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Biomedical subjects

L Brandt

Publications and source records attributed to L Brandt.

At least 145 records · Page 8Linked to original sources
PubMed1990

Heat production rate in blood lymphocytes as a prognostic factor in non-Hodgkin's lymphoma.

The heat production rate in peripheral blood lymphocytes was evaluated by direct calorimetry in 76 untreated adults with non-Hodgkin's lymphoma (NHL). Elevated values were recorded for 20 out of 54 patients with lymphomas of high or intermediate malignancy grade (37%) and for 1 out of 22 patients (5%) with low grade lymphomas (p = 0.01). Median survival was 39 months for patients with normal values and 8.5 months for those with elevated values (p = 0.005). In a subgroup of 38 patients with high or intermediate grade NHL stage III-IV, 17 patients with abnormally high lymphocyte heat production rates had a significantly shorter survival than 21 patients with normal values (p = 0.01). In a multivariate analysis the prognostic impact of lymphocyte heat production was superior to histologic malignancy grade, clinical stage and age.

Adult↗
PubMed1990

Correlation of transcranial Doppler sonography findings with timing of aneurysm surgery.

Thirty-six patients with a proven first subarachnoid hemorrhage (SAH) from a ruptured supratentorial aneurysm were subjected to repeated transcranial Doppler sonography assessments. Eighteen individuals (Group A) were operated on within 48 hours, while the other 18 (Group B) had surgery between 49 and 96 hours after SAH. The patients represented two clinically comparable groups. In the first 72 hours post-SAH, no increased flow velocities suggestive of arterial narrowing or vasospasm were recorded. There was no significant difference in preoperative flow velocities between the groups. Postoperative flow velocities were significantly lower in patients operated on within 48 hours (p less than 0.001). Two patients, who had surgery on Day 4 post-SAH and who showed the highest recorded postoperative flow velocities, died from cerebral vasospasm and infarction. The results favor a referral system which enables early surgical intervention not only to prevent rebleeds but also aimed at reducing delayed ischemic dysfunction.

Adult↗
PubMed1990

Low birthweight, congenital malformations, and spontaneous abortions among dry-cleaning workers in Scandinavia.

With a common study protocol, case-referent studies within cohorts were performed in Denmark, Norway, Sweden, and Finland to study reproductive hazards of women doing dry-cleaning work. Due to national differences not all of the studies could follow exactly the same procedures in data collection, but they were all based on the linkage of cohorts of dry-cleaning and laundry workers to national registers of births and reproductive failures. Summary measures from each study were combined without the data being pooled. The most significant finding was an increased risk of spontaneous abortion among the most exposed women in the Finnish data. This finding was only supported by the results of the other studies to a minor degree, and the combined odds ratio had confidence limits which included unity.

Abortion, Spontaneous↗
PubMed1990

[Analgesia and sedation in neurosurgical intensive care patients].

Different concepts for analgosedation of neurosurgical patients are recommended during postoperative ventilation. In 30 neurosurgical patients (2 groups of 15 patients), we studied a continuous i.v. application of alfentanil (Rapifen) and midazolam (Dormicum) compared to an application of continuously given alfentanil with discontinuously given midazolam. A good analgosedation (i.e. sufficient sedation with good neurological judgement) was more frequently achieved (8/15 patients) by continuous application of both substances (alfentanil 0.023 mg/kg b.w./h, midazolam 0.10 mg/kg b.w./h), compared to discontinuous application of midazolam (4.5/15 patients; alfentanil 0.028 mg/kg b.w./h, midazolam 0.13 mg/kg b.w./h). No differences in extubation times were observed. We conclude from our results that a continuous application of both substances is superior to a discontinuous application of midazolam with continuously given alfentanil. A lower dosage of each substance is necessary to maintain a better state of analgosedation.

Alfentanil↗
PubMed1989

Hyperoxic intubation apnoea: an in vivo model for the proof of the Christiansen-Douglas-Haldane effect.

