Tubular Cell and HIV-1 gp120 Interaction Products Promote Migration of Monocytes

Renal interstitial accumulation of monocytes is an important feature of HIV-associated nephropathy. We studied the effects of proximal tubular cell products (TCP) and proximal tubular cell-gp120 interaction products (TC-120IP) on the migration of monocytes across a modified Boyden chamber. TC-120IP promoted (P<0.001) the migration of monocytes when compared with TCP (TCP, 45.0 ± 5.9 vs. TC-120IP, 192.3 ± 39.5 migrated monocytes/field). This effect of TC-120IP on monocyte migration was dose dependent. Anti-MCP-1 (TCP, 24.7 ± 2.6; TC-120IP, 82.3 ± 5.5; TC120-IP + anti-MCP-1 antibody, 46.5 ± 3.5 migrated monocytes/field) as well as anti-TGF- antibodies (TCP, 25.8 ± 3.4; TC120-IP, 80.3 ± 6.9; TC-120IP + anti-TGF- antibody, 43.8 ± 5.6 migrated monocytes/field) partly attenuated TC-120IP-induced migration of monocytes across a filter. Moreover, anti-MCP-1 and anti-TGF antibodies showed an additive inhibitory effect on TC-1201P-induced migration of monocytes across a filter. These results suggest that TC-120IP-induced migration of monocytes may be mediated through the generation of MCP-1 and TGF- by tubular cells. The present study provides the basis for a hypothesis that HIV-1 gp120 protein may be contributing to the infiltration of monocytes in the renal interstitium of patients with HIV-associated nephropathy.     

Morphine Stimulates Mesangial Cell TNF-α and Nitrite Production

Background: Intravenous opiate abusers are susceptible to develop heroin and HIV-associated nephropathies; however, the role of opiates in the development of these kidney lesions is not clear. Patients with opiate addiction are prone to recurrent infections. Methods: The effect of morphine was studied on the generation of TNF- with or without LPS (lipopolysaccharide) by cultured mouse mesangial cells. In addition, the effect of morphine was evaluated on mesangial cell nitrite production. To evaluate the role of opiate receptors, we studied the effect of naloxone and naltrexone on mesangial cell TNF- and nitrite production. To determine the role of TNF- on mesangial cell nitrite production, we examined the effect of anti-TNF- antibody on morphine-induced nitrite production. Assay of TNF- and nitrite production was carried by ELISA and Griess method respectively. Results: Morphine alone did not enhance the generation of TNF- by mesangial cells, however, an enhanced (P < 0.001) TNF- production was observed when mesangial cells were first treated with morphine for 18 h and then activated further with LPS. Maximum release of TNF- was seen at a concentration of 10^–12 M of morphine. Opiate receptor antagonists (naloxone and naltrexone) inhibited the effect of morphine. Morphine also amplified (P < 0.0002) the effect of LPS on mesangial cell nitrite production. Anti-TNF- antibody attenuated morphine induced nitrite generation. Conclusion: We conclude that morphine stimulates the generation of TNF- by LPS-activated mesangial cells. This effect of morphine seems to be opiate receptor mediated and has a downstream effect in the form of mesangial cell nitrite generation. The present in vitro study provides the basis for a hypothesis that morphine may be playing a role in the development of heroin and HIV-associated nephropathies.     

Fas-mediated apoptosis of neutrophils in sera of patients with infection

In the presence of infection, neutropenia is considered to be a marker of poor prognosis; conversely, neutrophilia may not be a determinant of a better prognosis. Since apoptotic neutrophils are compromised functionally, we evaluated the effect of infection on neutrophil apoptosis. The rate of apoptosis was greater for neutrophils isolated from patients with infection than for healthy controls. Escherichia coli did not directly modulate the rate of neutrophil apoptosis. However, sera from infected patients promoted (P < 0.001) neutrophil apoptosis. Interestingly, the sera of patients with different types of infection (gram negative, gram positive, or culture negative) exerted a more or less identical response on neutrophil apoptosis. Sera of infected patients showed a fivefold greater content of FasL compared to controls. Moreover, anti-FasL antibody partly attenuated the infected-serum-induced neutrophil apoptosis. In in vitro studies, E. coli enhanced monocyte FasL expression. Moreover, conditioned media prepared from activated macrophages from control mice showed enhanced apoptosis of human as well as mouse neutrophils. On the contrary, conditioned media prepared from activated macrophages isolated from FasL-deficient mice induced only a mild degree of neutrophil apoptosis. These results suggest that neutrophils in patients with infection undergo apoptosis at an accelerated rate. Infection not only promoted monocyte expression of FasL but also increased FasL content of the serum. Because the functional status of apoptotic cells is compromised, a significant number of neutrophils may not be participating in the body's defense. Since neutrophils play the most important role in innate immunity, their compromised status in the presence of infection may transfer the host defense burden from an innate response to acquired immunity. The present study provides some insight into the lack of correlation between neutrophilia and the outcome of infection.     

