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Metabolic bone disease (MBD) is an important cause of morbidity in premature, very low birth weight (VLBW) and sick infants and, if left undiagnosed, may lead to structural deformities and spontaneous fractures. MBD is defined as impaired bone mineralization in a neonate with lower than expected bone mineral levels in either a fetus or a neonate of comparable gestational age and/or weight, coupled with biochemical abnormalities with or without accompanying radiological manifestations. MBD has been reported to occur in 16% to 40% of extremely low birth weight neonates and presents by 6-16 weeks after birth. Insufficient calcium and phosphorous stores during the phase of accelerated growth predispose to MBD in neonates along with the use of some medications such as caffeine or steroids, prolonged parenteral nutrition and chronic immobilization. Enhanced physical activity in preterm infants facilitates bone mineralization and weight gain. Biochemical abnormalities tend to worsen significantly, as the severity of disease progresses. These abnormalities may include hypocalcemia, hypophosphatemia, hyperphosphatasia and secondary hyperparathyroidism. In addition, urinary phosphate wasting and hypovitaminosis D can be additional complications. Conversely, biochemical abnormalities may not be accompanied by rachitic changes. Newer diagnostic modalities include non-invasive bone densitometry by quantitative ultrasound over the mid-tibial shaft. The management of MBD includes adequate calcium, phosphorous and vitamin D supplementation, along with optimum nutrition and physical activity. Similarly, preventive strategies for MBD should target nutritional enhancement in combination with enhanced physical activity. MBD usually results in preventable morbidity in preterm and VLBW neonates. Treatment consists of optimum nutritional supplementation and enhanced physical activity.

Despite a substantial understanding of the factors regulating oligodendrocyte differentiation, the signaling mechanisms involved in this process are not well-understood. This study elaborates on the findings (Bhat NR, Zhang P (1997) FASEB J 11:A925; Baron W, Metz B, Bansal R, Hoekstra D, de Vries H (2000) Mol Cell Neurosci 15:314-329) of a role for p38 MAP kinase signaling in oligodendrocyte differentiation and myelin gene expression. When proliferating oligodendrocyte progenitors were switched to a growth factor-free differentiation medium, there was a rapid activation of p38 kinase that correlated with an increased phosphorylation of CREB, a down-stream target and a factor involved in oligodendrocyte differentiation. Addition of forskolin, a known inducer of intracellular c-AMP and of oligodendrocyte differentiation, also stimulated CREB phosphorylation in a p38 kinase dependent way. Pharmacological inhibition of p38 interfered with the morphological and antigenic changes associated with differentiating oligodendrocytes as well as with the developmental and forskolin-induced expression of myelin basic protein, thereby supporting an essential role for p38 MAPK pathway in oligodendrocyte differentiation.

Purpose: Metabolic bone disease of prematurity (MBDP) remains a significant cause of morbidity in extremely premature newborns. In high-risk patients, suspected diagnosis and subsequent treatment modifications, with limitations in terms of sensitivity and specificity, rely on low phosphorus levels and/or high levels of alkaline phosphatase (ALP). We investigated the potential of fibroblast growth factor-23 (FGF23) as an early marker for MBDP when measured at 3–4 weeks of life in at-risk patients. Methods: A single-center prospective observational non-interventional study including preterm newborns of both sexes, with a gestational age of less than 32 weeks and/or a birth weight of less than 1500 g. In the standard biochemical screening for MBDP performed between 3 and 4 weeks of life within a nutritional profile, the determination of FGF23 was included along with other clinical and metabolic studies. The study was conducted at Marqués de Valdecilla University Hospital in Santander, Spain, from April 2020 to March 2021. Participants provided informed consent. Biochemical analyses were conducted using various platforms, and follow-up evaluations were performed at the discretion of neonatologists. Patients at high risk for MBDP received modifications in treatment accordingly. The sample was descriptively analyzed, presenting measures of central tendency and dispersion for continuous variables, and absolute numbers/percentages for categorical ones. Tests used included t-tests, Mann‒Whitney U tests, chi-square tests, logistic regressions, Pearson correlation, and ROC curve analysis (IBM SPSS Statistics version 19). Significance level: P < 0.05. Results: In the study involving 25 at-risk premature newborns, it was found that 20% (n = 5) were diagnosed with MBDP. Three of these patients (60%) were identified as high-risk based on standard biochemical evaluation at 3–4 weeks of age, while the other two patients (40%) were diagnosed in subsequent weeks. However, in all 5 patients, measurement of FGF23 levels would allow for early identification and optimization of treatment before other markers become altered. Low levels of FGF23 at 3–4 weeks, even with normal phosphorus and ALP levels, indicate the need for modifications in nutritional supplementation. Conclusions: MBDP remains a significant concern in extremely premature newborns. Current diagnostic methods rely on limited biochemical markers. Early detection of low FGF23 levels enables timely interventions, potentially averting demineralization. Key points: Question: Is fibroblast growth factor-23 (FGF23) measured at 3–4 weeks of life a reliable early marker for metabolic bone disease of prematurity (MBDP) in at-risk preterm newborns? Findings: This study was a single-center prospective observational noninterventional study conducted in a neonatal unit in Spain. The primary outcome was to investigate FGF23 as a potential early marker for MBDP. The study found that low levels of FGF23 at 3–4 weeks of life, even with normal phosphorus and alkaline phosphatase levels, indicated the need for modifications in nutritional supplementation. FGF23 levels at this time point were found to predict subsequent hypophosphatemic status, making it the most sensitive early marker for MBDP in at-risk preterm newborns. Meaning: Early detection of low FGF23 levels at 3–4 weeks of life can help identify at-risk preterm newborns with MBDP and prompt timely treatment modifications, potentially preventing demineralization and improving outcomes in this vulnerable population. [ABSTRACT FROM AUTHOR]

