Using complexity theory to build interventions that improve health care delivery in primary care

Previous observational research confirms abundant variation in primary care practice. While variation is sometimes viewed as problematic, its presence may also be highly informative in uncovering ways to enhance health care delivery when it represents unique adaptations to the values and needs of people within the practice and interactions with the local community and health care system. We describe a theoretical perspective for use in developing interventions to improve care that acknowledges the uniqueness of primary care practices and encourages flexibility in the form of intervention implementation, while maintaining fidelity to its essential functions.     

Local treatment of Pseudomonas infection of the ear. A small clinical study

Infections of the middle and external ear caused by the problem-micro-organism Pseudomonas aeruginosa can be cured by local therapy with Ciprofloxacin and Tutofusin very quickly and without any complications. Drum ruptures caused by ear secretions close up again spontaneously. Tympanon tubes can be left in situ. Function disturbances of the middle and internal ear clear up and the functions return to normal.     

Effect of the white blood count on the clinical management of the febrile infant

BACKGROUND. The white blood count is commonly used in the evaluation of the febrile infant without a focal source of infection. This study describes the physician's use of diagnostic tests in this clinical situation and also evaluates the effect of an elevated white blood count (WBC) on diagnostic test ordering and patient management. METHODS. A case scenario describing a febrile infant was mailed to all 294 pediatric, family, general, and emergency physician members of the Academy of Medicine of Cleveland. Questions about test ordering and case management were asked, both before and after the patient's WBC was known. Physicians were randomly assigned to receive a case scenario with either a normal or an elevated WBC. RESULTS. Of the 294 physicians contracted, 196 (67%) returned usable questionnaires. Physicians ordered an average of 1.4 tests in the initial management of the case, for an average cost of $82. Emergency physicians ordered more tests than other physicians (2.4 vs 1.2 tests, P = .001). Once the WBC was known, physicians in the high WBC group ordered more additional tests than the normal WBC group (0.89 vs 0.33 tests, P less than .001), and were more likely to change to a more aggressive therapeutic management strategy (P less than .001). CONCLUSIONS. The cost of physician-ordered laboratory testing is significant for the clinical scenario of a febrile infant without a localizing source. An elevated WBC affects physician management by causing more tests to be ordered and by influencing some physicians to choose more aggressive management strategies.     

Frequent ongoing T-cell receptor rearrangements in childhood B- precursor acute lymphoblastic leukemia: implications for monitoring minimal residual disease

Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.     

The effect of harmaline on intestinal sodium transport and on sodium-dependentd-glucose transport in brush-border membrane vesicles from rabbit jejunum

Harmaline inhibition of sodium uptake and of sodium-dependentd-glucose transport was investigated using brush-border membrane vesicles from frozen rabbit jejunum. Under sodium-gradient conditions, initiald-glucose uptake (20 s) was inhibited by harmaline at concentrations above 0.5 mM, but at lower harmaline concentrationsd-glucose uptake was stimulated by 10–15%. When a similar potassium gradient was used, harmaline had no effect. At concentrations upt to 2 mM, harmaline did not alter the equilibrium uptake ofd-glucose ord-mannitol. After pre-equlibration with sodium (25 mM),d-glucose uptake was inhibited at harmaline concentrations ranging from 0.1 to 2 mM. Sodium (10 mM) uptake was also inhibited by harmaline. Increasing the sodium concentration reduced the inhibitory effect of harmaline on tracer sodium uptake as well as on sodium-dependentd-glucose uptake. Similar to phlorizin, harmaline (1 mM) was able to prevent glucose-induced sodium influx across the brush-border membrane.Sodium uptake into brush-border membrane vesicles seems to be inhibited at lower harmaline concentrations than sodium-dependentd-glucose uptake. At high (2 mM) inhibitor concentrations, however, sodium-dependent glucose uptake is more strongly inhibited than sodium uptake. These results suggest that harmaline inhibits both sodium and sodium-dependent transport across intestinal brush-border membranes by interacting with specific sodium-binding sites.