Acute respiratory distress syndrome in a community hospital ICU

OBJECTIVE

To estimate the incidence of the acute respiratory distress syndrome (ARDS) in an Australian urban community, and to describe the pattern of disease and outcomes in a community hospital intensive care unit (ICU).

SETTING

An eight-bed general ICU in a community hospital.

DESIGN

Retrospective chart review.

PATIENTS

32 patients identified over a 4-year period as having ARDS.

MEASUREMENTS AND RESULTS

The incidence of ARDS in an Australian urban community was estimated to be 7.3-9.3 cases/100,000 population per year. In-hospital mortality was 59%, while ICU mortality was 47%. Sepsis, pneumonia and aspiration were the main aetiological factors accounting for 94% of the patient population. There was no trauma. The Acute Physiology and Chronic Health Evaluation and Murray scores and values for the ratio of the partial pressure of oxygen in arterial blood and fractional inspired oxygen on admission to the ICU were similar between survivors and nonsurvivors, and none of these parameters were reliable predictors of outcome. Mean age, however, was different between survivors (56 +/- 16 years) and non-survivors (69 +/- 9 years) (p < or = 0.01). Mean daily fluid balance was also different between survivors (536 +/- 545 ml/day) and non-survivors (1576 +/- 1255 ml/day) (p < or = 0.02). Haemodynamic data were collected on 21 of the 32 patients within 72 h of the onset of ARDS. None of the haemodynamic parameters reached significance. There was, however, a trend for better cardiac function and oxygen consumption in the survivors.

CONCLUSIONS

These data show that for ARDS, at least, mortality outcome can be comparable in a community ICU to a tertiary referral institution. The pattern of disease in an urban Australian community hospital is different to that often reported from tertiary centres. The incidence of ARDS in an Australian urban community is comparable to the reported incidence in North America and Western Europe.

Conformations of cis- and trans-2,3-methanomethionine stereoisomers in the tripeptide mimic system Ac[cyclo-M]NHiPr

Quenched molecular dynamics (QMD) was used to simulate low-energy conformers of the tripeptide mimics Ac¿cyclo-Met¿NHiPr, where the 2.3-methanomethionine is the cis-derivative (2R,3S)-cyclo-Met and the trans-derivative (2R,3R)-cyclo-Met. Variations of the favored omicron, upsilon values. and differences between the simulated preferred conformations for the two structures, were rationalized and discussed. Physical data for the cis-derivative (NMR, CD and FT-IR) gave no conclusive evidence for any preferred conformation. However for the trans-derivative, Ac¿(2R,3R)-cyclo-Met¿NHiPr, the physical data suggests that a conformer with partial helical structure is favored. This work provides details of how the rigidly constrained side chain and cyclopropane of 2,3-methanoamino acids can be used to manipulate phi, psi values in a logical fashion.

Synthesis and solution conformation of cyclo[RGDRGD]: a cyclic peptide with selectivity for the alpha V beta 3 receptor

Three peptides, cyclo[RGDRGD], cyclo[RGDRGd] (d = D-Asp), and the linear sequence RGDRGD, were prepared via solid phase syntheses. These were tested in binding assays based upon the alpha IIb/beta 3-fibrinogen and the alpha V beta 3-vitronectin interactions and found to be selective for the alpha V beta 3 integrin. The alpha V beta 3-vitronectin is important in bone regeneration, hence the compounds were also tested in an osteoclast regeneration assay; all three compounds, cyclo-[RGDRGD], cyclo[RGDRGd], and RGDRGD, showed modest activities. Molecular modeling, NMR, and CD studies were undertaken to elucidate the conformational preferences of cyclo-[RGDRGD], in aqueous solutions. Results from these studies strongly suggest that the molecule tends to adopt a type I beta-turn conformation with a relatively short distance between the Asp and Arg side chains. These observations are in harmony with the first correlations made between alpha V beta 3 selectivity and solution conformation for a peptide ligand (Pfaff, M.; et al. J. Biol. Chem. 1994, 269, 20233).

