Asthma in children--problems in diagnosis

Bronchial asthma in children may be difficult to diagnose. Education of the parents regarding allergic conditions, specifically bronchial asthma, is exceedingly important in order to assure satisfactory treatment and clinical results. Chest symptoms of unexplained origin in early life should immediately arouse suspicion of allergic disease. Other causes of asthmatic symptoms must be borne in mind and excluded before a positive diagnosis of bronchial asthma is established. Of the many factors to be considered in investigating a child with asthma, a comprehensive history is most essential. The climate to which the patient is exposed and the psychic influences must be taken into account. Physical examination, x-ray films and laboratory procedures should be carefully executed. Skin testing, especially with food allergens, should not be relied upon to give all the information in allergic disease. Some form of diet trial, such as elimination diets, should be used if sensitivity to food is suspected.     

Variation in Total Energy Expenditure in Humans

The purpose of this paper is to review current data regarding the factors contributing to variability in total energy expenditure (TEE) among humans. Variation arising from within and between individuals and between study groups will be considered. For within- subject variation, issues relating to experimental and theoretical measurement error will be considered in addition to inherent physiological variation. The literature reporting TEE in various study groups is reviewed, highlighting deficiencies in current comparison methods, and a framework by which TEE can be compared between studies and populations is suggested. For between-subject variation, the effects of differences in body composition, obesity, age and gender upon variation in TEE are examined. Finally, data will be reviewed relating to changes in TEE in response to external manipulation (e.g., activity, overfeeding, stress).     

The role of bioregenerative life-support systems in a manned future in space

Thus far in the manned space program, human life support has depended on storage of air, water, food, and energy. There are no refrigerators on Shuttle, and fresh foods are limited to what can be stowed in lockers for the first 3 days of a mission, when spoilage becomes a factor. Oxygen is stored, CO2 is scrubbed, and water is stored and treated. As we approach the Space Station era, life support will be a combination of storage and resupply. Duty cycles will be 90 days, and physico-chemical (P/C) systems will be important for recycling oxygen and water. Nutritionists seek a capability for refrigerated storage of fresh food on Station. However, most food still will be thermostabilized, rehydratables that can be stored at room temperature. Present Shuttle food is not much more sophisticated than repackaged camp food, and tends to be high in salt content. Hopefully, menus will be healthier on Station, where dietary countermeasures against biomedical responses to chronic microgravity might be implemented, and certainly need to be studied.     

Tuberculosis in childhood

Those physicians who deal with children have much to contribute toward case finding in tuberculosis among these patients as well as adults. The tuberculin test is the most accurate weapon at hand. Contacts other than the parents should be looked for. Symptoms, beside fever, to be noted are eye and skin complaints. In the physical examination the chest is relatively unimportant as compared to the eye, the skin, the lymphatic and skeletal systems. In the roentgenographic examination, epituberculosis and atelectasis should be differentiated. When stomach washings are necessary for the diagnosis, the tuberculin test on the guinea-pig should not be forgotten. Careful laboratory studies will clear up roentgenographic confusion. In the treatment, removal of contact is essential, and often all that is necessary, but other factors should be considered. Of the more common complications, atelectasis, bronchiectasis, and cavitation or reinfection, may be treated surgically with all the accepted methods except thoracoplasty. Heliotherapy should not be forgotten in bone and joint tuberculosis. It is to be hoped that BCG will prove efficacious in vaccination, but published reports are not scientifically convincing. It destroys the value of the tuberculin test where used, and it should never be substituted for removal of contact as a prophylactic measure.     

Interferon therapy in acute lymphatic leukemia and hepatitis B in childhood

1. The use of interferon in hepatitis B will bring about a favourable course of the disease, which is reflected in a normalisation of liver function tests. 2. The concentration of surface antigens is distinctly reduced, with a lower titre remaining for a longer period of time. 3. The level of the dosage chosen seems to be optimal. However, treatment has to be continued for a period of several months, probably for about 1 year. 4. In childhood the side-effects of interferon are minimal, they are restricted to febrile reactions. 5. In our investigations no sure hematological deviations could be identified in the treatment with interferon. 6. The study must be complemented by analysing further antigens, such as E antigen, allowing the course of disease to be characterised more distinctly. 7. In order to give a final assessment of the therapy the observation of patients must be continued after terminating the treatment, the histological improvement in the further course having to be confirmed by liver biopsies.     

