Identification by NMR spectroscopy of the two stereoisomers of the platinum complex [PtCl2(S-ahaz)] (S-ahaz = 3(S)-aminohexahydroazepine) bound to a DNA 14-mer oligonucleotide. NMR evidence of structural alteration of a platinated A x T-rich 14-mer DNA duplex.

The enantiomers of the asymmetric, chiral platinum(II) complex [PtCl(2)(S-ahaz)] (S-ahaz = 3(S)-aminohexahydroazepine) each form two stereoisomers on binding to GpG sequences of DNA: one in which the primary amine is directed toward the 5' end of the DNA and one in which it is directed toward the 3' end. Previous binding studies have revealed that the S-enantiomer forms the two stereoisomers in a 7:1 ratio while the R-enantiomer forms them in close to a 1:1 ratio. In an attempt to elucidate the reasons behind the stereoselectivity displayed by the S-enantiomer and to establish which isomer is formed in the greater amount, we report here its reaction with a 14-mer oligodeoxyribonucleotide having a single GpG site. The two stereoisomers that formed were separated using HPLC methods, and their integrities were confirmed by electrospray ionization mass spectrometry. The DNA duplex was formed by combination of each of the purified reaction products with the complementary strand of DNA. Identification of both of the stereoisomers was achieved using 2D NMR spectroscopy, which is the first time this has been achieved for an unsymmetric platinum complex bound to DNA. The minor stereoisomer, with the bulk of the ahaz ring directed toward the 3' end of the platinated strand, induced considerable disruption to the 14-mer DNA duplex structure. The primary amine of the ahaz ligand was oriented toward the 3' side of the duplex in the major isomer, giving a DNA structure that was less disrupted and was more akin to the structure of the DNA on binding of cisplatin to the same sequence.

Sema7A is a potent monocyte stimulator.

Sema7A is a recently described member of the semaphorin family that is associated with the cell surface via a glycophosphatidylinositol linkage. This study examined the mRNA expression and biological properties of this protein. Although the expression of Sema7A was demonstrated in lymphoid and myeloid cells, no stimulation of cytokine production or proliferation was evident in B or T cells. In contrast, Sema7A is an extremely potent monocyte activator, stimulating chemotaxis at 0.1 pm and inflammatory cytokine production (interleukin-1 (IL-1beta), tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8) and superoxide release at 1-10 pm. Sema7A is less effective at stimulating neutrophils. Sema7A also significantly increases granulocyte-macrophage colony-stimulating factor (GM-CSF) production from monocytes but has no consistent effect on IL-10, IL-12 or IL-18. Sema7A can also induce monocytes toward a dendritic cell morphology. Sema7A is expressed in monocytes and probably released through proteolysis and acts as a very potent autocrine activator of these cells.

A foodborne outbreak of Vero cytotoxin-producing Escherichia coli O157:H-phage type 8 in hospital.

This paper describes the epidemiological and microbiological aspects of the largest outbreak of Vero cytotoxin-producing Escherichia coli O157 (VTEC O157) infection in a hospital setting in which the route of transmission was foodborne. The outbreak, which was caused by a relatively uncommon phage type of VTEC O157, occurred in four geriatric continuing care wards in May 1997. The total number of people found to be excreting the organism was 37, of whom 16 were inpatients and 11 were staff. Twelve people displayed enteric symptoms. In addition, all but two of 10 cases identified in the local community were thought to be associated with the outbreak. An epidemiological investigation amongst the hospital patients revealed a statistically significant association between VTEC O157 infection and attendance at a concert party on the continuing care wards on 17 May 1997 (relative risk = 3.22;P= 0.006). There was an even stronger relationship between consumption of home-baked cream-filled cakes brought to that party and evidence of infection (relative risk = 19.35;P= 0.00002). Further investigations in the local community, coupled with microbiological evidence, supported the epidemiological finding that homemade cream cakes brought into the hospital were the vehicle of infection for the outbreak. There was no secondary spread within the hospital. The outbreak serves as a reminder of the hazard posed by foodstuffs brought into a hospital from outside.

