Is herpes simplex virus associated with peptic ulcer disease?

Pancreas 2000. My journey with the central organ

The European Pancreatic Club Lifetime Achievement Award is a distinction awarded for research on the pancreas and service to European Pancreatology. It comes with the obligation to submit a review article to our society's journal, Pancreatology. It was awarded to me 2023 and I take this opportunity to highlight my journey with the central organ AKA the pancreas, that is inseparatable from "Pancreas 2000" - an educational program for future pancreatologists, inaugurated by Karolinska Institutet.

Prolonged Intractable Hiccups Associated with HSV (I&II) Esophagitis and H. pylori Gastritis

An immunocompetent male presented with an intractable hiccup. EGD revealed circumferential ulceration of middistal esophagus and biopsies confirmed HSV (I&II) esophagitis and H. pylori gastritis. He was prescribed triple therapy for H. pylori and acyclovir for HSV esophagitis. HSV esophagitis and H. pylori should be included in differential for intractable hiccups.

Gastric herpes simplex virus type 1 infection is associated with functional gastrointestinal disorders in the presence and absence of comorbid fibromyalgia: a pilot case-control study

PURPOSE

Animal studies have linked gastric herpesvirus infections to symptoms associated with functional gastrointestinal disorders (FGIDs). Herpesviruses have also been hypothesized to contribute to fibromyalgia (FM), a chronic pain syndrome frequently comorbid with FGIDs. The purpose of this study was to compare the prevalence of gastric herpesvirus infection in patients with FGIDs, with and without comorbid FM, to that of controls.

METHODS

For this pilot case-control study, we enrolled 30 patients who met both the Rome IV diagnostic criteria for one or more FGIDs and the American College of Rheumatology 2010 criteria for FM, 15 patients with one or more FGIDs without comorbid FM, and 15 control patients. Following endoscopic examination, gastric biopsies were analyzed for herpesvirus DNA and protein, Helicobacter pylori infection, and histological evidence of gastritis. Importantly, the viral nonstructural protein ICP8 was used as a marker to differentiate cell-associated actively replicating virus from latent infection and/or free virus passing through the GI tract.

RESULTS

Gastric herpes simplex virus type 1 (HSV-1) infection, as indicated by ICP8 presence, was significantly associated with FGIDs in the presence (OR 70.00, 95% CI 7.42-660.50; P < .001) and absence (OR 38.50, 95% CI 3.75-395.40; P < .001) of comorbid FM. Neither histological gastritis nor H. pylori infection were found to be associated with FGIDs or FM.

CONCLUSIONS

HSV-1 infection was identified in gastric mucosal biopsies from patients with diverse FGIDs, with and without comorbid FM. Larger, multi-center studies investigating the prevalence of this association are warranted.

Persistent Herpes Simplex Virus Type 1 Infection of Enteric Neurons Triggers CD8+ T Cell Response and Gastrointestinal Neuromuscular Dysfunction

Behind the central nervous system, neurotropic viruses can reach and persist even in the enteric nervous system (ENS), the neuronal network embedded in the gut wall. We recently reported that immediately following orogastric (OG) administration, Herpes simplex virus (HSV)-1 infects murine enteric neurons and recruits mononuclear cells in the myenteric plexus. In the current work, we took those findings a step forward by investigating the persistence of HSV-1 in the ENS and the local adaptive immune responses against HSV-1 that might contribute to neuronal damage in an animal model. Our study demonstrated specific viral RNA transcripts and proteins in the longitudinal muscle layer containing the myenteric plexus (LMMP) up to 10 weeks post HSV-1 infection. CD3⁺CD8⁺INFγ⁺ lymphocytes skewed towards HSV-1 antigens infiltrated the myenteric ganglia starting from the 6^th week of infection and persist up to 10 weeks post-OG HSV-1 inoculation. CD3⁺CD8⁺ cells isolated from the LMMP of the infected mice recognized HSV-1 antigens expressed by infected enteric neurons. In vivo, infiltrating activated lymphocytes were involved in controlling viral replication and intestinal neuromuscular dysfunction. Indeed, by depleting the CD8⁺ cells by administering specific monoclonal antibody we observed a partial amelioration of intestinal dysmotility in HSV-1 infected mice but increased expression of viral genes. Our findings demonstrate that HSV-1 persistently infects enteric neurons that in turn express viral antigens, leading them to recruit activated CD3⁺CD8⁺ lymphocytes. The T-cell responses toward HSV-1 antigens persistently expressed in enteric neurons can alter the integrity of the ENS predisposing to neuromuscular dysfunction.

Pathologic Features of Infectious Gastritis

This manuscript presents a review of infectious causes of gastritis aimed at the practicing anatomic pathologist. We shall highlight unique histologic findings and clinical attributes that will assist those analyzing endoscopically obtained mucosal biopsies of the stomach or resection specimens.