Energy transfer in photosynthesis

The results of recent spectroscopic measurements on chlorophyll a in bilayers and lipid vesicles stimulated a re-examination of energy transfer in photosynthesis. The Förster resonance transfer mechanism is believed to be applicable under reasonable assumptions despite recent criticism. The Förster parameter was newly determined to be R₀ = 65 Å; previous uncertainty due to unknown transition moment orientation can be avoided by assuming the black film dichroic result to be applicable in vivo. The effect due to the still incompletely known thylakoid structure and chlorophyll aggregation is discussed qualitatively. Agreement with experimental fluorescence lifetimes and quantum efficiencies may be obtained with a reasonable choice of parameters.     

Phospholipids in myofibrils

The myofibrils were shown to be lipoprotein structures. Lipoprotein nature of these structures was confirmed by their lipid phosphorus to protein ratio in a completely dispersed myofibril preparation of the skeletal muscle cells. The ratio was found to be 49.65 ± 3.95 microgram P / mg protein. The phospholipids present in the myofibril preparation were determined to be phosphatidylcholine and phosphatidylethanolamine.     

Role of Soils in Determining Sites for Lowland Heathland Reconstruction in England

No guidelines are currently available that advise which soil properties of arable land can be used to suggest suitable locations for heathland reconstruction. This paper reviews studies comparing soil properties of heathland or semi-natural grassland with those of adjacent arable fields, investigations in the autecology of the dominant heathland plant, Calluna vulgaris (common heather), and long-term experiments of fertilizer inputs on arable soils. Three properties must be assessed before the suitability of a field can be determined: extractable phosphorus, exchangeable calcium, and pH. A number of other nutrients may also be important, but evidence is currently insufficient to substantiate this. Natural changes in levels of extractable phosphorus, exchangeable calcium, and pH appear to be very slow, so nutrient stripping and acidification will be necessary where recommended levels are exceeded to successfully restore heathland vegetation.     

Ageism in cardiology

This article supports the argument that ageism exists in health care, particularly on the equity of access to cardiological services. Rates of use of potentially life saving and life promoting interventions and investigations decline as the patient gets older. Higher rates of cardiological interventions occur among younger people, despite the high incidence of the condition among older individuals. Any ageism in clinical medicine and policy is simply a reflection of the presence of ageist attitudes in wider society, where the youth receives a higher priority over age. Ageism in medicine needs to be addressed to preserve or recapture this trust within an aging population. A wide ranging approach is necessary if equity in the provision of health care services is to be ensured which includes improvement of clinical guidelines and more specific monitoring of health care. Educational efforts to raise awareness that age stereotyping and ageist attitudes are unethical should be initiated. Research initiatives, which cover large numbers of older people, should be developed and older people should be empowered to influence choices and standards of treatments. Finally, legislation may be required to eradicate ageism in society.     

Diel variation in fish assemblages in tidal creeks in southern Brazil.

Tidal creeks are strongly influenced by tides and are therefore exposed to large differences in salinity and depth daily. Here we compare fish assemblages in tidal creeks between day and night in two tidal creeks in southern Brazil. Monthly day and night, simultaneous collections were carried out in both creeks using fyke nets. Clupeiformes tended to be caught more during the day. Cathorops spixii, Genidens genidens and Rypticus randalli tended to be caught at night. Sciaenidae also tended to be caught more during the night. In general, pelagic species were diurnal, while deep water species were nocturnal. These trends are probably due to a variety of causes, such as phylogeny, predation and net avoidance.     

Recent approaches in acute lymphoblastic leukemia in adults

In the last decades outcome of adult acute lymphoblastic leukemia (ALL) has improved considerably. In large multicenter studies remission rates range from 75% to 89%, and long-term leukemia-free survival (LFS) from 28% to 39%. Major progress has also been made regarding better characterization of subtypes of ALL. Complete diagnostic procedures are essential to identify these subtypes which have significant differences in clinical and laboratory features and prognosis. LFS of > 50% can be expected in favorable subtypes such as T-ALL or mature B-ALL, while LFS of < 20% is expected in Ph/BCR-ABL positive ALL. Prognostic factors can be used for risk stratification and selection of treatment strategies can be adapted to the subtype and relapse risk. This includes measurement of minimal residual disease (MRD) to evaluate individualized treatment strategies adapted to the molecular response. Several new approaches for improvement in chemotherapy and stem cell transplantation (SCT) are under investigation. They include the use of intensified anthracyclines, asparaginase, cyclophosphamide or high-dose cytarabine during induction and intensive rotational chemotherapy during consolidation. Also SCT - mainly from sibling donors - is now part of standard treatment of de novo ALL, although it remains open whether indications should be based on prognostic factors or whether SCT should be offered to all patients with sibling donor. However, substantial progress can only be achieved by new, experimental strategies. These include new approaches for SCT, such as nonmyeloablative SCT, measurement of MRD, causal treatment with molecular targeting, e.g. with kinase inhibitors, and antibody therapy.     

