Treatment of acute cerebral infarction with arginine esterase: a controlled study with heparin

BACKGROUND AND PURPOSE

[corrected] There is no treatment proven to be of definitive benefit for ischemic stroke. Arginine esterase, a natural product from a snake venom, has been shown to reduce the serum fibrinogen level in human beings and may be useful in the treatment of ischemic stroke. In the present study, we compared the therapeutic effect of arginine esterase with that of heparin.

SUBJECTS AND METHODS

We studied 50 consecutive patients with acute ischemic stroke who were admitted to the Asan Medical Center. We randomly administered either arginine esterase 0.005 unit/kg x 2 times/day or heparin (activated partial thromboplastin time 2-3 times of baseline value) intravenously for 7 days. Antiplatelets were administered afterwards in both groups. Blood fibrinogen, fibrinogen degradation product (FDP) and D-dimer levels were measured at 0, 6, 12, 18 h and 1, 2, 3, 7 and 30 days after the onset of stroke. NIH stroke scale was measured daily by 2 neurologists while Barthel index and Rankin scale were assessed at 7 days and 1 month after the onset of stroke by a research nurse. All these investigators were blinded to the therapeutic regimen each patient received.

RESULTS

There were no significant differences in the mean age, gender proportion, stroke subtypes and baseline neurological severity between the two groups. One patient in the arginine esterase group died in an acute stage due to massive herniation and 1 in the heparin group underwent surgery for herniation. One (arginine esterase group) died of massive gastrointestinal bleeding due to previously unrecognized stomach cancer. Otherwise, no significant clinical and laboratory side effects were observed in both groups. In the arginine-esterase treated group, D-dimer and FDP levels were significantly (p < 0.05) elevated, and fibrinogen level significantly (p < 0.05) decreased at 2-7 days after the onset of stroke compared to the heparin-treated group. However, there was no significant difference in the neurological improvement reflected by NIH stroke scale, Barthel index and Rankin scale.

CONCLUSION

Arginine esterase seems to be safe and has significant fibrinolytic effects when administered in the patients with acute ischemic stroke. However, in this preliminary study, it was not superior to heparin in terms of the improvement of neurological deficits. Further studies with larger doses and a larger number of subjects are required.

Development and characterization of an oxygen-dependent inducible promoter system, the modified nar promoter in a mutant Escherichia coli

A nar promoter system (a modified nar promoter in a mutant host Escherichia coli (pMW618/W3110narL(-))), which is maximally induced under microaerobic conditions, was developed and characterized through batch and fed-batch culture to see whether the modified nar promoter can be used as an oxygen-dependent inducible promoter in the absence of nitrate ion. The modified nar promoter (pMW618) derived by mutations at -10 and -35 regions of the wild-type nar promoter does not require nitrate ion for the full induction, while a mutant host E. coli, W3110narL(-), does not express nitrate-dependent regulatory protein, NARL, from the host chromosome. In this study, it was found from fed-batch culture that the specific beta-galactosidase activity expressed from the lacZ gene fused to the modified nar promoter in the absence of nitrate ion was maximal when E. coli was grown under aerobic conditions (dissolved oxygen (DO) at 80%) to absorbance at 600 nm (OD(600)) of 35, and then the modified nar promoter was induced by lowering DO to 1-2% with alternating microaerobic and aerobic conditions. The maximal specific beta-galactosidase activity became 58,000 Miller at OD(600) of 160 with an induction ratio of 20. On the basis of these results, we conclude that the modified nar promoter system (pMW618/W3110narL(-)), requiring only reduction of DO for the full induction, provides a convenient and effective high-level expression system under conditions of fed-batch culture.

