bluuebunny/crossref_metadata_2025 huggingface dataset:
Echocardiographic Evidence of Altered Cardiac Status in Predialysis Diabetics and Those on Dialysis
Authors: Iqbal M.m. , Banerjee S.k. , Islam N. , Islam S. , Hossain R.m. , Rahman A. , Banik D.
Published: December 2004

Cardiovascular complications affect diabetic subjects early and the more susceptible ones are those on hemodialysis.

Objective:  This study was designed to observe prevalent cardiac involvement in both pre‐ and already on dialysis diabetics.

Method:  Sixty diabetics, 30 predialysis (predialysis diabetics, group 1), and 30 on maintenance hemodialysis (MHD, group 2) were randomly selected and their different clinical, biochemical, and echocardiographic parameters were compared.

Result:  Both groups of patients were matched for age, sex, and body mass index (BMI). Features like systolic and diastolic blood pressure were lower in predialysis diabetics group than in MHD group [138 ± 19 vs. 152 ± 32, p < 0.02 and 74 ± 10 vs. 87 ± 10 mmHg (p < 0.001)]; hemoglobin higher [10.3 ± 2.1 vs. 7.5 ± 1.5 g/dL (p < 0.001)]; serum creatinine was lower [3.49 ± 1.8 vs. 9.5 ± 2.5 mg/dL (p < 0.001)] (due to recruitment criteria); left ventricular muscle mass index (LVMI) also lower [137 ± 96 vs. 211 ± 77 g/m2 (p < 0.001)]; left ventricular end diastolic volume index (LVEDVI) less [58 ± 21 vs. 85 ± 25 mL/m2 (p < 0.001) and fractional shortening (FS, %) higher [33 ± 4.3 vs. 28 ± 5.8 (p < 0.006)]. Only 11% of Pre subjects had LV hypertrophy (LVMI >131 g/m2 in male and in female LVMI >110 g/m2) whereas it was 51% in MHD (p < 0.001). Systolic dysfunction (FS = <25%) was 4% in Pre subjects and 24% in MHD (p < 0.03) group. Correlation study showed systolic and diastolic blood pressure; both had positive correlation with LVMI (r = 0.38, p < 0.008 and r = 0.32, p < 0.02) and LVEDVI (r = 0.36, p < 0.01 and r = 0.35, p < 0.01) and also similarly positive with serum creatinine (r = 0.35, p < 0.02 and r = 0.5, p < 0.001).

Conclusion:  It may be concluded that cardiac parameters are grossly altered in majority of diabetics on dialysis and higher serum creatinine and uncontrolled blood pressure may be responsible for this.
Return on Investment: An Economic Guideline for Selecting Home Daily/Nocturnal Hemodialysis Patients
Authors: Kroeker A. , White S. , Lindsay R.m.
Published: December 2004

Starting any new program, especially one without a proven track record, raises questions about cost‐effectiveness of the treatment.

Purpose:  This research investigated how long patients should be expected to remain as daily/nocturnal hemodialysis patients in order to justify the initial investment in sending them home.

Methods:  Costs for 10 short‐hour daily (SHD) and 12 slow nocturnal hemodialysis (NHD) were compared with the savings incurred by switching those patients from conventional hemodialysis (CHD). One‐time expenses were divided by net savings to determine the minimum length of time the patients should be expected to remain at home on these modalities.

Results:  One‐time training, installation, and home equipment expenses were comparable for the SHD and NHD patients. NHD patients without monitoring noticed that these costs recovered in 1 year. NHD patients with monitoring took approximately 16 months to recover these costs, while initial SHD costs were offset in 20 months.

Conclusions:  Patients selected for home NHD and SHD should be expected to be able to remain at home for at least 12–20 months. Subsequent investigation indicates that these costs and time periods may be further reduced.

NHD

Costs ($Can)
Daily (SHD)
Excluding monitoring
Including monitoring

One‐time
$21,281
$19,772
$21,465

Savings
$12,836
$20,484
$16,703

ROI (years)
1.7
1.0
1.3
Hot Water Reuse (HWR) of Dialyzers Gives Smoother Dialysis than Single Use (SU) or Chemical Reuse (CRU)
Authors: Kjellstrand C.M. , Twardowski Z.J. , Bower J. , Jackson M.S. , Blagg C.R.
Published: December 2004

Background:  Hemodialyzers can be used once or reused after treatment with chemicals or hot water. SU results in infusion of plastic compounds, particularly phthalic acid metabolites, into patients and chemical reuse releases formaldehyde, glutaraldehyde, or peracetic acid into the blood during dialysis.

Methods:  We studied the increase in pulse rate (PR) and fall in systolic and diastolic blood pressure (BP) and patients' subjective overall quality evaluation (OE) of dialysis (1 worst, 5 best) during 3706 daily dialyses in 23 patients. Fall in blood pressure and rise in PR during dialysis and overall quality evaluation were compared as patients changed from SU or chemical reuse to hot water reuse. During SU and chemical reuse, dialysis time was shorter (121 vs. 148 min), urea clearance higher (241 vs. 175 ml/min) but ultrafiltration lower (1.5 vs. 1.7 kg/dialysis) than during hot water reuse.

Results:  The results are summarized in the table.

Methods
n
Systolic BP
Diastolic BP
PR
OE

CRU
  98
−30 ± 19
−17 ± 21
   4 ± 4
3.8 ± 0.4

SU
2443
−17 ± 21
 −6 ± 13
   2 ± 13
4.0 ± 0.7

HWR
1165
 −8 ± 21
 −1 ± 11
−0.2 ± 12
4.2 ± 0.7

All comparisons were of SU and chemical reuse to hot water reuse, p < 0.0001. The results were the same whether cellulosic or polysulfone membranes were used. Hot water reuse, up to 25 times, did not result in changes in urea clearance, albumin leakage or Kuf, and β‐2‐microglobulin reduction rates declined by only 10% over 15 reuses.

