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1.
J Psychosom Res ; 173: 111460, 2023 10.
Article in English | MEDLINE | ID: mdl-37607421

ABSTRACT

OBJECTIVE: Somatic Symptom and Related Disorders(SSRD) are characterised by an intense focus on somatic symptoms that causes significant distress. A self-report scale developed to assess distress as symptom-related thoughts, feelings, and behaviors (SSD-12) has proved to be a reliable, valid and time-efficient measure for Somatic Symptom Disorder(SSD). This cross-sectional study aimed to compare the SSD-12 with psychiatric assessment as gold standard in a Dutch clinical population for SSRD compared to other widely used measures. METHODS: Data were collected from adult patients visiting a specialised mental health outpatient clinic for SSRD in the Netherlands, between 2015 and 2017. Analyses included item evaluation, scale reliability, construct validity, diagnostic utility and cut points. Performance of SSD-12, Whiteley Index(WI) and PHQ-15 were compared in Receiver operating characteristics (ROC) curves. RESULTS: 223 patients with SSD, Functional Neurological Disorder, Illness Anxiety(IA) and no SSRD participated. SSD-12 items were normally distributed; total scores correlated with measures of health anxiety, anxiety and depression. The optimal cut point for the SSD-12 was 22 (sensitivity 75.9%, specificity 63.6%). The ROC area under the curve for SSD-12 was 0.75 compared to 0.68 for the WI and 0.65 for the PHQ-15. Combinations of those questionnaires did not yield better results than for the SSD-12 alone. CONCLUSION: The SSD-12 alone outperformed the WI and PHQ-15 and combined scales in effectively distinguishing SSRDs from other mental disorders. This may suggest that distress is a more accurate indicator of SSRD than earlier diagnostic criteria as operationalised in the WI and PHQ-15.


Subject(s)
Conversion Disorder , Medically Unexplained Symptoms , Adult , Humans , Cross-Sectional Studies , Reproducibility of Results , Surveys and Questionnaires , Somatoform Disorders/diagnosis , Somatoform Disorders/psychology
2.
Int J Obes (Lond) ; 41(6): 990-994, 2017 06.
Article in English | MEDLINE | ID: mdl-28194012

ABSTRACT

We investigated five methylation markers recently linked to body mass index, for their role in the neuropathology of obesity. In neuroimaging experiments, our analysis involving 23 participants showed that methylation levels for the cg07814318 site, which lies within the KLF13 gene, correlated with brain activity in the claustrum, putamen, cingulate gyrus and frontal gyri, some of which have been previously associated to food signaling, obesity or reward. Methylation levels at cg07814318 also positively correlated with ghrelin levels. Moreover, expression of KLF13 was augmented in the brains of obese and starved mice. Our results suggest the cg07814318 site could be involved in orexigenic processes, and also implicate KLF13 in obesity. Our findings are the first to associate methylation levels in blood with brain activity in obesity-related regions, and further support previous findings between ghrelin, brain activity and genetic differences.


Subject(s)
Cell Cycle Proteins/genetics , DNA Methylation , Ghrelin/metabolism , Kruppel-Like Transcription Factors/genetics , Neurons/metabolism , Obesity/genetics , Obesity/metabolism , Orexins/metabolism , Repressor Proteins/genetics , Animals , Appetite Regulation , Brain/cytology , Brain/diagnostic imaging , Brain/metabolism , Cell Cycle Proteins/metabolism , Feeding Behavior/physiology , Functional Neuroimaging , Gene Expression Regulation , Humans , Kruppel-Like Transcription Factors/metabolism , Male , Mice , Obesity/physiopathology , Receptors, Ghrelin/metabolism , Repressor Proteins/metabolism , Reward
3.
Vox Sang ; 107(4): 420-7, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25040600

