Abstract LB052: Melanoma-secreted amyloid beta suppresses neuroinflammation and promotes brain metastasis

Brain metastasis is a significant cause of morbidity and mortality in multiple cancer types and represents an unmet clinical need. The mechanisms that mediate metastatic cancer growth in the brain parenchyma are largely unknown. Melanoma, which has the highest rate of brain metastasis among common cancer types, is an ideal model to study how cancer cells adapt to the brain parenchyma. Our unbiased proteomics analysis of melanoma short-term cultures revealed that proteins implicated in neurodegenerative pathologies are differentially expressed in melanoma cells explanted from brain metastases compared to those derived from extracranial metastases. We showed that melanoma cells require amyloid beta (Aβ) for growth and survival in the brain parenchyma. Melanoma-secreted Aβ activates surrounding astrocytes to a prometastatic, anti-inflammatory phenotype and prevents phagocytosis of melanoma by microglia. Finally, we demonstrate that pharmacological inhibition of Aβ decreases brain metastatic burden. Our results reveal a novel mechanistic connection between brain metastasis and Alzheimer’s disease - two previously unrelated pathologies, establish Aβ as a promising therapeutic target for brain metastasis, and demonstrate suppression of neuroinflammation as a critical feature of metastatic adaptation to the brain parenchyma.

Citation Format: Kevin Kleffman, Grace Levinson, Indigo V. Rose, Lili Blumenberg, Sorin A. Shadaloey, Avantika Dhabaria, Eitan Wong, Francisco Galán-Echevarría, Alcida Karz, Diana Argibay, Richard Von-Itter, Alfredo Floristán, Gillian Baptiste, Nicole Eskow, James Tranos, Jenny Chen, Eleazar C. Vega Saenz de Miera, Melissa Call, Robert Rogers, George Jour, Youssef Zaim Wadghiri, Iman Osman, Yue Ming Li, Paul Mathews, Ronald Demattos, Beatrix Ueberheide, Kelly Ruggles, Shane A. Liddelow, Robert J. Schneider, Eva Hernando. Melanoma-secreted amyloid beta suppresses neuroinflammation and promotes brain metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB052.

Melanoma-secreted Amyloid Beta Suppresses Neuroinflammation and Promotes Brain Metastasis

Brain metastasis is a significant cause of morbidity and mortality in multiple cancer types and represents an unmet clinical need. The mechanisms that mediate metastatic cancer growth in the brain parenchyma are largely unknown. Melanoma, which has the highest rate of brain metastasis among common cancer types, is an ideal model to study how cancer cells adapt to the brain parenchyma. Our unbiased proteomics analysis of melanoma short-term cultures revealed that proteins implicated in neurodegenerative pathologies are differentially expressed in melanoma cells explanted from brain metastases compared to those derived from extracranial metastases. We showed that melanoma cells require amyloid beta (AB) for growth and survival in the brain parenchyma. Melanoma-secreted AB activates surrounding astrocytes to a pro-metastatic, anti-inflammatory phenotype and prevents phagocytosis of melanoma by microglia. Finally, we demonstrate that pharmacological inhibition of AB decreases brain metastatic burden.

Is routine pre-entry chest radiograph necessary in a high tuberculosis prevalence country?

CONTEXT

Chest radiographs have been used worldwide as a screening tool before employment and training, by various healthcare and other government and nongovernment institutions. Many studies done in the past have demonstrated a relatively low yield for tuberculosis detection and therefore, the authors have questioned this practice.

AIMS

To compare the value of the preadmission/employment chest radiograph in two groups, namely, those who have been previously exposed to a healthcare setting (post-exposure group) and those who have not been exposed (pre-exposure group) and to determine if there is a significant difference in tuberculosis detection between these two groups.

SETTINGS AND DESIGN

A retrospective review of the reports of the chest radiographs of all candidates appearing for admission to various undergraduate and postgraduate courses in our institute between 2014 and 2017 was performed.

MATERIALS AND METHODS

The various abnormalities detected were recorded and the findings in the two groups were compared.

STATISTICAL ANALYSIS USED

Chi-square test was used to compare between two group proportions.

RESULTS

Thirty out of 4333 (0.69%) candidates in the pre-exposure group and 53 out of 3379 (1.57%) candidates in the post-exposure group showed abnormalities on chest radiographs involving the lung parenchyma, mediastinum, heart, or pleura. In the pre-exposure group, six (0.14%) were found to have underlying cardiac disease and one (0.02%) had tuberculosis. Among the six candidates in the post-exposure group who underwent further investigations in our institute, five (0.15%) were diagnosed to have tuberculosis. Although there was no statistically significant difference in tuberculosis detection between the groups (P = 0.051), there is a trend towards higher detection of tuberculosis in the post-exposure group.