Endoscopic characteristics of infection-associated peptic ulcers

BACKGROUND

Aside from Helicobacter pylori, another cause for the development or worsening of gastrointestinal ulcers is scrub typhus, an acute febrile disease caused by Orientia tsutsugamushi. We aimed to compare the endoscopic characteristics of peptic ulcers caused by these infectious agents.

METHODS

This retrospective case-control study involved patients who underwent upper gastrointestinal endoscopy at Chosun University Hospital in Korea. We compared endoscopic features and demographic characteristics between patients with H. pylori infection and those with O. tsutsugamushi infection.

RESULTS

A total of 141 patients with peptic ulcer were included in the study. Compared to patients with O. tsutsugamushi infection (n = 62; age, 63.8 ± 12.1 years; male sex, 42%), those with H. pylori infection (n = 79; age, 53.0 ± 14.8 years; male sex, 81%) were younger and more likely to be male (P < .001 for both). Patients with O. tsutsugamushi infection were more likely to have multiple lesions (40/62, 64.5% vs 37/79, 46.8%; P = .042) and irregular-shaped lesions (27/62, 43.6% vs 20/79, 25.3%; P = .031). Patients with H. pylori infection had higher incidence of hemorrhagic ulcers (26/79, 32.9% vs 8/62, 12.9%; P = .007), and lesions occurred most often in the duodenum (43.0%), followed by the antrum (36.7%), body (34.2%), and angle (12.7%) of the stomach. In patients with O. tsutsugamushi infection, lesions occurred most often in the antrum (70.97%), followed by the duodenum (35.5%), body (22.6%), and angle (14.5%) of the stomach. In both groups, gastric ulcer lesions occurred most often in the antrum, followed by the body and angle of the stomach (36.7% vs 70.97%, 34.2% vs 22.6%, and 12.7% vs 14.5% for gastric ulcers associated with H. pylori and O. tsutsugamushi infection, respectively). Patients with O. tsutsugamushi infection had significantly higher incidence of ulcers on the antrum (70.97% vs 36.7%, P < .001) and the greater curvature (45.2% vs 24.0%, P = .012). Finally, 35.5% of patients with gastric ulcer caused by scrub typhus also had duodenal ulcer.

CONCLUSION

This is the first study to compare endoscopic features of peptic ulcers caused by H. pylori and O. tsutsugamushi. Peptic ulcers in patients with H. pylori infection occurred predominantly in the antrum/body/lesser curvature and presented with single, round/oval lesions, while ulcers in patients with scrub typhus occurred predominantly in the antrum/greater curvature and presented with multiple, irregular lesions. Scrub typhus should be considered as a cause of duodenal ulcer in scrub typhus-endemic areas.

First demonstration of equid gammaherpesviruses within the gastric mucosal epithelium of horses

Horses commonly develop gastric mucosal ulcers, similar to humans, a condition known as equine gastric ulcer syndrome (EGUS) that can lead to poor performance and lost training time and care expenses. Unlike humans, however, an infectious bacterial cause of ulcers has not been conclusively identified. Herpesviruses, while well-established causative agents of diseases such as cold sores, genital lesions, and certain types of cancer, have also been implicated in the development of a subset of gastric ulcers in humans. The presence of equid herpesviruses in the gastrointestinal tract and their potential contribution to EGUS has not been evaluated. Here, we provide the first evidence of equid gammaherpesviruses 2 and 5 (EHV-2 and -5) within the epithelium of the gastric mucosa of horses. These viruses were initially detected by a nested PCR screen of gastric tissue samples obtained from client- and university-owned horses with and without ulcers; however, no association with EGUS was found in this limited sample set. We then validated a highly sensitive in situ hybridization (ISH) assay and used this assay to characterize the distribution of these viruses in necropsy gastric tissue samples from five racehorses. Analyses revealed frequent EHV-2 and EHV-5 co-infections within the gastric mucosal epithelium, regardless of the ulcer status. These results are the first to demonstrate the presence of equid gammaherpesviruses in the gastric mucosa of horses and warrants further investigation to determine the contribution of these viruses to the development of EGUS and/or other gastrointestinal diseases.

Herpes simplex virus duodenitis accompanying Crohn's disease

Herpes simplex virus (HSV) is a recognized cause of gastrointestinal infection in immunodeficient patients. Although a few cases of HSV gastritis and colitis in immunocompromised patients have been reported, there are no reports of HSV duodenitis in patients with Crohn's disease (CD). A 74-year-old female was admitted with general weakness and refractory epigastric pain. She had been diagnosed with CD three years ago. Esophagogastroduodenoscopy (EGD) revealed diffuse edematous and whitish mucosa with multiple erosions in the duodenum. Considering the possibility of viral co-infection, cytomegalovirus (CMV) immunohistochemical staining, PCR, and cultures of duodenal biopsies were performed, all of which were negative with the exception of the isolation of HSV in culture. After administration of intravenous acyclovir for 1 week, follow-up EGD showed almost complete resolution of the lesions and the patient's symptoms improved. In CD patients with refractory gastro-intestinal symptoms, HSV, as well as CMV, should be considered as a possible cause of infection, so that the diagnosis of viral infection is not delayed and the appropriate antiviral treatment can be initiated.

