Time for change? Feasibility of introducing micromodules into medical student education: a randomised controlled trial.

INTRODUCTION: Didactic lectures have been the foundation of learning for many medical students. However, in recent years, the flipped classroom model has become increasingly popular in medical education. This approach enhances pre-class learning, allowing the limited contact time between clinicians and medical students to be focused on practical issues. This study evaluated the effectiveness and non-inferiority of online micromodule teaching in terms of knowledge transfer concerning specific urology topics. METHODS: Medical students without prior exposure to the urology subspecialty were enrolled in the study, then randomised to a traditional didactic lecture group or an online micromodule group. Knowledge transfer was assessed by pre-intervention and post-intervention multiple-choice questions and objective structured clinical examinations that involved the acquisition of medical histories from real patients. RESULTS: In total, 45 medical students were enrolled (22 in the traditional didactic group and 23 in the online micromodule group). In terms of knowledge transfer (assessed by objective structured clinical examinations), the efficacy of online micromodules was comparable to traditional didactic lectures, although the difference was not statistically significant (P=0.823). There were no significant differences in terms of knowledge acquisition, retention, or clinical application between the two groups. CONCLUSION: In terms of acquiring, retaining, and applying foundational urological knowledge, online micromodules can help medical students to achieve outcomes comparable with the outcomes of didactic lectures. Online micromodules may be a viable alternative to traditional didactic lectures in urology education.

[Study on 4 cases of mushroom poisoning with amanita and identification of poison].

Different kinds of poisonous mushrooms contain different toxic components. Acute liver injury caused by amanita mushroom is the main cause of death from poisonous mushroom poisoning in China. Consumption of poisonous mushrooms has an incubation period, there is a false recovery period in the clinical process, and the early performance is slight and does not attract enough attention from doctors, and it is easy to miss the treatment opportunity. The clinical characteristics, treatment and identification of mushrooms containing amanita in 4 patients were analyzed in order to improve clinicians' understanding of the diagnosis and treatment of mushroom poisoning and early species identification.

Isolation of a cDNA clone encoding a KATP channel-like protein expressed in insulin-secreting cells, localization of the human gene to chromosome band 21q22.1, and linkage studies with NIDDM.

The metabolism of glucose in insulin-secreting cells leads to closure of ATP-sensitive K+ channels (KATP), an event that initiates the insulin secretory process. Defects in insulin secretion are a common feature of non-insulin-dependent diabetes mellitus (NIDDM), and the beta-cell KATP that couples metabolism and membrane potential is a candidate for contributing to the development of this clinically and genetically heterogeneous disorder. We screened a hamster insulinoma cDNA library by low-stringency hybridization with a probe coding for the G-protein-coupled inwardly rectifying K+ channel GIRK1/KGA and isolated clones encoding a protein, KATP-2, whose sequence is 90% similar to that of the recently described KATP-1, an ATP-sensitive K+ channel expressed in heart and other tissues. RNA blotting showed that KATP mRNA was present in insulin-secreting cells and brain but not in heart. To assess the contribution of KATP-2 to the development of NIDDM, the human KATP-2 gene (symbol KCNJ7) was isolated and mapped to chromosome band 21q22.1 by fluorescence in situ hybridization. A simple tandem repeat DNA polymorphism, D21S1255, was identified in the region of the KATP-2 gene, and linkage studies between this marker and NIDDM were carried out in a group of Mexican-American sib pairs with NIDDM. There was no evidence for linkage between D21S1255 and NIDDM, indicating that KATP-2 is not a major susceptibility gene in this population.

Novel variant of p230 trans-Golgi network protein identified by serum from Sjögren's syndrome patient.

