Breastfeeding vs. breast milk transmission during COVID-19 pandemic, which is more important?

The catastrophic coronavirus disease 2019 (COVID-19) pandemic has raised many health questions, and whether breast milk from SARS-CoV-2 infected mothers may be a vector for SARS-CoV-2 transmission has become a hot topic of concern worldwide. Currently, there are extremely limited and conflicting data on the risk of infection in infants through breastfeeding. For this reason, we investigated almost all current clinical studies and systematically analyzed the presence of SARS-CoV-2 and antibodies in the breast milk of mothers infected with SARS-CoV-2, their effects on newborns, and the mechanisms involved. A total of 82 studies were included in this review, of which 66 examined the presence of SARS-CoV-2 in breast milk samples from mothers diagnosed with COVID-19, 29 reported results of antibody detection of SARS-CoV-2 in breast milk, and 13 reported both nucleic acid and antibody test results. Seventeen studies indicated the presence of detectable SARS-CoV-2 nucleic acid in breast milk samples, and only two studies monitored viral activity, both of which reported that infectious viruses could not be cultured from RNA-positive breast milk samples. All 29 studies indicated the presence of at least one of the three antibodies, IgA, IgG and IgM, in breast milk. Five studies indicated the presence of at least one antibody in the serum of breastfed newborns. No COVID-19-related deaths were reported in all 1,346 newborns. Our study suggests that direct breastfeeding does not pose an additional risk of infection to newborns and that breast milk is a beneficial source of anti-SARS-CoV-2 antibodies that provide passive immune protection to infants. In addition, direct breastfeeding would provide maternal benefits. Our review supports the recommendation to encourage direct breastfeeding under appropriate infection control guidelines. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier: 458043.

Correlation between COVID-19 vaccination and diabetes mellitus: A systematic review.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is one of the current global public health threats and vaccination is the most effective tool to reduce the spread and decrease the severity of COVID-19. Diabetes is one of the important chronic diseases threatening human health and is a common comorbidity of COVID-19. What is the impact of diabetes on the immunization effect of COVID-19 vaccination? Conversely, does vaccination against COVID-19 exacerbate the severity of pre-existing diseases in patients with diabetes? There are limited and conflicting data on the interrelationship between diabetes and COVID-19 vaccination. AIM: To explore the clinical factors and possible mechanisms underlying the interaction between COVID-19 vaccination and diabetes. METHODS: We conducted a comprehensive search of PubMed, MEDLINE, EMBASE, and Reference Citation Analysis (https://www.referencecitationanalysis.com) online databases, and medRxiv and bioRxiv gray literature using the keywords "SARS-CoV-2", "COVID-19", "vaccine", "vaccination", "antibody", and "diabetes" individually or in combination, with a cut-off date of December 2, 2022. We followed inclusion and exclusion criteria and after excluding duplicate publications, studies with quantifiable evidence were included in the full-text review, plus three manually searched publications, resulting in 54 studies being included in this review. RESULTS: A total of 54 studies were included, from 17 countries. There were no randomized controlled studies. The largest sample size was 350963. The youngest of the included samples was 5 years old and the oldest was 98 years old. The included population included the general population and also some special populations with pediatric diabetes, hemodialysis, solid organ transplantation, and autoimmune diseases. The earliest study began in November 2020. Thirty studies discussed the effect of diabetes on vaccination, with the majority indicating that diabetes reduces the response to COVID-19 vaccination. The other 24 studies were on the effect of vaccination on diabetes, which included 18 case reports/series. Most of the studies concluded that COVID-19 vaccination had a risk of causing elevated blood glucose. A total of 12 of the 54 included studies indicated a "no effect" relationship between diabetes and vaccination. CONCLUSION: There is a complex relationship between vaccination and diabetes with a bidirectional effect. Vaccination may contribute to the risk of worsening blood glucose in diabetic patients and diabetic patients may have a lower antibody response after vaccination than the general population.

Carbon quantum dot fluorescent probe for labeling and imaging of stellate cell on liver frozen section below freezing point.

