A study of the relationship between seed dormancy and pentose phosphate pathway activity in Avena fatua

The hypothesis that loss of seed dormancy is associated with an increased activity of the pentose phosphate pathway (PPP) relative to glycolysis and the Krebs cycle was tested. The PPP activity was monitored by measuring the C6/C1 ratio in embryos excised from incubated caryopses of two genetically pure nondormant (ND) lines and in three dormant (D) lines of Avena fatua L., the wild oat. The C6/C1 ratios of all lines were similar at the commencement of incubation. In the two ND lines the ratio increased steadily prior to and during emergence of the radicle. In the three D lines the ratio increased during the first 24 h and then remained almost constant; there was no germination. When gibberellin treatment was used to overcome dormancy in the D lines, the C6/C1 ratio increased during the first 24 h in two of the lines and continued to increase parallel to germination in a manner similar to normal germination in ND lines. In the third D line, despite loss of dormancy from gibberellin treatment, the ratio did not increase after 24 h. Loss of dormancy during dry storage of seeds of a D-type pure line was accompanied by an increase in the C6/C1 ratio, as measured in freshly imbibed seeds. This indicates a decreased activity of the PPP relative to glycolysis and the Krebs cycle. These findings are contrary to Roberts's hypothesis that loss of dormancy in wild oats is associated with a relative decrease in the C6/C1 ratio.

Relationship between plasma desipramine levels and clinical outcome for RDC major depressive inpatients

Depressed patients (N = 31), who met Research Diagnostic Criteria for major affective disorder-depressed, were severely ill and maintained drug-free for a 1-week period on inpatient status. They received a fixed dose (150 mg/day) of desipramine for a 4-week period with drug plasma level determination and clinical ratings performed at fixed time intervals throughout the study. Despite these rigid criteria for entrance and clinical outcome measures, no obvious relationship between plasma desipramine level and clinical outcome was found. The clinical implications of this finding are discussed.

Chronic phencyclidine abuse and physical assault

When the authors investigated aggressive behavior on a phencyclidine (PCP) detoxification and rehabilitation unit and compared similar types of behavior on a heroin unit, they found no differences between the two units. The urinary PCP levels of a subgroup of 75 patients admitted to the PCP unit who had PCP-positive urine were significantly higher than those of 75 patients admitted to an acute psychiatric ward because of violent behavior who also had PCP-positive urine. The authors discuss the implications of these findings and the need for more information on the relationship between PCP levels in blood and urine and behavior.

Urinary phencyclidine excretion in chronic abusers

Data on usage patterns of 100 hospitalized chronic phencyclidine abusers was collected. Weekly urine samples were monitored using a new gas chromatographic nitrogen detector analysis for PCP. Abusers were found to be, on the average, young males who had used PCP for approximately 40 months (range 12 to 96 months) and approximately 3 to 4 d/week. Except for one subject, urines became negative for PCP within 30 d after last use with a mean of 14 d. There was rapid excretion during the first 9 d followed by a more gradual reduction in urine PCP levels.

'Loads' alert

"Loads," a combination of glutethimide and codeine, are a relatively new form of drug abuse that is increasing in popularity in the Los Angeles area as a heroin-substitute. Preliminary findings based on interviews and treatment of a group of preferential Loads abusers seen over a one-year period suggest that this combination has a potential for serious intoxications and withdrawal complications. The common withdrawal symptoms include those produced by both a sedative-hypnotic and a major narcotic and necessitate a detoxification plan based on the pharmacologic rationale of the abused combination.

Management of tardive dyskinesia: current update

Tardive dyskinesia is now widely recognised as a neurological side effect produced in susceptible individuals by ingestion of neuroleptics. In general, the disorder tends to be late in onset, but has also been reported in a small number of individuals who have received neuroleptics for only brief periods. Much effort has been spent searching for predisposing factors, but the only consistent findings are that subjects are usually elderly (and elderly females in particular), in addition to having been exposed to neuroleptic agents. More recently, the increased finding of the presence of buccolingual facial movements in elderly populations never exposed to neuroleptics may bring out a re-evaluation of the role of these agents in the aetiology of tardive dyskinesia. Although much information on tardive dyskinesia has accrued in recent years, the precise definition, subtypes and pathophysiology remain unclear. With the development and availability of standardised rating scales, the clinical description of tardive dyskinesia has expanded from the initial buccolingual masticatory syndrome to include various abnormal movements of the fingers, arms, legs etc. Efforts have been made to distinguish withdrawal tardive dyskinesia from persistent tardive dyskinesia, but, irrespective of the classification, the disorder is in many instances reversible. However, it is impossible at present to predict the reversibility of each patient: therefore early detection of tardive dyskinesia remains an important clinical goal. Pharmacological treatments are based on the currently accepted hypothesis of dopamine receptor hypersensitivity. Selective dopamine blockers (D2) which suppress tardive dyskinesia without causing an increase in Parkinsonian symptoms are at various stages of development. Acetylcholine and gamma-aminobutyric acid (GABA) also appear to play a reciprocal role with dopamine as seen by moderate success using cholinergics and 'GABAergics'. However, there is no completely satisfactory treatment at present, indicating that prevention must be the primary aim. Above all, clinicians should carefully evaluate the indication for neuroleptic drugs, and avoid their use in conditions which may be treated with more benign drugs. A strategy for management of tardive dyskinesia is presented, and indications for withdrawing or continuing neuroleptics, the treatment of withdrawal dyskinesias and the role of experimental therapies are discussed.

