dehydration and (or) CPD when the cells undergo substantial shrinkage. One of the possible mechanisms by which the cell shrinkage could induce FLP formation follows. A prefixed spherical cell which settles down to the substratum sticks to it at some discrete points on the cell surface. As a result of the subsequent cell shrinkage, FLP could be formed and then stretched, connecting the same points on the cell surface with the points of the initial cell-substratum adhesion.

Animals↗
PubMed1997

An experimental model of human leukemic meningitis in the nude rat.

An experimental animal model of meningeal leukemia was developed in the nude rat, rnu/rnu, using the human-derived acute lymphoblastic leukemia cell line HPB-ALL. Anesthetized rats were placed in a modified stereotaxic frame and then injected intrathecally, at the level of the cisterna magna, with human leukemic cells. Cerebrospinal fluid and tissue samples from brain, spinal cord, heart, liver, kidney, spleen, bone marrow, and cervical lymph nodes were subjected to histopathologic examination and molecular genetic screening by clonotype primer-directed polymerase chain reaction (CPD-PCR). Ninety-three percent of animals (n = 14) developed signs of meningeal irritation leading to death 30 to 63 days postinjection (median, 36.0 days, mean, 38.7); death occurred between 30 and 39 days in 77% of all animals. Leukemic cells progressively infiltrated the pericerebellar and pericerebral subarachnoid space and infiltrated the Virchow-Robin (perivascular) space. The infiltrating meningeal leukemia closely resembled the pathologic presentation in the human condition. By CPD-PCR, leukemic cells were first detected in cerebrospinal fluid (CSF) on day 4 postinjection, were variably present over the ensuing 17 days, and were consistently detected after day 21. At terminal stages, CPD-PCR tissue surveys showed leukemic DNA in all brains and spinal cords and rarely in cervical lymph nodes, but leukemic DNA was not detected in any other tissue screened. Leukemic meningitis was reliably produced with a predictable survival time. Intrathecal administration of leukemic cells was an efficient means of transmitting leukemic meningitis and it compartmentalized the disease to the central nervous system (CNS), eliminating potential complications of systemic illness. The use of human-derived cell lines may render this model more relevant to the development of future therapeutic strategies to treat leukemia and lymphoma that invade the CNS.

Animals↗
PubMed1997

Sunlight induces pyrimidine dimers preferentially at 5-methylcytosine bases.

The most prevalent DNA lesion induced by UV irradiation is the cyclobutane pyrimidine dimer (CPD), which forms at positions of neighboring pyrimidines. Here we show that the rare DNA base 5-methylcytosine is the preferred target for CPD formation when cells are irradiated with natural sunlight. We have mapped the distribution of CPDs formed in normal human keratinocytes along exons of the p53 gene. Codons 196, 245, 248, and 282, which are mutational hot spots in skin cancers, are only weakly to moderately susceptible to formation of CPDs after irradiation with UVC (254 nm) or UVB (320 nm) light sources. However, when cells were exposed to natural sunlight, CPD formation was enhanced up to 15-fold at these codons due to the presence of 5-methylcytosine bases. These results suggest that CPDs containing 5-methylcytosine may play an important role in formation of sunlight-induced skin tumors and that methylation of CpG sequences, besides being involved in spontaneous mutagenesis processes, can also create preferential targets for environmental mutagens and carcinogens.

5-Methylcytosine↗
PubMed1997

An analysis of the determinants of urinary urea and creatinine clearance in patients on continuous peritoneal dialysis.