Conclusion:  Hot water reuse results in the most comfortable dialysis and the best cardiovascular stability, with less decline in blood pressure and less tachycardia, when compared to chemical reuse or SU of dialyzers.
Interleukin‐6 and C‐Reactive Protein Production and Interaction in CRF and Dialysis
Authors: Yonova D. , Garsia R.
Published: December 2004

Plasma fibrinogen is a well‐known predictor of cardiovascular disturbances, and C‐reactive protein (CRP) is associated with elevated causes of myocardial infarction and sudden cardiac death. That is the reason to look for the causes of increased CRP levels in CRF and haemodialysis (HD). The study tries to find whether interleukin‐6 (IL‐6) is a consistent factor for CRP elevation in CRF and/or in HD patients, when a dialysis‐induced IL‐6 synthesis may occur, as IL‐6 has been claimed as a responsible factor for production of some acute phase proteins like CRP. CRP [enzyme‐linked immunosorbent assay (ELISA) technique, limit 0.1 µg/L], IL‐6 (ELISA, Medgenix, Brussels, Belgium), and fibrinogen (photometric technique) were tested in 45 stable predialytic CRF patients (mean age 48 ± 7 years) and in 50 stable HD patients (mean age 62 ± 15). In CRF patients, a positive correlation was found between plasma fibrinogen (mean 356 ± 167 mg/dL) and CRP (r = 0.51, p < 0.01) and between fibrinogen and proteinuria (r = 0.32, p < 0.01), but no correlation was found between CRP and IL‐6. In HD patients, a high positive correlation was registered between CRP (mean 6.93 ± 5.88 mg/L) and IL‐6 (mean 9.4 ± 10.6 pg/mL) (r = 0.84, p < 0.001) and between CRP and fibrinogen (mean 325 ± 110 mg/dL) (r = 0.59, p < 0.001). The study suggests that, in HD patients, one of the factors stimulating hepatic production of CRP is probably IL‐6, which is synthesized by the dialysis‐related, activated macrophages. In predialytic patients, the bacterial products in dialysate and their effect on macrophages are absent and there is no correlation between CRP and IL‐6.
Training Patients for Nocturnal Home Hemodialysis
Authors: Stokvis S.j.a.m. , Verhallen A.m. , Kooistra M.P.
Published: December 2004

Purpose:  Nocturnal home hemodialysis (NHHD, 6–7 times weekly 6–9 h) results in better clinical outcome than conventional 3 times weekly hemodialysis. A good training program for patient and partner is a prequisite for success. We developed a training course for patients and partners.

Methods:  Since December 2001, we trained 20 patients and their partners to perform NHHD in 2 succeeding groups. The first group, consisting of 15 patients and their partners, started a NHHD pilot study. During this pilot study, we improved the training course. The second group of 5 were trained with this improved program. All 5 participants were home hemodialysis patients for over 1 month before starting the NHHD course. First, they learned how to handle the single needle system. Then, they performed single needle hemodialysis for 2 weeks at home. This was followed by an in‐center NHHD training, consisting of 4 conventional day‐time and 3 long (8 h) nocturnal dialysis treatments. Main targets during this training period are to learn to deal with safety precautions, online monitoring, and special machine features, and to check biochemistry and heparinization during long dialysis. 1 month after the training we evaluated the course with all participants.

Results:  For 9 of 15 couples in the first group, the training appeared to be exhausting. Stress factors were an overloaded program and too little experience with several new skills including needle technique before starting NHHD. The second group started the NHHD training 2 weeks after the single needle training. This second group was pleased with the training protocol.

Conclusion:  The training course for NHHD should not be overloaded. Patients need time to learn new skills before starting NHHD.
Nocturnal Home Hemodialysis: Patient's Perspective
Authors: Vos H. , Stokvis S.J.A , Verhallen A. , Kooistra. M.P.
Published: December 2004

Purpose:  Several studies have showed that nocturnal home hemodialysis (NHD, 6 times weekly 6–8 h) results in a better outcome. How do patients and their partners experience this very intensive treatment that has a great impact on daily life?

Methods:  We followed a cohort of 12 patients (11 male, 1 female, mean age 46.8 ± 9.4 years, time for renal replacement 11.3 ± 9.4 years) and their partners during a year after starting NHD, using questionnaires and interviews and the SF‐36.

Results:  Both the physical and the mental components of the SF‐36 showed an improvement in all aspects (p < 0.05), even in this small group. All couples considered NHD a tremendous improvement over routine thrice weekly dialysis. The drawbacks (such as daily routine and the intrusion of the treatment in bed) are outweighed by the advantages (such as better clinical condition, less fatigue, less uremic symptoms, better quality of life, more time, and free diet). Following are a few comments on NHD: “NHD is a difference of day and night,”“NHD gave me independence,”“Since I do NHD, I do aerobics,”“I am becoming too fat now!,”“My husband now is much faster than I am when we walk or ride the bicycle,”“There is no reason now why I won't live long,”“I got an excellent, but demanding new job, which is possible thanks to NHD,”“Being a good team is a prerequisite for success,”“Don't expect too much. You will remain a chronic patient,”“Become confident with ‘conventional’ home hemodialysis first before you start NHD.”

Conclusion:  NHD results in a tremendous improvement of quality of life. However, patients and partners need active support.
Hemodialysis in the Elderly
Authors: Christopoulou S.
Published: December 2004

During the last decade, the number of patients starting renal replacement therapy has increased for all ages, but the increase for patients over 65 years old has been particularly dramatic.

Objective:  The aim of our study was the analysis of the outcome of all the patients who were over 65 years of age at the time they started chronic hemodialysis, in our Center (n, 52).

