Development and validation of a rule-based algorithm to identify periodontal diagnosis using structured electronic health record data

AIM

To develop and validate an automated electronic health record (EHR)-based algorithm to suggest a periodontal diagnosis based on the 2017 World Workshop on the Classification of Periodontal Diseases and Conditions.

MATERIALS AND METHODS

Using material published from the 2017 World Workshop, a tool was iteratively developed to suggest a periodontal diagnosis based on clinical data within the EHR. Pertinent clinical data included clinical attachment level (CAL), gingival margin to cemento-enamel junction distance, probing depth, furcation involvement (if present) and mobility. Chart reviews were conducted to confirm the algorithm's ability to accurately extract clinical data from the EHR, and then to test its ability to suggest an accurate diagnosis. Subsequently, refinements were made to address limitations of the data and specific clinical situations. Each refinement was evaluated through chart reviews by expert periodontists at the study sites.

RESULTS

Three-hundred and twenty-three charts were manually reviewed, and a periodontal diagnosis (healthy, gingivitis or periodontitis including stage and grade) was made by expert periodontists for each case. After developing the initial version of the algorithm using the unmodified 2017 World Workshop criteria, accuracy was 71.8% for stage alone and 64.7% for stage and grade. Subsequently, 16 modifications to the algorithm were proposed and 14 were accepted. This refined version of the algorithm had 79.6% accuracy for stage alone and 68.8% for stage and grade together.

CONCLUSIONS

Our findings suggest that a rule-based algorithm for suggesting a periodontal diagnosis using EHR data can be implemented with moderate accuracy in support of chairside clinical diagnostic decision making, especially for inexperienced clinicians. Grey-zone cases still exist, where clinical judgement will be required. Future applications of similar algorithms with improved performance will depend upon the quality (completeness/accuracy) of EHR data.

Systematically assessing the quality of dental electronic health record data for an investigation into oral health care disparities

OBJECTIVES

This work describes the process by which the quality of electronic health care data for a public health study was determined. The objectives were to adapt, develop, and implement data quality assessments (DQAs) based on the National Institutes of Health Pragmatic Trials Collaboratory (NIHPTC) data quality framework within the three domains of completeness, accuracy, and consistency, for an investigation into oral health care disparities of a preventive care program.

METHODS

Electronic health record data for eligible children in a dental accountable care organization of 30 offices, in Oregon, were extracted iteratively from January 1, 2014, through March 31, 2022. Baseline eligibility criteria included: children ages 0-18 with a baseline examination, Oregon home address, and either Medicaid or commercial dental benefits at least once between 2014 and 2108. Using the NIHPTC framework as a guide, DQAs were conducted throughout data element identification, extraction, staging, profiling, review, and documentation.

RESULTS

The data set included 91,487 subjects, 11 data tables comprising 75 data variables (columns), with a total of 6,861,525 data elements. Data completeness was 97.2%, the accuracy of EHR data elements in extracts was 100%, and consistency between offices was strong; 29 of 30 offices within 2 standard deviations of the mean (s = 94%).

CONCLUSIONS

The NIHPTC framework proved to be a useful approach, to identify, document, and characterize the dataset. The concepts of completeness, accuracy, and consistency were adapted by the multidisciplinary research team and the overall quality of the data are demonstrated to be of high quality.

Improvements in appropriate placement of dental sealants after implementation of a clinical decision support system

BACKGROUND

Dental sealants are effective for the prevention of caries in children at elevated risk levels, and increasing the proportion of children and adolescents who have dental sealants on 1 or more molars is a Healthy People 2030 objective. Electronic health record (EHR)-based clinical decision support systems (CDSSs) have the ability to improve patient care. A dental quality measure related to dental sealant placement for children at elevated risk of caries was targeted for improvement using a CDSS.

METHODS

A validated dental quality measure was adapted to assess a patient's need for dental sealant placement. A CDSS was implemented to advise care team members whether a child was at elevated risk of developing caries and had sealant-eligible first or second molars. Data on dental sealant placement at examination visits during a 5-year period were analyzed, including 32 months before CDSS implementation and 28 months after CDSS implementation.

