Meta-analysis of NAD(P)(H) quantification results exhibits variability across mammalian tissues

Nicotinamide Adenine Dinucleotide (NAD⁺) plays an important role in energy metabolism and signaling pathways controlling crucial cellular functions. The increased interest in NAD⁺ metabolism and NAD⁺-boosting therapies has reinforced the necessity for accurate NAD⁺ quantification. To examine the published NAD(P)(H) measures across mammalian tissues, we performed a meta-analysis of the existing data. An Ovid MEDLINE database search identified articles with NAD(P)(H) quantification results obtained from mammalian tissues published between 1961 and 2021. We screened 4890 records and extracted quantitative data, as well as the quantification methods, pre-analytical conditions, and subject characteristics. The extracted physiological NAD(P)(H) concentrations in various tissues from mice, rats, and humans, revealed an important inter- and intra-method variability that extended to recent publications. This highlights the relatively poor potential for cross-experimental analyses for NAD(P)(H) quantitative data and the importance of standardization for NAD(P)(H) quantification methods and pre-analytical procedures for future preclinical and clinical studies.

Midwives' perspectives on perinatal mental health: A qualitative exploratory study in a maternity setting in Karachi, Pakistan

Women experience perinatal mental health problems (PMHP), such as anxiety and depression antenatally and/or postnatally. Among Asian countries, Pakistan has the highest prevalence of postnatal depression ranging from 28% to 63%. This study aimed to explore midwives' perceptions, understanding, thoughts, and feelings regarding perinatal mental health (PMH), as well as experiences and roles in identifying and managing perinatal women cases suffering from PMHP. A qualitative, descriptive, exploratory design was used. The study was conducted at Koohi Goth Hospital. Purposive sampling was used to recruit practicing midwives holding diplomas in midwifery and public health, and with at least two years of experience. Ten participants were recruited. Data were collected by conducting in-depth interviews using a semi-structured interview guide, translated into Urdu. Interviews were audio recorded. Ethics approval was attained by the institutional Ethical Review Committee. Data analysis was done manually by using the content analysis steps described by Creswell. From the analysis, three themes emerged: 1) Dearth of PMH competencies; 2) Importance of PMH; and 3) Myths related to PMH. PMHP undermine mothers' and infants outcomes, thus, midwives should be competent in assessing and managing symptoms in perinatal women to reduce suffering.

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.

Abstract P5-11-07: The significance of androgen receptor co-expression in ER+ metastatic breast cancer patients treated with palbociclib

Background: The PALOMA-1 and PALOMA-3 studies demonstrated a significant progression-free survival (PFS) advantage for palbociclib, a CDK4/6 inhibitor, in combination with letrozole or fulvestrant in the first or second line setting compared to these therapies alone in estrogen receptor (ER)+, HER2-negative metastatic breast cancer (MBC). Recent studies have revealed preliminary efficacy signals for androgen receptor (AR) blockade in MBC, predominately in AR+, triple negative patients. We sought to further evaluate AR expression and its significance in ER+ MBC patients treated with palbociclib early in their metastatic treatment course.

Methods: A retrospective review identified 22 patients treated with palbociclib for ER+, HER2- MBC after its FDA approval between January 1st, 2015 and October 1st, 2016 at our center with available pre-treatment tumor samples for analysis. Records were reviewed and clinical characteristics for each patient were analyzed. Archival tumor tissue was tested for AR, phosphorylated retinoblastoma (pRb), CDK6, p16, and CyclinE1 by immunohistochemistry assay for each patient. For AR, nuclear staining >0% was considered positive. For all other IHC studies, intensity of staining >2+ or staining in >10% of cells was considered positive.

Results: The median age was 63.5 years (range 34-84); 23% were ≥ age 70. Our cohort was 35% African American, 60% Caucasian, and 5% Asian American. 64% of patients were post-menopausal and 59% had visceral metastases. 45% of patients were on their first line of treatment, 23% second line, and 32% third line. 68% of patients were on an aromatase inhibitor. Median follow up was 18.7 months (95% CI 13.9, 23.3 months). The AR was expressed in 59% of patients; 55% had expression >10% and 41% had expression >20%. AR+ patients were significantly more likely to experience event-free survival (EFS) (HR 0.26, p=0.01), with a median EFS of 18.8 months (AR- median EFS 5.4 months). AR expression was significantly associated with expression of pRb (100% of AR+ patients, p=0.02). CDK6, p16, and CyclinE1 expression were not associated with AR expression or EFS.

