IC Group Research Articles

Different mechanisms for the inhibition of progesterone secretion by ACTH and corticosterone in pregnant rats.

The present study investigated possible sites through which ACTH or corticosterone inhibit progesterone secretion in pregnant rats, and the role of placental factors in blocking the inhibitory effect. The number of conceptuses was adjusted to one (IC group) or more than ten (FC group) on day 7 of pregnancy by aspirating the desired number. Serum concentrations of progesterone, testosterone and oestradiol were significantly (P less than 0.01) lower on day 15 in the 1C group than in the FC group. Corpora lutea (CL) obtained on day 15 were incubated for 6 h with corticosterone or ACTH. Corticosterone (1 mumol/l) significantly (P less than 0.05) inhibited progesterone secretion in the 1C group but not in the FC group. The inhibitory effect of corticosterone in the 1C group was completely blocked by co-addition of 1 mumol testosterone/l or 1 mumol oestradiol/l but not by 1 mumol dihydrotestosterone/l. ACTH (1 microgram/l-1 mg/l) had no direct effect on progesterone secretion in either the 1C or the FC groups, although ACTH apparently decreases progesterone secretion in vivo. Placentae obtained from rats of the FC group on day 15 were incubated for 24 h with or without ACTH (1 mg/l). The supernatant after placental incubation without ACTH significantly (P less than 0.01) increased progesterone secretion by the CL in both the 1C and FC groups, and also eliminated the inhibitory effect of corticosterone in the 1C group. The supernatant after placental incubation with ACTH also increased progesterone secretion in the FC group as effectively as the supernatant from the control incubation, but it had no effect in the 1C group.(ABSTRACT TRUNCATED AT 250 WORDS)

The Interaction of Antiarrhythmic Drugs and the Energy for Cardioversion of Chronic Atrial Fibrillation

Antiarrhythmic drugs may alter the energy for cardioversion of ventricular arrhythmias. This study compares the energy necessary for cardioverting chronic atrial fibrillation in 57 patients taking type Ia, Ic, or type III antiarrhythmic drugs. Patients taking Ia (n = 22) or III (n = 14) drugs had a median energy for cardioversion of 100 joules, while the patients taking Ic (n = 17) drugs had a median energy of 200 joules (P = 0.03). There were no differences in the frequency of unsuccessful cardioversion. There were no serious adverse events in any of the three groups, although three patients in the Ic group had greater than 3 second pauses after the shock. The data suggest that the use of Ic antiarrhythmic drugs results in a higher energy for cardioversion of atrial fibrillation. However with higher energies, conversion is as successful as for type Ia and type III.

Searching for interference among consistent and inconsistent editors: The role of analytic and wholistic processing

Three groups of 10 computer-naive subjects each learned two command-based experimental text editors on days 1 and 2 and practised them in an alternating sequence on the following two days. Editors differed in the consistency of the mapping from the commands to response keys. Group CI first learned a mainly consistent system, then an inconsistent one. Group IC had the reverse order, and a control group II learned and performed on two inconsistent editors. Under the conditions of the study, the consistent mapping was not exploited if it was encountered subsequently to the study of an overall inconsistent system. Subjects who learned a consistent system first also exhibited strong effects of consistency, i.e. relatively slower execution times on an inconsistent system. The fact of previously having experienced the consistency principle was actually shown to interfere with the learning of an inconsistent editor. The results suggest that the different mapping-rules induce different modes of processing that carry over into a session in which a new rule applies. The consistent system strengthens an analytic mode that is based on the decomposition of the command into its function and object components. Interference follows from the attempt to apply this mode to a subsequent largely inconsistent system. Inconsistency forces the subjects to rely on a wholistic fact-retrieval mode that integrates the separate key presses into a single code.

