Immune checkpoint inhibitor therapy for hepatocellular carcinoma.

Liver cancer is the third most common cause of cancer-associated death. Advances in the last decade have provided more options for treating hepatocellular carcinoma. The use of immune checkpoint inhibitors represents a leap forward and broadens the armamentarium for clinicians. In this article, we provide a state-of-the-art review of molecular therapy. We also detail the mechanisms of checkpoint inhibitor therapy, which blocks the interaction of programmed cell death receptor protein with programmed cell death ligand, reducing the immune checkpoint activity on regulatory T cells, thereby inhibiting tumor cell growth.

Adverse events associated with transoral incisionless fundoplication (TIF) for chronic gastroesophageal reflux disease: a MAUDE database analysis.

BACKGROUND: Transoral incisionless fundoplication (TIF) has been used for treating chronic gastroesophageal reflux disease (GERD) refractory to medical therapy. We aim to investigate the complications associated with TIF using a national database. METHODS: We analyzed post-marketing surveillance data from the FDA Manufacturer and User Facility Device Experience (MAUDE) database from Jan 2011 through Jan 2021. RESULTS: During the study period, approximately 95 event cases reported to the FDA. Approximately 131 patient complications were identified. The number of adverse events declined from 2011 to 2016 (R2 = 0.96) but increased from 2016 to 2020 (R2 = 0.99). The most common adverse event was perforation (19.8%), followed by laceration 17.6%, bleeding (9.2%), and pleural effusion (9.2%). The most common patient complications were treated using endoscopic clips (12.3%), chest tube or drain insertion (12.3%), use of endoscopic retriever device (11.1%), esophageal stent (8.6%), and emergent or open surgery (11.1%). CONCLUSIONS: Adverse events from TIF range from mild to severe. Further research is needed to develop approaches aimed at reducing patient risks.

Through-the-needle biopsy of pancreatic cystic lesions: current evidence and implications for clinical practice.

INTRODUCTION: There is increasing evidence to support the efficacy of endoscopic ultrasound (EUS)-guided through-the-needle biopsy (TTNB) technique as a means of sampling pancreatic cystic lesions (PCLs). Results provide evidence demonstrating the benefits of this procedure over standard EUS fine-needle aspiration (FNA), thus supporting a push for its widespread implementation in clinical practice. Though this technique has demonstrated advantages, achieving these advantages in clinical practice is contingent upon careful considerations to ensure safety and efficacy. AREAS COVERED: The purpose of this review is to assess the level of evidence supporting the use of through-the-needle biopsy, revise its main technical and procedural characteristics, and to develop suggested guidelines outlining the safe assimilation of this device in clinical practice. EXPERT OPINION: EUS-TTNB enables more definitive and accurate diagnosis of PCLs by providing higher-quality histological samples. However, EUS-TTNB is not appropriate for all PCLs. Selection of suitable patients as well as morphology and risk factors of the cystic lesion is a crucial component of achieving the described benefits of this procedure while minimizing risks of adverse effects. Subjects with weak or absent indications for this procedure are susceptible to a range of complications and may even result in fatality.

Complications 18 years after polyacrylamide hydrogel augmentation mammoplasty: a case report and histopathological analysis.

Polyacrylamide hydrogel (PAAG) is a synthetic substance previously used as an injectable material for augmentation mammoplasty. Current literature has demonstrated that the average time from PAAG injection to the onset of complication ranges from 6 to 39 months. We present a unique case report describing the onset of complications 18 years after PAAG augmentation mammoplasty. To the best of our knowledge, the presentation of a healthy female who experienced unprovoked expansion of breast tissue >15 years after polyacrylamide injection has not been previously reported in surgical literature. This suggests that serious complications of PAAG injection may occur later than the literature has previously described. Importantly, this case is the first demonstration of the successful surgical removal of polyacrylamide 18 years after injection. Additionally, this case also provides a histopathological analysis of breast capsules which showed evidence of an extensive chronic inflammatory reaction to polyacrylamide, consistent with previous reports.

POMC overexpression in the ventral tegmental area ameliorates dietary obesity.

