PubMed Health⌕ Search

Biomedical subjects

Alexander Schneider

Publications and source records attributed to Alexander Schneider.

At least 19 recordsLinked to original sources

A comparison of MRI, radiographic and clinical findings of the position of the TMJ articular disc following open treatment of condylar neck fractures.

We examined the position and function of the articular disc after open treatment of condylar fractures by comparing magnetic resonance images (MRI) and radiographs with clinical data. MRI and radiographs were taken after treatment of 28 patients with 33 fractures of the mandibular condyles. In all cases, the disc was located in the fossa after open reduction and internal fixation (ORIF). The MRI, radiographic and clinical findings did not correlate, and damage to the temporomandibular joint (TMJ) could be seen more clearly on MRI than on clinical or radiographic examination. Damage to soft tissues seen on MRI after treatment was more pronounced in dislocated than in displaced fractures.

Adult↗

Enhanced expression of interleukin-18 in serum and pancreas of patients with chronic pancreatitis.

AIM: To investigate interleukin-18 (IL-18) in patients with chronic panreatitis (CP). METHODS: We studied 29 patients with CP and 30 healthy controls. Peripheral blood mononuclear cells (PBMC) were isolated and incubated with 50 mmol/L ethanol, lipopolysaccharide (LPS) (doses 25 g/L, 250 g/L, 2500 g/L) and both agents for 24 h. Levels of IL-18 in the supernatants, and levels of IL-18, IL-12, interferon (IFN)-gamma and soluble CD14 in the serum were analysed by ELISA technique. Expression of IL-18 in PBMC was investigated by reverse-transcription (RT)-PCR. IL-18 protein levels in CP tissue and in normal pancreas were studied by ELISA technique. IL-18 levels in PBMC and pancreatic tissue were determined by Western blot. Immunohistochemistry for pancreatic IL-18 expression was performed. RESULTS: In patients, IL-18 serum levels were significantly enhanced by 76% (mean: 289.9+/-167.7 ng/L) compared with controls (mean: 165.2+/-43.6 ng/L; P<0.0005). IL-12 levels were enhanced by 25% in patients (18.3+/-7.3 ng/L) compared with controls (14.7+/-6.8 ng/L, P=0.0576) although not reaching the statistical significance. IFN-gamma and soluble CD14 levels were not increased. In vitro, LPS stimulated significantly and dose-dependently IL-18 secretion from PBMC. Incubation with ethanol reduced LPS-stimulated IL-18 secretion by about 50%. The mRNA expression of IL-18 in PBMC and the response of PBMC to ethanol and LPS was similar in CP patients and controls. In PBMC, no significant differences in IL-18 protein levels were detected between patients and controls. IL-18 protein levels were increased in CP tissues compared to normal pancreatic tissues. IL-18 was expressed by pancreatic acinar cells and by infiltrating inflammatory cells within the pancreas. CONCLUSION: IL-18 originates from the chronically inflammed pancreas and appears to be involved in the fibrotic destruction of the organ.

Adult↗

The unchanging incidence and case-fatality of stroke in the 1990s: a population-based study.

BACKGROUND AND PURPOSE: Many advances were made in stroke prevention strategies during the 1990s, and yet temporal trends in stroke incidence and case-fatality have not been reported in the United States. Blacks have a 2-fold higher risk of stroke; however, there are no data over time showing if any progress has been made in reducing racial disparity in stroke incidence. The objective of this study was to examine temporal trends in stroke incidence and case-fatality within a large, biracial population during the 1990s. METHODS: Within a biracial population of 1.3 million, all strokes were ascertained at all local hospitals using International Classification of Diseases, 9th Revision codes during July 1993 to June 1994 and again in 1999. A sampling scheme was used to ascertain cases in the out-of-hospital setting. Race-specific incidence and case-fatality rates were calculated and standardized to the 2000 US Census population. A population-based telephone survey regarding stroke risk factor prevalence and medication use was performed in 1995 and 2000. RESULTS: There were 1954 first-ever strokes in 1993-1994 and 2063 first-ever strokes in 1999. The annual incidence of first-ever hospitalized stroke did not significantly change between study periods: 158 per 100,000 in both 1993-1994 and 1999 (P=0.97). Blacks continue to have higher stroke incidence than whites, especially in the young; however, case-fatality rates continue to be similar between races and are not changing over time. Medication use for treatment of stroke risk factors significantly increased in the general population between study periods. CONCLUSIONS: Despite advances in stroke prevention treatments during the 1990s, the incidence of hospitalized stroke did not decrease within our population. Case-fatality also did not change between study periods. Excess stroke mortality rates seen in blacks nationally are likely the result of excess stroke incidence and not case-fatality, and the racial disparity in stroke incidence did not change over time.