Trans-Golgi network (TGN) protein p230 is a peripheral membrane protein associated with the cytoplasmic face of the TGN. TGNp230 is an extensively coiled-coil protein with flexible amino- and carboxyl-terminal ends, associates with non-clathrin-coated vesicles arising from the TGN, and is implicated in vesicle biogenesis. Here we used an autoimmune serum from a patient with S ogren's syndrome to clone partial cDNAs from a human hepatoma HepG2 expression library. The partial cDNAs encoded a novel amino-terminal splice variant of TGNp230. Specific reactivity of the autoimmune serum for p230 is supported by immunofluorescene staining of the Golgi apparatus, immunoblotting of a > 200-kDa HeLa cell protein, and reactivity with a bacterially expressed GST-p230 fusion protein. The alternative splicing occurs within the first proline-rich domain of p230. It comprises a deletion of 30 bp followed immediately by an additional 66 bp absent in the published sequence. RT-PCR analysis indicated that the splicing occurs independently of previously reported carboxyl-terminal splicing, and that this novel splice variant is more frequent than the previously reported p230. The novel splice variant of p230 is also located at the TGN. We propose that p230 splice variants may be implicated in selection of cargo molecules for vesicles arising from the TGN.

Expression of B-type endothelin receptor gene during neural development.

Mutations of the B-type endothelin receptor (ETRB) gene have been found to cause defects in the development of enteric neurons, which resulted in aganglionic megacolon in rodents and humans. To determine the distribution of ETRB mRNA during neural development, mainly in the CNS, in situ hybridization was applied at various developmental stages of rat. ETRB gene was abundantly expressed prenatally in the ventricular and subventricular zones, as well as postnatally in the ependymal and subependymal cells. ETRB mRNA was also strongly detected prenatally in the dorsal root ganglia, as well as postnatally in the cerebellar Bergmann glial cells and epithelial cells of choroid plexus. Our data suggest that ETRB acts as a regulator in the differentiation, proliferation, or migration of neural cells during development.

Limkain b1, a novel human autoantigen localized to a subset of ABCD3 and PXF marked peroxisomes.

Detection of self-reactive antibodies has an established role in the diagnosis and monitoring of many human autoimmune diseases. Autoantibodies with restricted reactivity to cytoplasmic compartments and structures are an occasional incidental finding following routine examination of serum for antinuclear antibody reactivity. A prerequisite for rational exploitation of self-reactive antibodies, in either clinical or research settings, is the establishment of the molecular identity of the target autoantigen(s). Here we report on the identification of a novel autoantigen that co-localizes with a subset of cytoplasmic microbodies marked by ABCD3 (PMP-70) and/or PXF (PEX19). Immunoscreening a HeLa cell cDNA expression library with a human autoimmune serum identified two clones that encode fragments of limkain b1 (LKAP). We demonstrate that mouse polyclonal antibodies raised against a bacterially expressed fragment of limkain b1 mark the same cytoplasmic structures as human serum, as does an EGFP:LKAPCT429 fusion protein expressed in HeLa cells. An immunoblot screen against a bacterially expressed MBP:LKAPCT429 fusion protein substrate, using a cohort of 16 additional human sera that display Hep 2 cell cytoplasmic staining patterns similar to the prototype serum, identified three additional sera reactive to limkain b1. This is the first report establishing the molecular identity of a peroxisomal autoantigen. Preliminary results suggest that limkain b1 may be a relatively common target of human autoantibodies reactive to cytoplasmic vesicle-like structures.

Chimeric Galphaq subunits can distinguish the long form of the Xenopus Mel1c melatonin receptor from the mammalian mt1 and MT2 melatonin receptors.

The family of melatonin receptors is composed of the mt1, MT2, and Mel1c subtypes. The Mel1c is further divided into one long and two short isoforms. A recent study has shown that, unlike mt1 and MT2, the long form of Mel1c is incapable of activating the pertussis toxin-insensitive G16. Here we used three well-characterized Galphaq chimeras to explore the coupling specificity of the melatonin receptors. The qi5, qo5, and qz5 chimeras can link numerous Gi-coupled receptors to the stimulation of phosphoinositide-specific phospholipase C. Both mt1 and MT2 receptors interacted productively with the Galphaq chimeras, while the long form of Mel1c was totally ineffective. Among the Galphaq chimeras, qo5 was less efficiently coupled to the melatonin receptors. Such differential coupling is best explained by structural differences between the melatonin receptors as well as among the Galphaq chimeras. Since the long form of Mel1c receptor possesses an exceptionally large C-terminal tail, we tested the ability of four melatonin receptor C-terminal tail chimeras (Chi 1-4) to interact with the Galphaq chimeras. The presence of the large C-terminal tail of Mel1c in Chi 1 and Chi 3 markedly hindered their coupling to the Galphaq chimeras. On the other hand, the attachment of either the mtl or MT2 C-terminal tail to a Mel1c backbone produced chimeras (Chi 2 and Chi 4) that were capable of activating the Galphaq chimeras. These findings suggest the involvement of C-terminal regions of melatonin receptors in the recognition of G proteins.

