Portland cement as pulp dressing agent in pulpotomy treatment of primary molars: a 12-month clinical study

AIM

Pulpotomy is the most frequent endodontic treatment performed on primary teeth. Different pulpotomy procedures and materials have been studied during the last years and recently interest has been focused on the use of Portland Cement (PC) as an alternative to these materials including Mineral Trioxide Aggregate (MTA), but still few clinical studies have been carried out. The aim of this study was to analyse the clinical and radiographic response to the use of Portland cement (PC) in primary molars pulpotomies through a clinical study in paediatric patients.

MATERIALS AND METHODS

Eleven carious primary mandibular molars of children aged 3-9 years old were treated by a conventional pulpotomy technique using PC. The teeth were restored with stainless steel crown. Clinical and radiographic follow-up was performed 6 and 12 months after the treatment.

RESULTS

All the treated molars were clinically and radiographically successful at all the follow-up appointments as no pathological findings were observed in any molar. Reparative dentin formation was observed in 100% of the treated molars.

CONCLUSIONS

PC could be considered a reasonable alternative to the use of MTA in pulpotomy treatments in primary molars, although more long-term clinical studies are needed to confirm these results.

Study of hyperglycemia in non critically-ill patients receiving parenteral nutrition: incidence and risk factors

BACKGROUND

The objectives of our study on non-critically ill patients receiving parenteral nutrition (PN) are to assess the incidence of hyperglycemia, the risk factors associated to its development and its influence in patient's evolution.

METHODS

A multicentric prospective observational study was performed in 9 hospitals. Four multivariate studies were developed to study the temporal risk in the occurrence of hyperglycemia (endpoint), intensive care unit (ICU) admission, length of stay (LOS) and death. Demographics, nutrients, drugs and clinical variables were collected. Independent variables studied as a possible risk factors were: sex, diabetes mellitus 2, baseline glycemia, albuminemia, pancreatitis, surgery in the 7 days prior to the end point, infection, insulin/somatostatin/corticoids administration during the study, glomerular filtration rate (GFR), and difference in the amount of glucose administration between the endpoint and one day before.

RESULTS

119 patients were enrolled in the study, 25 cases of hyperglycemia were detected. In the clinical factors associated with PN hyperglycemia, significant variables were: surgery in the 7 days before the end point, GFR, glucose load in the 24 hours previous to the end point insulin administration and somatostatine/octreotide administration during the study. Hyperglycemia was significantly associated with ICU admission and increased LOS.

CONCLUSIONS

Glucose administration in non-critically ill patients receiving PN should be reassessed downwards, especially in the immediate postsurgery, renal impairment and in patients treated with somatostatin analogues. It should be taken into account that an increase in glucose dose may lead to hyperglycemia in these patients and hyperglycemia correlates with longer hospital stay and increased frequency of ICU admissions.

Microbiological analysis of gingivitis in pediatric patients under orthodontic treatment

AIM

The aim of this study was to determine the relationship between gingival inflammation and changes in bacteria of the gingival sulcus in children in orthodontic treatment with brackets.

STUDY DESIGN

this prospective study assessed gingival and plaque index of two groups: children with brackets (Group 1) and without brackets (Group 2). The sample was selected from patients treated at the Faculty of Dentistry, Complutense University of Madrid, Spain. Microbiological assessment was performed in every child and all data were statistically analysed.

RESULTS

Group 1 showed significantly higher microbiological values and the difference was greater in lower teeth. Comparing the total plaque percentage, it was significantly higher in Group 1.

STATISTICS

there was no significant correlation between gingival and plaque indexes in any group. No significant correlation was found between plaque index and bacteria.

CONCLUSION

Children using brackets showed significantly higher gingival and plaque indices than children without brackets. No direct relationship was found between the increase in gingival and plaque indices and the presence and quantity of bacteria; therefore it was not possible to identify specific bacteria as responsible for the high gingival index in patients with brackets.

Relationship between mesiodistal crown diameters of permanent first molars and deciduous second molars

AIM

To determine whether there is a relationship between the mesiodistal crown diameters of permanent first molars and deciduous second molars, and to update their odontometric values for the Spanish population.

MATERIALS AND METHODS

A cross-sectional descriptive study was performed of a sample of molars in 101 children (46 boys and 55 girls) of Spanish parents.The measurements were performed on cast dental models using a fine-tipped caliper with accuracy of ± 0.05 mm.

