Impact of a laboratory developed phenotypic rapid susceptibility test directly from positive blood cultures on time to narrowest effective therapy in patients with Gram-negative bacteremia: a prospective randomized trial

Background

Antimicrobial susceptibility testing (AST) is often needed prior to antimicrobial optimization for patients with gram-negative bloodstream infections (GN-BSIs). Rapid AST (rAST) in combination with antimicrobial stewardship (AS) may decrease time to administration of narrower antibiotics.

Methods

This was a prospective, nonblinded, randomized trial evaluating the impact of a phenotypic rAST method vs conventional AST (cAST) in hospitalized patients with GN-BSI and source control. The primary outcome was time to narrowest effective therapy.

Results

Two hundred seventy-four patients were randomized and 205 underwent analysis (97 cAST, 108 rAST). Median (interquartile range [IQR]) time to susceptibility results was 23 hours shorter in the rAST group (cAST: 62 [59–67] hours vs rAST: 39 [IQR, 35–46] hours; P < .001). Median (IQR) time to narrowest effective therapy was similar between groups (cAST: 73 [44–138] hours vs rAST: 64 [42–92] hours; P = .10). Median (IQR) time to narrowest effective therapy was significantly shorter in a prespecified subgroup of patients not initially on narrowest therapy and during AS working hours (cAST: 93 [56–154] hours vs rAST: 62 [43–164] hours; P = .004). Significant decreases were observed in median (IQR) time to oral therapy (cAST: 126 [76–209] hours vs rAST: 91 [66–154] hours; P = .02) and median (IQR) length of hospital stay (cAST: 7 [4–13] days vs rAST: 5 [4–8] days; P = .04).

Conclusions

In patients with GN-BSI, rAST did not significantly decrease time to narrowest effective therapy but did decrease time to oral antibiotics and length of hospital stay. Rapid AST using existing microbiology platforms has potential to optimize patient outcomes.

Remdesivir and Mortality in Patients with COVID-19

Background

The impact of remdesivir (RDV) on mortality rates in coronavirus disease 2019 (COVID-19) is controversial, and the mortality effect in subgroups of baseline disease severity has been incompletely explored. The purpose of this study was to assess the association of RDV with mortality rates in patients with COVID-19.

Methods

In this retrospective cohort study we compared persons receiving RDV with those receiving best supportive care (BSC). Patients hospitalized between 28 February and 28 May 2020 with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection were included with the development of COVID-19 pneumonia on chest radiography and hypoxia requiring supplemental oxygen or oxygen saturation ≤94% with room air. The primary outcome was overall survival, assessed with time-dependent Cox proportional hazards regression and multivariable adjustment, including calendar time, baseline patient characteristics, corticosteroid use, and random effects for hospital.

Results

A total of 1138 patients were enrolled, including 286 who received RDV and 852 treated with BSC, 400 of whom received hydroxychloroquine. Corticosteroids were used in 20.4% of the cohort (12.6% in RDV and 23% in BSC). Comparing persons receiving RDV with those receiving BSC, the hazard ratio (95% confidence interval) for death was 0.46 (.31–.69) in the univariate model (P < .001) and 0.60 (.40–.90) in the risk-adjusted model (P = .01). In the subgroup of persons with baseline use of low-flow oxygen, the hazard ratio (95% confidence interval) for death in RDV compared with BSC was 0.63 (.39–1.00; P = .049).

Conclusion

Treatment with RDV was associated with lower mortality rates than BSC. These findings remain the same in the subgroup with baseline use of low-flow oxygen.

Newly Approved Antimicrobials

In recent years, government-backed policies have promoted the development of new antimicrobials to combat increases in antibiotic-resistant organisms. This article summarizes the 10 new antibacterial agents to be approved in the last 5 years.

Fragrance contact allergens in 5588 cosmetic products identified through a novel smartphone application

BACKGROUND

More than 25% of the adult European population suffers from contact allergy, with fragrance substances recognized as one of the main causes. Since 2005, 26 fragrance contact allergens have been mandatory to label in cosmetic products within the EU if present at 10 ppm or above in leave-on and 100 ppm or above in wash-off cosmetics.

