Combining spore germination and heat inactivation to decontaminate materials contaminated with Bacillus anthracis spores.

AIMS: To add a spore germination step in order to reduce decontamination temperature and time requirements compared to the current hot, humid air decontamination parameters, which are 75-80°C, ≥72 h, 70-90% RH, down to ≤60°C and ≤24 h total decontamination time. METHODS AND RESULTS: Bacillus anthracis spore germination with l-alanine+inosine+calcium dipicolinate (CaDPA) was quantified at 0-40°C, several time points and spore concentrations of 5-9 log10 per ml. Germination efficiency at 0-40°C was >99% at <8 log10 spores per ml. The temperature optimum was 20°C. Germination efficiency was significantly higher but slower at 0°C compared to ≥30°C at ≥8 log10 spores per ml. A single germinant application followed by 60°C, 1-h treatment consistently inactivated >2 log10 (>99%) of spores. However, a repeat application of germinant was needed to achieve the objective of ≥6 log10 spore inactivation out of a 7 log10 challenge (≥99·9999%) for ≤24 h total decontamination time for nylon and aircraft performance coating. CONCLUSIONS: l-alanine+inosine+CaDPA stimulated germination across wide temperature and spore concentration ranges. SIGNIFICANCE AND IMPACT OF THE STUDY: Germination expands the scope of spore decontamination to include materials from any industry sector that can be sprayed with an aqueous germinant solution.

Communications: The structure of Rh(8) (+) in the gas phase.

The geometric structure of the Rh(8) (+) cation is investigated using a combination of far-infrared multiple photon dissociation spectroscopy and density functional theory (DFT) calculations. The energetic ordering of the different structural motifs is found to depend sensitively on the choice of pure or hybrid exchange functionals. Comparison of experimental and calculated spectra suggests the cluster to have a close-packed, bicapped octahedral structure, in contrast to recent predictions of a cubic structure for the neutral cluster. Our findings demonstrate the importance of including some exact exchange contributions in the DFT calculations, via hybrid functionals, when applied to rhodium clusters, and cast doubt on the application of pure functionals for late transition metal clusters in general.

Probing the structures of gas-phase rhodium cluster cations by far-infrared spectroscopy.

The geometric structures of small cationic rhodium clusters Rh(n)(+) (n = 6-12) are investigated by comparison of experimental far-infrared multiple photon dissociation spectra with spectra calculated using density functional theory. The clusters are found to favor structures based on octahedral and tetrahedral motifs for most of the sizes considered, in contrast to previous theoretical predictions that rhodium clusters should favor cubic motifs. Our findings highlight the need for further development of theoretical and computational methods to treat these high-spin transition metal clusters.

Synthesis and release of Hageman factor (Factor XII) by the isolated perfused rat liver.

The site of synthesis of Hageman factor (HF, Factor XII) has not been previously demonstrated with certainty. We have studied the production and release of HF in the isolated perfused rat liver and have compared rates of synthesis in this system with absolute rates of degradation measured in vivo. Rat livers, perfused for 5 h with a recycling fluid consisting of a perfluorochemical emulsion (Fluosol 43), were used to demonstrate a cumulative increase of HF in the perfusate as measured by a specific and sensitive radioimmunoassay. The rate of increase in the perfusate pool of HF during the final 4 h of perfusion yielded a mean synthetic rate of 3.5 micrograms/h per 100 g body wt, which was approximately 0.2% of the synthetic rate of albumin in the same system. The cumulative appearance of albumin and transferrin was linear after 1 h and calculated rates of synthesis were 2,012 micrograms/h per 100 g and 263 micrograms/h per 100 g body wt, respectively. De novo synthesis of HF was confirmed by demonstrating incorporation of [14C]lysine into specific immunoprecipitates of HF, and by the observations that both specific incorporation of labeled amino acid and net release of immunoassayable HF were inhibited by the administration of cycloheximide. Finally, it was evident that the rates of synthesis observed in the isolated perfused liver agreed closely with absolute rates of degradation of HF measured in vivo with 125I-rat HF (4.0 micrograms/h per 100 g). From these data we conclude that the liver is the principal site of synthesis of HF.

