Gland Hypertrophy Research Articles

Secretion properties, clearance, and therapy in airway disease.

Chronic airway diseases like cystic fibrosis, chronic bronchitis, asthma, diffuse panbronchiolitis, and bronchiectasis are all associated with chronic inflammation. The airway mucosa responds to infection and inflammation in part by surface mucous (goblet) cell and submucosal gland hyperplasia and hypertrophy with mucus hypersecretion. Products of inflammation including neutrophil derived DNA and filamentous actin, effete cells, bacteria, and cell debris all contribute to mucus purulence and, when this is expectorated it is called sputum. Mucus is usually cleared by ciliary movement, and sputum is cleared by cough.These airway diseases each are associated with the production of mucus and sputum with characteristic composition, polymer structure, and biophysical properties. These properties change with the progress of the disease making it possible to use sputum analysis to identify the potential cause and severity of airway diseases. This information has also been important for the development of effective mucoactive therapy to promote airway hygiene.

Activation of Nrf2 in keratinocytes causes chloracne (MADISH)‐like skin disease in mice

The transcription factor Nrf2 is a key regulator of the cellular stress response, and pharmacological Nrf2 activation is a promising strategy for skin protection and cancer prevention. We show here that prolonged Nrf2 activation in keratinocytes causes sebaceous gland enlargement and seborrhea in mice due to upregulation of the growth factor epigen, which we identified as a novel Nrf2 target. This was accompanied by thickening and hyperkeratosis of hair follicle infundibula. These abnormalities caused dilatation of infundibula, hair loss, and cyst development upon aging. Upregulation of epigen, secretory leukocyte peptidase inhibitor (Slpi), and small proline-rich protein 2d (Sprr2d) in hair follicles was identified as the likely cause of infundibular acanthosis, hyperkeratosis, and cyst formation. These alterations were highly reminiscent to the phenotype of chloracne/“metabolizing acquired dioxin-induced skin hamartomas” (MADISH) patients. Indeed, SLPI, SPRR2, and epigen were strongly expressed in cysts of MADISH patients and upregulated by dioxin in human keratinocytes in an NRF2-dependent manner. These results identify novel Nrf2 activities in the pilosebaceous unit and point to a role of NRF2 in MADISH pathogenesis.

Long-acting muscarinic receptor antagonists for the treatment of chronic airway diseases.

Acetylcholine (neuronal and non-neuronal origin) regulates bronchoconstriction, and mucus secretion. It has an inflammatory effect by inducing attraction, survival and cytokine release from inflammatory cells. Muscarinic receptors throughout the bronchial tree are mainly restricted to muscarinic M1, M2 and M3 receptors. Three long-acting muscarinic receptor antagonists (LAMAs) were approved for the treatment of chronic obstructive pulmonary disease (COPD) in Europe: once-daily tiotropium bromide; once-daily glycopyrronium bromide; and twice-daily aclidinium bromide. All have higher selectivity for M3 receptors than for M2 receptors, and dissociate more slowly from the M3 receptors than they do from the M2 receptors. Some LAMAs showed anti-inflammatory effects [inhibition of neutrophil chemotactic activity and migration of alveolar neutrophils, decrease of several cytokines in the bronchoalveolar lavage (BAL) including interleukin (IL)-6, tumor necrosis factor (TNF)-α and leukotriene (LT)B4] and antiremodeling effects (inhibition of mucus gland hypertrophy and decrease in MUC5AC-positive goblet cell number, decrease in MUC5AC overexpression). In the clinic, LAMAs showed a significant improvement of forced expiratory volume in 1 second (FEV1), quality of life, dyspnea and reduced the number of exacerbations in COPD and more recently in asthma. This review will focus on the three LAMAs approved in Europe in the treatment of chronic airway diseases.

Research of interrenal and chromaffin glands in barfin plaice Liopsetta pinnifasciata from Amursky Bay (Peter the Great Bay, Sea of Japan)

Studies of the barfin plaice Liopsetta pinnifasciata inhabiting Amursky Bay (Peter the Great Bay, Sea of Japan) performed in 1999–2005 showed a twofold reduction in the area of cell nuclei of the interrenal and chromaffin glands after 2001, which indicates a significant weakening of the damaging effect of the environment on fish. It is assumed that one of the main causes of the hypertrophy of both glands in barfin plaices before 2001 was the phenolic pollution of the environment. The study points to the sensitivity of the adrenal system of the barfin plaice to changes in the quality of environment.