The nucleocapsid (N) protein of bovine respiratory syncytial virus (BRSV) in the baculovirus expression system was evaluated as a source of antigen in an enzyme-linked immunosorbent assay (ELISA) for the detection of respiratory syncytial virus (RSV) antibodies. The recombinant N protein was purified from infected-cell extracts by sucrose gradient centrifugation and used in the ELISA for the detection of antibodies to various RSV strains. The ELISA was compared with the virus neutralization (VN) test for determining BRSV antibodies in 10 consecutive serum samples from four calves vaccinated with a live modified BRSV vaccine and from two nonvaccinated control calves. The ELISA compared favorably with the VN test for detecting serological responses. All serum samples which were positive in the VN test were also positive in the ELISA. None of the serum samples collected from the two nonvaccinated calves reacted in the ELISA. To determine the usefulness of the ELISA for epidemiological studies, 58 cattle serum samples were tested in the ELISA and the VN test. Approximately 94% (42 of 45) of field serum samples which were positive in the ELISA were also positive in the VN test. No case was found in which the ELISA result was negative and the VN test result was positive. Thirteen of the serum samples were negative in both methods. Our results indicate that the ELISA with the baculovirus-expressed N protein as an antigen is an efficient, sensitive, and specific method for detecting serum antibodies to RSV.

The coding region of the gene for the nucleocapsid (N) protein of bovine respiratory syncytial virus has been inserted into the genome of Autographa californica nuclear polyhedrosis virus (AcNPV) using transfer vector pVL 1393. Infection of Spodoptera frugiperda cells with recombinant virus resulted in the synthesis of high levels of N protein. This protein was indistinguishable from the authentic bovine respiratory syncytial virus (BRSV) N protein by SDS-gel electrophoresis and immunoprecipitation with anti-BRSV serum. [35S]methionine-labeled N protein synthesized in S. frugiperda cells was used in a protein-blotting protein overlay assay for its interactions with BRSV-infected cell proteins. The N protein synthesized in S. frugiperda cells was found to specifically interact with the phosphoprotein (P) and M2 protein of BRSV but only with the P protein of human RSV. Our results suggest that the recombinant N protein produced in S. frugiperda cells could be used to determine the domains on N protein required for binding to P and M2 proteins.

The nucleotide sequence of the gene encoding the major nucleocapsid (N) protein of bovine respiratory syncytial virus (BRSV) has been determined. The N mRNA is 1196 nucleotides long with a single, large open reading frame. The derived polypeptide has 391 amino acids corresponding to a calculated molecular weight of 42,600 Da. This is in agreement with the molecular weight of 43,000 Da determined for the BRSV N protein by SDS-polyacrylamide gel electrophoresis (PAGE). Comparison of the nucleotide sequence of BRSV N gene with the sequence of the N gene of human respiratory syncytial virus (HRSV) revealed a homology of 80.7%. There is a 93.3% homology at the amino acid level between the N proteins of BRSV and HRSV. The 5'- and 3'-terminal untranslated sequences that are conserved among HRSV mRNAs were also identified in the N mRNA of BRSV. The results indicate that the N genes are highly conserved in the bovine and human strains of respiratory syncytial virus.

