Chlamydia pneumoniae infection significantly exacerbates aortic atherosclerosis in an LDLR–/– mouse model within six months

We have previously shown that infection with the C. pneumoniae AR39 strain once monthly for 9 consecutive months significantly exacerbated atherosclerosis in mice with LDL receptor deficiency (LDLR–/–) in the presence of a high cholesterol diet. To further optimize the LDLR–/– mouse model for studying the mechanisms of C. pneumoniae atherogenesis, we have tested a different infection protocol with intranasal inoculation twice monthly for 6 consecutive months in the present study. We found that C. pneumoniae infection for 6 months was sufficient to produce a 130%, significantly greater exacerbation of aortic atherosclerosis in LDLR–/– mice in the presence of a high cholesterol diet. Mice receiving a high cholesterol diet alone displayed a lesion area index of 18.2 ± 6.1 (S.D.) while mice treated with both the high cholesterol diet and C. pneumoniae infection had a lesion area index of 41.8 ± 15.2 (S.D.). However, the chlamydial infection did not significantly alter the mouse serum total cholesterol or the LDL levels induced by the high cholesterol diet. This study not only confirms our previous findings that C. pneumoniae infection can exacerbate aortic atherosclerosis lesion in the LDLR–/– mice, but also further optimizes the LDLR–/– mouse model for future mechanism studies.     

Prostaglandins E and F, and 19-hydroxylated E and F (series I and II) in semen of fertile men : Gas and liquid chromatographic separation with selected ion detection

Low concentrations of prostaglandins (PG) could be related to male clinical infertility although relevant experimental data are scarce. The aim of this work is to establish reliable seminal PG levels in fertile men by rigorous sample control, to prevent degradation, and by rapid and simple extraction and assay procedures.Single semen samples from healthy fertile men were immediately centrifuged (within 30 min of ejaculation) adding PGF_2α D₄ to the seminal plasma as internal standard. The samples were next ultrafiltered and the PGs in the ultrafiltrate were derivatized with a mixture of N,O-bis(trimethylsilyl)trifluoroacetamide and piperidine (1:1) at 60° for 30 min. Optimum gas—liquid chromatographic separation of all of the peaks of interest was achieved on 4 m × 1/4 in. I.D. Dexsil 300 packed columns at 280°. The detection and quantitation of all the peaks of interest depends on the selected ion monitoring of specific masses. The values obtained (in μg/ml, range in parentheses) were: PGEs, 63.5 ± 49.3 (9–164); PGFs, 2.6 ± 1.92 (0.95–6.63); 19-OH PGEs, 592.6 ± 312.5 (142.1–1047); and 19-OH PGFs, 12.66 ± 5.21 (4–19). Individual values for members of both series I and II are also presented.The sample collection and extraction procedures were further checked by high-performance liquid chromatography on a μPorasil column, with individual isolation and collection of all of the PGs, including the 19-OH PGs not previously separated by liquid chromatography.     

Restoration of Tropical Peat Swamp Rotifer Communities after Perturbation: an Experimental Study of Recovery of Rotifers from the Resting Egg Bank

In order to assess the recovery potential of tropical freshwater communities after disturbance, we performed an experimental study on the effects of exposure conditions and durations of storage on hatching of rotifer resting eggs in sediment. Well-mixed surface sediment samples from Mai Khao peat swamp on Phuket Island, Thailand, were stored under three conditions (cold –4 °C & dark: CD; ambient –32–42 °C & dark: AD; and ambient & daylight conditions: AL), for different periods of time (1, 2, 4, 6, 12, 18 and 24 months).The number of species hatching from the sediment was significantly affected by treatment for both short- (1–6 months) and long-term (6–20 months) exposure. Significant effects of short- and long-term exposure within treatments were also present. Both factors interacted significantly. Regarding numbers of specimens hatching, no short-term effects of differences in treatment condition were found, but increasing the duration did have an effect. Significant effects of treatment occurred after 6 months, in addition to prolonged effects of duration. Again, both factors interacted significantly. These experiments indicate that exposure time has a strong impact on the viability of resting eggs, whereas, an effect of exposure condition appears only after 6 months. So, recovery of rotifer communities from resident sediment egg banks in disturbed peat swamps can only be effectively attained when restoration occurs within a relatively short period after perturbation.     

