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An environmentally benign method for the mineralization of sulfur mustard has been proposed involving chemical hydrolysis of sulfur mustard to thiodiglycol, and then the biological degradation of thiodiglycol to generate biomass and gaseous carbon dioxide. Alcaligenes xylosoxidans (SH91) was isolated based on its ability to utilize thiodiglycol as a sole carbon source. This article compares different biological reactor designs and experimentally assesses their relative effectiveness in degrading thiodiglycol using pure cultures of SH91. The reactor configurations studied are batch, continuous stirred-tank reactor (CSTR), and CSTR with cell recycle. From the results, it is clear that the CSTR with cell recycle offers superior performance for a given residence time or volume. These pure culture data are necessary for accurate design of a pilot-scale system where mixed cultures will be employed because of a possible incomplete chemical hydrolysis step.

Escherichia coli strain F-122 was used to determine if there are additional physiological effects, other than decreasing energetic efficiency accompanied by the excretion of the acetate, on foreign protein production. This organism was the host for expressing HIV582-beta-galactosidase fusion protein under the control of the trp promoter, with ampicillin resistance. By comparing parallel batch cultures with and without acetate addition, it was found that the presence of acetate in the media did not influence beta-galactosidase activity. In these experiments, it appears that the low protein productivity often observed during acetate formation is the result of inefficient cell metabolism, rather than acetate acting as a specific inhibitor of protein production.

An integrated metabolic model for the production of acetate by Escherichia coli growing on glucose under aerobic conditions was presented previously (Ko et al., 1993). The resulting model equations can be used to explain phenomena often observed with industrial fermentations, i.e., increased acetate production which follows from high glucose uptake rate, a low dissolved oxygen concentration, a high specific growth rate, or a combination of these conditions. However, several questions still need to be addressed. First, cell composition is growth rate and media dependent. Second, the macromolecular composition varied between E. coli strains. And finally, a model that represents the carbon fluxes between the Embden-Meyerhof-Parnas (EMP) and the hexose monophosphate (HMP) pathways when cells are subject to internal and/or external stresses is still not well defined. In the present work, we have made an effort to account for these effects, and the resulting model equations show good agreement for wild-type and recombinant E. coli experimental data for the acetate concentration, the onset of acetate secretion, and cell yield based on glucose. These results are useful for optimizing aerobic E. coli fermentation processes. More specifically, we have determined the EMP pathway carbon flux profiles required by the integrated metabolic model for an accurate fit of the acetic acid profile data from a wild-type E. coli strain ML308. These EMP carbon flux profiles were correlated with a dimensionless measurement of biomass and then used to predict the acetic acid profiles for E. coli strain F-122 expressing human immunodeficiency virus-(HIV(528)) beta-galactosidase fusion protein. The effect of different macromolecular compositions and growth rates between these two E. coli strains required a constant scaling factor for improved quantitative predictions.

An integrated metabolic model for the production of acetate by growing Escherichia coli on glucose under aerobic conditions is presented. The model is based on parameters which are easily determined by experiments. Forming the basis for this integrated metabolic model are the 12 principal precursor metabolites for biosynthetic pathways, the Embden-Meyerhof-Parnas pathway, the pentose phosphate cycle, the tricarboxylic acid cycle and the anapleurotic reactions, the Crabtree effect, the Pasteur effect, and the details of bacterial respiration. The result can be used to explain phenomena often observed in industrial fermentations, i.e., increased acetate production which follows from high glucose uptake rate, a low oxygen concentration, a high specific growth rate, or a combination of these conditions., ((c) 1993 John Wiley & Sons, Inc.)

A predictive, simple, structured model describing the synthesis of alpha-amylase by Bacillus amyloliquefaciens was formulated. Three key intracellular processes were identified (i.e, translation, and excretion) along with two key intracellular components (i.e., mRNA and the intracellular form of the alpha-amylase enzyme). Nearly all the model parameters were estimated by means of performing independent experiments, primarily fed-batch experiments. The model was shown to predict transient system behavior in batch and in fed-batch operation with some limitation and minor model parameter revisions. Since a principal objective was to demonstrate that independent experimental parameter determination can be used to construct the predictive model, further fine-tuning of the parameters may be necessary before application for optimization and control purposes.