Methods:  A total of 76 patients were treated by the chronic hemodialysis program of 251 Hellenic Air Force and VA General Hospital, between 1992 and 2002, while totally 309 patients were offered dialysis at this time. We found that 52 of them (68.4%) were over 65 years old [40 male (76.9%), 12 female (23.1%)].

Results:  Elderly patients manifest more often intradialytic complications, such as hypotensive episodes (28.8%) and arrhythmias (23.1%), due to their hemodynamic instability. Polypharmacy is a big deal for dialysis patients, especially elderly ones. Each patient was taking 9.1 PO and 1.9 IV medications on average, per day. Most of them (84.6%) required recombinant human erythropoietin. The most common co‐morbid factors we observed in this population were cardiovascular diseases (36.5%), neurological problems, respiratory failure, bone disease, malignancy (17.3%), depression, malnutrition, and infections (30.8%). Deaths were often associated with more than one morbid factors. Survival and the quality of life in the elderly patients on hemodialysis are frequently acceptable. The 1, 3 and 5‐year patient survival rates during 1990–2000 were 63.4%, 56.1%, and 26.8%.

Conclusion:  We believe that if there are no extracontraindications, elderly patients can benefit from hemodialysis, taking into consideration that we should adapt the therapy to the geriatric special needs.
Central Venous Catheter Access in Children on HD
Authors: George C. , Jones L.L. , Johnson S.L. , Andrews W.S. , Warady B.A.
Published: December 2004

Central venous catheters (CVC) remain a frequently used form of vascular access in children receiving chronic hemodialysis (HD). Whereas standard dual‐lumen catheters (DL) are used in many centers, the Tesio catheter has proven to be superior to the DL catheter in terms of catheter survival and infection rates in at least one pediatric study (Sheth RD et al. Am J Kidney Dis. 2001). Recently, the Ash Split catheter became available which, while similar to the Tesio internally, being comprised of 2 separate catheters, may be preferable because of the requirement for only one skin puncture for placement vs. two for the Tesio. However, no pediatric data pertaining to the Ash Split catheter have been published to date. Therefore, we reviewed and compared our experience with a small number of Ash Split (# 16) and Tesio (# 8) catheters used for semipermanent vascular access in our chronic HD population with reference to survival, infectious complications, patency, and dialysis adequacy. The results of this experience are as follows:

Tesio
Ash Split

Survival >3 months
6/8
12/15

Sepsis (epi/catheter mo)
1/30
1/25

Exit‐site infection (epi/catheter mo)
1/8.6
1/19

sp Kt/V urea
1.67
1.88

% sp Kt/V urea >1.2
100
90

Reasons for the removal of Tesio catheters were transplant (4), sepsis (1), deterioration of tubing (1), and accidental (1). Ash Split catheter removal resulted from sepsis (2), fistula placement (4), thrombosis (1), and accidental (2). This preliminary experience reveals similar outcome data for the Tesio and Ash Split catheters when used in pediatric HD patients. Definitive statements regarding the superiority of either catheter awaits additional data collection and analysis.
Kinetic Studies on Urea Extraction with Hemodialysis in Adolescents by On‐line Monitoring of Dialysate Urea
Authors: Kreuzer M. , Drossert T. , Stein A. , Arbeiter A. , Vester U. , Bonzel K‐E.
Published: December 2004

Kinetics of urea extraction during a single dialysis session in children are unknown, because analysis of solutes in dialysate is difficult due to their extreme dilution.

>Objective:  A novel urea monitor of the Gambro Company might be of help in studying urea kinetics also in children.

Methods:  We studied 107 urea kinetics in 5 adolescents aged 13–19 years, weighing 26–58 kg, and looked for influences of membrane size, blood flow, and duration of one dialysis session. Urea measurement applies to the change of electric dialysate conductivity due to ionization because of urea splitting by urease. Bicarbonate dialysis regimen was 4–5 h each, 3 times a week, using polysulfone high‐flux dialyzers (Fresenius F60 or F80, depending on body size).

Results:  Average 4‐h urea Kt/V values for F60 (n = 85) were 1.69±0.53 and for F80 (n = 21) 1.63±0.25, extracted urea mass was 16.0±5.4 g and 32.5±5.4 g, respectively (p < 0.05); Kt/V urea results for blood flows of 180–220 mL/min were 1.36±0.52 and for <180 mL/min 1.10±0.43; extracted urea mass was 17.3±8.0 and 11.7±4.9 g, respectively (p < 0.05). Total average urea extraction ratio after 2 h of dialysis (n = 107) was 64.8±5.6%. Extraction ratio during the 4th h of dialysis was only 15.3±4.1% and during the 5th h not more than 9.0±3.6% of total urea extraction.

Conclusion:  Kinetics of urea extraction helps understanding dialysis processes in children. Adapting the size of the dialyzer according to body size raises urea extraction and maintains urea clearance Kt/V at the desired quality level. An inadequate blood flow lowers both urea extraction and urea clearance Kt/V. Prolonging dialysis beyond 4 h is, at least in concern of urea kinetic modelling, a rather ineffective means. We speculate that children with blood flow problems should be dialysed more often.
Daily Online Hemodiafiltration: Rescue Dialysis Modality for Children?
Authors: Fischbach M. , Terzic J. , Laugel V. , Helms P. , Livolsi A.
Published: December 2004

