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Neural pathways connecting the deutocerebrum and lateral protocerebrum in the brains of decapod crustaceans.

The olfactory and accessory lobes of eureptantian decapod crustaceans are bilateral brain neuropil regions located within the deutocerebrum. Although the olfactory lobe seems to receive only primary olfactory inputs, the accessory lobe receives higher-order multimodal (including olfactory) inputs. The output pathways from both the olfactory and accessory lobes are provided by the axons of a large population of projection neurons, whose somata lie adjacent to the lobes. The axons of these neurons form a large tract that projects bilaterally to the medulla terminalis and hemiellipsoid body in the lateral protocerebrum. To gain insights into the ways in which olfactory information is processed on leaving the deutocerebrum, we examined the neuroanatomy of the projection neuron pathways of three species of eureptantian decapod crustaceans: the freshwater crayfish, Procambarus clarkii and Orconectes rusticus, and the clawed lobster, Homarus americanus. Projection neurons were labeled by focal injections of the lipophilic tracers DiI and DiA into the olfactory and accessory lobes. In all three species, projection neurons innervating the accessory lobe were found to exclusively innervate the neuropils of the hemiellipsoid body. In contrast, projection neurons innervating the olfactory lobes primarily target neuropil regions of the medulla terminalis. The results of this study indicate, therefore, that the projection neuron pathways from the olfactory and accessory lobes project to separate, largely nonoverlapping regions of the lateral protocerebrum. The implications of these findings for our understanding of the processing of olfactory information in the brains of decapod crustaceans are discussed.

Animals↗

Localization of NADPH diaphorase in the lumbosacral spinal cord and dorsal root ganglia of the cat.

The distribution of NADPH-d activity in the spinal cord and dorsal root ganglia of the cat was studied to evaluate the role of nitric oxide in lumbosacral afferent and spinal autonomic pathways. At all levels of the spinal cord NADPH-d staining was present in neurons and fibers in the superficial dorsal horn and in neurons around the central canal and in the dorsal commissure. In addition, the sympathetic autonomic nucleus in the rostral lumbar segments exhibited prominent NADPH-d cellular staining whereas the parasympathetic nucleus in the sacral segments was not well stained. The most prominent NADPH-d activity in the sacral segments occurred in fibers extending from Lissauer's tract through laminae I along the lateral edge of the dorsal horn to lamina V and the region of the sacral parasympathetic nucleus. These fibers were very similar to VIP-containing and pelvic nerve afferent projections in the same region. They were prominent in the S1-S3 segments but not in adjacent segments (L6-L7 and Cx1) or in thoracolumbar and cervical segments. NADPH-d activity and VIP immunoreactivity in Lissauer's tract and the lateral dorsal horn were eliminated or greatly reduced after dorsal-ventral rhizotomy (S1-S3), indicating the fibers represent primary afferent projections. A population of small diameter afferent neurons in the L7-S2 dorsal root ganglia were intensely stained for NADPH-d. The functional significance of the NADPH-d histochemical stain remains to be determined; however, if NADPH-d is nitric oxide synthase then this would suggest that nitric oxide may function as a transmitter in thoracolumbar sympathetic preganglionic efferent pathways and in sacral parasympathetic afferent pathways in the cat.

Afferent Pathways↗

Late effects surveillance system for sarcoma patients.