The Christiansen-Douglas-Haldane effect, commonly known as the HALDANE effect, describes the dependence of the CO2 binding of blood on the degree of oxygenation of haemoglobin. Under the physiological conditions of an "open" system between blood and alveoli the partial pressure of arterial CO2, after CO2 delivery to the alveoli for example, can only range below the value of mixed venous blood. However, during the unphysiological circumstances of a "closed" system, e.g. the state of hyperoxic apnoea, i.e. oxygen uptake and lacking CO2 delivery, the paCO2 cannot only approximate the mixed venous value but must even exceed it. Without the Haldane effect coming into force, a rapid adjustment of arterial to mixed venous pCO2 would have to be expected during apnoea, due to the lacking CO2 delivery. If however, as a consequence of adequate preoxygenation (a high alveolar pO2) and failure to eliminate CO2 (i.e. the CO2 concentration remains constant) a sufficient oxygenation of blood takes place during the passage through the lung capillaries, then this leads to a rightwards shift of the CO2 binding curve--the Haldane effect. The resulting increase in pCO2 as shown here, actually leads to an arterial-mixed venous CO2 partial pressure difference of 2.8 +/- 1.8 mmHg, where pvCO2 decreases paCO2. The results described substantiate for the first time the existence of the Haldane effect under clinical conditions, too.

Apnea↗
PubMed1989

Late magnetic resonance imaging related to neurobehavioral functioning after aneurysmal subarachnoid hemorrhage.

Twenty patients who underwent early aneurysm surgery--that is, surgery within 72 hours after rupture--underwent further follow-up examination including magnetic resonance imaging (MRI) of the brain and a comprehensive neuropsychological assessment. Significant statistical correlation between tissue loss as seen on a late MRI scan and neurobehavioral deficits could not be established. Among 9 patients with no tissue loss seen on MRI, 3 exhibited substantial cognitive dysfunction and 6 had mild impairment. Three patients showed minor but corresponding tissue loss and deficits. In 3 patients with pronounced pathological indications on MRI, evidence of cognitive dysfunction was absent in 2, and 1 patient showed substantial impairment. The remaining 5 individuals displayed moderate pathological indications on MRI, with no obvious correspondence to cognitive functioning. In 7 patients, small white matter lesions, probably silent infarcts not seen on computed tomographic scan, were discovered on MRI. There was a clear relationship between arterial hypertension prior to aneurysm rupture and the extent of tissue loss seen on MRI. Absence of pathological findings on MRI scan did not exclude cognitive malfunctioning, and vice-versa.

Adult↗
PubMed1989

Cognitive functioning after subarachnoid haemorrhage of unknown origin.

Twenty patients, who had sustained a proven subarachnoid haemorrhage (SAH) and in whom cerebral panangiography had failed to reveal any source of the bleeding (SAH-NUD), were subjected to a neuropsychological examination involving memory functions, spatial perceptual organization, visuoconstructive abilities, reasoning, perceptual speed and accuracy, and concept formation. Cognitive functioning in SAH-NUD patients was compared with normal reference values and also related to the cognitive performance of neurologically intact patients having sustained an aneurysmal bleeding (SAH-AN). SAH-NUD patients showed significant reduction of verbal learning and retention, and of abilities involving abstract attitude and concept formation, i.e., functions related to frontotemporal structures. In all other respects the performance of these patients approached normality. Unexpectedly, there were no significant differences in mean test scores separating SAH-NUD from aneurysmal SAH patients. Collapsing the patient groups produced an increased number of significant deviations from normality, which was interpreted as the effect of the contribution of a greater number of relatively more impaired SAH-AN patients. This was supported by the finding that the ratio of impaired individuals to total number of subjects differed in the groups; the proportion of individuals showing cognitive sequelae was larger among SAH-AN patients throughout all comparisons but one. Although SAH of unknown aetiology represents much less of a catastrophe as compared with haemorrhage of aneurysmal origin, it does not preclude cognitive disturbances. Thus, the presence of blood per se anywhere in the subarachnoid spaces appears to affect higher brain function(s).

Adolescent↗
PubMed1989

Relation between occupational exposure to organic solvents and chromosome aberrations in non-Hodgkin's lymphoma.