The activation of proopiomelanocortin (POMC) neurons in different regions of the brain, including the arcuate nucleus of the hypothalamus (ARC) and the nucleus of the solitary tract curtails feeding and attenuates body weight. In this study, we compared the effects of delivery of a recombinant adeno-associated viral (rAAV) construct encoding POMC to the ARC with delivery to the ventral tegmental area (VTA). F344×Brown Norway rats were high-fat (HF) fed for 14 days after which self-complementary rAAV constructs expressing either green fluorescent protein or the POMC gene were injected using coordinates targeting either the VTA or the ARC. Corresponding increased POMC levels were found at the predicted injection sites and subsequent α-melanocyte-stimulating hormone levels were observed. Food intake and body weight were measured for 4 months. Although caloric intake was unaltered by POMC overexpression, weight gain was tempered with POMC overexpression in either the VTA or the ARC compared with controls. There were parallel decreases in adipose tissue reserves. In addition, levels of oxygen consumption and brown adipose tissue uncoupling protein 1 were significantly elevated with POMC treatment in the VTA. Interestingly, tyrosine hydroxylase levels were increased in both the ARC and VTA with POMC overexpression in either the ARC or the VTA. In conclusion, these data indicate a role for POMC overexpression within the VTA reward center to combat HF-induced obesity.

Prevention and reversal of diet-induced leptin resistance with a sugar-free diet despite high fat content.

Chronic consumption of a Western-type diet, containing both elevated sugar and fat, results in leptin resistance. We hypothesised that fructose, as part of the sugar component of Western-type diets, is one causative ingredient in the development of leptin resistance and that removal of this component will prevent leptin resistance despite high fat (HF) content. We fed rats a sugar-free (SF), 30 % HF (SF/HF) diet or a 40 % high-fructose (HFr), 30 % HF (HFr/HF) diet for 134 d. The HFr/HF diet resulted in impaired anorexic and body-weight responses to both peripherally (0·6 mg/kg, assessed on day 65 of the diet) and centrally (1·5 µg/d, assessed on days 129-134) administered leptin, whereas SF/HF-fed rats were fully leptin responsive. At day 70, half the HFr/HF-fed animals were switched to the SF/HF diet, reversing the leptin resistance (assessed 18 d after the diet switch). The HFr/HF diet elevated serum leptin and reduced adiponectin, and levels were restored abruptly at day 3 after switching to the SF/HF diet. These data demonstrate that a diet containing both HFr and fat leads to leptin resistance, while an isoenergetic SF/HF diet does not. Moreover, removal of fructose from this diet reverses the leptin resistance and the elevated leptin, suggesting a cause-and-effect relationship. These data suggest that fructose is the bioactive component of a HF/high-sugar diet that is essential for the induction of leptin resistance.

The act of voluntary wheel running reverses dietary hyperphagia and increases leptin signaling in ventral tegmental area of aged obese rats.

To test the hypothesis that exercise increases central leptin signaling, and thus reduces dietary weight gain in an aged obese model, we assessed the effects of voluntary wheel running (WR) in 23-month-old F344×BN rats fed a 60% high-fat (HF) diet for 3 months. After 2 months on the HF diet, half of the rats were provided access to running wheels for 2 weeks while the other half remained sedentary. Following the removal of the wheels, physical performance was evaluated, and 4 weeks later leptin signaling was assessed in hypothalamus and VTA after an acute bout of WR. Introduction of a HF diet led to prolonged hyperphagia (63.9 ± 7.8 kcal/day on chow diet vs. 88.1 ± 8.2 kcal/day on high-fat diet (when food intake stabilized), p < 0.001). As little as 9 (ranging to 135) wheel revolutions per day significantly reduced caloric consumption of HF food (46.8 ± 11.2 kcal/day) to a level below that on chow diet (63.9 ± 7.8 kcal/day, p < 0.001). After 2 weeks of WR, body weight was significantly reduced (7.9 ± 2.1% compared with prerunning weight, p < 0.001), and physical performance (latency to fall from an incline plane) was significantly improved (p = 0.04). WR significantly increased both basal (p = 0.04) and leptin-stimulated (p = 0.001) STAT3 phosphorylation in the ventral tegmental area (VTA), but not in the hypothalamus. Thus, in aged dietary obese rats, the act but not the extent of voluntary WR is highly effective in reversing HF consumption, decreasing body weight, and improving physical performance. It appears to trigger a response that substitutes for the reward of highly palatable food that may be mediated by increased leptin signaling in the VTA.

