Novel Pt(IV) complex OAP2 induces STING activation and pyroptosis via mitochondrial membrane remodeling for synergistic chemo-immunotherapy

Mitochondrial membrane remodeling can trigger the release of mitochondrial DNA (mtDNA), leading to the activation of cellular oxidative stress and immune responses. While the role of mitochondrial membrane remodeling in promoting inflammation in hepatocytes is well-established, its effects on tumors have remained unclear. In this study, we designed a novel Pt(IV) complex, OAP2, which is composed of oxaliplatin (Oxa) and acetaminophen (APAP), to enhance its anti-tumor effects and amplify the immune response. Our findings demonstrate that OAP2 induces nuclear DNA damage, resulting in the production of nuclear DNA. Additionally, OAP2 downregulates the expression of mitochondrial Sam50, to promote mitochondrial membrane remodeling and trigger mtDNA secretion, leading to double-stranded DNA accumulation and ultimately synergistically activating the intracellular cGAS-STING pathway. The mitochondrial membrane remodeling induced by OAP2 overcomes the limitations of Oxa in activating the STING pathway and simultaneously promotes gasdermin-D-mediated cell pyroptosis. OAP2 also promotes dendritic cell maturation and enhances the quantity and efficacy of cytotoxic T cells, thereby inhibiting cancer cell proliferation and metastasis. Briefly, our study introduces the first novel small-molecule inhibitor that regulates mitochondrial membrane remodeling for active immunotherapy in anti-tumor research, which may provide a creative idea for targeting organelle in anti-tumor therapy.

A novel mitochondria-targeting DHODH inhibitor induces robust ferroptosis and alleviates immune suppression

Dihydroorotate dehydrogenase (DHODH)-mediated ferroptosis defense is a targetable vulnerability in cancer. Currently, only a few DHODH inhibitors have been utilized in clinical practice. To further enhance DHODH targeting, we introduced the mitochondrial targeting group triphenylphosphine (TPP) to brequinar (BRQ), a robust DHODH inhibitor, resulting in the creation of active molecule B2. This compound exhibits heightened anticancer activity, effectively inhibiting proliferation in various cancer cells, and restraining tumor growth in melanoma xenografts in mice. B2 achieves these effects by targeting DHODH, triggering the formation of reactive oxygen species (ROS), promoting mitochondrial lipid peroxidation, and inducing ferroptosis in B16F10 and A375 cells. Surprisingly, B2 significantly downregulates PD-L1 and alleviates immune suppression. Importantly, B2 exhibits no apparent adverse effects in mice. Collectively, these findings highlight that enhancing the mitochondrial targeting capability of the DHODH inhibitor is a promising therapeutic approach for melanoma treatment.

Degradation of Hexokinase 2 Blocks Glycolysis and Induces GSDME-Dependent Pyroptosis to Amplify Immunogenic Cell Death for Breast Cancer Therapy

Hexokinase 2 (HK2) is the principal rate-limiting enzyme in the aerobic glycolysis pathway and determines the quantity of glucose entering glycolysis. However, the current HK2 inhibitors have poor activity, so we used proteolysis-targeting chimera (PROTAC) technology to design and synthesize novel HK2 degraders. Among them, C-02 has the best activity to degrade HK2 protein and inhibit breast cancer cells. It is demonstrated that C-02 could block glycolysis, cause mitochondrial damage, and then induce GSDME-dependent pyroptosis. Furthermore, pyroptosis induces cell immunogenic death (ICD) and activates antitumor immunity, thus improving antitumor immunotherapy in vitro and in vivo. These findings show that the degradation of HK2 can effectively inhibit the aerobic metabolism of breast cancer cells, thereby inhibiting their malignant proliferation and reversing the immunosuppressive microenvironment.

2: A Novel Potent Platinum(IV) Prodrug Enhances Chemo-Immunotherapy by Facilitating PD-L1 Degradation in the Cytoplasm and Cytomembrane

Platinum drugs as primary chemotherapy drugs have been applied to various cancer patients. However, their therapeutic applicability is limited due to the adverse effects and immunosuppression. To minimize the side effects and boost the immune response, we designed and synthesized platinum(IV) prodrugs that introduced BRD4 inhibitor JQ-1. Among them, CJ2 had the most potent therapeutic activity and less toxicity. With the introduction of ligand JQ-1, CJ2-reduced PD-L1 protein was found in the cytoplasm and cytomembrane for the first time. By interfering with the PD-L1 synthesis, CJ2 could arouse the immune system and promote CD8+ T cell infiltration. Meanwhile, CJ2 could accelerate PD-L1 degradation in the cytoplasm to block DNA damage repair. In vivo, CJ2 markedly suppressed tumor growth by reversing the immunosuppression microenvironment and enhancing DNA damage. These findings provide an effective approach to improve the selectivity and activity of the platinum drugs with elevated immune response.

Coronary calcification is independently associated with major adverse cardiovascular events in men with recurrent prostate cancer while aortic calcification is not

Background

Cardiovascular disease is an important cause of morbidity and mortality in men with prostate cancer. Coronary and aortic calcification have been associated with major adverse cardiovascular events (MACE) in the general population, and are readily seen on staging cancer positron emission tomography (PET)/computed tomography (CT) scans. The utility of vascular calcification on non-gated CT for cardiovascular risk assessment in men with prostate cancer is not known.

Purpose

We determined the association between coronary and aortic calcification on non-gated CT imaging and MACE in men with prostate cancer.

Methods

We studied 354 men who underwent indium-111 capromab pendetide PET/CT for recurrent prostate cancer at our institution between 2012–2016. Clinical data were obtained from the medical record. Coronary and aortic calcification were qualitatively assessed using a standardized scoring system. The primary outcome of MACE included myocardial infarction, stroke, coronary and/or peripheral revascularization, heart failure hospitalization, and all-cause mortality.

Results

Over 5 years of follow-up, 63 patients (18%) met the primary outcome. Vascular calcification was common in this cohort (median 68 years of age), with 214 patients (60%) having coronary calcification and 296 patients (84%) having aortic calcification. Older patients had greater coronary and aortic calcification, and also higher rate of MACE. In adjusted models for age and diabetes, coronary calcification was associated with higher rate of MACE (hazard ratio [HR] 2.1, interquartile range [IQR] 1.1–4.0, p=0.02) while aortic calcification was not (HR 2.7, IQR 0.8–9.0, p=0.12). Undifferentiated vascular calcification was not associated with MACE (p=0.24).

Conclusions

Coronary calcification on non-gated CT scan is independently associated with MACE in men with recurrent prostate cancer while aortic calcification is not. The presence of coronary calcification should be included in staging PET/CT reports, and this information should prompt implementation of cardiovascular risk modification strategies.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): This study was supported by the Mentors in Medicine Program, Department of Internal Medicine, Washington University School of Medicine.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Predictors of progression from moderate to severe coronavirus disease 2019: a retrospective cohort

OBJECTIVE

Most cases of coronavirus disease 2019 (COVID-19) are identified as moderate, which is defined as having a fever or dry cough and lung imaging with ground-glass opacities. The risk factors and predictors of prognosis in such cohorts remain uncertain.