CONCLUSIONS

In a country where the prevalence of tuberculosis is high, the pre-employment chest radiograph may still have a role in detecting tuberculosis in the post-exposure group.

α7-Nicotinic acetylcholine receptor inhibition by indinavir: implications for cognitive dysfunction in treated HIV disease

OBJECTIVE

The study set out to determine if the HIV protease inhibitor, indinavir, alters responsiveness of α7-nicotinic acetylcholine receptors to acetylcholine.

DESIGN

Treatment with HAART has dramatically reduced development of HIV-associated dementia and more severe forms of cognitive impairment. However, many individuals continue to experience cognitive decline of uncertain cause. Previous studies have failed to demonstrate significant alterations of functional brain connectivity, structural brain changes, or changes in cerebral blood flow sufficient to explain cognitive decline in virally suppressed individuals. This suggests that the mechanisms underlying development and progression of cognitive problems likely occurs at a micro rather than macro level, such as disruptions in neurotransmitter system signaling.

MATERIALS AND METHODS

Indinavir's effects on α7-nicotinic acetylcholine receptor activity was tested using a ScreenPatch IonWorks Barracuda-based assay in a mammalian cell model.

RESULTS

At low concentrations (0.0003-10 μmol/l) indinavir acts as a positive allosteric modulator (EC50 = 0.021 μmol/l), whereas at concentrations greater than 10 μmol/l (30-100 μmol/l) indinavir acts as an inhibitor of the α7-nicotinic acetylcholine receptor.

CONCLUSION

At concentrations greater than 10 μmol/l indinavir reduces synaptic transmission in the acetylcholine neurotransmitter system, which could possibly contribute to cognitive dysfunction. These results suggest that further experiments should be considered to assess whether patients might benefit from treatment with cholinesterase inhibitors that counteract the effects of indinavir.

A different way of doing nursing

The transition from nursing manager to NZNO lead organiser has proved to be just another way of nursing.

Enabling Anyone to Translate Clinically Relevant Ideas to Therapies

How do we inspire new ideas that could lead to potential treatments for rare or neglected diseases, and allow for serendipity that could help to catalyze them? How many potentially good ideas are lost because they are never tested? What if those ideas could have lead to new therapeutic approaches and major healthcare advances? If a clinician or anyone for that matter, has a new idea they want to test to develop a molecule or therapeutic that they could translate to the clinic, how would they do it without a laboratory or funding? These are not idle theoretical questions but addressing them could have potentially huge economic implications for nations. If we fail to capture the diversity of ideas and test them we may also lose out on the next blockbuster treatments. Many of those involved in the process of ideation may be discouraged and simply not know where to go. We try to address these questions and describe how there are options to raising funding, how even small scale investments can foster preclinical or clinical translation, and how there are several approaches to outsourcing the experiments, whether to collaborators or commercial enterprises. While these are not new or far from complete solutions, they are first steps that can be taken by virtually anyone while we work on other solutions to build a more concrete structure for the "idea-hypothesis testing-proof of concept-translation-breakthrough pathway".

Family and fertility: kin influence on the progression to a second birth in the British Household Panel Study

Particular features of human female life history, such as short birth intervals and the early cessation of female reproduction (menopause), are argued to be evidence that humans are ‘cooperative breeders’, with a reproductive strategy adapted to conditions where mothers receive substantial assistance in childraising. Evolutionary anthropologists have so far largely focussed on measuring the influence of kin on reproduction in natural fertility populations. Here we look at the effect in a present-day low-fertility population, by analysing whether kin affect parity progression in the British Household Panel Study. Two explanatory variables related to kin influence significantly increase the odds of a female having a second birth: i) having relatives who provide childcare and ii) having a larger number of frequently contacted and emotionally close relatives. Both effects were measured subject to numerous socio-economic controls and appear to be independent of one another. We therefore conclude that kin may influence the progression to a second birth. This influence is possibly due to two proximate mechanisms: kin priming through communication and kin assistance with childcare.

Synergistic effects of A1896, T1653 and T1762/A1764 mutations in genotype c2 hepatitis B virus on development of hepatocellular carcinoma

