Increased leaf area index and efficiency drive enhanced production under elevated atmospheric [CO2 ] in a pine-dominated stand showing no progressive nitrogen limitation.

Enhancement of net primary production (NPP) in forests as atmospheric [CO2 ] increases is likely limited by the availability of other growth resources. The Duke Free Air CO2 Enrichment (FACE) experiment was located on a moderate-fertility site in the southeastern US, in a loblolly pine (Pinus taeda L.) plantation with broadleaved species growing mostly in mid-canopy and understory. Duke FACE ran from 1994 to 2010 and combined elevated [CO2 ] (eCO2 ) with nitrogen (N) additions. We assessed the spatial and temporal variation of NPP response using a dataset that includes previously unpublished data from 6 years of the replicated CO2 × N experiment and extends to 2 years beyond the termination of enrichment. Averaged over time (1997-2010), NPP of pine and broadleaved species were 38% and 52% higher under eCO2 compared to ambient conditions. Furthermore, there was no evidence of a decline in enhancement over time in any plot regardless of its native site quality. The relation between spatial variation in the response and native site quality was suggested but inconclusive. Nitrogen amendments under eCO2 , in turn, resulted in an additional 11% increase in pine NPP. For pine, the eCO2 -induced increase in NPP was similar above- and belowground and was driven by both increased leaf area index (L) and production efficiency (PE = NPP/L). For broadleaved species, coarse-root biomass production was more than 200% higher under eCO2 and accounted for the entire production response, driven by increased PE. Notably, the fraction of annual NPP retained in total living biomass was higher under eCO2 , reflecting a slight shift in allocation fraction to woody mass and a lower mortality rate. Our findings also imply that tree growth may not have been only N-limited, but perhaps constrained by the availability of other nutrients. The observed sustained NPP enhancement, even without N-additions, demonstrates no progressive N limitation.

Comment on "Mycorrhizal association as a primary control of the CO2 fertilization effect".

Terrer et al (Reports, 1 July 2016, p. 72) used meta-analysis of carbon dioxide (CO2) enrichment experiments as evidence of an interaction between mycorrhizal symbiosis and soil nitrogen availability. We challenge their database and biomass as the response metric and, hence, their recommendation that incorporation of mycorrhizae in models will improve predictions of terrestrial ecosystem responses to increasing atmospheric CO2.

Pharmacokinetics of 5-fluorouracil following different routes of intrahepatic administration in the canine model.

In an effort to achieve high concentrations of 5-fluorouracil (5-FUra) in the hepatic circulation while minimizing systemic exposure, several routes of intrahepatic administration were compared in the canine model. To ascertain these data, 5-FUra (30 mg/kg) was given as a bolus into either a systemic vein (femoral vein), hepatic artery, hepatic artery distal to its ligation after hepatic dearterialization, or through the portal vein. Three dogs were studied for each route with concomitant blood samples taken from the inferior vena cava and hepatic vein at 1, 2, 3, 5, 10, 15, 30, and 60 min after injection. 5-FUra levels were determined in plasma by high-pressure liquid chromatography. Blood flow in the portal vein and hepatic artery was measured by an electromagnetic flowmeter. The data were best described by a multicompartmental model including the measured flows. Hepatic components of the model were separate arterial and portal compartments, with elimination from each described by linear kinetics. Analysis of the results indicated that the highest hepatic levels with the least systemic exposure, as indicated by drug levels in hepatic and peripheral vein, were realized following hepatic artery administration distal to its ligation after hepatic dearterialization.

Differential effects of photoperiodic history on the responses of gonadotrophins and prolactin to intermediate daylengths in the male Syrian hamster.

The effect of photoperiodic history on the neuroendocrine response to intermediate daylengths (11-13.5 hr of light) was investigated in the male Syrian hamster. The duration of the nocturnal peak of pineal melatonin content was inversely proportional to photoperiod and independent of photoperiodic history. Serum levels of prolactin were lower in animals exposed to shorter photoperiods. Photoperiodic history had little effect on the response of serum prolactin to intermediate daylengths. Serum luteinizing hormone (LH) concentrations were also lower in shorter photoperiods, but in addition were sensitive to the direction of photoperiodic change, so that a single photoperiod could be interpreted as either stimulatory or inhibitory to LH secretion. This effect of photoperiodic history was expressed at intermediate photoperiods with 12-13.5 hr of light. The sensitivity of serum follicle-stimulating hormone (FSH) levels to photoperiodic history was masked by an early onset of photorefractoriness. Testicular size and serum testosterone levels revealed weaker effects of photoperiodic history; these were attributed to the dissociation between gonadotrophin and prolactin secretion induced by intermediate daylengths. The contrasting effects of photoperiodic history on the secretion of LH and prolactin may represent the expression of multiple photoperiodic time-measuring systems.

