The nature of learning and memory impairments in schizophrenia

The California Verbal Learning Test was used to characterize the learning and memory impairment in schizophrenia (SC) and to evaluate potential clinical and demographic factors associated with this impairment. SC patients (n = 175) performed worse than normal comparison (NC) subjects (n = 229) on all learning, recall, and recognition memory measures. The most important clinical correlates of these impairments were earlier age of onset, more negative symptoms, and greater anticholinergic medication dosage. SC patients showed a prominent retrieval deficit as indicated by disproportionate improvement when tested in a recognition, rather than a free recall, format. A residual impairment seen with recognition testing suggests a mild encoding deficit as well. In contrast, the relative absence of a storage deficit is suggested by the lack of rapid forgetting. Using a discriminant function analysis that differentiates cortical dementia [i.e., Alzheimer's disease (AD)], subcortical dementia [i.e., Huntington's disease (HD)], and normals, it was found that 50% of the SC patients were classified as having a subcortical memory profile and 35% were classified as having a normal profile, whereas only 15% were classified as having a cortical memory profile. Although these findings reflect the clinical heterogeneity often found in SC, results suggest that most SC patients demonstrate a pattern of learning and memory impairments that resembles the pattern seen in patients with primary subcortical (specifically striatal) pathology.

Home care comes full circle

Health care practices in the US are changing as managed care, government regulations, and patient preferences alter care delivery. Home care will play a major role in these changes if the industry takes advantage of this trend toward a more flexible, independent patient model--returning health care to its origins as it completes the journey from home to institutions...and back again.

Information-processing deficits and thought disorder in schizophrenia

OBJECTIVE

The goal of this investigation was to study the relationship between information-processing deficits and thought disorder in schizophrenic patients.

METHOD

Fifty-two subjects diagnosed with schizophrenia were administered tests of information processing and thought disorder. The information-processing tests included visual backward masking and prepulse inhibition of the startle reflex. Thought disorder was measured with the Magical Ideation Scale, the Scale for the Assessment of Positive Symptoms, the alogia subscale of the Scale for the Assessment of Negative Symptoms, and the Ego Impairment Index-human experience variable and its subcomponents derived from the Rorschach.

RESULTS

Elevated poor responses on the Ego Impairment Index-human experience variable were significantly correlated with information-processing deficits. In a simultaneous multiple regression, the auditory prepulse inhibition measure was the best predictor of poor responses on the Ego Impairment Index-human experience variable.

CONCLUSIONS

The results suggest a correlative relationship between information-processing deficits and thought disorder. The relationship is most apparent when highly sensitive measures of both information processing and thought disorder are used. Furthermore, the prediction of poor responses on the Ego Impairment Index-human experience variable by auditory prepulse inhibition is important, since the neural circuitry of prepulse inhibition is known and involves the modulatory influences of the cortical-striatal-pallidal-thalamic circuit. These findings lend support to the hypothesis that information-processing failures are associated with cognitive fragmentation and thought disorder. More speculatively, these results allow us to hypothesize that impairments in part of the cortical-striatal-pallidal-thalamic circuit may lead to thought disorder, as well as prepulse inhibition deficits.

Osteoporosis in a largely self-referred population: high prevalence but low medical priority: why?

Dual photon bone density screening for osteoporosis (OP) and osteopenia of the lumbar spine was performed in 108 women aged 34-75 years of whom 91% were self-referred in a cross-sectional study. OP was present in 18.6% when defined as greater than 2 SD bone mineral density (BMD) reduction compared to young normals and in 41.6% with osteopenia (1 SD BMD reduction). Twelve percent gave an actual history of previous fractures. In those who showed reduced BMD (60%), 69.5% had a family history and 54% scalp hair loss although this was not a good prognostic sign. An Osteoporosis Risk Questionnaire was not an accurate predictor of BMD, thus bone density screening remains essential for early and accurate diagnosis. Previous oral contraceptive use appears to be protective (p = 0.004). Sex hormone replacement therapy (sHRT) taken by 20% of the postmenopausal patients had not yet provided significant protection (p = 0.15) probably due to its late introduction, short exposure and failure to optimise dose levels. Despite detailed information and questionnaires provided to their doctors, of 53 patients with OP or osteopenia 15 (28%) started sHRT without additional investigation, 19 (36%) remained untreated, while the outcome in the rest, 19 (36%), was unknown. A disturbing indifference by doctors and patients continues to the prevention and treatment of OP and low BMD, a potentially preventable and reversible condition, which signals a higher risk of future fragility fracture.