There is a growing interest in the use of daily dialysis since long‐term experiences have shown good results. Online hemodiafiltration (OL‐HDF) is an HDF technique that combines diffusion with high convection in which the ultrapure dialysis fluid itself is used as a reinfusion solution. The aim of this study was to demonstrate the beneficial effect of the more effective dialysis schedule (daily dialysis) with the dialysis modality that offers the highest uremic toxin removal (OL‐HDF). Five children with left ventricular hypertrophy, mean age 12.3 ± 6.2 years, on standard 3– 4 h 3 times a week OL‐HDF at least during the last 6 months, were switched to D‐OL‐HDF, 3– 4 h 6 times per week with a minimal follow up of 6 months. Dialysis parameters were similar during both periods and only frequency of each session was changed. Tolerance, anemia control, phosphatemia, and phosphate binders, need of blood pressure medications, and left ventricular hypertrophy were evaluated. Only 3 of the 5 enrolled children could be followed 12 months, 1 was transplanted after 3 months, the other after 5 months D‐OL‐HDF. For all the children the disappearance of postdialysis fatigue was rapidly reported. There was a significant decrease in predialysis levels of phosphatemia (from 1.67±0.23 to 1.28±0.29 mmol/L) despite phosphate binders reduction of more than 50%. Hemoglobin significantly increased (from 11.8±0.9 to 13.4±1.3 g percentage ml) allowing EPO doses reduction. Left ventricular hypertrophy disappeared after 6 months D‐OL‐HDF, fractional shortening increased, allowing registration on transplantation list for 1 child. Our results clearly demonstrate that daily online HDF is able to offer to children on chronic dialysis a marked reduction of the cardiovascular risk factors. Is it ethical to reserve this dialysis modality only to selected children?
Experience with the Gambro Phoenix Hemodialysis Machine using Diascan and Exalis in a Pediatric Hemodialysis Unit
Authors: Paille L. , Hann P. , Lirenman D.S. , Carter J.E.
Published: December 2004

Introduction:  In 2001 our Renal Dialysis Unit underwent a major renovation to five stations. The new space and funding allowed for acquisition of new state‐of‐the‐art hemodialysis machines. We describe our experience with the Gambro Phoenix with Diascan and Exalis. Prior to the move an evaluation was undertaken. Criteria for selection with a scoring tool were utilized to rate machine performance for use in children. The decision for the Gambro Phoenix machine was based on: the performance rated highly due to ease of set up; large viewing touch screen; compatibility with existing equipment; benefits of online clearance monitoring (Diascan); network data management system (Exalis) and the future availability of blood volume monitoring (Hemoscan). Our program was the first center to dialyze a pediatric patient on the Phoenix machine in Canada.

Patients and results:  13 patients (age 2–23 years) were hemodialyzed between May 2002 and September 2003 for periods of 2 week to 16 months, greater than 5000 h of dialysis time. The move was not uneventful. During the first months of operation issues such as inadequate electrical supply for the new machines, reverse osmosis (RO) pump failure, leaks, and no emergency power to the RO were prevalent. The new software also exposed glitches. Subsequent Phoenix use proceeded uneventfully. Staff were able to problem solve easily with clinical and technical support from Gambro Canada. Education for the online clearance monitoring, Diascan and Exalis, was necessary. No major problems with dialysis were encountered. The benefits and reliability of Diascan have been previously described (Lindsay RM, Sternby J, Semin Dial. 2001; 14:300). Diascan readings provided real‐time measurement of sodium (Na), which correlated well with laboratory values. Automatic readouts of Kt/V allowed for monitoring of dialysis adequacy which was consistent with calculated percent reduction in urea (PRU). At this point, use of the Phoenix has been demonstrated to work well in a pediatric facility.
Dialysis Staff Time and Supply Cost for the LifeSite System vs. Hemodialysis Catheters
Authors: Shore D , Vega S
Published: December 2004

The LifeSite System is a new subcutaneous vascular access option for hemodialysis patients. As the procedure for accessing the LifeSite differs from hemodialysis catheters, we prospectively studied the differences in time required to initiate and discontinue treatments for LifeSite patients compared to patients with hemodialysis catheters. We also collected data on the cost of supplies and the number of alarms during dialysis for both groups. 5 LifeSite and 5 catheter patients were chosen at random for participation in the study. The time required for the ON and OFF procedures was recorded for 3 consecutive dialysis sessions for each patient for a total of 15 observations/group. The average staff time required per session for supply preparation, ON/OFF procedure, dressing changes, and responding to alarms was 15.9 min for the LifeSite and 16.9 min for catheters. Catheter patients experienced 4.5 access‐related alarms per session compared to 2.5 access‐related alarms per session for LifeSite patients. This increase in the number alarms for catheter patients resulted in an increase in average staff time required to resolve the cause of these alarms vs. LifeSite patients (3.4 vs. 0.87 min/session). There was a minimal difference in the cost of access‐related supplies between LifeSite and catheter patients at our center ($3.71 vs. $3.88 per session, respectively) based on dialysis center acquisition costs. This study demonstrates that attaining a critical mass of LifeSite patients in a dialysis unit enables the dialysis staff to develop the skill to initiate and discontinue treatments for patients with the LifeSite in a timeframe similar to that required to do the same for catheter patients. The overall cost of supplies to care for LifeSite patients in a dialysis unit is also similar to those used for catheter patients.
Accuracy of Online Conductivity Monitor Compared with Daugirdas (dPVV/Kt/V) Model. Use in the Clinical Field
Authors: Cigarrán S. , Coronel F. , Torrente J. , Sevilla M. , Baylón J.C.D.
Published: December 2004

