N-acetylcysteine for therapy-resistant tobacco use disorder: a pilot study

Abstract

Introduction

N-Acetylcysteine (NAC) may have efficacy in treating tobacco use disorder (TUD) by reducing craving and smoking reward. This study examines whether treatment with NAC may have a clinical efficacy in the treatment of TUD.

Methods

A 12-week double blind randomized controlled trial was conducted to compare the clinical efficacy of NAC 3 g/day versus placebo. We recruited 34 outpatients with therapy resistant TUD concurrently treated with smoking-focused group behavioral therapy. Participants had assessments of daily cigarette use (primary outcome), exhaled carbon monoxide (CO_EXH) (secondary outcome), and quit rates as defined by CO_EXH<6 ppm. Depression was measured with the Hamilton Depression Rating Scale (HDRS). Data were analyzed using conventional and modified intention-to-treat endpoint analyses.

Results

NAC treatment significantly reduced the daily number of cigarettes used (Δ mean±SD = ?10.9 ± 7.9 in the NAC-treated versus ?3.2 ± 6.1 in the placebo group) and CO_EXH (Δ mean± SD = ?10.4 ± 8.6 ppm in the NAC-treated versus ?1.5 ± 4.5 ppm in the placebo group); 47.1% of those treated with NAC versus 21.4% of placebo-treated patients were able to quit smoking as defined by CO_EXH<6 ppm. NAC treatment significantly reduced the HDRS score in patients with tobacco use disorder.

Conclusions

These data show that treatment with NAC may have a clinical efficacy in TUD. NAC combined with appropriate psychotherapy appears to be an efficient treatment option for TUD.     

新疆准噶尔盆地早侏罗世掌鳞杉科植物化石 及古大气CO2浓度

植物化石气孔参数分析是目前恢复古大气二氧化碳浓度较为精准的方法之一,银杏类和松柏类等是恢复古大气CO_2浓度常用的化石类群。本文利用新疆准噶尔盆地下侏罗统三工河组的松柏类掌鳞杉科Brachyphyllum(Hirmeriella?)sp.化石对早侏罗世大气CO_2浓度进行了重建,获得早侏罗世大气CO_2浓度为～1200ppm,丰富了早侏罗世大气CO_2浓度信息,进一步说明掌鳞杉科植物通过气孔比率法在重建侏罗纪大气CO_2浓度方面的可靠性。掌鳞杉科植物的旱生构造和较高的大气CO_2浓度表明早侏罗世Toarcian期大洋缺氧事件在陆地生态系统内可能产生了一定的响应。     

Energetic assessment of fixation of CO<Subscript>2</Subscript> and subsequent biofuel production using <Emphasis Type="Italic">B. cereus</Emphasis> SM1 isolated from sewage treatment plant

The ongoing work on global warming resulting from green house gases (GHGs) has led to explore the possibility of bacterial strains which can fix carbon dioxide (CO₂) and can generate value-added products. The present work is an effort in this direction and has carried out an exhaustive batch experiments for the fixation of CO₂ using B. Cereus SM1 isolated from sewage treatment plant (STP). The work has incorporated 5-day batch run for gaseous phase inlet CO₂ concentration of 13 ± 1 % (%v/v). 84.6 (±5.76) % of CO₂ removal was obtained in the gaseous phase at mentioned CO₂ concentration (%v/v). Energetic requirement for CO₂ fixation was assessed by varying Fe[II] ion concentration (0–200 ppm) on the per-day basis. The cell lysate obtained from CO₂ fixation studies (Fe[II] ion = 100 ppm) was analyzed using Fourier transformation infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy (GC–MS). This analysis confirmed the presence of fatty acids and hydrocarbon as valuable products. The hydrocarbons were found in the range of C₁₁–C₂₂ which is equivalent to light oil. The obtained fatty acids were found in the range of C₁₁–C₁₉. The possibility of fatty acid conversion to biodiesel was explored by carrying out the transesterification reaction. The yield of biodiesel was obtained as 86.5 (±0.048) % under the transesterification reaction conditions. Results of this research work can provide the valuable information in the implementation of biomitigation of CO₂ at real scenario.     