Root productivity in a lowland tropical rain forest in Mexico

Fine root productivity was estimated in a lowland tropical rain forest at Los Tuxtlas (SE Mexico) and examined in relation to climatic factors. Two root diameter classes were defined (class I,<1 mm; class II, 1–3 mm). Total root productivity was estimated to 1.95 t ha^–1 year^–1, a value which is lower than those reported from other rain forest sites. Significant differences in root dry weight were found among months and between diameter classes throughout the year. Class I monthly means formed two groups: one corresponding to the months of highest precipitation, and the other to the relatively dry season. Class II monthly means also formed two groups, although these were unrelated to the regional precipitation pattern. A multiplicative regression model of productivity on precipitation was significant for both root classes when rainfall data of the previous month were used, while a linear regression model was significant only for class I roots when temperature data of two months before were used; these results suggest a delay in the effect of climatic conditions on root productivity. While the seasonal pattern of root productivity is clearly related to the annual rainfall distribution, the low total annual productivity may be related to the very high soil fertility at Los Tuxtlas.     

Chemical characteristics,with particular reference to phosphorus,of the rivers draining into Lake Naivasha,Kenya

The loss of phosphorus from the catchment of Lake Naivasha, Kenya, was 0.2 kg ha^–1 ann^–1, 76% of it particulate in a `normal' year of wet and dry periods. It rose to a mean of 1.8 kg ha^–1 ann^–1, 90% of which was particulate, in the months following the extreme rainfall which followed the 1997–1998 El Niño event in the Southern Atlantic. Total and particulate phosphorus were positively correlated with suspended solids and with discharge, and conductivity was negatively correlated with discharge. The magnitude of losses pose both threats to the water quality of Lake Naivasha and to the sustainable soils resources of the catchment.     

Reproductive ecology of red-chinned lizards (Sceloporus undulatus erythrocheilus) in Southcentral Colorado: comparisons with other populations of a wide-ranging species

Summary We studied the reproductive ecology of a population of Sceloporus undulatus erythrocheilus near Walsenburg, CO during the summers of 1987–1990. Reproductive activity commences soon after emergence in early May and continues until the middle of July. Females mature in their second year following hatching at an age of 20–21 months and a size of 60–63 mm snout-vent length (SVL). Two clutches, averaging10.9 eggs, are produced per year. Larger females produce larger clutches with an increase of one egg per 3 mm SVL. Average SVL of females was 71 mm. Eggs are reasonably large (0.32 g) and relative clutch mass was the largest reported for the species (34% of body mass). A principal component analysis was used to examine relationships among reproductive characters in 12 populations of Sceloporus undulatus. The analysis suggested that patterns of reproduction in this wide-ranging species result from several factors reflecting both adaptive and phylogenetic sources of variation.     

Frozen storage stimulates the formation of embryo-like structures and elongating shoots in explants from mature Larix decidua and L. x eurolepsis trees

Branches were collected from a Larix decidua and a L. x eurolepis tree, both 36 years old, in mid-winter. These branches were placed in freezers at –5°C, –10°C, and –18°C. Primordial shoot explants were excised after 2 to 9 months of frozen storage. The material remained viable at all three temperatures for at least 9 months. The frozen storage stimulated formation of embryo-like structures that were capable of forming shoots with elongated stems.Abbreviations 1/2 LM half strength Litvay medium     

Nitrogen fixation of field-inoculatedLeucaena leucocephala (Lam.) de Wit estimated by the15N and the difference methods

The amount of nitrogen fixed byLeucaena leucocephala (Lam.) de Wit was assessed on an Alfisol at the International Institute of Tropical Agriculture located in southwestern Nigeria. Estimated by the difference method, nitrogen fixation of leucaena inoculated with Rhizobium strain IRc 1045 was 133 kg ha^–1 in six months. Inoculation with Rhizobium strain IRc 1050 gave a lower nitrogen fixation of 76 kg ha^–1. Fertilization with 40 and 80 kg N ha^–1 inhibited nitrogen fixation by 43–76% and 49–71%, respectively. Estimates with the¹⁵N dilution method gave nitrogen fixation of 134 kg ha^–1 in six months when leucaena was inoculated with Rhizobium strain IRc 1045 and 98 kg ha^–1 for leucaena inoculated with Rhizobium strain IRc 1050. This nitrogen fixation represented 34–39% of the plant nitrogen. Inoculated leucaena derived 5–6% of its nitrogen from applied fertilizer and 56–54% from soil.     