The targeted labeling imaging of stellate cells on liver frozen section by immunofluorescence is a very promising visualization technique to study the distribution of stellate cells in the liver. In this study, water soluble carbon quantum dots that can emit blue, green and yellow fluorescence are synthesized by the hydrothermal method, and their sizes are 3.2, 3.7, and 4.3 nm, respectively. The three carbon quantum dots have good fluorescence stability, and the quantum yields are 36.1%, 26.3% and 21%, respectively. When the mass fraction of KCl in the blue carbon quantum dot dispersion system is 13%, it still maintains the liquid state at -30 °C. The final fluorescent probe is obtained after the carbon quantum dots are coupled with the secondary antibody, spectral characterizations confirm that the conjugate probe still maintains protein immunoactivity and has good stability. Cell experiments prove that the probe has good biocompatibility, the rabbit anti-mouse Desmin antibody is used as the primary antibody, the results of cellular immunofluorescence imaging and flow cytometry show that the probe can specifically label hepatic stellate cell at -20 °C. The results of liver frozen section experiments show that hepatic stellate cell can be specifically targeted and labeled by the fluorescent probe. This labeling technology provides an important technical means for elucidating the structure and function of the liver at the cellular level, exploring the liver pathological change, and designing and developing drug.

Simultaneous labeling and multicolor fluorescence imaging of multiple immune cells on liver frozen section by polychromatic quantum dots below freezing points.

A method for simultaneous labeling and multicolor fluorescence imaging of different hepatic immune cells below freezing point is established based on quantum dots. In the experiment, carbon quantum dots with emission wavelength of 435 nm, CdTe@CdS quantum dots at 542 nm and CdSe@ZnS quantum dots at 604 nm are synthesized respectively, it is found that when the mass fractions of KCl (as antifreeze) are 12 %, 14 %, and 12 %, respectively, the three quantum dot dispersion systems remain liquid state at -20 °C. After they are conjugated with the corresponding secondary antibodies, agarose gel electrophoresis, circular dichroism and capillary electrophoresis confirm the effectiveness of conjugation. By indirect immunofluorescence method, the above three quantum dot fluorescent probes are used to simultaneously and specifically target a variety of liver immune cells, and the multi-color simultaneous imaging of different liver immune cells is realized under the same excitation wavelength, it is found that hepatic macrophages are arranged radially in the liver, hepatic stellate cells present punctate distribution, and hepatic sinusoidal endothelial cells present circular distribution, which is consistent with the results of H&E staining and ultrathin section TEM. This study provides an important technical means for elucidating the structure and function of the liver.

Correlation between COVID-19 and hepatitis B: A systematic review.

BACKGROUND: There is growing evidence that patients with coronavirus disease 2019 (COVID-19) frequently present with liver impairment. Hepatitis B virus (HBV) remains a major public health threat in current society. Both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HBV can cause liver damage, and current findings on whether HBV infection increases disease severity in COVID-19 patients are inconsistent, and whether SARS-CoV-2 infection accelerates hepatitis B progression or leads to a worse prognosis in hepatitis B patients has not been adequately elucidated. AIM: To explore the complex relationship between COVID-19 and hepatitis B in order to inform the research and management of patients co-infected with SARS-CoV-2 and HBV. METHODS: An experienced information specialist searched the literature in the following online databases: PubMed, China National Knowledge Infrastructure, Google Scholar, Scopus, Wiley, Web of Science, Cochrane, and ScienceDirect. The literature published from December 2019 to September 1, 2022 was included in the search. We also searched medRxiv and bioRxiv for gray literature and manually scanned references of included articles. Articles reporting studies conducted in humans discussing hepatitis B and COVID-19 were included. We excluded duplicate publications. News reports, reports, and other gray literature were included if they contained quantifiable evidence (case reports, findings, and qualitative analysis). Some topics that included HBV or COVID-19 samples but did not have quantitative evidence were excluded from the review. RESULTS: A total of 57 studies were eligible and included in this review. They were from 11 countries, of which 33 (57.9%) were from China. Forty-two of the 57 studies reported abnormalities in liver enzymes, three mainly reported abnormalities in blood parameters, four indicated no significant liver function alterations, and another eight studies did not provide data on changes in liver function. Fifty-seven studies were retrospective and the total number of co-infections was 1932, the largest sample size was 7723, and the largest number of co-infections was 353. Most of the studies suggested an interaction between hepatitis B and COVID-19, while 12 studies clearly indicated no interaction between hepatitis B and COVID-19. Six of the 57 studies clearly reported HBV activation. Six studies were related to liver transplant patients. CONCLUSION: There is some association between COVID-19 and hepatitis B. Future high-quality randomized trials are needed to further elucidate the interaction between COVID-19 and hepatitis B.

