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P Gross

Publications and source records attributed to P Gross.

At least 91 records · Page 5Linked to original sources
PubMed1994

Colicins: structures, modes of action, transfer through membranes, and evolution.

This article intends to inform a broader audience on a fascinating class of protein toxins (bacteriocins) which usually kill only cells of the same species. Those who gained a deeper interest in bacteriocins can find a comprehensive description of the field in a recent book based on a conference (James et al. 1992), and in more specialized review articles dealing with certain aspects (Pugsley 1984a, b), or certain colicins (De Graaf and Oudega 1986; Harkness and Olschläger 1991; Lazdunski et al. 1988). The older literature has been reviewed by Brandis and Smarda (1971), Reeves (1972), Hardy (1975) and Konisky (1982).

Bacterial Outer Membrane Proteins↗
PubMed1994

[Conservative treatment in chronic kidney insufficiency].

Modern therapeutic concepts of chronic renal insufficiency are based on observations showing a retardation of progressive renal failure by therapeutic measures. In the context emphasis is now placed on the treatment of arterial hypertension and on the patient's adherence to a protein-restricted diet. In addition to these conservative measures it is important to avoid nephrotoxins, to hydrate the patient sufficiently and to treat advanced hyperlipidemias. Deficiencies of active vitamin D should be treated by oral vitamin D substitution after correction of hyperphosphatemia. In the treatment of the latter, preparations of calcium carbonate are now the preferred mode of treatment. In advanced renal insufficiency it is important to maintain a salt-restricted diet and to treat any attendant hyperkalemia and hyponatremia.

Dietary Proteins↗
PubMed1993

Translocation of cytoplasm and nucleus to fungal penetration sites is associated with depolymerization of microtubules and defence gene activation in infected, cultured parsley cells.

We describe a novel system of reduced complexity for analysing molecular plant-fungus interactions. The system consists of suspension-cultured parsley (Petroselinum crispum) cells infected with a phytopathogenic fungus (Phytophthora infestans) which adheres to a coated glass plate and thus immobilizes the plant cells for live microscopy. Conventional light and electron microscopy as well as time-lapse video microscopy confirmed the virtual identity of fungal infection structures and of several characteristic early plant defence reactions in the cultured cells and whole-plant tissue. Using this new system to approach previously unresolved questions, we made four major discoveries: (i) rapid translocation of plant cell cytoplasm and nucleus to the fungal penetration site was associated with local depolymerization of the microtubular network; (ii) the directed translocation was dependent on intact actin filaments; (iii) a typical plant defence-related gene was activated in the fungus-invaded cell; and (iv) simultaneous activation of this gene in adjacent, non-invaded cells did not require hypersensitive death of the directly affected cell.

Actins↗
PubMed1993

Domains of colicin M involved in uptake and activity.

Colicin M inhibits murein biosynthesis by interfering with bactoprenyl phosphate carrier regeneration. It belongs to the group B colicins the uptake of which through the outer membrane depends on the TonB, ExbB and ExbD proteins. These colicins contain a sequence, called the TonB box, which has been implicated in transport via TonB. Point mutations were introduced by PCR into the TonB box of the structural gene for colicin M, cma, resulting in derivatives that no longer killed cells. Mutations in the tonB gene suppressed, in an allele-specific manner, some of the cma mutations, suggesting that interaction of colicin M with TonB may be required for colicin M uptake. Among the hydroxylamine-generated colicin M-inactive cma mutants was one which carried cysteine in place of arginine at position 115. This colicin derivative still bound to the FhuA receptor and killed cells when translocated across the outer membrane by osmotic shock treatment. It apparently represents a new type of transport-deficient colicin M. Additional hydroxylamine-generated inactive derivatives of colicin M carried mutations centered on residues 193-197 and 223-252. Since these did not kill osmotically shocked cells the mutations must be located in a region which is important for colicin M activity. It is concluded that the TonB box at the N-terminal end of colicin M must be involved in colicin uptake via TonB across the outer membrane and that the C-terminal portion of the molecule is likely to contain the activity domain.

Alleles↗
PubMed1993

[Balance sheet of CETRADIM after 10 years of functioning as an alternative to hospitalization].