Growth dynamics of superficial roots in Portuguese plantations ofEucalyptus globulus Labill. studied with a mesh bag technique

Summary The variation in growth of the fine roots of blue gum (Eucalyptus globulus labill. ssp.globulus) in the 0–40 cm soil layer was studied from March 1982 to March 1983 at Quinta do Furaduoro, Óbidos, Portugal. A mesh bag method was used; bags of nylon net were inserted into a clay soil and a sandy soil and filled with root-free soil. They were resampled after 2, 4, 6 and 12 months in both places and, in a separate series in the sandy soil every second month throughout the year.The ingrowth of roots was high during the winter months but there was also a surprisingly high ingrowth during the spring-early summer period. There was also some root growth during the driest part of the yearviz. July–September.The amount of fine roots reached a maximum of about 260 g dw m^–2 after about 6 months in the sandy soil, whereas it took at least 12 months to reach the somewhat higher level of 450 g dw m^–2 in the clay soil. At that level the decomposition of dead roots was expected to equal the formation of new roots. Dead roots appeared after only 2 months. There was a higher proportion of dead roots in the clay soil than in the sandy soil, 35% as compared with 20% on an average, which indicates a slower decomposition or a higher mortality at equal decomposition rates in the clay than and in the sandy soil. The present data gives an indication of a minimum fine root production in mature Eucalyptus stands of at least 600 g dw m^–2 yr^–1.     

Seasonal influence on the reproductive performance of swine in the humid zone of Ghana

Relationships between month and climatic factors (ambient temperature, relative humidity, RH, and rainfall) with litter size, conception rate, days from weaning to conception and mortalities at birth and preweaning were studied in large white pigs under research station (RS) and commercial farm (CF) conditions. In RS and CF 868 and 572 farrowing records, respectively, were involved. Litter size was almost evenly distributed in all months of the year, at both farms, despite significant (P<0.05) negative but low correlations between litter size and maximum (r=–0.272, RS) and minimum (r=–0.233, CR) temperatures in the month after conception. There were no significant differences in conception rate between months. However under RS conditions there were significant (P<0.05) correlations between minimum temperature and conception rate in the months prior to (r=–0.362) and at conception (r=–0.221). Days from weaning to conception were bimodally distributed with peak values occurring between January and June and October and December. Significant mortality at birth (P<0.05) and preweaning was generally highest in the cold rainy months of May to October. However, only under CF conditions were there significant correlations between minimum temperature in the month of birth and percentage mortalities at birth (r=–0.217) and preweaning (r=–0.250). Rainfall and RH had no significant (P>0.05) correlation with birth and preweaning mortalities.     

Seasonal patterns of nutrient deposition in a Quercus douglasii woodland in central California

The monthly deposition of total nitrogen, phosphorus, potassium, calcium and magnesium via canopy throughfall, and various components of the litterfall was measured for 31 months under mature Quercus douglasii and in the bulk precipitation in the surrounding open grassland. Seasonal patterns of nutrient concentration in leaf litter, throughfall, and precipitation were also measured. Total annual subcanopy deposition exceeded open precipitation deposition by approximately 45–60x for nitrogen, 5–15x for phosphorus, 30–35x for potassium, 25–35x for calcium, and 5–10x for magnesium. Total annual subcanopy deposition was low in comparison to other oak woodland sites reported in the literature. Throughfall and leaf litter were the primary sources of nutrients and thus determined the seasonal peaks of nutrient deposition. The first autumn rains and leaf fall were associated with one peak in nutrient deposition, and throughfall during early spring leaf emergence was associated with a second peak in potassium, magnesium and phosphorus. Non-leaf plant litter (excluding acorns) provided approximately 15–35% of most nutrients, with twigs and bark depositing over 12% of the annual calcium flux in 1987–1988, and flower litter depositing over 8% of the annual nitrogen flux in 1986–1987. Acorns had high concentrations of phosphorus and nitrogen and during the mast season of 1987–1988 they contained a large proportion of the total subcanopy annual flux of these elements. With acorns excluded, total annual nutrient deposition was similar between years, but timing of nutrient deposition differed. Late summer leaf fall associated with drought, variation in precipitation, and variation in deposition of non-leaf parts were associated with seasonal differences in nutrient deposition between years.     

Long-term (30 years) dynamics of Chironomidae (Diptera) fauna in the Kuibyshev water reservoir associated with eutrophication processes

Benthos investigations were carried out in the channel and flood-plain of the Kuibyshev water reservoir during 1958–1985. Hydrobiological monitoring data obtained at 12–16 stations in all Deeps excluding littoral areas are discussed. In 1987–1900 benthofauna distribution was also studied at the Priplotinny Deep. An increase of the reservoir trophic state is reported. The observed trend was an increase of the total benthos biomass. Changes in both species and trophic structure of the chironomid community due to the eutrophication problem are discussed.     

