Understanding preferences for receiving health communications and information about clinical trials: a cross-sectional study among US adults

OBJECTIVE

Effective health communication is critical for understanding and acting on health information. This cross-sectional study explored participants' understanding of their health condition, their preferences for receiving health communications, and their interest in receiving clinical trial results across several therapeutic areas.

METHODS

The study recruited participants via social media, email newsletters, and advocacy organizations. An online screener captured demographic information (health conditions, age, race/ethnicity, gender, and education). Eligible participants were emailed an online survey assessing preferred sources and formats for receiving health information, interest in learning about topics related to the results of clinical trials, and health literacy levels.

RESULTS

In total, 449 participants (median age, 35 years [range, 18─76]; White, 53%; higher education, 65%; mean (range) health literacy score, 1.9 [0.4 ─ 3.0]) from 45 US states completed the survey representing 12 disease indications (bipolar, blood and solid tumor cancers, irritable bowel syndrome, inflammatory bowel disease, major depressive disorder, migraine, Parkinson's, psoriasis/atopic dermatitis, retinal vein occlusion/macular degeneration, rheumatoid arthritis, and spasticity). Healthcare providers were the preferred source of health information (59%), followed by internet searches (11%). Least preferred sources were social media (5%), friends/family (3%), and email newsletters (2%). Participants preferred multiple formats and ranked reading materials online as most preferred (33%), along with videos (28%) and infographics (27%). Printed materials (14%) and audio podcasts (9%) were the least preferred formats. A majority of the participants reported that the health information they found was hard to understand (57%) and confusing (62%). Most participants (85%) were somewhat/very interested in learning about clinical trial results, with the highest interest in short summaries of safety (78%) and efficacy (74%) results.

CONCLUSION

Effective health communication may be achieved via multiple formats shared directly by healthcare providers.

Responses and functions of dopamine in nucleus accumbens core during social behaviors

Social behaviors are among the most important motivated behaviors. How dopamine (DA), a "reward" signal, releases during social behaviors has been a topic of interest for decades. Here, we use a genetically encoded DA sensor, GRABDA2m, to record DA activity in the nucleus accumbens (NAc) core during various social behaviors in male and female mice. We find that DA releases during approach, investigation and consummation phases of social behaviors signal animals' motivation, familiarity of the social target, and valence of the experience, respectively. Positive and negative social experiences evoke opposite DA patterns. Furthermore, DA releases during mating and fighting are sexually dimorphic with a higher level in males than in females. At the functional level, increasing DA in NAc enhances social interest toward a familiar conspecific and alleviates defeat-induced social avoidance. Altogether, our results reveal complex information encoded by NAc DA activity during social behaviors and their multistage functional roles.

Lung lymphatic thrombosis and dysfunction caused by cigarette smoke exposure precedes emphysema in mice

The lymphatic vasculature is critical for lung function, but defects in lymphatic function in the pathogenesis of lung disease is understudied. In mice, lymphatic dysfunction alone is sufficient to cause lung injury that resembles human emphysema. Whether lymphatic function is disrupted in cigarette smoke (CS)-induced emphysema is unknown. In this study, we investigated the effect of CS on lung lymphatic function. Analysis of human lung tissue revealed significant lung lymphatic thrombosis in patients with emphysema compared to control smokers that increased with disease severity. In a mouse model, CS exposure led to lung lymphatic thrombosis, decreased lymphatic drainage, and impaired leukocyte trafficking that all preceded the development of emphysema. Proteomic analysis demonstrated an increased abundance of coagulation factors in the lymph draining from the lungs of CS-exposed mice compared to control mice. In addition, in vitro assays demonstrated a direct effect of CS on lymphatic endothelial cell integrity. These data show that CS exposure results in lung lymphatic dysfunction and a shift in thoracic lymph towards a prothrombic state. Furthermore, our data suggest that lymphatic dysfunction is due to effects of CS on the lymphatic vasculature that precede emphysema. These studies demonstrate a novel component of CS-induced lung injury that occurs early in the pathogenesis of emphysema.

Association of glucose metabolism and blood pressure during pregnancy with subsequent maternal blood pressure

The goal of this study was to examine associations of measures of maternal glucose metabolism and blood pressure during pregnancy with blood pressure at follow-up in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort. The HAPO Follow-Up Study included 4747 women who had a 75-g oral glucose tolerance test (OGTT) at ~28 weeks' gestation. Of these, 4572 women who did not have chronic hypertension during their pregnancy or other excluding factors, had blood pressure evaluation 10-14 years after the birth of their HAPO child. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension (SBP ≥ 140 and/or DBP ≥ 90 or treatment for hypertension) at follow-up. Blood pressure during pregnancy was associated with all blood pressure outcomes at follow-up independent of glucose and insulin sensitivity during pregnancy. The sum of glucose z-scores was associated with blood pressure outcomes at follow-up but associations were attenuated in models that included pregnancy blood pressure measures. Associations with SBP were significant in adjusted models, while associations with DBP and hypertension were not. Insulin sensitivity during pregnancy was associated with all blood pressure outcomes at follow-up, and although attenuated after adjustments, remained statistically significant (hypertension OR 0.79, 95%CI 0.68-0.92; SBP beta -0.91, 95% CI -1.34 to -0.49; DBP beta -0.50, 95% CI -0.81 to -0.19). In conclusion, maternal glucose values at the pregnancy OGTT were not independently associated with maternal blood pressure outcomes 10-14 years postpartum; however, insulin sensitivity during pregnancy was associated independently of blood pressure, BMI, and other covariates measured during pregnancy.

First application of a digital mirror Langmuir probe for real-time plasma diagnosis

For the first time, a digital Mirror Langmuir Probe (MLP) has successfully sampled plasma temperature, ion saturation current, and floating potential together on a single probe tip in real time in a radio-frequency driven helicon linear plasma device. This is accomplished by feedback control of the bias sweep to ensure a good fit to I-V characteristics with a high frequency, high power digital amplifier, and field-programmable gate array controller. Measurements taken by the MLP were validated by a low speed I-V characteristic manually collected during static plasma conditions. Plasma fluctuations, induced by varying the axial magnetic field (f̃ = 10 Hz), were also successfully monitored with the MLP. Further refinement of the digital MLP pushes it toward a turn-key system that minimizes the time to deployment and lessens the learning curve, positioning the digital MLP as a capable diagnostic for the study of low radio-frequency plasma physics. These demonstrations bolster confidence in fielding such digital MLP diagnostics in magnetic confinement experiments with high spatial and adequate temporal resolution, such as edge plasma, scrape-off layer, and divertor probes.

