Claude E Gagna - Academia.edu (original) (raw)

Papers by Claude E Gagna

PubMed, 1991

The purpose of this study was to reveal the presence of Z-helical conformation in normal crystall... more The purpose of this study was to reveal the presence of Z-helical conformation in normal crystalline lens DNA. Z-DNA antigen was prepared against poly(dG-dC).poly(dG-dC), which had been converted to the Z-helix conformation in high salt and then stabilized by bromination. Circular dichroism (CD) spectra confirmed the presence of left-handed Z-helix DNA. Antibodies to Z-DNA were raised in three rabbits immunized with brominated (Br-) poly(dG-dC).poly(dG-dC). These antibodies do not cross-react with polynucleotides in the B-helical form, but are specific to the left-handed Z-DNA conformation. DNA was isolated from three different regions of the calf lens. Anti-Z-DNA antisera, affinity purified IgG polyclonal anti-Z-DNA antibodies and monoclonal anti-Z-DNA antibodies were used as immunoprobes to detect the presence of S-DNA sequences. DNA from the cortex region of the lens reacted strongly with the anti-Z-DNA antibodies, but no binding could be observed in the DNA from the nucleus region. Digestion of lens DNA with DNase 1 dramatically decreased Z-DNA antibody binding, while RNase A and T1 treatment had no effect on Z-DNA immunoreactivity. This study has demonstrated that: (a) Z-DNA antibodies developed for our study can bind in high salt solutions (4M NaCl) to purified lens DNA sequences isolated from a variety of different calf lens cell types. By this criterion, lens DNA contains sequence determinants which may assume or are in the Z-helix conformation.

Clinics in Dermatology, Dec 31, 2023

We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying... more We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying dermatophytes in human skin tissue sections (ie, B-DNA dermatophyte assay) and demonstrate, for the first time, the presence of dermatophytes in tissue using immunohistochemistry to detect canonical right-handed double-stranded (ds) B-DNA. Immunohistochemistry was performed using anti-ds-B-DNA monoclonal antibodies with formalin-fixed paraffin-embedded tissues to determine the presence of dermatophytes. The B-DNA assay resulted in a more accurate identification of dermatophytes, nuclear morphology, dimensions, and gene expression of dermatophytes (ie, optical density values) than periodic acid-Schiff (PAS), Grocott melhenamine silver (GMS), or hematoxylin and eosin (H&E) stains. The novel assay guided by artificial intelligence allowed for efficient identification of different types of dermatophytes (eg. hyphae, microconidia, macroconidia, and arthroconidia). Using the B-DNA dermatophyte assay as a clinical tool for diagnosing dermatophytes is an alternative to PAS, OMS, and H&E as a fast and inexpensive way Lo accurately detect dermatophytosis and reduce the number of false negatives. Our assay resulted in superior identification, sensitivity, life cycle stages, and morphology compared to H&E, PAS. and OMS stains. This method detects a specific structural marker (ie, ds-B-DNA), which can assist with diagnosis of dermatophytes. It represents a significant advantage over methods currently in use.

Clinics in Dermatology, 2024

We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying... more We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying dermatophytes in human skin tissue sections (ie, B-DNA dermatophyte assay) and demonstrate, for the first time, the presence of dermatophytes in tissue using immunohistochemistry to detect canonical right-handed double-stranded (ds) B-DNA. Immunohistochemistry was performed using anti-ds-B-DNA monoclonal antibodies with formalin-fixed paraffin-embedded tissues to determine the presence of dermatophytes. The B-DNA assay resulted in a more accurate identification of dermatophytes, nuclear morphology, dimensions, and gene expression of dermatophytes (ie, optical density values) than periodic acid-Schiff (PAS), Grocott melhenamine silver (GMS), or hematoxylin and eosin (H&E) stains. The novel assay guided by artificial intelligence allowed for efficient identification of different types of dermatophytes (eg. hyphae, microconidia, macroconidia, and arthroconidia). Using the B-DNA dermatophyte assay as a clinical tool for diagnosing dermatophytes is an alternative to PAS, OMS, and H&E as a fast and inexpensive way Lo accurately detect dermatophytosis and reduce the number of false negatives. Our assay resulted in superior identification, sensitivity, life cycle stages, and morphology compared to H&E, PAS. and OMS stains. This method detects a specific structural marker (ie, ds-B-DNA), which can assist with diagnosis of dermatophytes. It represents a significant advantage over methods currently in use.