Adolescent↗

Community socioeconomic status and prehospital times in acute stroke and transient ischemic attack: do poorer patients have longer delays from 911 call to the emergency department?

BACKGROUND AND PURPOSE: Timely access to medical treatment is critical for patients with acute stroke because acute therapies must be given very quickly after symptom onset. We examined the effect of socioeconomic status on prehospital delays in stroke and transient ischemic attack (TIA) patients within a large, biracial population. METHODS: By screening all local hospital ICD-9 codes 430 to 436, all stroke and TIA patients were identified during the calendar year of 1999. Cases must have used emergency medical services (EMS), lived at home, had their stroke at home, and had documented times of the 911 call and arrival to the emergency department. Socioeconomic status was estimated using economic data regarding the geocoded home residence census tract. RESULTS: Only 38% of stroke and TIA patients used EMS. There were 978 cases of stroke and TIA included in this analysis. The mean times were call to arrival on scene 6.5 minutes, on-scene time 14.1 minutes, and transport time 13.1 minutes. Lower community socioeconomic status was associated with all 3 EMS time intervals; however, all time differences were small: the largest difference was 5 minutes. CONCLUSIONS: Within our population, living in a poorer area does not appear to delay access to acute care for stroke in a clinically significant way. We did find small, statistically significant delays in prehospital times that were associated with poorer communities, black race, and increasing age. However, delays related to public recognition of stroke symptoms, and limited use of 911, are likely much more important than these small delays that occur with EMS systems.

Emergency Medical Services↗

Temporal trends in the incidence and case fatality of stroke in children and adolescents.

A recent study reported that mortality from stroke in children and adolescents decreased by 58% from 1979 to 1998, although it wasn't clear if the case fatality or the incidence of stroke in this age group is decreasing. We report trends of stroke incidence and case fatality in children and adolescents within a large biracial population. The study involved collection of all strokes in the study population between January 1, 1988 and December 31, 1989, July 1, 1993 and June 30, 1994, and January 1, 1999 and December 31, 1999, at all of the regional hospitals serving the Greater Cincinnati/Northern Kentucky population (only the children's hospital in 1988). Study nurses reviewed the medical records of all inpatients with stroke-related discharge diagnoses and abstracted relevant data. A study physician reviewed each abstract to determine whether a stroke or transient ischemic attack had occurred. A total of 54 strokes occurred in children or adolescents younger than 20 years during the three study periods (30% African American, 70% Caucasian, and 56% female). The overall incidence rate of all strokes in children younger than 15 years was 6.4/100,000 in 1999, a nonsignificant increase when compared to 1988. The 30-day case-fatality rates were 18% in 1988-1989, 9% in 1993-1994, and 9% in 1999. We found that the incidence of strokes in children has been stable over the past 10 years. The previously reported nationwide decrease in overall stroke mortality in children might be due to decreasing case fatality after stroke and not decreasing stroke incidence. Based on our data, we conservatively estimated that approximately 3000 children less than 20 years old would have a stroke in the United States in 2004.

Adolescent↗

Keratin 8 mutations are not associated with familial, sporadic and alcoholic pancreatitis in a population from the United States.

