Effect of shared care on blood pressure in patients with chronic kidney disease: a cluster randomised controlled trial

Background

Chronic kidney disease (CKD) is highly prevalent in patients with diabetes or hypertension in primary care. A shared care model could improve quality of care in these patients

Aim

To assess the effect of a shared care model in managing patients with CKD who also have diabetes or hypertension.

Design and setting

A cluster randomised controlled trial in nine general practices in The Netherlands.

Method

Five practices were allocated to the shared care model and four practices to usual care for 1 year. Primary outcome was the achievement of blood pressure targets (130/80 mmHg) and lowering of blood pressure in patients with diabetes mellitus or hypertension and an estimated glomerular filtration rate (eGFR)<60ml/min/1.73m².

Results

Data of 90 intervention and 74 control patients could be analysed. Blood pressure in the intervention group decreased with 8.1 (95% CI = 4.8 to 11.3)/1.1 (95% CI = −1.0 to 3.2) compared to −0.2 (95% CI = −3.8 to 3.3)/−0.5 (95% CI = −2.9 to 1.8) in the control group. Use of lipid-lowering drugs, angiotensin-system inhibitors and vitamin D was higher in the intervention group than in the control group (73% versus 51%, 81% versus 64%, and 15% versus 1%, respectively, [P = 0.004, P = 0.01, and P = 0.002]).

Conclusion

A shared care model between GP, nurse practitioner and nephrologist is beneficial in reducing systolic blood pressure in patients with CKD in primary care.     

Optimal spatial field control for controlled release

Most distributed parameter control problems involve manipulation within the spatial domain. Such problems arise in a variety of applications including epidemiology, tissue engineering, and cancer treatment. This paper proposes an approach to solve a state‐constrained spatial field control problem that is motivated by a biomedical application. In particular, the considered manipulation over a spatial field is described by partial differential equations (PDEs) with spatial frequency constraints. The proposed optimization algorithm for tracking a reference spatial field combines three‐dimensional Fourier series, which are truncated to satisfy the spatial frequency constraints, with exploitation of structural characteristics of the PDEs. The computational efficiency and performance of the optimization algorithm are demonstrated in a numerical example. In the example, the spatial tracking error is shown to be almost entirely due to the limitation on the spatial frequency of the manipulated field. The numerical results suggest that the proposed optimal control approach has promise for controlling the release of macromolecules in tissue engineering applications.     

B-cell growth factor receptor expression and B-cell growth factor response of leukemic B cell precursors and B lineage lymphoid progenitor cells

The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS- sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11-13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.     

Factors affecting mortality of critical care trauma patients

Background

Critically-ill trauma patients have a high mortality.

Objective

To study the factors affecting the mortality of ICU trauma patients treated at Al-Ain Hospital, United Arab Emirates (UAE).

Methods

All trauma patients who were admitted to the ICU were prospectively collected over three years (2003–2006). Univariate and multivariate analysis were used to compare patients who died and who did not. Gender, age, nationality, mechanism of injury, systolic blood pressure and GCS on arrival, the need for ventilation, presence of head or chest injuries, AIS for the chest and head injuries and the ISS were studied.

Results

There were 202 patients (181 males). The most common mechanism of injury was road traffic collisions (72.3 %). The overall mortality was 13.9%. A direct logistic regression model has shown that factors that affected mortality were decreased GCS (p < 0.0001), mechanism of injury (p = 0.004) with burns having the highest mortality, increased age (p = 0.004), and increased ISS (p = 0.02). The best GCS that predicted mortality was 5.5 while the best ISS that predicted mortality was 13.5.

Conclusion

Road traffic collision is the most common cause of serious trauma in UAE followed by falls. Decreased GCS was the most significant factor that predicted mortality in the ICU trauma patients.     

