Augmentation of the in vitro humoral immune response by pharmacologic agents. I: An explanation for the differential enhancement of humoral immunity via agents that elevate cAMP.

Agents that elevate intracellular concentrations of cAMP in cultured spleen cells can augment the in vitro 19s humoral immune response to SRBC. DBcAMP and 8BrcAMP were more effective than MIX, CT, PGE1, or ISO in producing the enhanced PFC response, when they were present only during an early stage of immune induction. The thesis is presented that the differential ability of these agents to augment humoral immunity results from their relative ability to maintain elevated concentrations of intracellular cAMP. Studies on the cellular mechanism by which cAMP elevation produces immune enhancement reveal that DBcAMP effects are on a T-cell-deficient population of murine spleen cells (predominantly B cells and macrophages). In addition, we showed that DBcAMP cannot replace the need for helper T cells in the induction of the PFC response to SRBC. Taken collectively, these results suggest that cAMP may be an important immunoregulatory signal, and that a variety of pharmacologic agents that modulate the induction of the humoral immune response may operate via this as a final common biochemical pathway.


Effect of solvent on the histamine-releasing, enzyme-releasing, and mitogenic properties of the calcium ionophore A23187.

The potency of the calcium ionophore A23187 in inducing three activities of human leukocytes (histamine secretion from basophils, enzyme secretion from PMNs, and proliferation of lymphocytes) was markedly dependent on the solvent (DMSO versus ethanol versus aqueous buffer) used for its initial sonication. While 0.1 micrograms/ml of DMSO- and ethanol-solubilized A23187 induced maximal histamine release from basophils and histaminase release from PMNs, concentrations of aqueous buffer-sonicated ionophore of greater than or equal to 1 microgram/ml were required for an equivalent response. Ionophore sonicated in organic solvents caused a maximum release of 40% of PMN beta-glucuronidase, at an optimal concentration tenfold higher than that required for maximal histaminase release; ionophore sonicated in aqueous buffers, even at high concentrations, effected a release of less than 5% of cellular beta-glucuronidase. A23187 also induced lymphocyte proliferation over a narrow concentration range; 0.05 micrograms/l of DMSO-sonicated ionophore induced optimal proliferation and concentrations greater than or equal to 0.2 micrograms/ml were toxic. Twofold higher concentrations of ethanol-sonicated ionophore and fourfold higher concentrations of aqueous-sonicated ionophore were necessary for maximal proliferation, and the magnitude of the maximal response with aqueous-sonicated A23187 was only one-half that of DMSO-solubilized agent. Ionophore-induced release of histamine from basophils and enzymes from PMNs was not cytotoxic, since ionophore induced neither LDH nor histamine release from heat-treated (47 degrees C) cells. These results explain several previous, discordant reports on the presence or absence of an effect of A23187 on cellular secretory events, on differing dose-response relationships, and on cytotoxic versus noncytotoxic mechanisms of action.


Spin labeling studies of the interactions of P815 mouse mastocytoma cells with antiserum to histocompatibility antigens, H-2d.

The effect of antiserum to histocompatibility antigens on the membrane organization of murine neoplastic mast cells (P815) has been studied by spin labeling. Incubation of in vivo passaged cells, labeled with a nitroxide derivative of methyl stearate, with antiserum to membrane carried histocompatibility antigens, H-2d, resulted in an apparent decrease in membrane fluidity that was accompanied by histamine release. This electron spin resonance (esr) detectable change was found to be temperature, time, and dose dependent. Treatment of the cells with cytochalasin B, a drug disrupting microfilament structure, inhibited the effects induced by H-2d antiserum. In contrast, vinblastine, which disrupts microtubules, did not modulate the effect of this antiserum. Other data presented here suggest that some of the large spectral change observed on treatment of the cells with anti-H-2d serum may result from hydrolysis of the spin label fatty acid ester via activation of a membrane-associated esterase. The relationship of these results to other immunologically induced membrane phenomena is discussed.


Alpha-fetoprotein-associated alterations of New Zealand mouse immunopathology.

The influence(s) of chronic injections of alpha-fetoprotein (AFP), derived from murine amniotic fluid, on the natural history of immunopathology and autoantibody production in New Zealand mice was studied and compared to analagous treatment with albumin, transferrin, or phosphate-buffered saline. Treatment of young New Zealand Black (NZB) mice with AFP, at sera levels of 60-210 micrograms/ml, significantly reduces the titer of IgG1, IgG2, and IgA antierythrocyte antibodies. Similarly, such treated mice have relatively normal levels of splenic Thy-1.2-bearing cells and sera immunoglobulins, at older ages, compared to control groups. In contrast, AFP has no apparent effect on the appearance of either naturally occurring thymocytotoxic antibodies (NTa) or lymphoma. Moreover, the positive features of AFP on disease were only noted for mice treated early in life; AFP had no effect when injected into older animals. Similar, but not as dramatic, changes were observed in NZB x NZW F1 hybrids. It is concluded that in pharmacologic doses, mouse aminotic fluid enriched with AFP may alter the appearance of thymic-dependent autoantibodies.


Atrial bigeminy with block associated with bradycardia and paroxysmal atrial fibrillation -- an important variant of the tachycardia-bradycardia syndrome.

Serial 2-channel 24 h dynamic ECGs in 7 patients who were referred with the "tachy-brady" syndrome for consideration for permanent cardiac pacing revealed: 1. atrial premature beats (APBs) which were conducted to the ventricles normally or aberrantly; 2. intermittent atrial bigeminy with block towards the ventricles (this rhythm mimicked sinus bradycardia with ventricular rates of 38-45 beats/min and the ectopic P waves were visible on only one of the ECG channels); 3. paroxysms of atrial fibrillation initiated by closely coupled APBs. These findings suggested that both the ventricular bradycardia and the atrial fibrillation were caused by frequent APBs and that pacing therapy was unnecessary. Disopyramide was given to 5 patients resulting in suppression of the arrhythmia and relief of symptoms. In one patient there was spontaneous resolution and one patient refused treatment. This variant of the "tachy-brady" syndrome can be successfully treated by suppression of abnormal atrial impulse formation without recourse to pacemaker implantation.


The epidemiology of inguinal hernia. A survey in western Jerusalem.

The epidemiology of inguinal hernia was investigated in a community survey in a neighbourhood of western Jerusalem in 1969-71. The current prevalence rate, excluding operated hernias, was 18 per 100 men aged 25 and over, and the lifetime prevalence, including operated hernias, was 24 per 100. Prevalence rose markedly with age; the lifetime prevalence rate reached 40 per 100 men at the ages of 65-74 and 47 per 100 at 75 and over. The prevalence of hernia was significantly higher in the presence of varicose veins, in men who reported symptoms of prostatic hypertrophy, and, among lean men only, in the presence of haemorrhoids. These associations may reflect the role of increased abdominal pressure. The prevalence of hernia was low in the presence of overweight or adiposity, suggesting that obesity is a protective factor. No significant age-independent associations were found with chronic cough, constipation, physical activity at work, or a number of other variables. Two-thirds of the hernias had not been operated upon. The prevalence of unrepaired hernias rose with age; 13% of all men aged 65-74 and 23% of those aged 75 and over had unoperated groin swellings. One in every five operated hernias showed evidence of recurrence. No significant age-independent associations were found between evidence of occurrence and other characteristics. A comparison of interview responses and examination findings showed that interview data on the presence of hernias were of low validity, mainly because of under-reporting.


Erythrocytes of the human neonate.

This review has focused on the fetal erythrocyte. Fetal erythropoiesis, the production of a red cell with a shortened life-span, and the unique characteristics of this cell with respect to membrane structure and function, energy metabolism, and hemoglobin synthesis have been described. The hematologic manifestations of a variety of red cell abnormalities of structure, metabolism, and hemoglobin synthesis have been presented, as well as a discussion of the anemia of prematurity and selected nutritional disturbances that may distort this normal physiologic adaptation. We hope this review has served to further the reader's appreciation of this complicated and fascinating cell. Much more needs to be learned about the fetal erythrocyte. It is to be hoped that a fuller understanding of the fetal erythrocyte will provide insights into fetal development in general.


Evidence that piracetam has an anxiolytic action.

In the social interaction test of anxiety Piracetam (100 mg/kg) had an anxiolytic profile very similar to that seen after 5 days of administration of chlordiazepoxide (5 mg/kg). Piracetam (50-300 mg/kg) produced no signs of sedation and it was therefore suggested that it might be a non-sedative anxiolytic drug. Piracetam (100 mg/kg) produced significantly higher cortical concentrations of 5-hydroxytryptamine and lower concentrations of 5-hydroxyindoleacetic acid, indicating a reduced 5-HT turnover. There were no drug-induced changes in noradrenaline or dopamine in any brain region, either with or without pretreatment with alpha-methylparatyrosine. The cortical concentrations of 7 amino acids were measured and were unchanged by treatment with Piracetam.


Quantitative aspects of the Naphthol Yellow S staining for proteins studied in a model system of polyacrylamide films and in isolated rat liver cells and nuclei.

After staining with Naphthol Yellow S (NYS) at optimal conditions of pH (2.8), the protein content of rat liver cells isolated by means of a collagenase perfusion technique was found to be cytophotometrically immeasurable, because of too high local dye absorbances. In order to lower the absorption values, techniques to flatten the cells, off-peak measurements and NYS staining at non-optimal pH levels were applied. With polyacrylamide model films incorporated with albumin, the reliability of off-peak measurements and the quantitative aspects of the modified protein staining procedures have been investigated. It was found that NYS is a quantitative protein stain not only at pH 2.8, but also at pH 2.0, 3.5 and 4.0 respectively. Off-peak measurements can also produce quantitative results. In cases of a combined Feulgen-NYS staining, the Feulgen-DNA values were not significantly influenced by any of the NYS staining procedures.


The first attack of acute pancreatitis: a clinical study.

Acute pancreatitis of biliary tract origin and that of alcoholic origin may be difficult to separate on clinical grounds alone. Such separation is important since operation prevents recurrent attacks in gallstone pancreatitis. We examined the records of 78 patients in the first attack of pancreatitis from gallstones or alcohol. The gallstone group were usually women, older, and had a shorter period of abdominal pain. Pancreatic complications occurred more frequently in the alcoholic group and led to two deaths. Amylase values were diagnostically helpful in that a level greater than 1000 units in patients of the proper age and sex, and a level greater than 2000 units by itself indicated gallstone pancreatitis.


