The long-term evolution of melanocytic nevi among high-risk adults.

BACKGROUND: There is little understanding regarding the long-term natural history of melanocytic nevi among adults. OBJECTIVE: The objective of the study was to describe the long-term natural history of individual nevi located on the torso of high-risk patients. METHODS: All patients attending Memorial Sloan Kettering Cancer Center (MSKCC) who underwent two total body photography (TBP) sessions 15+ years apart were included ('retrospective' group). To account for a potential selection bias, we also included consecutive patients who had TBP 15+ years ago and consented to undergo follow-up TBP ('prospective' group). We compared baseline and follow-up torso images on the TBPs and evaluated the number of total, new and disappearing nevi; number of seborrheic keratoses and actinic keratoses; each nevus' diameter at both time points; each nevus' colour change; the presence of clinical atypia; and when dermoscopy was available, the dermoscopic features at each time point. RESULTS: One hundred six patients were included in the study. Although the average age of the patients was 40 at baseline TBP, most patients developed new nevi between imaging sessions (median 16.4 years) with an average of 2.6 (SD = 4.8) nevi per participant. The average number of disappearing nevi was 0.3 (SD = 0.6). In addition, 62/106 (58%) patients had an absolute increase, and 9/106 (8%) patients had an absolute decrease in their total nevus count. Roughly half (49%: 1416/2890) of the nevi that could be evaluated at both time points increased in diameter by at least 25%. Only 6% (159/2890) of nevi shrunk in diameter by at least 25%. Patients with a history of melanoma had a higher rate of disappearing nevi, and their nevi were more likely to grow. Most nevi demonstrated no significant dermoscopic changes. CONCLUSIONS: High-risk patients acquire new nevi throughout life with very few nevi disappearing over time. Contrary to prior reports, most nevi in adults increase in diameter, while few nevi shrink.

The differences in clinical and dermoscopic features between in situ and invasive nevus-associated melanomas and de novo melanomas.

BACKGROUND: Nevus-associated melanomas (NAM) account for 30% of all melanomas and are associated with younger age and with thinner Breslow thickness. Previous studies of NAM dermoscopy found conflicting results. OBJECTIVE: To compare the clinical and dermoscopic features of NAM and de novo melanomas (DNM), stratified by melanoma thickness, in a relatively large cohort of patients. METHODS: A cross-sectional study of all melanomas biopsied between 2004 and 2019 at a large cancer centre. Lesions were categorized as in situ and invasive NAM or DNM. Dermoscopic images were reviewed and annotated. Associations between melanoma subtype and dermoscopic features were analysed via logistic regression modelling. Bivariate analyses were conducted using non-parametric bootstrap and chi-squared methods. RESULTS: The study included 160 NAM (86 in situ and 74 invasive) and 218 DNM (109 in situ and 109 invasive). NAM were associated with younger age, greater likelihood of being present on the torso, and thinner Breslow thickness. NAM were 2.5 times more likely to show a negative pigment network than DNM. In situ NAM were 2.1 and two times more likely to display dermoscopic area without definable structures and tan structureless areas than DNM, respectively. In situ melanomas were more likely to present a pigment network, and invasive melanomas more commonly presented scar-like depigmentation and shiny white structures. Streaks, blotches and shiny white structures were associated with deeper Breslow depth. CONCLUSIONS: Even though the nevus component of NAM could not be identified dermoscopically in the current series, negative pigment network, tan structureless areas and areas without definable structures are dermoscopic clues for NAM.

Oral vaccination of baculovirus-expressed VP28 displays enhanced protection against White Spot Syndrome Virus in Penaeus monodon.