RESULTS

From January 1, 2018, through December 31, 2022, the authors assessed 59,047 examination visits for children at elevated risk of developing caries and with sealant-eligible teeth. With the implementation of a CDSS and training to support the clinical care team members in September 2020, the appropriate placement of dental sealants at examination visits increased from 27% through 60% (P < .00001).

CONCLUSIONS

Integration of a CDSS into the EHR as part of a quality improvement program was effective in increasing the delivery of sealants in eligible first and second molars of children aged 5 through 15 years and considered at high risk of developing caries.

PRACTICAL IMPLICATIONS

An EHR-based CDSS can be implemented to improve standardization and provide timely and appropriate patient care in dental practices.

Use GPT-J Prompt Generation with RoBERTa for NER Models on Diagnosis Extraction of Periodontal Diagnosis from Electronic Dental Records

This study explored the usability of prompt generation on named entity recognition (NER) tasks and the performance in different settings of the prompt. The prompt generation by GPT-J models was utilized to directly test the gold standard as well as to generate the seed and further fed to the RoBERTa model with the spaCy package. In the direct test, a lower ratio of negative examples with higher numbers of examples in prompt achieved the best results with a F1 score of 0.72. The performance revealed consistency, 0.92-0.97 in the F1 score, in all settings after training with the RoBERTa model. The study highlighted the importance of seed quality rather than quantity in feeding NER models. This research reports on an efficient and accurate way to mine clinical notes for periodontal diagnoses, allowing researchers to easily and quickly build a NER model with the prompt generation approach.

Developing Automated Computer Algorithms to Phenotype Periodontal Disease Diagnoses in Electronic Dental Records

OBJECTIVE

 Our objective was to phenotype periodontal disease (PD) diagnoses from three different sections (diagnosis codes, clinical notes, and periodontal charting) of the electronic dental records (EDR) by developing two automated computer algorithms.

METHODS

 We conducted a retrospective study using EDR data of patients (n = 27,138) who received care at Temple University Maurice H. Kornberg School of Dentistry from January 1, 2017 to August 31, 2021. We determined the completeness of patient demographics, periodontal charting, and PD diagnoses information in the EDR. Next, we developed two automated computer algorithms to automatically diagnose patients' PD statuses from clinical notes and periodontal charting data. Last, we phenotyped PD diagnoses using automated computer algorithms and reported the improved completeness of diagnosis.

RESULTS

 The completeness of PD diagnosis from the EDR was as follows: periodontal diagnosis codes 36% (n = 9,834), diagnoses in clinical notes 18% (n = 4,867), and charting information 80% (n = 21,710). After phenotyping, the completeness of PD diagnoses improved to 100%. Eleven percent of patients had healthy periodontium, 43% were with gingivitis, 3% with stage I, 36% with stage II, and 7% with stage III/IV periodontitis.

CONCLUSIONS

 We successfully developed, tested, and deployed two automated algorithms on big EDR datasets to improve the completeness of PD diagnoses. After phenotyping, EDR provided 100% completeness of PD diagnoses of 27,138 unique patients for research purposes. This approach is recommended for use in other large databases for the evaluation of their EDR data quality and for phenotyping PD diagnoses and other relevant variables.

Translating periodontal data to knowledge in a learning health system

BACKGROUND

A learning health system (LHS) is a health system in which patients and clinicians work together to choose care on the basis of best evidence and to drive discovery as a natural outgrowth of every clinical encounter to ensure the right care at the right time. An LHS for dentistry is now feasible, as an increased number of oral health care encounters are captured in electronic health records (EHRs).

METHODS

The authors used EHRs data to track periodontal health outcomes at 3 large dental institutions. The 2 outcomes of interest were a new periodontitis case (for patients who had not received a diagnosis of periodontitis previously) and tooth loss due to progression of periodontal disease.

RESULTS

The authors assessed a total of 494,272 examinations (new periodontitis outcome: n = 168,442; new tooth loss outcome: n = 325,830), representing a total of 194,984 patients. Dynamic dashboards displaying performance on both measures over time allow users to compare demographic and risk factors for patients. The incidence of new periodontitis and tooth loss was 4.3% and 1.2%, respectively.

