Biomedical subjects

D Hu

Publications and source records attributed to D Hu.

At least 37 records · Page 2Linked to original sources

PubMed2001

Molecular aspects of healing in stabilized and non-stabilized fractures.

Bone formation is a continuous process that is initiated during fetal development and persists in adults in the form of bone regeneration and remodeling. These latter two aspects of bone formation are clearly influenced by the mechanical environment. In this study we tested the hypothesis that alterations in the mechanical environment regulate the program of mesenchymal cell differentiation, and thus the formation of a cartilage or bony callus, at the site of injury. As a first step in testing this hypothesis we produced stabilized and non-stabilized tibial fractures in a mouse model, then used molecular and cellular methods to examine the stage of healing. Using the "molecular map" of the fracture callus, we divided our analyzes into three phases of fracture healing: the inflammatory or initial phase of healing, the soft callus or intermediate stage, and the hard callus stage. Our results show that indian hedgehog(ihh), which regulates aspects of chondrocyte maturation during fetal and early postnatal skeletogenesis, was expressed earlier in an non-stabilized fracture callus as compared to a stabilized callus. ihh persisted in the non-stabilized fracture whereas its expression was down-regulated in the stabilized bone. IHH exerts its effects on chondrocyte maturation through a feedback loop that may involve bone morphogenetic protein 6 [bmp6; (S. Pathi, J.B. Rutenberg, R.L. Johnson, A. Vortkamp, Developmental Biology 209 (1999) 239-253)] and the transcription factor gli3. bmp6 and gli3 were re-induced in domain adjacent to the ihh-positive cells during the soft and hard callus stages of healing. Thus, stabilizing the fracture, which circumvents or decreases the cartilaginous phase of bone repair, correlates with a decrease in ihh signaling in the fracture callus. Collectively, our results illustrate that the ihh signaling pathway participates in fracture repair, and that the mechanical environment affects the temporal induction of ihh, bmp6 and gli3. These data support the hypothesis that mechanical influences affect mesenchymal cell differentiation to bone.

Animals↗

PubMed2001

Valacyclovir inhibition of recovery of ocular herpes simplex virus type 1 after experimental reactivation by laser in situ keratomileusis.

PURPOSE: To determine whether the systemic administration of valacyclovir (Valtrex) reduces ocular shedding of herpes simplex virus type 1 (HSV-1) after laser in situ keratomileusis (LASIK) in the New Zealand White (NZW) rabbit latency model. SETTING: Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA. METHODS: New Zealand White rabbits latently infected with HSV-1 W strain were divided into 3 groups. The first received 100 mg/kg/day of valacyclovir; the second, 200 mg/kg/day of valacyclovir; and the third (control), saline. One half the total dose of valacyclovir was delivered via intraperitoneal injections twice daily for 7 days beginning with 1 dose before LASIK. The HSV-1 ocular shedding was determined from eye cultures for 7 days after LASIK. RESULTS: The administration of both 100 mg/kg/day and 200 mg/kg/day of valacyclovir significantly reduced the number of eyes (1/16 in both groups) and the total number of HSV-1 shedding days (1/122 and 2/122, respectively) from which HSV-1 was recovered compared to the control group (7/16 [P =.0396] and 14/129 [P <.007], respectively). CONCLUSIONS: Systemic administration of valacyclovir significantly reduced HSV-1 ocular shedding after LASIK in the NZW rabbit latency model. The clinical implications of this study suggest that patients with a history of recurrent ocular herpes may be able to safely have LASIK with less risk of a recurrent herpetic episode while on valacyclovir antiviral prophylaxis.

Acyclovir↗

PubMed2001

Bone marrow transplantation for T-B- severe combined immunodeficiency disease in Athabascan-speaking native Americans.