Conclusions: Our data show preliminary evidence of the significance of ER and AR co-expression in ER+, HER2- MBC. ER+, AR+ patients have significantly improved EFS when treated with palbociclib and endocrine therapy as compared with AR-, ER+ patients. There is evidence that AR expression is associated with pRB expression, which may represent a mechanism by which cell cycle inhibition with palbociclib is particularly efficacious in these patients. AR expression rates in ER+, HER2- MBC are significant, and may provide rationale for combining CDK4/6 inhibitors with AR targeting as a subsequent line of targeted therapy in these patients before cytotoxic chemotherapy is initiated. Further studies based on these results are underway.

Citation Format: Landry CA, Ru M, Jaffer S, Dimitrova M, Tiersten A. The significance of androgen receptor co-expression in ER+ metastatic breast cancer patients treated with palbociclib [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-11-07.

Abstract P4-06-01: Human mammary tumor virus, HMTV, is an MMTV-adapted human pathogen

Forty percent of American women's breast cancers contain HMTV, a betaretrovirus 90-98% homologous to MMTV, the causative agent for breast cancer in mice. HMTV is reverse-transcribed and integrated into chromosomal DNA of human breast cells. MMTV contamination of our analyses has been definitively excluded. In 8% of unselected American mothers HMTV is found in cells in milk, but in 21% of milks from women previously biopsied for unconfirmed cancer suspicion. In breasts biopsied for suspicion of cancer before a later diagnosis of breast cancer, we see suggestive morphologic changes if the subsequent breast cancer is HMTV+. HMTV is infectious in vitro for B and T lymphocytes, dendritic cells, and human mammary epithelial cells. Infecting MCF-10 breast cell lines with HMTV produces molecular changes of epithelial-mesenchymal transition with upregulation of vimentin ,and downregualtion of E-cadherin. The excess of breast cancer in western European countries and their former colonies (age standardized rates of 47 to 92 per 100,000 per year) compared to Asian incidence (29 to 43 ASR/y) can be explained by excess HMTV-related breast cancer incidence. In 7 West European, American and Oceania countries, 30 to 60% contain HMTV, while in 5 Asian nations HMTV in breast cancers ranges from 0 to 22% Different indigenous murine species with disparate MMTV burdens parallel these findings: mus domesticus in the West with much MMTV in its genome, and m. castaneus or m.musculus in the East with less. Ancient contamination of the food chain, and current lactational transfer perpetuate infection. HMTV poses a new and challenging dimension to breast cancer research involving diagnosis, molecular mechanisms, epidemiology, therapy and prevention.

Citation Format: Holland JF, Jaffer S, Melana S, Nartey T, Gnjatic S, Pogo BG-T. Human mammary tumor virus, HMTV, is an MMTV-adapted human pathogen. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-06-01.

Development and evaluation of The KIT: Keeping It Together™ for Youth (the 'Youth KIT') to assist youth with disabilities in managing information

BACKGROUND

This article presents findings from the development and evaluation of The KIT: Keeping It Together™ for Youth (the 'Youth KIT'). The Youth KIT is a resource intended to assist youth with disabilities during their teenage years and during the transition to adulthood to give information to others about themselves, get from others about themselves, and organize their own information to the best of their ability.

METHODS

Thirty-six youth between the ages of 12 and 25 with physical and developmental disabilities were active participants in the development of the Youth KIT and partnered with a multidisciplinary team to conduct the qualitative evaluation. Focus groups and individual interviews were used in three phases of evaluation.

RESULTS

The results of qualitative content analysis found the Youth KIT to be useful for a variety of youth in different contexts. The themes that emerged about the utility and impact of the Youth KIT were: (1) self-discovery for youth; and (2) the importance of the 'fit' between youth and mentors to support youth as they started to use the Youth KIT.

CONCLUSION

Clinical implications for healthcare providers working with youth during the transition to adulthood include recognition that discussions about adult goals should be a continuous dialogue throughout adolescence rather than a 'special' conversation occurring at the time of discharge from paediatric services.