Cushing's disease with 'normal suppression' due to decreased dexamethasone clearance.

Suppression of urinary corticosteroids during low-dose dexamethasone testing (0.5 mg every six hours eight times) has commonly been recognized as a response that excludes the diagnosis of Cushing's syndrome. Although "normal suppression" has been reported previously in Cushing's disease, rarely has an explanation been provided for this aberrant response. We report a case of proven Cushing's disease in which normal suppression was observed with low-dose dexamethasone testing. Further study suggested that this phenomenon, which is not widely recognized, was related to an abnormally decreased clearance of dexamethasone. We therefore suggest that whenever responses to testing appear discordant with the clinical index of suspicion, simultaneous plasma dexamethasone and cortisol levels should be obtained to exclude abnormalities in dexamethasone clearance.

Metabolic clearance and plasma half disappearance time of exogenous gonadotropin releasing hormone in normal subjects and in patients with liver disease and chronic renal failure.

The metabolic clearance rate (MCR) and half disappearance time (t 1/2) of gonadotropin releasing hormone (GnRH) has been measured during and after cessation of constant infusion of exogenous GnRH. Studies were performed on normal subjects and patients with severe renal and liver disease. GnRH was quantified by a sensitive and specific radioimmunoassay which does not measure GnRH fragments. The MCR of GnRH in normal subjects was 1640+/-59.7 ml/min (23.7+/-1.8 ml/min/kg), similar to values found in 4 patients with liver disease. However in chronic renal failure an MCR of only 631+/-62 ml/min (9.1+/-0.7 ml/min/kg) was obtained. The t1/2 of GnRH after infusion was linear for 8-10 min, after which a much slower component was observed. The t1/2 of the first component ranged from 5.5 to 8 min in normal subjects, 6.5-8 min in patients with liver disease but prolonged (12-16.5 min) in patients with renal failure. It would appear that GnRH is cleared rapidly in normal subjects, that moderate liver dysfunction does not alter this, but that impaired renal function significantly prolongs the t1/2 and lowers the MCR. The kidney might be an important catabolic organ for infused GnRH; alternatively, uremia might impair catabolism non-specifically.

Effects of isothiocyanate alkyl chain-length on hamster liver cytochrome P-450 activity.

The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is metabolized by various isozymes of cytochrome P-450 present in microsomes. In this study, we examined the effects of the isothiocyanate homologues, phenyl isothiocyanate (PITC), benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC) and phenylpropyl isothiocyanate (PPITC) on the mutagenicity and in vitro metabolism of NNK by Syrian golden hamster liver microsomes and on the in vitro microsomal metabolism of testosterone. Each isothiocyanate compound inhibited N-oxidation and alpha-hydroxylation reactions of NNK that, except for PITC, correlated with an inhibition of microsomal-mediated mutagenicity of NNK in Salmonella typhimurium TA1535. Each isothiocyanate also inhibited cytochrome P-450-mediated hydroxylation reactions of the metabolism of testosterone. In general, the inhibitory potency of the isothiocyanates corresponded with the length of the alkyl chain of the compound. Our data support the ability of isothiocyanates to inhibit the activity of a number of isozymes of cytochrome P-450.

Effects of capsaicin on liver microsomal metabolism of the tobacco-specific nitrosamine NNK.

Chemically-induced mutagenesis and carcinogenesis is modulated by various plant products, some of which are present in the human diet. 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent carcinogen in tobacco and tobacco smoke, is activated by microsomal enzymes. In this study, we investigated the effects of capsaicin on the in vitro metabolism of NNK. Capsaicin is the principal component of Capsicum fruits used widely by humans as a food additive. Liver microsomes from saline-injected, phenobarbital-induced and beta-naphthoflavone-induced hamsters were used. Microsomes from phenobarbital and beta-naphthoflavone-induced animals expressed decreased NNK reduction and enhanced pyridine-N-oxidation, but did not significantly alter alpha-carbon hydroxylation of NNK. Capsaicin (0.5 mM) inhibited the formation of all metabolites of NNK by all microsomal fractions and inhibited alpha-hydroxylation by phenobarbital-induced microsomes more than by either of the other two treatments. Our results suggest that capsaicin, as a naturally occurring dietary constituent, possesses antimutagenic and anticarcinogenic properties through the inhibition of xenobiotic metabolizing enzymes.