The influence of dialysis prescription on outcome is well established. Hemodialysis dose has been shown to have a distinct impact upon the morbidity and mortality rate in patients on regular treatment therapy. Hence, adequacy of dialysis should be guaranteed. New devices based in online conductivity measures have been developed to achieve an adequate dialysis dose. The aim of this study was to compare online conductivity monitor (OCM) with dialysis dose standard methods (Daugirdas Kt/V). 24 anuric patients were included in a cross‐sectional study: 20.8% were diabetics, mean age 64.7 ± 18.2 years; 16% females. Access blood were AVFi and the effective dialyzed blood flow was set at 350 mL/min, with recirculation <5%. BMI was 25.4 ± 3.8 kg/m2 and body weight was 69.7 ± 12 kg. All patients were dialyzed thrice weekly (245 ± 21 min) with dialysis machine 4008H (Fresenius Medical Care) equipped with OCM monitor and the hollow fiber high‐flux polysulfone membrane (HF‐80 1.8 m2) and helixone (Fx‐60, 1.6 m2). Dialysate flow was maintained at 500 mL/min, with standard dialysate liquid. Drug therapy was not varied. Each patient was subjected to OCM on midweek day, during 3 consecutive weeks on the same day that blood Kt/V samples were taken as well. Each patient got 3 OCM measurements and Kt/V samples. Data were processed and statistically analyzed with SPSS 11.0 software package. Kt/V OCM relation to other baseline characteristics was assessed by using contingency tables, t‐tests, analysis of variance, and linear regression, as appropriate. All the tests were performed for a 0.05 significance level.

Descriptives (n = 24)

Mean
SD

Age (year)
  64.75
  18.243

Dry weight
  69.7125
  12.01178

Interdialysis weight gain
2266.67
1016.673

BMI
  25.4155
   3.83630

HD time
 245.21
  21.340

OCM
   1.29921
   0.201072

Daugirdas Kt/V
   1.3287
   0.21043

Watson volume (L)
  36.833
   6.3095

Linear regression analysis: Kt/V OCM relationship

Variable
Regression coefficient (β)
r2
p

Age (year)
−0.631
0.398
<0.001

Daugirdas Kt/V
−0.981
0.962
<0.001

BMI
−0.327
0.107
NS

Watson volume (L)
−0.833
0.694
<0.001

The OCM option correlates well with Daugirdas Kt/V obtained from blood samples, in 96.2%, and provides a safe and accurate tool for hemodialysis, adding efficiency to dialysis adequacy monitoring in clinical practice. Also, OCM allows for an individualized dialysis dose. Furthers studies are required to evaluate its influence on patients' evolution.
Risk of Inadequate Dialysis Dose in Hemodialysis Patients with High Watson Volume. A Warning
Authors: Cigarrán S. , Coronel F. , Torrente J. , Sevilla M. , Baylón J.C.D.
Published: December 2004

Quality control of dialysis treatment has received wide attention since inadequate dialysis dose was an independent risk factor of morbidity and mortality in hemodialysis patients. Each 0.1 decrease in Kt/V less than 1.2 is estimated to increase the relative risk of death by 5–7%. A higher Kt/V can be achieved by increasing treatment time, using a larger dialyzer or increasing blood or dialysate flow rates. The aim of this cross‐sectional study was to know, using online conductivity monitor (OCM) routinely, whether a certain subgroup of patients is being treated inadequately. 24 anuric patients were included in a cross‐sectional study: 20.8% were diabetics, mean age 64.7 ± 18.2 years; 16% females. Access blood were AVFI and the effective dialyzed blood flow was set at 350 mL/min, with recirculation <5%. BMI was 25.4 ± 3.8 kg/m2 and body weight was 69.7 ± 12 kg. All patients were dialyzed thrice weekly (245 ± 21 min) with dialysis machine 4008H (Fresenius Medical Care) equipped with OCM monitor and the hollow fiber high‐flux polysulfone membrane (HF‐80 1.8 m2) and helixone (Fx‐60, 1.6 m2). Dialysate flow was maintained at 500 mL/min, with standard dialysate liquid. Drug therapy was not varied. OCM was validated for our population and reported in other abstracts (r2 = 0.96, p < 0.001). Inadequate dialysis dose was considered at OCM Kt/V less than 1.2. Data were processed and statistically analyzed with SPSS 11.0 software package. Watson volume (Wv) to other baseline characteristics was assessed by using contingency tables, t‐tests, analysis of variance, and linear regression, as appropriate. All the tests were performed for a 0.05 significance level. The OCM Kt/V weekly was inversely related to Wv (r = −0.833, p < 0.001). 20.8% of our patients are at risk of inadequate dialysis dose, and it reflects our current practice of dialysis prescription. All of them are anuric young men with a Wv > 40 L. Specific efforts are required to deliver an adequate dialysis dose in this kind of patients. This can be achieved by altering dialysis frequency, increasing membrane surface, and/or increasing dialysis flow. OCM Kt/V device permits a daily dialysis dose delivery and, consequently, an individualized prescription. Prospective studies are required to establish whether adequate dialysis dose in patients with Wv > 40 L may further improve their survival.

Variable
n
OCM Kt/V
Age (year)
THD (min)
Watson volume (L)

OCM Kt/V

  <1.2
5 (20.8%)
1.05 ± 0.03*
45.2 ± 12.91*
240 ± 21.21
45.02 ± 3.03*

OCM Kt/V

  ≥1.2
19 (79.2%)
1.36 ± 0.17
69.89 ± 15.9
246 ± 21.21
34.6 ± 4.9

p < 0.001.
Survival of End‐Stage Renal Disease Diabetic Patients on Hemodialysis
Authors: Maiza H.a. , Thomas M.j. , Dorcely A.
Published: December 2004

Purpose:  To analyze survival and causes of mortality in end‐stage renal disease (ESRD) diabetic patients treated by hemodialysis.

Methods:  Data of 1203 ESRD hemodialyzed patients between 1975 and 2002 were analyzed, 116 patients were excluded and 1087 patients included in the study. We studied the prevalence of the diabetic nephropathy, the rate of survival and causes of death by comparing diabetic patients with a control group of patients without diabetes.