Factors affecting the process of obtaining informed consent to surgery among patients and relatives in a developing country: results from Pakistan

Efforts have been made in Pakistan to create ethical guidelines for research and medical practice. This study explored the perceptions of and factors affecting the process of obtaining informed consent to surgery among inpatients and families at a tertiary-care hospital in Karachi. A random sample of 400 post-surgery adult patients answered a pre-tested, structured questionnaire. Overall, 233 patients (58.3%) had signed the surgery consent form themselves, while 167 relatives (41.7%) had signed on behalf of the patient. Perceived factors significantly associated with patients not signing the consent form themselves were: language used (adjusted OR = 4.6), medical terminology used (aOR = 2.7), insufficient time allocation (aOR = 3.8), cultural/traditional reasons (aOR = 1.5) and low education (aOR = 2.4). Inappropriate timing for taking consent and not being informed/asked about consent were not statistically significant factors. Health-care practitioners should encourage patients to sign the consent form themselves.

Development of an outcome measurement system for service planning for children and youth with special needs

AIM

This study described the process used in developing an outcome measurement framework for system planning to improve services for children and youth with special needs and their families in a Canadian province. The study reports the results of several parent-completed measures, which would be useful in service planning as well as the acceptability and utility of these measures for use by families and service centres.

METHODS/RESULTS

Development of a theoretical framework, consultation with key stakeholders, testing the utility of selected outcome measures and initial dissemination of results were critical elements in the successful development of an outcome system. Consultation with stakeholders confirmed use of the International Classification of Functioning, Disability and Health and the child-within-family-within community model as theoretical frameworks while building valuable partnerships and identifying potential barriers to implementation. Pilot testing showed three outcome measures were feasible for families to complete and the measures provided information about services for children that was valuable to families as well as service providers. Gaps in service delivery were identified and the need for better communication between service providers and communities to facilitate integrated services was highlighted.

CONCLUSION

The findings from this study can be used to implement an outcome measurement system for children with special needs and may serve as a resource for international researchers who are working to develop valid tools as well as outcome systems that are useful for system planning.

Correlation of Oncotype DX Recurrence Score with Cyclin D1 and ErbB2

Background: The Oncotype DX assay predicts the risk of recurrence in patients with stage I-II ER+, node negative breast cancer treated with tamoxifen. It is not understood if the Oncotype DX assay predicts the natural aggressiveness of an individual breast cancer or if it identifies a subtype of tamoxifen resistant breast cancer. In clinical practice, a high recurrence score (RS) on Oncotype DX is interpreted as a more aggressive tumor and is used to justify the use of chemotherapy. However, if the RS was actually predictive of tamoxifen resistance, patients may benefit from the use of an aromatase inhibitor, and chemotherapy may be unnecessary. Cyclin D1 and ErbB2 are two biomarkers shown to predict tamoxifen resistance.Cyclin D1 is overexpressed in approximately 35% of breast cancers. The Austrian Breast and Colorectal Cancer Study Group assessed expression of Cyclin D1 in patients taking tamoxifen within the ABCSG trial 05 and ABCSG trial 06. In both trials, Cyclin D1 overexpression correlated with a lower relapse free survival and overall survival compared to patients without Cyclin D1 overexpression.Erb2 is overexpressed in 15-30% of breast cancers. In the Gruppo Universitario Napoletano 1 trial, ER+ patients with early stage node negative breast cancer who overexpressed ErbB2 had no improvement in progression free survival and overall survival with 2 years of adjuvant tamoxifen therapy. Additional retrospective studies have supported initial reports of an association between overexpression of ErbB2 and tamoxifen resistance.Methods: 69 patients who had the Oncotype DX assay performed and had unstained pathology slides available were assessed for ErbB2 and Cyclin D1 expression. ErbB2 overexpression status was also obtained in another 74 patients who had the Oncotype DX assay performed. ErbB2 overexpression was determined from a review of medical records where ErbB2 was defined as being positive if immunohistochemical (IHC) staining intensity was 3+ with >90% of cells expressing ErbB2 or FISH revealed an amplification of >2.0. IHC analysis of Cyclin D1 was performed according to standard protocol and using commercially available antibodies. Scoring of slides for Cyclin D1 staining were performed by blinded pathologists who assessed both extent and intensity of nuclear staining for Cyclin D1.Results: The median Oncotype Dx RS within ErbB2+ patients was significantly higher than ErbB2- patients (36.5 vs. 18 p<0.0001), and approximately 50% of patients within each RS grouping (high, intermediate, and low) overexpressed cyclin D1.Conclusion: ErbB2 overexpression among high RS patients suggests the Oncotype DX assay may predict tamoxifen resistance and other markers for tamoxifen resistance need to be correlated with the RS. Although preliminary analysis of the IHC staining for Cyclin D1 does not correlate with a high RS, high Cyclin D1 expression among patients within the low RS subgroup is concerning since this subgroup may have an increased likelihood of disease relapse when treated with adjuvant tamoxifen alone.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3035.