Chromosome analysis of lymphoma cells was performed in 54 untreated patients with non-Hodgkin's lymphoma (NHL). 10 patients had a history of daily occupational handling of organic solvents for at least 1 year (exposed group) and 44 patients had never (or only for shorter periods) worked with solvents (unexposed group). There were no differences between exposed and unexposed patients regarding age, clinical stage or histologic malignancy grade. The patients were assigned to three categories: Patients with 0-4, 5-9, or greater than or equal to 10 cytogenetic events producing clonal aberrations of the lymphoma cells. The proportions of exposed patients in these categories were 2/26 (8%), 5/20 (25%) and 3/8 (38%); respectively, i.e. with increasing numbers of events there was an increasing probability of previous exposure to solvents (p = 0.035, trend analysis). 5 of 7 exposed patients (71%) with intermediate or high-grade lymphomas displayed translocations involving the band 14q32. Such 14q+ markers were found in only 5 out of 28 unexposed patients (18%) with lymphomas of comparable malignancy grade (p = 0.01). Among unexposed patients with intermediate or high-grade lymphoma the most common clonal aberration was 6q- which occurred in 10 out of 28 patients (36%). This abnormality was not observed in the exposed patients with lymphomas of corresponding malignancy grades (p = 0.08). It thus appears that the number of clonal chromosome aberrations is especially large in NHL patients with a history of occupational exposure to organic solvents. Moreover, such exposure may be associated with characteristic cytogenetic changes in the lymphoma cells.

Adult↗
PubMed1989

Regional and species differences in vascular reactivity to extracellular potassium.

In-vitro vasoreactivity to extracellular potassium (Ko+) was tested in isolated human pial and mesenteric arteries as well as basilar and mesenteric arteries from rabbits and rats. Contractions were induced by stepwise increases in [K+]o and were measured isometrically with a force-displacement transducer, in small-volume organ baths. Significant differences between species as well as between regions were found. The threshold of [K+]o for eliciting contraction in human cerebral arteries in hyperosmotic solutions was 10 mM, in rabbit cerebral arteries 17 mM and in rat cerebral arteries 27 mM. The threshold concentration for contraction in mesenteric arteries was significantly higher compared to cerebral arteries in humans and rabbits, but lower in rats: 20 mM in humans, 26 mM in rabbits and 25 mM in rats. In all species the contractile amplitudes were significantly higher in both cerebral and mesenteric arteries when [K+]o was increased under isotonic conditions in the buffer solution than when hyperosomolality was created. This difference increased with increasing hyperosmolality. In hyperosmotic solutions, the EC50 for [K+]o was lower in cerebral and mesenteric arteries from man than in vessels from rabbit and rat. When the solutions were isotonic, this pattern was seen only in mesenteric arteries. It is concluded that significant species and regional differences in vascular responses to [K+]o exist. Considering that [K+]o is increased in cerebral ischaemia, the observed significantly lower threshold for K+-induced contractions in human cerebral arteries may be of importance, especially in human cerebral ischaemic events.

Animals↗
PubMed1989

Arterial and mixed venous blood gas status during apnoea of intubation--proof of the Christiansen-Douglas-Haldane effect in vivo.

The Christiansen-Douglas-Haldane effect, in short the Haldane effect, describes the dependence of the CO2 binding of blood on the degree of oxygenation of haemoglobin. Under the physiological conditions of an 'open' system between blood and alveoli the partial pressure of arterial CO2 (PaCO2), must be less than that of mixed venous blood (PvCO2). During the unphysiological conditions of a 'closed' system, e.g. hyperoxic apnoea, i.e. continuous oxygen uptake without CO2 delivery by the lungs, the PaCO2 will not only approximate the PvCO2 but will even exceed it. Without the Haldane effect, rapid adjustment of PaCO2 to PvCO2 would be expected during apnoea due to the lack of CO2 excretion. If, however, as undertaken in this study, ongoing oxygenation (high alveolar PO2 (PACO2) with concomitant lack of CO2 delivery (apnoea, i.e. the CO2 concentration remains constant) lead to a continuing sufficient oxygenation of blood during its passage through the lung capillaries, then this leads to a rightwards shift of the CO2 binding curve--the Haldane effect. The resulting increase in PCO2 as shown here actually leads to an arterial-mixed venous CO2 partial pressure difference (avDPCO2) of 2.8 +/- 1.8 mmHg. The results described substantiate for the first time the existence of the Haldane effect under clinical conditions.

Apnea↗
PubMed1989

HLA-typing in a family with six intracranial aneurysms.

