BACKGROUND: Congenital erythropoietic porphyria (CEP) is an inherited disease caused by a deficiency of uroporphyrinogen III synthase, the fourth enzyme of the haem biosynthesis pathway. It is characterized by accumulation of uroporphyrin I in the bone marrow, peripheral blood and other organs. The prognosis of CEP is poor with death occurring in early adult life and available treatments are only symptomatic and unsatisfactory. In vitro gene transfer experiments have documented the feasibility of gene therapy via haematopoietic stem cells to treat this disease. To facilitate future ex vivo gene therapy in humans, the design of efficient selection procedures to increase the frequency of genetically corrected cells prior to autologous transplantation is a critical step. METHODS: An alternative selection procedure based upon expression of a transferred gene was performed on a lymphoblastoid (LB) cell line from a patient with congenital erythropoietic porphyria to obtain high frequencies of genetically modified cells. The presence of exogeneous delta-aminolevulinic acid (ALA), a haem precursor, induces an increase in porphyrin accumulation in LB deficient cells. Porphyrins exhibit a specific fluorescent emission and can be detected by cytofluorimetry under ultraviolet excitation. RESULTS: In genetically modified cells, the restored metabolic flow from ALA to haem led to a lesser accumulation of porphyrins in the cells, which were easily separated from the deficient cells by flow cytometry cell sorting. CONCLUSION: This selection process represents a rapid and efficient procedure and an excellent alternative to the use of potentially harmful gene markers in retroviral vectors.

Adult↗

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Subthalamic prelemniscal radiation stimulation for the treatment of Parkinson's disease: electrophysiological characterization of the area.

Previous reports have provided evidence of a reticulo-thalamic system, extending from the mesencephalic reticular formation (MRF) to the ventrolateral thalamus (VL), involved in the production of tremor. In humans, a funnel of fibers in the posterior subthalamus named the prelemniscal radiations (Raprl) has been described as an exquisite target to treat tremor in cases of Parkinson's disease. In the present study, a group of 14 patients suffering from Parkinson's disease, with prominent unilateral tremor and rigidity, were implanted with tetrapolar depth brain stimulation (DBS) electrodes in Raprl to perform chronic electrical stimulation (ES) for the treatment of patient symptoms. Electrodes were left externalized to corroborate their placement throughout MRI studies and also to perform the following electrophysiological battery: (a) recording of somatosensory-evoked responses (SEP) through different electrode contacts and scalp by means of a paradigm to study the attention process; (b) evoking scalp EEG responses by stimulation with low (3 cps, 6 cps) and high (60-120 cps) frequencies with stimuli delivered through different electrode contacts, and (c) studying recovery cycle (RC) potentials in the Raprl while the upper MRF was being stimulated and, conversely, the RC in MRF while Raprl was being stimulated, before and after subacute Raprl stimulation. Thereafter, the electrodes were internalized and connected to a pulse generator (IPG) to carry on chronic ES, while the effects of stimulation were determined through a quantitative evaluation that measured phasic and tonic muscular activity with EMG recordings during different motor tasks. Results indicate the following: (a) that late, but not early, SEP components were recorded in Raprl and modulated in different attentive conditions; (b) that bilateral recruiting responses and spike and wave complexes were elicited by Raprl through low-frequency stimulation, while bilateral positive DC shifts induced by high-frequency stimulation were recorded, similar to those obtained in animals from MRF, and (c) that Raprl-ES induced RC inhibition at Raprl, but Raprl ES did not change MRF-RC. Long-term Raprl-ES induced a significant decrease in tremor and rigidity. It was concluded that Raprl represents a subthalamic circuit electrophysiologically related to MRF in the genesis of tremor and rigidity and in the process of selective attention. Raprl-ES induced a significant improvement in tremor and rigidity by causing inhibition of the stimulated area.

Action Potentials↗

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Penetration of cefotaxime into bronchial secretions.

The penetration into bronchial secretions of cefotaxime, a new, highly active cephalosporin, was studied in 45 patients with respiratory infections. Ten patients received 0.75 g and 25 received 1 g of cefotaxime intramuscularly; 10 patients received a 30-min intravenous infusion of 2 g of cefotaxime. Samples of bronchial secretions were obtained by means of fiber-optic bronchoscopy after a single dose in all patients and after three and seven days of treatment in 30 and 15 patients, respectively. Simultaneous serum samples were collected for determination of the relationship between the levels of drug in bronchial secretions and those in serum. Assays were performed by microbiologic agar diffusion. In 30 cases bacteriologic analysis determined the minimal inhibitory concentrations of cefotaxime for the bacteria isolated from sputum. Mean peaks in bronchial secretions reached 1.5-2.5 microgram/ml (according to the groups) after 3 hr; individual concentrations varied according to the dose, the route of administration, and the duration of the treatment. Ratios between the levels in bronchial secretions and the corresponding levels in serum were approximately 8%-25% after 3 hr, as is usual for other cephalosporins. Cefotaxime reached significant concentrations in bronchial secretions, exceeding the minimal inhibitory concentrations for microorganisms responsible for respiratory infections.

Bronchi↗

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Reversible effects of long-term treatment with D-Trp6-LH-RH-microcapsules on pituitary-gonadal axis, spermatogenesis and prostate morphology in adolescent and adult dogs.

The effect of long term treatment with D-Trp6-LH-RH in microcapsules (GnRH-A) on pituitary gonadal axis was studied in a adolescent and adult Fox-terrier dogs. They received intramuscularly 50 micrograms/GnRH-A/kg, on day 1 and 21 and every 4 weeks thereafter. Three adult dogs received 4 injections. cLH, cFSH and T levels were undetectable on day 7. Detectable then normal levels occurred 60 and 90 days respectively after the last injection on day 77. Testis thickness was respectively 22.1 +/- 0.8 mm and 16.3 +/- 0.8 mm on days 0 and 77; initial values were observed 90 days later. Spermatozoa disappeared from the ejaculate on day 21 in 2 dogs; reappearance and complete recovery were observed on days 161-175 and 252 respectively. Histological findings showed on day 91 atrophic lesions of testis and prostate and spermatogonia were present in all seminiferous tubules. After recovery a normal histological appearance was noticed. Three adolescent 29 weeks old dogs received 14 injections, the last one on day 357. cLH, cFSH and T levels were undetectable only from day 105. Testis thickness were respectively 15.8 +/- 0.7 mm, 18.1 +/- 0.7 mm, 12.5 +/- 0.3 mm and 21.4 +/- 0.7 mm on day 0, 21, 357 and 490. Initially, no spermatozoa were present in the ejaculates, they appeared in 2 dogs after 2 months for 20 to 40 days then disappeared until day 449. Normal semen characteristics were observed in all three dogs on day 581. Histological findings on day 371 were comparable to those observed in the adult dogs. This study demonstrates that longterm treatment with D-Trp6-LH-RH in microcapsules leads to a reversible inhibition of spermatogenesis in dogs. The delayed response in adolescent dogs might be due to a transient resistance to therapy related to.

Animals↗

PubMedDate not supplied