The Ego Impairment Index and schizophrenia: a validation study

This study is an extension of our work on a new scale, the Ego Impairment Index (EII; Perry & Viglione, 1991). The index is theoretically based on Beres's (1956) model of ego assessment and was empirically developed on a sample of melancholic, depressed outpatients, diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (3rd ed. [DSM-III]; American Psychiatric Association, 1980). The EII is derived from the Rorschach Inkblot Test and offers a single composite score of ego impairment. This study validates the use of the EII with a heterogeneous sample of schizophrenic patients. In support of the trait-like characteristics of the scale, the EII continues to be expressed as a single factor, with a correlation of .98 when comparing the original factor derived from a melancholic population with this sample of schizophrenic patients. Significant correlations were also found between the EII and other clinical indices, including the Magical Ideation Scale, the Schizophrenia Index, and the Minnesota Multiphasic Personality Inventory (MMPI). Finally, the EII was found to differentiate between a paranoid subgroup and a mixed undifferentiated/disorganized subgroup who theoretically have more ego impairment. These results offer support for the use of the EII as an empirical means of quantitatively and qualitatively assessing thought disorder within a theoretical framework. Further research is needed to understand the application of the EII across different diagnostic groups and its relationship to other indices of psychological disturbance.

The Ego Impairment Index as a predictor of outcome in melancholic depressed patients treated with tricyclic antidepressants

The standard model of assessing ego impairment relies on patients' accurate self-report and description of their behavior. This study offers an alternative approach to assessing ego impairment in a population of major depression, melancholic type outpatients treated with tricyclic antidepressants. A new index called the Ego Impairment Index (EII) was developed. The index is derived from the Rorschach test and offers a single composite score of ego impairment. It was hypothesized that those melancholic, biologically depressed individuals who were lacking in ego resources were less likely to benefit from tricyclic antidepressant treatment. Thus, the EII could predict overall outcome while on antidepressants. The results support that the level of ego impairment, as assessed by the EII, could predict depression outcome averaged over 9 weeks of tricyclic antidepressant treatment.

Insertional mutations in transgenic mice

Insertional mutagenesis represents a promising approach to the identification of new genes involved in mammalian development. In this paper, we have presented a brief review of the literature on the analysis of mutations caused by DNA and retroviral insertion into the mouse genome. We have discussed several methods that we and others have used to identify recessive insertional mutations among transgenic mouse lines. Finally, we have summarized the results of our studies to date on three recessive prenatal lethal mutations that we have identified.

Rifampicin, halothane and glucose as mediators of lysosomal enzyme release and tissue damage

It is suggested that the important drugs rifampicin and halothane and the raised glucose levels in diabetes mellitus exert injurous effects on cells through a lysosomal mechanism. Further evidence is given of by time rifampicin induction of beta-glucuronidase and beta-N acetylglucosaminidase and its possible relation to hepatitis and pancreatitis. On the basis of preliminary data halothane may cause hepatitis connected to lysosomal enzyme release in the presence of other aggravating factors common to the perioperative period. The onset of diabetic vascular complications may be related to the similar raised levels of lysosomal enzymes found in insulin, drug and diet controlled disease. Release of these enzymes into plasma may be a marker of important changes in the lysosome, whether due to enzyme induction or damage, and could be a primary mechanism of many disease processes including some thought to be mainly autoimmune in character. Routine estimation in the clinical laboratory along with existing cytoplasmic and microsomally derived enzymes in the chemical screen would be a useful way of surveying lysosomal changes in the wide spectrum of disease in a general hospital.

Plasma gamma glutamyltransferase levels during rifampicin therapy for tuberculosis

A possible effect of rifampicin enzyme induction on microsomally derived plasma gamma glutamyltransferase (gamma GT) during treatment for tuberculosis patients with spinal bone disease and pulmonary or lymph node involvement was studied. Of 10 patients with bone disease 5 had raised levels prior to therapy (greater than 60 IU/l) and none were alcohol consumers. Gamma GT is not known to be present in bone and this probably represents an indirect effect on the liver. Changes in gamma GT in the first 2 months of rifampicin/isoniazid treatment were variable and will not serve as an index of response to therapy. Of 69 patients with lung or lymph node disease 15 had raised levels during treatment and 9 had a high alcohol intake, when the alcohol group were excluded there was no significant difference from controls who had completed treatment (p greater than 0.1). We conclude that plasma gamma GT, a standard clinical estimation of liver dysfunction, is a useful index of suspicion for alcoholics among the tuberculous group but the disease itself can produce similar levels. It did not reflect the known hepatic microsomal inducing properties of rifampicin and thus differs from the anticonvulsant model. Clinical value would be enhanced if specific liver isoenzymes in plasma were identified which separated tissue injury, enzyme induction and the effect of extrahepatic infection on the liver.

