Delayed sleep phase disorder in a Swedish cohort of adolescents and young adults: Prevalence and associated factors

A delayed sleep–wake and circadian rhythm often occurs during puberty. While some individuals only develop a delayed sleep phase (DSP), others will fulfill the criteria for the diagnosis of delayed sleep phase disorder (DSPD). All previous studies have however not separated DSP from DSPD, and, as a result, the prevalence and associated factors are largely unknown for the two conditions individually. We estimated the prevalence of DSP and DSPD in a Swedish cohort of adolescents and young adults. We also investigated associated factors in the two conditions relative to each other and individuals with no DSP. A questionnaire regarding sleep patterns, demographics, substance use/abuse and symptoms of depression, anxiety, worry and rumination was sent to 1000 randomly selected participants (16–26 years of age) in Uppsala, Sweden (response rate = 68%). DSP was defined as a late sleep onset and a preferred late wake-up time. The DSPD diagnosis was further operationalized according to the Diagnostic and Statistical Manual of Mental Disorders, Edition 5 (DSM-5) criteria including insomnia or excessive sleepiness, distress or dysfunction caused by the DSP and that the sleep problem had been evident for 3 months. DSP occurred at a frequency of 4.6% and DSPD at a frequency of 4% in the investigated cohort. DSP was more common in males and was associated with not attending educational activity or work, having shift work, nicotine and alcohol use and less rumination. DSPD was equally common in males and females and was associated with not attending educational activity or work and with elevated levels of anxiety. Both DSP and DSPD appear to be common in adolescents and young adults in this Swedish cohort. No educational activity or work was associated with both DSP and DSPD. However, there were also apparent differences between the two groups in shift work, substance use and mental health, relative to persons with no DSP. Thus, it seems reasonable to assess DSP and DSPD as distinct entities in future studies.     

The influence of ectomycorrhiza on nitrogen nutrition and growth of Pinus sylvestris seedlings

Ectomycorrhizal seedlings of Scots pine ( Pinus sylvestris L. cv.), inoculated with the fungus Suillus bovinus (L. ex Fr.) O. Kuntze, and non-mycorrhizal controls were grown in growth units with a circulating culture solution. Steady-state nutrition and constant relative growth rates were achieved by means of varied relative nutrient addition rates and free access of nutrients. Typical mycorrhizas always formed within a short period of time after inoculation. The nutrition/growth relationships were in principle similar to previous studies under steady-state conditions: there were close linear relationships between relative addition rate, relative growth rate and internal nitrogen concentration, i.e. an equilibrium established between nutrients added and taken up. This occurred when infected and uninfected seedlings were grown separately. When grown together in the same growth unit, there are indications that the fungus influenced the exudation pattern of the uninfected seedlings. More carbon was thus provided to the unspecified microflora in the cultivation system, and it was able to grow and withhold nitrogen from the seedlings. The mycorrhizal infection did not increase the specific uptake capacity of the roots, and the fungus constituted a sink for carbon. However, the nitrogen productivity (growth rate per unit of nitrogen per unit of time) was similar for mycorrhizal and non-mycorrhizal seedlings, so that there might be mechanisms which compensate for the carbon cost.     