BACKGROUND AND AIMS: Genetic predispositions play a major role in the development of chronic pancreatitis. Recently, a mutation in the keratin 8 gene (G62C) was reported to be associated with chronic pancreatitis in Italy. We determined whether mutations in the keratin 8 gene are associated with familial, sporadic and alcoholic recurrent acute or chronic pancreatitis in a population from the United States. METHODS: We investigated the relevant genomic region of the keratin 8 gene in 80 patients with familial pancreatitis without a cationic trypsinogen (PRSS1) gene mutation from 52 different families, 21 patients with familial hereditary pancreatitis and a PRSS1 mutation from 20 different families, 126 patients with sporadic pancreatitis without a PRSS1 mutation, 61 patients with alcoholic pancreatitis and 271 controls by direct DNA sequencing. RESULTS: We found the heterozygous G62C mutation in n = 3/80 patients (n = 2/52 patients from different families, 3.8%) with familial pancreatitis without PRSS1 mutation and in n = 3/126 patients (2.4%) with sporadic pancreatitis. We detected an adjacent heterozygous I63V mutation in n = 2/80 patients (n = 2/52 patients from different families, 3.8%) with familial pancreatitis without PRSS1 mutation and in n = 1/61 patients (1.6%) with alcoholic pancreatitis. We found the G62C mutation in n = 2/271 controls (0.7%) and the I63V mutation in n = 2/271 controls (0.7%). There were no statistically significant differences in the genotype frequencies between patients and controls (p > 0.05). Screening of additional available family members revealed that these variants did not segregate with the disease phenotype. There was no statistically significant difference in the frequency of these keratin 8 variants between patients with chronic pancreatitis and controls (p > 0.05). CONCLUSION: These keratin 8 variants are not associated with familial, sporadic or alcoholic pancreatitis.

Adult↗

Association of apolipoprotein E4 and haplotypes of the apolipoprotein E gene with lobar intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Conflicting reports in the literature exist with regard to the association of apolipoprotein E (apo E) alleles and lobar intracerebral hemorrhage (ICH). We genotyped 12 single-nucleotide polymorphisms in the 5' upstream regulatory, exonic, and intronic regions of the apo E gene and performed genotype and haplotype association analyses. METHODS: We prospectively enrolled subjects with hemorrhagic stroke and matched them with 2 controls based on age, race, and sex. Each case was reviewed by a physician to determine case status and location of the ICH. Multivariate logistic-regression modeling with backward elimination was used to determine significant risk factors for lobar ICH. Associations at the genotype and haplotype levels and linkage disequilibrium were conducted according to standard statistical methods. RESULTS: Between May 1997 and December 2002, 315 cases of ICH were recruited, of whom 107 were lobar ICH cases matched to 205 controls. No association was found for apo E2, E3, or E4 with nonlobar ICH. Independent, significant risk factors for lobar ICH included apo E4, untreated hypertension, anticoagulant use, a first-degree relative with ICH, and < or =high school education (compared with >high school education). Treated hypercholesterolemia compared with "no history of hypercholesterolemia" was associated with a decreased risk of lobar ICH. Haplotype association analysis demonstrated a significant association of the apo E gene with lobar ICH among whites (P<0.0001) and blacks (P=0.0024). CONCLUSIONS: Apo E4 is independently associated with lobar ICH but not nonlobar ICH. Haplotypes of the apo E gene are associated with lobar ICH. Untreated hypertension is a risk factor for lobar ICH.

Alleles↗

Racial variations in location and risk of intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Risk factors for intracerebral hemorrhage (ICH) vary by location. Incidence rates of ICH are known to be higher in American blacks than whites, but how rates may differ by hemorrhage location is unknown. We sought to define incidence rates for different ICH locations in a biracial population. METHODS: All hospitalized patients age > or =20 years with spontaneous ICH were identified in the Greater Cincinnati/Northern Kentucky metropolitan area from May 1998 to July 2001 and August 2002 to April 2003. Incidence rates per 100,000 persons were age, sex, and race adjusted as appropriate to the 2000 US population. Risk ratios (RRs) with 95% CIs were calculated from unadjusted incidence rates. RESULTS: There were 1038 qualifying ICHs. Annual incidence rates per 100,000 persons > or =20 years of age were 48.9 for blacks and 26.6 for whites. Annual incidence rates per 100,000 blacks in lobar, deep cerebral, brain stem, and cerebellar locations were 15.2, 25.7, 5.1, and 2.9, respectively. Annual incidence rates per 100,000 whites in the same locations were 9.4, 13.0, 1.3, and 2.9. The greatest excess risk of ICH in blacks compared with whites was found among young to middle-aged (35 to 54 years) persons with brain stem (RR, 9.8; 95% CI, 4.2 to 23.0) and deep cerebral (RR, 4.5; 3.0 to 6.8) hemorrhage. CONCLUSIONS: The excess risk of ICH in American blacks is largely attributable to higher hemorrhage rates in young and middle-aged persons, particularly for deep cerebral and brain stem locations. Hypertension is the predominant risk factor for hemorrhages in these locations.

