Human Y chromosome azoospermia factors (AZF) mapped to different subregions in Yq11

In a large collaborative screening project, 370 men with idiopathic azoospermia or severe oligozoospermia were analysed for deletions of 76 DNA loci in Yq11. In 12 individuals, we observed de novo microdeletions involving several DNA loci, while an additional patient had an inherited deletion. They were mapped to three different subregions in Yq11. One subregion coincides to the AZF region defined recently in distal Yq11. The second and third subregion were mapped proximal to it, in proximal and middle Yq11, respectively. The different deletions observed were not overlapping but the extension of the deleted Y DNA in each subregion was similar in each patient analysed. In testis tissue sections, disruption of spermatogenesis was shown to be at the same phase when the microdeletion occurred in the same Yq11 subregion but at a different phase when the microdeletion occurred in a different Yq11 subregion. Therefore, we propose the presence of not one but three spermatogenesis loci in Yq11 and that each locus is active during a different phase of male germ cell development. As the most severe phenotype after deletion of each locus is azoospermia, we designated them as: AZFa, AZFb and AZFc. Their probable phase of function in human spermatogenesis and candidate genes involved will be discussed.      

Highly poly(ethylene) glycolylated islets improve long-term islet allograft survival without immunosuppressive medication

The surface modification of islets using poly(ethylene glycol) (PEG) is being studied as a means of preventing host immune responses against transplanted islets. In this study, to completely shield islets with PEG molecules, we increased the amount of PEG conjugated to islet surfaces, by multiple PEGylation or amplified PEGylation using poly-L-lysine, poly(allylamine), or poly(ethyleneimine), respectively. Amplified PEGylation was associated with islet cytotoxicity and functional impairment, but multiple PEGylation affected neither islet viability nor functionality. In addition, when triply PEGylated islets were allotransplanted into diabetic recipients, these islets survived in 3 of the 7 recipients for more than 100 days without any immunosuppressive treatment. Moreover, the blood glucose levels of these 3 recipients were stable and in the normal range. Immunohistochemical analysis showed that 3 of 7 triply PEGylated islets transplants survived for 100 days and that 4 that were rejected before day 20 were all immunologically protected from immune cells. However, unmodified islets were completely destroyed within 1 week. Consequently, we suggest that multiple PEGylation offers an effective means of reducing the immunogenicity of transplanted islets by increasing the amount of surface-bound PEG.     

Inhibiting Mer receptor tyrosine kinase suppresses STAT1, SOCS1/3, and NF-κB activation and enhances inflammatory responses in lipopolysaccharide-induced acute lung injury

Mer signaling participates in a novel inhibitory pathway in TLR activation. The purpose of the present study was to examine the role of Mer signaling in the down-regulation of TLR4 activation-driven immune responses in mice, i.t.-treated with LPS, using the specific Mer-blocking antibody. At 4 h and 24 h after LPS treatment, expression of Mer protein in alveolar macrophages and lung tissue decreased, sMer in BALF increased significantly, and Mer activation increased. Pretreatment with anti-Mer antibody did not influence the protein levels of Mer and sMer levels. Anti-Mer antibody significantly reduced LPS-induced Mer activation, phosphorylation of Akt and FAK, STAT1 activation, and expression of SOCS1 and -3. Anti-Mer antibody enhanced LPS-induced inflammatory responses, including activation of the NF-κB pathway; the production of TNF-α, IL-1β, and MIP-2 and MMP-9 activity; and accumulation of inflammatory cells and the total protein levels in BALF. These results indicate that Mer plays as an intrinsic feedback inhibitor of the TLR4- and inflammatory mediator-driven immune responses during acute lung injury.     