OBJECTIVE

To examine exposure, based on ingredient labelling, to the 26 fragrances in a sample of 5588 fragranced cosmetic products.

METHODS

The investigated products were identified through a novel, non-profit smartphone application (app), designed to provide information to consumers about chemical substances in cosmetic products. Products registered through the app between December 2015 and October 2016 were label checked according to International Nomenclature of Cosmetic Ingredients (INCI) for the presence of the 26 fragrance substances or the wording 'fragrance/parfum/aroma'.

RESULTS

The largest product categories investigated were 'cream, lotion and oil' (n = 1192), 'shampoo and conditioner' (n = 968) and 'deodorants' (n = 632). Among cosmetic products labelled to contain at least one of the 26 fragrances, 85.5% and 73.9% contained at least two and at least three of the 26 fragrances, respectively. Linalool (49.5%) and limonene (48.5%) were labelled most often among all investigated products. Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC/Lyral^® ) was found in 13.5% of deodorants. Six of the 26 fragrance substances were labelled on less than one per cent of all products, including the natural extracts Evernia furfuracea (tree moss) and Evernia prunastri (oak moss). A total of 329 (5.9%) products had one or more of the 26 fragrance substances labelled but did not have 'parfum/fragrance/aroma' listed on the label.

CONCLUSIONS

Consumers are widely exposed to, often multiple, well-established fragrance contact allergens through various cosmetic products intended for daily use. Several fragrance substances that are common causes of contact allergy were rarely labelled in this large sample of cosmetic products.

The police, social services, and psychiatry (PSP) cooperation as a platform for dealing with concerns of radicalization

The police, social services, and psychiatry (PSP) is a structured cooperation between the police, social services, and the psychiatric system in Denmark. The aim of PSP is to ensure that relevant information is shared and supportive measures enhanced concerning citizens at risk, and it involves PSP representatives from each sector meeting frequently. PSP is implemented nationwide by law. In recent years, dealing with radicalization and the threat of terrorism have become key issues in society. The PSP cooperation already facilitates the identification of citizens at many kinds of risk (e.g. suicide, substance abuse, social decline, mental illness), and coordinates relevant intervention and treatment. The existing PSP cooperation is, therefore, an obvious forum for identifying and handling concerns of radicalization and extremism. The new working model includes an upgrade of all local PSP groups and an implementation of a nationwide evaluation of the initiative. This is a presentation of the working model and the experiences in practice.

Methods for detecting acylated homoserine lactones produced by Gram-negative bacteria and their application in studies of AHL-production kinetics

In the process of evaluating the role of acylated homoserine lactones (AHLs) in food-spoiling Gram-negative bacteria, we have combined a range of bacterial AHL monitor systems to determine the AHL-profile and the kinetics of AHL-production. AHL production from 148 strains of Enterobacteriaceae isolated from foods was tested using Escherichia coli pSB403 (LuxR), Agrobacterium tumefaciens A136 (TraR) and both induction and inhibition of Chromobacterium violaceum CV026 (CviR). All strains except one was found to produce AHL(s). In no case could a single monitor system identify more than 64% of the Enterobacteriaceae as AHL-producers, showing that the simultaneous use of monitor strains is required in the process of screening bacterial populations for AHL-production. AHLs from 20 selected strains were profiled by thin layer chromatography. Most strains produced more than one AHL with 3-N-oxo-hexanoyl homoserine lactone being the most prominent. It was found that the simultaneous use of monitor strains in the top-layer was necessary for the detection of (presumably) all the AHLs. An agar well-diffusion assay based on A. tumefaciens pDZLR4 was used for quantifying AHLs from bacterial supernatants and enabled an assessment of the kinetics of AHL-production of 3 strains (Serratia proteamaculans strain B5a, Erwinia carotovora ATCC 39048 and V. fischeri strain MJ-1). As expected, the production of AHL (OHHL) and luminescence in Vibrio fischeri strain MJ-1 increased faster than growth indicating up-regulation of the AHL regulated phenotype and auto-induction of AHL production. In contrast, production kinetics of AHL (OHHL) in the two Enterobacteriaceae indicated lack of auto-induction.

