[Role of preoperative ultrasound-guided inferior parathyroid gland localization and new classification to assist intraoperative search and protection of parathyroid glands]

Objective: To investigate the role and significance of ultrasound-guided inferior parathyroid gland (IPTG) localization in searching and protecting parathyroid glands before thyroid surgery. Methods: A randomized controlled trial study was conducted. A total of 306 patients (433 cases of lateral parathyroidectomy) who underwent primary thyroidectomy and central lymph node dissection in Beijing Tongren Hosipital from March to October 2021 were enrolled. In order to locate IPTG more quickly and effectively, new IPTG classification and the definition of quadrant position were carried out. The patients were divided into the study group (n=228) and the control group (n=205). The study group underwent ultrasound-guided IPTG examination before operation and measured the distance between the IPTG and the lower pole of the thyroid and the midline of the trachea. During the operation, the IPTG was found and protected depending on the localization. The control group did not use any auxiliary preoperative positioning method. The distribution ratio of IPTG and the coincidence rate between intraoperative validation and ultrasound localization were calculated. Results: There were 306 patients enrolled in the final analysis (95 males and 211 females), with a median age of 41 years old (18-70). Type Ⅱ and Ⅲ IPTG accounted for 77.2% (176/228) of the total cases. The total coincidence rate ranged from 72.8% to 79.4% in different IPTG groups. Type Ⅲ and quadrant 2 IPTG had the highest coincidence rate [92.4% (73/79) and 92.9% (79/85), respectively]. The study group had better in situ retention rate [82.0% (187/228) vs 73.2% (150/205), χ²=4.896, P=0.027] and less implantation rate [8.8% (20/228) vs 16.1% (33/205), χ²=5.393, P=0.020] than those of the control group. The in situ retention rate were better in type Ⅲ IPTG group, compared with those of the control group [94.9% (74/78) vs 77.4% (48/62), χ²=7.898, P=0.005]. There was no permanent hypoparathyroidism in two groups and the temporary hypoparathyroidism rate was 32.0% (24/75) and 34.6% (18/52), respectively (χ²=0.095, P=0.758). Conclusion: Ultrasound-guided IPTG localization examination has important implications for searching and protecting IPTG during operation, which can significantly increase in situ retention rate of IPTG and decrease the implantation rate.

Virtual family physician care during COVID-19: a mixed methods study using health administrative data and qualitative interviews

BACKGROUND

The onset of the COVID-19 pandemic necessitated a rapid shift in primary health care from predominantly in-person to high volumes of virtual care. The pandemic afforded the opportunity to conduct a deep regional examination of virtual care by family physicians in London and Middlesex County, Ontario, Canada that would inform the foundation for virtual care in our region post-pandemic.

OBJECTIVES

(1) to determine volumes of in-person and virtual family physicians visits and characteristics of the family physicians and patients using them during the early COVID-19 pandemic; (2) to determine how virtual visit volumes changed over the pandemic, compared to in-person; and (3) to explore family physicians' experience in virtual visit adoption and implementation.

METHODS

We conducted a concurrent mixed-methods study of family physicians from March to October 2020. The quantitative component examined mean weekly number of total, in-person and virtual visits using health administrative data. Differences in outcomes according to physician and practice characteristics for pandemic periods were compared to pre-pandemic. The qualitative study employed Constructivist Grounded Theory, conducting semi-structured family physicians interviews; analyzing data iteratively using constant comparative analysis. We mapped themes from the qualitative analysis to quantitative findings.

RESULTS

Initial volumes of patients decreased, driven by fewer in-person visits. Virtual visit volumes increased dramatically; family physicians described using telephone almost entirely. Rural family physicians reported video connectivity issues. By early second wave, total family physician visit volume returned to pre-pandemic volumes. In-person visits increased substantially; family physicians reported this happened because previously scarce personal protective equipment became available. Patients seen during the pandemic were older, sicker, and more materially deprived.

CONCLUSION

These results can inform the future of virtual family physician care including the importance of continued virtual care compensation, the need for equitable family physician payment models, and the need to attend to equity for vulnerable patients. Given the move to virtual care was primarily a move to telephone care, the modality of care delivery that is acceptable to both family physicians and their patients must be considered.