Antiviral drug valacyclovir treatment combined with a clean feeding system enhances the suppression of salivary gland hypertrophy in laboratory colonies of Glossina pallidipes.

BackgroundHytrosaviridae cause salivary gland hypertrophy (SGH) syndrome in some infected tsetse flies (Diptera: Glossinidae). Infected male and female G. pallidipes with SGH have a reduced fecundity and fertility. Due to the deleterious impact of the virus on G. pallidipes colonies, adding the antiviral drug valacyclovir to the blood diet and changing the feeding regime to a clean feeding system (each fly receives for each feeding a fresh clean blood meal) have been investigated to develop virus management strategies. Although both approaches used alone successfully reduced the virus load and the SGH prevalence in small experimental groups, considerable time was needed to obtain the desired SGH reduction and both systems were only demonstrated with colonies that had a low initial virus prevalence (SGH ≤ 10%). As problems with SGH are often only recognized once the incidence is already high, it was necessary to demonstrate that this combination would also work for high prevalence colonies.FindingsCombining both methods at colony level successfully suppressed the SGH in G. pallidipes colonies that had a high initial virus prevalence (average SGH of 24%). Six months after starting the combined treatment SGH symptoms were eliminated from the treated colony, in contrast to 28 months required to obtain the same results using clean feeding alone and 21 months using antiviral drug alone.ConclusionsCombining valacyclovir treatment with the clean feeding system provides faster control of SGH in tsetse than either method alone and is effective even when the initial SGH prevalence is high.

Ameliorative effect of Koflet formulations against pyridine-induced pharyngitis in rats

In present study two formulations of Koflet (syrup and lozenges) were evaluated against pyridine-induced pharyngitis in rats. Topical application of 10% pyridine showed extravasation of Evans blue stain as a characteristic feature of on-going inflammation. In addition, the levels of TNF-α (p < 0.01) and IL-6 (p < 0.01) were significantly increased compared to control. Further, histopathology of the pharyngeal tissue showed submucosal gland hypertrophy, severe mucosal inflammation characterized by presence of mononuclear cells and neutrophils along with haemorrhages and congestion; however, saline applied animals (normal control) showed normal cytoarchitecture of the pharynx. Interestingly, pre-treatment with dexamethasone (1 mg/kg, p.o.), Koflet lozenges (KL) (500 and 1000 mg/kg, p.o.) and Koflet syrup (KS) (2 and 4 ml/kg, p.o.) for 7 days showed significant and dose dependent protection by decreasing the EB dye extravasation, and serum levels of TNF-α and IL-6. In addition, histopathological findings have further supported the protective effect of Koflet formulations. These findings suggest that, both Koflet syrup and Koflet lozenges are highly effective in treating non-infectious type of pharyngitis. Among the two formulations KS was found to be more potent than KL, and possible mechanism of action thought to be mediating through inhibition of TNF-α and/or phospholipids–arachidonic acid pathway.

Epidemiology of MdSGHV in Musca Domestica

Musca domestica salivary gland hypertrophy virus (MdSGHV) is a disease that enlarges the salivary glands of Musca domestica (the common house fly), as well as causes infertility in female house flies. An infected female fly will no longer produce or lay eggs and will refuse a male’s mating attempts. Collaborating with the University of Florida’s Entomology and Nematology Department, we have hypothesized that the virus is primarily transmitted through male-male interactions. The constant interaction between males causes damage to the flies’ cuticle. When the virus is present on the cuticle, this damage allows the virus entry into the hemocoel, which subsequently infects the internal organs and in particular the salivary glands. The virus adheres to the fly cuticle at contaminated resting sites and contaminated feeding sites. Infection per os is another possible mode of transmission but insu cient to sustain the virus in the fly population. For females, MdSGHV seems to be transmitted largely per os with random occurrences of cuticular damage that take place at the contaminated food and resting sites. There is no evidence that females exhibit aggressive behavior, or that mating causes cuticular damage. Vertical transmission does not seem to be a mode of transmission. We developed a system of di↵erential equations to model the transmission of MdSGHV for a population of Musca domestica at Florida dairy farms. The model is based on the above understanding of the transmission of the virus together with some other simplifying

