UNASSIGNED: To investigate the application value of computed tomography (CT) value (HU) in the diagnosis and differential diagnosis of pulmonary cryptococcosis (PC) and to construct a prediction model.
UNASSIGNED: Retrospective analysis of the clinical data of 73 patients who presented with nodular/mass-type occupations on lung CT and confirmed by histopathology in our hospital from January 2019 to May 2022 were divided into PC group (23 patients) and non-PC group (50 patients) according to the pathological findings, and the CT values of each patient\'s lung lesions were measured. The differences in age, gender, symptoms, lesion involvement in one/both lungs, lung lobe distribution, number of lesions, maximum lesion diameter (cm), lesion margin condition, and CT value results were compared between the two groups. Independent risk factors for PC were analyzed for indicators with statistically significant differences, clinical prediction models were constructed and column line plots were drawn, C (correction) indices were calculated, subject characteristics (ROC) curves were drawn, calibration curves and clinical decision curve analysis (DCA) were performed to further evaluate the predictive efficacy of the models.
UNASSIGNED: Comparative analysis of patient data between the two groups showed statistically significant differences in central, peripheral and global CT values (P < 0.05), and multiple regression analysis indicated that central CT value, peripheral CT value and global CT value could be used as independent risk factors for the diagnosis and differential diagnosis of PC. The area under the ROC curve of the model predicting PC was 0.814 (95 % CI: 0.7011-0.9267), and the corrected C-index (Bootstrap = 1000) was 0.781; the actual curve overlapped well with the calibration curve; the DCA results indicated that the column line graph model has high clinical application value.
UNASSIGNED: CT value measurements of lesions can be used as an independent risk factor for PC, and clinical prediction models based on the above factors are predictive for the diagnosis and differential diagnosis of PC.

OBJECTIVE: Radioiodine (I-131) therapy for hyperthyroidism is a well-established and safe treatment option. This study aimed to investigate the relationship between the computed tomography (CT) value and the function and volume of the thyroid gland by identifying the factors that induce changes in the CT value of patients with hyperthyroidism.
METHODS: This retrospective study evaluated 38 patients with Graves\' disease and 10 patients with Plummer disease. To obtain the mean CT value and volume of the thyroid gland, the entire thyroid gland was set as the region of interest. A test dose of 3.7 MBq I-131 was administered before initiating I-131 therapy, and the radioiodine uptake (RIU) rate was assessed after 3, 24, 96, and 168 h. An approximate curve was plotted based on the RIU values obtained, and the effective half-life (EHL) was calculated. The correlation between the mean CT value and the volume of the thyroid gland, 24-h RIU, EHL, and the free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), and TSH receptor antibody (TRAb) levels was evaluated.
RESULTS: The CT value exhibited a significant positive correlation with EHL in patients with Graves\' disease (r = 0.62, p < 0.0001) as well as patients with Plummer disease (r = 0.74, p < 0.05). However, it did not display any correlation with the remaining parameters.
CONCLUSIONS: The CT value is significantly correlated with EHL, suggesting that it reflects thyroid function and is mainly related to the factors associated with iodine discharge.

Forecasting COVID-19 waves helps with public health planning and resource allocation. Cycle threshold (Ct) values obtained from positive SARS-CoV-2 nucleic acid amplification test (NAAT) results offer limited value for individual patient management, but real-time analysis of temporal trends of aggregated Ct values may provide helpful information to predict the trajectories of COVID-19 waves in the community. Ct value trends on 59,609 SARS-CoV-2 NAAT-positive results from 574,403 tests using a single testing assay system, between September 2021 and January 2023, were examined to monitor the trend of the proportion of positive NAAT with lower Ct values (≤28) in relation to changing COVID-19 case numbers over time. We applied regression with autoregressive integrated moving average errors modelling approach to study the relation between Ct values and case counts. We also developed an insight product to monitor the temporal trends with Ct values obtained from SARS-CoV-2 NAAT-positive results. In this study, the proportion of lower Ct values preceded by a range of 7-32 days the rising population COVID-19 testing rate reflecting onset of a COVID-19 wave. Monitoring population Ct values may assist in predicting increased disease activity.

