Correlation of physicohemical and antigenic properties of human leukocyte interferon subspecies

Summary Human leukocyte interferon produced in primary cultures of buffy coat cells and human fibroblast interferon from cultures of the FS-4 foreskin cell strain were subjected to isoelectric focusing in polyacrylamide gels. Leukocyte interferon could be resolved into three major components (pI 5.5, 6.2 and 6.6, respectively) and one minor component (pI 7.0). Fibroblast interferon activity focused in a broad pH range of 6.8–7.8.The isoelectrically distinct subspecies of human leukocyte interferon were isolated and compared as to their antigenic nature, heterospecific antiviral activity in cultures of bovine cells, and apparent molecular weights upon electrophoresis in sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE). The three major subspecies (pI 5.5, 6.2 and 6.6) were similar in their neutralization by antiserum against whole leukocyte interferon and in their relative heterospecific activities on bovine cells. When analyzed on SDS-PAGE, the component focusing at pH 5.5 migrated to a position corresponding to a molecular weight of 17,500 (Le _f), the component with the pI of 6.6 had its major peak corresponding to a molecular weight of 23,000 (Le _s), while the pI 6.2 component contained a mixture of the two molecular weight species. The minor isoelectric component focusing at pI 7.0 contained interferon with the antigenic specificity of fibroblast (F) interferon. It is concluded that the two major antigenic species of human interferon (Le andF) and two known subspecies of human leukocyte interferon (Le _s andLe _f) can be resolved by isoelectric focusing.With 3 Figures     

"Discordant" increases in CD4 cell count relative to plasma viral load in a closely followed cohort of patients initiating antiretroviral therapy

BACKGROUND: In HIV-positive persons receiving antiretroviral therapy, CD4 cell responses are associated with optimal suppression of viral replication. However, increases in CD4 cell counts in the absence of viral suppression have been reported. We characterized plasma viral load (pVL) and CD4 cell count increases in closely followed patients to evaluate determinants and the prevalence of CD4 cell responses at a populational level. METHODS: All HIV-positive patients in the province of British Columbia, Canada, who were antiretroviral naive and initiated therapy between August 1996 and May 1998 were eligible for the study. The selection criteria were that patients had to have CD4 cell counts and pVLs measured at baseline and at least once during eight 16-week periods after the initiation of therapy. We characterized CD4 cell responses and sought patients who had a "discordant" increase at 1 year, which was defined as an increase in CD4 cell count of >or=50/mm3 with a <1 log10 decrease in pVL. We also evaluated adherence and antiretroviral use. RESULTS: Overall, when baseline and 1-year pVLs and CD4 cell counts were compared, 6.2% of patients had CD4 cell count increases without pVL decreases of >or=1 log10. However, when all pVLs before 1 year were considered, 92% of the discordant increases could be attributed to prior transient or partial viral suppression. Furthermore, although substantial increases in CD4 cell counts were observed in transient virologic responders, the cumulative number of antiretroviral agents used by this group was significantly higher than that used by full virologic responders (p <.001). CONCLUSIONS: Our results demonstrate that virtually all CD4 cell count increases can be attributed to transient or partial pVL suppression. Unmeasured pVL suppression likely explains discordant responses that have been previously reported. Similarities between transient and full virologic responders also appear to be time limited and are often associated with greater cumulative use of antiretroviral therapy by transient virologic responders.     

The Differential Effects of Social Media on Depressive Symptoms and Suicidal Ideation Among the Younger and Older Adult Population in Hong Kong During the COVID-19 Pandemic: Population-Based Cross-sectional Survey Study