BACKGROUND: In 1998, a prospective multicenter pilot study of the 'Late Effects Surveillance System' (LESS) was started to investigate late effects of patients with Ewing, osteo- or soft-tissue sarcoma. PROCEDURE: Two hundred thirty patients were included in this pilot study. The patients were treated between 1/1/1998 and 6/30/1999 according to the sarcoma protocols COSS-96, CWS-96, and EICESS-92, the median cumulative doses of the focussed drugs were for cisplatin: 360 mg/m(2), for doxorubicin: 270 mg/m(2), and for ifosfamide: 24 g/m(2). The patients were investigated using an organ related standardized screening methodology. We report on toxicities in the first year after cessation of therapy-the beginning of the patient follow-up-and the feasibility of LESS. RESULTS: Cardiotoxicity: 16/129 (12%) patients treated with doxorubicin exhibited a reduced systolic heart function (fractional shortening (FS) <29%). Altogether three patients required cardiac drug therapy. Ototoxicity: In 5/73 (7%) patients treated with cisplatin a hearing deficit <4 kHz (>20 dB) was found. One patient needed a hearing aid. Nephrotoxicity: 2 of 214 (1%) patients treated with ifosfamide suffered from a tubulopathy, which required supplementation therapy. 10/50 (20%) showed a reduced fractional phosphate reabsorption. Incidence of hypomagnesemia was significantly increased in patients additionally treated with cisplatin. CONCLUSIONS: Some relevant impairments are noted in the first year after antineoplastic therapy. We expect to detect more major late sequelae in our prospective study during the increasing posttherapeutic interval. Our pilot study shows the feasibility of the methodology.

Adolescent↗

Application of the Australian river bioassessment system (AUSRIVAS) in the Brantas River, East Java, Indonesia.

Assessment of river 'health' using biological methods, particularly those based on macro-invertebrates, is now commonplace in most developed countries. However, this is not the case in most developing countries, where physical and chemical methods are used to assess water quality, with very little use of biological assessment methods. This paper reports on a project that aimed to assess the possible introduction of biological assessment of river condition using the Australian River Assessment System (AUSRIVAS) into Indonesia. The paper addresses three components of the project: (1) science--does the bioassessment method work in this tropical region? (2) resources--are they adequate and if not what additional resources are needed? (3) politics--what needs to be done to convince the agencies (both central and provincial) to take up such a new philosophy and approach? A pilot study was run in the upper Brantas River, East Java. A total of 66 reference sites and 15 test sites were sampled and the macro-invertebrates collected were identified to family level. A rigorous quality-control protocol was introduced to ensure the data were reliable and reproducible. The macro-invertebrate data were used to develop a predictive model of the AUSRIVAS type for the upper Brantas River, and the model was then used to assess the 'health' of sites that were presumed to be damaged in this section of the river. A number of difficulties were experienced during the study, including: locating reference sites sufficiently unmodified by humans; lack of skills to identify animals collected; and a paucity of facilities required for aquatic macro-invertebrate identification (e.g. identification keys and good quality binocular microscopes). For resources, the major constraint to the introduction of a bioassessment capability in Indonesia is the lack of personnel trained in the bioassessment techniques. An 'on-the-job' training approach was adopted, largely because of the specialist nature of this work. Six Indonesians were trained and will now become the 'trainers' of further Indonesian scientists (we have called this process 'training-the-trainers'). For politics, it was hoped that the AUSRIVAS method would be suitable for introduction into the Indonesian national Clean River Program. A strategy was developed and implemented to ensure the method and its outputs were accepted technically by the Indonesian scientific community, and also by the resource managers and relevant government officials. Experience shows that if the latter do not see how the bioassessment information will be used for management purposes they will not accept the method even if it is scientifically sound.

Animals↗

Localization and phosphorylation of Abl-interactor proteins, Abi-1 and Abi-2, in the developing nervous system.

Abl-interactor (Abi) proteins are targets of Abl-family nonreceptor tyrosine kinases and are required for Rac-dependent cytoskeletal reorganization in response to growth factor stimulation. We asked if the expression, phosphorylation, and cellular localization of Abi-1 and Abi-2 supports a role for these proteins in Abl signaling in the developing and adult mouse nervous system. In mid- to late-gestation embryos, abi-2 message is elevated in the central and peripheral nervous systems (CNS and PNS). Abi-1 mRNA is present, but not enhanced, in the CNS, and is not observed in PNS structures. Abi proteins from brain lysates undergo changes in apparent molecular weight and phosphorylation with increasing age. In the postnatal brain, abi-1 and abi-2 are expressed most prominently in cortical layers populated by projection neurons. In cultured neurons, Abi-1 and Abi-2 are concentrated in puncta throughout the cell body and processes. Both Abi and Abl proteins are present in synaptosomes and growth cone particles. Therefore, the Abi adaptors exhibit proper expression patterns and subcellular localization to participate in Abl kinase signaling in the nervous system.