UNASSIGNED: This study aimed to determine the SARS-CoV-2 variants in the first four COVID-19 waves using polymerase chain reaction (PCR)-based variant detection in Addis Ababa, Ethiopia.
UNASSIGNED: A cross-sectional study was conducted using repository nasopharyngeal samples stored at the Ethiopian Public Health Institute COVID-19 testing laboratory. Stored positive samples were randomly selected from the first four waves based on their sample collection date. A total of 641 nasopharyngeal samples were selected and re-tested for SARS-CoV-2. RNA was extracted using nucleic acid purification instrument. Then, SARS-CoV-2 detection was carried out using 10 μl RNA and 20 μl reverse transcription-PCR fluorescent mix. Cycle threshold values <38 were considered positive.
UNASSIGNED: A total of 374 samples qualified for B.1.617 Lineage and six spike gene mutation variant typing kits. The variant typing kits identified 267 (71.4%) from the total qualifying samples. Alpha, Beta, Delta, and Omicron were dominantly identified variants from waves I, II, III, and IV, respectively. From the total identified positive study samples, 243 of 267 (91%) of variants identified from samples had cycle threshold values <30.
UNASSIGNED: The study data demonstrated that reverse transcription-PCR-based variant typing can provide additional screening opportunities where sequencing opportunity is inaccessible. The assays could be implemented in laboratories performing SARS-CoV-2 molecular testing.

This study aimed to evaluate maxillary bone healing and computed tomography (CT) values after Le Fort I osteotomy with sagittal split ramus osteotomy in patients with class II and III malocclusion. Four absorbable plates and screws were used to fix the maxillary segments in all patients. For 112 sides (58 patients), the bone defect areas at the anterior and posterior sites between the maxillary segments were measured using 3-dimensional CT views reconstructed over a constant CT value at 1 week and 1 year postoperatively. Subsequently, CT values at the upper, middle, and lower sites around the osteotomy line in the medial, middle, and lateral regions were measured. The bone defect area after 1 year increased at the anterior site in class III and at both the anterior and posterior sites in class II (P < 0.05). This study suggests that the increase in bone defect area was affected by lower CT values at the middle site of the middle and lateral regions in class II, and that bony defects between fragments in the maxilla could partially remain in both classes II and III within 1 year after Le Fort I osteotomy.

UNASSIGNED: To explore the influencing factors to predict the negative nucleic acid conversion time and ORF1ab gene CT value changes in patients with asymptomatic and mild COVID-19.
UNASSIGNED: A total of 73,456 patients with asymptomatic and mild COVID-19 admitted to the Mobile Cabin Hospital in Shanghai from April 3 to April 23, 2022 were selected as the research objects. Epidemiological, clinical, and laboratory data were collected. Correlation analysis was performed.
UNASSIGNED: In patients <18 years old and ≥65 years old, COVID-19 vaccine can shorten the negative nucleic acid conversion time, which is reflected in the lower median or 75% quantile (P<0.001, P<0.05). In patients with underlying diseases, the negative nucleic acid conversion time of booster vaccination and complete vaccination was lower than that of non-vaccinated group (P<0.001, P<0.05). In patients ≤18 years of age or >65 years of age, patients with comorbidity and patients with symptoms, compared with patients 18-65 years of age, patients without comorbidity and patients without symptoms, there was a greater difference in the rate of rise of CT values between vaccinated and unvaccinated patients (P<0.05).
UNASSIGNED: The time of nucleic acid conversion to negative in patients with asymptomatic and mild COVID-19 is affected by age, comorbidity, and first nucleic acid CT value. Vaccination could shorten the negative nucleic acid conversion time of the older population, those with complications or symptoms. The vaccination of older patients does not increase the risk of symptoms.