Amylase-creatinine clearance ratios and serum amylase isoenzymes in moderate renal insufficiency.

Both the amylase-creatinine clearance ratio (normal 1.55%) and proportion of pancreatic isoamylase in serum (normal 41.0%) increase in acute pancreatitis, and are therefore useful measurements to support that diagnosis. Whether renal insufficiency interferes with the accuracy and specificity of these tests has been debated. Our study indicates that even moderate renal insufficiency (creatinine clearance 30.5 ml/minute) raises the amylase-creatinine clearance ratio (3.23%) close enough to values characteristic of acute pancreatitis (4.41%) to cause potential diagnostic confusion. The fraction of pancreatic isoamylase in serum is also increased (69.9%), but not to the levels of acute pancreatitis (91.0%). We therefore caution against the use of the amylase-creatinine clearance ratio for the diagnosis of acute pancreatitis in patients with moderate renal insufficiency.


Effect on rats and mice of a diet with low tryptophan content (maize flour).

Female Wistar rats when crowded together become aggressive if fed a diet with low tryptophan (Trp) content (maize, flour, Mf). When isolated during 30 days and fed Mf they show a decrease of weight, of total plasma Trp, and of Trp and 5-hydroxytryptamine (5-HT) in brain stem, but 5-hydroxyindolacetic acid (5-HIAA) of the same cerebral area does not change. These results partially agree with other authors observations. Mice isolated during 47 days and fed with Mf do not show any significant weight variation, the hypermotility of isolated mice on normal diet persists, but 5-HT and 5-HIAA significantly decreases in total brain, an effect that has been observed by another author. The effect on 5-HIAA does not depend on the diet, either balanced or with low Trp content.


Fetal erythropoiesis in stress hematopoiesis.

Fetal erythropoiesis occurs during chronic bone marrow failure, or during recovery from marrow suppression. Fetal erythrocytes have HB F, with more G gamma than A gamma chains, "i" antigen, large MCV, characteristic enzyme levels, low carbonic anhydrase, low HB A2, and short life span. Many of these fetal characteristics are present in the red cells of patients with temporary or chronic hematopoietic stress. In those in whom normal hematopoiesis ensues, the fetal erythrocytes disappear. The fetal phase of recovery may be with homologous stem cells after bone marrow engraftment, or with autologous cells. Chronic fetal erythropoiesis is seen in patients with constitutional aplastic anemia, such as Fanconi's anemia or Diamond-Blackfan anemia. In one patient with the latter disorder, fetal erythropoiesis accompanied chronic anemia, and actually decreased slightly during the acute phase of clinical improvement. Culture of late erythroid precursor cells (CFU-Es) from a patient with transient erythroblastopenia of childhood led to in vitro development of colonies with HB F, an event not seen in normal marrow cultures. Thus fetal erythropoiesis occurs during hematopoietic stress, whether chronic or transient, if there is some marrow activity, and may be due to expansion of fetal clones.


Experience in staging testis tumors with bleomycin 57cobalt and present role of 67gallium scan.

A technique was developed using bleomycin and 57cobalt to study nodal metastases in testis tumors. Comparative studies were made on 15 cases with 67gallium, lymphangiography, supraclavicular node biopsy, liver and spleen scans, chest x-ray, excretory urogram, bone survey and pathological study of surgical specimens when possible. The results with the bleomycin-57cobalt complex and 67gallium were discouraging. The bleomycin-57cobalt study was discontinued. Pathological staging is still the most accurate of all modalities available for staging testicular malignancies.


Leiomyosarcoma of the inferior vena cava.

The thirty-second case of leiomyosarcoma of the inferior vena cava and the twelfth resectable patient in the series is presented. A review of the literature demonstrates a marked female preponderance (5 to 1). The most common presenting symptom is right abdominal pain and a palpable mass. The different surgical problems generated by the involved segment of the cava are discussed. Noteworthy is the high incidence of Budd-Chiari syndrome owing to hepatic vein obstruction with involvement of the upper third of the cava in the postmortem cases. An argument is developed for debulking the tumor for palliation when it is not completely removable.


Intractable bladder hemorrhage: therapeutic angiographic embolization of the hypogastric arteries.

Malignant intractable bladder hemorrhage in an elderly, high risk patient was controlled effectively with bilateral hypogastric artery occlusion by angiographic placement of oxycel autologous clot emboli. Therapeutic alternatives for intractable bladder hemorrhage are reviewed briefly with particular emphasis on angiographic arterial occlusion. Appropriate anatomic and physiologic aspects of this therapy are discussed.


Infants in a public school system: the indicators of early health and educational need.

The Brookline Early Education Project (BEEP) is a demonstration model in which a public school system in collaboration with a pediatric center has extended teaching and diagnostic services to the earliest days of life. In most cases, enrollment and data collection began three months before the children were born. A comprehensive diagnostic component including health, neurologic, sensory, developmental, and psychological assessments was performed periodically. The present study, the first of several reports, is an analysis of positive indicators of health and developmental need during the first six months of life. At the time of initial surveillance, age 2 weeks, a high yield of physical and demographic findings, along with perinatal stresses, was observed. It was noted that demographic, neurologic, physical, and perinatal stress factors appeared as independent variables. At the three- and six-month checkpoints, there were more overlapping findings between the categories of physical assessment, developmental examination, and neurologic evaluation. Over the six-month period, there was a tendency toward instability of findings: The group of youngsters thought to have special needs at the age of 2 weeks, 3 months, and 6 months differed in composition from each other. Likewise, there was significant flux in membership between the three- and six-month groups with needs. The study may have public policy implications, insofar as early education services should not be constructed to admit only "high-risk newborns" since this would exclude many children whose needs would become manifest later and would take in a number of children falsely identified as in need but with the resiliency to overcome this. The BEEP program has relevance for pediatric practice in demonstrating a component of health care with greater diagnostic and therapeutic responsibility for educational competence in young children.


Large molecular weight TSH-beta: the sole immunoactive form of TSH-beta in certain human sera.

The beta subunit of TSH (TSH-beta) usually cannot be detected (less than 0.2 ng/ml) in the serum of normal individuals, whereas patients with primary hypothyroidism exhibit elevated TSH-beta levels (0.2-9.3 ng/ml), which increase further after the administration of TRH. Two patients were found to have large TSH-beta as the only form of serum TSH-beta immunoactivity. Patient A was a euthyroid woman with a goiter; TSH and alpha subunit levels were normal (1 microU/ml and 0.6 ng/ml, respectively); TSH-beta was elevated (8-24 ng/ml). Patient B was a woman with borderline hypothyroidism, an elevated serum TSH level (19 microunits/ml), a normal serum alpha level (2.4 ng/ml), and an elevated serum TSH-beta level (1.8-3.6 ng/ml). Dilutions of both patients' sera demonstrated nonparallelism of their serum TSH-beta to standard TSH-beta. The elevated serum TSH-beta levels did not increase after TRH, although TSH and alpha subunit increased appropriately. After the administration of dexamethasone or T4 to patient B, serum TSH-beta did not decrease, although TSH and alpha decreased. Gel chromatography and rechromatography of the patients' sera on a Sephadex G-100 column showed elution of all TSH-beta immunoactivity in or near the void volume (Vo; greater than 150,000 mol wt), whereas sera of hypothyroid patients demonstrated less than 7% of TSH-beta immunoactivity in the Vo. By chromatography on a Sephadex G-200 column, the TSH-beta immunoactivity had a 160,000 mol wt in patient A and 200,000 mol wt in patient B. Incubation of labeled or unlabeled TSH-beta with serum or gamma-globulin fractions from both patients resulted in no significant increase in the binding of TSH-beta to serum components, as determined by both gel chromatography and precipitation with antihuman gamma-globulin. Large TSH-beta was stable after incubation with 6 M guanidine. Ribonuclease failed to affect the large TSH-beta. Inter-chain disulfide bonding was not demonstrated in large TSH-beta after treatment with three different reducing agents (mercaptoethanol, sodium sulfite, and dithioerythritol). Treatment with trypsin did not convert the large TSH-beta immunoactivity to standard TSH-beta. These experiments demonstrated that the large TSH-beta immunoactivity was not caused by binding of TSH-beta to an immunoglobulin or other serum protein or by aggregation of TSH-beta molecules. The significance of these apparently covalently bonded large forms of TSH-beta immunoactivity is not yet known; the presence of small amounts of a large molecular weight form in the serum of hypothyroid patients and normal pituitary extracts raises the possibility that they may be components of normal TSH biosynthesis or represent posttranslational modifications.


Oral progestational activity of spironolactone.

Spironolactone has progestational activity in the rabbit and rhesus monkey. It produced glandular development in the endometrium of the estrogen-primed immature female rabbit over the dosage range of 50 to 200 mg/kg and, at 400 mg/monkey, it delayed estrogen-withdrawal bleeding in ovariectomized monkeys and it inhibited menstruation in regularly cycling monkeys. These data are consistent with the menstrual irregularity and amenorrhea seen in women during treatment with spironolactone.


Highly sensitive radioimmunoassay for chorionic gonadotropin in human urine.

The value of RIAs that measure hCG levels in human urine has been limited principally because of cross-reactivity with human LH. Recently, antisera generated to antigenic determinants on the intact hCG beta subunit and its carboxyl-terminal peptide have been shown to exhibit substantially reduced human LH cross-reactivity. To take maximal advantage of these antisera and to minimize interference by nonspecific substances in urine, a procedure for extracting and concentrating hCG from 24-h urine samples was developed. The procedure involves preparation of a standard kaolin-acetone urine concentrate and adsorption of the hCG in the concentrate to Concanavalin A covalently linked to agarose for purification and subsequent RIA. In urine samples obtained from patients with gestational trophoblastic disease, there was a direct correlation between hCG levels measured by RIA and those estimated by mouse uterine weight bioassay. In individual subjects, hCG levels were determined in serum and urine obtained the same day. When hCG was clearly detectable in the serum at levels greater than 1 ng/ml, the quantity of hCG measured in the urine concentrate exceeded 500 ng/24 h. The concentrates prepared from the urine of normal persons contained an hCG-like glycoprotein substance with antigenic determinants similar to those of the carboxyl-terminal peptide of hCG beta. As the range of hCG immunoreactivity measured in the urine concentrates of normal subjects was 6-52 ng/24 h, specific and sensitive detection of urinary hCG could be accomplished in patients whose sera contained hCG undetectable by conventional RIA. Partial purification and concentration of urinary hCG by this procedure with subsequent RIA provides a sensitive and reliable method for detecting hCG in urine.