BackgroundSocial media has become a ubiquitous part of daily life during the COVID-19 pandemic isolation. However, the role of social media use in depression and suicidal ideation of the general public remains unclear. Related empirical studies were limited and reported inconsistent findings. Little is known about the potential underlying mechanisms that may illustrate the relationship between social media use and depression and suicidal ideation during the COVID-19 pandemic.ObjectiveThis study tested the mediation effects of social loneliness and posttraumatic stress disorder (PTSD) symptoms on the relationship between social media use and depressive symptoms and suicidal ideation, as well as the moderation effect of age on the mediation models.MethodsWe administered a population-based random telephone survey in May and June 2020, when infection control measures were being vigorously implemented in Hong Kong. A total of 1070 adults (658 social media users and 412 nonusers) completed the survey. Structural equation modeling (SEM) and multigroup SEM were conducted to test the mediation and moderation effects.ResultsThe weighted prevalence of probable depression was 11.6%; 1.6% had suicidal ideation in the past 2 weeks. Both moderated mediation models of depressive symptoms (χ²₆₂=335.3; P<.05; comparative fit index [CFI]=0.94; nonnormed fit index [NNFI]=0.92; root mean square error of approximation [RMSEA]=0.06) and suicidal ideation (χ²₃₄=50.8; P<.05; CFI=0.99; NNFI=0.99; RMSEA=0.02) showed acceptable model fit. There was a significantly negative direct effect of social media use on depressive symptoms among older people (β=–.07; P=.04) but not among younger people (β=.04; P=.55). The indirect effect via PTSD symptoms was significantly positive among both younger people (β=.09; P=.02) and older people (β=.10; P=.01). The indirect effect via social loneliness was significant among older people (β=–.01; P=.04) but not among younger people (β=.01; P=.31). The direct effect of social media use on suicidal ideation was not statistically significant in either age group (P>.05). The indirect effects via PTSD symptoms were statistically significant among younger people (β=.02; P=.04) and older people (β=.03; P=.01). Social loneliness was not a significant mediator between social media use and suicidal ideation among either age group (P>.05).ConclusionsSocial media may be a “double-edged sword” for psychosocial well-being during the COVID-19 pandemic, and its roles vary across age groups. The mediators identified in this study can be addressed by psychological interventions to prevent severe mental health problems during and after the COVID-19 pandemic.     

Territorywide Study of Early Coronavirus Disease Outbreak,Hong Kong,China

Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10⁻³ substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.     

A specific enhanced recovery protocol decreases opioid use after thyroid and parathyroid surgery

BackgroundEnhanced recovery protocols have not been investigated previously for cervical endocrine surgery. The study aim was to determine whether systematic implementation of an enhanced recovery protocol specific for thyroid/parathyroid surgery can improve postoperative outcomes.MethodsA customized enhanced recovery protocol for thyroid/parathyroid surgery was designed and utilized systematically for all patients who underwent parathyroidectomy, thyroid lobectomy, or total thyroidectomy. Outcomes were assessed 12 months before enhanced recovery protocol implementation (n = 464 patients) and after enhanced recovery protocol implementation (n = 654 patients).ResultsEnhanced recovery protocol implementation was associated with a 72% decrease in mean oral morphine equivalents utilized in-house (before 82 ± 64 versus after 23 ± 28; P < .0001) and many enhanced recovery protocol patients were entirely opioid-free (0.2% vs 21%, P < .0001). When used, the enhanced recovery protocol was associated with a lesser mean amount of ondansetron to treat postoperative nausea and vomiting (5.5 mg ± 3 vs 4.5 ± 2: P < .0001). Duration of stay was short before implementation of the enhanced recovery protocol and did not change substantially after implementation (1.1 days ± 0.7 vs 1.1 ± 0.7; P = .26).ConclusionThe systematic use of a simple, cervical, endocrine surgery-specific enhanced recovery protocol decreased perioperative opioid use by ~70%, with significantly less postoperative nausea and vomiting. Implementation of a multidisciplinary enhanced recovery protocol may be an important initial step toward limiting opioid overuse during common operative procedures.     

Risks of AKI and Major Adverse Clinical Outcomes in Patients with Severe Acute Respiratory Syndrome or Coronavirus Disease 2019

