Forward genetics combined with unsupervised classifications identified zebrafish mutants affecting biliary system formation.

Impaired formation of the biliary network can lead to congenital cholestatic liver diseases; however, the genes responsible for proper biliary system formation and maintenance have not been fully identified. Combining computational network structure analysis algorithms with a zebrafish forward genetic screen, we identified 24 new zebrafish mutants that display impaired intrahepatic biliary network formation. Complementation tests suggested these 24 mutations affect 24 different genes. We applied unsupervised clustering algorithms to unbiasedly classify the recovered mutants into three classes. Further computational analysis revealed that each of the recovered mutations in these three classes has a unique phenotype on node-subtype composition and distribution within the intrahepatic biliary network. In addition, we found most of the recovered mutations are viable. In those mutant fish, which are already good animal models to study chronic cholestatic liver diseases, the biliary network phenotypes persist into adulthood. Altogether, this study provides unique genetic and computational toolsets that advance our understanding of the molecular pathways leading to biliary system malformation and cholestatic liver diseases.

Research the Thermal Decomposition Processes of Copolymers Based on Polypropyleneglycolfumaratephthalate with Acrylic Acid.

Kinetics of thermal degradation of polymeric materials is usually studied by weight loss at a constant temperature or during heating. Hence, the activation energy and other kinetic parameters of the thermal destruction process are determined. One of the fastest and most accessible methods for studying the kinetics of these processes is TGA. Weight methods of TGA do not provide an opportunity to judge the proportion of gaseous degradation products. This is especially true for processes associated with the release of hydrogen and other substances with low molecular weights, the accuracy of determining the amount of which by the weight method is low. Meanwhile, the study of the gas evolution process can provide additional information about the kinetics and mechanism of thermal destruction processes. Of great interest is also the joint study of the total weight loss and gas evolution during the polymer heating. Using mass spectrometry, IR spectroscopy combined with thermal analysis (TGA/DSC-IR and TGA/DSC-MS) we have defined product composition and thermal destruction kinetics. As a result of the TGA/DSC-MS study of gaseous products of thermolysis in nitrogen atmosphere, there were found products with 44, 45, 59, 60, 68, and 88 phr. Quite a similar pattern for p-PGFPh:AA copolymers is also observed in TGA/DSC-IR studies: the same products and the same temperature range. However, in contrast to the TGA/DSC-MS study, CO release was also recorded by this method (weak signal). Kinetic characteristics of the processes were determined based on Friedman, Ozawa-Flynn-Wall and modified NPC methods. Obtained values of the activation energy and thermodynamic characteristics make it possible to predict the composition of polymers, which make a significant contribution to the development of theoretical ideas about the features of the physicochemical properties of polymers.

Higher efficacy of a single dosage albendazole and different soil-transmitted helminths re-infection profiles amongst indigenous Negritos from inland jungle versus those in resettlement at town peripheries.

Demarginalization through initiation of resettlement program since 1978 is an inevitable progress faced by the indigenous Orang Asli (OA) population in Peninsular Malaysia. As Malaysian huntergatherers, the Negrito has been exposed to various environmental-cultural variations. These changes may influence the pattern of soil-transmitted helminth (STH) infections, the common malady amongst OA. This study evaluated the deworming effects of single-dosage albendazole (400 mg) and STH-reinfection rate between Negritos who are still living in the inland jungle versus those living in resettlements at town peripheries (RPS). Stool samples from the consented participants were first examined using the direct faecal smear, formalin-ether sedimentation and Kato Katz techniques. Subsequently, stool collections were carried out in three time points following treatment (i.e., 21 days, 3 months and 6 months). In brief, a total number of 54 Negritos (inland: 24; RPS: 30) with a complete set of stool collection was included in this longitudinal study. This study revealed 72.2% cure rate against T. trichiura in the inland but only 15.0% in the RPS. Although the efficacy of albendazole against T. trichiura was ultimately low in the RPS, 62.6% egg reduction rate (ERR) (arithmetic mean) was noted (p = 0.001). For A. lumbricoides and hookworm, high cure rates were found in both communities (85.7-100.0%). Reinfection for T. trichiura was seen in less than 1 month with higher rate in the RPS (90.0%) as opposed to the inland (44.4%) at 21 days following treatment. This study found that the inland OA had better tolerability to single-dosage albendazole and experienced slower STH reinfection rates versus the RPS. Hence, the selection of albendazole dosage should be targeted and the use of single- dosage albendazole (biannually) would be more suitable for the inland OA. Conversely, we propose the use of 3-days albendazole regimens in the resettled RPS population.

