Splenectomy in children. A correlative review of indications and complications in fifty patients

We have reported our experience with splenectomy in fifty patients less than fourteen years old. The indications, results, and complications were enumerated. These data were then correlated with the recent literature regarding pediatric splenctomy. Of special note is the problem of immunologic incompetency associated with splenectomy in the patients less than five years old.     

Mathematical models of strontium-90 behavior in a "water--fresh-water fish spawn" system in several individual cases of radionuclide entry into bodies of water

A group of 72 gilts, aged between eight and nine months, were treated 20 days each by administration of 5 g Suisynchronpr?mix (Zinc Metallibur/Sui), followed by 24-hour treatment with 750 IU PMS (Prolosanserum). Fifty per cent of the group received 500 IU per animal of HCG (Gonabion) at 11 a.m., on the fourth day after Sui. All animals were artificially inseminated at 3.30 p.m. on the fifth day after Sui. and at 7.30 a.m. on the sixth day after Sui. Laparotomy was performed on 50 per cent of the HCG-treated and untreated animals in the afternoon of the sixth day after Sui. Animals with no recordable ovulation had to undergo another laparotomy in the morning of the seventh day. The above approach resulted in regrouping by four therapeutic categories: 1. HCG with laparotomy, 2. No HCG, 3. HCG with no laparotomy, 4. No HCG and no laparotomy. In the afternoon of the sixth day after Sui (51-56 hours after HCG) ovulation had begun in all 17 measurable animals of the first group, but only in one of 18 animals of the second. The animals were slaughtered between the seventh and twelfth days after Sui, and the following ovulation percentages were established: 100 per cent in the first group, 83.3 per cent in the second, 55.6 per cent in the third, and 72.2 per cent in the fourth. The animals that had been given HCG treatment (Groups 1 and 3) were found to be superior in terms of percentual ovulation to the untreated animals (Groups 2 and 4). However, Group 2 was the only group that had been exposed to the extraordinary stress of two laparotomies, and this should be borne in mind for evaluation. Ovarian cysts (more than 10 mm) began to develop on the eighth day on the laparotomised groups (1 and 2) and on the tenth day on the non-laparotomized groups (3 and 4). Cysts developed in 41.1 per cent of all animals in Group 1, 38.9 per cent in Group 2, 27.8 per cent in Group 3, and 22.2 per cent in Group 4. Therefore, cyst formation is thought to have been stimulated by laparotomy. Ovocyte tests suggested fertilisation of all animals in the first group. The embryonation rates of the second, third, and fourth groups are discussed with reference to the dates of insemination.     

Collisions and traffic violations of alcohol, cannabis and cocaine abuse clients before and after treatment

Prior research has shown that those with alcohol problems have significantly elevated rates of traffic events (i.e. traffic violations and collisions) than licensed drivers from the general population and that treatment is associated with reductions in alcohol-related collisions. However, very little research exists on traffic events and the impact of treatment for cannabis or cocaine clients. The objectives of this research are: (1) to determine whether clients in treatment for a primary problem of alcohol, cannabis or cocaine have significantly elevated rates of traffic events than a matched control group of licensed drivers; and (2) to assess whether a significant reduction in traffic events occurs after treatment for each client group compared to a control group. Driver records of patients admitted to substance abuse treatment in 1994 for a primary problem of alcohol (n = 117), cannabis (n = 80) or cocaine (n = 169) were accessed from the Ministry of Transportation for Ontario, Canada. A comparison group of 504 licensed drivers frequency matched by age, sex and place of residence, was also randomly selected. Data was collapsed into two 6-year time periods: 1988-1993 (i.e. before treatment) and 1995-2000 (i.e. after treatment). Six repeated measures analysis of variance tests were conducted where traffic violations and collisions of three treatment groups (i.e. alcohol, cannabis or cocaine) and a control group were compared before and after treatment. All three treatment groups had significantly more traffic violations than the control group and no significant interactions between time period and group membership were found. For collisions, there was a significant interaction between the alcohol and control groups and between the cocaine and control groups. The average number of collisions for the alcohol and cocaine groups decreased after completing treatment, whereas the number for the control group was stable over the same time periods. Neither the interaction term nor the between group effect was significant in the comparison of the cannabis and control groups. When rates of collisions were calculated based on the period that each driver had a valid license, the interaction term was still significant for the comparison of the alcohol and control groups but not for the cocaine and control groups. The results contribute to existing literature by demonstrating that cocaine and cannabis clients have a higher risk of traffic violations than matched controls and that reductions in collision risk was found after treatment for the alcohol and cocaine groups. More research is needed to better understand the reasons for the higher risk of traffic events and to determine reasons for declines.     

