PubMed Health⌕ Search

Biomedical subjects

J Robin

Publications and source records attributed to J Robin.

At least 55 records · Page 3Linked to original sources
PubMed1994

Bipolar intramyocardial electrogram from an implanted telemetric pacemaker for the diagnosis of cardiac allograft rejection.

Noninvasive detection of acute cardiac allograft rejection remains a challenge. Analysis of the epicardial electrogram transmitted by unipolar telemetric pacemaker can be of help in the detection of rejection with myocytolysis but is hampered by extracardiac factors. Instead, the contribution of a bipolar pacemaker for this purpose was studied. The bipolar peak-to-peak amplitude of epicardial electrograms (BPPA) from 25 patients implanted with a bipolar pacemaker at the time of heart transplantation was measured at the time of endomyocardial biopsies. BPPA was expressed as a percent of the baseline value. A voltage drop of more than 10% was considered an indication of rejection. Of 118 biopsies, 80 were free of rejection and 38 showed mild to moderate rejection (Grade 1A = 12; Grade 1B = 17; Grade 2 or 3 = 9). The mean value of BPPA was less for grade 2 biopsies (86.4 +/- 17%) than for biopsies with no or mild rejection (101.3 +/- 14.3% for Grade 0, 101.4 +/- 13.8% for Grade 1A, and 98.6 +/- 18% in Grade 1; P < 0.05). Diagnostic concordance between BPPA measurement and biopsy results increased with the histological severity of rejection (Grade 1A = 1/12, Grade 1B = 5/17, Grade > 2 = 7/9). Acute rejection was diagnosed with a sensitivity of 34% for Grade 1A, 46% for Grade 1B, and 78% for rejection episodes with myocytolysis (Grade > or = 2). Specificity remained approximately 90% for all histologic grades.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

[Hemomediastinum caused by spontaneous rupture of the thoracic aorta].

The authors report the rare case of spontaneous rupture of the aortic isthmus in the absence of preexisting aortic aneurysm or dissection in a hypertensive woman presenting with chest pain and haemomediastinum. The history of trauma 30 years previously, could have been a predisposing factor. The diagnosis of this condition remains difficult and is often missed. The physiopathological, aetiological, clinical and diagnostic features are reviewed. Transoesophageal echocardiography showing an intraparietal haematoma confirmed the aortic origin of the haemomediastinum. Conventional angiography was of no value in the reported case because of the absence of rupture of continuity or of an intimal tear.

Aged↗
PubMed1994

[Mitral valve replacement in infants using the "Saint-Jude Médical" prosthesis].

The authors report their experience of mitral valve replacement in infants under 2 years of age. A St Jude medical mitral prosthesis was implanted in 8 children, 7 with mitral regurgitation and 1 with mitral stenosis. The average age at surgery was 9 months with an average body weight of 6.6 Kg. Two children had prior mitral valvuloplasty. All patients were in the NYHA functional Class IV. One patient died after surgery (12.5%). There was one secondary death during follow-up. Six children were followed up for an average of 61 months (range 34 to 104 months). The 6 survivors are asymptomatic and receive oral anticoagulant therapy. Regular postoperative Doppler echocardiographic assessment has shown a gradual increase of the mean transprosthetic pressure gradient in all children. To date, no reoperation on the prosthetic valve has been necessary. Mitral valve replacement is an effective option in infants with severe cardiac failure in whom mitral valve repair is impossible. In these cases, the St. Jude medical prosthesis is a good choice. Effective anticoagulation is recommended, even at this age. Growth of the child will necessitate changing the prosthesis in later years.

Anticoagulants↗
PubMed1994

Pulsatility improves hemodynamics during fetal bypass. Experimental comparative study of pulsatile versus steady flow.

