Radiotherapy for childhood cancer and risk for congenital malformations in offspring: a population-based cohort study

Offspring of childhood cancer survivors may be at risk of genetic disease due to the mutagenic cancer treatments received by their parents. Congenital malformations were evaluated in a population-based cohort study of 1715 offspring of 3963 childhood cancer survivors and 6009 offspring of 5657 survivors' siblings. The Danish Central Population Register, Cancer Registry and Hospital Register were used to identify study subjects and congenital malformations. Gonadal and uterine radiation doses were characterized based on standard radiation-treatment regimens. The prevalence of congenital malformations at birth in offspring of survivors (44 cases, 2.6%) was slightly higher but not statistically different from that of offspring of siblings (140 cases, 2.3%) [prevalence proportion ratio (PPR), 1.1; 95% confidence interval, 0.8-1.5] or of the general population (observed-to-expected ratio, 1.2; 0.9-1.6). Including malformations diagnosed later in life did not change the ratios appreciably. The risk for malformations was slightly higher in the offspring of irradiated parents than in that of non-irradiated parents (PPR 1.2 vs 1.0) but was unrelated to gonadal dose. This study provides evidence that cancer therapy of children does not increase the risk for malformations in their offspring. Continued monitoring of genetic risks among their offspring, however, is warranted.

Mortality in Danish patients with nonmelanoma skin cancer, 1978-2001

BACKGROUND

Nonmelanoma skin cancer (NMSC) is a growing public health problem among Caucasians, thus mortality data that may provide insight into the clinical course and foster our understanding of NMSC are important.

OBJECTIVES

We examined total and cause-specific mortality among patients with NMSC registered in the Danish Cancer Registry from 1978 to 2001.

METHODS

A total of 82 837 patients with basal cell carcinoma (BCC) and 13 453 patients with squamous cell carcinoma (SCC) were followed through the National Death Registry for specific causes of death. Standardized mortality ratios (SMRs) were computed based on mortality rates in the general population.

RESULTS

Among patients with BCC, we found a slightly reduced total mortality [SMR 0.97, 95% confidence interval (CI) 0.96-0.98] with decreased SMRs seen for chronic obstructive pulmonary disease (COPD), cardiovascular disease (CVD) and diabetes mellitus. The SMR for suicide was increased. Among patients with SCC, we found an increased total mortality (SMR 1.30, 95% CI 1.26-1.33) due primarily to excess deaths from cancers, COPD, CVD and infectious diseases.

CONCLUSIONS

We found markedly different mortality patterns among patients with BCC and those with SCC, suggesting important differences in the clinical course of these patients.

Cancer in siblings of children with cancer in the Nordic countries: a population-based cohort study

BACKGROUND

In some rare inherited disorders such as Li-Fraumeni syndrome, relatives of children with cancer are at increased risk of cancer. We aimed to assess relations between childhood cancer and sibling risk, and evaluate the influence of recessive conditions in cancer causation.

METHODS

We did a population-based cohort study in the Nordic countries of 42277 siblings of 25605 children with cancer. Children with cancer were identified from records in the five Nordic cancer registries, and their siblings from nationwide population registries. Cancers in siblings were documented through record linkage with cancer registries and compared with national incidence rates. We also assessed cancer incidence in parents to identify familial cancer syndromes.

FINDINGS

284.2 cancers were expected in siblings, whereas 353 were diagnosed (standardised incidence ratio 1.24 95% CI 1.12-1.38). Risk ratios for siblings were highest in the first decade of life (2.59, 1.89-3.46). We excluded 56 families with genetic syndromes linked to cancer, which reduced this ratio from 1.7 to 1.0 (0.7-1.3) for siblings younger than 20 years, and from 1.3 to 1.0 (0.8-1.3) for those aged 20-29 years. We found no new patterns of familial cancer that indicated inherited susceptibility, or evidence that recessive conditions might contribute to cancers not explained by syndromes. 40% of cancers in siblings that occurred before age 20 years could be attributed to known genetic factors, whereas 60% remained unexplained.

INTERPRETATION

Apart from rare cancer syndromes, paediatric cancer is not an indicator of increased cancer risk in siblings.

