User perceptions of COVID-19 telemedicine testing services, disease risk, and pandemic preparedness: findings from a private clinic in Hong Kong.

INTRODUCTION: During the coronavirus disease 2019 (COVID-19) pandemic, telemedicine has been regarded as a method for providing safe access to healthcare. Here, we explored the experiences of individuals using telemedicine in Hong Kong during the COVID-19 pandemic to understand their risk perceptions and preparedness measures. METHODS: We conducted a cross-sectional online survey of telemedicine users of private clinic-based COVID-19 testing services from 6 April to 11 May 2020. All users were invited to complete an anonymous online survey regarding COVID-19 risk perception and preparedness measures. The results of the survey were compared with the findings of a previous territory-wide survey. RESULTS: In total, 141 of 187 telemedicine users agreed to participate; the response rate was 75.4%. Of the participants, 95.1% (116/122) believed that telemedicine consultations were useful. Nearly half of the participants (49.0%) agreed or strongly agreed that telemedicine consultations were appropriate during the COVID-19 pandemic. Most participants believed that telemedicine consultations could perform the functions of 'health protection, promotion and disease prevention' (73.6%) and 'diagnosis' (64.0%). Concerning the choice of telemedicine provider, almost all participants (99.2%) were willing to consult medical doctors; more than half of the participants (54.1%) were willing to consult registered nurses, but only 13.1% were willing to consult non-clinical staff who had been trained to provide telemedicine services. CONCLUSION: The use of telemedicine for screening and patient education can be encouraged during the COVID-19 pandemic in Hong Kong.

Development of a quantitative assay for SARS coronavirus and correlation of GAPDH mRNA with SARS coronavirus in clinical specimens.

AIMS: To develop a quantitative reverse transcriptase polymerase chain reaction (Q-RT-PCR) for severe acute respiratory syndrome coronavirus (SARS-CoV) detection and explore the potential of using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA as an internal control to exclude false negative results. METHODS: SARS-CoV and GAPDH mRNA were both measured in 26 specimens from 16 patients with SARS, 40 follow up specimens from the same batch of patients, and appropriate control subjects. The relation between SARS positivity and GAPDH mRNA concentration was investigated using the chi2 test. Increasing the sensitivity for SARS-CoV and GAPDH mRNA detection was investigated in follow up specimens in which SARS-CoV and GAPDH mRNA were not detected initially. RESULTS: Varying amounts of SARS-CoV were found in the 26 SARS-CoV positive specimens and SARS-CoV was not detected in the 40 follow up specimens and controls. In addition, concentrations of GAPDH mRNA were significantly different between the patients with SARS, follow up specimens, and healthy controls (Kruskal-Wallis test, p<0.05). Moreover, GAPDH mRNA concentrations were highly correlated with SARS-CoV positivity (chi2 = 5.43; p<0.05). Finally, SARS-CoV and GAPDH mRNA were both detected in three follow up urine specimens that were initially negative when the amount of cDNA used was increased from 5 microl to 10 and 15 microl. CONCLUSIONS: This Q-RT-PCR assay can be used to detect SARS-CoV. Moreover, GAPDH mRNA may be useful to rule out false negative results in SARS-CoV detection, and the current extraction method for urine may not be sensitive enough to detect low titres of SARS-CoV.

Circadian time of morning light administration and therapeutic response in winter depression.

BACKGROUND: We investigated a possible mechanism of action for the antidepressant response to light-phase advances of the circadian clock-by measuring the onset of melatonin secretion before and after light treatment in the morning or evening. METHODS: Plasma melatonin was sampled in 42 patients with seasonal affective disorder, in the evening or overnight while depressed and after 10 to 14 days of light therapy (10 000 lux for 30 minutes) when symptoms were reassessed. RESULTS: Morning light produced phase advances of the melatonin rhythm, while evening light produced delays, the magnitude depending on the interval between melatonin onset and light exposure, or circadian time (morning, 7.5 to 11 hours; evening, 1.5 to 3 hours). Delays were larger the later the evening light (r = 0.40), while advances were larger the earlier the morning light (r = 0.50). Although depression ratings were similar with light at either time of day, response to morning light increased with the size of phase advances up to 2.7 hours (r = 0.44) regardless of baseline phase position, while there was no such correlation for evening light. In an expanded sample (N = 80) with the sleep midpoint used as a reference anchor for circadian time, early morning light exposure was superior to late morning and to evening exposure. CONCLUSION: The antidepressant effect of light is potentiated by early-morning administration in circadian time, optimally about 8.5 hours after melatonin onset or 2.5 hours after the sleep midpoint.

