A comparison of the efficiency of melatonin treatments in advancing oestrus in ewes

Early oestrous cycles were induced in adult, maiden, 18-month-old Suffolk-cross ewes, maintained from birth in natural photoperiod by the following treatments applied from mid-June: subcutaneous implantation of melatonin (1 g) in Silastic packets, daily, oral, melatonin administration (3 mg/ewe) at 15:30 h, an artificial photoperiod of 8L:16D (lights on 07:30 h). Ovarian cycles began 5-10 weeks before those of control ewes maintained in a natural photoperiod. In contrast, the onset of ovarian cycles in ewes given s.c. implants of melatonin (1 g) in April, and a further group in May, was highly variable, and not significantly different from that of the control ewes. Plasma melatonin profiles in sheep with implants showed a night-time rise super-imposed on a constant level, which was itself within the physiological night-time range. Implant-derived melatonin declined with time but remained at or above physiological night-time levels for at least 3 1/2 months. These results indicate that melatonin implants in June, but not in April or May, advance onset of oestrus in the non-lactating, adult ewe. The effects of melatonin implants in June on onset of ovarian cycles were indistinguishable from those of melatonin feeding or artificial short photoperiod initiated at this time of year.     

Tentative immunohistochemical demonstration of melatonin in the rat pineal gland

Summary In the present study an attempt was made to demonstrate melatonin in the rat pineal gland by means of immunohistochemistry. The anti-body used was raised against 5-methoxy-N-acetyltryptophan which is chemically similar to melatonin. Specific fluorescence was demonstrable only in pineals from rats killed during the night, when melatonin formation is high. It was restricted to parenchymal cells lying in a marginal zone of the organ. These results are discussed in relation to a subdivision of the pineal parenchyma into cortical and medullary areas.Supported by a grant of the Deutsche Forschungsgemeinschaft (VO 135/4) within the Schwerpunktprogramm Neuroendokrinologie     

Lysogeny in Leuconostoc oenos.

Thirty strains of Leuconostoc oenos were exposed to mitomycin C to induce lysogenic bacteriophages. Lysis curves typical for lysogenic strains were obtained with 19 strains. Indicator strans were found for 17 of these phages. Five were characterized by electron microscopy, lytic spectrum, molecular masses of the proteins, sequencing of five N-terminal amino acids of the two major proteins and DNA analysis (restriction patterns, cross hybridization). The results revealed a very close relationship between the phages. Hybridization experiments between the DNAs of the temperate phages and the appropriate lysogenic strains revealed phage-related sequences in the DNA of the lysogenic strain.     

Retardation of pubertal development by prenatal long days in goat kids born in autumn.

Goat kids born in spring attain sexual maturity during the first autumn after birth in temperate regions, at about 30 weeks of age. This study observed sexual development in autumn-born kids and the influence of late-summer, prenatal light treatment on onset of puberty. The breeding season of 14 female British Saanen dairy goats was artificially advanced by 4 months, using a treatment of long days during the winter followed by melatonin treatment in spring. Five goats were treated with a photoperiod of 20 h light:4 h dark (lights on 04.00 h) for 62.1 +/- 1.4 days (mean +/- SEM, n = 5) prepartum (14 August to 15 October). The remaining nine goats were kept under a natural photoperiod: 20 kids from these mothers were followed, five males and five females from each group. Testicular development was assessed by means of weekly measurement of scrotal circumference. Blood samples were taken once a week from all kids from 4 weeks of age for 5 months. Plasma was assayed for progesterone in females and testosterone in males. Autumn-born female kids initiated oestrous cyclicity in January, at a mean age of 12.8 +/- 0.8 weeks. Puberty onset was significantly delayed (P less than 0.03, unpaired Student's t test) in females exposed to 20 h light:4 h dark in utero and occurred at a mean age of 16.5 +/- 1.4 weeks. Testicular development was significantly delayed and plasma testosterone concentrations were lower in autumn-born male kids that experienced 20 h light:4 h dark in utero than in kids from mothers in a natural photoperiod.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation and characterization of Leuconostoc oenos phages from German wines