CETRADIM (Educational Centre for the Treatment of Diabetes and Nutritional Diseases) is a hospital department of the Roubaix (France) general hospital functioning uniquely as an alternative to conventional hospital care (outpatient clinics, day hospital, weekday hospital). Its catchment area is essentially local, covering a population of about 200,000. Its vocation is triple: care (including education), training and the supply of information to the treating team and general public. The aim of this study was to evaluate the effect of the existence of a unit of this kind on the frequency of admission of patients for conventional hospital care to the various medical departments of the Roubaix hospital. The indicator used was the percentage of conventional hospitalisation (PCH) in the Endocrinology/Diabetology/Nutrition department, calculated by dividing the number of conventional hospital stay in this specialty by the total number of hospital stay days. Data were obtained for the Roubaix hospital and for 3 hospitals in the Northern region serving comparable types of population but lacking any institution functioning totally as an alternative to hospital care. The PCH was 4.3% for the Roubaix Hospital Centre and 8.2, 8.46 and 10.6% respectively for the other three hospitals. These findings suggest that the existence of an institution such as CETRADIM reduces the number of conventional hospital stay days of patients with Endocrine/Diabetes/Nutrition diseases. Its effects on the constitution of new local care units is discussed, and arguments in favour of its role in the improvement of health care and education costs developed.

Diabetes Mellitus↗
PubMed1993

Work absenteeism in type 2 diabetes mellitus: results of the prospective Diabetes Intervention Study.

Newly diagnosed mild Type 2 diabetic patients, aged 30-55 years, were included in the prospective, multi-centre Diabetes Intervention Study. They were randomly allotted to either an intervention group receiving intensified health education or to a control group on usual care. This paper reports the incidence, duration of and causes for absence from work due to any disease in the patients who were working during the first 5-year follow-up. Data from 817 patients could be taken into account. 14.5% of the intervention patients and 17.3% of the control patients had never been on the sick list. Those patients who had undergone intensified health education were listed sick less often. Women showed a higher work absenteeism in either group; they had higher blood pressure and higher body mass index at entry. Cardiovascular diseases and musculo-skeletal disorders were major reasons for absence from work. However, when compared to the general population, these Type 2-diabetic patients were approximately four times more often on the sick list. Thus, the health education programme of the Diabetes Intervention Study was shown to be effective with respect to work absenteeism. Teaching patients is recommended as an important part of the therapeutic regimen.

Absenteeism↗
PubMed1992

[Different effects of fibrates on the lipoprotein profile. Comparison of the effectiveness of gemfibrozil and bezafibrate in various types of hyperlipoproteinemia].

AIMS: To compare the efficacy and tolerability of Gemfibrozil and Bezafibrate in patients with hyperlipoproteinemia, types IIa, IIb and IV. METHOD: In an open, randomized parallel study, the tolerability and efficacy of Gemfibrozil (G) and Bezafibrate (B) were investigated over a period of 12 weeks in 178 hyperlipidemic (HLP) patients first submitted to an 8-week "wash-out" (diet only) phase. In HLP type IIa patients, LDL cholesterol was lowered (G: -13%, B: -10%). In HLP type IIb, a decrease in triglyceride (TG) levels (G: -41%, B: -31%), an increase in HDL-cholesterol (G: +19%, B: +5%), and a decrease in the total cholesterol/HDL cholesterol ratio (G: -32%, B: -9%) predominated. Patients with type IV HLP responded to both fibrates with an appreciable reduction in TG levels (G: -45%, B: -42%). The effects of the preparations differed significantly with respect to the elevation of HDL cholesterol and a decrease in the total cholesterol/HDL cholesterol ratio in HLP type IIb patients. The respective lipid baseline concentration appeared to be of importance for the sense and extent of the changes induced.

Adult↗
PubMed1992

Internalization of V2-vasopressin receptors in LLC-PK1-cells: evidence for receptor-mediated endocytosis.

The mechanism of internalization of the vasopressin-receptor (V2-subtype) of LLC-PK1-cells, a pig renal tubular cell line, is unknown. We studied internalization utilizing a novel, highly specific vasopressin analogue ((125I)-[8-p(OH)-phenylpropionyl]-LVP, 2000 Ci/mmol). Scatchard analysis performed with membranes of LLC-PK1-cells revealed a Kd of 0.8 +/- 0.2 nM and a Bmax of 366 +/- 41 fmol/mg of protein. Degradation of the ligand was excluded by RP-HPLC-analysis. Internalization was proven by the acid-wash technique, quantitative light-microscopic autoradiography and electron microscopy. The ligand was internalized in a time- and temperature-dependent manner. At 4 degrees C, no uptake was found; at 22 degrees C, after 30 min of incubation, more than 50% of the radioligand was found inside the cell. Electron microscopy demonstrated that plasma-membrane bound vasopressin receptors are internalized by receptor-mediated endocytosis via coated pits.

Animals↗
PubMed1992

Intracellular distribution of endothelin-1 receptors in rat liver cells.