METHODS

All adults with COVID-19 of moderate severity diagnosed using quantitative RT-PCR and hospitalized at the Central Hospital of Wuhan, China, from 1 January to 20 March 2020 were enrolled in this retrospective study. The main outcomes were progression from moderate to severe or critical condition or death.

RESULTS

Among the 456 enrolled patients with moderate COVID-19, 251/456 (55.0%) had poor prognosis. Multivariate logistic regression analysis identified higher neutrophil count: lymphocyte count ratio (NLR) on admission (OR 1.032, 95% CI 1.042-1.230, p 0.004) and higher C-reactive protein (CRP) on admission (OR 3.017, 95% CI 1.941-4.690, p < 0.001) were associated with increased OR of poor prognosis. The area under the receiver operating characteristic curve (AUC) for NLR and CRP in predicting progression to critical condition was 0.77 (95% CI 0.694-0.846, p < 0.001) and 0.84 (95% CI 0.780-0.905, p < 0.001), with a cut-off value of 2.79 and 25.95 mg/L, respectively. The AUC of NLR and CRP in predicting death was 0.81 (95% CI 0.732-0.878, p < 0.001) and 0.89 (95% CI 0.825-0.946, p < 0.001), with a cut-off value of 3.19 and 33.4 mg/L, respectively.

CONCLUSIONS

Higher levels of NLR and CRP at admission were associated with poor prognosis of individuals with moderate COVID-19. NLR and CRP were good predictors of progression to critical condition and death.

Single Shot Characterization of High Transformer Ratio Wakefields in Nonlinear Plasma Acceleration

Plasma wakefields can enable very high accelerating gradients for frontier high energy particle accelerators, in excess of 10  GeV/m. To overcome limits on single stage acceleration, specially shaped drive beams can be used in both linear and nonlinear plasma wakefield accelerators (PWFA), to increase the transformer ratio, implying that the drive beam deceleration is minimized relative to acceleration obtained in the wake. In this Letter, we report the results of a nonlinear PWFA, high transformer ratio experiment using high-charge, longitudinally asymmetric drive beams in a plasma cell. An emittance exchange process is used to generate variable drive current profiles, in conjunction with a long (multiple plasma wavelength) witness beam. The witness beam is energy modulated by the wakefield, yielding a response that contains detailed spectral information in a single-shot measurement. Using these methods, we generate a variety of beam profiles and characterize the wakefields, directly observing transformer ratios up to R=7.8. Furthermore, a spectrally based reconstruction technique, validated by 3D particle-in-cell simulations, is introduced to obtain the drive beam current profile from the decelerating wake data.

Fish consumption is associated with a decreased risk of death among adults with diabetes: 18-year follow-up of a national cohort

BACKGROUND

There is a paucity of studies examining the beneficial effects of fish consumption on cardiovascular diseases (CVDs) among adults with diabetes, who experience a substantially high risk of CVDs.

METHODS AND RESULTS

We analyzed the data of 1136 adults with diabetes mellitus aged 18 years and older who participated in the National Health and Nutrition Examination Survey, 1988-1994, and were followed up through December 31, 2010. We used Cox regression to estimate the adjusted hazard ratios (HRs) for the relative risk across the levels of fish consumption. A total of 698 deaths were recorded at the end of 11,465 person-years follow-up with a mortality rate of 60.88 per 1000 person-years. CVDs were listed as a contributing cause for 326 deaths, thus accounting for 46.4% of total deaths. Stroke-specific mortality rate among patients who ate fish less than once a week was more than twice as high as that among patients who ate fish more than twice a week, 6.23 vs. 2.36 per 1000 person-years, respectively. The corresponding CVD-specific rate was 34.38 vs. 22.99 per 1000 person-years, respectively. The adjusted HRs of death due to stroke were 1.00 (reference), 0.55 (95% confidence interval = 0.28-1.07), and 0.30 (0.11-0.80) among patients who ate fish <1, 1-2, and 2 + times a week, and the corresponding HRs of death due to CVDs were 1.00 (reference), 0.78 (0.60-1.02), and 0.69 (0.50-0.96), respectively.

CONCLUSIONS

A high consumption of fish was associated with a low risk of death due to CVDs, especially stroke, among adults with diabetes.

A 39-gene signature is associated with early occurrence of distant metastasis in primary lymph-node negative breast cancers

Risk factors of the development of distant metastasis in primary node-negative breast cancer patients are heterogeneous. Identification of patients at high risk of early distant metastasis is of important clinical significance. In the current study, using the already published datasets, we develop a gene signature that can robustly predict early distant metastasis for patients with primary node-negative breast cancer. We identified a 39-gene signature, which were associated with distant metastasis and shorter distant metastasis free survival (DMFS) in node-negative breast cancers. Using the survival prediction analysis method in BRB-Array tools, this signature can stratify patients into early- and late- distant metastasis subgroups with different DMFS in VDX training dataset (AUC=0.734, P < 0.01). And we further validated the reliability of the prognostic value of this 39-gene signature in another two independent breast cancer cohorts (NKI dataset, AUC=0.642, P<0.0167; TRANSBIG dataset, AUC=0.711, P<0.0167). Furthermore, the early distant metastasis subgroups defined by the 39-gene signature exhibited a significant association with ER negative status and more aggressive molecular subtypes in all three datasets, and with poor differentiation status in two datasets. In summary, we developed a novel distant metastasis-related gene signature for predicting early occurrence of distant metastasis in node-negative breast cancers, what might be useful in making treatment decisions for these early metastasis patients.

Molecular events are associated with resistance to vinblastine in bladder cancer

Bladder cancer occurs in the majority of cases in males, which represents the fourth highest incident cancer in men and tenth in women. It is associated with a high rate of recurrence, and prognosis is poor once the cancer metastasizes to distant sites. Transitional cell cancer (TCC) is the most predominant histological type. Bladder cancer is highly chemosensitive. However, the presence of acquired drug resistance is one of the primary impediments to the success of chemotherapy. To differentiate and delineate the molecular events, we developed drug resistant human transitional bladder cancer T24 cells (DRC) by treating cells with the increasing concentration of vinblastine. We found that DRC was resistant to vinblastine in comparison to parental T24 cells. We analyzed the contributory factors that may be involved in the development of resistance. As expected, expression of permeability glycoprotein (P&mdash;gp) was up&mdash;regulated in DRC. In addition, levels of Caveolin&mdash;1 (Cav&mdash;1), Fatty acid synthase (FASN) and Cytochrome P450 (CYP450) were elevated in DRC. Downregulation of these proteins by respective specific pharmacological inhibitors and/or by siRNAs resensitized cells to vinblastine. These results suggested that differential levels of P&mdash;gp, Cav&mdash;1 and FASN except CYP450 play a major role in acquired resistant phenotype in bladder cancer.

COUP-TFII regulates metastasis of colorectal adenocarcinoma cells by modulating Snail1

Background:

Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, also known as NR2F2) promotes metastasis by functioning in the tumour microenvironment; however, the role of COUP-TFII in colorectal cancer remains unknown.

