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  • 1
    ISSN: 1432-0851
    Keywords: Bispecific monoclonal antibody ; Lymphokine-activated killer cell ; Rat ; CD8
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In vivo targeting of lymphokine-activated killer (LAK) cells to tumour deposits by bispecific monoclonal antibodies (bimAb) may be a way to improve adoptive immunotherapy. We developed a bimAb against adherent LAK (ALAK) cells and colon tumour CC531 in Wag rats. The bimAb was produced by somatic hybridization of two mouse hybridomas, one producing monoclonal antibodies (mAb) against CD8 (IgG2b, OX8), and the other producing mAb against a CC531-associated antigen (IgG1, CC52). A bimAb-producing clone was selected by an enzyme-linked immunosorbent assay with CC531 tumour cells. BimAb were purified from ascitic fluid by protein A affinity chromatography. Each of five pooled peak fractions was analysed by flow cytometry for the presence of bimAb. Most bimAb were found in a fraction that was eluted at pH 4.5 from protein A. FPLC analysis of this fraction revealed that no parental antibodies were present. The OX8 × CC52 bimAb greatly increased conjugate formation in vitro between ALAK cells and CC531. Results of51Cr-release assays with CC531 as target cells and ALAK cells as effector cells were not significantly different in the presence or in the absence of the bimAb. The methods we used here, a cell enzyme-linked immunosorbent assay and flow cytometry, are simple methods for development and purification of a bimAb when a functional selection method is not a priori available. The OX8 × CC52 bimAb we developed this way may increase in vivo tumour targeting of ALAK cells and thus augment antitumour effect in vivo.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1106
    Keywords: Fibroblast growth factor receptor ; Basic fibroblast growth factor ; Forebrain ischemia ; Astrocyte ; In situ hybridization ; Hippocampus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recently, we demonstrated that transient forebrain ischemia in rats leads to an early and strong induction of basic fibroblast growth factor (bFGF) synthesis in astrocytes in the injured brain regions. In this study, in order to clarify the targets of such raised endogenous bFGF levels, the messenger RNA (mRNA) expression of its receptors (flg and bek) at in the hippocampus following transient forebrain ischemia induced by four-vessel occlusion for 20 min was investigated using an in situ hybridization technique. Transient forebrain ischemia induced an increase in the number of flg mRNA-positive cells from an early stage (24 h after ischemia) in the hippocampal CA1 subfield where delayed neuronal death occurred later (48–72 h after ischemia). This increase became more marked with the progression of neuronal death and was still evident in the same area 30 days later. The time course of the appearance and distribution pattern of flg mRNA-positive cells in the CA1 subfield were quite similar to those of bFGF mRNA-positive cells. On the other hand, in situ hybridization for bek mRNA showed only slight and transient (observed 72 h and 5 days after ischemia) increases in the number of mRNA-positive cells in the CA1 subfield following ischemia. The use of in situ hybridization and glial fibrillary acidic protein immunohistochemistry in combination demonstrated that the cells in the CA1 subfield that exhibited ischemia-induced flg or bek mRNA expression were astrocytes. These data indicate that transient forebrain ischemia induces upregulation of fibroblast growth factor-receptor expression, accompanied by increased bFGF expression in astrocytes, and suggest that the increased astrocytic bFGF levels in injured brain regions act on the astrocytes via autocrine systems and are involved in the development and maintenance of astrocytosis.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2013
    Keywords: Rat ; Renal function ; Micropuncture ; Blood gases ; Anaesthesia ; Thiopentone ; Thiobutabarbitone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The thiobutabarbitone(TB, Inactin)-anaesthetised rat is an extremely widely used preparation for the study of renal function at the whole-organ and nephron levels. The recent withdrawal of TB from the market has made it essential to find an anaesthetic producing experimental conditions as similar as possible to TB to allow comparison of past and future data. Blood gas analysis, clearance and micropuncture studies were therefore performed in rats anaesthetised with TB or the related thiobarbiturate thiopentone (TP) (both 100 mg/ kg body weight) to establish whether the latter meets this requirement. Both barbiturates caused similar transient respiratory depression and acidosis. Mean values (TP versus TB) over the total 8-h observation