Biochemical characteristics of five rotavirus-like viruses isolated from striped bass (Morone saxatilis), turbot (Scophthalmus maximus), smelt (Osmerus mordax) and Atlantic salmon (Salmo salar) in North America and Europe were compared. The genome of each isolate was composed of 11 segments of dsRNA and each isolate had a unique electropherotype in polyacrylamide gels. Agarose gel electrophoresis showed similar RNA profiles for all four isolates from North America, whereas the RNA profile of the isolate from Europe was different. Analysis of virion proteins revealed that each virus had five structural proteins ranging in Mr from 130,000 to 34,000. Each isolate had a unique polypeptide profile but their overall polypeptide patterns were similar. Reciprocal RNA-RNA blot hybridization demonstrated that all these rotavirus-like viruses cross-hybridized with each other except for the isolate from Europe which did not hybridize with the RNA from any of the other isolates. No genetic relationship was found between these rotavirus-like viruses of fish and a true group A rotavirus (SA11).

Rickets results from impaired mineralization of growing bone due to alterations in calcium and phosphate homeostasis. Clinical signs of rickets are related to the age of the patient, the duration of the disease, and the underlying disorder. The most common signs of rickets are swelling of the wrists, knees or ankles, bowing of the legs (knock-knees, outward bowing, or both) and inability to walk. However, clinical features alone cannot differentiate between the various forms of rickets. Rickets includes a heterogeneous group of acquired and inherited diseases. Nutritional rickets is due to a deficiency of vitamin D, dietary calcium or phosphate. Mutations in genes responsible for vitamin D metabolism or function, the production or breakdown of fibroblast growth factor 23, renal phosphate regulation, or bone mineralization can lead to the hereditary form of rickets. This position paper reviews the relevant literature and presents the expertise of the Bone and Mineral Metabolism Group of the Italian Society of Pediatric Endocrinology and Diabetology (SIEDP). The aim of this document is to provide practical guidance to specialists and healthcare professionals on the main criteria for diagnosis, treatment, and management of patients with rickets. The various forms of rickets are discussed, and detailed references for the discussion of each form are provided. Algorithms to guide the diagnostic approach and recommendations to manage patients with rare forms of hereditary rickets are proposed. [ABSTRACT FROM AUTHOR]

Background: Physiological processes rely on phosphate, which is an essential component of adenosine triphosphate (ATP). Hypophosphatasia can affect nearly every organ system in the body. It is crucial to monitor newborns with risk factors for hypophosphatemia and provide them with the proper supplements. We aimed to evaluate the risk factors and develop a nomogram for early hypophosphatemia in term infants. Methods: We conducted a retrospective study involving 416 term infants measured serum phosphorus within three days of birth. The study included 82 term infants with hypophosphatemia (HP group) and 334 term infants without hypophosphatemia (NHP group). We collected data on the characteristics of mothers, newborn babies, and childbirth. Furthermore, univariate and multivariate logistic regression analyses were performed to identify independent risk factors for hypophosphatemia in term infants, and a nomogram was developed and validated based on the final independent risk factors. Results: According to our analysis, the multivariate logistic regression analysis showed that male, maternal diabetes, cesarean delivery, lower serum magnesium, and lower birth weight were independent risk factors for early hypophosphatemia in term infants. In addition, the C-index of the developed nomogram was 0.732 (95% CI = 0.668–0.796). Moreover, the calibration curve indicated good consistency between the hypophosphatemia diagnosis and the predicted probability, and a decision curve analysis (DCA) confirmed the clinical utility of the nomogram. Conclusions: The analysis revealed that we successfully developed and validated a nomogram for predicting early hypophosphatemia in term infants. [ABSTRACT FROM AUTHOR]

Background: In standard fortification of human milk (HM), the HM macronutrient content is assumed, and a fixed amount of a multinutrient fortifier is added to achieve recommended nutrient intakes. In target fortification, the HM macronutrient content is regularly measured, guiding the addition of modular macronutrient supplements to the fortified HM, to achieve the nutritional targets more precisely. Objective: The study aimed to investigate whether this addition of modular supplements, unaccompanied by mineral supplementation, predispose to metabolic bone disease (MBD). Methods: This is a secondary analysis of a larger study of infants born with <33 weeks gestational age. Fortifications based on the assumed (Group 1) or measured (Group 2) of the HM macronutrient content were compared, using low serum phosphate levels as an indicator of MBD, and length growth as a surrogate of bone growth. Results: Eighty‑four infants were included, 35 in Group 1 and 49 in Group 2. During the exposure period, infants of Group 2 received higher mean fat (6.1 vs. 5.3 g/kg/day, P < 0.001) and carbohydrate (13.0 vs. 11.7 g/kg/day, P < 0.001) intakes; in addition, they exhibited lower mean serum phosphate (5.5 vs. 6.0 mg/dL, P = 0.022) and faster mean length velocity (1.06 vs. 0.89 cm/week, P = 0.003). Conclusions: These findings suggest that feeding fortified HM with extra fat and carbohydrate content, unaccompanied by mineral supplementation, promotes increased bone growth, as indicated by accelerated length growth, but with insufficiently mineralized osteoid, indicated by low serum phosphate levels. Intervention studies using direct biomarkers of bone mass content and mineral density are necessary to corroborate our findings. [ABSTRACT FROM AUTHOR]