The relative contribution of urinary volume (UV) and urine-to-plasma concentration ratios for urea (U/PUr) and creatinine (U/PCr) to urinary Kt/V urea (Kt/VU) and urinary uncorrected creatinine clearance (CCrU), respectively, was studied by simple and multiple linear regression analysis in 236 urea kinetic studies and 233 creatinine kinetic studies performed in 135 patients on continuous peritoneal dialysis (CPD). The following simple regressions were obtained: Kt/VU = 0.09 + 0.72 (UV), r = 0.75; Kt/VU = -0.01 + 0.11 (U/PUr), r = 0.55; CCrU = 12.06 + 56.46 + 46.46 (UV), r = 0.62; CCrU = 3.51 + 3.40 (U/PCr), r = 0.58. All r values were significant (p < 0.001). According to these regressions, a loss of 0.2 L/24 hours in UV leads to a loss of 0.15 weekly in Kt/VU and 11.3 L/1.73 m2 weekly in corrected CCrU (approximately 8 L/1.73 m2 weekly in corrected CCrU). By multiple linear regression, (1) Kt/VU = -0.38 + 0.70 (UV) + 0.10 (U/PUr). Standardized coefficients were 0.72 for UV and 0.51 for U/PUr (2) CCrU = -33.36 + 59.83 (UV) + 3.63 (U/PCr). Standardized coefficients were 0.65 for UV and 0.61 for U/PCr. UV is the most important determinant of both urea and creatinine urinary clearances in CPD patients. The contribution of the U/P ratios to the urinary clearances is important, but less than that of UV. The primary dependence of urinary clearances on UV allows the use of UV, which can be easily monitored by patients, as a first approximation index of changing residual renal function in CPD.

Creatinine↗
PubMed1997

Quality of life assessment in chronic peritoneal dialysis patients.

Previous studies by our group have attempted to examine quality of life (QoL) issues in a cohort of end-stage renal disease (ESRD) patients maintained on chronic peritoneal dialysis (CPD) by assessing a variety of psychological tests and by asking patients to rate their own QoL. The present study was undertaken to extend previous observations by asking patients to spontaneously select those domains of life experience that they think are most important in determining their quality of life. Sixty-eight medically stable CPD patients were asked to spontaneously select those three to five domains felt to be most important to them in defining their QoL. The 307 responses were then grouped into 22 broad categories by three investigators. The most frequently selected domains focused on interpersonal relationships. Domains that enhance the quality of one's day and add meaning to one's life were selected with a midrange frequency. Some domains that might intuitively seem to be important for a patient's QoL were selected with a surprisingly low frequency. These findings suggest that to understand what CPD patients value in assessing their QoL can best be determined by asking them directly and not by using predetermined variables.

Adult↗
PubMed1997

Copy number, epigenetic state and expression of the rRNA genes in young and senescent rat embryo fibroblasts.

The recent cloning of the gene that causes the premature aging in Werner syndrome patients has evoked speculations that deficits in expression of the ribosomal RNA genes could be related to cellular aging in general. Here we compare the state of the rRNA genes and the rRNA metabolism in young and senescent (aged) rat embryo fibroblasts (REF). Southern blot analysis revealed that the copy number and the methylation state of the genes did not change significantly with increasing cumulative population doublings (CPD) of the culture. Hence, young (low numbers of CPD) and senescent REF (high numbers of CPD), respectively, have the same repertoire of rDNA units that can be transcribed. The rRNA synthesis in these cells was analyzed by incorporation of labeled uridine at conditions allowing the measurement of absolute rather than relative rRNA synthesis rates. We revealed that the cell density dependence of the rRNA synthesis diminishes in senescent cells. Exponentially growing young REF exhibited an rRNA synthesis of 16 amol uridine incorporation per minute and cell. The rRNA synthesis decreased 10-fold in quiescent cells at saturating cell densities. Exponentially growing REF near the end of their replicative lifespan exhibited a 2-fold lower rRNA synthesis rate compared to young cells. However, in senescent REF the rRNA synthesis rate decreased only 2-fold with increasing cell densities resulting in a 3-fold higher rRNA synthesis rate compared to young cells at saturating cell densities. These data could be confirmed by calculating the rRNA synthesis rates from the rRNA content, the rRNA half-life, and the proliferation rate of the cells. Hence, senescent REF exhibited a higher rRNA synthesis rate when compared to young cells at similar growth rates resulting in the generally observed higher rRNA content (and cell size) of senescent cells. We conclude that cellular senescence of REF is not accompanied by rRNA expression deficiencies.

Animals↗
PubMedDate not supplied

Peritoneal dialysis in children under 5 years of age.