Serial dexamethasone suppression tests and plasma dexamethasone levels. Effects of clinical response to electroconvulsive therapy in major depression.

Serial 1-mg dexamethasone suppression tests with concurrent plasma dexamethasone assessments were conducted in 58 patients with endogenous depression treated with electroconvulsive therapy (ECT). Plasma cortisol levels decreased significantly from pretreatment to immediately posttreatment, and they declined further during the first week after the ECT course, when patients remained drug free. Plasma dexamethasone levels showed an opposite pattern of progressive increases over these three time points. The progressive changes in plasma dexamethasone and cortisol levels seen during the week after ECT indicate that alterations in the bioavailability of dexamethasone and in hypothalamic-pituitary-adrenal axis function may be incomplete immediately after the ECT course. This may partly account for previous inconsistencies in serial dexamethasone suppression test findings with this treatment modality. The major finding was that clinical response was associated with increased plasma dexamethasone levels, whereas changes in cortisol levels were independent of clinical outcome. With ECT, changes in plasma dexamethasone levels may be more related to changes in clinical state than changes in postdexamethasone cortisol levels. The extent to which clinical recovery with other treatments in depression is associated with altered bioavailability of dexamethasone and perhaps other compounds is unknown and in need of investigation.

Dexamethasone suppression test and plasma dexamethasone levels in bulimia.

A 1-mg dexamethasone suppression test (DST) was carried out in 66 women with bulimia and in 26 age- and sex-matched controls. Blood samples were obtained at 4 PM on the day following dexamethasone ingestion, and levels of cortisol and of dexamethasone in the plasma were measured. Thirty-two percent of the patients vs only 7% of the controls had plasma cortisol levels of 140 nmol/L (5 micrograms/dL) or greater following the DST (a positive DST). The plasma levels of dexamethasone varied substantially, and there was a significant inverse relationship between the plasma level of cortisol and that of dexamethasone. Patients with positive DST results had lower levels of plasma dexamethasone than did those with negative DST results, and the mean plasma level of dexamethasone was lower in the bulimic group than in the control group. These results suggest that factors other than a disturbance of hypothalamic-pituitary-adrenal activity may contribute to positive DST results in bulimia.

Nuclear beta-catenin expression is rare and its potential association with short survival in colorectal signet-ring cell carcinoma.

Colorectal signet-ring cell carcinoma (SRCC) is a rare cancer and the prognosis is usually very poor. The biologic pathways involved in its oncogenesis are unknown. beta-catenin, a key target in the Wnt-signaling pathway, is recognized to play an important role in the carcinogenesis in conventional colorectal carcinoma. This study explores the involvement of Wnt-signaling molecules beta-catenin and cyclin D1, cell cycle regulators cyclin D3, proliferative index Ki-67, apoptotic index, and angiogenic indicator CD31 in 20 colorectal SRCC paraffin-embedded specimens. Results showed that there were 2 specimens with nuclear beta-catenin and higher expression of cyclin D1 than the remaining 18 specimens. Surprisingly, those 2 patients had a much shorter survival of 6 months than the remaining 15 patients, who had around 24 months. Moreover, all colorectal SRCC specimens had an overexpression of cyclin D1, cyclin D3, and Ki-67, as well as much more angiogenesis and apoptosis than adjacent normal epithelial tissues. The authors make the preliminary comment that nuclear beta-catenin is a rare phenomenon in colorectal SRCC, but the involvement of it may indicate a worse prognosis with shorter survival than colorectal SRCC without nuclear beta-catenin expression. Besides, overexpression of cyclin D1, cyclin D3, Ki-67, and increased angiogenesis and apoptosis may play a vital role in promoting colorectal SRCC development.

