PubMed Health⌕ Search

Biomedical subjects

C Kremer

Publications and source records attributed to C Kremer.

At least 19 recordsLinked to original sources
PubMed2006

Short report: analysis of clonal relationship among Shigella sonnei isolates circulating in Argentina.

Thirty-five isolates of Shigella sonnei from patients with diarrhoea in three geographic regions of Argentina were examined for genetic diversity by pulsed-field gel electrophoresis (PFGE) and plasmid profile. PFGE of XbaI and BlnI DNA digests confirmed the occurrence of outbreaks in two regions caused by two separate predominant clones of S. sonnei. The third region was characterized by three circulating clones, one of which was possibly associated with an outbreak. Similar plasmids were found in distinct clones and in one outbreak clone five different plasmid profiles were identified. Antimicrobial resistance of the isolates varied from fully susceptible to the agents tested, to resistance to cotrimoxazole, ampicillin and ciprofloxacin. Antibiotic resistance did not correlate with plasmid content. This information will form the basis for active surveillance of shigellosis in Argentina and elsewhere in the region through the PulseNet International Network.

Anti-Infective Agents↗
PubMed2006

Ductus venosus blood flow alterations in fetuses with obstructive lesions of the right heart.

OBJECTIVE: To assess the impact of isolated lesions of the fetal right heart on ductus venosus (DV) blood flow profiles. METHODS: Retrospective evaluation of DV blood flow profiles in 83 fetuses with isolated right-sided cardiac lesions. Cases were divided into two groups. Group A had right-sided cardiac lesions associated with a large ventricular septal defect that equalized interventricular pressures (double outlet right ventricle (n = 12), tetralogy of Fallot (n = 19), pulmonary atresia (n = 5)). Group B had right-sided cardiac lesions with obstruction of the inflow (tricuspid atresia with ventricular septal defect (n = 14)) or obstruction of the outflow with intact ventricular septum (Ebstein's anomaly (n = 13), pulmonary stenosis (n = 13) and pulmonary atresia (n = 7)). Comparisons were made with 585 uneventful singleton pregnancies and previously published normative values. RESULTS: Fetuses in Group B had significantly higher rates of abnormal DV flow profiles compared to Group A and controls (P < 0.01). Conversely, there were no significant differences concerning DV parameters between fetuses in Group A and controls. Despite these different DV flow characteristics, there were no significant differences concerning signs of cardiac failure and/or survival to the perinatal period between the two groups. CONCLUSIONS: Right-sided cardiac lesions with obstruction of the inflow or outflow with intact ventricular septum are significantly associated with abnormally high pulsatilities in the DV and may even cause a reversal of flow during atrial contraction. These changes do not necessarily indicate cardiac failure, as they are primarily attributable to the special hemodynamics of the cardiac defect.

Analysis of Variance↗
PubMed2005

[Subsequent treatment of surgically managed, fresh, anterior cruciate ligament ruptures--a randomized, prospective study].

The prospective study examined two different postoperative treatments on 46 patients with acute and isolated disruption of the anterior cruciate ligament (acl), who were treated with reconstruction and augmentation using the semitendinosus-tendon. The patients were randomised and divided into two groups either to use a postoperative brace (Donjoy Ind.) set at full extension (group A) or to use the same brace set at a flexion of 20 degrees (group B) on the first 3 days after surgery. All patients undertook a standard "accelerated" rehabilitation protocol and were evaluated after 3, 6 and 12 months after surgery. The results were as follow: the patients of group A reached the full extension faster than group B without any loss of knee stability. Postoperative extension even led to an earlier return to work and sport activities. The muscle strength side-to-side difference (Cybex-measurement) was lower in group A. The severity and intensity of postoperative pain, swelling and giving-way was reduced in group A as was the risk of arthrofibrosis. Evaluated with the scoring scales of the "Orthopädische Arbeitsgruppe Knie" (OAK), the "International Knee Documentation Committee" (IKDC), the Tegner activity score and the Lysholm score, the clinical outcome and activity-level were higher in group A than in group B. This prospective study shows, that immediate postoperative extension, compared to the postoperative flexion of 20 degrees, reduces the term of rehabilitation and optimizes the operative results after acl-reconstruction.

