Measuring readmission rates.

OBJECTIVE--To assess the feasibility of extracting data on readmissions and readmission rates from Körner data for use as health service indicators. DESIGN--Retrospective analysis of inpatient Körner data for January 1988 to April 1989. SETTING--Three districts in North East Thames region. MAIN OUTCOME MEASURES--Number of readmissions after index discharge for all acute specialties combined and by specialty (general medicine, general surgery, gynaecology, trauma and orthopaedics, and geriatrics); readmission rates at 28 days after index discharge; and rates standardised for age group and sex by specialty and by consultant. RESULTS--All specialties showed an early peak in number of admissions, which levelled off by 28 days. Readmission rates at 28 days were appreciably lower in surgical specialties than in medical specialties (for example, general surgery 4.1% v geriatric medicine 15.1%). They were related to age and sex of the patient. Rates standardised for these variables did not significantly differ by district. Likewise, significant differences in standardised rates were not obtained for consultants within a specialty in one district. CONCLUSIONS--Readmission rates may be measured with Körner data. The pattern of readmissions with time means that readmission rates should be measured at not more than 28 days after the index discharge; the rates require standardisation for age and sex. Annual comparisons of standardised rates may be made among districts for combinations of specialties; those among individual consultants or specialties are unlikely to be statistically valid.     

Structural organization and functional analysis of centromeric DNA in the fission yeast Schizosaccharomyces pombe.

Centromeric DNA in the fission yeast Schizosaccharomyces pombe was isolated by chromosome walking and by field inversion gel electrophoretic fractionation of large genomic DNA restriction fragments. The centromere regions of the three chromosomes were contained on three SalI fragments (120 kilobases [kb], chromosome III; 90 kb, chromosome II; and 50 kb, chromosome I). Each fragment contained several repetitive DNA sequences, including repeat K (6.4 kb), repeat L (6.0 kb), and repeat B, that occurred only in the three centromere regions. On chromosome II, these repeats were organized into a 35-kb inverted repeat that included one copy of K and L in each arm of the repeat. Site-directed integration of a plasmid containing the yeast LEU2 gene into K repeats at each of the centromeres or integration of an intact K repeat into a chromosome arm had no effect on mitotic or meiotic centromere function. The centromeric repeat sequences were not transcribed and possessed many of the properties of constitutive heterochromatin. Thus, S. pombe is an excellent model system for studies on the role of repetitive sequence elements in centromere function.     

Blood glucose discrimination training in insulin-dependent diabetes mellitus (IDDM) patients

Self-management of insulin-dependent diabetes mellitus (IDDM) is dependent on a negative feedback loop of blood glucose (BG) fluctuations, which in turn directs treatment decisions to maintain normal BG. Although this feedback is typically accomplished by self-monitoring of blood glucose (SMBG), SMBG has limitations, and patients often rely on what their BG "feels" like. Two studies were performed to evaluate whether patients could learn to more accurately "feel"/discriminate their BG on the basis of internal cues or internal plus external BG cues. In Study I, BG Awareness Training significantly improved pre- to posttreatment BG estimation accuracy, relative to a control group. Study II replicated BG Awareness Training efficacy in improving BG estimation accuracy. Improvement in estimation accuracy was related only to initial accuracy; those who were initially less accurate improved the most. This improvement was represented in a 31% reduction in dangerous BG estimation errors and a 9% increase in accurate estimates. Resulting estimations were, however, still significantly less accurate than SMBG at the end of training.     

DNA sequence analyses of the ribosomal spacer regions in theTriticeae

Two regions of the ribosomal DNA (rDNA) were sequenced from a range of species from the tribeTriticeae. One region, the central spacer, was found to be more divergent in sequence than the other, the 18 S-spacer junction. Both regions contained sequences 20–30 bp long which were more highly conserved than the remainder of the region and their possible significance in rDNA expression is discussed. Phenetic relationships based on the sequence data were generally consistent with the relationships based on other criteria. Species possessing the S, E, J₁J₂, D, and B genomes clustered together, with the H genome species being the most distinct of those examined. The R, P, and V genome species occupy an intermediate position in the overall pattern of relationships. Some relationships differed in detail from those established by other parameters, for example the position of the N genome species, and explanations for discrepancies of this type are discussed.     