Respiration in the burrowing brittlestar, Hemipholis elongata say (Echinodermata, Ophiuroidea): a study of the effects of environmental variables on oxygen uptake

The burrowing brittlestar Hemipholis elongata (Say) maintains a constant M(O2)of 3.79+/-1.47 micromol O(2) g(-1) h(-1) (for 0.2-0.3 g animals, mean+/-S.D., n=7), measured in the burrow, over a broad range of PO(2). Below the critical PO(2) of 37 mm Hg, M(O(2)) becomes dependent on the oxygen tension. M(O2) is a function of the size of H. elongata; the scaling exponent is 0. 83 and is similar to those reported for other echinoderms. The M(O2) of H. elongata is unaffected by removal from the burrow, by hypercapnia, by exposure to hydrogen sulfide, or by temperature change in the range from 20 to 32 degrees C. The relative insensitivity of H. elongata to these factors may be an adaptation to life in the highly variable estuarine and tidal creek environments where the animals are frequently found.

Assessment of flhDC mRNA levels in Serratia liquefaciens swarm cells

We reported previously that artificial overexpression of the flhDC operon in liquid-grown Serratia liquefaciens resulted in the formation of filamentous, multinucleated, and hyperflagellated cells that were indistinguishable from surface-induced swarm cells (L. Eberl, G. Christiansen, S. Molin, and M. Givskov, J. Bacteriol. 178:554-559, 1996). In the present report we show by means of reporter gene measurements, Northern analysis, and in situ reverse transcription-PCR that the amount of flhDC mRNA in surface-grown swarm cells does not exceed the maximum level found in nondifferentiated, vegetative cells. This suggests that surface-induced S. liquefaciens swarm cell differentiation, although dependent on flhDC gene expression, does not occur through elevated flhDC mRNA levels.

A prospective, controlled, randomized study of the effect of a slow-release silver device on the frequency of urinary tract infection in newly catheterized patients

OBJECTIVE

To test the effect on urinary tract infections (UTIs) in patients needing continuous indwelling catheterization, of a newly designed urine-collecting system containing an antibacterial device which slowly releases silver ions onto the inner surface of the system.

PATIENTS AND METHODS

The study comprised a prospective controlled randomized trial; 213 patients fulfilled the inclusion criteria. They were randomized to a urine drainage system (comprising a Unometer 400 metering system or PP 2000N closed urine-bag system, both from Maersk Medical, Denmark) either with or without the antibacterial device. The efficacy was assessed as the number of UTIs and the time to infection in the 170 patients eligible for analysis.

RESULTS

There were fewer UTIs in those using the system containing the antibacterial device (19% vs 24%), but the difference was not statistically significant (P < 0.05).

CONCLUSION

The potential importance of different infection routes were highlighted, suggesting that modifications to Foley catheters and urine-collecting systems attempting to prevent UTIs should focus not only on the intraluminal pathway, but on the internal and external pathways of infection.

Production of acylated homoserine lactones by psychrotrophic members of the Enterobacteriaceae isolated from foods

Bacteria are able to communicate and gene regulation can be mediated through the production of acylated homoserine lactone (AHL) signal molecules. These signals play important roles in several pathogenic and symbiotic bacteria. The following study was undertaken to investigate whether AHLs are produced by bacteria found in food at temperatures and NaCl conditions commercially used for food preservation and storage. A minimum of 116 of 154 psychrotrophic Enterobacteriaceae strains isolated from cold-smoked salmon or vacuum-packed chilled meat produced AHLs. Analysis by thin-layer chromatography indicated that N-3-oxo-hexanoyl homoserine lactone was the major AHL of several of the strains isolated from cold-smoked salmon and meat. AHL-positive strains cultured at 5 degrees C in medium supplemented with 4% NaCl produced detectable amounts of AHL(s) at cell densities of 10(6) CFU/ml. AHLs were detected in cold-smoked salmon inoculated with strains of Enterobacteriaceae stored at 5 degrees C under an N(2) atmosphere when mean cell densities increased to 10(6) CFU/g and above. Similarly, AHLs were detected in uninoculated samples of commercially produced cold-smoked salmon when the level of indigenous Enterobacteriaceae reached 10(6) CFU/g. This level of Enterobacteriaceae is often found in lightly preserved foods, and AHL-mediated gene regulation may play a role in bacteria associated with food spoilage or food toxicity.