CONCLUSIONS

Periodontal disease, diagnosis, prevention, and treatment are particularly well suited for an LHS model. The results showed the feasibility of automated extraction and interpretation of critical data elements from the EHRs. The 2 outcome measures are being implemented as part of a dental LHS. The authors are using this knowledge to target the main drivers of poorer periodontal outcomes in a specific patient population, and they continue to use clinical health data for the purpose of learning and improvement.

PRACTICAL IMPLICATIONS

Dental institutions of any size can conduct contemporaneous self-evaluation and immediately implement targeted strategies to improve oral health outcomes.

Caries Risk Documentation And Prevention: eMeasures For Dental Electronic Health Records

BACKGROUND

Longitudinal patient level data available in the electronic health record (EHR) allows for the development, implementation, and validations of dental quality measures (eMeasures).

OBJECTIVE

We report the feasibility and validity of implementing two eMeasures. The eMeasures determined the proportion of patients receiving a caries risk assessment (eCRA) and corresponding appropriate risk-based preventative treatments for patients at elevated risk of caries (appropriateness of care [eAoC]) in two academic institutions and one accountable care organization, in the 2019 reporting year.

METHODS

Both eMeasures define the numerator and denominator beginning at the patient level, populations' specifications, and validated the automated queries. For eCRA, patients who completed a comprehensive or periodic oral evaluation formed the denominator, and patients of any age who received a CRA formed the numerator. The eAoC evaluated the proportion of patients at elevated caries risk who received the corresponding appropriate risk-based preventative treatments.

RESULTS

EHR automated queries identified in three sites 269,536 patients who met the inclusion criteria for receiving a CRA. The overall proportion of patients who received a CRA was 94.4% (eCRA). In eAoC, patients at elevated caries risk levels (moderate, high, or extreme) received fluoride preventive treatment ranging from 56 to 93.8%. For patients at high and extreme risk, antimicrobials were prescribed more frequently site 3 (80.6%) than sites 2 (16.7%) and 1 (2.9%).

CONCLUSION

Patient-level data available in the EHRs can be used to implement process-of-care dental eCRA and AoC, eAoC measures identify gaps in clinical practice. EHR-based measures can be useful in improving delivery of evidence-based preventative treatments to reduce risk, prevent tooth decay, and improve oral health.

Assessing the completeness of periodontal disease documentation in the EHR: a first step in measuring the quality of care

Background

Our objective was to measure the proportion of patients for which comprehensive periodontal charting, periodontal disease risk factors (diabetes status, tobacco use, and oral home care compliance), and periodontal diagnoses were documented in the electronic health record (EHR). We developed an EHR-based quality measure to assess how well four dental institutions documented periodontal disease-related information. An automated database script was developed and implemented in the EHR at each institution. The measure was validated by comparing the findings from the measure with a manual review of charts.

Results

The overall measure scores varied significantly across the four institutions (institution 1 = 20.47%, institution 2 = 0.97%, institution 3 = 22.27% institution 4 = 99.49%, p-value < 0.0001). The largest gaps in documentation were related to periodontal diagnoses and capturing oral homecare compliance. A random sample of 1224 charts were manually reviewed and showed excellent validity when compared with the data generated from the EHR-based measure (Sensitivity, Specificity, PPV, and NPV > 80%).

Conclusion

Our results demonstrate the feasibility of developing automated data extraction scripts using structured data from EHRs, and successfully implementing these to identify and measure the periodontal documentation completeness within and across different dental institutions.

An innovative approach to assess comprehensive care: Temple University's patient wellness report

PURPOSE

The transition from a paper-based to an all-electronic patient health record took a major step forward in 2018, with the implementation of an electronic health record that supports the School's patient-centered comprehensive care model and facilitates outcomes assessment. The Patient Wellness Report (PWR) summarizes findings of the patient assessment, and it does so automatically by locating data already entered in axiUm forms. This study aimed to describe the PWR implementation procedures and to examine outcomes and characteristics among patients with completed treatment plans during an 18-month period.

METHODS

Outcome data were extracted from axiUm for patients aged ≥16 years who completed comprehensive care treatment plans. Each PWR contained 14 metrics related to "dimensions" of wellness (quality of life, general health factors, oral hygiene, caries risk, and degree of periodontal inflammation and pocketing), each of which is rated on a 3-point scale based on best available scientific evidence.

