Biomedical subjects

M Krause

Publications and source records attributed to M Krause.

At least 343 records · Page 19Linked to original sources

PubMedDate not supplied

Native and prosthetic valve endocarditis caused by Rothia dentocariosa: diagnostic and therapeutic considerations.

Three cases, one each of native valve, prosthetic valve and composite graft endocarditis caused by Rothia dentocariosa are described. The first patient presented with multiple brain abscesses and severe congestive heart failure due to destructive endocarditis with large vegetations on the mitral valve. He died shortly after emergency valve replacement. Gram-positive coccoid rods were identified in the vegetations of the excised mitral valve. The second patient had a R. dentocariosa endocarditis of a prosthetic aortic valve that was treated empirically with netilmicin and teicoplanin, due to an allergy to penicillin. Both antibiotics were replaced according to susceptibility testing in vitro with rifampin and ciprofloxacin, and the endocarditis was cured within 9 weeks. The third patient presented with a circular root abscess of an aortic composite graft that was successfully treated with rifampin and ceftriaxone without surgery. All patients had extensive periodontal disease which was thought to be responsible for hematogenic spread and seeding of the microorganism. The microbiological identification and antibiotic resistance pattern of the isolates, as well as therapeutic implications are discussed.

Actinomycetales↗

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Validation of the use of field effect transistors for extracellular signal recording in pharmacological bioassays.

The use of field effect transistors (FETs) in biomedical research has been in rapid progression in recent years. The present study aims to demonstrate a quantitative use of these devices in pharmacological bioassays. FETs were made as a 4 x 4 matrix of gates with a width of 200 microm separating each gate. The surface of the FETs (silicon oxide), covered with a layer of laminin, fibronectin, or nitro cellulose was suitable for cell adhesion. The cultured dissociated cardiac myocytes were spontaneously active within 24 to 48 h after initial plating. Simultaneous intracellular patch clamp recordings were used to verify the electrophysiological signals of cells that were coupled to the gates. All positive chronotropes (isoproterenol, norepinephrine) and negative chronotropes (verapamil, carbamylcholine, SDZ PCO400) showed their characteristic effects on heart cells in terms of changes of beat frequency. As the myocytes were in a complete syncitium on each FET, the cells need not be directly coupled to the gate in order to detect any ionic changes. This enables global cellular responses to be analyzed. The system also offers an opportunity to study the interconnections and communications between different cells. Furthermore, the changes of signal shapes in the presence of different agents could also be detected. The present study demonstrates how versatile and sensitive this recording system is in distinguishing different ionic signal shapes. The authors believe that this system has the potential to replace some currently employed in vitro methods, offering an alternative, which can substantially reduce animal use in pharmacological experiments.

Action Potentials↗

PubMedDate not supplied

[Damage to the brachial plexus in vaginal delivery from breech presentation--correlation with reducing the extended arm].

BACKGROUND: Brachial plexus injuries in foetuses delivered spontaneously by breech presentation is very rare. The aim of this study was to evaluate the frequency of brachial plexus injuries in connection with the rate of the reduction of the extended arm. MATERIALS AND METHODS: In our retrospective study we examined 1194 vaginally intended breech deliveries (> 32 completed weeks) for the frequency of extended arms and subsequent plexus brachialis palsies. RESULTS: One brachial plexus injury occurred in 796 vaginally delivered newborns (1.2@1000). The outcome corresponds with the frequency of brachial plexus palsy in spontaneous deliveries with cephalic presentation (1@1000). The mean frequency of reduction of the extended arm in vaginal deliveries in breech is 10-20%. CONCLUSION: We found that the rate of reduction of the extended arm was not associated with an increase in morbidity of newborns. DISCUSSION: Many reports in the literature demonstrate that a higher rate of caesarean section does not prevent these severe foetal injuries. Noxious factors already occurring during the prenatal phase of development can be suspected as possible causes.

Adult↗

PubMedDate not supplied

[New concepts of corticosteroid treatment in pulmonary diseases of the premature infant].