Higher efficacy of a single dosage albendazole and different soil-transmitted helminths re-infection profiles amongst indigenous Negritos from inland jungle versus those in resettlement at town peripheries

@#Demarginalization through initiation of resettlement program since 1978 is an inevitable progress faced by the indigenous Orang Asli (OA) population in Peninsular Malaysia. As Malaysian huntergatherers, the Negrito has been exposed to various environmental-cultural variations. These changes may influence the pattern of soil-transmitted helminth (STH) infections, the common malady amongst OA. This study evaluated the deworming effects of single-dosage albendazole (400 mg) and STH-reinfection rate between Negritos who are still living in the inland jungle versus those living in resettlements at town peripheries (RPS). Stool samples from the consented participants were first examined using the direct faecal smear, formalin-ether sedimentation and Kato Katz techniques. Subsequently, stool collections were carried out in three time points following treatment (i.e., 21 days, 3 months and 6 months). In brief, a total number of 54 Negritos (inland: 24; RPS: 30) with a complete set of stool collection was included in this longitudinal study. This study revealed 72.2% cure rate against T. trichiura in the inland but only 15.0% in the RPS. Although the efficacy of albendazole against T. trichiura was ultimately low in the RPS, 62.6% egg reduction rate (ERR) (arithmetic mean) was noted (p = 0.001). For A. lumbricoides and hookworm, high cure rates were found in both communities (85.7–100.0%). Reinfection for T. trichiura was seen in less than 1 month with higher rate in the RPS (90.0%) as opposed to the inland (44.4%) at 21 days following treatment. This study found that the inland OA had better tolerability to single-dosage albendazole and experienced slower STH reinfection rates versus the RPS. Hence, the selection of albendazole dosage should be targeted and the use of single- dosage albendazole (biannually) would be more suitable for the inland OA. Conversely, we propose the use of 3-days albendazole regimens in the resettled RPS population.

Changes of Certain Metabolic and Cardiovascular Markers Fructosamine, H-FABP and Lipoprotein (a) in Patients with Hypothyroidism.

BACKGROUND: Disorders of thyroid gland are common in general population, and it's the most common affecting the endocrine system after diabetes mellitus. Thyroid function regulates a wide range of metabolic parameters, as well as affects some cardiovascular disease risk factors. Fructosamine is produced by a reaction between albumin (protein) and glucose; it is used to monitor patients with diabetes for short-term glycemic changes. H-FABP is present in the cytoplasm of cardiac myocytes, and delivers fatty acids into these cells. It has been shown to increase in myocardial injury. Lipoprotein LP(a) is consist of a special apolipoprotein called apoprotein (a), and it's recognized as a cardiovascular disease independent risk factor. OBJECTIVE: To study whether certain metabolic and cardiovascular markers (fructosamine, H-FABP and lipoprotein (a) are changed in hypothyroid patients. METHODS: The current study included 280 overt hypothyroid, 272 with subclinical hypothyroidism compared with 270 healthy individuals of matched age and gender. For all subjects serum (TSH, T4, T3, FBS, HbA1c, fructosamine, triglycerides, cholesterol, lipoprotein (a), and Heart-type Fatty Acid-Binding Protein (H-FABP)) was measured. RESULTS: Serum fructosamine level significantly elevated (p value <0.05) in patient with hypothyroidism when compared with control group, and no significant change between subclinical and control groups. There is no significant change in serum H-FABP between study subjects. There is significant increase in lipoprotein (a) in patient with hypothyroidism and those with subclinical group when compared with control group. CONCLUSION: Serum fructosamine and level is significantly changed in patients with overt hypothyroidism when compared with euthyroid subjects. Also, we conclude that hypothyroidism increase risk of cardiovascular diseases by changing non-traditional marker such as lipoprotein (a), and no effect on H-FABP concentration.

Predictive Value of C-reactive Protein, Lactate Dehydrogenase, Ferritin and D-dimer Levels in Diagnosing COVID-19 Patients: a Retrospective Study.