The herpes simplex virus type 1 latency-associated transcript can protect neuron-derived C1300 and Neuro2A cells from granzyme B-induced apoptosis and CD8 T-cell killing

The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) is the only HSV-1 gene transcript abundantly expressed throughout latency. LAT null mutants have a significantly reduced reactivation phenotype. LAT's antiapoptosis activity is the major LAT factor involved in supporting the wild-type reactivation phenotype. During HSV-1 latency, some ganglionic neurons are surrounded by CD8 T cells, and it has been proposed that these CD8 T cells help maintain HSV-1 latency by suppressing viral reactivations. Surprisingly, despite injection of cytotoxic lytic granules by these CD8 T cells into latently infected neurons, neither apoptosis nor neuronal cell death appears to occur. We hypothesized that protection of latently infected neurons against cytotoxic CD8 T-cell killing is due to LAT's antiapoptosis activity. Since CD8 T-cell cytotoxic lytic granule-mediated apoptosis is critically dependent on granzyme B (GrB), we examined LAT's ability to block GrB-induced apoptosis. We report here that (i) LAT can interfere with GrB-induced apoptosis in cell cultures, (ii) LAT can block GrB-induced cleavage (activation) of caspase-3 both in cell culture and in a cell-free in vitro cell extract assay, and (iii) LAT can protect C1300 and Neuro2A cells from cytotoxic CD8 T-cell killing in vitro. These findings support the hypothesis that LAT's antiapoptosis activity can protect latently infected neurons from being killed by CD8 T-cell lytic granules in vivo.

Herpes virus reactivation by low-intensity diode and CO₂ lasers

BACKGROUND

The herpes virus enters into latency after symptomatic or asymptomatic herpetic infection. During latency, the virus has no impact on infected cells. However, internal or external stimuli, including certain lasers, can induce virus reactivation.

OBJECTIVE

The aim was to study the reactivation power of the low-intensity diode and CO(2) lasers on the latent herpes virus.

MATERIALS AND METHODS

The bovine herpesvirus 1 (BHV-1) was inoculated in either the nasal cavity or the lacrimal film of an animal model. Once the virus entered into latency, the trigeminal ganglia of animals were exposed to either a low-intensity diode or CO(2) laser. The reactivation of the virus was then explored by PCR, RT-PCR, and dot-blot hybridization on nasal or lacrimal swabs. The accuracy, sensitivity, and specificity of the aforementioned techniques were compared.

RESULTS

The low-intensity diode laser reactivated the herpes virus less than the CO(2) laser. The nasally inoculated virus was more liable for reactivation by both lasers. PCR was considered as the standard method for the detection of the reactivated virus.

CONCLUSIONS

Low-intensity diode and CO(2) lasers can induce herpes virus reactivation, with the diode laser less likely to reactivate the virus than the CO(2) laser.

Towards an understanding of the herpes simplex virus type 1 latency-reactivation cycle

Infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system. Recurrent ocular shedding can lead to corneal scarring and vision loss making HSV-1 a leading cause of corneal blindness due to an infectious agent. The primary site of HSV-1 latency is sensory neurons within trigeminal ganglia. Periodically, reactivation from latency occurs resulting in virus transmission and recurrent disease. During latency, the latency-associated transcript (LAT) is abundantly expressed. LAT expression is important for the latency-reactivation cycle in animal models, in part, because it inhibits apoptosis, viral gene expression, and productive infection. A novel transcript within LAT coding sequences (AL3) and small nonprotein coding RNAs are also expressed in trigeminal ganglia of latently infected mice. In this review, an update of viral factors that are expressed during latency and their potential roles in regulating the latency-reactivation cycle is discussed.

Review article: Helicobacter pylori-negative duodenal ulcer disease

BACKGROUND

Helicobacter pylori infection rates in duodenal ulcer (DU) patients may be lower than previously estimated.

AIM

To review the real prevalence of H. pylori-negative DUs and its possible causes.

METHODS

Bibliographical searches in MEDLINE looking for the terms 'H. pylori' and 'duodenal ulcer'.

RESULTS

Mean prevalence of H. pylori infection in DU disease, calculated from studies published during the last 10 years including a total of 16 080 patients, was 81%, and this figure was lower (77%) when only the last 5 years were considered. Associations with H. pylori-negative DU were: (1) False negative results of diagnostic methods, (2) NSAID use (21% in studies with <90% infection rate), (3) Complicated DU (bleeding, obstruction, perforation), (4) Smoking, (5) Isolated H. pylori duodenal colonization, (6) Older age, (7) Gastric hypersecretion, (8) Diseases of the duodenal mucosa, (9) Helicobacter'heilmanii' infection and (10) Concomitant diseases.