Corticosteroids for treatment or prevention of pulmonary disease are milestones in the management of preterm infants nowadays. Prenatal maternal administration as well as postnatal treatment of the mechanically ventilated preterm infant with bronchopulmonary dysplasia (BPD) are considered to be established concepts. However, the side effects of systemically given corticosteroids can be considerable (e.g., increased mortality, which cannot be explained by a specific side effect). In order to avoid as many side effects as possible and to attain an optimal response determining the best regimen is under current investigation. This review describes new concepts of corticosteroid application from the last years which have focused on "pulse"-therapy, inhalative therapy and early administration of corticosteroids. In conclusion, the trend is using corticosteroids as a prophylaxis for BPD in preterm infants instead of as a consequent treatment.

Adrenal Cortex Hormones↗

PubMedDate not supplied

Characterization of the T, L, I, S, M and P cell surface (immobilization) antigens of Tetrahymena thermophila: molecular weights, isoforms, and cross-reactivity of antisera.

In the ciliate protist Tetrahymena thermophila the L, H, T, I, S, M and P cell surface proteins (immobilization antigens) are expressed under different conditions of temperature (L, H, T), culture media (I, S), and mutant genotype (M, P). Immunoblot and autoradiographic studies using antisera to purified protein show that the molecular weights of these proteins range from 25,000 to 59,000. The H, T, S, M and P antigens are recognized as single polypeptides, whereas L, I, and one allelic form of T each appear to consist of a family of polypeptides. Although antisera are specific in immobilization and immunofluorescence assays of surface protein in living cells, cross-reactivity is seen with denatured protein on immunoblots. It is hypothesized that the surface protein genes are organized into families of evolutionarily related isoloci.

Animals↗

PubMedDate not supplied

Comparison of analgesia and akinesia after retrobulbar injections at different speeds.

PURPOSE: To assess how the speed of injection of local anesthetic solutions affected pain of injection, bulbar akinesia and analgesia with retrobulbar anesthesia (RBA). METHODS: 70 patients undergoing RBA for cataract surgery were enrolled in a prospective masked trial. They were allocated randomly to receive 5 ml anesthetic solution injected either within 20 seconds (group A) or within 60 seconds (group B). Additionally, akinesia of the orbicularis muscle was created according to O'Brien's technique. The pain of injection was registered on an ordinal analogue scale immediately before and after RBA. The following data were collected before and 20 minutes after retrobulbar injection: eye motility (Kestenbaum test), and corneal sensitivity (0: no sensitivity; 1: sensitivity remaining). Data were also collected on age, sex, and bulbar length, and any side effects of the intervention. RESULTS: Injection pain did not differ in the two groups. After RBA horizontal and vertical eye motility was slightly lower in group A than group B. Persistent motility was found in 18 patients in group A and 16 in group B. Median horizontal and vertical motility was 0 mm in both groups. Four patients in group A and five in group B had corneal sensitivity persisting after RBA. CONCLUSIONS: This comparison of different injection velocities brought to light no significant differences regarding bulbar analgesia and akinesia after RBA.

Adult↗

PubMedDate not supplied

Risk factors for anatomical success and visual outcome in patients undergoing silicone oil removal.

PURPOSE: To define risk factors for anatomical success and visual outcome in patients undergoing removal of silicone oil. METHODS: This retrospective study included patients who had silicone oil removed at this hospital between 1996 and 2000. All were followed for at least six months. Patients with recurrent retinal detachment after silicone oil removal were compared with patients without this complication. We also compared patients whose vision improved or stabilized with patients whose vision deteriorated. Risk factors for anatomical success and visual outcome were identified. RESULTS: We analysed 94 eyes of 92 patients with silicone oil removal. Nineteen eyes (20%) had recurrent retinal detachment, and in 30 eyes (32%), the vision deteriorated after removal of the oil. Initial vision less than ambulatory vision, initial pathology of giant retinal tears and recurrent retinal detachment, postoperative hypotony and postoperative epiretinal membrane occurred more frequently in eyes with than without recurrent retinal detachment. Pre- and postoperative hypotony, postoperative epiretinal membranes and postoperative recurrent retinal detachment were also more frequent in eyes with deteriorated vision. CONCLUSIONS: When treating giant retinal tears or recurrent retinal detachments with silicone oil tamponade, surgeons and their patients need to be aware of the higher possibility of unfavorable results, particularly when the initial vision is less than ambulatory vision. The presence of risk factors before and after silicone oil removal should remind surgeons of the higher risk profile of this particular surgery.

Adolescent↗

PubMedDate not supplied

Short-time predegenerated peripheral nerve grafts promote regrowth of injured hippocampal neurites.

