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Biomedical subjects

P Lopez

Publications and source records attributed to P Lopez.

At least 145 records · Page 8Linked to original sources
PubMed1981

Phi W-14 DNA inhibits transfection of Bacillus subtilis by SPP1 DNA.

The DNA of bacteriophage phi W-14 is unusual in that half of the thymine residues are replaced with the hypermodified pyrimidine alpha-putrescinylthymine (Kropinski et al., Biochemistry 12:151-157, 1973). Bacteriophage phi W-14 DNA and Bacillus subtilis DNA exhibited comparable competing abilities for the uptake of transfecting bacteriophage SPP1 DNA by competent cells of B. subtilis. B. subtilis DNA decreased transfection and uptake to the same extent, indicating that it merely competed with SPP1 DNA for uptake. Phi W-14 DNA, however, decreased transfection up to 30 times more effectively than it inhibited uptake. Phi W-14 DNA did not alter the kinetics of transfection. The degree of inhibition of transfection was dependent upon the time of addition of Phi W-14 DNA relative to the time of addition of SPP1 DNA. If failed to inhibit when added 30 min after SPP1 DNA. It had a fourfold-greater effect when added 10 min before, rather than simultaneously with, SPP1, but this enhancement was abolished by high concentrations of SPP1 DNA. The nature of the transfection process was not altered in those cells escaping inhibition by Phi W-14 DNA: two molecules of transfecting SPP1 DNA were required to form a transfectant with or without Phi W-14 DNA. Free putrescine did not affect transfection by SPP1 DNA. It was concluded that the putrescine groups covalently attached to phi W-14 DNA allowed this DNA to interfere with the transfection process at the intracellular level.

Bacillus subtilis↗
PubMed1981

The results of angiographic studies of abdominal masses.

This study reveals the continuing great viability of angiography in the investigation of abdominal masses. It is a fundamentally important procedure within the context of presurgical evaluation. Certain points should be underlined. - The radiological definition of the histological nature of an abdominal mass during angiography remains difficult, practically impossible in certain regions. - Borrowed vascularizations still pose complex diagnostic problems at different levels. - The benefit of angiography should be compared with other modern radiodiagnostic methods, especially the less aggressive ones. - The importance of each of these points has led us to develop them separately: - The diagnostic reliability of angiography in abdominal masses (from anatomico-radiological correlations). To be published - The borrowed vascularisation of abdominal masses. To be published - The tomodensitometry of abdominal masses. To be published - Diagnostic strategy in case of an abdominal mass. To be published.

Abdominal Neoplasms↗
PubMed1981

The parasitic blood supply of abdominal masses.

Many lesions, and particularly hyper-vascularized ones, acquire an aberrant blood supply. These parasitic vascular supplies are defined as tumour vascularizations derived from neighbouring organs or structures, and supplement the normal blood supply of the diseased organ. Their existence is essential for the angiography of abdominal masses. We selected 35 cases of abdominal masses with parasitic vascular networks. Twenty-four belonged to an initial review of 117 angiographic studies of abdominal masses. Eleven have been added in accordance with the theme of this work. Parasitic circulations should be taken into account because of their effects on the angiographic technique, their diagnostic possibilities and limitations, and their importance in the management of the patient.

Abdominal Neoplasms↗
PubMed1980

Interactions of homologous and heterologous deoxyribonucleic acids and competent Bacillus subtilis cells.

Glucosylated and nonglucosylated bacteriophage T4 deoxyribonucleic acids (DNAs) are able to bind to competent cells of Bacillus subtilis, although the former does so in a rather unstable fashion, probably because of the glucosylation. Several heterologous DNAs compete with homologous DNA for the same receptors in binding and in transformation. A different pattern in competition for DNA binding was observed for homologous and T4 glucosylated DNAs in intact cells as compared with protoplasts or membrane vesicles. The results are consistent with the existence of two types of receptor sites on the membrane of competent B. subtilis cells.

Bacillus subtilis↗
PubMed1979

[Computerized tomography: physiological reheightering of the images by sugars (author's transl)].

During experimental utilization on the dog (per os) of several types of materials capable to be modified by the liver after digestive absorption, sugars appeared naturally opaques in the gastric cavity and so they could substitute in C.T. to the habitual materials of contrast, we also notice some belated modifications on intra hepatic density that might be in relation with the metabolism of intra hepatic glucose.

Animals↗
PubMed1978

Further studies on the competence development in exponentially growing cultures of Bacillus subtilis.

Bacillus subtilis, growing in Bott and Wilson's medium, develops two peaks of competence in batch cultures. The first maximum developed during the exponential growth phase and it has been studied comparatively with the competence level reached in continuous culture at Dt = 2.5 h. In both cases, 100 microgram/ml of arginine inhibited competence. Continuous cultures treated with arginine recovered competence specifically after the addition of Mn2+. In addition, a reduction in the synthesis of aconitase and fumarase was observed in the arginine-inhibited continuous cultures.