The effects of genomic changes in hepatitis B virus (HBV) on the occurrence of hepatocellular carcinoma (HCC) are still unclear, especially in relation to the genotype of HBV. In this study, we examined the effects of genomic changes in HBV of genotype C2 on the development of HCC. A total of 318 patients with HBV-associated HCC and 234 patients with chronic hepatitis B (CHB) were studied. All of HCC cases were diagnosed histologically and treated with surgical resection. The whole of the X, S, basal core promoter (BCP) and precore regions of the viral genome from sera or liver tissues were sequenced. All subjects had HBV of genotype C2. The prevalence of the T1653 mutation in the X region and the A1896 mutation in the precore region of HBV was significantly higher in the HCC group than in the control CHB group (22% vs 11%, P = 0.003; 50% vs 23%, P < 0.001, respectively). Moreover, the T1762/A1764 mutations in the BCP region in combination with either T1653 or A1896 were more common in the HCC compared with the CHB group (BCP+X1653: 18% vs 11%, P = 0.05; BCP+PC, 40% vs 15%, P < 0.001, respectively). In multivariate analysis, T1653 and A1896 were revealed to be independent risk factors for HCC development. G1896A in the precore region and C1653T mutation in the X region of genotype C2 HBV are important risk factors for HCC development. Also, the A1762T/G1764A double mutation may act in synergy with C1653T to increase the risk of HCC in patients chronically infected with HBV genotype C2.

Does solid culture for tuberculosis influence clinical decision making in India?

SETTING

Medical units at an academic tertiary referral hospital in Southern India.

OBJECTIVE

To investigate the impact of solid culture on Löwenstein-Jensen medium on clinical decision making.

DESIGN

In a retrospective review of 150 culture-positive and 150 culture-negative consecutively sampled tuberculosis (TB) suspects, treatment decisions were analysed at presentation, after the availability of culture detection results and after the availability of drug susceptibility testing (DST) culture results.

RESULTS

A total of 124 (82.7%) culture-positive patients and 35 (23.3%) culture-negative patients started anti-tuberculosis treatment prior to receiving their culture results; 101 patients (33.7%) returned for their results; two (1.3%) initiated treatment based on positive culture and no culture-negative patients discontinued treatment. DST was performed on 119 (79.3%) positive cultures: 30 (25.2%) showed any resistance, eight (6.7%) showed multidrug resistance and one (0.84%) showed extensively drug-resistant TB. Twenty-eight patients (23.5%) returned for their DST results. Based on DST, treatment was modified in four patients (3.4%).

CONCLUSION

Using solid culture, 150 cultures need to be tested for one treatment modification and 30 for DST. The cost of the widespread application of culture will need to be balanced against its impact on treatment decisions in India.

Alzheimer-specific variants in the 3'UTR of Amyloid precursor protein affect microRNA function

Background

APP expression misregulation can cause genetic Alzheimer's disease (AD). Recent evidences support the hypothesis that polymorphisms located in microRNA (miRNA) target sites could influence the risk of developing neurodegenerative disorders such as Parkinson's disease (PD) and frontotemporal dementia. Recently, a number of single nucleotide polymorphisms (SNPs) located in the 3'UTR of APP have been found in AD patients with family history of dementia. Because miRNAs have previously been implicated in APP expression regulation, we set out to determine whether these polymorphisms could affect miRNA function and therefore APP levels.

Results

Bioinformatics analysis identified twelve putative miRNA bindings sites located in or near the APP 3'UTR variants T117C, A454G and A833C. Among those candidates, seven miRNAs, including miR-20a, miR-17, miR-147, miR-655, miR-323-3p, miR-644, and miR-153 could regulate APP expression in vitro and under physiological conditions in cells. Using luciferase-based assays, we could show that the T117C variant inhibited miR-147 binding, whereas the A454G variant increased miR-20a binding, consequently having opposite effects on APP expression.

Conclusions

Taken together, our results provide proof-of-principle that APP 3'UTR polymorphisms could affect AD risk through modulation of APP expression regulation, and set the stage for further association studies in genetic and sporadic AD.

Deficiency in neuronal TGF-beta signaling promotes neurodegeneration and Alzheimer's pathology

Alzheimer's disease (AD) is characterized by progressive neurodegeneration and cerebral accumulation of the beta-amyloid peptide (Abeta), but it is unknown what makes neurons susceptible to degeneration. We report that the TGF-beta type II receptor (TbetaRII) is mainly expressed by neurons, and that TbetaRII levels are reduced in human AD brain and correlate with pathological hallmarks of the disease. Reducing neuronal TGF-beta signaling in mice resulted in age-dependent neurodegeneration and promoted Abeta accumulation and dendritic loss in a mouse model of AD. In cultured cells, reduced TGF-beta signaling caused neuronal degeneration and resulted in increased levels of secreted Abeta and beta-secretase-cleaved soluble amyloid precursor protein. These results show that reduced neuronal TGF-beta signaling increases age-dependent neurodegeneration and AD-like disease in vivo. Increasing neuronal TGF-beta signaling may thus reduce neurodegeneration and be beneficial in AD.

Respiratory care manpower issues

OBJECTIVE

Although respiratory care is a relatively new profession, its practitioners are deeply involved in providing patient care in the critical care. In preparation for writing this article, we sought to explore the respiratory therapy manpower needs and activities designed to fulfill those needs in critical care practice.