Adult↗
PubMed2004

Prognosis of asymptomatic stenosis of the middle cerebral artery.

BACKGROUND: The risk of ischaemic events in asymptomatic intracranial atherosclerosis is unknown. OBJECTIVE: To follow up patients with asymptomatic atherosclerotic middle cerebral artery stenosis (MCAS) to evaluate the long term stroke risk in its territory. METHODS: Consecutive white patients with asymptomatic atherosclerotic MCAS were enrolled. Patients with MCAS of possible or proven non-atherosclerotic origin were excluded. MCAS was assessed by transcranial colour duplex sonography according to published angiography validated criteria. Medical treatment was given at the discretion of the treating physician. RESULTS: 50 patients were included and followed for (mean (SD)) 815 (351) days; three were lost to follow up. MCAS was < 50% in 38 and > or = 50% in 12. No patient suffered an ischaemic event in the MCAS territory; one had a transient ischaemic attack in the contralateral hemisphere. Three patients died, one from a subdural haematoma in the contralateral hemisphere, and two from non-stroke-related causes. Medical treatment at baseline included antithrombotic drugs in 42 cases (antiplatelet agent, n = 39; warfarin, n = 3), and statins in 22; at the end of follow up 45 of the 47 survivors were on antithrombotic drugs (antiplatelet agent, n = 37; warfarin, n = 8), and 30 were on statins. CONCLUSIONS: Asymptomatic MCAS of atherosclerotic origin appears to have a benign long term prognosis with a low risk of ipsilateral stroke in medically treated white patients.

Adult↗
PubMed2004

Mechanism of ischemic infarct in spontaneous carotid dissection.

BACKGROUND AND PURPOSE: It is unclear whether stroke in patients with spontaneous dissection of the cervical internal carotid artery (ICAD) is due to thromboembolism or impaired hemodynamics. This study investigated the mechanism of stroke in ICAD by examining brain imaging and cerebrovascular findings of such patients. METHODS: We retrospectively evaluated the prospectively collected brain CT, MR, and ultrasound findings of 141 consecutive patients with 143 ICADs causing ischemic stroke. Eleven patients were not included because they had an inappropriate temporal bone window (n=6) or were treated with thrombolysis (n=5). Thus, the data of 130 patients (76 men, 54 women) with 131 ICADs were analyzed. RESULTS: All patients had territorial infarcts; 6 patients (5%) also had border-zone infarct patterns. Territorial infarcts affected the middle cerebral artery (MCA) in 130 of 131 cases (99%) and the anterior cerebral artery (ACA) in 1 case (1%). Additional vascular territories were affected in 8 patients with MCA infarcts (ACA, n=5 [4%]; posterior cerebral artery, n=3 [2%]). The pattern (hemodynamic versus thromboembolic) and extent of infarction were not influenced by vascular findings (MCA stenosis or occlusion, ACA occlusion, degree of obstruction in the dissected ICA, pattern of cross-flow in 115 patients with >80% ICA stenosis or occlusion). CONCLUSIONS: This study suggests that thromboembolism, not hemodynamic infarction, is the essential stroke mechanism in ICAD.

Brain Ischemia↗
PubMed2003

Carotid dissection with permanent and transient occlusion or severe stenosis: Long-term outcome.