Methods:

Human colon adenocarcinoma tissues were collected to test COUP-TFII expression. Wound-healing and cell invasion assay were used to evaluate migration and invasion of cells. Chicken ovalbumin upstream promoter-transcription factor II and related protein expression was assessed by immunostaining, immunoblotting and real-time PCR assay. Tamoxifen-inducible COUP-TFII knockout mice were employed to test COUP-TFII functions on colon cancer metastasis in vivo.

Results:

Elevated expression of COUP-TFII in colorectal adenocarcinoma tissue correlated with overexpression of the Snail1 transcription factor. High COUP-TFII expression correlated with metastasis and shorter patient survival. Chicken ovalbumin upstream promoter-transcription factor II regulated the migration and invasion of cancer cells. With Snail1, COUP-TFII inhibited expression of adherence molecules such as ZO-1, E-cadherin and β-catenin in colorectal cancer cells. Overexpression of COUP-TFII was required for cancer cells to metastasise in vivo. Chicken ovalbumin upstream promoter-transcription factor II regulated the transcription and expression of Snail1 by directly targeting the Snail1 promoter and regulated associated genes.

Conclusions:

Chicken ovalbumin upstream promoter-transcription factor II was crucial for colorectal cancer metastasis and regulated cell migration and metastasis in conjunction with Snail1. Chicken ovalbumin upstream promoter-transcription factor II was found to be a biomarker associated with patient survival and colorectal cancer metastasis.

A long-term frequency stabilized deep ultraviolet laser for Mg+ ions trapping experiments

As many precision laser spectroscopy experiments require frequency stabilized lasers, development of long-term stabilized lasers is of great interest. In this work, we report long-term frequency stabilization of a 280 nm deep ultraviolet laser to a high precision wavemeter with digital servo control such that the long-term drift of the laser frequency was greatly reduced. Long-term laser frequency drift was measured with a fiber frequency comb system over 8 h. After locking, the maximum drift rate of the 280 nm laser was lowered from 576 MHz/h to 6.4 MHz/h. With proper environment control of the wavemeter, the maximum drift rate of the 280 nm laser was further lowered to less than 480 kHz/h. The locked laser system was successfully used in a Mg(+) ions trapping experiment, which was also discussed in this work.

Expression of putative stem marker nestin and CD133 in advanced serous ovarian cancer

It is hypothesized that "cancer stem cells" are responsible for the resistance to chemotherapy of cancer cells in ovarian cancers. The objective of the studies was to explore if the stem cell biomarkers could be used to predict the tumor chemotherapy-resistance in serous ovarian cancer patients. Expression of two putative stem cell markers CD133 and nestin, and vascular epithelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) were detected in 123 cases of advanced serous ovarian cancer specimens by immunohistochemistry. To estimate intra-tumoral microvessel density (MVD), CD34 immunostaining was also performed. CD133 and nestin were defined to be positive in 35.0% and 32.5% of the serous ovarian carcinoma tissues, respectively. It was observed that overexpression of nestin but not CD133 was associated with the cisplatin-based chemotherapy resistance and shorter overall survival of the patients, and nestin was found to be an independent prognostic factor. Moreover, positive nestin expression also correlated to increased expression of EGFR and VEGF, and elevated MVD in tumors. The results of this study suggest that serous ovarian cancers with high expression level of nestin represent an aggressive malignant phenotype associated with poor prognosis, and treatment targeted the nestin positive cancer cells might be a promising therapeutic strategy for this subgroups.

Effect of influenza on cardiorespiratory and all-cause mortality in Hong Kong, Singapore and Guangzhou

1. Using a common modelling approach, mortality attributable to influenza was higher in the two subtropical cities Guangzhou and Hong Kong than in the tropical city Singapore. 2. The virus activity appeared more synchronised in subtropical cities, whereas seasonality of influenza tended to be less marked in the tropical city. 3. High temperature was associated with increased mortality after influenza infection in Hong Kong, whereas relative humidity was an effect modifier for influenza in Guangzhou. No effect modification was found for Singapore. 4. Seasonal and environmental factors probably play a more important role than socioeconomic factors in regulating seasonality and disease burden of influenza. Further studies are needed in identifying the mechanism behind the regulatory role of environmental factors.

GABAergic neural activity involved in salicylate-induced auditory cortex gain enhancement

Although high doses of sodium salicylate impair cochlear function, it paradoxically enhances sound-evoked activity in the auditory cortex (AC) and augments acoustic startle reflex responses, neural and behavioral metrics associated with hyperexcitability and hyperacusis. To explore the neural mechanisms underlying salicylate (SS)-induced hyperexcitability and "increased central gain," we examined the effects of GABA receptor agonists and antagonists on SS-induced hyperexcitability in the AC and startle reflex responses. Consistent with our previous findings, local or systemic application of SS significantly increased the amplitude of sound-evoked AC neural activity, but generally reduced spontaneous activity in the AC. Systemic injection of SS also significantly increased the acoustic startle reflex. S-baclofen or R-baclofen, GABA-B agonists, which suppressed sound-evoked AC neural firing rate and local field potentials, also suppressed the SS-induced enhancement of the AC field potential and the acoustic startle reflex. Local application of vigabatrin, which enhances GABA concentration in the brain, suppressed the SS-induced enhancement of AC firing rate. Systemic injection of vigabatrin also reduced the SS-induced enhancement of acoustic startle reflex. Collectively, these results suggest that the sound-evoked behavioral and neural hyperactivity induced by SS may arise from a SS-induced suppression of GABAergic inhibition in the AC.

Abstract PD03-09: Metformin Induces Apoptosis in Triple Negative Breast Cancer Cells Via Inhibition of Stat3 Activity

Background: Metformin inhibits breast cancer cell proliferation and colony formation, with S phase arrest and the induction of apoptosis in triple negative breast cancer cells in vitro. In these cells, metformin down-regulates Cyclin D1 and Cyclin E, as well as EGFR, p-EGFR, p-AKT, p-MAPK, p-Src and p-mTOR, whereas it up-regulates p-AMPK (Liu, et al. Cell Cycle, 2009). Non-triple negative breast cancer cells are resistant to metformin induced apoptosis, although they show similar changes in p-AMPK induction with metformin (Alimova, et al. Cell Cycle, 2009). We hypothesized that there are unique signaling intermediates associated with metformin responsivity in triple negative cells and have identified the signal transducer and activator of transcription 3 (Stat3) as a potential target. Stat3 is constitutively activated in a wide range of tumors, including breast cancer (up to 60%). It reportedly promotes cancer cell proliferation and survival.

Methods: Human triple negative breast cancer cell lines (MDA-468, MDA-231, BT20 and HCC70) were used to evaluate interactions between metformin and Stat3 signaling. Activation of Stat3 was examined by Western blot analysis with phosphorylation-specific antibodies. Cell proliferation was determined by MTS assay. Apoptosis was quantitated by an apoptosis ELISA assay and Western blots for PARP and caspase cleavage. In these 4 cell lines, Stat3-over-expressing clones were obtained via transfection of a constitutive active (CA) construct of Stat3. Specific knock-down of Stat3 expression was achieved by using a lentiviral system containing Stat3 small hairpin RNA.