RESULTS

A total of 2074 patients completed planned procedures between July 2018 and January 2020, and met the study eligibility criteria. Improvement of several conditions was observed between baseline and follow-up in caries lesions (21%), blood pressure (9%), and periodontal pocket (3.2%). A majority of patients rated in good condition at baseline had their scores unchanged at follow-up in the following areas: dental anxiety (92%), speaking (88%), smoking (87%), and alcohol consumption (79%).

CONCLUSION

Improvements in dental caries and blood pressure metrics were easily monitored using the PWR. In addition, disparities exist in improvement of patient outcomes by race/ethnicity.

Increasing value, reducing waste: tailoring the application of dental sealants according to individual caries risk

OBJECTIVES

Despite a significant national investment in oral health, there is little understanding of the return in terms of quality. Value-based payments aim to refocus provider reimbursement based on the value created to the patient. Our objectives were to apply a set of dental quality measures to help determine the value of preventive dental care provided to children at two academic dental school clinics.

METHODS

We queried the institutional electronic health records (EHRs) for patients between the ages of 6-14 years with sealable first or second permanent molars, determined caries risk status, identified if dental sealants were placed, and finally if the teeth showed evidence of new caries experience. In order to determine the cost-effectiveness of EHR-based triage of applying dental sealants, we calculated the incremental cost-effectiveness ratio (ICER) for the dental quality measures supported sealing program.

RESULTS

Between the two academic sites, there were 6,155 unique children for a total of 12,302 eligible teeth without a sealant and 32,811 eligible teeth with a sealant. Teeth without a sealant were more likely to have decay (4.8 percent) than those with a sealant (1.7 percent). At both sites, patients with high caries risk were more likely to benefit from sealants compared to those patients with low risk.

CONCLUSION

Implementation of caries risk stratified fissure sealant quality measures demonstrates the potential for extracting better value in oral health care.

Developing and Testing Electronic Health Record-Derived Caries Indices

Caries indices, the basis of epidemiologic caries measures, are not easily obtained in clinical settings. This study's objective was to design, test, and validate an automated program (Valid Electronic Health Record Dental Caries Indices Calculator Tool [VERDICT]) to calculate caries indices from an electronic health record (EHR). Synthetic use case scenarios and actual patient cases of primary, mixed, and permanent dentition, including decayed, missing, and filled teeth (DMFT/dmft) and tooth surfaces (DMFS/dmfs) were entered into the EHR. VERDICT measures were compared to a previously validated clinical electronic data capture (EDC) system and statistical program to calculate caries indices. Four university clinician-researchers abstracted EHR caries exam data for 45 synthetic use cases into the EDC and post-processed with SAS software creating a gold standard to compare the -VERDICT-derived caries indices. Then, 2 senior researchers abstracted EHR caries exam data and calculated caries indices for 24 patients, allowing further comparisons to VERDICT indices. Agreement statistics were computed among abstractors, and discrepancies were resolved by consensus. Agreement statistics between the 2 final-phase abstractors and the VERDICT measures showed extremely high concordance: Lin's concordance coefficients (LCCs) >0.99 for dmfs, dmft, DS, ds, DT, dt, ms, mt, FS, fs, FT, and ft; LCCs >0.95 for DMFS and DMFT; and LCCs of 0.92-0.93 for MS and MT. Caries indices, essential to developing primary health outcome measures for research, can be reliably derived from an EHR using VERDICT. Using these indices will enable population oral health management approaches and inform quality improvement efforts.

Using a stakeholder-engaged approach to develop and validate electronic clinical quality measures

Objective

To describe the stakeholder-engaged processes used to develop, specify, and validate 2 oral health care electronic clinical quality measures.

Materials and Methods

A broad range of stakeholders were engaged from conception through testing to develop measures and test feasibility, reliability, and validity following National Quality Forum guidance. We assessed data element feasibility through semistructured interviews with key stakeholders using a National Quality Forum-recommended scorecard. We created test datasets of synthetic patients to test measure implementation feasibility and reliability within and across electronic health record (EHR) systems. We validated implementation with automated reporting of EHR clinical data against manual record reviews, using the kappa statistic.