OBJECTIVE: To compare the rate of ischemic events and intracranial hemorrhage in the long-term follow-up of patients with persistent and transient severe stenosis or occlusion of the internal carotid artery (ICA) due to spontaneous dissection (ICAD). METHODS: One hundred and sixty-one consecutive patients with unilateral ICAD causing severe stenosis or occlusion were examined clinically and by ultrasound 1 year after symptom onset. Forty-six cases with persistent and 46 age- and latency-matched cases with transient (recanalization complete or less than 50% stenosis) severe stenosis or occlusion of the ICA were enrolled. Nine patients with surgical, endovascular, or fibrinolytic therapy for ICAD or associated stroke were excluded. Antithrombotic therapy was given at the discretion of the treating physician. Clinical follow-ups were done annually. RESULTS: Antithrombotic therapy and follow-up were similar in patients with permanent (6.2 +/- 3.4 years) and transient (7.2 +/- 4.3 years) severe stenosis or occlusion of the ICA. Cases with permanent carotid stenosis or occlusion showed annual rates of 0.7% for ipsilateral carotid territory stroke and of 1.4% for any stroke. Cases with transient carotid stenosis or occlusion showed annual rates of 0.3% for ipsilateral carotid territory stroke and of 0.6% for any stroke. CONCLUSIONS: This study suggests that ICAD has a benign long-term prognosis with low rates of ipsilateral carotid territory and any stroke and that the stroke rate in ICAD is not related to the persistence of severe carotid stenosis or occlusion. These results question the rationale of surgical or catheter-based revascularization in patients with ICAD.

Adult↗
PubMed2002

Outcome after endovascular therapy of ruptured intracranial aneurysms: morbidity and impact of rebleeding.

We evaluated midterm functional outcome after endovascular occlusion of aneurysms in patients with subarachnoid haemorrhage (SAH) and determined the incidence of late rebleeding as an additional prognostic parameter. We treated 79 consecutive patients with SAH from an intracranial aneurysm admitted from a neurological intensive care unit by the endovascular route between 1993 and 1997 and 52 survivors were followed up in 1999-2000. The mean interval between SAH and follow-up was 41 months (range 13-74 months). Outcome was determined by the Glasgow outcome (GOS) and Rankin (RS) scales and by questions concerning neuropsychological disorders. The patients were analysed according to Hunt and Hess (H & H) grades I-III or IV-V on admission. We observed two episodes of rebleeding (3%) with impact on outcome at 907 and 2010 days after SAH, respectively. A complete recovery (GOS 5) was achieved in 53% of H & H grade I-III and 17% of grade IV-V patients; with death rates 19% and 50%, and morbidity according to the RS (5-2) 18% and 29%, respectively. Midterm morbidity after endovascular therapy is thus low. Rebleeding with an impact on outcome can be observed up to 2010 days after SAH, suggesting that long-term angiographic follow-up is indispensable.

Adult↗
PubMed2001

Heterobimetallic oxalato-bridged Cu(II)Re(IV) complexes. Synthesis, crystal structure and magnetic properties.