RESULTS

Statistically significant differences were detected between sexes both for the permanent first molars and for the deciduous second molars. However, no differences were detected between antimeric teeth. The size of the deciduous second molars was related to the size of the permanent first molar, and this relationship was statistically significant.

CONCLUSION

As a correlation was found between the mesiodistal crown diameters of permanent first molars and deciduous second molars, the findings of this study may be used as a predictive factor for tooth-jaw size disharmony, and therefore for possible crowding of the permanent dentition.

Standards for mesiodistal and buccolingual crown size and height of primary molars in a sample of Spanish children

AIM

The aim of this study was to obtain mesiodistal, buccolingual and height sizes of dental crowns of first and second primary molars in a sample of Spanish children given, not only their anthropological and forensic significance, but also their clinical interest for the future analysis of restorative and orthodontic treatments.

MATERIALS AND METHODS

Measurements of mesiodistal, buccolingual size and height of the crowns of primary molars were studied. A transversally descriptive design was carried out and the interrelationship between these three dimensions was established. A sample of 703 first and second primary molars was selected from healthy Spanish boys and girls from 4 to 9 years old. Molars presenting anomalies of the crowns, caries or restorations were excluded. Measurements were made on dental plaster models, using a vernier caliper. Descriptive statistics and Pearson correlation coefficient was obtained and Wilcoxon's non- parametric test was applied for comparison of the mean, analysis of sexual dimorphism and comparison of antimeric teeth.

RESULTS

Average sizes of each group of molars were obtained. Sexual dimorphism was studied utilizing the Wilcoxon test. A variability of relationship between the measurements was found in each molar studied. Primary second molars had less variability than first molars in the three measurements obtained. The measurement with the least variability was height, followed by mesiodistal size.

CONCLUSIONS

Measurements of primary molars showed that average sizes of boys' molars were significantly larger than those of girls. Relationship between the three measurements studied was variable but second molars showed less variability than first molars. The relationship between height and width was found significant in most of the molars. i.

Paediatric patients receiving oncology therapy: review of the literature and oral management guidelines

AIM

In recent years, neoplastic diseases in children have acquired growing importance in the field of paediatrics. This has been accompanied by significant advances in the treatment of children's cancer, with long-term survival rates of 90% in the case of some tumors, resulting in the need for more medical and health care on all levels. With these advances comes a new responsibility to do everything possible to prevent complications stemming from neoplasia and its treatment. Among the side effects of cancer therapies (mainly chemotherapy and radiation treatment) are chronic or acute oral manifestations that are frequent sources of discomfort, focal points of systemic infections and other side effects, depending on the child's stage of development. In most cases, the incidence and severity of oral complications are associated with preexisting factors (cavities, gum disease and poor hygiene) that clearly affect their emergence, increase and persistence. The aim of this article is to propose a guideline for managing oral complications of paediatric cancer treatments.

CONCLUSIONS

It is fundamental for the patient and their parents to be aware of the possibility of preventing or reducing problems in the oral cavity through preventive measures and simple oral treatment.

Multiple agenesis and anhidrotic ectodermal dysplasia: a comparative longitudinal study of dental similarities and genetic differences in two groups of children

AIM

Dental anomalies in shape and number may be present isolated or associated with other manifestations. In anhidrotic ectodermal dysplasia they occur more frequently and severely. The authors examined a group of children with similar dental anomalies but no other ectodermal or extra-ectodermal signs.

METHODS

This study makes a comparative evaluation of similarities and differences of dental anomalies between two groups: A anhidrotic ectodermal dysplasia and B similar dental finding but without extra- dental anomalies.

RESULTS

In group A, the average number of agenesis in primary teeth was 3.5 (upper) and 5.33 (lower); in permanent teeth it was 5.4 and 5.8, respectively. In group B, the average was 1.62 (upper) and 0.25 (lower) in primary teeth, and 4.0 and 4.25 in permanent teeth respectively, with no constant pattern of occurrence. The study of tooth morphology of both groups revealed numerous anomalies in both dentitions. No differences were found in the average number of agenesis and morphological anomalies in the permanent teeth between both groups, but in the primary dentition group B presented a lower degree of incidence.

CONCLUSION

The presence of almost normal primary dentition (regarding to number), but with morphological anomalies, should lead to suspect their exacerbation in the permanent dentition.