Central overexpression of leptin antagonist reduces wheel running and underscores importance of endogenous leptin receptor activity in energy homeostasis.

We used recombinant adeno-associated virus (rAAV)-mediated gene delivery to overexpress a mutant of rat leptin yielding a protein that acts as a neutral leptin receptor antagonist. The long-term consequences of this overexpression on body weight homeostasis and physical activity, as assessed by voluntary wheel running (WR), were determined in F344 x Brown Norway (BN) rats. Leptin antagonist overexpression was confirmed by examination of mRNA levels in the hypothalamus. Food consumption and body weight gain were exacerbated in the antagonist group during both chow and high-fat feeding periods over the 192-day experiment. In a second experiment, a lower dose of antagonist vector was used that resulted in no change in food consumption but still increased body weight. The degree of antagonist overexpression was sufficient to partially block signal transducer and activator of transcription 3 (STAT3) phosphorylation due to administration of an acute submaximal dose of leptin. Rats were provided free access to running wheels for 4 days during both the chow and high-fat feeding periods. With both antagonist doses and during both chow and high-fat feeding, WR was substantially less with antagonist overexpression. In contrast, when leptin was overexpressed in the hypothalamus, WR activity was increased by greater than twofold. At death, adiposity and serum leptin levels were greater in the antagonist group. These data indicate that submaximal central leptin receptor blockade promotes obesity and diminishes WR activity. These findings underscore the critical role of unrestrained leptin receptor activity in long-term energy homeostasis and suggest that even minor disruption of leptin receptor function can promote obesity.

Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding.

It has been suggested that increased fructose intake is associated with obesity. We hypothesized that chronic fructose consumption causes leptin resistance, which subsequently may promote the development of obesity in response to a high-fat diet. Sprague-Dawley rats were fed a fructose-free control or 60% fructose diet for 6 mo and then tested for leptin resistance. Half of the rats in each group were then switched to high-fat diet for 2 wk, while the other half continued on their respective diets. Chronic fructose consumption caused leptin resistance, while serum leptin levels, weight, and adiposity were the same as in control rats that were leptin responsive. Intraperitoneal leptin injections reduced 24-h food intake in the fructose-free group (73.7 +/- 6.3 vs. 58.1 +/- 8 kcal, P = 0.02) but had no effect in fructose-fed rats (71.2 +/- 6.6 vs. 72.4 +/- 6.4 kcal, P = 0.9). Absence of anorexic response to intraperitoneal leptin injection was associated with 25.7% decrease in hypothalamic signal transducer and activator of transcription 3 phosphorylation in the high-fructose-fed rats compared with controls (P = 0.015). Subsequent exposure of the fructose-mediated, leptin-resistant rats to a high-fat diet led to exacerbated weight gain (50.2 +/- 2 g) compared with correspondingly fed leptin-responsive animals that were pretreated with the fructose-free diet (30.4 +/- 5.8 g, P = 0.012). Our data indicate that chronic fructose consumption induces leptin resistance prior to body weight, adiposity, serum leptin, insulin, or glucose increases, and this fructose-induced leptin resistance accelerates high-fat induced obesity.

Synergy between leptin therapy and a seemingly negligible amount of voluntary wheel running prevents progression of dietary obesity in leptin-resistant rats.