Insight into intraindividual variability across neuropsychological tests and its association with cognitive dysfunction in patients with lupus

Objective

Dispersion, or variability in an individual’s performance across multiple tasks at a single assessment visit, has been associated with cognitive dysfunction (CD) in many neurodegenerative and neurodevelopmental disorders. We aimed to compute a dispersion score using neuropsychological battery (NB) tests and determine its association with CD in patients with SLE.

Methods

CD was defined as a z-score of ≤−1.5 on ≥2 domains of the NB. To compute a type of dispersion score known as the intraindividual SD (ISD), the SD of age-adjusted and sex-adjusted z-scores was calculated for each visit in each patient. To estimate the association between ISD and cognitive status (CD and non-CD), we used multilevel logistic regression, adjusting for clinically important covariates.

Results

A total of 301 adult patients with SLE completed the NB at baseline, 187 of whom were reassessed at 6 months and 189 at 12 months. CD was observed in 35.2% of patients at baseline, 27.8% at 6 months and 28.0% at 12 months. Prior to covariate adjustment, the mean ISD for non-CD was 1.10±0.31 compared with 1.50±0.70 for CD. After adjusting for ethnicity, education, employment, socioeconomic status and anxiety/depression, there was a statistically significant association between ISD and CD (OR for one-unit increase in ISD: 13.56, 95% CI 4.80 to 38.31; OR for 1/10th-unit increase in ISD: 1.30, 95% CI 1.17 to 1.44). Findings were valid across multiple sensitivity analyses.

Conclusion

This is the first study to show that patients with SLE who were classified as having CD by the NB had more variability across the NB tests (ie, higher ISD score) compared with those who were not classified as having CD.

Cortical stroke affects activity and stability of theta/delta states in remote hippocampal regions

Cognitive impairment is a common outcome of ischemic stroke. Our previous work has shown that an experimental stroke in the cortex reduces activity in remote hippocampal layers in rats. This study seeks to uncover the underlying functional connections between these areas by analyzing changes to oscillatory activity, signal power, and communication. We induced an ischemic stroke in the left somatosensory cortex of rats and used linear micro-electrode arrays to simultaneously record from cortex and hippocampus under urethane anesthesia at two weeks and one month after stroke. We found significant increase in signal power, as well as an increase in the number of brain state changes in response to stroke. Our results suggest that the cortex modulates the activity and stability of hippocampal oscillations, which is disrupted following cortical stroke that can lead to cognitive impairment.

[A clinical study of Proteus syndrome caused by a mosaic somatic mutation in AKT1 gene]

Objective: Proteus syndrome is a rare disease. The aim of the present study was to analyze the clinical characteristics and gene mutations of Proteus syndrome with a case report and relevant literature review. Methods: Clinical data of the patient with Proteus syndrome were collected in detail and biochemical measurements and radiological examinations were conducted. Tissues from phalanges with lesions were obtained to extract DNA, and Sanger sequencing of AKT1 gene was carried on. The pathogenic mutation was further tested in peripheral blood samples of the patient, his parents and 250 healthy volunteers. Orthopaedic surgery was performed on the affected limbs of the patient. Results: The patient was presented with progressive overgrowth of the right extremity, scoliosis, cerebral connective tissue nevus and lower extremity venous. A heterozygous mutation of AKT1 gene (c. 49G>A) was identified in DNA extracted from the affected bone tissue of the patient, but not be found in genomic DNA of peripheral blood samples from the patient, his parents and 250 healthy volunteers. Movement function of the affected limb improved significantly after the operations. Conclusions: The prominent features of Proteus syndrome are overgrowth of one extremity and cerebral connective tissue nevus. A mosaic somatic mutation of AKT1 gene is one of the pathogenic mutations for Proteus syndrome, and orthopedic surgery may be a good way to improve symptoms of the disease.

The levels of bone turnover markers 25(OH)D and PTH and their relationship with bone mineral density in postmenopausal women in a suburban district in China

This study evaluated the levels of bone turnover markers (BTMs) and investigated relationships between them and bone mineral density (BMD) in postmenopausal women in China suburban district. The prevalence of osteoporosis was 25.03 % at lumbar spine and 6.23 % at femoral neck, and BTMs were negatively correlated with BMDs.