Results:  Among the 1087 patients requiring dialysis, 272 (25%) were diabetic and 815 non‐diabetic whose causal nephropathy was nephroangiosclerosis 32%, glomerulonephritis 15%, chronic interstitial nephropathy 14%, and others 14%. The diabetics were older at the beginning of dialysis than non‐diabetic patients: 60.33 ± 11.39 years vs. 52.23 ± 17.20 years, p < 0.001. Average time on dialysis is more important in non‐diabetic than diabetic group [5.90 ± 5.73 years vs. 2.71. ± 2.48 years, p < 0.001]. The rate of death was higher in diabetics than in control group [71.7% vs. 55.8%, respectively, p < 0.003]. The difference in survival between the two groups remains significant for the same age. Death caused by cardiovascular disorders is higher in diabetics (68.8%) than non‐diabetics (31.2%) (p < 0.05). Among death causes, stroke is the most frequent cause in diabetics (18.4% vs. 11.6%) in non‐diabetics, p < 0.05. Death by heart failure and infections is higher in diabetics but the difference is not statistically significant (12.3% in diabetics vs. 9.4% in non‐diabetics for heart failure and 13.8% vs. 11.4% for infections). Death due to neoplasms is higher in non‐diabetics (4.39% vs. 1.02% in diabetics, p < 0.05).

Conclusion:  In our cohort, mortality in diabetic patients is higher than in non‐diabetic patients. Cardio‐vascular disorders are the most cause of death in diabetics and above all stroke, whereas mortality due to neoplasms is higher in non‐diabetic patients. Diabetes is an important risk factor of mortality in hemodialysis patients.
Quality of Life in Chronic Kidney Disease Patients and Hemodialysis Patients
Authors: Iliescu E.a. , Yeates K.e. , Holland D.c.
Published: December 2004

The aim of this cross‐sectional study is to assess quality of life (QOL) in 119 chronic kidney disease (CKD) patients and 89 hemodialysis (HD) patients using the SF‐36 instrument (PF = physical function, RP = role limitations physical, BP = bodily pain, GH = general health perceptions, VT = vitality, SF = social function, RE = role limitations emotional, MH = mental health, MCS = mental summary, and PCS = physical summary). The mean (range) s‐creatinine in the CKD group was 325 μmol/L (133–809 μmol/L). There were no differences in SF‐36 scores between CKD and HD patients (Figure). CKD/HD status did not predict MCS or PCS in multivariate analyses controlling for age (p < 0.01 for PCS), sex, depression (p = 0.01 for PCS), Charlson comorbidity score (p < 0.01 for PCS), s‐albumin (p = 0.05 for PCS), hemoglobin, presence of partner, and level of education.

We conclude that QOL is related to comorbid illness and decreases even before dialysis is started. Longitudinal studies of QOL in CKD patients are needed to evaluate the influence of dialysis initiation on QOL.
Physical disturbance of an upland grassland influences the impact of elevated UV‐B radiation on metabolic profiles of below‐ground micro‐organisms
Authors: Avery L. M. , Thorpe P. C. , Thompson K. , Paul N. D. , Grime J. P. , West H. M.
Published: December 2004

This investigation determined the response of soil microbial communities to enhanced UV‐B radiation and disturbance in upland grassland. A factorial field experiment encompassing two levels of UV‐B supplementation (simulating ambient and a 30% increase in stratospheric ozone) and two levels of disturbance (disturbed and undisturbed) was established at Buxton Climate Change Impacts Laboratory, Derbyshire, UK, and maintained for 7 years prior to sampling.

Enhanced UV‐B increased microbial utilization of carbohydrates, carboxylic acids, polymers and aromatic compounds present in Biolog® GN plates when inoculated with soils taken from disturbed plots, but did not affect carbon utilization of soil microbial communities associated with undisturbed plots (UV‐B×Disturbance interaction, P<0.05 for each substrate type).

UV‐B treatment did not affect numbers of bacteria or fungi. Direct microscopic counts showed fewer bacteria in soil originating from disturbed plots than from undisturbed plots (Disturbance, P<0.001), although a greater number of culturable bacteria and fungi were isolated from disturbed than from undisturbed soils (Disturbance, P<0.001). No UV‐B‐ or disturbance‐related differences in protein, starch or urea hydrolysis were exhibited by bacterial isolates.

UV‐B treatment did not affect total plant biomass within undisturbed plots or the biomass of individual groupings of grasses, forbs and mosses. Per cent root length colonized by arbuscular mycorrhizal fungi (AMF) was not affected by enhanced UV‐B radiation in the undisturbed plots. Neither AMF nor plant biomass was measured in disturbed plots.

The key findings of this study show that UV‐B‐mediated alterations in carbon utilization occurred in soil microbial communities subjected to disturbance, but such changes were not observed in communities sampled from undisturbed grassland. Differences in the catabolic potential of microbial communities from disturbed grassland subjected to enhanced UV‐B are probably related to plant‐mediated changes in resource availability or quality.
A multiyear synthesis of soil respiration responses to elevated atmospheric CO2from four forest FACE experiments
Authors: King John S. , Hanson Paul J. , Bernhardt Emily , DeAngelis Paolo , Norby Richard J. , Pregitzer Kurt S.
Published: December 2004