The characteristics of a rotaviruslike (SBR) virus isolated from striped bass (Morone saxatilis) were examined following purification of viruses from infected cell cultures. Virions had a double-layered capsid of icosahedral symmetry and a diameter of 75 nm. Purified viruses contained five polypeptides ranging in molecular mass from 130 to 35 kDa. None of the structural proteins were glycosylated. Treatment with EDTA did not remove the outer capsid. By using enzymes and a chaotropic agent, it was shown that VP5 was the most external polypeptide. The genome of SBR virus was composed of 11 segments of double-stranded RNA (dsRNA). The electrophoretic pattern of the dsRNA of SBR virus was different from that of reovirus type 1 (Lang) and rotavirus (SA11) dsRNA. The SBR virus was compared with reovirus type 1 and SA11 virus by RNA-RNA blot hybridization. There was no cross-hybridization between any of the genome segments of the SBR, reovirus type 1, or SA11 viruses. Antigenic comparison of SBR virus and SA11 virus by cross-immunoprecipitation and cross-immunofluorescence tests did not show any relationship. These results suggest that SBR virus could represent a new genus within the family Reoviridae.

Ten virus-specific polypeptides ranging in molecular weight from approximately 200k to 11k were identified in bovine respiratory syncytial virus (BRSV-)infected cells. Time course analysis of the induction of the viral polypeptides indicated that they could be detected as early as 30 min post-infection and their synthesis reached a plateau 12 h after infection. Cell free translation of total infected-cell mRNA in a rabbit reticulocyte system yielded 7 proteins corresponding in size to virus-specific proteins synthesized in BRSV-infected cells. The P protein was highly phosphorylated; G and F were identified as glycoproteins by [3H]glucosamine labeling. Glycosylation of G protein was largely resistant to tunicamycin, suggesting that the majority of the carbohydrate residues are attached via O-glycosidic bonds, whereas the F protein was N-linked glycosylated. Tunicamycin caused a drastic reduction in the yield of infectious virus titer indicating that the carbohydrate moieties serve a critical role in the infectious cycle of BRSV.

Background: Metabolic bone disease (MBD) is an important cause of morbidity in premature, very low birth weight (VLBW), and sick infants and, if left undiagnosed, may lead to structural deformities and spontaneous fractures. The objective of the present study was to study the profile of MBD and to determine the incidence of MBD in infants ≤ 32 weeks/≤ 1250 g at birth. Method: A total of 57 infants ≤ 32 weeks/≤ 1250 g at birth admitted in our NICU from October 2020 to July 2021 were included in the study. These infants underwent screening for MBD at 4 weeks of age. They were stratified into three groups based on their gestation (≤ 28 weeks, 29–30 weeks, 31–32 weeks). Results: MBD was observed in 100% of extreme preterm babies and 69% of very preterm babies. Overall, the incidence of MBD was 73%. Serum phosphorus level normalized by 42–44 weeks post menstrual age (PMA) across all gestations. Alkaline phosphatase (ALP) levels normalized by 42–44 weeks only in very preterm babies. Seventeen babies ≤ 30 weeks required inorganic phosphorus supplementation in addition to calcium phosphate supplementation in order to correct the MBD. Drugs like caffeine, steroids, and furosemide have significant impact on the development of MBD. The time to reach full feeds with fortification had no statistically significant effect on the incidence of MBD as detected by serum phosphorus level and serum ALP level. Conclusion: The profile outlined in the present study matches the literature reports in many aspects, revealing the importance of characterizing this group for the prognosis and short- and long-term follow-up of newborns with bone metabolic disease. [ABSTRACT FROM AUTHOR]