CONCLUSION

In patients with H. pylori-negative DU disease, one should carefully confirm that the assessment of H. pylori status is reliable. In truly H. pylori-negative patients, the most common single cause of DU is, by far, the use of NSAIDs. Ulcers not associated with H. pylori, NSAIDs or other obvious causes should, for the present, be viewed as 'idiopathic'. True idiopathic DU disease only exceptionally exists.

Identification of a novel herpes simplex virus type 1 transcript and protein (AL3) expressed during latency

The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) is abundantly expressed in latently infected sensory neurons. In small animal models of infection, expression of the first 1.5 kb of LAT coding sequences is necessary and sufficient for wild-type reactivation from latency. The ability of LAT to inhibit apoptosis is important for reactivation from latency. Within the first 1.5 kb of LAT coding sequences and LAT promoter sequences, additional transcripts have been identified. For example, the anti-sense to LAT transcript (AL) is expressed in the opposite direction to LAT from the 5' end of LAT and LAT promoter sequences. In addition, the upstream of LAT (UOL) transcript is expressed in the LAT direction from sequences in the LAT promoter. Further examination of the first 1.5 kb of LAT coding sequences revealed two small ORFs that are anti-sense with respect to LAT (AL2 and AL3). A transcript spanning AL3 was detected in productively infected cells, mouse neuroblastoma cells stably expressing LAT and trigeminal ganglia (TG) of latently infected mice. Peptide-specific IgG directed against AL3 specifically recognized a protein migrating near 15 kDa in cells stably transfected with LAT, mouse neuroblastoma cells transfected with a plasmid containing the AL3 ORF and TG of latently infected mice. The inability to detect the AL3 protein during productive infection may have been because the 5' terminus of the AL3 transcript was downstream of the first in-frame methionine of the AL3 ORF during productive infection.

Distribution of latent bovine herpesvirus 2 DNA in tissues of experimentally infected sheep

The biology of latent infection by bovine herpesvirus 2 (BoHV-2), the agent of mammillitis in cows, remains largely unknown. We herein report attempts to reactivate the latent infection and investigated the sites of BoHV-2 latency in experimentally infected sheep. Ewes inoculated with BoHV-2 in the udder's skin shed virus for up to five days, developed mammillitis and seroconverted. However, attempts to reactivate latent infection by dexamethasone administration at day 40 pi failed. Nevertheless, viral DNA--and not infectious virus--was detected by PCR in several nerve ganglia and/or regional lymph nodes (LNs) of all animals at day 40 post-reactivation. Likewise, lambs previously inoculated with BoHV-2 in the nose harbored latent viral DNA in trigeminal ganglia, tonsils and regional LNs. These results demonstrate that BoHV-2 establishes latent infection in nerve ganglia and in regional lymphoid tissues, yet virus reactivation is not easily achieved by standard protocols used.

Herpes simplex virus and the alimentary tract

Herpes simplex virus (HSV) infection is well known as a sexually transmitted disease. However, relatively little has been published concerning the presentations and treatment of HSV infection within the gastrointestinal tract, where HSV most commonly affects the esophagus in both immunocompromised and immunocompetent patients. HSV proctitis is not uncommon and occurs primarily in males having sex with males. In patients with normal immune systems, gastrointestinal HSV infections are generally self-limited and rarely require antiviral therapy. Treatment of infection is suggested for immunocompromised patients, though no large randomized controlled trials have been performed. This article reviews the manifestations of HSV infection within the luminal gastrointestinal tract and options for diagnosis and treatment.

The role of psychosocial factors in peptic ulcer disease: beyond Helicobacter pylori and NSAIDs

A variety of organic etiologies are associated with peptic ulcer disease, and the most relevant of these are infection with Helicobacter pylori and use of nonsteroidal anti-inflammatory drugs. Between 5% and 20% of patients with gastric or duodenal ulcer, however, lack an identifiable organic etiology. In these patients particularly and in all ulcer patients in general, psychosocial factors may play a significant role. At present, there is no definitive study proving a causal relationship between psychological stress and the development of ulcer disease. Studies to date suffer from significant methodological limitations and have not effectively addressed the poor correlation between ulcer craters and ulcer symptoms. A conservative application of available data would suggest that psychosocial factors play a significant role in symptom perception and reporting in patients with dyspeptic symptoms and may play a role in ulcer formation.

The herpes simplex virus type 1 locus that encodes the latency-associated transcript enhances the frequency of encephalitis in male BALB/c mice

Herpes simplex virus type 1 (HSV-1) is the leading cause of virus-induced encephalitis; however, the viral genes that regulate encephalitis have not been well characterized. In this study, we tested whether the LAT (latency-associated transcript) locus regulates the frequency of encephalitis in male or female mice. Male BALB/c mice are more susceptible to HSV-1-induced encephalitis than age-matched female BALB/c mice. Deletion of LAT coding sequences reduced the frequency of encephalitis. A recombinant virus containing the first 1.5 kb of the LAT coding sequence induces levels of encephalitis in male BALB/c mice similar to those induced by wild-type HSV-1.