Results

A stakeholder workgroup was formed and guided all development and testing processes. All critical data elements passed feasibility testing. Four test datasets, representing 577 synthetic patients, were developed and implemented within EHR vendors' software, demonstrating measure implementation feasibility. Measure reliability and validity were established through implementation at clinical practice sites, with kappa statistic values in the "almost perfect" agreement range of 0.80-0.99 for all but 1 measure component, which demonstrated "substantial" agreement. The 2 validated measures were published in the United States Health Information Knowledgebase.

Conclusion

The stakeholder-engaged processes used in this study facilitated a successful measure development and testing cycle. Engaging stakeholders early and throughout development and testing promotes early identification of and attention to potential threats to feasibility, reliability, and validity, thereby averting significant resource investments that are unlikely to be fruitful.

Neuromuscular response differences to power vs strength back squat exercise in elite athletes

The study's aim was to establish the neuromuscular responses in elite athletes during and following maximal 'explosive' regular back squat exercise at heavy, moderate, and light loads. Ten elite track and field athletes completed 10 sets of five maximal squat repetitions on three separate days. Knee extension maximal isometric voluntary contraction (MIVC), rate of force development (RFD) and evoked peak twitch force (Pt) assessments were made pre- and post-session. Surface electromyography [root mean square (RMS)] and mechanical measurements were recorded during repetitions. The heavy session resulted in the greatest repetition impulse in comparison to moderate and light sessions (P < 0.001), while the latter showed highest repetition power (P < 0.001). MIVC, RFD, and Pt were significantly reduced post-session (P < 0.01), with greatest reduction observed after the heavy, followed by the moderate and light sessions accordingly. Power significantly reduced during the heavy session only (P < 0.001), and greater increases in RMS occurred during heavy session (P < 0.001), followed by moderate, with no change during light session. In conclusion, this study has shown in elite athletes that the moderate load is optimal for providing a neuromuscular stimulus but with limited fatigue. This type of intervention could be potentially used in the development of both strength and power in elite athletic populations.

The second generation of the International Equine Gene Mapping Workshop half-sibling linkage map

A low-density, male-based linkage map was constructed as one of the objectives of the International Equine Gene Mapping Workshop. Here we report the second generation map based on testing 503 half-sibling offspring from 13 sire families for 344 informative markers using the CRIMAP program. The multipoint linkage analysis localized 310 markers (90%) with 257 markers being linearly ordered. The map included 34 linkage groups representing all 31 autosomes and spanning 2262 cM with an average interval between loci of 10.1 cM. This map is a milestone in that it is the first map with linkage groups assigned to each of the 31 automosomes and a single linkage group to all but three chromosomes.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Report of the International Equine Gene Mapping Workshop: male linkage map

The goal of the First International Equine Gene Mapping Workshop, held in 1995, was the construction of a low density, male linkage map for the horse. For this purpose, the International Horse Reference Family Panel (IHRFP) was established, consisting of 12 paternal half-sib families with 448 half-sib offspring provided by 10 laboratories. Blood samples were collected and DNA extracted in each laboratory and sent to the Lexington laboratory (KY, USA) for dispatch in aliquots to 14 typing laboratories. In total, 161 markers (144 microsatellites, seven blood groups and 10 proteins) were tested for all families for which the sire was heterozygous. Genealogies and typing data were sent for analysis to the INRA laboratory (Jouy-en-Josas, France) according to a specific format and entered into a database with input verification and output processes. Linkage analysis was performed with the CRIMAP program. Significant linkage was detected for 124 loci, of which 95 were unambiguously ordered using a multipoint analysis with an average spacing of 14.2 CM. These loci were distributed among 29 linkage groups. A more comprehensive analysis including synteny group data and FISH data suggested that 26 autosomes out of 31 are covered. The complete map spans 936 CM.

Genome duplications and other features in 12 Mb of DNA sequence from human chromosome 16p and 16q

Several publicly funded large-scale sequencing efforts have been initiated with the goal of completing the first reference human genome sequence by the year 2005. Here we present the results of analysis of 11.8 Mb of genomic sequence from chromosome 16. The apparent gene density varies throughout the region, but the number of genes predicted (84) suggests that this is a gene-poor region. This result may also suggest that the total number of human genes is likely to be at the lower end of published estimates. One of the most interesting aspects of this region of the genome is the presence of highly homologous, recently duplicated tracts of sequence distributed throughout the p-arm. Such duplications have implications for mapping and gene analysis as well as the predisposition to recurrent chromosomal structural rearrangements associated with genetic disease.