Adaptor Proteins, Signal Transducing↗

Hepatitis B mass immunization of adolescents: a pilot study in a community.

The National Type Specific Hepatitis Surveillance System (SEIEVA) and seroepidemiological studies have shown that in addition to newborns from mothers who are carriers for hepatitis B surface antigen (HBsAg), adolescents are at high risk of acquiring type B hepatitis virus because of increasing importance of the heterosexual transmission of this virus. In order to evaluate logistic problems and acceptance rate of adolescents to mass vaccination against hepatitis B, a pilot study was carried out among all 7th grade children registered in the 9 schools of an hepatitis B endemic area located in the suburbs of Naples. After meetings held by the local health department with school teachers and parents, 1219 out of 1250 (97.5%) invited children received the first dose of hepatitis B vaccine; 1215 and 1209 received, respectively, the second and third doses. Anti-hepatitis B surface antigen (anti-HBs) values were studied in 406 subjects one month after the third dose, and 21 out of 406 (5.2%) had anti-HBs values less than 10 IU/L. We consider 95% of subjects with anti-HBs values greater than 9 IU/L a good achievement for a field vaccination program. The high acceptance rate of vaccination found in our study outlines the importance of active offer of vaccination combined with school involvement.

Adolescent↗

Down syndrome: effects of demographic factors and prenatal diagnosis on the future livebirth prevalence.

In northwest European countries maternal age is increasing. This will lead to an increase of the prevalence of Down syndrome conceptuses. Meanwhile, the increased use of prenatal cytogenetic diagnosis (PCD) will lead to a decrease in the prevalence of Down syndrome among livebirths. We were interested to know what the result of these two opposite developments would be in the near future, and we describe here a model to quantify these processes and the resulting livebirth prevalence of Down syndrome. The model is demonstrated for The Netherlands from 1992 to 2001. The predicted livebirth prevalence for The Netherlands in 1992 is 1.36 per 1000. Demographic factors will cause an increase to 1.76 per 1000 in 2001 with present indications for PCD and a utilization ratio of 50%. An increase of the utilization ratio to 90% in 2001 will lead to a prevalence of 1.22 per 1000, a little less than the present prevalence. Alternative screening programs, including maternal serum screening, could lead to a further decrease of the livebirth prevalence. The model described here can be used for evaluation of the consequences of alternative forms of Down syndrome screening.

Birth Rate↗

A small population of retinal ganglion cells projecting to the retina of the other eye. An experimental study in the rat and the rabbit.

We traced the retino-retinal projection with Rhodamine B isothiocyanate (RITC), Rhodamin labelled latex microspheres (RLM), horseradish peroxidase (HRP) and choleratoxin conjugated horseradish peroxidase (BHRP). The number and distribution of ganglion cells projecting to the contralateral eye were recorded. Newborn and young rats have up to about 130 ganglion cells projecting to the other retina; this confirms previous findings. We extended these findings in two ways. First, we describe a similar projection in rabbits consisting of fewer cells; second, we describe the persistence of a small component of this projection into adulthood. In addition we show with RITC and Nuclear Yellow double tracing that some of the retino-retinal ganglion cells have an axon collateral which projects to the superior colliculus. We performed control experiments in order to exclude spillover of tracer which might produce false positive labelling.

Animals↗

Selenium and the risk of postmenopausal breast cancer in the DOM cohort.