Herpes simplex virus type 1 in peptic ulcer disease: An inverse association with Helicobacter pylori

AIM: To assess the frequency of herpes simplex virus type I in upper gastrointestinal tract ulcers and normal mucosa with the modern and better assays and also with a larger number of well characterized patients and controls and its relationship to Helicobacter pylori(H pylori).

METHODS: Biopsy specimens from 90 patients (34 with gastric ulcer of the prepyloric area and 56 with duodenal ulcer) were evaluated. Biopsies from 50 patients with endoscopically healthy mucosa were considered as the control group. The method used to identify herpes simplex virus-1 (HSV-1) was polymerase chain reaction. H pylori was detected by the CLO-test and by histological method.

RESULTS: Herpes simplex virus-1 was detected in 28 of 90 patients with peptic ulcer (31%) [11 of 34 patients with gastric ulcer (32.4%) and 17 of 56 with duodenal ulcer (30.4%)] exclusively close to the ulcerous lesion. All control group samples were negative for HSV-1. The likelihood of H pylori negativity among peptic ulcer patients was significantly higher in HSV-1 positive cases than in HSV-1 negative cases (P = 0.009). Gastric ulcer patients with HSV-1 positivity were strongly associated with an increased possibility of Helicobacter pylori negativity compared to duodenal ulcer patients (P = 0.010).

CONCLUSION: HSV-1 is frequent in upper gastro-intestinal tract ulcers but not in normal gastric and duodenal mucosa. There is an inverse association between HSV-1 and H pylori infection.

The locus encompassing the latency-associated transcript of herpes simplex virus type 1 interferes with and delays interferon expression in productively infected neuroblastoma cells and trigeminal Ganglia of acutely infected mice

The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) is the only abundant viral transcript expressed in latently infected neurons. LAT inhibits apoptosis, suggesting that it regulates latency by promoting the survival of infected neurons. The LAT locus also contains a newly described gene (AL), which is antisense to LAT and partially overlaps LAT encoding sequences. When human (SK-N-SH) or mouse (neuro-2A) neuroblastoma cells were infected with a virus that does not express LAT or AL gene products (dLAT2903), beta interferon (IFN-beta) and IFN-alpha RNA expression was detected earlier relative to the same cells infected with HSV-1 strains that express LAT and AL. Infection of neuro-2A cells with dLAT2903 also led to higher levels of IFN-beta promoter activity than in cells infected with wild-type (wt) HSV-1. In contrast, IFN RNA expression was the same when human lung fibroblasts were infected with dLAT2903 or wt HSV-1. When BALB/c mice were infected with dLAT2903, IFN-alpha and IFN-beta RNA expression was readily detected in trigeminal ganglia (TG) 4 days after infection. These transcripts were not detected in TG of mice infected with wt HSV-1 or dLAT2903R (marker-rescued dLAT2903) until 6 days postinfection. When TG single-cell suspensions from infected BALB/c mice were prepared and incubated in vitro with wt HSV-1 as a source of antigen, TG cultures prepared from mice infected with dLAT2903 produced and secreted higher levels of IFN protein than wt HSV-1 or dLAT2903R. Collectively, these studies suggest that the LAT locus interferes with and delays IFN expression.

Intrapreputial infection of young bulls with bovine herpesvirus type 1.2 (BHV-1.2): acute balanoposthitis, latent infection and detection of viral DNA in regional neural and non-neural tissues 50 days after experimental reactivation

Venereal infection of bulls with bovine herpesvirus type 1.2 (BHV-1.2) may result in acute balanoposthitis followed by the establishment of latent infection, presumably in dorsal root nerve ganglia. We herein report the characterization of the acute and latent infection of young bulls with a Brazilian BHV-1.2 isolate and the investigation of neural and non-neural sites in which viral DNA persists during latent infection, i.e. 110 days after inoculation and 50 days after experimental reactivation. Intrapreputial inoculation of BHV-1.2 isolate SV-56/90 (10(6.5)pfu per animal) resulted in severe balanoposthitis, characterized by redness of the penis and preputial mucosa, coalescent vesicles and fibrinous exsudate in all four infected bulls. Virus shedding was detected in preputial secretions and semen up to days 14 and 13 pi, respectively. Dexamethasone administration at day 60 pi led to reactivation of the infection in all animals, resulting in virus shedding in preputial secretions and/or in semen. At day 50 post-reactivation (pr), the animals were euthanized and regional tissues were collected for PCR and virus isolation. Viral DNA was consistently detected in the dorsal root ganglia of nerves genito-femoral (4/4) and obturator (4/4); frequently in the pudendal (3/4), sciatic (3/4) and rectal caudal nerve ganglia (2/3). In addition, viral DNA was detected in the pelvic sympathetic plexus of one bull and in regional lymph nodes (deep inguinal (2/4); sacral (1/4); medial iliac (1/4)) of two bulls. No infectious virus could be recovered from homogenates of DNA positive tissues, indicating the absence of actively replicating virus. These results demonstrate that BHV-1.2 DNA may persist in several sacral nerve ganglia and in regional lymph nodes as well during latent infection, i.e. 50 days after experimental reactivation. These findings may help in understanding the pathogenesis of acute and latent genital infection by BHV-1.2.

