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Biomedical subjects

J Fischer

Publications and source records attributed to J Fischer.

At least 253 records · Page 14Linked to original sources
PubMed1994

Is the unpaid/paid donation debate for better or for worse?--a commercial viewpoint.

The European Association of the Plasma Products Industry represents the private sector member companies that manufacture and provide plasma products throughout Europe. EAPPI believes that the most important aspect of self-sufficiency is a sufficient supply of safe and efficacious product; the question of paid or unpaid donations is of lower importance. To achieve a supply of high quality plasma, EAPPI considers it is necessary to harmonize standards throughout Europe, and suggests a five-point programme towards improving public confidence in the available plasma products.

Blood Banks↗
PubMed1994

Endoscopic-guided clipping of cerebral aneurysms.

An endoscopic probe has been used intraoperatively to facilitate the obliteration of cerebral aneurysms. This method has been used in 24 patients with 30 arterial aneurysms. There were 13 males and 11 females. They ranged in age from 22 to 73 years (mean age 48 years). The mean time of surgery was 7.3 days after subarachnoid haemorrhage (ranging from 2 to 24 days). In three cases there was intraoperative rupture of the aneurysm and with one patient the operation had to be abandoned because of severe brain oedema. The follow-up ranged from 12 to 48 weeks (average 31.8 weeks). The overall outcome was good in 14 cases (58.3%), eight patients (33.3%) showed moderate disability, severe disability occurred in one patient (4%) and one patient (4%) died. In all cases when the endoscope was used, there was a striking improvement in the visualisation of the anatomy of the aneurysm and surrounding structures. Furthermore, the position of the clip and the state of the vessels leading to and from the aneurysm could be easily examined.

Adult↗
PubMed1994

[Why still use myelography in neurosurgery?].

Recently CT scan and NMR imaging have become diagnostic routine methods for spine lesions, while myelography is no longer the method of choice in most cases. From the experience of our clinic, however, there remain some neurosurgical indications, which will be the contents of this publication. We would like to give a review of the present literature. Still remaining indications are: 1. Traumatic nerve root lesions 2. Anomalies of lumbosacral nerve roots 3. Cervical disc herniation: anterior disc excision vs. posterior operation. 4. Stenosis of the spinal canal in more than 2 levels 5. Neurological deficit after trauma of the spine 6. Functional Myelography 7. Spinal arteriovenous malformations 3 Patients are presented in the crucial phase of diagnostic evaluation. Based on their outcome, the indications of myelography are discussed.

Diagnosis, Differential↗
PubMed1994

Pathogenicity of a bovine attaching effacing Escherichia coli isolate lacking Shiga-like toxins.

Escherichia coli isolate 7996-90, obtained from a calf with diarrhea, had negative results of tests for K-88, K-99, 987P, F41, CS31A, F1845, F165 or E. coli adherence factor adhesins and had negative results of tests for the toxins heat-labile, heat-stable A, heat-stable B, Shiga-like toxin (SLT)-I or SLT-II. Strain 7996-90 had localized adherence to HEp-2 cells, caused actin rearrangement in host cells to which it adhered, hybridized with the eaeA probe, and produced the 94-kd outer membrane protein associated with attaching effacing lesions. This isolate caused attaching effacing lesions in Caco-2 cell polar monolayers, rabbit intestinal loops, and the intestines of gnotobiotic pigs. The isolate belongs to serotype O26: NM and is considered a class-II attaching effacing enteropathogenic E coli. Until recent addition of more sensitive assays at veterinary diagnostic laboratories, isolates such as 7996-90 were not readily recognized as pathogens because they failed to fit into the enterohemorrhagic E coli group, members of which, be definition, produce SLT. The assays described can facilitate diagnosis of attaching effacing E coli infection when histologic evaluation is hampered by autolysis.

Animals↗
PubMed1994

[Lectin-histochemical characteristics of bone tumors. I. Stage-related changes in lectin-binding of giant cells in osteoclastoma].

Authors examined 18 cases of osteoclastoma chosen at random with different lectins. The fibroblast-like type I stromal cells taking part in the formation of the ground substance were Con A positive. The strength of the Con A bond and the number of positive cells increased with the progress of the stage. The PNA lectin bond following the digestion with neuraminidase was in the single stages of different character and intensity. Whereas in the Gr I osteeoclastomas 30 per cent of the reacting osteoclast was localized to a well defined segment of the membrane in the Gr III tumors the ratio of the negative cells moved around 1 per cent, and in 60 per cent of the positive cells strong diffuse intracytoplasmatic reaction could be observed. Authors think that the lectin histochemical examinations give help to the definition of the activity of the tumor forming cells.

Adult↗
PubMed1994

[The sintering process of fired dental metal-ceramic alloys].

