bluuebunny/crossref_metadata_2025 huggingface dataset:
Inequitable Experiences Between Black and White Women Discussing Sexual Health with Healthcare Providers: Findings from a U.S. Probability Sample
Authors: Townes Ashley , Rosenberg Molly , Guerra-Reyes Lucia , Murray Maresa , Herbenick Debby
Published: July 2020

Background

In the United States, efforts to achieve health equity and reduce sexual health disparities remain a national priority; however, limited research has focused on understanding racial differences in patient/provider discussions about sexual health.

Aim

To quantify racial differences between black and white women (aged 18–49 years) in the United States discussing sexual health with a healthcare provider in the past year.

Methods

Data were analyzed from a subset of 1,654 women aged 18–49 years who participated in the 2018 National Survey of Sexual Health and Behavior. Measures of interest included visiting a healthcare provider and discussing sexual health with the provider in the past year. Log binomial models were developed to estimate risk ratios for the likelihood of sexual health topics encountered by black women; models were adjusted for age, marital status, education level, and annual income.

Main Outcome

Black women were significantly more likely to report having a healthcare visit in the past year compared to white women and were more likely to have discussed their sexual health activities.

Results

The adjusted risk ratio (ARR) for black women who reported discussing sex or sexual health with a healthcare provider was 1.16 (95% CI: 1.06–1.26). The ARR for black women who were asked if they were sexually active was 1.16 (95% CI: 1.06–1.26) and about their condom use was 1.49 (95% CI: 1.27–1.74). Black women were nearly 2 times more likely to be offered sexually transmitted disease testing (ARR: 1.72, 95% CI: 1.46–2.02) and to report that they were provided condoms for future use (ARR: 1.94, 95% CI: 1.12–3.36).

Clinical Translation

Healthcare providers are encouraged to have routine sexual health discussions with all patients; however, we found that there are differences among black and white women in discussing their sexual health activities.

Strengths & Limitations

The present study utilized a nationally representative probability survey, including an oversample of black women. The study focused on sexual health discussions of black and white women with a healthcare provider, and therefore, women who did not have a healthcare visit in the past year were excluded from the analysis.

Conclusion

Black women reported having conversations about their sexual activities (eg, condom use) and were offered sexually transmitted disease testing more often than white women. These data provide insights that will impact patient/provider communication and aid in improving the delivery of sexual healthcare for all women.
Male and Female Sexual Dysfunction in Pediatric Cancer Survivors
Authors: Greenberg Daniel R. , Khandwala Yash S. , Bhambhvani Hriday P. , Simon Pamela J. , Eisenberg Michael L.
Published: July 2020

Background

Pediatric cancer survivors suffer indirect long-term effects of their disease; however, there is a paucity of data regarding the effect of pediatric cancer survivorship on sexual function.

Aim

To assess the prevalence and risk factors associated with sexual dysfunction among pediatric cancer survivors.

Methods

Pediatric cancer survivors were recruited to complete an online survey using the Female Sexual Function Index (FSFI) or the International Index of Erectile Function (IIEF-5), both validated questionnaires to assess female sexual dysfunction (FSD) and erectile dysfunction (ED). Patient demographics, oncologic history, prior treatment, and sexual habits were also queried. Logistic regression was used to evaluate risk factors for sexual dysfunction, and Mann-Whitney U test was used to identify factors associated with individual domains of the FSFI.

Outcomes

The main outcome measures were FSFI and IIEF-5 score, which are used to diagnose FSD (FSFI<26.55) and ED (IIEF-5<22).

Results

A total of 21 (72.4%) female respondents and 20 (71.4%) male respondents were sexually active and completed the survey and FSFI or IIEF-5 questionnaire, respectively. Mean (±SD) age was 23.7 (4.1) years, and average age at diagnosis was 9.1 (5.0), with no difference between genders. Overall, 25.0% (5/20) of male and 52.4% (11/21) of female pediatric cancer survivors reported sexual dysfunction (P = .11). Oncologic history and prior treatment were not associated with sexual function. Females who reported difficulty relaxing during intercourse in the last 6 months had higher odds of reporting sexual dysfunction (odds ratio: 13.6, 95% confidence interval: 1.2–151.2, P = .03). Subgroup analysis of FSFI domains found that previous radiation therapy was correlated with decreased lubrication and satisfaction during intercourse, whereas previous treatment to the pelvic region significantly reduced satisfaction and increased pain during intercourse.

Clinical Implications

Female pediatric cancer survivors have higher odds of reporting sexual dysfunction after treatment and should be screened appropriately to provide early intervention and to mitigate risk.

Strength & Limitations

Our study includes validated questionnaires to assess FSD and ED and queries specific characteristics to assess their association with sexual dysfunction. However, the study is limited by sample size and its cross-sectional survey design.

