Regulatory compliance and readability of informed consent forms in industry-sponsored drug development clinical trials.

BACKGROUND/AIMS: An informed consent form is essential in drug development clinical trials. This study aimed to evaluate regulatory compliance and readability of informed consent forms currently being used in industry-sponsored drug development clinical trials. METHODS: This descriptive, cross-sectional study evaluated the informed consent forms of industry-sponsored drug development clinical trials conducted at the Faculty of Medicine, Chiang Mai University, between 2019 and 2020. The informed consent form's compliance with the three major ethical guidelines and regulations (i.e. International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use E6(R2) Good Clinical Practice; Declaration of Helsinki; and the revised Common Rule) were analyzed. The document length and the readability scores (using Flesch Reading Ease and Flesch-Kincaid Reading Grade) were assessed. RESULTS: Of 64 reviewed informed consent forms, the average page length was 22.0 ± 7.4 pages. More than half of their length was mainly devoted to three elements: trial procedures (22.9%), risks and discomforts (19.1%), and confidentiality and the limit of confidentiality (10.1%). Although most of the required elements of the informed consent form content were included in most informed consent forms, we identified four elements with often missing information in the form: aspects of research that are experimental (n = 43, 67.2%), involvement of whole-genome sequencing (n = 35, 54.7%), commercial profit sharing (n = 31, 48.4%), and posttrial provisions (n = 28, 43.8%). CONCLUSION: The informed consent forms in industry-sponsored drug development clinical trials were long but incomplete. Our findings draw attention to ongoing challenges in industry-sponsored drug development clinical trials, where deficient informed consent form quality continues to exist.

What information and the extent of information to be provided in an informed assent/consent form of pediatric drug trials.

BACKGROUND: This study aimed to determine the elements and the extent of information that child participants and their parents would like to read in an informed assent form (IAF)/informed consent form (ICF) of a pediatric drug trial. METHODS: A descriptive survey was conducted to determine the perceived importance of each element of the ICF content from child participants and their parents who underwent informed assent/consent of a multi-center pediatric drug trial. The respondents were asked to indicate the level of importance of each item in a questionnaire, by giving a rating scale from 1 (not important) to 5 (very important). RESULTS: A total of 22 families, 17 child participants with the diagnosis of hematology or oncology diseases and 27 parents, were enrolled. Among 30 items, risk-benefit aspects (i.e., direct health benefit [mean: 4.71 for child respondents, 4.89 for parent respondents], indirect/societal benefit [mean: 4.65, 4.85], major foreseeable risk [mean: 4.47, 4.78], post-trial benefit/provision [mean: 4.59, 4.74], and all adverse effects of the drug including uncommon adverse effects [mean: 4.53, 4.74]) were perceived to be of most concerning items from both child participants' and parents' viewpoint. None of the items were considered 'slightly important' or lower by more than 20% of the respondents. CONCLUSIONS: For pediatric drug trials, risk-benefit information (including direct health benefit, indirect/societal benefit, and post-trial benefit/provision, as well as major foreseeable risk and adverse effects of the drug) should be made a salient feature of an IAF/ICF. This empirical data could help related stakeholders arrange essential information in order of importance and tailor an IAF/ICF to better suit child participants' and parents' needs, particularly for pediatric drug trials involving children with the diagnosis of hematology or oncology diseases.

Ethical considerations and challenges in herbal drug trials with the focus on scientific validity and risk assessment.

Scientific validity and risk assessment are two main ethical issues which raise specific challenges and are unique to clinical trials investigating crude extracts/fractions from herbal materials. There are considerable challenges for both clinical investigators and ethics committee members in dealing with such issues, many of them remain unresolved, resulting in a large variation in ethical requirements, justification, and decisions. Despite a remarkable surge in herbal medicine research globally, a number of clinical investigators or even ethics committee members have limited confidence in dealing with related ethical issues. In this article, we extensively review and discuss the two main ethical issues (i.e., scientific validity and risk assessment) and highlight key considerations that are important for ethical review and justification for the conduct of herbal drug trials.

Taeniasis among Refugees Living on Thailand-Myanmar Border, 2012.