MATERIALS AND METHODS

We began by delineating the historical development of respiratory care as a profession, the development of its education, and the professional credentialing system. We then conducted several literature reviews with few articles generated. We requested and received data from the American Association for Respiratory Care (AARC), The National Board for Respiratory Care (NBRC), and the Committee on Accreditation of Respiratory Care education (CoARC) relative to their membership, number of credentialed individuals, and educational program student and graduate data for 2000 through 2004. We then conducted two electronic surveys. Survey 1 was a six-item survey that examined the use of mandatory overtime in respiratory care departments. We used a convenience sample of 30 hospitals stratified by size (<or=200 beds, 201-499 beds, >or=500 beds). Survey 2 was a five-item instrument distributed by blast E-mail to the Society of Critical Care Medicine's Respiratory Care Section members and members of the RC_World list serve. This survey elicited 51 usable and non-duplicative responses from geographically and size-varied institutions. We analyzed these data in several ways from distribution analysis to one-way analysis of variance procedure and appropriate post hoc analysis techniques. Where appropriate, a matched-pairs analysis was performed and these were compared across the variables intensive care unit (ICU) beds per actual number of respiratory care practitioners (RCPs) and ICU beds per preferred number of RCPs.

RESULTS

The data gathered from the professional organizations indicated a relatively stable attrition rate (35.2%+/-1.7-3.1%), even in the face of varying enrollments (6,231 in 2004 vs. 4,589 in 2002). In survey 1, we looked at the institution of mandatory overtime policies and their use in 30 size-stratified hospitals. Mandatory overtime was selected as a survey topic under the supposition that manpower shortages might lead to the development of such procedures and also to their utilization. Fourteen of the 30 hospitals responding indicated that they had a policy addressing mandatory over time. Of the 14 hospitals with policies, only ten had disciplinary actions specific to refusing the overtime. Seven of the 30 hospitals indicated that they used mandatory overtime monthly of more frequently. Survey 2 data revealed that there was a wide variation in bed size, number of ICUs, and number of RCP staff assigned to the ICU. Serendipitously, our 51 responding centers were distributed among small (16), medium (19), and large (16) hospitals in a manner that appeared to reflect the national distribution pattern. We were able to use these data to develop a closeness of fit diagram ICU beds to preferred numbers of RCPs (DF=48; p<.0001; RSq=0.77; RMSE=4.114). The number of beds per preferred number of RCPs was 9.445 to 1.0 while the actual bed to RCP ratio was 10.75 to 1.

CONCLUSION

This article provides a short history of the development of respiratory care and its historical relationship with critical care. We have, perhaps for the first time, provided a unified data set of key demographic information from the three professional bodies guiding the development of the respiratory therapy profession. This data set provides time-linked data on admissions and graduations from the CoARC, membership numbers for the AARC, and the numbers of active credentialed RCP from the NBRC. By two focused surveys, we were able to show that while mandatory overtime is a common practice in respiratory care departments, it was not overwhelming utilized. We also learned that in most hospitals, regardless of bed size, there is a perceived need for 1.3 RCPs more than the actual staff and that it appears that the critical staffing level between actual to preferred RCP to beds is between 9 and 11 beds.

Alzheimer amyloid precursor aspartyl proteinase activity in CHAPSO homogenates of Spodoptera frugiperda cells

Presenilins are polytopic, integral proteins that control intramembranous proteolysis at the "gamma-" and "epsilon-" cleavage sites of the Alzheimer amyloid-beta precursor protein (APP) to yield amyloid-beta peptide (Abeta) and the APP intracellular domain (AICD). We have overexpressed a constitutively active, pathogenic form of PS1 (known as PS1 Delta exon 9) together with its substrate, APP-C99, in Spodoptera frugiperda (Sf9) cells. Sf9 cells have been reported to lack endogenous gamma-secretase, an unexpected finding since there exists an insect homologue of PS1. In our hands, neither intact insect cells coexpressing PS1 Delta exon 9/APP-C99 nor the aqueous homogenates of these cells displayed obvious products of the gamma- or epsilon-secretase reactions, as reported. Surprisingly, when APP-C99-expressing cells were homogenized in 3[(3-cholamidopropyl) dimethylammonio]-2-hydroxypropanesulfonic acid (CHAPSO), a detergent known to support gamma-secretase activity, subsequent incubation led to the accumulation of an AICD-like peptide (AICD-L). Aspartyl proteinase inhibitors were effective in preventing the appearance of AICD-L, but inhibitors of other classes of proteinases were ineffective. Immunoprecipitation-mass spectrometry of AICD-L revealed its identity as the minor of the two known AICDs.

