Different Degrees Of Infection Research Articles

Identification of Marker Genes in Infectious Diseases from ScRNA-seq Data Using Interpretable Machine Learning.

A common result of infection is an abnormal immune response, which may be detrimental to the host. To control the infection, the immune system might undergo regulation, therefore producing an excess of either pro-inflammatory or anti-inflammatory pathways that can lead to widespread inflammation, tissue damage, and organ failure. A dysregulated immune response can manifest as changes in differentiated immune cell populations and concentrations of circulating biomarkers. To propose an early diagnostic system that enables differentiation and identifies the severity of immune-dysregulated syndromes, we built an artificial intelligence tool that uses input data from single-cell RNA sequencing. In our results, single-cell transcriptomics successfully distinguished between mild and severe sepsis and COVID-19 infections. Moreover, by interpreting the decision patterns of our classification system, we identified that different immune cells upregulating or downregulating the expression of the genes CD3, CD14, CD16, FOSB, S100A12, and TCRɣδ can accurately differentiate between different degrees of infection. Our research has identified genes of significance that effectively distinguish between infections, offering promising prospects as diagnostic markers and providing potential targets for therapeutic intervention.

Post-Chemotherapy Clinical Perianal Infection Features in Patients with Acute Leukemia

Objective: This study aims to examine the incidence of post-chemotherapy perianal infection and its influencing factors in patients with acute leukemia.<br>Methods: A total of 243 patients with acute leukemia who underwent chemotherapy in the Three Gorges Hospital affiliated to Chongqing University, China, between January 2019 and December 2020 were selected as study subjects. In the present retrospective study, patients with post-chemotherapy perianal infection were monitored, and the perianal infection rate and clinical features of perianal infection were determined. Categorical variables were compared using the Chi-square test, and the influencing factors of post-chemotherapy perianal infection in patients with acute leukemia were evaluated using logistic analysis.<br>Results: A total of 24 patients (9.88%) with acute leukemia suffered post-chemotherapy perianal infection. Age, basic perianal disease (hemorrhoids) history, constipation, diarrhea, duration of agranulocytosis, and length of hospital stay were compared among the patients. Perianal disease classification, perianal ultrasound, colonoscopy, postoperative pathology, and other clinical data were compared and discussed in relation to the occurrence and development of the disease. The results showed that there were no significant differences in perianal infection degrees between genders and among different types of leukemia (p > 0.05). There were no statistically significant differences in age, pain score, minimum white blood cell count, deficiency duration, and length of hospital stay among patients with different degrees of infection. The Spearman rank correlation test showed that the perianal infection degree was positively correlated with the highest hypersensitive C-reactive protein (hs-CRP) level (p < 0.05). The difference was statistically significant; the higher the maximum hs-CRP/procalcitonin levels, the more serious the perianal infection.<br>Conclusions: Perianal infections are common in the procession of chemotherapy or myelosuppression. This is worthy of clinical recognition. Early recognition of perianal infection and the strengthening of infection risk factor control may be beneficial to improving the subjective feelings of patients with acute leukemia undergoing chemotherapy.

Concordance of bone culture and deep tissue culture during the operation of diabetic foot osteomyelitis and clinical characteristics of patients.

To retrospectively analyze the concordance of bacterial culture between bone tissue and deep soft tissue in diabetic foot osteomyelitis (DFO) patients and clinical characteristics of patients. This study collected samples from 155 patients with suspected DFO (who required amputation after clinical evaluation). Bacterial culture and drug susceptibility tests were performed on the patients' deep soft tissue and bone tissue, and the consistency between the two was compared. In addition, the differences among DFO patients with different degrees of infection were compared classified by the PEDIS classifications. Among the 155 patients diagnosed with DFO, the positive rate of bone culture was 78.7% (122/155). This study cultured 162 strains, including 73 Gram-positive bacteria, 83 Gram-negative bacteria, and 6 fungi. Staphylococcus aureus (33 strains) was the most common bacteria. The overall agreement between bone culture and tissue culture was 42.8%, with Staphylococcus aureus and Enterobacteria having the best (64.3%) and least agreements (27.3%), respectively. The drug sensitivity results in bone culture showed that Staphylococcus aureus was the main Gram-positive bacteria. The bacteria were sensitive to linezolid and vancomycin. Proteus mirabilis was the main Gram-negative bacteria. These were more sensitive than biapenem and piperacillin/tazobactam. Fungi were more sensitive to voriconazole and itraconazole. The culture results of deep soft tissues near the bone cannot accurately represent the true pathogen of DFO. For DFO patients, bone culture should be taken as much as possible, and appropriate antibiotics should be selected according to the drug susceptibility results.

