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Biomedical subjects

C Boesch

Publications and source records attributed to C Boesch.

At least 109 records · Page 6Linked to original sources
PubMed1990

Brainstem lesion revealed by MRI in a case of Leigh's disease with respiratory failure.

This 6-year-old girl was admitted with insufficient involuntary breathing and generalized hypotonia. T2-weighted MR images showed bilateral symmetrical tubular hyperintense lesions in the medio-caudal part of the medulla oblongata that correlated well with demyelination and gliosis in the regions of the reticular formation and the nucleus solitarius found at autopsy. The typical lesions of Leigh's disease in the basal ganglia were not present, which made the diagnosis uncertain prior to the histopathological findings. MRI was very helpful in deciding on further management of the patient.

Brain Diseases, Metabolic↗
PubMed1990

Development of the human cerebellum observed with high-field-strength MR imaging.

A retrospective study of 160 pediatric subjects, aged 32-410 weeks after conception, was conducted to determine the normal developmental patterns of the human cerebellum by means of magnetic resonance (MR) imaging. On the basis of axial T2-weighted spin-echo images (repetition time, 3,000 msec; echo time, 120 msec), which provided the best contrast between gray matter and white matter, five distinct developmental stages were defined. At term, the medial lemnisci as well as the parasagittal cerebellum were myelinated. The appearance of myelin in the middle cerebellar peduncles and the basilar pons preceded that in the corpus medullare of the cerebellum. The normal age ranges for the different stages were defined with statistical analysis. These ranges are applicable to the daily routine of image interpretation. The sequence of myelination in the cerebellum observed at MR imaging correlates with the known patterns observed in pathologic studies but lags behind by an average of 6 months.

Cerebellum↗
PubMed1990

Tool use and tool making in wild chimpanzees.

Reported incidences of tool use and tool making for three wild chimpanzee populations increase from Mahale (12 and 3 types of use and making, respectively), Gombe (16 and 3) to Taï (19 and 6). Sticks are commonly used and prepared at all three sites. However, Taï chimpanzees seem to perform more modifications on the material before using it. They are also the only chimpanzees seen to pound objects with tools and to combine two different tool uses to get access to one food item. Tool making is the rule for abundant material (grass, twigs), but appears to be rarer for scarce, hard material (clubs, stones). Factors involved in the acquisition and the benefit of tool use are discussed along with factors affecting the frequency and complexity of tool making in chimpanzees.

Animals↗
PubMed1990

[Frequency of painless myocardial ischemia during hemodialysis in 50 patients with chronic kidney failure].

The authors carried out a prospective study to determine the frequency of silent ischemia (SI) in 50 consecutive patients with end stage renal failure during dialysis by Holter monitoring. Twenty patients had SI (40%). This event was related to the number of cardiovascular risk factors (p = 0.0025), principally diabetes, smoking and the underlying renal disease (p = 0.018), and to a history of coronary artery disease (p = 0.0015). Two patients died during the nine months follow-up period and both had SI on Holter monitoring. Dialysis therapy in anaemic patients may predispose to and facilitate the detection of myocardial ischemia by the simultaneous interplay of hypotension, hypovolemia, hypoxia and tachycardia. The detection of these ischemic events may allow identification of a subgroup of dialysis patients with a high cardiovascular risk. The prognosis of these patients and best therapeutic approach require further study.

Adult↗
PubMed1990

In vivo NMR spectroscopy: investigation of brain metabolism in neonates and infants.

Magnetic resonance imaging (MRI) is a noninvasive investigation technique that uses non ionizing radio waves of low quantum energy, rendering it suitable for application in children. Monitoring and anesthesia techniques allow MRL including immobilisation in a special incubator to be carried out in small infants. In vivo magnetic resonance spectroscopy (MRS) provides biochemical information on living organisms in a non-invasive manner. Such a technique has recently been used to study neonatal brain energy metabolism. High energy phosphate metabolism and phospholipid metabolism can be evaluated in this manner and available clinical correlations can be made regarding eg seizures or long term neurologic sequelae associated with a decreased phosphocreatine: orthophosphate ratio. Future trends in neonatal MRS will provide further information on morphologic and metabolic brain development.

Aging↗
PubMed1989

Prehospital use of APSAC: results of a placebo-controlled study.