OBJECTIVE: We report our experience with maintenance peritoneal dialysis (PD) in small children. DESIGN: This is a retrospective analysis of the patient records of all children under the age of 5 years treated with continuous peritoneal dialysis (CPD) between 1986 and 1994 in Finland. SETTING: Treatment was started and the patients were seen at the outpatient clinic at the Hospital for Children and Adolescents, University of Helsinki, every 3 months. Between these visits, they had controls at their local hospital every 2-4 weeks. PATIENTS: The most common primary renal disease in these 34 patients was congenital nephrotic syndrome of the Finnish type (27 patients). Others were: congenital nephrotic syndrome (3 patients), polycystic kidney disease (1), urethral valve (1), neuroblastoma (1), and renal dysplasia (1). RESULTS: Mean age at onset was 1.6 years and median treatment time 9.3 months. Time spent in hospital decreased from 270 days/year in the 1980s to 150 days/year in the 1990s. Two children died (5.9%). The peritonitis rate on continuous cyclic peritoneal dialysis was 1:11.5 patient-months. Hernias were diagnosed in 29% of the patients. After 3 months half of the patients were on antihypertensive medication. Pulmonary edema was diagnosed once in 12 patients and twice in 2 patients. During the first 6 months on PD the mean height standard deviation score (hSDS) increased from -2.13 to -1.66 (p < 0.0001). The 6-month change in hSDS before initiation and 6 months after the start of CPD increased from -0.12 +/-0.68 to +0.59 +/- 0.64 (p = 0.0008). CONCLUSIONS: Our results indicate that peritoneal dialysis is feasible and safe in small children. Mortality was low and growth was good. The major challenges presented by CPD therapy were maintenance of optimal nutrition, avoidance of peritonitis, and control of volemia.

Age of Onset↗
PubMed1976

The contribution of anticoagulants to platelet dysfunction with extracorporeal circulation.

This investigations evaluates the effects of anticoagulants on platelet function. Fresh human blood from 40 nonmedicated volunteers was anticoagulated with 4.3 units per milliliter heparin and/or acid-citrate-dextrose (ACD) solution 1:9. Retention of platelets from whole blood on glass beads was performed by the method of Bowie. Platelet retention of heparinized blood averaged 88.1 +/- S.E. 1.5 per cent; ACD platelets averaged 24.6 +/- S.E. 2.8 per cent. Platelet retention with citrate-phosphate-dextrose (CPD) and ethylenediaminetetraacetic acid (EDTA) yielded 26.0 +/- S.E. 3.9 per cent and 19.1 +/- S.E. 7.5 respectively. The addition of ACD to heparinized blood decreased platelet retention (19.7 +/- S.E. 3.1 per cent). The addition of heparin to ACD or CPD blood did not alter the original decreased retention. Calcium added, even in excess, to blood containing heparin and ACD did not reverse the depressed retention (29.3 +/- S.E. 4.6 per cent). The substitution of CPD gave similar results. With mixtures of separately collected ACD and heparininzed blood, depression of platelet retention was directly proportional to the amount of ACD blood present. Altering the pH of the ACD blood did not affect its depressed retention of platelets. Neutralizing heparinized blood 50 per cent with protamine or Polybrene also significantly depressed platelet retention 34.6 +/- S.E. 5.8 per cent and 35.5 +/- S.E. 4.0 per cent, respectively. Neither protamine nor Polybrene had any effect upon ACD blood. These data indicate that anticoagulants may play a significant role in the depressed platelt function observed during and following extracorporeal circulation.

Anticoagulants↗
PubMed1998

Reliability and validity of the aggregate method of determining number of cigarettes smoked per day.

The authors evaluated the reliability of two pretreatment assessments (screening and intake) of cigarettes smoked per day (CPD) by the commonly used aggregate method. The validity of the aggregate method was also determined by comparison with results of the timeline followback (TLFB) method for the identical periods. The study participants were 49 outpatients undergoing nicotine patch treatment. The reliability of the two aggregate method evaluations of CPD was quite high by Pearson product-moment correlation (r) and good when based on the intraclass correlation. Correspondence between the CPD assessments based on the aggregate and TLFB methods for the two time-points ranged from fair (screening) to good (intake). Overall, the study findings indicate that the aggregate method provides reasonably consistent data.