A Detection Model for Cucumber Root-Knot Nematodes Based on Modified YOLOv5-CMS

The development of resistant cucumber varieties is of a great importance for reducing the production loss caused by root-knot nematodes. After cucumber plants are infected with root-knot nematodes, their roots will swell into spherical bumps. Rapid and accurate detection of the infected sites and assessment of the disease severity play a key role in selecting resistant cucumber varieties. Because the locations and sizes of the spherical bumps formed after different degrees of infection are random, the currently available detection and counting methods based on manual operation are extremely time-consuming and labor-intensive, and are prone to human error. In response to these problems, this paper proposes a cucumber root-knot nematode detection model based on the modified YOLOv5s model (i.e., YOLOv5-CMS) in order to support the breeding of resistant cucumber varieties. In the proposed model, the dual attention module (CBAM-CA) was adopted to enhance the model’s ability of extracting key features, the K-means++ clustering algorithm was applied to optimize the selection of the initial cluster center, which effectively improved the model’s performance, and a novel bounding box regression loss function (SIoU) was used to fuse the direction information between the ground-truth box and the predicted box so as to improve the detection precision. The experiment results show that the recall (R) and mAP of the YOLOv5s-CMS model were improved by 3% and 3.1%, respectively, compared to the original YOLOv5s model, which means it can achieve a better performance in cucumber root-knot nematode detection. This study provides an effective method for obtaining more intuitive and accurate data sources during the breeding of cucumber varieties resistant to root-knot nematode.

The Levels of Amyloid β-Protein and P181 in Peripheral Blood of Patients with Alzheimer's Disease Combined with Helicobacter pylori Infection and Their Clinical Significance.

Objective To analyze the levels of amyloid β-protein and P181 in peripheral blood of patients with Alzheimer's disease combined with Helicobacter pylori infection and their clinical significance. Method From January 2019 to June 2020, 59 patients were enrolled in this experiment including the AD group with 27 patients and the normal control group with 32 patients. The patients were divided into two groups: Alzheimer's disease (AD) group (n = 27) and control group (n = 32), collecting the general data of patients, analyzing the diagnostic specificity and sensitivity of serum p-tau181 and Aβ42 and their influence on prognosis, and comparing the serum Aβ42 and p-tau181 concentrations for different HP infection degrees. Result Single diagnostic sensitivity of Aβ42, p-tau181, and Aβ42 combined p-tau181 was 0.863, 0.854, and 0.972, respectively, and their specificity was 0.048, 0.206, and 0.305, respectively. Compared with the single diagnosis of serum Aβ42 and p-tau181, the combined diagnosis has higher sensitivity and specificity (P < 0.05); age, years of education, serum Aβ42, and p-tau181 are factors affecting the prognosis of patients with Alzheimer's disease combined with Helicobacter pylori infection; the concentration of Aβ42 in the control group was higher than that in the AD group, there was a statistical difference in the Aβ42 concentration between the two groups (P < 0.05), and there was no statistical difference in the concentration of p-tau181 between the two groups (P > 0.05); the HP positive infection rate of the AD group and the control group was 63.0% and 35.7%, respectively. The HP negative infection rate of the AD group and the control group was 37.0% and 64.3%, respectively. Compared with the control group, the positive rate of HP in the AD group was higher, and the difference was statistically significant (P < 0.05); compared with HP-negative patients, HP-positive patients had a higher Aβ42 concentration, and the difference was statistically significant (P < 0.05). The concentration of p-tau181 in the two groups was not statistically significant (P > 0.05); Aβ42 gradually increases with increasing HP infection degree, and there are significant differences in serum Aβ42 levels between different degrees of infection. However, the level of serum p-tau181 does not change significantly with the increase of infection. Conclusion There are significant alterations in the expression levels of Aβ42 and p-tau181 in peripheral blood of AD patients, and the levels of Aβ42 are related to HP infection; Aβ42 and p-tau181 are potential biomarkers for AD diagnosis and treatment.