The role of the inferior prefrontal convexity in performance of delayed nonmatching-to-sample

Findings in an earlier study (B achevalier, J. and M ishkin, M. Behav. Brain Res. 20, 249–261, 1986) indicated that ventromedial prefrontal cortex, which receives thalamic projections from the limbo-diencephalic system, is critical for visual recognition; whereas the dorsolateral prefrontal cortex, which receives no such thalamic projections, makes little or no contribution to this type of memory. In the present study, we examined the role in recognition of another prefrontal area outside the thalamic projection zone of the limbo-diencephalic system, namely, the inferior prefrontal convexity. In the first experiment, monkeys with lesions of this cortex (Group IC) were found to be impaired in relearning delayed nonmatching-to-sample (DNMS), but not on the subsequent DNMS performance test in which memory demands were greatly increased. In a second experiment, monkeys with combined lesions of the inferior and dorsolateral prefrontal cortex (Group LAT) were also found to be impaired in relearning DNMS, but in this case they were impaired, in addition, on the subsequent performance test. Neither group (IC or LAT) showed retardation in acquiring visual discrimination habits. Analysis of the DNMS behavior of both groups suggested that their deficits on this task were due not to a loss in recognition memory, but to various forms of perseverative interference. The results support the view that the inferior prefrontal convexity, like the dorsolateral prefrontal cortex, lies outside the limbo-diencephalic memory system not only anatomically but also functionally.

The use of a specific hypofractionated radiation therapy reg imen versus classical fractionation in the treatment of breast cancer: A randomized study of 230 patients

An ongoing randomized study of a specific regimen of hypofractionated radiation therapy (IHF) versus classical or standard radiation therapy (IC) for breast cancer was begun in the Department of Radiation Therapy of the Necker Hospital, Paris France, in January 1982. Breast cancer patients entered into this study received either IC to deliver 45 Gy in 25 fractions over 33 days or a specific IHF regimen to deliver 23 Gy in 4 fractions over 17 days. As of June 1989, 525 patients had been entered into the study. The first 230 patients treated from 1982 through December 1984 had a minimum follow-up of 4 years (range: 4 to 7 years). Preliminary analysis of the results in these first 230 patients are presented. The distribution of patients in this initial group according to clinical staging, associated treatments, and pathological nodes is as follows: T1 = 22%, T2 = 61%, T3 + T4 = 17%, palpable nodes = 28%, inflammatory signs = 7%, surgical treatment = 79% (mastectomy = 35%, tumorectomy + Ir.192 = 44%), radiation alone + neoadjuvant chemotherapy = 21%, N+ = 50% of patients undergoing surgery. Loco-regional recurrences developed in 7% ( 9 125 ) of patients in the IHF group and in 5% ( 5 105 ) of patients in the IC group. Complications were minor. The addition of the percentage of each complication noted results in a total of 23% for the IHF group and 19% for the IC group (one patient could present several complications). As we had previously observed when comparing these two fractionation regimens in other studies with other tumors, these preliminary results showed no evident difference in the effectiveness and rate of complications whether IHF or IC was used to treat patients with breast cancer.

15-DEOXYSPERGUALIN FOR INDUCTION OF GRAFT NONREACTIVITY AFTER CARDIAC AND RENAL ALLOTRANSPLANTATION IN PRIMATES

In order to assess the immunosuppressive potentials of 15-deoxyspergualin (15-DS) in a preclinical experiment, heterotopic cardiac (n = 27, group I) and classic renal (n = 25, group II) allotransplantations were performed in Chacma baboons. The following immunosuppressive regimens were applied: Groups IB and IIB were treated with 15-DS alone (4 mg/kg/day) for p.o. days 0-9. Groups IC and IIC were treated with cyclosporine A (10-40 mg/kg/day) for p.o. days 0-30. Groups ID and IID received a combination of 15-DS (for p.o. days 0-9) and CsA (for p.o. days 0-30). Groups IA and IIA served as control and received no medication. The mean graft survival was 11.0 days for group IA, 28.2 days for group IB (P less than 0.05; IB vs. IA), 32.4 days for group IC, and 43.1 days for group ID (P less than 0.025; ID vs. IA). After renal transplantation, the corresponding figures were 12.3 days for group IIA, 8.5 days for group IIB, 30.4 days for group IIC and 148.9 days for group IID (P less than 0.025; IID vs. IIA). After cardiac and renal transplantation, acute rejection was the main cause of graft failure. Treatment-related side effects, mainly gastrointestinal complications, were observed only in primates, who were treated with 15-DS alone. After cardiac transplantation, permanent graft non-reactivity was not achieved, but a delayed rejection occurred within a mean of 21.8 days after immunosuppression had been stopped. Following renal transplantation, graft nonreactivity was also not achieved in groups IIB and IIC. In group IID, however, 4 of 8 animals (50%) were graft-tolerant 340, 256, 244, and 164 days after treatment discontinuation. Thus, the combination of 15-DS and CsA led to a significant prolongation of graft survival in both groups. Long-term nonreactivity was achieved only after renal transplantation, when initially treated with 15-DS and CsA.