Assignment of the proton Nmr chemical shifts of the T-N3H and G-N1H proton resonances in isolated AT and GC Watson-Crick base pairs in double-stranded deoxy oligonucleotides in aqueous solution

The 300-MHz proton nmr spectra (between 11 and 14 ppm) of a series of double-stranded deoxy oligonucleotides of known sequence have been recorded in H₂O solution. These resonances have been assigned to the G? N₁H and T? N₃H protons of specific base pairs from an evaluation of the temperature dependence of the ring NH linewidths and from the selective ring NH chemical shift changes on actinomycin-D binding. The deoxy oligonucleotides exist predominantly in the DNA-B conformation as evaluated from antibiotic binding studies. Ring-current calculations have been utilized to evaluate the up-field shifts of the G? N₁H and T? N₃H protons in Watson-Crick base pairs due to the ring currents from the pyrimidine and purine rings of nearest neighbor base pairs in regular DNA-B- and RNA-A-type helices. The perturbations on these up-field ring-current contributions that arise from twisting and tilting a base pair adjacent to the ring NH under study have been evaluated and found to change the calculated chemical shift by ±0.6 ppm for twist and tilt distortions of <30°C in a single adjacent base pair. A knowledge of the experimentally assigned ring NH chemical shifts of specific base pairs in known sequences of double-stranded deoxy oligonucleotides coupled with the ring-current tables for the DNA-B helical structure permit the assignment of 13.6 ± 0.1 ppm and 14.6 ± 0.2 ppm for the G? N₁H proton of an isolated GC base pair and the T? N₃H proton of an isolated AT base pair, respectively.     

Impact of In-Situ CO2 Nano-Bubbles Generation on Freezing Parameters of Selected Liquid Foods

The impact of in-situ CO₂ nano-bubbles generation on the freezing properties of soft serve, milk, and apple juice was investigated. Carbonated (0, 1000, and 2000 ppm) liquid foods contained in a tube were submerged and cooled for 90 min in a pre-set ethylene glycol bath (−15 °C). Before the enclosed liquid reached 0 °C, the vibration was discharged through ultrasound in the bath to create nano-bubbles within the carbonated food samples, and the changes in temperature for 90 min of each food were recorded as a freezing curve. The time for onset of nucleation of control soft serve mix was halved in samples with 2000-ppm CO₂ due to the presence of nano-bubbles. Likewise, the nucleation time for milk with and without nano-bubbles at the same CO₂ concentration of 2000 ppm was 7.9 ± 0.1 and 2.8 ± 0.8 min_, respectively. The generation of CO₂ nano-bubbles from 2000-ppm CO₂ level in 10 ^oBx apple juice displayed −9.3 ± 0.3 °C nucleation temperature while the control one had −11.7 ± 0.9 °C.

     

Larvicidal activity of acetone extract and green synthesized silver nanoparticles from Allium sativum L. (Amaryllidaceae) against the dengue vector Aedes aegypti L. (Diptera: Culicidae)

Mosquito vectors of major human diseases are currently controlled using chemical and biological products. Extensive insecticide use has led to resistance development and human/environmental health risks, and alternative sustainable control options are needed; in this study, activity of an extract of garlic (Allium sativum; Amaryllidaceae), and silver nanoparticles (AgNPs) synthesized from the extract, were evaluated against 2nd and 3rd instar larvae of the yellow fever mosquito, Ae. aegypti (Diptera: Culicidae). Synthesis of AgNPs was confirmed using UV–Vis spectroscopy, and characterised using powdered X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Larvae were exposed to five concentrations (50, 100, 150, 200, 250 ppm) of garlic extract or synthesized AgNPs, with distilled water and silver nitrate solution (1 mM) as controls. The mortality of larvae was recorded after 6, 12, 24, 36, and 48 h following addition of the respective extracts.Dose- and time-dependent toxicity were recorded in both treatment groups with no mortality in control groups. Exposure to AgNPs at 250 ppm for 48 h yielded 100% mortality for both larval instars, with corresponding LC₅₀ values of 44.77 (2nd) and 62.82 ppm (3rd). Exposure to garlic extract resulted in similar 48-hour mortality (99 ± 0.77% (2nd) and 98 ± 1.10% (3rd), but consistently higher LC₅₀ values after all exposure times compared to AgNPs (e.g. 48-hour exposure: 108.42 ppm (2nd), 129.11 ppm (3rd), suggesting that AgNPs may potentially be used at lower concentrations for Ae. aegypti control.     