We studied the binding of (125I)-endothelin-1 as well as that of the vasopressin analogue (125I)-[8-phenylpropionyl]-LVP to purified plasma membranes, Golgi cisternae and cell nuclei from rat liver. Cell organelles were isolated by differential centrifugation and discontinuous sucrose gradients. Endothelin-1 exhibited specific binding to plasma membranes, Golgi cisternae and nuclei, while the binding of (125I)-[8-phenylpropionyl]-LVP was restricted to the plasma membranes. The number of receptors (Bmax) and the binding constants (Kd) were determined by Scatchard analysis of competition binding studies. In all cases only one class of Et-1 binding sites could be detected. The presence of Et-1 receptors on the Golgi complex either indicates that the receptor is glycosylated within the cisternae or alternatively, there exists a recycling pathway. The unexpected finding of Et-1 receptors on highly purified nuclei suggests that this peptide may exert part of its biological functions intracellularly via the nucleus.

Animals↗
PubMed1992

[Appendicitis in children].

In 1992, appendicitis is still common among children. Mortality due to a belated or erroneous diagnosis is far from being nil. The disease must always be present in the clinician's mind, and its diagnosis is purely clinical. No significant advance has been made on this subject, and clinical findings remain of paramount importance. Hospitalization for observation at the slightest doubt and emergency surgery when the diagnosis is probable are the best means of improving the management of appendicitis in children.

Acute Disease↗
PubMed1992

Hemodynamic effects of isradipine and nifedipine in chronic sustained hypertension.

As isradipine is known to be less cardiodepressant than nifedipine, myocardial wall stress--an important determinant of cardiac oxygen demand--may also be more favorably influenced by isradipine. Therefore, the acute effects of an intravenous (i.v.) infusion of isradipine (0.4 mg) vs. nifedipine (2.0 mg) on cardiac hemodynamics and systolic wall stress were investigated in a crossover study of 12 hypertensive patients. Vasodilation-induced reflex activation was limited by pretreatment with i.v. propranolol at 0.1 mg/kg of body weight. The hemodynamic parameters measured were statistically comparable at baseline and after propranolol with both calcium antagonists, as was blood pressure reduction. However, the end-systolic volume decreased with isradipine, but not with nifedipine [before: 69 +/- 7.0 ml (mean +/- SEM); after: 61 +/- 6.1 ml; 2p less than 0.01 vs. before: 62 +/- 6.1 ml; after: 64 +/- 7.0 ml; NS, (difference between changes in response to treatments: 2p less than 0.05)]. The ejection fraction increased only with isradipine vs. nifedipine [before: 48 +/- 2.3%; after: 54 +/- 2.3%; 2p less than 0.001 vs. before: 52 +/- 2.0%; after: 52 +/- 2.3%; NS (difference between changes in response to treatments: 2p less than 0.05)]. Systolic wall stress decreased significantly more with isradipine than with nifedipine [before: 2,767 +/- 231; after: 2,153 +/- 162 relative units; 2p less than 0.001 vs. before: 2,636 +/- 212; after: 2,310 +/- 199 relative units; 2p less than 0.05 (difference between changes in response to treatments: 2p less than 0.05)]. These results suggest that isradipine, given acutely, unloads the heart more than does nifedipine.

Aged↗
PubMed1991

Evaluation of (13C)ethanol incorporation into very-low-density lipoprotein triglycerides using gas chromatography/isotope ratio mass spectrometry coupling.

Gas chromatography/isotope ratio mass spectrometry (GC/IRMS) coupling was used to evaluate (13C)ethanol incorporation into plasmatic very-low-density lipoprotein (VLDL) triglycerides of three healthy human volunteers. After the perfusion of 13C-enriched alcohol, VLDL triglyceride fractions were extracted from plasma samples and prepared for the analysis of (13C)fatty acid methyl esters. The GC/IRMS coupling line, the analytical procedure and the data collection are described. The results show that ethanol itself may be used as a substrate for lipogenesis, though to a small extent: less than 10% of VLDL triglycerides may be derived from this metabolic pathway. Ethanol incorporates predominantly into myristic and palmitic acid. The small amount of sample material required for analysis, which minimizes the amount of isotope-labelled substrate required, makes this technique a valuable tool for metabolic investigations in human subjects.

Carbon Isotopes↗
PubMed1991

[Significance of hyponatremia in patients with oropharyngeal tumors].

We observed 29 patients with hyponatremia associated with oropharyngeal carcinoma. In 19/29 the hyponatremia was attributable to a decreased effective arterial blood volume whereas in the remainder (10/29) the presence of SIADH could be demonstrated. These etiologies of hyponatremia were best differentiated by the plasma urea concentration (less than 30 mg/dl in SIADH), urate concentration (less than 4,0 mg/dl in SIADH) and creatinine concentration (less than 0,9 mg/dl in SIADH). Furthermore, SIADH patients had a spontaneous natriuresis. The mainstay of therapy in either form of hyponatremia is fluid restriction (less than 1 l/d).

Carcinoma, Squamous Cell↗