Inhibition of cancer cell growth by ruthenium(II) arene complexes.

Inhibition of the growth of the human ovarian cancer cell line A2780 by organometallic ruthenium(II) complexes of the type [(eta(6)-arene)Ru(X)(Y)(Z)], where arene is benzene or substituted benzene, X, Y, and Z are halide, acetonitrile, or isonicotinamide, or X,Y is ethylenediamine (en) or N-ethylethylenediamine, has been investigated. The X-ray crystal structures of the complexes [(eta(6)-p-cymene)Ru(en)Cl]PF(6) (5), [(eta(6)-p-cymene)RuCl(2)(isonicotinamide)] (7), and [(eta(6)-biphenyl)Ru(en)Cl]PF(6) (9) are reported. They have "piano stool" geometries with eta(6) coordination of the arene ligand. Complexes with X,Y as a chelated en ligand and Z as a monofunctional leaving group had the highest activity. Complexes 5, 6 (the iodo analogue of 5), 9, and 10 (ethylethylenediamine analogue of 9) were as active as carboplatin. Hydrolysis of the reactive Ru-Cl bond in complex 5 was detected by HPLC but was suppressed by the addition of chloride ions. Complex 5 binds strongly and selectively to G bases on DNA oligonucleotides to form monofunctional adducts. No inhibition of topoisomerase I or II by complexes 5, 6, or 9 was detected. These chelated Ru(II) arene complexes have potential as novel metal-based anticancer agents with a mechanism of action different from that of the Ru(III) complex currently on clinical trial.

The central Scotland Escherichia coli O157:H7 outbreak: risk factors for the hemolytic uremic syndrome and death among hospitalized patients.

Little is known about risk factors for complications of Escherichia coli O157:H7 infection in adults. The 1996 outbreak in central Scotland involved the largest number of adult case patients in whom hemolytic uremic syndrome (HUS) developed and, ultimately, the largest number of deaths associated with E. coli O157:H7 infection that has yet been recorded. We investigated risk factors for HUS in a retrospective study of all hospitalized case patients in this outbreak. Of 120 case patients, 34 had HUS develop, 28 of whom were adults. Sixteen adults died. Significant risk factors for HUS were age <15 years or >65 years (odds ratio [OR], 4.4; 95% confidence interval [CI], 1.3-14.4), hypochlorhydria (OR, 6.7; 95% CI, 1.9-24.0), and coincidental antibiotics (OR, 4.7; 95% CI 1.4-16.5). Factors associated with HUS were as follows: white blood cell count >20 x 10(9) cells/L (OR, 8.25; 95% CI, 1.1-60.3), neutrophil count >15 x 10(9) cells/L (OR, 8.5; 95% CI, 1.5-50.1), and serum albumin level <35 g/L (OR, 7.2; 95% CI, 1.2-42.5) < or =3 days after symptom onset. Deaths were confined to case patients >65 years of age. Early identification of risk factors for HUS is vital and could select case patients for trials of preventative and treatment therapies.

Sequence-dependent bending of DNA induced by cisplatin: NMR structures of an A.T-rich 14-mer duplex.

The NMR solution structure of the A.T rich DNA 14-mer duplex d(ATACATGGTACATA).d(TATGTACCATGTAT) is reported. This is compared with the NMR structure of the same duplex intrastrand cross-linked at the d(G*pG*) site by cis-(Pt(NH3)2¿2+, derived from the anticancer drug cisplatin. The unmodified duplex has B-DNA geometry, but there is a large positive base-pair roll (roll angle 24 +/- 2 degrees) at the T9-A10 step on the 3' side of the central GG site. Platination of the DNA duplex causes the adjacent guanine bases to roll toward one another (roll angle 44 +/- 4 degrees), leading to an overall helix bend of 52 +/- 9 degrees. The platinum atom is displaced from the planes of the coordinated G7* and G8* by 0.8 A and 0.3 A, respectively. The minor groove opposite the platinum lesion is widened and flattened, with geometric parameters similar to those of A-form DNA. The unwinding of the helix at the platination site is 26 degrees. Platination causes the DNA duplex to bend toward the 3'-end (with respect to the G*G* strand), in contrast to G C-rich structures reported previously, which bend toward the 5'-end. This difference can be attributed to the predisposition of the A.T rich duplex toward bending in this region. Protein recognition of bent platinated G*G* lesions may therefore exhibit a strong dependence on the local DNA structure.