period for glomerular filtration rate (0.94 versus 1.05 ml/min), urine flow (3.8 versus 4.4 μl/min) and K+ excretion (0.98 versus 1.18 μmol/min) were slightly lower (P〈0.05) in TP rats, whereas renal blood flow (6.26 versus 6.24 ml/min), filtration fraction (0.31 versus 0.34) and Na+ excretion (0.11 versus 0.098 μmol/min) did not differ. The single-nephron filtration rate (SNGFR) (42.1 versus 41.1 nl/min) and fractional reabsorption (42% versus 47%), both measured in the proximal tubule, did not differ, although in the TP group SNGFR rose with time (4.4%/h) whereas the fractional reabsorption did not change significantly; in the TB group SNGFR was constant but fractional reabsorption declined with time (1.5%/h). Fractional reabsorption up to the distal convoluted tubule declined with time, this was more pronounced in the TP group. SNGFR measured at this site did not differ between TP and TB (30.3 versus 30.1 nl/min) but increased with time with TP (2.7%/h). Although renal function under TP is somewhat less stable than under TB, the differences are minor and, given that the latter is also characterised by non-steady-state conditions, it is concluded that TP is a reasonable replacement for TB.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1912
    Keywords: CCK-A receptor ; Food intake ; Locomotor activity ; cGMP levels ; Dopaminergic cells ; Rat ; Mouse ; CCK antagonist
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The activity of SR 27897, a potent and selective CCK-A vs CCK-B receptor antagonist (Ki = 0.2 nM on guinea-pig pancreas vs 2000 nM on rat brain) was studied on behavioural, electrophysiological and biochemical effects induced by peripheral or central injection of CCK-8S. For comparative purposes, devazepide, a reference CCK-A receptor antagonist, was investigated in these same models. CCK-induced hypophagia and CCK-induced hypolocomotion in rats, two behavioural changes associated with the stimulation of peripheral CCK-A receptors, were dose-dependently antagonized by SR 27897 (ED50 = 0.003 and 0.002 mg/kg i.p., respectively) and devazepide (ED50 = 0.02 and 0.1 mg/kg i.p., respectively). CCK-induced decrease of cerebellar cGMP levels in mice was also reduced by SR 27897 (ED50 = 0.013 mg/kg) and by devazepide (0.084 mg/kg). The CCK-induced turning behaviour after intrastriatal injection in mice, and the potentiation of the rate suppressant activity of apomorphine on rat DA neurons, were blocked by higher doses of SR 27897 and devazepide, consistent with the probable central origin of these effects. The respective ED50s were 0.2 mg/kg i.p. for SR 27897 and 4.9 mg/kg i.p. for devazepide in the former model, while the respective minimal effective doses were 1.25 and 5 mg/kg i.p. in the latter test. In most tests the i.p./p.o. ratio for SR 27897 was near unity, suggesting a high oral bioavailability of the compound. Taken together, these findings support the notion that SR 27897 behaves as a potent CCK-A antagonist able to cross the blood brain barrier.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric surgery international 8 (1993), S. 41-44 
    ISSN: 1437-9813
    Keywords: Testicular ischaemia ; Tubular atrophy ; Paternity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of testicular ischaemia on fertility as assessed by paternity rate was studied in seven groups of male Sprague-Dawley pubertal rats. Transient unilateral occlusion of the testicular artery and venous outflow was performed for 30, 60, 90, and 120 min using non-crushing microvascular clamps in groups 1–4 (n = 6). Group 5 (n = 12, Fowler-Stephens) had division of both the testicular artery and vein, whereas group 6 (n = 12, Refluo) had division of the testicular artery only. Group 7 (n = 6) consisted of controls upon whom a sham operation was performed. Testicular biopsy 6 weeks after transient testicular ischaemia of 30, 60, and 90 min showed tubular atrophy in 20%–33% of the testes. Ischaemia of 120 min led to tubular atrophy in 84% of testes. Division of only the testicular artery caused tubular atrophy in 58% of testes. Division of both testicular artery and venous outflow was associated with total tubular destruction and necrosis in 78% of testes and 22% had variable tubular atrophy. A paternity rate of 50%–80% was noted in groups 1–4 following transient unilateral testicular ischaemia and contralateral vasectomy. This compared well with the expected 75% paternity rate for a control rat population. Chronic ischaemia (group 5) together with testicular venous interruption was associated with observably lower fertility and a paternity rate of 18%. However, when venous outflow was preserved (group 6), chronic ischaemia after testicular artery division did not affect the paternity rate (50%) significantly.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 94 (1993), S. 193-202 