Characteristics of an antiluteinizing hormone isoantibody produced during gonadotropin induction of ovulation.

Production of an antihuman LH antibody was suspected in a woman with isolated LH deficiency who received human pituitary gonadotropin (hPG) to induce ovulation and who developed secondary drug failure associated with very high "serum LH' values. Binding of [125I]LH to various dilutions of the patient's serum was demonstrated by precipitation with polyethylene glycol or sheep antihuman immunoglobulin G (anti-IgG) but not by precipitation with sheep antihuman immunoglobulin M (anti-IgM). Unlabeled LH competitively displaced [125I]LH from a 1:200 final dilution of the patient's serum, and indicated a single class of binding sites with a binding affinity of 1.5 X 1011 M-1 and a binding capacity of 84 ng LH/ml serum. The isoantibody was reactive against antigenic determinants in hPG, LH, and hCG but not against human FSH. Further examination showed binding to the beta, but not the alpha, subunit of two LH preparations and to beta hCG. It is concluded that repeated administration of hPG to this patient with isolated LH deficiency evoked IgG isoantibody formation against the beta subunit of LH.


Thyroid-stimulating activity of chorionic gonadotropin and luteinizing hormone.

While recent evidence indicates that the hCG molecule has intrinsic thyroid-stimulating activity (TSA), it is not clear whether a thyrotropic molecule other than hCG accounts for some of the TSA apparent in the crude or highly purified hCG. To determine if a thyrotropic factor is excluded from crude urinary hCG during purification of hCG, the ratio of interstitial cell-stimulating activity (ICSA) to TSA was determined in the starting material used for hCG preparation as well as in the highly purified hCG preparation. The ratio of the two biological activities did not change significantly during purification, suggesting that no factor present in crude hCG other than hCG itself accounts for the TSA. The highly purified hCG preparation was gel-filtered on Sephadex G-100 and the main protein peak was divided into three fractions. The ratio of TSA to ICSA was the same in each fraction, further indicating that these activities are intrinsic to the same molecule. If hCG has intrinsic thyrotropic activity, as these data indicate, then thyrotropic activity would be expected to be a secondary biological activity of LH, since there are strong structural and functional similarities between LH and hCG. In order to assess the LH molecule for intrinsic TSA, an LH preparation with minimal TSH contamination was prepared by recombining subunits exhibiting minimal TSH immunoreactivity. The LH molecule formed from the recombination of highly purified hCG alpha and ovine LH beta subunits exhibited TSA in the bioassay that was 25 times greater than that expected based on the immunoreactive TSH contamination. There was no evidence to support the existance of a thyrotropic factor other than hCG in either crude or highly purified hCG preparations. Our finding that a hybrid LH molecule structurally similar to hCG with potent ICSA also exhibits intrinsic TSA further extends and supports the hypothesis that TSA is an intrinsic property of the hCG molecule.


Adsorption of thyroid-stimulating antibody (TSAb) of Graves' disease by homologous and heterologous thyroid tissue.

Immunoglobulin G purified from the serum of patients with Graves' disease, stimulated the thyroid of man, calf, and guinea pig (cAMP accumulation as the end-point) in vitro, and the thyroid of the mouse in vivo (LATS bioassay). The stimulatory effect on the thyroids of all four species was removed by adsorption of the immunoglobulin G to human thyroid membranes and was diminished to a proportionately similar degree by adsorption with bovine thyroid membranes. All activity, as assessed by stimulation of the human thyroid in vitro. was recovered from both human and bovine membranes by elution with 2 M NaSCN solution. The data support the concept that the thyroid-stimulating antibody of Graves' disease is homologous to a human thyroid antigen and, in some instances, cross-reacts with a similar antigen in the thyroid of a distant species and so stimulates the heterologous gland.


Subnormal tissue 3 alpha-androstanediol and androsterone in prostatic hyperplasia.

We investigated the role of 3 alpha-androstanediol (3 alpha-diol) in the development of benign prostatic hyperplasia (BPH) and the apparent equilibrium of enzymes which metabolize it in normal and hyperplastic prostatic tissue of humans. We determined the endogenous concentrations of 3 alpha-diol, androsterone, its 3 alpha-17-keto metabolite or precursor, and 5 alpha-dihydrotestosterone (DHT), its 3-keto,17 beta-hydroxy product of precursor, by RIA after extraction and paper chromatography of the androgens from normal and hyperplastic prostate glands. The mean concentrations of 3 alpha-diol and androsterone were about one-third of normal in BPH. The mean ratio of the concentration of DHT to 3 alpha-diol was significantly higher (P less than 0.005) than normal in BPH, whereas no statistical difference was observed for the mean ratio of the tissue levels of 3 alpha-diol to androsterone in the two groups. Our data do not support the postulate that 3 alpha-diol is causally related to the development of BPH. However, they indicate that the apparent equilibrium of the 3 alpha-hydroxysteroid oxidoreductase favors the formation of the 3-keto-oxidized product, DHT, which may have relevance to the occurrence of the renewed growth of the prostate of aging men.


Correlation among prostate stroma, plasma estrogen levels, and urinary estrogen excretion in patients with benign prostatic hypertrophy.

Plasma testosterone, plasma estradiol, and the total estrogen excretion in the urine were obtained from patients with benign prostatic hypertrophy and correlated to the histological pattern of the resected or enucleated prostates. There was a highly significant increase of prostate stroma in association with higher individual estradiol concentrations and urinary estrogen excretion, while no apparent correlation could be found with testosterone.


Human tumour-associated and tumour-specific antigens: some concepts in relation to clinical oncology.

The concept of tumour-specific antigens is constantly undergoing reappraisal with the development of more sensitive methods for their detection. This has resulted in the finding that the many 'new' antigens produced by human tumours or materials immunologically closely related to them are also present in non-neoplastic tissues, albeit in small amounts. However, other antigens still appear to exist almost entirely in or on tumour cells so that the antigens of human tumours may be subdivided into either tumour-associated macromolecules or tumour-specific antigens. The elucidation of the chemical nature of the tumour-specific antigens may result in important advances in cancer diagnosis and therapy. As many are organ specific, it should be possible to evolve test systems which will enable tumours to be diagnosed and located before they become apparent clinically. On the other hand the tumour-associated macromolecules, of which the oncofetal antigens are the principal examples, are found in elevated amounts in some non-neoplastic disorders. It is now clear that serial estimation of the levels of these macromolecules is of considerably more diagnostic value than single random measurements. Current work is establishing their value in the detection of recurrent and metastatic tumours before they become apparent by other methods, which is probably their most important role, and also their value as aids to monitor therapeutic efficacy. The future use of both types of antigen may unfold a new era in cancer detection and therapy but many basic chemical and immunological studies are needed before their clinical use can be fully defined.


[Nucleoproteins in endometrial hyperplasia of the uterine body].

Sixty women aged 25-72 years were examined. Endometrium of the uterine body was the direct exploratory material. The whole of the material was divided into 5 groups. Endometrium of the uterine body of women with normal menstrual cycle was considered as a control group. The investigated material was estimated histologically and histochemically. Beginning with the most benign hyperplasis of the hyperplasia glanduralis endometrium type up to malignant neoplasms, a distinct increase in accumulation of both nucleic and cytoplasmatic nucleoproteins as compared to the control group was found.


[Determination of the ribonuclease activity of the duodenal contents of children as a test in the differential diagnosis of cystic fibrosis and pancreatic exocrine insufficiency].

Ribonuclease activity was determined in the duodenal contents of healthy children, in children with cystic fibrosis and with pancreatic exocrine insufficiency. Assays were made at 7.0, in 0.05 M buffer without and with 0.35 M NaCl. The ratio of activity in 0.35 M NaCl to that in buffer alone was found to be 2.4 +/- 1.3 for children with cystic fibrosis as compared with 12 +/- 5 for the control group and children with pancreatic exocrine insufficiency.


Characterization of atrial fibrillation in man: studies following open heart surgery.

The nature of localized atrial activation during atrial fibrillation was characterized in 34 patients following open heart surgery. Bipolar atrial electrograms (AEG) recorded in each patient with atrial fibrillation exhibited a myriad of sizes, shapes, polarities, amplitudes, and beat-to-beat intervals. On the basis of the AEG morphology and the nature of its baseline, we have classified the recordings into four Types. Type I was characterized by discrete AEG complexes separated by an isoelectric baseline free of perturbation, Type II by discrete AEG complexes but with perturbations of the baseline between complexes, Type III by AEGs which failed to demonstrate either discrete complexes or isoelectric intervals, and Type IV in which AEGs of Type III alternated with periods characteristic of Type I and/or Type II. In 22 patients, the AEGs were recorded a second time, and in 11 of these patients the type of atrial fibrillation changed between the first and second recording period. An atrial flutter-fibrillation pattern in the ECG was associated with a relatively ordered atrial activation pattern and a relatively slow atrial rate. Human atrial fibrillation is not an electrophysiologically homogeneous process when compared among different patients or ad seriatim in the same patient.


Permanent cardiac pacing in infants and children.

This clinical review details our 15 year experience with permanent cardiac pacemakers in 81 infants and children. Pacing was found inappropriate in one infant. The other 80 patients were paced because of congenital heart block [24], post-operative block [50], or sick sinus syndrome [6]. Maintenance of long-term pacing requires all too frequent re-operation for battery depletion [37%], lead related problems [32%] or wound dehiscence [31%]. Problems related to pacemaker size and the presence of a high myocardial threshold are particularly important in the pediatric patient. In spite of these problems, children requiring cardiac pacemakers can be extremely well, their prognosis depending almost entirely on the presence of underlying heart disease.


Preliminary experience with the pH-triggered pacemaker.

A cardiac pacemaker capable of responding to blood acidosis by change in its stimulation rate allows adjustment to a patient's metabolic needs. The blood pH is sensed by an iridium oxide electrode in the right atrium. During exercise, the venous pH decreases and the paced ventricular rate increases. If acidosis persists, the paced rate gradually returns to baseline and reaches it after about 70 minutes. A pH-triggered pacemaker has been implanted in a 72-year-old male. The pacemaker remained responsive one year after implant, increasing rate during exercise, cold pressor stress, ischemia of the arms and emotional stress.


Permanent pacing in the elderly.