Distribution of bovine herpesvirus type 5 DNA in the central nervous systems of latently, experimentally infected calves

Bovine herpesvirus type 5 (BHV-5) is an alphaherpesvirus associated with meningoencephalitis, a disease highly prevalent in South America. In this study, we investigated the distribution of BHV-5 DNA in the brains of latently, experimentally infected calves by using a PCR for the glycoprotein B gene. Twelve calves inoculated intranasally with a Brazilian BHV-5 isolate were divided into two groups: group A calves (n = 4) were euthanized 55 days postinoculation (p.i.) for tissue collection; group B calves (n = 8) were submitted to dexamethasone administration at day 60 p.i. for reactivation of latent infection and were euthanized 50 days later. Latent infection was reactivated in all group B calves, as demonstrated by virus isolation from nasal secretions and/or seroconversion. Three calves developed neurological disease and died or were euthanized in extremis. For group A calves, viral DNA was consistently detected in the trigeminal ganglia (4/4), midbrain (4/4), thalamus (4/4), and olfactory cortex (4/4) and less frequently in the pons (3/4), cerebellum (3/4), anterior cerebral cortex (2/4), and olfactory bulb (2/4). For calves previously submitted to reactivation (group B), viral DNA was detected with roughly the same frequency in the same areas as for the group A calves. In addition, viral DNA was detected in the posterior (5/5) and dorso-lateral cortex (3/5). All DNA-positive tissues were negative for infectivity and viral antigens. These results demonstrated that latent BHV-5 DNA is present in several areas of the brain during latent infection and that virus reactivation may result in the establishment of latent infection in additional sites of the brain.

Herpes simplex virus type 1 and bovine herpesvirus 1 latency

Primary infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system, upper respiratory tract, and gastrointestinal tract. Recurrent ocular shedding leads to corneal scarring that can progress to vision loss. Consequently, HSV-1 is the leading cause of corneal blindness due to an infectious agent. Bovine herpesvirus 1 (BHV-1) has similar biological properties to HSV-1 and is a significant health concern to the cattle industry. Latency of BHV-1 and HSV-1 is established in sensory neurons of trigeminal ganglia, but latency can be interrupted periodically, leading to reactivation from latency and spread of infectious virus. The ability of HSV-1 and BHV-1 to reactivate from latency leads to virus transmission and can lead to recurrent disease in individuals latently infected with HSV-1. During latency, the only abundant HSV-1 RNA expressed is the latency-associated transcript (LAT). In latently infected cattle, the latency-related (LR) RNA is the only abundant transcript that is expressed. LAT and LR RNA are antisense to ICP0 or bICP0, viral genes that are crucial for productive infection, suggesting that LAT and LR RNA interfere with productive infection by inhibiting ICP0 or bICP0 expression. Numerous studies have concluded that LAT expression is important for the latency-reactivation cycle in animal models. The LR gene has recently been demonstrated to be required for the latency-reactivation cycle in cattle. Several recent studies have demonstrated that LAT and the LR gene inhibit apoptosis (programmed cell death) in trigeminal ganglia of infected animals and transiently transfected cells. The antiapoptotic properties of LAT map to the same sequences that are necessary for promoting reactivation from latency. This review summarizes our current knowledge of factors regulating the latency-reactivation cycle of HSV-1 and BHV-1.

Management of peptic ulcer disease not related to Helicobacter pylori or NSAIDs

Helicobacter pylori (H. pylori) infection is widely accepted as the most important factor in the pathogenesis of duodenal ulcer. However, in parallel with more effective eradication of H. pylori, the prevalence of H. pylori is changing, and H. pylori-negative peptic ulcer disease appears to be increasing. When making a diagnosis of H. pylori-negative peptic ulcer disease, it is essential to avoid misclassification because of inaccurate diagnosis. In addition, secondary causes may need to be excluded with appropriate investigations. In the absence of H. pylori, nonsteroidal anti-inflammatory drug usage is the most common cause of peptic ulcer; surreptitious nonsteroidal anti-inflammatory drug usage is a cause of unexplained ulcer disease in up to 60% of patients. Hypersecretory syndromes such as Zollinger-Ellison syndrome, although rare, need to be excluded. Once all known etiological factors are excluded, there remains a group of patients with so-called "idiopathic ulcers." The interplay of etiological factors in the pathogenesis of idiopathic peptic ulcer disease is poorly defined but may include a genetic predisposition, altered acid secretion, rapid gastric emptying, defective mucosal defense mechanisms, psychological stress, and smoking. The management of idiopathic peptic ulcers is not defined; they appear to be more resistant to standard therapy, can be associated with more frequent complications, and those that relapse may require long-term maintenance therapy.