SU-8 polymer enclosed microchannels with interconnect and nanohole arrays as an optical detection device for biospecies

We present for the first time the integration of nanohole arrays for surface plasmon resonance (SPR) sensing together with SU-8 polymer microfluidic channels containing special packaging structures for chip-to-chip and world-to-chip interconnect. Primary steps towards an optical biospecies detection device are presented including observing the effect of period on transmission peak location, examining new materials for the enclosed microchannels, and demonstrating nanohole array SPR transmission data through water contained in the microchannels. Additionally, the enclosed microchannels are integrated with interconnect structures that facilitate interfacing with macro-scale test equipment and microfluidic components and systems such as lab-on-a-chip. Results demonstrate the potential of the polymer microchannels with integrated nanohole arrays and interconnect as a packaged optical SPR detection device.

Pleomorphic adenoma of the breast. A case report and distinction from mucinous carcinoma

Pleomorphic adenoma of the breast is a rare, benign tumor accounting for 68 cases in the literature. It is most commonly seen in postmenopausal women and is characterized by an admixture of epithelial and myoepithelial cells embedded in abundant myxomatous stroma. Its clinical and histologic appearance can be challenging and may lead to a misdiagnosis of invasive carcinoma. We report a case of mammary pleomorphic adenoma in an asymptomatic 59-year-old woman and briefly discuss its distinction from mucinous carcinoma through the use of special stains.

CXCR3 expression in human central nervous system diseases

The CXCR3 chemokine receptor, expressed on activated T lymphocytes, is seen within the central nervous system (CNS) in inflammatory conditions where a T-cell response is prominent. However, the distribution of CXCR3 in parenchymal CNS cells is unknown. Using a monoclonal antibody against CXCR3 and post-mortem tissue of patients with and without CNS pathology, we have determined its expression pattern. CXCR3 was found in subpopulations of cells morphologically consistent with astrocytes, particularly reactive astrocytes, and in cerebellar Purkinje cells. It was also detected in arterial endothelial and smooth muscle cells, particularly in areas associated with atherosclerotic plaques. CXCR3-positive astrocytes were particularly prominent in the CNS of HIV-positive patients, in patients with Multiple Sclerosis (MS), in ischaemic infarcts and in astrocytic neoplasms. Immunofluorescence studies of mixed adult primary glial cultures and fetal glial cultures also showed expression of CXCR3 in astrocytes. CXCR3 mRNA was detected in Purkinje cells by in situ hybridization with a CXCR3-specific probe. Thus, the predominant expression of CXCR3 in reactive astrocytes may indicate that it plays a role in the development of reactive gliosis in a variety of infectious, inflammatory, vascular and neoplastic processes in the CNS. The relationship between CXCR3 expression in astrocytes to its expression in Purkinje cells, endothelial cells and smooth muscle cells is yet to be determined.

Cytology of melanotic schwannoma in a fine needle aspirate and pleural fluid. A case report

BACKGROUND

Melanotic schwannoma (MS) is a rare pigmented neural tumor most commonly occurring in the paraspinal region and involving spinal nerve roots and sympathetic ganglia. Few case reports describe the fine needle aspiration (FNA) cytology of MS. We report an additional case and for the first time describe the cytologic findings of MS in pleural fluid.

CASE

A 44-year-old man presented with a 9.0-cm paraspinal mass associated with multiple lung nodules. FNA cytology of the paraspinal mass showed solitary and syncytially arranged spindled cells, with prominent nucleoli and variable amounts of cytoplasmic brown pigment. In pleural fluid, prominent isolated single cells were rounded and had a signet ring cell morphology. Tumor cells in both the aspirate and pleural fluid expressed S-100 protein and HMB-45.

CONCLUSION

The FNA cytology findings of MS correlate well with the histologic findings. In pleural fluid, however, the cells are epithelioid, and some have a signet ring morphology, mimicking adenocarcinoma.