Novel experimental model of non-infectious pharyngitis in rats

IntroductionCurrently, there is a paucity of scientific literature and reports related to screening models for non-infectious type of pharyngitis. In this context, we made a sincere attempt to establish a novel animal model for screening drugs against non-infectious pharyngitis in rats. We have considered the use of pyridine, croton oil and their combination for inducing non-infectious pharyngitis in rats. MethodsVarious concentrations of pyridine were applied topically to the pharyngeal region of rats and the extent of inflammation was assessed by Evans Blue (EB) dye exudation test, evaluating the serum levels of proinflammatory cytokines and histopathology. Dexamethasone and diclofenac were used as reference standards. ResultsUpon pyridine application (2.5%, 5%, 10%, 20%, 40% and 80% in saline), dose-dependent increase in EB dye extravasation was observed (increased vascular permeability). In addition, the levels of TNF-α (P<0.01) and IL-6 (P<0.01) were significantly increased compared to control. Furthermore, the histopathology of pharyngeal tissue showed hypertrophy of submucosal glands, severe inflammation of the pharynx characterised by presence of mononuclear cells, neutrophils along with haemorrhages and congestion; however, normal control animals showed normal cytoarchitecture of pharynx. Indeed, dexamethasone (0.25, 0.5 and 1mg/kg, i.v.) and diclofenac (1, 2.5 and 5mg/kg, i.v.) showed dose-dependent protection against pyridine-induced pharyngitis. Further, the possible mechanism of pyridine-induced pharyngitis is thought to be primarily mediated through phospholipase A2 and cyclooxygenase (COX) pathway. ConclusionThese findings suggest that pyridine-induced pharyngitis is a simple and versatile novel animal model for screening the drugs against non-infectious pharyngitis in rats.

Effect of phenytoin treatment on cell proliferation in the hippocampus and the heart and related neuroendocrine changes under non-stress and stress conditions

Objective: Phenytoin is an antiepileptic drug that has been shown to reduce some neurotoxic effects of glutamate in states when glutamate neurotransmission is increased, such as neurodegeneration and stress. In the present study, we tested the hypothesis that treatment with phenytoin prevents stress-induced alterations in the production of new cells in the hippocampus and in the heart.Methods: Adult male Wistar rats were exposed to repeated hypokinesis (restraint, 2 hours daily) and were treated with phenytoin (20 mg/kg/day, s.c.) or vehicle for 8 days. On the 7th day, all animals were treated with 5-bromo-2'-deoxyuridine (BrdU), a marker of cell proliferation.Results: The treatment with phenytoin under both control and stress conditions resulted in an inhibitory effect on cell proliferation, which was more evident in the heart than in the hippocampus. Repeated treatment with phenytoin led to adrenal gland hypertrophy as well as to a marginal increase in plasma renin activity. Basal and stress-induced concentrations of adrenal steroids were unchanged by phenytoin administration.Discussion: Treatment with the glutamate release inhibiting drug phenytoin did not prevent negative consequences of repeated stress exposure on cell proliferation in Wistar rats. Treatment with phenytoin even deepened stress-induced reduction of cell proliferation in the heart. It cannot be excluded that the phenytoin-induced increase in plasma renin activity observed in the present study may occur during therapeutic use of phenytoin and contribute to its adverse effects.

Adaptive Parotid Gland Hypertrophy Induced by Dietary Treatment of GSE in Rats

In a 13-week feeding toxicity study of grape skin extract (GSE) performed previously, 5.0% GSE showed diffuse hypertrophy and basophilia in rat parotid glands. To clarify whether the change in the parotid glands was an adverse effect of GSE, 6-week-old male F344 rats were fed a diet containing 5.0% GSE or were administered a dose corresponding to the dietary concentration via gavage for 4 weeks, and the treatment was stopped for 2 weeks. To ascertain the effect of astringency, other animals were fed a diet containing 5.0% tannic acid (TA) using the same protocol as the GSE feed group. Control groups were fed a basal diet or were administered sterilized distilled water by gavage. In the GSE and TA feed groups, diffuse severe hypertrophy and basophilia in the parotid glandular epithelial cells were observed. Macroscopic, microscopic, and ultrastructural characteristics consistent with cellular hypertrophy was less apparent after the recovery period in both feed groups. In contrast, no changes were observed in the parotid glands of the gavage GSE and control groups at week 4. Based on these findings of parotid hypertrophy without cytotoxicity, the data from this and previous studies suggest that hypertrophy of the parotid glands induced by feeding treatment with GSE is an adaptive non-adverse effect that is reversible upon removal of the sialotrophic agent.