Genetic analysis of HAV strains isolated from patients with acute hepatitis in Korea, 2005-2006

Hepatitis A virus (HAV) is a causative agent of acute viral hepatitis, which represents a significant public health problem. HAV is usually transmitted by oral-fecal route and prevalent not only in developing countries but also in developed countries worldwide. To characterize the HAV wild type strains circulating in Korea, the VP3/VP1 and VP1/P2A junction regions were detected by RT-PCR from HAV IgM positives during 2005 and 2006. Among 160 HAV IgM positive sera, 30% (n = 48) were positive for HAV RNA. Additionally, the VP3/VP1 junction regions were detected all six stools, which collected from outbreak in Gyeonggi province. Phylogenetic analysis of the sequences obtained from 54 distinct HAV isolates revealed that most of the strains (n = 45) belonged to genotype IA and the others including nine strains belonged to genotype IIIA. Interestingly, a Q --> S amino acid change was dominantly observed at position 810 of the VP1/P2A junction region in 14 isolates. The molecular epidemiology of HAV infection in Korea has changed with the co-circulation of at least two genotypes and 810Q --> S amino acid substitutions were found to be prevalent. These results strongly suggest that various HAV strains, including genotype IIIA, might be imported from high-endemic countries into Korea.     

Mutation of Glu78 of the AVP-NPII gene impairs neurophysin as a carrier protein for arginine vasopressin in a family with neurohypophyseal diabetes insipidus

Familial neurohypophyseal diabetes insipidus (FNDI; OMIM 192340) is a rare inherited disorder with an autosomal dominant inheritance pattern. It is characterized by persistent polydipsia and polyuria induced by deficient or absent secretion of arginine vasopressin (AVP). We report a Korean kindred in whom FNDI is associated with a novel deletion mutation in exon 2 of the AVP-NPII gene encoding the neurophysin II moiety. An 18-yr-old man with polyuria and polydipsia was shown to have central diabetes insipidus by using the water deprivation test. Four family members were suspected to have symptomatic vasopressin-deficient diabetes insipidus. Direct sequencing of the AVP-NPII gene showed a heterozygous GAG deletion mutation in exon 2, which results in in-frame deletion of glutamic acid (c.232_234delGAG; p.Glu78del). The mutation was predicted to yield an abnormal AVP precursor lacking Glu78 (E78) in its neurophysin II moiety. Because Glu78 is essential for neurophysin II molecules to form a salt bridge with AVP, the function of neurophysin as a carrier protein for AVP would be impaired. The proband's mother and sister have the same mutation. Presence of this mutation suggests that the portion of the neurophysin peptide encoded by this sequence is important for the appropriate expression of vasopressin.     

Laparoscopy-assisted urologic surgery through minilaparotomy

Minimally invasive surgery has gained wide acceptance as a method of reducing postoperative pain and curtailing the convalescence period. We have devised a modified surgical technique of laparoscopy-assisted surgery through minilaparotomy. It is a hybridized form of conventional open and laparoscopic surgery and it combines the benefits of both techniques by reducing postoperative pain and scarring as in laparoscopy, but at the same time maintaining the safety of conventional open surgery. From January 1992 to September 1999, we performed laparoscopy-assisted surgery through minilaparotomy in 167 patients. The operative time for laparoscopy-assisted surgery through minilaparotomy ranged from 79 to 290 minutes (mean 125). There was no conversion to open surgery, no peri- or postoperative complications, and only 3 patients needed a blood transfusion at any stage. Pain was significant on the first day but resolved quickly. All patients resumed consistent oral intake on the second day. All patients commenced ambulation by the second postoperative day and were able to resume full ambulatory activity by the fourth postoperative day. The final would size did not exceed 10 cm in size and all patients expressed satisfaction with their wounds. In conclusion, we believe that laparoscopy-assisted minilaparotomy surgery is a truly minimally invasive technique maintaining the advantages of conventional surgery. Our method could become a first-line approach for simple nephrectomy, living donor nephrectomy and radical nephrectomy, as well as surgery for kidney and ureter stones.     