Three copper(II)-rhenium(IV) bimetallic complexes of formula [ReCl(4)(mu-ox)Cu(phen)(2)] (1), [ReCl(4)(mu-ox)Cu(phen)(2)].CH(3)CN (2), and [ReCl(4)(mu-ox)Cu(terpy) (H(2)O)][ReCl(4)(mu-ox)Cu(terpy)(CH(3)CN)] (3) (ox = oxalate anion, phen = 1,10-phenanthroline, and terpy = 2,2':6,2"- terpyridine) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. Complex 1 crystallizes in the triclinic system, space group P(-1), with a = 9.776(2), b = 11.744(3), c = 14.183(3) A, alpha =102.09(2) degrees, beta = 109.42(2) degrees, gamma = 107.11(2) degrees, and Z = 2, whereas 2 and 3 crystallize in the monoclinic system, space groups P2(1)/n and P2(1)/c, respectively, with a = 12.837(3), b = 17.761(4), c = 12.914(3) A, beta = 91.32(2) degrees, and Z = 4 for 2, and a = 8.930(2), b = 18.543(4), c = 27.503(6) A, beta = 94.67(2) degrees, and Z = 4 for 3. The structures of 1 and 2 are made up of neutral [ReCl(4)(mu-ox)Cu(phen)(2)] bimetallic units. Re(IV) and Cu(II) metal ions exhibit distorted octahedral coordination geometries, being bridged by a bis(bidentate) oxalato ligand. The presence of acetonitrile molecules of crystallization in 2 causes a somewhat greater separation between the bimetallic complexes and a different packing of these units in the crystal structure with respect to 1. The copper-rhenium separation across oxalato is 5.628(2) in 1 and 5.649(3) A in 2. The structure of 3 is made up of two different and neutral bimetallic units, [ReCl(4)(mu-ox)Cu(terpy)(H(2)O)] and [ReCl(4)(mu-ox)Cu(terpy)(CH(3)CN)]. In the first one, the oxalate group behaves as a bis(bidentate) ligand occupying one equatorial and one axial position in the elongated octahedral environment of Cu(II). The water molecule is axially coordinated. In the second one, the oxalate group behaves as a bidentate/monodentate ligand occupying the axial position in the square pyramidal environment of Cu(II). The acetonitrile molecule occupies a basal coordination position around the copper atom. These units are arranged in such a way that a chlorine atom of the first unit (Cl(1)) points toward the copper atom (Cu(2))of the second one (3.077(2) A for Cl(1)(.)Cu(2)), forming a tetranuclear species. The copper-rhenium separation across bis(didentate) oxalato is 5.504(3) A, whereas that through bidentate/monodentate oxalato is 5.436(2) A. The magnetic behavior of 2 and 3 has been investigated over the temperature range 1.8-300 K. A very weak and nearly identical antiferromagnetic coupling between Re(IV) and Cu(II) through bis(bidentate) oxalato occurs in 2 (J = -0.90 cm(-1)) and 3 (J = -0.83 cm(-1)); it is ferromagnetic in 3 through both the bidentate-monodentate oxalato (J = +5.60 cm(-1)) and the chloro (J = +0.70 cm(-1)) bridges.

Journal Article↗
PubMed2001

Comparison of operative and endovascular treatment of anterior circulation aneurysms in patients in poor grades.

We assessed the outcome of surgical and endovascular treatment in patients in poor (Hunt & Hess IV or V) grade following subarachnoid haemorrhage due to anterior circulation aneurysm (ACA). There were 41 patients, treated surgically (20), by the endovascular route (20) or both (1). The aneurysms were clipped in 20 patients, wrapped in one; 19 were treated with Guglielmi detachable coils (GDC), one by parent vessel occlusion using detachable balloons. One GDC treatment was interrupted and the aneurysm was surgically clipped instead. We treated five patients surgically to evacuate accompanying intracerebral clots. We treated 14 (66%) patients by the endovascular route and 15 (71%) surgically within 72 h of the haemorrhage. The frequency of delayed ischaemic neurological deficit and/or cerebral infarct due to vasospasm did not differ significantly between the endovascular and surgical groups. We had one surgical and three endovascular procedure-related complications with clinical manifestations. Outcome was evaluated after 6 months. After GDC treatment, angiographic follow-up was carried out between 8 and 26 months (mean 17 months). Good outcomes were achieved in six (29%) of the surgically treated patients (40% of the survivors) and six (30%) of the endovascular treatment patients (60% of the survivors). Outcome was similar after surgical and endovascular approaches. The decision as to which treatment to chosen is influenced mainly by clinical factors such as cerebral haematoma or age.

Adult↗
PubMed2001

Microembolic signal counts increase during hyperbaric exposure in patients with prosthetic heart valves.

BACKGROUND: Patients with prosthetic heart valves have an increased risk of thromboembolic events, and transcranial Doppler sonography reveals microembolic signals. Whereas microembolic signals were initially assumed to be of particulate matter, recent studies suggest that they are partially gaseous in origin. If this is true, alteration of environmental pressure should change microembolic signal counts. We undertook this study to evaluate the influence of hyperbaric exposure on microembolic signal counts in persons with prosthetic heart valves. METHODS AND RESULTS: Microembolic signal counts were monitored by transcranial Doppler sonography of both middle cerebral arteries under normobaria (normobaria 1), 2 subsequent periods of hyperbaria (2.5 and 1.75 bar), and a second period of normobaria (normobaria 2) in 15 patients with prosthetic heart valves. Each monitoring period lasted 30 minutes. Compression and decompression rates were 0.1 bar/min. Microembolic signal counts increased from 20 (12-78) at normobaria 1 to 79 (30-165) at 2.5 bar (P <.01 vs normobaria 1 and 2), decreased to 44 (18-128) at 1.75 bar (P <.01 vs normobaria 1 and 2.5 bar; P <.001 vs normobaria 2), and returned to 20 (8-96) at normobaria 2 (values are medians and 95% confidence intervals). CONCLUSIONS: Our results strongly suggest that gaseous bubbles are underlying material for part of the microembolic signals detected in patients with prosthetic heart valves.