BACKGROUND: Since December 2019. millions of people in the world have been affected with the novel Coronavirus disease-2019 (COVID-19) pandemic, and high economic impact has affect many countries especially low socioeconomic one like Iraq due to the high cost and limited availability of RT-PCR for diagnosis of COVID-19, so there should be predictive low cost easily available laboratory tests that can be used before proceeding to the high cost techniques. OBJECTIVE: In this retrospective study we aimed to evaluate the diagnostic accuracy of CRP, ferritin, LDH and D-dimer in predicting positive cases of COVID-19 in Iraq. METHODS: It is a retrospective observational cohort study based on STARD guidelines to determine the diagnostic accuracy of (CRP, LDH, ferritin and D dimer) for COVID-19 of electronic medical records of private medical center in Najaf city, at which 566 individuals were recruited. The investigated subjects were either in close contact with previously COVID-19 positive patients or have one or more symptoms of COVID-19. They were categorized into 2 groups, 205 subjects diagnosed with RT-PCR as COVID-19 negative, and 361 COVID-19 positive patients, results of study variables of the cohort were recruited from the medical records. RESULTS: Combining of these parameters had the following findings: CRP + ferritin; AUC: 0.77 with 55% sensitivity and 97% specificity, Ferritin + LDH; AUC: 0.83 with 65% sensitivity and 92% specificity, CRP+LDH; AUC: 0.78 with 56% sensitivity and 98% specificity, CRP + LDH + ferritin; AUC: 0.85, with 73% sensitivity and 88% specificity, CRP + LDH + ferritin + D dimer; AUC: 0.85 75% sensitivity and 87% specificity. CONCLUSION: Combination of routine laboratory biomarkers (CRP, LDH and ferritin ±D dimer) can be used to predict the diagnosis of COVID-19 with an accepted sensitivity and specificity before proceeding to definitive diagnosis by RT-PCR.

Hepatitis B virus infection: Epidemiology and seroprevalence rate amongst Negrito tribe in Malaysia.

INTRODUCTION: Prevalence of Hepatitis B virus (HBV) infection among the non-indigenous people in Malaysia has been well established and range between 3% and 5%. However, data from the indigenous (Orang Asli) people is still lacking. The Negrito population is the most remotely located Orang Asli tribe with limited access to health care facilities. This study was undertaken to determine the epidemiology and seroprevalence of HBV infection among the Negrito. METHODS: Surveys were conducted in five Negrito settlements in Kelantan and Perak states in Malaysia. A total of 150 participants were recruited. Clinical history was taken and physical examination was performed. Five millilitres of whole blood were collected and tested for hepatitis B surface antigen (HBsAg) using electrochemiluminescence immunoassay. RESULTS: Participants were mainly from the Bateq (49.3%) and Mendriq (29.4%) sub-tribes. Overall, 13 subjects (8.7 %); nine males and four females were HBsAg positive. Nine of the HBsAg positive subjects were ≥35 years old. All of them had history of home deliver without evidence of antenatal record. Six (46%) of the HBsAg positive subjects had tattoo and body piercing in the past. CONCLUSION: The prevalence of HBV infection rate amongst the Negrito tribe is almost three-fold compared to the national rates. The reason for this finding remains unclear. Tattooing, body piercing and vertical transmission could be the main possible routes of transmission of HBV among the Negrito population in Malaysia.

Induction of Systemic Resistance in Cucumber by Hypovirulent Binucleate Rhizoctonia against Anthracnose Caused by Colletotrichum orbiculare.

Treatment with hypovirulent binucleate Rhizoctonia (HBNR) isolates induced systemic resistance against anthracnose infected by Colletotrichum orbiculare in cucumber, as there were no direct interaction between HBNR and C. orbiculare. This is because of the different distances between HBNR and C. orbiculare, where the root was treated with HBNR isolate and C. orbiculare was challenged and inoculated in leaves or first true leaves were treated with HBNR isolate and C. orbiculare was challenged and inoculated in second true leaves. The use of barley grain inocula and culture filtrates of HBNR significantly reduced the lesion diameter compared to the control (p = 0.05). The total lesion diameter reduction by applying barley grain inoculum of HBNR L2, W1, W7, and Rhv7 was 28%, 44%, 39%, and 40%, respectively. Similar results was also observed in treatment using culture filtrate, and the reduction of total lesion diameter by culture filtrate of HBNR L2, W1, W7, and Rhv7 was 45%, 46%, 42%, and 48%, respectively. When cucumber root was treated with culture filtrates of HBNR, the lignin was enhanced at the pathogen penetration, which is spread along the epidermis tissue of cucumber hypocotyls. Peroxidase activity in hypocotyls in the treated cucumber plant with culture filtrates of HBNR significantly increased before and after inoculation of pathogens as compared to the control. Significant enhancement was also observed in the fast-moving anodic peroxidase isozymes in the treated plants with culture filtrates of HBNR. The results showed the elicitor(s) contained in culture filtrates in HBNR. The lignin deposition as well as the peroxidase activity is an important step to prevent systemically immunised plants from pathogen infection.