Energy expenditure associated with CPAP and T-piece spontaneous ventilatory trials. Changes following prolonged mechanical ventilation.

The use of portable metabolic carts to assess energy expenditure (EE) by measuring oxygen consumption (VO2) and carbon dioxide production (VCO2) has recently been applied to patients undergoing weaning from mechanical ventilation. The VO2 and EE can be used to estimate changes in the work of breathing (WOB) associated with different weaning strategies. The purpose of this study was to use VO2 and EE to assess changes in the WOB when assisted mechanical ventilation (AMV) was replaced with two spontaneous ventilatory trial (SVT) techniques: continuous positive airway pressure (CPAP) and T-piece. Nine difficult-to-wean patients were studied during the initial weaning period following 26 +/- 18 days (mean +/- SD) of mechanical ventilatory support. The VO2 and EE during all AMV were 296 +/- 75 ml/min and 2069 +/- 519 kcal/day, respectively. Compared to the baseline AMV levels, during CPAP overall VO2 and EE increased 14 percent and 13 percent, respectively, and during T-piece overall VO2 and EE increased 20 percent and 19 percent, respectively. Respiration rate (f) increased and tidal volume (VT) decreased during both SVTs compared to AMV although no significant change in minute ventilation was seen. The WOB, as judged from changes in VO2, was only 5 percent higher during T-piece compared to CPAP; however, patients tolerated an average of only 141 +/- 45 min on T-piece vs 165 +/- 29 minutes on CPAP. We conclude that during the initial weaning stages in patients who have received prolonged mechanical ventilatory support, the WOB associated with SVTs is increased compared to AMV but that the WOB associated with T-piece is not significantly greater than that for CPAP.

Virilization with diffuse involvement of ovarian androgen secreting cells.

A case is reported in which virilization of long duration and gradual progression was found in association with ovarian hyperthecosis and bilateral hilar cell lesions. The frequency occurrence of both masculinizing and nonmasculinizing ovarian tumors in association with ovarian hyperthecosis and polycystic ovaries is discussed.

The impact of regionalization on a surgery program in the Canadian health care system.

OBJECTIVE: To examine the impact of the regionalization of health care on the provision of surgical services in the Capital Health Region (Edmonton) of the province of Alberta. DESIGN: A 4-year retrospective descriptive analysis using data from the Canadian Institute for Health Information and from the Capital Health Region data banks. SETTING: To control health care costs, the provincially funded health care system in Alberta reformed its governance structure and service provision model. We studied community hospitals and an academic health sciences center. PATIENTS: All patients undergoing surgical care in the region. INTERVENTIONS: Regionalization of the organizational structure with the elimination of hospital boards, consolidation of services on specific sites within the regional system, and a major reduction in funding. OUTCOME MEASURES: Inpatient and day surgery procedure volumes, average length of hospital stay, relative value units, bed use, and mortality. RESULTS: The Capital Health Region has a population of 723,000 people, with 5 acute care institutions. Eighteen clinical programs now provide care through 2 referral hospitals and 3 community health centers. The reduction in operating dollars for this region was $167.1 million from fiscal years 1992-1993 to 1996-1997. Redistribution of surgical services occurred on July 1, 1995, resulting in an 18% inpatient bed reduction. Regionally, the number of acute care beds has declined from 2.25 to 1.47 per 1000 population (P < .001). Bed use has fallen from 637 to 442 inpatient days per 1000 population (P < .001). The surgery volume (1995-1996) was 44770 procedures (-3.1%). Redistribution of surgical services into high- and low-acuity settings has resulted in most surgeons working on 2 sites. Overall average length of hospital stay has decreased significantly (P < .001); however, it has increased, together with the average relative value units, in the institutions caring for patients with high-acuity surgical illnesses. Mortality remains unchanged. CONCLUSIONS: Regionalization and funding reductions within the surgical program in the Capital Health Region have resulted in a small reduction in surgical volumes. There have been major changes in service provision and the way surgeons practice.