BackgroundSevere acute respiratory syndrome (SARS) and coronavirus disease 2019 (COVID-19) are closely related. The effect of AKI on the clinical outcomes of these two conditions is unclear.MethodsThis retrospective, territory-wide cohort study used an electronic public healthcare database in Hong Kong to identify patients with SARS or COVID-19 by diagnosis codes, virologic results, or both. The primary endpoint was a composite of intensive care unit admission, use of invasive mechanical ventilation, and/or death.ResultsWe identified 1670 patients with SARS and 1040 patients with COVID-19 (median ages, 41 versus 35 years, respectively). Among patients with SARS, 26% met the primary endpoint versus 5.3% of those with COVID-19. Diabetes mellitus, abnormal liver function, and AKI were factors significantly associated with the primary endpoint among patients with either SARS or COVID-19. Among patients with SARS, 7.9%, 2.1%, and 3.7% developed stage 1, stage 2, and stage 3 AKI, respectively; among those with COVID-19, 6.6%, 0.4%, and 1.1% developed stage 1, stage 2, and stage 3 AKI, respectively. In both groups, factors significantly associated with AKI included diabetes mellitus and hypertension. Among patients with AKI, those with COVID-19 had a lower rate of major adverse clinical outcomes versus patients with SARS. Renal function recovery usually occurred within 30 days after an initial AKI event.ConclusionsAKI rates were higher among patients with SARS than those with COVID-19. AKI was associated with major adverse clinical outcomes for both diseases. Patients with diabetes mellitus and abnormal liver function were also at risk of developing severe consequences after SARS and COVID-19 infection.     

Emergency surgery comparison of right versus left acute colonic diverticulitis: A 10-year outcome analysis

IntroductionThe difference in outcome between right (RCD) and left colonic diverticulitis (LCD) is not well established. The aim of this study was to analyse the presentation and surgical outcome of RCD versus left-sided disease following emergency surgery.MethodWe conducted a retrospective review of patients presenting with acute diverticulitis over a 10-year period from 2004 to 2014 to a tertiary unit. Patient demographics, Hinchey classification, need for emergency surgery, perioperative outcome and recurrence were evaluated.ResultsIn total 360 patients presented with acute diverticulitis, 218 (61%) were right-sided and 142 (39%) were left-sided. The mean age (57 yrs vs 68 yrs) and median length of stay (4 days vs 5 days) were significantly less in RCD (p < 0.001). The need for emergency surgery was similar between RCD and LCD (30.7% vs 23.2%, p = 0.12). Sixty-seven (31%) patients with RCD required emergency surgery, 42 (62.7%) of these were based on a presumptive diagnosis of appendicitis and underwent laparoscopic appendicectomy only. Operative morbidity (10.4% vs 51.5%, p < 0.001) and mortality were significantly higher in LCD (1.5% v 15.2%, p = 0.007). Subgroup analysis of non-appendicectomy, RCD patients, showed LCD were more likely to require surgery (11.5% vs 23.2%, p = 0.003). There was no difference in recurrence (p = 0.6).ConclusionRight colonic diverticulitis patients are younger and disease course is more benign compared to LCD. Presentation can be confused with appendicitis without proper imaging. In the rare cases where emergency surgery is required, RCD is associated with a lower operative morbidity and mortality compared to left-sided disease.     

Can parturients distinguish between intravenous and epidural fentanyl?

We tested the hypothesis that the sedative, euphoric, and analgesic effects of intravenous fentanyl would distinguish intravenous from epidural administration. One hundred ASA I and II labouring parturients received 100 μg fentanyl either iv or via an epidural catheter in a double-blind, randomized, crossover fashion. Nineteen anaesthetists (8 staff and 11 residents) participated and correctly guessed the route of administration of the fentanyl in 61/66 intravenous doses and in 69/75 epidural doses yielding a sensitivity of 92.4%, a specificity of 92.0%, a positive predictive value of 91.0%, and a negative predictive value of 93.2%. Of the 41 patients that were crossed over, 38 (92.7%) were able to detect a difference between the routes of administration. Most patients experienced prompt, short-lived symptoms with iv fentanyl but no important differences in fetal heart rate pattern or in maternal desaturation were seen between the groups. This study suggests that subjective symptoms will accurately distinguish intravenous from epidural fentanyl administration in labouring parturients (P < 0.001), and should serve as a safe and reliable intravenous test dose for epidural anaesthesia in the obstetric population.     

Information technology in dental education

The use of information technology in dental education is continually increasing. In this article, IT is defined, and its uses in teaching and learning explored. Examples of the appropriateness of multimedia teaching in dental education are given. Successful multimedia teaching, especially in clinical settings, relies on the proper use of IT and an implementation strategy. The applications of IT to curriculum development, computer-assisted learning (CAL), educational administration, dental practice, hospital administration, and clinical research are also considered.