The 11q;22q translocation: A European collaborative analysis of 43 cases

Summary Translocation between the long arms of chromosomes 11 and 22 is usually detected in offspring with an unbalanced karyotype following a 3:1 disjunction resulting in partial trisomy. Since by the end of 1976 it was suspected that this translocation might be more frequent than one would deduce from published reports, it was decided to call for a collaborative effort in Europe to collect unpublished cases. In response, 42 cases were collected in Europe, and one case from New Zealand was added. The following countries were represented with the number of cases indicated in parentheses: Czechoslovakia (2), Denmark (4), Finland (3), France (6), Germany (1), Italy (5), The Netherlands (9), Sweden (6), United Kingdom (4), Yugoslavia (2). The wide geographical distribution indicates a multifocal origin of the translocation. Among the unpublished cases, 31 were ascertained as unbalanced carriers [47,XX or XY,+der(22),t(11;22)] and 12 as balanced balanced carriers [46,XX and XY,t(11;22)]. Among the published cases, 10 were ascertained in unbalanced and 3 in balanced carriers. The breakpoints of the translocations indicated by the contributors varied, the most frequently reported being 11q23;22q11 (25 cases), followed by q25;q13 (10 cases). While the first one seems more likely, it was not possible to decide whether the breakpoints were the same in all cases.All 32 probands with unbalanced karyotypes had inherited the translocation, 31 from the mother and only 1 from the father. This ratio became 43:1 when the published cases were added. A segregation analysis revealed that in families ascertained through probands with unbalanced karyotypes there was a ratio of carriers to normal (all karyotyped) 54:55, not a significant difference. The formal maximum (minimum) recurrence risk for this unbalanced translocation was calculated to be 5.6% (2.7%). When the ascertainment was through a balanced proband, the maximum risk was 2.7%. The risk was calculated as 5.7% for female and 4.3% for male carriers. The mean family size was 1.67 for the offspring of female carriers and 0.78 for the offspring of male carriers. This significant difference suggests that heterozygosity for the translocation reduces fertility in males. Indeed, several of the probands with balanced karyotypes were ascertained because of sub- or infertility. Only 2 de novo translocations were found among the 59 probands, and both, were among the 12 cases ascertained as balanced carriers. The source, quality, and quantity of the clinical data for the subjects with unbalanced karyotypes were variable, and no definite conclusions were possible about phenotypes. The following signs were recorded in 10 or more of the 45 cases: low birth weight, delayed psychomotor development, hypotonia, microcephaly, craniofacial asymmetry, malformed ears with pits and tags, cleft palate, micro-/retrognathia, large beaked nose, strabismus, congenital heart disease, cryptorchidism, and congenital dislocation of the hip joints. Many signs were similar to those considered typical of trisomy 11q, and the phenotype coincided almost completely with the presumptive phenotype of complete trisomy 22. No cases with coloboma was recorded, while other signs of the cat-eye syndrome were found in several probands. This might indicate that individuals with the cat-eye syndrome and carriers of the unbalanced 11/22 translocation have the same segment of 22 in triplicate plus or minus another chromosome segment.     

Milk transfer of inorganic mercury to suckling rats

The transport of mercury into rat milk, and uptake in the suckling offspring was studied after peroral administration of inorganic mercury to lactating control rats, and to rats fed selenite in the diet. On day 8, 9, 10, or 11 of lactation, dams were administered a single oral dose of 0.1, 0.4, 0.7, 1.3, or 5.8 mg Hg/kg bw labeled with 203mercuric acetate. There was a linear relationship between mercury concentrations in dam's plasma and milk. The level of mercury in milk was approximately 25% of the level in plasma. After 3 d, milk levels were reduced to half the levels at 24 h. In the suckling offspring, exposed to mercury via milk during 3 d, the mercury level in blood was approximately 1% of the level in maternal blood. Mercury concentration in milk was linearly correlated to the levels in kidney, liver, and brain in the suckling offspring after 3 d exposure to mercury via milk. Selenite treatment of rats, 1.3 micrograms Se/g diet for 5 mo, resulted in increased transport of mercury to milk, probably because of increased plasma levels of mercury. However, selenite treatment of the dams did not cause any increased tissue levels of mercury in the suckling offspring.     

Size-dependent B lymphocyte subpopulations: relationship of cell volume to surface phenotype, cell cycle, proliferative response, and requirements for antibody production to TNP-Ficoll and TNP-BA