Effects of electroconvulsive therapy on plasma vasopressin and oxytocin.

BACKGROUND: Animal studies suggest that vasopressin has cognitive-enhancing properties and oxytocin may have amnestic effects. A clinical report suggests that the acute increase in oxytocin-associated neurophysin predicts clinical response to electroconvulsive therapy (ECT) in depressed patients. METHODS: Medication-free patients with major depression were randomized to receive right unilateral or bilateral ECT administered with electrical stimulus intensity at either just above seizure threshold or at 150% above seizure threshold. The associations between plasma vasopressin, oxytocin, ECT treatment parameters, clinical outcome, and cognitive effects were assessed. RESULTS: The sample comprised 55 patients. At the second ECT, patients receiving ECT at 150% above initial seizure threshold had significantly greater increases in plasma vasopressin than patients receiving low-dose ECT (ps < .01-.04), with no effects of electrode placement. At the second and ninth ECT treatments, the vasopressin or oxytocin surges were not associated with clinical improvement, seizure duration, time to orientation, or memory test performance. There were inverse trend-level associations between the acute surge in oxytocin levels at the ninth ECT and clinical response, contradicting a report in the literature. CONCLUSIONS: Overall, these findings do not support the hypothesis that diencephalic seizure propagation is central to the mechanism of action of ECT.

Pharmacokinetics of betamethasone in twin and singleton pregnancy.

OBJECTIVE: The aims of the study were to compare the pharmacokinetics of betamethasone in singleton pregnancy with the pharmacokinetics in twin pregnancy and to assess the adrenal suppression produced by betamethasone. STUDY DESIGN: We measured serial betamethasone and cortisol levels in 30 singleton and 21 twin pregnancies after the first dose of betamethasone and calculated the pharmacokinetic parameters for betamethasone including volume of distribution, half-life, and clearance. We also measured cord and maternal blood levels of betamethasone at the birth of infants of 13 singleton and 9 twin pregnancies. RESULTS: The half-life of betamethasone in mothers with twin pregnancies was significantly shorter than that in mothers with singleton pregnancies (7.2 +/-2.4 versus 9.0 +/- 2.7 hours; P <.017). Clearance of betamethasone in the twin pregnancies appeared greater than in singleton pregnancies (8.4 +/- 6.4 versus 5.7+/- 3.1 L/h; P =.06) but did not reach statistical significance. Volume of distribution was similar in the two groups. Because the time between the last dose of betamethasone and birth varied widely (range, 2-158 hours), mothers with a longer interval after treatment tended to have a higher cord-to-maternal betamethasone ratio than did mothers with a shorter interval in both twin and singleton pregnancies. This finding indicated delayed fetal clearance, but the correlation was weak (R (2) = 0.29 for twins and 0.08 for singletons). CONCLUSION: The shorter half-life of betamethasone in twin pregnancy than in singleton pregnancy may cause the level of betamethasone to be subtherapeutic for lung maturation in twin pregnancy.

Fluphenazine plasma levels, dosage, efficacy, and side effects.

OBJECTIVE: The authors sought to determine whether fluphenazine dose or plasma level predicts clinical improvement or side effects during acute treatment. METHOD: Oral fluphenazine was given in fixed, randomized, double-blind doses (10, 20, or 30 mg/day) for 4 weeks to 72 inpatients with acute schizophrenic exacerbations. Outcome measures included percentage improvement in ratings of positive symptoms (hallucinations, delusions, and thought disorder), percentage improvement in negative symptoms, and maximum score for extrapyramidal symptoms. Response was defined as an improvement in positive symptoms of 40% or more. RESULTS: The 42 responders had a shorter duration of illness, less chronic course, and lower rate of akathisia. Plasma level and dose did not differentiate responders and nonresponders, but they did predict percentage improvement in positive symptoms within the responder subgroup. Akathisia was more common and extrapyramidal symptoms were more severe at higher plasma levels. CONCLUSIONS: Responders showed the greatest improvement at fluphenazine plasma levels above 1.0 ng/ml and doses above 0.20-0.25 mg/kg per day. Since the literature suggests that optimal plasma levels are similar during acute and maintenance treatment, monitoring of plasma levels may thus be useful. Conditions for applying the "responder-only" analytic strategy in future studies are discussed.