Effects of microgravity on the larval development, metamorphosis and reproduction of the urodele amphibian Pleurodeles waltl

The FERTILE experiment was twice performed onboard the Mir space station during the Cassiopée and Pégase French space missions. The goal was to analyze the effects of microgravity on fertilization and embryonic development, and then on further development on the ground in the amphibian Pleurodeles waltl. The present paper reports development that occurred in the laboratory after landing. Recovered on the ground at the hatching stage, young larvae reared at room temperature underwent metamorphosis and became adults without obvious abnormalities. Of particular interest was the rearing temperature that induced a delayed metamorphosis for animals from the Cassiopée space mission, but not for animals from the Pégase mission. The rate of development and the morphology were analogous in these animals and in ground controls reared in a similar annual period. Analysis of offspring was performed using these animals. Males born in space were first mated with control ground-born females and then with females born in space. The mating gave progeny that developed normally. Depending on the methods used and on the limits of the analyses, the results clearly demonstrated that animals born in space were able to live and reproduce after return to the ground.

Sex reversal of germ cell gametogenesis in chimeras of Pleurodeles waltl (urodele amphibian): genetic and immunogenetic demonstration using tolerance or rejection of skin grafts

Viable chimeras were constituted with two cranial and caudal complementary pieces of embryos derived from two distinct histocompatible AA and BB strains, which were incompatible with each other. The embryonic gonads of the resulting chimeras constituted two homo- or heterosexual territories. In most heterosexual chimeras, the testicular territory sex reversed the ovarian territory. The offspring analysis of a male chimera conclusively proved that ZW germ cells derived from the posterior female piece differentiated into spermatozoa. Nevertheless, the opposite situation was also demonstrated with a female chimera in which ZZ germ cells derived from the anterior male piece differentiated into oocytes. These gametogenesis reversions were tested by genetic and immunogenetic analyses of chimera offspring. The phenomenon of tolerance or rejection of skin allo- and autograft was used as a marker of origin of the chimera germ cells, which had produced the offspring. Moreover, in the first stage of the study, the origin of the pieces of adult chimeras was determined using skin grafts. During this stage, the embryonic tolerance was confirmed by the acquisition of four pieces of pairs of chimeras, and by the preservation of skin immunogenicity that was derived from each piece of the chimeras.

Design of specific hardware to obtain embryos and maintain adult urodele amphibians aboard a space station

The study of the influence of weightlessness on fertilization and embryonic development of a vertebrate is of importance in the understanding of basic embryogenesis and in the preparation of the future exploration of space. Accordingly, specific hardware was designed to perform experiments on board the MIR space station with an amphibian vertebrate model, taking into account the biological requirements and the multiple constraints of a long-term mission. This paper describes the biological uses and presents the technological specifications of the device developed under CNES management. The hardware was adapted to and is compatible with biological requirements as confirmed by three experiments performed in space on board the orbital MIR station.

Microgravity and hypergravity effects on fertilization of the salamander Pleurodeles waltl (urodele amphibian)

Effects of microgravity (microG) on fertilization were studied in the urodele amphibian Pleurodeles waltl on board the MIR space station. Genetic and cytomorphologic analyses ruled out parthenogenesis or gynogenesis and proved that fertilization did occur in microG. Actual fertilization was demonstrated by the analysis of the distribution of peptidase-1 genes, a polymorphic sex-linked enzyme, in progenies obtained in microG. Further evidence of fertilization was provided by the presence of spermatozoa in the perivitelline space and in the fertilization layer of the microG eggs and by the presence of a female pronucleus and male pronuclei in the egg cytoplasm. Experiments in microG and in 1.4G, 2G, and 3G hypergravity showed for the first time that, compared to eggs in 1G, several characteristics of the fertilization process including the cortical reaction and the microvillus transformations were altered depending on the gravitational force applied to the eggs. Microvillus elevation, the most evident feature, was reduced on microG-eggs and amplified on eggs submitted to 2G and 3G. No lethal consequences of these alterations on the early development of microG-eggs were observed.

