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Biomedical subjects

J Kramer

Publications and source records attributed to J Kramer.

At least 19 recordsLinked to original sources
PubMed2001

Effect of gender on the outcomes of contemporary percutaneous coronary intervention.

Limited information exists regarding the outcomes of newer percutaneous coronary intervention (PCI) technologies in women. This study sought to determine whether female gender is an independent risk factor for PCI mortality and/or complications in contemporary practice. Using information from the National Cardiovascular Network (NCN) Database on 109,708 (33% women) PCI cases from 22 hospitals between January 1994 and January 1998, we examined the association of gender with unadjusted and risk-adjusted procedural outcomes. Women undergoing PCI were older, smaller, and had more comorbid illness than men, but less extensive coronary disease. Temporal trends in PCI device selection were similar in men and women. Compared with men, women had higher unadjusted procedural mortality rates (1.8% vs 1.0%, p <0.001), more strokes (0.4% vs 0.2%, p <0.001), and higher vascular complication rates (5.4% vs 2.7%, p <0.001). However, after adjusting for baseline clinical risk factors, and importantly, body surface area, women and men had similar PCI mortality risks (adjusted odds ratio 1.07, 95% confidence interval 0.92 to 1.24). Gender was not an independent risk factor for mortality among subgroups receiving coronary stent or atherectomy devices after risk adjustment. However, women undergoing PCI remained at higher risk for stroke, vascular complications, and repeat in-hospital revascularization than men, even after risk adjustment. We conclude that in contemporary practice, a patient's body size rather than gender, conveys independent risk for mortality after PCI.

Angioplasty, Balloon, Coronary↗
PubMed2001

Fracture repair of the distal portion of the radius by use of a condylar screw implant in an adult horse.

An 8-year-old American Quarter Horse gelding was evaluated because of an open fracture involving the left radius. The horse had fallen during training and became immediately non-weight-bearing in the left forelimb. On initial evaluation, the horse was unable to bear weight on that limb; radiography revealed a long oblique fracture of the distal metaphysis of the radius with minimal displacement of the fracture fragments. Because of the configuration of the fracture, we recommended surgical intervention with internal fixation. A condylar screw implant and 4.5-mm broad dynamic compression plate were applied to the medial and dorsolateral aspects of the radius, respectively. The horse recovered in a sling and full-limb bandage. Six months after discharge, the horse was reevaluated because of a grade 4/5 lameness in the same limb. Palpation revealed signs of severe pain over the distomedial aspect of the radius. Radiography of the left radius revealed severe osteolysis beneath the distal aspect of the condylar screw implant. Surgical removal of the medial plate was performed. Sixteen months after the initial fracture repair, the horse had returned to light training without signs of lameness. Removal of the dorsal plate may be indicated if this horse is to return to aggressive training or becomes lame in the left forelimb.

Animals↗
PubMed2001

Characterization of the innate and adaptive immunity to Salmonella enteritidis PT1 infection in four broiler lines.

Four broiler lines were inoculated orally with Salmonella enteritidis phage type 1 at the age of 7 days (experiment A: lines 1 and 2) and at the age of 1 day (experiment B: lines 3 and 4). At various days post-infection chickens were sacrificed and the number of Salmonella in the caeca, liver, and spleen were determined. Furthermore, phagocytic activity, cellular immune responses, and humoral responses were determined using, respectively, single-cell suspensions of spleen or intestine and serum. In both experiments, similar trends were seen. Increased numbers of S. enteritidis were found in the caeca of lines 1 and 3, whereas at the same time a decreased colonization was found in the spleen and in the liver, as compared to lines 2 and 4. In the latter two lines, the phagocytic activity of the phagocytes was higher and the humoral responses were lower. Observations from this study suggest that lower activity of phagocytes and higher humoral activity prevent systemic S. enteritidis infection.

Animals↗
PubMed2001

[Cysts and cystoid formations].