Rhodium and osmium in iron meteorites

Rh and Os were quantified by instrumental neutron activation analysis in 106 iron meteorites. The data for Rh are the first extensive values to be reported for this element in iron meteorites. The Rh vs. Ni concentration plot allows for good spatial separation of groups IB, IC, IIA, IIB, IIC, IID, high-Ni IIICD, IVA and IVB. Low-Ni IIICD meteorites (Nandan and Cranbourne) seem to belong spatially to Group IA to which they were originally assigned. Os concentrations are strongly correlated with those of Ir. A plot of Os vs. Ni gives poorer group separations than that of Rh vs. Ni. Only in the cases of groups IB, IID, high-Ni IIICD and IVB are there convincing spatial separations. Once again, the low-Ni Nandan and Cranbourne fall within the IA field. Other data lend additional support to a previous proposal that Lamesa and Dayton be paired because of their similar chemical composition.

DNA sequence analysis of the mitochondrial ND4L-ND5 gene complex from Podospora anserina: Duplication of the ND4L gene within its intron

A 15 kb region of the 100 kb mitochondrial genome of Podospora anserina has been mapped and sequenced (1 kb = 10 3 base-pairs). The genes for ND4L and ND5 are identified as contiguous genes with overlapping termination and initiation codons. In race A (101 kb) the gene for ND4L (4.3 kb) has a gene duplication within an intron including a second subgroup IC intron. Race s (95 kb) lacks this second gene complex. Each intron has the identical 5′ exon boundary. Secondary structure analysis showed that the closest relative of the second intron is the first intron itself. The open reading frames of the two introns are also closely related to each other as well as to their counterpart in the ND4L gene of Neurospora crassa. The 9.9 kb ND5 gene starts immediately at the termination codon of ND4L and is split by two group IB introns, one group IC intron and one group II intron. The group II intron is closely related to other group II introns although its open reading frame sequence similarity with retroviral reverse transcriptase appears to be more divergent. The similarities in secondary structure and open reading frames for these six introns are discussed.

Polyinosinic-Polycytidylic Acid, an Interferon Inducer, Ameliorates Bleomycin-Induced Lung Fibrosis in Mice

The inhibitory effect of polyinosinic-polycytidylic acid (Poly IC), an inducer of interferons, on bleomycin-induced lung collagen accumulation was investigated in mice. Poly IC (10 mg/kg, intraperitoneally) or saline was given for 2 days and immediately prior to intratracheal instillation of bleomycin (0.125 units/mouse) or an equivalent volume of saline and thereafter daily for 13 days. Lung hydroxyproline levels in saline-saline (control), Poly IC-saline (Poly IC), bleomycin-saline and bleomycin-Poly IC groups averaged 279, 287, 459, and 358 micrograms/lung, respectively. The bleomycin + Poly IC mice had significantly less lung hydroxyproline than bleomycin mice, but significantly more hydroxyproline than control or Poly IC mice. Similarly, bleomycin + Poly IC mice had significantly less protein in bronchoalveolar lavage fluid (BALF) supernatant than bleomycin mice, but significantly more protein than control or Poly IC mice. Total cell counts for cells recovered from BALF showed significant increases of 174 and 167% in bleomycin and bleomycin + Poly IC as compared to controls, while the Poly IC group showed a significant decrease of 47% which was primarily due to a decrease in alveolar macrophages. The bleomycin group had significantly more neutrophils, monocytes, macrophages, and lymphocytes than control mice, while bleomycin + Poly IC mice lacked the significant increase in lymphocytes. Bleomycin + Poly IC mice had significantly more monocytes than the bleomycin group. All bleomycin-treated mice had lung lesions, but no lesions were observed in control or Poly IC mice. Bleomycin + Poly IC mice had significantly more (58%) lesions than bleomycin. In contrast, the volume of interstitial lesion in bleomycin + Poly IC mice showed significantly less extracellular fibers (decreased by 62%) and no difference in fibroblasts as compared to bleomycin mice. Fibrotic lesions in bleomycin mice were multifocal and varied from large areas of organized connective tissue to thickened septa lined by cuboidal epithelial cells. Interstitial lesions in bleomycin + Poly IC had a significantly greater volume of mononuclear phagocytes and lymphocytes, but less organized connective tissue than the bleomycin group. Poly IC treatment ameliorated bleomycin-induced lung collagen accumulation.