Thrombolytic treatment efficacy is greater when the delay between onset of pain and treatment is short. To give treatment before admission to a coronary care unit, responsibility needs to be transferred from cardiologists to other physicians working in mobile care units. We conducted a 2-part feasibility study to investigate this strategy. Part 1 evaluated the diagnostic accuracy of mobile care unit physicians. Results from this study indicate that with regard to the diagnosis of acute myocardial infarction, the risk of a wrong diagnosis is low. Part 2 was a placebo-controlled trial involving 100 patients in which 57 received anisoylated plasminogen streptokinase activator complex (APSAC) (30 U) at home and 43 received placebo at home. Patients receiving placebo at home were reevaluated on arrival in a coronary care unit and received APSAC (30 U) if indicated. The main results were that (1) diagnostic accuracy was good--all patients had an acute coronary syndrome and 97 of 100 patients had myocardial infarction; (2) time gain was approximately 60 minutes; (3) coronary patency rate was 72%; (4) ejection fraction was higher in the prehospital group (56.7%) than in the control group (53.4%), but the difference was not significant; (5) there was no rhythmic or bleeding complication related to the prehospital treatment; (6) 5 patients died from cardiogenic shock--2 between home and hospital and 3 in the hospital (3 received thrombolytic treatment at home and 2 received placebo at home and APSAC in the hospital); and (7) prehospital administration of APSAC did not induce a delay in arrival to the coronary care unit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Hunting behavior of wild chimpanzees in the Taï National Park.

Hunting is often considered one of the major behaviors that shaped early hominids' evolution, along with the shift toward a drier and more open habitat. We suggest that a precise comparison of the hunting behavior of a species closely related to man might help us understand which aspects of hunting could be affected by environmental conditions. The hunting behavior of wild chimpanzees is discussed, and new observations on a population living in the tropical rain forest of the Taï National Park, Ivory Coast, are presented. Some of the forest chimpanzees' hunting performances are similar to those of savanna-woodlands populations; others are different. Forest chimpanzees have a more specialized prey image, intentionally search for more adult prey, and hunt in larger groups and with a more elaborate cooperative level than savanna-woodlands chimpanzees. In addition, forest chimpanzees tend to share meat more actively and more frequently. These findings are related to some theories on aspects of hunting behavior in early hominids and discussed in order to understand some factors influencing the hunting behavior of wild chimpanzees. Finally, the hunting behavior of primates is compared with that of social carnivores.

Animals↗
PubMed1989

Magnetic resonance imaging of the brain in congenital cytomegalovirus infection.

Ten children (age 2 months to 8 years) with a congenital cytomegalovirus (CMV) infection were studied by magnetic resonance imaging (MRI) using a 2.35 Tesla magnet. CMV infection was confirmed by serological investigations and virus culture in the neonatal period. Nine children had severe mental retardation and cerebral palsy, 1 patient suffered from microcephaly, ataxia and deafness. The cranial MRI examination showed the following abnormalities (N): dilated lateral ventricles (10) and subarachnoid space (8), oligo/pachygyria (8), delayed/pathological myelination (7), paraventricular cysts (6), intracerebral calcification (1). This lack of sensitivity for calcification is explainable by the basic principles of MRI. The paraventricular cystic lesions were adjacent to the occipital horns of the lateral ventricles and separated only by a thin membrane. This finding might represent a "new sign" for congenital CMV infection in MRI examinations, being characteristic but nevertheless nonspecific, like calcification in CT.

Brain↗
PubMed1989

Larynx: MR imaging at 2.35 T.

To study the consequences of an improvement in spatial resolution, the authors compared magnetic resonance (MR) images of nine laryngeal specimens with whole-organ histologic slides of the same specimens. Five of the specimens were obtained during laryngectomies performed on patients with high-stage tumors of the larynx. Four specimens were from patients with no known disease. The MR images were obtained on a 2.35-T system with a closely fitting probe head. A conventional spin-echo sequence was used, with T1- and T2-weighted settings. The in-plane resolution obtained was about 0.3 mm. The T2-weighted images generally showed better contrast and allowed identification of the perichondrium. The resolutions used were not much greater than those clinically available. The findings suggest that there will be important advances in clinical MR imaging of the larynx in the near future.

Aged↗
PubMed1989

Variations in the in vivo P-31 MR spectra of the developing human brain during postnatal life. Work in progress.