The rapidly rising concentration of atmospheric CO2has the potential to alter forest and global carbon cycles by altering important processes that occur in soil. Forest soils contain the largest and longest lived carbon pools in terrestrial ecosystems and are therefore extremely important to the land–atmosphere exchange of carbon and future climate. Soil respiration is a sensitive integrator of many soil processes that control carbon storage in soil, and is therefore a good metric of changes to soil carbon cycling. Here, we summarize soil respiration data from four forest free‐air carbon dioxide enrichment (FACE) experiments in developing and established forests that have been exposed to elevated atmospheric [CO2] (168 μL L−1average enrichment) for 2–6 years. The sites have similar experimental design and use similar methodology (closed‐path infrared gas analyzers) to measure soil respiration, but differ in species composition of the respective forest communities. We found that elevated atmospheric [CO2] stimulated soil respiration at all sites, and this response persisted for up to 6 years. Young developing stands experienced greater stimulation than did more established stands, increasing 39% and 16%, respectively, averaged over all years and communities. Further, at sites that had more than one community, we found that species composition of the dominant trees was a major controller of the absolute soil CO2efflux and the degree of stimulation from CO2enrichment. Interestingly, we found that the temperature sensitivity of bulk soil respiration appeared to be unaffected by elevated atmospheric CO2. These findings suggest that stage of stand development and species composition should be explicitly accounted for when extrapolating results from elevated CO2experiments or modeling forest and global carbon cycles.
Effects of nitrogen deposition and insect herbivory on patterns of ecosystem‐level carbon and nitrogen dynamics: results from the CENTURY model
Authors: Throop Heather L. , Holland Elisabeth A. , Parton William J. , Ojima Dennis S. , Keough Cynthia A.
Published: December 2004

Atmospheric nitrogen deposition may indirectly affect ecosystems through deposition‐induced changes in the rates of insect herbivory. Plant nitrogen (N) status can affect the consumption rates and population dynamics of herbivorous insects, but the extent to which N deposition‐induced changes in herbivory might lead to changes in ecosystem‐level carbon (C) and N dynamics is unknown. We created three insect herbivory functions based on empirical responses of insect consumption and population dynamics to changes in foliar N and implemented them into the CENTURY model. We modeled the responses of C and N storage patterns and flux rates to N deposition and insect herbivory in an herbaceous system. Results from the model indicate that N deposition caused a strong increase in plant production, decreased plant C : N ratios, increased soil organic C (SOC), and enhanced rates of N mineralization. In contrast, herbivory decreased both vegetative and SOC storage and depressed N mineralization rates. The results suggest that herbivory plays a particularly important role in affecting ecosystem processes by regulating the threshold value of N deposition at which ecosystem C storage saturates; C storage saturated at lower rates of N deposition with increasing intensity of herbivory. Differences in the results among the modeled insect herbivory functions suggests that distinct physiological and population response of insect herbivores can have a large impact on ecosystem processes. Including the effects of herbivory in ecosystem studies, particularly in systems where rates of herbivory are high and linked to plant C : N, will be important in generating accurate predictions of the effects of atmospheric N deposition on ecosystem C and N dynamics.
Sensitivity of a dynamic global vegetation model to climate and atmospheric CO2
Authors: Gerber Stefan , Joos Fortunat , Prentice I. Colin
Published: December 2004

The equilibrium carbon storage capacity of the terrestrial biosphere has been investigated by running the Lund–Potsdam–Jena Dynamic Global Vegetation Model to equilibrium for a range of CO2 concentrations and idealized climate states. Local climate is defined by the combination of an observation‐based climatology and perturbation patterns derived from a 4 × CO2 warming simulations, which are linearly scaled to global mean temperature deviations, ΔTglob. Global carbon storage remains close to its optimum for ΔTglob in the range of ±3°C in simulations with constant atmospheric CO2. The magnitude of the carbon loss to the atmosphere per unit change in global average surface temperature shows a pronounced nonlinear threshold behavior. About twice as much carbon is lost per degree warming for ΔTglob above 3°C than for present climate. Tropical, temperate, and boreal trees spread poleward with global warming. Vegetation dynamics govern the distribution of soil carbon storage and turnover in the climate space. For cold climate conditions, the global average decomposition rate of litter and soil decreases with warming, despite local increases in turnover rates. This result is not compatible with the assumption, commonly made in global box models, that soil turnover increases exponentially with global average surface temperature, over a wide temperature range.
Detecting changes in arctic tundra plant communities in response to warming over decadal time scales
Authors: Epstein Howard E. , Calef Monika P. , Walker Marilyn D. , Stuart Chapin F. , Starfield Anthony M.
Published: December 2004

Detecting the response of vegetation to climate forcing as distinct from spatial and temporal variability may be difficult, if not impossible, over the typical duration of most field studies. We analyzed the spatial and interannual variability of plant functional type biomass from field studies in low arctic tussock tundra and compared these to climate change simulations of plant community composition using a dynamic tundra vegetation model (ArcVeg). Spatial heterogeneity of peak season live aboveground biomass was estimated using field samples taken from low arctic tundra at Ivotuk, Alaska (68.5°N, 155.7°W) in 1999. Coefficients of variation for live aboveground biomass at the 1 m2 scale ranged from 14.6% for deciduous shrubs, 18.5% for graminoids and 25.3% for mosses to over 57% for forbs and lichens. Spatial heterogeneity in the ArcVeg dynamic vegetation model was simulated to be greater than the field data, ranging from 37.1% for deciduous shrubs to 107.9% for forbs. Disturbances in the model, such as caribou grazing and freezing–thawing of soil, as well as demographic stochasticity, led to the greater variability in the simulated results. Temporal variances of aboveground live biomass over a 19‐year period using data from Toolik Lake, AK fell within the range of field and simulation spatial variances. However, simulations using ArcVeg suggest that temporal variability can be substantially less than site‐scale spatial variability. Field data coupled with ArcVeg simulations of climate change scenarios indicate that some changes in plant community composition may be detectable within two decades following the onset of warming, and shrubs and mosses might be the key indicators of community change. Model simulations also project increasing landscape scale spatial heterogeneity (particularly of shrubs) with increasing temperatures.
Effects of calcium concentration on the SOD activity and UVB‐induced cytotoxicity in cultured human keratinocytes
Authors: Sasaki Hiroko , Itoh Taketo , Akamatsu Hirohiko , Okamoto Hiroyuki , Horio Takeshi
Published: December 2004

Background/Purpose: Cellular differentiation due to the extracellular calcium (Ca2+) concentration affects the level of several antioxidant enzymes in cultured human keratinocytes. Because the epidermis includes well‐ and un‐differentiated keratinocytes, we expected that keratinocytes possess different antioxidant capacity and sensitivity to damaging effects of ultraviolet‐B (UVB) depending on the differentiation. We examined the effects of Ca2+ concentration of culture medium (DMEM (Dulbecco's modified Eagle's medium)) on the superoxide dismutase (SOD) activity and UVB‐induced cytotoxicity in cultured human keratinocytes in order to investigate the relationship between cell differentiation and antioxidant defense.