Accuracy of self-reported educational attainment among diverse patient populations: a preliminary investigation

Despite speculation concerning the accuracy of self-reported information, particularly from certain patient populations, many neuropsychologists continue to estimate premorbid intellectual functioning on the basis of self-reported educational attainment. This study examined 116 individuals with diverse diagnoses [i.e., alcoholism, posttraumatic stress disorder (PTSD), schizophrenia or schizoaffective, and dementia] to determine the accuracy of their self-reported high school educational attainment. Results suggest that at least half of all participants were inaccurate as defined by discrepancies between actual and estimated GPA greater than.5 on a traditional 4-point grading scale. Most patients were inaccurate in the direction of overestimating their educational attainment. Patients diagnosed with alcoholism and PTSD were significantly less accurate in recalling their educational history when compared to a group of normal-control subjects. Several subjects, whose records could not be verified, were found to have not attended high school as they had claimed. These results underscore the potential inaccuracy that exists when estimating premorbid intelligence using self-reported information.

A gene map of the human genome

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

Detection of bovine herpesvirus-1 in bovine semen by a nested PCR assay

A nested PCR assay targeting a portion of the glycoprotein IV gene has been developed for the detection of Bovine Herpesvirus-1 (BHV-1). Rapid and sensitive detection of the PCR products was achieved using a nonisotopic reverse dot-blot format with a visible color readout. Cross-reactivity of this PCR assay was not observed with the closely related BHV-3. The sensitivity of this assay when tested on a supernatant from a BHV-1 cell culture was approximately 4.5 TCID50 (50% tissue culture infectious dose). A procedure using the chelating resin Chelex 100 was used to prepare viral DNA from artificially inoculated samples of extended and raw semen for use in the PCR assay. In combination with nested PCR and reverse dot blot, this method allowed the detection of 5 x 10(3) TCID per 0.5 ml of semen, which is comparable to the detection in the Cornell Semen Test. The whole procedure can be completed in approximately 8 h. This assay has therefore the potential of replacing the currently available yet time consuming and costly detection methods for BHV-1 in bovine semen.

Molecular cloning and sequencing of an Australian isolate of proviral bovine leukaemia virus DNA: comparison with other isolates

The molecular cloning and characterization of an EcoRI fragment, 8.26 kb in size, of an Australian isolate of bovine leukaemia virus (pBLV-A1) is described. This fragment includes most of the proviral genome as well as 340 bp of flanking bovine DNA sequence at the 5' end. Approximately 790 bp, including the 3' long terminal repeat, was missing from this clone. At the level of restriction enzyme mapping, this isolate could be distinguished from American, Belgian and Japanese isolates. DNA sequencing of the entire clone demonstrated some variation at the amino acid level between pBLV-A1 and the Japanese and Belgian isolates, particularly in the gag gene. In that gene there were 59 amino acid changes compared to the Japanese isolate and 24 compared to the Belgian isolate. The greater number in the case of the Japanese isolate was due to both single nucleotide changes and frameshift in a single region of the gene. This study also demonstrates that there are large tracts of amino acid sequence, particularly within the env and pol genes, that are highly conserved in different isolates. Some of these conserved sequences exist in regions containing epitopes important in virus infectivity.

Lymphosarcoma development in sheep experimentally infected with bovine leukaemia virus

Twelve sheep were experimentally infected with a phytohemagglutinin (PHA) treated short term culture of lymphocytes from a cow naturally infected with BLV at the PL stage. Five of 12 (42%) BLV infected sheep had histologically confirmed lymphosarcoma 10-16 months after infection. The PBL's were increased to leukemic levels 3-21 weeks before death due to lymphoblastic leukemia. Lymphocyte proliferation and appearance of immature lymphocytes and lymphoblastic cells in the blood were a characteristic feature of tumour development following inoculation with an Australian strain of BLV. In contrast to a number of previous studies the peripheral lymph nodes of all infected sheep were clinically normal throughout the experimental period but at death gross tumours were evident in the mesentric lymph nodes and the heart in all cases. All the other lymph nodes, liver, spleen, kidney and lung were histologically infiltrated with lymphoid tumour cells. Gross tumours were present in the abomasum (1 out of 5) in the urinary tract (2 out of 5) and in the uterus (1 out of 2). The majority of the tumour cells isolated from the various tissues were centroblastic demonstrating that the malignant leukemia in experimentally infected sheep was of a multicentric centroblastic type. The central nervous system was not involved in any case.