Genetic diversity of tomato yellow leaf curl virus isolates and the effect of virus on the hormones content of tomato (Solanum lycopersicum) plants

Tomato yellow leaf curl virus (TYLCV) is one of the most economically important plant viruses globally and due to its continuing quick spread, now it afflicts many tomato growing countries in the Mediterranean basin, Africa, southern Asia, as well as South, Central and North America. Infection of tomato plants with TYLCV can reach 100% causing a severe reduction in tomato production, especially when plants are infected in the early stage of growth. Therefore, this study was conducted, during the growing season 2018-19 at the college of Agriculture, Kerbala University, Iraq, to isolate and diagnose three different isolates of TYLCV, infecting tomato, using the polymerase chain reaction technology (PCR) and determining the nucleotide sequences of PCR- amplified products and the effect of TYLCV infection on the plant contents of some hormones (gibberellin, cytokinin, and Indole acetic acid). Results of PCR amplification showed the possibility of amplifying a 789bp PCR product from each virus isolate (1, 2, 3, and 4). Analysis of the nucleotide sequences of PCR products using BLAST showed that all the diagnosed isolates belong to TYLCV. By comparing the sequences of nucleotide sequences, there was a genetic similarity of 100% among these isolates. However, all tomato genotypes tested in this study were found to be susceptible to TYLCV with different degrees of infection. TYLCV infection also had a significant effect in reducing the level of the hormone gibberellin in the infected genotypes. Increased levels of the cytokinin and indole acetic acid hormones were also observed in the TYLCV-infected genotypes.

Reconstruction of Large Area of Deep Wound in the Foot and Ankle with Chimeric Anterolateral Thigh Perforator Flap.

ObjectiveTo evaluate the clinical application and surgical efficacy of the chimeric perforator flap pedicled with the descending branch of the lateral circumflex femoral artery and the lateral thigh muscle flap for the reconstruction of the large area of deep wound in foot and ankle.MethodsClinical data of 32 cases who underwent chimeric anterolateral thigh perforator flap to repair the large area of deep wound of the foot and ankle from January 2015 to December 2018 were retrospectively analyzed. The sizes of the defects ranged from 18 cm × 10 cm to 35 cm × 20 cm, with exposed tendon and bone and/or partial defects and necrosis, contaminations, accompanied by different degrees of infection. Following the radical debridement and VSD, chimeric anterolateral thigh perforator flap was employed to repair the deep wounds according to the position, site and deep‐tissue injury of the soft‐tissue defects. The skin flap and muscle flap were fanned out on the wound, and single‐ or two‐staged split‐thickness skin grafting was performed on the muscle flap. The operation time and blood loss were recorded. The survival and healing conditions of the operational site with chimeric anterolateral thigh perforator flap were evaluated post‐operationally. Complications at both recipient site and donor site were carefully recorded.ResultsThe mean time of the operation was 325.5 min and average blood loss was 424.8 mL. Among the 32 cases, two cases developed vascular crisis, which were alleviated with intensive investigation and treatment; Four cases suffered from partial necrosis of the flap or skin graft on the muscle flap or on the residual local wound, which were improved after treatment of further dressing change and skin grafting. Another four cases experienced post‐traumatic osteomyelitis accompanied by bone defect were treated with simple bone grafting or Mesquelet bone grafting at 6–8 months after wound healing. Postoperatively, the wounds were properly healed, and the infection was effectively controlled without sinus tract forming. Overall, all 32 cases received satisfactory efficacy, without influencing subsequent functional reconstruction, and observed infection during the 12–36 months post‐operational follow‐up.ConclusionThe chimeric perforator flap pedicled with the descending branch of the lateral circumflex femoral artery and the lateral thigh muscle flap provides an effective and relative safe procedure for the repair of a large area of deep wound in the foot and ankle, particularly with irregular defect or deep dead space.

Clinical Application of Serum Inflammatory Factors Combined with Dynamic Detection in the Diagnosis and Treatment of Neonatal Sepsis.