Tardive dyskinesia and abnormal tongue movements

Forty-two subjects, 20 with and 22 without clinically diagnosed tardive dyskinesia (TD), were rated for TD on the scale of Simpson et al. They also performed a tongue protrusion test and had the presence of tongue movements within the buccal cavity observed. Fifty per cent of the severe or definite TD subjects as classified by rating scale were unable to maintain tongue protrusion for a minimum of 30 seconds, and 85 per cent of them had abnormal tongue movements. In 45 per cent of the possible TDs and in 9 per cent of the doubtful subjects, the movement test was also positive.

Prediction of steady state plasma and saliva levels of desmethylimipramine using a single dose, single time point procedure

In normal volunteer study (20 subjects) where each ingested 75 mg desmethylimipramine (DMI), blood and saliva samples were collected at 1, 2, 3, 4, 5, 7, 12, 24, and 32 h post dose. Each subject then was given DMI 25 mg b.i.d. for 15 days. Blood and saliva samples were collected on days 3, 4, 12, 13, 14, and 15. All samples were analyzed for total DMI content. Strong correlations were found between the blood samples collected 12, 24, and 32 h post dose (r = 0.93, 0.96, 0.95) and saliva samples collected 24 and 32 h post single dose (r = 0.91, 0.84) and the subjects' respective steady states. Although the correlation between blood and saliva levels was weaker (r = 0.7) because of considerable interindividual variation in the saliva/plasma DMI ratio (16-fold variation), this ratio in individual subjects was stable. These data suggest that, as has been shown for other psychotropic drugs, single blood measures at 24 h post ingestion of 75 mg DMI can be used to predict optimal dosage in individual patients. Acceptable predictions of steady state plasma levels were obtained when this technique was applied to patient data available in the literature. It is also suggested that if the saliva/plasma ratio is established for each individual patient, their drug level monitoring may be possible using this noninvasive approach.

The treatment of refractory schizophrenia: pharmacotherapy and clinical implications of blood level measurement of neuroleptics

The treatment of refractory schizophrenia requires careful definition. This is usually a statement based on clinical and/or intuitive experience. The definition can be extended and tightened if laboratory evidence is incorporated into this definition. Suggestions on how to accomplish this, e.g. measuring blood levels of antipsychotic agents, are made. Strategies for "trials of therapy' in nonresponsive patients and for decisions for changing to a new antipsychotic agent are presented. Clinical and laboratory difficulties in tackling this problem are also discussed.

Endogenous hormones in afterripening wild oat (Avena fatua) seed

Levels of gibberellins and cytokinins in dormant Avena fatua L. seeds were measured by bioassay during the afterripening process. Little change in the level of either hormone was detected in the dry seed. Following imbibition of fully afterripened seed, however, gibberellin levels increased while cytokinin levels declined. Seed strains varying in their degree of dormancy were also analysed for hormone levels; a significantly higher level of cytokinin activity was found in the most dormant strain compared with the least dormant strain. Low levels of bound hormones, including cytokinin ribotides and gibberellin glucose conjugates, were detected following enzyme hydrolysis but neither class of compounds varied greatly in level during afterripening.The major cytokinins detected in Avena fatua seeds cochromatographed with zeatin-9-glucoside, zeatin riboside, and zeatin on both HPLC columns and chromatography paper. The major gibberellin activity cochromatographed with GA4/GA7 on silica gel partition columns and thin-layer plates.Germination studies demonstrated that GA4/7 is significantly more active than GA3 in promoting the germination of dormant Avena fatua seeds. External applications of cytokinins were not found to affect the germination of dormant seed, but did promote germination in partially afterripened material.

Research as an impetus to improved treatment

The relation between psychiatric research and treatment remains a controversial subject. A psychopharmacological research program implemented in a state psychiatric hospital resulted in a significantly improved treatment milieu. Diagnosis, length of stay, amounts and types of medications administered, legal commitment status, seclusion and restraint time, etc, were targeted as variables with which to measure change in the milieu. The variables showed significant changes, ie, improvement during the research period, as compared with a control period. The research discipline created a more rigorous approach to diagnosis and treatment. This, in turn, created an improved treatment milieu in which the research protocols could be implemented more meaningfully.