Cystic and cyst-like lesions of bone are very common. They can be of primary origin or secondarily caused by several diseases. For exact diagnosis or at least narrow differential diagnosis the assessment of radiological findings is important. However, patient data, clinical symptoms, laboratory parameters, and site of the lesion have to be included for a reasonable final diagnosis or differential diagnosis.

Bone Cysts↗
PubMed2001

Verbal and design fluency in patients with frontal lobe lesions.

The ability to generate items belonging to categories in verbal fluency tasks has been attributed to frontal cortex. Nonverbal fluency (e.g., design fluency) has been assessed separately and found to rely on the right hemisphere or right frontal cortex. The current study assessed both verbal and nonverbal fluency in a single group of patients with focal, frontal lobe lesions and age- and education-matched control participants. In the verbal fluency task, participants generated items belonging to both letter cues (F, A, and S) and category cues (animals and boys' names). In the design fluency task, participants generated novel designs by connecting dot arrays with 4 straight lines. A switching condition was included in both verbal and design fluency tasks and required participants to switch back and forth between different sets (e.g., between naming fruits and furniture). As a group, patients with frontal lobe lesions were impaired, compared to control participants, on both verbal and design fluency tasks. Patients with left frontal lesions performed worse than patients with right frontal lesions on the verbal fluency task, but the 2 groups performed comparably on the design fluency task. Both patients and control participants were impacted similarly by the switching conditions. These results suggest that verbal fluency is more dependent on left frontal cortex, while nonverbal fluency tasks, such as design fluency, recruit both right and left frontal processes.

Aged↗
PubMed2001

Centrosomes and the Scrambled protein coordinate microtubule-independent actin reorganization.

In Drosophila syncytial blastoderm embryos, centrosomes specify the position of actin-based interphase caps and mitotic furrows. Mutations in the scrambled locus prevent assembly of mitotic furrows, but do not block actin cap formation. The scrambled gene encodes a protein that localizes to the mitotic furrows and centrosomes. Sced localization, actin reorganization from caps into mitotic furrows, and centrosome-coordinated assembly of actin caps are not blocked by microtubule disruption. Our results indicate that centrosomes may coordinate assembly of cortical actin caps through a microtubule-independent mechanism, and that Scrambled mediates a second microtubule-independent process that drives mitotic furrow assembly.

Actins↗
PubMed2001

[Magnetic resonance imaging and magnetic resonance arthrography of the acetabular labrum: comparison with surgical findings].

AIM OF THE STUDY: To evaluate the accuracy of magnetic resonance imaging (MRI) and magnetic resonance (MR) arthrography in detecting acetabular labral lesions in correlation to surgical findings. PATIENTS AND METHODS: Forty patients (40 hips) with chronic hip pain and a strong clinical suspicion of labral lesions were examined with MRI in the coronal and axial plane by obtaining T1 weighted and proton density-weighted spin echo sequences. Additionally, MR arthrography of the hip joint in the coronal oblique and sagittal oblique plane was performed by obtaining T1-weighted three-dimensional gradientecho sequences after the intraarticular injection of gadopentate dimeglumine. The labra were prospectively evaluated on the basis of morphology, signal intensity, the presence or absence of a tear, and their attachment to the acetabulum. All patients underwent surgery, and the MRI findings and MR arthrography findings were compared with the surgical results. RESULTS: Surgically, 34 labral lesions, and 6 normal labra were detected. MRI correctly depicted labral lesions in 24 patients and two normal labra, and MR arthrography correctly depicted labral lesions in 30 patients and 5 normal labra compared with the surgical results. The sensitivity of MRI was 80%, the accuracy of MRI was 65%, the sensitivity of MR arthrography was 95%, and the accuracy of MR arthrography was 88%. CONCLUSIONS: MR arthrography enables considerably more accurate detection of acetabular labral lesions than MRI. MR arthrography should be the method of choice for the diagnosis of the presence or absence of acetabular labral lesions in patients with chronic hip pain and a strong clinical suspicion of labral lesions.