    ISSN: 1432-1106
    Keywords: Ubiquitin ; Heat shock protein 72 kD ; c-Fos ; Entorhinal cortex ; NMDA ; Neuronal loss ; Alzheimer's disease ; Stress protein ; Neurodegeneration ; Neurotoxicity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The entorhinal cortex (EC) appears to be one of the earliest regions to express cellular pathology in aging and Alzheimer's disease. The relationships between cellular stress protein responses and the temporal and spatial aspects of cell death induced by N-methyl-D-aspartate (NMDA) was investigated in this anatomical region. Low doses of NMDA were infused stereotactically into the medial EC of the rat. At intervals starting from 0.5 h up to 7 days after a 1.25-μl EC infusion of 15 mM NMDA, 30 mM NMDA, or saline, the expression of ubiquitin (Ub), 72-kDa heat shock protein (HSP 72), and c-Fos was determined in relation to neuronal death. Volumes of entorhinal Ub- and HSP 72-like immunoreactivity peaked between 18 and 48 h after either 15 or 30 mM NMDA infusions. After 15 mM NMDA infusions, maximal volumes of HSP 72- and Ub-like immunoreactivity in the EC at 48 h were similar to the subsequent maximal volume of neuronal loss in the EC seen after 96 hours. After infusion of 30 mM NMDA, the final EC volume of neuronal loss seen at 7 days after NMDA corresponded to 70–80% of the maximal HSP-Ub stress protein response seen at 2 days, implying that a population of HSP 72- and Ub-immunopositive cells survived the NMDA insult. C-Fos expression as determined by immunoreactivity for the nuclear phosphoprotein (Fos) indicated neuronal activation at NMDA infusion sites, in the perirhinal cortex, hippocampus, and other sites throughout the injected hemisphere. In the EC, c-Fos immunoreactivity returned to baseline levels by 8 h, well before the dramatic increases in HSP 72 and Ub volumes. Our results demonstrate that HSP 72 and Ub expression in vivo precedes and correlates with, but does not necessarily lead to, neuronal death following glutamate receptor-mediated toxicity in the EC.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1106
    Keywords: Dopamine ; Substantia nigra ; Striatum ; Hemitransection ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied the ability of the vigilance-promoting drug modafinil to modulate the anterograde and retrograde changes in tyrosine hydroxylase (TH) immunoreactivity and in dopamine (DA) stores in the nigro-neostriatal DA neurons, following a partial hemitransection of this ascending DA system, using a combined morphometrical, biochemical and behavioural analysis. Modafinil was given daily i.p. in doses of 10–100 mg/kg, starting 15 min after the lesion, and the partially hemitransected rats were killed 2 weeks later. Changes in TH-immunoreactive nerve cell bodies and nerve terminals induced by the partial hemitransection were studied in the substantia nigra and neostriatum in combination with image analysis. The substantia nigra and neostriatum were also subjected to biochemical analysis of DA, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels. Modafinil treatment dose-dependently (10–100 mg/kg) counteracted the hemitransection-induced disappearance of nigral TH-immunoreactive nerve cell body profiles and neostriatal TH-immunoreactive nerve terminal profiles. A 2-week treatment with 100 mg/kg of modafinil also counteracted the hemitransection-induced depletion of DA stores in the neostriatum and the ventral midbrain. Moreover, the repeated daily treatment with modafinil (100 mg/kg) protected against the hemitransection-induced disappearance of striatal 5-hydroxytryptamine, 5-hydroxyindoleacetic acid and noradrenaline levels. Striatal DA function was analysed by studying apomorphine-induced (1 mg/kg, s.c.) ipsilateral rotational behaviour 4 and 11 days after the operation. A marked dose-dependent reduction of ipsilateral rotational behaviour was demonstrated after the daily modafinil treatment in the partially hemitransected rats. In another model involving unilateral nigral microinjections of 6-hydroxydopamine, acute (one single dose) modafinil (100 mg/kg) did not affect the contralateral rotational behaviour induced by apomorphine (0.05 mg/kg s.c.), when given 30 min before the apomorphine. Taken together, morphological, neurochemical and behavioural evidence has been obtained that anterograde and retrograde changes induced in the DA stores and TH immunoreactivity of the nigro-neostriatal DA neurons by a partial hemitransection are counteracted by modafinil in a dose dependent way with 100 mg/kg producing a significant protective action against impairment of DA transmission. The results of this study open up the possibility that modafinil may protect against the anterograde and retrograde degeneration of nigrostriatal DA neurons seen after mechanically induced injury.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0003-276X