A chalcone synthase with an unusual substrate preference is expressed in barley leaves in response to UV light and pathogen attack

A cDNA clone was isolated by differential hybridization from a library prepared from barley leaves inoculated with the fungus Blumeria graminis f.sp. hordei (Bgh). The open reading frame of the insert (designated HvCHS2) encoded a polypeptide with 72-79% identity to chalcone synthases (CHS) and 65-68% identity to stilbene synthases. Alignments of the amino acid sequence of HvCHS2 with the consensus sequence of naringenin-CHS (EC 2.3.1.74) reveals significant differences between HvCHS2 and naringenin-CHS. HvCHS2 transcripts accumulate strongly in barley leaves in response to inoculation with Bgh, whereas only insignificant accumulation of barley naringenin-CHS (CHS1) transcripts is seen upon the inoculation. The accumulation of HvCHS2 transcripts is also elicited by UV light. To compare the activity of HvCHS2 with the activity of CHS1, the two enzymes were expressed in Escherichia coli. Both HvCHS2 and CHS1 catalyse the formation of chalcones. However, HvCHS2 and CHS1 differ in their substrate requirements. CHS1 uses cinnamoyl-CoA and 4-coumaroyl-CoA at comparable rates whereas feruloyl-CoA is a poor substrate for this enzyme. In contrast, HvCHS2 converts feruloyl-CoA and caffeoyl-CoA at the highest rate whereas cinnamoyl-CoA is a poor substrate. Thus, HvCHS2 is a novel pathogen and UV light induces homoeriodictyol/eriodictyol CHS involved in the direct production of flavonoids possessing multi-substituted B-rings.

Two separate regulatory systems participate in control of swarming motility of Serratia liquefaciens MG1

Swarming motility of Serratia liquefaciens MG1 requires the expression of two genetic loci, flhDC and swrI. Here we demonstrate that the products of the flhDC operon (the flagellar master regulator) and the swrI gene (the extracellular signal molecule N-butanoyl-L-homoserine lactone) are global regulators which control two separate regulons.

A flavonoid 7-O-methyltransferase is expressed in barley leaves in response to pathogen attack

We have shown previously that transcripts corresponding to the cDNA clone pBH72-F1, with similarities to O-methyltransferases (OMT), accumulated in barley leaves in response to attack by the pathogenic fungus Blumeria graminis (Plant Mol Biol 26 (1994) 1797). To investigate the accumulation pattern in the defence response and the organ localization of the pBH72-F1-encoded polypeptide (F1-OMT), an antiserum was raised against Escherichia coli expressed F1-OMT. The 43 kDa protein was absent in normal leaves but accumulated strongly in response to pathogen attack. The F1-OMT protein accumulated faster in barley lines inoculated with an avirulent B. graminis isolates compared to a virulent isolate. Additionally, F1-OMT related proteins were detected in developing kernels. F1-OMT was expressed as a functional enzyme in E. coli and the substrate specificity was investigated. The enzyme exhibited OMT activity towards flavonoid aglycones with the highest activity against apigenin (4',5,7-trihydroxyflavone). In contrast, caffeic acid did not serve as substrate for F1-OMT. The product of F1-OMT was analyzed by HPLC and GC-MS and found to be genkwanin (4',5-dihydroxy-7-methoxyflavone). Initial velocity data were best represented by a sequential bi-bi mechanism, and kinetic parameters of KSAM = 10.9 microM, Kapigenin = 4.6 microM and a specific activity of 0.45 mukat/g were obtained. Barley F1-OMT, apigenin 7-O-methyltransferase, is suggested to be involved in the production of a methylated flavonoid phytoalexin.