Terminal deoxynucleotidyl transferase associated with split G-quadruplex/hemin deoxyribozyme amplification detection for various contaminants in milk based on pregnancy test strip platform.

Contaminant residue analysis in milk can provide essential assistance for safety quality and contamination level management of milk production, which is critical for safeguarding public health. In this study, the pregnancy test strip is employed to achieve multiple analytes detection based on the specific recognition of aptamer and terminal deoxynucleotidyl transferase associated with split G-quadruplex/hemin deoxyribozyme system. Through the subsequent enzyme catalyzed reaction, the detection signal can be further amplified to improve the sensitivity. The method does not need to assemble test strip, prepare and purify antibodies/haptens, nor design complex probe sequences. By coupling human chorionic gonadotrophin with DNA probes and combining magnetic separation technology, the targets can be determined via the test strip. Under the optimized conditions, the visual detection limits for mercury ion, bisphenol A, and penicillin are 1, 0.1 and 0.05 nM, respectively. The detection results show that the method displays good accuracy and practicability in spiked milk sample. The method presents a simple scheme, low cost as well as good design versatility, which demonstrates great application prospect for the sensitive, low-cost, and convenient detection of food matrices.

A simple fluorescent strategy for liver capillary labeling with carbon quantum dot-lectin nanoprobe.

Taking the hepatic sinusoid (HS) as the main delivery area of liver nutrients and metabolic waste, recognizing its structure is important for a deep understanding of liver function. In this paper, based on lycopersicon esculentum lectin (LEL), with targeting ability for endothelial cells, and carbon quantum dots (CQDs), with high biosafety, an LEL-coupled CQD immunofluorescence probe (CQD@LEL) that can label microvessels is designed and used for the fluorescence labeling and imaging of HS in liver tissue sections. The CQD size is approximately 2 nm. Blue fluorescence is emitted under excitation; its optimal excitation wavelength is 400 nm while the emission is at about 450 nm. Gel electrophoresis and capillary electrophoresis confirm that glutaraldehyde can couple LEL to CQD, and the obtained CQD@LEL retains the fluorescence property and has good stability. Optimization experiments show that its labeling effect is positively correlated with time and probe concentration for dyeing the blood vessels of mouse liver slices. In order to improve the effect further, a probe concentration of 0.17 mg mL-1 and incubation time of 3 h were chosen to label the liver tissue sections. The results show that the liver microvessels are formed by interstitial structures among the hepatic cords, and the HS presents a granular or patchy appearance. H&E and ultrathin section TEM show that the microvascular wall of the liver is composed of discontinuous endothelial cells, and there are Kupffer cells and other cells in the tubes, proving that our probe can clearly label the structure and morphology of liver microvessels. This work is of great significance for the visualization of HS.

CdTe@CdS quantum dots for labeling and imaging macrophages in liver frozen sections below the freezing point.

CdTe@CdS core-shell quantum dots with different particle sizes are synthesized by an aqueous method, and coating them with a CdS shell layer improves the quantum yield (36% → 59%) and fluorescence stability (37% → 77%) of CdTe@CdS quantum dots. When the KCl concentration (mass fraction) in the system is 15%, the CdTe@CdS quantum dot dispersion system remains in the liquid state at -20 °C, and the low temperature increases the fluorescence intensity. A QD-Ab probe is obtained after CdTe@CdS quantum dots are coupled with IgG; the circular dichroism shows that the IgG protein structure is not destroyed, while capillary electrophoresis, agarose gel electrophoresis and flow cytometry verify the conjugation efficiency. With rabbit anti-mouse EMR1 antibody as the primary antibody and QD-Ab as the secondary antibody, the hepatic macrophages in liver frozen sections are fluorescently labeled at -20 °C, and it is found that they are radially distributed in hepatic sinusoids with specific and highly efficient labeling; these results are verified by H&E staining and TEM. This technology can provide important technical support for in-depth understanding of the distribution of liver immune cells in the liver, and it can further provide a scientific basis to understand the relationship between the liver structure and function and pathological changes.