A distinct form of autosomal recessive T-B- severe combined immunodeficiency disease occurs with a high frequency among Athabascan-speaking Native Americans (SCIDA), including Navajo and Apache Indians from the southwestern US and Dene Indians from the Canadian Northwest Territories. The SCIDA gene has been linked to markers on chromosome 10p although its identity and role in the pathogenesis of this disease are unknown. We report our experience in treating 18 Navajo and Dene children with SCIDA between 1984 and 1999; 16 underwent bone marrow transplants (BMT). All children were symptomatic within 2 months of birth, had the T-B- NK(+)SCID phenotype and 67% presented with oral and/or genital ulcers. Three children had evidence of maternal engraftment prior to transplant. Two children died shortly after diagnosis. Three children required more than one BMT and 12 are alive with T cell reconstitution at a median follow-up of 7 years. Three children developed normal B cell immunity, two of whom received ablative conditioning therapy with either radiation or busulfan. Three of the four children who died received therapy with either radiation or busulfan and two of eight long-term survivors who were also recipients of cytotoxic chemotherapy have failed to develop secondary teeth. These results demonstrate the efficacy of BMT in treating infants with this distinct form of SCID, although B cell reconstitution remains a problem even with HLA-matched donors. Without conditioning, T cell engraftment is likely when closely HLA-matched donors are used. With T cell depletion of haplocompatible marrow, conditioning with immunosuppressive therapy may be necessary; however, children with SCIDA who were treated with intensive immunosuppressive and myeloablative therapy had a poor outcome.

B-Lymphocytes↗

PubMed2001

Evaluation of United States-licensed human immunodeficiency virus immunoassays for detection of group M viral variants.

Six Food and Drug Administration (FDA)-licensed human immunodeficiency virus type 1 (HIV-1) and HIV-1/2 immunoassays, including five enzyme immunoassays and one rapid test, were challenged with up to 250 serum samples collected from various global sites. The serum samples were from individuals known to be infected with variants of HIV-1 including group M subtypes A, B, B', C, D, E, F, and G and group O. All immunoassays detected the vast majority of samples tested. Three samples produced low signal over cutoff values in one or more tests: a clade B sample, an untypeable sample with a low antibody titer, and a group O sample. It is concluded that HIV-1 immunoassays used in the United States are capable of detecting most HIV-1 group M variants.

AIDS Serodiagnosis↗

PubMed2001

Velocardiofacial syndrome: are structural changes in the temporal and mesial temporal regions related to schizophrenia?

OBJECTIVE: Velocardiofacial syndrome results from a microdeletion on chromosome 22 (22q11.2). Clinical studies indicate that more than 30% of children with the syndrome will develop schizophrenia. The authors sought to determine whether neuroanatomical features in velocardiofacial syndrome are similar to those reported in the literature on schizophrenia by measuring the volumes of the temporal lobe, superior temporal gyrus, and mesial temporal structures in children and adolescents with velocardiofacial syndrome. METHOD: Twenty-three children and adolescents with velocardiofacial syndrome and 23 comparison subjects, individually matched for age and gender, received brain magnetic resonance imaging (MRI) scans. Analysis of covariance models were used to compare regional brain volumes. Correlations between residualized brain volumes and age were standardized and compared with the Fisher r-to-z transformation. RESULTS: Children with velocardiofacial syndrome had significantly smaller average temporal lobe, superior temporal gyrus, and hippocampal volumes than normal comparison children, although these differences were commensurate with a lower overall brain size in the affected children. In a cross-sectional analysis, children with velocardiofacial syndrome exhibited aberrant volumetric reductions with age that were localized to the temporal lobe and left hippocampal regions. CONCLUSIONS: Abnormal temporal lobe and hippocampal development in velocardiofacial syndrome is potentially concordant with MRI findings in the schizophrenia literature. Temporal lobe and mesial temporal structures may represent a shared substrate for the effects of the 22q11.2 deletion and for the complex etiological pathways that lead to schizophrenia. Longitudinal research may help determine which children with velocardiofacial syndrome are at risk for serious psychiatric illness in adulthood.

Abnormalities, Multiple↗

PubMed2001

Local retinoid signaling coordinates forebrain and facial morphogenesis by maintaining FGF8 and SHH.