Hypothalamic Control of Conspecific Self-Defense

Active defense against a conspecific aggressor is essential for survival. Previous studies revealed strong c-Fos expression in the ventrolateral part of the ventromedial hypothalamus (VMHvl) in defeated animals. Here, we examined the functional relevance and in vivo responses of the VMHvl during conspecific defense. We found that VMHvl cells expressing estrogen receptor α (Esr1) are acutely excited during active conspecific defense. Optogenetic inhibition of the cells compromised an animal’s ability to actively defend against an aggressor, whereas activating the cells elicited defense-like behaviors. Furthermore, the VMHvl is known for its role in aggression. In vivo recording and c-Fos mapping revealed differential organization of the defense and aggression-responsive cells in the VMHvl. Specifically, defense-activated cells are concentrated in the anterior part of the VMHvl, which preferentially targets the periaqueductal gray (PAG). Thus, our study identified an essential neural substrate for active conspecific defense and expanded the function of the VMHvl.

Active defense against conspecific aggressors is essential for survival, but its underlying neural substrates remain largely unknown. Through a series of in vivo recordings and functional manipulations, Wang et al. demonstrate that cells expressing estrogen receptor α in a small medial hypothalamic nucleus are essential for defense against a bully.

Combining transfer of TTF-1 and Pax-8 gene: a potential strategy to promote radioiodine therapy of thyroid carcinoma

Cotransfer of thyroid-specific transcription factor (TTF)-1 and Pax-8 gene to tumor cells, resulting in the re-expression of iodide metabolism-associated proteins, such as sodium iodide symporter (NIS), thyroglobulin (Tg), thyroperoxidase (TPO), offers the possibility of radioiodine therapy to non-iodide-concentrating tumor because the expression of iodide metabolism-associated proteins in thyroid are mediated by the thyroid transcription factor TTF-1 and Pax-8. The human TTF-1 and Pax-8 gene were transducted into the human thyroid carcinoma (K1 and F133) cells by the recombinant adenovirus, AdTTF-1 and AdPax-8. Re-expression of NIS mRNA and protein, but not TPO and Tg mRNA and protein, was detected in AdTTF-1-infected F133 cells, following with increasing radioiodine uptake (6.1-7.4 times), scarcely iodide organification and rapid iodide efflux (t(1/2) ≈ 8-min in vitro, t(1/2) ≈ 4.7-h in vivo). On contrast, all of the re-expression of NIS, TPO and Tg mRNA and proteins were detected in F133 cells coinfected with AdTTF-1 and AdPax-8. AdTTF-1- and AdPax-8-coinfected K1 and F133 cells could effectively accumulate radioiodine (6.6-7.5 times) and obviously retarded radioiodine retention (t(1/2) ≈ 25-30-min in vitro, t(1/2) ≈ 12-h in vivo) (P<0.05). Accordingly, the effect of radioiodine therapy of TTF-1 and Pax-8 cotransducted K1 and F133 cells (21-25% survival rate in vitro) was better than that of TTF-1-transducted cells (40% survival rate in vitro) (P<0.05). These results indicate that single TTF-1 gene transfer may have limited efficacy of radioiodine therapy because of rapid radioiodine efflux. The cotransduction of TTF-1 and Pax-8 gene, with resulting NIS-mediated radioiodine accumulation and TPO and Tg-mediated radioiodine organification and intracellular retention, may lead to effective radioiodine therapy of thyroid carcinoma.

Radioiodine therapy of thyroid carcinoma following Pax-8 gene transfer

The thyroid transcription factor Pax-8 could bind with the promoter/enhancer of thyroid-specific genes such as thyroglobulin (Tg), thyroperoxidase (TPO) and sodium iodide symporter (NIS), and regulate the expression of these proteins in thyrocyte. Promoting iodide accumulation in tumor cells by re-expression of Pax-8 provides a possible strategy for radioiodine therapy of tumor. Therefore, we investigated the effect of Pax-8 gene transfer on radioiodine therapy of thyroid carcinoma. The human Pax-8 gene was transfected into the human thyroid carcinoma (K1 and F133) cells by the recombinant adenovirus vector. Although the NIS mRNA was not detected, the expression of mRNA and proteins of Tg and TPO in AdPax-8-infected F133 cells were activated by Pax-8. Iodide uptake in thyroid carcinoma cells was reactivated by Pax-8 (increasing 3.3-fold in K1 cells and 5.7-fold in F133 cells). Moreover, Pax-8 promoted iodide organification and the retention time of iodine in Pax-8-expressing cells apparently prolonged in vitro and in vivo (P<0.05). Pax-8-expressing thyroid carcinoma cells were selectively killed by radioiodine. The AdPax-8-infected tumors in vivo clearly visualized in scanning images at 12 h after administration of radioiodine. These results indicate that Pax-8 can promote iodide uptake, and specifically prolong the retention time of iodide in thyroid cancer in vitro and in vivo by promoting the expression of TPO and Tg proteins. Pax-8 gene transfection may lead to effective radioiodine therapy of tumor.

Targeting of tumor radioiodine therapy by expression of the sodium iodide symporter under control of the survivin promoter

To test the feasibility of using the survivin promoter to induce specific expression of sodium/iodide symporter (NIS) in cancer cell lines and tumors for targeted use of radionuclide therapy, a recombinant adenovirus, Ad-SUR-NIS, that expressed the NIS gene under control of the survivin promoter was constructed. Ad-SUR-NIS mediating iodide uptake and cytotoxicity was performed in vitro. Scintigraphic, biodistribution and radioiodine therapy studies were performed in vivo. PC-3 (prostate); HepG2 (hepatoma) and A375 (melanoma) cancer cells all exhibited perchlorate-sensitive iodide uptake after infection with Ad-SUR-NIS, ∼50 times higher than that of negative control Ad-CMV-GFP-infected cells. No significant iodide uptake was observed in normal human dental pulp fibroblast (DPF) cells after infection with Ad-SUR-NIS. Clonogenic assays demonstrated that Ad-SUR-NIS-infected cancer cells were selectively killed by exposure to ¹³¹I. Ad-SUR-NIS-infected tumors show significant radioiodine accumulation (13.3±2.85% ID per g at 2 h post-injection), and the effective half-life was 3.1 h. Moreover, infection with Ad-SUR-NIS in combination with ¹³¹I suppressed tumor growth. These results indicate that expression of NIS under control of the survivin promoter can likely be used to achieve cancer-specific expression of NIS in many types of cancers. In combination with radioiodine therapy, this strategy is a possible method of cancer gene therapy.

[Development of Brassica rapa L. embryos under conditions of microgravity]

Results of comparative studies of the embryos of identical age formed under microgravity and ground laboratory control are presented. Significant similarity of a rate of embryo development and degree of their differentiation in both variants has been shown. The single cases of the disturbances in embryo formation, and also a certain acceleration of endosperm development at the early stages of seed formation in microgravity are revealed.