[Community psychiatric treatment and needs of admission of psychiatric patients. A controlled study 5 years after introduction of a community psychiatric center]

The utilization of the psychiatric in-patient services was evaluated in the intervention district and compared with a selected control district. The number of admissions and in-patient days were similar before admission to the community psychiatric service. As a result of the intervention the number of admissions to hospital and the length of in-patient hospital stay decreased significantly, resulting in a reduction of total number of in-patient days by 47%. The findings of other recent studies follow the same pattern. The reduction in in-patient days was significant in the group of schizophrenic patients.

A putative O-methyltransferase from barley is induced by fungal pathogens and UV light

A cDNA clone, pBH72-F1 (F1), was isolated from a cDNA library prepared from barley leaves 72 h after inoculation with Erysiphe graminis f.sp. hordei. The 1388 bp nucleotide sequence of pBH72-F1 contains an open reading frame encoding a 42.3 kDa polypeptide of 390 amino acids which shows sequence similarity to O-methyltransferases (OMTs) from different plant species; the highest identity (41%) was observed with a putative OMT expressed in roots of maize. A phylogenetic analysis shows that the barley and maize sequences are distinctly different from the ortho-diphenol-OMTs involved in lignin formation. A putative S-adenosyl-L-methionine-binding motif (KELVDDSITN) determined for a rabbit protein-carboxyl OMT is partially conserved in the encoded amino acid sequence. Genomic Southern blot hybridization shows that pBH72-F1 probably represents a single copy gene. The F1 clone corresponds to a gene transcript exhibiting a relatively late accumulation in mildew-infected barley leaves compared to other pathogen-induced transcripts, such as transcripts encoding PR proteins, a peroxidase, and transcripts homologous to a maize caffeic acid OMT. No transcript was detected in plants exhibiting papilla resistance at time points when resistance is thought to be manifested. The atypical transcript accumulation pattern for F1 was also observed after infection by other pathogens and after UV-light treatment.

[Therapeutic need of acute psychiatric patients and offered care during a 10-year period]

With reference to the great changes made in recent years within the Danish psychiatric services, we compared the demand for care of acute psychiatric patients with the care offered. Over a period of three months in 1991 we prospectively registered all 243 acute psychiatric referrals to Svendborg Hospital, with regard to age, sex, way and source of referral, diagnosis, need for care and care offered. The result was compared with similar surveys in 1980 and 1985. We found that optimal treatment was not available to approximately 20% of the acute psychiatric referrals, the care we most often were unable to offer was acute admission to the psychiatric ward of Svendborg Hospital. We also found that from 1980 to 1991 there were no changes in the number of daily referrals, in the sex ratio or the age distribution of the patients. Our ability to meet the specific needs for care changes quantitatively throughout the period. The survey concludes that we are still unable to meet the specific needs for treatment of acute psychiatric referrals. Various suggestions are made as to how to improve the services offered to acute psychiatric patients.

[In-hospital day for patients connected with the District Psychiatric Center in Svendborg. A controlled study]

As of 31.12.1990, the employment of bed-days and admissions was calculated for patients who had been connected with a district psychiatric centre for more than three years. A before-and-after comparison revealed a percentage reduction in the employment of bed-days as compared with a control group. This corresponds to the findings in other investigations. In the before-and-after analysis, various reductions are described according to the diagnostic groups. The reduction in bed-day employment consisted mainly of fewer readmissions and reduction in the group of long-term hospitalisations. A reduction also occurred in the group of patients who could characterized as least ill. In this group, a marked percentage reduction in bed-days was observed as compared with the control group and this was probably due to the good and continuous treatment after discharge offered by the district psychiatric centre. This investigation revealed that the employment of bed-days for a patient population receiving district psychiatric treatment after discharge can be reduced. Nevertheless, the most severely ill patients will still require periodic admission to hospital. The value of treatment after discharge of the "Svendborg Model" type does not provide scientifically valid arguments that hospital admission can be avoided where the most severely ill patients are concerned.