ABSTRACT

One of the most controversial policies in blood transfusion worldwide is the permanent deferral from donating blood of men with sexual contacts to other men (MSM). This policy was implemented for safety reasons as sex between men is known to be a high risk factor for acquiring severe infectious diseases transmissible by blood transfusion. Sexual contacts among heterosexual persons may hold similar risks but a clear-cut discrimination between different individual risks is impossible. Nevertheless, the current blood donor deferral periods defined by European Union (EU) legislation depend on a distinction of different grades of risk with respect to sexual behaviour. Under the aegis of the Steering Committee on Blood Transfusion (CD-P-TS) of the Council of Europe (CoE), an international working group evaluated epidemiological and behavioural data, modelling studies on residual risk and spread of infections, and studies on adherence to donor selection criteria. The aim was to distinguish sexual behaviour of different risk categories. It was concluded, that existing data confirm that MSM and commercial sex workers (CSW) are groups at high risk. Any further grading lacks a scientific data base. Modelling studies indicate that adherence to deferral policies is of major relevance suggesting that good donor adherence may outweigh the small negative effects on blood safety postulated for changing from permanent to temporary deferral periods for high risk sexual behaviours. The fact that a considerable percentage of donors are MSM - despite the permanent deferral policy - demonstrates the need to increase donor understanding and adherence.


Subject(s)
Blood Donors , Homosexuality, Male , Blood Safety , Donor Selection , Europe , Female , HIV Infections/etiology , Humans , Male , Models, Theoretical , Risk-Taking , Sexual Behavior , Surveys and Questionnaires , Transfusion Reaction
4.
Lung Cancer ; 76(1): 112-7, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22018880

ABSTRACT

Cachexia is a prevalent phenomenon of non-small cell lung cancer (NSCLC) which is responsible for increased mortality and deterioration of physical performance. Preclinical research indicates that systemic inflammation induces cachexia-related muscle wasting through muscular Nuclear Factor-kappa B (NF-κB) signaling and subsequent ubiquitin proteasome system (UPS)-mediated proteolysis. As these pathways could be a target for early intervention strategies, it needs to be elucidated whether increased activation of these pathways is already present in early stage NSCLC cachexia. The aim of the present study was therefore to assess muscular NF-κB and UPS activation in patients with NSCLC pre-cachexia. Sixteen patients with newly diagnosed stages I-III NSCLC having <10% weight loss and ten healthy controls were studied. Body composition, systemic inflammation and exercise capacity were assessed in all subjects and NF-κB and UPS activity in vastus lateralis muscle biopsies in a subset. Patients showed increased plasma levels of C-reactive protein (CRP) (P<0.001), soluble Tumor Necrosis Factor receptor 1 (sTNF-R1) (P<0.05), fibrinogen (P<0.001) and decreased levels of albumin (P<0.001). No changes in fat free body mass or skeletal muscle NF-κB and UPS activity were observed, while peak oxygen consumption ( [Formula: see text] ) was significantly decreased in patients compared with healthy controls. In conclusion, this exploratory study demonstrates significantly reduced exercise capacity in NSCLC pre-cachexia despite maintenance of muscle mass and unaltered indices of UPS activation. The absence of muscular NF-κB-dependent inflammatory signaling supports the notion that transition of systemic to local inflammation is required to initiate UPS-dependent muscle wasting characteristic for (experimental) cachexia.


Subject(s)
Cachexia/pathology , Carcinoma, Non-Small-Cell Lung/pathology , Inflammation/pathology , Muscle, Skeletal/pathology , Proteasome Endopeptidase Complex/metabolism , Ubiquitin/metabolism , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Aged , C-Reactive Protein/metabolism , Cachexia/genetics , Cachexia/metabolism , Carcinoma, Large Cell/genetics , Carcinoma, Large Cell/metabolism , Carcinoma, Large Cell/pathology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Case-Control Studies , Exercise , Female , Follow-Up Studies , Humans , Inflammation/genetics , Inflammation/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Male , Middle Aged , Muscle, Skeletal/metabolism , Muscular Atrophy/metabolism , Muscular Atrophy/pathology , NF-kappa B/genetics , NF-kappa B/metabolism , Neoplasm Staging , Prognosis , Proteolysis , Respiratory Function Tests , Signal Transduction , Weight Loss
5.
Hum Mol Genet ; 13(19): 2333-41, 2004 Oct 01.
Article in English | MEDLINE | ID: mdl-15294876