Dynamics of storage reserve deposition during Brassica rapa L. pollen and seed development in microgravity

Pollen and seeds share a developmental sequence characterized by intense metabolic activity during reserve deposition before drying to a cryptobiotic form. Neither pollen nor seed development has been well studied in the absence of gravity, despite the importance of these structures in supporting future long-duration manned habitation away from Earth. Using immature seeds (3-15 d postpollination) of Brassica rapa L. cv. Astroplants produced on the STS-87 flight of the space shuttle Columbia, we compared the progress of storage reserve deposition in cotyledon cells during early stages of seed development. Brassica pollen development was studied in flowers produced on plants grown entirely in microgravity on the Mir space station and fixed while on orbit. Cytochemical localization of storage reserves showed differences in starch accumulation between spaceflight and ground control plants in interior layers of the developing seed coat as early as 9 d after pollination. At this age, the embryo is in the cotyledon elongation stage, and there are numerous starch grains in the cotyledon cells in both flight and ground control seeds. In the spaceflight seeds, starch was retained after this stage, while starch grains decreased in size in the ground control seeds. Large and well-developed protein bodies were observed in cotyledon cells of ground control seeds at 15 d postpollination, but their development was delayed in the seeds produced during spaceflight. Like the developing cotyledonary tissues, cells of the anther wall and filaments from the spaceflight plants contained numerous large starch grains, while these were rarely seen in the ground controls. The tapetum remained swollen and persisted to a later developmental stage in the spaceflight plants than in the ground controls, even though most pollen grains appeared normal. These developmental markers indicate that Brassica seeds and pollen produced in microgravity were physiologically younger than those produced in 1 g. We hypothesize that microgravity limits mixing of the gaseous microenvironments inside the closed tissues and that the resulting gas composition surrounding the seeds and pollen retards their development.

Development of studies of TPO gene and its application in nuclear medicine

Thyroperoxidase (TPO) is a glycosylated protein bound to the apical plasma membrane of thyrocytes. It is the key enzyme in the synthesis of thyroid hormones. Its gene structure and transcriptional regulation have been studied in detail. This article reviews the structure, function and transcriptional regulation of the TPO gene, and the relationship between TPO, thyroid diseases and radioactive iodide therapy.

Reserve nutrient substance accumulation in Brassica rapa L. seeds in microgravity conditions (STS-87)

The results of study of Brassica embryo differentiation and reserve nutrient substance accumulation in the seeds were represented. Near resemblance of the spaceflight and around control embryo development was revealed. Different character of the reserve substance accumulation was noted, despite of the morphologic similarity in seeds produced in spaceflight and on the ground. It allows to consider spaceflight embryos morphologically more younger compared to the ground control.

[A comparison of the kinetic characters of NT-3, NT-4 and BDNF retrogradely transported in facial nerve]

OBJECTIVE

To compare the kinetic characters of retrograde transport of neurotrophin-3 (NT-3), neurotrophin-4 (NT-4) and brain-derived neurotrophin factor (BDNF) in facial nerve.

METHODS

Radioactive tracer technique was used. After one lateral facial nerve trunk of adult rabbit was transected, a silicone chamber was inserted between the stumps, and 3.7 MBq of 125I-NT-3 or 125I-NT-4 or 125I-BDNF or 125I-HSA was administered into the chamber. At different time-points after injection, the facial nerve trunk and facial nerve motor neurone of brain-stem were collected and the uptake rates were measured. The kinetic parameters of each labeled compound were calculated using 3P87 program of kinetics.

RESULTS

The transport amount of neurotrophin retrogradely transported by facial nerve is NT-3 > BDNF > NT-4 (P < 0.05), the transport rate is NT-4 > NT-3 > BDNF (P < 0.05).

CONCLUSION

The findings could serve as the kinetic characters of retrograde transport of neurotrophins.

[The binding characteristics of insulin-MTX to insulin receptor]

OBJECTIVE

It has been reported that several kinds of tumors express increased insulin receptor and the molecules of insulin can be internalized in cells and may thence enter into the nuclei mediated by insulin receptor. In this study, we investigated the receptor binding characteristics of insulin-MTX for the possibility of using insulin as a carrier for carcinoma targeted therapy by receptor mediation.

METHODS

MTX(methotrexate) was covalently linked to insulin directly. The insulin-MTX conjugate was purified by polyacrylamine agarose gel electrophoresis and analysed by high performance liquid chromatography and SDS- polyacrylamine agarose gel electrophoresis. Histologically confirmed human hepatocellular carcinoma specimens were obtained from patients at surgery and immediately frozen under -80 degrees C. Cell membrane fractions were isolated by sucrose density gradient centrifugation. Competitive displacement of 125I-insulin with insulin and insulin-MTX binding to insulin receptor were carried out and the values of IC50 and Ki were calculated so as to observe the characteristics of insulin-MTX binding to insulin receptor.

RESULTS

Insulin-MTX competed as effectively as insulin with 125I-insulin for insulin receptor. The values of IC50 and Ki for insulin-MTX were 93.82 +/- 19.32 nmol/L and 91.88 +/- 16.86 nmol/L respectively, while the values of IC50 and Ki for insulin were 5.01 +/- 1.24 nmol/L and 4.85 +/- 1.12 nmol/L respectively.

CONCLUSION

Insulin-MTX could bind with insulin receptor with high affinity. The result demonstrates us that there is a possibility of using insulin as a carrier for carcinoma targeted therapy by receptor mediation.

[A study comparing 131I versus 131I plus antithyroid drug in the management of Graves' disease]

OBJECTIVE

To ascertain whether the therapoutic effect of 131I is affected by the additional use of thyrostatic medication.

METHODS

One hundred and eighty-seven patients with Graves' disease (GD) were randomly assigned to treatment with 131I alone or plus thyrostatic medication(PTU) 3 days after the beginning of 131I therapy. All patients were examined every month for six months after treatment.

RESULTS

The cure of hyperthyroidism occurred in 71 of 93 patients(76.3%) treated with 131I alone and in 76 of 94 patients(80.5%) treated with 131I plus thyrostatic medication(PTU). There were no significant differences in cure rate between the two groups.

CONCLUSION

The additional use of thyrostatic medication 3 days after the beginning of 131I therapy will not affect the efficacy of 131I in the treatment of GD.

[A comparison between 99mTc-Q3 and 201Tl on clearance and retention properties at varying coronary flow rates in isolated rabbit heart]

OBJECTIVE

This study was intended to investigate and compare technetium-99m-N, N'-ethylenebis(acetylacetoneiminato)bis[tris (3-methoxy-1-propyl) phosphine] (99mTc-Q3) versus 201Tl on clearance and retention properties at varying coronary flow rates in isolated rabbit heart.

METHODS

20 New Zealand White rabbits were anaesthetized and excised through a median sternotomy. The hearts were isolated and arrested in ice-cold saline. The external perfusion models with isolated rabbit hearts were installed and were perfused at flow rates ranging from 0.52 to 3.75 ml/(g wet wt.min) in the absence of tracer recirculation. Furthermore, 99mTc-Q3 experimental relations between uptake, clearance and retention were explored in comparison with 201Tl.