Infrared cameras overestimate skin temperature during rewarming from cold exposure

ObjectiveThe primary aim of this study was to assess the accuracy of an infrared camera and that of a skin thermistor, both commercially available. The study aimed to assess the agreement over a wide range of skin temperatures following cold exposure.MethodsFifty-two males placed their right hand in a thin plastic bag and immersed it in 8 °C water for 30 min whilst seated in an air temperature of 30 °C. Following hand immersion, participants removed the bag and rested their hand at heart level for 10 min. Index finger skin temperature (T_sk) was measured with a thermistor, affixed to the finger pad, and an infrared camera measured 1 cm distally to the thermistor. Agreement between the infrared camera and thermistor was assessed by mean difference (infrared camera minus thermistor) and 95% limits of agreement analysis, accounting for the repeated measures over time. The clinically significant threshold for T_sk differences was set at ±0.5 °C and limits of agreement ±1 °C.ResultsAs an average across all time points, the infrared camera recorded T_sk 1.80 (SD 1.16) °C warmer than the thermistor, with 95% limits of agreement ranging from −0.46 °C to 4.07 °C.ConclusionCollectively, the results show the infrared camera overestimated T_sk at every time point following local cooling. Further, measurement of finger T_sk from the infrared camera consistently fell outside the acceptable level of agreement (i.e. mean difference exceeding ±0.5 °C). Considering these results, infrared cameras may overestimate peripheral T_sk following cold exposure and clinicians and practitioners should, therefore, adjust their risk/withdrawal criteria accordingly.     

1H NMR studies of a two-iron: two-sulfur ferredoxin from halobacterium of the dead sea

Ferredoxin isolated from Halobacterium of the Dead Sea (HFd) was found to be stable and retain its conformation in 4–0.5 M salt solutions. Reconstitution of the denatured protein to the oxidized form in ²H₂O indicated that the resonances shifted to the 8–10 ppm region, which include 18 protons, are nonexchangeable -NH protons. The C₂H and C₄H resonances of His-119 were assigned in both oxidized and reduced HFd. pH titration curves of these resonances yielded a pK_a for this His of 6.57 ± 0.1 and 6.65 ± 0.1 in oxidized and reduced HFd, respectively. pH titration curves, T₁ relaxation times, and the temperature dependence of the chemical shift were obtained for resonances between 6 and 10 ppm of oxidized HFd. In oxidized HFd a paramagnetically shifted resonance was observed at 15 ppm with 1 H intensity, and an anti-Curie temperature dependence. In reduced HFd eight resonances each with 1 H intensity were shifted downfield by 10–50 ppm and one resonance with 1 H intensity was shifted upfield to ?6.8 ppm. Four of these resonances exhibited an anti-Curie temperature dependence, two exhibited a moderate Curie dependence, and three were temperature independent.     