The potential use of a dopamine neuron antibody and a striatal-derived neurotrophic factor as diagnostic markers in Parkinson's disease.

The cerebral spinal fluid (CSF) of patients with Parkinson's disease (PD) contains an antibody that immunocytochemically reacts with dopamine (DA) neurons in the substantia nigra (SN). This antibody was found in 78% of the CSF samples taken from patients with clinical PD. In contrast, only 3% of the CSF samples taken from control patients or patients with neurologic symptoms other than PD possessed this antibody. The production of this antibody might contribute to disease progression but does not appear to be the etiologic factor responsible for PD. In other experiments, concentrates of the CSF of patients with PD enhanced growth of mesencephalic cultures relative to control CSF. Both the antibody and the growth-promoting activity found in CSF are associated with degeneration of the SN and might therefore be useful as potential diagnostic markers for PD.

A study of the possible etiologic association of Epstein-Barr virus with reactive hemophagocytic syndrome in Hong Kong Chinese.

The herpes group of viruses, particularly Epstein-Barr virus (EBV), has frequently been implicated in the causation of reactive hemophagocytic syndrome (RHS) in the Western populations. EBV has also been implicated in the rare fulminant form of RHS occurring in Oriental children. However, our previous adult-predominant study indicated little clinical and serological evidence of EBV infection in patients with RHS in Hong Kong. In the present study, we further examined this issue using a more sensitive and specific technique for the demonstration of EBV, ie, in situ hybridization for EBV encoded RNA (EBER). The 43 Chinese patients studied were mostly adults with a mean age of 44 years, and a male to female ratio of 1.5:1. About two-thirds (28) of patients had associated malignant lymphoma at the time of diagnosis. Five patients had documented infection (typhoid fever 2; systemic candidiasis 1; adenovirus pneumonia 1; viral encephalitis 1), and two had systemic lupus erythematosus. EBER signals were detected in only 11 cases (25.6%). All positive cases were associated with malignant lymphoma, and the positive signals were exclusively localized to the lymphoma cells but not in the histiocytes. On comparing the results (11 of 28 cases positive; 39.3%) with our previous data on EBER-expression in malignant lymphomas in Hong Kong, no significant difference is observed in the frequency of EBV-positivity between the two groups of lymphomas. Thus, a definite pathogenetic link between EBV and lymphoma-associated RHS cannot be established. However, the overrepresentation of T and T/NK lineage lymphoma in this sample of lymphoma-associated with RHS (61%) versus nonselected cases of lymphomas (31%) suggests that it is the T and T/NK cell origin of the lymphoma rather than the EBV positivity that predisposes to RHS. Notwithstanding the previous findings, EBER in situ hybridization may still serve as a useful adjunct in the investigation of patients with RHS, because the presence of EBER-positive cells should raise a strong suspicion of an underlying malignant lymphoma.

Effect of extended depot fluphenazine treatment and withdrawal on social and other behaviors of Cebus apella monkeys.