Detection of human Sarcocystosis using dried blood on filter papers: An Immunofluorescent Antibody Test.

Sarcocystosis, a parasitic infection caused by a protozoa belonging to the genus Sarcocystis, is found worldwide in both and animals. Sarcocystis spp., require two animal hosts to complete their life cycle. The infection has gathered more global attention after recent outbreaks, especially amongst wester travellers to Malaysia. Other than sporadic cases and the current outbreaks, little information is available regarding human Sarcocystis infection in Malaysia. The present study aims to determine the prevalence of sarcocystosis among humans using an immunofluorescent antibody (IFA) test applied to dried blood on filter papers. A total of 200 blood samples were collected on filter papers from autopsy cases at two Malaysian hospitals: Sungai Buloh Hospital (peninsular Malaysia) and Queen Elizabeth Hospital (Malaysian Borneo). Antigens were prepared from bradyzoites harvested from positive goats' muscle samples. Of the 200 samples, 32 (16%) had Sarcocystis antibodies that showed positive fluorescence reactions on filter papers. There was no significant difference (t-test, p value > 0.05) in prevalence rates between samples collected from autopsies at peninsular Malaysia and Malaysian Borneo. The results demonstrated that the filter paper technique can be used as one of the alternative serological tests in the diagnostic of human sarcocystosis.

Detection of human Sarcocystosis using dried blood on filter papers: An Immunofluorescent Antibody Test

@#Sarcocystosis, a parasitic infection caused by a protozoa belonging to the genus Sarcocystis, is found worldwide in both and animals. Sarcocystis spp., require two animal hosts to complete their life cycle. The infection has gathered more global attention after recent outbreaks, especially amongst wester travellers to Malaysia. Other than sporadic cases and the current outbreaks, little information is available regarding human Sarcocystis infection in Malaysia. The present study aims to determine the prevalence of sarcocystosis among humans using an immunofluorescent antibody (IFA) test applied to dried blood on filter papers. A total of 200 blood samples were collected on filter papers from autopsy cases at two Malaysian hospitals: Sungai Buloh Hospital (peninsular Malaysia) and Queen Elizabeth Hospital (Malaysian Borneo). Antigens were prepared from bradyzoites harvested from positive goats’ muscle samples. Of the 200 samples, 32 (16%) had Sarcocystis antibodies that showed positive fluorescence reactions on filter papers. There was no significant difference (t-test, p value > 0.05) in prevalence rates between samples collected from autopsies at peninsular Malaysia and Malaysian Borneo. The results demonstrated that the filter paper technique can be used as one of the alternative serological tests in the diagnostic of human sarcocystosis.

Health education to diabetic patients before the start of Ramadan: Experience from a teaching hospital in Dammam.

BACKGROUND AND OBJECTIVE: Studies have shown that pre-Ramadan structured educational program for patients with diabetes mellitus (DM) is beneficial. In this study, our aim was to evaluate the degree of adherence of treating physicians to such programs and their influence on the patient's knowledge and behavior. MATERIALS AND METHODS: This cross-sectional study was carried out on adult patients with DM attending a university hospital, who were observed while fasting during Ramadan 1436/2015. Data was collected using a questionnaire-based interview. Baseline characteristics were obtained, and patients were asked whether they had had pre-Ramadan education or not and who the provider was. Patients' knowledge of the components of the recommended structured pre-Ramadan educational program was also tested. Comparison between patients who had the education and those who did not was done using Chi-square test and independent samples Student's t-test; p ≤ 0.05 was considered statistically significant. RESULTS: A total of 298 patients with type 1 or type 2 DM were included in the study; 75.5% of the patients were aged 40 years or older. Only 30% had pre-Ramadan education delivered mainly by diabetic educators or the treating physicians (52% and 44%, respectively). Patients who had the education were younger (mean age: 45.6 ± 17.4 vs. 50.3 ± 14.4, respectively, p = 0.0048), had higher educational qualifications, were more likely to be employed, and self-monitored their blood glucose more frequently (p = 0.0001). There was no difference between the two groups with regard to their knowledge of diet and exercise. CONCLUSION: The adherence to the pre-Ramadan educational program by the treating physician was low. It is necessary to increase the awareness about the importance of these programs among health-care professionals. The programs should target the less educated, the unemployed, and older patients.