OBJECTIVE: We examined whether chronic leptin treatment of diet-induced obese rats promotes or alleviates the susceptibility to continued high-fat feeding. Second, we examined if voluntary wheel running is beneficial in reducing the trajectory of weight gain in high-fat-raised leptin-resistant rats. RESEARCH DESIGN AND METHODS: Sprague-Dawley rats were fed a standard diet or a high-fat diet for 5 months, and then hypothalamic leptin overexpression was induced through central administration of adeno-associated virus-encoding leptin while continuing either the standard or high-fat diet. Two weeks later, half of the rats in each group were provided access to running wheels for 38 days while being maintained on either a standard or high-fat diet. RESULTS; In standard diet-raised rats, either wheel running or leptin reduced the trajectory of weight gain, and the combined effect of both treatments was additive. In high-fat-raised leptin-resistant rats, leptin overexpression first transiently reduced weight gain but then accelerated the weight gain twofold over controls. Wheel running in high-fat-raised rats was sixfold less than in standard diet-raised rats and did not affect weight gain. Surprisingly, wheel running plus leptin completely prevented weight gain. This synergy was associated with enhanced hypothalamic signal transducer and activator of transcription (STAT) 3 phosphorylation and suppressor of cytokine signaling 3 expression in wheel running plus leptin compared with leptin-treated sedentary high-fat counterparts. This enhanced STAT3 signaling associated with the combination treatment occurred only in high-fat-raised, leptin-resistant rats and not in standard diet-raised, leptin-responsive rats. CONCLUSIONS: Chronic leptin treatment in diet-induced obese rats accelerates dietary obesity. However, leptin combined with wheel running prevents further dietary weight gain. Thus, this combination therapy may be a viable antiobesity treatment.

Development of the insect pathogenic alga Helicosporidium.

This study examined the morphogenesis and replication dynamics of the different life stages (cysts, filamentous cells, vegetative cells) of Helicosporidium sp., a non-photosynthetic, entomopathogenic alga. The isolate (SjHe) used originated from an infected black fly larva. Filamentous cell transformation into vegetative cells and autosporulation during vegetative cell replication were observed under controlled in vitro conditions. The transformation process was initiated by a partial swelling of the filamentous cell along with the reorganization of the nuclear material. Two subsequent nuclear and cell divisions resulted in the release of 4 rod-shaped daughter cells, which divided into oval to spherical vegetative cells. These underwent several cycles of autosporogenic cell division. Multiple-passaged vegetative cell cultures formed non-motile, adherent cell clusters (palmelloid colonies). Vegetative replication dynamics were also observed in 2 experimental noctuid hosts, Spodoptera exigua and Helicoverpa zea. The average density of helicosporidial cells produced per microliter hemolymph exceeded cell concentrations obtained in vitro by 15- and 46-fold in S. exigua and H. zea, respectively. Cyst morphogenesis was only observed in the hemolymph, whereas no cysts differentiated at various in vitro conditions.

Molecular and biological characterization of a Cypovirus from the mosquito Culex restuans.

A cypovirus from the mosquito Culex restuans (named CrCPV) was isolated and its biology, morphology, and molecular characteristics were investigated. CrCPV is characterized by small (0.1-1.0 microm), irregularly shaped inclusion bodies that are multiply embedded. Laboratory studies demonstrated that divalent cations influenced transmission of CrCPV to Culex quinquefasciatus larvae; magnesium enhanced CrCPV transmission by approximately 30% while calcium inhibited transmission. CrCPV is the second cypovirus from a mosquito that has been confirmed by using molecular analysis. CrCPV has a genome composed of 10 dsRNA segments with an electropherotype similar to the recently discovered UsCPV-17 from the mosquito Uranotaenia sapphirina, but distinct from the lepidopteran cypoviruses BmCPV-1 (Bombyx mori) and TnCPV-15 (Trichoplusia ni). Nucleotide and deduced amino acid sequence analysis of CrCPV segment 10 (polyhedrin) suggests that CrCPV is closely related (83% nucleotide sequence identity and 87% amino acid sequence identity) to the newly characterized UsCPV-17 but is unrelated to the 16 remaining CPV species from lepidopteran hosts. A comparison of the terminal segment regions of CrCPV and UsCPV-17, an additional method for differentiating various Cypovirus species, revealed a high level of conservation. Therefore, we propose that CrCPV is a member of the Cypovirus-17 group and designate this species as CrCPV-17.