To examine whether or not prolonged exposure to a depot neuroleptic has either residual or "tardive pathological" effects on normal behavior, 38 Cebus apella monkeys were observed daily for 108 weeks. The issue of stress influencing such effects was also addressed. During weeks 25-48 half of the monkeys received 0.22 mg/kg fluphenazine decanoate, IM, every 3 weeks, with the dose increased to 0.33 mg/kg during weeks 49-72. Behavioral measures were combined to form composite behavioral variables which quantify four major aspects of behavior: self- and environment-directed behavior, affiliation, aggression, and normal locomotor activity. Mean plasma fluphenazine levels at 48 h post-injection were 0.13 (+/- 0.03) ng/ml for injections 3-8 and 0.24 (+/- 0.07) ng/ml for injections 11-16. The pre-study null hypothesis that the four major aspects of behavior would not be adversely affected by this treatment during the drug-discontinuation phase of the study (weeks 73-108) was not statistically negated. There were highly significant decreases in self- and environment-directed behaviors and affiliation during the treatment periods, implying that treatment may contribute to the negative symptoms of treated schizophrenics. Stress reduced the above effects. Aggression showed some increase during early drug discontinuation, accentuated by stress. Recovery of normal (baseline) behavioral scores began by week 7 after the last treatment. Mild (bucco-lingual) tardive dyskinesias persisted in 30% of the animals for a prolonged time.

Prodynorphin processing by rat CNS fractions and purified enzymes: Formation of Dynorphin A 1-8 by sulfhydryl-activated carboxypeptidase and peptidyl dipeptidase.

The conversion of selected prodynorphin fragments to form the octapeptide Dynorphin A 1-8 was studied in rat brain or spinal cord fractions, and the results compared to the action of purified carboxypeptidases and angiotension converting enzyme. The particulates were shown to convert Dynorphin A or 1-13 to the octapeptide as measured by radioimmunoassay, and by reverse phase high performance liquid chromatography. Detergent extracts of these particulates contained and enzyme converting 1-13 to 1-12 with release of C-terminal lysine, and active over a wide pH range of 4.8-7.6. Purification of these extracts by affinity chromatography (p-amino-benzoyl-arginine-Sepharose-6B) using Bz-Ala-Arg as the substrate led to isolation of a carboxypeptidase converting 1-13 to 1-12 active over the same pH range. Since Dynorphin 1-13 was converted to 1-8 by the consecutive use of purified carboxypeptidase B and angiotensin converting enzyme, the possibility exists that this mechanism might account for some octapeptide production in situ. The properties and substrate specificity of the carboxypeptidase B were compared to a carboxypeptidase A active optimally at pH 5.5 and assayed with Z-Glu-Tyr. The carboxypeptidase B acted only on prodynorphins with C-terminal basic residues as contrasted to a nonspecific action by the carboxypeptidase A. The carboxypeptidase B was characterized by a strong activation by -SH agents and Zn(2+), and thus could be differentiated from other opioid converting enzymes. The enzyme was inhibited by guanidinoethyl succinic acid (GEMSA), and p-chloromercuriphenyl-sulphonic acid (PCMS) but not by benzylsuccinic acid, a potent inhibitor of carboxypeptidase A.

An optimised protocol for the extraction of non-viral mRNA from human plasma frozen for three years.

AIMS: To detect non-viral mRNA in human plasma that has been frozen for three years using a new protocol. METHODS: Plasma from 15 patients with colorectal cancer and 10 normal subjects was separated and frozen with Trizol at -80 degrees C for three years. As a control measure, plasma from 10 of the 15 patients was separated using the same protocol but no Trizol during storage. After three years, all samples were extracted using Trizol and RNeasy before the reverse transcriptase polymerase chain reaction was performed to detect non-viral beta catenin mRNA. In addition, extraction of three plasma samples by Trizol or RNeasy independently was carried out for comparison. RESULTS: beta Catenin mRNA was detected in all 15 patient plasma samples and only one of the 10 normal subjects. In contrast, no beta catenin mRNA was found in the control and patient samples that were independently extracted by Trizol and RNeasy kit. CONCLUSIONS: This new protocol is a reliable method for extracting non-viral mRNA from the plasma of patients with cancer after longterm storage for three years. Extractions using Trizol and RNeasy kits independently could not isolate mRNA with sufficient quantity and quality for detection.

Detection of hepatitis B pre-core mutant by allele specific polymerase chain reaction.