The pedigree of a family where three of nine siblings had suffered from aneurysmal subarachnoid haemorrhage (SAH) was explored, by means of interviews and revisions of population and medical records. We thus found two nephews with previously ruptured intracranial aneurysms. Subsequently high resolution computerised tomography (CT) scans were performed in the remaining six siblings, one of which was shown to harbor an intracranial aneurysm. This individual was subjected to uncomplicated clipping of the aneurysm. Typing of human leukocyte antigen (HLA) was performed in 15 individuals of the pedigree. Three of the six HLA-antigens recently reported to occur in increased frequently in a series of (non-familial) patients with ruptured aneurysm were found, namely B7, DR2 and Cw2. Most noteable was the expression of the antigen B7 in five of the six individuals with aneurysm in the investigated family. At present HLA-typing is not a useful screening tool to identify individuals in the general population with an increased risk of developing intracranial aneurysms. The present study shows that HLA-typing could neither be used to predict the occurrence of intracranial aneurysms in the siblings in the investigated family. HLA-typing may provide further clues to our understanding of the etiology of intracranial aneurysms, especially concerning possible genetic factors. The authors thus would like to encourage HLA-typing in previously known and newly detected families with accumulation of intracranial aneurysms.

Adult↗
PubMed1989

Magnetic resonance imaging and aneurysm clips. Magnetic properties and image artifacts.

The magnetic properties of 12 different types of aneurysm clip were investigated in order to identify which clips allow postoperative magnetic resonance (MR) imaging without risk. Clip-induced MR artifacts were also quantitatively studied using a geometrical phantom. Nonferromagnetic aneurysm clips like the Yaşargil Phynox, Sugita Elgiloy, and Vari-Angle McFadden clips do not appear to contraindicate MR studies performed with a FONAR beta-3000M imager. There is no clip movement upon introduction of the phantom into the MR imager, and the image artifacts caused by the clips are so limited that patients harboring such clips may well be considered for MR imaging. This examination may reveal information not obtainable by any other radiological modality.

Aneurysm↗
PubMed1989

Transcranial Doppler sonography within 12 hours after subarachnoid hemorrhage.

Twenty-one patients were subjected to repeated assessment of cerebral blood flow velocities by means of transcranial Doppler sonography (TCDS) during the first 12 hours after subarachnoid hemorrhage (SAH). In 19 patients the study was performed following the first SAH, and in two after early rebleeds. Flow velocities did not indicate an early phase of arterial narrowing in any case. Following the first TCDS assessment, flows were evaluated repeatedly in the 19 survivors. Increased flow velocities suggesting arterial narrowing or vasospasm occurred only after a delay of at least 4 days. The results of this study favor the restoration of normal velocity patterns in surviving patients and do not indicate that an acute phase of vasospasm exists either immediately after or in the first 12 hours after SAH.

Blood Flow Velocity↗
PubMed1989

[The status of arterial and mixed venous blood gases in the initial phase of intubation apnea. Studies on the Christiansen-Douglas-Haldane effect].