Long-term results of bladder neck incision in men

A retrospective cohort of 163 male patients having either uni- (UI) or bilateral incision (BI) of the bladder neck to relieve infravesical obstruction was reviewed. Short-term results were excellent with significant improvement of flow rates. 82% (UI) and 87% (BI) of the incised patients were satisfied. Long-term results were assessed by a life-table analysis. 17% (UI) and 12% (BI) of the patients needed a reoperation during the observation period of 6 years. It is concluded that bladder neck incision is a method with few complications and favourable long-term results.

Gastrointestinal permeability to polyethylene glycol: an evaluation of urinary recovery of an oral load of polyethylene glycol as a parameter of intestinal permeability in man

The permeability of the gastrointestinal tract was investigated by means of polyethylene glycol (PEG), given orally. The PEG solutions contained oligomers with molecular weights from 414 to 1206. The urinary recovery of ingested PEG was determined by high performance liquid chromatography (HPLC). Considerable inter- and intra-individual variations in recovery were found in a reference group of 33 healthy subjects. Intake of food did not change the recovery of PEG, 6.11% (SEM 0.52, n = 13) compared with that for the reference group, 6.45% (SEM 0.39, n = 33). The PEG recovery in a group of ileostomy patients was 5.86% (SEM 0.62, n = 13). No correlation was found between PEG recovery and small bowel transit time. The lipophillic properties of PEG were determined by measuring the partition coefficients in 1-octanol/water and in methylhexanoate/water systems. From these results, correlated with the values for the hydrodynamic volumes of PEG, it was concluded that the intestinal permeation of PEG observed was probably determined by the hydrophillic/hydrophobic properties of the mucosal membrane, rather than by the presence of intercellular junctions or paracellular pores. The PEG molecules with molecular weights from 414 to 1206 were, therefore, not suitable as solitary probes for permeability studies in man.

Treatment of hydrocele testis by injection of tetracycline

In a prospective study 27 hydroceles were treated with single aspiration and injection of 500 mg tetracycline. The median observation period was 6 months (range 3-15 months). One month after therapy 9 recurrences were observed; but 5 disappeared spontaneously during the next 2 months, giving an overall success rate of 85% (95% confidence limits 66-96%). No serious complications occurred. Dilution of tetracycline in lidocaine prevented acute scrotal pain. Sclerotherapy with tetracycline is efficient, easy and inexpensive and, therefore, economical and beneficial for the patient.

Assessment of tibial stiffness by vibration testing in situ--III. Sensitivity of different modes and interpretation of vibration measurements

Post mortem vibration measurements on one human tibia during gradual transection reveal the vibration modes and frequencies of a tibia during a simulated healing. The modes are identified in a tibia in an above knee amputation specimen with the leg in two positions: hanging down with the knee flexed (90 degrees) and supported in a special designed bone clamping splint (knee flexed 45 degrees). The vibration measurements are analysed using Modal Analysis and are translated to mechanical stiffness by mathematical modelling. The single bending 'free-free' mode turned out to be more sensitive to weakening of one cross-section than the 'rigid body' and single bending 'hinged-spring' modes. The error on the assessed value of the stiffness is a multiple of the error on the measured frequencies. This multiplication factor decreases for more sensitive modes. In this experiment, the results are accurate enough to reflect the asymmetric weakening imposed upon the tibia. Attempts are made towards automatization of the measurement and analysis in order to get a system for clinical use. The actual system is still too cumbersome and time consuming for standard clinical use.

Determination of 99mTc-DTPA clearance by a single plasma sample method

To derive a formula for determination of 99mTc-DTPA clearance (Cl) from the radioactivity in a single plasma sample, the relation Cl = ECV/t was used, where ECV is the extracellular volume and t is the mean transit time of the tracer in the organism. By studying 99mTc-DTPA time activity curves of 45 consecutive patients we found that ECV could be estimated from the body surface area, and that t could be calculated from the radioactivity in a single plasma sample. Cl calculated by the single sample method was almost identical to Cl calculated by a standard multiple sample method (r = 0.987). It is concluded that the single sample method is accurate and that it may prove useful as a routine method provided that the method is not used in patients with 99mTc-DTPA clearance less than 30 ml min-1, since this investigation includes only patients with Cl greater than 30 ml min-1; the method is not used for children, since the test material did not contain any children; the method is only used for plasma samples drawn at 180 less than or equal to t less than or equal to 300 min.

