The organization of rapid eye movement activity during rapid eye movement sleep is further impaired in very old human subjects.

Rapid eye movement activity (REMA) during rapid eye movement (REM) sleep was studied in seven very old ('old-old') subjects. Beyond global quantitative features (REMA density), we evaluated the organizational aspects of REMA, that is its occurrence in burst mode, which were compared to a group of younger elderly subjects ('young-old'). REMA density in 'old-old' subjects is not significantly different from that of 'young-old' subjects. The same lack of difference in the two groups is found for the number of REMA bursts. By contrast, the duration of REMA bursts is reduced in the 'old-old' subjects, as well as the 'burst state-to-burst-state' probability, i.e. the probability for successive inter-REMA time intervals to be part of the same REMA burst. Our results clearly show that the trend towards an impairment of REMA organizational aspects continues with aging. This is consistent with the hypothesis that sleep disorganization keeps worsening with age. However, it is of interest to observe that the capability of producing REMA bursts is preserved despite aging.

The organization of rapid eye movement activity during rapid eye movement sleep is impaired in the elderly.

Rapid eye movement activity (REMA) during rapid eye movement activity (REM) sleep was studied in eight elderly subjects and six young adults as a control group. Beyond global quantitative features (REMA density), we evaluated the organizational aspects of REMA, that is its occurrence in burst mode, still largely unknown in the aged. REMA density in the elderly is not significantly different than that of young adults. By contrast, the duration of REMA bursts is reduced in the elderly, as well as the 'burst state-to-burst-state' probability, i.e. the probability for successive inter-REMA time intervals to be part of the same REMA burst. These results show that global aspects of the quantitative features of REMA are preserved in the elderly, whereas their organizational aspects are impaired. These data are consistent with the hypothesis that aging is associated with a difficulty in maintaining physiological processes over time.

The production of steel factor mRNA in Diamond-Blackfan anaemia long-term cultures and interactions of steel factor with erythropoietin and interleukin-3.

Diamond-Blackfan anaemia (DBA) is a congenital macrocytic anaemia. To investigate whether DBA is due to hyporesponsiveness to or hypoproduction of Steel factor (SF), we compared the in vitro responsiveness of the BFU-E contained in the Ficoll-Hypaque non-adherent cell fraction of six DBA marrows with that of four normal marrows and one transient erythroblastopenia of childhood (TEC) marrow. In addition, we studied the effect of soluble SF on long-term marrow cultures (LTMC) and analysed the stromal cells from these cultures for SF mRNA transcripts. All the patients showed an erythropoietin dose-related increase of small BFU-E. The number and size of BFU-E was increased with the addition to the epo of IL-3 or SF; IL-3+SF was not synergistic. The addition of soluble SF to LTMC of DBA patients was associated with a small but consistent increase in non-adherent cell production and an increase in the number of progenitors. Messenger RNA from immortalized stromal cell lines of three patients and from primary bone marrow stromal cells of one patient showed the presence of expected SF transcripts by PCR analysis. These results demonstrate that this group of DBA patients responds to SF and produces SF mRNA normally, indicating that SF itself is not involved in DBA pathophysiology. The effects observed suggest that, despite the lack of evidence for a causative role, SF may prove to be effective treatment for such patients.

The effect of zinc bacitracin and roxarsone on performance of broiler chickens when fed in combination with narasin.

Six trials were conducted at various locations to determine the response of broiler chickens to combinations of zinc bacitracin and roxarsone when fed in the presence of narasin. The addition of zinc bacitracin at 55 mg per kg significantly improved growth rate and feed utilization when data from all locations were combined. There was no effect of roxarsone fed at 50 mg per kg on BW or feed utilization, nor was there an interaction of roxarsone and zinc bacitracin on BW. There was a significant interaction of roxarsone and zinc bacitracin for feed utilization; addition of zinc bacitracin significantly improved feed utilization both in the presence and absence of roxarsone, but the improvement was greater in the absence of roxarsone.

Survival of severe neuroleptic malignant syndrome in a 78-year-old man treated with dantrolene.

The authors report a case of neuroleptic malignant syndrome in a 78-year-old man. The patient presented with a lack of contact with reality, hallucinations to which he was responding incoherently, and agitation and belligerence. He showed much improvement following treatment with dantrolene and was released to a nursing home 24 days after admission.

Response of broiler chickens to dietary supplementation with roxarsone and bacitracin methylene disalicylate in diets containing narasin.

Six trials were conducted at different locations to examine the response of broiler chickens to roxarsone and bacitracin in the form of bacitracin methylene disalicylate (BMD) in the presence of the anticoccidal narasin. All diets contained narasin (80 mg/kg) and were fortified with a factorial arrangement of roxarsone (0 to 50 mg/kg) and BMD (0 or 55 mg/kg). Broilers were grown to market weights with narasin and roxarsone removed from the diets for the final 5 days. Addition of both roxarsone and BMD resulted in significant (P less than .05) improvements in body weight and feed utilization. Response to roxarsone for feed utilization was influenced to some extent by the presence or absence of BMD. Although the response to roxarsone was always positive, the degree of response was lessened by the presence of BMD. This resulted in a significant (P less than .10) interaction between roxarsone and BMD for feed utilization but not for body weight.

The control and prevention of necrotic enteritis in broilers with zinc bacitracin.

The effectiveness of zinc bacitracin in controlling andpreventing necrotic enteritis was tested by growing broilers in a facility where necrotic enteritis outbreaks had previously occurred. Broiler-crossed chicks were fed a commercial-type broiler diet containing 0 mg./kg., 33 mg./kg., or 55 mg./kg. of zinc bacitracin in the diet. Each treatment was replicated six times. Mortality, weight gain, feed conversion, and pigmentation were measured. The control group had 7.4% mortality due to necrotic enteritis as determined by necropsy of each bird upon death. Zinc bacitracin at 10 grams per ton had two mortalities, or 0.4% mortality due to necrotic enteritis. No mortality due to necrotic enteritis occurred with the higher levels of zinc bacitracin. The addition of zinc bacitracin significantly improved (P less than 0.01) the parameters of weight gain, feed conversion, and pigmentation.