[Cistanches tubulosa water extract protects the testis against cyclophosphamide-induced injury: Effect and mechanism].

OBJECTIVE: To investigate the protective effect of Cistanche tubulosa water extract (CTWE) against cyclophosphamide (CTX)-induced testis injury (TI) in mice and its action mechanism. METHODS: Thirty male mice were equally randomized into a normal control, a CTX-induced TI model control and a CTWE treatment group. After 7 days of adaptive feeding, the mice in the CTWE treatment group were treated intragastrically with CTWE at 10 g/kg/d, those in the normal control and TI model control groups with the same volume of normal saline qd all for 35 successive days, and those in the TI model control and CTWE treatment groups by intraperitoneal injection of cyclophosphamide at 80 mg/kg/d at 7, 14, 21, 28 and 35 days. Then all the animals were weighed, blood samples collected, and their testes and epididymides harvested for detection of the serum T content, examination of semen quality, measurement of testis weight, observation of histopathological changes in the testis, and determination of the levels of super oxide dismutase (SOD) and malondialdehyde (MDA) in the testis tissue and the mRNA expressions of the genes related to the nuclear factor erythroid-2-related factor (Nrf2) signaling pathway. RESULTS: The mice in the TI model control group, compared with the normal controls, showed significant decreases in the body weight (ï¼»34.13 ± 1.56ï¼½ vs ï¼»47.08 ± 1.98ï¼½ g, P < 0.05), testis weight (ï¼»81.82 ± 10.61ï¼½ vs ï¼»148.50 ± 14.82ï¼½ mg, P < 0.05), sperm concentration (ï¼»32.60 ± 5.29ï¼½ vs ï¼»78.90 ± 7.95ï¼½ ×106/ml, P < 0.05), sperm motility (ï¼»45.20 ± 7.09ï¼½% vs ï¼»86.70 ± 5.64ï¼½%, P < 0.05), serum T content (ï¼»7.49 ± 1.03ï¼½ vs ï¼»15.93 ± 1.36ï¼½ ng/L, P < 0.05), and SOD level (ï¼»152.22 ± 10.66ï¼½ vs ï¼»356.10 ± 30.95ï¼½ U/mg prot, P < 0.05), but remarkable increases in the percentage of morphologically abnormal sperm (MAS) (ï¼»39.30 ± 7.36ï¼½% vs ï¼»14.40 ± 3.53ï¼½ %, P < 0.05) and MDA level (ï¼»54.91 ± 5.12ï¼½ vs ï¼»31.71 ± 3.57ï¼½ nmol/mg prot, P < 0.05). The animals treated with CTWE, in comparison with the TI model controls, exhibited markedly increased body weight (ï¼»40.67 ± 2.13ï¼½ vs ï¼»34.13 ± 1.56ï¼½ g, P<0.05), testis weight (ï¼»121.21 ± 17.38ï¼½ vs ï¼»81.82 ± 10.61ï¼½ mg, P<0.05), sperm concentration (ï¼»58.40 ± 9.94ï¼½ vs ï¼»32.60 ± 5.29ï¼½ ×106/ml, P < 0.05), sperm motility (ï¼»72.30 ± 7.51ï¼½ % vs ï¼»45.20 ± 7.09ï¼½ %, P < 0.05), serum T content (ï¼»10.89 ± 1.07ï¼½ vs ï¼»7.49 ± 1.03ï¼½ ng/L, P < 0.05) and SOD level (ï¼»217.69 ± 24.59ï¼½ vs ï¼»152.22 ± 10.66ï¼½ U/mg prot, P < 0.05), but decreased percentage of MAS (ï¼»22.20 ± 6.07ï¼½% vs ï¼»39.30 ± 7.36ï¼½%, P < 0.05) and MDA level (ï¼»36.41 ± 4.27ï¼½ vs ï¼»54.91 ± 5.12ï¼½ nmol/mg prot, P < 0.05). The mRNA expressions of Nrf2, HO-1 and NQO-1 in the testis tissue were significantly down-regulated in the TI model controls compared with those in the normal controls (P < 0.05), and remarkably up-regulated in the CTWE treatment group in comparison with those in the TI model group (P < 0.05), while that of Caspase3 markedly increased in the TI model controls (P< 0.05) and decreased in the CTWE treatment group (P < 0.05). Histopathologically, the testis tissue of the TI model controls showed indistinct outlines from the base of the seminiferous tubule to the lumen surface, with disarranged and reduced layers of spermatogenic cells and decreased number of sperm in the seminiferous tubules, while the structure of the spermatogenic tubules recovered almost to normal in the CTWE treatment group. CONCLUSION: Cistanches tubulosa water extract can effectively inhibit cyclophosphamide-induced testis injury by enhancing the activity of antioxidant enzyme and regulating the expressions of the Nrf2 signaling pathway-related genes.