The making of diabetic guinea pigs by streptozotocin and high incidence of triggered activity in the ventricular muscle.

Myoplasmic Ca2+ metabolism is reported to be impaired in diabetic rat heart. We studied the possibility that the ventricular muscles of diabetic guinea pig are prone to develop delayed afterdepolarizations (DADs) and triggered activity (TA), because DADs and TA are believed to be a possible index of increased level of intracellular Ca2+ concentration. To establish an experimental diabetic model from the guinea pig, male animals were divided into four groups: 1) control group: intracardiac injection of citrate buffer; 2) IP group: intraperitoneal injection of streptozotocin (STZ, 200 mg/kg); 3) IC group: intracardiac injection of STZ; and 4) Ins-IC group: intracardiac injection of STZ after pretreatment with insulin (20 IU/kg). We found that: 1) only in the Ins-IC group was the fasting plasma glucose concentration (determined 40 days after STZ injection) significantly higher than in the control group; 2) oral glucose tolerance test performed 40 days after treatment also showed glucose intolerance in the Ins-IC group. These findings evinced the successful making of diabetic guinea pigs by an intracardiac one-shot injection of STZ during development of insulin-induced hypoglycemia. In vitro electrophysiological experiments were performed on ventricular papillary muscle from diabetic animals (Ins-IC group) by conventional glass microelectrode techniques. Transmembrane action potentials were elicited by pulse trains with various rates (2-5 Hz) and durations (10-30 stimuli) in the presence of ouabain (1 microM) and various Ca2+ concentrations (1.8-7.2 mM). The incidence of TA in the muscles from diabetic animals was significantly higher (chi 2-test, p less than 0.05) than that from controls. The findings gave evidence that Ca2+ homeostasis in the myocardium of diabetic guinea pigs is impaired, and this may be a cause of arrhythmia.

ＩＣ群抗不整脈薬の心室筋伝導に対する効果

ＩＣ群抗不整脈薬の心室筋伝導に対する効果

Oxygen consumption after massive sympathetic nervous system discharge.

We evaluated the possibility that massive, sympathetic nervous system (SNS) activation [as may precede the development of neurogenic pulmonary edema (NPE)] increases O2 demand. O2 consumption (VO2) and plasma concentrations of the calorigenic agents, epinephrine (EPI) and norepinephrine (NE) were measured in alpha-chloralose-anesthetized dogs under control conditions and for 3 h after the administration of either 1) intracisternal (ic) veratrine to activate the SNS, 2) intravenous (iv) veratrine, 3) ic saline, or 4) ic veratrine, after clamping the adrenal blood vessels. VO2 increased 31.7 +/- 3.6% (SE), and EPI and NE increased to, respectively, 30,853 +/- 8,347 and 8,176 +/- 2,104 pg/ml in the ic veratrine group. No increases in VO2 and EPI and attenuated increases in NE were observed in the ic veratrine animals with clamped adrenals. No significant increases in VO2 or catecholamine concentrations were observed after ic saline or iv veratrine administration. These data suggest that the elevated VO2 may have been mediated by adrenal catecholamines and that an increased metabolic rate may complicate the ability of patients with severe NPE to balance O2 supply with demand.