Conclusions

The prevalence of female sexual dysfunction in this cohort is higher than that in the general population of equivalent-aged individuals, and clinicians should be aware of these potential long-term sequelae.
Self-lubricating composites with 2D materials as reinforcement: A new perspective
Authors: Sahoo Seshadev
Published: July 2020

In recent years, composite materials have acquired vast potential in the automotive, aerospace, marine and defence sectors due to suitable mechanical and physical properties. On the other hand, these composites limit their application due to the inferior tribological properties. To improve the tribological properties of composite materials, researchers have suggested the introduction of solid lubricants as a reinforcing phase in the matrix phase for the fabrication of composite materials, which will reduce the friction. Apart from different types of solid lubricants, 2D materials such as graphene, WS2, and MoS2 have emerged as novel solid lubricants with a greater potential to reduce friction. The present paper discusses self-lubrication composite materials, types of 2D solid lubricants, and future challenges and opportunities.
Can Private Forecasters Beat the USDA? Analysis of Relative Accuracy of Crop Acreage and Production Forecasts
Authors: Isengildina-Massa Olga , Karali Berna , Irwin Scott H.
Published: July 2020

This study examines the accuracy of United States Department of Agriculture (USDA) crop Acreage and Production forecasts for corn, soybeans, and winter wheat relative to their private counterparts over 1970–2019. Our main findings suggest that USDA forecasts often had significantly smaller errors than their private counterparts. The accuracy of both USDA and private forecasts has improved over time, but the accuracy of USDA forecasts has improved more than that of private forecasts, maintaining the USDA’s relative accuracy advantage. The accuracy advantage of Prospective Plantings and Acreage reports highlights the importance of survey-based approaches used for these forecasts.
ARABIC TRANSLATION OF GALEN'S ON THE AFFECTED PARTS AND THE GREEK TEXTUAL TRADITION
Authors: ǦumʿA Nashwa , Hamed Iman M. , Pormann Peter E.
Published: July 2020

Galen's highly influential treatise On the Affected Parts (Περὶ τῶν πεπονθότων τόπων, often referred to by its Latin title De locis affectis, hereafter indicated with the abbreviation De loc. aff.) is currently being critically edited by the Corpus Medicorum Graecorum at the Berlin-Brandenburg Academy of Sciences. Over the last decade, a team of scholars, including the present authors as well as the late and lamented Aḥmad ʿEtmān, have worked on producing a critical edition of the Arabic translation of this text, and their efforts are now drawing to a close. Here we present new insights into how this Arabic translation relates to the Greek textual tradition.
The Intermingling of State and Private Companies: Analysing Censorship of the 19th National Communist Party Congress on WeChat
Authors: Ruan Lotus , Crete-Nishihata Masashi , Knockel Jeffrey , Xiong Ruohan , Dalek Jakub
Published: July 2020

This paper examines the relationship between political events and information control on WeChat through a longitudinal analysis of keyword censorship related to China's 19th National Communist Party Congress (NCPC19). We use a novel method to track censorship on WeChat before, during and after the NCPC19 to probe the following questions. Does censorship change after an event is over? What roles do the government and private companies play in information control in China? Our findings show that the system of information control in China can trigger blunt reactions to political events. In addition to critical content around the Congress and leaders, WeChat also censored neutral and potentially positive references to government policies and ideological concepts. The decision making behind this censorship is a product of the interaction between the government, which influences actions through directives, and the companies, which ultimately implement controls on their platforms. While this system is effective in compelling companies to implement censorship, the intermingling of the state and private companies can lead to outcomes that may not align with government strategies. We call for a deeper understanding of the role of private companies in censorship and a more nuanced assessment of the government's capacity to control social media.
Premalignant Changes Identified by Enzyme-Histochemistry with Methacrylate Sections
Authors: Pretlow Theresa P , Pretlow Thomas G
Published: July 2020

The development of cancer is characterized by a long latency between the initial exposure to a carcinogenic substance and the final appearance of a macroscopic tumor. Histochemistry has provided the means to identify specific cells involved in this process and many of the changes that take place during the transformation of normal cells to malignant ones. Putative premalignant lesions have been studied extensively in liver carcinogenesis. Histological sections of grossly normal appearing liver a few weeks after treating animals with carcinogen contain discrete areas or “islands” of aberrant enzyme activity that can be detected with enzyme histochemistry and are commonly called “enzyme-altered foci.” These foci display altered activity of one or more enzymes; one of the most common is increased γ-glutamyl transpeptidase (GGT) activity. Since the activities of most enzymes are destroyed by the heat and solvents used for paraffin-embedding, most of this work was done with frozen sections that are often 10 μm in thickness
Immunogold Labelling of Large Cell Lymphoma with Monoclonal TIA-1 Antibody
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Minda J M , Felgar RE , Salhany KE , Pietra GG
Published: July 2020

Large cell (T - cell) lymphoma is a malignant neoplasm derived from activated lymphoid cells, involving lymph nodes, spleen, subcutaneous lesions. Ultrastructural examination facilitates the determination of this particular type of lymphoma, specifically by the presence of lytic granules in the cytoplasm containing proteins involved in the target cell destruction. One of these, expressed specifically is TIA-1, a cytotoxic granule-associated protein with RNA binding domains initially identified using a monoclonal antibody reactive with a 15KD protein present in the granules of cytotoxic lymphocytes.