Background:To investigate the clinical application value of the combination of the inflammatory factors and dynamic detection in the diagnosis and treatment of neonatal sepsis by detecting serum inflammatory factor C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) levels before and after treatment of neonatal infection.Methods:A total of 138 neonates with different degrees of infection were randomly enrolled, including 88 cases in the sepsis group and 50 cases in the virus infection group. Another 50 non-infected newborns in the same period were enrolled as the normal control group. Venous blood of all subjects for CRP, PCT, IL-6 detection, and send bacterial blood culture for sepsis and virus infection groups were collected at the same time. In the recovery period, venous blood of children in sepsis group was collected again to review CRP, PCT, IL-6, and differences in each test index of each group were compared.Results:The serum CRP, PCT, IL-6 levels in the sepsis group were significantly higher than those in the virus infection group (all P <0.05); serum CRP, PCT, IL-6 levels in the sepsis group were significantly lower than before treatment (P <0.05); the sensitivity and accuracy of the combined detection of indicators for the diagnosis of neonatal sepsis were significantly improved.Conclusion:The inflammatory factors CRP, PCT, and IL-6 are closely related to the occurrence and development of neonatal sepsis. Combined detection can effectively improve the diagnostic accordance rate, which is beneficial to the early diagnosis and early clinical intervention of neonatal sepsis.

Perkinsus mediterraneus infection induces oxidative stress in the mollusc Mimachlamys varia.

Perkinsus mediterraneus is a protozoan parasite that can cause marine mollusc diseases known as perkinsosis being a serious threat for clam cultures worldwide. The aim of the present study was first to determine the Perkinsus species infecting the variegated scallop Mimachlamys varia and then to evaluate the existence of oxidative stress in gills of M.varia according to different degrees of infection. DNA sequencing confirmed that P.mediterraneus was the species infecting M.varia. ROS production was progressively increasing with the degree of infection although the differences were only significant in the high-infected group. Low degree of infection significantly increased superoxide dismutase (SOD) and glutathione S-transferase (GST) activities and nitrite levels with respect to the control group. In the high-infected group, a significant increase was evidenced in all analysed enzymes, catalase, SOD, glutathione reductase and GST. Non-significant differences in MDA levels were observed between the control and low-infected groups; however, a significant increase in MDA levels was observed in the high-infected group. In conclusion, the infection by Perkinsus mediterraneus in M.varia induces oxidative stress and an antioxidant response directly related to the infection degree that can contribute to the pathogenicity of the infection.

Genetic Determinants of Virulence between Two Foot-and-Mouth Disease Virus Isolates Which Caused Outbreaks of Differing Severity.

Individual foot-and-mouth disease virus (FMDV) strains reveal different degrees of infectivity and pathogenicity in host animals. The differences in severity among outbreaks might be ascribable to these differences in infectivity among FMDV strains. To investigate the molecular mechanisms underlying these differences, we estimated the infectivity of O/JPN/2000 and O/JPN/2010, which caused outbreaks of markedly different scales, in cell lines, Holstein cattle, and suckling mice. Viral growth of the two strains in cells was not remarkably different; however, O/JPN/2000 showed apparently low transmissibility in cattle. Mortality rates of suckling mice inoculated intraperitoneally with a 50% tissue culture infective dose (TCID50) of 10 for O/JPN/2000 and O/JPN/2010 also differed, at 0% and 100%, respectively. To identify genes responsible for this difference in infectivity, genetic regions of the full-length cDNA of O/JPN/2010 were replaced with corresponding fragments of O/JPN/2000. A total of eight recombinant viruses were successfully recovered, and suckling mice were intraperitoneally inoculated. Strikingly, recombinants having either VP1 or 3D derived from O/JPN/2000 showed 0% mortality in suckling mice, whereas other recombinants showed 100% mortality. This finding indicates that VP1, the outermost component of the virus particle, and 3D, an RNA-dependent RNA polymerase, are individually involved in the virulence of O/JPN/2010. Three-dimensional structural analysis of VP1 confirmed that amino acid differences between the two strains were located mainly at the domain interacting with the cellular receptor. On the other hand, measurement of their mutation frequencies demonstrated that O/JPN/2000 had higher replication fidelity than O/JPN/2010.IMPORTANCE Efforts to understand the universal mechanism of foot-and-mouth disease virus (FMDV) infection may be aided by knowledge of the molecular mechanisms which underlie differences in virulence beyond multiple topotypes and serotypes of FMDV. Here, we demonstrated independent genetic determinants of two FMDV isolates which have different transmissibility in cattle, namely, VP1 and 3D protein. Findings suggested that the selectivity of VP1 for host cell receptors and replication fidelity during replication were important individual factors in the induction of differences in virulence in the host as well as in the severity of outbreaks in the field. These findings will aid the development of safe live vaccines and antivirals which obstruct viral infection in natural hosts.