Normal brain development in PS1 hypomorphic mice with markedly reduced gamma-secretase cleavage of betaAPP

Presenilin 1-null mice die at birth from brain and skeletal developmental deformities due to disrupted Notch signaling. Presenilin 1-null mice also have severely reduced gamma-secretase cleavage of betaAPP. The assumption has been that facilitation of Notch signaling and betaAPP processing by presenilin 1 are analogous functions. Here we describe a presenilin 1-targetted mouse model that expresses extremely low levels ( approximately 1% of normal) of mutant PS1-M146L. Homozygous mice have significantly reduced viability due to a Notch-like phenotype. The animals that survive have severe axial skeletal deformities and markedly diminished gamma-secretase activity and accumulation of betaAPP-C100, but no obvious abnormalities in brain development. These results suggest that, in mice, a marked reduction of PS1-facilitated gamma-secretase activity is not detrimental to normal brain development.

Penile metastasis arising from transitional cell carcinoma of the urinary bladder

Metastatic spread of transitional cell carcinoma of the bladder to the penis is very rare. We present 1 such case in a 63-year-old man that was treated by total penectomy and adjuvant systemic chemotherapy.

Nursing and respiratory: partners in care

Learn about RCP licensure and nursing's support of this process, as well as the clinical advancements, new and altered procedures, and novel applications of drugs and devices in respiratory care.

Mycobacterium fortuitum endocarditis and meningitis after balloon mitral valvotomy

Mycobacteria rarely cause endocardial infections. We describe the clinical course of a patient who developed endocarditis, and meningitis with Mycobacterium fortuitum following balloon mitral valvotomy. The patient was treated with amikacin and clarithromycin but did not respond. She developed haemolytic anaemia as the terminal event.

Voice changes and thyroid surgery: is pre-operative indirect laryngoscopy necessary?

BACKGROUND

Indirect laryngoscopy (IDL) is often performed prior to thyroid surgery to detect pre-existing vocal cord pathology.

METHODS

A retrospective chart review of 201 patients undergoing thyroid surgery at the Prince of Wales Hospital was undertaken in order to study the patterns of pre-operative and postoperative voice changes and IDL findings.

RESULTS

A total of 9% of patients had pre-operative voice symptoms, and 22% of this group had abnormalities detected on pre-operative IDL. Of 160 documented IDL, 4% revealed vocal cord pathology in asymptomatic patients, including an asymptomatic recurrent laryngeal nerve palsy.

CONCLUSIONS

Indirect laryngoscopy remains a useful but flawed pre-operative screening tool for patients with voice symptoms, but the literature suggests that more advanced phoniatric tests will provide superior diagnostic sensitivity. The role of routine pre-operative laryngoscopy for asymptomatic patients is of debatable value.

The phonology-morphosyntax interface: affixed words in agrammatism

In three experiments with nondysarthric agrammatics, we explored the association between phonology and morphosyntax. (1) Contrasting phonological and nonphonological factors on inflectional-affix production of English verbs across three tasks in eight agrammatics, longer stem-syllabic length and stem-final-CC status resulted in poorer affix-production. (2) Studying verb inflections in six agrammatic Spanish-speakers, affix-length and affix-stress correlated with poorer repetition, as did low affix frequency. (3) Four English-speaking agrammatics read aloud and repeated derived words varying in syllable-length and stem-stress reassignment; both contributed independently to word-production difficulty. Phonological complexity of affixes and stems appears to reduce resources for morphological processing in nondysarthric agrammatics.

Movement detection at the human big toe

1. To be detected, movements of the interphalangeal joint of the big toe must be greater than at other joints. This poor acuity may arise because the anatomy of the foot and ankle results in poor coupling between the toe and the muscles that operate it. To vary this coupling, the effect of ankle position on proprioceptive acuity at the toe was measured. 2. We measured proprioceptive acuity at the toe with the ankle in different positions and found that ankle plantarflexion did improve acuity. This implies that, with the ankle at mid-range or dorsiflexed, toe movement is inadequately transferred to muscle fascicles. 3. To determine actual changes in fascicle length of the toe extensor, movements of extensor hallucis longus near the toe and at the muscle-tendon junction were measured during surgical exposure in one subject. Ankle position greatly affected movement transfer from toe to muscle-tendon junction: no tendon movement was transferred with the ankle dorsiflexed, but all movement was transferred with the ankle plantarflexed. 4. When the relationship between joint rotation and muscle fascicle length measured in vivo was used to express the smallest detectable movements of the toe as proportional changes in muscle fascicle length, these detectable changes were similar to those at all other limb joints. This suggests that change in muscle fascicle length is of major interest to the nervous system.