Murine splenic B lymphocytes were separated into size-dependent subpopulations by using counterflow centrifugation. Spleen cells were rigorously depleted of T lymphocytes to yield a population of cells that were greater than 90% surface immunoglobulin (Ig)-positive and that had a mean cell volume of 136.6 +/- 3.3 microns. From this population, five fractions of cells were obtained with mean cell volumes that ranged from 115.8 +/- 3.7 microns in fraction 1 to 168.0 +/- 6 microns in fraction 5. The cells in these five subpopulations were characterized by analysis on a fluorescence-activated cell sorter after staining with acridine orange to evaluate RNA and DNA content, and with fluorescein-conjugated anti-mu, anti-delta, and anti-Ia antibodies to evaluate their surface membrane phenotypes. DNA analysis revealed that virtually all of the cells in fractions 1 to 4 had 2 N DNA. Between 7 and 21% of fraction 5 cells were either in S-phase or contained 4 N DNA. In contrast, RNA content increased through the fractions, suggesting a transition from G0 to G1 in the subpopulations with increasing B cell size. As another measure of cell activation seen with increasing cell size, we observed a progressive increase in the expression of surface Ia and a decrease in the expression of surface IgD. In the absence of in vitro stimulation, the larger cells showed significantly higher levels of thymidine incorporation. When polyclonal B cell activators such as LPS or anti-Ig antibody were added, peak proliferative responses were similar in all of the fractions, but the time necessary to achieve a maximal response was shorter for the larger-sized cell subpopulations than it was for the smaller-sized cell subpopulations. Unprimed, size-dependent B lymphocyte subpopulations exhibited spontaneous or "background" antibody formation that occurred primarily in the subpopulations containing the largest cells. T cell factors present in EL4 supernatant enhanced the efficiency of in vitro differentiation of these same subpopulations. When cultured in the absence of T cell help, the thymus-independent type 1 (TI-1) antigen TNP-Brucella abortus (TNP-BA) or the thymus-independent type 2 (TI-2) antigen TNP-Ficoll induced the largest anti-TNP plaque-forming cell (PFC) responses in the fractions containing intermediate-sized cells, suggesting that in vitro, antigen-specific responses came primarily from B cells that have been influenced in vivo to leave their small resting state. The subpopulations containing the smallest size B cells required the presence of both a TI antigen and EL4 supernatant for efficient differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Growth inhibitors in oat grains. I. Leakage of inhibiting factors from oat grains during imbibition and the effect of these on germination and growth

Spikes of barley ( Hordeum vulgare L.) cultivar Bomi and high-lysine mutants Riso 1508 and Riso 56 were cultured on liquid media at varying N and sucrose levels. Bomi accumulated N in response to increasing N levels in the medium and a higher level was reached than in spikes of intact plants. The distribution of N in salt-soluble, hordein, and non-protein N fractions appeared to be normal. Endosperm dry weight and starch were lower than in intact plants and declined at higher N levels. A linear relationship was observed between starch content and the concentration of sucrose in the endosperm water. Uptake of culture medium by the spikes was affected by both N and sucrose concentration. The mutants had lower dry weights and starch contents, and higher sucrose contents than Bomi. At high N levels, the mutants accumulated less hordein, and more non-protein N than Bomi.     

Progression of bacterial infections studied in real time--novel perspectives provided by multiphoton microscopy

The holy grail of infection biology is to study a pathogen within its natural infectious environment, the living host. Advances in in vivo imaging techniques have begun to introduce the possibility to visualize, in real time, infection progression within a living model. In this review we detail the current advancements and knowledge in multiphoton microscopy and how it can be related to the field of microbial infections. This technology is a new and very valuable tool for in vivo imaging, and using this technique it is possible to begin to study various microbes within their natural infectious environment - the living host.     

Real-time studies of the progression of bacterial infections and immediate tissue responses in live animals

By combining intravital multiphoton microscopy and bacterial genetics we have developed a technique enabling real-time imaging of bacterial proliferation and tissue responses in a live animal. Spatial and temporal control of the infection process was achieved by microinjecting GFP(+)-expressing uropathogenic Escherichia coli (UPEC) into tubules of exteriorized kidneys in live rats. GFP(+) was introduced in the clinical UPEC strain CFT073 as a single-copy chromosomal gene fusion. Within hours, bacterial colonization was accompanied by marked ischaemic effects, perivascular leakage, loss of tubular integrity and localized recruitment of immune cells. The pathophysiology was altered in response to an isogenic bacterial strain lacking the exotoxin haemolysin, revealing the subtle and temporal roles of bacterial virulence factors in vivo. Microdissection and RNA extraction of the injected nephron allowed molecular analysis of prokaryotic and eukaryotic gene expression. The techniques described here can be applied to study the integrated cell communication evoked by a variety of bacterial pathogens, assisting in the design of strategies to combat bacterial infections.