Optimization of ultraviolet ozone treatment process for improvement of polycaprolactone (PCL) microcarrier performance

Growing cells on microcarriers may have overcome the limitation of conventional cell culture system. However, the surface functionality of certain polymeric microcarriers for effective cell attachment and growth remains a challenge. Polycaprolactone (PCL), a biodegradable polymer has received considerable attention due to its good mechanical properties and degradation rate. The drawback is the non-polar hydrocarbon moiety which makes it not readily suitable for cell attachment. This report concerns the modification of PCL microcarrier surface (introduction of functional oxygen groups) using ultraviolet irradiation and ozone (UV/O₃) system and investigation of the effects of ozone concentration, the amount of PCL and exposure time; where the optimum conditions were found to be at 60,110.52 ppm, 5.5 g PCL and 60 min, respectively. The optimum concentration of carboxyl group (COOH) absorbed on the surface was 1495.92 nmol/g and the amount of gelatin immobilized was 320 ± 0.9 µg/g on UV/O₃ treated microcarriers as compared to the untreated (26.83 ± 3 µg/g) microcarriers. The absorption of functional oxygen groups on the surface and the immobilized gelatin was confirmed with the attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) and the enhancement of hydrophilicity of the surface was confirmed using water contact angle measurement which decreased (86.93°–49.34°) after UV/O₃ treatment and subsequently after immobilization of gelatin. The attachment and growth kinetics for HaCaT skin keratinocyte cells showed that adhesion occurred much more rapidly for oxidized surfaces and gelatin immobilized surface as compared to untreated PCL.     

Edible oil degradation by using yeast coculture of <Emphasis Type="Italic">Rhodotorula pacifica</Emphasis> ST3411 and <Emphasis Type="Italic">Cryptococcus laurentii</Emphasis> ST3412

To develop a microbial treatment of edible oil-contaminated wastewater, microorganisms capable of rapidly degrading edible oil were screened. The screening study yielded a yeast coculture comprising Rhodotorula pacifica strain ST3411 and Cryptococcus laurentii strain ST3412. The coculture was able to degrade efficiently even at low contents of nitrogen ([NH₄–N] = 240 mg/L) and phosphorus sources ([PO₄–P] = 90 mg/L). The 24-h degradation rate of 3,000 ppm mixed oils (salad oil/lard/beef tallow, 1:1 w/w) at 20°C was 39.8% ± 9.9% (means ± standard deviations of eight replicates). The highest degradation rate was observed at 20°C and pH 8. In a scaled-up experiment, the salad oil was rapidly degraded by the coculture from 671 ± 52.0 to 143 ± 96.7 ppm in 24 h, and the degradation rate was 79.4% ± 13.8% (means ± standard deviations of three replicates). In addition, a repetitive degradation was observed with the cell growth by only pH adjustment without addition of the cells.     

Responses of Corpuscles of Stannius to intra-peritoneal vitamin-D3 administration in teleost Labeo rohita (Hamilton, 1822) reared in water with two different levels of calcium concentration

This study assessed the responses of vitamin-D₃ intraperitoneally injected to Rohu, Labeo rohita @ of 0 IU/kg bw (only solvent), 100 IU/kg bw and 500 IU/kg bw reared in 20 and 40 ppm of calcium (Ca) enriched water. The cellular changes in Corpuscles of Stannius (CS) gland, serum Ca, and inorganic phosphate (P_i) level were analysed up to the 60th day. Rohu administered with 100 IU/kg bw D₃ and exposed to 40 ppm Ca-rich water exhibited notable hyperplasia of CS compared with their control groups. Notable changes with high serum Ca level (13.87 ± 0.3 mg/dl) was detected on the 5th day in fish exposed to 40 ppm Ca-rich water, while related values attained (13.74 ± 0.1 mg/dl) only after 7 days in 20 ppm Ca-rich water of 500 IU/kg bw vitamin D₃ injection. Similarly, high serum P_i level (7.66 ± 0.2 mg/dl) in 40 ppm Ca injected with D₃ at 500 IU/kg bw. The results demonstrated that the Ca homeostasis of Labeo rohita is influenced by intra-peritoneal vitamin D₃. Progressive studies should be conducted by increasing the dose of vitamin D₃ to investigate optimum dose/supplement in feed for commercially important aquaculture teleost Labeo rohita for maximum and sustainable absorption of Ca from the variable water Calcium levels to maintain Ca²⁺ homeostasis.     