The Griess test: an inexpensive screening test for asymptomatic bacteriuria in pregnancy

This study was designed to compare urine microscopy and the Griess test as screening tests for asymptomatic bacteriuria (AB) in pregnancy, using urine culture as a gold standard. Urine microscopy, Griess test and urine culture were carried out on urine samples from 483 antenatal women. AB was detected by urine culture in 30 (6.8%) of the patients. The Griess test and urine microscopy were found to have a sensitivity of 63.3% and 60%, specificity of 99.5% and 83.6%; and positive predictive value of 90.5% and 21.1% respectively. Most of the infections missed by the Griess test were either <100,000 colony count on culture or caused by gram positive cocci. The cost of the Griess test was only one tenth of that of urine microscopy. The Griess test is a simple and inexpensive test that when compared to urine microscopy has equal sensitivity, and better specificity and positive predictive value for the detection of AB in pregnancy than urine microscopy.

Expression of androgen receptor and growth factors in premalignant lesions of the prostate

Analysis of growth factors and receptors in putative premalignant lesions of prostatic adenocarcinoma should aid our understanding of their growth pathways. Sixty prostatic TURP (transurethral resection of the prostate) specimens exhibiting atypical adenomatous hyperplasia (AAH) and/or prostatic intraepithelial neoplasia (PIN) lesions were assayed by immunohistochemistry for androgen receptor (AR), epidermal growth factor receptor (EGFR), c-erbB-2, transforming growth factor-alpha (TGF-alpha), vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), MIB-1, E-cadherin, and high molecular weight keratin. Expression of these factors in the lesions was compared with that in the co-existing benign prostatic hyperplasia (BPH) or prostatic adenocarcinoma. Strong AR nuclear staining was observed in the luminal cells, but not the basal cells, of BPH and PIN lesions and in all the carcinomas examined. A similar growth factor and receptor profile was demonstrated in the secretory epithelium of high-grade PIN and carcinoma with a tendency to higher expression of membranous EGFR and c-erbB-2 and cytoplasmic TGF-alpha, and lower levels of FGF-2 than in low-grade PIN or BPH glands. Also, increased rates of proliferation, as estimated by MIB-1 stained cells, were observed in high-grade PIN in comparison with low-grade PIN and BPH and were not confined to the basal layer. AAH lesions resembled neither BPH nor carcinoma. Proliferation was virtually absent (MIB-1 expression); both AR and E-cadherin expression was significantly reduced; and, with the exception of FGF-2, all the other growth factors and receptors studied were absent. The results presented would support a premalignant role for high-grade PIN, whilst AAH would appear to represent a quiescent phenotype unlikely to progress to neoplasia.

Cellular expression and proteolytic processing of presenilin proteins is developmentally regulated during neuronal differentiation

We have determined the expression of the Alzheimer's disease-associated proteins presenilin-1 and presenilin-2 in primary cultures of rat hippocampal neurons. Neurons highly express presenilin-1 and presenilin-2, whereas both proteins were not detected in astrocytes. Further, we have analyzed the subcellular localization and expression in rat hippocampal neurons during development. Although presenilin proteins were localized predominantly to the endoplasmic reticulum in nonneuronal cells transfected with presenilin cDNAs, in neurons, presenilin proteins were also found in compartments not staining with antibodies to grp78(BiP). Presenilin-1 and presenilin-2 were predominantly detected in vesicular structures within the somatodendritic compartment with much less expression in axons. Polarized distribution of presenilin-1 and presenilin-2 differs slightly, with more presenilin-2 expressed in axons compared with presenilin-1. Presenilin expression was found to be developmentally regulated. Presenilin expression strongly increased during neuronal differentiation until full morphological polarization and then declined. No full-length presenilin-1 or presenilin-2 could be detected within cell lysates. At early developmental stages the expected approximately 34-kDa N-terminal proteolytic fragment of presenilin-1 and the approximately 38-kDa fragment of presenilin-2 were detected. Later during differentiation we predominantly detected a approximately 38-kDa fragment for presenilin-1 and a approximately 42-kDa fragment for presenilin-2. By epitope mapping, we show that these slower migrating peptides represent N-terminal proteolytic fragments, cleaved C-terminal to the conventional site of processing. It is noteworthy that both presenilin-1 and presenilin-2 undergo alternative proteolytic cleavage at the same stage of neuronal differentiation. Regulation of presenilin expression and proteolytic processing might have implications for the pathological as well as the biological function of presenilins during aging in the human brain.

