PubMed Health⌕ Search

Biomedical subjects

C Marquis

Publications and source records attributed to C Marquis.

17 recordsLinked to original sources
PubMed1999

Finger dominance.

Two hundred and ninety-eight normal participants were reviewed to assess finger dominance. Participants were recruited from several large hospitals across the north-west of England and the study was done under blind conditions. From the 298 people originally in the trial, six had to be excluded as the dominant finger could not be confirmed with certainty. The index finger was the most dominant in 82.5% of the test group. However, in 10.6% of the test group, the middle finger was found to be the most dominant.

Fingers↗
PubMed1993

Dynamic structure of Agrobacterium tumefaciens Ti plasmids.

Agrobacterium tumefaciens C58F is a variant of strain C58 which generates a high proportion of avirulent mutants in the presence of the virulence (vir) gene inducer acetosyringone. These mutants are altered in the Ti plasmid and do not respond to the acetosyringone signal (C. Fortin, E. W. Nester, and P. Dion, J. Bacteriol. 174:5676-5685, 1992). The physical organization of the Ti plasmid was compared in strain C58 and its variant. One feature distinguishing pTiC58F from its parent plasmid was the presence of the insertion element IS426. Three copies of this element were detected in the strain C58 chromosome, whereas two additional copies were found in strain C58F, including one copy in the Ti plasmid. This particular copy of IS426 was associated with the region of arginine and nopaline catabolism of pTiC58F. Most of the avirulent mutants recovered following growth of strain C58F in the presence of acetosyringone were complemented by clones carrying either virA or virG. Element IS426 was no longer found in the arginine and nopaline catabolism region of the Ti plasmids from the virA and virG mutants, but it resided in the particular KpnI fragment containing the modified vir locus. Behavior of a strain C58F derivative, which was inactivated in a chromosomal component required for the response to acetosyringone, was consistent with the possibility that vir gene induction is essential to the massive production of avirulent mutants.

Acetophenones↗
PubMed1985

[Quantitative measurement of blood flow with an 128-channel Doppler device. Present status of research and future outlook].

The recent development of a new multigate pulsed Doppler system used in conjunction with an A-mode scan allows real time display of the velocity profiles across the vessel and quantitative flow measurement. Experimental in-vitro and in-vivo studies showed an excellent correlation between flow measurements obtained by this noninvasive method and by direct timed collection. Preliminary results of the post-occlusive hyperaemic response in normals and in patients with iliac stenosis are presented. Although no statistical comparison is allowed, it appears that the hyperaemic response is diminished when an iliac stenosis is present. A non-invasive method of quantifying the haemodynamic significance of profunda femoris artery stenosis is described. Finally, the velocity profiles and the flow curves in PTFE grafts were studied and compared to the flow patterns of the normal superficial femoral artery. The differences observed between the two conditions might explain the low patency rate of the synthetic grafts. Other fields of application of the method are suggested. The future development of a Duplex scanner combining B-mode imaging and the multigate Doppler system will allow the exploration of vessels within the abdomen and thorax: portal vein, in situ or transplanted renal arteries, ascending and abdominal aorta.

Adult↗
PubMed1984

Pulsed Doppler assessment of deep femoral artery hemodynamics: a preliminary report.

The functional capability of the deep femoral artery (DFA) as a collateral channel is an important feature in patients suffering peripheral arterial occlusive disease (PAOD). A noninvasive method of indirect quantification of the DFA blood flow volume is presented. In normal lower limbs, it was found that the common femoral artery (CFA) mean blood flow volume was maintained at 59% of its resting value when the superficial femoral artery (SFA) was occluded by a pneumatic cuff placed around the thigh. The reduction of the mean flow volume is mainly due to an increase of the diastolic backward flow, while the maximum systolic flow remains constant. In a few patients with various degrees of stenosis of the DFA, we observed a much greater drop in mean CFA blood flow volume than in normal subjects. On the basis of this preliminary study, we conclude that: --When the normal SFA is occluded, pulsatile flow through the CFA is maintained. --Occlusion flow reflects the runoff and the compliance of the DFA bed. --Occlusion flow is diminished in patients with DFA stenosis. It is suggested that this non-invasive test might help the physician to assess the involvement of the DFA in PAOD. Further investigation is needed to establish the correlation between quantitative occlusion blood flow volume and the degree of DFA stenosis.

Adult↗
PubMed1983

[Modification of arterial blood flow using venous occlusion plethysmography].

Arterial blood flow volume was registered simultaneously by pulsed Doppler and venous occlusion plethysmography in 14 limbs of healthy subjects aged 25 to 36 years. The results were as follows: from the beginning of venous occlusion and during venous filling phase, arterial flow diminishes to 73% of its initial value. This diminution is due to a progressive decrease in arterial systolic flow as well as an increase in diastolic arterial reflux. The results reflect the increase in peripheral resistance as well as the elasticity of the arteries, which, during the diastole, return upstream a part of the arterial systolic flow.

Adult↗
PubMed1983

Long-term follow-up after a distal splenorenal shunt procedure. A clinical and hemodynamic study.