INTRODUCTION

The aims of this study were to evaluate the levels of bone turnover markers (BTMs), including serum N-terminal procollagen of type I collagen (P1NP), beta C-terminal cross-linked of type I collagen (β-CTX), 25-hydroxyvitamin D [25(OH)D], and parathyroid hormone (PTH), and to investigate relationships between these markers and bone mineral density (BMD) as well the prevalence of osteoporosis in postmenopausal women of suburban district.

METHODS

A population of 4822 postmenopausal women aged 55-69 years old (62.22 ± 6.75) from the suburban district was recruited voluntarily. BMD was measured at the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry; 2251 women in this group had the serum BTMs 25(OH)D and PTH tested.

RESULTS

The prevalence of osteoporosis was 25.03 % at lumbar spine and 6.23 % at femoral neck. The median (interquartile range) values of serum P1NP, β-CTX, 25(OH)D, and PTH were 59.3 ng/mL (44.7-75.52), 0.370 ng/mL (0.280-0.490), 23.0 ng/mL (17.1-30.5), and 31.4 pg/mL (24.9-39.7), respectively. Serum P1NP and β-CTX levels presented significantly negative correlations with BMDs at the all the sites (Beta_std = -0.098 to -0.208, respectively, P < 0.001), whereas PTH levels were negatively correlated with BMDs of the femoral neck and total hip (Beta_std = -0.062 and -0.054, P < 0.01, respectively). Serum 25(OH)D had positive associations with BMDs at total hip (Beta_std = 0.051, P < 0.01).

CONCLUSIONS

The BMD of postmenopausal women in China suburban area is higher than that in downtown area, and over 60 % of the participants had their serum 25(OH)D level over 20 ng/mL. BTMs were negatively correlated with BMDs, suggesting that BTMs are reliable factors for early declines in BMD.

Associations of polymorphisms in the SOST gene and bone mineral density in postmenopausal Chinese Women

The bone mineral density (BMD) of a total of 1,379 healthy postmenopausal Chinese women was measured. Ten tagging SNPs of the sclerostin (SOST) gene were genotyped. Our results suggest that the polymorphisms of the rs2023794 and rs74252774 in the SOST gene were associated with BMD of the lumbar spine in postmenopausal Chinese women.

INTRODUCTION

The purpose of the study was to determine the associations between polymorphisms of SOST gene and BMD in postmenopausal Chinese women.

METHODS

A total of 1,379 independent healthy postmenopausal Chinese women including 703 in our previous study were recruited. The BMD of the lumbar spine 1-4 (L1-4) and left proximal femur including total hip and femoral neck were measured by dual-energy X-ray absorptiometry. Ten tagging SNPs (rs1234612, rs1513670, rs1634330, rs1708635, rs2023794, rs7220711, rs74252774, rs851057, rs851058, and rs865429) of the SOST gene were genotyped.

RESULTS

The rs2023794 and rs74252774 and the haplotype ACCATTCT of SOST gene were associated with age and body mass index (BMI) adjusted L1-4 BMD (P values were 0.010, 0.007, and 0.007, respectively) even after performing the Bonferroni multiple-significance-test correction. There was a clear trend in these regions that the CC genotype of the rs2023794 and the TT genotype of the rs74252774 have higher BMD values than other genotypes. The contributions of the rs2023794 and rs74252774 to the phenotypic variation of L1-4 BMD were 0.6 and 0.7 %, respectively. We failed to find any association between the 10 SNPs and 6 haplotypes of the SOST gene and BMD at the hip site in this study.

CONCLUSIONS

Our results suggest that the polymorphisms of the rs2023794 and rs74252774 in the SOST gene were associated with BMD of the lumbar spine in a large sample of postmenopausal Chinese women.