In a randomized trial of 58 cancer patients receiving strongly emetogenic cytostatic drugs (cisplatin or comparable cytostatic agents, alone or in combination), the anti-emetic action of oral metoclopramide was tested, alone or combined with prednisone. Patients of group A (33 during 46 treatment cycles) received three times 50 mg metoclopramide and three times 25 mg prednisone. Those of group B (25 patients during 35 cycles) received three times 50 mg metoclopramide. The drug was given two hours before as well as two hours and six hours after administration of the cytostatic drugs. Good or satisfactory prophylaxis of nausea and vomiting (no or at most three vomits) was achieved during 37 cycles (80.5%) of group A patients and 30 (85.7%) of group B patients. Complete absence of vomiting was obtained in 52% of cycles in group A, 46% of cycles in group B; complete absence of nausea in 39% and 32%, respectively. There was no statistically significant difference between the two treatments in their preventive action. Three times 50 mg metoclopramide (with or without prednisone) four hours apart during one cytostatic-drug cycle was well tolerated by patients in both groups and can be recommended as a simple, practical prophylaxis of nausea and vomiting in the course of strongly emetogenic treatment of cancer.

The effects of recombinant plasmid size on cell growth and viability, plasmid copy number, and synthesis of plasmid-encoded protein were investigated in Escherichia coli using plasmid pUC8 and four recombinant derivatives containing inserts of Drosophila melanogaster DNA of 1.7-6.0 kb. Growth in log phase was unaffected by plasmid size, but as plasmid size increased, maximum cell density decreased and, with the largest plasmid, cell death was accelerated after the stationary phase was reached. There was also a correlation between increasing plasmid size and decreased viability at high ampicillin concentrations, resistance to which is conferred by the plasmids. These effects were shown not to be due to transcription or translation of Drosophila sequences carried on the recombinant plasmids. Cells harboring the largest plasmid, pBS5 (8.7 kb), fared poorly in competition with plasmid-free cells in mixed cultures, compared with cells harboring pUC8 (2.7 kb). In addition, pBS5 was harbored at significantly fewer copies per cell than pUC8 at all phases of growth and supported much less production of the plasmid-encoded protein, beta-lactamase, than did pUC8. The results suggest that recombinant plasmid size may be an important parameter in the optimization of large-scale production of plasmid-encoded proteins.

The time variation of changes in the chlorpromazine-induced pupil diameter decrease was studied following varying bolus and slowly infused intravenous doses administered to rabbits. The observed pharmacological response data were coverted, via, the use of a dose-effect curve, to values theoretically corresponding to relative biophasic drug levels. These values were, in turn, used to construct a linear pharmacokinetic model of the drug bioavailability input equilibrium pharmacological response output dynamics of the system. The use of a time domain, MULTIFIT, computerized method of fitting the data to obtain a pharmacokinetic model was compared to the use of a frequency response, PLTEST, approach. The fidelity of the model in quantitatively relating the time course of systemic drug bioavailability to observed pupil response was verified by the satisfactory agreement obtained by directly comparing experimentally known amounts of drug intravenously infused with corresponding values computed from observed changes in pupil size. The applicability of using pharmacological data for quantitative bioavailability and pharmacokinetic analysis of chlorpromazine is demonstrated. This finding is particularly significant because no suitable chemical or radiological direct assay technique exists for determining levels of chlorpromazine, except for high doses, in body fluids.