Acetabulum↗
PubMed2001

Introduction of the new Centers for Disease Control and Prevention group B streptococcal prevention guideline at a large West Coast health maintenance organization.

OBJECTIVE: Our purpose was to assess the impact of new consensus guidelines issued by the Centers for Disease Control and Prevention, The American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics to prevent perinatal group B streptococcal disease. STUDY DESIGN: We performed a descriptive analysis and a before-and-after analysis of implementation of the group B streptococcal disease prevention guidelines among singleton-birth pregnancies in 2 Group Health Cooperative hospitals from October 1, 1995, through December 31, 1997. We studied the speed and completeness of implementation and the effect on pregnancy care practices including intrapartum antibiotic use, test ordering, and maternal and neonatal health. RESULTS: Guideline implementation occurred rapidly. The proportion of term pregnancies screened according to the guideline increased markedly, and overall intrapartum antibiotic use more than doubled. Among group B streptococci-positive women, intrapartum antibiotic prophylaxis increased from 24% before to 74% after guideline implementation. Median duration of treatment before delivery increased from 1.8 to 4.3 hours. The rate of rash did not increase, and there were no cases of anaphylaxis or pseudomembranous colitis. The proportion of infants undergoing evaluation decreased after implementation of the neonatal guidelines; among infants of group B streptococci-negative women, test ordering dropped by almost 40%. CONCLUSIONS: Implementation of the new guidelines is feasible and can be accomplished rapidly. The guidelines were associated with increased maternal intrapartum antibiotic use, particularly among women at highest risk, and with a decrease in laboratory use for infants.

Adult↗
PubMed2001

Hip abduction-adduction strength and one-leg hop tests: test-retest reliability and relationship to function in elite ice hockey players.

STUDY DESIGN: Single group, test-retest. OBJECTIVES: To determine: (1) hip abduction and adduction torques during concentric and eccentric muscle actions, (2) medial and lateral one-leg hop distances, (3) the test-retest reliability of these measurements, and (4) the relationship between isokinetic measures of hip muscle strength and hop distances in elite ice hockey players. BACKGROUND: The skating motion used in ice hockey requires strong contractions of the hip and knee musculature. However, baseline scores for hip strength and hop distances, their test-retest reliability, and measures of the extent to which these tests are related for this population are not available. METHODS AND MEASURES: The dominant leg of 27 men (mean age 20 +/- 3 yrs) was tested on 2 occasions. Hip abduction and adduction movements were completed at 60 degrees.s(-1) angular velocity, with the subject lying on the non-test side and the test leg moving vertically in the subject's coronal plane. One-leg hops requiring jumping from and landing on the same leg without losing balance were completed in the medial and lateral directions. RESULTS: Hip adduction torques were significantly greater than abduction torques during both concentric and eccentric muscle actions, while no significant difference was observed between medial and lateral hop distances. Although hop test scores produced excellent ICCs (> 0.75) when determined using scores on 1 occasion, torques needed to be averaged over 2 test occasions to reach this level. Correlations between the strength and hop tests ranged from slight to low (r = -0.26 to 0.27) and were characterized by wide 95% confidence intervals (-0.54 to 0.61). CONCLUSIONS: Isokinetic tests of hip abduction and adduction did not provide a strong indication of performance during sideways hop tests. Although isokinetic tests can provide a measure of muscular strength under specific test conditions, they should not be relied upon as a primary indicator of functional abilities or readiness to return to activity.

Adult↗
PubMed2000

Interleukin 21 and its receptor are involved in NK cell expansion and regulation of lymphocyte function.