Acute and long-term nephrotoxicity of cis-platinum in man

To detect whether the nephrotoxicity of cis-diamminedichloroplatinum (DDP) is acute and can be demonstrated at an early stage in man, a method for estimating the function of the kidneys during intensive hydration was devised. The method includes a calculation of the clearance of 125I-orthoiodohippurate and an estimation of the glomerular filtration rate (GFR) from fast changes of the extracellular volume (ECV) and the mean transit time of 99mTc-DTPA in this volume. We examined nine patients with testicular cancer on 2 consecutive days for acute nephrotoxicity while they were undergoing treatment with cis-platinum. Placebo was given on day 1, cis-platinum on day 2. On both days the patients were hydrated with 4 l saline, glucose, and mannitol (0.51) over a period of 4 h, which resulted in an increase of 125I-orthoiodohippurate clearance on both days (P less than 0.01). The increase was, however, lower on the day of treatment with cis-platinum than on the day with placebo (P less than 0.05). There were no acute changes in the GFR. This indicates that treatment with DDP inhibits the active transport of 125I-orthoiodohippurate in the tubules; that is to say there is an acute effect on the kidney function. There were no acute changes in the GFR, but in the long-term followup study we found that the GFR had decreased significantly (P less than 0.05) after 2 months of treatment. During the first year after the initiation of treatment the GFR changes were found to progress. A significant increase in se-creatinine was not observed until 6 months after the initiation of treatment (P less than 0.05). The degree of chronic nephrotoxicity did not correlate in individual patients with the acute changes in kidney function.

Assessment of tibial stiffness by vibration testing in situ--II. Influence of soft tissues, joints and fibula

The influence of soft tissues and joints on the vibration of the human tibia was examined by modal analysis on amputated lower limbs, where the soft tissues and the fibula were dissected gradually. Measurements were made in two different set ups, IFR and BRA, which were both designed to monitor fracture healing. In IFR, vibrations are generated by hammer impact on a relaxed hanging lower leg, with the knee flexed. Resonant frequencies are determined by a computer Fourier transform procedure. In BRA, a steady state vibration is induced in a lower leg, supported near the ankle and the tibial tuberosity, using an electromagnetic shaker. Resonant frequencies are determined from the maxima in vibration amplitudes. In both set ups the soft tissues have a similar influence on the vibration of the tibia: the skin hardly influences the determined modal parameter. The mass of the muscles influences both the resonant frequency and the damping. The fibula has a stiffening effect on the tibia. The influence of the joints is small in the IFR-set up: the tibia vibrates in conditions close to those for the free-free vibration. In the BRA-set up, the supports determine the boundary conditions.

Assessment of tibial stiffness by vibration testing in situ--I. Identification of mode shapes in different supporting conditions

Vibrational methods to monitor fracture healing, the BRA and the IFR, are compared under different supporting conditions, excitation technique and signal processing. Mode shapes are identified by modal analysis. A wet excised human tibia and an amputation specimen are investigated. Excitation technique and signal processing caused only minor differences in the resonance frequencies. The supporting conditions had an important influence on the single bending modes changing both mode-shapes and frequencies. Thus the BRA-splint imposed a node at the malleolus. Modal analysis revealed the following modes in the two supporting conditions: BRA-splint: A 'rigid body' mode of 165 Hz in the sagittal plane. A single bending mode of 315 Hz close to the sagittal plane. IFR-hanging leg: A 'rigid-body' mode of 167 Hz close to the sagittal plane. Two single bending modes ('free-free'), a mode of 303 Hz close to the frontal plane and a mode of 470 Hz in the sagittal plane.