Expression of multiple functional chemokine receptors and monocyte chemoattractant protein-1 in human neurons

Functional chemokine receptors and chemokines are expressed by glial cells within the CNS, though relatively little is known about the patterns of neuronal chemokine receptor expression and function. We developed monoclonal antibodies to the CCR1, CCR2, CCR3, CCR6, CXCR2, CXCR3 and CXCR4 chemokine receptors to study their expression in human fetal neurons cultured from brain tissue as well as the clonally derived NT2.N human neuronal cell line (NTera 2/cl.D1). Specific monoclonal antibody labeling demonstrated expression of CCR2, CXCR2, CXCR3 and CXCR4 on neurons from both sources. Co-labeling studies revealed strong expression of CXCR3 and CXCR4 on both dendritic and axonal processes, with a weaker expression of CXCR2 and CCR2. Reverse transcriptase-polymerase chain reaction analysis of pure NT2.N neurons confirmed RNA expression for CCR2, CXCR2, CXCR3 and CXCR4. No changes in the neuronal labeling pattern of chemokine receptor expression were noted when NT2.N neurons were grown on a supporting layer of astrocytes, again consistent with similar patterns seen in primary human fetal brain cultures. Analysis of single-cell calcium transients revealed a robust response to stromal derived factor-1alpha (CXCR4) and melanocyte growth-stimulating activity (CXCR2), and variable response to monocyte chemoattractant protein-1 (CCR2) or interferon-gamma inducible protein-10 (CXCR3). Finally, we detected the release of monocyte chemoattractant protein-1 from pure cultures of NT2.N neurons, but not undifferentiated NT2 cells. These data indicate that individual neurons may not only co-express multiple functional chemokine receptors, but also that neurons themselves produce chemokines which may influence cellular function within the central nervous system.

Functional expression of the seven-transmembrane HIV-1 co-receptor APJ in neural cells

APJ is a recently described seven-transmembrane (7TM) receptor that is abundantly expressed in the central nervous system (CNS). This suggests an important role for APJ in neural development and/or function, but neither its cellular distribution nor its function have been defined. APJ can also serve as a co-receptor with CD4 for fusion and infection by some strains of human immunodeficiency virus (HIV-1) in vitro, suggesting a role in HIV neuropathogenesis if it were expressed on CD4-positive CNS cells. To address this, we examined APJ expression in cultured neurons, astrocytes, oligodendrocytes, microglia and monocyte-derived macrophages utilizing both immunocytochemical staining with a polyclonal anti-APJ antibody and RT - PCR. We also analyzed the ability of a recently identified APJ peptide ligand, apelin, to induce calcium elevations in cultured neural cells. APJ was expressed at a high level in neurons and oligodendrocytes, and at lower levels in astrocytes. In contrast, APJ was not expressed in either primary microglia or monocyte-derived macrophages. Several forms of the APJ peptide ligand induced calcium elevations in neurons. Thus, APJ is selectively expressed in certain CNS cell types and mediates intracellular signals in neurons, suggesting that APJ may normally play a role in signaling in the CNS. However, the absence of APJ expression in microglia and macrophages, the prinicpal CD4-positive cell types in the brain, indicates that APJ is unlikely to mediate HIV-1 infection in the CNS.

Physiological significance of early deceleration time prolongation in asymptomatic elderly subjects

BACKGROUND

Alterations in Doppler-derived diastolic filling patterns are common among elderly persons, but their physiological and prognostic significance remains uncertain, particularly in asymptomatic older persons without overt cardiac disease. This study was designed to determine whether early mitral inflow deceleration time (DT) prolongation is of physiological significance in asymptomatic elderly subjects.

METHODS AND RESULTS

In 15 asymptomatic patients aged 60 to 93 years with no history of heart failure (HF) or edema, we performed two-dimensional and Doppler echocardiography and 60-minute head-out, isothermic water immersion to produce circulatory volume expansion. Plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured immediately before and after water immersion. Seven of 15 patients had a normal mitral early DT (160 to 240 milliseconds; group 1) and 8 of 15 patients had DT prolongation (> 240 milliseconds; group 2). Group 2 subjects had significantly smaller chamber sizes and increased relative wall thickness without increased left ventricular mass. Head-out water immersion produced greater increases in plasma ANP levels in group 2 subjects with longer DTs despite similar degrees of circulatory volume expansion in each group. In contrast, plasma BNP levels did not increase significantly with water immersion in either group.