Labeling of liver cells with CdSe/ZnS quantum dot-based fluorescence probe below freezing point.

In this paper, CdSe/ZnS quantum dots (QDs) with particle size of 5.5 ~ 9.3 nm were synthesized, and the fluorescence emission ranged from 545 ~ 616 nm. When the volume fraction of ethanol was 30%, the water-soluble QD dispersion system remained liquid under -20 °C freezing conditions, the fluorescence intensity increased with a decrease in temperature, and the quantum yield reached 79% at -20 °C. The endothelial cell adhesion molecule CD31 antibody (anti-CD31) was used as the primary antibody, QDs were coupled with IgG as the secondary antibody (QD-Ab), and effective labeling of hepatic sinusoid endothelial cells was achieved at -20 °C. Fluorescence imaging and flow cytometry analysis showed that the labeling efficiency was as high as 97%, indicating that QDs have an important application prospect in microscopic section tomography of the liver.

Clinical characteristics, diagnosis, and treatment of COVID-19: A case report.

BACKGROUND: Since December 2019, many cases of pneumonia caused by novel coronavirus have been discovered in Wuhan, China, and such cases have spread nationwide quickly. At present, coronavirus disease 2019 (COVID-19) is a worldwide pandemic. What are the clinical features of this disease? What is the clinical diagnosis and how should such patients be treated? As a clinician, mastery of the clinical characteristics, basic diagnosis, and treatment methods of COVID-19 are required to provide help to patients. CASE SUMMARY: A 42-year-old male patient with a cough lasting 6 d without obvious cause, as well as fever and fatigue for 1 d, was admitted to Hankou Hospital on January 22, 2020 and transferred to Huoshenshan Hospital on February 4. The main clinical symptoms were dry cough, fatigue, and fever. He was diagnosed with COVID-19. From the 4th d of admission, the patient's condition gradually worsened, with increased respiratory rate and body temperature. Peripheral blood lymphocytes decreased progressively. On the 8th d of admission, the patient's highest temperature was 40.7 °C, and oxygen saturation was 83% despite high-flow oxygen inhalation. Chest computed tomography results showed that the virus progressed rapidly. The number of lesions significantly increased with expanded scope and increased density. The distribution of lesions advanced from peripheral to central. In addition to nasal catheter oxygen inhalation and symptomatic support, antiviral drugs were used throughout the treatment. On January 22, oseltamivir phosphate capsules were given orally (75 mg, twice daily) for 6 d. On January 24, three tablets of lopinavir and ritonavir were added orally (twice daily). After 6 d, this was changed to 0.2 g (two tablets) arbidol, taken orally (three times daily) for 5 d. During the severe stage, methylprednisolone was given (40 mg) once every 12 h, immunoglobulin (20 g) was administered by intravenous drip infusion once daily, and thymosin (1.6 mg) was injected subcutaneously once daily combined with immunotherapy. On February 2, symptoms decreased, various indicators improved, and pulmonary inflammation was obviously reduced. Throat swabs on February 4 and 9 were negative for novel coronavirus nucleic acid. After 19 d in the hospital, the patient was successfully treated and discharged. CONCLUSION: COVID-19 in young adults can be successfully treated with active treatment. We report a typical case of COVID-19, analyze its clinical characteristics, summarize its clinical diagnosis and treatment experience, and provide a reference for clinical colleagues.