Spontaneous rhythmic field potentials of isolated mouse hippocampal-subicular-entorhinal cortices in vitro

The rodent hippocampal circuit is capable of exhibiting in vitro spontaneous rhythmic field potentials (SRFPs) of 1-4 Hz that originate from the CA3 area and spread to the CA1 area. These SRFPs are largely correlated with GABA-A IPSPs in pyramidal neurons and repetitive discharges in inhibitory interneurons. As such, their generation is thought to result from cooperative network activities involving both pyramidal neurons and GABAergic interneurons. Considering that the hippocampus, subiculum and entorhinal cortex function as an integrated system crucial for memory and cognition, it is of interest to know whether similar SRFPs occur in hippocampal output structures (that is, the subiculum and entorhinal cortex), and if so, to understand the cellular basis of these subicular and entorhinal SRFPs as well as their temporal relation to hippocampal SRFPs. We explored these issues in the present study using thick hippocampal-subicular-entorhinal cortical slices prepared from adult mice. SRFPs were found to spread from the CA1 area to the subicular and entorhinal cortical areas. Subicular and entorhinal cortical SRFPs were correlated with mixed IPSPs/EPSPs in local pyramidal neurons, and their generation was dependent upon the activities of GABA-A and AMPA glutamate receptors. In addition, the isolated subicular circuit could elicit SRFPs independent of CA3 inputs. We hypothesize that the SRFPs represent a basal oscillatory activity of the hippocampal-subicular-entorhinal cortices and that the subiculum functions as both a relay and an amplifier, spreading the SRFPs from the hippocampus to the entorhinal cortex.

Air quality modeling for Houston-Galveston-Brazoria area

A coupled numerical model of the atmospheric thermo-hydrodynamics and pollutant photochemical transport is described. This model can be used to study the complex relationships between the chemical and thermo-hydrodynamic processes in the atmosphere of urban areas with an emphasis on photochemical ozone formation. Preliminary numerical results of ozone and other key chemical atmospheric pollutant concentrations and distribution across the Houston-Galveston-Brazoria area using virtual emission data from area and mobile sources are presented.

Construction and identification of a single stranded cDNA clone containing full-length genome of hepatitis G virus

AIM

To construct a single cDNA clone with full-length genome of hepatitis G virus (HGV) could be transcribed and expressed in vitro.

METHODS

The 5 initial HGV cDNA fragments of Iw5, Iwq2, Iwh6, Iw3 and Iw3 used in this study were amplified from serum of a Japanese non A-E hepatitis patient. These fragments overlapped and covered the entire genome from 5'-end to 3'-end of HGV cDNA. Overlap extension PCR and ligation methods were used with 12 primers for the construction of a full-length genomic HGV cDNA clone from the subgenomic fragments.

RESULTS

A single HGV cDNA clone (pHGVqz) was successfully constructed, physical mapping of the generated pHGVqz found identical to what we expected, and the sequence was deposited with the GenBank under the Accession number AF081782. The analysis of the full-length sequence, which was able to be in vitro transcribed and expressed, showed that this single clone contained 9373 nucleotides (encoding 2873 amino acids), and shared high homologies with other compared HGV isolates.

CONCLUSION

A full-length genomic HGV cDNA clone is generated for the first of the kind in this study, it could be expressed and transcripted. This single cDNA clone is expected to be of importance in the investigation on replication and pathogenicity of HGV.

Heme oxygenase1 (HSP-32) is induced in myelin-phagocytosing Schwann cells of injured sciatic nerves in the rat

Schwann cells participate in myelin phagocytosis in the early stage of Wallerian degeneration, prior to the recruitment of macrophages. This is the first report that Schwann cells induce heme oxygenase-1 (HO-1), a 32-kDa heat shock protein, only when they have transformed into myelin-phagocytosing cells from myelinating cells (days 2-3) immediately after crush injury of rat sciatic nerves. Double immunofluorescent labelling for HO-1 and transferrin receptors revealed that HO-1-immunoreactive Schwann cells also expressed transferrin receptors suggesting activation of iron metabolism. The transient induction of HO-1 in Schwann cells may contribute to the adaptive function in an altered environment when the cells have lost contact with axons, and may play a crucial role in the ensuing regeneration.

Morphological features of nerve terminal degeneration as part of the remodeling process in the motor endplate in adult muscles

With the exception of signs of retraction and withdrawal, there have been few morphological data concerning degenerated neural profiles in adult motor endplates. Here, investigation into the ultrastructure of the soleus motor endplates of adult rats (4 months old) turned up particular axonal degeneration in approximately 3% of the subjects. These axons occur as synaptic debris in the synaptic matrix of the motor endplate, adjacent to thin processes of the perisynaptic cells occupying the outermost layer of the motor endplate and were devoid of basal lamina. They often possessed dense-cored vesicles (50-80 nm). Axonal debris released from Schwann cell processes occurred during the period of acute sciatic neurectomy, when nerve terminals progressively disrupted within the motor endplate-associated Schwann cells. Finally, immunohistochemical staining for antibodies to label macrophages (ED1 or ED2) has shown that nerve fiber-associated macrophages are located near the motor endplate. The results suggest that during the course of endplate remodeling, a few parts of the terminal branches are disposed of through spontaneous collapse, subsequent release from the Schwann cell investment, and eventual ingestion by macrophages in the perisynaptic space.