A Mathematic Model That Describes Modes of MdSGHV Transmission within House Fly Populations.

In this paper it is proposed that one potential component by which the Musca domestica salivary gland hypertrophy virus (MdSGHV) infects individual flies is through cuticular damage. Breaks in the cuticle allow entry of the virus into the hemocoel causing the infection. Male flies typically have a higher rate of infection and a higher rate of cuticular damage than females. A model for the transmission of MdSGHV was formulated assuming several potential and recognized means of transmission. The model yields results that are in agreement with field data that measured the infection rate in house flies on dairy farms in Florida. The results from this model indicate that MdSGHV will be maintained at a stable rate within house fly populations and support the future use of MdSGHV as a birth control agent in house fly management.

Effects of Lersivirine on Canine and Rodent Thyroid Function

Lersivirine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) being developed for the treatment of HIV-1 infection. Like other NNRTIs, lersivirine is a potent enzyme inducer in rodents capable of inducing a number of hepatic enzymes including those involved in its own metabolism. Preclinically lersivirine has been associated with hepatocellular hypertrophy and thyroid gland follicular cell hypertrophy in rats, mice, and dogs. In rodents, we show that development of thyroid hypertrophy is related to the classic mechanism, namely increased thyroxine (T4) clearance secondary to induction of uridine-diphosphoglucuronosyltransferase (UDPGT) in the liver and a resulting increase in thyroid-stimulating hormone. Similarly, lersivirine-exposed dogs exhibit a significant increase in hepatic UDPGT enzyme activity along with increased T4 clearance although clear effects on serum thyroid hormone levels were less apparent. These effects on thyroid hormonal clearance in the dog suggest that thyroid gland hypertrophy in this species is due to the same mechanism shown to occur in rodents although, as expected, dogs better adapt to these effects and therefore maintain relatively normal thyroid hormonal balance. It is also notable that the minimal thyroid follicular hypertrophy that occurs in dogs does not progress as is seen in rodents. As is the case with rodents, these adaptive changes in the dog are not considered indicative of a human health risk.

Dynamic sonography and CT findings of unilateral submandibular gland agenesis associated with herniated hypertrophic sublingual gland

Congenital agenesis of the submandibular gland is uncommon. We report dynamic sonography and CT findings of the unilateral submandibular gland agenesis associated with herniated hypertrophic sublingual gland tissue through the mylohyoid gap. The dynamic sonography examination applied at rest and during the modified Valsalva maneuver demonstrated hypertrophied sublingual gland prolapsing to the anterior part through the mylohyoid gap. This may be the first reported case describing dynamic sonography findings of this entity. CT confirmed the agenesis of the left submandibular gland and compensatory hypertrophy of the ipsilateral sublingual gland.