RESULTS

201Tl net uptake was higher and also more affected by flow rates (P < 0.05) as compared with 99mTc-Q3 net uptake. 201Tl clearance was faster than 99mTc-Q3 clearance within 4 to 25 minutes after radiopharmaceuticals injection in high flow rates group, and 201Tl clearance was faster than 99mTc-Q3 clearance within 40 minutes after radiopharmaceuticals injection in low flow rates group. 201Tl earlier rapid clearance observed in the high flow rates group did not appear in the low flow rates group, but 99mTc-Q3 did not display early rapid clearance either in the high flow rates group or in the low flow rates group.

CONCLUSION

Owing to faster clearance, the superiority of 201Tl over 99mTc-Q3 as a myocardial perfusion imaging agent would be lost entirely within 10 minutes after injection of agent, therefore 99mTc-Q3 is still a good myocardial perfusion imaging agent, and further study is worth doing.

Influence of atmospheric oxygen on leaf structure and starch deposition in Arabidopsis thaliana

Plant culture in oxygen concentrations below ambient is known to stimulate vegetative growth, but apart from reports on increased leaf number and weight, little is known about development at subambient oxygen concentrations. Arabidopsis thaliana (L.) Heynh. (cv. Columbia) plants were grown full term in pre-mixed atmospheres with oxygen partial pressures of 2.5, 5.1, 10.1, 16.2, and 21.3 kPa O2, 0.035 kPa CO2 and the balance nitrogen under continuous light. Fully expanded leaves were harvested and processed for light and transmission electron microscopy or for starch quantification. Growth in subambient oxygen concentrations caused changes in leaf anatomy (increased thickness, stomatal density and starch content) that have also been described for plants grown under carbon dioxide enrichment. However, at the lowest oxygen treatment (2.5 kPa), developmental changes occurred that could not be explained by changes in carbon budget caused by suppressed photorespiration, resulting in very thick leaves and a dwarf morphology. This study establishes the leaf parameters that change during growth under low O2, and identifies the lower concentration at which O2 limitation on transport and biosynthetic pathways detrimentally affects leaf development. Grant numbers: NAG5-3756, NAG2-1020, NAG2-1375.

[99mTc-Q3 uptake property at varying coronary flow rates in isolated rabbit heart: comparison between 99mTc-Q3 and 201Tl]

OBJECTIVE

This experiment was designed to explore myocardial 99mTc-Q3 uptake property.

METHODS

20 New Zealand White rabbit heart perfusion models were prepared and the isolated rabbit hearts were perfused by double-radionuclide method at varying coronary flow rates from 0.52 to 3.75 ml/g wet wt/min using developed perfusion liquid with autoblood in comparison with 201Tl in the absence of tracers recirculation.

RESULTS

Mean 99mTc-Q3 peak instantaneous uptake was lower(0.65 +/- 0.077) and more affected by low rates (P < 0.05) than 201Tl peak instantaneous uptake (0.82 +/- 0.07, P < 0.01).

CONCLUSION

These data were interpreted to indicate: 1. 99mTc-Q3 is not as well extracted as 201Tl; 2. varying the coronary flow rate has significant effects on the uptake of 99mTc-Q3 and 201Tl; 3. similarly to 201Tl, the coronary blood flow conditions may be overestimated by the myocardial radioactive uptake acquired with low flow perfusion, but the coronary blood flow conditions may be underestimated by the myocardial radioactive uptake acquired with high flow perfusion. Further studies on retention and clearance of 99mTc-Q3 need to be conducted.

[The research of receptor-mediated drug carrier]

One way to increase the concentration of drug in diseased tissue is to attach drug to a suitable carrier such as protein or peptides, which can improve the pharmacokinetic properties of drug and decrease it's side-effect on normal tissue. The developments of receptor-mediated transporting of drug assotiated with protein or peptides are reviewed in this paper. The most frequently used receptors and drug carriers and the bonds between the drug and the carrier are introduced. The machanism of transporting and the factors that affect the efficiency of the drug carrier are discussed as well.

Evidence of root zone hypoxia in Brassica rapa L. grown in microgravity

A series of experiments was conducted aboard the U.S. space shuttle and the Mir space station to evaluate microgravity-induced root zone hypoxia in rapid-cycling Brassica (Brassica rapa L.), using both root and foliar indicators of low-oxygen stress to the root zone. Root systems from two groups of plants 15 and 30 d after planting, grown in a phenolic foam nutrient delivery system on the shuttle (STS-87), were harvested and fixed for microscopy or frozen for enzyme assays immediately postflight or following a ground-based control. Activities of fermentative enzymes were measured as indicators of root zone hypoxia and metabolism. Following 16 d of microgravity, ADH (alcohol dehydrogenase) activity was increased in the spaceflight roots 47% and 475% in the 15-d-old and 30-d-old plants, respectively, relative to the ground control. Cytochemical localization showed ADH activity in only the root tips of the space-grown plants. Shoots from plants that were grown from seed in flight in a particulate medium on the Mir station were harvested at 13 d after planting and quick-frozen and stored in flight in a gaseous nitrogen freezer or chemically fixed in flight for subsequent microscopy. When compared to material from a high-fidelity ground control, concentrations of shoot sucrose and total soluble carbohydrate were significantly greater in the spaceflight treatment according to enzymatic carbohydrate analysis. Stereological analysis of micrographs of sections from leaf and cotyledon tissue fixed in flight and compared with ground controls indicated no changes in the volume of protoplast, cell wall, and intercellular space in parenchyma cells. Within the protoplasm, the volume occupied by starch was threefold higher in the spaceflight than in the ground control, with a concomitant decrease in vacuolar volume in the spaceflight treatment. Both induction of fermentative enzyme activity in roots and accumulation of carbohydrates in foliage have been repeatedly shown to occur in response to root zone oxygen deprivation. These results indicate that root zone hypoxia is a persistent challenge in spaceflight plant growth experiments and may be caused by microgravity-induced changes in fluid and gas distribution.

[Dynamic study of hepatocellular pathological change and uptake rate of 125I-insulin during experimental hepatocarcinogenesis]

This study was designed to observe the hepatocellular pathological change and uptake rate of 125I-insulin during experimental hepatocarcinogenesis in rats and clarify the possible mechanism of increasing uptake of 125I-insulin. 80 SD rats were divided into 2 groups, control and experimental groups. All of the rats were given common feed, and the rats of experimental group were given extra diethylnitrosamine (DENA) 70 mg/kg each week. At 6th, 11th, 15th and 20th week after start of the experiment, 10 control and 10 experimental rats were killed 1 hour post administration of 125I-insulin by tail vein. Blood, liver, lung, spleen, kidney, muscle and bone were collected; the radioactivity was measured and calculated %ID/g. The data of 2 groups were compared and examined with t-test. All of livers were pathologically examined. The results showed all livers of control group were normal. At 6th week, the surfaces of experimental rats' livers were coarse. Hepatocellular hyperplasia was observed, 125I-insulin-uptake rate was 1.86 time as much as that of control group. At 11th week, the liver's colour became lighter than that of control group. Hyperplasia and hepatocirrhosis were observed, 125I-insulin-uptake rate was 1.50 time as much as that of control group. At 15th week, hyperplastic nodules were observed in all experimental rats' livers. Hepatomacellulae were observed in 6 rat livers. 125I-insulin-uptake rate was 1.56 time as much as that of control group. At 20th week, the livers became enlarged out of shape. There were a lot of big or small greyish white nodules in all livers. Necrosis, liquefaction and hemorrhage were observed. Hepatomacellulae were observed in all of experimental rats livers. 125I-insulin-uptake rate was 1.46 time as much as that of control group. The differences of 125I-insulin-uptake rate between experimental and control groups were significant. These results demonstrated that the liver ability of uptaking 125I-insulin increased which mainly took place during the period of hepatocellular hyperplasia, and the hepatomacellulae kept this characteristic.