Differential expression of chitin synthase (CHS) and glucan synthase (FKS) genes correlates with the formation of a modified, thinner cell wall in in vivo-produced Beauveria bassiana cells.

During infection (in vivo), the entomopathogenic fungus Beauveria bassiana produces yeast-like cells that are surrounded by modified cell walls. These modifications have been related to the fungus ability to limit recognition by the host defense system. The composition of the in vivo cell wall was analyzed using a combination of cytochemical and molecular techniques. The in vivo cell walls still contained both chitin and 1,3-beta-glucan, but they were significantly thinner than in vitro cell walls (50-60 nm versus 100-160 nm, respectively). The difference in cell wall thickness was correlated with transcriptional regulation of cell wall-related genes: quantitative RT-PCR reactions demonstrated that B. bassiana chitin synthase (CHS) and glucan synthase (FKS) genes are down regulated in vivo. These analyses indicate that in vivo-triggered phenotypic modifications, including cell wall adjustments, are controlled by molecular mechanisms that include regulation of gene expression at the transcriptional level.

Morphological and molecular characterization of a Cypovirus (Reoviridae) from the mosquito Uranotaenia sapphirina (Diptera: Culicidae).

A novel cypovirus has been isolated from the mosquito Uranotaenia sapphirina (UsCPV) and shown to cause a chronic infection confined to the cytoplasm of epithelial cells of the gastric ceca and posterior stomach. The production of large numbers of virions and inclusion bodies and their arrangement into paracrystalline arrays gives the gut of infected insects a distinctive blue iridescence. The virions, which were examined by electron microscopy, are icosahedral (55 to 65 nm in diameter) with a central core that is surrounded by a single capsid layer. They are usually packaged individually within cubic inclusion bodies (polyhedra, approximately 100 nm across), although two to eight virus particles were sometimes occluded together. The virus was experimentally transmitted per os to several mosquito species. The transmission rate was enhanced by the presence of magnesium ions but was inhibited by calcium ions. Most of the infected larvae survived to adulthood, and the adults retained the infection. Electrophoretic analysis of the UsCPV genome segments (using 1% agarose gels) generated a migration pattern (electropherotype) that is different from those of the 16 Cypovirus species already recognized. UsCPV genome segment 10 (Seg-10) showed no significant nucleotide sequence similarity to the corresponding segment of the other cypoviruses that have previously been analyzed, and it has different "conserved" termini. A BLAST search of the UsCPV deduced amino acid sequence also showed little similarity to Antheraea mylitta CPV-4 (67 of 290 [23%]) or Choristoneura fumiferana CPV-16 (33 of 111 [29%]). We conclude that UsCPV should be recognized as a member of a new Cypovirus species (Cypovirus 17, strain UsCPV-17).

Review of microsporidia-mosquito relationships: from the simple to the complex.

Microsporidia in mosquitoes can be divided into two categories based on their life cycles and host-parasite relationships. Some species of microsporidia exhibit simple life cycles with one spore type responsible for oral (horizontal) transmission. They affect only one generation of the mosquito and are not usually host or tissue specific. Brachiola algerae and Vavraia culicis are examples of species isolated from mosquitoes with relatively straightforward life cycles (one spore type) and simple host-parasite relationships. B. algerae and a close relative of V. culicis have also been isolated from a vertebrate (human) host but sources for these infections are unknown. In contrast to B. algerae and V. culicis, polymorphic (heterosporous) microsporidia in mosquitoes are characterized by complex life cycles involving multiple spore types responsible for horizontal and vertical transmission. They affect two generations of the mosquito and some involve an obligate intermediate host. These microsporidia are generally very host and tissue specific with complex developmental sequences comprised of unique stages and events. The microsporidium Edhazardia aedis is a pathogen of Aedes aegypti and does not require an intermediate host. The developmental cycle of E. aedis is characterized by four sporulation sequences, two in the parental host and two in the filial generation. Recent speculation relative to the source of B. algerae human infection have implicated infected mosquitoes and raised concerns about the safety of mosquito microsporidia in general. The subject of this review is to compare and contrast three species of microsporidia from mosquitoes, two with broad host ranges (B. algerae and V. culicis) and one specific to mosquitoes (E. aedis). This review describes features that distinguish mosquito-parasitic microsporidia with simple life cycles and broad host ranges from truly mosquito-specific microsporidian parasites with complex life cycles.