Groove Pancreatitis: A Rare Cause of Abdominal Pain

Purpose: A 54 year-old man was referred to our outpatient gastroenterology clinic for several weeks of upper abdominal pain. He had a history of acid reflux and Barrett's esophagus, but his symptoms were well-controlled on a proton pump inhibitor. For 3 weeks prior to presentation, he experienced dull epigastric abdominal pain that was at times severe. The pain did not radiate to the back and had no definite relation to food. His weight was stable, and he had not experienced similar symptoms in the past. There was no change in bowel habits. History revealed that he consumed 3-4 alcoholic drinks per night. Physical exam was notable for a well-appearing man with a benign abdomen. There was no epigastric tenderness to palpation, scleral icterus, hepatosplenomegaly, or jaundice. Blood studies, including liver function tests, were normal except for a minimally elevated lipase of 59 U/L. Abdominal ultrasound revealed fatty infiltration of the liver. An esophagogastroduodenoscopy (EGD) was then performed and notable for erythema and edema of the duodenal bulb. The remainder of the examination was unremarkable. A subsequent computed tomography (CT) scan of the abdomen displayed inflammation of the pancreaticoduodenal groove with associated ill-defined appearance of the head of the pancreas. The patient's abdominal pain was attributed to groove pancreatitis. His symptoms improved with conservative management and cessation of alcohol use. First described in Germany in 1973, groove pancreatitis is a chronic pancreatitis that affects the region between the pancreatic head, duodenum, and common bile duct (CBD), also known as the groove area. The exact incidence of this condition is unknown, but most patients with groove pancreatitis are men aged between 40-50 years with a history of alcohol abuse. The pathogenesis is also unclear, but it has been postulated that duodenal stenosis, obstruction of the minor papilla, and Brunner's gland hypertrophy may play a role. Clinical presentation and laboratory findings are similar to chronic pancreatitis, but nausea, vomiting, and weight loss are often more severe in groove pancreatitis. Prognosis varies widely. Conservative measures such as cessation of alcohol, initiation of pain control, and pancreatic rest can lead to resolution of symptoms. Surgery, however, may be required in the set of patients who fail to improve. Additionally, distinguishing between groove pancreatitis and adenocarcinoma of the head of the pancreas or autoimmune pancreatitis may be problematic. Clinicians must thus be aware of this disease entity since surgery can be curative. In patients who do not undergo surgical resection, close follow-up is necessary.

Bilateral Submandibular Gland Aplasia With Hypertrophy of the Sublingual Glands of a Patient With a Cleft Lip and Palate

Aplasia of major salivary glands is a rare disorder with only a handful of cases reported in the literature. The cause of congenital absence of the salivary glands has not been determined, but it may be associated with ectodermal defects of the first and second branchial arches. Patients may be asymptomatic or may experience dysphagia, xerostomia, several periodontal disease, or multiple caries. There are few reports of patients with congenital gland aplasia with cleft lip and palate. We document the case of a 41-year-old patient with repaired unilateral cleft lip palate, bilateral submandibular gland aplasia, and compensatory hypertrophy of the sublingual glands. To the best of our knowledge, there are no previous reports that can be found in the literature with a combination of such findings.

Is post-mortem ultrasonography a useful tool for forensic purposes?

To investigate the interest of post-mortem ultrasonography in the diagnosis of pathological background, and manner and cause of death. Post-mortem ultrasonography exams were carried out on 38 fresh human adult cadavers referred to the Department of Forensic Medicine and Pathology (Garches, France). Data obtained from ultrasonography were independently compared with further forensic autopsy findings. Two important limitations relative to ultrasound utilization appeared: hyper-echoic abdominal and thoracic walls, with gas distension of the whole digestive tube and subcutaneous tissues (due to precocious putrefactive gas releasing); and difficulty in accessing lateral and posterior structures (i.e. liver, spleen, kidneys, lung bases, aorta) due to rigor mortis and evident non-compliance of the subject. Post-mortem diagnoses (moderate ascites, gallbladder stones, bladder globe, chronic kidney disease, cirrhosis, thyroid gland cysts and hypertrophy, intrauterine device), were strongly limited. False negative diagnoses comprised fatty liver, pleural effusion, thoracic aortic dissection, and focal organ and/or soft tissues lesions (for example, wounds or infarcts). According to the results, post-mortem ultrasonography seems to have a very limited role for forensic purposes. Other post-mortem utilizations are cited, proposed, and discussed.

Dynamic sonography and CT findings of unilateral submandibular gland agenesis associated with herniated hypertrophic sublingual gland

Congenital agenesis of the submandibular gland is uncommon. We report dynamic sonography and CT findings of the unilateral submandibular gland agenesis associated with herniated hypertrophic sublingual gland tissue through the mylohyoid gap. The dynamic sonography examination applied at rest and during the modified Valsalva maneuver demonstrated hypertrophied sublingual gland prolapsing to the anterior part through the mylohyoid gap. This may be the first reported case describing dynamic sonography findings of this entity. CT confirmed the agenesis of the left submandibular gland and compensatory hypertrophy of the ipsilateral sublingual gland.