Aortic Valve↗
PubMed2001

Does mirtazapine have a more rapid onset than SSRIs?

BACKGROUND: A single study utilizing a cross-sectional analysis of scores on the Hamilton Rating Scale for Depression (HAM-D) suggested that mirtazapine has a more rapid onset than selective serotonin reuptake inhibitors (SSRIs). Analysis based on the HAM-D may favor drugs with sleep-producing effects. The purpose of the present study was to determine if a review of all studies comparing an SSRI with mirtazapine, utilizing persistent improvement as the dependent variable, would suggest that mirtazapine had a more rapid onset than SSRIs. METHOD: All double-blind studies comparing mirtazapine with SSRIs were analyzed. Included in the analysis to determine speed of onset were 298 patients taking mirtazapine and 285 taking an SSRI. Pattern analysis, which has been described and used by other researchers, was employed to study speed of onset. RESULTS: At the end of each of the 3 studies, the total number of responders for each of the drugs did not differ. However, the proportion of responders with onset of persistent improvement in week 1 was greater for mirtazapine (13%, 38/298) than for the SSRIs (6%, 18/285; chi2 = 6.95, df = 1, p = .008). CONCLUSION: These data support the possibility that mirtazapine may have a more rapid onset than SSRIs. This observation should be considered preliminary because of the retrospective nature of the analysis and the absence of a placebo group.

Antidepressive Agents, Tricyclic↗
PubMed2000

Patient satisfaction with outpatient hysteroscopy versus day case hysteroscopy: randomised controlled trial.

OBJECTIVE: To compare outpatient hysteroscopy with day case hysteroscopy in terms of patient satisfaction and acceptability. SETTING: Gynaecology clinic of a teaching hospital. PARTICIPANTS: 100 women. DESIGN AND INTERVENTIONS: Patients were randomly allocated to outpatient hysteroscopy or day case hysteroscopy provided they had no preference for either procedure. MAIN OUTCOME MEASURES: Satisfaction rate, requirements for postoperative analgesia, speed of recovery, time away from home, and time off work. RESULTS: The outpatient group recovered preoperative fitness more quickly than the day case group (2 days (range 1-2.7) versus 3 days (2-4), P<0.05). After the procedure, the outpatient group were also fully mobile more quickly than the day case group (0 minutes (0-5) versus 105 minutes (80-120), P<0.001). Requirements for postoperative analgesia were similar in both groups. Overall, 78% of patients considered that the pain from outpatient hysteroscopy was less than that usually experienced during menstruation. Patient satisfaction was similar in both groups (83.6% in the outpatient group versus 77.0% in the day case group). CONCLUSIONS: Outpatient hysteroscopy and day case hysteroscopy were equally acceptable to patients. Patients recovered significantly more quickly from outpatient hysteroscopy than from day case hysteroscopy.

Adult↗
PubMed2000

In vitro studies of cryoablation of the endometrium.