A picorna-like virus from the red imported fire ant, Solenopsis invicta: initial discovery, genome sequence, and characterization.

We report the first discovery and genome sequence of a virus infecting the red imported fire ant, Solenopsis invicta. The 8026 nucleotide, polyadenylated, RNA genome encoded two large open reading frames (ORF1 and ORF2), flanked and separated by 27, 223, and 171 nucleotide untranslated regions, respectively. The predicted amino acid sequence of the 5' proximal ORF1 (nucleotides 28 to 4218) exhibited significant identity and possessed consensus sequences characteristic of the helicase, cysteine protease, and RNA-dependent RNA polymerase sequence motifs from picornaviruses, picorna-like viruses, comoviruses, caliciviruses, and sequiviruses. The predicted amino acid sequence of the 3' proximal ORF2 (nucleotides 4390-7803) showed similarity to structural proteins in picorna-like viruses, especially the acute bee paralysis virus. Electron microscopic examination of negatively stained samples from virus-infected fire ants revealed isometric particles with a diameter of 31 nm, consistent with Picornaviridae. A survey for the fire ant virus from areas around Florida revealed a pattern of fairly widespread distribution. Among 168 nests surveyed, 22.9% were infected. The virus was found to infect all fire ant caste members and developmental stages, including eggs, early (1st-2nd) and late (3rd-4th) instars, worker pupae, workers, sexual pupae, alates ( male symbol and female symbol ), and queens. The virus, tentatively named S. invicta virus (SINV-1), appears to belong to the picorna-like viruses. We did not observe any perceptible symptoms among infected nests in the field. However, in every case where an SINV-1-infected colony was excavated from the field with an inseminated queen and held in the laboratory, all of the brood in these colonies died within 3 months.

A nucleopolyhedrovirus from Uranotaenia sapphirina (Diptera: Culicidae).

In this report we present data on biology, gross pathology, ultrastructure, and host range studies of a naturally occurring nucleopolyhedrovirus from the mosquito Uranotaenia sapphirina (UrsaNPV). Development of this virus was restricted to nuclei of epithelial cells in posterior midgut and distal gastric caecum. Occlusion bodies contained numerous singly enveloped rod-shaped virions. Early occlusion bodies were irregularly shaped and seemed to subsequently coalesce to form larger polyhedra. Mature occlusion bodies had a unique dumbbell shape, and lacked a polyhedron envelope and crystalline structure. Developmental and structural features of UrsaNPV were generally similar to other mosquito NPVs, with major differences in occlusion body shape and size. Transmission tests showed that only members of Uranotaenia (Ur. sapphirina and Ur. lowii) were susceptible to this virus. Transmission was facilitated by magnesium. Field collected Ur. sapphirina larvae had a relatively high rate of dual infections with UrsaNPV and UrsaCPV (cypovirus).

Hyphal tip growth in Achlya bisexualis. II. Distribution of cellulose in elongating and non-elongating regions of the wall.

Cellulose has been localized in the hyphal wall of elongating and non-elongating hyphae of Achlya bisexualis using a direct enzyme-colloidal-gold method. A number of controls, including several different types of fixation, support the idea that this labeling is specific for cellulose. Both TEM and SEM were used and they gave similar results. The apical area of an elongating hypha lacks cellulose, but the same area of a non-elongating hypha contains cellulose. We have used specific culture media and light microscopic measurements to ensure that we could distinguish between elongating and non-elongating hyphae. The lack of cellulose at the apex of elongating hyphae seems to require a reevaluation of the current concepts of hyphal tip growth in Achlya and related genera. A major question now is to determine whether or not the lack of a microfibrillar component is a universal pattern among all organisms having tip growth.