Objective: In 2017, our Level IV NICU switched from providing bovine-derived (BOV-fort) to human milk-derived fortifiers (HM-fort) and donor human milk (DHM) to premature infants born ≤ 30 weeks or ≤1250 g. Following this change, providers anecdotally observed increased hypoglycemia, hypercalcemia, and hyperphosphatemia. This study investigated potential laboratory differences between infants fed Bovine vs. Human milk derived fortifier., Methods: Lab measurements from 402 infants (232 BOV-fort, 170 HM-fort) born between 2015 and 2019 were compared between groups., Results: The proportion of infants ever having a blood glucose ≤ 45 mg/dL (p < 0.0001) was higher in the HM-fort group. The proportion of infants ever experiencing a phosphorus > 8.0 mg/dL were higher in the HM-fort group (p < 0.0001). The proportion of infants ever experiencing calcium > 11.4 mg/dL was higher in the HM-Fort group (p = 0.019)., Conclusions: Provision of HM-Fort and DHM to extremely premature infants is associated with metabolic derangements., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Objective: Prompted by an alarmingly low screening rate for metabolic bone disease of prematurity (MBDP), we aimed to increase MBDP screening with serum calcium, phosphorous, and alkaline phosphatase at four to six weeks of life in infants born at <1500 g and <32 gestational weeks from a baseline of 27.37% to 90% within one year., Study Design: We used the Institute for Healthcare Improvement's Model for Improvement as a framework. A key driver diagram informed the interventions which were carried out through four Plan-Do-Study-Act cycles., Results: There were 129 and 130 neonates in the pre-intervention baseline group and post-intervention MBDP bundle group, respectively. MBDP bundled primary screening rates increased from 27.37% to 95.56% (p < 0.001). Furthermore, 20% of infants had an individualized change in their enteral mineral supplementation after the initiative., Conclusions: An interdisciplinary team-based quality improvement approach was effective in altering clinical practice to improve screening and subsequent treatment for MBDP., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Multiple sclerosis (MS) is a chronic autoimmune and demyelinating disease of the central nervous system (CNS) which leads to focal demyelinated lesions in the brain and spinal cord. Failure of remyelination contributes to chronic disability in young adults. Characterization of events occurring during the demyelination and remyelination processes and those of which subsequently limit remyelination or contribute to demyelination can provide the possibility of new therapies development for MS. Most of the currently available therapies and investigations modulate immune responses and mediators. Since most therapeutic strategies have unsatisfied outcomes, developing new therapies that enhance brain lesion repair is a priority. A close look at cellular and chemical components of MS lesions will pave the way to a better understanding of lesions pathology and will provide possible opportunities for repair strategies and targeted pharmacotherapy. This review summarizes the lesion components and features, particularly the detrimental elements, and discusses the possibility of suggesting new potential targets as therapies for demyelinating diseases like MS. [ABSTRACT FROM AUTHOR]

The evolution of nutritional care in preterm infants, particularly those classified as extremely preterm, has undergone significant advancements in recent years. These infants, born at less than 28 weeks of gestation, face unique challenges related to their elevated nutrient requirements, underdeveloped organ systems and minimal reserves, posing a need for timely and specialised nutritional strategies. Historically, the nutritional management of preterm infants focussed on short-term goals to promote survival. In recent years, the focus has shifted to the quality of nutrient provision to optimise neurodevelopment and longer-term health outcomes. This review highlights the shift from a generalised nutritional approach to a robust, evidence-based approach for preterm infants, acknowledging the intricate interplay between nutrition, holistic care and developmental outcomes. As neonatal care continues to evolve, ongoing research will refine nutritional interventions, optimise growth and enhance the long-term health outcomes of these vulnerable infants., (© 2024 The British Dietetic Association Ltd.)

This study was conducted to evaluate the prevalence of bovine gammaherpesvirus 4 (BoHV-4) among healthy cattle and buffaloes as well as those associated with different diseases (respiratory tract infection, mastitis and reproductive tract infection) in District Chakwal, Pakistan. Blood, swab and milk samples of cattle and buffaloes were randomly collected from different areas of Chakwal. DNA was isolated from the samples and subjected to nested PCR using thymidine kinase gene primers. Out of 300 samples (200 blood, 50 swab and 50 milk samples) from both species (cattle and buffalo), an overall prevalence of BoHV-4 of 3.33% was obtained. Samples from cattle showed a higher species-specific prevalence (4.16%) than samples from buffalo (2.78%). One sample out of 50 swab samples and 1 out of 50 milk samples were also positive for BoHV-4. DNA sequencing of a positive PCR product from cattle confirmed that the sequence was from the thymidine kinase gene of BoHV-4. Phylogenetic analysis also revealed close similarities with other BOHV-4 thymidine kinase sequences. To detect BoHV-4 antibodies, an indirect ELISA was also performed. Two hundred blood samples were also collected from the same animals in nonanticoagulant-containing tubes for the isolation of serum and were subjected to indirect ELISA. Sixteen samples (8%) were positive for BoHV-4 antibodies. This study will be useful in further diagnoses of BoHV-4 in Pakistan and in devising measures to control the spread of BoHV-4. [ABSTRACT FROM AUTHOR]