Selenium has been claimed to have chemo-preventive properties. However, data showing that in humans selenium levels are already decreased prior to diagnosis of breast cancer were not available. Such information is mandatory before oral selenium supplementation in the primary prevention of (breast) cancer in humans is acceptable. This question of a 'preventive-potential' of selenium was evaluated in a case-control study nested in a cohort, because this design allows determination of the time-order of preceding selenium levels and subsequent cancer risk. The cohort consisted of 5577 women aged 55-70 years from the DOM project, a population based breast cancer screening program in the Netherlands. Instrumental Neutron Activation Analysis was used to measure the selenium content of toenail clippings. The 69 cases of breast cancer found during follow-up after screening. represent 'recent' tumours since all women had a negative screening mammogram 3-5 years previously. No decreased selenium levels, as measured in nail clippings from the big toes, could be detected in cases-to-be, either when compared to 4 age matched controls per case or when compared with a random control group drawn from the entire cohort. On the contrary, a tendency for slightly higher selenium levels among 'future' cancer cases was observed. As to the sensitivity of detecting differences in selenium by nail clippings, lower selenium could be detected in nails of current smokers. The smoking-related decrease in nail selenium level was of the same order as the differences between breast cancer cases and controls, but was independent of the breast cancer risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

The prognosis of adult-onset motor neuron disease: a prospective study based on the Scottish Motor Neuron Disease Register.

The Scottish Motor Neuron Disease Register (SMNDR) is a prospective, collaborative, population-based project which has been collecting data on incident patients since 1989. In this report we present the clinical features of 229 patients with motor neuron disease (218 sporadic and 11 familial) diagnosed in 1989 and 1990 and compare their prognosis with previous studies of survival. The overall 50% survival from symptom onset was 2.5 years (95% CI, 2.2-3.0) and 5-year survival 28% (95% CI, 20-36%). The presence of progressive bulbar palsy (PBP), either at presentation or developing during the course of the illness, significantly reduced survival and was the most important prognostic indicator. Patients who survived longer than 5 years from symptom onset did not have PBP as part of their presenting illness. The prognosis was worse for women, and this was in part related to the higher frequency of PBP in older women, but age was also an independent adverse risk factor. Differences in survival between this and previous series can probably be explained on the basis of variation in case definition and ascertainment methods.

Adolescent↗

The demographics of unfunded pensions.

The performance of pay-as-you-go old-age insurance under different demographic conditions can be estimated from a metric consisting of the implicit rate of return to successive cohorts. The author shows a positive return for the prospective population over the next few years, but for cohorts born after the end of the century returns will become sharply negative. A decline in returns is typical of pay-as-you-go schemes as they mature, and a change to negative returns is typical in particular as the birth rate falls under fixed economic conditions. The return can be kept positive by greatly increased fertility or immigration. Taking labor-force participation rates into account, and supposing entitlement independent of contribution, gives much larger negative rates of return, however. The main calculations considered here are for schemes with a constant pension. If the contribution rather than the pension is kept constant then the disparities between cohorts with respect to their returns are smaller, and although the negative returns for future generations then set in earlier they are smaller. The conclusions of the paper are broadly applicable to any population that showed a baby boom after World War II and replacement-level or lower fertility subsequently.

Americas↗

Surveillance in hereditary nonpolyposis colorectal cancer: an international cooperative study of 165 families. The International Collaborative Group on HNPCC.

During its second meeting at Amsterdam in 1990, the International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer (ICG-HNPCC) decided to carry out a pilot study on colorectal cancer surveillance in HNPCC. The objectives of the study were to ascertain in each of the participating centers the number of HNPCC families, the recommended screening procedures, the age at diagnosis of colorectal cancer (CRC), and the occurrence of interval cancers. Nine centers in seven countries including Denmark, Finland, Italy, Japan, The Netherlands, Switzerland, and the United States participated. Data were derived from a total of 165 families. With respect to screening, half of the centers advise colonoscopy as the only procedure. The interval between the consecutive examinations varies from one to three years. In the majority of the centers, screening begins at 20 to 25 years. Lifelong screening is recommended by three centers, while the rest advise discontinuation at age 60 to 75 years. The family material included 840 patients with colorectal cancer. The mean age at diagnosis was 45 years, and about 15 percent were diagnosed at age 60 or later. A total of 682 high-risk relatives are being followed. After the follow-up of 1 to 10 years in these families, only six cases of interval cancers were encountered.

Adolescent↗