We tested refugee camp residents on the Thailand-Myanmar border for Taenia solium infection. Taeniasis prevalence was consistent with that for other disease-endemic regions, but seropositivity indicating T. solium taeniasis was rare. Seropositivity indicating cysticercosis was 5.5% in humans, and 3.2% in pigs. Corralling pigs and providing latrines may control transmission of these tapeworms within this camp.

Identification of Fasciola species based on mitochondrial and nuclear DNA reveals the co-existence of intermediate Fasciola and Fasciola gigantica in Thailand.

Molecular techniques were used to identify Fasciola species collected from Chiang Mai Thailand. Morphometrically, 65 stained and 45 fresh worms collected from cattle suggested the possible occurrence of both F. gigantica and F. hepatica. Twenty-two worms comprising 15 from cattle and 7 from human patients, were identified subsequently based on three genetic markers: mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1), mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS2). All of them presented the F. gigantica type in maternally inherited mitochondrial sequences (nad1 and cox1), with six types in each sequence (FgNDI-CM1 to FgNDI-CM6 and FgCOI-CM1 to FgCOI-CM6, respectively). Remarkably, the predominant nad1 type, FgNDI-CM6, was identical to that of aspermic Fasciola sp. formerly reported from Thailand, Japan, Korea, China, Vietnam, and Myanmar. ITS2 sequences were analyzed successfully in 20 worms. Fifteen worms showed the F. gigantica type and five (including one worm from a patient) had mixed ITS2 sequences of both F. gigantica and F. hepatica in the same worms, with additional heterogeneity within both ITS2 types. This study revealed the intermediate form of Fasciola coexisting with F. gigantica for the first time in Thailand.

Detection of Ehrlichia canis in canine blood samples by real-time fluorescence resonance energy transfer (FRET) PCR and melting curve analysis.

Ehrlichia canis is a small pleomorphic gram-negative, coccoid, obligatory intracellular bacterium and the cause of canine monocytic ehrlichiosis. A real-time fluorescence resonance energy transfer polymerase chain reaction (real-time FRET PCR) coupled with melting curve analysis was established for detection of E. canis infection in canine blood samples. The VirB9 gene was amplified using one pair of primers and the melting curve analysis was generated by heating the hybridizing probes and amplified products. Eight E. canis-infected dog blood samples were initially identified using the Giemsa staining/microscopic method followed by conventional PCR (cPCR)/Sanger sequencing for confirmation. The sensitivity and specificity of the real-time FRET PCR detection were 87.5% and 100%, respectively and the limit of detection was 6.6 x 10(3) copies of positive E. canis control plasmids. The real-time FRET PCR with melting curve analysis reported here is better than microscopic visualization or cPCR because the method is not affected by the false bias inherent in the microscopic method. Furthermore, many samples can be processed rapidly at the same time. This convenient tool is beneficial as an alternative assay for the epidemiologic study of canine ehrlichiosis as well as for eradication of these organisms in prevention and control programs in endemic areas.

The vasculature of nurse cells infected with non-encapsulated Trichinella species.

The vasculature surrounding the nurse cells of encapsulated Trichinella spiralis has been described previously. It has been postulated the function of these vessels is to support the growth of the parasite. We describe here for the first time the vasculature surrounding the nurse cells of non-encapsulated T. pseudospiralis and T. papuae. Similar to the vasculature of uninfected muscle cells, the vessels surrounding non-encapsulated Trichinella nurse cells are dense and branched longitudinally along the long axis of the muscle cells; they also appear to be similar in diameter. The netting pattern of enlarged vessels found around T. spiralis (encapsulated) nurse cells is not present in non-encapsulated Trichinella infections. The vessels surrounding non-encapsulated Trichinella nurse cells seem to exist prior to parasite invasion of the muscle cell.

High prevalence of haplorchiasis in Nan and Lampang provinces, Thailand, proven by adult worm recovery from suspected opisthorchiasis cases.