The effect of levamisole in calves experimentally infected with bovine viral diarrhea virus was evaluated in a double-blind study. The infection was mild and there was no difference in severity of infection or speed of recovery between levamisole-treated and 0.9% NaCl solution-treated (control) calves. Also, the serum antibody titers and viral recovery data of these calves were comparable. The white blood cell counts were consistently higher in the treated group than in the control group, with the difference peaking on postinoculation day 15. The detection of marked lymphopenia in control calves but not in levamisole-treated calves indicated a potential use of levamisole in bovine viral diarrhea.

Calves exposed by intranasal (IN) or intratracheal (IT) or both routes of inoculation to bovine respiratory syncytial (BRS) virus had a transient increase in body temperature for 2 days. Histopathologic changes indicative of pneumonia, along with multinucleated giant cells, were observed in alveolar lumen. The virus was recovered from infected calves, and their serologic response was poor. In a limited serologic survey with 100 serums from cattle in Maryland, low levels of serum-neutralizing (SN) antibody to the virus were prevalent in 38% of the serums.

Pretreatment of bovine turbinate (BTu) cells with cloned human interferon (IFN)-alpha 2a reduced the yield of infectious bovine parainfluenza-3 virus (PI-3 V). Intracellular synthesis of HN glycoprotein was reduced on postinfection day 1 (PID 1), but it recovered to normal levels subsequently. However, reduction of this protein persisted in the released virus through PID 2. Thin section electron microscopy demonstrated a drastically reduced release of mature virions and an accumulation of viral nucleocapsids inside the cytoplasm on PID 2. These results suggest that cloned human IFN-alpha 2a affects the glycoprotein synthesis, and morphogenesis of bovine PI-3 V, and thus inhibits the release of viral particles from treated cells.

Calves exposed to a bovine respiratory syncytial virus showed mild clinical signs of respiratory illness and responded serologically. The disease occurred in the presence or absence of circulating antibodies, but there was no evidence of exacerbation of the disease due to preexisting serum antibody. Nasal secretory antibody appeared to protect the calves against the disease. Calves previously exposed to the virus were immune to challenge. The virus was recovered at a high frequency when specimens of nasal secretion (not subjected to freezing and thawing) were inoculated into susceptible cells within 1 hr after collection.

Reciprocal cross-titrations using constant concentrations of bovine antiserum (1: 100) to either bovine herpesvirus (BHV) 1 or BHV 4 (obtained from controlled infection status) against varying concentrations of both viral antigens in enzyme-linked immunosorbent assay (ELISA) indicated a subtle difference between the antigenic composition of these 2 agents. Although control antiserum consistently yielded higher ELISA titers against homologous viral antigen, a considerable cross-reactivity between the 2 viruses was observed. Based on control sera results, serologic profiling of field bovine serum samples against both BHVs 1 and 4 antigen preparations indicated that the ELISA was unsatisfactory for distinguishing between previous BHV 1 or 4 exposure. The ELISA, however, was more sensitive than the virus neutralization test for detecting antibodies to BHVs 1 and 4 in cattle sera.

An antibody-complement-mediated cytotoxicity assay was employed to determine whether susceptible host cells infected with bovine parainfluenza-3 virus could be destroyed by the humoral immune mechanism. The cytotoxicity assay yielded 21.5% to 76.9% specific release of 51Cr with sera collected from calves 28 days after inoculation with the virus. A multiplicity of infection of 5, a postinfection period of 2 days, an antibody dilution of 1:10, and an incubation period of 12 hours with antibody and complement were found to be optimal for this assay.

From Aug 1, 1979 to Aug 15, 1980, a total of 624 samples were collected from the vaginas, cervices, and uteri of 208 dairy cows 30 to 37 days after parturition. An additional 90 samples were collected from the reproductive tracts from 30 of the 208 cows. The 30 cows had aborted or were repeat breeders. Samples from cows that had aborted were collected within a week after clinical abortion or immediately after rectal palpation revealed subclinical abortion. All samples were tested for the presence of cytopathogenic viruses. All samples were negative.