How COVID-19 Affected Healthcare Workers in the Hospital Locked Down due to Early COVID-19 Cases in Korea

BackgroundThe healthcare workers (HCWs) were exposed to never-experienced psychological distress during the early stage of the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to investigate how the COVID-19 pandemic affected the mental health of HCWs during the hospital lockdown period due to mass healthcare-associated infection during the early spread of COVID-19.MethodsA real-time online survey was conducted between April 14–18, 2020 among HCWs who worked at the university hospital where COVID-19 was confirmed in a patient, and the hospital was shut down for 3 weeks. Along with demographic variables and work-related information, psychological distress was measured using the Generalized Anxiety Disorder-7 (GAD-7), the Patient Health Questionnaire-9 (PHQ-9), the Maslach Burnout Inventory-General Survey scale, and the Stress and Anxiety to Viral Epidemics-9.ResultsThe HCWs working in the cohort ward and those who have experienced social discrimination had significantly higher level of depression (PHQ-9 score; 5.24 ± 4.48 vs. 4.15 ± 4.38; P < 0.01 and 5.89 ± 4.78 vs. 3.25 ± 3.77; P < 0.001, respectively) and anxiety (GAD-7 score; 3.69 ± 3.68 vs. 2.87 ± 3.73; P < 0.05 and 4.20 ± 4.22 vs. 2.17 ± 3.06; P < 0.001, respectively) compared to other HCWs. Worries regarding the peer relationship and the skepticism about job were associated with depression (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.07–1.79; P < 0.05 and OR, 1.69; 95% CI, 1.31–2.17; P < 0.001, respectively) and anxiety (OR, 1.73; 95% CI, 1.21–2.49; P < 0.01 and OR, 1.54; 95% CI, 1.09–2.17; P < 0.05, respectively), while fear of infection or worsening of health was not. Path analysis showed that work-related stress associated with the viral epidemic rather than anxiety about the viral epidemic mainly contributed to depression.ConclusionThe present observational study indicates that mental health problems of HCWs exposed to COVID-19 are associated with distress in work and social relationship. Early intervention programs focusing on these factors are necessary.     

Alteration of the CNS pathway to the hippocampus in a mouse model of Niemann-Pick, type C disease

Niemann-Pick type C disease (NPC) is an autosomal recessive disorder that results in premature death due to progressive neurodegeneration including dementia. To understand neuronal pathways connecting to the hippocampus, retrograde transneuronal labeling method with Bartha strain of pseudorabies virus (PRV) was employed in 40 NPC+/+, NPC+/− and NPC−/− mice. Immunohistochemistry using polyclonal antibody against PRV and streological counting were used. The number of neurons and synapse in CA2&3 regions of the hippocampus decreased dramatically in the NPC−/− mouse compared to the NPC+/+ or +/− mouse. The number of PRV positive cell was significantly decreased in several regions including the entorhinal and piriform cortex in the NPC−/− mouse. More severely, lateral septal dorsal nucleus, dorsal entorhinal cortex and medial geniculate body showed no positive labeling in the NPC−/− mouse. However, the hippocampus, medial septal and supramammilary nuclei showed increased immunoreactivity in the NPC−/− mouse. Our data suggest that the synaptic loss and discontinuity of the CNS hippocampal pathway may contribute to understanding the mechanism of symptoms and functional disabilities such as memory and learning disturbance in NPC patients.     

The anatomical characteristics of the stria terminalis in the human brain: a diffusion tensor tractography study

The role played by spinal adrenergic and cholinergic receptors in the antinociceptive effects of intrathecal sildenafil in formalin-induced nociception was examined. Intrathecal catheters were inserted into the subarachnoid space of male Sprague-Dawley rats, and nociception was assessed using the formalin test, consisting of a subcutaneous injection of 50 μL of 5% formalin solution into the hind paw. We examined the effects of an alpha 1 adrenergic receptor antagonist (prazosin), an alpha 2 adrenergic receptor antagonist (yohimbine), a muscarinic acetylcholine receptor antagonist (atropine), and a nicotinic acetylcholine receptor antagonist (mecamylamine) on sildenafil-induced antinociception. Intrathecal sildenafil (3, 10, and 30 μg) suppressed, in a dose-dependent manner, formalin-induced flinching during phases 1 and 2 of the test. Intrathecal sildenafil (30 μg) could not show any effects against intrathecal prazosin (3 μg), yohimbine (10 μg), atropine (10 μg), and mecamylamine (10 μg) pretreatment during both phases of the formalin test. These results suggest that intrathecal sildenafil effectively attenuated the pain evoked by formalin injection. Additionally, spinal alpha 1, alpha 2, muscarinic and nicotinic receptors might play a role in sildenafil-induced antinociception.