ABSTRACT

We explored the function of the human DEAD-box Y RNA helicase DBY (DDX3Y) gene located in the (AZFa) region on the human Y chromosome (Yq11.21). Deletion of this Y interval is known to be a major cause for the occurrence of a severe testicular pathology, the Sertoli-cell-only (SCO) syndrome. DBY has a structural homologue on the short arm of the X chromosome DBX (DDX3X) (Xp11.4). We found widespread transcription of both genes in each tissue analyzed, although predominantly in testis tissue. However, translation of DBY was detected only in the male germ line, whereas DBX protein was expressed in all tissues analyzed. In testis tissue sections, DBY protein was found predominantly in spermatogonia, whereas DBX protein was expressed after meiosis in spermatids. We conclude that although both RNA helicases are structurally very similar, they have diverged functionally to fulfill different roles in the RNA metabolism of human spermatogenesis, and that deletion of the DBY gene is the most likely cause of the severe testicular pathology observed in men with AZFa deletions.


Subject(s)
Chromosomes, Human, Y , Protein Biosynthesis , Proteins/metabolism , Testis/metabolism , Transcription, Genetic , DEAD-box RNA Helicases , Germ Cells/metabolism , Humans , Male , Minor Histocompatibility Antigens , Proteins/genetics , RNA Helicases/genetics , RNA Helicases/metabolism
6.
Biochem J ; 359(Pt 3): 721-7, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11672448

ABSTRACT

The zinc finger gene family represents one of the largest in the mammalian genome, with several of these genes reported to be involved in spermatogenesis. A newly discovered gene has been identified that is expressed abundantly in the testicular tissue of fertile men as determined by mRNA differential display. The gene encodes a C(3)HC(4)-type zinc finger protein motif (ring finger motif) consistent with a role in pre-meiotic or post-meiotic sperm development. The gene was named ZNF230 and mapped to the short arm of chromosome 11 (11p15). ZNF230 has two transcripts, of 1 kb and 4.4 kb in length. The shorter 1 kb transcript was only detected in testicular tissue whereas the longer 4.4 kb transcript was not detected in testis but was found in several other tissues. The lack of detectable ZNF230 expression in azoospermic patients by reverse transcriptase-mediated PCR analysis is interpreted to mean that this gene is involved in maintaining normal human male fertility.


Subject(s)
DNA-Binding Proteins/genetics , Fertility/genetics , Spermatogenesis/physiology , Testis/physiology , Transcription Factors , Zinc Fingers/genetics , Amino Acid Sequence , Base Sequence , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Fertility/physiology , Fetus/physiology , Humans , In Situ Hybridization, Fluorescence , Male , Molecular Sequence Data , Oligospermia/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Tissue Distribution
7.
Mol Hum Reprod ; 7(10): 987-94, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11574668

ABSTRACT

We have developed a rapid screening protocol for deletion analysis of the complete AZFa sequence (i.e. 792 kb) on the Y chromosome of patients with idiopathic Sertoli-cell-only (SCO) syndrome. This Y deletion was mapped earlier in proximal Yq11 and first found in the Y chromosome of the SCO patient JOLAR, now designated as the AZFa reference patient. We now show that similar AZFa deletions occur with a frequency of 9% in the SCO patient group. In two multiplex polymerase chain reaction experiments, deletions of the complete AZFa sequence were identified by a typical deletion pattern of four new sequence-tagged sites (STS): AZFa-prox1, positive; AZFa-prox2, negative; AZFa-dist1, negative; AZFa-dist2, positive. The STS were established in the proximal and distal neighbourhoods of the two retroviral sequence blocks (HERV15yq1 and HERV15yq2) which encompass the break-point sites for AZFa deletions of the human Y chromosome. We have found deletions of the complete AZFa sequence always associated with a uniform SCO pattern on testicular biopsies. Patients with other testicular histologies as described in the literature and in this paper have only partial AZFa deletions. The current AZFa screening protocols can therefore be improved by analysing the extension of AZFa deletions. This may provide a valuable prognostic tool for infertility clinics performing testicular sperm extraction, as it would enable the exclusion of AZFa patients with a complete SCO syndrome.