Periodic notch inhibition by lunatic fringe underlies the chick segmentation clock

The segmented aspect of the vertebrate body plan first arises through the sequential formation of somites. The periodicity of somitogenesis is thought to be regulated by a molecular oscillator, the segmentation clock, which functions in presomitic mesoderm cells. This oscillator controls the periodic expression of 'cyclic genes', which are all related to the Notch pathway. The mechanism underlying this oscillator is not understood. Here we show that the protein product of the cyclic gene lunatic fringe (Lfng), which encodes a glycosyltransferase that can modify Notch activity, oscillates in the chick presomitic mesoderm. Overexpressing Lfng in the paraxial mesoderm abolishes the expression of cyclic genes including endogenous Lfng and leads to defects in segmentation. This effect on cyclic genes phenocopies inhibition of Notch signalling in the presomitic mesoderm. We therefore propose that Lfng establishes a negative feedback loop that implements periodic inhibition of Notch, which in turn controls the rhythmic expression of cyclic genes in the chick presomitic mesoderm. This feedback loop provides a molecular basis for the oscillator underlying the avian segmentation clock.

A molecular clock involved in somite segmentation

Somites are transient embryonic structures that are formed from the unsegmented presomitic mesoderm (PSM) in a highly regulated process called somitogenesis. Somite, formation can be considered as the result of several sequential processes: generation of a basic metameric pattern, specification of the antero-posterior identity of each somite, and, finally, formation of the somitic border. Evidence for the existence of a molecular clock or oscillator linked to somitogenesis has been provided by the discovery of the rhythmic and dynamic expression in the PSM of c-hairy1 and lunatic fringe, two genes potentially related to the Notch signaling pathway. These oscillating expression patterns suggest that an important role of the molecular clock could reside in the temporal control of periodic Notch activation, ultimately resulting in the regular array of the somites. We discuss both the importance of the Notch signaling pathway in the molecular events of somitogenesis and its relationship with the molecular clock, and, finally, in that context we review a number of other genes known to play a role in somitogenesis.

Control of Drosophila paramyosin/miniparamyosin gene expression. Differential regulatory mechanisms for muscle-specific transcription

To define the transcriptional mechanisms contributing to stage- and tissue-specific expression of muscle genes, we performed transgenic analysis of Drosophila paramyosin gene regulation. This gene has two promoters, one for paramyosin and one for miniparamyosin, which are active in partially overlapping domains. Regions between -0.9 and -1.7 kilobases upstream of each initiation site contribute to the temporal and spatial expression patterns. By comparing the Drosophila melanogaster and Drosophila virilis promoters, conserved binding sites were found for known myogenic factors, including one MEF2 site and three E boxes. In contrast with previous data, our experiments with the paramyosin promoter indicate that the MEF2 site is essential but not sufficient for proper paramyosin gene transcription. Mutations in the three E boxes, on the other hand, do not produce any effect in embryonic/larval muscles. Thus MEF2 site- and E box-binding proteins can play different roles in the regulation of different muscle-specific genes. For the miniparamyosin promoters, several conserved sequences were shown to correspond to functionally important regions. Our data further show that the two promoters work independently. Even when both promoters are active in the same muscle fiber, the transcription driven by one of the promoters is not affected by transcription driven by the other.

Effect of venlafaxine hydrochloride in different preparations of isolated guinea-pig and rat organ tissues

A study was undertaken to know better the effects of venlafaxine hydrochloride on the responses of isolated rat vas deferens to noradrenaline and dopamine, those of isolated rat uterus to serotonin and histamine, and those of isolated guinea-pig ileum to acetylcholine and histamine. Venlafaxine hydrochloride increased the response of rat vas deferens to noradrenaline but not to dopamine. Venlafaxine did not alter the response of rat isolated uterus to serotonin. In rat uterus, venlafaxine did not modify the response to histamine but was able to increase it in guinea-pig ileum. An anticholinergic effect was observed with the lowest concentration tested. Although venlafaxine is a selective serotonine reuptake inhibitor in the central nervous system, serotonin uptake was not seen in the rat uterus. The anticholinergic effects observed in the present study might be consistent with some of the side-effects associated with venlafaxine.