Methods: Human keratinocytes (HaCaT cells) were incubated in high Ca2+ (>1 mM) or low Ca2+ (<0.1 mM) concentration DMEM for 24 h at 37°C in 5% CO2. Then, we measured total SOD activity and also individual Cu,Zn‐ and Mn‐SOD activities in keratinocytes. Furthermore, after incubation in high or low Ca2+ concentration DMEM, human keratinocytes were irradiated with 10, 20 or 30 mJ/cm2 UVB. The quantity of lactate dehydrogenase (LDH) leaked in the supernatant from damaged keratinocytes, cell viability and TdT‐mediated dUTP nick end labelings (TUNEL) positive keratinocytes were measured at 24 h after UVB irradiation.

Results: Total SOD activity and Cu,Zn‐SOD activity in human keratinocytes cultured in low Ca2+ were significantly lower than in keratinocytes cultured in high Ca2+ concentration DMEM. In contrast, Mn‐SOD activity was not affected. LDH leakage in the supernatant from keratinocytes cultured in low Ca2+ concentration was significantly higher than that from keratinocytes cultured in high Ca2+ concentration DMEM after UVB irradiation. The cell viability of keratinocytes cultured in low Ca2+ concentration DMEM was significantly decreased compared to that of keratinocytes cultured in high Ca2+ concentration DMEM after UVB irradiation. Furthermore, UVB‐induced apoptosis was increased in keratinocytes cultured in low Ca2+ concentration DMEM by the TUNEL method.

Conclusions: These results suggest that cellular differentiation due to the change of Ca2+ concentration of culture medium affects the Cu,Zn‐SOD activity and UVB‐induced cytotoxicity in cultured human keratinocytes.
Conflict Management Strategies Used by Successful Family Businesses
Authors: Sorenson Ritch L.
Published: December 2004

This paper reports the analyses of a survey of 59 family businesses. Findings indicate that in comparison to nonfamily businesses, family businesses have a more complex set of issues to consider when managing conflict. Collaboration, accommodation, and compromise strategies produce relatively better outcomes for both family and business. A competitive strategy results in relatively negative outcomes for both business and family. High levels of collaboration contribute to positive outcomes for both family and business, and high levels of compromise and accommodation contribute to positive family outcomes. Based on a comparison of means, this paper identifies conflict management profiles for achieving positive outcomes for both business and family.
H1 receptor‐mediated vasodilatation contributes to postexercise hypotension
Authors: Lockwood Jennifer M. , Wilkins Brad W. , Halliwill John R.
Published: December 2004

In normally active individuals, postexercise hypotension after a single bout of aerobic exercise is due to an unexplained peripheral vasodilatation. Histamine has been shown to be released during exercise and could contribute to postexercise vasodilatation via H1 receptors in the peripheral vasculature. The purpose of this study was to determine the potential contribution of an H1 receptor‐mediated vasodilatation to postexercise hypotension. We studied 14 healthy normotensive men and women (ages 21.9 ± 2.1 years) before and through to 90 min after a 60 min bout of cycling at 60% on randomized control and H1 receptor antagonist days (540 mg oral fexofenadine hydrochloride; Allegra). Arterial blood pressure (automated auscultation) and femoral blood flow (Doppler ultrasound) were measured in the supine position. Femoral vascular conductance was calculated as flow/pressure. Fexofenadine had no effect on pre‐exercise femoral vascular conductance or mean arterial pressure (P > 0.5). At 30 min postexercise on the control day, femoral vascular conductance was increased (Δ+33.7 ± 7.8%; P < 0.05 versus pre‐exercise) while mean arterial pressure was reduced (Δ−6.5 ± 1.6 mmHg; P < 0.05 versus pre‐exercise). In contrast, at 30 min postexercise on the fexofenadine day, femoral vascular conductance was not elevated (Δ+10.7 ± 9.8%; P= 0.7 versus pre‐exercise) and mean arterial pressure was not reduced (Δ−1.7 ± 1.2 mmHg; P= 0.2 versus pre‐exercise). Thus, ingestion of an H1 receptor antagonist markedly reduces vasodilatation after exercise and blunts postexercise hypotension. These data suggest H1 receptor‐mediated vasodilatation contributes to postexercise hypotension.
Wayward Sisters
Authors: Beckman Mary
Published: December 2004

Like fraternal twins, two versions of the same hormone behave quite differently. New research in monkeys shows that the progestin most commonly used in hormone replacement therapies in the United States contributes to heart damage, whereas a version more commonly found in European countries does not. The results highlight how little researchers know about these drugs and their effect on women's physiology.
Homing In on a Hormone
Authors: Davenport R. John
Published: December 2004

COLD SPRING HARBOR, NEW YORK
--A phantom hormone hampers worm survival and promotes aging. Now, researchers have taken a step toward identifying the furtive molecule, according to work presented here on 7 October 2004 at the Molecular Genetics of Aging meeting. The advance should help scientists pad their knowledge about pathways that tweak longevity in nematodes.
Stuck in the Skin
Authors: Leslie Mitch
Published: December 2004

Like Paul Revere on his midnight ride, immune cells that encounter intruders rush to alert other defenders. But the skewed proportions of blood fats characteristic of atherosclerosis can hobble the cells, according to new research. A particular protein releases the cells, suggesting a possible way to derail atherosclerosis.