In a preliminary open bioequivalence investigation of orientating character (n =4) a single 100 mg dose of spironolactone (study I) led to maximum canrenone plasma levels (determined by HPLC) of 126.5 +/- 28.4 ng/ml (standard formulation 1) and 130 +/- 13.1 ng/ml (test formulation 2). The corresponding values for the sum of the fluorogenic metabolites were 418.9 +/- 43.5 ng (eq)/ml formulation 1 and 469.9 +/- 80.3 ng (eq)/ml formulation 2. A comparison of AUCs for both total fluorogenic metabolites and canrenone showed no marked differences. In a 2nd cross-over bioequivalence study with multiple dosing, mean minimum steady-state levels of 102.5 +/- 14 ng/ml (formulation 1) and 98.1 +/- 14.1 ng/ml (formulation 2) were obtained for canrenone, and 389 +/- 35.8 ng (eq)/ml (formulation 1) and 391.4 +/- 18.9 ng (eq)/ml (formulation 2) for total fluorescence. The AUCs for post-steady-state elimination, starting with the final spironolactone dose on day 10, were comparable. They were calculated to be 13226 +/-828 ng (eq)/ml . h (formulation 1) and 13858 +/- 651 ng (eq)/ml . h (formulation 2) for total fluorescence, and 3222 +/- 217 ng/ml (formulation 1) and 3167 +/- 195 ng/ml (formulation 2) for canrenone. Both spironolactone formulations can be considered as bioequivalent. The elimination half-lives (t 1/2) after a single 100 mg dose of spironolactone are (Study I) 16.4--19.1 h for canrenone and 13.6--14.0 h for the sum of the active (i.e., antagonistic to aldosterone) metabolites. Certain therapeutic conditions (e.g. multiple dosing of 100 mg spironolactone with tau = 12 h, Study II) can lead to slightly increased t 1/2 values for both canrenone (18.6--21.4 (h)) and total fluorogenic metabolites (15.8--16.9 (h)). The steady-state level for both formulations is reached by the third day of treatment.

Acute inhalation toxicity studies with diiodotetrafluoroethane in rats following an exposure of 4 h to concentrations of 6-197.5 ppm show that 16.5 ppm to 197.5 ppm impaired dose-related the animals' attitude and posture, motoricity, autonomic reactions and respiratory function. At concentrations of more than about 90 ppm death occurred as a result of cardiac and circulatory failure. On the basis of these results it could be demonstrated that the no-effect level is 6 ppm and the approximate mean lethal concentration (LC50) would be 75 ppm.

Growth and alpha-amylase production characteristics of Bacillus amyloliquefaciens strain F (ATCC 23350) in batch cultures are examined using glucose or maltose as the carbon source. While the cell growth is rapid when glucose is used as the carbon source, higher cell mass, higher total and specific enzyme activities, and higher enzyme production rates are obtained when maltose is used as the carbon source. The overall specific enzyme activity decreases with an increase in the initial concentration of carbon source. The oxygen requirement and carbon dioxide generation vary linearly with the maximum amount of cell mass produced. For experiments conducted using glucose as the carbon source, the kinetics of cell growth and glucose consumption are described using a special form of the Vavilin equation. For a given amount of initial carbon source, the enzyme synthesis capability is retained by the microorganism, although at a substantially reduced level, under severe oxygen limitation.

Rats of two different ages (72 and 490 days) were subjected to a 3-day fast and then refed for the same period a high-protein (89%) or high-carbohydrate (99%) diet. This experimental model served to study whether alterations occur in the content of the main lipid components, triacylglycerol, phospholipids and cholesterol in liver. It also examined whether the aging process itself has any effect on the lipid pattern. With the high-protein diet the content of all lipids returned to or nearly to the control level regardless of age. Refeeding the 72-day-old rats the high-carbohydrate diet led to a 2.4-fold overshoot in the triacylglycerol content, while the phospholipids and the cholesterol remained far below their control levels. In the 490-day-old rats the total lipids, phospholipids and cholesterol remained at the starvation level. With aging, the total cholesterol content showed a marked increase of about four-fold when corrected for growth.