Results: In a dose and time dependent manner, metformin inhibits Stat3 phosphorylation at sites Tyr705 and Ser727, Cyclin D1 and E protein expression, cleavage of PARP and the pro-caspases 3, 8, and 9. Overexpression of the CA-Stat3 attenuates the aforementioned meformin-associated PARP and caspase cleavage as well as apoptosis, and it suppresses metformin induced cell cycle arrest and changes in cyclin D1 and E. In contrast, specific knock-down of Stat3 expression sensitizes the triple negative breast cancer cells to metformin-mediated apoptosis and cell cycle arrest, enhancing the signaling changes we describe above. Conclusion: These data indicate that Stat3 is a critical intermediary for metformin action in triple negative breast cancer cells. Our studies suggest that targeting Stat3 activation may be a useful strategy to treat breast cancer patients with triple negative phenotype.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD03-09.

Nephrogenic systemic fibrosis with a spectrum of clinical and histopathological presentation: a disorder of aberrant dermal remodeling

BACKGROUND

Nephrogenic fibrosing dermopathy (NFD) has emerged as a clinicopathologic entity since 1997 and recently renamed as nephrogenic systemic fibrosis (NSF). The etiology and pathogenesis remain uncertain. Characteristic clinical presentation is described as diffuse thickening and hardening of the skin occurring in patients with renal insufficiency. Typical histological features include proliferation of CD34 positive fibrocytes, increased thick collagen bundles and mucin deposition, without significant inflammatory infiltrate. Variations in clinical presentations have been reported, including papular and plaque-like skin lesions, focal lesion only, as well as systemic involvement. Histological changes can be subtle and non-specific, overlapping with other disease processes and harboring features including calcification and osteoclast-like giant cells with osseous metaplasia.

METHODS

We reviewed patients with NSF that presented to our dermatology clinic by chart review, clinical examination and histological examination. Skin biopsy specimens were obtained from all cases. Histopathology evaluations were carried out by three dermatopathologists (AD, BS and GK) independently and the features were compared among all the cases. Special stains and immunohistochemistry study were also performed to highlight the histological features.

RESULTS

Seven cases of NSF presented with a spectrum of clinical manifestations, from classic diffuse hardening of the skin to localized linear plaques. On histological examination, proliferation of CD34-positive fibrocytes ranged from sparse to dense, collagen bundles ranged from thin to thick, and the interstitial dermal mucin accumulation ranged from scant-patchy to abundant. In addition, the lesion displayed various degrees of vascular proliferation, inflammatory infiltrates and intensities of CD68 and Factor XIIIa staining. Two cases showed extensive dermal calcification and ossification.

CONCLUSION

NSF may present with a spectrum of clinical abnormalities, and exhibit overlapping histopathological features resembling cicatrix and other dermal reparative/regenerative processes. NSF may in fact to be a disorder of aberrant extracellular matrix remodeling in patients with renal insufficiency.

Inflammation in subcutaneous adipose tissue: relationship to adipose cell size

AIMS/HYPOTHESIS

Inflammation is associated with increased body mass and purportedly with increased size of adipose cells. We sought to determine whether increased size of adipose cells is associated with localised inflammation in weight-stable, moderately obese humans.

METHODS

We recruited 49 healthy, moderately obese individuals for quantification of insulin resistance (modified insulin suppression test) and subcutaneous abdominal adipose tissue biopsy. Cell size distribution was analysed with a multisizer device and inflammatory gene expression with real-time PCR. Correlations between inflammatory gene expression and cell size variables, with adjustment for sex and insulin resistance, were calculated.

RESULTS

Adipose cells were bimodally distributed, with 47% in a 'large' cell population and the remainder in a 'small' cell population. The median diameter of the large adipose cells was not associated with expression of inflammatory genes. Rather, the fraction of small adipose cells was consistently associated with inflammatory gene expression, independently of sex, insulin resistance and BMI. This association was more pronounced in insulin-resistant than insulin-sensitive individuals. Insulin resistance also independently predicted expression of inflammatory genes.

CONCLUSIONS/INTERPRETATION

This study demonstrates that among moderately obese, weight-stable individuals an increased proportion of small adipose cells is associated with inflammation in subcutaneous adipose tissue, whereas size of mature adipose cells is not. The observed association between small adipose cells and inflammation may reflect impaired adipogenesis and/or terminal differentiation. However, it is unclear whether this is a cause or consequence of inflammation. This question and whether small vs large adipose cells contribute differently to inflammation in adipose tissue are topics for future research.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00285844.

Salicylate increases the gain of the central auditory system

High doses of salicylate, the anti-inflammatory component of aspirin, induce transient tinnitus and hearing loss. Systemic injection of 250 mg/kg of salicylate, a dose that reliably induces tinnitus in rats, significantly reduced the sound evoked output of the rat cochlea. Paradoxically, salicylate significantly increased the amplitude of the sound-evoked field potential from the auditory cortex (AC) of conscious rats, but not the inferior colliculus (IC). When rats were anesthetized with isoflurane, which increases GABA-mediated inhibition, the salicylate-induced AC amplitude enhancement was abolished, whereas ketamine, which blocks N-methyl-d-aspartate receptors, further increased the salicylate-induced AC amplitude enhancement. Direct application of salicylate to the cochlea, however, reduced the response amplitude of the cochlea, IC and AC, suggesting the AC amplitude enhancement induced by systemic injection of salicylate does not originate from the cochlea. To identify a behavioral correlate of the salicylate-induced AC enhancement, the acoustic startle response was measured before and after salicylate treatment. Salicylate significantly increased the amplitude of the startle response. Collectively, these results suggest that high doses of salicylate increase the gain of the central auditory system, presumably by down-regulating GABA-mediated inhibition, leading to an exaggerated acoustic startle response. The enhanced startle response may be the behavioral correlate of hyperacusis that often accompanies tinnitus and hearing loss.

Insulin resistance is associated with a modest increase in inflammation in subcutaneous adipose tissue of moderately obese women

AIMS/HYPOTHESIS

We have previously described differences in adipose cell size distribution and expression of genes related to adipocyte differentiation in subcutaneous abdominal fat obtained from insulin-sensitive (IS) and -resistant (IR) persons, matched for degree of moderate obesity. To determine whether other biological properties also differ between IR and IS obese individuals, we quantified markers of inflammatory activity in adipose tissue from overweight IR and IS individuals.

METHODS

Subcutaneous abdominal tissue was obtained from moderately obese women, divided into IR (n = 14) and IS (n = 19) subgroups by determining their steady-state plasma glucose (SSPG) concentrations during the insulin suppression test. Inflammatory activity was assessed by comparing expression of nine relevant genes and by immunohistochemical quantification of CD45- and CD68-containing cells.