The Christiansen-Douglas-Haldane effect describes the reduced CO2 binding capacity of oxygenated as compared to deoxygenated hemoglobin on the basis of its increased acidity. This study describes the development of the above effect during the first 2 min of hyperoxic intubation apnea. METHODS. After institutional approval 12 patients (NYHA III, ASA IV) scheduled for coronary-artery bypass grafting were studied after written informed consent. Routine monitoring measures included invasive arterial and pulmonary-arterial pressure monitoring. Pulse oximetry (Nellcor N 101) was also used during intubation apnea. Premedication consisted of flunitrazepam 2.0 mg p.o. the evening before operation and another 2.0 mg p.o. 90-120 min before induction of anesthesia. Following standardized preoxygenation induction of anesthesia was performed with 20-25 micrograms/kg fentanyl and 0.1 mg/kg pancuronium. After cessation of spontaneous respiration, controlled ventilation was continued with 100% oxygen until intubation. Thirteen arterial (a) and mixed-venous (v) blood samples were drawn sequentially immediately before and during the first 2 min of apnea and analyzed using Corning 150 pH/blood gas analyzer and a Corning 2500 CO-oximeter. RESULTS. As shown in Table 1 and Fig. 1, paO2 decreased from 485 +/- 100 mmHg before apnea to 376 +/- 68 mmHg after 2 min of apnea while pvO2 remained constant at 47-50 mmHg. Arterial oxygen saturation (saO2) showed stable values greater than 97% while svO2 slightly increased from 81.9% to 82.4% until the end of apnea. A biphasic increase was observed in paCO2 from 41.2 +/- 3.4 mmHg before to 54.5 +/- 3.9 mmHg at the end of apnea. An increase in pvO2 during apnea was linear from 45.7 +/- 3.9 mmHg to 51.9 +/- 4.0 mmHg. After 28.5 s of apnea paCO2 exceeded pvCO2 due to the Haldane effect ("pCO2 reversal"). During apnea, pHa decreased biphasically from 7.40 +/- 0.03 to 7.31 +/- 0.02. The speed of decrease was 0.106 pH units/min (5-35 s) in the 1st and 0.023 pH units/min in the 2nd min of apnea; pHv decreased almost linearly from 7.37 +/- 0.03 mmHg (5s) to 7.33 +/- 0.02 mmHg (115s). After 20.66 s of apnea pHa exceeded pHv ("pH reversal"); pH-reversal occurred earlier than pCO2 reversal (p less than = 0.05). CONCLUSIONS. During early hyperoxic apnea, venoarterial pH and pCO2 reversal can be observed due to the Christiansen-Douglas-Haldane effect. pH reversal starts earlier than pCO2 reversal. Reversal time is dependent on arterial-mixed-venous pCO2 difference (avDpCO2) before apnea, arterial-mixed-venous O2 saturation difference (avDsO2) and cardiac output. The amount of reversal is dependent on avDsO2, i.e. the pH difference of arterial and m

Aged↗
PubMed1989

[The use of pulse oximetry in the perioperative monitoring of pediatric patients at risk using the surgical correction of a laparoschisis as an example].

Pulse oximetry has been recently introduced into anesthetic practice as an additional monitoring technique. In contrast to other methods (ECG, inspection, auscultation, blood gas analysis), it immediately detects an impending lack of oxygen, whatever its cause. Therefore, especially in pediatric risk patients, precious time can be saved. This is illustrated during the perioperative period for correction of gastroschisis. Even with a critical look at the mishaps of this method - overestimation of true O2 saturation (sO2) and partial O2 saturation (psO2) and overestimation of hemoglobin derivatives--pulse oximetry seems superior to the established monitoring techniques in the perioperative period. Therefore, we believe pulse oximetry to be an useful tool for additional monitoring, especially in pediatric risk patients. It is a suitable continuous and noninvasive in vivo technique for the early detection of hypooxygenation. Due to the special disadvantages of the method, we consider it advisable to perform control measurements with a CO-oximeter from time to time.

Abdominal Muscles↗
PubMed1989

[Fentanyl versus sufentanil basic anesthesia. Hypnotic effect, muscle rigidity and efficacy of competitive muscle relaxants].

As induction agents for cardioanesthesia, sufentanil (S) and fentanyl (F) are usually employed in combination with nondepolarizing muscle relaxants. We investigated potential interactions of these opioids with the relaxant component, paying special regard to the role of muscular rigidity and opioid-induced alterations of hemodynamics. Narcotic anesthesia was induced randomly in 45 coronary artery bypass patients with either F (20 micrograms/kg) or S (4 micrograms/kg). After 6 min, neuromuscular blockade was initiated within each group randomly with either vecuronium (V) or pancuronium (P) (0.01 mg/kg each). During opiate administration, the times for cessation of spontaneous respiration and loss of responsiveness to verbal and tactile stimuli were measured. The degree of opiate-induced muscular rigidity, simultaneous changes in arterial paCO2, cardiac indices (CI) prior to opioid and relaxant administration, onset and recovery from neuromuscular blockade (by electromyographic train-of-four registration), and motor response to laryngoscopy and intubation were recorded. The onset of spontaneous apnea (TK = time to breathing upon command only) and unresponsiveness (TM = time to controlled mask ventilation) was significantly faster with S than with F. Muscular rigidity was moderate in 25% of patients and severe in 35%-40%, during the administration of both narcotics. No significant differences between S and F were observed. During ventilation by face mask, patients with clinically apparent rigidity showed a statistically significant mean increase in paCO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetics↗