Opisthorchiasis, a risk factor for cholangiocarcinoma in humans, is of public health importance in Thailand. The Annual Surveillance Reports from Nan and Lampang Provinces, Thailand, for the year 2011 showed an opisthorchiasis prevalence of over 70% by recovery of eggs in the feces. This study investigated whether most cases are actually due to minute intestinal flukes (MIF) rather than Opisthorchis viverrini, as the eggs of both can hardly be differentiated by morphology. Fifty and 100 cases from residents in Nan and Lampang, respectively, had stools positive for eggs initially assumed to be those of O. viverrini. Each patient was given praziquantel at 40 mg/kg in a single dose. After 2 hr, 30-45 ml of the purgative magnesium sulfate was given, and stools were collected up to 4 times sequentially. The stools were examined for adult worms by simple sedimentation. It was found that 39 of 50 cases (78.0%) from Nan Province had Haplorchis taichui, with intensities ranging from 5 to 1,250 with an average of 62 worms/case. Taenia saginata (7 cases) and Enterobius vermicularis (1 case) were other helminths recovered as the co-infectants. In Lampang Province, H. taichui was recovered from 69 cases (69.0%). The number of flukes recovered ranged from 1 to 4,277, with an average of 326 worms/case. Four cases had Phaneropsolus bonnei, and 10 T. saginata as the co-infectants. Adult specimens of O. viverrini were not recovered from any stool. Clearly, MIF infection, especially haplorchiasis, is more common in northern Thailand. These findings should encourage the Public Health Office to employ more specific tools than Kato's method for surveillance of opisthorchiasis in Thailand.

Susceptibility of laboratory rodents to Trichinella papuae.

Members of the genus Trichinella are small nematodes that can infect a wide range of animal hosts. However, their infectivity varies depending on the parasite and host species combination. In this study, we examined the susceptibility of 4 species of laboratory rodents, i.e., mice, rats, hamsters, and gerbils to Trichinella papuae, an emerging non-encapsulated Trichinella species. Trichinella spiralis and Trichinella pseudospiralis were also included in this study for comparison. Fifteen animals of each rodent species were infected orally with 100 muscle larvae of each Trichinella species. Intestinal worm burden was determined at day 6 and 10 post-inoculation (PI). The numbers of muscle larvae were examined at day 45 PI. The reproductive capacity index (RCI) of the 3 Trichinella species in different rodent hosts was determined. By day 6 PI, 33.2-69.6% of the inoculated larvae of the 3 Trichinella species became adult worms in the small intestines of the host animals. However, in rats, more than 96% of adult worms of all 3 Trichinella species were expelled from the gut by day 10 PI. In gerbils, only 4.8-18.1% of adult worms were expelled by day 10 PI. In accordance with the intestinal worm burden and the persistence of adults, the RCI was the highest in gerbils with values of 241.5±41.0 for T. papuae, 432.6±48 for T. pseudospiralis, and 528.6±20.6 for T. spiralis. Hamsters ranked second and mice ranked third in susceptibility in terms of the RCI, Rats yielded the lowest parasite RCI for all 3 Trichinella species. Gerbils may be an alternative laboratory animal for isolation and maintenance of Trichinella spp.

Evaluation of IgG4 subclass antibody detection by peptide-based ELISA for the diagnosis of human paragonimiasis heterotrema.

A synthetic peptide was prepared based on the antigenic region of Paragonimus westermani pre-procathepsin L, and its applicability for immunodiagnosis for human paragonimiasis (due to Paragonimus heterotremus) was tested using an ELISA to detect IgG4 antibodies in the sera of patients. Sera from other helminthiases, tuberculosis, and healthy volunteers were used as the references. This peptide-based assay system gave sensitivity, specificity, accuracy, and positive and negative predictive values of 100%, 94.6%, 96.2%, 100%, and 88.9%, respectively. Cross reactivity was frequently seen against the sera of fascioliasis (75%) and hookworm infections (50%). Since differential diagnosis between paragonimiasis and fascioliasis can be easily done by clinical presentation and fascioliasis serology, this cross reaction is not a serious problem. Sera from patients with other parasitoses (0-25%) rarely responded to this synthetic antigen. This synthetic peptide antigen seems to be useful for development of a standardized diagnostic system for paragonimiasis.

Molecular detection of Ancylostoma duodenale, Ancylostoma ceylanicum, and Necator americanus in humans in northeastern and southern Thailand.