OBJECTIVE: The aims of this study were to quantify the tissue damage in vitro of a series of freezing protocols with the Endocryo (Spembley Medical Ltd, Andover, United Kingdom) cryoprobe for ablation of the endometrium and to determine the relative importance of the freezing parameters contributing to the cryolesion. STUDY DESIGN: The efficacy and safety of the Endocryo cryoprobe were assessed in vitro with 84 different experiments on freshly excised uterine specimens. Tissue necrosis was quantified by means of a histochemical technique after incubation of the uterine specimens under nearly physiologic conditions. RESULTS: A typical lesion was made up of a superficial area of tissue necrosis and a deeper area of sublethal damage. Tissue necrosis was >3 mm when the probe was in direct contact with the endometrium. Consistent tissue necrosis was only observed with tissue temperatures below -30 degrees C. Safe tissue damage was only consistently seen after < or =2 minutes of freezing. When the gap between the probe and the endometrium was filled with distention medium and was >2 mm, tissue damage was insufficient for clinical purposes irrespective of the medium used. CONCLUSION: The Endocryo cryoprobe provided a successful means of achieving endometrial ablation in vitro. The use of a uterine distention medium appeared to be of little value in improving the efficacy of the probe in vitro.

Cell Death↗
PubMed2000

[1,3-Bis(diphenylphosphino)propane]trichlorooxorhenium(V).

Trichlorooxo[1,3-propanediylbis(diphenylphosphine)-P,P ']rhenium(V), [ReCl(3)O(C(27)H(26)P(2))], crystallizes with four formula units per unit cell. The crystal structure consists of neutral complexes of [ReOCl(3)(dppp)] [dppp is 1,3-bis(diphenylphosphino)propane] packed by H.pi-ring interactions. The Re atom is octahedrally coordinated to the oxo anion, three Cl atoms and two P atoms from the dppp ligand. The six-membered ring formed by the bidentate dppp ligand and the rhenium metal centre is in a chair conformation. The title compound is an intermediate in the synthesis of bis(dppp) complexes of rhenium.

Crystallography, X-Ray↗
PubMed1999

Outcome after endovascular treatment of Hunt and Hess grade IV or V aneurysms: comparison of anterior versus posterior circulation.

BACKGROUND AND PURPOSE: The most common cause of poor treatment outcome in patients suffering aneurysmal subarachnoid hemorrhage is cerebral vasospasm, especially in cases of poor Hunt and Hess grades (IV and V). A further prognostic factor in surgically treated patients is aneurysm localization. The aim of the present retrospective study is to compare the endovascular treatment outcome in such poor-grade patients according to aneurysm localization in either the anterior (AC) or posterior (PC) circulation. METHODS: Forty poor-grade patients admitted between 1993 and July 1998 were treated by endovascular approach within 23 days after aneurysm rupture. Eighteen had aneurysms in the AC, 22 in the PC. Mean treatment delay was 4 days after rupture and median, 2 days. One patient showed multiple aneurysms. In 36 cases, aneurysms were occluded by Guglielmi detachable coils; in 4 cases, by parent vessel balloon occlusion. RESULTS: The incidence of delayed ischemic neurological dysfunction or cerebral infarct due to vasospasm did not differ significantly between the AC and PC groups. Two procedure-related complications with clinical effect were observed in each group. At 6 months' follow-up, the result was good in 5 patients and poor in 13 in the AC group and good in 11 patients and poor in 11 in the PC group. CONCLUSION: Given comparable incidence of vasospasm in poor-grade patients, a tendency toward better treatment outcome was found in patients with aneurysms in the posterior circulation (chi(2)=2.04; P=0.15) than in the anterior circulation. Endovascular therapy for poor-grade patients is recommended, as are further studies to determine treatment differences.

Adolescent↗
PubMed1998

Flexible outpatient hysteroscopy without anaesthesia: a safe, successful and well tolerated procedure.

The objective of this study was to assess the feasibility and tolerance of diagnostic outpatient flexible hysteroscopy without anaesthesia. Records from 554 consecutive patients were analysed retrospectively. Success rate, reasons for failure, adverse reactions and level of pain were the main outcome measures. Hysteroscopy was successful in 90.5% of patients and well tolerated in 93.3%; 5.4% experienced moderate to severe pain. Inability to negotiate the cervical canal accounted for 47% of failed procedures and poor view for 42%. These results suggest that flexible outpatient hysteroscopy without anaesthesia is a successful and well tolerated procedure.

Adult↗