The effect of nitrogen dioxide exposure on the release of surfactant isolated from neonatal rabbit type II pneumocytes in culture

Nitrogen dioxide (NO₂) is a well-known environmental air toxin, produced from a variety of sources, including cigarette smoke. Because of the growing knowledge of the harmful effects of passive smoking on children, we decided to study the effect of NO₂ exposure on the release of surfactant from isolated neonatal type II pulmonary epithelial cells. After isolation from 1 to 4 day old rabbits, type II epithelial cells were allowed to adhere for 18 hours, washed, media changed, and were exposed to either 5% CO₂ in room air or NO₂, 5 ppm, for 2 hours (all results mean ± sd; comparisons, paired t-test). There was no difference in cell number or viability prior to exposure. Cells exposed to NO₂ had an increase in LDH release [LDH activity in media/(LDH in media + cells) x 100], air 12.6 ± 2.2%, NO₂ 21.7 ± 3.7%, (p < 0.05). NO₂-exposed cells also had an increase in total phospholipid (μg/cell culture dish) in media compared to air exposed, air 170.13 ± 7.54, NO₂ 195.15 ± 11.2, (p < 0.05). ³H-choline incorporation as a precursor to disaturated phosphati-dylcholine (DSPC) was also conducted during exposure to either air or NO₂. Incorporation of ³H-choline into surfactant lipid was increased in media from cells after NO₂ exposure compared to air, 58.23 ± 15.16 air, 76.81 ± 19.86 NO₂ (cpm/μg protein; p < 0.05). These results show that 2 hours of 5 ppm NO₂ exposure is associated with an increase in release of surfactant from neonatal type II cells in culture. © 1996 John Wiley & Sons, Inc.     

Slight mistuning of a cryogenic probe significantly perturbs the water <Superscript>1</Superscript>H precession frequency

A shift of the water proton precession frequency is described that can introduce errors in chemical shifts derived using the water signal as the chemical shift reference. This shift, f_s, arises as a consequence of radiation damping when the water proton and detector circuit resonance frequencies differ. Herein it is shown that experimental values of f_s, measured as a function of detector circuit tuning offset for 500 and 900 MHz cryogenic probes, are in good agreement with theory. Of importance is the fact that even a small degree of mistuning, which does not significantly impact the performance of a pulse sequence, introduces chemical shift errors of ±0.03 ppm, that negatively impact many types of experiments. A simple remedy that attenuates the frequency shift is presented.     

Hydrogen sulfide concentrations in indoor air of thermal springs

This study aimed to assess hydrogen sulfide (H₂S) concentrations in the pool indoor air of hot springs and its link to some physicochemical properties of the springs in Ardabil province. Twenty-two hot springs from different regions were selected and monitored for H₂S concentrations using a portable gas meter. Respective mean concentrations of H₂S in hot springs indoor air were 9.11 ± 11. Ghotour Souei hot springs had the highest concentration of H₂S with a mean concentration of 29.4 ± 7.7 and 25.2 ± 8.16 ppm at the source and general pool areas, respectively. Oxidation-reduction potential and pH of the water were the most important factor influencing H₂S concentrations in the hot springs. H₂S concentrations in indoor air of Ardabil hot springs were noticeably higher than OEL-TWA and OEL-STEL, and therefore may pose important risks for human health on both short-and long-term exposures.     

Dissolved carbon in an urban area of a river in the Brazilian Amazon

The main objective of this study was to evaluate dissolved organic and inorganic carbon dynamics along upstream and downstream reaches of the Acre River draining the city of Rio Branco, in the state of Acre, Brazil. Dissolved organic carbon (DOC) concentrations in the Acre River were significantly higher during the wet season, ranging from 385 ± 160 to 430 ± 131 ??M among the stations, with no difference in upstream and downstream concentrations. Dissolved inorganic carbon (DIC) showed an inverse pattern, with higher concentrations in the dry season, ranging from 816 ± 215 to 998 ± 754 ??M among the stations, as well as no difference in upstream and downstream DIC concentrations. Bicarbonate was the dominant DIC fraction and was mainly observed during the dry season. Due to lower pH values during the wet season, CO₂ partial pressure (pCO₂) in the Acre River was higher in the wet season, with values ranging from 4,567 ± 1,813 to 4,893 ± 837 ppm among the stations. Our results indicate that, although the Acre River drains a large city with significant sewage disposal into the river, seasonal hydrological processes are the main driver of dissolved carbon dynamics, even in the downstream study reach directly influenced by urbanization.     