Journal of Investigative Dermatology, Aug 1, 2022

The FASEB Journal, Apr 1, 2013

Biophysical Journal, 2014

Journal of Histochemistry and Cytochemistry, Nov 1, 1997

Pharmacogenomics, May 1, 2009

The FASEB Journal, Apr 1, 2018

Microscopy and Microanalysis, Aug 1, 2001

The purpose of this research project was to characterize the distribution of left-handed Z-RNA se... more The purpose of this research project was to characterize the distribution of left-handed Z-RNA sequences within the epithelial cells of the adult noncataractous crystalline dog lens: the meridional rows (MR). This was achieved by using anti-Z-RNA IgG polyclonal antibody probes. Both light microscopy (LM) and electron microscopy (EM) were used to analyze the tissue binding of the anti- Z-RNA antibodies. Nucleic acids can adopt many different helical conformations (1), such as Z-DNA (Fig. 1) and Z-RNA (2,3). The lens is made up of a single cell type, which is a monolayer of undifferentiated epithelial cells covering its anterior surface (Fig. 2). At the equator of the lens, these cells elongate and form concentric layers of the secondary (nucleated) fiber cells, which undergo cell death-terminal differentiation (denucleation). The epithelial monolayer consists of several cell types, each of which has unique characteristics.The production of anti-Z-RNA polyclonal antibody probes was achieved using four

Actinic keratoses (AKs) are extremely common proliferations of epidermal keratinocytes which show... more Actinic keratoses (AKs) are extremely common proliferations of epidermal keratinocytes which show cytological atypia and impaired ability to mature as the cells that comprise them migrate from the basal layer of the epidermis to higher levels of the epidermis. A small percentage of AKs are well known to progress to cutaneous squamous cell carcinomas (SCCs). However, progression of AKs to cutaneous basal cell carcinomas (BCCs) has not been convincingly documented despite several attempts, even though BCCs are significantly more common than SCCs in the general US and European populations. Documented cases have been dismissed as actinic keratoses that have simply occurred superimposed upon basal cell carcinomas due to chance occurrence of two common sun induced skin lesions at the same sites. In a university based referral dermatopathology service, one of us (WCL) observed 21 cases of AKs progressing to BCCs during a 29 year period (January 1, 1985 to December 31, 2013) of continuous observation in which 115,898 cases of AKs, 10,188 cases of BCCs and 4,809 cases of SCCs were diagnosed. Only cases in which a continuous progression of cells from those showing changes typical of AKs to those showing changes typical of BCCs was observed were included. During the same interval 308 cases of AKs progressing to SCCs were diagnosed. To further test the hypothesis that AKs can progress to BCCs, cases of AKs that progressed to BCCs were further examined to determine those in which neither the AK nor the BCC occupied the entire skin surface (i.e., length of the epidermal basement membrane) present in the specimen. Of the 21 cases, 13 met this criterion. All were shave biopsies of sun damaged skin. For each biopsy, the proportion of the surface covered by the AK, the proportion occupied by the BCC, and the proportion of the surface overlapped by both lesions were measured and the proportion of overlap was compared to the proportion of overlap expected due to chance. Statistical analysis showed that the observed overlap exceeded the expected overlap by 32 per cent with p < 0.05. We conclude that progression of AKs to BCCs, while not as common as progression of AKs to SCCs, does occur in a small proportion of cases. Citation Format: W Clark Lambert, Claude E. Gagna, Muriel W. Lambert. Development of cutaneous basal cell carcinomas from cutaneous actinic keratoses. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5161.