Tubular cell senescence and expression of TGF-beta1 and p21(WAF1/CIP1) in tubulointerstitial fibrosis of aging rats

Kidney aging has been recognized as a chronic process of compromised renal function and structural changes in the tubulointerstitium and glomerulus. Cell senescence is associated with alterations in cell structure and function, including expression of cytokines and structural and regulatory components of extracellular matrix proteins. In this investigation, we tested the hypothesis that senescent renal cells may accumulate in vivo with advancing age. We also evaluated the expression of transforming growth factor (TGF)-beta1 and p21WAF1/CIP1 in aging kidneys. Sprague-Dawley rats at the ages of 3, 12, and 24 months were used for this study. Renal tissues were processed for morphometric and senescence analysis. Expression of TGF-beta1 and p21WAF1/CIP1 was evaluated by Northern or Western blot analysis and immunohistochemistry. Substantial tubulointerstitial injury occurred at the age of 12 months, but significant glomerular structure alteration was observed at the age of 24 months. Tubular cells developed senescence, which was detected by beta-galactosidase staining. This staining increased in frequency and intensity with age. Renal cortices showed a significant increase in the mRNA expression for TGF-beta1 and protein level for p21WAF1/CIP1. The enhanced expression of TGF-beta1 and p21WAF1/CIP1 was localized in the tubulointersititial cells. These data suggest that tubular cells undergo senescence and express increased TGF-beta1 and p21WAF1/CIP1 with advancing age. These age-related cellular and molecular alterations may play an important role in the initiation and/or progression of tubulointerstitial fibrosis and glomerulosclerosis in aging.     

Double ProGlide preclose technique for vascular access closure after leadless pacemaker implantation

Journal of Interventional Cardiac Electrophysiology - The use of vascular closure devices in patients receiving the Micra leadless pacemaker may shorten time to ambulation, facilitate same-day...     

Bottom-up analysis of emergent properties of N-acetylcysteine as an adjuvant therapy for COVID-19

N-acetylcysteine (NAC) is an abundantly available antioxidant with a wide range of antidotal properties currently best studied for its use in treating acetaminophen overdose. It has a robustly established safety profile with easily tolerated side effects and presents the Food and Drug Administration's approval for use in treating acetaminophen overdose patients. It has been proven efficacious in off-label uses, such as in respiratory diseases, heart disease, cancer, human immunodeficiency virus infection, and seasonal influenza. Clinical trials have recently shown that NAC's capacity to replenish glutathione stores may significantly improve coronavirus disease 2019 (COVID-19) outcomes, especially in high risk individuals. Interestingly, individuals with glucose 6-phosphate dehydrogenase deficiency have been shown to experience even greater benefit. The same study has concluded that NAC's ability to mitigate the impact of the cytokine storm and prevent elevation of liver enzymes, C-reactive protein, and ferritin is associated with higher success rates weaning from the ventilator and return to normal function in COVID-19 patients. Considering the background knowledge of biochemistry, current uses of NAC in clinical practice, and newly acquired evidence on its potential efficacy against COVID-19, it is worthwhile to investigate further whether this agent can be used as a treatment or adjuvant for COVID-19.     

Spinal extradural solitary fibrous tumor with retiform and papillary features

We report a 66-year-old man with a spinal, extradural solitary fibrous tumor showing unique retiform and papillary architecture. The patient presented in May 2008 with worsening right-sided lower back pain and urinary frequency. Magnetic resonance imaging of the spine documented a heterogeneously enhancing dumbbell-shaped extradural lesion causing cord compression at T11/12 level. The tumor extended to the paravertebral soft tissue and invaded the right adjacent vertebral pedicles and laminae. An angiogram showed prominent vascular supply mainly from the right T11 radicular artery. The patient underwent surgery to relieve cord compression in May 2008 and a second operation following embolization with coils in October 2009. No recurrence was observed at the last neuroimaging follow-up in June 2012. The tumor was composed of vimentin, CD34, Bcl-2, and CD99-positive rounded or slightly elongated cells with scant cytoplasm and oval to spindle nuclei. Several pseudovascular spaces reminiscent of the rete testis were present, and several of them contained papillary projections. Cytologic atypia was minimal, and mitotic activity was low. Focal infiltration of the paraspinal adipose tissue was seen at microscopic level. To our knowledge, retiform and papillary features have never been reported in a solitary fibrous tumor.     

The Effect of Storage and Extraction Methods on Amplification of Plasmodium falciparum DNA from Dried Blood Spots

Extraction and amplification of DNA from dried blood spots (DBS) collected in field studies is commonly used for detection of Plasmodium falciparum. However, there have been few systematic efforts to determine the effects of storage and extraction methods on the sensitivity of DNA amplification. We investigated the effects of storage conditions, length of storage, and DNA extraction methods on amplification via three PCR-based assays using field samples and laboratory controls. Samples stored as DBS for 2 or more years at ambient temperature showed a significant loss of sensitivity that increased with time; after 10 years only 10% samples with parasite densities > 1,000 parasites/μL were detectable by nested polymerase chain reaction (PCR). Conversely, DBS and extracted DNA stored at −20°C showed no loss of sensitivity with time. Samples with low parasite densities amplified more successfully with saponin/Chelex compared with spin-column-based extraction, though the latter method performed better on samples with higher parasite densities stored for 2 years at ambient temperature. DNA extracted via both methods was stable after 20 freeze-thaw cycles. Our results suggest that DBS should be stored at −20°C or extracted immediately, especially if anticipating 2 or more years of storage.     

Prediction of primary vs secondary hypertension in children

Despite current guidelines, variability exists in the workup of hypertensive children due to physician preferences. The study evaluates primary vs secondary hypertension diagnosis from investigations routinely performed in hypertensive children. This retrospective study included children 5 to 19 years with primary and secondary hypertension. The proportions of abnormal laboratory and imaging tests were compared between primary and secondary hypertension groups. Risk factors for primary vs secondary hypertension were evaluated by logistic regression and likelihood function analysis. Patients with secondary hypertension were younger (5-12 years) and had a higher proportion of abnormal creatinine, renal ultrasound, and echocardiogram findings. There was no significant difference in abnormal results of thyroid function, urine catecholamines, plasma renin, and aldosterone. Abnormal renal ultrasound findings and age were predictors of secondary hypertension by regression and likelihood function analysis. Children aged 5 to 12 years with abnormal renal ultrasound findings and high diastolic blood pressures are at higher risk for secondary hypertension that requires detailed evaluation.