CONCLUSION

Early DT prolongation in asymptomatic elderly subjects is associated with increased relative wall thickness and enhanced ANP increments after central volume expansion. Such exaggerated responses suggest that, in the elderly, a prolonged DT has physiological significance and may represent a precursor to symptomatic diastolic HF, a condition known to be associated with advancing age.

Targeting of HIV- and SIV-infected cells by CD4-chemokine receptor pseudotypes

Retroviral vectors containing CD4 and an appropriate chemokine receptor were evaluated for the ability to transduce cells infected with human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). These CD4-chemokine receptor pseudotypes were able to target HIV- and SIV-infected cell lines and monocyte-derived macrophages in a manner that corresponded to the specificity of the viral envelope glycoprotein for its CD4-chemokine receptor complex. This approach could offer a way to deliver antiviral genes directly to HIV-infected cells in vivo and could provide an additional treatment strategy in conjunction with existing antiviral therapies.

Contralateral axillary lymph node metastasis as the first evidence of locally recurrent breast carcinoma

BACKGROUND

Carcinoma of the breast infrequently presents initially as axillary adenopathy. In such cases, after biopsy proves the presence of metastatic carcinoma, the primary tumor generally is assumed to be in the ipsilateral breast, despite negative mammographic findings and the lack of a clinically palpable breast mass.

METHODS

The authors recently studied a case of a 50-year-old woman in whom recurrent neuroendocrine carcinoma of the breast presented as a contralateral axillary lymph node metastasis. After mastectomy ipsilateral to the metastasis proved negative for tumor, a histologic comparison of the previous contralateral tumor with that in the lymph node was performed, followed by biopsy of the clinically and mammographically negative original lumpectomy site.

RESULTS

Histologic and immunohistochemical studies proved that the original, metastatic, and locally recurrent tumors were identical, sharing unusual neuroendocrine features. The patient is currently disease free after chemotherapy.

CONCLUSION

Contralateral mammary carcinoma should be considered in the workup of a patient who presents with evidence of an axillary lymph node metastasis. Locally recurrent breast carcinoma may be clinically and mammographically occult. Histologic review of prior biopsy material and comparison with current tissue is essential in proper patient management.

Effects of macrophage supernatants on mesangial cell migration and hillock formation

There is considerable evidence suggesting a role for the macrophage (M phi) in the development of glomerulosclerosis (GS) and atherosclerosis, lesions which appear to be analogous. Migration of mesangial cells (MC), which are modified smooth muscle cells, may play a role in the pathogenesis of glomerular injury, and smooth muscle migration may play a role in the pathogenesis of atherosclerosis as well. We undertook the present study to determine the effects of M phi supernatants (M phi SN) on MC migration and formation of MC hillocks, which are considered an in vitro model of GS. By means of a migration assay using wounded cultures of confluent, growth-arrested MC, MC migration was found to be significantly enhanced by incubation with M phi SN at 24 hr (migration score: M phi SN, 24.3 +/- 1.3; control, 11.6 +/- 1.0, P < 0.001) as well as 48 hr incubation (migration score: M phi SN, 34.0 +/- 1.4; control, 15.4 +/- 1.4, P < 0.001). Enhanced MC migration following prolonged incubation with M phi SN was also shown using phase contrast microscopy and scanning electron microscopy. MC hillock formation was enhanced by M phi SN in a concentration-related manner as was hillock size. These data demonstrate that M phi SN can directly enhance MC migration and hillock formation, processes that may in part account for the observed role for the M phi in the development of mesangial expansion and GS as well as atherosclerosis.