The long-term time trends of peptic ulcer and ulcerative colitis are interrelated

OBJECTIVE

A birth-cohort phenomenon in the time trends of a disease indicates that exposure to relevant risk factors must have occurred during an early period of life. The aim of this study was to determine whether birth-cohort patterns are common features of ulcerative colitis, gastric ulcer, and duodenal ulcer in different countries.

METHODS

The number of deaths from ulcerative colitis, gastric, and duodenal ulcer in England, Netherlands, Italy, Switzerland, United States, and Scotland were retrieved from the respective national statistics offices. The death rates from the six countries were plotted against the period of birth. Age-standardized cohort mortality ratios were calculated as a summary of the overall mortality associated with each consecutive birth-cohort.

RESULTS

In all countries alike, mortality from ulcerative colitis, gastric, and duodenal ulcer increased among successive generations born during the 19th century and, after reaching a sharp peak around the turn of the 20th century, declined among generations born subsequently. The rise in mortality from gastric ulcer preceded a similar rise in mortality from duodenal ulcer by 10-20 yr, and the temporal changes of duodenal ulcer coincided with those of ulcerative colitis.

CONCLUSIONS

The sudden rise of peptic ulcer disease during the 19th century and the 10-20-yr time lag between gastric and duodenal ulcer are difficult to explain based on changing infection rates with Helicobacterpylori alone. The similarity between the time trends of duodenal ulcer and ulcerative colitis suggests the influence of one or more shared risk factors.

Peptic ulcer disease in children

A peptic ulcer in a child looks the same as it does in an adult, and many of the aetiologies of peptic ulcer disease in children are similar to those in adults. However, there are many differences between children and adults, especially in the areas of clinical presentation, the prevalences of different types of ulcer disease, and the prevalence of complications of ulcer disease. Therefore the approach to diagnosis and management in children is often at variance with that in adults. One important example is the approach to suspected Helicobacter pylori (H. pylori) disease in children, in which consensus groups have advised a considerably different approach in children. While the chapter deals with the full range of peptic ulcer disease in children, the focus is on those aspects in which there are differences between adults and children.

Molecular aspects of herpes simplex virus I latency, reactivation, and recurrence

The application of molecular biology in the study of the pathogenesis of herpes simplex virus type 1 (HSV-1) has led to significant advances in our understanding of mechanisms that regulate virus behavior in sensory neurons and epithelial tissue. Such study has provided insight into the relationship of host and viral factors that regulate latency, reactivation, and recurrent disease. This review attempts to distill decades of information involving human, animal, and cell culture studies of HSV-1 with the goal of correlating molecular events with the clinical and laboratory behavior of the virus during latency, reactivation, and recurrent disease. The purpose of such an attempt is to acquaint the clinician/scientist with the current thinking in the field, and to provide key references upon which current opinions rest.

Latent herpes simplex virus type 1 gene expression in ganglia innervating the human gastrointestinal tract

Using in situ hybridization, we demonstrated that latent herpes simplex virus type 1 (HSV-1) gene expression is prevalent in human adult nodose ganglia. This suggests that infection of gastrointestinal sensory nerves, probably through swallowed virus-laden oral secretions, occurs commonly and that HSV-1 reactivating from this site may play a role in recurrent gastrointestinal disorders.

The effect of tripotassium dicitrato bismuthate on the rat stomach

BACKGROUND

Bismuth has been used as symptomatic treatment of dyspepsia for many years. It promotes healing of peptic ulcers and reduces their recurrence. The beneficial effect of bismuth on duodenal ulcer disease is thought to be due to an effect on Helicobacter pylori, although it has a rather weak bactericidal effect on H. pylori in vitro. Eradication of H. pylori in duodenal ulcer patients by a combination of bismuth, tetracycline and metronidazole has been reported to increase the density of somatostatin-producing D cells in the antrum. A reduced D cell density in the antral mucosa of duodenal ulcer patients could explain their exaggerated gastrin release.

AIMS/METHODS

To test the possibility that bismuth could affect the neuroendocrine cells independently of the presence of H. pylori or not, we gave rats a diluted tripotassium dicitrato bismuthate solution by gastric gavage for 14 days.

RESULTS

Tripotassium dicitrato bismuthate treatment did not affect maximal pentagastrin-stimulated acid secretion or histamine release in isolated rat stomachs or the density of argyrophil cells in the oxyntic and antral mucosa. However, it significantly reduced the duodenal concentration of gastrin and calcitonin gene-related peptide, and the density of G cells in the antrum and duodenum.

CONCLUSION

The effect of tripotassium dicitrato bismuthate on the G cell may be of significance for its beneficial effect on duodenal ulcer disease.