Subject(s)
Oligospermia/genetics , Seminal Plasma Proteins/genetics , Sequence Deletion , Chromosomes, Artificial, Bacterial , Contig Mapping , Genetic Loci , Humans , Male , Polymerase Chain Reaction/methods , Sequence Tagged Sites , Sertoli Cells , Syndrome , Y Chromosome
8.
Hum Mol Genet ; 9(17): 2563-72, 2000 Oct 12.
Article in English | MEDLINE | ID: mdl-11030762

ABSTRACT

We mapped the breakpoints of the AZoospermia factor a (AZFa) microdeletion located in proximal Yq11 in six men with complete germ cell aplasia, i.e. Sertoli Cell Only syndrome (SCO). The proximal breakpoints were identified in a long retroviral sequence block (HERV15yq1: 9747 nucleotides) at the 5' end of the DYS11 DNA locus in Yq11, interval D3. The distal breakpoints were found in a homologous HERV15 sequence block mapped to the Yq11 interval D6, i.e. in the distal part of the AZFa region (HERV15yq2: 9969 nucleotides). Compared with the HERV15yq1 sequence, HERV15yq2 is marked by a deletion of a HERV15 sequence domain at its 5' end and insertion of an LINE 1 3'-UTR sequence block (L1PA4) of similar length at its 3' end. The deletion of the L1PA4 element was recognized as the molecular origin of the DYS11 12f2 restriction fragment length polymorphism. For all six AZFa patients it was possible to perform PCR experiments bridging both retroviral sequence blocks, which map in a distance of 781.557 kb in proximal Yq11 in fertile men. The AZFa breakpoint-fusion regions were located in their recombined HERV15yq1/HERV15yq2 sequence blocks in either one of two long identical sequence domains (ID1 and ID2). We therefore assume that intrachromosomal recombination events between the two homologous retroviral sequence blocks in proximal Yq11 are probably the causative agents for most of the AZFa microdeletions observed in men with SCO syndrome. A mean value of 792 kb was estimated for their molecular lengths.


Subject(s)
Endogenous Retroviruses/genetics , Oligospermia/genetics , Recombination, Genetic , Sequence Deletion , Y Chromosome/genetics , Humans , Male , Physical Chromosome Mapping , Polymerase Chain Reaction , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length
9.
Ann Neurol ; 37(1): 24-9, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7818253

ABSTRACT

Ragged red fibers are an important marker for mitochondrial disease. To evaluate the hypothesis that mitochondrial dysfunction may play a role in the pathogenesis of aging and inclusion body myositis, we studied the frequency of ragged red fibers in muscle biopsy specimens from 15 young and 13 old normal adults, and from 27 patients with inclusion body myositis, polymyositis, or dermatomyositis. Serial transverse cryostat sections were stained with modified Gomori trichrome, modified succinic dehydrogenase, and cytochrome c oxidase. The frequency of ragged red fibers, determined by measuring the percent number of succinic dehydrogenase-positive ragged red fiber equivalents, was significantly higher in old compared to young normal subjects (0.33 vs. 0.02%, p < 0.0001). With the exception of a single polymyositis biopsy specimen showing a large number of ragged red fibers, the frequency of ragged red fibers in patients with polymyositis or dermatomyositis was similar to that of age-matched normal control subjects. The frequency of ragged red fibers was more than 1% in 7 of 8 patients with inclusion body myositis (maximum, 15%). The modified succinic dehydrogenase stain was more sensitive than the modified Gomori trichrome in detecting accumulation of mitochondria in muscle fibers. Cytochrome c oxidase activity was deficient in most ragged red fibers. We conclude that the number of ragged red fibers increases with normal aging and may reflect an age-related decline in muscle mitochondrial oxidative metabolism. The frequent occurrence of ragged red fibers in inclusion body myositis suggests that mitochondrial function may be impaired in this disease.