Expert Opinion on Drug Discovery, Mar 1, 2007

Biophysical Journal, 2014

Journal of Histochemistry and Cytochemistry, Oct 1, 2007

Microscopy and Microanalysis, Aug 1, 1999

Our goal was to determine the cellular localization of left-handed Z-RNA, within preeguatorial zo... more Our goal was to determine the cellular localization of left-handed Z-RNA, within preeguatorial zone (PZ) epithelium of the normal adult dog ocular lens (1.5 yr) (Fig. 1), employing anti-Z-RNA IgG polyclonal antibodies. B-DNA has the ability to adopt the Z-DNA configurationin vitro(1). A-RNA can be transformed into Z-RNA under certain conditions (2). Z-RNA has been localized in cultured cells (3). Strong evidence supports the presence of Z-DNAin vivo(1). Elimination of DNA binding proteins by certain fixatives can initiate DNA supercoiling which stabilizes Z-DNA sequences (1). Z-DNA may play a role in regulatingin vivotranscriptional enhancement (1).Anti-Z-RNA antibody probes were produced in 3 rabbits immunized with injections of Z-RNA: Br-poly[ribosomal(G-C)]. Concerning light microscopy [immunohistochemistry (ABC method)], lens tissues were fixed in Carnoy's, embedded in paraffin and sectioned (3 μm) (Fig. 2). Image analysis was performed using a Leitz DM-RB microscope and Leica Quantiment 500 + image analyzer.

Microscopy and Microanalysis, Aug 1, 2000

The goal of this project was to analyze the cellular localization of Z-RNA, within middle fibers ... more The goal of this project was to analyze the cellular localization of Z-RNA, within middle fibers (MF) of the adult dog ocular lens (1.5 yr) (Fig. 1), using anti-Z-RNA IgG polyclonal antibodies. B-DNA can adopt the left-handed Z-DNA conformation in vitro (1). Right-handed A-RNA can be transformed into left-handed Z-RNA (2). Z-RNA has been studied in cultured cells (3). Evidence supports the presence of Z-DNA in vivo (1). Removal of DNA binding proteins by fixatives can initiate supercoiling which stabilizes Z-DNA sequences (1).Anti-Z-RNA polyclonal antibody probes were developed in rabbits immunized with multiple injections of Z-RNA: Br-poly[ribosomal(G-C)]. Regarding immunohistochemistry, lens tissues were fixed in Carnoy's, embedded in paraffin and sectioned (2.5 μm) (Fig. 2). Computerized image analysis was performed using a Leitz DM-RB microscope and Leica Quantiment 500 + image analyzer.

PubMed, 1991

The purpose of this study was to reveal the presence of Z-helical conformation in normal crystall... more The purpose of this study was to reveal the presence of Z-helical conformation in normal crystalline lens DNA. Z-DNA antigen was prepared against poly(dG-dC).poly(dG-dC), which had been converted to the Z-helix conformation in high salt and then stabilized by bromination. Circular dichroism (CD) spectra confirmed the presence of left-handed Z-helix DNA. Antibodies to Z-DNA were raised in three rabbits immunized with brominated (Br-) poly(dG-dC).poly(dG-dC). These antibodies do not cross-react with polynucleotides in the B-helical form, but are specific to the left-handed Z-DNA conformation. DNA was isolated from three different regions of the calf lens. Anti-Z-DNA antisera, affinity purified IgG polyclonal anti-Z-DNA antibodies and monoclonal anti-Z-DNA antibodies were used as immunoprobes to detect the presence of S-DNA sequences. DNA from the cortex region of the lens reacted strongly with the anti-Z-DNA antibodies, but no binding could be observed in the DNA from the nucleus region. Digestion of lens DNA with DNase 1 dramatically decreased Z-DNA antibody binding, while RNase A and T1 treatment had no effect on Z-DNA immunoreactivity. This study has demonstrated that: (a) Z-DNA antibodies developed for our study can bind in high salt solutions (4M NaCl) to purified lens DNA sequences isolated from a variety of different calf lens cell types. By this criterion, lens DNA contains sequence determinants which may assume or are in the Z-helix conformation.