Trying to understand routine stroke outcome data: the need for adequate casemix adjustment and some practical considerations.

OBJECTIVE: To determine how far the difference in published stroke case fatality between the Western General Hospital (WGH), Edinburgh and the Falkirk and District Royal Infirmary (FDRI) for the period 1990-93 can be explained by adjusting more fully for casemix. DESIGN: The cases were ascertained and followed prospectively at the WGH and retrospectively at the FDRI; casemix correction was performed using a validated logistic regression model. SETTING: The WGH is a teaching hospital and the FDRI a district general hospital. SUBJECTS: Four hundred and thirty seven patients with a verified acute stroke at the WGH; 471 patients assigned a cerebrovascular disease discharge diagnostic code at the FDRI. OUTCOME MEASURE: Thirty day case fatality. RESULTS: About half of the difference in the two hospitals' published stroke case fatality could be accounted for by variation in measured casemix. The residual difference in adjusted case fatality might have been due to differences in the structure of stroke care or simply to remaining differences in casemix. Full investigation of the cause was prevented by the destruction of the deceased patients records. CONCLUSIONS: Comparisons of routinely collected stroke outcomes will remain difficult to interpret unless casemix is properly accounted for and deceased patients' records stored for several years.

A Novel Dinuclear Diaminoplatinum(II) Glutathione Macrochelate.

Both oxidized and reduced glutathione (gamma-L-Glu-L-Cys-Gly) react with the anticancer complex [Pt(en)Cl(2)] to form the bicyclic complex illustrated (en=ethylenediamine). This unprecedented structure, which was determined from extensive NMR experiments, contains a ten-membered macrochelate ring.

Kinetics of formation and stability of [Pt(dien)]2+ complexes with octamer and 14-mer DNA oligonucleotides containing a GG sequence.

Reaction of [Pt(dien)Cl]+ (1) with the 14-mer oligonucleotide 5'-d(ATACATGGTACATA) (I) gave rise to two major species which corresponded to the 5'-G and 3'-G platinated monofunctional adducts, and a minor amount of the bis-platinated adduct formed during the later stages of the reaction. The reaction of (1) with the related octamer 5'-d(ATA-CATGG) (II) was also investigated. Kinetic data obtained by HPLC showed that the 5'-G and 3'-G bases of the 14-mer oligonucleotide were platinated at similar rates: the second-order rate constant is 53 x 10(-2) M-1 s-1 at 298 K in 0.1 M NaClO4. However, the platination rate of 5'-G of the octamer (II) (k = 69 x 10(-2) M-1 s-1) was enhanced by a factor of three compared to the rate of platination at 3'-G (k = 22 x 10(-2) M-1 s-1). All the adducts were separated by HPLC and characterized by NMR spectroscopy, enzymatic digestion and MALDITOF mass spectrometry. 1H and 15N NMR shifts suggest that there are distinct conformational differences between 14-mer duplexes platinated at 5'-G (I5' ds) and 3'-G (I3' ds). Molecular mechanics modelling indicates that rotation around the Pt-N7 bond is more restricted in the case of the 5'-G adduct than in that of the 3'-G adduct. The binding of {Pt(dien)}2+ to 5'-GN7 and 3'-GN7 in the monofunctional adducts of (I) was shown to be reversible upon the addition of high concentrations of chloride ions.

Costing for long-term care: the development of Scottish health service resource utilization groups as a casemix instrument.