Prevention of meningococcal disease during the Hajj and Umrah mass gatherings: past and current measures and future prospects.

The Kingdom of Saudi Arabia (KSA) has a long history of instituting preventative measures against meningococcal disease (MD). KSA is at risk of outbreaks of MD due to its geographic location, demography, and especially because it hosts the annual Hajj and Umrah mass gatherings. Preventative measures for Hajj and Umrah include vaccination, targeted chemoprophylaxis, health awareness and educational campaigns, as well as an active disease surveillance and response system. Preventative measures have been introduced and updated in accordance with changes in the epidemiology of MD and available preventative tools. The mandatory meningococcal vaccination policy for pilgrims has possibly been the major factor in preventing outbreaks during the pilgrimages. The policy of chemoprophylaxis for all pilgrims arriving from the African meningitis belt has also probably been important in reducing the carriage and transmission of Neisseria meningitidis in KSA and beyond. The preventative measures for Hajj and Umrah are likely to continue to focus on vaccination, but to favour the conjugate vaccine for its extra benefits over the polysaccharide vaccines. Additionally, the surveillance system will continue to be strengthened to ensure early detection and response to cases and outbreaks; ongoing disease awareness campaigns for pilgrims will continue, as will chemoprophylaxis for target groups. Local and worldwide surveillance of the disease and drug-resistant N. meningitidis are crucial in informing future recommendations for vaccination, chemoprophylaxis, and treatment. Preventative measures should be reviewed regularly and updated accordingly, and compliance with these measures should be monitored and enhanced to prevent MD during Hajj and Umrah, as well as local and international outbreaks.

Light microscopy and molecular identification of Sarcocystis spp. in meat producing animals in Selangor, Malaysia.

One thousand and forty-five tissue samples of skeletal muscles, tongue, heart, diaphragm and esophagus were collected from 209 animals (43 sheep, 89 goats and 77 cattle) from an abattoir in Selangor between February and October, 2013. Each sample was divided into three pieces with each piece measuring 2-3 mm3. Each piece was then squeezed between two glass slides and examined microscopically at x 10 magnification for the presence of sarcocystosis. Three positive samples from each animal species were then fixed in 10% formalin for histological processing. Seven positive samples collected from each animal species were preserved at -80°C or 90% ethanol for gene expression studies. Microsarcocysts were detected in 114 (54.5%) animals by light microscopy (LM). The infection rates in sheep, goat and cattle were 86, 61.8 and 28.6% respectively. The highest rate of infection was in the skeletal muscles of sheep (64.9%) and goats (63.6%) and in the heart of cattle (63.6%). The cysts were spindle to oval in shape and two stages were recognized, the peripheral metrocytes and centrally located banana-shaped bradyzoites. 18S rRNA gene expression studies confirmed the isolates from the sheep as S. ovicanis, goats as S. capracanis and cattle as S. bovicanis. This, to the best of our knowledge, is the first molecular identification of an isolate of S. ovicanis and S. capracanis in Malaysia. Further studies with electron microscopy (EM) are required in the future to compare the features of different types of Sarcocysts spp.

Light microscopy and molecular identification of Sarcocystis spp. in meat producing animals in Selangor, Malaysia

One thousand and forty-five tissue samples of skeletal muscles, tongue, heart, diaphragm and esophagus were collected from 209 animals (43 sheep, 89 goats and 77 cattle) from an abattoir in Selangor between February and October, 2013. Each sample was divided into three pieces with each piece measuring 2-3 mm3. Each piece was then squeezed between two glass slides and examined microscopically at x 10 magnification for the presence of sarcocystosis. Three positive samples from each animal species were then fixed in 10% formalin for histological processing. Seven positive samples collected from each animal species were preserved at -80°C or 90% ethanol for gene expression studies. Microsarcocysts were detected in 114 (54.5%) animals by light microscopy (LM). The infection rates in sheep, goat and cattle were 86, 61.8 and 28.6% respectively. The highest rate of infection was in the skeletal muscles of sheep (64.9%) and goats (63.6%) and in the heart of cattle (63.6%). The cysts were spindle to oval in shape and two stages were recognized, the peripheral metrocytes and centrally located banana-shaped bradyzoites. 18S rRNA gene expression studies confirmed the isolates from the sheep as S. ovicanis, goats as S. capracanis and cattle as S. bovicanis. This, to the best of our knowledge, is the first molecular identification of an isolate of S. ovicanis and S. capracanis in Malaysia. Further studies with electron microscopy (EM) are required in the future to compare the features of different types of Sarcocysts spp.