Tissue from seven cases of large cell lymphoma from the archives of our department were fixed for electron microscopy studies with a mixture of4% paraformaldehyde and 1% glutaraldehyde in 0.1M sodium cacodylate buffer and embedded either in Poly/Bed 812 with osmium tetroxide postfixation, or in LR White without osmication. For immunogold labelling, ultrathin sections placed on Nickel grids were incubated with a murine monoclonal TIA-1 antibody (1:50) (Coulter Co) overnight at 4°C.
C-Ret Proto-Oncogene Expression in Human Prostate: An Immunohistochemical Evaluation
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Dawson DM , Lawrence E G , MacLennan G , Pretlow TG
Published: July 2020

C-ret proto-oncogene encodes a protein in the tyrosine kinase (TK) family of transmembrane receptors for growth factors. C-ret expression has been identified in normal tissues and tumors of neural crest origin such as inherited MEN (multiple endocrine neoplasia) syndromes, particularly medullary thyroid cancers where there are confirmed germ-line mutations. Gene rearrangement has been observed in papillary thyroid carcinomas (PTC) and has been shown to have cytoplasmic localization of the altered gene product. C-ret proto-oncogene product is also necessary for the normal development of the peripheral nervous system, enteric nervous system and the kidney. A recent profile of the TK receptors in prostate cancer (PCA) identified c-ret protein in prostate cancer tissue and xenograft derived from human PCA. This study is the first to report the immunohistochemical (IH) evaluation of c-ret in human prostatic tissue.

Thirty radical prostatectomy specimens for PCA were formalin-fixed, sectioned at 5mm and paraffin-embedded.
Vitamin C and K3-Induced Oxidative Stress in Human Prostate Tumor Cells: Mitochondrial Ultrastructural Alterations.
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Jamison JM , Gilloteaux J , Koch J A , Nicastro E , Docherty JJ , Jasso J , Summers JL
Published: July 2020

Vitamins C (VC) and K3 (VK3) and a VC: VK3 combination with a VC: VK3 ratio of 100:1 were assayed for their antitumor activity against a DU 145 human prostate cancer cell line. Co-administration of the vitamins enhanced the antitumor activity 20-25 fold even with a lh exposure time. While exogenous catalase destroyed the antitumor activity, hydrogen peroxide-induced lipid peroxidation was negligible. The results of additional assays revealed: a transient increase in ATP production, a decrease in DNA synthesis, and increase in protein synthesis and a decrease in thiol levels. Subsequently the DU145 cells were treated with each vitamin alone or with the vitamin combination at their 50% cytotoxic doses and then examined using transmission electron microscopy. Treatment of DU145 cells with the vitamin combination exacerbated the cytotoxic effects induced by individual vitamin treatment.

Untreated DU145 cells show numerous mitochondria whose pale matrices are in sharp contrast to the cytoplasmic background (Fig. 1).
Earliest Steps in Primary Tumor Formation and Micrometastasis Resolved with Histochemical Marker Gene-Tagged Tumor Cells
Authors: Culp L A , Lin W-c , Kleinman N , O'Connor K , Lechner R
Published: July 2020

To facilitate detection of tumor cells at the highest resolution in an athymic nude mouse model system, Balb/c 3T3 cells transformed with the Harvey ras oncogene were transfected with the histochemical marker gene, bacterial lacZ (LZEJ cells). Alternatively, 3T3 cells transformed with the human sis oncogene were transfected with human placental alkaline phosphatase marker gene (APSI cells). Within minutes of subcutaneous injection, these tumor cells could be detected histochemically and the fate of cells followed with time. APSI or LZEJ cells gave very different single-cell morphologies at this site but yielded similar aggregation patterns of cells. Clearance of some cells could readily be detected by diffusion of histochemical product as “curly-haired” organizations of cells condensed into ovoid collections. Expansion of the population occurred with division of many cells in the population, not just one or a few cells. Cell number was quantitated by the development of ultrasensitive luminometry assays for the two histochemical marker enzymes; different kinetics were observed for establishment of LZEJ or APSI cells.
Molecular Mechanisms of Tumor Cell Survival, Growth, and Apoptosis During Organ-Specific Metastasis
Authors: Radinsky R , Bucana C D , Cho C H
Published: July 2020

Metastasis is a highly selective nonrandom process favoring the survival of minor subpopulations of metatastatic cells that preexist within the primary tumor. The cellular and molecular mechanisms that regulate the metastasis of tumor cells to specific organs are diverse and both tumor and organ-specific (1). Many examples exist in which malignant tumors metastasize to specific organs. As Paget proposed in 1889 (2), and as our recent biological and molecular evidence demonstrates, the organ microenvironment influences the invasion, survival, growth, and apoptosis of particular tumor cells. This hypothesis explains metastatic colonization patterns that cannot be due to solely mechanical lodgement/anatomical considerations (1). Successful metastasis therefore involves the interaction of tumor cells with a compatible milieu provided by a particular organ environment.

Recent experimental evidence suggests that paracrine stimulation of tumor cells by organ-derived growth factors and cytokines is one mechanism which determines the target organ preference of disseminated cancer cells.
Oxidative Damage to Axonal Cytoskeletal Proteins
Authors: Perry G , Zelasko D A , Sayre L M , Smith M A
Published: July 2020

Proteins of the axonal cytoskeleton, particularly neurofilament and microtubule-associated protein τ, should be particularly sensitive to the effects of oxidative modification due to their high content of lysine, an amino acid that is particularly susceptible to direct oxidization as well as adduction by carbonyls produced from lipid and sugar oxidation. To understand the susceptibility of the cytoskeleton to oxidative modification and whether such modification is related to the physiological function of the cytoskeleton, we undertook a cytological analysis of motor neurons isolated from mouse spinal cord. These neurons contain an abundant axonal cytoskeleton that can be readily analyzed distinct from the cell body. Immunocytochemistry, using antibodies against protein-adducts of the highly reactive lipid peroxidation product, hydroxynonenal (HNE), representing Michael addition or pyrrole formation, revealed that HNE-immunoreactive adducts are found in all axons. This in situ distribution of HNE-adducts is consistent with immunoblots prepared from axons which show selective HNE modification of neurofilament heavy subunit (NFH) but not of other cytoskeletal proteins.
Effect of Gasohol on The Rat Liver
Authors: MacDuff BA , Singh A , Chu I
Published: July 2020