Subject(s)
Aging/pathology , Muscle, Skeletal/pathology , Myositis/pathology , Adult , Aged , Biopsy , Dermatomyositis/pathology , Female , Humans , Male , Middle Aged , Mitochondria, Muscle/metabolism , Muscle, Skeletal/anatomy & histology , Muscle, Skeletal/enzymology , Myositis/enzymology , Polymyositis/pathology , Succinate Dehydrogenase/analysis
10.
J Microsc ; 176(Pt 2): 132-42, 1994 Nov.
Article in English | MEDLINE | ID: mdl-7853387

ABSTRACT

Microscope slides were coated with a layer of gelatin, the thickness of the gelatin increasing linearly along the long axis. The bacterial suspension is applied to the dried gelatin and covered by a coverslip. The medium is absorbed by the gelatin and thus the cells applied against the coverslip. By this method, cultures of concentrations below 10(8) cells/ml provide statistically relevant numbers for observation without prior concentration steps. It is easier to apply than the existing methods for the observation of bacterial nucleoids by phase contrast imaging. Because the cells are maintained in growing conditions the method is useful for the vital fluorescence DAPI-staining of various bacterial species and for observations of plasmolysis and its reversal at different physiological conditions and extracellular osmolalities. The previously generally assumed view that the plasmolytic changes of the cell morphology are immediate upon the hyperosmotic shock and are rapidly repaired when the cell is able to metabolize actively was confirmed; this is in contrast to some recent claims.


Subject(s)
Bacillus/cytology , Bacteriolysis , Escherichia coli/cytology , Microscopy, Fluorescence/methods , Escherichia coli/ultrastructure , Fluorescent Dyes , Gelatin , Indoles , Microscopy, Phase-Contrast , Osmotic Pressure
11.
Neurology ; 43(11): 2372-7, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8232959

ABSTRACT

We compared the muscle pathology and clinical course in eight patients with congenital nemaline myopathy. An abundance of large intranuclear rods was present in the muscle fibers of one patient with a rapid, fatal course. Intranuclear rods were not present in the muscles of seven patients with a benign course. The large intranuclear rods and the smaller sarcoplasmic rods were similar ultrastructurally and exhibited positive immunoperoxidase staining with anti-alpha-actinin antibodies. The accumulation of alpha-actinin within myonuclei may reflect a severe disturbance of normal intracellular processes regulating myofibrillar synthesis. Since two previously reported infants with intranuclear nemaline rods also had a fatal outcome, the presence of intranuclear rods may represent a marker for a severe form of congenital nemaline myopathy.


Subject(s)
Cell Nucleus/ultrastructure , Inclusion Bodies/ultrastructure , Muscles/ultrastructure , Myopathies, Nemaline/pathology , Adolescent , Adult , Child , Female , Humans , Immunohistochemistry , Infant , Infant, Newborn , Male , Microscopy, Electron
12.
Z Lebensm Unters Forsch ; 194(5): 456-60, 1992 May.
Article in English | MEDLINE | ID: mdl-1621448