[153Sm-EDTMP in the treatment of bone metastasis of lung cancer]

BACKGROUND

To explore the clinical effect of 153Sm-EDTMP therapy in the treatment of bone metastasis of lung cancer.

METHODS

One hundred and ten patients with painful bone metastasis were entered into this study. The patients were administrated with two steps. At first , they were injected with tracer dose of 153Sm-EDTMP. After a series of index were calculated , such as urine discharge , bone uptake , cumulated skeletal activity , absorbed dose of red marrow and total dose , the second injection was given.

RESULTS

Of 110 cases , 98 (89. 1 %) experienced pain relief with complete response in 38 cases and partial response in 60 ones. Pain relief occurred from 3 h to 4 weeks (7. 5 d +/-6. 3 d) . Duration of pain relief from single injection ranged from 2 to 4 weeks. Follow-up imaging studies were performed within 3 months. In 12 cases , metastatic foci disappeared completely (CR) , Karnofsky score increased by 20 , and analgesic were discontinued. In 20 patients , both number and diameter of metastatic foci decreased (PR) , with an improvement in Karnofsky score ranging from 10 to 15. There were significant decreases in WBC and platelet count found in 35 of 110 patients after therapy , however , blood cell counts returned to baseline within 1 to 3 months.

CONCLUSIONS

153Sm-EDTMP has proven to be a safe and effective therapy for bone pain in lung cancer , and often results in shrinkage or disappearance of metastatic foci.

[The measurement of tracheo-bronchial mucociliary clearance by technetium-99m DTPA aerosol scintigraphy]

Mucociliary clearance of respiratory channels is one of the important mechanisms guarding against retention of foreign particles within the lungs. Thus objective assay of the system is essential to recognizing and understanding its abnormalities. In this study, 18 healthy subjects and 32 patients with chronic obstructive pulmonary diseases (COPD) were examined by technetium-99m-DTPA aerosol scintigraphy. Monitoring was performed by visual inspection (cinescintigraphy) and quantitative analysis. The mucociliary clearance rates of 18 healthy subjects and 32 COPD patients were 3.89 +/- 0.92 mm/min and 1.32 +/- 0.59 mm/min respectively. Statistical analysis indicated that the airway clearance rate and mucociliary clearance rate of COPD patients were significantly lower than those of normal subjects (P < 0.01). The method of assay reported here is simple and objective. It has not only the advantage of visual inspection and quantitative analysis, but also the potential usefulness in studying other bronchial diseases and evaluating therapeutic effectiveness of drugs.

[Methodological study on preparation of a novel myocardial perfusion imaging agent: 99mTc-Q3]

This study was intended to explore the methods of preparing technetium-99m-N, N'-ethylenebis (acetylacetoneiminato) bis [tris (3-methoxy-1-propyl) phosphine] (99mTc-Q3) as a newer cationic myocardial perfusion imaging agent. The optimum scheme of technetium labeling on the basis of exploring the effects of differently labeled conditions on radiochemical purity was established by a multivariate orthogonal experimental design. A newer agent for myocardial perfusion imaging was developed based on the optimum scheme by a stannous chloride reduction method. Preparation, separation, purification and quality control were performed by a chromatography. Experiments for stability (in vitro), sterility, apyrogen, safeness, and for imaging in animals were carried out. "A2B2C2" was chosen as the optimum scheme of this labeled complex. There each of A, B and C factors has significant effect on the radiochemical purity, and there is no one-class cross effect on the radiochemical purity between them. The labeling efficiency and radiochemical purity were measured over 99% labeled 10 min later (at R. T.). The stability (in vitro) was good and kept up to 4 hr or testing (range: 92%-99.37%). The prepared product was sterile, apyrogenic and safe. The scintigraphic imaging in rabbits demonstrated that the tracer accumulated early in the heart and the myocardial imaging displayed clearly up to 3 hr. The results of this methodological study demonstrate that not only high quality 99mTc-Q3 can be obtained but also a standardized procedure for labeling all kinds of 99mTc-agents can be set up, and on this basis, the one-step kit of 99mTc-Q3 may be developed.

Influence of microgravity on ultrastructure and storage reserves in seeds of Brassica rapa L

Successful plant reproduction under spaceflight conditions has been problematic in the past. During a 122 d opportunity on the Mir space station, full life cycles of Brassica rapa L. were completed in microgravity in a series of three experiments in the Svet greenhouse. Ultrastructural and cytochemical analyses of storage reserves in mature dry seeds produced in these experiments were compared with those of seeds produced during a high-fidelity ground control. Additional analyses were performed on developing Brassica embryos, 15 d post pollination, which were produced during a separate experiment on the Shuttle (STS-87). Seeds produced on Mir had less than 20% of the cotyledon cell number found in seeds harvested from the ground control. Cytochemical localization of storage reserves in mature cotyledons showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in ground control seeds. Protein bodies in mature cotyledons produced in space were 44% smaller than those in the ground control seeds. Fifteen days after pollination, cotyledon cells from mature embryos formed in space had large numbers of starch grains, and protein bodies were absent, while in developing ground control seeds at the same stage, protein bodies had already formed and fewer starch grains were evident. These data suggest that both the late stage of seed development and maturation are changed in Brassica by growth in a microgravity environment. While gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

Safety and efficiency of metered dose inhaler delivery of salbutamol in the intubated rabbit

OBJECTIVE

To determine the safety and efficiency of metered dose inhaler salbutamol delivered to the intubated rabbit.

DESIGN

Prospective, comparative, five-group laboratory investigation.

SETTING

Animal laboratory, Department of Nuclear Medicine.

SUBJECTS

A total of 30 adult, anesthetized New Zealand White rabbits.

INTERVENTIONS

Three groups of rabbits underwent tracheal intubation through a tracheostomy and received 5 puffs of 99mTcO4 salbutamol delivered at the elbow connector (group 1) or via a catheter with its distal tip positioned at the midpoint (group 2) or bevel of the endotracheal tube (group 3). No intervention was provided for the rabbits in the fourth group. A fifth group underwent tracheal intubation through the mouth and received salbutamol (5 puffs) delivered at the bevel of the endotracheal tube.