Although there are a variety of gasoline ethanol mixtures proposed as neat fuels (ethanol 85% + gasoline 15% = E85; E95) for automobiles, gasohol (gasoline 90% + ethanol 10%) is presently used as a fuel in the United States. The adverse effects, if any, of gasohol ingestion are unknown; effects on the liver of rats administered gasohol are examined in this study.

Twenty-four female Sprague-Dawley rats received daily, via gavage, one of the three concentrations of gasohol for 28 days; LD50/20, LD50/100 and LD50/1000, where LD50 = 1.5g ethanol / kg body weight (bw) and 14g gasoline / kg bw. The LD50 was based on that of gasoline, which was obtained from literature value.1 The amount of ethanol added to stock gasohol was only 1/10 its LD50, required to maintain the gasoline ethanol proportion of 9:1. Gasohol was administered in corn oil with total volume 10 ml. Animals that received only corn oil served as controls.
Novel Second Generation Platinum Containing Antineoplastic Agents Ssp, Sap, and Poly-Plat and Their Effect on Glucose 6 Phosphate Dehydrogenase (Ec 1.1.1.49) in the Liver and Kidney of Male Wistar Rats.
Authors: Multhaupt T P , Aggarwal SK
Published: July 2020

Poly-(trans-l,2-diaminocyclohexane) platinumj-carboxyamylose (Poly-Plat); 5-SuIfosalicylato-trans-(l,2-diaminocyclohexane) platinum (SSP); and 4-Hydroxy-a-sulfonylphenylacetato (trans 1,2-diaminocyclohexane) platinum (II) (SAP) (Andrulis Pharmaceuticals, Bethesda, MD) are three novel second generation platinum containing antineoplastic compounds. Initial studies indicate that these agents are more effective in the treatment of cancer while at the same time less toxic to the organism as a whole than cisplatin (CDDP). The present study was undertaken to examine the effects of these new compounds on glucose-6-phosphate dehydrogenase (G-6-PDH) as compared to CDDP treated and normal kidney and liver tissues.

Wistar rats (100-120g) were given intraperitoneal injections of CDDP (9 mg/ kg) and Poly-Plat, SSP and SAP (10 mg/ kg) over a 5 day period. On day 6 the animals were sacrificed and tissues (kidney and liver) were freeze sectioned (7 μm). Sections were incubated in media according to the accepted method specific for the G-6-PDH localization at a pH of 7.46 for 30 min.
Acute Ocular Effects of Mustard Gas: Anatomic Pathology and Immunohistopathology of Exposed Cornea
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Petrali JP , Hamilton TA , Finger AV , Dick E J
Published: July 2020

Sulfur mustard gas (HD), a synthetic vesicating agent used effectively as a major chemical warfare agent during World War 1, continues to be a modern day threat agent. Unfortunately there is no specific pretreatment or antidotal therapy for those who may become exposed. Whole body exposure results in cutaneous, respiratory and ocular effects. of these, eye impairment leads to the most immediate incapacitation. However HD-induced eye lesions remain to be fully characterized. In the present study we explore histological, ultrastructural and immunopathological effects of a vesicating dose of HD in rabbit cornea occurring during the first 24 hours following exposure.

A 0.4μl drop of liquid HD was placed on the left cornea of anesthetized rabbits. The right cornea served as an unexposed control. Following exposure animals were returned to their cages and given appropriate care by an attending veterinarian. Eye injury was evaluated by clinical observations and given scores of severity from simple conjunctival redness to apparent corneal damage.
Morphologic Identification of Viral Gastroenteritis Caused by a Human Calicivirus Strain Undetected Initially by Molecular or Immunologic Methods
Authors: Humphrey C D , Noel J S , Liu B L , Rodriguez E M , Lambden P R , Clarke I N , Dwyer D M , Ando T , Glass RI , Monroe S S
Published: July 2020

Molecular and immunologie assays for virus identification and characterization are well known for their high specificity and sensitivity. High specificity occasionally hampers efforts to detect virus strains distantly related to previously recognized types and may allow infectious agents to be undetected when these techniques are used for identification. We describe in this report such an example with an outbreak of foodborne gastroenteritis.