Adult↗

Incidence and short-term prognosis of transient ischemic attack in a population-based study.

BACKGROUND AND PURPOSE: Transient ischemic attacks (TIAs) have been shown to be a strong predictor of subsequent stroke and death. We present the incidence and short-term prognosis of TIA within a large population with a significant proportion of minorities with out-of-hospital TIA. METHODS: TIA cases were identified between July 1, 1993 and June 30, 1994 from the Greater Cincinnati/Northern Kentucky population of 1.3 million inhabitants by previously published surveillance methods, including inpatient and out-of-hospital events. Incidence rates were adjusted to the 1990 population, and life-table analyses were used for prognosis. RESULTS: The overall race, age, and gender-adjusted incidence rate for TIA within our population was 83 per 100,000, with age, race, and gender adjusted to the 1990 US population. Blacks and men had significantly higher rates of TIA than whites and women. Risk of stroke after TIA was 14.6% at 3 months, and risk of TIA/stroke/death was 25.2%. Age, race, and sex were not associated with recurrent TIA or subsequent stroke in our population, but age was associated with mortality. CONCLUSIONS: Using our incidence rates for TIA in blacks and whites, we conservatively estimate that approximately 240 000 TIAs occurred in 2002 in the United States. Our incidence rate of TIA is slightly higher than previously reported, which may be related to the inclusion of blacks and out-of-hospital events. There are racial and gender-related differences in the incidence of TIA. We found a striking risk of adverse events after TIA; however, there were no racial or gender differences predicting these events. Further study is warranted in interventions to prevent these adverse events after TIA.

Adult↗

The effect of ethanol and alcoholic beverages on gastric emptying of solid meals in humans.

AIMS: The systematic study of the effect of pure ethanol, alcoholic beverages, and their non-alcoholic components on gastric emptying of solid meals in humans. METHODS: 16 fasting healthy male subjects received once weekly 300 ml of the following solutions in random order: 4 and 10% (v/v) ethanol, beer, red wine, 5.5 and 11.4% (w/v) glucose, and water. The test solutions were given either together with a low caloric (270 kcal, n = 8) or a high caloric (740 kcal, n = 8) solid meal. Ultrasonography of the antrum was used to determine gastric emptying. RESULTS: Gastric half emptying time (t(1/2) ) of the high caloric solid meal with water was 131.3 +/- 7 min. The ingestion of 4 and 10% (v/v) ethanol (158.8 +/- 9.3 and 165.6 +/- 6.2 min, respectively), beer (163.1 +/- 11 min), and red wine (186.3 +/- 8.4 min) resulted in a significantly longer t(1/2) than water. The lag phases after 4 and 10% (v/v) ethanol, beer, and red wine were not significantly different from that of water (48.1 +/- 6.5 min). Compared with water, the ingestion of 5.5 and 11.4% (w/v) glucose resulted in a significantly longer t(1/2) (153.8 +/- 5 and 168.1 +/- 14.4 min, respectively) by increasing the duration of the lag phase. The high caloric meals resulted in a 2-fold prolongation of t(1/2) when compared with the low caloric meals. The effect of the solutions on the gastric emptying times, however, was similar for both test meals. CONCLUSIONS: (i) Ethanol in low concentrations of 4 and 10% (v/v) prolongs gastric emptying of solid meals; this inhibitory effect is not dose-dependent. (ii) Alcoholic beverages (beer and red wine) also result in a prolongation of gastric emptying. The inhibitory effect of red wine, but not of beer, is more pronounced than that of the corresponding ethanol concentration and amount. (iii) The inhibitory effect of ethanol and alcoholic beverages is mainly induced by a prolongation of the gastric emptying phase (without affecting the lag phase), whereas 5.5 and 11.4% (w/v) glucose prolong the lag phase in a dose-dependent manner. (iv) The inhibitory effect of ethanol, beer, and red wine on gastric emptying does not depend on the caloric content of the meal.

Adult↗

A description of Canadian and United States physician reimbursement for thrombolytic therapy administration in acute ischemic stroke.