A total of 89 patients, age 80 years or older at the time of initial permanent pacemaker implantation, were followed for 10 to 128 months [mean 32.7]. There were 54 males and 35 females. The mean age was 84.8 years. There were 51 patients age 80-84, 25 age 85-89, and 13 age 90-94. The actuarial 5-year survival was 45%. Complications occurred in 23 patients [40 episodes]. To date, 41 patients have already required at least one pulse generator replacement and 2 patients have already required 5 replacements. All but 3 patients were symptomatic prior to pacing and 56 were asymptomatic at last follow-up. Permanent pacing in the elderly is therapeutically rewarding and not associated with excess morbidity.


Risks of delayed potentials in pacemaker patients prone to ventricular tachycardia.

Late potentials occurring after completion of the QRS complex have been observed in patients prone to ventricular tachycardia. They were recorded either during epicardial studies or in the catheterization laboratory. This paper describes such abnormal myocardial activity and discusses their potential effects on cardiac pacemakers.


Symptomatic improvement in a patient with sick sinus syndrome after the onset of stable atrial flutter.

A patient with sick sinus syndrome (SSS) presented with episodic lightheadedness and weakness. The electrocardiographic features were marked supraventricular bradyarrhythmias and paroxysmal atrial flutter. The symptoms lasted for four years and disappeared with the onset of stable atrial flutter which has persisted for the past seven years. Over the 11-year period of observation, there has been progressive involvement of the His-Purkinje system manifested by the development of left anterior fascicular block, right bundle-branch block, and prolongation of the HV conduction time. The patient has refused pacemaker implantation. In the absence of angina and in the presence of a normal heart size, the etiology of his SSS is postulated to be idiopathic fibrosis of his conduction system.


Additional evidence for re-entry within the bundle branches in man.

A repetitive, non-paced ventricular beat (V3) often occurs during ventricular extrastimulus testing at short coupling intervals when critical retrograde His-Purkinje conduction delay is achieved. Though re-entry within the bundle branches has been proposed as the mechanism for V3, it has been difficult to exclude local re-entry. In the present case, we consistently recorded a right bundle branch potential as well as a bundle of His potential before each V3. The anterograde activation sequence of these potentials provides evidence against local re-entry and supports re-entry involving the bundle branches as the mechanism for V3.


Termination of symptoms in the sick sinus syndrome by atrial fibrillation.

A female patient with symptomatic sick sinus syndrome (SSS) had a permanent pacemaker implanted. She later developed chronic atrial fibrillation with an adequate ventricular rate. When the pulse generator failed she was found to be clinically asymptomatic. This patient had never adjusted emotionally to her pacemaker and, since she was asymptomatic and in a stable rhythm, the failed pacemaker was not replaced. Possibly, thought should be given to the discontinuance of pacing for the SSS when, in the presence of adequate A-V conduction, stable atrial fibrillation develops.


Reprogramming of implanted pacemaker following external defibrillation.

This report describes reprogramming of a pulse generator consequent to cardiac defibrillation. Analysis of the explanted pulse generator revealed normal function. We tested the electrical properties of several defibrillators and our studies suggest that erratic electrostatic discharges at the time of paddle application before defibrillation may create a signal sequence capable of reprogramming the particular pulse generator by activating either the reed switch or internal electronics.


Apparent malfunction of demand pacemakers due to spurious potentials generated by contact between two endocardial electrodes.

Malfunction of both temporary and permanent demand transvenous pacemakers was caused by contact between the two endocardial electrodes. Contact between these electrodes created spurious potentials which resulted in irregular inhibition of both demand units. The potentials were demonstrated by recording from the temporary wire. There was no interference with either pacemaker in the fixed rate mode and malfunction ceased when the temporary wire was removed.


Investigation of the response to some haptenic determinants in penicillin allergy by skin and in vitro allergy tests.

The role of three penicillin metabolites in human allergic reaction to penicillin has been assessed using sensitive in vitro tests in addition to skin testing. Conjugates of the benzylpenicilloyl (BPO), benzylpenicillenate (BPE) and penicillamine (PA) groups with human serum albumin (HSA) and bovine gamma globulin (BGG) have been made. In the passive haemagglutination test antibodies specific for all three determinants were found but there was no difference between allergic and non-allergic groups. However, the ratio IgG/IgM, specific for each determinant, was higher in normals than in allergics. In skin tests, histamine release from leucocytes and the lymphocyte transformation test, the BPO group was confirmed as the major determinant, but in some individuals the BPE or PA groups are more important.


Late onset asthma due to inhalation of Aspergillus niger.

Clinical observations and immunological evidence are presented to support a diagnosis of late onset asthma due to exposure to Aspergillus niger in a 70-year-old man. Asthma occurred on only three occasions, each time approximately 6 hr after exposure to an area containing Aspergillus niger. His sputum culture contained the same organism. Immunological correlates using the Aspergillus niger extract included positive immediate and late skin tests, histamine release from leukocytes, and serum precipitins.


Increased survival of experimental skin flaps in rats following treatment with antiadrenergic drugs.

The effect upon the survival of skin flaps of several drugs which affect the adrenergic system was studied in rats. In control animals 41% of the skin flaps had survived seven days after the operation. Reserpine (1 mg/kg) injected intraperitoneally (i.p.) three days and one day before the flap operation increased the surviving flap area by 75% (p less than 0.001) as compared to control rats injected with saline. I.p. injection of guanethidine (5 mg/kg) or bretylium (10 mg/kg) every 12 hours, starting 24 hours before surgery and continued for 5 consecutive days, also increased the surviving flap area (19 and 33% respectively p less than 0.001). The surviving flap area was unchanged when desipramine (5 mg/kg) was injected in the same way and was decreased by 15% (p less than 0.05) following i.p. injection of the MAO inhibitor pheniprazine (5 mg/kg). Treatment with alpha-methyl-p-tyrosine (75 mg/kg), i.p. 30 min before surgery or 6-hydroxydopamine (50 mg/kg) i.v. 24 hours prior to surgery also increased the flap survival (56 and 49% increase in surviving flap area, respectively, p less than 0.001). The results demonstrated that the survival of skin flaps increased when the function of the adrenergic nervous system was inhibited. Enhanced sympathetic nervous activity slightly reduced or did not affect skin flap survival.


[Heredopathia atactica polyneuritiformis. Hexadecanoic acid storage disease (Refsum's disease). Definition, treatment and pathogenesis. A short review].

Heredopathia atactica polyneuritiformis is a clinical-genetic-biochemical entity. It is therefore not a syndrome, but a nosological entity, a morbus sui generis and it is caused by a single autosomal gene. The importance of phytanic acid accumulation in this disease was first demonstrated by Klenk and Kahlke. To the author's knowledge no case with all the typical symptoms and signs of heredopathia atactica polyneuritiformis and without any atypical clinical features, has yet been reported without a concomitant disturbance of phytanic acid metabolism. The dietary treatment--(a low phytol, low phytanic acid diet)--was first proposed by Eldjarn, when the preliminary experimental results indicated that the phytanic acid was of exogenous origin. Whatever the biochemical mechanism is between accumulation of phytanic acid and clinical manifestations in heredopathia atactica polyneuritiformis, it appears that the observations made on patients following successful dietary treatment are convincing and leave little doubt that most, if not all, the manifestations in this disease are caused in some way by the accumulation of phytanic acid.


[Indications for relief and palliative operations].

Torkildsen and Spitz-Holter drainages and/or osteoclastic trepanation were performed on 29 patients suffering from a severe increase in intracranial pressure and/or a severely worsened general condition as a relieving intervention in order to permit a tumor operation later. The relieving measure enabled a tumor operation in 28 patients. The same procedure was used as a palliative step for another group of 73 patients suffering from inoperable tumorous processes. Evaluation in these cases showed that the release of pressure via the liquor system brought a prolongation of life while at the same time alleviating painful symptoms, in 50 per cent of the patients. Osteoclastic trepanation, on the other hand, appeared to be unsuitable as a palliative measure. The text is accompanied by tables.


Phenethyl alcohol inhibition of sn-glycerol 3-phosphate acylation in Escherichia coli.

In vivo and in vitro experiments were performed to determine how phenethyl alcohol (PEA) inhibits phospholipid synthesis in Escherichia coli. This drug drastically reduced the rate of incorporation of sn-glycerol 3-phosphate into the phospholipids of an sn-glycerol 3-phosphate auxotroph. PEA also reduced the rate of fatty acid incorporation into the phospholipids of a fatty acid auxotroph. The kinetics of PEA inhibition of the rate of incorporation of sn-glycerol 3-phosphate were almost identical to those of PEA inhibition of the rate of fatty acid incorporation into phospholipids. The in vivo experiments suggested that the rate-limiting step(s) in phospholipid biosynthesis inhibited by PEA is at the level of the acylation of sn-glycerol 3-phosphate or beyond this step. PEA inhibited the sn-glycerol 3-phosphate acyltransferase with either palmitoyl coenzyme A or palmitoyl-acyl carrier protein as the acyl donor. This drug, however, had no effect on the cytidine 5'-diphosphate-diglyceride:glycerol 3-phosphate phosphatidyl transferase, cytidine 5'-diphosphate-diglyceride:L-serine phosphatidyl transferase, and acyl coenzyme A:lysophatidic acid acyltransferase. The in vitro findings suggested that PEA inhibits phospholipid synthesis primarily at the level of sn-glycerol 3-phosphate acyltransferase.


Lipophilic O-antigens in Rhodospirillum tenue.

Lipopolysaccharides of eight wild-type strains of the phototrophic bacterium Rhodospirillum tenue have been analyzed. All of the lipopolysaccharides are highly lipophilic. The compositions of preparations obtained by the phenol-water or by the phenol-chloroform-petroleum ether procedure are very similar. The polysaccharide moiety, obtained by mild acid hydrolysis of lipopolysaccharide, consists mainly of aldoheptoses: L-glycero-D-mannoheptose is present in all strains, whereas D-glycero-D-mannoheptose is an additional constituent in some strains. Galactosaminuronic acid and two unknown ninhydrin-positive components were detected in the lipopolysaccharides of six strains. Spermidine and putrescine are present in large amounts in a salt-like linkage in the lipopolysaccharides from three strains. 2-Keto-3-deoxyoctonate forms the linkage between the polysaccharide moiety and lipid A. The lipid A fraction contains all the glucosamine and all the D-arabinose present in the lipopolysaccharide. D-Arabinose is an invariable constituent of the lipid A from the Rhodopseudomonas tenue lipopolysaccharides investigated. The principal fatty acids are beta-hydroxycapric, myristic, and palmitic acids. The isolated R. tenue lipopolysaccharides (O-antigens) react with rabbit antisera prepared against homologous cells. The titers in passive hemagglutination are low, similar to those found with enterobacterial R-lipopolysaccharides. R. tenue O-antigens containing only L-glycero-D-mannoheptose and those containing both the L- and D-epimers of glycero-D-mannoheptose could not be differentiated by serological means.