Nutritional aspects of soft drinks

The metabolic consequences in man, both immediate and long term, of consuming soft drinks are discussed. Emphasis is placed on the role in energy and lipid metabolism of various carbohydrate constituents, on the effects on gastric emptying of the various constituents and on the biochemical implications of fructose containing drinks.     

A proximal femoral implant preserves physiological bone deformation: a biomechanical investigation in cadaveric bones

The aim of this study was to compare the perturbances in bone deformation patterns of the proximal femur due to a conventional cemented femoral stem and a novel uncemented implant designed on the principles of osseointegration. Five matched pairs of fresh frozen human femora were mechanically tested. Bone deformation patterns, measured with a video digitizing system under 1.5 kN joint force, showed that the cemented Spectron femoral implant caused significant alterations to the proximal femoral deformation pattern, whereas the Gothenburg osseointegrated titanium femoral implant did not significantly alter the bone behaviour (p < 0.05). Vertical micromotions measured under 1 kN after 1000 cycles were within the threshold of movement tolerable for bone ingrowth (21 microm for the Gothenburg system and 26 microm for the cemented implant).     

Peripheral synapses at identified mechanosensory neurons in spiders: three-dimensional reconstruction and GABA immunocytochemistry

The mechanosensory organs of arachnids receive diverse peripheral inputs. Little is known about the origin, distribution, and function of these chemical synapses, which we examined in lyriform slit sense organ VS-3 of the spider Cupiennius salei. The cuticular slits of this organ are each associated with two large bipolar mechanosensory neurons with different adaptation rates. With intracellular recording, we have now been able to correlate directly the staining intensity of a neuron for acetylcholinesterase with its adaptation rate, thus allowing us simply to stain a neuron to identify its functional type. All rapidly adapting neurons stain more heavily than slowly adapting neurons. Immunostaining of whole-mount preparations reveals GABA-like immunoreactive fibers forming numerous varicosities at the surface of all sensory neurons in VS-3; peripheral GABA-like immunoreactive somata are lacking. Sectioning the leg nerve procures rapid degeneration of most fiber profiles, confirming that the fibers are efferent. Punctate synapsin-like immunoreactivity colocalizes to these varicosities, although some synapsin-like immunoreactive puncta are GABA-immunonegative. Fibers with similar immunoreactivities are also associated with trichobothria, tactile hairs, internal joint receptors, i.e. other types of spider mechanosensory organs. In organ VS-3, immunoreactivity is most dense across the initial axon segment. The exact distribution of peripheral synapses was reconstructed from a 10-microm-long electron micrograph series of the dendritic, somatic, and initial axon regions of acetylcholinesterase-stained VS-3 neurons. These reveal a pattern similar to that of the synapsin-like immunoreactivity. Two different types of synapse were distinguished on the basis of their presynaptic vesicle populations. Many peripheral synapses thus appear to derive from efferent GABA-like immunoreactive fibers and probably provide centrifugal inhibitory control of primary mechanosensory activities.     

The use of channel flow cells for electrochemical kinetic studies in high temperature aqueous solutions

It has been shown that, for the case of one-step reactions of arbitrary order, the relationship between the average current density and the limiting current density on a working electrode mounted on the inner radius of an annular flow channel of arbitrary length obeys, with great accuracy, the same relations as does a reaction on a uniformly accessible surface. This allows us to combine the advantages of non-uniformly accessible surfaces (high sensitivity, and no need to use rotating contacts) with the advantages of uniformly accessible surface systems (simple treatment of experimental data). This feature can be very important when investigating systems at high temperatures and pressures, where RDEs are difficult to employ. Using this approach, and by employing previously measured polarization data, the kinetic parameters (exchange current density and anodic transfer coefficient) for the oxidation of hydrogen on platinized nickel in 0.1 M NaOH + 0.7 × 10⁻³ m H₂ at temperatures between 25 °C and 300 °C have been derived. The anodic transfer coefficient is found to be almost temperature independent with a value of 0.43. The exchange current density displays Arrhenius behavior with temperature, increasing from 1.9 × 10⁻⁴ A cm⁻² at 25 °C to 3.9 × 10⁻³ A cm⁻² at 300 °C.