BACKGROUND AND PURPOSE: Acute ischemic stroke patients are infrequently treated with rtPA, despite its proven effectiveness. Poor physician reimbursement for acute stroke care is one possible explanation for the low frequency of use. We describe the physician reimbursement for thrombolytic therapy for the stroke team physicians serving the Greater Cincinnati/Northern Kentucky region (GCNK), and the Alberta region. METHODS: GCNK: billing logs were accessed for the study period of 7/01-12/02, and cross-matched to stroke call logs. University of Calgary (UC): treatment records of a single physician were reviewed from 4/02-3/04. A telephone survey of Canadian provinces was conducted regarding billing practices. RESULTS: GCNK: During the study period, 151 patients received rtPA. For treated pts. the average time spent was 2.6 hours, and average reimbursement received was 472 dollars (of those with insurance). The highest reimbursement was received by billing critical care codes. Reimbursement for critical care was similar to or lower than common office procedures for neurologists. UC: during the study period, 131 patients received rtPA. Average reimbursement for rtPA treated patients was 340 dollars US, not including on-call payments. Survey across Canada revealed many provinces with weekend/after hour premium stipends and on-call stipends. CONCLUSIONS: Physician reimbursement for the evaluation and treatment of acute stroke, when compared with other diagnoses commonly treated by neurologists, is relatively low in both the U.S. and Canada. Health policy decision-makers in the US and Canada should be made aware of the importance of providing a more balanced plan to provide medical care to stroke patients.

Alberta↗

Serine protease inhibitor kazal type 1 mutations and pancreatitis.

SPINKI is thought to play an important role in protecting the pancreas against excessive trypsinogen activation. SPINK1 mutations are associated with the development of acute and chronic pancreatitis and have been detected in all forms of chronic pancreatitis. The strong association of mutations in the PRSS1 gene and in the SPINKI gene with chronic pancreatitis supports the concept of intracellular trypsin activation as an initiating and extremely important step in the development of pancreatitis. The N34S mutation represents the most frequently observed pancreatitis-associated SPINKI variant. Because the SPINKI N34Smutation is very common in the general population, it is unlikely that this mutation alone can initiate the development of chronic pancreatitis. Thus, it rather appears that in most patients with SPINKI-associated chronic pancreatitis, this genetic variant acts as disease modifier or within a polygenic model with other yet unidentified genes or environmental co-factors. The possible interaction of mutations in the SPINK1 gene with other pancreatitis-associated susceptibility genes has to be investigated in future research efforts. The most promising candidate gene for such an interaction is the CFTR gene, because genetic alterations within the CFTRgene are also common in the general population and already have been associated with chronic pancreatitis.

Carrier Proteins↗

Lag screw osteosynthesis of fractures of the mandibular condyle: potential benefit of preoperative planning using multiplanar CT reconstruction.

OBJECTIVE: The purpose of the study was to develop a method of multiplanar CT reconstruction in fractures of the mandibular condyle in order to evaluate the feasibility of lag screw osteosynthesis. STUDY DESIGN: Angulated axial and sagittal images of the mandibular ramus were calculated using collected CT data. In 183 mandibular rami the optimal position of the screw axis was determined retrospectively. The thickness of the covering bone as well as the degree of screw exposure were measured. RESULTS: Application of the method led to medial (28.4% of cases) or lateral (3.8% of cases) correction of the usual screw axis. In 1.6% of cases an extraosseous position of screws could not be avoided by this correction. CONCLUSIONS: Evaluation of the feasibility of lag screw osteosynthesis by this method is possible. Medial or lateral change of the axis ensures the optimal intraosseous screw position. Intraosseous screw placement is almost always possible.

Bone Screws↗

Alcoholic pancreatitis.

A history of excessive alcohol consumption is found in the majority of patients with chronic pancreatitis, and numerous research efforts revealed insights into the pathogenesis of alcohol-induced pancreatic damage. However, the exact mechanisms underlying the disease are not yet clarified, and the origin of alcoholic chronic pancreatitis continues to be the topic of speculation and investigation. This article provides an overview about the epidemiology of alcoholic chronic pancreatitis, the epidemiologic association of alcohol intake and pancreatitis and the clinical course of the disease. Finally, this article summarizes several hypothetical concepts that try to explain the early and late pathophysiological mechanisms of acute and chronic pancreatitis.