Degradation and endoplasmic reticulum retention of unassembled alpha- and beta-subunits of Na,K-ATPase correlate with interaction of BiP

Assembly of alpha- and beta-subunits in the endoplasmic reticulum is a prerequisite for the structural and functional maturation of oligomeric P-type ATPases. In Xenopus oocytes, overexpressed, unassembled alpha- and beta-subunits of Xenopus Na,K-ATPase are retained in the endoplasmic reticulum (ER) and are degraded with different kinetics, while unassembled beta-subunits of gastric H, K-ATPase leave the ER. In this study, we have investigated the role of the immunoglobulin-binding protein, BiP, in the folding, assembly, and ER retention of ATPase subunits. We determined the primary sequence of Xenopus BiP and used polyclonal antibodies to examine the interaction with BiP of various wild type and mutant alpha- and beta-subunits overexpressed in Xenopus oocytes. Our results show that ER-retained, unassembled Na,K-ATPase beta-subunits, but not transport-competent H,K-ATPase beta-subunits, efficiently associate with BiP until assembly with alpha-subunits occurs. Furthermore, the kinetics of BiP interaction with unassembled wild type and with mutant Na,K-ATPase beta-subunits parallels their respective stability against cellular degradation. Finally, alpha-subunits that are overexpressed in oocytes and are rapidly degraded and endogenous oocyte alpha-subunits that are stably expressed as individual assembly-competent proteins also interact with oocyte or exogenous BiP, and the interaction time correlates with the protein's stability. These data demonstrate for the first time that BiP might be involved in a long term maturation arrest and/or in the ER quality control of a multimembrane-spanning protein and lend support for a universal chaperone function of BiP.

Glomerular filtration rate in Indian non-insulin-dependent diabetics at various stages of albuminuria

Sixty-seven non-insulin-dependent diabetic subjects were selected to estimate the glomerular filtration rate (GFR). All patients had satisfactory glycaemic control (HbA1 < 9.5%). GFR was determined using Technetium 99m DTPA by the method devised by Gates. Thirty-eight subjects had normal albumin excretion (UAE < 20 micrograms/min), 15 had UAE in the microalbuminuric range (20-100 micrograms/min), and the rest were macroalbuminuric (> 200 micrograms/min). GFR was lower in the normoalbuminuric patients as compared to the controls, but the decrease was not significant (71.5 (21.4) vs. 98.3 (16.1) ml/min per 1.73 m2. GFR was significantly decreased in both micro and macroalbuminuric groups (64.0 (24.5) and 53.8 (27.3) ml/min per 1.73 m2, respectively) (P < 0.05). No appreciable change in GFR was observed in normoalbuminuric patients with increasing duration of diabetes, however, there was a steady decline in GFR with time in both micro- and macroalbuminuric patients. Hypertension was present in 79%, 47% and 16% of macro-, micro- and normoalbuminuric patients, respectively. GFR was significantly lower in hypertensive diabetic patients compared to normotensives (52.3 vs. 76.1 ml/min per 1.73 m2) (P < 0.01), while this difference was not significant in the micro- and macroalbuminuric groups. We conclude from our study that the stage of hyperfiltration could not be detected in non-insulin-dependent diabetes and that hypertension has a significant influence on the rate of decline of GFR.

Caregiver involvement in a large clinical systems project

The Kaiser Permanente Northern California Region (KPNCR) CareGiver Workstation (CGW) Project's mission is to develop and implement a clinical workstation system that will enhance each caregiver-member interaction and aid in the decision-making processes of direct patient care in the inpatient and outpatient settings. The requirements analysis approach for CareGiver Workstation (CGW) is based on the belief that extensive caregiver involvement will provide a better understanding of the diverse needs of Kaiser Permanente Northern California Region (KPNCR). In order to involve as many caregivers as reasonably possible, CGW included a 16 member caregiver core team and 6 different Medical Centers in the requirements definition process. The Medical Centers are referred to as "focus facilities". A "focus group" (caregiver team) at each selected focus facility consisted of a site coordinator and a 24-30 person multidisciplinary team involving physicians, nurses, therapists and other caregivers. The Medical Center selection process identified facilities that provided the best cross-sectional representation of KPNCR. The Lead Focus Facility participated in the initial round of requirements definition activities. These sessions assisted in the design of a simulation that was used at five additional Medical Centers to validate requirements. The five additional Focus Facilities participated in simulation review sessions. Feedback from these sessions was used to revise the simulation and update the requirements document. Caregivers from all six focus facilities and other identified groups participated in a requirements survey to assist CGW with identification of high priority features. Caregiver commitment and continuing involvement are essential for the success of CGW.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneously occurring antibodies to parathyroid hormone

A 76-yr-old female with acute pancreatitis and a normal/borderline elevated serum calcium level was found to have an elevated immunoreactive circulating PTH concentration using a C-terminal assay. This high PTH concentration misled the attending physicians and resulted, in retrospect, in an unnecessary neck exploration. When the patient's serum was examined it was found to contain a binding component that bound both C-terminal and PTH-(1-84). This binding component was not retained on a Sep-Pak column and was precipitated by antiserum directed against human immunoglobulin M. The presence of circulating anti-PTH immunoglobulin M explains the apparently high PTH concentrations measured by RIA. The antibodies occurred spontaneously. To the best of our knowledge, this phenomenon has not previously been described.