Troponin-T is a calcium-binding protein in insect muscle: in vivo phosphorylation, muscle-specific isoforms and developmental profile in Drosophila melanogaster

Two sets of muscle polypeptides showing calcium-binding capacity and intense labelling in vivo with 32P were purified and characterized from Drosophila melanogaster adult extracts. The polypeptides exhibit crossed immunoreactivity and share similar biochemical properties such as those involved in purification. They have been identified as isoforms of troponin-T (TnT) by sequence analysis of a cDNA clone isolated from an embryonic library. The two sets of TnT polypeptides correspond to the fibrillar and non-fibrillar muscle isoforms, respectively. The non-fibrillar muscle isoforms separate into two bands which are differentially expressed during development. Analysis of TnT isoforms in bee thoraces indicates that the expression of the fibrillar muscle isoform correlates with the acquisition of functional flight capability. In vivo labelling experiments reveal that the two TnT sets are readily phosphorylated. The Drosophila TnTs show calcium-binding properties by three different types of assays. Our results suggest that this property could be specific to insect TnTs and may be related to the long, extremely acidic polyglutamic carboxy-terminus present in these polypeptides, which does not occur in non-arthropod TnTs.

Regulation of dorsal somitic cell fates: BMPs and Noggin control the timing and pattern of myogenic regulator expression

Previous work has indicated that signals from the neural tube, notochord, and surface ectoderm promote somitic myogenesis. Here, we show that somitic myogenesis is under negative regulation as well; BMP signaling serves to inhibit the activation of MyoD and Myf5 in Pax3-expressing cells. Furthermore, we show that the BMP antagonist Noggin is expressed within the dorsomedial lip of the dermomyotome, where Pax3-expressing cells first initiate the expression of MyoD and Myf5 to give rise to myotomal cells in the medial somite. Consistent with the expression of Noggin in dorsomedial dermomyotomal cells that lie adjacent to the dorsal neural tube, we have found that coculture of somites with fibroblasts programmed to secrete Wnt1, which is expressed in dorsal neural tube, can induce somitic Noggin expression. Ectopic expression of Noggin lateral to the somite dramatically expands MyoD expression into the lateral regions of the somite, represses Pax3 expression in this tissue, and induces formation of a lateral myotome. Together, our findings indicate that the timing and location of myogenesis within the somite is controlled by relative levels of BMP activity and localized expression of a BMP antagonist.

Ectopic Pax-3 activates MyoD and Myf-5 expression in embryonic mesoderm and neural tissue

To understand how the skeletal muscle lineage is induced during vertebrate embryogenesis, we have sought to identify the regulatory molecules that mediate induction of the myogenic regulatory factors MyoD and Myf-5. In this work, we demonstrate that either signals from the overlying ectoderm or Wnt and Sonic hedgehog signals can induce somitic expression of the paired box transcription factors, Pax-3 and Pax-7, concomitant with expression of Myf-5 and prior to that of MyoD. Moreover, infection of embryonic tissues in vitro with a retrovirus encoding Pax-3 is sufficient to induce expression of MyoD, Myf-5, and myogenin in both paraxial and lateral plate mesoderm in the absence of inducing tissues as well as in the neural tube. Together, these findings imply that Pax-3 may mediate activation of MyoD and Myf-5 in response to muscle-inducing signals from either the axial tissues or overlying ectoderm and identify Pax-3 as a key regulator of somitic myogenesis.

Effect of 4-aminopyridine and 3,4-diaminopyridine on guinea-pig isolated ileum

1. 4-Aminopyridine and 3,4-diaminopyridine produced concentration-dependent contraction on guinea-pig isolated ileum incubated in Tyrode solution. The EC30 values were 1.14 x 10(-4) and 1.39 x 10(-4) M, respectively. 2. Calcium channel blockers such as verapamil, diltiazem, nifedipine, flunarizine, and lanthanum chloride antagonized the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 3. Diazoxide and atropine sulphate behaved similarly as antagonists of the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 4. It is concluded that the aminopyridines exert their effects through the release of acetylcholine from parasympathetic nerve terminals.