Alcohol Drinking↗

Treatment of alcoholic pancreatitis.

Chronic pancreatitis is characterized by progressive and irreversible loss of pancreatic exocrine and endocrine function. The majority of cases in the Western world are related to alcohol consumption. Treatment of alcoholic chronic pancreatitis has been difficult, since the mechanisms of disease progression and the causes of pain are poorly understood. The conservative management of chronic pancreatitis focuses on (a) avoidance of precipitating factors such as alcohol and smoking; (b) treatment of pain, and (c) replacement of exocrine and endocrine function. There is a lack of good controlled, randomized treatment trials in alcoholic pancreatitis. However, there is good evidence that lifestyle changes, such as alcohol cessation, hamper progression of the disease. Conservative treatment of pain should be based on a stepwise approach; however, underlying causes such as pseudocysts may require endoscopic or surgical therapy. Treatment of exocrine insufficiency requires pancreatic enzyme supplementation and adjustment to several smaller meals per day, while treatment of endocrine insufficiency requires insulin treatment.

Alcoholism↗

Epidemiology of ischemic stroke in patients with diabetes: the greater Cincinnati/Northern Kentucky Stroke Study.

OBJECTIVE: Diabetes is a well known risk factor for stroke, but the impact of diabetes on stroke incidence rates is not known. This study uses a population-based study to describe the epidemiology of ischemic stroke in diabetic patients. RESEARCH DESIGN AND METHODS: Hospitalized cases were ascertained by ICD-9 discharge codes, prospective screening of emergency department admission logs, and review of coroner's cases. A sampling scheme was used to ascertain cases in the out-of-hospital setting. All potential cases underwent detailed chart abstraction by study nurses followed by physician review. Diabetes-specific incidence rates, case fatality rates, and population-attributable risks were estimated. RESULTS: Ischemic stroke patients with diabetes are younger, more likely to be African American, and more likely to have hypertension, myocardial infarction, and high cholesterol than nondiabetic patients. Age-specific incidence rates and rate ratios show that diabetes increases ischemic stroke incidence at all ages, but this risk is most prominent before age 55 in African Americans and before age 65 in whites. One-year case fatality rates after ischemic stroke are not different between those patients with and without diabetes. CONCLUSIONS: Given the "epidemic" of diabetes, with substantially increasing diabetes prevalence each year across all age- and race/ethnicity groups, the significance of diabetes as a risk factor for stroke is becoming more evident. Diabetes is clearly one of the most important risk factors for ischemic stroke, especially in those patients less than 65 years of age. We estimate that 37-42% of all ischemic strokes in both African Americans and whites are attributable to the effects of diabetes alone or in combination with hypertension.

Adult↗

Transforming growth factor-beta1, interleukin-10 and interferon-gamma cytokine polymorphisms in patients with hereditary, familial and sporadic chronic pancreatitis.

BACKGROUND: The genetic influence is undefined in about 40% of patients with hereditary and familial pancreatitis and in the majority of patients with sporadic chronic pancreatitis. The pathophysiological mechanisms underlying the progression from acute to chronic pancreatitis have not been clarified. Cytokines participate in the immunological progression of pancreatic inflammation and may play an important role in the development of pancreatic fibrosis. AIMS: We determined whether functional polymorphisms in the transforming growth factor-beta1 gene at positions -509, +869 (codon 10) and +915 (codon 25), in the interleukin-10 gene at position -1082, and in the intron 1 of the interferon-gamma gene at position +874 are associated with hereditary, familial or sporadic pancreatitis. METHODS: We investigated 78 patients with hereditary and familial pancreatitis and 62 patients with sporadic pancreatitis that were tested negative for cationic trypsinogen gene mutations, and 73 controls. Mutational analysis was performed by direct DNA sequencing or by amplification refractory mutational system polymerase chain reaction. We used the age at onset as marker of disease severity. RESULTS: The genotype frequencies were similar between patients and controls for all investigated cytokine polymorphisms (p > 0.05). We did not find an association between the different genotypes and the age at onset of the disease, and we did not detect different genotype distributions in patients with morphological alterations on pancreatic imaging after a disease duration of up to 5 years. CONCLUSION: These genetic variants do not play a dominant role in hereditary, familial or sporadic chronic pancreatitis.

Adolescent↗