The 2 principal species of hookworms infecting humans are Necator americanus and Ancylostoma duodenale. Case studies on zoonotic hookworm infections with Ancylostoma ceylanicum and/or Ancylostoma caninum are known mainly from Asian countries. Of these 2 zoonotic species, only A. ceylanicum can develop to adulthood in humans. In the present study, we report a molecular-based survey of human hookworm infections present in southern and northeastern Thailand. Thirty larval hookworm samples were obtained from fecal agar plate cultures of 10 patients in northeastren Thailand and 20 in southern Thailand. Partial ITS1, 5.8S, and ITS2 regions of the ribosomal DNA genes were amplified using PCR. The amplicons were sequenced, aligned, and compared with other hookworm sequences in GenBank database. The results showed that, in Thailand, N. americanus is more prevalent than Ancylostoma spp. and is found in both study areas. Sporadic cases of A. ceylanicum and A. duodenale infection were seen in northeastern Thailand.

Current status of the research ethics committees in Thailand.

BACKGROUND: Many research ethics committees (RECs) have been established to review biomedical research involving human subjects in many research institutes. The purpose is "To protect rights and welfare of human research participants". It is necessary to determine how many research ethics committees have been established in Thailand and whether they have a high enough standard toprotect the rights and welfare of human research subjects. OBJECTIVE: To determine the status of research ethics committees in Thailand. MATERIAL AND METHOD: One hundred thirty survey questionnaires were distributed by mail to medical schools of universities, public hospitals under the Ministry of Public Health, private hospitals, and research institutes. RESULTS: Seventy-eight questionnaires were returned. Thirty respondents had standard Operating Procedures (SOP). Twenty-two RECs had their own office while 36 had to share the office with other departments or units. Board meeting frequency was once a month. The average number of committee members was 14 and the majority was scientific members. Absence of nonaffiliated members was found in RECs (20.6%). Thirty RECs had never provided training for REC members and investigators, the other 48 provided training at least once a year Decision are made by consensus in 51 and majority vote in 14 RECs. Twenty-two respondents managed conflicts of interest (COI) by asking those members to leave the meeting before a decision was finalized. Thirty-nine RECs required continuous review after approval of the protocols. CONCLUSION: Strong support from the organization leader is a key factor to efficiency and high standards of REC operation. Developing a network of RECs will be useful for future development. REC members still need knowledge to better protect the rights, safety, and well-being of research participants.

An enzyme-linked immunosorbent assay as screening tool for human intestinal capillariasis.

Human intestinal capillariasis caused by Capillaria philippinensis is characterized by chronic diarrhea which may lead to death if left untreated. The mortality is highest among patients who are negative by conventional stool examination. Therefore this study explored the application of an enzyme-linked immunosorbent assay (ELISA) as a screening test for human intestinal capillariasis. The ELISA was developed using Trichinella spiralis soluble antigen for the detection of antibodies against C. philippinensis. A cut-off level at the upper 99% limit of the absorbance values of the healthy controls was established for positivity. All intestinal capillariasis sera showed positive ELISA, demonstrating 100% sensitivity, while all healthy control sera gave absorbance values below the cut-off level, resulting in 100% specificity. The ELISA was also positive with 75% of trichinellosis, 13.9% of strongyloidiasis, 9.1% of trichuriasis, and 4.2% of opisthorchiasis sera. The ELISA and immunoblot were in agreement in 91.1% of the sera tested. It was suggested that the here-presented ELISA is capable to detect intestinal capillariasis cases in endemic areas whose coproscopy is negative for worm eggs, larvae or adults.

Identification and characterization of a cathepsin L-like cysteine protease from Gnathostoma spinigerum.