Preservation of fresh BCG scarification vaccine at 4, −25, and −70° C

Summary Batches of BCG to be used as a scarification vaccine by suspension in a new liquid may be preserved at 4, –25, and –70° C. During storage the colony-forming units have been found to be practically unchanged after 3 months at 4° C, 9 months at –25° C, and 3 years at –70° C. The biological controls in animals agree with those in vitro.     

Androgen Function in “Psychogenic” and “Constitutional” Types of Impotence

Androgen function was studied in twenty-five physically healthy “primarily” impotent males classified on clinical criteria into “psychogenic” or “constitutional” groups. The mean urinary testosterone level in the former was significantly higher than in the latter group (P<0·005). Important variables associated significantly with higher urinary testosterone levels (P<0·05) were (a) “late onset” impotence, (b) shorter duration than two years, (c) stronger “sex drive,” and (d) an alternative sexual outlet to orgasm and ejaculation in the three months preceding referral; the last-mentioned appeared to be the single most important discriminatory feature.It is suggested that testosterone excretion patterns—namely, high, average, and low—may be one method of classifying impotence.     

Potential-dependent calcium channels in neurons from mollusks of varying ages

It was shown that with holding potentials (E_h) ranging from –50 to –30 mV the amplitudes of the incoming calcium current of identified neurons of the small parietal ganglion are significantly higher in elderly (20–24 month) Lymnaea stagnalis mollusks than in adult (10–12 months) ones.Gerontology Scientific-Research Institute, Kiev. Translated from Neirofiziologiya, Vol. 23, No. 6, pp. 643–647, November–December, 1991.     

Comparative toxicity of Pfiesteria spp., prolonging toxicity of P. piscicida in culture and evaluation of toxin(s) stability

Toxicity of Pfiesteria piscicida (strain CAAE #2200) in the presence of fish (juvenile hybrid tilapia, Oreochromis sp., total length 3–6 cm) has been maintained in the laboratory for 19 months by serial transfer of toxic cells using a modified maintenance protocol. Toxicity was re-induced when toxin-producing P. piscicida cells were separated from fish and cultured on algal prey for 50 days and then re-introduced to new tanks containing fish. We confirmed toxicity in a strain of P. shumwayae (strain CAAE #101272). Toxicity to fish was demonstrated in culture filtrates (0.2 μm) derived from cultures of both Pfiesteria spp., however, it was markedly reduced in comparison to unfiltered water. Filtrates retained toxic activity when stored at −20 °C for up to 6 months. Toxicity to fish was retained when filtrates were held at room temperature for 48 h, at 70 °C for 30 min or at 88–92 °C for 2 h. P. piscicida killed all finfish species tested. Grass shrimp (Paleomonetes pugio; adult 2–3 cm), blue crab (Callinectes sapidus; juvenile 4–7 cm) and brine shrimp (Artemia sp.; 18–24 h post-hatch) were unaffected by concentrations of toxin(s) that killed juvenile tilapia in 4–24 h. Ichthyotoxic activity of filtrates from fish-killing cultures and stability of the toxic activity were similar among P. piscicida and P. shumwayae. These results confirm previously reported observations on toxicity of P. piscicidaand P. shumwayae to finfish. We have maintained toxicity in the laboratory for longer periods than have previously been routinely achieved, and we have demonstrated that the toxic activity is heat stable. In contrast to previous studies with other toxic P. piscicida strains, we did not observe toxic activity to blue crabs or other crustaceans.     

Effects of age on morphology,protein synthesis and secretagogoue-evoked secretory responses in the rat lacrimal gland

This study investigated changes in the morphology and protein synthesis and protein and peroxidase secretion due to peptidergic and aminergic stimulation from rat lacrimal gland acinar cells of 3–5, 9, 12, 20 and 24 month old rats. There was a marked reduction in the presence of Golgi apparatus in the acinar cells of glands from the 24 month old rats coupled to dilatation and degeneration of rough endoplasmic reticulum, when compared to that in the acinar cells of glands from 3–5 and 12 month old rats. Following incorporation of tritiated leucine for 360 min (6 h), the amount of newly synthesised protein in acinar cells of the 12 month old rats was significantly (p < 0.01) higher than that in the acinar cells of 3–5 month old animals. However, at 20 months the amount of newly synthesised protein in these acinar cells was significantly (p < 0.01) reduced to less than that in acinar cells of both the 3–5 and 12 month old animals. Immunohistochemical and immunofluorescence studies identified the presence of substance P (SP), vasoactive intestinal peptide (VIP), histamine and 5-hydroxytryptamine (5-HT) in the lacrimal glands of 3–5 month old rats. Stimulation by either SP, VIP, histamine or 5-HT resulted in significant increases in total protein output and peroxidase release from acinar cells of the 3–5 month old rats. However, all responses to the secretagogues were reduced with ageing from 3–5 to 24 months of age. The results indicate that ageing is associated with alteration in the ability of acinar cells to synthesise and secrete proteins.     