With use of a modified surface coil technique, the authors recorded phosphorus-31 magnetic resonance (MR) spectra of the brains of 40 neonates and infants (48 examinations) ranging from 33 weeks postconceptional age to 6 years of age. Signals of phosphorus metabolites were collected in the frontotemporal region of the brain, and various P-31 MR spectral variables were compared at different times during postnatal life. The ratio of the phosphomonoester signal to the phosphodiester signal, which is related to phospholipid synthesis, decreases within the first 6 months of life; during the same time period, the ratio of the phosphocreatine (PCr) signal to the beta-adenosine triphosphate (ATP) signal increases. In addition, a difference was observed between the areas under the alpha- and beta-ATP peaks. This difference increases with age and correlates with the PCr/beta-ATP signal ratio. The variation of the alpha-ATP peak with age might be explained by overlap of the signals of nicotinamide adenine dinucleotide (NAD) and alpha-ATP.

Adenosine Triphosphate↗
PubMed1989

[Prehospital thrombolysis. Evaluation of preliminary experiences at Val-de-Marne].

Benefits of thrombolysis have been shown to be greater when therapy is administered early, and this led us to consider the value of starting thrombolytic treatment in the patient's home. However, this implies the transfer of responsibility of patient management from the cardiologist to the physician in charge of the mobile emergency care team. A study was undertaken in the Val-de-Marne department to assess the benefits and risks of this therapeutic approach. The first phase was designed to evaluate the reliability of the emergency care team's diagnosis and the second phase of the study was a randomised double blind prehospital therapeutic trial of a thrombolytic agent, acylated streptokinase (intravenous bolus of 30 units in 4 minutes) against placebo. The nature of prehospital treatment was revealed on hospital admission and thrombolytic therapy was immediately given to those patients allocated to placebo at home providing the admitting cardiologist confirmed the indication. A total of 100 patients were included; 57 were allocated to thrombolytic therapy and 43 to placebo in the prehospital phase. The diagnosis of acute coronary insufficiency was confirmed in all cases and 97 p. 100 of patients had signs of acute myocardial infarction. No complications were attributable to prehospital administration of the thrombolytic. The average time gain in instituting treatment was 60 minutes. At control coronary angiography, 72 p. 100 of the coronary arteries thought to the responsible for the infarct were shown to be patent. The global left ventricular ejection fraction of patients treated with thrombolysis at home was 56.7 p. 100 compared with 53.4 p. 100 in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulances↗
PubMed1989

[6 months' results of coronary angioplasty after thrombolysis of myocardial infarction].

Transluminal coronary angioplasty (TCA) has become the treatment of choice of residual stenosis after thrombolysis for myocardial infarction, but the long-term results of TCA are imperfectly evaluated. Seventy patients underwent TCA after thrombolysis on account of a significant (greater than 50 p. 100) residual stenosis of the artery responsible for the infarction. TCA was performed less than 6 hours after the onset of symptoms in 15 patients who had neither clinical nor electrocardiographic evidence of reperfusion; 4 of these patients were in a state of cardiogenic shock. In the remaining patients TCA was performed 1 to 10 days (mean 3.2 days) after thrombolysis. A primary success was obtained in 64 patients (91 p. 100). Two patients had emergency aorto-coronary bypass. During their stay in hospital, 5 patients presented with symptoms of reocclusion which in 4 of them occurred less than 24 hours after TAC, and 2 of these 4 patients had to be reoperated upon; 2 patients died suddenly. During a 6 to 18 months' follow-up period (mean 10.5 months), the infarction recurred in 3 patients; the recurrence took place during the 3rd month in 2 of them (1 had another thrombolysis and later TAC) and during the 6th month in the third one. At 6 months, 4 patients were suffering from exertion angina and 2 asymptomatic patients had a positive exercise test. Fifty-two control coronary arteriographies were performed at 6 months. Thirteen patients (25 p. 100) had an occluded artery which was clinically silent in 11; 39 patients had a patent artery with restenosis in 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Home thrombolysis for myocardial infarction. A multicenter study of the feasibility and evaluation of short-term prognosis].