Review article: the use of gastric acid-inhibitory drugs--physiological and pathophysiological considerations

All vertebrates secrete gastric acid. Acid denatures the proteins in the food and thus makes them more accessible to proteolytic enzymes, and it kills swallowed micro-organisms. Gastric acid plays an important pathogenetic role in peptic ulcer disease and reflux oesophagitis. In these diseases, drugs that inhibit secretion of gastric acid will heal the lesions and suppress the symptoms. However, both reflux oesophagitis and peptic ulcer tend to recur when the acid-inhibitory treatment is stopped. Therefore, these patients often require long-term treatment with acid-inhibitors. In this overview the potential risks of long-term profound inhibition of acid secretion, raising the pH above 4 for a considerable time, resulting in reduced killing of micro-organisms and secondary hypergastrinaemia, are discussed. Gastrin regulates both the function (production and release of histamine) and growth of the enterochromaffin-like (ECL) cell. Hitherto, the role that this cell plays in gastric carcinogenesis appears to have been underestimated.

Detection of viral DNA in neonatal herpes encephalitis autopsy tissues by solution-phase PCR: comparison with pathology and immunohistochemistry

To detect DNA sequences of herpes simplex virus (HSV) in neural and non-neural tissue sections in disseminated human neonatal HSV infection, a solution polymerase chain reaction (PCR) protocol was developed which amplified HSV thymidine kinase and host genomic DNA sequences that were hybridized with sequence-specific probes in Southern blots. Serial sections of formalin-fixed, paraffin embedded autopsy tissues were tested by PCR and compared to histology and HSV antigen detection. The sensitivity, specificity and reproducibility of this PCR protocol were determined on uninfected and HSV-infected mouse tissues and on HSV DNA from infected tissue culture cells. Samples estimated to contain as few as 60 copies of preserved HSV DNA target sequence gave a positive PCR result. In nine neonates that died during acute HSV infection, all non-neural tissues and a minority of neural tissues with histological lesions had HSV antigen; when DNA could be amplified, HSV DNA sequences were detected by PCR. Together, these findings indicate a direct role for virus in the pathogenesis of these lesions. In the same cases, some or all brain samples were negative for HSV antigen, but nevertheless had HSV DNA sequences detected by PCR. The possible explanations for this finding are discussed. In one neonate dying seven weeks after birth, HSV sequences were found in brain lesions in the absence of HSV antigen; neither HSV DNA nor antigen were found in non-neural tissues, suggesting a latent HSV infection in brain. It is practical to apply PCR methods to detect minute quantities of viral DNA in formalin-fixed, paraffin embedded autopsy tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Biology and molecular aspects of herpes simplex and varicella-zoster virus infections

The herpes simplex and varicella-zoster viruses are members of the subfamily alpha herpesviruses with specific properties of the virion and with the capacity to establish latent infections in humans. The genome of each of these viruses has been determined with an estimate of the number of genes and proteins encoded. The biology and molecular events of the herpes simplex virus productive and latent infection have been detailed with the use of both in vitro and in vivo model systems. The neuron is the site of latency in the ganglia with a limited transcription of genes expressed during the latent period. The specific molecular regulation of latency and reactivation are not well established. There are co-cultivation, electron microscopy, and biochemical studies that support the concept of corneal latency, although this has not been proven conclusively. Details about the varicella-zoster virus biology and molecular events are not as well advanced since animal models have been lacking. The biology of the productive infection (varicella) is different from herpes simplex virus infection since the portal of entry is the respiratory system. Data support the concept of the maintenance of latency within satellite cells in the ganglia rather than within neurons. There are multiple genes expressed during this latency. These features may explain the different clinical presentations and course of reactivation (zoster) compared with herpes simplex virus reactivation.

A review of the molecular mechanism of HSV-1 latency

The neurotropic herpes viruses, as typified by herpes simplex virus type 1, are noted for their ability to form latent infections. The latent infection differs from the acute infection both in gene expression and the physical state of the viral genome. Latency can be divided into several stages--establishment, maintenance of reactivation--each of which are active areas of research. This review describes the molecular biology of HSV-1 latency and presents the current level of understanding of the molecular mechanism of HSV-1 latency.

Detection of cytomegalovirus nucleic acid sequences in pancreas in type 2 diabetes

Nucleic acid sequences specific for human cytomegalovirus (CMV) were found in samples of pancreatic tissue from patients with non-insulin-dependent (type 2) diabetes mellitus. RNA extracted from paraffin-embedded or fresh-frozen specimens from 14 of 32 (44%) diabetic patients but from none of 49 non-diabetic controls reacted with 10 kb (pJN201) or 6.6 kb (pCM3) probes of human CMV immediate-early or late gene products, respectively. The RNA from the 32 diabetic patients did not react with nucleic acid probes for mumps, rubella, or coxsackie B viruses. In-situ nucleic acid hybridisation on tissues from 5 randomly selected human-CMV-positive patients showed that the human CMV signal was localised primarily in the islets of Langerhans and not in exocrine cells. Despite the clear viral nucleic acid signal in tissues of human-CMV-positive patients, there were no morphological injuries to the islets, no inflammatory cells in the islets, and no perivascular inflammatory cell cuffing. These findings suggest a possible association of human CMV with type 2 diabetes in human beings.