Comparative deposition and clearance of various nickel compounds exposed by inhalation in rats

Wistar male rats were exposed to three types of nickel compounds, NiO(G), NiO(B), and Ni₃S₂, for 6 h/d, 5 d/wk for 6 mo. The solubility of these chemicals to saline solution was 0.3 ppm for NiO(G), 3.5 ppm for NiO(B), and 310 ppm for Ni₃S₂. Controls were exposed to clean air under similar conditions. Some rats were sacrificed 24 h after the termination of the final repeated exposure, and the remaining rats were kept for a 12-mo clearance period before sacrifice. There was no significant difference in body weight between exposed rats and controls and also no significant differences in organs weights, except for lungs in the case of Ni₃S₂, between exposed rats and controls. Nickel concentration in the lungs just after the exposure to nickel compounds was the highest when compared to other organs. The apparent deposition fractions (%) in the lungs were 0.5 ± 0.1 for NiO(G), 1.0 ± 0.3 for NiO(B), and 0.5 ± 0.1 for Ni₃S₂., After the clearance period, there were no significant differences in organ weights, except for the lungs in case of Ni₃S₂, between the exposed rats and the controls. During the 12 mo of clearance, 82% of deposited NiO(G), 73% of NiO(B), and 98% of Ni₃S₂ were cleared from lungs.     

Evaluation of mean skin temperature formulas by infrared thermography

 To study the reliabiliity of formulas for calculating mean skin temperature (T _sk), values were computed by 18 different techniques and were compared with the mean of 10,841 skin temperatures measured by infrared thermography. One hundred whole-body infrared thermograms were scanned in ten resting males while changing the air temperature from 40° C to 4° C. Local, regional average and mean skin temperatures were obtained using an image processing system. The agreement frequency, defined as the percentage of the calculated T _sk values which agreed with the corresponding infrared thermographic T _sk within ±0.2° C, ranged for with the various formulas from 7% to 80%. In many sites, the local skin temperature did not coincide with the regional average skin temperature. When the local skin temperatures which showed the highest percentage similarity to the regional average skin temperature within ±0.4° C were applied to the formula, the agreement frequency was markedly improved for all formulas. However, the agreement frequency was not affected by changing the weighting factors from specific constants to individually measured values of regional surface area. By applying the physiologically reliable accuracy range of ±0.2° C in the moderate and ±0.4° C in the cool condition, agreement frequencies of at least 95% were observed in formulas involving seven or more skin temperature measurement sites, including the hand and foot. We conclude that calculation of a reliable mean skin temperature must involve more than seven skin temperature measurement sites regardless of ambient temperature. Optimal sites for skin temperature measurement are proposed for various formulas. Received: 2 December 1996 / Accepted: 25 June 1997     

Rise in CO<Subscript>2</Subscript> affects soil water transport through repellency