An improved method for avulsion of lumbar nerve roots as an experimental model of nitric oxide-mediated neuronal degeneration

A root avulsion lesion on the spinal nerve of adult animals is a useful technique to make a model for axotomy-induced motoneuronal degeneration, which is thought to be mediated by nitric oxide (NO). Here, we show a simplified version of extravertebral avulsion in the young adult rat. The L4 nerve always runs under the transverse process of the L5 vertebra, which is located just rostral to the delineation of the iliac crest. We used the iliac crest as a clue for the identification of the L4 nerve during surgery, including before skin incision. In almost all animals the L4 nerve was successfully avulsed at the exit point from the spinal cord. This experimental result was similar to that shown in the previous literature; the number of either Nissl-stained or ChAT-immunoreactive (-ir) motoneurons (MN) gradually decreased, while NOS immunoreactivity was induced in the MN after avulsion. Furthermore, a combined method of confocal laser scanning microscopy and double fluorescent procedures carried out in this model suggested the existence of cellular interaction between NOS-ir MN and OX42-ir or ED1-ir microglia. It is concluded that this simple and fast method of spinal root avulsion is very useful for making a reproducible model of NO-mediated MN cell death, with which the mechanism of neuronal cell death, including neuron-glia interaction, can be further explored.

A novel hepatitis B virus variant S 129 (Gln-->Leu): lack of correlation between antigenicity and immunogenicity

A point mutation has been detected in the "a" determinant of hepatitis B surface antigen (HBsAg) in an infant immunised with hepatitis B vaccine after exposure to hepatitis B virus (HBV). This A-to-T point mutation at nucleotide 540 resulted in a glutamine-to-leucine substitution at amino acid residue 129 (129L). The S gene fragment (nucleotide 58-1072) of this isolate was cloned and used to substitute the wild-type S gene in a plasmid (p3.8II), containing 1.2 copy of full-length HBV genome with expression and replication efficiency. This plasmid p3.8II-129L was used to transfect HepG2 cells. HBsAg expressed by p3.8II-129L showed higher binding efficiency compared with the original plasmid containing the wild-type clone. A panel of 24 anti-HBs monoclonal antibodies (MAbs) was used to characterise the binding efficiency of HBsAg expressed by p3.8II-129L. Eighteen showed higher binding to the antigen, whereas HBsAg expressed by p3.8II-145R gave a consistently lower absorbance or were negative. Surprisingly, when the immunogenicity of plasmid constructs was used for DNA immunisation in Balb/c mice, the anti-HBs response induced by p3.8II-129L was significantly lower than that of the wild-type p3.8II. The lack of correlation between the antigenicity profile (binding of expressed HBsAg to anti-HBs in vitro), and the immunogenicity (induction of anti-HBs by plasmid DNA in vivo) of HBsAg with leucine substitution at position 129 indicates that biological characteristics other than the binding efficiency of HBsAg to anti-HBs could occur in HBsAg variants. These different aspects of the biological characteristics of S mutants merit further investigation.

Changes in the distribution of peanut agglutinin (PNA) binding molecules during muscle reinnervation following nerve crush injury

Peanut agglutinin (PNA) staining during muscle reinnervation following a crushing injury of the sciatic nerve was performed in reference to the neural profiles immunolabeled with the PGP 9.5 antibody. PNA staining in the normal controls exhibited dots, granules, or lines along the length of the nerve fibers in the nerve trunk, but was faint or absent in the motor endplate. At seven days post-crush, PNA staining was detected around the vacuolated neural structures in the disorganized nerve trunk, but was still faint or absent in the motor endplate. At twenty-one days post-crush, when PGP 9.5-positive regenerating axons appeared in most of the motor endplates, PNA staining, either faint or strong, followed the pathway of the nerve fibers delineated by PGP 9.5-like immunoreactivity. During reinnervation to the motor endplates, PNA staining displayed signs of remodeling in the nerve trunk, such as marked variations in density and profile in the nerve fiber-associated dots or patches; it increased in intensity in the connective tissue covering the area of the motor endplate, as well as in the junctional myofiber surface. The structures recognizable by PNA coincided with components of the connective tissue such as collagen fibers and capillaries. Results suggest that: 1) the expression of PNA-binding molecules is dependent on the state of innervation, and 2) the spatiotemporal relationship between neural profiles and PNA staining provides sequences of axonal extension and subsequent nerve terminal maturation during regeneration in the motor endplate.