Fast-starts in hunting fish: decision-making in small networks of identified neurons

Decision-making networks must be tuned according to the rules that govern which action will be rewarded for a given constellation of current sensory information. Somehow these rules must be implemented in the networks that translate the sensory cues to actions but the nature of this representation is enigmatic. Recent findings suggest that Mauthner-associated networks in some fish can govern surprisingly sophisticated and plastic decisions in which the rules of prey motion govern what speed and direction must be selected to be at the right point at the right time. With the key cellular players individually identifiable, fish can help us to discover the nature of how rules are represented in decision-making circuitry of the vertebrate brain.     

The role of excitatory amino acids in synaptic transmission in the hippocampus

We have highlighted some aspects of the action of excitatory amino acid transmission in the hippocampus. Fast epsps can be blocked by CNQX to reveal a component of synaptic transmission which is mediated by NMDA receptors. Extracellular recordings of ionic activities show that NMDA and non-NMDA ionophores are permeable to the major monovalent cations, while NMDA ionophores also appear to be permeable to Ca2+. Interactions of agonists applied by iontophoresis may be correlates of phenomena such as LTP, which can be evoked by appropriate synaptic stimulation.     

Premalignant Variations in Extracellular Matrix Composition in Chemically Induced Hepatocellular Carcinoma in Rats

Chemical composition of extracellular matrix (ECM) plays a pivotal role in cellular and tissue development, regeneration, and differentiation. It also plays a key role in pathogenesis of hepatocellular carcinoma (HCC). This study explored premalignant changes in the liver tissue content of collagen (as hydroxyproline, HP), total glycosaminoglycans (TGAGs), free glucosamine (FGA), total sialic acid (TSA), lysosomal membrane integrity variations (calculated as total and free cathepsin D activities), and liver histology. Serum alfa-fetoprotein (AFP) level was used as an early marker for HCC in two groups of Wistar rats. One group of rats served as control and was provided normal saline orally. The other group was provided trichloroacetic acid (TCA) as 0.5 g/kg/day for five consecutive days by oral gavage. Animals were killed before tumor development. The treatment revealed dysplastic changes in addition to microsteatosis (fatty changes). Both sinusoids and the portal vein among dysplastic cells were dilated and congested. These dysplastic foci are believed to be premalignant and may be precancerous lesions. The following things were observed: a highly significant increase in serum AFP (as a key marker for HCC), a significant decrease in HP and TSA, a significant increase in FGA, nonsignificant decrease in TGAGs, significant up-regulation of free cathepsin D, nonsignificant decrease in total cathepsin D activities, and destabilization of lysosomal membrane integrity. Down-regulation of HP, TSA, and TGAGs seems to be a prerequisite for cancer development. This might be stimulated by up-regulation of free cathepsin D activity. Perhaps tissue fibrosis is not a condition for developing HCC because collagen was significantly depressed. Up-regulated FGA could be assumed to be a defense mechanism against TCA-induced proteolysis of membrane proteins because it is frequently reported to be of value in cancer chemotherapy. Studied ECM perturbations can be assumed as preliminary changes during chemical hepatocarcinogenesis at the tissue level. Prospective studies on blood levels of cathepsins, TGAGs, and individual ECM variables such as TSA, FGA, and Hp in patients at risk for HCC, performed in parallel with assessments of AFP, may provide a cost-effective way to find new links between tissue changes and circulation that would permit early prediction of disease. It may also provide a way to monitor HCC and compensate for the missed peak AFP values.     