Stringent regulation of the synthesis of a transfer ribonucleic acid biosynthetic enzyme: transfer ribonucleic acid(m5U)methyltransferase from Escherichia coli.

This paper describes the regulation of a transfer ribonucleic acid (tRNA) biosynthetic enzyme, the tRNA(m5U)methyltransferase (EC 2.1.1.35). This enzyme catalyzes the formation of 5-methyluridine (m5U, ribothymidine) in all tRNA chains of Escherichia coli. Partial deprivation of charged tRNAVal can be imposed by shifting strains carrying a temperature-sensitive valyl-tRNA ligase from a permissive to a semipermissive temperature. By using two such strains differing only in the allelic state of the relA gene, it was possible to show the tRNA(m5U)methyltransferase to be stringently regulated. Upon partial deprivation of charged tRNAVal, the differential rate of tRNA(m5U)methyltransferase synthesis was found to decrease in a strain with stringent RNA control (relA+), whereas it increased in the strain carrying the relA allele. This increase of accumulation of tRNA(m5U)methyltransferase activity required protein synthesis. Thus, when tRNA is partially uncharged in the cell, the relA gene product influences the expression of tRNA(m5U)methyltransferase gene.


Study of ansamycin inhibition of a ribonucleic acid-directed deoxyribonucleic acid polymerase by an immobilized template assay.

A series of structurally related ansamycins have been analyzed, in a new immobilized template assay, to determine the mechanism by which they inhibit a ribonucleic acid-directed deoxyribonucleic acid (DNA) polymerase from Moloney murine leukemia virus. By this assay, we can better correlate specific structures of these drugs with inhibitory mechanisms. Using an immobilized template, we were also able to observe drug effects on the stability of complexes formed between the polymerase, a template (polyadenylic acid-agarose), and a primer, as well as to monitor the synthesis of DNA in the presence of drug. For each drug, we determined the complex (intermediate in DNA synthesis) which was primarily affected and whether the effect was due to a destabilization process. Although the activity and specificity of the unsubstituted ansamycins (streptovaricins and rifamycin SV) were modulated by conformation of the molecule and electron density of the aromatic ring, the principal mode of inhibition is, apparently, drug binding to a polymerase-template complex; the drug binds in a manner which prevents subsequent formation of a polymerase-template-primer complex. However, some derivatives of rifamycin SV, when substituted at carbon-3 with bulky or hydrophobic side chains, displayed markedly different modes of action. For example, demethyl dimethyl rifampin prevented the formation of polymerase-template complexes, whereas rifazacyclo 16 acted by promoting the dissociation of polymerase-template-primer complexes.


Serologic studies in juvenile rheumatoid arthritis: a review.

Careful study of inflammatory and immunologic parameters in JRA and other connective tissue diseases of childhood has contributed to our current understanding of these diseases. Examination of serum for acute phase reactants, and antibodies to immunoglobulin antigens and nuclear antigens, combined with radiologic evaluation of symptomatic joints and, when indicated, examination of joint fluid or synovial membrane, may confirm the diagnosis of JRA. Changes in inflammatory indicators can be used as an index of adequacy of treatment. An ANA positivity in the child with pauciarticular arthritis should always prompt frequent slit-lamp examinations for asymptomatic iridocyclitis. The role played by auto-antibodies in the pathogenesis of JRA is unknown, as is the possible effect of proteins like CRP on the regulation of the inflammatory process in these children.


Ineffectiveness of bleomycin in verrucous carcinoma of the vulva.

A case of verrucous carcinoma of the vulva is reported and the literature concerning verrucous carcinoma of the vulva is reviewed. The difficulties about the therapy are discussed.


Changes in peripheral hormone levels after therapeutic abortion.

Plasma levels of progesterone, 17 alpha-OH progesterone, hPL and beta-subunit hCG were measured in a group of women for 24 h after therapeutic abortion. Progesterone, hCG and hPL levels fell more rapidly than 17 alpha-OH progesterone levels. This might suggest that the main site of synthesis of 17 alpha-OH progesterone is probably in the corpus luteum of pregnancy or that the prolonged half-life of hCG maintains the corpus luteum to secrete longer. Human placental lactogen fell dramatically within 4 h but the hCG level was maintained. This difference probably reflects only the differences in half-lives of these hormones.


Formation of HCG in the human fetoplacental unit.

HCG and beta-HCG were determined in umbilical arterial and venous blood immediately after spontaneous term delivery. HCG and beta-HCG are present in higher concentrations in arterial than in venous umbilical cord blood. The data are consistent with the hypothesis that HCG and beta-HCG are produced in the fetal compartment of the human fetoplacental unit, with a larger contribution of the female fetus as compared with the male.


Effect of interferon on growth and division cycle of Friend erythroleukemic murine cells in vitro.

The administration of appropriate doses of interferon to cultures of Friend leukemia cells causes a pronounced inhibition of cell growth. Several lines of evidence indicate that this effect is due to interferon itself, rather than to unknown contaminants of interferon preparations. Autoradiograph analysis of growth parameters of Friend leukemia cells during treatment with interferon demonstrates that the rate of entry into the S phase, the percent decline of unlabeled mitoses, and the mitotic indexes are significantly lower in interferon-treated cell cultures than in control untreated cultures when tritiated thymidine was added 12 h after the administration of interferon. These data indicate that fractions of interferon-treated cell population are delayed in both G1 and in G2 phases of the cell cycle. This was confirmed by exact measurements of the length of the various phases of the cycle. The interferon-induced inhibition of growth of Friend leukemia cells is reversible after removal of the compound. Autoradiograph data obtained from control cultures and from cultures previously treated with interferon that had been washed free of interferon and reseeded in interferon-free medium, demonstrate that during the first 12 h after removal of interferon, a large majority of the cells previously treated with interferon had a deranged flow into the S phase, a high number of unlabeled mitoses, and a low mitotic index. These data provide further evidence for the above-mentioned prolongations of G1 and G2 phases of the cell cycle. All growth parameters tested reverted to normal values within 12 h after washing out interferon.


Diffusion rates of cell surface antigens of mouse-human heterokaryons. II. Effect of membrane potential on lateral diffusion.

The rate of appearance, in a population of mouse-human heterokaryons, of cells with intermixed mouse and human surface antigens may be used to estimate the rate of lateral diffusion of the antigens in a single cell. Most heterokaryons appear to restrict diffusion of their surface antigens. These restrictions are altered by exposing either heterokaryons or their parent cells to conditions that change cell surface membrane potential. Media containing unphysiological concentrations of potassium ion, drugs, affecting the Na+,K+ ATPase, or a channel-forming antibiotic, gramicidin, all affect lateral mobility of cell surface antigens in a manner consistent with a common effect on membrane potential.


Immunological induction of T lymphocytes: role of antigen and the lymphocyte costimulator.

In vitro T cell activation requires both antigen presentation and a second stimulus provided by the lymphocyte costimulator. Neither alone is sufficient to induce specific T cell activation. The S+ phenotype of stimulating cells is dependent on the metabolic activity of these cells. This finding is consistent with the notion that production and/or release of the costimulator is a function of metabolically active cells. The costimulator acts at an early stage of the interaction between lymphocyte and antigen, and the costimulator, or a separate maintenance factor, is required throughout the culture period for the expression of full cytotoxic activity. The lymphocyte costimulator is not strain specific but is phylogenetically specific. The activation of cytotoxic T cells by S+ cells is also phylogenetically specific, and this specificity of cellular activation can be accounted for by the species specificity of the lymphocyte costimulator.


An analysis of arcurate staining with B&L SOFLENS. Part II.

A study of 72 eyes fit with hydrophilic lenses reveals that 46 per cent manifested arcuate staining. Arcuate staining is epithelial, superficial and located in an area between four and eight o'clock on the cornea. The authors relate several factors of soft lens fitting to the occurrence of arcuate staining.


Ultrastructural localization of transcription sites and of RNA distribution during the cell cycle of synchronized CHO cells.

The ultrastructural localization of [3H]uridine-labelled RNA synthesized in the course of the cell cycle of synchronized CHO cells is studied using high resolution autoradiography combined with a differential staining for nucleoproteins. It is shown that sites of RNA transcription can already be visualized on the periphery of chromosomes of apparently late metaphase-early anaphase cells with no visible association with the reforming nuclear membrane. In interphase cells they are associated with the border of intranucleolar chromatin or condensed nucleoplasmic chromatin, wherever this localization is made possible by the degree of chromatin dispersion. In cells labeled for 1 or 3 h, the rate of RNA synthesis is higher in S and G2 than in G1. When cells fixed immediately after a [3H]uridine pulse are compared with those post-incubated for 13 h in isotope-free medium, there is a clear difference in intensity of labelling between the nucleus and the cytoplasm. However, the localization pattern of radioactive RNA in the nucleus is similar for all incubation periods as well as for all phases of interphase. The groups of interchromatin granules are generally labeled weakly with radioactivity associated rather with the periphery of their clusters, or remain unlabelled. These results are discussed in the context of other recent findings concerning the distribution of RNA and RNP-structures in the nucleus.


[Chemotherapy of malignant lymphomas].

The indications for chemical treatment (with or without radiation) and modalities tailored to Hodgkin and non-Hodgkin forms (and their histological types), and to the different stages of malignant lymphoma are described. Reference is also made to the results that may be expected.


Expression of the regulation of cAMP metabolism in somatic cell hybrids.