Frequent duplication and deletion events in the 5S RNA genes and the associated spacer regions of theTriticeae

The 5 S DNA units from 15 grasses in theTriticeae were analysed at the DNA sequence level. Four units carried duplications near the 3-end of the 5 S RNA gene with 3 of the duplications centred on the same base pairs as a duplication previously reported byGerlach & Dyer. The fourth duplication was located 3 downstream from the gene, in the spacer region. Apparent deletions were very frequent when units of the different grasses were compared and it was clear that these deletions did not extend into a 75 bp spacer region upstream from the 5 S RNA gene. This 75 bp region also tended to be more conserved between the grasses as compared to the high level of sequence change in the rest of the spacer region. — Phenetic relationships were established between the grasses using the sequence data. The relationships were generally consistent with the data from other parameters and, in addition, showed that two Australian grasses were closely related to the other Northern hemisphere genera examined. The data concerning the Australian grasses is discussed in relation to the isolated nature of Australia.     

An experiment in enzyme evolution studies withPseudomonas aeruginosa amidase

The regulation of amidase synthesis inP. aeruginosa is under positive control. This review describes the experimental evolution of amidase and its regulator protein for the hydrolysis of novel substrates and experiments to elucidate the mechanism of the control system.     

Agroinfection and nucleotide sequence of cloned wheat dwarf virus DNA

Cloned DNA of the geminivirus wheat dwarf virus (WDV) was successfully used to infect seedling wheat plants. The clone was derived from circular double-stranded viral DNA isolated from naturally infected tissue. The initiation of infection was mediated by Agrobacterium tumefaciens using cloned dimeric WDV genomes in a binary Agrobacterium vector. The WDV DNA which comprised the infectious clone was sequenced and is compared with the published sequence of a Swedish isolate of the same virus. The results confirm that the single WDV genome component of 2.75 kb carries all the information necessary for production of viral symptoms, virus particles and viral double- and single-stranded DNA forms.     

Two Developmentally Regulated Isoenzymes of Calmodulin-Stimulated Protein Kinase II in Rat Forebrain

Soluble calmodulin-stimulated protein kinase II has been purified from adult and 10-day-old rat forebrain. By autoradiography, the alpha/beta subunit ratios of the 10-day and adult enzymes were 0.67 +/- 0.03 and 2.20 +/- 0.15, respectively. By silver staining, the alpha/beta subunit ratios were 1.02 +/- 0.06 and 2.36 +/- 0.10, respectively. The apparent holoenzyme molecular masses of the purified 10-day and adult enzymes were 500,000 daltons and 700,000 daltons. However, varying the purification conditions revealed higher and lower molecular mass forms at both ages and suggested that the form of the kinase that is usually purified is merely that which has the highest affinity for calmodulin-Sepharose and may not be the form of the kinase that exists in vivo. The subunits of the adult and 10-day enzymes were indistinguishable by one- and two-dimensional electrophoresis and one-dimensional proteolytic peptide maps. These results are consistent with the suggestion that at least two developmentally regulated isoenzymes of this kinase exist in rat forebrain.     

Differential Regulation by Calmodulin of Basal, GTP-, and Dopamine-Stimulated Adenylate Cyclase Activities in Bovine Striatum

The concentration requirements of calmodulin in altering basal, GTP-, and dopamine-stimulated adenylate cyclase activities in an EGTA-washed particulate fraction from bovine striatum were examined. In the bovine striatal particulate fraction, calmodulin activated basal adenylate cyclase activity 3.5-fold, with an EC50 of 110 nM. Calmodulin also potentiated the activation of adenylate cyclase by GTP by decreasing the EC50 for GTP from 303 +/- 56 nM to 60 +/- 10 nM. Calmodulin did not alter the maximal response to GTP. The EC50 for calmodulin in potentiating the GTP response was only 11 nM as compared to 110 nM for activation of basal activity. Similarly, calmodulin increased the maximal stimulation of adenylate cyclase by dopamine by 50-60%. The EC50 for calmodulin in eliciting this response was 35 nM. These data demonstrate that calmodulin can both activate basal adenylate cyclase and potentiate adenylate cyclase activities that involve the activating GTP-binding protein, Ns. Mechanisms that involve potentiation of Ns-mediated effects are much more sensitive to calmodulin than is the activation of basal adenylate cyclase activity. Potentiation of GTP-stimulated adenylate cyclase activity by calmodulin was apparent at 3 and 5 mM MgCl2, but not at 1 or 10 mM MgCl2. These data further support a role for calmodulin in hormonal signalling and suggest that calmodulin can regulate cyclic AMP formation by more than one mechanism.