BACKGROUND: The main advantage of pulsatile flow compared with steady flow during cardiopulmonary bypass is to prevent a rise in systemic vascular resistances. We hypothesized that pulsatile flow could overcome the progressive rise in peripheral and placental vascular resistances observed during fetal bypass and leading to progressive irreversible hypoxemia. METHODS AND RESULTS: A study was undertaken in 17 fetal lambs (110 to 140 days of gestation). Fetal bypass was established for a 30-minute period through right atrial and main pulmonary artery cannulation. The circuit had no oxygenator. Flow was delivered by a standard roller pump for the continuous study (group 1, n = 9) or by a centrifugal pulsatile pump for the pulsatile study (group 2, n = 8). Oxymetric and hemodynamic parameters, along with organ blood flow determined by radiolabeled microspheres counting, were recorded before (T1) and after 10 minutes (T2) and 30 minutes (T3) of bypass. SaO2 and PaO2 were significantly higher in group 2 than in group 1 at T2 but thereafter deteriorated similarly in both groups, whereas PCO2 remained unchanged. Pump flow in group 2 was significantly higher than in group 1 at T2 and T3 (957.6 +/- 49 and 1104 +/- 152 versus 437.6 +/- 23 and 467.8 +/- 43 mL/min, respectively). Systemic vascular resistances during pulsatile bypass were also significantly lower than in group 1 at T2 (402 +/- 12 versus 930 +/- 79 dynes/sec/cm-5) and T3 (374 +/- 60 versus 1017 +/- 192 dynes/sec/cm-5). At T2 and T3, all individual blood flows except the brain but including the placenta were statistically higher in group 2 than in group 1. Placental vascular resistances gradually increased during bypass in group 1 to reach 2.9 +/- 0.2 mm Hg.mL-1.min-1.kg-1 at T3 and remained approximately stable in group 2 during 30 minutes of pulsatile bypass, varying from 0.35 +/- 0.02 to 1.26 +/- 0.14 from T2 to T3 (P < .01). CONCLUSIONS: The data suggest that pulsatile flow for 30 minutes of bypass in a fetal lamb preparation temporarily prevents the progressive hypoxemia observed under steady-flow bypass. Pulsatile flow allows higher pump flow through a significant decrease in systemic vascular resistances. Individual organ blood flow, including placenta, was significantly higher under pulsatile bypass. With technical improvements in the design of pulsatile devices adapted to more physiological beat rates, pulsatility may become a valuable adjunct to overcome placental dysfunction observed during experimental fetal cardiac surgery.

Animals↗
PubMed1992

[Use of the internal mammary artery as a free graft with reimplantation of the proximal end onto the ascending aorta. Apropos of 39 cases].

From January 1987 to January 1991, 104 patients received bilateral internal mammary artery grafts and 39 of them had coronary bypass with a free graft implanted on the ascending aorta. There were 35 men, with a mean age of 57.35 years (range 41 to 70 years). 87% of them had stable angina, and 23 had preoperative myocardial infarction. The left ventricular function was good in 77 per cent of cases. 23 patients had three vessel disease (61.5%), 13 two vessel diseases (30.7%), 2 one vessel disease (5.12%) and one a left main coronary stenosis. Left internal mammary artery was used in two patients on the left descending artery and the right internal mammary artery was used in 37 patients: 15 on the circumflex, 15 on the right coronary, 4 on the LDA and 3 on the diagonal artery. Five patients had one graft, 32 two grafts and one three grafts (bilateral mammary and saphenous vein). Hospital mortality was 2.56% (1 patient) and there were 2 late deaths (5.12%). There were 5 perioperative myocardial infractions (12.8%) and no sternal infections. The mean follow up is 21 months (range 3 to 46 months). At follow-up, 34 patients (87.2%) were asymptomatic, and there were no myocardial infarctions. Postoperative angiography in 8 patients (mean postoperative time 2.5 months) showed that all the grafts were patent. This analysis demonstrates that free IMA graft has a low operative risk and provides excellent long term functional improvement and survival.

Adult↗
PubMed1992

[Interposition of a prosthetic graft between the ascending aorta and the abdominal aorta in the treatment of complicated or longstanding coarctations in adults].

Although the direct approach to the aortic isthmus is unquestionable for an isolated coarctation of the thoracic aorta, recurrent coarctations of coarctation with associated cardiac lesions require a concomitant procedure, raise difficult surgical problems and expose to a high operative risk. Another technique consists of performing an ascending aorta-abdominal aorta by-pass, with a prosthetic tube. From 1977 to 1988, this technique was performed in 8 patients: 3 with recurrent coarctations, 4 with coarctation associated with a surgical aortic insufficiency (2 ascending aortic aneurysms with aortic insufficiency) and 1 with abdominal aorta coarctation. The mean age was 48.3 years (range from 31 to 72 years), the mean follow-up was 44.3 months (range from 4 months to 10 years 5 months). There was no mortality and no morbidity during the follow-up. The functional result is good, without high blood pressure and with no blood pressure difference between the arms and the legs. Postoperative angiographies showed that all the by-passed were patent.