Clinics in Dermatology, Dec 31, 2023

We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying... more We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying dermatophytes in human skin tissue sections (ie, B-DNA dermatophyte assay) and demonstrate, for the first time, the presence of dermatophytes in tissue using immunohistochemistry to detect canonical right-handed double-stranded (ds) B-DNA. Immunohistochemistry was performed using anti-ds-B-DNA monoclonal antibodies with formalin-fixed paraffin-embedded tissues to determine the presence of dermatophytes. The B-DNA assay resulted in a more accurate identification of dermatophytes, nuclear morphology, dimensions, and gene expression of dermatophytes (ie, optical density values) than periodic acid-Schiff (PAS), Grocott melhenamine silver (GMS), or hematoxylin and eosin (H&E) stains. The novel assay guided by artificial intelligence allowed for efficient identification of different types of dermatophytes (eg. hyphae, microconidia, macroconidia, and arthroconidia). Using the B-DNA dermatophyte assay as a clinical tool for diagnosing dermatophytes is an alternative to PAS, OMS, and H&E as a fast and inexpensive way Lo accurately detect dermatophytosis and reduce the number of false negatives. Our assay resulted in superior identification, sensitivity, life cycle stages, and morphology compared to H&E, PAS. and OMS stains. This method detects a specific structural marker (ie, ds-B-DNA), which can assist with diagnosis of dermatophytes. It represents a significant advantage over methods currently in use.

Clinics in Dermatology, 2024

We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying... more We describe a novel assay and artificial intelligence-driven histopalhologic approach identifying dermatophytes in human skin tissue sections (ie, B-DNA dermatophyte assay) and demonstrate, for the first time, the presence of dermatophytes in tissue using immunohistochemistry to detect canonical right-handed double-stranded (ds) B-DNA. Immunohistochemistry was performed using anti-ds-B-DNA monoclonal antibodies with formalin-fixed paraffin-embedded tissues to determine the presence of dermatophytes. The B-DNA assay resulted in a more accurate identification of dermatophytes, nuclear morphology, dimensions, and gene expression of dermatophytes (ie, optical density values) than periodic acid-Schiff (PAS), Grocott melhenamine silver (GMS), or hematoxylin and eosin (H&E) stains. The novel assay guided by artificial intelligence allowed for efficient identification of different types of dermatophytes (eg. hyphae, microconidia, macroconidia, and arthroconidia). Using the B-DNA dermatophyte assay as a clinical tool for diagnosing dermatophytes is an alternative to PAS, OMS, and H&E as a fast and inexpensive way Lo accurately detect dermatophytosis and reduce the number of false negatives. Our assay resulted in superior identification, sensitivity, life cycle stages, and morphology compared to H&E, PAS. and OMS stains. This method detects a specific structural marker (ie, ds-B-DNA), which can assist with diagnosis of dermatophytes. It represents a significant advantage over methods currently in use.

Journal of Investigative Dermatology, Aug 1, 2022

The FASEB Journal, Apr 1, 2013

Biophysical Journal, 2014

Journal of Histochemistry and Cytochemistry, Nov 1, 1997

Pharmacogenomics, May 1, 2009

The FASEB Journal, Apr 1, 2018

Microscopy and Microanalysis, Aug 1, 2001

The purpose of this research project was to characterize the distribution of left-handed Z-RNA se... more The purpose of this research project was to characterize the distribution of left-handed Z-RNA sequences within the epithelial cells of the adult noncataractous crystalline dog lens: the meridional rows (MR). This was achieved by using anti-Z-RNA IgG polyclonal antibody probes. Both light microscopy (LM) and electron microscopy (EM) were used to analyze the tissue binding of the anti- Z-RNA antibodies. Nucleic acids can adopt many different helical conformations (1), such as Z-DNA (Fig. 1) and Z-RNA (2,3). The lens is made up of a single cell type, which is a monolayer of undifferentiated epithelial cells covering its anterior surface (Fig. 2). At the equator of the lens, these cells elongate and form concentric layers of the secondary (nucleated) fiber cells, which undergo cell death-terminal differentiation (denucleation). The epithelial monolayer consists of several cell types, each of which has unique characteristics.The production of anti-Z-RNA polyclonal antibody probes was achieved using four

