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Biomedical subjects

M Jaber

Publications and source records attributed to M Jaber.

49 records · Page 3Linked to original sources
PubMed1994

Differential influence of haloperidol and sulpiride on dopamine receptors and peptide mRNA levels in the rat striatum and pituitary.

We examined the effect of chronic administration (14 days) of haloperidol (2 mg/kg/day) or sulpiride (100 mg/kg/day), on the mRNA levels of various genes in the rat striatum and pituitary by quantitative in situ and Northern blot hybridizations. In the pituitary, haloperidol and sulpiride induced similar increases of mRNAs of pro-opiomelanocortin (POMC) (+65% and +73%), prolactin (PRL) (+821% and +840%) and growth hormone (GH) (+32% and +47%), but sulpiride induced a greater increase of D2R mRNA (+125%) than haloperidol (+92%). In the striatum, sulpiride and haloperidol had different effects: sulpiride induced a higher increase than haloperidol of both preproenkephalin A (PPA) mRNA (+67% versus +47%) and D2 dopamine receptor (D2R) mRNAs (+72% versus +40%). Moreover, haloperidol and sulpiride had opposite effects on substance P (SP) mRNA. Haloperidol decreased the amount of SP mRNA by 20% while sulpiride increased it by 20%. The D1 dopamine receptor (D1R) mRNA level was not significantly modified after either treatment. Our results demonstrate that the effect of a chronic haloperidol treatment on striatal dopamine receptors and neuropeptide mRNA levels is different to that of sulpiride, whereas it is similar on pituitary hormones mRNA levels.

Animals↗
PubMed1994

Expression of polyadenylated and non-polyadenylated trkC transcripts in the rodent central nervous system.

We have previously isolated a full-length cDNA clone encoding rat TrkC, a member of the Trk family of tyrosine kinase receptors, that specifically mediates biological responses to neurotrophin-3. Here, we report the identification of five major trkC transcripts in the adult and developing rat and mouse brain suggesting the presence of several TrkC receptors. Northern blot hybridizations revealed that three of these trkC transcripts (of 14, 3.9 and 4.8 kb) were poly(A)+ messenger RNAs, while the two others, of shorter size (1.1 and 0.7 kb), were poly(A)- messenger RNAs. All transcripts were expressed in 11 brain regions but poly(A)- messenger RNAs were found at much higher levels than poly(A)+ messenger RNAs in the cerebellum. Hybridization with five oligonucleotide and two complementary DNA probes, corresponding to different parts of the full-length trkC complementary DNA, revealed that the two poly(A)- transcripts may encode for receptors truncated in their extracellular and kinase intracellular domains. During ontogeny, poly(A)- trkC messenger RNAs were found at low amounts at prenatal and early postnatal ages with a drastic increase in the cerebellum at postnatal day 30. No poly(A)- transcript was identified for the trk B gene. In situ hybridization revealed that trkC messenger RNAs are expressed both in granular and Purkinje cells in the cerebellum. Northern blot on RNA extracted from mice mutant strains with degeneration of either granular or both granular and Purkinje cells suggested that poly(A)- and poly(A)+ trkC messenger RNAs are expressed within the same cells. We have demonstrated the existence of several trkC transcripts that differ both by their size and polyadenylation. This phenomenon could be of physiological relevance in regulating TrkC functions. To the best of our knowledge, this is an original feature for a mammalian gene expression. Studies focused on poly(A)- messenger RNAs could give rise to the identification of other genes expressed in a similar fashion.

Animals↗
PubMed1994

Evaluation of a safe sputum processing method for detecting tuberculosis.

AIMS: To evaluate a safe sputum processing method for detection of tuberculosis in developing countries. METHODS: A sample processing method was developed in which acid fast bacilli were killed with 1% sodium hypochlorite and concentrated by flotation on a layer of xylene before staining by the Ziehl Neelsen or auramine O methods. RESULTS: Best results were obtained by auramine O staining after flotation. Staining by the Ziehl Neelsen method after flotation gave better results than direct Ziehl Neelsen staining without flotation. CONCLUSIONS: The flotation method with Ziehl Neelsen staining offers advantages for smear preparation in the tuberculosis control programmes of developing countries.

Bacteriological Techniques↗
PubMed1993

Prenatal D1, D1b and D3 dopamine receptor gene expression in the rat forebrain: detection by reverse polymerase chain reaction.

Three dopamine receptor mRNAs were detected by reverse polymerase chain reaction in the rat forebrain during ontogeny. The D1 receptor mRNA gave a faint signal from gestational day 11 (G11) on, while the D1b receptor was not detectable before G12. The D3 receptor mRNA was slightly expressed at G11 and clearly present at G14. Our results show that these mRNAs are present at early stages of fetal life, each one with its specific time of appearance.