Vector and reservoir host of a case of human Brugia pahangi infection in Selangor, peninsular Malaysia.

A case of human eye infection caused by Brugia pahangi was reported in 2010 in a semi rural village in Selangor, peninsular Malaysia. Our report here reveals results of investigation on the vector and animal host for the transmission of the infection. We conducted entomological survey and cat blood examination in the vicinity of the patient's home. The mosquito species Armigeres subalbatus was incriminated as the vector, whereas cat served as the reservoir host.

Features associated with severe disease in hospitalized children with 2009 influenza A (H1N1) infection at a university hospital in Riyadh, Saudi Arabia.

BACKGROUND AND OBJECTIVES: In 2009, pandemic H1N1 influenza A caused significant morbidity and mortality worldwide; however, available data on disease characteristics and outcome of hospitalized children is limited. DESIGN AND SETTING: A prospective cohort study of children who required hospitalization because of the influenza A (H1N1) infection at King Khalid University Hospital in Riyadh, Saudi Arabia, over 6 months (July- December, 2009). PATIENTS AND METHODS: Data was collected using a predesigned form for all admitted pediatric cases (0-12 years) presenting with the influenza-like illness and who tested positive for the novel influenza (H1N1) using reverse transcriptase polymerase chain reaction assay. The clinical course and features associated with the severe disease among such children were described RESULTS: Out of 1103 children with the influenza-like illness, 375 (34%) were confirmed pediatric cases of influenza A (H1N1), of whom 50 (13.3%) required hospitalization. The median age was 3 years (range, 1 month-12 years). Fever was the most frequent symptom (94%) at admission, followed by cough (86%) and other symptoms including vomiting and diarrhea. The majority (70%) of children had at least one underlying medical condition, with bronchial asthma being the most common (40%). All cases were treated with oseltamivir. Five children (10%) were admitted to the ICU, 4 required mechanical ventilation, and 2 died (4%). CONCLUSIONS: The majority of children with 2009 H1N1 influenza A-associated hospitalization in this series had an uncomplicated course. Respiratory complications and ICU admissions were more frequent in those with underlying disease, especially asthma and neuromuscular diseases. Efforts need to be focused prior to each influenza season and special emphasis needs to be given to children by immunizing them with H1N1 influenza A vaccination to avoid severe disease and minimize complications.

Control of Fusarium Crown and Root Rot of Tomato with Hypovirulent Binucleate Rhizoctonia in Soil and Rock Wool Systems.

Hypovirulent binucleate Rhizoctonia (HBNR) isolates L2, W1, W7, and Rhv7 were studied as potential antagonists of Fusarium crown and root rot of tomato (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici, in either soil or hydroponic rock wool systems. Reduction of FCRR on tomato by HBNR isolates was different depending on the isolate, days after inoculation of pathogen, and experiments. In the greenhouse soil system, HBNR isolates significantly (P = 0.01) reduced vascular discoloration and discoloration of total roots systems by 90 to 100% and by 73 to 89%, respectively, in three experiments. Under field soil conditions, HBNR W1 provided significant (P = 0.05) reduction of vascular discoloration by 71%. In the rock wool system, all HBNR isolates except L2 in experiment 1 significantly reduced (P = 0.05) vascular discoloration by 18 to 100% in four experiments. Plants treated with all HBNR isolates had foliar symptoms reduced by 41 to 100% in four experiments under the rock wool system. Application of HBNR also resulted in increases of marketable and total yields of tomatoes as much as 70 and 73%, respectively, over the untreated plants. The number of colony forming units of F. oxysporum f. sp. radicis-lycopersici per gram fresh weight of roots and stems was significantly reduced (P = 0.05) in plants treated with HBNR in both soil and rock wool systems. HBNR was re-isolated at a high frequency from roots grown inside paper pots containing soil infested with HBNR, but rarely isolated from the roots grown in soil infested with only F. oxysporum f. sp. radicis-lycopersici outside the paper pots. HBNR was not re-isolated from the tomato stems. Stem extracts from HBNR-treated and pathogen-challenged plants in the rock wool system inhibited germination and production of budding cells of F. oxysporum f. sp. radicis-lycopersici.