Photoperiodic influences on sexual behavior in male Syrian hamsters.

The effect of photoperiodic conditions on sexual behavior was investigated in male Syrian hamsters that were either gonadally intact, or castrated and treated with low doses of testosterone throughout the experiment. Hamsters were exposed to long (LD 16:8) or short (LD 8:16) days for 7 weeks; for the next 8 weeks, either they were exposed to an intermediate daylength (LD 12:12), or daylength conditions remained unchanged. Sexual behavior was affected by photoperiod conditions in both gonadally intact animals and testosterone-treated castrates, but to different degrees. Intact males exposed to short days for 15 weeks exhibited gonadal regression, and their copulatory performance was impaired. The percentage of animals that intromitted or ejaculated was significantly reduced. Additional measures of sexual performance among the copulating males were also affected. In contrast, among the castrates with testosterone clamped at low but stable levels, the proportion of males that mounted, intromitted, or ejaculated was not affected by photoperiod. However, among the males that continued to copulate, sexual performance changes were present in the short-day castrates that resembled those displayed by the intact males. We infer that these behavioral effects in both hormonal conditions reflect primarily a difficulty in the attainment of intromission. Gonadal regression alone cannot easily account for the behavioral deficits of the intact males, because circulating testosterone levels at the end of the experiment were not significantly different between the gonadally intact hamsters and the castrated, testosterone-treated hamsters exposed continuously to short days. Males transferred from either long or short days to the intermediate-daylength condition responded behaviorally to this photoperiod as if it were a short day, that is, their ejaculatory frequency declined. We conclude that male hamsters exposed to photoinhibitory daylengths exhibit deficits in their sexual behavior, not only because endogenous levels of testosterone decrease, but also because the substrates on which this hormone acts become less responsive. We hypothesize that under physiological conditions, the episodic secretion of testosterone imposes constraints on the maintenance or restoration of copulation, and that the potent behavioral effects achieved by constant-release implants of testosterone may mask the presence of photoperiodically induced alterations in the hamster's sensitivity to this gonadal hormone.

Analysis of the primary sex ratio, sex chromosome aneuploidy and diploidy in human sperm using dual-colour fluorescence in situ hybridisation.

In situ hybridisation technology provides a new tool for chromosome analysis of human spermatozoa. We have used dual-colour fluorescence in situ with probes specific for the X and Y chromosomes and chromosomes 1 and 12 to (a) identify the primary male gametic sex chromosome ratio; (b) assess the number of numerical sex chromosome abnormalities, and (c) quantify the incidence of diploid sperm. We have examined over 60,000 sperm from three normal males and found the primary sex ratio to be indistinguishable from unity. The frequency of hyperhaploid sperm was 0.8, 1.03 and 2.27 per thousand for XX, YY and XY respectively, whilst 1.67 per thousand sperm were diploid. A comparison of our results with estimates of sex chromosome aneuploidy in human populations suggests that sperm carrying two sex chromosomes may be at a selective disadvantage.

A 6p22 reference map of leukocyte DNA: exclusion of rearrangement in four cases of atypical haemochromatosis.

We describe a 4 Mb reference map of the haemochromatosis gene region in leukocyte DNA from seven controls and four atypical haemochromatosis patients. Three patients had normal coding sequence for HFE, the candidate gene for genetic haemochromatosis (GH). The fourth patient had classical GH but was heterozygous for Cys282Tyr with otherwise normal coding sequence. The genomic DNA was mapped by pulsed-field gel electrophoresis (PFGE) using five rare-cutting enzymes. Seventeen probes including HFE were positioned on the map. Despite proximity to the highly polymorphic major histocompatibility complex (MHC), no polymorphism was observed in the control group with these telomeric probes. Furthermore, major rearrangement of the HFE region was excluded as a mutation contributing to iron overload in these atypical patients. Maps of cloned DNA are linked through genes and other probes to this reference map of the HFE region in uncloned genomic DNA.