Inactivation Mechanism and Apoptotic-Like Changes in Aeromonas hydrophila Induced by Slightly Acidic Electrolyzed Water in Freshwater

Abstract. This study investigated the suppressive effect and the inactivation mechanism of slightly acidic electrolyzed water (SAEW) on . The experiment compared different inhibition effects with SAEW and two antibiotics, gentamicin and norfloxacin. The conditions of pH of 6.5, oxidation-reduction potential (ORP) of 890 mV, available chlorine concentration (ACC) of 28 mg L-1 of SAEW, and volume ratios of 1:10, 1:15, and 1:20 were used. Using exposure times of 5 and 10 min to analyze the inactivation mechanism of SAEW from the perspectives of cell membrane permeability, cell nuclear morphology, cell fluorescence staining, and other aspects, the anti-infection effects of SAEW were tested using tilapia () culture experiments. SAEW had a stronger bacteriostasis effect than the antibiotics used. SAEW can inhibit the ability to reproduce, causing abnormal cell morphology and cell elongation. The cell volume was increased with a change in the membrane permeability. The cell nuclear morphology was changed, further inducing apoptosis. Based on study of tilapia in a control group, the organs (intestine, stomach, and liver) developed different degrees of infection. No obvious infection was observed in muscle samples. After SAEW treatment, SAEW showed a better antibacterial effect and improvement effects on the inflammation and structural damage induced by , which could be helpful in aquaculture application. Keywords: A. hydrophila, Antibiotics, Anti-infection, Cell apoptosis, Membrane permeability, Slightly acidic electrolyzed water.

SIMULTANEOUS REPAIR OF TIBIA BONE DEFECT AND REFRACTORY SOFT TISSUE DEFECT BY BONE TRANSPORT TECHNIQUE

To explore the feasibility and effectiveness of bone transport technique for simultaneous repair of tibia defect and refractory soft tissue defect. Thirty-five patients with tibia bone defect combined with refractory soft tissue defect were treated between January 2010 and December 2014, and the clinical data were retrospectively analyzed. There were 21 males and 14 females with an average age of 29 years (range, 18-47 years). All patients had Gustilo type Ⅲ open tibial fractures, which were caused by traffic accident. Fracture located at the upper 1/3 of the tibia in 1 case, at the middle 1/3 of the tibia in 19 cases, and at the lower 1/3 of the tibia in 15 cases. All patients underwent external fixation after 4-10 hours of trauma, and tibial skin necrosis, infection, and purulent exudation were observed after 5-10 days of operation. The time from injury to admission was 21 days to 5 months (mean, 2 months). After debridement, the average length of tibia defect was 8 cm (range, 6-11 cm); the area of soft tissue defect was 6 cm×5 cm to 10 cm×8 cm. Orthofix external fixation was applied to tract the bone and soft. All 35 patients were followed up 12-22 months (mean, 16 months). The average time of bony healing was 15 months (range, 9-20 months), and no obvious force line offset was found. Osteotomy segment was extended from 6 to 11 cm (mean, 8 cm); after treatment, the external fixation support was retained for 2 to 10 months (mean, 5 months). No blood vessel and nerve injuries were found during treatment, and no osteomyelitis and refracture happened after operation. The skin and soft tissue defects healed, and the healing time was 1 to 3 months (mean, 1.3 months). Different degrees of infection occurred in 5 cases, and was cured after dressing change. According to Johner-Wruhs' evaluation criteria after external fixator was removed, the results were excellent in 26 cases, good in 5 cases, and moderate in 4 cases, with an excellent and good rate of 88.6%. Bone transport technique can simultaneously repair tibia bone defect and soft tissue defect by continuous bone and soft tissue traction.

Tingkat Kejadian Aeromonasis pada Ikan Koi (Cyprinus carpio carpio) yang Terinfeksi Myxobolus koi pada Derajat Infeksi yang Berbeda &lt;br&gt;&lt;i&gt;[ Aeromonasis Incidence Rate In Koi (Cyprinus carpio carpio) That Infected Myxobolus koi At Different Degrees Of Infection ]&lt;i&gt;