Normal rat liver cells (BRL-1) that respond to isoproterenol (beta+2), prostaglandin E1 (PGE+1) and adenosine (Ado+) with a rise in adenosine 3':5'-monophosphate (cAMP) content have been hybridized with rat hepatoma cells (H35) which do not respond to any of these agonists (beta-2, PGE-1 and Ado-). Both the initial hybrid line (BF5) and a subclone (BF5-1-1) expressed a beta+2, PGE+1, Ado- phenotype. However, full expression of the responsive phenotype in the BF5 line was apparent only if phosphodiesterase activity was blocked, for example, by methylisobutylxanthine (MIX). Direct measurements showed the rate of degradation of cAMP to be 7 times greater in intact BF5 cells than in the BRL-1 parent. In contrast to BF5 cells, the BF5-1-1 cells did not express maximal responsiveness to any of the agonists even in the presence of MIX. The differential accumulation of intracellular cAMP observed with BRL-1, BF5 and BF5-1-1 cells in response to isoproterenol was shown not to be as a result of differential rates of excretion of cAMP. Furthermore, no differences in the apparent affinities of the beta 2-catecholamine receptors for isoproterenol were observed. It is suggested that the increased degradative capacity of BF5 cells accounts for the difference in cAMP accumulation in these cells compared with the BRL-1 parent. The reduced responsiveness of BF5-1-1 cells, however, does not appear to be solely due to increased phosphodiesterase activity. It appears that the beta 2- phenotype may not always be dominant in hybrid crosses of this type as has been reported previously.


Asymmetric decondensation of the L cell heterochromatin by Hoechst 33258.

A benzimidazole derivative, Hoechst 33258 can induce decondensation of constitutive heterochromatin in the mouse derived L cell chromosomes when the compound is given in sufficiently high concentration (40 micrograms/ml) to the L cell culture. Hoechst 33258 at low concentration (1 micrograms/ml, 16 h) cannot produce this effect on L cell chromosomes. Bromodeoxyuridine (BUdR) incorporation for one cell cycle simultaneous with the Hoechst 33258 treatment at low concentration could decondense heterochromatin segments in metaphase chromosomes. The heterochromatin decondensation, however, was asymmetric; it was observed only on one chromatid and the other of a chromosome remained in condensed state. The observation of asymmetric decondensation of heterochromatin by Hoechst 33258 after BUdR incorporation for one cell cycle, the association of A-T rich satellite DNA to mouse heterochromatin, and available data on the specific binding of Hoechst 33258 to A-T base pairs of DNA and on the higher affinity of the compound to BUdR substituted DNA than to ordinary DNA implied that the binding of Hoechst 33258 molecules to A-T rich satellite DNA is the cause of heterochromatin decondensation.


Phosphoribosylpyrophosphate in erythrocytes of ten mammalian species: concentration, synthesis and degradation.

1. The concentration of PRPP and the activity of PRPP synthetase have been measured in hemolysates from man and nine other mammalian species. PRPP synthetase activity was very low in dog hemolysate. 2. High concentrations of PRPP appeared to be associated with low levels of HGPRT activity, suggesting that HGPRT is the major pathway for utilization of PRPP in mammalian erythrocytes. 3. An alternative catabolic route for PRPP was observed in mammalian hemolysates, which seemed to be associated with acid phosphatase activity. The activity of acid phosphatase in mammalian hemolysates was measured.


Immunochemical comparison of human and goat haptoglobin and alpha 2-macroglobulin.

1. A non-haptoglobin alpha 2-globulin was observed in the plasma of goats (Capra hircus) after inflammatory stresses. 2. This stress reaction protein exhibited an electrophoretic mobility and molecular weight similar to goat haptoglobin. 3. Complete immunological cross-reactivity was demonstrated between the goat protein and human alpha 2-macroglobulin. 4. The functional and evolutionary significance of these observations are discussed.


Immunochemical comparisons among myelin basic proteins.

1. The relationships among myelin encephalitogenic or basic proteins were immunochemically examined. 2. Rabbit antisera to myelin basic proteins isolated from chicken, rabbit, bovine, guinea-pig, and human brain specimens were prepared. By quantitative microcomplement fixation these rabbit antisera were used to measure cross-reactions among the myelin basic proteins of the turtle, chicken, rat, rabbit, cow, pig, sheep, dog, guinea-pig, monkey and human. 3. A spectrum of cross-reactivities was detected even though some cross-reactivity persisted across major phylogenetic barriers. Varying, but sometimes marked, differences existed in reactivities of the small and large basic proteins of the rat. Reciprocity of cross-reactivities among basic proteins was inconstant. 4. This study demonstrates the range of immunochemical cross-reactivities among myelin basic proteins and the sensitivity of quantitative microcomplement fixation in assessing such antigenic or conformational differences.


Comparative studies on immunochemical properties of female-specific serum protein and egg yolk proteins in rainbow trout (Salmo gairdneri).

1. Female-specific serum protein (FS) and egg yolk proteins of mature female rainbow trout (Salmo gairdneri) were studied comparatively with reference to their immunological and some physicochemical properties. 2. FS was considered to be composed of two egg proteins, E1 and E2, which were isolated from the egg yolk by gel filtration. 3. The molecular weights of FS, E1 and E2 were estimated by gel filtration to be approx 600,000, 300,000 and 35,000, respectively. 4. The analysis with sodium dodecyl sulphate electrophoresis indicated that E1 consisted of two subunits with molecular weights of 90,000 and 15,000, and E2 was estimated to be a dimer of a molecule of 15,000. 5. Male and immature female trout were injected with estradiol-17 beta, and the production of proteins with the same antigenicity with FS was demonstrated.


A study of rabbit plasma progressive antithrombinic activity during acute phase inflammatory reaction and in experimental nephrotic syndrome.

1. The development of the progressive antithrombinic activity in rabbit plasma as a function of the level of the two alpha-macroglobulins in two experimental pathologies: acute phase inflammatory reaction and nephrotic syndrome, were studied. 2. In the first case, the antithrombinic activity is a result of the increased biosynthesis of plasmatic antithrombins: antithrombin III, alpha 1 antitrypsin and alpha macroglobulins. 3. In the nephrotic syndrome, this activity follows the increase in the alpha M levels, the other antithrombins having been massively eliminated from the circulation in the urine.


Amylase activity, glycoprotein and electrolyte concentration in rat's submaxillary salivary gland during heat acclimation.

1. Amylase activity, glycoproteins, Na and K concentrations were measured in submaxillary salivary gland of the rat during heat acclimation (34 degrees C). 2. Acclimation resulted in a decrease in glycoprotein concentration and amylase activity, whereas Na and K concentrations and the Na/K ratio increased. 3. It is suggested that heat acclimation results in an increase in glandular activity leading to increased water secretion and depletion of the glycoprotein store. The decrease in amylase activity is probably due to liver atrophy which occurs during prolonged heat exposure.


Cytoplasmic RNA from hen reticulocytes, mouse sarcoma 180 ascites cells, rat liver and barley embryos. Their preparation and purification by a standard procedure and characterization by polyacrylamide gel electrophoresis.

1. This paper describes a standard procedure for the preparation and purification of RNA from the post-mitochondrial supernatants of a number of eukaryotes. 2. Cytoplasmic RNA was fractionated by NaCl precipitation. The 28S (26S), 18S and 5.8S rRNA, and 9S RNA, in the NaCl insoluble fraction were separated by a two-step sucrose gradient fractionation procedure. Poly(A)-containing mRNA in hen 9S RNA was purified by affinity chromatography. The 5S rRNA and tRNA in the NaCl-soluble fraction were fractionated by gel filtration. 3. Polyacrylamide gel electrophoresis showed that the above RNA species were remarkably stable and homogeneous. Differences were found in the 26-28S rRNA, 5.8S rRNA, and 9S RNA of different eukaryotes, but other cytoplasmic RNA species were identical.


Inhibition of rat and bovine trypsins and chymotrypsins by soybean, bovine basic pancreatic, and bovine colostrum trypsin inhibitors.

1. Bovine (Bos taurus) trypsin and trypsin activity in rat (Rattus norvegicus) pancreatic extract were inhibited by soybean trypsin inhibitor and by bovine basic pancreatic and colostrum inhibitors. 2. Bovine alpha-chymotrypsin was inhibited by soybean and bovine basic pancreatic inhibitors but only weakly by colostrum inhibitor. 3. Chymotrypsin activity in rat pancreatic extract was due to at least three different components against all of which the inhibitors were largely ineffective. 4. It is concluded that bovine colostrum inhibitor has a more limited inhibition spectrum than the phylogenetically related basic pancreatic inhibitor which, in turn, is less active against rat than against bovine enzymes.


Dose response kinetics of serum vitellogenin, liver DNA, RNA, protein and lipid after induction by estradiol-17 beta in male flounders (Platichthys flesus L.).

1. Male flounders receiving 100 micrograms estradiol each second day were fully induced to vitellogenin synthesis within 11 days, while fishes given 5 micrograms doses continued to accumulate vitellogenin in the serum at a progressive rate through 17 days. 2. Liver DNA per unit fish remained constant, while RNA per unit fish in flounders given 100 and 5 micrograms doses attained values 80 and 25% respectively, above the values found in control animals. 3. Liver RNA per unit DNA increased at maximal rate within 6 days in fishes receiving 100 micrograms doses. RNA synthesis continued at a progressive rate through 17 days in fishes given 5 micrograms doses of estradiol. 4. Liver protein per unit DNA elevated at a plateau 60% above control within 6 days with 100 micrograms doses. Doses of 5 micrograms had only little effect on liver protein. 5. Estradiol had a lipogenic effect on the liver. Cellular lipid rose 120 and 60% above control after treatment with 100 and 5 micrograms respectively. 6. Liver dry weight per unit DNA increased 60 and 55% above control with 100 and 5 micrograms doses respectively. Cellular hypertrophy in fishes receiving the smaller dose was primarily associated with an increase in lipid concentration, while protein and lipid contributed almost equally to cellular growth in fishes receiving the high dose.


Photoperiodically induced variation in testicular RNA, DNA and protein content in hamsters and ground squirrels.

1. The total testicular content of RNA, DNA and protein was found to decrease sharply in hamsters with shortened photoperiod and in ground squirrels during the spring breeding season. 2. RNA and DNA per g testes were found to increase in both animals, while protein per g testes remained fairly stable. 3. Cell-free protein synthesis by testicular PMS during testicular regression remained constant when expressed per mg of testicular RNA, but decreased 75% when expressed per testes. 4. These findings suggest that decreases in testicular protein synthesis are due to a decrease in RNA content and not to alteration of the translational activity of the RNA.


Amylase levels in the tissues and body fluids of the domestic cat (Felis catus).

1. The amylase activities of serum, liver, pancreas, submaxillary and parotid glands, saliva, duodenum, colon, lung, heart, spleen, kidney and skeletal muscle of the domestic cat, were determined. 2. As in most mammals, the highest amylase content was found in the pancreas. Levels in saliva and salivary glands were very low. 3. Amylase activities of the serum, liver and pancreas have an optimum pH 7.0-7.5. 4. Amylases of serum, liver and pancreas were inactivated by removal of chloride and these activities mainly restored by addition of chloride.