Animals↗
PubMed1993

Detection of antigens of Mycobacterium tuberculosis in patients of infertility by monoclonal antibody based sandwiched enzyme linked immunosorbent assay (ELISA).

A sandwich ELISA to detect specific protein antigens of Mycobacterium tuberculosis was developed by using polyclonal anti-BCG rabbit antibodies as the primary capture antibodies. The mycobacterial antigens were detected with horseradish peroxidase conjugated monoclonal antibodies (P 6) as secondary antibodies. The enzyme was detected by using 1,2 Phenylenediamine dihydrochloride (OPD) and Hydrogen peroxide as substrate. The antigen could be quantitated through linear regression analysis with lower detection limit of 1.25 micrograms/ml. 50 consecutive cases of infertility were examined by laparoscopy and tested for the presence of the antigen in the serum. Mycobacterial antigen could be detected in 9 of the 12 cases with definitive diagnosis of tuberculosis, 5 of the 23 where the diagnosis of tuberculosis was probable and in only 1 of 15 patients who had no laparoscopic abnormalities indicative of tuberculosis.

Adult↗
PubMed1993

Universal precautions--a critical review.

The route of HIV transmission are now well defined. For health care workers the major occupational risk is from parenteral exposure to infected blood or other body fluids. To prevent such exposures, it would be prudent for HCWs to assume that all patients are potentially infected and a set of precautions applicable universally be followed in contacts with all patients. The provisions of "Universal Precautions" apply to blood, CSF, genital secretions and all body fluids. It is essential that barrier protection and washing of hands be practiced, body fluids be handled with care, correct sterilization and disinfection procedures be followed and a suitable system of waste disposal be evolved. Although the Universal Precautions have been useful in abating some of the more extreme behavior associated with treating AIDS patients and in establishing a rational approach to infection control, some of the recommendations have not been found to be efficacious or cost effective. Preventive measures recommend on the basis of demonstrated efficacy and aimed at routes of exposure that represent true risk are needed. The risks for occupational infection with blood borne pathogens have been a source of concern for health care workers (HCWs) because of their frequent and often substantial exposure to patient blood and body fluids. HCWs have long been identified as a group "at risk" for occupationally acquired Hepatitis B infection. With the development of acquired immunodeficiency syndrome (AIDS) epidemic, both HCWs and policy makers have become increasingly concerned about occupational risk from blood borne infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Gloves, Protective↗
PubMed1992

Reserpine treatment stimulates enkephalin and D2 dopamine receptor gene expression in the rat striatum.

We investigated the effect of catecholamine depletion on gene expression for preproenkephalin A (PPA) and D2 dopamine receptor (D2R) in the rat nigrostriatal complex, using quantitative Northern blot analysis. The D2R probe indifferently recognizes the two mRNA isoforms generated by alternative splicing from the same gene. Short-term and chronic reserpine treatment increase the level of PPA and D2R mRNA in the striatum in a complex manner. For short-term treatment, we injected 10 mg/kg of reserpine the first day, 5 mg/kg 24 h later and sacrificed the rats at various times after the last injection. This treatment resulted in an increase of the level of PPA mRNA by 50% and D2R mRNA up to 150%. For chronic treatment, we injected 0.5 mg/kg of reserpine for 21 days, sacrificed the rats one day after the last injection and observed an increase in PPA and D2R mRNA levels by 100%. Statistical analysis revealed that the PPA mRNA level after chronic treatment was significantly higher from the one obtained after short-term treatment while no such difference was observed for the D2R mRNA. In contrast, reserpine treatment does not modify the level of D2R mRNA in the substantia nigra suggesting that catecholamine depletion has postsynaptic but not presynaptic consequences in the rat nigrostriatal complex. These results demonstrate that reserpine acts at the gene or the mRNA level to induce dopamine supersensitivity in striatal dopaminoceptive neurons.

Animals↗
PubMed1992

Molecular cloning of rat trkC and distribution of cells expressing messenger RNAs for members of the trk family in the rat central nervous system.