Summary Thirty-four wines that showed problems during malolactic fermentation were obtained from five different German wineries and were examined for the presence of phages using electron microscopy and the agar spot-test. Phages were discovered in 11 of the wines and host strains were found for ten of these phages. The phages were characterized on the basis of their morphology, host range and protein profiles. Furthermore the ten phages could be divided into four groups by restriction enzyme analysis of the phage DNA. This grouping was consistent with results based on morphology, protein composition and host range analysis. Correspondence to: E. K. Arendt     

Development of cell surface saccharides on embryonic pancreatic cells

Using a battery of seven lectin-ferritin conjugates as probes for cell surface glycoconjugates, we have studied the pattern of plasmalemmal differentiation of cells in the embryonic rat pancreas from day 15 in utero to the early postpartum stage. Our results indicate that differentiation of plasmalemmal glycoconjugates on acinar, endocrine, and centroacinar cells is temporally correlated with development and is unique for each cell type, as indicated by lectin-ferritin binding. Specifically, (a) expression of adult cell surface saccharide phenotype can be detected on presumptive acinar cells as early as 15 d in utero, as indicated by soybean agglutinin binding, and precedes development of intracellular organelles characteristic of mature acinar cells; (b) maturation of the plasmalemma of acinar cells is reached after intracellular cytodifferentiation is completed, as indicated by appearance of Con A and fucoselectin binding sites only at day 19 of development; conversely, maturation of the endocrine cell plasmalemma is accompanied by "loss" (masking) of ricinus communis II agglutinin receptors; and (c) binding sites for fucose lectins and for soybean agglutinin are absent on endocrine and centroacinar cells at all stages examined. We conclude that acinar, centroacinar, and endocrine cells develop from a common progenitor cell(s) whose plasmalemmal carbohydrate composition resembles most closely that of the adult centroacinar cell. Finally, appearance of acinar lumina beginning at approximately 17 d in utero is accompanied by differenetiation of apical and basolateral plasmalemmal domains of epithelial cells, as indicated by enhanced binding of several lectin-ferritin conjugates to the apical plasmalemmal, a pattern that persists from this stage through adult life.     

Age-Specific Mortality During the 1918 Influenza Pandemic: Unravelling the Mystery of High Young Adult Mortality

The worldwide spread of a novel influenza A (H1N1) virus in 2009 showed that influenza remains a significant health threat, even for individuals in the prime of life. This paper focuses on the unusually high young adult mortality observed during the Spanish flu pandemic of 1918. Using historical records from Canada and the U.S., we report a peak of mortality at the exact age of 28 during the pandemic and argue that this increased mortality resulted from an early life exposure to influenza during the previous Russian flu pandemic of 1889–90. We posit that in specific instances, development of immunological memory to an influenza virus strain in early life may lead to a dysregulated immune response to antigenically novel strains encountered in later life, thereby increasing the risk of death. Exposure during critical periods of development could also create holes in the T cell repertoire and impair fetal maturation in general, thereby increasing mortality from infectious diseases later in life. Knowledge of the age-pattern of susceptibility to mortality from influenza could improve crisis management during future influenza pandemics.

“The war is over – and I must go” Egon Schiele, 1890–1918.

     

Patterns of time since last meal revealed by sparse PCA in an observational LC–MS based metabolomics study

In metabolomics studies, liquid chromatography mass spectrometry (LC–MS) provides comprehensive information on biological samples. However, extraction of few relevant metabolites from this large and complex data is cumbersome. To resolve this issue, we have employed sparse principal component analysis (SPCA) to capture the underlying patterns and select relevant metabolites from LC–MS plasma profiles. The study involves a small pilot cohort with 270 subjects where each subject’s time since last meal (TSLM) has been recorded prior to plasma sampling. Our results have demonstrated that both PCA and SPCA can capture the TSLM patterns. Nevertheless, SPCA provides more easily interpretable loadings in terms of selection of relevant metabolites, which are identified as amino acids and lyso-lipids. This study demonstrates the utility of SPCA as a pattern recognition and variable selection tool in metabolomics. Furthermore, amino acids and lyso-lipids are determined as dominating compounds in response to TSLM.