Prediction of the duration of hospitalization in patients with respiratory syncytial virus infection: use of clinical parameters

To assess the possibility that clinical data available at the time of hospital admission for patients with respiratory syncytial virus infection could predict the length of hospitalization without antiviral therapy, the charts of all 102 patients admitted with laboratory documented respiratory syncytial virus infection during 1982 to 1985 were reviewed. Two thirds (65) of the patients remained hospitalized greater than three days. Prolonged hospitalization could have been predicted for 40 of the 65 patients (61.5%) based on the need for intubation and ventilation on admission (14 patients) or the presence of underlying cardiac or respiratory disease (28 patients). Of the infants hospitalized when they were less than 2 months of age, 40% required intubation and mechanical ventilation, although only 16% had underlying cardiac or respiratory disease. Mechanical ventilation was required at the time of admission or subsequently for 14% (5/36) of the 2- to 4-month-old infants with respiratory syncytial virus infection. Among the 56 patients without underlying cardiac or respiratory disease who did not require intubation at the time of admission, 25 (45%) remained hospitalized longer than three days (mean hospital stay for these 25 patients, regardless of age, was six days). Neither the respiratory rate nor the presence or absence of fever on admission was useful in predicting the likelihood of a longer hospital stay for the patients who did not require intubation. In addition, none of the initial laboratory data, including the WBC count, the percentage of band forms or polymorphonuclear leukocytes, the presence or absence of hypoxia, or the chest x-ray film findings could be correlated with a longer or shorter duration of hospitalization.(ABSTRACT TRUNCATED AT 250 WORDS)

Integration of bovine leukaemia virus in the ovine genome

Circulating lymphocytes and tumour cells from 12 sheep experimentally infected with bovine leukaemia virus (BLV), for periods of time varying from 9 to 48 weeks, were analysed for evidence of integrated and unintegrated provirus. Hybridization analysis demonstrated that the provirus was integrated at one or two sites in all cases. Integration was observed at different sites in the animals studied and there was no evidence of unintegrated virus molecules in infected sheep lymphocytes or tumour cells. The data obtained support a monoclonal origin of different tumours in the same sheep.

Lymphatic and blood vessels of the popliteal node in sheep

Our aim was to describe the lymphatic and blood vascular pathways to and from the popliteal lymph node in sheep. The blood vessels and lymphatics were filled with Microfil, and were cleared in methyl salicylate. Afferent lymphatics divide and anastomose as they pass dorsally along the lateral saphenous vein, and 6-12 lymphatics reach the node. Each branches extensively on the surface of the node giving rise to 20-50 terminal afferents which enter the node over a roughly circular area. Most enter the subcapsular sinus, but some penetrate deeply into the node. Lymph leaves the node through numerous initial efferent lymphatics, many of which contain valves. These join forming progressively larger vessels, and 2-4 efferent trunks emerge from the hilus. The hilus varies considerably in shape, depth and location, and it is filled with fat. Either a single artery, or up to 10-12 arteries derived from an anastomotic network or circle, enter the node from the hilar fat pad. Arteries may also enter at other sites. The arteries originate from the caudal femoral, or the medial circumflex femoral artery; a single node may receive blood from both arteries. This arrangement may help to maintain blood flow especially during an immune response, and despite external pressures applied to the arteries and node during movements of the animal.

Preregistration training of medical graduates in Queensland hospitals, 1977

This paper reports a survey of the 1976 graduates of The University of Queensland Medical School which was conducted as they completed their preregistration training. Study of the residents' perceptions of the adequacy of their training during the year revealed no significant difference between hospitals in terms of training in patient management. The nonmetropolitan hospitals were rated significantly higher than the metropolitan hospitals for training in procedures.