Several studies have shown improved soil stability under elevated atmospheric CO₂ caused by increased plant and microbial biomass. These studies have not quantified the mechanisms responsible for soil stabilisation or the effect on water relations. The objective of this study was to assess changes in water repellency under elevated CO₂. We hypothesised that increased plant biomass will drive an increase in water repellency, either directly or through secondary microbial processes. Barley plants were grown at ambient (360 ppm) and elevated (720 ppm) CO₂ concentrations in controlled chambers. Each plant was grown in a separate tube of 1.2 m length constructed from 22 mm depth × 47 mm width plastic conduit trunk and packed with sieved arable soil to 55% porosity. After 10 weeks growth the soil was dried at 40°C before measuring water sorptivity, ethanol sorptivity and repellency at many depths with a 0.14 mm radius microinfiltrometer. This provided a microscale measure of the capacity of soil to rewet after severe drying. At testing roots extended throughout the depth of the soil in the tube. The depth of the measurement had no effect on sorptivity or repellency. A rise in CO₂ resulted in a decrease in water sorptivity from 1.13 ± 0.06 (s.e) mm s^−1/2 to 1.00 ± 0.05 mm s^−1/2 (P < 0.05) and an increase in water repellency from 1.80 ± 0.09 to 2.07 ± 0.08 (P < 0.05). Ethanol sorptivity was not affected by CO₂ concentration, suggesting a similar pore structure. Repellency was therefore the primary cause of decreased water sorptivity. The implications will be both positive and negative, with repellency potentially increasing soil stability but also causing patchier wetting of the root-zone.     

The role of GA3 in the germination process of high-mountain endemic and threatened species: Leontopodium nivalePinguicula fiorii and Soldanella minima subsp. samnitica (central Apennines,Italy)

The ex situ conservation of biodiversity is an essential tool for environmental protection interventions. Germination studies of seeds that belong to endangered species are essential for ex situ conservation strategies. In this study, we investigate the germination responses of three high-altitude endemic and vulnerable species (Leontopodium nivale, Pinguicula fiorii and Soldanella minima subsp. samnitica). Specifically we identified potential dormancy mechanisms by investigating the responses of germination percentage and rate to different concentrations of gibberellic acid (GA₃), by performing a general linear model. L. nivale reached a germination percentage of 98.0 ± 2.0% (mean ± SE) under control conditions (20°C; 12/12 photoperiod; no GA₃ addition). P. fiorii showed the highest germination percentage (78.0 ± 2.0%) in the treatment with GA₃ 500 ppm. S. minima subsp. samnitica did not show sensitivity to GA₃ but responded positively to cold stratification (6 month at 5°C) with a germination percentage of 90 ± 6%. This study made it possible to acquire important information on the germination process of threatened and rare endemic taxa.     

Dietary zinc effects on zinc, calcium, and magnesium content in bones of growing rats

The aim of the present study was to assess dietary zinc effects on femur weight and mineral content in growing rats. For this purpose, 70 weanling Sprague-Dawley rats were divided into four groups. Each group was subject to a diet containing 2 (BZ), 5 (DZ), 10 (MZ), and 30 (CZ) ppm zinc. The calcium and magnesium content in all diets was 5 g/kg and 507 mg/kg, respectively. The animals were kept on this regime for 28 d and then sacrificed and their femurs were removed for analysis using atomic absorption spectrophotometry. The weights of the BZ and DZ groups were significantly different from the MZ and CZ groups (38.5±10.5, 89.9±13.7, 118.6±13.6 and 134±19.9 g, p<0.01) respectively. There were no differences between the MZ and CZ groups. Femur weight also varied with dietary zinc, as it was significantly different among all groups (BZ, 265±49 mg; DZ, 380±40 mg; MZ, 452±54 mg; CZ, 735±66 mg; p<0.01). The femur zinc content varied with diets, following a different pattern than the above parameters. Femur zinc from the BZ group (51.5±5.4 ppm) was significantly different from the MZ and CZ groups (115.9±14.2 and 175.0±13.5 ppm, respectively), whereas the DZ group (62.5±11.3 ppm) did not differ from the other three groups. The femur content of calcium (BZ, 83.2±9.8 mg/g; DZ, 88.0±9.2 mg/g; MZ, 90.2±13.6 mg/g; CZ, 83.1±14.7 mg/g) and magnesium (BZ, 1.82±0.13 mg/g; DZ, 1.98±0.09 mg/g; MZ, 1.93±14 mg/g; CZ, 1.83±0.19 mg/g) were not significantly different among the groups, nor was the calcium-magnesium ratio. These results suggest that although dietary zinc deficiency retards growth and causes bone fragility, bone deposition of calcium and magnesium and its ratio are not affected.