The inconsistency in naming and labeling bovine herpesviruses (BHVs), other than BHV types 1 and 2 (BHV-1 and BHV-2), found in the literature is reviewed. To resolve the confusion and misunderstanding caused by the use of BHV-3, BHV-4 and BHV-5 for the same kind of BHVs, the most used label BHV-4 is proposed for designating Movar-type BHVs (which also were named 'orphan viruses' or 'cytomegaloviruses').

Earlier we reported a reduction to 1/30th-1/100th of the original number of infectious particles in the infectious vesicular stomatitis virus (VSV) released from L cells treated with 10 or 30 reference units of interferon per ml. However, in these cultures virus particle production, as measured by VSV particle-associated viral RNA, virus nucleocapsid protein, and viral transcriptase, was inhibited by less than 10%. Data reported in this paper show that there was a significant reduction in glycoprotein and membrane protein of VSV particles released from interferon-treated cells. Evidence supporting the deficiency of glycoprotein in VSV released from interferon-treated cells was derived from electron microscopic studies. Under conditions where glycoprotein spikes or projections were clearly detectable on the surface of VSV released from cells not treated with interferon, very few spikes were observed on VSV released from interferon-treated cells. These results suggested that interferon-treated cells produced VSV particles with low infectivity and that this low infectivity may be related to the reduced amount of glycoprotein and membrane protein incorporated into such particles.

Daily injection of 2-deoxy-D-glucose (2-dG) had no protective effect against respiratory tract infection in calves caused by infectious bovine rhinotracheitis virus. It also did not reduce the severity of this infection. Ocular instillation of the drug, however, markedly reduced the severity of viral-induced conjunctivitis and keratoconjunctivitis. The drug was effective when given at the time of ocular infection or after clinical conjunctivitis developed.

The effect of a single therapeutic dose of levamisole in calves experimentally infected with bovine viral diarrhea virus (BVDV) was evaluated in 2 separate double-blind experiments. The infection was mild and there was no difference in severity of infection or speed of recovery between levamisole-treated and 0.9% Nacl solution-treated (control) calves. There were no significant differences between drug-treated and control calves in respect to total white blood cell, lymphocyte, and neutrophil counts, and the viral recovery data from these calves were comparable. The differences in blastogenic response of lymphocytes to the mitogen phytohemagglutinin and serum antibody titers of the 2 groups of calves were also insignificant. An increased lymphocytic hyperplasia was observed in a larger number of lymphoid tissues of drug-treated calves than in those of control calves. It appeared that a single therapeutic dose of levamisole was ineffective in altering the response of calves infected with BVDV.

The effect of tunicamycin (TM) treatment on the production, glycosylation, morphology and infectivity of vesicular stomatitis virus (VSV) released from mouse (LB), monkey (Cos-1 and VERO), bovine (MDBK), hamster (BHK) and human (HeLa, U and GM2504) cells was investigated. The yield of VSV particles released from TM treated cells, as measured by total viral proteins, was inhibited only 2-10 fold while the infectivity of these particles was greatly reduced (10-1000 fold). The morphology of VSV particles formed in the presence of TM appeared similar to that of VSV particles released from untreated cells as demonstrated by electronmicroscopy. Analysis of intracellular and extracellular virus specific proteins by SDS polyacrylamide gel electrophoresis revealed that TM blocks the glycosylation of VSV glycoprotein G in all cells tested. These results suggest that inhibition of glycosylation of VSV G protein could affect the biological infectivity of the VSV particle released from the treated cells.

Human lymphoblastoid interferon (IFN) had an antiviral activity in bovine embryonic kidney cells that resulted in the release of vesicular stomatitis virus (VSV) particles with decreased infectivity. The inhibition was dose dependent and the cells were highly sensitive to human IFN. Examination of the proteins of VSV released from bovine cells after IFN treatment showed a reduction in the glycoprotein. Electron microscopic studies revealed a large number of VSV particles with characteristic spike-like surface projections released from nontreated cells. There was a reduction in the number of mature virions produced in IFN-treated cells and the virions lacked the characteristic surface projections.

Six structural proteins of bovine parainfluenza-3 virus (PI-3V) labeled with [35S]-methionine could be resolved by polyacrylamide gel electrophoresis (PAGE). Five structural proteins of this virus had been previously reported. The 6 proteins found in this study were: L, a 180,000 (180 kD) molecular weight (MW) large protein; P, 83 kD phosphoprotein; HN, 69 kD hemagglutinin-neuraminidase glycoprotein; NP, 66 kD nucleocapsid protein; F, 55 kD fusion glycoprotein; and M, 38 kD matrix protein. Selective labeling with [2-3H]-mannose revealed only HN and F glycoprotein bands. A cellular actin protein (43 kD), associated with many enveloped viruses, was also found as a seventh protein in bovine PI-3V.

