Batch suspension culture.

Batch culture involves the inoculation of a known volume or mass of cells into a volume of (normally) defined medium. Growth is allowed to proceed, and the resulting biomass is harvested at some stage during the growth cycle. Throughout the growth period, no additions are made to the media, with the exception of acid and alkali, if needed, for pH control. The scale of operation depends on the requirements.

Production systems.

This chapter ties together ideas introduced in previous articles of this volume in the search for ways to use plant cell cultures as industrial production systems. The economics of a process must always be carefully considered when examining the suitability of plant cell culture for the manufacture of target compounds. The object is to produce the maximum amount of required product in as short a time as possible, using the most cost-effective method. New processes can then be compared with existing systems, and their feasibility assessed. This also requires a knowledge of the market valueof the product under consideration, the projected stability (or growth) of themarket, and the potential market share that your product could hope to attain.

[3H] diazepam binding to human granulocytes.

[3H]-diazepam binds to sites on human granulocyte membranes, with little or no binding to platelets or lymphocytes. These [3H]-diazepam binding sites are of the peripheral type, being strongly inhibited by R05-4864 (Ki = 6.23nM) but only weakly by clonazepam (Ki = 14 microM). Binding of [3H] diazepam at 0 degree is saturable, specific and stereoselective. Scatchard analysis indicates a single class of sites with Bmax of 109 +/- 17f moles per mg of protein and KD of 3.07 +/- 0.53nM. Hill plots of saturation experiments gave straight lines with a mean Hill coefficient of 1.03 +/- 0.014. Binding is time dependent and reversible and it varies linearly with granulocyte protein concentration over the range 0.025-0.300 mg of protein.

Platelet alpha-adrenergic receptor activity and pizotifen in migrainous children.

Adrenoceptors have been measured in the platelets from migrainous children, using (3H) yohimbine. Maximum binding (Bmax) was not significantly different in migrainous children and controls, 259 +/- 21 and 265 +/- 19 f moles per mg of protein respectively. Dissociation constants (KD) were significantly higher in the migraine group than in the controls 2.62 +/- 0.18 and 2.17 +/- 0.07 respectively (p less than 0.02). Bmax values were lower in 6 out of 9 cases following treatment with pizotifen. In 8 out of 9 cases KD values were lower following pizotifen treatment; in one case there was no change.

Monoamine metabolism during chronic benzodiazepine treatment and withdrawal.

Long-term normal-dose benzodiazepine treatment in seven patients was associated with reduced urinary excretion of MOPEG (4-hydroxy-3-methoxy-phenylglycol). Following the discontinuation of the drugs a characteristic withdrawal reaction occurred, with an increase towards normal values of the MOPEG excretion levels and changes in the excretion of 5-HIAA (5-hydroxyindoleacetic acid). No significant changes in the 24-hr urinary excretion of free cortisol or HMMA (3-methoxy-hydroxy-mandelic acid) were detected.

Monoamine oxidase (MAO) of platelets, plasma, lymphocytes and granulocytes in schizophrenia.

Monoamine oxidase (MAO) levels in plasma, platelets, lymphocytes and granulocytes have been compared in schizophrenics and controls using three substrates. No significant difference was found between MAO levels in controls and the schizophrenic group as a whole, but platelets and lymphocytes of the latter (tyramine or benzylamine substrate) showed greater variation and in some cases higher values than controls, irrespective of treatment. Schizophrenics who experienced auditory hallucinations had significantly lower MAO levels in lymphocytes and platelets than those who did not.

Properties of monoamine oxidase (MAO) in human blood platelets, plasma, lymphocytes and granulocytes.

The properties of monoamine oxidase in plasma, platelets, lymphocytes and granulocytes have been studied using cells prepared from a single small (about 20 ml) sample of blood. The three substrates, 5-hydroxytryptamine, tyramine and benzylamine, have been used to obtain a more complete picture of blood monoamine oxidase than was previously possible. Measurement of Michaelis constants, use of selective inhibitors, and activity against the three substrates distinguished three types of activity. The monoamine oxidases in platelets and lymphocytes are very similar, being most active with tyramine or benzylamine as substrate and inhibited by low concentrations of deprenil. The enzymes in plasma and granulocytes are similar in their relatively high activity against 5-hydroxytryptamine and in their inhibition by semicarbazide and cuprizone with tyramine or benzylamine as substrates. They differ in their affinities for 5-hydroxytryptamine and their activity against tyramine. The activity in platelets, plasma, lymphocytes and granulocytes has been measured in a group of 15 normal subjects using three substrates.

Urinary excretion of the sulphate and glucuronide of 3-methoxy-4-hydroxyphenylethyleneglycol in a manic-depressive patient.

The sulphate and glucuronide conjugates of 4-OH-3-methoxyphenylethyleneglycol (MOPEG) and 4-OH-3-methoxymandelic acid (VMA) have been serially studied in the urine of a manic-depressive patient before and after a therapeutic response to lithium carbonate. Excretion of both conjugates correlates with changes in mood. Some reasons to suggest that the sulphate might be a more useful measure of brain activity are stated.

The distribution of lithium, sodium and magnesium in rat brain and plasma after various periods of administration of lithium in the diet.

1 The tissue solubilizer Soluene-100 provides an efficient and easy means of preparing small amounts of rat tissue for cation analysis. 2 Administration of lithium ions to rats for two days to 42 days by the addition of lithium chloride to the diet at a concentration of 30 mmol/kg dry weight results in (a) the uniform distribution of lithium throughout the brain at a concentration comparable to that found in plasma; (b) decrease in the brain sodium concentration: (c) a decrease in brain magnesium concentration and an increase in plasma magnesium concentration; (d)no change in brain water content. 3 The inclusion of LiCl in the diet at a concentration of 30 mmol/kg dry food gives consistent and predictable plasma and brain levels of lithium in the rat without the occurrence of serious side effects over periods of up to 42 days.

The effect of lithium and related metal ions on the urinary excretion of 2-oxoglutarate and citrate in the rat.

1 Administration of lithium ions to rats, either acutely by intraperitoneal injection or chronically in food, causes increased excretion of 2-oxoglutarate and citrate.2 Chronic administration in food of rubidium and caesium causes decreased excretion of 2-oxoglutarate and citrate.3 The effects described are not due to changes in urine volume, nor pH, nor are they simply related to the excretion of the injected ion.4 Acute administration of lithium caused an increased level of 2-oxoglutarate in kidney and reduced the ratio of glutamate to 2-oxoglutarate.5 Renal gluconeogenesis in slices was only slightly affected by either acute administration of lithium to the animals or by its presence in the incubation medium of renal slices.

The effect of lithium salts on the urinary excretion of -oxoglutarate in man.

1. Lithium ions in therapeutic doses cause an increase in the renal excretion of alpha-oxoglutarate and glutaric acid.2. The excretion is probably due to reduced renal tubular reabsorption.3. Neither citrate, lactate nor pyruvate excretion rises.