Pulmonary resection for lung trauma.

BACKGROUND: Pulmonary resection is rarely required for trauma, and its mortality is reportedly high. METHODS: A 10-year retrospective review of pulmonary resections for trauma was done. RESULTS: Of 2,455 patients with chest trauma, 183 (7.4%) underwent thoracotomy and 32 (1.3%) required pulmonary resection. Mean age was 28.4 years and mean injury severity score was 24.5. Mechanism of injury was stab wound in 14 patients, gunshot wound in 6, and blunt trauma in 12. Blunt trauma patients had a higher injury severity score (29.6) than penetrating trauma patients (21.4), but this was not significant (p < 0.07). Indications for thoracotomy were hemorrhage in 24 patients, airway disruption in 4, and other indications in 4. Operations consisted of wedge resection (19 patients), lobectomy (9), and pneumonectomy (4). Four (12.5%) patients (pneumonectomy, 2; lobectomy, 1; wedge, 1) died. Mortality for pneumonectomy was 50%, but this was not significantly higher than for lesser resections. Blunt trauma had a higher mortality (33%) than penetrating trauma (0%) (p < 0.02). Nonsurvivors had higher injury severity scores (44.2) than survivors (21.6) (p < 0.001). CONCLUSIONS: Pulmonary resection is infrequently required for lung injury. Overall mortality is lower than previously reported, but pneumonectomy has a high mortality. Blunt trauma has a higher mortality than penetrating trauma. Injury severity scores are higher for nonsurvivors than survivors; this shows the importance of associated injuries on outcome.

Effects of isothiocyanates on the metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene by hamster and rat liver microsomes.

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC) strongly inhibited the N-pyridine oxidation and alpha-carbon hydroxylation pathways of the in vitro metabolism of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by Syrian golden hamster liver microsomes from saline-injected (noninduced) animals. PEITC was more potent than BITC. NNK-reduction was enhanced by both isothiocyanates. Both N-oxidation and alpha-hydroxylation activities were several-fold greater in hamster liver microsomes compared with F344 rat liver microsomes. Consequently, the inhibitory effect of BITC and PEITC on rat liver microsomes (noninduced) was not as pronounced. NNK-reduction in rat liver microsomes was not significantly different from hamster and was not enhanced by BITC and PEITC. Neither BITC nor PEITC had a strong inhibitory effect on the in vitro metabolism of benzo[a]pyrene (BaP) by either hamster or F344 rat liver microsomes from beta-naphthoflavone treated animals. The extent of BaP metabolism was similar for the two microsome groups. Since the metabolism of NNK and BaP depends upon cytochrome P450-mediated reactions that may utilize different isozymes of cytochrome P450, our data suggest that BITC and PEITC may inhibit the activity of some isozymes and not others. Our results also indicate that the inhibition of the metabolism of NNK by isothiocyanates as previously described for the mouse and rat can now be extended to include the hamster as well.

Effects of isothiocyanates on cytochrome P-450 1A1 and 1A2 activity and on the mutagenicity of heterocyclic amines.