Correlations between facial anomalies and brain defects are well characterized throughout the clinical literature, yet a developmental basis for this association has not been identified. We demonstrate that the frontonasal process, which gives rise to the mid- and upper face, and the forebrain are linked early in their morphogenesis by a local retinoid signaling event that maintains the expression of key regulatory molecules. First, we show that aldehyde dehydrogenase 6, which synthesizes the ligand, retinoic acid, is localized to the ventral epithelium of the presumptive frontonasal process of chick embryos. At least two retinoid receptors are expressed in adjacent populations of mesenchyme. Second, using synthetic pan-specific retinoid antagonists, we transiently inhibit the ability of retinoid receptors to bind retinoic acid in the rostral head and we generate embryos with a hypoplastic forebrain, fused eyes, and no frontonasal process-derived structures such as the upper beak. These defects are not due to eliminating mesenchymal progenitors, as neural crest cells still migrate into the frontonasal process, despite disruptions to retinoid signaling. Rather, these malformations result from loss of fibroblast growth factor 8 and sonic hedgehog expression, which leads to increased programmed cell death and decreased proliferation in the forebrain and frontonasal process. Most significantly, we can rescue the morphological defects by re-introducing retinoic acid, or fibroblast growth factor and sonic hedgehog proteins into antagonist-treated embryos. We propose that the local source of retinoic acid in the rostral head initiates a regulatory cascade that coordinates forebrain and frontonasal process morphogenesis.

Animals↗

PubMed2001

Effect of long-acting isosorbide-5-mononitrate administration on large artery distensibility in patients with essential hypertension.

To evaluate the clinical efficacy of long-acting nitrates, isosorbide-5-mononitrate (IS-5-MN), on large artery distensibility in patients with essential hypertension. Large arterial distensibility was assessed by automatic noninvasive measurement of the carotid-femoral pulse wave velocity (PWV). Seventeen patients aged 62.53+/-7.94 years (mean+/-SD) with essential hypertension undering long-term antihypertensive therapy were studied in this trial. PWV was measured 2 weeks and 4 weeks after oral administration of IS-5-MN (30 mg once daily) with previous therapy. There was no significant difference in systolic blood pressure, diastolic blood pressure, pulse pressure or heart rate at 2 weeks and 4 weeks after treatment compared with baseline. The carotid-femoral PWV decreased significantly at 2 and 4 weeks after treatment (p<0.05, p< 0.05, respectively). Long-acting nitrates have potential value in improving large arterial distensibility in patients with essential hypertension independent of blood pressure alteration. It might be used as an effectively additive drug in hypertension control.

Administration, Oral↗

PubMed2001

Hepatitis C virus infection and morphologic study in B lymphocytes of patient with hepatitis C.

OBJECTIVE: To study hepatitis C virus (HCV) infection in B lymphocytes of patients with hepatitis C and to establish a B cell line with HCV infection and observe the hepatitis C virus like particles. METHODS: A B lymphoblastoid cell line was established by Epstein-Barr virus induced transformation directly from peripheral blood mononuclear cells of a patient with hepatitis C. The HCV antigen and HCV RNA were detected by immunohistochemical technique. Reverse transcription-polymerase chain reaction(RT-PCR) and in situ hybridization and HCV particle were detected by electron microscopy. RESULTS: Positive HCV RNA was found in supernatants of B cell line. HCV Ag and HCV RNA were also showed positive. Electron microscopy observed HCV spherical virus like particles with a diameter of approximately 65 nm and 110 nm and the "bud mutation" of HCV in the cytoplasmic vesicles of B lymphocytes. CONCLUSIONS: HCV could infect B lymphocytes and replicate in the cell line. HCV particles are formed by "bud mutation" of HCV in the cytoplasmic vesicles of B-lymphocytes.

B-Lymphocytes↗

PubMed2001

Nationality differences in distributions of serum lipids, lipoproteins and apolipoproteins levels in Xinjiang China.

OBJECTIVE: To reveal the distribution characteristics of serum lipids, lipoproteins, and apolipoproteins levels in different nationalities. METHODS: Quantitative levels of those traits mentioned above were determined and body height (H), weight (W) and body mass index (BMI = W/H2) were assessed in 773 Kazaks (men 360 and women 413) and 911 Han nationality (men 466 and women 445) from the Xinjiang Autonomous Region of China. RESULTS: Kazaks men and women, respectively, had significantly higher serum levels of HDL-c and ApoA1 (all P < 0.001) and significantly lower serum levels of TG (men P < 0.01, women P < 0.001), Lp(a) (all P < 0.005), ApoB (men P < 0.005, women P < 0.001) and ApoB/A1 (men P < 0.01, women P < 0.001) than their Han nationality controls. The threshold points of ApoA1 (< 1.2 g/L) and ApoB (> 1.2 g/L) are higher in Hans than in Kazaks for ApoA1 (20.7 vs 9.8%) and ApoB (18.6 vs 14.3%); the serum levels of TG, HDL-c, Lp(a), ApoA1 and ApoB/A1 are all closely correlated with nationality (P < 0.001, P = 0.001, and P < 0.05, respectively). CONCLUSION: The results suggest that the nationality differences exist in serum levels of lipids, lipoproteins, and apolipoproteins, and Kazaks have a superior serum lipid pedigree to Hans. This differences may come from genetic differences, which affect the serum levels of lipids, lipoproteins, and apolipoproteins by controlling lipid metabolism patterns. Future study will be needed to dissect to the role of genetic factors on serum lipids.