Appearance and evolution of calcitic and aragonitic otoconia during Pleurodeles waltl development

The aim of this study is to determine the stages of appearance, morphology, crystallographic structure and chemical composition of otoconia during the inner ear development of an urodele amphibian, Pleurodeles waltl. The first otoconia are detected in the otocyst. Near hatching, calcitic otoconia are polyhedral in the saccule and cylindrical in the utricle. During the following stages, the saccular otoconia agglomerate and constitute a polyhedral calcitic otolith. At larval stage 44, aragonitic fusiform otoconia appear on the otolithic surface. At stage 52, X-ray diffraction analysis shows calcite and aragonite patterns. In adults, all the saccular otoconia are aragonitic. In contrast, the utricular otoconia do not show any modification up to adulthood. In the endolymphatic sac, otoconia appear at stage 45 and in the lagena at stage 49. They remain aragonitic up to adulthood. Energy dispersive X-ray spectroscopy (EDXS) elemental analysis of the otoconia reveals a high quantity of calcium with trace quantities of sodium, magnesium, phosphorus, sulfur, chlorine and potassium. However, magnesium and sulfur have a lower concentration in lagenar aragonitic otoconia than in utricular and saccular calcitic ones. As in adults, trace amounts of strontium are only found in aragonitic otoconia.

Crystallographic and chemical composition of otoconia in the salamander Pleurodeles waltl

The aim of the present study was to define the morphology and the crystallographic and chemical composition of otoconia in different regions of the inner ear in Pleurodeles waltl (urodele amphibian). The inner ear of adults was microdissected and otoconia were analyzed by scanning electron microscopy (SEM), X-ray diffraction, energy dispersive X-ray (EDX) and transmission electron microscopy. Two types of crystals were detected by SEM. Otoconia had different shapes depending on their location in the membranous labyrinth. One type had a cylindrical body with a triplanar smooth facet at each end, the other ones had either a prismatic shape with flat sides and end faces or a fusiform shape with rounded body and pointed end. The forms corresponded to those previously identified by other authors. These two types of otoconia had different X-ray diffraction patterns. The cylindrical otoconia were calcitic and located in the utricle, the other ones were aragonitic and located in the saccule, lagena and endolymphatic sac. An analysis by EDX indicated that both types of otoconia contained about 95% calcium with trace quantities of sodium, magnesium, phosphorus, sulfur, chlorine and potassium. Trace amounts of strontium was only found in the aragonitic otoconia.

Expression of hindlimb abnormalities under rearing temperature effects during the larval development of the salamander Pleurodeles waltl (urodele amphibian)

Anomalie m.p. is a spontaneous and heritable hindlimb abnormality described earlier. Twenty years later, Pleurodeles waltl larvae from the strain bearing anomalie m.p. and reared at room temperature or at 30 degrees C, expressed abnormalities (ectrodactylia, hemimelia, ectromelia). A morphological study of all the hindlimbs and an analysis of the hindlimb skeleton of samples from the experimental animals confirmed that most of the skeletal malformations were identical to those previously reported and affected the disto-proximal and prepostaxial pattern of the hindlimb. Analysis of the effects of rearing temperature on the expression of anomalie m.p. showed that the effects varied according to the developmental period at which the heat treatment was applied; the sooner the heat treatment began, the more numerous and more various were the degrees of severity of the malformations. Moreover, heat treatment induced the expression of two additional malformations not yet described: the first one, named 'reversed knee joint', was characterized by a reversal of the knee joint, and the second one, named 'twisted foot', by a downward twisting of the foot. The epigenetic effects of rearing at 30 degrees C on hindlimb development are discussed with regard to the differentiation or patterning.

Grafts of ovaries in males and females of Pleurodeles waltl (urodele amphibia): evidence of a long-term tolerance of allografts; application following a space biology experiment

Ovary grafts were investigated in the salamander Pleurodeles using juveniles and adults as donors and hosts. Ovaries were provided by standard or histo-compatible strains and by standard females which had been submitted to a space flight. Laparotomy of the hosts was used to control viability of grafts. Entire juvenile ovaries transplanted into castrated juvenile females or males were tolerated and developed. Ovarian parts of adult females, which contained a majority of oogonies, could also be tolerated by juvenile animals. In addition, ovarian parts supported a better recovery and differentiation than parts that mainly included mature oocytes. About 24 months after the ovary grafts, some hosts (genetical females or males and standard or spatialized females) crossed with standard males provided progenies originating from oocytes of the grafted ovaries. The protocols applied offer a new range of potentialities, adapted to various experimental purposes such as life science research in space or sex differentiation studies.