Gnathostoma spinigerum is a causative agent of human gnathostomiasis, a common parasitic disease involving skin and visceral organs, especially the central nervous system. In this study, we identified a cDNA encoding a cathepsin L-like cysteine protease (GsCL1) from the lambdaZAP cDNA library of G. spinigerum advanced third-stage larva (aL3) and characterized the biochemical properties of the recombinant enzyme. The cloned cDNA of 1484bp encoded 398 amino acids which contained a typical signal peptide sequence (23 amino acids), a pro-domain (156 amino acids), and a mature domain (219 amino acids) with an approximate molecular weight of 24kDa. The deduced amino acid sequence of GsCL1 gene showed 53-64% identity to cathepsin L proteases of various organisms including a cathepsin L family member (cpl-1) of Caenorhabditis elegans. Recombinant proGsCL1 expressed in Pichia pastoris showed typical biochemical characteristics of cysteine proteases. The expressed enzyme displayed optimal protease activity toward Z-Phe-Arg-AMC substrate at pH 6.0 but not toward Z-Arg-Arg-AMC. The activity was sensitive to cysteine protease inhibitors E-64 and K11777. The preference for large hydrophilic and aromatic residues in the P2 position (I, L, F, W, U, V) was typical of cathepsin L proteases. Mouse anti-GST-proGsCL1 serum showed reactivity with 35-, 38- and 45-kDa proteins in the aL3 extracts. These proteins were shown to localize inside the intestinal cells of aL3.

Hypereosinophilia and abdominopulmonary gnathostomiasis.

A 16-year-old Thai male presented with sudden onset severe epigastric and right upper quadrant pain, fever (39 degrees C), chills and malaise. He gave no history of underlying disease, migratory swelling or urticarial skin rash. He had a history of frequently eating raw pork. Physical examination revealed a soft abdomen with markedly tender hepatomegaly. His blood count showed extreme leukocytosis with hypereosinophilia. After admission he developed a non-productive cough with left sided chest pain, a chest x-ray showed a left pleural effusion. Serological findings were positive for Gnathostoma larval antigen but not Fasciola antigen. The patient recovered completely after albendazole treatment. His clinical presentation is compatible with abdominopulmonary hypereosinophilic syndrome or visceral larva gnathostomiasis. The presented case is interesting not only for physicians who work in endemic areas of gnathostomiasis but also for clinicians who work in travel medicine clinics in developed countries, to consider abdominopulmonary gnathostomiasis when patients present with the signs and symptoms of visceral larva migrans.

The epidemiology of Dirofilaria immitis infection in outpatient dogs at Chiang Mai University Small Animal Hospital, Thailand.

Five hundred eighty-nine dog blood samples from the small animal hospital of Chiang Mai University were examined for Dirofilaria immitis prevalence using a microhematocrit tube technique for microfilaria detection. In parallel, a once a month follow-up study on 36 D. immitis negative dogs was conducted to detect the time of acquiring infection in each animal. The diagnostic criteria for the incidence study was based on microfilaria detection or on positive findings against D. immitis antigen using the Witness commercial kit. The estimated prevalence was 18.2% (15-21%; 95% CI). There was no statistical difference between male and female infection rates. The age-specific prevalence of dogs under 2 years old was 6.4%, which was lower than the 2-4 year old group and all the other age groups at a 95% confidence level. In older dogs the prevalence reached 41.5%. Most of the dogs housed outdoors had a statistically higher infection rate than the dogs housed indoors (chi-square = 9.662, 1 df, p = 0.002). Only 109 dogs received chemoprophylaxis resulting in a significantly lower infection rate than in the non-heartworm prevention dogs (chi-square =14.424, 1 df, p = 0.000). The overall incidence density and the incidence during the rainy, cool and hot seasons were 5.2, 6.9, 3.5, and 2.7 animals per 100 animal-months, respectively. The incidence rate ratio between wet/dry, rainy/cool, rainy/summer, and cool/hot seasons were 2.18, 1.98, 2.59 and 1.30, respectively. The 95% confidence interval revealed no difference among seasons. In conclusion, dogs in D. immitis endemic northern Thailand contract infection in about 2 years.

Evaluation of IgG4 and total IgG antibodies against cysticerci and peptide antigens for the diagnosis of human neurocysticercosis by ELISA.