Apolipoproteins↗

PubMed2001

[Effect of hypertonic saline solution on the viscoelasticities of erythrocyte membrane in rats subjected to hemorrhagic shock].

We have studied the effect of hypertonic saline solution on the viscoelasticities of erythrocyte membrane in hemorrhage-shocked rats using micropippette aspiration technique. Wistar rats were randomly divided into three groups of 0.9% NaCl(NS), 7.5% NaCl (HS) and 5% NaCl-3.5% NaAc (HSA), respectively. The animals were bled to reach a mean arterial pressure of 5.3 kPa in 10 minutes and maintained in shock for 90 minutes. 4 ml/kg NS, HS and HSA was given intravenously and respectively in 5 minutes following hemorrhagic shock. The blood was collected to determine the viscoelasticities of erythrocyte membrane at baseline, shock and after treatment. The results showed that the elastic moduli and viscous coefficients of erythrocyte membrane were increased obviously following hemorrhagic shock. HS raised elastic moduli and reduced viscous coefficients significantly compared with NS after treatment. The elastic moduli and viscous coefficients of erythrocyte membrane were decreased remarkably in HSA group than in NS and HS group. These data suggested that HSA could improve the viscoelasticities of erythrocyte membrane significantly in rats subjected to hemorrhagic shock.

Animals↗

PubMed2001

[Correlation of coronary angiographic morphology with clinical presentation in unstable angina].

OBJECTIVE: To seek the relation between clinical presentation (Braunwald classification) or electrocardiogram(ECG) and angiographic morphology in patients with unstable angina (UA) and to determine which clinical markers could reliably predict unstable lesions and in-hospital cardiac events. METHODS: 120 hospitalized patients with a clinical diagnosis of UA and an abnormal angiograms(>or=50% diameter stenosis) were selected. Patients were classified according to Braunwald criteria before cardiac catheterization was performed. Coronary arteriograms were reviewed. The lesion morphology (including simple lesion, complex lesion and intracoronary thrombus [ICT]) and in-hospital events (including acute myocardial infarction,cardiac death and prompt revascularization) were observed. Logistic regression was used to evaluate the ability of clinical markers (Braunwald classification or an abnormal ST segment of ECG) to predict unstable lesions and cardiac events. RESULTS: There were more complex lesions in class III group(61%, or 20 of 33) than in class I group(30%, or 13 of 43, P < 0.05) and more ICT in class III group(18%, or 6 of 33) than in class II group (2%, or 1 of 44, P < 0.05). The rate of cardiac events was higher in class III patients (58%, or 19 of 33) than in class I patients (19%, or 8 of 43, P = 0.01 ) or class II patients (25%, or 11 of 44, P < 0.01). Logistic regression analysis demonstrated that an abnormal ST segment of ECG or Braunwald class III were highly predictive of the presence of complex lesion morphology (P < 0.01, OR 4.9; P < 0.01, OR 3.3, respectively). An abnormal ECG was the single predictive clinical indicator of triple vessel disease (P < 0.01, OR 3.9) and cardiac events (P < 0.001, OR 4.8). CONCLUSION: Complex lesion can be best identified by the clinical feature of recent onset refractory angina at rest and abnormal ST segment of ECG in UA patients. Patients with abnormal ST segment represents a high risk of triple vessel disease and cardiac events.

Aged↗

PubMed2001

[The clinical importance of persistent elevation of electrocardiographic ST segment in acute myocardial infarction patients after reperfusion therapy].