Intra-hypothalamic melatonin blocks photoperiodic responsiveness in the male Syrian hamster.

Exposure of male Syrian hamsters to a short daylength of 8L:16D leads to gonadal regression. This effect of photoperiod was prevented by pinealectomy or chronic exposure of the brain to exogenous melatonin delivered from in-dwelling cannulae. However, the effect of melatonin was dependent on the neural site of application. Melatonin delivered into the mid-brain, lateral hypothalamus or amygdala was ineffective. In contrast, bilateral administration of melatonin to the medial or amygdala was ineffective. In contrast, bilateral administration of melatonin to the medial hypothalamus prevented testicular regression and maintained high circulating levels of luteinizing hormone and prolactin. These findings suggest that the medial hypothalamus contains target sites for melatonin involved in pineal-mediated photoperiodic responses.

Effect of asymmetrical reductions of photoperiod on pineal melatonin, locomotor activity and gonadal condition of male Syrian hamsters.

This study investigated the relationship of two overt circadian rhythms, locomotor activity and melatonin synthesis in the pineal gland, by comparing their responses to asymmetrical reductions in photoperiod. Transfer of male Syrian hamsters from long to short daylengths led to an increase in the duration of both locomotor activity and the period of melatonin synthesis. Over the course of re-entrainment, the two rhythms were held in a stable phase relationship, and the direction of the switch did not influence the rate of decompression or the final phase relationships established after 8 weeks in short daylengths. Decompression of the activity rhythm was not influenced by pinealectomy. Exposure to short photoperiods caused gonadal regression and a consequent decline in serum testosterone levels from 10 to less than 1 nmol/l. The direction of the photoperiodic switch did not affect the time-course of gonadal regression. These data demonstrate the important influence of photoperiod upon the duration of the nocturnal peak of melatonin production by the pineal and also demonstrate that this effect is one example of a more widespread response of the circadian system. A qualitatively similar signal controls both locomotor activity and melatonin synthesis, although the neural basis of this common mechanism is unclear.

The hypothalamus and photoperiodic control of FSH secretion by melatonin in the male Syrian hamster.

In the photoinhibited castrated male Syrian hamster, removal of the pineal gland or transfer to long photoperiods was followed by a rapid increase in the serum concentration of FSH. Levels were significantly above those of controls within 10 days. Central passive immunization of pineal-intact photoinhibited castrated animals against melatonin had a stimulatory effect on serum FSH levels, comparable with that observed following pinealectomy or transfer to short days. The effects of pinealectomy were blocked by programmed s.c. infusions of melatonin in a time-dependent manner. Serum FSH levels remained low in animals receiving 100 ng melatonin delivered over 10 h but the same mass of melatonin delivered over 4 h had no effect on the response to pinealectomy. Lesions of the anterior hypothalamus had no effect on the pinealectomy-induced increase of serum FSH in animals receiving saline infusions. However, in lesioned animals, programmed infusions of melatonin were no longer able to suppress the rise in FSH following pinealectomy. These results demonstrated that pineal melatonin is the mediator of central photoperiodic control of FSH secretion. The duration of the melatonin signal determines its effectiveness and an intact anterior hypothalamus is necessary for the signal to be read and/or the appropriate neuroendocrine response expressed.

Lip pits and deletion 1q32----41.

A patient with an interstitial deletion of chromosome 1q[del(1q32----41)] was found to have, among other anomalies, congenital lower-lip pits. Lip pits are rare and are found mainly in association with the van der Woude syndrome and the popliteal pterygium syndrome; we cannot find a report of their association with a chromosome anomaly. To our knowledge, interstitial deletion of the segment 1q32----41 has not been reported. This observation raises the possibility that the van der Woude syndrome may be due to a submicroscopic deletion of chromosome 1q.

Partial duplication 8q12----q21.2 in two sibs with maternally derived insertional and reciprocal translocations: case reports and review of partial duplications of chromosome 8.