AMP deaminase in the gill of trout (Salmo gairdneri R.). Modalities of an activation by cellular proteolytic enzymes.

1. The AMP deaminase activity present in a crude extract of trout gill increased with time. 2. Soybean trypsin inhibitor and alpha2-macroglobulin inhibited the AMP deaminase activation. NEM was also inhibitory at 10-3 M. 3. The activation process is followed by a decrease of activity which is inhibited by EGTA and enhanced by Mg2+. These two compounds were without effect on the activation process itself. 4. Trypsin induces a sharp activation of AMP deaminase in a fresh gill extract but is without effect on a fully activated extract. 5. Overall, the results suggest that neutral proteinases are implicated in AMP deaminase activation.


Influence of molt cycle and beta-ecdysone on protein synthesis in the chelicerate arthropod, Limulus polyphemus.

1. The effect of molt cycle stage and beta-ecdysone on protein synthesis in the horsehoe crab, Limulus polyphemus, was examined. 2. A pronounced decline in protein specific radioactivity after incubation with 14C-leucine was noted in muscle, midgut gland and operculum from postmolt to intermolt to premolt and in gut and gill tissue from intermolt to premolt. 3. beta-Ecdysone injections produced an early stimulation of protein synthesis in the midgut gland followed by strong inhibition within 48 hr. 4. Results are compared with those obtained in mandibulate arthropods.


Selected enzyme activities in Mya arenaria hemolymph.

1. The activities of lysozyme, acid and alkaline phosphatases, beta-glucuronidase, amylase, lipase, glutamate-oxalacetate transaminase, and glutamate-pyruvate transaminase in the whole hemolymph and 4000 g pellets and supernatants of Mya arenaria were determined. 2. All of these enzymes, except for amylase, occurred in whole hemolymph as well as in the 4000 g pellet and supernatant. 3. Based on earlier observations, these enzymes are believed to be of cellular origin within hemolymph cells. 4. In the case of amylase, it only occurred in the whole hemolymph and/or serum and is believed to have originated from the crystalline style.


Nematode chromosomal proteins--I. Isolation of chromatin and preliminary characterization of the chromosomal proteins of Caenorhabditis elegans.

1. A procedure is described which gives clean chromatin preparations from the free-living nematode Caenorhabditis elegans. It involves homogenization using glass beads, collection of the precipitate from a low speed centrifugation, removal of cell membranes with Triton X-100, several washes with 0.14 M NaCl, sucrose density gradient centrifugation, a cycle of extraction and reprecipitation using dilute Tris buffer and 0.14 M NaCl respectively, and final extraction of the purified deoxyribonucleoprotein in 10 mM Tris-HCl (pH 8). 2. Acidic urea gel electrophoresis of the histones from C. elegans yielded 4 main groups which were preliminary identified as H1, H2a (+ H3?), H2b, H4 and moved on the gels in that order of increasing mobility. the coincidence of histone H3 with H2a was putative, but its presence was firmly suggested by the generation of a dimeric form in oxidizing conditions. 3. By SDS-Tris-glycine gel electrophoresis of the non-histone chromosomal proteins of C. elegans, about 18 proteins were distinguished with molecular weights ranging from 15,000 to 100,000 daltons.


Clinical use of high dose methotrexate within the Queensland Radium Institute.

The Royal Brisbane Hospitals Group is the second largest user of methotrexate in Australia. The Queensland Radium Institute and the Royal Children's Hospital are both members of the Royal Brisbane Hospitals Group and they are responsible for high dose methotrexate treatment of adults and children within the Group. Children requiring such treatment are seen by staff from both centres. Therefore, the report which follows describes the usage in both adults and children.


Comparative response of male rats to parathion and lindane: histopathological and biochemical studies.

Exposure of male rats to parathion (2.6 mg/kg), lindane (17.6 mg/kg), or their combination through oral intubation daily for a period of 90 days produced histological and biochemical alterations in the liver and testis. The focal necrosis of the liver, although observed in all the treatments, was very prominent in the animals exposed to lindane alone. The kidney and epididymis, however, did not show any significant histological lesions. The activity of acetylcholine esterase in blood and brain decreased markedly, whereas that of succinic dehydrogenase, adenosine triphosphatase, and the alkaline and acid phosphate in liver and testis showed significant alterations for all three treatments.


Inhibition of fast axoplasmic transport by acrylamide.

The effect of acrylamide on fast axoplasmic transport in the cat sciatic nerve was studied in vivo and in vitro by the technique of isotope injection. [14C]leucine was injected into the lumbar dorsal root ganglia. In cats fed daily doses of acrylamide over 1 to 4 weeks, the rate of transport was 286 mm/day compared with 424 mm/day in controls. In vitro incubation of the sciatic nerve with acrylamide (2 x 10(-2) M and 2 x 10(-4) M) demonstrated no such inhibition. Study of the results and review of the literature suggest that acrylamide acted subacutely on metabolism of amino acid and protein in the nerve axon, probably in the smooth endoplasmic reticulum.


Cadmium, a metallic inhibitor of antibody-mediated immunity in mice.

Chronic administration of cadmium chloride to B10-A-2R mice was discovered to severely depress the numbers and to delay the onset of appearance of splenic IgG and IgM plaque-forming cells (PFC) following injection of sheep erythrocytes. A recovery period of at least 1 month following cessation of administration of CdCl2 resulted in no increase in IgM PFC and only a minimal increase in IgG PFC. An apparent cadmium-induced splenomegaly was also noted in the intoxicated mice. Application of immune adherence and rosetting techniques as well as immunofluorescence to study the cellular morphology of these spleens indicated that the cell type most responsible for the increased spleen size had Fc and complement receptors as well as surface or cytoplasmic immunoglobulins. Populations of polymorphs and macrophages were not found to significantly contribute to the hyperplasia observed.


Effect of neurotensin, substance P and morphine sulfate on the secretion of prolactin and growth hormone in the rat.

Neurotensin (NT), substance P (SP) and morphine sulfate (MS) elevate plasma prolactin and growth hormone levels in both normal or estrogen-progesterone pretreated male rats. By contrast, steroid priming is required for TRF to exhibit PRL-releasing activity. Naloxone, an opiate receptor blocker, reverses the stimulatory effect of MS only. Diphenhydramine, a histamine antagonist, inhibits the response to NT, SP and MS without affecting the response to TRF. These results suggest the involvement of a histaminic step in the action of NT, SP and MS. TRF, NT and SP do not appear to stimulate PRL and GH through activation of an opiate receptor.


Further evidence for inhibition of episodic luteinizing hormone release in ovariectomized rats by stimulation of dopamine receptors.

Stimulation of dopamine receptors by apomorphine inhibits episodic LH release in ovariectomized rats. The present study was designed to examine further the role of dopamine in this process. Unrestrained, unanesthetized rats with indwelling right atrial cannulae were bled continuously (30 or 50 microliters of whole blood/5 min for 3-6 h) and whole blood samples analyzed for LH by radioimmunoassay. Animals were treated with various compounds reported to stimulate or block dopamine receptors. ET 495, a long acting dopamine receptor stimulating agent, caused a marked inhibition of episodic LH release (2 1/2-4 h). Control injections of distilled water had no effect. d-Butaclamol, a blocker of dopamine receptors, did not itself alter episodic LH release but prevented the inhibitory effects seen following apomorphine or ET 495. I-butaclamol, a biologically inactive form of butaclamol, had no effect. Measurement of plasma corticosterone levels in these same animals indicated increased values following apomorphine or ET 495 alone (when LH release was inhibited), as well as after apomorphine or ET 495 administration to d-butaclamol-pretreated rats (when LH levels did not change). These data support our previous hypothesis that in ovariectomized adult rats, activation of dopamine receptors is capable of inhibiting episodic LH release, but that dopamine may not play an inhibitory role under normal physiological conditions in the modulation of LH secretion. In addition, the inhibitory action of apomorphine and ET 495 does not appear to be exerted via a stress-induced release of adrenal corticosterone.


A new substance resembling luteinizing hormone in the blood of rhesus monkeys.

Sera from a number of rhesus monkeys showed low or undetectable levels of LH according to radioimmunoassays which employ radioiodinated rhesus LH and antisera against rhesus LH or hCG. These same sera, when assayed by a system utilizing radioiodinated ovine LH and a unique anti-ovine LH serum which cross-reacts with LH from a variety of species, appeared to contain large and variable quantities of LH. The chromatographic behavior on Sephadex G-100 of the LH-like material in these sera was indistinguishable from that of authentic rhesus LH. Chromatographic fractions containing this LH-like material, as well as the sera from which they were derived, generated dose-response curves in the ovine:anti-ovine radioimmunoassay with steeper slopes than those produced by rhesus LH. These same chromatographic fractions had negligible activity in an alpha subunit radioimmunoassay which detects not only free rhesus alpha subunit but also the alpha component of undissociated rhesus glycoprotein hormones including LH. Treatment of these fractions with 4M guanidine-HCl produced a substance of smaller molecular size which, like rhLH beta, was active in the ovine:anti-ovine assay. A substance closely resembling the serum LH-like material but having a somewhat greater molecular size is also present in the rhesus adenohypophysis, but its relationship to the serum substance remains uncertain.


The value of the amylase/creatinine clearance ratio in the diagnosis of acute pancreatitis.

Acute pancreatitis usually confronts the clinician with a difficult diagnostic task. For years, the primary laboratory diagnostic tests were the serum and urine amylase and the serum lipase determinations. Recent studies have introduced the concept of the amylase/creatinine clearance ratio as a means of increasing the specificity of the laboratory diagnosis. This paper reviews the laboratory evaluation of acute pancreatitis with emphasis on the rationale, derivation, and specificity of the amylase/creatinine clearance ratio.


A peculiar rhythmic EEG activity from ventrobasal thalamus during paradoxical sleep in man.

A peculiar 3/sec rhythmic EEG activity (named Vc rhythm) was consistently found at the ventrobasal thalamus (nucleus ventrocaudalis) during paradoxical sleep of patients with implanted electrodes used as an electrophysiological procedure for identification of the thalamic targets for the surgical treatment of tremor and rigidity. The Vc rhythm was formed by high voltage, sharp biphasic positive negative potentials which were absent during wakefulness, rare and isolated during slow wave sleep, increased in number and organized in trains during paradoxical sleep and blocked during arousal. Significant changes in number of Vc waves were found when patients shifted through these wakefulness-sleep states. Integrated EMG multiple unit activity also showed significant changes during these wakefulness-sleep shifts, which were parallel although inverse to those showed by Vc waves. A significant negative correlation (r = -0.7126) between number of Vc waves and EMG units was found. In contrast, Vc waves showed no correlation with other electrophysiological indicators of thalamic excitability (multiple unit activity and early evoked potentials) and sleep (scalp EEG frequency and ocular movements).