Tyrosine protein kinases trk, trkB and trkC are signal-transducing receptors for the neurotrophins nerve growth factor, brain-derived nerve growth factor, neurotrophin-3 and neurotrophin-4. Here we report on the isolation of cDNA fragments encoding a part of rat trk and trkB proteins, respectively, and characterization of a full-length cDNA clone encoding rat trkC. Cells expressing mRNAs for the different members of the trk family were identified in the rat central nervous system by in situ hybridization using oligonucleotide probes designed from the isolated cDNA sequences and complementary to mRNA sequences coding for the extracellular region of the receptors. The expression of trk mRNA was found to be restricted to neurons of the basal forebrain, caudate-putamen with features of cholinergic cells and to magnocellular neurons of several brainstem nuclei. In contrast, cells expressing trkB and trkC mRNAs were widely distributed in the brain. Areas expressing high levels of trkB or trkC mRNAs included olfactory formations, neocortex, hippocampus, thalamic and hypothalamic nuclei, brainstem nuclei, cerebellum and spinal cord motoneurons. A similar distribution for trkB and trkC mRNAs was shown in most areas but each probe specific for these mRNAs also provided distinct labeling patterns in different subregions, layers and cells. Comparison between our data and previous analyses of cells expressing mRNAs for neurotrophins and the low-affinity nerve growth factor receptor suggests that different modes of action and different combinations of receptors mediate biological responses to neurotrophins in the adult rat brain.

Animals↗
PubMed1992

Early effects on the morphology of mouse small intestine of single or combined modality treatment with hyperthermia and X-irradiation.

This study describes the effects of hyperthermia and X-irradiation on the morphological appearance of normal, at risk tissues in the ileum of the mouse. The early morphological effects 1 day after a combined modality treatment are compared with those due to either hyperthermia or X-irradiation given alone. The response was assessed qualitatively and semiquantitatively using scanning electron microscopy and a villous scoring technique. Early post-irradiation effects on topography did not differ significantly from those observed after small intestine exteriorisation without treatment. The villous scores for the combined modality treatments reflected greater damage than would be expected from the sum of villous scores for each modality treatment on its own. This suggests that the combined modality treatment had a synergistic or enhancing effect. A 4 hour time interval between the two treatments did not seem to reduce the enhancing effect. Further studies are required to investigate the effects of fractionated combined treatment.

Animals↗
PubMed1991

Aromatic L-amino-acid decarboxylase (DOPA decarboxylase) gene expression in dopaminergic and serotoninergic cells of the rat brainstem.

In situ hybridization was performed in the rat brain to detect aromatic L-amino acid decarboxylase (AADC) mRNA using 35S-labeled oligonucleotide probes derived from rat kidney AADC cDNA. Results demonstrated AADC mRNA in areas containing dopaminergic and serotoninergic cell bodies. Combined immunohistochemistry for tyrosine- or tryptophan hydroxylase and in situ hybridization for AADC mRNA demonstrated the dopaminergic or serotoninergic nature of cells containing AADC mRNA. Tyrosine hydroxylase-positive mesencephalic neurons containing a very low or no AADC mRNA signal were also observed.

5-Hydroxytryptophan↗
PubMed1987

Reliability and predictive value of salivary theophylline levels.

The reliability and accuracy of salivary theophylline levels as a predictor of serum theophylline levels was investigated in 28 hospitalized chronic asthmatics, free of other chronic diseases, on continuous aminophylline infusion for greater than 24 hours. Twenty paired blood and saliva theophylline levels from 12 patients (group 1) were used to develop a formula for predicting serum theophylline levels from salivary levels. Twenty-one paired blood and saliva theophylline levels from 16 patients (group 2) were used to test the formula obtained. The formula predicted the serum theophylline concentration within 1.51 microgram/mL in 76% of the samples and within 1.88 microgram/mL in 100% of the samples. There was an excellent correlation between the predicted and actual serum theophylline concentrations, r = .93; thus under controlled conditions of steady-state pharmacokinetics in patients free of other diseases, salivary theophylline levels can be used to accurately predict serum levels.

Adolescent↗
PubMedDate not supplied

Nasoseptal variation in relation to sinusitis. A computerized tomographic evaluation.

Paraseptal structural abnormalities are common in patients with sinusitis. They may coexist with radiographic changes suggestive of sinusitis. Their etiological role in patients with no history of sinus disease is still controversial. In this study, computerized tomographic scan of orbits of 89 cases with no history of sinusitis were reviewed between 1996 and 1998. The incidence of septal deviation, concha bullosa and paradoxical middle turbinates was looked at. Their correlation with sinusitis was analyzed using CM-square statistical method. Results showed that the presence of these anatomical abnormalities is not associated with an increased incidence of sinusitis as shown radiologically. We conclude that the presence of septal deviation or large middle turbine on routine rhinoscopy does not mandate further radiological evaluation of the sinuses in the absence of history of sinusitis.

Adolescent↗