We report on two sibs with duplication of the segment 8q12----8q21.2 resulting from malsegregation of a maternal insertional translocation: [inv ins (5;8)(p13;q12q21.2)]. The mother also carries a reciprocal translocation [t(1;6)(q31;q5)], which was transmitted in the balanced state to the propositi and to a phenotypically normal son and daughter. The literature on two translocations occurring in one individual and on insertional rearrangements is reviewed in terms of reproductive risks to balanced carriers. The two affected infants have a previously undescribed partial duplication of an interstitial segment of 8q and a pattern of abnormalities distinct from those seen in other partial duplications of 8. These infants are reviewed with 78 other cases of partial duplications of chromosome 8 with regard to phenotype-karyotype correlations.

Interstitial deletion of the long arm of chromosome 3: case report, review, and definition of a phenotype.

Interstitial deletions of 3q have, to our knowledge, been reported in only four patients. We present an additional patient with interstitial deletion of 3q, with breakpoints at 3q23 and 3q25. The patient was small for gestational age and had a multiple congenital anomalies (MCA) syndrome including microcephaly; unusual facial appearance with bilateral microphthalmia, blepharophimosis, and ptosis; ventricular septal defect; and bilateral clubfeet. Comparison between the clinical and cytogenetic findings of the present case and those of previously reported cases suggests that a recognizable phenotype may be associated with deletions of 3q2.

The influence of photoperiod on the hypothalamic content of Beta-endorphin and the luteinizing hormone responses to naloxone and to steroid withdrawal in the male Syrian hamster.

Abstract The aim of this study was to investigate the influence of inhibitory photoperiods upon opioidergic function, as determined by changes in the hypothalamic content of beta-endorphin and the luteinizing hormone response to opioidergic receptor blockade, in the male Syrian hamster over the course of gonadal involution and spontaneous gonadal recrudescence. Animals exposed to an 8 h light: 16 h dark cycle (8L: 16D) for 14 weeks underwent gonadal regression. Regression was also observed in animals held for 7 weeks on one of a range of short daylengths of between 11.5 h and 13.5 h, the degree of atrophy being greatest in those animals on the shortest daylength. The tissue concentration of beta-endorphin within the mediobasal hypothalamus was significantly higher in animals exposed to 8L: 16D for 14 weeks than in gonadally active controls held on long days (16L: 8D). Exposure to photoperiods of less than 13.5 h for 7 weeks also caused a significant increase in the beta-endorphin content of the mediobasal hypothalamus and there was a positive correlation between the concentration of beta-endorphin, the degree of gonadal atrophy and the shortness of the photoperiod. Endorphin levels within the preoptic area were not affected by photoperiodic treatments. Exposure of intact animals to 8L: 16D for 12 weeks caused gonadal atrophy and an associated loss of the luteinizing hormone responses to both naloxone and castration. Castrated animals receiving testosterone replacement (cast + T) also exhibited photoinhibition, in the form of reduced serum levels of luteinizing hormone, and this was similarly accompanied by a loss of sensitivity to naloxone and to withdrawal of steroid. Prolonged exposure to 8L:16D led to spontaneous reactivation of the gonadotrophic axis as a consequence of the development of scotorefractoriness. In both gondally intact animals and in cast + T groups, this was associated with a restoration, in parallel, of the luteinizing hormone responses to naloxone and to castration/ steroid withdrawal. The time-course of the restoration of the response to steroid withdrawal in castrates was not significantly different to that observed in intact animals. The luteinizing hormone response to naloxone took significantly longer to redevelop in cast + T groups than it did in gonadally intact animals. The data demonstrate that central opioid systems are sensitive to photoperiod and are consistent with the hypothesis that opioids are involved in the neuroendocrine regulation of reproductive responses to daylength.

A prospective study of the microflora of nonpuerperal breast abscess.

The majority of reports concerning nonpuerperal breast abscess (NPBA) identify aerobic and facultative bacterial isolates as the predominant flora in this disease. In the present study, fine-needle aspiration was performed in 29 women with NPBA; 12 (41%) of the patients had a history of chronic NPBA. The mean age of patients was 39.2 years. The aspirated material was cultured both anaerobically and aerobically. A total of 108 bacterial strains were recovered from 32 specimens; two specimens yielded no bacterial growth. A mean of 3.6 different bacteria were recovered from each culture-positive specimen. Anaerobic recovery outweighed aerobic-facultative recovery by a factor of 2:1. Significantly, 37 strains (five aerobes and 32 anaerobes) were harvested only from enriched broth subcultured for four to 14 days after initial culture processing. Coagulase-negative staphylococci (60% of total aerobes) and peptostreptococci (47% of total anaerobes) were the predominant bacterial isolates. These findings indicate that NPBA is due to a mixed flora with a major anaerobic component. Furthermore, the results suggest that routine cultures often overlook the involvement of anaerobes in these infections.