Haptoglobin in lung defence

Haptoglobin (Hp) has been known to be associated with the host defence response to infection and inflammation. The biological functions of Hp can be related to its ability to bind haemoglobin or to modulate immune response. Hp is expressed at a high level in lung cells, yet its protective role(s) in the lung is not known. Using transgenic mice overexpressing Hp, we demonstrated that Hp can reduce blood-induced lung injury. Hp-mediated haemoglobin catabolism in lung cells appears to be linked to iron mobilization, and may be an efficient mechanism to reduce oxidative damage associated with haemolysis.     

Collagen in developing chick muscle in vivo and in vitro

Because of the known role of collagen in chick skeletal muscle differentiation the collagen synthesized by embryonic chick muscle was studied. The major collagen synthesized by this muscle was found to be type I collagen. In addition, the effectiveness of types I, II, III and IV collagens in promoting myoblast fusion in vitro was compared. These collagens were found to be equally effective as in vitro substrates.     

Chromosome aberrations produced in human lymphocytes by in vivo and in vitro irradiation

The production of chromosome aberrations in vivo has been studied in lymphocytes from a patient undergoing a wholebody treatment with gamma-radiation up to a cumulative dose of 1.4 Gy. These results were compared with the observations performed on whole blood samples irradiated in vitro with doses from 0.05 up to 2 Gy of gamma-rays. The frequency of chromosome aberrations, particularly the dicentrics, was found to be similar in vivo and in vitro. The yield of dicentrics could be best related to the dose by using a linear-quadratic model in both cases, the ratio of the coefficients a/b being of 0.56 and 0.69 Gy, respectively in vivo and in vitro. These observations confirm that in vitro dose response curves may be used to evaluate accurately an in vivo absorbed dose.     

Visually guided orientation in flies: case studies in computational neuroethology

To understand the functioning of nervous systems and, in particular, how they control behaviour we must bridge many levels of complexity from molecules, cells and synapses to perception behaviour. Although experimental analysis is a precondition for understanding by nervous systems, it is in no way sufficient. The understanding is aided at all levels of complexity by modelling. Modelling proved to be an inevitable tool to test the experimentally established hypotheses. In this review it will by exemplified by three case studies that the appropriate level of modelling needs to be adjusted to the particular computational problems that are to be solved. (1) Specific features of the highly virtuosic pursuit behaviour of male flies can be understood on the basis of a phenomenological model that relates the visual input to the motor output. (2) The processing of retinal image motion as is experienced by freely moving animals can be understood on the basis of a model consisting of algorithmic components and components which represent a simple equivalent circuit of nerve cells. (3) Behaviourally relevant features of the reliability of encoding of visual motion information can be understood by modelling the transformation of postsynaptic potentials into sequences of spike trains.     

Drinking in adolescents--qualitative analysis

The aim of this paper was to explore alcohol consumption and the development of this habit in the adolescent population based on qualitative data from 59 anonymous essays written by high school students. We found that the most of adolescents had their first experiences with alcohol in the seventh or eighth grades. They reported that they usually drank alcohol to be happy, to relax, to be courageous in approaching the opposite sex, to fit into society, and to be popular. Factors affecting drinking are influence of peers, family and social attitude towards drinking, laws and enforcement of legislation. In further prevention programs, we must be able to demonstrate that "having a good time" does not mean drinking alcohol. Programs for the prevention of alcohol-related problems must begin by adolescence, including both sexes equally and can be achieved through a coordinated and intense public health effort.     

Measuring and Understanding Depression in Women in Kisoro,Uganda

Depression is highly prevalent and the cause of considerable suffering for peoples across the globe. Case finding for depression is challenging because individuals often do not recognize the symptoms in themselves or may resist the diagnosis as a result of cultural stigma. Screening instruments, to be accurate, must be valid in the particular setting in which they are being applied, and diagnosis in primary care settings, is further made challenging because patients often present with a wide variety of somatic symptoms that could be medical. 115 women were screened for depression in this study in one community in Uganda, and 87 were found to be depressed using the SRQ-20. The cognitive impairment and decreased energy sub-scales of the SRQ-20 seemed to best differentiate for depression. We then interviewed the 87 women and found that, overwhelmingly, their complaints were somatic, and that their expectation for treatment was to receive medical tests and medications. Caregivers in primary care clinics in Uganda should know that in the reporting of their somatic symptoms patients may be trying to communicate more about themselves than just the state of their physical health; and that feelings of uselessness or of hopelessness when expressed by a patient should lead them to suspect severe mental illness since these symptoms were not found to be characteristic of the milder depression that is highly prevalent in Ugandan women.