OBJECTIVE: To detect the viral RNA load of SARS-CoV-2 in conjunctival swabs of COVID-19 patients, and compare with nasopharyngeal swabs.
METHODS: Conjunctival swabs of COVID-19 patients (with PCR positive nasopharyngeal swabs) were subjected to quantitative reverse transcription-polymerase chain reaction (RT-PCR) for detection of SARS-CoV-2 RNA. The cycle threshold (Ct) values of Open Reading Frame 1 (ORF 1 Ab gene) and nucleoprotein (N gene) PCRs were used to assess the viral RNA load, and compare them with the baseline values of nasopharyngeal swabs.
RESULTS: Of 93 patients, 17 (18.27%) demonstrated SARS-CoV-2 RNA in conjunctival swabs. Baseline nasopharyngeal swabs were collected at a median of 2 days; while, the conjunctival swabs were collected at median 7 days, from onset of illness (p < 0.001). Despite a significant delay in conjunctival swab collection than nasopharyngeal swabs, the Ct values (ORF or N gene PCRs) were comparable between nasopharyngeal swab and conjunctival swab samples. Subsequently, during the recovery period, in four of these 17 patients (with conjunctival swab positivity), when the second nasopharyngeal swab was \'negative\', the conjunctival swab was \'positive\'.
CONCLUSIONS: The conjunctival swabs demonstrated SARS-CoV-2 RNA in 17 (18.27%) of 93 COVID-19 patients. Our results may suggest a delayed or a prolonged shedding of the virus/viral RNA on the ocular surface than in nasopharyngeal mucosa.

BACKGROUND: Nucleic acid amplification tests (NAATs) play a pivotal role in clinical laboratories for diagnosing COVID-19. This study aimed to elucidate the accuracy of these tests.
METHODS: In 2021, an external quality assessment of NAATs for SARS-CoV-2 was conducted in 47 laboratories in Tokyo, Japan. In open testing, where the laboratories knew that the samples were intended for the survey, a simulated nasopharyngeal swab suspension sample was used, featuring a positive sample A with a viral concentration of 50 copies/μL, positive sample B with 5 copies/μL, and a negative sample. Laboratories employing real-time RT-PCR were required to report cycle threshold (Ct) values. In blind testing, where the samples were processed as normal test samples, a positive sample C with 50 copies/μL was prepared using a simulated saliva sample.
RESULTS: Of the 47 laboratories, 41 were engaged in open testing. For sample A, all 41 laboratories yielded positive results, whereas for sample B, 36 laboratories reported positive results, 3 laboratories reported \"test decision pending\", 1 laboratory reported \"suspected positive\", and 1 laboratory did not respond. All 41 laboratories correctly identified the negative samples as negative. The mean Ct values were 32.2 for sample A and 35.2 for sample B. In the blind test, six laboratories received samples. Sample C was identified as positive by five laboratories and negative by one laboratory.
CONCLUSIONS: The nature of the specimen, specifically the saliva, may have influenced the blind test outcomes. The identified issues must be meticulously investigated and rectified to ensure accurate results.

Ozone is often used as an antimicrobial agent at the final step in purified water processing. When used in purified bottled water manufacturing, residual ozone should not exceed 0.4 mg/L, per US-FDA regulations. These regulations require the control of Escherichia coli and other coliform bacteria; however, non-coliform pathogens can contaminate bottled water. Hence, it is prudent to test the efficacy of ozone against such pathogens to determine if the regulated ozone level adequately ensures the safety of the product. Inactivation of selected pathogenic and non-pathogenic bacteria in purified water was investigated as a function of ozone dose, expressed in Ct units (mg O3*min/L). Bacterial species tested were Enterococcus faecium, E. coli (two serotypes), Listeria monocytogenes (three strains), Pseudomonas aeruginosa, and Salmonella enterica (three serovars). Resulting dose (Ct)-response (reduction in populations\' log10 CFU/mL) relationships were mostly linear with obvious heteroscedasticity. This heteroscedastic relationship required developing a novel statistical approach to analyze these data so that the lower bound of the dose-response relationships can be determined and appropriate predictive models for such a bound can be formulated. An example of this analysis was determining the 95%-confidence lower bound equation for the pooled dose-responses of all tested species; the model can be presented as follows: Logpopulationreduction = 3.80Ct + 1.84. Based on this relationship, application ozone at a Ct of 0.832 and 21°C achieves ≥ 5-log reduction in the population of any of the tested pathogenic and non-pathogenic bacteria. This dose can be implemented by applying ozone at 0.832 mg/L for 1 min, 0.416 mg/L for 2 min, or other combinations. The study also proved the suitability of E. faecium ATCC 8459 as a surrogate strain for the pathogens tested in the current study for validating water decontamination processes by ozone. In conclusion, the study findings can be usefully implemented in processing validation of purified water and possibly other water types.

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