Activation of Fos-like immunoreactivity in the medial preoptic area and limbic structures by maternal and social interactions in rats

The researchers examined the number of cells showing Fos-like immunoreactivity (Fos-lir) in the brains of hormonally primed parturient rat dams immediately following their first behavioral interactions with pups. Groups were exposed to newborn pups (pup), adult conspecifics (social), or a new food (food), or they were left alone in cages (control/isolate) for a 1-hr period. Rats were then killed, and their brains were prepared for immunohistochemical detection of Fos-lir. Rats in the pup group had higher numbers of cells showing. Fos-lir within the medial preoptic area (MPOA) nuclei than did the social, control/isolate, and, marginally, food groups and higher levels of Fos-lir in a number of amygdaloid nuclei (medial and cortical) and in cingulate and somatosensory cortices than did control/isolate or food groups. Fos-lir in amygdala did not differ between pup and social groups. There were also group differences in Fos-labeling in the olfactory bulbs, with the pup group showing the highest densities. These results show elevated expression of Fos-lir in brain structures that were activated during the expression of maternal behavior, including the olfactory structures, amygdala, and MPOA.

Situational influences on gender differences in agency and communion

Gender differences were examined in the context of situational effects. Participants monitored interpersonal behavior for 20 days, using an event-sampling strategy. The monitored behaviors reflected dominance and submissiveness (components of agency) and agreeableness and quarrelsomeness (components of communion). The situations reflected differences in the status of work roles: interactions with boss, co-worker, and supervisee. Status influenced agency. Individuals were most agentic when with a supervisee and least agentic when with a boss. Gender did not influence agency but did influence communal behaviors. Women were more communal regardless of social role status; women were especially communal with other women, compared with men with men. Findings about agency supported a social role theory interpretation of gender differences. Results for communion were consistent with accounts of the influence of sex segregation on interpersonal relationships.

Situational influences on gender differences in agency and communion

Gender differences were examined in the context of situational effects. Participants monitored interpersonal behavior for 20 days, using an event-sampling strategy. The monitored behaviors reflected dominance and submissiveness (components of agency) and agreeableness and quarrelsomeness (components of communion). The situations reflected differences in the status of work roles: interactions with boss, co-worker, and supervisee. Status influenced agency. Individuals were most agentic when with a supervisee and least agentic when with a boss. Gender did not influence agency but did influence communal behaviors. Women were more communal regardless of social role status; women were especially communal with other women, compared with men with men. Findings about agency supported a social role theory interpretation of gender differences. Results for communion were consistent with accounts of the influence of sex segregation on interpersonal relationships.

Noradrenergic involvement in the consolidation of maternal experience in postpartum rats

If postpartum rats are separated from pups following cesarean delivery, their maternal responsiveness declines such that in tests on day 10 they show maternal onset latencies that do not differ from those shown by virgin rats. If, however, dams are permitted a 1-h experience with pups within 36 h of cesarean delivery, rats exhibit a high level of responsiveness to foster pups on day 10 after c-section. The present research investigates the effect of the noradrenergic system in the long-term consolidation of a brief maternal experience in new mother rats. Groups of dams were cesarean delivered and were either given pups for a brief period 36 h after section (experienced) or received no experience (inexperienced). Immediately following the experience phase, dams were injected with different concentrations of the beta-adrenergic antagonist, propranolol (0, 0.5, 1.0, 5.0 mg/kg), or the adrenergic agonist, isoproterenol (0, 0.25 or 0.5 mg/kg). Ten days after cesarean delivery rats were given maternal induction tests. Rats receiving 60 min of experience and injected with propranolol exhibited significantly longer maternal onset latencies than did saline-injected rats, although their latencies were not as long as shown by the maternally inexperienced groups. In contrast, rats receiving 15 min of experience and injected with isoproterenol exhibited significantly shorter onset latencies than did saline-injected rats, whether or not they exhibited maternal behavior during the initial 15 min exposure period. These results suggest that the noradrenergic system is involved in the consolidation of a maternal experience.

Regional localization of the human genes for S-adenosylhomocysteine hydrolase (cen----q131) and adenosine deaminase (q131----qter) on chromosome 20

The gene loci for S-adenosylhomocysteine hydrolase ( AHCY ) and adenosine deaminase (ADA), two enzymes with related metabolic functions, have both been assigned to human chromosome 20. We have used rodent-human somatic hybrids containing translocations involving human chromosome 20 to more precisely determine the relative locations of the AHCY and ADA loci. Our results assign the AHCY locus to the long arm of chromosome 20, in the region cen---- q131 , and ADA to the region q131 ----qter.