Of 26 patients who underwent distal splenorenal shunting 4 or more years ago (1969 to 1978), 10 died 3 to 87 months postoperatively (mean 38.5 months). Six deaths were due to liver failure, two to hemorrhagic peptic ulcer disease (the shunt remained patent in each patient), one to brain hemorrhage, and one to sepsis. Eight of the surviving patients resumed professional activity, one showed transient signs of encephalopathy, one had a single episode of recurrent variceal bleeding that could be managed conservatively, and no patient had ascites. Eight patients were investigated angiographically and endoscopically. Preoperative and postoperative measurements of the portal vein showed a decreased diameter in five patients and no opacification in the other three 29 to 97 months after surgery. At endoscopy four patients had small residual esophageal varices, one patient had none, and the other three had large varicosities with variceal pressures between 30 and 40 cm H2O in two and above 40 cm H2O in one. Although the incidence of postoperative encephalopathy and variceal bleeding was low after distal splenorenal shunting, the operation did not prevent a decrease in hepatopetal portal flow and did not always abolish the esophageal varices.

Adult↗
PubMed1983

Comparison between segmental and selective blood flow volume of the lower limbs: a plethysmographic and ultrasonic study of normal subjects at rest.

In order to find the correlations existing between segmental and selective arterial blood flow volume, 20 healthy subjects have been submitted to calf venous occlusion plethysmography and Multichannel Digital Pulsed Doppler examination of the common femoral and popliteal arteries at rest. We found a linear correlation only between mean popliteal artery blood flow volume and plethysmographic calf blood flow volume (r = 0,41; p less than 0,01). We therefore suggest that venous occlusion plethysmography should not be used for the assessment of aorto-iliac and common femoral hemodynamics after direct arterial reconstructive surgery. Its use should be complementary to pulsed Doppler blood flow volume determination at the femoro-popliteal level, along with the usual pressure measurement.

Adult↗
PubMed1982

Strain gauge plethysmographic studies after clipping of the inferior vena cava.

Assessment of the hemodynamic effects of the IVC clipping by strain gauge plethysmography provides accurate quantitative data. These correlate very well with the other means of investigation used in the study. Eight patients were controlled in the Vascular Laboratory 9 to 43 months after clipping of the inferior vena cava. They submitted to clinical evaluation, Doppler ultrasound, isotopic venography, abdominal sonography, and strain gauge plethysmography of the lower extremities. This last method provided quantitative data; maximal venous outflow was found to be equivalent in the 8 patients included in the study and in a control group of 20 healthy young volunteers. Strain gauge plethysmography results correlate well with the other means of investigation and demonstrate the efficacy of the dilated venous collateral channels in restoring a normal venous return.

Abdomen↗
PubMedDate not supplied

Quantitative pulsed Doppler measurement of common femoral artery blood flow variables during postocclusive reactive hyperemia.

Quantitative blood flow measurements were performed on 37 normal lower limbs with a 128-channel digital pulsed Doppler (MDPD) system. The evolution of mean flow (QM), peak systolic flow (QS), diastolic flow (QD), and prograde stroke volume (PSV) was observed at rest, during postocclusive reactive hyperemia (PORH), and at 1-, 2-, and 3-min intervals. The QM at rest was 2.9 +/- 1.1 ml/s; PORH induced a four- to fivefold increase in QM and PSV secondary to a slight increase in QS and the disappearance of the reverse protodiastolic component of resting flow. Reverse flow was restored after 1 min. Both QS and QD returned to resting values after 2 min, whereas QM remained significantly higher after 3 min. To provide a better description of the hyperemic response, we also studied the evolution of the pulsatility index as as applied the flow curve (PIQ). Similarly, the systolic amplitude index (SAI) is presented. Our study demonstrates that pulsed Doppler techniques can be used for noninvasive quantitative assessment of blood flow at rest and during PORH. The values obtained on normal subjects provide base-line data for further investigation of pathological conditions.

Adult↗
PubMedDate not supplied

Chronic pancreatic pleural effusions and ascites.

The occurrence of pleural effusion or ascites, secondary to internal pancreatic fistula, is a rare clinical syndrome and diagnosis is, therefore, often missed. The fluid accumulation has been attributed to disruption of the pancreatic duct or to rupture of a pseudocyst. In a 20 year period, 106 patients were hospitalized in the department of surgery, CHUV, with a diagnosis of chronic or chronic relapsing pancreatitis, and 77 with that of pancreatic pseudocyst. During this time, five patients with chronic pancreatic and pleural or peritoneal effusions have been observed. These five cases present a good pattern of the possible causes and evolution of the disease. Wirsungography is of great value for the surgical management of these patients, allowing the right technique to be chosen for each particular case. Surgery caused disappearance of the effusions in our five patients.

Adult↗
PubMedDate not supplied

[Clipping for prophylactic partial occlusion of the inferior vena cava].

The partial occlusion of the inferior vena cava in the prevention of fatal pulmonary embolism has been used for years in different ways. Over a period of one, and a half year, we put 11 clips of Miles, once for prophylaxis and 10 times after pulmonary embolism. Two patients died during the first 15 postoperative days. Seven patients had a phlebologic control by a Doppler ultrasound, venous plethysmography, isotopic cavography, and grey scale ultrasound. It has been proved that the inferior vena cava was permeable in 6 of the 7 controlled patients. The indications as well as the late results of these operations are discussed.

Adolescent↗