Phytoplankton primary production in a eutrophic cooling water pond

The seasonal variation of phytoplankton photosynthesis was measured with ¹⁴C-method in a warmed ice-free pond in central Finland. Simultaneously with in situ measurements the photosynthesis was also measured in an incubator with different water temperatures and constant light (ca. 16 W m^–2). The total annual photosynthesis was 57.2 C m^–2 a^–1. The portion of the winter and spring production of the annual photosynthesis was 18.4%, that of the autumn production ws 17.4%. Thus 64.3% of the total annual phytoplankton photosynthesis occurred in the three summer months. The range of the daily integrated photosynthesis per unit area was 1.9—563 mg C m^–2d^–1. The photosynthetic rate per unit chlorophyll a varied in situ from 0.94 to 33.1 mg C (mg chl. a)^–1 d^–1. The highest value was measured in the beginning of July and the lowest in mid-January. The photosynthetic rate increased in situ exponentially with increasing water temperature. In the incubator the highest photosynthetic rate values were also found in July and August (at+20 °C) when the phytoplankton population was increasing and the minimum values occurred after every diatom maximum both in spring and autumn. Light was a limiting factor for photosynthesis from September to Mid-January, low water temperature was a limiting factor from late January through May. The efficiency of the photosynthesis varied between 0.1 and 0.7% of P.A.R. According to the incubator experiments the Q₁₀ values for the photosynthesis were 2.45 and 2.44 for the winter population between 1 and 10° C and for the summer population between 5 and 15° C, respectively, but the Q₁₀ values decrease at the higher temperatures. The main effect of the warm effluents on the yearly photosynthesis was the increase of production in spring months due to the lack of ice cover. However, the increase of total annual phytoplankton photosynthesis was only ca. 10–15%, because the water temperature was during the spring months below 10° C.     

Diagnosis of zinc deficiency in seedlings of a tropical eucalypt (Eucalyptus urophylla S. T. Blake)

A glasshouse experiment was undertaken to establish the internal Zn requirement for shoot growth of Eucalyptus urophylla, a fast-growing commercial plantation species widely planted in tropical regions of the world. A Zn-deficient sand was supplemented with ten rates of Zn and seedlings were harvested after three months. In Zn-deficient plants the new growth was dwarfed with small, necrotic leaves and short internodes. Foliar Zn concentrations declined markedly with leaf age in both Zn-deficient and Zn-adequate plants. The critical Zn concentration for the diagnosis of Zn deficiency also fell with leaf age. Zinc concentrations in the youngest fully expanded leaf ranged from 8–11 g Zn g^–1 dry weight in plants with severe symptoms to 30–37 g Zn g^–1 dry weight in non-deficient plants. The critical Zn concentration for the diagnosis of Zn deficiency at 90% of maximum shoot growth in the same leaf was 21 g Zn g^–1 dry weight. This value is nearly twice that reported for several other species of eucalypts and may indicate a higher internal demand for Zn in tropical than in temperate eucalypts.     

Immuno-electron-microscopic study of the prolactin cells in the pituitary gland of male Wistar rats during aging

Summary Prolactin cells were identified by means of immunocytochemistry with protein-A gold as a marker on ultrathin sections of the pituitary gland of young (3–4 months), middle-aged (16–19 months), and aged (26–30 months) male Wistar rats. Point-counting volumetry revealed that the prolactin (PRL) cell-volume density in middle-aged rats was significantly increased in comparison to the volume densities in young and aged rats. Within the PRL-cell population, four types of PRL cells were distinguished on the basis of the shape and size of their secretory granules. During aging, dramatic changes occurred in the relative volumes of the four cell types. The volume percentage of cells with round granules (type I, granule diameter 150–250 nm, and type IIA, granule diameter 250–350 nm) increased from ±30% in young rats to ±90% in old rats. The volume percentage of cells with round and polymorphic granules (type IIB; granule diameter 350–400 nm and type III; granule diameter 500–600 nm) decreased from ±70% in young rats to ±7% in old rats. Age-related changes in serum PRL levels were not found. It is concluded that although during the life span of the male Wistar rat considerable changes in PRL-cell volume densities and in the ratios of PRL-cell types occur serum, PRL levels remain more or less constant.