Prostaglandin release in multiple sclerosis: correlation with disease activity

Release of prostaglandin E (PGE) was examined in leukocyte cultures from patients with definite MS who had had at least one recent exacerbation, others with chronic progressive or stable MS, and healthy controls. MS patients had higher baseline levels of PGE than did controls. Patients with active symptoms exhibited a sharp increase in PGE release early in or just before the onset of clinical symptoms. Levels dropped early in exacerbation immediately after the burst in PGE synthesis activity. Values gradually increased to control levels and then to preexacerbation levels. Similar rises and falls were not seen in stable MS. MS patients may have a circulating population of activated leukocytes that produce PGE.

Note on the enzyme assay for urinary D-glucaric acid and correlation with rifampicin-induced mixed function oxidase activity

The enzyme assay for urinary D-glucaric acid is the simplest specific procedure for measuring drug-mediated hepatic enzyme induction in an ordinary laboratory without complex equipment. The problem of lactone conversion and interfering substances in the urine is examined. The normal range showed no significant difference between males (mean +/- SD = 42.60 +/- 19.80 mumol/day) and females (mean +/- SD = 40.40 +/- 31.50 mumol/day). Storage of urine at -20 degrees C longer than 6 months caused a decline in recovery probably due to further breakdown of D-glucarate. During rifampicin/streptomycin treatment a negative correlation was found between decline in antipyrine half-life (t1/2), a measure of mixed function oxidase activity, and rise in urinary D-glucaric acid (r = -0.7614, p less than 0.05). However, in 63 patients receiving rifampicin/isoniazid therapy no rise in D-glucaric acid was detected. Isoniazid appears to be an inhibitor of the glucuronic acid pathway in man at the level of uronlactonase or glucuronolactone dehydrogenase.

Hepatic mixed function oxidase induction during rifampicin/isoniazid therapy in Indian vegetarians

To determine the effect of rifampicin therapy on hepatic oxidase activity in animal protein deficient patients antipyrine and quinine t 1/2 and 6B-hydroxycortisol (6B-OHF) excretion was studied in 8 Indian vegetarians during treatment for tuberculosis. In 4 patients at the start of treatment rifampicin/streptomycin caused a steady decline in by time antipyrine t 1/2 which was complete in 3 weeks, in one patient introduction of isoniazid produced a temporary reversal. After 4 months rifampicin/isoniazid 6B-OHF excretion was increased 2 to 10 fold in all patients although one followed serially showed a marked fall when isoniazid was begun. Decline in antipyrine t 1/2 persisted in 4 patients at the end of 18 months therapy and in one of these concurrent quinine t 1/2 confirmed partial isoniazid reversal of this decline. Rifampicin-mediated mixed function oxidase induction appeared similar to that reported for non-vegetarians and largely persists with combination therapy throughout treatment. Isoniazid can act as a competitive inhibitor of hepatic oxidase activity in some patients.

Methicillin-resistant Staphylococcus aureus strains in New York City hospitals: inter-hospital spread of resistant strains of type 88

A survey of methicillin-resistant strains of Staphylococcus aureus received for phage typing indicated a marked increase of resistant strains received in 1982 and 1983. Of 62 hospitals in New York City which sent strains for phage typing, 35 had methicillin-resistant isolates. A significant development was the presence of strains of the same phage type at several hospitals, indicating a possible inter-hospital spread of these strains. Among strains present at several hospitals, the largest group was of experimental phage type 88. Strains of type 88 were received from 23 hospitals, representing 56% of all methicillin-resistant strains received from New York City hospitals. Strains of type 88 were resistant to all antistaphylococcal antibiotics, with the exception of vancomycin, and represented a major source of nosocomial infections at 13 hospitals. As experimental phage 88 is not routinely used for typing in U.S. laboratories, the nationwide distribution of strains of type 88 is difficult to assess.

Situs inversus totalis with embryonal cell carcinoma of ovaries

A very rare association between situs inversus totalis and embryonal cell carcinoma of the ovary is presented in a 20-year-old Saudi female. Recurrence of the tumor in the form of metastases to the left lobe of the liver was successfully treated using a combination of bleomycin, vinblastine++ and cis-platinum. Second-look laparotomy has confirmed the complete remission.