The manufacture of fixed prostheses by means of the porcelain-fused-to-metal technique is done by sintering a ceramic powder onto the metal frame work. During this process the ceramic is condensed due to fusion of the powder, accompanied by a loss of volume of the whole material. In this study the sintering process of the dental ceramic VMK 68 was investigated by means of scanning electron microscopy and determination of density. The results showed, that the sintering takes place between 680 degrees C and 950 degrees C, while the density increases from 1.56 g/cm3 to 2.54 g/cm3. The volume shrinkage amounts to 36%. Thermomechanical analyses confirmed that the starting temperature of the sintering process depends on the heating rate. The investigations showed that the instructions for use, given by the manufacturer, represent optimal conditions.

Materials Testing↗
PubMed1994

[Prenatal substitution therapy in fetal alloimmune thrombocytopenia].

Fetal alloimmune thrombocytopenia is caused by maternofetal transfer of platelet antibodies. Since the thrombocytopenic fetus is threatened by intracranial hemorrhage, prenatal observation and, if necessary, treatment is required. However, the benefit of therapeutic options, including intravenous IgG (ivIgG) or platelet transfusions, is still controversial. In this study we have evaluated the effect of maternal ivIgG and intraumbilical platelet transfusions on fetal platelet counts in 7 cases. All patients were multiparous women who were immunized against the Zwa antigen during previous pregnancies and had given birth to at least one severely thrombocytopenic infant. First umbilical blood was sampled at the 26th week of gestation. Maternal treatment of ivIgG was given over 7 weeks, the mean number of intrauterine platelet transfusions was 5.9. In 6 of 7 cases the basal platelet count before transfusion did not rise or even further decreased during maternal ivIgG treatment. In one case the baseline platelet count increased from 18,000/microliter to 60,000/microliter during ivIgG. We conclude that, in general, ivIgG alone has no detectable effect on fetal alloimmune thrombocytopenia. Since platelet counts can be very low as early as 20 weeks of gestation, careful fetal monitoring by umbilical blood sampling is required. Platelet transfusions in short intervals appear to be the only effective regimen to increase platelet counts in extremely thrombocytopenic fetuses.

Antigens, Human Platelet↗
PubMed1993

[Threatening thiamine deficiency in severe hyperemesis gravidarum].

We report the case of a patient with severe hyperemesis gravidarum. During parenteral nutrition the patient developed threatening thiamine deficiency. Wernicke's encephalopathy and tachycardia were predominant in the clinical course. Severe lactic acidosis and prolonged prothrombin time were the leading laboratory features. Thiamine deficiency as a cause of severe metabolic acidosis or coma can be easily ruled out or validated by intravenous thiamine administration.

Acidosis, Lactic↗
PubMed1993

Sacral anterior root stimulation: prerequisites and indications.

An intact sacral reflex arc, or at least an intact second motor-neuron and a detrusor being able to contract, are the two prerequisites for implanting an anterior sacral root stimulator. Transrectal electrostimulation or direct needle stimulation of the sacral roots may reveal if patients despite absent or only weak detrusor contractions on routine investigation are suitable. Patients with a complete midthoracic paraplegia are the ideal candidates, but tetraplegics also benefit. Patients with incomplete lesions and preserved pain sensations are suitable provided that they can undergo posterior sacral root rhizotomy. Non-traumatic spinal cord lesions follow the same rules, provided that the type of lesion does not allow recovery and is not progressive. Myelomeningocele patients may be suitable provided that the pathoanatomy of the sacral roots permits the operation (may be possible only in thoracolumbar myelomeningocele). Vesico-uretero-renal reflux is no contraindication; it may even be a strong indication, if a low compliance bladder or high detrusor contractions are the main reasons for it. In most patients the procedure should or must be combined with posterior sacral root rhizotomy in order to normalize a low compliance, to abolish spontaneous reflex contractions, and to achieve continence. The benefit of following these rules is reflected in our own series of 30 patients. In all of them the operation has improved considerably the quality of life and no patient so far has regretted the operation.

Electric Stimulation Therapy↗
PubMed1993

Somatosensory and auditory brainstem evoked potentials during choroid plexus angioma removal.

Intraoperative combined SEP and BAEP monitoring provides a high level of safety for patients undergoing high risk intracranial surgical procedures. We performed this type of monitoring in a rare case of choroid plexus angioma, embedded into the pulvinar of the right thalamus, which was resected via a transcallosal approach. The SEP pattern deteriorated during parietal brain retraction and thalamic dissection, but never completely disappeared. The BAEP pattern remained unchanged during the entire operation. The patient suffered incomplete hemiparesis postoperatively, but recovered completely within 10 days. After this time the SEP pattern returned to normal. This case points out that pathological change of intraoperative SEP pattern without loss of components suggests an incomplete hemiparesis. There is, however, a good chance of full recovery in the early postoperative period.