Technical and surgical aspects of continuous vascular access in freely moving small animals

Many systems and techniques for continuous vascular access in small animals have been described. Problems with these systems have included (1) insufficient free movement, (2) sepsis, (3) high cost, (4) complicated construction, (4) thrombosis, and (5) dislocations of the intravenous catheter. The described operative techniques and a new experimental setup overcome these complications. The apparatus involves a swivel that is connected with an intravenously placed polyurethane catheter. A leather harness on the back of the animal is connected with the end of the swivel joint via a silicone tube in which the intravenous catheter runs to the swivel. The swivel, a modified conventional glass syringe, is positioned in ball bearings and a Johnson joint. The swivel, ball bearings, and Johnson joint are counterbalanced and can move up and down. When this system was used, the catheters functioned well for as long as 28 days, with a mean duration of 24.4 +/- 1.8 days (n = 420). Five catheter dislocations resulted from harness failure, and three dislocations were caused by animals twisting. All animals gained weight (3.53 +/- 0.37 gm/day (mean +/- SEM)). The rotary portion of the swivel and the Johnson joint secure stressless movement of the animal, avoiding twisting and dislocation of the catheter, which overcomes typical problems of existing methods. The low thrombogenicity of the polyurethane catheter also reduces complications. A further advantage is low cost, because prefabricated, reusable materials are used.

Pathophysiological and clinical aspects of the CO2 pneumoperitoneum (CO2-PP)

Experimental studies demonstrated a severe cardiac load of the CO2 pneumoperitoneum caused by an accelerated after- and a decreased preload. Patients displaying cardiovascular risks are therefore often rejected from laparoscopic surgery. Hence, the pathophysiological changes and the intraoperative risk of the CO2 pneumoperitoneum in high-risk cardiopulmonary patients (NYHA II-III, n = 15) undergoing laparoscopic cholecystectomy are described. The changes in cardiac after- and preload seem to be due to the elevated intraabdominal pressure rather than transperitoneally resorbed CO2 and are reversible by desufflation. In one patient conversion to open operation had to be performed because of a severe drop in cardiac output and right ventricle ejection fraction. Mixed oxygen saturation was predicting intraoperative worsening in this case. The described pathophysiological changes may seem to be well tolerated even in high-risk cardiac patients. Monitoring of hemodynamics should include an arterial catheter line and blood gas analyses. Pharmacologic interventions or pressureless laparoscopic procedures might not be necessary as long as laparoscopic cholecystectomy is performed.

[Cancer in the parents of children with cancer]

Certain types of cancer in children and young adults have been linked with an increased risk of cancer in close relatives. However, the relation between childhood cancer and familial risk remains to be fully assessed in population-based studies. We conducted a nationwide study in Denmark of 11,380 parents of children with cancer. The children were identified from records in the Danish Cancer Registry; their parents were identified from population registers. The occurrence and rate of cancer in the parents were determined with use of the Cancer Registry's files and compared with national incidence rates for various categories of tumour. Overall, 1445 cancers were diagnosed in the parents, as compared with 1496 expected from national incidence rates, to yield standardized incidence ratios of 0.97 (95 percent confidence interval, 0.92 to 1.02) for all parents, 0.99 for mothers, and 0.94 for fathers. The lower rate of cancer among fathers reflected their lower standardized incidence ratio for lung cancer (0.76; 95 percent confidence interval, 0.63 to 0.91), as calculated from 114 observations. Genetic determinants are important in several types of childhood cancer, but the genetic susceptibility to tumours does not generally extend to the parents of children with cancer, not do the patterns of incidence point to the influence of shared environmental factors. Thus, cancer in children should not be viewed as a general marker for an increased risk of cancer in the patient's parents.