Forty-six cases of gastrointestinal illness were reported in May 1994 among adult staff of a Parkville, Md., school after a catered luncheon. Symptoms included stomach cramps, nausea, diarrhea, and vomiting. Seven stool specimens, negative by routine bacteriological screening, and 14 acute-and convalescent-phase sera from patients involved in the outbreak were tested for viruses. The stool specimens were examined by electron microscopy (EM) and reverse transcription-polymerase chain reaction (RT-PCR) designed to detect small round structured viruses (SRSVs). In addition, serum specimens were tested for IgG antibody to recombinant capsid proteins from Norwalk virus (rNV) and Toronto virus (rTV) using a direct enzyme immunoassay (EIA).
Effects of Atovaquone on the Ultrastructural Morphology of Pneumocystis Carinii
Authors: Goheen MP , Bartlett MS , Shaw MM , Meshnick SR , Smith JW
Published: July 2020

Pneumocystis carinii pneumonia (PCP) occurs at some time in most patients with acquired immunodeficiency syndrome (AIDS). Trimethoprim/sulfamethoxazole or pentamidine isothionate are the traditional modes of therapy for treatment and prophylaxis of PCP. Unfortunately these drugs are associated with a significant incidence of adverse side effects particularly in patients with AIDS. Toxicity and a growing concern that P. carinii strains are becoming resistant to these compounds is providing the impetus for the search for additional drugs to combat P. carinii. Atovaquone, developed as an antimalarial agent, has activity against a wide range of other organisms, including Toxoplasma sp. and P. carinii, with a lower incidence of adverse reactions during clinical trials. Atovaquone inhibits mitochondrial respiration in P. falciparum and P. carinii. In this study transmission electron microscopy (TEM) was used to observe the effects of atovaquone on P. carinii organisms in short term spinner flask culture.

Spinner flask cultures of human embryonic lung cells were inoculated with P. carinii from infected rat lung.
Towards Understanding the Structural Basis of Endogenous Transcription in dsRNA Viruses
Authors: Venkataram Prasad B V , Lawton J A , Zeng C Q -Y , Estes M K
Published: July 2020

In double-stranded RNA (dsRNA) viruses found in animals, bacteria, and yeast, the genome is transcribed within the structurally intact core of the virion with extraordinary efficiency. How is the genome transcribed within the confines of the intact core particles? How are the nascent mRNA transcripts released through the capsid layers? Critical to our understanding of the structural basis of endogenous transcription is the characterization of the internal organization in terms of genome and transcription enzymes in these viruses. Our recent structural studies on rotavirus, a prototypical dsRNA virus, have begun to provide a better understanding of this process.

Rotaviruses are the major pathogens of infantile gastroenteritis. These are complex and relatively large (1000 Å in diameter), nonenveloped icosahedral viruses. The structure of rotavirus is composed of three concentric capsid protein layers enclosing eleven strands of dsRNA (Fig. 1a). Although previous structural studies using electron cryomicroscopy and computer image processing, have described the overall architecture of the rotavirus, the structural details of internal organization has been elusive.
Effects of Varying Salinity on the Endoplasmic Reticulum System in Leaf Epidermal Cells of Ruppia Maritima
Authors: Barnabas AD
Published: July 2020

Ruppia maritima L. is a submerged halophyte which is capable of growing in a wide range of salinities. In a previous study, the effects of varying salinity on the ultrastructure of leaf blade epidermal cells of R. maritima were investigated. The ultrastructural morphology of the cells, including organelle number and distribution, differed at different salinities. However, salinity effects on the endoplasmic reticulum (ER) system could not be assessed since this cytoplasmic component was not readily discernible in material processed in the conventional manner for transmission electron microscopy (TEM). In the present study, selective staining of the ER was achieved, and the response of this membrane system to different salinities ascertained.

Leaf material from plants growing at two salinities (5‰and 20‰) was examined. The zinc iodide-osmium tetroxide (ZIO) impregnation technique was used to stain the ER, and its morphology and distribution determined in leaf blade epidermal cells exposed to the different salinities. Leaf samples were fixed in glutaraldehyde, post fixed in an aqueous mixture of ZIO, dehydrated, and embedded in resin. Controls were processed in exactly the same way, but without ZIO post fixation. Sections with dark gold to purple interference colours were cut and examined unstained with a Phillips 301 TEM.
Characterization of Waxy Material of the Giant Whitefly, Aleurodicus Dugesii, Using Scanning Electron Microscopy (SEM) and Capillary Gas Chromatography-Mass Spectrometry (CGC-MS)
Authors: Freeman T P , Nelson D R , Buckner J S , Ruud R L , Fatland C L
Published: July 2020

The giant whitefly is a pest, particularly of Hibiscus and sometimes avocados, in southern California. The insect is unique in that the nymphal stages produce copious quantities of waxy material differing in structure and chemical composition. Adults produce a waxy material (waxy particles) which covers them and surrounding surfaces, and the female also produces a waxy material with which she forms a circular trail of wax strands on the abaxial leaf surface.

Waxy particles produced by male and female adults consisted of long-chain aldehydes and alcohols, largely 32 carbons in chain length. As waxy ribbons extruded from anterior abdominal wax plates, they are periodically broken off by the tibia and the resulting particles coat adults, nymphs and surrounding surfaces. The female has a second set of wax plates posteriorly on her abdomen which produce waxy strands. As her abdomen drags along the abaxial leaf surface during oviposition these strands break off forming a waxy trail camouflaging the eggs.

The nymphs produce several types of waxy material. Two types are produced at the same time from 10 pores on the dorsal surface; waxy material is extruded as a filament on which a second waxy material curls off as extrusion occurs.
Squid Gill - a System for Studying Biorhythms
Authors: Guha T , Sen A , Brahmachary R L
Published: July 2020

It is well known that cephalopods ( octopus, squid, cuttle fish etc. ) have various pulsatile systems in their bodies. We have now used the gills of Loliolus investigatoris and Loligo dauvauceli, two small squids found in the Bay of Bengal, as a system for studying such autonomous pulsations. The gills excised out of squids cast on the beach from fishing nets can be maintained in pasteurised sea water for 3 4 or 5 days in petri dish where they continue to execute the rhythmic movements.