Cytokines are important in the regulation of haematopoiesis and immune responses, and can influence lymphocyte development. Here we have identified a class I cytokine receptor that is selectively expressed in lymphoid tissues and is capable of signal transduction. The full-length receptor was expressed in BaF3 cells, which created a functional assay for ligand detection and cloning. Conditioned media from activated human CD3+ T cells supported proliferation of the assay cell line. We constructed a complementary DNA expression library from activated human CD3+ T cells, and identified a cytokine with a four-helix-bundle structure using functional cloning. This cytokine is most closely related to IL2 and IL15, and has been designated IL21 with the receptor designated IL21 R. In vitro assays suggest that IL21 has a role in the proliferation and maturation of natural killer (NK) cell populations from bone marrow, in the proliferation of mature B-cell populations co-stimulated with anti-CD40, and in the proliferation of T cells co-stimulated with anti-CD3.

Amino Acid Sequence↗
PubMed2000

Cognitive decline in women in relation to non-protein-bound oestradiol concentrations.

BACKGROUND: Previous studies have found no association between serum concentrations of total oestradiol and cognitive function, but these measurements may not reflect concentrations of hormone available to the brain. We tested the hypothesis that concentrations of non-protein-bound (free) and loosely bound (bioavailable) sex hormones are associated with cognitive function in older women. METHODS: We measured cognitive performance with a modified mini mental status examination (mMMSE) at baseline (1986-88) and 6 years later in 425 women (65 years or older). Concentrations of non-protein-bound and bioavailable oestradiol and total and non-protein-bound testosterone were measured by RIA in serum samples taken at baseline. FINDINGS: Initial cognitive scores did not differ by tertile of non-protein-bound oestradiol, bioavailable oestradiol, or testosterone. Cognitive impairment (a decrease of 3 points or more in mMMSE score) occurred in five (5%) of 94 women in the high tertile for non-protein-bound oestradiol and in 17 (16%) of 106 in the low tertile (odds ratio 0.3 [95% CI 0.1-0.8]). After adjustment for age, years of education, body-mass index, current oestrogen use, history of surgical menopause, and baseline mMMSE score, the odds ratio was 0.3 (0.1-0.9). The results were similar for bioavailable oestradiol (five [5%] vs 15 [15%]; adjusted odds ratio 0.3 [0.1-1.0]). There was no association between risk of cognitive impairment and serum testosterone. INTERPRETATION: Women with high serum concentrations of non-protein-bound and bioavailable oestradiol, but not testosterone, were less likely to develop cognitive impairment than women with low concentrations. This finding supports the hypothesis that higher concentrations of endogenous oestrogens prevent cognitive decline.

Aged↗
PubMed2000

Gastric impaction and obstruction of the small intestine associated with persimmon phytobezoar in a horse.

Signs of mild colic, intermittent lethargy, and weight loss of 6 weeks' duration in a 2-year-old Quarter Horse gelding were attributed to persimmon (Diospyros virginiana) phytobezoar formation. Diagnosis of the phytobezoar was facilitated by gastric endoscopy. Signs of gastrointestinal tract obstruction were associated with a large phytobezoar in the lumen of the stomach, gastric ulceration, and obstruction of the small intestine (as a consequence of fragmentation of the primary bezoar). Conservative treatment, using mineral oil and dioctyl sodium sulfosuccinate, was unsuccessful. A celiotomy was performed, and gastric impaction and partial obstruction of the small intestine associated with phytobezoar formation and fragmentation were identified. The horse made a complete recovery following removal of all phytobezoars. Persimmon phytobezoar should be considered in the fall and winter as a possible cause of lethargy, colic, and weight loss in horses allowed access to persimmon fruit.

Animals↗
PubMed2000

Comparative genomic sequence analysis of the human and mouse cystic fibrosis transmembrane conductance regulator genes.