Abstract Myxobolus infection in koi fish allows followed by opportunistic microorganisms infection. Aeromonas hydrophila bacteria classified as opportunistic because it can cause illness in certain condition such as when environmental conditions change, stress and the condition of the host that has been infected by the parasite. This study purpose to determine the incidence rate Aeromonasis in koi (Cyprinus carpio carpio) infected Myxobolus koi at different degrees of infection. The results showed that of 120 samples taken, infected with M. koi in a mild degree of infection is 68.3%. Furthermore the medium infection is 22.5%, 1.7% severe infection and uninfected fish 7.5%. Each level of infection of M. koi taken samples for examination bacteria with skin samples and water. The results of bacterial examination showed that 17 positive samples of fish infected with A. hydrophila (85%) from 20 fish sample. 17 positive samples of fish infected with A. hydrophila consist of 3 sample normal fish, 7 sample M. koi mild infection, 6 sample M. koi medium infection and 1 sample severe infection. The results showed that the fish infected or not infected with M. koi, positive with A. hydrophila infection that needs to be done by using a bacterial colony calculation method of determining the Angka Lempeng Total (ALT) or Total Plate Count (TPC). The calculation results from the number of bacterial colony in various levels of infection of M. koi are sample 1 (normal koi fish) of 1.15 x108 CFU/ml, sample 2 (koi fish with a mild infection of M. koi) as much as 1.3 x108 CFU/ml. While the sample 3 (koi fish with a medium infection of M. koi) 2.02 x108 CFU/ml and sample 4 (with the severe infection of M. koi) 2.60 x108 CFU/ml.

Symptom expression of yellow leaf disease in sugarcane cultivars with different degrees of infection by Sugarcane yellow leaf virus

Sugarcane yellow leaf virus (ScYLV) is present in many sugarcane growing areas of the world. It is suspected to cause yellow leaf disease (formerly called YLS, yellow leaf syndrome) of sugarcane. This study investigated symptom expression in a selection of cultivars classified into three groups; ScYLV‐susceptible/infected, ScYLV‐resistant and intermediately infected cultivars grown in plantation fields in the islands of Hawaii. Incidence of yellow leaf symptoms was correlated, though not tightly, to the presence of ScYLV. The correlation is based on two factors: (i) only ScYLV‐infected cultivars (from both susceptible and intermediate groups) showed severe symptom expression, and (ii) ScYLV‐infected plants had four times higher symptom incidence than virus‐free plants of the same cultivar. The yellow leaf symptom expression fluctuated, peaking at 200, 350, 500 and 600 days after planting. These symptom peaks were correlated with an increase of ScYLV content in the intermediately infected group of cultivars. No nutritional, environmental or field factor could be identified which clearly influenced symptom expression. It is speculated that the symptom expression is elicited by assimilate backup in the stalks and that the fluctuation of symptom expression is caused by the growth rhythm of mature sugarcane stalks.

In vitro replication capacity of HIV-2 variants from long-term aviremic individuals

To establish whether efficient suppression of virus replication in HIV-2-infected individuals is associated with low replicative capacity of HIV-2, replication kinetics of HIV-2 variants from long-term aviremic individuals was analyzed and compared with that of the relatively slow-replicating HIV-1 variants from asymptomatics and long-term nonprogressors (AS/LTNP). On average, HIV-2 from aviremic individuals had lower replication rates than HIV-1 variants from AS/LTNP in cells of 8 donors (0.45 log 10 [range 0.14–0.77] vs. 0.58 log 10 [range 0.32–0.99] pg RT/ml/day, P = 0.036). The relatively low replication rate of HIV-2 compared to HIV-1 variants was not related to different sensitivities to inhibition by CD8 + T cells or different degrees of infectivity. HIV-2 replication rates increased with progressive infection and with switch from CCR5 to CXCR4 usage. The relatively low replicative capacity of HIV-2 variants from aviremic individuals likely contributes to the low viral load and benign course of infection in these individuals.

Physiological Modifications Caused by Plum Pox Virus in the Leaves of Peach and Apricot Tree

Symptomatic and asymptomatic leaves of peach (sel. IF7230685) and apricot (cv. Tyrinthos) infected by “plum pox virus” (PPV) were analysed for net photosynthesis, peroxidase activity and chlorophyl content. The presence of the PPV in the leaves excised was verified with the ELISA test. The PPV affected the photosynthetic system more strongly in peach than in apricot. Peroxidase activity (PA) and chlorophyl content were also affected. PA was a good indicator of infection, and also made it possible to distinguish different degrees of infection.