Childhood leukemia following phototherapy for neonatal hyperbilirubinemia (Denmark)

To test the hypothesis that exposure to high intensity lightning (around 400 nanometers) in neonatal nurseries increases the incidence of childhood leukemia, over 55,120 newborn children treated with phototherapy for hyperbilirubinemia were identified from the Danish Hospital Discharge Register for 1977-89. Linkage of the roster with the national cancer registry through 1991 revealed 87 childhood cancers, whereas 85 were expected from the rates for the general population. The incidence of leukemia in 34 children was not unusual (standardized incidence ratio [SIR] = 1.2, 95 percent confidence interval [CI] = 0.8-1.7). Subgroup analyses revealed no remarkable patterns for any category of leukemia subtype, gender, or age at diagnosis. We conclude that whole-body exposure to phototherapy (420-470 nm) shortly after birth is not a significant risk factor for childhood leukemia.

[Survival after childhood cancer in Denmark 1943-1987. A population-based study]

Survival from cancer in childhood and adolescence was studied in 8312 children aged 0-19 years notified to the Danish Cancer Registry during 1947-1987. During the first period (1943-1972), five-year survival rates from all malignant neoplasms increased from 23% (1943-1952) to 33% (1963-1972). The greatest improvement was seen during the period 1973-87 when five-year survival rates reached 64% (1983-1987). Between 1973-1977 and 1983-1987, five-year survival rates increased from 32% to 62% for leukaemia, from 40 to 70% for acute lymphoblastic leukaemia, from 35 to 54% for non-Hodgkin's lymphoma, from 50 to 66% for central nervous system neoplasms and from 25 to 49% for bone tumours. An improvement in five-year survival rates for Wilms' tumour was seen between 1960 (19%) and 1980 (81%). Up to 1972, the five-year survival rate from germ-cell neoplasms was approximately 40%; among patients diagnosed in 1973-1987, 76% survived for five years. Survival was similar for boys and girls during the early period, but was significantly higher for girls subsequently. A marked effect of age at diagnosis was seen in the early registration period where survival rates for the age group 0-9 years was substantially lower compared to the age group 10-19 years. This inequality persisted only for children less than two years of age in the later period.

Fate of the grafted ovaries from female salamander Pleurodeles waltl embarked on the Cosmos 2229 flight

The flight procedure of "Experience Triton" on Cosmos 2229 made necessary to sacrifice the embarked females just after landing. In order to detect genetic abnormalities in the progency of these adult females, we have performed a surgical procedure based on the transplantation of an ovarian piece on a recipient animal. One year later, as observed after laparotomy, the grafted ovaries exhibit oogonies and some growing oocytes. In present time, out of 10 castrated and grafted adult females only one is still alive bearing a large grafted ovary. Out of 5 castrated and grafted juvenile males, three are still alive, two of them exhibit a developing grafted ovary. The grafted animals will be ready for mating within a few months. Therefore, it will soon be possible to study the progeny of animals that have been submitted to space conditions.

Peptidase-1 expression in some organs of the salamander Pleurodeles waltl submitted to a 12-day space flight

In Pleurodeles, the peptidase-1 is a sex-linked enzyme encoded by two codominant genes (Pep-1A and Pep-1B) located on the Z and W sex chromosomes. The sexual genotype can be determined by the electrophoretic pattern of the peptidase from erythrocytes. ZAWB genotypic females characterized by 3 electrophoretic bands AA, AB and BB were embarked on Cosmos 2229. The pattern in ovary, muscles and gut issued from the embarked or synchrone females displayed the 3 characteristic bands. In heart and kidney, the bands AA and AB [correction of BB] were revealed, while the band BB appeared very faintly. The specific enzymatic activity in the same organs was compared. Except for the kidney, no statistical significant difference was observed between flight and synchrone samples. This enzyme can be efficiently used as sexual genotypic marker of Pleurodeles experimentally submitted to the effects of space environment.

Cancer in the parents of children with cancer

BACKGROUND

Certain types of cancer in children and young adults have been linked with an increased risk of cancer in close relatives. However, the relation between childhood cancer and familial risk remains to be fully assessed in population-based studies.

METHODS

We conducted a nationwide study in Denmark of 11,380 parents of children with cancer. The children were identified from records in the Danish Cancer Registry; their parents were identified from population registers. The occurrence and rate of cancer in the parents were determined with use of the Cancer Registry's files and compared with national incidence rates for various categories of tumor.