It has been proven since 1986 that in myocardial infarction the sooner thrombolysis is performed the better. Forty-four patients were selected to enter a double-blind randomized trial in which they received either an acylated plasminogen streptokinase activator complex or a placebo. The injections were given intravenously at home within the first 3 hours (within the first 2 hours in 26 of them), by doctors from Mobile care units. This home treatment in the acute phase made it possible to gain 75 minutes on average, and up to 90 minutes when it was performed by an anaesthetist trained in emergency management. No serious complication, such as haemorrhagic or allergic reaction, occurred, and arrhythmia was no more frequent in the treated group than in the placebo group. Home thrombolysis did not delay admission to a cardiology Intensive Care unit (66 min. versus 64 min). Mean coronary patency was 75 per cent, and up to 82 per cent, in patients treated within 2 hours of the first symptoms. There was no significant difference between areas of reperfused or not reperfused patients in relation to time (P less than 0.08). Diagnosis sensitivity was 100 per cent. Thus, home thrombolysis is feasible and safe when performed by trained emergency medical teams and when criteria for inclusion and exclusion are fulfilled.

Double-Blind Method↗
PubMed1988

Combined application of MR imaging and spectroscopy in neonates and children: installation and operation of a 2.35-T system in a clinical setting.

Published pediatric magnetic resonance (MR) imaging results are usually obtained with medium-field-strength whole-body systems, while MR spectroscopy is done on a different high-field-strength/small-bore laboratory system. The authors investigated metabolism and structural development of the brain in over 100 neonates and children with combined MR imaging and spectroscopy at 2.35 T. With a 40-cm-bore magnet, MR imaging and spectroscopy data are obtained in the same session with use of the same system. The approach demands modified technical devices and elaborate patient handling. Concepts for sedation in different age groups and for patient monitoring, as well as protocols for the combined use of imaging and spectroscopy, have been worked out. The data prove high quality of imaging and spectroscopy at 2.35 T.

Brain↗
PubMed1988

[Magnetic resonance in pediatric research and clinical practice. I. What can we expect from this new method?].

Nuclear Magnetic Resonance (NMR) was first observed over 40 years ago and has recently also entered the field of human medicine. It currently attracts increasing attention from biologists and clinicians alike, and the scope of its different applications is in a phase of explosive development. Two principle developments of the MR method are taking place over the recent years and are of special interest for pediatricians and neonatologists. One involves the possibility of obtaining images from any part of the human body, somewhat similar to those obtained with computer tomography (CT), but without any radiation hazard. Today clinicians are most familiar with this mode of MR application. The other development tries to adapt the MR method of elucidating the structure of molecules used in physics, molecular biology and organic chemistry for applications in medicine, allowing to study metabolism in vivo under non-invasive conditions. Again, such studies pose no health hazards and are, therefore, applicable to neonates and small infants. They will enhance our understanding of metabolic processes during normal development and disease, especially in organs like the brain, where biopsies are virtually impossible. Recent developments combine the two methods mentioned above, in order to obtain morphological as well as metabolic information from the same organ at the same time, which may provide even better insight into pathophysiological mechanisms and their response to therapeutic measures. This article attempts to give an overview to the medical researcher, the clinician, and especially the pediatrician and neonatologist of what MR is and what we can expect from it.

Brain↗
PubMed1988

[Magnetic resonance in pediatric research and clinical practice. II. Studies on the development and pathology of the brain in neonates, infants and young children].

We are investigating metabolism and morphological differentiation of the developing brain in neonates and children under non-invasive conditions combining MR imaging (MRI) with spectroscopy (MRS) on a high-field/small-bore (2.35 Tesla/40 cm) system. By the end of 1987, 116 neonates, infants and young children with various perinatal problems, congenital abnormalities and different neurological diseases have been examined with MRI. In addition, MRS studies were subsequently performed on 46 of these children using the same instrument and within the same session. The small, sometimes very sick and instable patients require careful monitoring and elaborate technical devices in the high magnetic field. We are presenting solutions for methodological and technical developments and adaptations, concepts for sedation and measurement protocols in various age groups and first results of the combined use of MRI and MRS to investigate the brain in neonates and infants.

Brain↗
PubMed1987

[Repeated valvular replacements. Apropos of 64 cases].

In a series of 833 operations with implantation of 1011 prosthetic valves there were 64 reoperations on 44 patients, an incidence of 7.6%. In almost 50% of the cases, reoperation was motivated by desinsertion. The incidence of desinsertions increased with the number of reoperations. In 40% of the cases, desinsertion was caused by endocarditis. The degeneration of bioprosthetic valves was rapid in children. Thromboembolic accidents occurred in patients with mitral valve mechanical prosthesis. Peri-operative mortality due to left ventricular dysfunction was 9%. Mortality rate was high after reoperation for endocarditis on a desinserted prosthetic valve. Surveillance and prevention of bacterial endocarditis remain of paramount importance.

Adolescent↗