Selection for partial resistance to downy mildew in peas by means of greenhouse tests

A partially downy mildew resistant pea line was back-crossed to a susceptible cultivar with more pods per node and lower seed weight. Breeding lines with different degrees of infection in a greenhouse test were selected. These lines and the two parental lines were investigated in field trials and tested in the greenhouse for four generations. Significant genetic variation among lines was found for infection of seedlings in greenhouse tests, and infection of pods, pod set and seed weight in field-trials. Infection of seedlings in the greenhouse was correlated with infection of pods in the field. In greenhouse tests, the non-genetic variance component was large in comparison with the genetic component and a significant genotype ★ trial interaction was found. Significant repeatability was obtained for downy mildew on seedlings and pods, number of pods per node and seed weight. An unfavourable correlation between susceptibility to downy mildew and number of pods per node was found. No single breeding line showed the ideal combination of good resistance, high number of pods per node and small seeds. However, one line showing better resistance than the susceptible parent, with smaller seeds and more pods per node than the resistant parent was found. The susceptible parent also carries some resistance factor that is not present in the resistant parent.

Hepatitis B e-antigen titres for evaluating infectivity during hepatitis B virus infection.

By means of an ELISA the level of hepatitis B e-antigen (HBeAg) titre was determined in 51 patients with acute and 123 patients with persistent hepatitis B virus (HBV) infection. We also investigated 120 sera of these patients for infectivity by detecting HBV-specific DNA polymerase (DNA-P). Additional determination of the HBeAg titre revealed that the detection of HBeAg at a dilution of at least 1:50 correlates with the detection of DNA-P in 95% of cases, while in sera with an HBeAg titre of 1:25 or less DNA-P is only detectable in up to 5% of cases. Since the detection of DNA-P indicates high infectivity, certain titres of HBeAg can be employed to differentiate three different degrees of infectivity: (1) Sera without HBeAg show no or only little infectivity; (2) sera containing HBeAg greater than or equal to 1:50 are highly infectious; (3) HBeAg titres up to 1:25 indicate a medium degree of infectivity. These three markers for different degrees of infectivity were applied to study the course of infectivity during acute and persistent forms of HBV infection. In acute hepatitis B the period for the elimination of HBeAg is independent of the HBeAg titre in the first serum sample. In all cases the elimination of HBeAg in acute hepatitis B did not exceed 4 months. Patients with persistent HBV infection and an initial HBeAg titre greater than or equal to 1:50 remained at this high degree of infectivity for at least 18-30 months in 70% of cases. Only 30% of this collective showed a decrease in infectivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemogram of Turkey Poults Experimentally Infected with Syngamus trachea

Yakimoff and Rastegaieff (10) reported an increase in the number of eosinophils in chickens infected with coccidia and cestodes. Olson and Levine (5) observed that the total number of heterophils and eosinophils per cu mm of blood was much greater in chickens experimentally infected with Capillaria columbae than in uninfected birds. Johnson and Lange (2) reported a marked heterophilia and a severe but irregular monocytosis in young turkeys affected with typhlohepatitis induced by experimental infection with Histomonas meleagridis. Wickware (7) found a significant increase in the heterophils and eosinophils of chickens infected with Heterakis gallinae. The present studies were undertaken to obtain information regarding the differential leukocyte response in turkeys to different degrees of infection with Syngamus trachea.

Infectivity of the Philippine Strain of Schistosoma japonicum in Oncomelania hupensis, O. formosana and O. nosophora

The geographic strains of Schistosoma japonicum show different degrees of infectivity in various species of oncomelanian snails. Hunter et al (1952) reported that the Japanese strain of S. japonicum can develop well in Oncomelania nosophora from Japan but hardly at all in 0. formosana from Formosa, China. DeWitt (1954) showed the following: (1) The Chinese strain of S. japonicum can develop in O. hupensis from Shanghai, China, but not in 0. formosana from Formosa, China; O. nosophora from Japan, nor in 0. quadrasi from the Philippines; (2) the Formosan strain can develop well in 0. formosana from Formosa, China; 0. nosophora from Japan, and to a lesser degree 0. quadrasi from the Philippines, but not in 0. hupensis from Shanghai, China; and (3) the Japanese strain can develop in 0. nosophora from Japan, and 0. hupensis from Shanghai, China, but not in 0. formosana from Formosa, China, nor in 0. quadrasi from the Philippines. As to the Philippine strain, although it should unquestionably infect 0. quadrasi from the Philippines, its infectivity in the oncomelanian snails from the other endemic areas has not been studied.** In order to complete our knowledge concerning the infectivity of various geographic strains of S. japonicum in different Oncomelania species, a study of the infectivity of the Philippine strain in 0. hupensis, 0. formosana, and 0. nosophora was initiated.