Drosophila paramyosin/miniparamyosin gene products show a large diversity in quantity, localization, and isoform pattern: a possible role in muscle maturation and function

The Drosophila paramyosin/miniparamyosin gene expresses two products of different molecular weight transcriptionally regulated from two different promoters. Distinct muscle types also have different relative amounts of myosin, paramyosin, and miniparamyosin, reflecting differences in the organization of their thick filaments. Immunofluorescence and EM data indicate that miniparamyosin is mainly located in the M line and at both ends of the thick filaments in Drosophila indirect flight muscles, while paramyosin is present all along the thick filaments. In the tergal depressor of the trochanter muscle, both proteins are distributed all along the A band. In contrast, in the waterbug, Lethocerus, both paramyosin and miniparamyosin are distributed along the length of the indirect flight and leg muscle thick filaments. Two-dimensional and one-dimensional Western blot analyses have revealed that miniparamyosin has several isoforms, focusing over a very wide pH range, all of which are phosphorylated in vivo. The changes in isoform patterns of miniparamyosin and paramyosin indicate a direct or indirect involvement of these proteins in muscle function and flight. This wide spectrum of potential regulatory characteristics underlines the key importance of paramyosin/miniparamyosin and its complex isoform pattern in the organization of the invertebrate thick filament.

Age-related changes in contractile responses to noradrenaline in isolated blood vessels from rat and rabbit

1. Age-related changes in vascular function have been studied using rat (1, 6 and 10 months) and rabbit (1 and 6 months) isolated aorta and rat (1, 6 and 10 months) mesenteric perfused artery. 2. The EC50 values of noradrenaline in rat aorta increased with age. Similarly, contractile response to noradrenaline (10(-6) M) and potassium (80 mM) increased with age. In rabbit aorta, contractile responses, both for noradrenaline and potassium, decreased with age. No changes were observed with age in sensitivity to noradrenaline in rat mesenteric perfused artery. 3. The results of the present study suggest that age-related changes may be different for different blood vessels. The sensitivity decrease to noradrenaline in rat aorta involved postreceptor mechanisms.

Analysis of the paramyosin/miniparamyosin gene. Miniparamyosin is an independently transcribed, distinct paramyosin isoform, widely distributed in invertebrates

Miniparamyosin, a distinct Drosophila melanogaster paramyosin isoform of 60 kDa, is shown here to be encoded by the same gene as paramyosin. The gene, located at 66D14, spans over 12.8 kilobases (kb) and is organized into 10 exons, 9 of which code for the paramyosin transcripts. An exon, located between exons 7 and 8, codes for the 5'-end of the miniparamyosin, and the two proteins share the two last exons of the gene. Mapping of the 5'-ends of these transcripts indicates that the paramyosin and miniparamyosin mRNAs arise from two overlapping transcriptional units; the miniparamyosin transcription initiation site is located inside a paramyosin intron, 8 kb downstream of the one used for paramyosin transcription. The existence of two different promoters and the conserved and nonconserved features of their sequences suggest a very complex regulation of these two muscle proteins. In fact, while paramyosin is expressed at two distinct stages of development as most other Drosophila muscle proteins, miniparamyosin appears late in development, being present only in the adult musculature. The absence of exon 1B, the specific exon of miniparamyosin, in the nematode Caenorhabditis elegans, as well as additional lines of evidence support the lack of miniparamyosin in this particular organism. However, it is present in most invertebrate species examined, including different arthropod, annelid, mollusc, and echinoderm species.

Enhancement of the immunocytochemical detection of antigens by microwave irradiation. Benefits and limitations analysed in isolated plant nuclei and Drosophila embryos in toto

Performing the antibody reaction under controlled heating through microwave irradiation results in significant improvements in the immunovisualization of antigens, such as shortening the times of incubation, lowering the antibody titres used and allowing the detection of difficult, inaccessible antigens. In addition to investigate the basis of the enhancement, we have extended to more intact samples such as isolated plant nuclei and in toto Drosophila embryos the results previously reported only with tissue sections. A drop of heterologous anti-nucleolin antibody covering isolated nuclei from onion root meristems spread on a glass slide was microwave irradiated, resulting in clear immunofluorescent labelling of the nucleoli. This result was never previously obtained in the absence of microwave treatment, even using the complicated procedure previously reported for the homologous identification of this nuclear protein. Using the much larger and to some extent impermeable Drosophila embryos, we were able to show that the incubation time and concentration of the anti-myosin antibody can be strongly reduced by performing the reaction at 45 degrees C under microwave irradiation. The controlled increase in temperature is the main factor responsible for these improvements; the importance of maintaining an adequate mixing of the samples is also emphasized. The proper implementation of these two experimental conditions will require the introduction of appropriate mixing accessories and temperature measuring probes for samples of small volume in current microwave laboratory ovens.