Actinic keratoses (AKs) are extremely common proliferations of epidermal keratinocytes which show... more Actinic keratoses (AKs) are extremely common proliferations of epidermal keratinocytes which show cytological atypia and impaired ability to mature as the cells that comprise them migrate from the basal layer of the epidermis to higher levels of the epidermis. A small percentage of AKs are well known to progress to cutaneous squamous cell carcinomas (SCCs). However, progression of AKs to cutaneous basal cell carcinomas (BCCs) has not been convincingly documented despite several attempts, even though BCCs are significantly more common than SCCs in the general US and European populations. Documented cases have been dismissed as actinic keratoses that have simply occurred superimposed upon basal cell carcinomas due to chance occurrence of two common sun induced skin lesions at the same sites. In a university based referral dermatopathology service, one of us (WCL) observed 21 cases of AKs progressing to BCCs during a 29 year period (January 1, 1985 to December 31, 2013) of continuous observation in which 115,898 cases of AKs, 10,188 cases of BCCs and 4,809 cases of SCCs were diagnosed. Only cases in which a continuous progression of cells from those showing changes typical of AKs to those showing changes typical of BCCs was observed were included. During the same interval 308 cases of AKs progressing to SCCs were diagnosed. To further test the hypothesis that AKs can progress to BCCs, cases of AKs that progressed to BCCs were further examined to determine those in which neither the AK nor the BCC occupied the entire skin surface (i.e., length of the epidermal basement membrane) present in the specimen. Of the 21 cases, 13 met this criterion. All were shave biopsies of sun damaged skin. For each biopsy, the proportion of the surface covered by the AK, the proportion occupied by the BCC, and the proportion of the surface overlapped by both lesions were measured and the proportion of overlap was compared to the proportion of overlap expected due to chance. Statistical analysis showed that the observed overlap exceeded the expected overlap by 32 per cent with p < 0.05. We conclude that progression of AKs to BCCs, while not as common as progression of AKs to SCCs, does occur in a small proportion of cases. Citation Format: W Clark Lambert, Claude E. Gagna, Muriel W. Lambert. Development of cutaneous basal cell carcinomas from cutaneous actinic keratoses. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5161.

Expert Opinion on Drug Discovery, Mar 1, 2007

Biophysical Journal, 2014

Journal of Histochemistry and Cytochemistry, Oct 1, 2007

Microscopy and Microanalysis, Aug 1, 1999

Our goal was to determine the cellular localization of left-handed Z-RNA, within preeguatorial zo... more Our goal was to determine the cellular localization of left-handed Z-RNA, within preeguatorial zone (PZ) epithelium of the normal adult dog ocular lens (1.5 yr) (Fig. 1), employing anti-Z-RNA IgG polyclonal antibodies. B-DNA has the ability to adopt the Z-DNA configurationin vitro(1). A-RNA can be transformed into Z-RNA under certain conditions (2). Z-RNA has been localized in cultured cells (3). Strong evidence supports the presence of Z-DNAin vivo(1). Elimination of DNA binding proteins by certain fixatives can initiate DNA supercoiling which stabilizes Z-DNA sequences (1). Z-DNA may play a role in regulatingin vivotranscriptional enhancement (1).Anti-Z-RNA antibody probes were produced in 3 rabbits immunized with injections of Z-RNA: Br-poly[ribosomal(G-C)]. Concerning light microscopy [immunohistochemistry (ABC method)], lens tissues were fixed in Carnoy's, embedded in paraffin and sectioned (3 μm) (Fig. 2). Image analysis was performed using a Leitz DM-RB microscope and Leica Quantiment 500 + image analyzer.

Microscopy and Microanalysis, Aug 1, 2000

The goal of this project was to analyze the cellular localization of Z-RNA, within middle fibers ... more The goal of this project was to analyze the cellular localization of Z-RNA, within middle fibers (MF) of the adult dog ocular lens (1.5 yr) (Fig. 1), using anti-Z-RNA IgG polyclonal antibodies. B-DNA can adopt the left-handed Z-DNA conformation in vitro (1). Right-handed A-RNA can be transformed into left-handed Z-RNA (2). Z-RNA has been studied in cultured cells (3). Evidence supports the presence of Z-DNA in vivo (1). Removal of DNA binding proteins by fixatives can initiate supercoiling which stabilizes Z-DNA sequences (1).Anti-Z-RNA polyclonal antibody probes were developed in rabbits immunized with multiple injections of Z-RNA: Br-poly[ribosomal(G-C)]. Regarding immunohistochemistry, lens tissues were fixed in Carnoy's, embedded in paraffin and sectioned (2.5 μm) (Fig. 2). Computerized image analysis was performed using a Leitz DM-RB microscope and Leica Quantiment 500 + image analyzer.