White Spot Syndrome Virus (WSSV) is an infectious pathogen of shrimp and other crustaceans, and neither effective vaccines nor adequate treatments are currently available. WSSV is an enveloped dsDNA virus, and one of its major envelope proteins, VP28, plays a pivotal role in WSSV infection. In an attempt to develop a vaccine against WSSV, we inserted the VP28 gene into a baculovirus vector tailored to express VP28 on the baculovirus surface under the WSSV ie1 promoter (Bac-VP28). The Bac-VP28 incorporated abundant quantity (65.3 µg/ml) of VP28. Shrimp were treated by oral and immersion vaccination with either Bac-VP28 or wild-type baculovirus (Bac-wt). The treatment was followed by challenge with WSSV after 3 and 15 days. Bac-VP28 vaccinated shrimp showed significantly higher survival rates (oral: 81.7% and 76.7%; immersion: 75% and 68.4%) than Bac-wt or non-treated shrimp (100% mortality). To verify the protective effects of Bac-VP28, we examined in vivo expression of VP28 by immunohistochemistry and quantified the WSSV copy number by qPCR. In addition to that, we quantified the expression levels shrimp genes LGBP and STAT by real-time RT-PCR from the samples obtained from Bac-VP28 vaccinated shrimp at different duration of vaccine regime. Our findings indicate that oral vaccination of shrimp with Bac-VP28 is an attractive preventative measure against WSSV infection that can be used in the field.

Localization of VP28 on the baculovirus envelope and its immunogenicity against white spot syndrome virus in Penaeus monodon.

White spot syndrome virus (WSSV) is a large dsDNA virus responsible for white spot disease in shrimp and other crustaceans. VP28 is one of the major envelope proteins of WSSV and plays a crucial role in viral infection. In an effort to develop a vaccine against WSSV, we have constructed a recombinant baculovirus with an immediate early promoter 1 which expresses VP28 at an early stage of infection in insect cells. Baculovirus expressed rVP28 was able to maintain its structural and antigenic conformity as indicated by immunofluorescence assay and western blot analysis. Interestingly, our results with confocal microscopy revealed that rVP28 was able to localize on the plasma membrane of insect cells infected with recombinant baculovirus. In addition, we demonstrated with transmission electron microscopy that baculovirus successfully acquired rVP28 from the insect cell membrane via the budding process. Using this baculovirus displaying VP28 as a vaccine against WSSV, we observed a significantly higher survival rate of 86.3% and 73.5% of WSSV-infected shrimp at 3 and 15 days post vaccination respectively. Quantitative real-time PCR also indicated that the WSSV viral load in vaccinated shrimp was significantly reduced at 7 days post challenge. Furthermore, our RT-PCR and immunohistochemistry results demonstrated that the recombinant baculovirus was able to express VP28 in vivo in shrimp tissues. This study will be of considerable significance in elucidating the morphogenesis of WSSV and will pave the way for new generation vaccines against WSSV.

Cloning and sequencing of capsid protein of Indian isolate of extra small virus from Macrobrachium rosenbergii.

White tail disease (WTD) is found to cause immense economic losses in hatcheries and farms, with mortalities often reaching 100% within 2 or 3 days. The pathogenic agents have been identified as Macrobrachium rosenbergii nodavirus (MrNV) associated with extra small virus (XSV), which are 27 and 15 nm in diameter, respectively. Experiments were carried out to characterize an Indian isolate of XSV capsid protein of 17 kDa (CP-17). The gene encoding CP-17 was cloned and its sequence analysed with sequences of other isolates such as French, Chinese, Taiwanese and Thai available in the GenBank using Bioinformatics tools such as BLASTn, clustal W and phylogenetic analysis. When compared with other isolates, 18-point mutations were observed in Indian isolate (XSV-IN) with few changes in amino acid residues. Homology comparison showed 99-96% identity with other isolates. Phylogenetic analysis revealed that the Indian isolate was closely related to Taiwanese and Chinese isolates than French and Thai. This shows that the possible origin of the disease in India was from Taiwan and China through the import of prawn seed decades ago.

Protective efficiency of DNA vaccination in Asian seabass (Lates calcarifer) against Vibrio anguillarum.

Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio. Vibriosis caused by Vibrio anguillarum produces a 38-kDa major outer membrane porin protein (OMP) for biofilm formation and bile resistant activity. The gene encoding the porin was used to construct DNA vaccine. The protective efficiency of such vaccine against V. anguillarum causing acute vibrio haemorrhagic septicaemia was evaluated in Asian seabass (Lates calcarifer Bloch), a common species of the Indian coast and a potential resource for the aquaculture industry. In vitro protein expression of porin gene was determined by fluorescent microscopy after transfection of seabass kidney cell line (SISK). Fish immunized with a single intramuscular injection of 20 microg of the OMP38 DNA vaccine showed significant serum antibody levels in 5th and 7th weeks after vaccination, compared to fish vaccinated with the control eukaryotic expression vector pcDNA3.1. Asian seabass vaccinated with the OMP38 DNA vaccine was challenged with pathogenic V. anguillarum by intramuscular injection. A relative percent survival (RPS) rate of 55.6% was recorded. Bacterial agglutination and serum complement activity was analysed by using DNA vaccinated seabass serum above 80% of analysed strain was killed at the highest agglutination titre. Histopathological signs of V. anguillarum challenged fish were observed in around 45% of pVAOMP38, 90% of PBS and 87% of pcDNA3.1-vaccinated control fish. The results indicate that L. calcarifer vaccinated with a single dose of DNA plasmid encoding the major outer membrane protein shows moderate protection against acute haemorrhagic septicaemia and mortality by V. anguillarum experimental infection.

Experimental transmission and tissue tropism of white spot syndrome virus (WSSV) in two species of lobsters, Panulirus homarus and Panulirus ornatus.

The susceptibility of two species of lobsters, Panulirus homarus and Panulirus ornatus to white spot syndrome virus (WSSV) was tested by oral route and intramuscular injection. The results revealed that these lobsters were as highly susceptible as marine shrimp when the WSSV was administered intramuscularly. The WSSV caused 100% mortality in both Panulirus homarus and Panulirus ornatus, at 168 and 120 h, respectively, after intramuscular injection and failed to cause mortality when given orally. The presence of WSSV in moribund lobsters was confirmed by single-step and nested PCR, Western blot, histology, and bioassay test. It was found in eyestalk, gill, head muscle, tail muscle, hemolymph, appendages, and stomach. In lobsters with oral route infection, all tested organs except stomach and head muscle was negative for WSSV by nested PCR at 120 h post-inoculation. The stomach and head muscle was positive by nested PCR at 120 h p.i., but negative at 168 h p.i. Western blot analysis was negative in all the tested organs of both species of lobster at 120 h post-inoculation by oral route.

Production of polyclonal antiserum against recombinant VP28 protein and its application for the detection of white spot syndrome virus in crustaceans.

The VP28 gene of white spot syndrome virus (WSSV) was cloned into pRSET B expression vector. The VP28 protein was expressed as a protein with a 6-histidine taq in Escherichia coli GJ1158 with NaCl induction. Antiserum was raised against this recombinant-VP28 protein in rabbits and it recognized VP28 protein in naturally and experimentally WSSV-infected shrimp, marine crabs, freshwater prawns and freshwater crabs. The antiserum did not recognize any of the other known WSSV structural proteins. Various organs such as eyestalks, head muscle, gill tissue, heart tissue, haemolymph, tail tissue and appendages were found to be good materials for detection of WSSV using the antiserum and detection of WSSV was successful in experimentally infected Penaeus monodon and P. indicus at 12 and 24 h post-infection (p.i.), respectively. The antiserum was capable of detecting WSSV in 5 ng of total haemolymph protein from WSSV-infected shrimp.

Experimental infection of twenty species of Indian marine crabs with white spot syndrome virus (WSSV).

Twenty species of Indian marine crabs were experimentally infected with white spot syndrome virus (WSSV), via the oral route and intramuscular injection, to determine their viral susceptibility. We determined that 16 species (Calappa philargius, Charybdis annulata, C. lucifera, Doclea hybrida, Grapsus albolineatus, Halimede ochtodes, Liagore rubronaculata, Lithodes maja, Matuta miersi, Paradorippe granulata, Parthenope prensor, Philyra syndactyla, Podophthalmus vigil, Portunus sanquinolentus, Scylla serrata and Thalamita danae) were susceptible and 4 (Atergatis integerrimus, Charybdis natator, Demania splendida or Menippe rumphii) were refractive at 50 d post-infection (p.i.). The presence of WSSV in these crabs was confirmed by PCR tests, histology and bioassay. WSSV was found in the gill, heart, eyestalks, striated muscle and cephalothoraxic tissue. The 4 WSSV-refractive species represent potential reservoirs or carriers of WSSV.