Urinary D-glucaric acid excretion during rifampicin/isoniazid and anticonvulsant enzyme induction

As measured by urinary D-glucaric acid excretion, an index of hepatic enzyme induction, glutethimide was the most powerful of six such inducers tested. In patients with tuberculosis, rifampicin, 450 mg daily, induced excretion rates of the lower dose range of anticonvulsants in epileptics. The effect was detectable in the first few days but the degree and rate of rise to maximum excretion were variable. This may be due either to disposition of rifampicin or to genetic susceptibility to enzyme induction. Plasma beta-glucuronidase, an essential enzyme of the glucuronic acid pathway, could be induced independently of an increase in D-glucaric acid excretion. Plasma gamma-glutamyltranspeptidase-levels, an index of hepatic microsomal enzyme induction, were elevated in only 20 of 83 subjects receiving rifampicin and isoniazid, and in all of them urinary D-glucaric acid excretion was normal. Neither of these indices, therefore, showed hepatic enzyme induction during combined therapy when other pathways such as oxidative metabolism continued to be induced. Different active sites of rifampicin and isoniazid on glucuronic acid and other biochemical pathways emphasize the complexity of final metabolic effects in patients on long-term therapy.

Interferon-mediated inhibition of prostaglandin synthesis in human mononuclear leukocytes

In this study, the question of whether human leukocyte-derived and fibroblast-derived interferon had an effect on prostaglandin metabolism in human peripheral blood mononuclear cells has been considered. Both leukocyte- and fibroblast-derived interferon were potent inhibitors of mononuclear cell prostaglandin synthesis at low physiological concentrations. Inhibition required a minimum incubation of 1 hr. Interferon had no effect on release of arachidonic acid; synthesis of hydroxy fatty acids was slightly increased.

Calcium Metabolism during Rifampicin and Isoniazid Therapy for Tuberculosis

Calcium metabolism was studied in 83 patients during eighteen months' rifampicin and isoniazid therapy for tuberculosis by measurements including calcium, alkaline phosphatase and 25-hydroxycholecalciferol (25-HCC). Five out of 52 Indian patients in the series were found to have osteomalacia, a prevalence probably no higher than in the Asian population in the UK at large. Moreover, osteomalacia responded to physiological supplementation with vitamin D. One European out of 31 had osteomalacia due to low vitamin D intake. Serum calcium was compared in 17 patients before and after six months of antituberculous chemotherapy but no significant difference was detected ( P>0.1). Two Indian patients were in positive calcium balance with low to normal plasma 25-HCC levels, indicating that an effect on 1,25 dihydroxyvitamin D activity during therapy was unlikely. It is concluded that rifampicin when combined with isoniazid has no significant effect on calcium metabolism over an eighteen-month treatment period.

Effect of partial hepatectomy on removal of O6-methylguanine from alkylated DNA by rat liver extracts

1. The activity of an enzyme catalysing the loss of O6-methylguanine from methylated DNA was increasing during liver regeneration after partial hepatectomy. Activity was increased 3-fold by 24h and was maximal (6-fold increase) over the period 48-72h after operation. 2. This activity could also be induced by chronic treatment with dimethylnitrosamine, but the maximal response amounted to a 2-3-fold change (with the greater effect in male rats) after 4-6 weeks of exposure to daily doses of 2 mg of dimethylnitrosamine/kg. 3. Neither partial hepatectomy nor treatment with dimethylnitrosamine increased the activities of two other enzymes repairing alkylated DNA, DNA (7-methylguanine-)glycosylase and DNA (3-methyladenine-)glycosylase. 4. These results therefore indicate that there is a selective induction of the O6-methylguanine removal system during hepatocyte proliferation. Since this product is known to lead to mutations and its persistence in DNA throughout cell replication has been implicated in tumour initiation, this induction may play a role in resistance to carcinogenesis by alkylating agents.

Emergence of gentamicin- and methicillin-resistant Staphylococcus aureus strains in New York City hospitals

Gentamicin- and methicillin-resistant strains of Staphylococcus aureus have been isolated from Spring 1979 to the present from many hospitals in New York City. A large proportion of the strains were resistant to the majority of antistaphylococcal antibiotics. The ratio of multiply resistant strains was highest among tetracycline-resistant strains. There were significant differences in phage susceptibility patterns and the resistance spectrum of strains isolated at different hospitals, whereas strains isolated at the same hospital often showed a marked degree of similarity. This suggests multiple origins of gentamicin- and methicillin-resistant strains isolated in New York City.