OBJECTIVE: To observe the clinical importance of persistent elevation of electrocardiographic ST segment in acute myocardial infarction (AMI) patients receiving direct percutaneous transluminal coronary angioplasty (PTCA). METHODS: Thirty patients with a first AMI successfully treated with direct coronary angioplasty were selected. The extent of the ST segment elevation and resolution in electrocardiograms on admission and one hour after direct PTCA was analyzed. All the patients were divided into two groups according to the extent of ST segment elevation and resolution. Group A: resolution of ST segment elevation >or=50%, n = 19; Group B: resolution of ST segments elevation < 50%, n = 11. Low-dose dobutamine stress echocardiogram was taken at (7 +/- 2) days after AMI and echocardiogram checked at 1, 2 and 3 months after AMI. RESULTS: Left ventricular ejection fraction (LVEF) in group A was higher than that in group B at the first week and the first, second and third month after AMI. Aortic blood peak acceleration, cardiac output and cardiac output index of group A were all significantly higher than those in group B at stress. Global wall motion score index (GWMSI) and infarct-zone wall motion score index (IWMSI) in group A were smaller than those in group B at baseline and stress. GWMSI in group A was smaller than that in group B at 1, 2 and 3 months after AMI. There was no significant difference of IWMSI between group A and group B at 1 and 2 months after AMI. IWMSI in group A was smaller than that in group B at the third month after AMI. CONCLUSIONS: The patients in group B had lower left ventricular contractile function and contractile reserve function and less recovery of infarct-zone wall motion than that in group A.

Adult↗

PubMed2001

[Autoantibodies against the myocardium beta 1-adrenergic and M2-muscarinic receptors in patients with heart failure].

OBJECTIVE: To determine whether the autoantibodies against beta(1)-adrenergic and M(2)-muscarinic receptors are related to congestive heart failure (CHF) patients with different cardiac diseases. METHODS: Both synthetic peptides corresponding to amino acids sequence of the second extracellular loops of the beta(1) and M(2) receptors were used as the antigens to screen the serum from CHF patients with ischemic cardiomyopathy (ICD, n = 42), idiopathic dilated cardiomyopathy (IDCM, n = 52) and hypertensive heart disease (HHD, n = 44). Meanwhile healthy donors were tested as normal controls (NC, n = 40). RESULTS: The positive rates of serum for beta(1)-adrenergic-receptor were 45.7% (86/188) and 10.4% (8/77) in CHF patients and controls respectively (P < 0.01); the positive rates of serum for M(2)-muscarinic receptor were 52.7% (99/188) and 11.7% (9/77) in CHF patients and controls (P < 0.01). The frequencies of the both receptor autoantibodies in patients with cardiac function of class II approximately III were significantly higher than those with cardiac function of class VI. CONCLUSIONS: Our finding indicates indicates that autoantibodies against beta(1)-adrenergic-receptor and M(2)-muscarinic receptor can be detected not only in the serum of CHF patients with IDCM, but also in CHF patients with ICM and HHD. It is suspected that autoantibodies against beta(1) and M(2) receptors may be related to the myocardial remodeling and/or CHF.

Adult↗

PubMed2001

Peri-operative treatment of most severely head-injured patients.

OBJECTIVE: To summarize the peri-operative experience from 53 patients with traumatic head injuries with GCS score 3-5. METHODS: Fifty-three most severely head-injured patients with GCS score 3-5 were admitted to our department and treated operatively from Oct. 1994 to Jun. 1998 and the data were analyzed retrospectively. RESULTS: Thirty-seven cases (69.8%) survived, among them 28 (52.8%) had a good recovery or moderate disability, and 9 (17%) had severe deficits. The other 16 (30.2%) died after therapy. CONCLUSIONS: The prognosis of most severely head-injured patients could be improved by peri-operative treatment including premedical care, early evacuation of intracranial hematoma with large decompressive craniectomies, intracranial hypertension monitoring, moderate hypothermia therapy, effective prevention and treatment of cerebral vasospasm and complications.

Adolescent↗

PubMed2001

[Repair of the postburn scar of face, neck and chest with extensive tissue expanding technique].

OBJECTIVE: To explore the treatment effects of extensive tissue expanding technique on the postburn scar of face, neck and chest. METHODS: The technique was applied in 13 patients with post-burn scar of face, neck and chest. Different number of expanders (usually 5-8) with volume of 30 ml to 450 ml each were implanted under the adjacent normal skin. The principle of plastic surgery was observed during the operation with attention to locating sear lines along leavage lines and in obscure areas. The criteria for cure were correct restoration of the position of the five organs on the face, restoration of the correct angle of jaw and neck and avoidance of skin grafting on the chest. RESULTS: All the postburn scar on face, neck and chest was removed en masse with all the flaps survived with satisfactory color and texture with this technique. In addition, the appearance and the function of facial organs and neck and chest were restored perfectly. CONCLUSION: Extensive tissue expanding technique is satisfactory in the repair of postburn scars of face, neck and chest.