The gill samples were fixed in 2% Gluteraldehyde in 0.1M Phosphate buffer (pH 7.4).for 48 hours, then washed with filtered pasteurised sea water, followed by washing in distilled water, dehydration in acetone and critical point drying in liquid CO2 and coating with gold.

Fig. 1.depicts an ablated gill which executes an oscillatory motion as a whole; more importantly, the individual finger like projections shown in fig. 2, exhibit rhythmic lateral movements and the blood-vessels, as a result of constrictions and dilation, seem to “tick” like a clock in rapid succession. Periodicity of the gill swinging as a whole is about one swing per 7-8 seconds, for the sidewise swing it varied from 35 to 70 seconds in one gill, 11-39 in another while the “ticking” is about once a second. This last one is, however, lost after a few hours.
Intracellular Traffic of Glucocorticoid Receptors: Studies With Green Fluorescent Protein Chimeras in Living Cells
Authors: Barsony J , Carroll J , McKoy W , Renyi I , Gould DL , Htun H , Hager G
Published: July 2020

As ligand-regulated transcription factors, glucocorticoid receptors (GR) must traffic through the cytoplasm, traverse the nuclear pores, and subsequently traffic within the the nucleus to reach their target genes. Due to technical difficulties with immunocytology, little is known about the translocation process or the intranuclear localization. The recent characterization of a chromophore, green fluorescent protein (GFP), provided a general tool to fluorescently label proteins in living cells. With the development of a transcriptionally active GFP-GR chimera, it became possible to visualize GR translocation and intranuclear distribution in living cells.

This chimeric receptor was transiently transfected into mouse adenocarcinoma cells, allowing the direct visualization of GR using real-time video and confocal laser scanning microscopy. Mobility of GFP-GR was analyzed with fluorescent recovery after photobleaching (FRAP).

The hormone-free GFP-GR was localized in the cytoplasm figure 1). Dexamethasone (lOnM) initiated GFP-GR translocation into the nucleus (Figure 2 and 3). The translocation rate was dose- and temperature-dependent, and occurred in a pulsatile manner along cytoplasmic fibrillar structures (Figure 2). FRAP experiments showed that GFP-GR remained in motion within the nucleus after translocation.
PIT-1 Protein Localization at Different Optical Sections in a Single Living Cell Using FRET Microscopy and Green Fluorescent Proteins
Authors: Periasamy Ammasi , Day Richard N
Published: July 2020

The pituitary specific transcription factor Pit-1 is required for transcriptional activity of the prolactin (PRL) gene. The Pit-1 protein is a member of the POU homeodomain transcription factors that is expressed in several different anterior pituitary cell types, where it functions as an important determinant of pituitary-specific gene expression. The Pit-1 protein generally interacts with DNA elements in the PRL gene promoter as a dimer, and has been demonstrated to associate with other transcription factors. The objective of our research is to define the critical molecular events involved in transcriptional regulation of the PRL gene in living cells. Methods that allow monitoring of the intimate interactions between protein partners in living cells provide an unparalleled perspective on these biological processes. Using the jellyfish green fluorescent protein (GFP) as a tag, we applied the fluorescence resonance energy transfer (FRET) technique to visualize where and when the Pit-1 protein interacts in the living cell. FRET is a quantum mechanical effect that occurs between donor (D) and acceptor (A) fluorophores provided: (i) the emission energy of D is coincident with the energy required to excite A, and (ii) the distance that separating the two fluorophores is 10-100 Å. Mutant forms of GFP that fluoresce either green or blue (BFP) have excitation and emission spectra that are suitable for FRET imaging.
Localization of HPV and SC35 Domains in SiHa and CaSki Cells by TSA Using Fluorescent Tyramides
Authors: Adler KE , Moen PT , Erickson TJ , Bobrow MN
Published: July 2020

Detection of integrated HPV DNA in SiHa and CaSki cells has been demonstrated by in situ PCR (1,2,3) and more recently TSA (4). These reports focused on high sensitivity single copy HPV detection using chromogenic techniques. Here we utilize high resolution and high sensitivity fluorescent methods of detection to analyze the spatial relationship of HPV DNA with respect to subnuclear domains enriched in splicing-related proteins, shown here by immunofluorescent detection of the SC-35 antigen (5). In situhybridization was performed using conventional reagents and the resulting probe signal amplified using fluorescent labeled tyramides (6). In contrast to techniques such as in situ PCR which require specialized procedures and equipment, detection of HPV DNA in SiHa cells was rapidly and routinely achieved using no specialized equipment. In addition, high target resolution was maintained, in contrast to in situ PCR, which is plagued by signal dispersion and difficult localization (7).
Epidermal Growth Factor Receptor mRNA Expression in Diseased Human Liver: An In Situ Hybridization Study Using Biotin-Labeled Oligonucleotide Probes and Tyramide-Enhanced Detection
Authors: G. Kömüves László , Feren Anna , Jones Albert , Fodor Eric
Published: July 2020

Deregulation of epidermal growth factor receptor (EGFR) gene expression is belived to be a major factor in the development of epithelial cell tumorigenesis, including hepatic carcinomas. To examine EGFR expression within the course of liver cirrhosis, we have identified its hepatic mRNA distribution using a biotinylated antisense oligonucleotide probe.