Differential response of macrophage subpopulations to myelin degradation in the injured rat sciatic nerve

Molecular mechanisms of myelin removal by macrophages were explored by examining the immunophenotypes of macrophages following injury of rat sciatic nerve, using a combined method of immunohistochemistry and confocal laser microscopy. In the crush injury model, the involvement in myelin clearance of a cytoplasmic antigen specific for monocytes/macrophages, ED1, was evident. The obvious recruitment of ED1-immunoreactive (-ir) cells was detected first at the crush injury site and then in the distal stump within which Wallerian degeneration had occurred. Double labelling revealed that the ED1-ir cells, except for monocyte-like round cells, always phagocytosed myelin basic protein-ir myelin debris. On the other hand, the expression of ED2, a surface antigen specific for resident macrophages, was significantly different; ED2-ir cells also increased while myelin removal was progressing from day 3 to day 7, but only some of the cells were engaged in myelin phagocytosis. The poor capacity of myelin phagocytosis by ED2-ir cells was supported by the transection model, in which the proximal stump was ligated to suppress regeneration. ED2 may be involved in events other than myelin removal, providing a local environment conducive to axonal regeneration. Our findings thus seem to suggest that ED1 is one of the most reliable markers for cells carrying out myelin phagocytosis, whereas ED2 may participate in entirely different functions. The expression of complement receptor type 3, OX42, was similar to that of ED1 in terms of the swift recruitment of immunopositive cells, their distribution with close association to myelin debris and their high phagocytotic capacity. This supports previously reported in vitro evidence that myelin phagocytosis by macrophages may be complement-mediated.

Mutations in the 'a' determinant of hepatitis B surface antigen among Chinese infants receiving active postexposure hepatitis B immunization

Twenty-four infants who became positive to the surface antigen of hepatitis B virus (HBsAg) despite a complete course of active postexposure immunization with plasma derived hepatitis B vaccine were studied. The polymerase chain reaction amplified products of the common neutralizing epitope 'a' determinant of HBsAg (Nucleotide 419-598) from serum samples were sequenced and analyzed for nucleotide mutations. Four cases (16.7%) had mutations that led to amino acid substitutions between codons 124 and 147. Only one case (N1) showed a substitution at codon 145 (from glycine to arginine, 145R), the other three were at codons 126-129. The mother of N1 was co-infected with the wild type and the mutant virus. Five years later, serum of N1 showed only the wild type virus. There was no significant relationship between the mutation rate and the anti-HBs response to hepatitis B vaccination. Results suggest that without immune selective pressure, 145R variant was not frequently observed, and was not stable. Mutation in the 'a' determinant was not an important cause of failure to prevent maternal-infant transmission of HBV by active postexposure hepatitis B immunization in Chinese children.

Partial structural determination of hepatotoxic peptides from Microcystis aeruginosa (cyanobacterium) collected in ponds of central China

Waterbloom samples of the colonial cyanobacterium Microcystis aeruginosa, collected in fish ponds at the Hydrobiological Institute, Wuhan, People's Republic of China, were hepatotoxic to mice. Lyophilized cells had an LD50 (i.p. mouse; 40 mg/kg) and signs of poisoning similar to that reported for other cyanobacterial hepatotoxic peptides. Two toxins, with an LD50 (i.p. mouse) of 40 and 150 micrograms/kg, were isolated using gel filtration and high performance liquid chromatography. The amino acid composition and mol. wt (994) of the 40 micrograms/kg toxin was the same as that for microcystin-LR, while the 150 micrograms/kg toxin had an amino acid composition and mol. wt (1048) different from any of the reported cyanobacteria heptapeptide toxins reported to date.