Treadmill exercise does not change gene expression of adrenal catecholamine biosynthetic enzymes in chronically stressed rats

Chronic isolation of adult animals represents a form of psychological stress that produces sympatho-adrenomedullar activation. Exercise training acts as an important modulator of sympatho-adrenomedullary system. This study aimed to investigate physical exercise-related changes in gene expression of catecholamine biosynthetic enzymes (tyrosine hydroxylase, dopamine-ß-hydroxylase and phenylethanolamine N-methyltransferase) and cyclic adenosine monophosphate response element-binding (CREB) in the adrenal medulla, concentrations of catecholamines and corticosterone (CORT) in the plasma and the weight of adrenal glands of chronically psychosocially stressed adult rats exposed daily to 20 min treadmill running for 12 weeks. Also, we examined how additional acute immobilization stress changes the mentioned parameters. Treadmill running did not result in modulation of gene expression of catecholamine synthesizing enzymes and it decreased the level of CREB mRNA in the adrenal medulla of chronically psychosocially stressed adult rats. The potentially negative physiological adaptations after treadmill running were recorded as increased concentrations of catecholamines and decreased morning CORT concentration in the plasma, as well as the adrenal gland hypertrophy of chronically psychosocially stressed rats. The additional acute immobilization stress increases gene expression of catecholamine biosynthetic enzymes in the adrenal medulla, as well as catecholamines and CORT levels in the plasma. Treadmill exercise does not change the activity of sympatho-adrenomedullary system of chronically psychosocially stressed rats.

Interwoven Biology of the Tsetse Holobiont

Microbial symbionts can be instrumental to the evolutionary success of their hosts. Here, we discuss medically significant tsetse flies (Diptera: Glossinidae), a group comprised of over 30 species, and their use as a valuable model system to study the evolution of the holobiont (i.e., the host and associated microbes). We first describe the tsetse microbiota, which, despite its simplicity, harbors a diverse range of associations. The maternally transmitted microbes consistently include two Gammaproteobacteria, the obligate mutualists Wigglesworthia spp. and the commensal Sodalis glossinidius, along with the parasitic Alphaproteobacteria Wolbachia. These associations differ in their establishment times, making them unique and distinct from previously characterized symbioses, where multiple microbial partners have associated with their host for a significant portion of its evolution. We then expand into discussing the functional roles and intracommunity dynamics within this holobiont, which enhances our understanding of tsetse biology to encompass the vital functions and interactions of the microbial community. Potential disturbances influencing the tsetse microbiome, including salivary gland hypertrophy virus and trypanosome infections, are highlighted. While previous studies have described evolutionary consequences of host association for symbionts, the initial steps facilitating their incorporation into a holobiont and integration of partner biology have only begun to be explored. Research on the tsetse holobiont will contribute to the understanding of how microbial metabolic integration and interdependency initially may develop within hosts, elucidating mechanisms driving adaptations leading to cooperation and coresidence within the microbial community. Lastly, increased knowledge of the tsetse holobiont may also contribute to generating novel African trypanosomiasis disease control strategies.

Managing Hytrosavirus Infections in Glossina pallidipes Colonies: Feeding Regime Affects the Prevalence of Salivary Gland Hypertrophy Syndrome

Many species of tsetse flies are infected by a virus that causes salivary gland hypertrophy (SGH) syndrome and the virus isolated from Glossina pallidipes (GpSGHV) has recently been sequenced. Flies with SGH have a reduced fecundity and fertility. Due to the deleterious impact of SGHV on G. pallidipes colonies, several approaches were investigated to develop a virus management strategy. Horizontal virus transmission is the major cause of the high prevalence of the GpSGHV in tsetse colonies. Implementation of a “clean feeding” regime (fresh blood offered to each set of flies so that there is only one feed per membrane), instead of the regular feeding regime (several successive feeds per membrane), was among the proposed approaches to reduce GpSGHV infections. However, due to the absence of disposable feeding equipment (feeding trays and silicone membranes), the implementation of a clean feeding approach remains economically difficult. We developed a new clean feeding approach applicable to large-scale tsetse production facilities using existing resources. The results indicate that implementing this approach is feasible and leads to a significant reduction in virus load from 109 virus copies in regular colonies to an average of 102.5 and eliminates the SGH syndrome from clean feeding colonies by28 months post implementation of this approach. The clean feeding approach also reduced the virus load from an average of 108 virus copy numbers to an average of 103 virus copies and SGH prevalence of 10% to 4% in flies fed after the clean fed colony. Taken together, these data indicate that the clean feeding approach is applicable in large-scale G. pallidipes production facilities and eliminates the deleterious effects of the virus and the SGH syndrome in these colonies.