Nicotine abstinence syndrome precipitated by an analog of neuropeptide FF

In a recently introduced rodent model of nicotine abstinence syndrome the observed behavioral signs closely resembled those typical of rat opiate abstinence syndrome. Nicotine-induced release of endogenous opioids may contribute to nicotine dependence; morphine potently reverses nicotine abstinence signs, while naloxone precipitates abstinence signs and prevents nicotine from alleviating them. Considerable evidence suggests that neuropeptide FF, an endogenous antiopiate peptide, contributes to opiate dependence. Third ventricle injection of neuropeptide FF precipitates abstinence syndrome in morphine-dependent rats, as does SC injection of its lipophilic analogs, dansyl-PQRFamide and dansyl-RFamide. Might NPFF also play a role in nicotine dependence? In the present study, SC injection of 15 or 25 mg/kg dansyl-RFamide or vehicle alone dose dependently precipitated an abstinence syndrome in nicotine-dependent rats. There was a significant, p < 0.01, positive linear trend of abstinence signs as a function of dose. Categories of abstinence signs had the same rank ordering by frequency as observed in spontaneous nicotine abstinence. Injection of 25 mg/kg dansyl-RFamide SC had no significant effect in nondependent rats.

Enhanced antiopiate activity and enzyme resistance in a peptidomimetic of FMRFamide containing E-2,3-methanomethionine and E-2,3-methanophenylalanine

FMRFamide is a molluscan peptide that has shown antiopiate activity in a number of mammalian test systems. Peptidomimetics of FMRFamide substituted with conformationally constrained stereoisomers of Z-2,3-methanomethionine or E-2,3-methanomethionine precipitated abstinence syndrome far more potently than FMRFamide itself. The current study determined the effect on antiopiate potency of an additional rigid substitution. A peptidomimetic containing a stereoisomer of E-2,3-methanomethionine was compared with a peptidomimetic additionally substituted at the C-terminal with E-2,3-methanophenylalanine. Morphine abstinence signs were observed after varying doses (0.125-25.0 micrograms) of these two peptidomimetics were injected into the third ventricle of morphine-dependent rats. The peptidomimetic containing both rigid substitutions was far more potent than the peptidomimetic of FMRFamide containing methanomethionine alone. The increased potency appears to be related to enzyme resistance rather than receptor affinity.

Postirradiated submandibular gland: a potential model to study salivary gland radioprotection and tumourigenesis

Theoretical reserve cells located in the intercalated and excretory ducts are postulated to be responsible for salivary gland tumourigenesis, with acinar cells playing no role in this process. Animal models, one using low-dose radiation to rat submandibular glands, indicate that this hypothesis is incorrect. Few human models have been devised to demonstrate and verify this theory. Submandibular glands in the field of ionizing radiation, as external-beam radiotherapy for head and neck tumours, were examined using an immunocytochemical technique and an antibody to proliferating cell nuclear antigen (PCNA), a specific marker for cycling cells. In the nonirradiated gland, nuclei positive for PCNA were seen in acinar as well as ductal cells of all types. Six months post irradiation, human submandibular glands show increased proliferative rates in both ductal and acinar cells that are significantly greater than control glands (p = .012). Based on this regenerative capacity, postirradiated human submandibular glands might serve as a model to investigate various treatment modalities for the prevention of radiation damage to acinar cells and the consequent patient morbidity that develops due to xerostomia. As well, these results suggest that even in humans, acinar cells are potential targets for carcinogenic agents and that current histogenic concepts for salivary gland tumourigenesis are incorrect.