MEASUREMENTS

Delivery efficiency was expressed as the ratio of radioactivity emitted from lungs and trachea to the total radioactivity of the administered dose. Histopathologic injury scores were assigned to each trachea or lung specimen.

MAIN RESULTS

Delivery efficiency was 30 times greater in groups 3 and 5 (full catheter) than in group 1 (elbow). The injury scores were similar in all groups.

CONCLUSION

We conclude that the increased efficiency obtained by administration of metered dose inhaler salbutamol at the distal tip of endotracheal tube is not necessarily associated with increased epithelial injury.

[Preclinical pharmacological study of a novel myocardial perfusion agent: 99mTc-Q3]

In order to provide an experimental foundation for clinical study, we made a preclinical pharmacological investigation of 99mTc-Q3, a novel myocardial perfusion imaging agent, technetium-99m-N,N'-ethylenebis (acetylace-toneiminato) bis (tris (3-methoxy-1-proply) phosphine). After the preparation of this compound, the kinetics of blood clearance in rabbits, biodistribution in mice, measurement of plasma protein binding rate, and myocardial perfusion imaging in dog were carried out. The labelling efficiency and radiochemical purity measured were over 99%, and the stability (in vitro) was good and stable up to 6 hr of testing at room temperature. The pharmacokinetics met the two-compartment model with 0.23 +/- 0.09 ml/min of excellent blood clearance, an initial half-time of 1.5979 +/- 0.4182 min, and a late half-time of 203 +/- 25.83 min. The biodistribution as shown in myocardial accumulation was earlier, the radioactive value was higher, and once extracted, it remained relatively constant in the myocardium for at least 4 hr. The tracer was rapidly cleared from the blood, lung and the liver. The scintigraphy imaging in dog demonstrated that it was rapidly cleared from the lung, and the radioactive concentration approached that of background 1 hr after injection. At 15 min after injection, the myocardial imaging displayed clearly up to 3 hr. In vitro protein binding rate was low (7.13 +/- 0.42%). The tolerance of this drug in mice was 500 times as much as in humans. In conclusion, 99mTc-Q3 exhibits favorable stability, biological property and safety, so clinical study of this preparation as a myocardial perfusion imaging agent is worthwhile.

Pollination and embryo development in Brassica rapa L. in microgravity

Plant reproduction under spaceflight conditions has been problematic in the past. In order to determine what aspect of reproductive development is affected by microgravity, we studied pollination and embryo development in Brassica rapa L. during 16 d in microgravity on the space shuttle (STS-87). Brassica is self-incompatible and requires mechanical transfer of pollen. Short-duration access to microgravity during parabolic flights on the KC-135A aircraft was used initially to confirm that equal numbers of pollen grains could be collected and transferred in the absence of gravity. Brassica was grown in the Plant Growth Facility flight hardware as follows. Three chambers each contained six plants that were 13 d old at launch. As these plants flowered, thin colored tape was used to indicate the date of hand pollination, resulting in silique populations aged 8-15 d postpollination at the end of the 16-d mission. The remaining three chambers contained dry seeds that germinated on orbit to produce 14-d-old plants just beginning to flower at the time of landing. Pollen produced by these plants had comparable viability (93%) with that produced in the 2-d-delayed ground control. Matched-age siliques yielded embryos of equivalent developmental stage in the spaceflight and ground control treatments. Carbohydrate and protein storage reserves in the embryos, assessed by cytochemical localization, were also comparable. In the spaceflight material, growth and development by embryos rescued from siliques 15 d after pollination lagged behind the ground controls by 12 d; however, in the subsequent generation, no differences between the two treatments were found. The results demonstrate that while no stage of reproductive development in Brassica is absolutely dependent upon gravity, lower embryo quality may result following development in microgravity.

[The use of insulin as carrier in targeted therapy]

Upon insulin binding to its receptor, the receptor-ligand complexes will be internalized into the target cell. The internalized insulin will leave the endosome and associate with the nuclear matrix. This process might be useful for targeted therapy. Some complex can link with the insulin be internalized into the target cell by insulin receptor-mediated endocytosis and enter the cell nuclei to cure some diseases.

Gravity independence of seed-to-seed cycling in Brassica rapa

Growth of higher plants in the microgravity environment of orbital platforms has been problematic. Plants typically developed more slowly in space and often failed at the reproductive phase. Short-duration experiments on the Space Shuttle showed that early stages in the reproductive process could occur normally in microgravity, so we sought a long-duration opportunity to test gravity's role throughout the complete life cycle. During a 122-d opportunity on the Mir space station, full life cycles were completed in microgravity with Brassica rapa L. in a series of three experiments in the Svet greenhouse. Plant material was preserved in space by chemical fixation, freezing, and drying, and then compared to material preserved in the same way during a high-fidelity ground control. At sampling times 13 d after planting, plants on Mir were the same size and had the same number of flower buds as ground control plants. Following hand-pollination of the flowers by the astronaut, siliques formed. In microgravity, siliques ripened basipetally and contained smaller seeds with less than 20% of the cotyledon cells found in the seeds harvested from the ground control. Cytochemical localization of storage reserves in the mature embryos showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in the ground control seeds. While these successful seed-to-seed cycles show that gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

[Prospects for antisense techniques]

Antisense technique, developed on the principle of base complementation, is a method using short strand oligonucleotide fragments complementary to target DNAs or target RANs for inhibition of gene expression. As a theoretically perfect and specific method to block the expression of gene, it has been rapidly developed over the last twenty years. This review expatiates on its techniques, its problem and possible way of problem-solving, and its recent application in medicine. Also this review discusses the trends of its further development.

Oxygen-depleted zones inside reproductive structures of Brassicaceae: implications for oxygen control of seed development

Growth of Arabidopsis thaliana (L.) Heynh. in decreasing oxygen partial pressures revealed a linear decrease in seed production below 15 kPa, with a complete absence of seed production at 2.5 kPa oxygen. This control of plant reproduction by oxygen had previously been attributed to an oxygen effect on the partitioning between vegetative and reproductive growth. However, plants grown in a series of decreasing oxygen concentrations produced progressively smaller embryos that had stopped developing at progressively younger stages, suggesting instead that their growth is limited by oxygen. Internal oxygen concentrations of buds, pistils, and developing siliques of Brassica rapa L. and siliques of Arabidopsis were measured using a small-diameter glass electrode that was moved into the structures using a micromanipulator. Oxygen partial pressures were found to be lowest in the developing perianth (11.1 kPa) and pistils (15.2 kPa) of the unopened buds. Pollination reduced oxygen concentration inside the pistils by 3 kPa after just 24 h. Inside Brassica silique locules, partial pressures of oxygen averaged 12.2 kPa in darkness, and increased linearly with increasing light levels to 16.2 kPa. Measurements inside Arabidopsis siliques averaged 6.1 kPa in the dark and rose to 12.2 kPa with light. Hypoxia in these microenvironments is postulated to be the point of control of plant reproduction by oxygen.