CdTe-detector registration of 99mTc-DTPA clearance. An assessment of kidney function without blood sampling

Since the most essential function of the kidneys is to regulate the composition and volume of the extracellular fluids the ratio of the extracellular volume (ECV) to the glomerular filtration rate (GFR) seems to be a relevant index of kidney function. This ratio is equal to the mean transit time (t) of an injected ECV-distributed tracer that is exclusively eliminated from the body by glomerular filtration. In 26 patients t was estimated by means of standard methods after an intravenous injection of 99mTc-DTPA and was found to be correlated (r = 0.98) to the reciprocal final slope of the time-activity curve obtained by means of small CdTe-detectors pasted laterally on the crus, 10-12 cm below the knee joint. It is concluded that this external measurement of kidney function, without blood sampling, may shorten the usual procedure from 4 to 1 h. Furthermore, due to the constant detection geometry throughout the investigation it may provide the means for prolonged continuous monitoring of the kidney function at steady state and when rapid changes are expected.

Satellite-borne limb scanning UV spectrometer for thermospheric remote sensing

A concave grating Wadsworth spectrometer designed to scan the UV limb of the earth was flown on a Defense Department meteorological satellite to obtain measurements of atmospheric emissions in the 85-395-nm wavelength range as a function of height above the solid earth. The instrument field of view was 0.14 x 3.8 degrees corresponding to 6 km in the vertical and 230 km in the horizontal at the limb. The scanning motion was controlled by a momentum compensated dc-torque motor mechanism that panned the line of sight across the limb corresponding to tangent altitudes of 80-480 km. A set of three photon counting detectors, each viewing a separate exit slit, provided simultaneous coverage of the wavelength bands of 85-120 nm (EUV), 110-163 nm (far UV), and 290-395 nm (UV) at a wavelength resolution of 0.4, 0.8, and 1.2 nm, respectively. A separate photometric channel isolated the atmospheric sodium doublet at 589.0-589.6 nm. The grating position and instrument view angle were controlled by digital circuitry operating on hardwired and uplinked command instructions. The operating modes included a variety of scanning and fixed wavelength and view angle operations. A description of the instrument and several examples of the data are presented. These include the dayglow emissions from thermospheric oxygen and nitrogen that form the basis of a thermospheric density determination, auroral enhancements observed in these emissions and in hydrogen Ly-alpha, and nighttime sodium emissions.

Ultraviolet downconverting phosphor for use with silicon CCD imagers

The properties and application of a UV downconverting phosphor (coronene) to silicon charge coupled devices are discussed. Measurements of the absorption spectrum have been extended to below 1000 A, and preliminary results indicate the existence of useful response to at least 584 A. The average conversion efficiency of coronene was measured to be ~20% at 2537 A. Imagery at 3650 A using a backside illuminated 800 x 800 CCD coated with coronene is presented.

Experimental nonsuture colonic anastomoses

A comparative study of sutured colonic anastomoses and anastomoses made by isobutylcyanoacrylate was performed in 60 rats. No difference in the strength of the anastomoses, as expressed by the bursting pressure, was found, and there was no difference in the frequency of adhesions or stenoses, provided the cyanoacrylate was meticulously covered by omentum. Histologic evidence of delayed healing was observed in the cyanoacrylate group; however, this did not seem to reduce the strength of the anastomosis. Provided it is covered with an omental tag, isobutylcyanoacrylate may prove to be a valuable adjunct to conventional suture techniques under special circumstances.

25-Hydroxycholecaliferol and fractures of the proximal

Plasma 25-hydroxycholecalciferol (25-H.C.C.) has been measured in 67 consective cases of fracture of the proximal femur. The values found in these patients were not different from values found in these patients were not different from those in control groups at the same time of the year. Plasma 25-H.C.C. was not correlated to plasma calcium or phosphorus, the Ca times P product, or the alkaline phosphatase. X-rays showed Looser zones in only 1 patient, in whom the lowest plasma 25-H.C.C. was found. Osteomalacia is not uncommon among elderly people in Denmark, but it is more likely to depend on a decline in the renal efficiency to convert 25-H.C.C. to 1,25-dihydroxycholecalciferol than a low dietary intake of vitamin D.