RESULTS

Overall, 1445 cancers were diagnosed in the parents, as compared with 1496 expected from national incidence rates, to yield standardized incidence ratios of 1.0 (95 percent confidence interval, 0.9 to 1.0) for all parents, 1.0 for mothers, and 0.9 for fathers. The lower rate of cancer among fathers reflected their lower standardized incidence ratio for lung cancer (0.8; 95 percent confidence interval, 0.6 to 0.9), as calculated from 144 observations.

CONCLUSIONS

Genetic determinants are important in several types of childhood cancer, but the genetic susceptibility to tumors does not generally extend to the parents of children with cancer, nor do the patterns of incidence point to the influence of shared environmental factors. Thus, cancer in children should not be viewed as a general marker for an increased risk of cancer in the patients' parents.

Trends in survival after childhood cancer in Denmark, 1943-87: a population-based study

Survival from cancer in childhood and adolescence was studied in a population-based series of 8312 cases in children aged 0-19 years notified to the Danish Cancer Registry during 1943-87. During the first period (1943-72), 5-year survival rates from all malignant neoplasms increased from 23% (1943-52) to 33% (1963-72). The greatest improvement was seen during the period 1973-87 when 5-year survival rates reached 64% (1983-87). Between 1973-77 and 1983-87, 5-year survival rates increased from 32% to 62% for leukaemia, from 40% to 70% for acute lymphoblastic leukaemia, from 35% to 54% for non-Hodgkin's lymphoma, from 50% to 66% for central nervous system neoplasms and from 25% to 49% for bone tumours. An improvement in 5-year survival rates from Wilms' tumour was seen between 1960 (19%) and 1980 (81%). Up to 1972, the 5-year survival rate from germ-cell neoplasms was approximately 40%; among patients diagnosed in 1983-87, 76% survived for 5-years. Annual lethality decreased by 2.5% for all malignant neoplasms in 1943-72 and by 4.4% in 1972-87. Lethality was similar for boys and girls during the period 1943-72, but was significantly lower for girls subsequently. A marked effect of age at diagnosis was seen in the early registration period, where lethality rate for the age group 0-9 years was substantially higher compared with that in the age group 10-19 years. This inequality persisted only for children less than 2 years of age at the time of diagnosis in the later period.

Benign anal lesions and the risk of anal cancer

BACKGROUND

Benign anal lesions are often considered to cause a predisposition to anal cancer. To reexamine this association, we linked national data on hospital discharge and cancer in Denmark.

METHODS

After making certain exclusions, we used the Danish Central Hospital Discharge Register to identify 68,549 patients hospitalized with benign anal lesions between 1977 and 1989. Through computerized linkage to the Danish Cancer Registry, all incident cases of epidermoid anal cancer and colorectal cancer among these patients were identified. Follow-up for the occurrence of cancer started the month after the date of the first hospital discharge and continued until the patient died (10.6 percent of the sample), emigrated (0.7 percent), or was lost to follow-up (0.04 percent) or until December 31, 1989 (88.6 percent), whichever came first.

RESULTS

The median follow-up period was 6.2 years. There were 23 epidermoid anal cancers and 416 colorectal cancers. The overall relative risk of anal cancer (observed vs. expected cases) was 4.4 (95 percent confidence interval, 2.8 to 6.6). The relative risk was 12.0 (95 percent confidence interval, 5.2 to 23.6) within the first year after hospitalization for benign lesions, 4.6 (95 percent confidence interval, 2.3 to 8.3) from one to four years after hospitalization, and 1.8 (95 percent confidence interval, 0.5 to 4.7) five or more years after hospitalization. The risk of colorectal cancer was significantly increased only during the first year after hospitalization (relative risk, 2.6; 95 percent confidence interval, 2.1 to 3.1).

CONCLUSIONS

There is a strong temporal association between the diagnosis of benign anal lesions and the diagnosis of anal cancer. Although we could not exclude the possibility of a moderate increase in the long-term risk of anal cancer, our data do not support the view that benign anal lesions cause anal cancer.