Effects of prostaglandin E2 on mesangial cell migration

Mesangial cell migration is a feature of certain renal diseases such as mesangiocapillary glomerulonephritis, a disorder which responds to treatment with cyclo-oxygenase inhibitors. We undertook the present study to determine whether prostaglandin E2 (PGE2) might have a direct effect on mesangial cell migration. PGE2 (10(-8) M) treated cells migrated a mean percent area of 16.8 +/- 0.5 during 24 h when compared to control cells which migrated only a mean percent area of 10.3 +/- 0.8 (p < 0.001). At 48 h, PGE2-treated cells migrated a mean percent area of 21.7 +/- 1.1 when compared to control cells which migrated only a mean percent area of 14.7 +/- 1.4 (p < 0.01). Meclofenamate (10(-5) M), a cyclo-oxygenase inhibitor, significantly (p < 0.02) inhibited migration of mesangial cells (at 48 h controls 13.4 +/- 0.5 vs. meclofenamate-treated cells 3.2 +/- 0.8). Since meclofenamate attenuates basal production of PGE2 by mesangial cells, inhibition of migration by mesangial cells by meclofenamate indicates that the basal production of PGE2 by mesangial cells also significantly contributes to the migration of mesangial cells. 3-Isobutyl-1-methylxanthine (IBMX, 10(-3) M), a phosphodiesterase inhibitor, also significantly (p < 0.001) enhanced migration of mesangial cells (controls 13.4 +/- 0.5 vs. IBMX-treated cells 20.8 +/- 0.5). These results suggest that mesangial cell migration is directly enhanced by PGE2. The present study provides a rationale for the use of cyclo-oxygenase therapy in patients with mesangiocapillary glomerulonephritis.

Opioids modulate migration, spreading and adherence of mesangial cells

Glomerular mesangial cells are considered to be modified smooth muscle cells and seem to play a role in the maintenance of glomerular hemodynamics. The present study was carried out to determine the effect of opioids on adhesiveness, spreading and migration of mesangial cells. Morphine enhanced spreading of mesangial cells at early time periods (5 mini, control 8 +/- 2% vs. morphine 15 +/- 1%, p < 0.05; 15 min, control 21 +/- 5% vs. morphine 38 +/- 2%, p < 0.05) as well as at later time periods when compared to control cells (at 2 h, control 23 +/- 1% vs. morphine 49 +/- 1%, p < 0.001; at 3 h, control 28 +/- 3% vs. morphine 63 +/- 2%, p < 0.05). beta-Endorphin also enhanced (p < 0.001) spreading of mesangial cells (at 2 h, control 23 +/- 1% vs. beta-endorphin 48 +/- 3%; at 3 h, control 28 +/- 3% vs. beta-endorphin 65 +/- 1%). Morphine decreased adhesion of mesangial cells to the plastic substrate at 24 h as well at 48 h when compared to the control cells. Naloxone attenuated the effect of morphine on adhesion to the substrate. Morphine enhanced (p < 0.05) migration (percentage of denuded area covered by mesangial cells when compared to control cells (control 26.07 +/- 1.08% vs. morphine 37.5 +/- 2.94%; n = 9). Since the morphine-induced decreased adhesiveness could be attenuated by naloxone, this effect of morphine on mesangial cells appears to be mediated by opioid receptors.

Inhibition of acetylcholine release from guinea pig myenteric neurons by neuropeptide Y: GTP-binding protein mediation

Neuropeptide Y (NPY) is a unique peptide with wide distribution in central and peripheral nervous systems. In the guinea pig, NPY-positive fibers are prominent in the myenteric plexus. To test whether NPY inhibits myenteric plexus acetylcholine (ACh) release and to define mechanisms, a purified preparation of myenteric plexus neurons was derived from the teniae coli of neonatal guinea pigs and maintained in primary culture. Incubation of cultured neurons labeled with [3H]ACh in the presence of NPY (10(-14)-10(-6) M) significantly inhibited basal ACh release (83 +/- 16 to 58 +/- 11% of control). NPY significantly inhibited ACh release stimulated by potassium (55 mM); by adenylate cyclase agonists forskolin (10(-6) M) and cholera toxin (10(-8) M); and by calcitonin gene-related peptide, cholecystokinin octapeptide, and vasoactive intestinal peptide (each 10(-8) M). In each instance, the inhibitory effects of NPY were reversed by preincubation with pertussis toxin. Reversal of inhibitory effects by pertussis toxin suggests that the actions of NPY are mediated via an inhibitory GTP-binding protein.

Stimulation of acetylcholine release in myenteric plexus by calcitonin gene-related peptide

The effects of calcitonin gene-related peptide (CGRP) on acetylcholine (ACh) release from myenteric plexus neurons in primary culture were investigated. CGRP (10(-12) to 10(-6) M) produced a dose-dependent increase in [3H]ACh release. The ACh release caused by CGRP was significantly inhibited (74 +/- 24%) by preincubation with dideoxyadenosine but was increased more than threefold by preincubation with theophylline. Incubation of myenteric plexus neurons with CGRP (10(-8) M) in the presence of diltiazem (10(-5) M) or in a calcium-free medium markedly reduced [3H]ACh release. CGRP potentiated [3H]ACh release stimulated by potassium or substance P but not by cholecystokinin octapeptide or forskolin. The results demonstrate that CGRP cause release of ACh from guinea pig myenteric plexus neurons and suggest that the peptide acts through an adenosine 3',5'-cyclic monophosphate-dependent mechanism that involves neuronal calcium channels.