In this study we investigated the effects of phenyl isothiocyanate (PITC), benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC) and phenylpropyl isothiocyanate (PPITC) on the mutagenicity of five heterocyclic amines, IQ, MeiQx, Trp-P-2, Glu-P-2 and PhIP in Salmonella typhimurium strain TA 98 in the presence of liver microsomes from male Syrian golden hamsters. In addition, the effects of these isothiocyanates on cytochrome P-450 1A1 and cytochrome P-450 1A2 activities were determined by measuring the deethylation and the demethylation of ethoxyresorufin (EROD) and methoxyresorufin (MROD) respectively. With the exception of Trp-P-2, all four isothiocyanates significantly inhibited HCA-induced mutagenesis in TA 98 at concentrations of 0.05 and 0.1 mumoles/plate. BITC was the only isothiocyanate tested that showed a dose-dependent inhibition of Trp-P-2-induced mutagenesis. These four isothiocyanates showed a dose-dependent inhibition of EROD activity and, with the exception, of BITC, of MROD activity also. This indicates that the inhibition of HCA-induced mutagenesis correlates with the inhibition of cytochrome P-450 1A1 and 1A2. These P450s are known to metabolically activate HCAs. The inhibitory effects of the isothiocyanates were greater toward HCA-induced mutagenesis in TA 98 than toward EROD and MROD activity. This indicates that the antimutagenic effects of PITC, BITC, PEITC and PPITC on HCA-induced mutagenesis in Salmonella typhimurium TA 98 involves more than the inhibition of cytochrome P-450 1A1 and 1A2 activity in hamster liver microsomes.

Inhibition of liver microsomal cytochrome P450 activity and metabolism of the tobacco-specific nitrosamine NNK by capsaicin and ellagic acid.

The tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3- pyridyl)-1-butanone (NNK), present in tobacco and tobacco smoke, is metabolically activated by microsomal enzymes. In this study, we examined the effect of capsaicin and ellagic acid on the in vitro metabolism of NNK by hamster and rat liver microsomes. Capsaicin is the principal component of Capsicum fruits used widely throughout the world as a food additive. Ellagic acid, with reported anticarcinogenic properties, is found in various soft fruits and nuts. Both capsaicin and ellagic acid inhibited the major pathways of NNK-reduction, N-pyridine oxidation and a-hydroxylation by hamster liver microsomes. Capsaicin inhibited NNK-reduction and a-hydroxylation and ellagic acid inhibited N-oxidation and a-hydroxylation by rat liver microsomes. The effects of capsaicin and ellagic acid on isozymes of cytochrome P450 were observed in the hydroxylation reactions of the metabolism of the steroid hormone testosterone. Results of these experiments indicated that both capsaicin and ellagic acid strongly inhibited the constitutive enzymes CYP 2A2, 3A1, 2C11, 2B1, 2B2 and 2C6. This study suggests that capsaicin and ellagic acid, as naturally occurring dietary constituents, possess antimutagenic and anticarcinogenic properties through the inhibition of xenobiotic metabolizing enzymes.

Comparison of balanol from Verticillium balanoides and ophiocordin from Cordyceps ophioglossoides.

Recently, we reported the isolation of the potent protein kinase C inhibitor balanol (1) from the fungus Verticillium balanoides. In an earlier study, König et al. reported the isolation of ophiocordin (3), a structural isomer of 1, from the fungus Cordyceps ophioglossoides. The present study was designed to clarify whether or not balanol and ophiocordin are different compounds. The results indicated that the two fungi produced the same compound, the structure being that assigned to balanol. In addition, a thirty-fold increase in the production of balanol from V. balanoides was observed when the culture medium was changed from cornmeal/tomato paste to soy meal/glycerol.

A cluster of patients with inferior rectus restriction following local anesthesia for cataract surgery.

During a 5-month period, four patients developed contracture of the inferior rectus muscle following local anesthesia for cataract surgery in the practice of one ophthalmologist. Two anesthesiologists administered retrobulbar anesthesia. All patients had persistent vertical diplopia caused by a large hypotropia of the operated eye. Forced duction testing revealed marked restriction to elevation of the eye. In two patients, MRI demonstrated segmental thickening of the inferior rectus muscle, just posterior to the globe. All patients had normal thyroid function tests. No patient had a previous history of strabismus. Three of the four have had strabismus surgery consisting of recession of the markedly restricted inferior rectus muscle on an adjustable suture. These three patients have regained fusion and are now asymptomatic.