Autoantibody to DNA excision repair enzyme hMYH in a patient with rheumatic disease.

We screened a human HepG2 cell cDNA expression library using serum from a patient with rheumatic disease. This serum had immunofluorescence reactivity to nuclei with a homogeneous staining pattern and to punctuate nuclear aggregates, chromosomal metaphase plate, midbody, and cytoplasmic bridge. YT1, the longest cDNA clone isolated, has sequence identity to hMYH, the human homologue of the Escherichia coli excision repair enzyme, DNA adenine glycosylase MutY. YT1 is a truncated cDNA of 1619 bp, encoding amino acids 22-535, and contains a full-length 3'-UTR sequence. We were unable to express a bacterial malE fusion protein incorporating amino acids 22 to 535 of hMYH. Consequently, we generated two additional malE fusion proteins of hMYH encoding amino acids 1-120 (pMAL-c2:hMYH(1-120)) and amino acids 121-535 (pMAL-c2:hMYH(121-535)). The patient serum immunoblotted only pMAL-c2:hMYH(1-120), suggesting that the autoepitope(s) is restricted to amino acids 22-120 of hMYH, and detected a protein of approximately 59-kDa in total HeLa and nuclear extracts consistent with reactivity to hMYH. Affinity-purified autoantibodies to pMAL-c2:hMYH(1-120) reacted by immunoblot to pMAL-c2:hMYH(1-120), with no reactivity to pMAL-c2:hMYH(121-535). By immunofluorescence, these antibodies displayed staining of nuclei. This is the first report of autoantibodies to hMYH in a patient with rheumatic disease. We were able to identify hMYH reactivity in relatively small cohorts of sera collected from rheumatoid factor-positive patients (6 of 18) and dsDNA-positive patients (1 of 18), with no reactivity detected in serum collected from 9 healthy subjects.

Myeloma cells can directly contribute to the pool of RANKL in bone bypassing the classic stromal and osteoblast pathway of osteoclast stimulation.

Summary The ratio of osteoprotegerin [OPG, tumour necrosis factor receptor superfamily, member 11b (TNFRSF11B)] to receptor activator of nuclear factor kappaB ligand [RANKL, tumour necrosis factor (ligand) superfamily, member 11 (TNFSF11)] in bone is critical for the regulation of bone remodelling. Myeloma cells can home to bone, triggering increased RANKL and decreased OPG expression by stromal cells, leading to osteolysis. Whether myeloma cells contribute directly to the pool of RANKL or OPG in bone has been contentious. Here we provide evidence of RANKL expression by reverse transcription polymerase chain reaction and in situ hybridization, demonstrating transcripts encoding both the membrane-bound and secreted forms of RANKL in five human multiple myeloma cell lines (LP-1, NCI-H929, OPM-2, RPMI8226, U266) and myeloma cells purified from bone marrow aspirates of myeloma patients. We demonstrated that RANKL encoding mRNAs are translated to protein by antibody detection of RANKL. In vitro assays showed that myeloma cells induced bone marrow derived mononuclear cells to differentiate into adherent tartrate-resistant acid phosphatase positive multinucleated cells, indicative of the formation of functional osteoclasts. This differentiation could also be achieved with passaged myeloma media alone, implicating secreted products. Finally, we provide evidence that the differentiation observed is at least in part the result of myeloma cell expression of RANKL. We therefore conclude that myeloma cells can directly contribute to the pool of RANKL in bone.