Our previous studies revealed that predegenerated peripheral nerve grafts facilitated neurite outgrowth from the injured hippocampus and that this effect was particularly distinct when 7-, 28-, and 35-days predegenerated nerve grafts were used. It is recently known that a totally transected peripheral nerve exhibits biphasic neurite-promoting activity. The early phase lasts 7 days. The aim of the present study was to find whether short-time predegenerated (1-6 days) peripheral nerve grafts exert any neurotrophic effect and when this influence is maximal. Experiments were carried out on adult male Wistar rats. Sciatic nerves were totally transected and following 1, 2, 3, 4, 5 and 6 days their distal stumps were implanted into the hippocampus. Control animals were treated with non-predegenerated sciatic nerve grafts. In all groups FITC-HRP was injected into the free end of graft six weeks following surgery. Special histochemic technique showed AChE-positive fibres inside the grafts of all examined groups. Fluorescence microscopic examination revealed the labeled cells in all examined groups, however their number was different in each group, depending on the predegeneration stage. They were most numerous at the fourth day of predegeneration.

Acetylcholinesterase↗

PubMedDate not supplied

Purified extracts from short-time-predegenerated rats' sciatic nerves promote the regrowth of injured hippocampal neurites.

Our previous studies revealed that purified extracts (submicrosomal fractions) obtained from peripheral nerves predegenerated for 7-, 28-, and 35-days facilitated neurite outgrowth from the injured hippocampus. It is recently known that totally transected peripheral nerve exhibits biphasic neurite-promoting activity. The early phase lasts 7 days. The aim of the present study was to find whether extracts obtained from short-time predegenerated (1-6 days) peripheral nerves exert any neurotrophic effect and when this influence is maximal. Experiments were carried out on adult male Wistar rats. Sciatic nerves were totally transected and following 1, 2, 3, 4, 5 and 6 days their distal stumps were homogenized and centrifuged. Extracts were implanted into the hippocampus by means of autologous connective tissue chambers. Reference groups were treated with extracts from non-predegenerated nerves, NGF solution or fibrin (groups C, NGF and B + F, respectively). In all groups FITC-HRP was injected into the extracranial end of chamber six weeks following surgery. Histochemic technique showed AChE-positive fibres inside the chambers of all examined groups. Fluorescence microscopic examination revealed the labeled cells in all examined groups, however their number was different in each group. They were most numerous at the fourth day of predegeneration.

Acetylcholinesterase↗

PubMedDate not supplied

[Spontaneous hematoma of the abdominal wall: diagnostic error of abruptio placentae].

An emergency cesarean section was performed in the 38th week of pregnancy in a patient with acute abdominal pain in the left upper quadrant. The ultrasound picture was interpreted as a retroplacentar hematoma. Cardiotocography demonstrated fetal tachycardia which was interpreted as asphyxia. A diagnosis of abruptio placentae was made, but was finally ruled out when the cesarean section was performed. The intraabdominal exploration revealed a large hematoma of the rectus sheath with about 800 ml of blood. After evacuation and drainage the postoperative recovery was uneventful. Sudden rupture of a deep epigastric vessel with formation of an abdominal wall hematoma also mimics intraabdominal conditions such as appendicitis, diverticulitis, cholecystitis, tumours and visceral injuries.

Abdominal Muscles↗

PubMedDate not supplied

[Severe autoimmune thrombocytopenia in pregnancy].

Maternal thrombocytopenia is a frequent finding in pregnancy. The clinically important causes of maternal thrombocytopenia in pregnancy are gestational thrombocytopenia and autoimmune thrombocytopenia. We report a case of refractory idiopathic thrombocytopenic purpura by a 30-year-old pregnant woman, gravida 3, para 2, successfully treated with high dose corticosteroids and immune globulins.

Adult↗

PubMedDate not supplied

Enumeration of probiotic bacilli spores in animal feed: interlaboratory study.

Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80 degrees C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (10(9) colony-forming units [CFU]/g) and low (10(5) CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the repeatability relative standard deviation (RSD(r)) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSD(r) values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards.

Animal Feed↗

PubMedDate not supplied

[What is the visual field?].

Eye movements were recorded in the course of visual field determination. The behaviour of the eye is various in different persons, defying any rule, except, contrary to the definition of the visual field, it does not remain immobile but executes one or more saccades. Discussing the results the authors present a new concept of the visual field.

Adult↗

PubMedDate not supplied