ABSTRACT

Aluminum has been determined by 24 laboratories in the context of a check sample survey. Samples studied were two duplicate diets, one of which was spiked with 15.87 mg Al/kg, and two blind duplicate milk powders. Target values for the duplicate diets were 11.80 and 27.90 mg Al/kg, respectively, and 15.65 mg Al/kg for the milk powders. Participants were requested to make only single determinations per sample. A two-step approach was used to assess the raw data. In the first step, those data were excluded that were outside a +/- 50% range of the duplicate diet spike and the target value for milk powder. Likewise, only one single data set per participant was accepted and results were ruled out stemming from procedures that have a detection limit of greater than 5 mg Al/kg. The remaining data were evaluated both statistically and in the context of the method performance parameters available. Best scores for aluminium were from laboratories applying wet-pressurized digestion in combination with electrothermal atomic absorption spectrometry. Results for laboratories applying dry-ashing for sample decomposition were unreliable. The overall performance for aluminium is very disappointing given the relatively high aluminium levels of the samples studied. Out of 24 laboratories 11 have one or more major problems with their aluminium determination. They should dramatically improve or replace their methodology for this element.


Subject(s)
Aluminum/analysis , Dairy Products/analysis , Food Analysis/standards , Animals , Reproducibility of Results , Spectrophotometry, Atomic/standards
13.
Z Lebensm Unters Forsch ; 193(4): 351-5, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1767596

ABSTRACT

Sodium, potassium, arsenic, selenium and tin have been determined in 38 different types of domestic and imported fresh fruits. All samples (n = 242) were analysed for Na und K whereas a limited number of samples (n = 85) of each fruit type was selected for the determination of As, Se and Sn. The median contents, in mass fractions of the edible portion, found for fresh fruits are: Na less than 0.001%; K 0.17%; As 4 micrograms/kg; Se 2 micrograms/kg and Sn less than 0.05 mg/kg. The corresponding 90th percentile values are: Na 0.002%, K 0.34%; As 12 micrograms/kg; Se 10 micrograms/kg and Sn 0.10 mg/kg. Results for selenium reported here differ substantially from those given for a number of fresh fruits in the German Food Composition Tables 1986/1987. The average consumption of 129 g fresh fruit by Dutch citizens in the age category of 22-75 years contributes, in general, marginally to the total daily dietary intake of sodium, arsenic, selenium and tin. Fresh fruit can contribute substantially, up to 23%, to the average oral daily intake of potassium.


Subject(s)
Arsenic/analysis , Electrolytes/analysis , Fruit/chemistry , Selenium/analysis , Tin/analysis , Food Contamination/analysis , Potassium/analysis , Sodium/analysis
14.
Z Lebensm Unters Forsch ; 190(3): 199-204, 1990 Mar.
Article in English | MEDLINE | ID: mdl-2330757

ABSTRACT

A flame atomic absorption spectroscopic (FAAS) method is described for the determination of calcium and magnesium in a wide variety of foods and biological substrates. Results for reference materials (n = 9) are presented that demonstrate the validity of the procedure. Samples are digested with nitric acid at 150 degrees C in a pressure decomposition vessel, diluted and adjusted to pH 2 with ammonia. Lanthanum chloride solution is added to suppress phosphate interferences and the ionization of calcium and magnesium in the AAS flame. Additional dilutions are made as appropriate, whereupon the atomic absorption of calcium and magnesium is measured in an oxidizing air-acetylene flame. The wavelength settings for calcium is 422.7 nm and for magnesium 285.2 nm. The method was tested in a collaborative trial involving a milk powder practice sample and four test samples, all of which were reference materials. Participants were requested to carry out duplicate determinations exclusively. Results were obtained from 12 laboratories. However, the results of 3 laboratories had to be rejected for various reasons. The remaining set of data was statistically evaluated according to ISO 5725; the method of analysis proved to be precise and accurate. Coefficients of variation values for calcium ranged from 1.19% to 4.44% within laboratories (CVr) and from 5.30% to 15.9% between laboratories (CVR). For magnesium, the corresponding values were CVr, 1.07% to 3.52% and CVR, 3.07% to 5.99%. The method is recommended for the determination of calcium and magnesium at the levels considered in foods and biological substrates.