Microcultures of swine whole blood, purified blood lymphocytes (PBL), spleen cells, and lymph node (LN) cells were tested for stimulation by concanavalin A (conA) and phytohemagglutinin (PHA). A cell concentration of 2 x 10(6)/ml and a 1:20 dilution of whole blood were needed for optimal stimulation of conA and PHA. Optimal stimulation of whole blood lymphocytes (WBL) and LN cells was obtained by 20 micrograms of conA/ml, but 10 micrograms/ml of this mitogen was adequate for spleen cells. The PBL and LN cells were optimally stimulated by 20 microliters of PHA/ml, but 80 microliters and 40 microliters/ml of this mitogen were required for stimulating the whole blood and spleen cells, respectively. Four days' incubation was needed for maximal blastogenesis of WBL with conA. This could be achieved after 3 days' incubation with PBL and spleen and LN cells. Whole blood and spleen cells were stimulated by PHA after 3 days' incubation, but PBL and LN cells required 4 days' incubation. Reproducibility, sensitivity, and comparison of various cultures were discussed.

Fertilized two-celled mouse eggs deprived of their zona pellucida were susceptible to infection with minute virus of mice. The virus had no deleterious effect on development of embryos cultivated in vitro.

Intracellular antigens of strain DN-599 bovine herpesvirus were detected in the cytoplasm and the nucleus of infected bovine embryonic kidney cells by the indirect immunoferritin (IF) technique. Specific tagging was observed in viral envelope and capsids. Aggregates of viral particles heavily coated with antibody were seen by immune electron microscopy (IEM).

Hemagglutinating DNA viruses of 20 nm diameter were isolated from bovine adenovirus types 1 and 2. The isolates were heat stable, chloroform resistant, and defective. Their densities were 1.38 to 1.39 g/cm3, and they were found to be serologically identical to the bovine adeno-associated virus strain X7. A partial antigenic relationship was found between these and the canine adeno-associated virus.

A defective transport of bovine parainfluenza-3 virus (PI-3V) hemagglutinin-neuraminidase (HN) glycoprotein was evidenced in interferon (IFN)-treated bovine turbinate (BTu) cells. Indirect immunofluorescence performed with monoclonal antibody to PI-3 HN glycoprotein demonstrated accumulation of this protein in the perinuclear cytoplasm of IFN-treated cells. Untreated, infected control cells had a generalized widespread fluorescence. Unfixed control cells showed a uniform surface fluorescence in contrast to a few specs of fluorescence on the plasma membrane of IFN-treated cells. Electron microscopic localization of HN protein was done by immuno-gold ultrastructural cytochemistry. Untreated cells had uniform gold label on the plasma membrane and around the budding virus particles with no label in the cytoplasm. In IFN-treated cells, however, there was an accumulation of gold particles in the cytoplasm with only a few particles on the cell surface. Quantitative analysis of HN protein on the cell surface by solid phase radioimmune-assay revealed a greater amount of this protein on the surface of control cells, than those on the IFN-treated cells.

2-Deoxy-D-glucose (2-dG) and glucosamine reversibly inhibited the replication and cytopathic effects of bovine respiratory syncytial virus in bovine turbinate cell cultures. The inhibitors were effective when added up to 12 hours after cell cultures were inoculated. Their effectiveness decreased as the time between inoculation of cells and drug treatment lengthened. The sugars did not inactivate the virus directly, and inoculation of drug-treated cells in drug-free medium produced normal yield of virus. Mannose fully reversed the inhibitory effects of 2-dG, but was ineffective for glucosamine. Protein synthesis was necessary for production and release of infective virus after removal of 2-dG and glucosamine blocks. Electron microscopic studies revealed a large amount of bovine respiratory syncytial virus production with characteristic spike-like projections on the viral envelopes in the absence of these inhibitors. There was a drastic reduction in the number of mature virions produced in inhibitor-treated bovine turbinate cells, and the virions lacked the characteristic surface projections.

Calves experimentally infected with bovine rhinovirus type 1 developed a mild respiratory disease and exhibited a cell mediated immune (CMI) response, as determined by leukocyte migration inhibition (LMI) and lymphocyte blastogenesis tests. The CMI response to the virus was detected by day 3 post-inoculation using direct and indirect LMI tests. It persisted through day 28, with maximal responses occurring between days 4 and 14. Measurement of cellular immunity by blast transformation, however, was not evidenced until day 12. The humoral antibody response was minimal with serum neutralizing titers ranging from 1:4 to 1:16 and this response was not evident until 3 weeks after inoculation.