OBJECTIVE: to create a casemix measure with a limited number of categories which discriminate in terms of resource use and will assist in the development of a currency for contracting for the provision of health care. DESIGN: nursing staff completed a questionnaire providing clinical data and also gave estimates of relative patient resource use; ward-based costs were collected from appropriate unit managers. SETTING: National Health Service continuing-care wards in 50 Scottish hospitals. SUBJECTS: 2783 long-stay patients aged 65 years and over. RESULTS: inter-rater reliability was assessed using 1402 patients; percentage agreement between raters for individual variables varied from 68% for feeding to 97% for clinically complex treatments. Nursing costs gave 62% agreement given categories of high, medium and low. The Scottish health service resource utilization groups (SHRUG) measure was developed using 606 cases, and 67% consistency was achieved for the five categories. The relative weights for the SHRUG categories ranged from 0.56 to 1.41. The five categories explain 35% of variance in costs. CONCLUSIONS: the five SHRUG casemix categories show good discrimination in terms of costs. The SHRUG measure compares favourably with diagnosis-related groups in the acute sector and with other casemix instruments for long-term care previously piloted in the UK. SHRUG is a useful measurement instrument in assessing the resource needs of elderly people in long-term care.

Platination of a GG site on single-stranded and double-stranded forms of a 14-base oligonucleotide with diaqua cisplatin followed by NMR and HPLC -- influence of the platinum ligands and base sequence on 5'-G versus 3'-G platination selectivity.

Detailed studies of the kinetics of platination of the single-stranded 14-base DNA oligonucleotide d(ATACATGGTACATA) and the corresponding duplex by cis-[Pt(NH3)2(H2O)2]2+ show that HPLC and NMR are complementary methods which provide similar results. The 5'-G and 3'-G monofunctional intermediates were trapped, separated and characterized by NMR (via 15NH3 labeling) and enzymatic digestion followed by mass spectrometry. The kinetic data are compared with those for the corresponding reactions of cis-[PtCl2(NH3)2] (cisplatin) and its monohydrolysed analogue. For both single and double strands of the oligonucleotide, the aqua complex shows little selectivity for the 5'-G or the 3'-G in the initial platination step, whereas the chloro-complex preferentially platinates the 3'-G. The base on the 3' side of the GG sequence appears to play an important role in controlling this selectivity; replacement of T by C increases the selectivity of duplex platination by the diaqua complex by a factor of about 6, and the selectivity of chelation of the 3'-G monofunctional adduct by a factor of about 3. In general the reactivity of the 5'-G in a GG sequence appears to be enhanced in a duplex compared with a single-strand. For both the aqua-monoadduct and chloro-monoadduct, cis-[Pt(NH3)2(N7G)(H2O or Cl)], the 5'-G monoadduct is much longer lived (t1/2 approximately 4 h at 288 K for aqua, 80 h at 298 K for chloro) than the 3'-G monoadduct (t1/2 < or = 45 min at 288 K for aqua, 6 h at 298 K for chloro). Inspection of molecular mechanics models of the end states of various monofunctional adducts provided insight into H-bonding and destacking interactions in these adducts and the sequence selectivity observed in their formation. Such adducts may play an important role in the mechanism of action of platinum anticancer drugs.

Recall of AIDS public service announcements and their impact on the ranking of AIDS as a national problem.

The efficacy of two public service announcements from Phase V of the "America Responds to AIDS" (ARTA) campaign was assessed at two sites. Participants were randomly assigned to view a local news program, one with an ARTA public service announcement appearing six times and the other with no AIDS public service announcements. During telephone interviews with 907 participants 1 to 3 nights after viewing, 21% at Site A and 59% at Site B could correctly recall the ARTA public service announcements. Absolute mentions of AIDS as an important national issue increased.

A study of respiratory infections in the elderly to assess the role of respiratory syncytial virus.

A prospective study was performed from 1 December 1981 to 31 May 1982 in two departments of geriatric medicine in Edinburgh. This yielded 159 cases of acute respiratory tract infection (RTI). Twelve of these were undoubtedly associated with respiratory syncytial virus (RSV), 14 with influenza A and 18 with influenza B (as established in each case by a fourfold or greater increase in antibody titre). Eighty-five of the 159 patients with RTI and RSV titres of 32 or greater. Their significance is discussed. The undoubted RSV infections all involved the lower respiratory tract and were associated with prolonged illness. This epidemic of RSV infection was confined to one of the two hospitals. It lasted less than four weeks and was probably hospital-acquired.