[Determination of sarafloxacin by high performance liquid chromatography (HPLC)]

A method for the separation and determination of Sarafloxacin by HPLC was developed. The sample was dissolved in a mixture of V(acetonitrile):V(water) = 1:1. Operating conditions were as follows: mu-Bondapak C18 column (3.9 mm x 300 mm), V(acetonitrile):V(methanol):V(2 mmol/L H3PO4, adjust pH 3.5 with triethylamine) = 30:5:65 as mobile phase with a flow rate of 1 mL/min, UV detection at 278 nm, and column temperature was 15 degrees C. Under the above conditions, Sarafloxacin and other impurities were separated from each other. The method was simple, rapid, sensitive and accurate.

[Rapid microdose 14C-urea breath test for detection of Helicobacter pylori infection]

The purpose of this study was to develop and evaluate a rapid microdose 14C-urea breath test (14C-UBT) with a simplified protocol for detecting the infection of hilicobacter pylori (HP). 157 fasting patients who underwent endoscopy with histological examination and rapid urease test (RUT) were given a drink of 37 kBq of 14C-urea. Samples of breath carbon dioxide (1 mmol) were collected at baseline and 10, 20 and 30 min after administration by trapping in hyamine solution. 14C activity was measured by liquid scintillation counting. Results were expressed as cpm. Histolal examination and RUT were used as gold standard for the detection of HP infection. The cutoff value was selected as 200 cpm at 10 min. The results showed that the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.79%, 90.16%, 93.81%, 91.60% and 92.99% respectively. In this study, a 10 min, single sample, 37 kBq 14C-urea breath test for detection HP was developed. The test has good diagnostic accuracy with minimal radiation exposure and low cost. Thus, the authors considered the test to be reliable, safe, convenient and cost-effective to clinical use.

Changes in Arabidopsis leaf ultrastructure, chlorophyll and carbohydrate content during spaceflight depend on ventilation

Leaf structure and function under spaceflight conditions have received little study despite their important implications for biological life support systems using plants. Previous reports described disruption of the membrane apparatus for photosynthesis and a general decrease in carbohydrate content in foliage. During a series of three short-duration experiments (Chromex-03, -04, -05) on the US space shuttle (STS-54, STS-51, STS-68), we examined Arabidopsis thaliana leaves. The plants were at the rosette stage at the time of loading onto the space shuttle, and received the same light, temperature, carbon dioxide and humidity regimes in the orbiter as in ground controls. The experiments differed according to the regime provided in the headspace around the plants: this was either sealed (on mission STS-54); sealed with high levels of carbon dioxide (on mission STS-51) or vented to the cabin air through a filtration system (on mission STS-68). Immediately post-flight, leaf materials were fixed for microscopy or frozen in liquid nitrogen for subsequent analyses of chlorophyll and foliar carbohydrates. At the ultrastructural level, no aberrations in membrane structure were observed in any of the experiments. When air-flow was provided, plastids developed large starch grains in both spaceflight and ground controls. In the experiments with sealed chambers, spaceflight plants differed from ground controls with regard to measured concentrations of carbohydrate and chlorophyll, but the addition of airflow eliminated these differences. The results point to the crucial importance of consideration of the foliage microenvironment when spaceflight effects on leaf structure and metabolism are studied.

Control of seed development in Arabidopsis thaliana by atmospheric oxygen

Seed development is known to be inhibited completely when plants are grown in oxygen concentrations below 5.1 kPa, but apart from reports of decreased seed weight little is known about embryogenesis at subambient oxygen concentrations above this critical level. Arabidopsis thaliana (L.) Heynh. plants were grown full term under continuous light in premixed atmospheres with oxygen partial pressures of 2.5, 5.1, 10.1, 16.2 and 21.3 kPa O2, 0.035 kPa CO2 and the balance nitrogen. Seeds were harvested for germination tests and microscopy when siliques had yellowed. Seed germination was depressed in O2 treatments below 16.2 kPa, and seeds from plants grown in 2.5 kPa O2 did not germinate at all. Fewer than 25% of the seeds from plants grown in 5.1 kPa oxygen germinated and most of the seedlings appeared abnormal. Light and scanning electron microscopic observation of non-germinated seeds showed that these embryos had stopped growing at different developmental stages depending upon the prevailing oxygen level. Embryos stopped growing at the heart-shaped to linear cotyledon stage in 5.1 kPa O2, at around the curled cotyledon stage in 10.1 kPa O2, and at the premature stage in 16.2 kPa O2. Globular and heart-shaped embryos were observed in sectioned seeds from plants grown in 2.5 kPa O2. Tissue degeneration caused by cell autolysis and changes in cell structure were observed in cotyledons and radicles. Transmission electron microscopy of mature seeds showed that storage substances, such as protein bodies, were reduced in subambient oxygen treatments. The results demonstrate control of embryo development by oxygen in Arabidopsis.

Plant reproduction in spaceflight environments

Because plant reproduction is a complex developmental process there are many possible sites of perturbation by the unusual environments of orbital spacecraft. Previous long-duration experiments on Soviet platforms shared features of slowed development through the vegetative stage of plant growth and aborted reproductive function. Our goal has been to understand how special features of the spaceflight environment impact physiological function and reproductive development. In a series of short-duration experiments in the Shuttle mid-deck we studied early reproductive development in Arabidopsis thaliana. Pollen and ovule development aborted at an early stage in the first experiment on STS-54 which utilized closed plant growth chambers. Post-flight analysis suggested that the plants may have been carbon dioxide limited. Subsequent experiments utilized carbon dioxide enrichment (on STS-51) and cabin air flow-through with an air exchange system (on STS-68). Both modifications allowed pollen and ovule development to occur normally on orbit, and full reproductive development up to the stage of an immature seed occurred on STS-68. However, analysis of plant roots from these experiments demonstrated a limitation in rootzone aeration in the spaceflight material that was not mitigated by these procedures. In the future, additional resources (crew time, upgraded flight hardware, and special platforms) will invite more elaborate, long-duration experimentation. On the ISS, a variable speed centrifuge and upgraded plant habitats will permit detailed experiments on the role of gravity in shaping the plant micro-environment, and what influence this plays during reproduction.