Chlorpromazine-induced depression of rectal temperatures in rabbits kept at 20 degrees was used to determine relative biophasic drug levels corresponding to observed hypothermic response intensities, which then served to establish a triexponential linear mathematical model describing drug transference and drug action in this system. Comparisons of various experimentally known, slow intravenous infusion drug inputs of chlorpromazine with drug inputs computed by deconvolution, using the derived model and observed temperature depressions, served to verify the accuracy of the model for the 0.50-4.0 mg/kg dosage range.

The growth of Bacillus amyloliquefaciens in the aqueous two-phase system, made up of polyethylene glycol, dextran, and water, was investigated. Generally, Bacillus partitions in the dextran phase, but the magnitude of the separation depends largely on the overall composition of polymers in the phase system. The kinetics of growth of Bacillus amyloliquefaciens was studied in the polyethylene glycol-rich continuous phase, dextran-rich dispersed phase, and in the mixed phase. From the kinetic data it appears that increasing the overall polymer composition causes the cells to adsorp at the interface. On the other hand, partition measurements indicate that increasing polymer concentrations make the cell partitioning more one-sided. This anomaly is explained by studying the interfacial adsorption of cells via dynamic surface tension measurements.

A computerized fermentation system was developed for use in a research environment. Major goals in the design and construction of the system were flexibility and versatility. Direct digital control is employed for all low-level and high-level control loops. A microminicomputer hierarchical configuration is used to implement this control structure. The microcomputer is also utilized to simplify the interface with the fermentor, both at the hardware and minicomputer software levels. This computerized fermentation system provides accurate data acquisition, excellent control, and flexibility in the fermentation operation.

Cell growth and enzyme (alpha-amylase) production characteristics of Bacillus subtilis TN106 containing the recombinant plasmid pAT5 are investigated in batch and continuous cultures using a defined medium with glucose as the limiting nutrient. The batch culture studies demonstrate that the recombinant plasmid, reported earlier(1) to be stably maintained in the host, suffers from segregational and structural instabilities. The structural instability of this strain occurred during culture storage and can be eliminated in bioreactor experiments by using a modified inoculum preparation procedure. Such elimination allows an unbiased investigation of segregational instability via continuous culture studies. Such studies conducted with this fast growing microorganism, in the absence of antibiotic selection pressure, indicate a very efficient glucose utilization (very low residual glucose concentrations) over a wide range of dilution rates (0.16 h(-1) - 0.94 h(-1)). The nearly time-invariant and low residual glucose concentrations at each such dilution rate enable convenient estimation of growth parameters of the host and recombinant cells and frequency of segregational instability from transients in the resulting mixed cultures. The specific alpha-amylase activity exhibits an inverse relationship to the specific growth rate of recombinant cells. The growth of recombinant cells is not affected by the presence of antibiotic (kanamycin). The growth advantage of host cells over recombinant cells diminishes with increasing dilution rate.

127 outpatients, 78 with acute purulent sinusitis and 49 with acute tonsillitis, were treated for 7 days with a benzylpyrimidine -sulphonamide combination. In this double-blind and randomized study 59 patients received co- tetroxazine (100 mg tetroxoprim and 250 mg sulphadiazine) b.i.d., whilst the reference substance, co-trimoxazole (160 mg trimethoprim and 800 mg sulphamethoxazole) was given to the remaining 68 patients b.i.d. The test criteria were the therapeutic efficacy and both subjective and objective tolerance. An improvement in clinical symptoms and signs occurred in both conditions under each therapeutic regimen. Clinical therapeutic success was rated very good or good in 96.6% treated with co- tetroxazine and in 97.1% of patients treated with co-trimoxazole. In the former group therapy failed in 1 patient with sinusitis and in 1 with acute tonsillitis . In 98.3% of patients treated with co- tetroxazine the tolerance was very good or good, whilst the respective figure for co-trimoxazole was only 91.2%. 6 patients suffered from side effects ( gastric spasm, gastralgia , nausea, vomiting, diarrhoea) which were so severe in 2 cases that treatment had to be prematurely terminated. The generally good tolerance to both preparations was confirmed by the results of the laboratory investigations.