In vivo fertilization and development in microgravity using pleurodele ("ZEUS" project)

The objectives of this experiment are to perform natural fertilization and to achieve embryonic development in microgravity. Pleurodeles waltl, an urodele amphibian, is considered by CNES and NASA to be suitable experimental material for achieving in vivo fertilization in space. Previously inseminated females can be embarked in the Frog Environmental Unit (FEU) developed by NASA. Laying of eggs will be provoked by hormonal stimulation in flight and development will be followed. Various technical problems have been resolved in laboratory experiments and during parabolic flights : the time of hormone stimulation after insemination, choice of hormone guaranteeing [correction of guarenteing] 95% success, other factors conditioning [correction of conditionning] the laying, experimental procedures to study developmental kinetics at phenotypic levels, and selection of cellular and molecular markers of development.

Demonstration by immunocytochemical staining of a somatostatin-28-(1-14)-like peptide in planarians (Plathyhelminthes Turbellaria Tricladida)

A specific polyclonal antiserum directed against the somatostatin-28(1-14) of vertebrates was applied to sections of the planarians Dugesia lugubris and Dendrocoelum lacteum. This made it possible to reveal nerve cells and processes specifically both in cerebral ganglia and in ventral nerve cords. The phylogenetic importance of this demonstration is pointed out.

Developmental patterns of peroxisomal enzymes in amphibian liver during spontaneous and triiodothyronine-induced metamorphosis

1. Liver catalase, D-amino acid oxidase, urate oxidase of Alytes obstetricans and Xenopus laevis (anuran amphibians) and fatty acyl-CoA oxidase of Alytes were present at all post-embryonic stages. 2. Catalase and D-amino acid oxidase activities increased during spontaneous metamorphosis of the two species. 3. During triiodothyronine-induced metamorphosis of Alytes larvae, catalase and D-amino acid oxidase activities increased after a latent period. 4. Our results suggest that expression of some hepatic peroxisomal enzymes is modulated by thyroid hormones.

Validation of the in-vitro dissolution method used for a new sustained-release theophylline pellet formulation

The in-vitro release method used within the scope of the galenical development of Euphylong pellets and subsequently employed on a routine basis is described. The suitability of the method is demonstrated by means of the validation procedure. The release system used is based on the standard USP XXI apparatus (paddle method) and consists of three essential components: a) dissolution apparatus (paddle model). b) measuring unit (spectrophotometer), c) data acquisition and analysis system. It is demonstrated that in-vitro release rates of theophylline from Euphylong pellets can be accurately investigated with other models as well, since the course of release is not affected by pH value, buffer capacity, surface tension, turbulence of the dissolution medium or agitation by the apparatus. The accuracy of the method as well as its precision and ruggedness are investigated and described. The influences arising from the withdrawal of specimens from the bulk product and of sampling from the release vessel are discussed. The accuracy of the analytical records generated by the computer system is shown and the ruggedness of the analytical program investigated under "worst case conditions". The documentation of the results obtained is described and examined with respect to reliability in the face of system and operating errors. All pertinent guidelines (GAP, FIP guidelines for dissolution testing, etc.) are taken into consideration and their relevance to the above investigation assessed.

Somatostatin-like peptide and regeneration capacities in planarians

The presence of a neuropeptide immunologically related to somatostatin (SRIF) has been investigated in the neurosecretory cells of two regenerating planarian species (Dugesia lugubris and Dendrocoelum lacteum). A correlation has been shown between the discharge of the SRIF-like-immunoreactive cells during the first hours after amputation and the capacity to regenerate, and between the persistence of numerous positive cells and the lack of regeneration. These results suggest that somatostatin might play a regulatory (inhibitory) role on the cellular proliferation which leads to the blastema edification.

[Histological and cytological study of neoblasts and fixed parenchymal cells in Dendrocoelum lacteum planarians deprived of their anterior region]

On amputating either at the root of the pharynx or between the mouth and the genital pore, the posterior parts which are thereby isolated do not regenerate. However they are capable of surviving for ever a year, without feeding. The wounded region is occupied by neoblasts which degenerate within a few days after an initial secretory activity. Their degeneration is of autophagic type. The abortive blastems disappear only slowly, because the degeneration of their neoblasts is partly compensated by the continual immigration of new regeneration cells which come from the posterior region. Several months after amputation, under the effect of prolonged starvation, neoblasts and fixed parenchymal cells begin to degenerate.