Adult↗
PubMed1993

Development of supratentorial astrocytomas.

Six cases of supratentorial astrocytomas are presented in this study in order to demonstrate the typical development of this kind of tumors. All patients were controlled regularly by CT scan. Five of them were operated two times, one patient three times. The tumor growth was quite similar in all cases. Time interval between the first intervention and tumor recurrence was larger than between second intervention and tumor recurrence. In all cases the tumors tended to "explosive" growth after the second operation. There are discussed pros and cons of an early reintervention after tumor recurrence.

Adult↗
PubMed1993

Peri-operative elastase-alpha-1 proteinase inhibitor in patients with postoperative intervertebral discitis.

In a prospective study of 251 patients operated upon for lumbar disc herniation it has been investigated whether the preoperative and early postoperative values of Elastase-alpha-1 Proteinase Inhibitor (EPI)-an indicator of inflammatory processes-and C-reactive Protein (CRP)-a well known predictor of some postoperative complications-were correlated to the later development of discitis. Postoperatively discitis developed in 14 patients. A randomly chosen group of 15 complication-free patients out of the total of 251 cases was used as control group. Elevated EPI plasma values, especially in the pre-operative and first postoperative days, turned out to be significantly related to the likelihood of later discitis development, but no such relation for the CRP plasma values could be established. Thus and early prediction of patients at risk for this complication seems to be possible by pre- and postoperative measurement of EPI. It could be justified-but its usefulness has yet to be proven-to give antibiotics prophylactically and other anti-inflammatory medication in patients with elevated pre- and postoperative EPI values.

Acute-Phase Reaction↗
PubMed1993

Determination of ivermectin in bovine plasma by column-switching LC using on-line solid-phase extraction and trace enrichment.

Ivermectin is a potent avermectin anthelmintic, derived from the soil organism Streptomyces avermitilis. Because of its potency, it is administered in very low doses (200 micrograms kg-1), giving rise to plasma levels in the ppb region, and hence sensitive methods are required for its determination in biological samples. A method is described for the determination of ivermectin in bovine plasma, based on a commercially available C18 column employing a mobile phase composed of acetonitrile-water-isopropanol (40:40:35, v/v/v). Extraction from plasma is carried out on-line using coupled-column technology; switching between the extraction and analytical columns is achieved using a six-port column-switching valve. The method is linear over the range 2-100 ng ml-1 (r = 0.9994) and has a limit of detection of 0.8 ng ml-1 (signal-to-noise ratio = 3). Reproducibility of the method, expressed as the overall mean relative standard deviation, is 6.7% (intra-assay) and 3.8% (inter-assay). The mean recovery of the drug from plasma is 76.4%. The method is simple and economical in its execution and is sufficiently reproducible to obviate the need for an internal standard.

1-Propanol↗
PubMed1993

Young adult offspring and their families of origin: cohesion, adaptability, and addiction.

This study examined relationships among measures of family functioning (FACES-II), number of family addictions, and risk of alcoholism (Short Michigan Alcoholism Screening Test, SMAST) in a college sample. Multiple regression analyses indicated that the number of family addictions and the additively combined FACES-II scales each predicted scores on the SMAST. Thus, addictions in the family contribute to offspring alcoholism both directly, through their presence, and indirectly, through family functioning. Information on the history of a wide range of family addictions and on the functioning style of the family of origin can be valuable in assessing and addressing addiction risk.

Adaptation, Psychological↗
PubMed1993

[Neuralgia of the glossopharyngeal nerve with syncope attacks].

The anatomical viewpoints of nervus IX and its surrounding structures are explained. The authors report on one case of symptomatology of glossopharyngeal neuralgia combined with cardiac arrests. Finally, pathogenesis and surgical treatment of glossopharyngeal neuralgia are discussed.

Craniotomy↗
PubMed1993

[Whiplash trauma of the cervical spine from the neurosurgical, traumatologic and psychologic viewpoint].

Since the early 50's, whiplash injury has been a subject of intensive study in order to find out the genesis of this disease. Unfortunately, most of the studies were planned retrospectively and were based on inhomogeneous groups of patients. In our prospective study, we tried to keep the patient group homogeneous. 62 patients were examined neurologically and radiologically immediately after the accident. Furthermore, they underwent a psychological test, the so-called Freiburg personality profile. 6 months later the patients were checked again. On the basis on our findings, the suspected psychological influence has to be confirmed. Preexisting degenerative lesions of the cervical spine, also, are undoubtedly prognostic for longer-lasting symptoms.

Adult↗