In this study liver samples from liver transplantation recipients were fixed with 4% formaldehyde in PBS for 24 h and embedded in paraffin. Following treatments aimed to promote probe penetration and eliminate non-specific probe binding, an EGFR antisense biotin-labeled oligonucleotide probe was hybridized to sections at 45°C for 4h. High and low stringency washes were designed to remove the unbound probe. Following the blocking of non-specific tissue binding, sections were incubated with streptavidin-peroxidase. Biotinylated tyramide was then used for signal amplification. After washing, streptavidin-peroxidase was reapplied, followed by colorimetric detection of peroxidase activity using DAB as substrate. The sections were counterstained with hematoxylin and coverslipped.
Constitutive Expression of Interferon β in Differentiated Epithelial Cells
Authors: Bielenberg DR , Fidler IJ , Bucana CD
Published: July 2020

Interferon beta (IFN β) is a member of the family of secreted proteins that compose the host defense against viral, bacterial, and parasitic infections and tumors. The interferons exert their activity indirectly by regulating a number of other proteins. Low level expression of IFN β has been reported in a variety of non-epithelial cells from normal animals. Here, we demonstrate the expression of IFN β in epithelial cells lining organs that are chronically exposed to a variety of environmental challenges.

Tissue samples from the digestive system, urinary bladder, mammary fat pad, skin and cornea of C3H/HeN mice were fixed with 10% formalin and processed for histology. Immunoperoxidase was performed on tissue sections that had been de-waxed and treated with trypsin. Briefly, the sections were incubated with rabbit anti mouse IFN β (Lee Biomolecular, San Diego, CA) overnight at 4°C, washed and incubated further with a peroxidase conjugated goat anti-rabbit IgG, (F(ab) 2) (Jackson ImmunoResearch Laboratories, Inc., West Grove, PA) for 1 h at ambient temperature.
Effect of Biotinylation on Fibrinogen Function and Fibrinogen-Platelet Interaction
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Mattson JC , Estry DW , Farrah DM , Wolak HH , Westley S
Published: July 2020

Biotinylation of antibodies to be used in immunolocalization studies is a well established approach to mapping epitopes in biological specimens at both the light and ultrastructural level. Biotinylation of antibodies does not appear to significantly alter their interaction with antigen. A similar approach has been proposed for examining ligand interaction with receptors. Producing a soluble biotinylated ligand that behaves similarly to unlabeled ligand avoids the problems introduced by particulate labels such as ferritin, gold and latex. Particulate labels for ligands can be especially problematic in studies of receptor behavior in live cells since viable cells may directly react to the particulate probe itself. The interaction of plasma fibrinogen with its receptor on blood platelets, GPIIb-IIIa, is required for platelet-platelet cohesion and subsequent formation of a hemostatic platelet plug at sites of vascular injury. To study the events that follow binding of fibrinogen to its receptor5 we have produced a series of fibrinogens biotinylated with molar ratios of biotin:fibrinogen that range from 5 to 50.
Effects of Cisplatin Administration on the Inducible Nitric Oxide Synthase and Somatostatin in the Pancreatic Islets
Authors: Wang Ying , K. Aggarwal Surinder
Published: July 2020

Cisplatin, a potent broad spectrum anti-cancer agent, has been proven effective in the treatments of bladder, lung, ovarian, head and neck, and testicular cancers. Drawbacks of this chemotherapeutic drug are its toxic side-effects, which include severe nausea, vomiting, stomach distention, peptic ulcer and hyperglycemia. Cisplatin treatment induces the hyperglycemia both in clinical situation and the rodents. Because of the role of the inducible nitric oxide synthase (i-NOS) and somatostatin on the dysfunction of the β-cell of the pancreatic islets and the suppression of the insulin secretion, these were studied using immunocytochemical methods before and after cisplatin treatments using rats.

Wistar rats (100-150 g) were divided into two groups of 6 animals each. One group received injections of cisplatin (9 mg/kg) in 0.85% saline in 5 divided dosages over a 5 days period. The other group received the vehicle of injection only. Rats were killed one day after the last injection.
Immunohistochemical Identification and Electron Microscopic Study on Early Migrating Neural Crest Cells in the Chick Embryo
Authors: Monteagudo de la Rosa M , González-Santander Martínez M , Martinez Cuadrado G , González Santander R
Published: July 2020

Just after neural fold fusion to form the neural tube, neural crest cells detach from the neural crest, a transient structure located in the dorsal region of the neural tube. Neural crest cells migrate and differentiate into many structures and cells. But the underlying controls of this detachment and initiation of emigration are unknown. Neural crest cells are usually not morphologically distinct from the adjacent neural epithelium (neural tube) and epidermal ectoderm (epiblast) flanking them. We are combining morphological and immunohistochemical approaches to study neural crest cells in their early stage of detachment from the neural crest.