The effect of embryonic ethanol exposure on detour learning in the chick

To examine the effects of embryonic ethanol exposure on survivability, posthatch growth and detour learning, 4 groups of 30 fertile black sex-linked eggs were given 200 μl injections of a solution of water and 0.0, 12.5, 37.5 or 50.0% (groups IC, L, M and H, respectively) ethanol (v/v) immediately preceding incubation. A fifth group of 33 eggs served as noninjected controls (NC). The results demonstrated that compared to group NC, a smaller percentage of groups M and H hatched and survived for behavioral testing, and that group H required more trials to reach criterion on the detour learning problem than did group IC. It was concluded that the teratogenic effects of ethanol are robust with respect to species and that the chick is an excellent model for studying some developmental and behavioral effects resulting from embryonic ethanol exposure.

ChemInform Abstract: Crystal Structure of In(PO3)3.

AbstractThe title compound crystallizes in the monoclinic space group Ic with Z=12.

Childhood stroke following intraoral trauma

first by the p r imary care physician ra ther than the physician performing the dilation. Therefore, physicians should suspect C N S infection in pat ients in whom neurologic signs and symptoms develop af ter esophageal dilation. In addit ion, because of the increased risk of infection af ter esophageal di lat ion in the pediatr ic age group, we believe it p rudent to provide ant ibiot ic prophylaxis for all infants and small chi ldren and for those with other known risk factors. Sui table choices would include ampicill in 50 m g / k g plus gen tamic in 2 mg/kg , 9 or cefoxitin 40 m g / k g given parentera l ly 30 minutes before the procedure; these may be repeated af te r 8 hours. Vancomycin 15 m g / k g by slow intravenous infusion should be used instead of ampicillin for pat ients allergic to penicillin.

Behavioral responses of juvenile rats (Rattus norvegicus) to neonates after infusion of maternal blood plasma.

Individual 18- or 30-day-old male and female Wistar rats (juveniles) were continuously exposed to 3-8-day-old pups for 5 days (sensitization) after intravenous (iv) infusion of maternal blood plasma (PL group) or 5% dextrose and water (IC group) through chronically implanted cannulas and were compared with nonhandled littermate controls (NHC group). The results showed complex interactions with sex and age of the animals tested, depending upon which maternal behaviors were examined. First, plasma from parturient females selectively increased retrieving behavior in 30-day-olds, and it was more powerful in females than in males. Second, on the first day, prior to sensitization, both PL and IC 30-day-olds showed higher frequencies of retrieving, crouching, anogenital licking, and contact than did nonhandled juveniles. Third, 30-day-olds that received maternal blood plasma continued to retrieve pups, with a latency peak for retrieving occurring at 72 hours, suggesting a long-term effect of plasma not seen in control animals. Fourth, 18-day-old subjects did not generally show effects of any of our manipulations, but they did show more nest building and contact behaviors than did 30-day-old subjects. Last, we found that the iv cannulation and infusion procedures led to a persistent dissociation of retrieving behavior from play in older animals and an integration of retrieving with crouching and licking regardless of whether maternal plasma or control infusion was administered. Retrieving behavior was associated with play behaviors (charge and pounce) in younger juveniles and in older, nonhandled control animals irrespective of treatment. For these animals, no integration of retrieving occurred with other maternal behaviors.

Value Orientations of English, French, and Italian Canadian Children

The value orientations of 118 8-and 9-year-old Canadian children from English (EC), French (FC), and Italian (IC) backgrounds were investigated relative to the constructs of self-image, ideal self, problem solving, and peer relations. Children were interviewed in their respective languages and their responses evaluated on 10 variables according to a system developed by the investigators. Individualistic and collectivistic value orientations for the EC and FC groups emerged as hypothesized for the self-image and ideal self constructs. ICs were more similar to ECs on these constructs. The significant interaction between sex and ethnicity on several variables underlying all constructs implies different standards of desirable behaviors for daughters and sons within the FC and IC groups. FC and IC parents seem to encourage idealized personal and social values in their daughters. FC girls displayed more interpersonal skills than FC boys, and IC boys demonstrated greater resourcefulness in problem solving. Results are discussed within the context of diminishing ethnic particularisms and distinctive gender-role socialization.