Termination of DNA synthesis by novel 3'-modified-deoxyribonucleoside 5'-triphosphates

Eight 3'-modified-dNTPs were synthesized and tested in two different DNA template assays for incorporation activity. From this enzymatic screen, two 3'-O-methyl-dNTPs were shown to terminate DNA syntheses mediated by a number of polymerases and may be used as alternative terminators in Sanger sequencing. 3'-O-(2-Nitrobenzyl)-dATP is a UV sensitive nucleotide and was shown to be incorporated by several thermostable DNA polymerases. Base specific termination and efficient photolytic removal of the 3'-protecting group was demonstrated. Following deprotection, DNA synthesis was reinitiated by the incorporation of natural nucleotides into DNA. The identification of this labile terminator and the demonstration of a one cycle stop-start DNA synthesis are initial steps in the development of a novel sequencing strategy.

Evaluation of "norpeptides" as potential inhibitors of HIV-proteases

Peptide mimics of substrates for HIV-proteases were prepared. These "norpeptides" are identical to a fragment of the HIV-polyprotein except that a crucial scissile bond was deleted, and an alpha,beta-disubstituted amino acid spans the P1 and P1 site. Thus all four stereoisomers of Leu psi[]Ala (i.e. H2NCH(CH2iPr)CH(Me)CO2H, 1) were incorporated into Ac-Ala-Arg-Val-Leu psi[]Ala-Glu-Ala-NH2 (all other residues being L-amino acids), and tested with respect to inhibition of HIV-1 and HIV-2 proteases.

Massive macroglossia as a presenting feature of hypothyroid-associated pericardial effusion

An 81-year-old woman presented with massive macroglossia and signs of both hypothyroidism and pericardial tamponade. Drainage of the pericardial effusion produced dramatic resolution of the macroglossia. Marked elevation of central venous pressure may result in macroglossia, possibly because of anomalous venous drainage of the tongue.

Enhanced antiopiate activity in peptidomimetics of FMRFamide containing Z-2,3-methanomethionine

FMRFa is a molluscan peptide that has shown antiopiate activity in a number of mammalian test systems. The current study determined the antiopiate potency of FMRFa and two conformationally constrained peptidomimetics of FMRFa containing stereoisomers of Z-2,3-methanomethionine. Morphine abstinence signs were observed after varying doses (0.25-25.0 micrograms) of these substances were injected into the third ventricle of morphine-dependent rats. Although both peptidomimetics were far more potent than FMRFa itself, they bound with lower affinity than FMRFa to rat spinal cord receptors for the mammalian FMRFa-like peptide, NPFF.

Subcutaneous injection of an analog of neuropeptide FF precipitates morphine abstinence syndrome

Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitation of opiate abstinence syndrome by third ventricle injection in morphine dependent rats. In the present study, dansyl-Pro-Gln-Arg-Phe-amide, a lipophilic analog of NPFF, was injected into morphine dependent rats and appropriate sham controls at a dose of 9 mg/kg s.c. Comparison groups were injected with ethanol/water vehicle alone. The NPFF analog precipitated a vigorous opiate abstinence syndrome in morphine dependent rats, but not in sham controls.

A dynamic role that improves the service. Combining triage and nurse practitioner roles in A&E

Increasing attendance in A&E departments has many negative knock-on effects. These can be reduced by introducing a triage system combined with a nurse practitioner role.

Q fever inflammatory pseudotumor of the lung

A 36-year-old man presented with malaise, myalgia, fever, and weight loss. Liver function tests were moderately abnormal and chest x-ray film revealed an irregular mass in the right lower lobe. Bronchoscopy with cytology was not helpful. Serology revealed markedly elevated titers to Q fever. The mass was presumed to represent the presence of a Q fever pseudotumor. The patient responded to therapy with resolution of symptoms and chest x-ray film and decrease in titers to Q fever.

Quinine-induced agranulocytosis: toxic effect of quinine bisulphate on bone marrow cultures in vitro

In a case of quinine-induced agranulocytosis marrow culture studies confirmed the inhibitory effect on the patient's cells of equivalent therapeutic plasma concentrations of quinine. Similar concentrations had no effect on normal marrow cells. Quinidine, the stereoisomer of quinine, had no effect on either cells from the patient or normal cells. The results encourage the use of in-vitro bone marrow cultures for identifying drugs responsible for agranulocytosis.