RESULTS

SSPG concentrations were approximately threefold higher in IR than in IS individuals. Expression levels of CD68, EMR1, IL8, IL6 and MCP/CCL2 mRNAs were modestly but significantly increased (p < 0.05) in IR compared with IS participants. Results of immunohistochemical staining were consistent with gene expression data, demonstrating modest differences between IR and IS individuals. Crown-like structures, in which macrophages surround single adipocytes, were rarely seen in tissue from either subgroup.

CONCLUSIONS/INTERPRETATION

A modest increase in inflammatory activity was seen in subcutaneous adipose tissue from IR compared with equally obese IS individuals. Together with previous evidence of impaired adipose cell differentiation in IR vs equally obese individuals, it appears that at least two biological processes in subcutaneous adipose tissue characterize the insulin-resistant state independent of obesity per se.

Naevus comedonicus: a spectrum of body involvement

Naevus comedonicus (NC) is a rare developmental anomaly, with < 200 cases reported in the literature. It usually occurs on the face, neck or chest, appearing as groups of closely arranged dilated follicular openings with keratin plugs. Several associations have been made in the literature. We review the current literature, emphasizing the clinical features, associated conditions and therapeutic options.

Coordination of kidney filtration and tubular reabsorption: considerations on the regulation of metabolic demand for tubular reabsorption

Kidney blood flow is highly regulated by a combination of myogenic autoregulation, multiple neurohormonal systems and the tubuloglomerular feedback system, the later of which specifically relates tubular reabsorption to the filtered load. Oxygen and substrate requirements of the kidney are dictated by both supply of oxygen and substrates and metabolic demands of the kidney. The tubuloglomerular feedback system utilizes mediators which are intimately linked to cellular metabolism, ATP and adenosine. This system based upon communication transfer between the macular densa and the afferent arteriole stabilizes kidney function and is not static but temporally adapts or resets to new external physiologic conditions. Such temporal adaptation occurs via modulators such as nitric oxide (NO), primarily derived from NOS-1, angiotensin II and COX-2 products. These hormonal influences also exert capacities to modulate cellular demands for oxygen, particularly NO which decreases oxygen consumption via multiple mechanisms. The several mechanisms whereby NO and other hormonal systems and transporter activity can regulate and produce changes in kidney metabolic demands are discussed. Modulators which influence temporal adaptation and resetting of TGF are also significant contributors to the regulation of cellular oxygen consumption in the kidney. These systems may act in concert to preserve the coordination of filtered load and tubular reabsorption and the metabolic demands of kidney function, thereby determining the ischemic threshold for kidney function.

Protease-activated receptor 2, a receptor involved in melanosome transfer, is upregulated in human skin by ultraviolet irradiation

Previous studies have shown that the protease-activated receptor 2 is involved in skin pigmentation through increased phagocytosis of melanosomes by keratinocytes. Ultraviolet irradiation is a potent stimulus for melanosome transfer. We show that protease-activated receptor 2 expression in human skin is upregulated by ultraviolet irradiation. Subjects with skin type I, II, or III were exposed to two or three minimal erythema doses of irradiation from a solar simulator. Biopsies were taken from nonexposed and irradiated skin 24 and 96 h after irradiation and protease-activated receptor 2 expression was detected using immunohistochemical staining. In nonirradiated skin, protease-activated receptor 2 expression was confined to keratinocytes in the lower one-third of the epidermis. After ultraviolet irradiation protease-activated receptor 2 expression was observed in keratinocytes in the upper two-thirds of the epidermis or the entire epidermis at both time points studied. Subjects with skin type I showed delayed upregulation of protease-activated receptor 2 expression, however, compared with subjects with skin types II and III. Irradiated cultured human keratinocytes showed upregulation in protease-activated receptor 2 expression as determined by immunofluorescence microscopy and Western blotting. Cell culture supernatants from irradiated keratinocytes also exhibited a dose-dependent increase in protease-activated receptor-2 cleavage activity. These results suggest an important role for protease-activated receptor-2 in pigmentation in vivo. Differences in protease-activated receptor 2 regulation in type I skin compared with skin types II and III suggest a potential mechanism for differences in tanning in subjects with different skin types.

Elevation of cystatin C in susceptible neurons in Alzheimer's disease

A common polymorphism in the cystatin C gene is associated with increased risk of developing Alzheimer's disease (AD). To explore possible neuropathological consequences of this genetic association, we examined expression of cystatin C in brains from 22 AD and 11 control patients by immunohistochemistry. In the temporal cortex of all AD brains, there was strong cystatin C immunostaining of neurons and activated glia, whereas staining was absent or minimal in 7 of the 11 control brains. Neuronal staining of cystatin C in AD brains was primarily limited to pyramidal neurons in cortical layers III and V, which are the neurons most susceptible to cell death in AD. The increase in cystatin C staining in AD was independent of cystatin C genotype. Immunostaining of cystatin C within neurons showed a punctate distribution, which co-localized with the endosomal/lysosomal proteinase, cathepsin B. A primarily glial source for cystatin C was suggested by parallel studies using in situ hybridization of mouse brain. In human AD brain, there was little co-localization of cystatin C with parenchymal Abeta deposits, although a small fraction of cerebral blood vessels and neurofibrillary tangles were cystatin C-positive. The regional distribution of cystatin C neuronal immunostaining also duplicated the pattern of neuronal susceptibility in AD brains: the strongest staining was found in the entorhinal cortex, in the hippocampus, and in the temporal cortex; fewer pyramidal neurons were stained in frontal, parietal, and occipital lobes. These neuropathological observations reinforce the association between cystatin C and AD, and support a model of cystatin C involvement in the process of neuronal death in AD.

Notch1 and amyloid precursor protein are competitive substrates for presenilin1-dependent gamma-secretase cleavage

Proteolytic processing of the amyloid precursor protein (APP) by beta- and gamma-secretases results in the production of a highly amyloidogenic Abeta peptide, which deposits in the brains of Alzheimer's disease patients. Similar gamma-secretase processing occurs in another transmembrane protein, Notch1, releasing a potent signaling molecule, the Notch C-terminal domain. It has been shown that both events are dependent on a presenilin-dependent protease. We now test the hypothesis that activated Notch1 and APP are competitive substrates for the same proteolytic activity in neurons. Treatment of neurons with the native Notch ligand, Delta, induces endogenous Notch1 intramembraneous cleavage and diminishes Abeta production in a dose-dependent manner. Complementary experiments showed that the converse was also true. Overexpressing human APP (APP(695Sw)) in neurons leads to a decrease in endogenous Notch1 signal transduction, as assessed by a CBF1 luciferase transcription assay, by Notch C-terminal domain nuclear translocation in vitro and by analysis of Notch C-terminal domain generation and Notch1 staining in vivo. In summary, two complementary approaches suggest that APP and Notch1 are physiologically relevant competitive substrates for gamma-secretase activity.