Further studies of hippocampal representation during odor discrimination learning

The contribution of hippocampal and nonhippocampal memory processing to simultaneous-cue odor discrimination learning was assessed. In this task, rats with hippocampal system damage consequent to fornix lesions (fornix rats) were severely and persistently impaired in discrimination learning, acquisition of learning set, and concurrent discrimination, although they occasionally solved some problems at a normal rate. By using those problems on which fornix rats succeeded, to permit comparisons of performance strategies with normal rats, differences between groups were shown on response latency measures and on probe trials involving the novel pairing of familiar odors. Normal rats had a bimodal distribution of response latencies, and their latency depended on where the S+ was presented. Fornix rats had short response latencies and responded equally quickly wherever the S+ was presented. Furthermore, when the representation of familiar S+ and S- odor pairs was challenged in probe trials, normal rats responded appropriately to the correct stimulus, whereas fornix rats behaved as if presented with a new odor pair. These data provide support for the view that the hippocampus participates in the representation of relations among odor (and other) stimuli and among other experiences and that it permits the flexible use of these representations in new contexts. In contrast, memory processing outside the hippocampal system can represent only the significance of individual stimuli and can be revealed only in a repetition of the original learning event.

Further studies of hippocampal representation during odor discrimination learning

The contribution of hippocampal and nonhippocampal memory processing to simultaneous-cue odor discrimination learning was assessed. In this task, rats with hippocampal system damage consequent to fornix lesions (fornix rats) were severely and persistently impaired in discrimination learning, acquisition of learning set, and concurrent discrimination, although they occasionally solved some problems at a normal rate. By using those problems on which fornix rats succeeded, to permit comparisons of performance strategies with normal rats, differences between groups were shown on response latency measures and on probe trials involving the novel pairing of familiar odors. Normal rats had a bimodal distribution of response latencies, and their latency depended on where the S+ was presented. Fornix rats had short response latencies and responded equally quickly wherever the S+ was presented. Furthermore, when the representation of familiar S+ and S- odor pairs was challenged in probe trials, normal rats responded appropriately to the correct stimulus, whereas fornix rats behaved as if presented with a new odor pair. These data provide support for the view that the hippocampus participates in the representation of relations among odor (and other) stimuli and among other experiences and that it permits the flexible use of these representations in new contexts. In contrast, memory processing outside the hippocampal system can represent only the significance of individual stimuli and can be revealed only in a repetition of the original learning event.

Hippocampal system dysfunction and odor discrimination learning in rats: impairment or facilitation depending on representational demands

The performance of normal rats and that of rats with hippocampal system damage were compared on acquisition of different versions of the same two-odor discrimination task that placed different encoding and representational demands on memory. Rats with fornix lesions were impaired when explicit comparisons among multiple odor cues and differential response choices were encouraged. However, when odor-cue comparison was hindered and explicit cues for response choice were eliminated, rats with fornix lesions out performed normal animals. The results support an hypothesis that the hippocampal system is critical to a memory representation based on encoding relations among multiple percepts, and other brain systems support performance adaptations based on encodings of stimuli individually.

Hippocampal system dysfunction and odor discrimination learning in rats: Impairment of facilitation depending on representational demands

The performance of normal rats and that of rats with hippocampal system damage were compared on acquisition of different versions of the same two-odor discrimination task that placed different encoding and representational demands on memory. Rats with fornix lesions were impaired when explicit comparisons among multiple odor cues and differential response choices were encouraged. However, when odor-cue comparison was hindered and explicit cues for response choice were eliminated, rats with fornix lesions out performed normal animals. The results support an hypothesis that the hippocampal system is critical to a memory representation based on encoding relations among multiple percepts, and other brain systems support performance adaptations based on encodings of stimuli individually.

Screening for hemolytic disease of the newborn by cord blood Coombs testing--analysis of a five-year experience

An accepted diagnostic feature of hemo lytic disease of the newborn due to isoimmu nization by any of the Rh factors is a posi tive direct antiglobulin reaction (Coombs test) with umbilical cord blood.

Not so well documented is the usefulness of the direct antiglobulin test for the recog nition of hemolytic disease associated with ABO grouping differences. Some believe the test to be generally negative or weakly posi tive in infants who clinically and hemato logically have hemolytic disease related to ABO incompatibility, whereas others claim to find the direct test positive in 90 per cent of such infants. The latter contention is supported by the findings in the study here described.

The direct Coombs test on cord blood is suggested as a useful screening test particu larly when Rh or ABO grouping of the parents is either not known, or so related to each other that a potential isoimmunization problem may ensue in the infant.