Arthropod model systems for studying complex biological processes in the space environment

Three arthropod systems are discussed in relation to their complementary and potential use in Space Biology. In a next biosatellite flight, Drosophila melanogaster pre-adapted during several months to different g levels will be flown in an automatic device that separates parental from first and second generations. In the same flight, flies will be exposed to microgravity conditions in an automatic unit in which fly motility can be recorded. In the International Microgravity Laboratory-2, several groups of Drosophila embryos will be grown in Space and the motility of a male fly population will be video-recorded. In the Biopan, an ESA exobiology facility that can be flown attached to the exterior of a Russian biosatellite, Artemia dormant gastrulae will be exposed to the space environment in the exterior of the satellite under a normal atmosphere or in the void. Gastrulae will be separated in hit and non-hit populations. The developmental and aging response of these animals will be studied upon recovery. With these experiments we will be able to establish whether exposure to the space environment influences arthropod development and aging, and elaborate on some of the cellular mechanisms involved which should be tested in future experiments.

Autophosphorylating protein kinase activity in titin-like arthropod projectin

The function of the high molecular weight structural proteins from muscle, namely vertebrate titin, arthropod projectin and nematode twitchin, remains to be established. Using a simple method for the purification of projectin from crayfish and Drosophila melanogaster, a polyclonal antibody has been raised against crayfish projectin, and shown to immunocrossreact with Drosophila projectin but not with rat titin. In this study, evidence is presented that projectin and twitchin may share functional protein kinase domains, indicating a possible relationship between them. Projectin has a serine/threonine protein kinase activity. This supports the relationship with twitchin since, in sequence analysis of the latter, a protein-kinase-like domain has been found. Moreover, projectin is capable of autophosphorylation in vitro. These kinase activities imply regulatory functions for this group of proteins, extending its previously assumed structural role in the sarcomere. We also show here that projectin is phosphorylated in vivo at serine residues, as described for titin.

Drosophila melanogaster paramyosin : developmental pattern, mapping and properties deduced from its complete coding sequence

Several cDNA clones encoding the complete Drosophila paramyosin sequence, including two potential polyadenylation sites, have been obtained. Southern analysis and in situ hybridization to polytene chromosomes indicate that in Drosophila the paramyosin gene is single copy, located on the left arm of the third chromosome at region 66D14. Northern analyses show predominantly two different RNAs which are the products of the choice between the two alternative polyadenylation sites. The two species begin to be synthesized around 10 h of development when embryonic muscles are formed, expression peaking at the end of embryogenesis. The protein is first expressed at germ band shortening in association with muscle precursor cells. A second maximum of paramyosin RNA expression occurs at late pupal stages when the higher molecular weight form becomes more abundant. In young adults this species becomes the main transcript detected. The 102 kDa polypeptide sequence is highly similar to that of Caenorhabditis elegans paramyosin. The protein has a central alpha-helical coiled-coil rod, organized in 29 groups of four typical seven-residue repeats and flanked by two short non-alpha-helical regions. Several leucine zippers are located on the hydrophobic face of the alpha-helix in paramyosin which, together with disulfide bonds between cysteines, are probably involved in the stabilization of the dimer. The structural and functional properties of Drosophila paramyosin deduced from the sequence are compared with those of known invertebrate myosins and paramyosins.

Microgravity effects on Drosophila melanogaster development and aging: comparative analysis of the results of the Fly experiment in the Biokosmos 9 biosatellite flight

The results are presented of the exposure of Drosophila melanogaster to microgravity conditions during a 15-day biosatellite flight, Biokosmos 9, in a joint ESA-URSS project. The experimental containers were loaded before launch with a set of Drosophila melanogaster Oregon R larvae so that imagoes were due to emerge half-way through the flight. A large number of normally developed larvae were recovered from the space-flown containers. These larvae were able to develop into normal adults confirming earlier results that Drosophila melanogaster of a wild-type constitution can develop normally in the absence of gravity. However, microgravity exposure clearly enhances the number of growing embryos laid by the flies and possibly slows down the developmental pace of the microgravity-exposed animals. Due to some problems in the experimental set-up, this slowing down needs to be verified in future experiments. No live adult that had been exposed to microgravity was recovered from the experiment, so that no life span studies could be carried out, but adult males emerged from the recovered embyros showed a slight shortening in life span and a lower performance in other experimental tests of aging. This agrees with the results of previous experiments performed by our groups.