Subject(s)
Calcium/analysis , Food Analysis/methods , Magnesium/analysis , Animals , Flour/analysis , Milk/analysis , Muscles/analysis , Reproducibility of Results , Spectrophotometry, Atomic
15.
Z Lebensm Unters Forsch ; 186(4): 308-10, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3381592

ABSTRACT

A 1-year stability study of ampouled polycyclic aromatic hydrocarbon (PAH) solutions was carried out. Two solutions of seven pure PAHs were prepared, one in acetonitrile and one in toluene, and ampouled. Solutions were tested for mass concentration and impurities before and after ampouling. No differences were found. After 0, 3, 6, 9 and 12 months, three ampoules were selected for analysis from the acetonitrile and the toluene lots stored at +20 degrees and at -20 degrees C. The acetonitrile solution was analysed by high performance liquid chromatography and the toluene solution by glass capillary gas chromatography. The results demonstrate that both solutions were stable and no contamination occurred during storage.


Subject(s)
Food Analysis , Polycyclic Compounds/analysis , Humans , Reference Standards , Solutions
16.
Cell Tissue Res ; 241(3): 593-6, 1985.
Article in English | MEDLINE | ID: mdl-3896512

ABSTRACT

The distribution of gonadotropin-releasing hormone (GnRH) immunoreactivity was studied in the African catfish, Clarias gariepinus, by means of immunofluorescence and immunoperoxidase techniques. Immunoreactive neurons were found throughout the preoptic nucleus (NPO). However, only a portion of the secretory perikarya in the NPO showed a positive reaction by use of an anti-LHRH serum. Numerous immunoreactive fibres were found to enter the pituitary and to terminate in its proximal pars distalis, the site of concentration of the gonadotropic cells. Since GnRH is present in the brain and pituitary of the African catfish, the lack of spontaneous ovulation in captivity is apparently due to an insufficient release of GnRH.


Subject(s)
Brain/cytology , Gonadotropin-Releasing Hormone/analysis , Neurons/cytology , Pituitary Gland/cytology , Animals , Female , Fishes , Fluorescent Antibody Technique , Immune Sera , Immunoenzyme Techniques
17.
Eur J Pharmacol ; 101(3-4): 223-8, 1984 Jun 01.
Article in English | MEDLINE | ID: mdl-6432557

ABSTRACT

The ability of bicuculline, a GABA antagonist, to enhance dopamine (DA) synthesis in retinas of rats 1, 4, 7, 15 and 60 days after eye opening was assessed and compared to the time course of postnatal development of the light-induced increase in DA synthesis. The accumulation of dihydroxyphenylalanine (DOPA) following administration of the L-aromatic amino acid decarboxylase inhibitor, NSD 1015, was used to estimate DA synthesis. In dark-adapted rats, neither bicuculline nor light enhanced DOPA accumulation 1 day after eye opening, but on the remaining days either treatment significantly augmented DA synthesis, and by day 15 the effects were as great as those observed in adult retinas. At each time point, the magnitude of the drug effect on DA synthesis in the dark was similar to that observed following light exposure. These results suggest that an endogenous GABAergic input to the DA neurons appears at the same time as the acquisition of the dopaminergic response to light. The effect of bicuculline treatment on DA synthesis in light-exposed animals was also assessed. At 4 and 7 days the drug significantly enhanced DOPA accumulation over that produced by exposure to light alone, but on later days bicuculline exerted no such additive effect. These data imply that early in the maturation of the light response mechanisms other than removal of an inhibitory GABAergic tone may be partially responsible for excitation of the DA neurons.


Subject(s)
Darkness , Dopamine/biosynthesis , Light , Retina/growth & development , Adaptation, Physiological , Aging , Animals , Bicuculline/pharmacology , Dihydroxyphenylalanine/metabolism , Female , Rats , Rats, Inbred Strains , Retina/metabolism , Time Factors , gamma-Aminobutyric Acid/metabolism
18.
Brain Res ; 278(1-2): 362-5, 1983 Nov 14.
Article in English | MEDLINE | ID: mdl-6640327

ABSTRACT

The intravitreal administration of strychnine produced a significant elevation of dopamine (DA) synthesis in the retinas of dark-adapted rats. Strychnine had no antagonistic effect on the ability of muscimol to suppress the normal increase in retinal DA synthesis observed after exposure of rats to light. This latter observation suggests that strychnine is not merely acting in a non-selective fashion to suppress the inhibitory GABAergic tone exerted on the DA neurons in darkness. These results suggest that there may be a direct or indirect strychnine-sensitive input to the retinal DA neurons in the dark. This input may not be glycinergic, however, as even high dosages of glycine did not suppress the light-mediated enhancement of DA synthesis in the retina.