Adult↗
PubMed1991

(Benzoylphenyl)piperidines: a new class of immunomodulators.

A series of (benzoylphenyl)piperidines has been synthesized and evaluated for activity as immunomodulators. Several of these compounds show good activity in primary screening on the basis of the lymphocytes mitogenic response to Con A, PHA, and PWM. A chloro group in position 4 of the benzoyl moiety as well as an amino group (or a carbamate derivative) para to the piperidine nucleus seems to be essential for activity. The depicted compounds may be considered as the first examples of a new series of immunomodulators.

Adjuvants, Immunologic↗
PubMed1991

[Retrospective study of 412 aortic valve replacements by Bjork-Shiley prosthesis implanted between January 1972 and October 1984. Actuarial survival, mortality, complications].

Between January 1972 and October 1984, 412 aortic valve replacements by Bjork-Shiley disk prosthesis were performed. 183 patients suffered from aortic incompetence, 132 from an aortic disease and 97 from aortic stenosis. 116 associated procedures (28%) were performed = 36 myocardial revascularizations, 61 Bentall operations, 12 patch grafts to the ascending aorta and 7 Wheat operations. The mean age was 53.6 years and 25% of the patients were over the age of 65 years. Fifty percent of the patients had stage III or IV disease according to the NYHA classification. The cardiac index was less than 2.3 l/min/m2 in 44.26% of cases. The early postoperative mortality was 4.85% and 20% of these deaths were related to the prosthesis. The late mortality was 17.25%, with 20% of deaths related to the valve. The mean follow-up 59.75 +/- 2 months (range: 1 to 166 months) with a cumulative survival of 2.092 patients-years. It was significantly influence by the existence of preoperative angina, another operation associated with AVR and a cardiac index less than 2.3 l/min/m2. Seventy-one complications were related to the prosthesis including dysfunction (0.05% patient-year), 3 valve thromboses (0.15% patient-year), 6 infected valves (0.31% patient-year), 12 cases of peri-prosthetic dehiscence (0.61% patient-year), 10 embolic complications (0.61% patient-year) and 37 complications related to anticoagulants, including 26 major complications (1.48% patient-year). The valve failure rate was 1.19% patient-year. The results of our series are comparable to those reported in the literature, which confirm the reliability of the Bjork-Shiley Valve.

Actuarial Analysis↗
PubMed1991

Proteoglycan molecules in keratoconus corneas.

Proteoglycan molecules in keratoconus corneas were studied by immunohistochemical and electron microscopic histochemical methods. Compared with normal human control subjects, the staining intensity with monoclonal antibody 9-A-2 was enhanced in the stroma of scarred keratoconus corneas, whereas the intensity with antibody J-19 was reduced. The 9-A-2 experiment showed an increased immunoreactivity of dermatan sulfate proteoglycan epitopes, and the J-19 experiment indicated a decreased immunoreactivity of sulfated keratan sulfate epitopes. Uronic acid analyses were consistent with the 9-A-2 data. Electron microscopy performed after cuprolinic blue staining showed apparent accumulation of abnormally thick, chondroitinase ABC-sensitive, dermatan sulfate proteoglycan filaments in keratoconus corneas. Such filaments were especially prominent in scarred areas. In addition, Keratan sulfate proteoglycan filaments appeared to be less abundant than those found in normal control corneas. Similar alterations of both types of proteoglycan molecules were also seen and reported in scarred corneas. The similarity suggests that the proteoglycan abnormalities found in keratoconus corneas may be secondary, at least in part, to scarring.

Adolescent↗
PubMed1990

Should we inhibit gastric acid secretion before cardiac surgery?