Adolescent↗

PubMed2001

[The effects of DiBaiRen decoction on the proliferation of human keratinocytes and its in vitro anti--oxidation role].

OBJECTIVE: To investigate the effects of DiBaiRen decoction on the proliferation of human keratinocytes and its in vitro anti -- oxidation role. METHODS: Human keratinocytes were cultured in vitro in the media containing gradient diluted DiBaiRen decoction. The cell proliferation rates at different culture times were recorded. Cellular oxidation injury inflicted by superoxide anion and hydroxyl anion was produced by adding hypoxanthine -- xanthine oxidase and hydrogen peroxide to the culture media. MTT colorimetry was employed to determine cellular activity. The antagonistic effects of DiBaiRen decoction on cellular oxidation injury were analyzed. RESULTS: In the case that DiBaiRen decoction was added to the culture in concentrations of 30 ml/L to 100 ml/L, there exhibited obvious accelerated proliferation of the keratinocytes, with evident shortening of the cell fusion time. In addition, the oxidation injury of cultured keratinocytes caused by hypoxanthine -- xanthine oxidase and hydrogen peroxide was ameliorated or eliminated by the addition of DiBaiRen decoction, and the effects were dose -- dependent. CONCLUSION: DiBaiRen decoction might possess anti -- oxidation effects and could promote the in vitro proliferation of cultured human keratinocytes, and it might be beneficial in wound protection and epithelization.

Antioxidants↗

PubMed2001

[Determination of rate constants of gas-phase reactions of alpha-pinene and beta-pinene with ozone].

alpha-pinene and beta-pinene are the most dominating species among natural terpenes. Terpenes are mainly emitted from forest trees, flowers and grass. In the lower troposphere terpenes can react fast with OH radical, ozone, NO3 radical and ground state oxygen atom. These reactions may contribute to the occurring of aerosols, peroxides (hydrogen peroxide and organic peroxide), carbon cycle (mainly CO), acid rain (organic acids, NO3- and SO4(2-), ozone and active radicals such as OH radical. Reactions with ozone occur both in the daytime and in the night. The study in this field in China began in the late 1980. The main work focus on the source emission and the experimental simulation has just started. It is most of our group's work. In this paper preliminary experimental simulation of the gas-phase reactions of alpha-pinene and beta-pinene with ozone were carried out in the quartz chamber. The rate constants of these reactions were measured using long-path Fourier transform infra-red combined with relative rate constant method. And the rate constants for the gas-phase reactions of alpha-pinene, beta-pinene with ozone were determined as 2.83 x 10(17) cm3.molecule-1.s-1 and 1.48 x 10(17) cm3.molecule-1.s-1 at 1.0 x 10(5) Pa and 296 +/- 3 K. The results are quite similar to the data from Atkinson group. No cyclohexane was added to the reaction system during the measurement to restrain the formation of OH radical. The formation of OH radical could not be quantified, so that the effect of subsidiary reactions induced by OH radical has not been calculated. In the later simulation study and model this effect should be considered.

Acid Rain↗

PubMed2000

Frequency of Shiga toxin-producing Escherichia coli in cattle at a breeding farm and at a slaughterhouse in Japan.

To investigate the frequency of Shiga toxin-producing Escherichia coli (STEC) infected calves at a breeding farm and cattle at a slaughterhouse in Tohoku area of Japan, the polymerase chain reaction (PCR) was used for detection of genes for Shiga toxin(s). The fecal samples from a total of 204 calves and 306 cattle were examined. The prevalence rates in calves less than 2 months of age, cattle 2-8 months of age, and adults greater than 1 year of age were 39.4, 78.9, and 40.8%, respectively. Detection frequency of STEC in the fecal specimens from calves aged 0-8 months was not different among the breeds of cattle (Holstein: H, Japanese black cattle: B, and F1: HxB). On the other hand, for calves over 12 months of age, the frequency of STEC in Japanese black cattle and F1 were significantly higher than in Holstein cattle. Serogroups of STEC usually identified in human cases of food poisoning (O157, O26, and O111) were not frequently found in the feces of the cattle.

Abattoirs↗