The identification of the cystic fibrosis transmembrane conductance regulator gene (CFTR) in 1989 represents a landmark accomplishment in human genetics. Since that time, there have been numerous advances in elucidating the function of the encoded protein and the physiological basis of cystic fibrosis. However, numerous areas of cystic fibrosis biology require additional investigation, some of which would be facilitated by information about the long-range sequence context of the CFTR gene. For example, the latter might provide clues about the sequence elements responsible for the temporal and spatial regulation of CFTR expression. We thus sought to establish the sequence of the chromosomal segments encompassing the human CFTR and mouse Cftr genes, with the hope of identifying conserved regions of biologic interest by sequence comparison. Bacterial clone-based physical maps of the relevant human and mouse genomic regions were constructed, and minimally overlapping sets of clones were selected and sequenced, eventually yielding approximately 1.6 Mb and approximately 358 kb of contiguous human and mouse sequence, respectively. These efforts have produced the complete sequence of the approximately 189-kb and approximately 152-kb segments containing the human CFTR and mouse Cftr genes, respectively, as well as significant amounts of flanking DNA. Analyses of the resulting data provide insights about the organization of the CFTR/Cftr genes and potential sequence elements regulating their expression. Furthermore, the generated sequence reveals the precise architecture of genes residing near CFTR/Cftr, including one known gene (WNT2/Wnt2) and two previously unknown genes that immediately flank CFTR/Cftr.

Animals↗
PubMed2000

[Diagnostic imaging in femur head necrosis].

Diagnosis of avascular necrosis (AVN) of the hip has been improved by the technical progress of imaging modalities during the last decade. For a long period, only plain radiographs had been available. Scintigraphy and computed tomography contributed to differential diagnosis and early detection of bone necrosis. In the meantime, MR imaging has gained special value in the evaluation of AVN. It is now the method of choice for early detection as well as for assessment in later stage disorders. Using the ARCO system, all imaging modalities and their diagnostic viability are described. Findings regarding the different stages of AVN are correlated to tissue-specific changes.

Diagnostic Imaging↗
PubMed2000

Embryonic stem cell-derived chondrogenic differentiation in vitro: activation by BMP-2 and BMP-4.

Differentiation of mouse embryonic stem (ES) cells via embryoid bodies was established as a suitable model to study development in vitro. Here, we show that differentiation of ES cells in vitro into chondrocytes can be modulated by members of the transforming growth factor-beta family (TGF-beta(1), BMP-2 and -4). ES cell differentiation into chondrocytes was characterized by the appearance of Alcian blue-stained areas and the expression of cartilage-associated genes and proteins. Different stages of cartilage differentiation could be distinguished according to the expression pattern of the transcription factor scleraxis, and the cartilage matrix protein collagen II. The number of Alcian-blue-stained areas decreased slightly after application of TGF-beta(1), whereas BMP-2 or -4 induced chondrogenic differentiation. The inducing effect of BMP-2 was found to be dependent on the time of application, consistent with its role to recruit precursor cells to the chondrogenic fate.

Aggrecans↗
PubMed2000

Cognitive consequences and central nervous system injury following treatment for childhood leukemia.

OBJECTIVES: To determine the relationship between membrane damage and intellectual and academic abilities in children with acute lymphoblastic leukemia (ALL) and pilot test a math intervention for children with ALL who were affected. DATA SOURCES: Research studies and review articles. CONCLUSIONS: Despite the prophylactic central nervous system (CNS) treatment for long-term disease-free survival, many children with ALL subsequently experience declines in intellectual and academic skills. IMPLICATIONS FOR NURSING PRACTICE: Improving academic abilities in children who have received CNS treatment is of high priority and may have longlasting implications on quality of life.

Analysis of Variance↗
PubMed2000

Streptokinase does not activate the complement system.

Streptokinase is an extensively used thrombolytic agent. However, different preparations cause severe hypotension during therapy, partially related to the complement cascade activation. In four ischaemic stroke patients treated with Streptase, an increased level of soluble terminal complement complex (SC5b-9) was measured. In the sera of normal subjects, the increase in SC5b-9 induced by Streptase, Kabikinase and Calbiochem streptokinases was highly significant (P < 0.005). Sigma streptokinase did not activate the complement system. Sigma streptokinase analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed a homogeneous band. The other three preparations were contaminated with albumin and other proteins. Based on our in vivo and in vitro data, we conclude that complement activation is related to contamination of different streptokinase products rather than the streptokinase itself.

Acute Disease↗