Minute eye movement during sleep.

The minute eye movements of 4 sleeping subjects were studied with a piezo-electric strain-gauge transducer. The frequency and amplitude of ocular microtremor activity diminished during sleep. Activity increased after auditory stimulation and with the appearance of a K complex in the EEG. The ocular microtremor activity also increased with the onset of rapid eye movement (REM). Low amplitude 'micronystagmoid' movements were observed at intervals throughout sleep. In contrast to the changes observed during sleep, ocular microtremor activity did not diminish during hypnosis. The transducer was far more sensitive than the conventional EOG recording system.


Comparison of the magnetoencephalogram and electroencephalogram.

The spatial response of the magnetoencephalogram (MEG) to sources in the brain's cortex is compared with that of the electroencephalogram (EEG). This is done using computer modeling of the head which is approximated by 4 concentric spherical regions that represent the brain and surrounding bone and tissue. Lead fields are calculated at points on the cortex for unipolar, bipolar and quadrupolar MEG and EEG measurements. Since lead fields are patterns of the sensitivity of these measurements to a source at various locations and orientations, they provide a convenient means for comparison. It is found that a unipolar MEG has a very different lead field than a unipolar EEG. Hence, this type of MEG detects sources at different locations and orientations than this EEG. Although bipolar MEG and EEG lead fields are found to have similar patterns, the MEG lead field is narrower than that of the EEG and hence 'sees' a smaller area on the cortex than the EEG. This is because the potentials measured by the EEG are 'smeared' by the low-conductivity skull; the magnetic fields measured by the MEG are not smeared. Quadrupolar MEG and EEG lead fields are found to be about the same. The responses of bipolar MEGs and EEGs to distributed sources, which are composed of aligned and randomly oriented dipoles, are compared. It is found that for both types of sources, the MEG 'sees' an area on the cortex which is approximately 0.3 times that for the EEG. Hence, the MEG appears to be useful for detecting a more restricted group of sources than the EEG.


A critical epileptic area in the cat's cortex and its relation to the cortical columns.

The critical size of active penicillin foci in cat's parietal cortex was determined in two different ways: (a) by gradually enlarging the area of drug application from 0.78 mm2 to 3.14 mm2; (b) by reducing the area of the active penicillin focus, using subpial incisions. Results indicate that a critical area of 0.7 mm2 is necessary. The possibility that in the parietal cortex a single functional column may be the basic generator unit for inter-ictal spikes is discussed. It is concluded that: (a) the size of the critical area is related to the cross-sectional area of a single functional column. This column is not yet determined by parallel anatomical findings; (b) inactivation of a given epileptic focus in the cat's cortex may be achieved by cutting layer III of the focus.


Local cerebral metabolism during enflurane anesthesia: identification of epileptogenic foci.

Electrocorticographic (ECoG) and depth recordings have previously demonstrated the epileptogenic nature of surgical concentrations of the volatile anesthetic enflurane. We contrasted ECoG activity with local cerebral glucose uptake [( 14C]2-deoxyglucose autoradiography) in 23 brain structures in order to identify the epileptogenic foci. Autoradiograms were obtained from sectioned rat brain following a 30 min period of steady-state anesthesia at 1, 1.5, or 2 MAC (minimum alveolar concentration) enflurane. Pseudo-epileptiform ECoGs were obtained at 1 MAC where bursts of slow waves and sharp waves were evoked by peripheral sensory stimulation. At 1.5 MAC, the ECoG displayed frank, spontaneous epileptiform activity with large amplitude spike-wave complexes; repetitive auditory stimulation occasionally precipitated grand-mal seizures. At 2 MAC, spike complexes were less frequent and could not be repetitively driven. At 1 MAC enflurane, regional cerebral metabolism was generally depressed approximately 14% from the awake controls. However, metabolism in the dentate gyrus of the hippocampus and other subcortical structures in the limbic brain was increased. At 1.5 MAC this dichotomy in local cerebral metabolic rate was maximal; we observed increased metabolism in the hippocampus, habenula, habenulo-interpeduncular tract and interpeduncular nucleus and pineal. Metabolism in all other structures was significantly depressed (P less than 0.05) compared to awake values. At 2 MAC, metabolism was decreased in all structures. We conclude that the low seizure threshold hippocampus and related structures associated with the limbic system and its pathways are the epileptogenic foci for seizures induced with enflurane in the rat. At 1.5 MAC, epileptiform activity spreads throughout the visceral brain when seizure threshold is at a minimum.


Television epilepsy--the role of pattern.

Patients with photosensitive epilepsy were asked to view normally functioning 625-line televisions while the EEG was monitored. In the first of two studies paroxysmal EEG activity was reliably induced by television at a viewing distance related to a patient's sensitivity to intermittent photic stimulation (IPS); patients who were sensitive to diffuse IPS at 50 Hz were sensitive to the television at greater viewing distances than those who were not. No such relationship was obtained with patterned IPS. On the other hand, patterned IPS was generally more epileptogenic than diffuse IPS with the same luminance. In the second study, where the angular subtense of the television screen and the subtense of its lines were manipulated independently, the convulsive response was found to be a function of both factors, the relative contribution of each depending on the viewing distance at which the patient was sensitive. For patients sensitive at normal viewing distances, where 50 Hz diffuse flicker appeared to be responsible for the induction of paroxysmal activity, the probability with which paroxysmal activity was induced was closely related to the subtense of the screen. For patients sensitive only at closer viewing distances the probability was influenced not by the subtense of the screen but by the subtense of its lines, suggesting that the paroxysmal activity was induced by the 25 Hz pattern alternation produced by the scan. A television with a small screen was considerably less epileptogenic than one with a large screen for all patients, presumably due to the reduced contribution of both diffuse flicker and pattern alternation.


Spike separation in multiunit records: a multivariate analysis of spike descriptive parameters.

Variables describing unit discharges from multiunit extracellular records were treated, using multivariate statistical analysis for further automatic spike separation. A spike was described by 8 parameters (3 amplitude values, 3 time values and 2 slopes). These 8 parameters were summarized by 2 new independent factors, the principal components (PC). Examination of the 2 PCs from each spike allowed the observer to determine PC families corresponding to spike populations. From these the spikes were automatically classified. PC analysis showed groups of redundant parameters. Elimination of redundancy decreased the computing time without lowering the separation efficiency of the method. Three parameters turned out to be sufficient for spike discrimination: the maximum and the minimum amplitudes and the time between these. This agrees well with the physical basis of current propagation in the conducting medium, from the firing neurone to the recording electrode.


Modifications of the pattern-evoked potential (PEP) in relation to the stimulated part of the visual field (clues for the most probable origin of each component).

A spatio-temporal analysis of the successive and simultaneous components of the pattern-evoked potential recorded on the scalp, and of their modifications according to which part of the visual field is stimulated, was carried out with 20 'normal' subjects, in order to shed some light on their most probable sites of origin. The stimulus consisted in the onset of a 20 degree checkerboard presented in runs of 75 stimuli each. Its duration was 750 msec and its frequency of occurrence was random (about 1 every 1500 msec). Twelve different visual field situations were recorded: whole field, half fields and quadrants and stimuli limited to the fovea, to the macula and to extramacular areas. Data were collected from 9 active electrodes (in line, forming a cross montage), and various reference electrodes (ear lobes, Fz, non-cephalic). Eye movements were simultaneously recorded. The electrophysiological data were digitized on line and processed by computer in the form of averaged spatio-temporal maps. In addition to the classical posterior components which peak on the midline (N 60, N 140, and P 200) or less than 4 cm away on both sides (P 90), a late negative wave (LN 210) was differentiated which peaked lower than the inion and more than 8 cm away from the midline on both hemispheres. The large inter-individual variability of the spatio-temporal organization of these components under the same conditions, as well as its very good intra-individual reproducibility, were emphasized. Interpreted on the basis of a simple dipole sheet model of the visual cortex, the changes observed for each component in the 12 experimental situations led to the following suggestions: only the first component N 60 could reflect the activity of the part of area 17 emerging on the convexity, whereas P 90 (Jeffreys' CI) is more likely to originate in area 19 and the midline components N 140 and P 200 in area 18. The topography and reactivity of LN 210 could fit with the hypothesis that it reflects activity of the infero-temporal cortex.


The effect of procaine hydrochloride and diazepam, separately or in combination, on cortico-generalized kindled seizures.

The effects of cortically kindled seizure responses of procaine hydrochloride, diazepam and combinations of these two drugs were tested in this study. The cortex was stimulated until seizure responses developed past the focal stage (accompanied primarily by brief tonic convulsions) to the cortico-generalized stage (accompanied, typically, by an early brief tonus followed by a longer clonic seizure that is characteristic of subcortically triggered seizures). Diazepam was found to block the generalized component of the cortico-generalized electrographic and motor seizure leaving the tonus only slightly suppressed. Procaine blocked the tonus leaving the clonic seizure and discharge that is characteristic of the generalized response relatively intact. Combinations of half doses of the two drugs completely blocked all electrographic and motor seizure responses in about half the animals. The remaining animals had a very brief discharge with no convulsive responses.


Contingent negative variation and accuracy of time estimation: a study on cats.

Slow cortical potential shifts, similar to the contingent negative variation (CNV) discovered in man, were analysed in cats submitted to a schedule of temporal conditioning. Two situations were compared, according to information delivered during a 7 sec delay: in the first (A), a fixed visual signal appeared on an oscilloscope screen; in the second (B), the signal moved across with time. In both cases, the cat had to press a lever 5-7 sec after signal onset. The CNV recorded during the delay had different amplitudes according to the cortical site involved. It could be dissociated into two components, which showed similar evolutions as a function of experimental conditions. The characteristics of the CNV as a whole varied with temporal parameters. CNV amplitude and time course were related to the accuracy of the cat's responses; prolonged training in unchanged experimental conditions led to a decline in negativity, which seemed to reflect automation of time estimation processes. These data suggest that CNV may be an index of a phase of information processing aimed at constituting internal time bases congruent with a particular situation.