Plant reproduction during spaceflight: importance of the gaseous environment

Plant reproduction is a complex developmental process likely to be disrupted by the unusual environmental conditions in orbital spacecraft. Previous results, reviewed herein, indicated difficulties in obtaining successful seen production in orbit, often relating to delayed plant development during the long-term growth necessary for a complete plant life cycle. Using short-duration exposure to spaceflight, we studied plant reproduction in Arabidopsis thaliana (L.) Heynh, during three flight experiments: CHROMEX-03 on STS-54 (6 d), CHROMEX-04 on STS-51 (10 d), and CHROMEX-05 on STS-68 (11 d). Plants were 13 - 14 d old (rosettes) at time of launch and initiated flowering shoots while in orbit. Plants were retrieved from the orbiters 2 - 3 h after landing and reproductive material was immediately processed for in-vivo observations of pollen viability, pollen tube growth, and esterase activity in the stigma, or fixed for later microscopy. Plants produced equal numbers of flowers to those controls growing on the ground but required special environmental conditions to permit fertilization and early seed development during spaceflight. In CHROMEX-03, plants were grown in closed plant growth chambers (PGCs), and male and female gametophyte development aborted at an early stage in the flight material. In CHROMEX-04, carbon dioxide enrichment was provided to the closed PGCs and reproductive development proceeded normally until the pollination stage, when there was an obstacle to pollen transfer in the spaceflight material. In CHROMEX-05, an air-exchange system was used to provide a slow purging of the PGCs with filtered cabin air. Under these conditions, the spaceflight plants apparently had reproductive development comparable to the ground controls, and immature seeds were produced. In every aspect examined, these seeds are similar to those produced by the ground control plants. The results suggest that if the physical environment around the plant under spaceflight conditions meets the physiological demands of the plant, then reproductive development can proceed normally on orbit.

Modification of reproductive development in Arabidopsis thaliana under spaceflight conditions

Reproductive development in Arabidopsis thaliana (L.) Heynh. cv. Columbia plants was investigated under spaceflight conditions on shuttle mission STS-51. Plants launched just prior to initiation of the reproductive phase developed flowers and siliques during the 10-d flight. Approximately 500 flowers were produced in total by the 12 plants in both the ground control and spaceflight material, and there was no significant difference in the number of flowers in each size class. The flower buds and siliques of the spaceflight plants were not morphologically different from the ground controls. Pollen viability tests immediately post-flight using fluorescein diacetate indicated that about 35% of the pollen was viable in the spaceflight material. Light-microscopy observations on this material showed that the female gametophytes also had developed normally to maturity. However, siliques from the spaceflight plants contained empty, shrunken ovules, and no evidence of pollen transfer to stigmatic papillae was found by light microscopy immediately post-flight or by scanning electron microscopy on fixed material. Short stamen length and indehiscent anthers were observed in the spaceflight material, and a film-like substance inside the anther that connected to the tapetum appeared to restrict the release of pollen from the anthers. These observations indicate that given appropriate growing conditions, early reproductive development in A. thaliana can occur normally under spaceflight conditions. On STS-51, reproductive development aborted due to obstacles in pollination or fertilization.

Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

Cytochemical localization of reserves during seed development in Arabidopsis thaliana under spaceflight conditions

Successful development of seeds under spaceflight conditions has been an elusive goal of numerous long-duration experiments with plants on orbital spacecraft. Because carbohydrate metabolism undergoes changes when plants are grown in microgravity, developing seed storage reserves might be detrimentally affected during spaceflight. Seed development in Arabidopsis thaliana plants that flowered during 11 d in space on shuttle mission STS-68 has been investigated in this study. Plants were grown to the rosette stage (13 d) on a nutrient agar medium on the ground and loaded into the Plant Growth Unit flight hardware 18 h prior to lift-off. Plants were retrieved 3 h after landing and siliques were immediately removed from plants. Young seeds were fixed and processed for microscopic observation. Seeds in both the ground control and flight plants are similar in their morphology and size. The oldest seeds from these plants contain completely developed embryos and seed coats. These embryos developed radicle, hypocotyl, meristematic apical tissue, and differentiated cotyledons. Protoderm, procambium, and primary ground tissue had differentiated. Reserves such as starch and protein were deposited in the embryos during tissue differentiation. The aleurone layer contains a large quantity of storage protein and starch grains. A seed coat developed from integuments of the ovule with gradual change in cell composition and cell material deposition. Carbohydrates were deposited in outer integument cells especially in the outside cell walls. Starch grains decreased in number per cell in the integument during seed coat development. All these characteristics during seed development represent normal features in the ground control plants and show that the spaceflight environment does not prevent normal development of seeds in Arabidopsis.

Pollen and ovule development in Arabidopsis thaliana under spaceflight conditions

The development of pollen and ovules in Arabidopsis thaliana on the space shuttle 'Endeavour' (STS-54) was investigated. Plants were grown on nutrient agar for 14 days prior to loading into closed plant growth chambers that received light and temperature control inside the Plant Growth Unit flight hardware on the shuttle middeck. After 6 days in spaceflight the plants were retrieved and immediately dissected and processed for light and electron microscope observation. Reproductive development aborted at an early stage. Pistils were collapsed and ovules inside were seen to he empty. No viable pollen was observed from STS-54 plants; young microspores were deformed and empty. At a late stage, the cytoplasm of the pollen contracted and became disorganized, but the pollen wall developed and the exine appeared normal. The tapetum in the flight flowers degenerated at early stages. Ovules from STS-54 flight plants stopped growing and the integuments and nucellus collapsed and degenerated. The megasporocytes appeared abnormal and rarely underwent meiosis. Apparently they enlarged, or occasionally produced a dyad or tetrad, to assume the form of a female gametophyte with the single nucleus located in an egglike cell that lacks a cell wall. Synergids, polar nuclei, and antipodals were not observed. The results demonstrate the types of lesions occurring in plant reproductive material under spaceflight conditions.

[Biodistribution and metabolism of 3H-gastrodigenin and 3H-gastrodin in mice]

The biodistribution and metabolism of 3H-gastrodigenin and 3H-gastrodin after intravenous injection were studied by the detection of their radioactivity in mice tissue; the radioactive elements of mice tissue extracts after intravenous injection of 3H-gastrodin were analyzed with thin-layer chromatography (TLC). The results demonstrated that gastrodin could penetrate through the blood-brain barrier into the brain, and it was rapidly decomposed into the gastrodigenin in brain, liver and blood. Then gastrodigenin preserved in brain and mediated its pharmacological inhibitive effects on the central nervous system. Most of the gastrodigenin and gastrodin were excreted by the kidney. The findings also suggested that gastrodin might exist in the enterohepatic circulation.

[125I-alpha-sec-butyl-p-hydroxybenzyl alcohol receptor competitive binding assays in animal body]

Based on the receptor competitive binding assays in the mice and rat body, it has been proved that both diazepam and alpha-sec-butyl-p-hydroxybenzyl alcohol (G-018) can inhibit 125I-G-018 binding with brain benzodiazepine receptor. Inhibiting effects were obvious in the cortex, cerebellum, hippocampus and midbrain. But in the medullao blongata and hypothalamus no inhibiting effect was observed. Experimental results have demonstrated that the inhibiting effect is consistent with distribution of benzodiazepine receptor in the brain. Also, experimental results have shown no difference between in vitro and in vivo. The G-018 binding with benzodiazepine receptor has been clarified under physiologic conditions.