Optimal control of one‐dimensional cellular uptake in tissue engineering

A control problem motivated by tissue engineering is formulated and solved, in which control of the uptake of growth factors (signaling molecules) is necessary to spatially and temporally regulate cellular processes for the desired growth or regeneration of a tissue. Four approaches are compared for determining one‐dimensional optimal boundary control trajectories for a distributed parameter model with reaction, diffusion, and convection: (i) basis function expansion, (ii) method of moments, (iii) internal model control, and (iv) model predictive control (MPC). The proposed method of moments approach is computationally efficient while enforcing a nonnegativity constraint on the control input. Although more computationally expensive than methods (i)–(iii), the MPC formulation significantly reduced the computational cost compared with simultaneous optimization of the entire control trajectory. A comparison of the pros and cons of each of the four approaches suggests that an algorithm that combines multiple approaches is most promising for solving the optimal control problem for multiple spatial dimensions. Copyright © 2012 John Wiley & Sons, Ltd.     

Relationship between hours of CPAP use and achieving normal levels of sleepiness and daily functioning

STUDY OBJECTIVES: Evidence suggests that, to maintain treatment effects, nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea (OSA) needs to be used every night. What remains unknown is the nightly duration of use required to normalize functioning. This study, employing probit analyses and piecewise regression to estimate dose-response functions, estimated likelihoods of return to normal levels of sleepiness and daily functioning relative to nightly duration of CPAP. DESIGN: Multicenter, quasi-experimental study. SETTING: Seven sleep centers in the United States and Canada. PARTICIPANTS: Patients with severe OSA (total cohort n = 149; the numbers of included participants from 85 - 120, depending on outcome analyzed.) Interventions: CPAP. MEASUREMENTS AND RESULTS: Before treatment and again after 3 months of therapy, participants completed a day of testing that included measures of objective and subjective daytime sleepiness and functional status. There were significant differences in mean nightly CPAP duration between treatment responders and nonresponders across outcomes. Thresholds above which further improvements were less likely relative to nightly duration of CPAP were identified for Epworth Sleepiness Scale score (4 hours), Multiple Sleep Latency Test (6 hours), and Functional Outcomes associated with Sleepiness Questionnaire (7.5 hours). A linear dose-response relationship (P < 0.01) between increased use and achieving normal levels was shown for objective and subjective daytime sleepiness, but only up to 7 hours use for functional status. CONCLUSIONS: Our analyses suggest that a greater percentage of patients will achieve normal functioning with longer nightly CPAP durations, but what constitutes adequate use varies between different outcomes.     

Intracortical haematogenous osteomyelitis

We present an unusual case of haematogenous osteomyelitis in the diaphysis of the tibia of an adult leading to a subacute presentation with an extracortical abscess. Fluid from the abscess grew methicillin resistant Staphylococcus aureus (MRSA) on culture; MRSA with the same antibiogram had been grown from the patient’s blood seven years earlier following a bowel resection. Drainage of the abscess and curettage of the bone lesion together with appropriate antibiotic therapy led to resolution of the osteomyelitis.     

Support of human cord blood progenitor cells on human stromal cell lines transformed by SV40 large T antigen under the influence of an inducible (metallothionein) promoter

We describe the development of a human bone marrow (BM) culture system which allows study of the interaction of stromal cell lines (SCL) and highly purified hematopoietic progenitor cells. Normal BM stromal cells were electroporated with a plasmid containing the simian virus 40 (SV40) large T antigen (SV40 T Ag) under the control of a synthetic metallothionein promoter (MT4); this construct is designated MT4 SV40 T Ag. SCL in which the rate of proliferation could be controlled by altering the zinc (Zn) concentration were characterized, demonstrating that the SCL were heterogeneous with respect to G-CSF and GM-CSF production. Suppression of SCL proliferation on removal of Zn made it possible to use these lines in coculture with purified CD34+ progenitor cells from umbilical cord blood. The ability to control proliferation of SCL has allowed us to maintain the survival and expansion of colony- forming cells in culture for up to 2 months. These lines have enabled us to test for stromal cell characteristics at a clonal level and provided us with a tool to analyze the events leading to lineage commitment and hematopoietic differentiation, as demonstrated by suppression of hematopoiesis by an antibody directed against the c-kit molecule.