Subject(s)
Bicuculline/pharmacology , Dark Adaptation , Dopamine/biosynthesis , Retina/metabolism , Strychnine/pharmacology , Animals , Glycine/pharmacology , Light , Male , Muscimol/pharmacology , Rats , Rats, Inbred Strains , Retina/drug effects
19.
Life Sci ; 33(14): 1419-26, 1983 Oct 03.
Article in English | MEDLINE | ID: mdl-6621247

ABSTRACT

Male Sprague-Dawley rats were divided into 2 groups. One group (experimental) was housed for 6 months in continuous low intensity light while the other (control) was exposed to standard 14 hr light: 10 hr dark cyclic lighting conditions for the entire time. For both the control and experimental groups the light intensity was 350-700 Lux. After 6 months, the experimental rats were returned to cyclic lighting. At one week and again at 2 months the light aversion behavior of all rats was tested in a light/dark test box. The experimental rats chose the dark side of the box only 58% of the time while control animals preferred the dark 79% of the time. Since rats normally are nocturnal and avoid light, these results suggest that the experimental rats may have permanently lost a functionally significant portion of the ability to detect light. After the second behavioral test all rats were dark adapted and 15 hr later the effect of short term (30 or 60 min) exposure to light on DA turnover in one retina from each rat was assessed. The other retina from each rat was fixed and examined histologically. Light significantly enhanced the alpha methyl-p-tyrosine induced decline of DA in the retinas of the control rats but exerted no similar effect in the experimental animals. The retinal DA contents of the experimental rats were substantially depleted. Histological examination suggested that the outer nuclear layers of the experimental retinas were more severely damaged than those from rats exposed to continuous light for 4 months but still contained a few pycnotic photoreceptor nuclei and nearly normal looking inner neural layers. These results indicate that extended exposure to light eventually abolishes light aversion behavior and at this time there is also a loss of the photosensitivity of the dopaminergic amacrine neurons.


Subject(s)
Dopamine/metabolism , Light , Photoreceptor Cells/physiology , Receptors, Dopamine/physiology , Retina/physiology , Animals , Dark Adaptation/drug effects , Escape Reaction/drug effects , Escape Reaction/physiology , Male , Methyltyrosines/pharmacology , Photoreceptor Cells/drug effects , Rats , Rats, Inbred Strains , Receptors, Dopamine/drug effects , Retina/drug effects , Time Factors
20.
Eur J Pharmacol ; 92(1-2): 139-42, 1983 Aug 19.
Article in English | MEDLINE | ID: mdl-6138258

ABSTRACT

Intraocular administration of quisqualate but not of N-methyl-D-aspartate or kainate augments dopamine synthesis in the retinas of dark-maintained rats. The effect of quisqualate is dosage-dependent but not blocked by the glutamate antagonist, glutamate diethyl ester. These results are the first to show that the quiescent dopamine neurons of the dark-adapted rat retina can be activated by an excitatory amino acid analogue of the putative endogenous neurotransmitter, glutamate.


Subject(s)
Amino Acids/pharmacology , Dopamine/biosynthesis , Retina/drug effects , Animals , Aspartic Acid/analogs & derivatives , Aspartic Acid/pharmacology , Glutamates/pharmacology , Glutamic Acid , Kainic Acid/pharmacology , Male , N-Methylaspartate , Oxadiazoles/pharmacology , Quisqualic Acid , Rats , Rats, Inbred Strains , Retina/metabolism
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