Outpatient evaluation of a rapid, direct test for detection of group A streptococci in throat swabs

A latex agglutination test (Marion Laboratories) was compared with standard culture methods for the detection of Group A streptococci in two studies of 500 throat swabs each. Swabs were first inoculated to sheep blood agar and then tested for Group A streptococcal antigen. The direct test performed with nearly identical sensitivity and specificity in the two phases of the study. Overall, Group A streptococci were isolated from 91 specimens, and 81 (89%) of these were detected by the direct latex test. The predictive value positive for the latex test was 90%, and the accuracy was 98%. The sensitivity of the latex test for detection of specimens having ten or more colonies of Group A streptococci was 95%. Non-Group A beta-hemolytic streptococci were isolated from 65 specimens, and all of these specimens had negative latex tests. The authors' findings suggest that this direct latex agglutination test is a reliable screening method for rapid detection of Group A streptococci in outpatient throat specimens.

Synthesis of chromophoric, spin label enzyme substrates useful for cryoenzymology

The spin label nitroxide derivative 3-(2,2,5,5-tetramethylpyrroline-1-oxyl)-propen-2-oic acid has been synthesized and characterized by chemical methods. It is a useful intermediate in the preparation of a new class of chromophoric spin label substrates for enzyme studies, as shown by the synthesis of O-3-(2,2,5,5-tetramethylpyrroline-1-oxyl)-propen-2-oyl-L-beta-phenyllactic acid, a specific ester substrate of bovine pancreatic carboxypeptidase A (peptidyl-L-amino acid hydrolase; EC 3.4.12.2). Kinetic parameters of the esterolytic reaction are conveniently determined by UV spectrophotometric methods, and a reaction intermediate can be stabilized in fluid cryosolvent mixtures at subzero temperatures. Results are presented of preliminary electron spin resonance studies to demonstrate that structural relationships of the spin label substrate in a catalytically active configuration to active site residues can be determined for this low temperature-stabilized reaction intermediate. This substrate thus demonstrates the utility of this new class of spin label derivatives for characterization of enzyme reaction intermediates stabilized by cryoenzymologic techniques.

Catalytic role of the metal ion of carboxypeptidase A in ester hydrolysis

The mechanism of action of bovine pancreatic carboxypeptidase. Aalpha (peptidyl-L-amino acid hydrolase; EC 3.4.12.2) has been investigated by application of cryoenzymologic methods. Kinetic studies of the hydrolysis of the specific ester substrate O-(trans-p-chlorocinnamoyl)-L-beta-phenyllactate have been carried out with both the native and the Co2+-substituted enzyme in the 25 to --45 degrees C temperature range. In the --25 to --45 degrees C temperature range with enzyme in excess, a biphasic reaction is observed for substrate hydrolysis characterized by rate constants for the fast (kf) and the slow (ks) processes. In Arrhenius plots, ks extrapolates to kcat at 25 degrees C for both enzymes in aqueous solution, indicating that the same catalytic rate-limiting step is observed. The slow process is analyzed for both metal enzymes, as previously reported (Makinen, M. W., Yamamura, K., and Kaiser, E. T. (1976) Proc Natl. Acad. Sci. U. S. A. 73, 3882-3886), to involve the deacylation of a mixed anhydride acyl-enzyme intermediate. Near --60 degrees C the acyl-enzyme intermediate of both metal enzymes can be stabilized for spectral characterization. The pH and temperature dependence of ks reveals a catalytic ionizing group with a metal ion-dependent shift in pKa and an enthalpy of ionization of 7.2 kcal/mol for the native enzyme and 6.2 kcal/mol for the Co2+ enzyme. These parameters identify the ionizing catalytic group as the metal-bound water molecule. Extrapolation of the pKa data to 25 degrees C indicates that this ionization coincides with that observed in the acidic limb of the pH profile of log(kcat/Km(app)) for substrate hydrolysis under steady state conditions. The results indicate that in the esterolytic reaction of carboxypeptidase. A deacylation of the mixed anhydride intermediate is catalyzed by a metal-bound hydroxide group.