Effect of antiparkinsonian medication on plasma levels of chlorpromazine

Twenty-one chronic schizophrenics were stabilized with chlorpromazine therapy at their therapeutic dosage for one month. Trihexyphenidyl hydrochloride or identical placebo was then added according to a double-blind, split crossover design. The duration of each half of the crossover was 15 days. Steady state blood samples were drawn three times weekly during the experimental period and the amount of chlorpromazine was determined. The results indicated there were no differences in the levels obtained between the trihexyphenidyl and the placebo phases. A two-hour postdrug blood sample was also drawn at the end of each phase and again, there were no differences between the two conditions. The importance of these results is discussed.

A rating scale for tardive dyskinesia

A rating scale for tardive dyskinesia was developed, consisting of nearly all signs seen by two groups of investigators over a 5-year period. Thirty-four items were included in the scale with a possibility of writing in idiosyncratic signs. The scale was shown to have good reliability and validity in studies carried out by both the New York and Boston groups. It is recommended as a suitable instrument for describing the breadth of tardive dyskinesia syndrome and also for quantifying the disorder. A second scale, "the abbreviated dyskinesia scale", contains 13 items which are more global than the items in the original scale. It also has been shown to be both reliable and valid. Its use is suited to situations requiring less extensively detailed assessments.

Effects of loxapine on the sleep of chronic schizophrenics

The sleep patterns of four male chronic schizophrenic patients were monitored throughout the various phases of a 1-year therapeutic trial with loxapine succinate, a newly developed neuroleptic. Compared with the initial drug-free baseline, the early drug period was characterized by an increase in REM percentage, REM density, and REM activity. During the drug maintenance period, the increase in REM phasic events was accompanied by an increase in total sleep. Severe insomnia was noted during the initial period of drug withdrawal. The absence of time lag between changes in drug administration schedule and the associated alterations in sleep patterns was in contrast with the time latency of the therapeutic response. This neuroleptic on sleep and on psychopathology are mediated by different mechanisms.

Evaluation of a slow-release lithium carbonate formulation

A slow-release lithium preparation was compared with a standard formulation in normal volunteers and in patients. Pharmacokinetic parameters of normal volunteers were examined after a single dose of each form and the steady-state levels after a b.i.d. dose of the slow-release form. These initial single-dose data suggested that the two formulations are not bioequivalent. However, the area under the curve of the two forms was similar, and the essentially complete recovery of lithium from urine in steady state indicates equal bioavailability. The patients' steady-state levels for the two formulations essentially confirmed the normal subjects' data: with the slow-release form plasma lithium levels were slightly higher, and the postdose lithium level variability was decreased by as much as 50%.

Tardive dyskinesia and psychotropic drug history

The adult population of a large mental hospital was screened for tardive dyskinesia (TD). Approximately 11% of the hospital population showed signs of TD; females and the elderly were over-represented in the TD group. A representative sample of those with TD was selected and a control (non-TD) patient was chosen to match each of the TD subjects in age, sex, length of hospitalization, diagnosis, and race. The charts of these subjects were searched for any indices of brain damage and the complete psychotropic medication history was recorded. There was no difference between the TD and controls in the amount of psychotropics ingested, in the duration of administration, in the kinds of drugs, or in the organicity history. Women as a group, however, tended to have more polypharmacy than men. The role of neuroleptics in TD is discussed as well as other possible etiological factors.

Loxapine succinate as a neuroleptic agent: evaluation in two populations of elderly psychiatric patients

Loxapine succinate, a newly developed neuroleptic drug, was administered to two groups of geropsychiatric patients: (a) 12 with psychosis and organic brain syndrome, and (b) 14 with chronic schizophrenia. After a two-week baseline period, loxapine was given for 12 weeks. The moderate therapeutic effect of loxapine in the "responders" was similar to that of other neuroleptic drugs. The therapeutic dosage range was found to be from 10 to 80 mg daily--about half that used for younger patients. The chief side effects were drowsiness, mild extrapyramidal symptoms, and a slight increase in blood pressure.

High- and low-potency neuroleptics in elderly psychiatric patients

The efficacy and side effects of a low-potency neuroleptic, thioridazine hydrochloride, and those of a high-potency neuroleptic, fluphenazine hydrochloride, were compared in 30 elderly chronic schizophrenic patients. Through a crossover design, each patient received both drugs with an intervening washout period. Although both drugs produced a similar degree of improvement, their side effects differed. Fluphenazine caused slightly more extrapyramidal effects than thioridazine, though few occurred with use of either drug. Thioridazine caused weight gain, blood pressure decreases, and ECG changes. High-potency neuroleptic agents appear to be the drugs of choice for elderly schizophrenic patients.