Effects of chronic naloxone treatment on brain-stimulation reward

Rats were tested on a rate-free psychophysical procedure in order to determine the absolute reinforcement thresholds for self-stimulation behavior. The administration of naloxone (16 mg/kg) for five days failed to alter the reinforcement thresholds on this procedure. To the extent that naloxone is an effective antagonist of endogenous opioids, we conclude that central endorphin systems are not necessary to support self-stimulation behavior.

Stimulation of transfer of methyl groups from O6-methylguanine in DNA to protein by rat liver extracts in response to hepatotoxins

An enzymatic activity present in rat liver extracts catalyzes the transfer of methyl groups from O6-methylguanine in DNA to protein. This activity was stimulated by treatment of rats with thioacetamide, carbon tetrachloride, 1,2-dimethylhydrazine, diethylnitrosamine, dimethylnitrosamine and by partial hepatectomy but not by treatment with N-methyl-N-nitrosourea or streptozotocin. These results suggest that an enhancement of this activity accompanies the increase in cell division brought about by these agents and is not necessarily a specific response to the presence of alkylated bases in DNA.

Effects of quinidine on serum digoxin concentration: a prospective study

Results of studies of 15 adults placed on quinidine therapy after their serum digoxin concentrations were stabilized showed significantly increased digoxin concentrations. The average digoxin concentration before quinidine therapy was 0.75 +/- 0.28 ng/mL and after 4 days of quinidine therapy was 1.41 +/- 0.43 ng/mL. During this period, the renal clearance of digoxin decreased from 53.4 +/- 21 mL/min . 1.73 m to 35.3 +/- 12.6 mL/ min . 1.73 m. No significant correlation was found between the individual rise in serum digoxin concentrations and the rise in serum quinidine concentrations. These results suggest that serum digoxin concentration should be monitored closely for at least the first 4 days of quinidine therapy.

Effects of d-amphetamine and naloxone on brain stimulation reward

Self-stimulation thresholds were determined in rats by means of a modification of the psychophysical method of limits. Reinforcement values were determined after the administration of d-amphetamine alone, naloxone alone, and naloxone administered concurrently with d-amphetamine. d-Amphetamine yielded dose-related decreases in the threshold (0.25--2.00 mg/kg IP), while naloxone alone (2.0--16 mg/kg IP) caused no consistent changes. For each animal, a dose of d-amphetamine that substantially lowered the threshold was then selected to be administered with varying doses of naloxone. The threshold-lowering effect of d-amphetamine was blocked by naloxone at doses as low as 2.0 or 4.0 mg/kg. This finding suggests the possible involvement of an opiate receptor in the mediation of the enhancement by d-amphetamine of brain stimulation reward.

Methicillin-resistant strains of Staphylococcus aureus phage type 92

Methicillin-resistant (Mec(r)) strains of Staphylococcus aureus received for phage typing from several hospitals in New York City were resistant to the international set of typing phages but susceptible to experimental phage 92. Subsequently, strains of type 92 were detected in two outbreaks with Mec(r) strains in two other locations in the United States. In all instances, type 92 was predominant among the Mec(r) strains isolated in each hospital. With the exception of one strain, the methicillin resistance of the Mec(r) strains investigated was homogeneous. In most instances, isolates from the same hospital were closely similar in their antibiotic resistance patterns. The strains isolated in New York City could be divided into three groups by the host range of their lysogenic phages and by antigenic structure. Transduction experiments indicated that the transfer of chromosomal tetracycline resistance from Mec(r) strains into a strain susceptible to several international typing phages renders the latter nontypable. However, the acceptor strain remains susceptible to experimental phages 92 and 88. Transduction of methicillin resistance had no effect on the phage susceptibility of the acceptor strain. It is possible that the presence of chromosomal tetracycline resistance is a determining factor in the phage susceptibility of Mec(r) strains isolated in New York City.

Hereditary hypophosphataemic rickets with autosomal recessive inheritance and severe osteosclerosis. A report of two cases

We have observed congenital hypophosphataemic rickets in two sons of a marriage between first cousins, their mother being clinically and biochemically normal. Both patients are now approaching middle age. In addition to severe childhood rickets and lifelong hypophosphataemia, their disease is characterised by gross osteosclerosis with extraskeletal ossification, clinically persistent osteomalacia in one and spinal cord compression in the other. The genetics of this disease can be satisfactorily explained only on the basis of autosomal recessive inheritance, a mode which has only once before been reported in the literature. The severity of certain features, which would be expected in a homozygous state, may help our understanding of the more usual X-linked form.