    Keywords: Spermatogenesis ; Testosterone ; Germ cell degeneration ; Testis ; Rat ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Rapid and complete withdrawal of intratesticular testosterone was achieved via the destruction of all Leydig cells with the specific Leydig cell cytotoxin ethane dimethanesulphonate (EDS). Restoration of testosterone levels was accomplished by administration of a single dose (25 mg) of testosterone esters (T) known to reverse the antispermatogenic effects of androgen withdrawal. Quantitation of the degenerating germ cells in cross sections of seminiferous tubules (ST) at stages IV-V, VII, IX, and X-XI of the spermatogenic cycle was used as a sensitive biological index of the effects of testosterone withdrawal and restoration upon the function of the Sertoli cells. Compared to control testicular tissues, the mean numbers of pyknotic germ cells per ST cross section at stages VII, IX and X-XI increased significantly (P 〈 0.01-0.001) between 4 to 8 days post-EDS treatment, but only in stage VII tubules was this trend reversed significantly (P 〈 0.005) within 2 days by T supplementation. In EDS-treated rats, stages VII, VIII, IX, and X-XI also exhibited significant (P 〈 0.05-0.001) increases (compared to controls) in the volumetric proportions by which intraepithelial vacuoles appeared within the seminiferous tubules. Again, in EDS+T supplemented rats, the appearance of vacuoles was significantly (P 〈 0.001) suppressed in stage VII and VIII. In contrast to tubules at stages VII-XI, those at stages IV-V were completely unaffected by testosterone withdrawal or replacement. The results show that at selected time intervals after EDS treatment, testosterone supplementation is capable of preventing/reversing these morphological changes within 2 days in stage VII tubules. It is suggested that the induction and subsequent prevention of seminiferous epithelial damage will serve as an important in vivo and in vitro approach for studies on the androgen-mediated changes in Sertoli cell biology during phases of impairment and recovery of their function. Manipulation of adult Sertoli cell function as provided by our model should permit identification of androgen-regulated gene products together with an understanding of their role(s) in normal and abnormal spermatogenesis. © 1993 Wiley-Liss, Inc.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1438-2199
    Keywords: Amino acids ; Asphyxia ; Hypothermia ; Glutamate receptors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Perinatal asphyxia was induced by keeping pups-containing uterus horns, removed by hysterectomy, in a 37°C or a 30°C water bath. Asphyxia for a period of 21–22 min at 37°C led to a 97% mortality within the first 20 min period following delivery. When the asphyctic period was extended to more than 22 min all the pups died following delivery. When the asphyxia was induced at 30°C, 100% of the delivered pups survived and were accepted by surrogate mothers. The protective effect of hypothermia could be observed even when the pups-containing uterus horns were exposed to a 45–46 min asphyctic period. Pretreatment with dizocilpine (0.2 mg/kg s.c.), or 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX) (3–30 mg/kg s.c.), administered to the mothers one hour before hysterectomy, reduced slightly the mortality induced by a 21–22 min asphyctic period at 37°C. An increase in survival following a 22–23 min asphyctic period could only be observed after the highest dose of NBQX.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Archives of gynecology and obstetrics 252 (1993), S. 191-195 
    ISSN: 1432-0711
    Keywords: Anastomosis ; Microsurgery ; Sutures ; Rat ; Uterine horn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study compares two simplified techniques, which use only 2 and 4 sutures respectively, with a conventional technique with 8 sutures for fallopian tube anastomosis. Experimentally these techniques were performed on the uterine horns of fifteen female rats. A 100% patency rate was obtained with all three techniques. No difference in the mucosal, muscular and serosal regeneration was observed in the three groups at 10, 20 and 60 days. Two months after surgery, the serosa, muscularis and mucosal layers were completely continuous in all groups. The operating with 2 sutures (5′ 30″±1′ 10″) was significantly less than with 4 (9′09″±0′55″,P〈0.05 ANOVA) and 8 sutures (15′12″ ± 1′41″,P〈0.05 ANOVA). A minimum inflammatory reaction to sutures was observed in all three groups at 60 days after surgery. The results suggest that with 2 sutures are all that is needed for tissue repair.
    Type of Medium: Electronic Resource
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