Pediatric Trauma Score. Predictor of hospital resource use?

The Pediatric Trauma Score has been recommended to triage children with scores of 8 or less to a level 1 pediatric trauma center. The Injury Severity Score correlates well with the Pediatric Trauma Score. During a 36-month period ending December 31, 1985, paramedics saw 983 pediatric trauma patients (aged 17 years and younger) and intervened with advanced life support procedures in 196 (20%). One hundred forty-four patients receiving advanced life support were transported to either a level 1 adult trauma center or a pediatric community hospital. Our data confirm the correlation between Pediatric Trauma Score and Injury Severity Score and support recommendations to transport patients with Pediatric Trauma Scores of 8 or less to trauma facilities. We also conclude that Pediatric Trauma Scores may be useful in predicting hospital resource use.

Pharmacoeconomic analysis of ampicillin-sulbactam versus cefoxitin in the treatment of intraabdominal infections.

We conducted a retrospective pharmacoeconomic analysis of a prospective, multicenter, double-blind, randomized, controlled trial comparing the beta-lactamase inhibitor combination ampicillin-sulbactam (96 patients) and the cephalosporin cefoxitin (101) in the treatment of intraabdominal infections. An institutional perspective was adopted for the analysis. The primary outcomes of interest were cure and failure rates, development of new infection, and antibiotic-related adverse events. Epidemiologic data pertaining to outcomes was retrieved primarily from the trial, although results of other published studies were taken into consideration through extensive sensitivity analyses. Data pertaining to potential resource use and economic impact were retrieved mainly from the University Health Consortium and hospital-specific sources. When considering only costs associated with drug acquisition through cost-minimization analysis, a potential savings of $37.24/patient may be realized with ampicillin-sulbactam relative to cefoxitin based on an average 7-day regimen. Outcome data collected for the entire hospitalization during the trial revealed an approximately 9% greater frequency of failure with cefoxitin relative to ampicillin-sulbactam. When considering all outcomes of interest in the initial base-case analysis, a potential cost savings of approximately $890/patient may be realized with ampicillin-sulbactam relative to cefoxitin. In assessing the impact of the significant variability in probability and cost estimates, Monte Carlo analysis revealed a savings of $425/patient for ampicillin-sulbactam over cefoxitin (95% CI -$618 to $1516 [corrected]). Given the model assumptions, our analysis suggests a 78% certainty level that savings will be experienced when ampicillin-sulbactam is chosen over cefoxitin.

Effect of zinc pyrithione on mitotic activity in normal human skin.

Two concentrations (0.02% and 0.002%) of zinc pyrithione (ZPT) in water and a water control were applied to normal forearms - both on normal skin (six subjects) and also where the skin had been stripped to the 'glistening layer' (six subjects) with adhesive tape. Measurements of labelling index (LI), mean epidermal thickness (MET), mean stratum-corneum thickness (MSCT), total epidermal thickness (TET) and basal/granular cell ratio (B/G) showed no significant differences between the three treatments on normal skin or the parameters studied in stripped skin. It is concluded that ZPT has no effect on epidermal renewal in normal skin in vivo.

Genetic hemochromatosis: detection, management, and population screening.

Genetic hemochromatosis (GH) is an inherited disease that results in iron overload, and, if untreated, causes irreversible organ damage. Knowledge and understanding of the early features of the condition, often nonspecific, and of the diagnostic route are necessary to detect iron overload and diagnose GH before irremedial damage has been done. Genetic testing now plays an important role in diagnosis. Management of the patient with established GH centers on venesection to return body iron levels to normal, treatment of the complications of GH, and family screening for GH. Population screening for GH, the ideal strategy to prevent any morbidity from iron overload, has not yet been accepted by public health professionals, largely because of the lack of data on the disease penetrance in genetically susceptible individuals.