Bidirectional voluntary heart rate control during static muscular exercise: metabolic and respiratory correlates.

ABSTRACTFollowing three sessions of instructed HR control with exteroceptive HR feedback (Group IFB) or without feedback (Group IC), subjects were required, on a fourth session, to increase and decrease HR whilst engaging in isometric arm exercises at 10%, 30%, and 50% of their maximal voluntary contractions. Significant increases and decreases from resting levels in HR were recorded during the first three sessions in which no exercise demands were made. When required to control HR whilst exercising, significant increases in HR above exercise‐only baselines were recorded but subjects were unable to decrease HR significantly below exercise‐only baselines. The extent of “voluntary’ HR control was inversely related to the concurrent level of isometric exercise and was unaffected by the provision of exteroceptive HR feedback. Since all significant variations in HR were accompanied by significant parallel variations in oxygen consumption and breathing patterns, it is concluded that subjects were unable to modulate the HR response to exercise.

Differential recruitment of expiratory muscles during opossum development.

Relationships between time-averaged electromyogram (EMG) discharge in abdominal (ABD) and lateralintercostal (IC) muscles (interspaces 1-10) were evaluated when Inactin-anesthetized supine opossums between 20 and 100 days of age were challenged by positive-pressure breathing (PPB) (3, 6, and 8 cmH2O). Expiratory activity upon initiation of PPB was observed in ABD muscles after the 30th postnatal day; recruitment of IC muscles requires further maturation. For example, at a PPB level of 6 cmH2O, animals up to 50-55 days of age recruited IC muscles from the lowest three interspaces on 44% of the occasions where ABD muscles were activated; in older animals the incidence of IC recruitment increased to 87%. Additionally, the occurrence of IC relative to ABD recruitment increased with increasing levels of PPB; IC muscles of highest interspaces (1-3) were activated less often at all pressures. At the onset of PPB, ABD muscles were usually recruited before IC muscles; this effect was more prominent in the younger animals. During the 5th min of PPB, ABD muscles were recruited earlier in expiration than IC muscles in the majority of animals at all ages. Since IC and ABD motor groups are activated from similar levels of the spinal cord, the delayed maturation of IC muscle responses to PPB may reflect developmental processes involving reflexes from the chest or abdomen, and/or may be a function of nonrespiratory utilization (i.e., postural) of ABD and IC muscles.

Hemodynamic adaptation to acute myocardial contusion complicating blunt chest injury

The immediate hemodynamic sequelae of blunt chest injury complicated by acute myocardial contusion were examined in multiply traumatized patients. Focal defects of ventricular wall motion defined by gated cardiac scintigraphy identified acute myocardial contusion In 28 of 43 patients, involving the right ventricle alone in 18 (group 1A), the left ventricle In 4 (group 1B) and both ventricles in 6 (group IC). Qualitatively normal ventricular wall motion was found in the 15 patients (group 2). Although there was no difference between groups 1A and 2 in mean systemic oxygen transport (620 ± 189 vs 627 ± 105 ml/min/m2), left ventricular ejection fraction (52 ± 14% vs 60 ± 9%) or calculated left ventricular end-diastolic and end-systolic volumes, mean right ventricular (RV) ejection fraction was significantly lower in group 1A (29 ± 9%) than In group 2 (47 ± 7%, p <0.01). Concomitantly, evidence of RV systolic dysfunction was apparent in group 1A (RV end-systolic volume 104 ± 56 ml/m 2) but not in group 2 (RV end-systolic volume, 50 ± 21 ml/m 2, p <0.05). RV stroke work was similar between the groups, and RV pump function was identical by virtue of a larger RV preload in group 1A (RV end-diastolic volume 143 ± 63 ml/m 2) than in group 2 (RV end-diastolic volume 93 ± 26 ml/m 2, p <0.05). Thus, use of the RV Frank-Starling mechanism In patients with traumatic RV contusion maintains RV pump function at a level similar to that In traumatized patients without acute myocardial contusion.