Hamburger and Hamilton (1951) stages 9 to 12 White Leghorn chick embryos. Fixation in 2.5% glutaraldehyde - 0.5% tanic acid and postfixation in 1% osmium tetroxide. Embryos contrasted in bloc using uranyl acetate and embedded in araldite. Semithin transversal sections stained with toluidine blue for light microscopy. Ultrathin sections contrasted with lead citrate.
Sclerotome Mitotic Activity in Stage 19 Chick Embryo Braquial Somites
Authors: González-Santander Martinez M , Monteagudo de la Rosa M , Martinez Cuadrado G , González Santander R
Published: July 2020

Somite disintegration begins with the disruption and dispersion of cells in its ventromedial region, that upon detaching from the somite form a defined group of cells called “sclerotome”. The sclerotome is formed by scleroblasts that originate paraxial segments. Scleroblasts disperse and migrate forming the “sclerotomal mesenchyma”. This sclerotomal mesenchyma, in its evolution and cell differentiation, will give rise to skeletal tissues. One of the first features of the scleroblast is the production of extracellular matrix rich in hialuronic acid that facilitates the spreading of filopodia and the migration of the sclerotome. Sclerotome development is closely associated to the microenvironment created by the extracellular matrix in which scleroblasts are located. Hialuronic acid is found in the ample intercellular spaces occupied by the hydrated matrix.

White Leghorn chick embryos at H.H. stages 9 to 12 were fixed in 2.5% glutaraldehyde, postfixed in 1 % osmium tetroxide and embedded in araldite. Semithin transversal sections were stained with toluidine blue and visualized under the light microscope to locate the sclerotome.
Rolling Circle Amplification of Cyclizable Dna Probes by ∅29 Dna Polymerase: A Tool for in Situ Single-Copy Gene Detection.
Authors: Lizardi Paul M , Bray-Ward Patricia , Ward David C
Published: July 2020

Oligonucleotide probes that can be cyclized by ligation (“padlock probes”) provide a very high degree of recognition specificity. Nilsson et al. have demonstrated the used of padlock probes for the cytological localization of alphoid repeats in chromosome 12. We have been extending the use of padlock probes to the detection of single copy sequences, and with this in mind have explored the amplification of DNA circles.

We designed a primer complementary to the arbitrary backbone (non-probing) sequence of a 92-base closed circular probe oligonucleotide and investigated the kinetics of rolling circle replication. Using the highly processive, strand-displacing DNA polymerase of phage ∅29 (kindly provided by Dr. Margarita Salas, CSIC, Madrid, Spain) we demonstrated that several hundred tandem copies of the circular oligonucleotide are generated in a few minutes of incubation at 32°C. Because the amplified DNA remains hybridized to the circle in a rolling circle reaction, this method of amplification offers unique advantages for in situ gene detection since the amplified DNA can not diffuse away from the site of synthesis.
New Insights Into the Three-Dimensional Structure of the Nucleus and Chromosomes
Authors: Sedat J , Marshall W , Dernburg A , Fung J , Agard D
Published: July 2020

Recent methodology, to be described, now makes possible specific localization and analysis of genetic loci within 3-Dimensional interphase nuclei in intact cells and tissues with minimal perturbation of the chromosome structure (Dernburg and Sedat, 1997). These techniques define genetic loci that specifically interact with the nuclear envelope and interior structures; we are able to map all loci to highly localized 3-dimensional positions within Drosophila embryonic nuclei (Marshall et al, 1996). S-Dimensions-as-a-function-of-time (4-D) studies of live nuclei, from Yeast and Drosophila, allow dynamic chromosome interactions to be probed and quantitated. Our results suggest a very dynamic but highly determined and organized nucleus. Using these approaches, we can now study specific mechanisms leading to homologue chromosome pairing and position-effect variegation (Dernburg et al., 1996).
Structural Analysis of Large-Scale Chromatin Organization
Authors: Belmont A S , Li G , Sudlow G , Tumbar T , Strukov Y , Basu S , Delaney A
Published: July 2020

Our laboratory is interested in understanding how 10 and 30 nm chromatin fibers fold to form interphase and mitotic chromosomes. Experimentally this has been a very difficult problem to investigate due to a number of technical difficulties. A common approach to this level of chromatin organization has been to use protein extraction conditions which experimentally “unravel” the native chromosome architecture. The difficulty with this approach is separating in vitro produced artifacts from remnants of in vivo structure.

As an alternative strategy we are focusing on changes in interphase chromosome structure during cell cycle progression and initiation of transcription or DNA replication, with the goal of identifying intermediates in the pathway of chromosome condensation or decondensation. A key element of this strategy is preserving chromosome structure as close as possible to its in vivo structure while using 3-dimensional light and electron microscopy reconstruction methods to “computationally” unravel native chromosome structure.
Laser Scanning Microscopy Applied to Studies of the Cell Cycle.
Authors: Luther Ed , Kamentsky Louis A
Published: July 2020

Non-confocal Laser Scanning Microscopy (LSCM) was developed to allow applying the tenents of flow cytometery to specimens attached to a microscope slide (1). Areas of the slide are scanned, fluorescently labled cells are automatically segmented, and a list of features for each cell is calculated and stored in a list mode data file. Figure 1 shows a block diagram of the LSCM. A collimated laser beam scans in the y direction, and values from photomultiplier and photodiode detectors are digitized to.25 micron resolution. The automated stage advances in.5 micron steps in the x direction. When cascading memory banks are filled, the “image” is segmented. Figure 2 shows contours drawn as part of the segmentation process. The innermost contour is drawn around pixels that exceed a predetermined threshold, and is used to define events. Other contours are used to define integration areas, background calculation and correction, and integrating nuclear vs. peripheral fluorescence areas.