Aconitate Hydratase↗
PubMed1978

Early stages in Bacillus subtilis transformation: association between homologous DNA and surface structures.

The addition of ethylenediaminetetraacetate to competent cultures of Bacillus subtilis irreversibly inhibited the transformability as well as the cellular binding of DNA. Our results show that the inhibition of DNA binding by ethylenediaminetetraacetate in whole cells, protoplasts, and membrane vesicles is mainly due to a permanent alteration of the DNA receptors. Transformation absolutely requires free magnesium ions, whereas DNA binding is a magnesium-independent step. In contrast to ethylenediaminetetraacetate, the absence of Mg2+ does not irreversibly affect the capacity of the competent cells to be transformed DNA-binding receptors located at the cell surface remain associated with the plasma membrane after protoplasting and after isolation of membrane vesicles. A Mg2+-dependent endonucleolytic activity associated with the membrane appears to be responsible for the lower levels of binding by protoplasts in the presence of this ion.

Bacillus subtilis↗
PubMedDate not supplied

Comparison of two low-calorie diets: a prospective study of effectiveness and safety.

OBJECTIVE: To evaluate the cost-effectiveness and safety of two distinct low calorie diets (LCD). DESIGN: Prospective controlled study. METHODS: 67 obese patients [body mass index (BMI) 40 kg/m2] were included in two study groups. Group A: 26 patients followed a 458 kcal diet given in three meals for 1 month. Group B: 41 patients followed a 800 kcal diet for 3 months and with outpatient control. MEASUREMENTS: Anthropometric, cardiovascular risk and nutritional profile changes were evaluated, as well as total direct and indirect costs, and the incidence of complications. RESULTS: No significant initial differences were observed between the two study groups. Eighty-six point two per cent of the patients completed the therapy correctly. After treatment a significant decrease was observed in the following variables for both groups, but no differences were detected between Groups A and B: mean weight loss (A= 9.28 kg, B= 8.7 kg), ponderal loss percentage (A/B= 7.2/6.8%), glycemia (A/B= 18.6/12.1 mg/dl), systolic blood pressure (SBP) (A/B= 11.8/6.5 mmHg), diastolic blood pressure (DBP) (A/B 5.9/6.8 mmHg), and final insulin-resistance (IR) index (A= 4.4, B= 4.3). Group A had the highest drop in total cholesterol (37.7 vs 8.1 mg/dl) and triglycerides (54.4 vs 2.5 mg/dl). No changes were observed in ureic acid, renal function and serum albumin. Thirty-six patients (55.3%) suffered trivial complications associated to the VLCD (16.9% gastrointestinal, 20% anxiety), with no differences between groups. Group A patients were on sick leave due to asthenia, and two patients in this group had serious complications (transient ischemic attack and atrial fibrillation). The total cost of Group A treatment was 3018.9 against 582.6 euros for Group B. CONCLUSIONS: The 3-month 800 kcal/day VLCD was more cost-effective and safer than the 1-month 458 kcal/day diet.

Adult↗
PubMedDate not supplied

Care paths. A new approach to high-risk maternal-child home visitation.

Care paths for the maternal and infant populations are used to define immediate and long-term outcomes related to care received in the home. This article describes a care path developed by public health nurses for intervention with an at-risk maternal-child population in a city/county health department. A public health nursing care management model provided the framework for developing this care path to foster cost-effective use of limited resources. It is crucial that public health nurses articulate clearly the services provided in the home both for those who may seek service and for policy makers who determine funding structure. The project demonstrated that care paths for home visitation involving high-risk prenatal clients are useful tools that streamline documentation, foster consistency and continuity of care, facilitate quality improvement efforts, and provide outcome data.

Adolescent↗
PubMedDate not supplied

[Bilateral adrenal pheochromocytoma associated with pregnancy. Simultaneous cesarean section and adrenalectomy].

An-25-year-old primigravida with bilateral phaeochromocytomas was managed from 6 weeks' gestation until 2 years following combined caesarean section and removal of adrenal tumours. Preoperative alpha-blockade was achieved by oral prazosin without deleterious effects. Intraoperative management comprised neuroleptanalgesia, arterial and pulmonary pressures monitoring, adequate heart loading with fluid replacement and sodium nitroprusside. Postoperatively mother and baby remained normotensive.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

[Complications of adrenal angiography (author's transl)].

Since new ways of radiodiagnostic exploration of the adrenal glands are now performed, it is important to take stock upon the complications of adrenal angiography. These complications are very different according to the fact that we explore pheochromocytomas or not. The complications of stimulation, of hypertensive accident or collapsus are quite specially observed during the angiography of pheochromocytomas. They must be prevented by a selection of the indications and a reanimation pre and per angiography. Lesions of glandular destruction that lead to a hormonal insufficiency (sometimes therapeutic) are observed outwards pheochromocytomas. Because they depend upon the explored adrenal lesion and specially of the angiographic conditions of the exploration, these complications must be prevented by a rigorous technic.

Adrenal Gland Neoplasms↗