Ornithine decarboxylase, kidney size, and the tubular hypothesis of glomerular hyperfiltration in experimental diabetes

In early diabetes, the kidney grows and the glomerular filtration rate (GFR) increases. This growth is linked to ornithine decarboxylase (ODC). The study of hyperfiltration has focused on microvascular abnormalities, but hyperfiltration may actually result from a prior increase in capacity for proximal reabsorption which reduces the signal for tubuloglomerular feedback (TGF). Experiments were performed in Wistar rats after 1 week of streptozotocin diabetes. Kidney weight, ODC activity, and GFR were correlated in diabetic and control rats given difluoromethylornithine (DFMO; Marion Merrell Dow, Cincinnati, Ohio, USA) to inhibit ODC. We assessed proximal reabsorption by micropuncture, using TGF as a tool for manipulating single-nephron GFR (SNGFR), then plotting proximal reabsorption versus SNGFR. ODC activity was elevated 15-fold in diabetic kidneys and normalized by DFMO, which also attenuated hyperfiltration and hypertrophy. Micropuncture data revealed an overall increase in proximal reabsorption in diabetic rats too great to be accounted for by glomerulotubular balance. DFMO prevented the overall increase in proximal reabsorption. These data confirm that ODC is required for the full effect of diabetes on kidney size and proximal reabsorption in early streptozotocin diabetes and are consistent with the hypothesis that diabetic hyperfiltration results from normal physiologic actions of TGF operating in a larger kidney, independent of any primary malfunction of the glomerular microvasculature.

The study on the relationship between serum vascular endothelial growth factor and proteinuria in adriamycin-induced nephrotic rats

To study the relationship between serum vascular endothelial growth factor (VEGF) and proteinuria in adriamycin-induced nephrotic rats, a rat model of adriamycin-induced nephrotitis was developed by injection of adriamycin into a tail vein in a rat. At different time points, 24-h urinary protein excretion was measured by using Coomassie brilliant blue method and the serum VEGF levels detected by using ELISA assay. The interventional effect of VEGF on this model was observed. The results showed that: (1) The adriamycin-induced nephrotic syndrome rat model was developed successfully; (2) Serum VEGF levels and proteinuria were significantly increased at 7th day after intravenous injection of adriamycin. There was a positive correlation between serum VEGF levels and 24-h urinary protein excretion (r = 0.67, P < 0.05). (3) The 24-h urinary protein excretion was significantly increased in the rats receiving administration of VEGF (P < 0.05). It was concluded that VEGF might play an important role in the pathogenesis of proteinuria in adriamycin-induced nephrotic rats.

No evidence for genetic association or linkage of the cathepsin D (CTSD) exon 2 polymorphism and Alzheimer disease

Two recent case-control studies have suggested a strong association of a missense polymorphism in exon 2 of the cathepsin D gene (CTSD) and Alzheimer disease (AD). However, these findings were not confirmed in another independent study. We analyzed this polymorphism in two large and independent AD study populations and did not detect an association between CTSD and AD. The first sample was family-based and included 436 subjects from 134 sibships discordant for AD that were analyzed using the sibship disequilibrium test (SDT, p = 0.68) and the sib transmission/disequilibrium test (Sib-TDT, p = 0.81). The second sample of 200 AD cases and 182 cognitively normal controls also failed to show significant differences in the allele or genotype distribution in cases versus controls (chi2, p = 0.91 and p = 0.88, respectively). In addition, two-point linkage analyses in an enlarged family sample (n = 670) did not show evidence for linkage of the chromosomal region around CTSD. Thus, our analyses on more than 800 subjects suggest that if an association between the CTSD exon 2 polymorphism and AD exists, it is likely to be smaller than previously reported.

Genetic association of a cystatin C gene polymorphism with late-onset Alzheimer disease

OBJECTIVE

To determine whether the cystatin C gene (CST3) is genetically associated with late-onset Alzheimer disease (AD).

DESIGN

A case-control study with 2 independent study populations of patients with AD and age-matched, cognitively normal control subjects.

SETTING

The Alzheimer's Disease Research Unit at the University Hospital Hamburg-Eppendorf, Hamburg, Germany, for the initial study (n = 260). For the independent multicenter study (n = 647), an international consortium that included the Massachusetts Alzheimer's Disease Research Center at the Massachusetts General Hospital, Boston; the Scientific Institute for Research and Patient Care, Brescia, Italy; and Alzheimer's research units at the Universities of Basel and Zurich, Switzerland, and Bonn, Goettingen, and Hamburg, Germany.

PARTICIPANTS

Five hundred seventeen patients with AD and 390 control subjects.

MEASURES

Molecular testing of the KspI polymorphisms in the 5' flanking region and exon 1 of CST3 and the apolipoprotein E (APOE) genotype. Mini-Mental State Examination scores for both patients with AD and control subjects.

RESULTS

Homozygosity for haplotype B of CST3 was significantly associated with late-onset AD in both study populations, with an odds ratio of 3.8 (95% confidence interval, 1.56-9.25) in the combined data set; heterozygosity was not associated with an increased risk. The odds ratios for CST3 B/B increased from 2.6 in those younger than 75 years to 8.8 for those aged 75 years and older. The association of CST3 B/B with AD was independent of APOE epsilon4; both genotypes independently reduced disease-free survival.

CONCLUSIONS

CST3 is a susceptibility gene for late-onset AD, especially in patients aged 75 years and older. To our knowledge, CST3 B is the first autosomal recessive risk allele in late-onset AD.

Adenosine formed by 5'-nucleotidase mediates tubuloglomerular feedback

Nephron function is stabilized by tubuloglomerular feedback (TGF). TGF operates within the juxtaglomerular apparatus, sensing changes in tubular flow and eliciting compensatory changes in single nephron GFR (SNGFR). The mediator(s) of TGF remains unconfirmed. One theory is that ATP consumed in active transport by the macula densa leads to formation of adenosine, which causes glomerular vasoconstriction. We performed micropuncture in rats to test this hypothesis. Adenosine activity was manipulated by microperfusing nephrons with adenosine A1 receptor blocker, A1-agonist, or 5'-nucleotidase inhibitor. Effects on TGF were characterized by changes in TGF efficiency (the compensation for small perturbations in tubular flow) and by changes in the maximum range over which TGF can cause SNGFR to change. These data were further applied to generate TGF profiles [SNGFR versus late proximal flow (V(LP))]. TGF efficiency was significantly reduced by blocking A1-receptors. TGF efficiency, TGF range, and the slope of the TGF profile (DeltaSNGFR/DeltaV(LP)) were all significantly reduced by blocking 5'-nucleotidase. When adenosine activity was clamped by combining 5'-nucleotidase inhibitor with A1-agonist to determine whether TGF requires adenosine to be present or to fluctuate, the TGF slope was reduced by 83%, indicating that adenosine activity must fluctuate for normal TGF to occur and that adenosine is a mediator of TGF.