Adult↗
PubMed1999

Long-term effects of repetitive exposure to a static magnetic field (1.5 T) on proliferation of human fetal lung fibroblasts.

The aim of the study was to assess the effects of repetitive exposures to a static magnetic field (1.5 T) on human fetal lung fibroblast (HFL) proliferation. HFL were exposed three times a week for 1 hr to a static magnetic field for 3 weeks. Cells were subcultured every week. Population doublings (PD) and cumulative population doublings (CPD) were calculated weekly. Colony formation assays, bromodeoxyuridine enzyme-linked immunosorbent assay, and cell cycle analysis were performed weekly. After the third week, proliferation kinetics were assessed. Over a period of 3 weeks no statistically significant differences between the PD and CPD of exposed and control cells could be detected. Clonogenic activity, DNA synthesis, cell cycle, and proliferation kinetics were not altered by magnetic field exposure. The data do not provide evidence that repetitive exposures to a static magnetic field (1.5 T) exert effects on HFL proliferation.

Cell Division↗
PubMed2002

Replicative aging of human articular chondrocytes during ex vivo expansion.

OBJECTIVE: To investigate the contribution of clinical ex vivo expansion protocols to replicative aging of human chondrocytes. METHODS: Primary human chondrocytes were cultured as monolayers after isolation from 7 articular cartilage specimens. Cells were passaged corresponding to 12-19 cell population doublings (cpd). Aliquots of the cells were collected from each passage and analyzed for telomere length and telomerase activity. RESULTS: The rate of telomere shortening was heterogeneous, ranging from 147 to 431 bp/cpd (mean +/- SD 305 +/- 122). Telomerase activity was detected at various time points during passaging in 5 of 7 primary chondrocytes analyzed, but not in native human articular cartilage specimens. According to our data, an 8-10-fold ( approximately 3 cpd) ex vivo expansion of articular chondrocytes, as typically performed for transplantation procedures, leads to telomere erosion in the range of 900 bp. This is comparable with 30 years of aging based on the in vivo rate of telomere shortening of 30 bp/year recently found in chondrocytes. CONCLUSION: If telomere shortening is an important determinant of aging in human articular cartilage, an additional telomere loss due to ex vivo expansion might affect the incidence or time of onset of age-related cartilage disorders. However, given the limited extent of expansion performed in the clinical setting to date, a significant telomere-mediated increase in the risk of malignant transformation or replicative exhaustion of the transplanted cells seems unlikely.

Adult↗
PubMed2005

Fixation protocols for subcellular imaging by synchrotron-based Fourier transform infrared microspectroscopy.

Synchrotron-based Fourier transform infrared (SR-FTIR) microspectroscopy is a powerful bioanalytical technique for the simultaneous analysis of lipids, proteins, carbohydrates, and a variety of phosphorylated molecules within intact cells. SR-FTIR microspectroscopy can be used in the imaging mode to generate biospectroscopic maps of the distribution and intensity profiles of subcellular biomolecular domains at diffraction-limited spatial resolution. However, the acquisition of highly spatially resolved IR images of cells is not only a function of instrumental parameters (source brightness, sampling aperture size) but also the cell preparation method employed. Additionally, for the IR data to be biochemically relevant the cells must be preserved in a life-like state without introducing artefacts. In the present study we demonstrate, for the first time, the differences in biomolecular localizations observed in SR-FTIR images of cells fixed by formalin, formalin-critical point drying (CPD), and glutaraldehyde-osmium tetroxide-CPD, using the PC-3 prostate cancer cell line. We compare these SR-FTIR images of fixed cells to unfixed cells. The influence of chemical fixatives on the IR spectrum is discussed in addition to the biological significance of the observed localizations. Our experiments reveal that formalin fixation at low concentration preserves lipid, phosphate, and protein components without significantly influencing the IR spectrum of the cell.

Animals↗
PubMed2004

Physician performance and assessment and their effect on continuing medical education and continuing professional development.

This article has three key points. The first proposes and illustrates a model for planning effective continuing medical education (CME) and continuing professional development (CPD) and how assessment might fit into it. The second reviews major trends in assessment, particularly with regard to regulation and CME. The third addresses challenges for CME and CPD.

Certification↗