To support the clinical diagnosis of human neurocysticercosis (NCC), we evaluated two peptides, HP6-3 and Ts45W-1, as well as crude saline extract (SE) of Tenia solium cysticerci as antigens for the detection of specific IgG4 subclass and total IgG antibodies by an enzyme-linked immunosorbent assay (ELISA). The sera of definitive diagnosed NCC patients, patients infected with other parasitoses and healthy controls were examined. The diagnostic sensitivity for IgG4 and total IgG detection of the ELISA against SE antigen was 100% and 64.3% with a high amount of cross-reactions to taeniasis saginata at 88.9% (8/9) and 100% (9/9), respectively. The SE-based IgG4-ELISA showed the highest specificity (80.9%). Both peptide-based IgG4-ELISAs provided a superior sensitivity (78.6%) to the total IgG tests whereas their specificity was 66.7% for HP6-3 and 69.8% for Ts45W-1 only. The SE-based ELISA for the detection of specific IgG4 antibody can be used for the diagnosis of neurocysticercosis as well as for serological surveys of NCC endemic areas. The peptide-based IgG4 ELISAs potentially provide a reliable and cost effective alternative method independent from live parasite supply.

Cystic echinococcosis in Thailand with a special note on detection by serology in one family.

Thailand is a nonendemic area of echinococcosis. We report, herein, 3 cases with a special note on the use of serology in detection of the disease in one family. All cases were Thais. The first case was a man, having a cystic mass in the liver. He was subsequently diagnosed as having echinococcosis following positive serology. The second case, a male, had a renal hydatid cyst revealed by histopathology, and a positive serological test. The third case, a wife of case 2, was positive by serological screening for echinococcosis and subsequently proven to have splenic and liver echinococcal cysts. The present findings support the use of serology in the case detection of echinococcosis in Thailand.

Potential use of Trichinella spiralis antigen for serodiagnosis of human capillariasis philippinensis by immunoblot analysis.

Intestinal capillariasis is an emerging helminthic zoonosis caused by Capillaria philippinensis and is frequently fatal if not diagnosed correctly. The present study demonstrates cross-reactivity between Trichinella spiralis larval antigens and C. philippinensis-infected human sera by immunoblotting. Sera from 16 proven intestinal capillariasis patients and 16 proven trichinosis patients were tested. The antigenic patterns recognized by intestinal capillariasis sera varied with the molecular masses, ranging from less than 20.1 to more than 94 kDa. The immunoblotting profiles of the trichinosis sera were similar to those of the intestinal capillariasis sera. The antigenic bands with 100% reactivity were located at 36.5, 40.5, and 54 kDa, respectively. Sera from patients with trichuriasis, strongyloidiasis, opisthorchiasis, and healthy controls differed clearly from the previous two and produced very faint patterns of reactivity and attenuated bands. This assay is potentially useful for large-scale screenings of persons at risk for C. philippinensis infection. Parasitological stool examinations of the positive cases are necessary as second-tier laboratory tests for confirming the diagnosis.

Morphology of immature stages of flesh flies, Boettcherisca nathani and Lioproctia pattoni (Diptera: Sarcophagidae).

The flesh flies are medically-important because the larvae found in the human corpses can provide evidence in forensic investigations through larva identification and their developmental rate. Firstly, we thoroughly described the larval morphology of Boettcherisca nathani and Lioproctia pattoni, using scanning electron microscopy (SEM). The third instar of the two species differed markedly in two characters: (1) spines between the prothorax and mesothorax-B. nathani has more or less slender triangular spines, with those at the posterior region more slender than the anterior region; whereas L. pattoni has stout triangular spines with one or two tips anteriorly, with smaller and tapered triangular shape, grouped two to four laterally in the posterior end, and (2) morphology of the peristigmatic tufts at the posterior spiracle-B. nathani has extensively branched long, fine hairs, whereas tufts in L. pattoni have moderately branched long, fine hairs. The anterior spiracle displayed similarity; B. nathani has two irregular rows of 21-27 papillae, while L. pattoni has a single irregular row of 20-28 papillae. Secondly, we use light microscopy to compare morphology of the third instar of the two species and additional three species, i.e., Bercaea africa, Parasarcophaga dux and Liopygia ruficornis. Particular attention was paid to the features of anterior spiracle, spines between prothorax and mesothorax and posterior spiracle. These results are useful in species identification and estimation of age of larvae found associated with corpses.