Lack of independent associations of apolipoprotein E promoter and intron 1 polymorphisms with Alzheimer's disease

Several studies have demonstrated genetic associations between Alzheimer's disease (AD) and polymorphisms in the promoter/enhancer regions of the apolipoprotein E (APOE) gene. These studies raise the possibility that APOE transcription control may be involved in altered risks for AD. We evaluated polymorphic sites in the intron-1 enhancer element (IE-1G/C) and in the APOE promoter (-219G/T). For the IE-1 polymorphism, we analyzed 433 individuals (183 AD and 250 controls), and found a strong linkage between the IE-1G allele and APOE-epsilon4. When we controlled for this linkage using log-linear model analysis, we found no independent association between the IE-1 polymorphism and AD. For the -219 polymorphism, we analyzed 475 individuals (168 AD cases, 234 controls, and 73 cases of cerebral amyloid angiopathy (CAA)). We found strong linkages between the -219G allele and APOE-epsilon2 and between the -219 T allele and APOE-epsilon4. Controlling for these linkages, we found no independent association between the -219 polymorphism and AD or CAA. Thus, our studies do not support independent associations between AD and either the IE-1 or the -219 polymorphisms.

[Elimination of CD28+ T cell in patients with chronic active hepatitis]

OBJECTIVE

To study the role of toxicyte T cell in active hepatitis.

METHODS

We examined CD28+ T cell in patients with chronic active/remission hepatitis by flow cytometry.

RESULTS

It shows that CD28+, CD8+CD28+ T cell in patients with chronic active hepatitis decreased significantly, compared with normal control or patients with liver cirrhosis and heptoma.

CONCLUSION

It implies that B7-CD28 costimulation pathway contribute to the tissue injury in hepatitis.

Experimental study on detached renal tubular epithelial cells in urine of nephropathia epidemic patients

To elucidate the pathogenesis of acute renal failure (ARF) with nephropathia epidemic (NE), provide experimental evidence for the new therapy to NE and observe the effects of Arg-Gly-Asp (RGD) peptides on adhesion of renal tubular epithelial cell (RTEC), urine specimens of patients were collected under sterile conditions. Detached RTECs were separated, cultured and identified. Hantan Virus antigen was determined by using indirect immunofluorescence method and effects of RGD on adhesion of RTECs was observed by subgroup counting as well as by flow cytometry. This study showed that: (1) sublethal RTECs existed in the urine of NE-ARF patients, which could be cultured in monolayer form; (2) there was NE antigen in RTECs; and (3) adhesion of RTECs could be inhibited by RGD.

[Regulating function of enzymization and deenzymization of the lactate dehydrogenase isozymes in the mouse tissues during hypoxia]

OBJECTIVE

Study the characteristics of changes of LDH enzyme map of mouse under slight hypoxia.

METHODS

Treated mouse with artificial hypoxia, various tissue biopsies were made for the test of LDH enzymatic activity by specific staining technical LDH(1-5)relative percent enzymatic activity were measured with CS-910 dual-wavelength thin-layer chromatography scanner.

RESULTS

The relative percent enzymatic activity of LDH isozymes of various tissues after slight hypoxia shift to the isozymes LDH1 and LDH2, whose principal subunits are H subunits, and the relative percent enzymatic activity of LDH1 (H4), LDH2-(H3M) increased (the relative percent enzymatic activity of LDH2 increased markedly, P < 0.05), while LDH (M4) in various tissues decreased prominently except the cardiac muscle, and that of LDH4 (HM3) decreased as well. After the PAGE of the hypoxia treated cardiac muscle specimen was made, activity subbands originated regularly in the isozyme pattern of LDH, with the regularity of LDH1 (0 subband), LDH2 (0-1 subbands), LDH3 (0-2 subbands), LDH4 (1-3 subbands), LDH5 (2-4 subbands). After adding appropriate amount of NAD+ to mouse cardiac muscle specimen with hypoxia, PAGE showed the numbers of subbands of four kinds of isozymes (LDH2-LDH5) decreased even totally disappeared in the isozyme pattern.

CONCLUSIONS

The negative feedback regulation of enzymization and deenzymization of LDH isozymes is one of mouse stress responses to slight hypoxia.

Serum lipoprotein (a) concentration in patients with nephrotic syndrome and its clinical implication

Serum lipoprotein(a) [Lp(a)] concentration was determined in 42 patients with primary nephrotic syndrome (NS) and the relationships between Lp (a) and plasma lipids, apolipoproteins, serum creatinine (Scr), albumin, urinary proteins (Upro) were also analyzed. The results showed that: (1) serum Lp(a) concentrations in the patients with NS were higher than those in healthy controls; (2) the levels of serum Lp(a) were correlated positively with total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), apolipoprotein B (Apo-B), Upros (Upro). It is concluded that the NS patients had the potential risk of suffering from coronary artery disease, glomerular sclerosis and thrombosis. The remission of NS may partially decrease the serum Lp(a) levels. Further studies are needed to explore the prevention and treatment of dislipedemia in patients with NS.

Metabotropic glutamate receptor subtype mGluR1alpha stimulates the secretion of the amyloid beta-protein precursor ectodomain

To examine the effects of glutamatergic neurotransmission on amyloid processing, we stably expressed the metabotropic glutamate receptor subtype 1alpha (mGlu-R1alpha) in HEK 293 cells. Both glutamate and the selective metabotropic agonist 1-amino-1,3-cyclopentanedicarboxylic acid (ACPD) rapidly increased phosphatidylinositol (PI) turnover four- to fivefold compared with control cells that were transfected with the expression vector alone. Increased PI turnover was effectively blocked by the metabotropic antagonist alpha-methyl-4-carbophenylglycine (MCPG), indicating that heterologous expression of mGluR1alpha resulted in efficient coupling of the receptors to G protein and phospholipase C activation. Stimulation of mGluR1alpha with glutamate, quisqualate, or ACPD rapidly increased secretion of the APP ectodomain (APPs); these effects were blocked by MCPG. The metabotropic receptors were coupled to APP processing by protein kinases and by phospholipase A2 (PLA2), and melittin, a peptide that stimulates PLA2, potently increased APPs secretion. These data indicate that mGluR1alpha can be involved in the regulation of APP processing. Together with previous findings that muscarinic and serotonergic receptor subtypes can increase the secretion of the APP ectodomain, these observations support the concept that proteolytic processing of APP is under the control of several major neurotransmitters.

Functional dissection of systemic lupus erythematosus using congenic mouse strains

We describe the in vivo phenotypes associated with three genomic intervals containing systemic lupus erythematosus (SLE)-susceptibility genes derived from the SLE-prone NZM2410 strain on a C57BL/6 genome. These intervals were identified previously via a genome-wide analysis of SLE susceptibility in a (NZM2410 x C57BL/6)F1 x NZM2410 backcross, and transferred independently on a C57BL/6 background to produce three congenic strains: B6.NZMc1 carrying Sle1, B6.NZMc4 carrying Sle2, and B6.NZMc7 carrying Sle3. B6.NZMc1 develops high titers of IgG anti-nuclear autoantibodies in the absence of any severe nephritis. B6.NZMc4 spontaneously develops elevated levels of IgM, but not IgG Abs against several Ags, indicative of polyclonal activation or polyreactivity affecting the B cell lineage. B6.NZMc7 causes the production of IgM and IgG Abs against both nuclear and non-nuclear Ags and the development of severe lupus nephritis. Therefore, our results show that three defined genomic intervals from the NZM2410 SLE-prone strain each contribute specific component phenotypes that have been associated with SLE, which in combination can mediate severe disease.