AIM: Development of a specific polymerase chain reaction (PCR) assay for detection of the pre-core, stop codon, mutant of hepatitis B virus (HBV). METHODS: PCR primers, specific at the 3'-end for nucleotide 1896 of either the pre-core, stop codon, mutant or wild type HBV, were synthesised using published sequence data. Positive control templates for both types of virus were synthesised by the PCR, incorporating sequences specific for each virus type at the appropriate position. These templates were used to optimise the specificity of the procedure. Formalin fixed, paraffin wax embedded human tissue from acute or fulminant HBV hepatitis from Hong Kong or Oxford was then investigated for presence of mutant or wild type virus. The HBV DNA was amplified from this tissue using a two step procedure, with an initial amplification phase followed by a second diagnostic phase on optimally diluted target DNA. RESULTS: Specific detection of mutant or wild type HBV was achieved. An important factor in determining specificity was the temperature of annealing, 70 degrees C proving to be highly specific. To overcome the inherent variation of target copy number in clinical samples and to provide an intrinsic positive control, it was important to generate and standardise the amount of target HBV used for the specific PCR. Two cases of fulminant hepatitis and four cases of acute hepatitis from Hong Kong, and one case of fulminant hepatitis from Oxford, contained only wild type HBV, with no evidence of a mutant virus. CONCLUSION: This method can be applied to FFPE tissues. It is rapid, non-radioactive, and specific for the stop codon mutation at nucleotide 1896 of HBV. Preliminary investigation of a small number of cases of fulminant hepatitis from Oxford and Hong Kong showed only wild type virus. The result differs from results published from Japan and Israel.

Integration of human papillomavirus types 16 and 18 in cervical adenocarcinoma.

AIMS: To determine which type of human papillomavirus (HPV) is associated with cervical adenocarcinoma and whether the virus was integrated or episomal in two continents. METHODS: Biopsy specimens from the UK (n = 16) and South Africa (n = 22) were analysed by non-isotopic in situ hybridisation (NISH) for HPV types 6, 11, 16, 18, 31, 33, and 35 on archival biopsy specimens using digoxigenin labelled probes. RESULTS: A total of 20 adenocarcinomas (53%) from both groups contained HPV DNA. In the UK group, seven and four cases contained HPV 18 (44%) and 16 (25%) respectively. In the South African group, nine cases contained HPV 18 (41%) while HPV DNA was not detectable in the other 13 cases. Hence HPV 18 was present in 80% of HPV positive adenocarcinomas. CONCLUSIONS: The HPV 16 or 18 genome was integrated in all viral positive cases. In two cases HPV 18 was also present in an episomal form. These data indicate that HPV integration is common to cervical adenocarcinoma in two continents by the same methodology. The lower prevalence of HPV 18 detection in the South African group may have been due to the presence of other or unsequenced HPV types.

Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients.

AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV.

Dexamethasone suppression test in children with major depressive disorder.

The authors report a study of 24-hour serial cortisol determinations, measured during baseline and after the administration of 0.25 and 0.5 mg of dexamethasone in a sample of predominantly outpatient children with major depressive disorder, nonaffective psychiatric controls, and normal controls. In this sample, 24-hour baseline cortisol and the dexamethasone suppression test (DST) do not discriminate between the three groups. In addition, the authors measured 24-hour serum dexamethasone levels. There were no significant between group differences in serum dexamethasone. These results raise questions as to the utility of this test in the diagnosis of affective disorders in children. Possible reasons for the discrepancies in the dexamethasone suppression test results between in- and outpatient studies are discussed.

Plasma dexamethasone and cortisol levels in depressed outpatients.

We investigated the 1-mg dexamethasone suppression test (DST) in 41 outpatients with major depressive disorder assessing the role of dexamethasone blood level, age and basal cortisol on DST results. Non-suppressors (approximately 25% of patients) had lower dexamethasone levels, and post-dexamethasone cortisol was negatively correlated with plasma dexamethasone; these findings were more significant after covarying out age and basal cortisol, factors that were also significantly associated to non-suppressors. A subgroup of patients (n = 19) also had 0.75-mg and 2.0-mg DST to evaluate whether a threshold dexamethasone blood level existed; a dexamethasone blood level greater than 1.5 ng/ml converted all non-suppressors to suppressors. Implications of these findings are discussed.