Stress can decrease intragastric pH and cause erosion of gastric mucosa. Because cardiac surgery and cardiopulmonary bypass represent a major stress, the effects on intragastric pH of an H2-receptor antagonist, ranitidine, and an M1-muscarinic antagonist, pirenzepine, were evaluated. Intragastric pH was measured throughout elective cardiac surgery in 60 patients by a digital pH-meter during fentanyl-diazepam-nitrous oxide (50%) anesthesia. The gastric content was sampled at closure of the chest for bacterial count. Oral preoperative medication given randomly included (n = 20 in each group) 0.3 mg/kg diazepam 1 h before induction (group 1); diazepam plus ranitidine (150 mg) 1 h before induction (group 2); and diazepam plus pirenzepine (50 mg) on the evening before surgery and 1 h before induction of anesthesia (group 3). At induction intragastric pH was higher in group 2 (mean +/- SD = 7.42 +/- 1.07) than in group 1 (5.28 +/- 2.14) (P less than 0.01) but was not significantly different in group 3 (5.78 +/- 1.89) than in group 1. In no group did intragastric pH change significantly during surgery. Gastric juice was sterile in 92% of group 1, in 25% of group 2, and in 71% of group 3 patients (P less than 0.01). Postoperatively no gastrointestinal complications occurred, but there was a trend toward more patients developing nosocomial pneumonias in groups 2 and 3 (15%) than in group 1 (0%) (P = 0.06). Intraoperative intragastric pH is relatively high after diazepam premedication, thus the preoperative addition of ranitidine or pirenzepine would not be necessary and may possibly be hazardous.

Adult↗
PubMed1990

[Replacement of the aortic arch for acute dissection. A new approach in the surgical technique].

In 15 to 20 per cent of Type A dissections of the aorta the initial tear is situated in the aortic arch. Between January 1st 1988 and May 1st 1989, our group has performed 5 prosthetic replacements of the aortic arch for this type of lesion. The indication of prosthetic replacement of the aortic arch was taken on different criteria: regressive neurological deficits (2 cases); radiological signs of dissection of the supraaortic vessels (2 cases), and at surgery in 1 case in which the intimal tear extended beyond the origin of the brachiocephalic artery. The originality of the technique is due to the use of a prefabricated prosthesis with three branches for termino-terminal anastomosis in normal tissues of the supraaortic arteries. The insertion of the prosthesis was performed during cardiac standstill (average 35 minutes) at 17 degrees C, and was accompanied in 3 out of 5 cases by replacement of segments 0 and I of the aorta using Cabrol's technique. The mortality in the first 30 days was nil. There was one definitive neurological complication leading to the death of one patient at 4 months and one totally regressive paraplegia at the 2nd month with the patient recovering independent walking function. There is no morbidity in the survivors with an average follow-up period of seven months.

Acute Disease↗
PubMed1989

Immunohistochemical studies of Peters' anomaly.

Peters' anomaly is a congenital abnormality that affects mainly the posterior cornea. The pathogenesis is unclear. By immunohistochemical methods, the authors determined the presence of extracellular matrix proteins, including fibronectin, laminin, and collagen types I, III, IV, V, and VI, in seven corneal buttons from five patients with Peters' anomaly. Type III collagen was the only protein absent in either the pathologic or normal human corneas. Compared with normal controls, the stromal lamellae in Peters' anomaly corneas were more irregular and more closely packed. In addition, the fibronectin staining was markedly enhanced in all seven Peters' anomaly corneas. Staining with collagen type VI was also mildly increased. These results suggest that extracellular matrix elements such as fibronectin may be important factors in this developmental disorder.

Aged↗
PubMed1988

Polypoid neurilemmoma of the trachea: an unusual cause of major airway obstruction.

Neurilemmomas (schwannomas) of the trachea are extremely rare. A case of near-total obstruction of the trachea by an intraluminal polypoid neurilemmomas is reported. Computerized tomographic imaging gave the exact localization of the polyp and the attachment of its stalk. Endoscopic excision has left the patient with an excellent prognosis and little chance of recurrence.

Adult↗
PubMed1987

Dermatitis due to orthopaedic implants. A review of the literature and report of three cases.

The cases of three patients who had dermatosis that was caused by an orthopaedic implant are reported. The main clinical pattern was localized or generalized eczema or urticaria. The diagnostic criteria that have been proposed by various authors are reviewed. Removal of the implant did not always result in rapid disappearance of the dermatosis, presumably because a few particles of metal remained in the area of the implant.

Adult↗