Functional dissection of systemic lupus erythematosus using congenic mouse strains

We describe the in vivo phenotypes associated with three genomic intervals containing systemic lupus erythematosus (SLE)-susceptibility genes derived from the SLE-prone NZM2410 strain on a C57BL/6 genome. These intervals were identified previously via a genome-wide analysis of SLE susceptibility in a (NZM2410 x C57BL/6)F1 x NZM2410 backcross, and transferred independently on a C57BL/6 background to produce three congenic strains: B6.NZMc1 carrying Sle1, B6.NZMc4 carrying Sle2, and B6.NZMc7 carrying Sle3. B6.NZMc1 develops high titers of IgG anti-nuclear autoantibodies in the absence of any severe nephritis. B6.NZMc4 spontaneously develops elevated levels of IgM, but not IgG Abs against several Ags, indicative of polyclonal activation or polyreactivity affecting the B cell lineage. B6.NZMc7 causes the production of IgM and IgG Abs against both nuclear and non-nuclear Ags and the development of severe lupus nephritis. Therefore, our results show that three defined genomic intervals from the NZM2410 SLE-prone strain each contribute specific component phenotypes that have been associated with SLE, which in combination can mediate severe disease.

Lipids, lipoproteins and apolipoproteins abnormalities in patients undergoing dialysis

Twenty hemodialysis (HD) patients and 20 patients on continuous ambulatory peritoneal dialysis (CAPD) were investigated for lipids, lipoproteins and apolipoproteins abnormalities. HD patients had elevated serum triglyceride, decreased high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (Apo A-I), while CAPD patients had elevated total cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-C), Apolipoprotein B (Apo B), Apo B/Apo A-I ratio, and decreased HDL-C, Apo A-I. Because of the molecular sieving effects of peritoneum, CAPD have a negative effect on these abnormalities. CAPD patients might be at greater risk of developing coronary artery disease than HD patients who are also at increased risk as compared with normals.

Impact of nitric oxide deficiency on blood pressure and glomerular hemodynamic adaptations to pregnancy in the rat

Studies were conducted to investigate the impact of nitric oxide synthesis inhibition on blood pressure and glomerular hemodynamic adaptations to pregnancy in the rat. In normal pregnancy, urinary excretion of NO2 + NO3 (NOx), reflecting increased nitric oxide (NO) production, progressively increased. Blockade of NO production in virgin and late pregnant Sprague-Dawley rats caused systemic hypertension, increased renal vascular resistance (RVR), reductions in RPF but GFR remained unchanged. In cortical nephrons, preglomerular and efferent arteriolar resistance (RA and RE) were elevated and glomerular capillary blood pressure (PGC) increased markedly. Glomerular plasma flow (QA) and the glomerular capillary ultrafiltration coefficient, Kf, were reduced without change in single nephron glomerular filtration rate (SNGFR) because of the large elevation in PGC. The pressor and glomerular hemodynamic responses to NO blockade were similar in virgins and pregnancy. Urinary NOx excretion was markedly reduced in all groups with chronic NO blockade. Inhibition was incomplete in pregnancy, however, and a level of NO production that was adequate for normal BP and renal function in virgins, led to severe vasoconstriction in pregnancy. The present studies suggest that chronic NO deficiency leads to derangement of the hemodynamic adaptations of pregnancy.

Glomerular hemodynamic effects of late pregnancy in rats with experimental membranous glomerulonephropathy

In these studies, the Fx1A model of accelerated, passive Heymann nephritis was used to produce membranous glomerulonephropathy. Female rats were studied at 7 wk after the administration of the Fx1A antibody either in the virgin state or in late pregnancy. The goals of these experiments were to determine whether preexisting membranous glomerulonephropathy compromises the pregnancy and whether the pregnancy acutely worsens the renal function. Virgin rats with membranous glomerulonephropathy developed massive proteinuria and exhibited glomerular capillary hypertension but without declines in GFR. In late pregnancy, there was no worsening of the proteinuria and glomerular blood pressure fell to normal values. Both afferent and efferent arteriolar resistances increased in pregnant rats with membranous glomerulonephropathy compared with virgins, leading to falls in glomerular plasma flow and single-nephron GFR. There were no histologic abnormalities in the glomeruli of either virgin or late pregnant rats with membranous glomerulonephropathy, and both groups exhibited similar immunoglobulin G and complement deposits. Up to Day 19 (term is 22 days), the pregnancy in rats with membranous glomerulonephropathy appeared uneventful. Thus, this study indicates that the Fx1A model of membranous glomerulonephropathy does not compromise the course of the pregnancy, at least until close to term. Pregnancy lowers glomerular blood pressure in rats with membranous glomerulonephropathy because of both a fall in systemic blood pressure and the atypical renal vasoconstriction, which leads to declines in single-nephron GFR.

Glomerular hemodynamic responses to pregnancy in rats with severe reduction of renal mass

These studies investigate glomerular hemodynamic responses to pregnancy in rats with 5/6th reduction of renal mass of four weeks duration. Both preglomerular and efferent arteriolar resistances (RA and RE) fell significantly at midterm although single nephron glomerular filtration rate (SNGFR) and glomerular plasma flow (QA) were unchanged versus virgins. In late pregnant rats with reduction of renal mass, the gestational fall in RA and RE was maintained and GFR, RPF, SNGFR and QA were higher compared to virgins. The gestational renal vasodilation was prolonged in this model of hypertension versus normals and a peripheral vasodilation is also indicated by the late fall in blood pressure. In virgins with 5/6th reduction of renal mass, PGC is elevated but in pregnant rats PGC fell towards term. The value of Kf was doubled in late pregnancy compared to virgins. All three groups of rats with reduction of renal mass showed similar proteinuria and similar levels of focal glomerular sclerosis, suggesting that pregnancy did not exacerbate the glomerular damage in this model of hypertension and renal disease. A decrease in hematocrit in late pregnancy compared with both virgin and midterm pregnancy indicated a plasma volume expansion. We conclude that when superimposed on hypertension with glomerular damage due to 5/6th reduction of renal mass, pregnancy induced gestational renal and peripheral vasodilation and plasma volume expansion. Since pregnancy was antihypertensive and lowered PGC, there was no hemodynamic basis for pregnancy-associated exacerbation of damage in this model of glomerular injury.

[Study on determination of gentamycin in serum by enhanced chemiluminesent immunoassay based on immobilized antibody and biotin-avidin system]

Gentamycin was determined by competition with biotin labeled gentamycin in the presence of an immobilized antibody to gentamycin. Microcrystalline cellulose was first coupled with sheep anti-rabbit antibody, then the anti-gentamycin antibody was conjugated and the competition reaction conducted. After separation, HRP-avidin was added to the precipitation and the amount of HRP conjugate determined by enhanced chemiluminescene. The limit of detection for gentamycin in serum was 63-78 ng/tube and the average recovery of gentamycin 103%. The correlation coefficient of the log-log regression equation. Magnitude of r was 0.991 +/- 0.006.