Non-cirrhotic portal hypertension in HIV mono-infected patients

BACKGROUND AND AIM

Unexplained liver injury including fibrosis and portal hypertension has rarely been reported among patients with HIV in the absence of co-infection with hepatitis B (HBV) or hepatitis C (HCV). We describe a series of HIV mono-infected patients with evidence of non-cirrhotic portal hypertension.

METHODS

HIV-infected patients with evidence of portal hypertension who were anti-HBV and anti-HCV negative and HBV and HCV RNA polymerase chain reaction (PCR) negative were identified from patients managed by the Victorian statewide HIV referral service located at The Alfred Hospital, Melbourne. Portal hypertension was defined as either radiological or endoscopic evidence of varices, portal vein flow obstruction, or elevated hepatic venous pressure gradient (HPVG).

RESULTS

Five patients were found to have portal hypertension. These patients were male, aged 41 to 65 years, with known duration of HIV infection between 11 to 25 years. All had been treated with antiretroviral therapy, including didanosine. Tests for metabolic, autoimmune, and hereditary causes of liver disease failed to establish an etiology for the liver injury. All had radiological or endoscopic findings of varices, and four patients had radiological features of portal vein obstruction or flow reversal. Only one patient underwent HPVG measurement, which was elevated. Non-invasive fibrosis assessment revealed increased liver stiffness in three (out of four) patients, and no cirrhotic features were found on those who underwent liver biopsy.

CONCLUSIONS

To our knowledge, this is the largest published series of non-cirrhotic portal hypertension in HIV mono-infected patients in Australia. Further research is needed to understand what relationship, if any, HIV or its treatments might have on liver injury over time.

The role of viral and host genetics in natural history and treatment of chronic HCV infection

Understanding of the natural history and treatment responsiveness of chronic hepatitis C virus (HCV) infection has evolved rapidly in recent years. Advances in HCV molecular virology and host genetics can now better predict spontaneous clearance and treatment outcomes. HCV genotype is the most important viral factor predicting interferon-α treatment responsiveness; HCV-1 subtype is emerging as a key determinant of the efficacy of direct acting antiviral therapy. Genome-wide association studies have recently identified several clinically important host determinants of the outcomes of peginterferon-α and ribavirin treatment outcome: IL28B polymorphism is associated with spontaneous clearance and treatment responsiveness; ITPA polymorphism protects against ribavirin-induced anaemia and dose reductions; genetic determinants of liver fibrosis progression rate have been proposed. In this review, we evaluate the role of viral and host genetics in the natural history and treatment outcomes of chronic HCV infection, and consider how this knowledge might help individualize clinical management in the era of DAA therapy.

Murray Valley encephalitis: a review of clinical features, diagnosis and treatment

Murray Valley encephalitis virus (MVEV) is a mosquito-borne virus that is found across Australia, Papua New Guinea and Irian Jaya. MVEV is endemic to northern Australia and causes occasional outbreaks across south-eastern Australia. 2011 saw a dramatic increase in MVEV activity in endemic regions and the re-emergence of MVEV in south-eastern Australia. This followed significant regional flooding and increased numbers of the main mosquito vector, Culex annulirostris, and was evident from the widespread seroconversion of sentinel chickens, fatalities among horses and several cases in humans, resulting in at least three deaths. The last major outbreak in Australia was in 1974, during which 58 cases were identified and the mortality rate was about 20%. With the potential for a further outbreak of MVEV in the 2011-2012 summer and following autumn, we highlight the importance of this disease, its clinical characteristics and radiological and laboratory features. We present a suspected but unproven case of MVEV infection to illustrate some of the challenges in clinical management. It remains difficult to establish an early diagnosis of MVEV infection, and there is a lack of proven therapeutic options.

Balamuthia mandrillaris brain abscess successfully treated with complete surgical excision and prolonged combination antimicrobial therapy

Amoebic encephalitis is an uncommon and usually fatal condition. This case describes successful treatment of a Balamuthia mandrillaris brain abscess using prolonged antimicrobial agents with complete excision. It illustrates the risk of dissemination from cutaneous to cerebral amoebic lesions, potential progression with corticosteroid therapy, and the prospect for curative excision.

Oseltamivir resistance in adult oncology and hematology patients infected with pandemic (H1N1) 2009 virus, Australia

We describe laboratory-confirmed influenza A pandemic (H1N1) 2009 in 17 hospitalized recipients of a hematopoietic stem cell transplant (HSCT) (8 allogeneic) and in 15 patients with malignancy treated at 6 Australian tertiary centers during winter 2009. Ten (31.3%) patients were admitted to intensive care, and 9 of them were HSCT recipients. All recipients of allogeneic HSCT with infection <100 days posttransplantation or severe graft-versus-host disease were admitted to an intensive care unit. In-hospital mortality rate was 21.9% (7/32). The H275Y neuraminidase mutation, which confers oseltamivir resistance developed in 4 of 7 patients with PCR positive for influenza after > or = 4 days of oseltamivir therapy. Three of these 4 patients were critically ill. Oseltamivir resistance in 4 (13.3%) of 30 patients who were administered oseltamivir highlights the need for ongoing surveillance of such resistance and further research on optimal antiviral therapy in the immunocompromised.

The contemporary surgical management of spasticity in children

Orthopedics and neurosurgery offer multiple surgical modalities for improving the function, care, and well-being of children with spasticity. One surgical approach is not the best for all children with spasticity not adequately controlled with more conservative measures. For that reason, a multidisciplinary evaluation is important to optimize outcome for these children.

Antibiotic therapy attenuates colitis in interleukin 10 gene-deficient mice

BACKGROUND & AIMS

Interleukin (IL)-10 gene-deficient mice, raised under germfree conditions, do not develop colitis, implying a role for bacteria. This study mapped the appearance of luminal colonic bacteria and, using antibiotic treatment, determined their association with colitis in IL-10 gene-deficient mice.

METHODS

Mice were treated with ciprofloxacin or with neomycin and metronidazole. The intestine was harvested for histological scoring and bacterial assessment.

RESULTS

At 2 weeks of age, before the development of colitis, IL-10 gene-deficient mice demonstrated an earlier appearance of Streptococcus and Clostridium sp., and had a greater proportion (P < 0.01) of bacteria adherent to the colonic mucosa. This pattern of increased adherent bacteria persisted for the 12 weeks of study. Treatment of mice before the onset of colonic inflammation, with either antibiotic regime, reduced mucosal adherent bacteria and prevented colitis (P < 0.01). In contrast, treatment of established colitis with neomycin and metronidazole did not reduce adherent bacterial levels, yet was more efficacious (P < 0.05) in treating established colitis than ciprofloxacin, which did reduce adherent colonic bacteria.

CONCLUSIONS

In the IL-10 gene-deficient mouse model, the appearance and number of mucosal adherent colonic bacteria are altered before the onset of colitis. Antibiotics both prevent and treat the colitis through correction of this primary bacterial alteration.

Interleukin-10 gene-deficient mice develop a primary intestinal permeability defect in response to enteric microflora

The normal intestinal epithelium provides a barrier relatively impermeable to luminal constituents. However, patients with inflammatory bowel disease experience enhanced intestinal permeability that correlates with the degree of injury. IL-10 gene-deficient mice were studied to determine whether increased intestinal permeability occurs as a primary defect before the onset of mucosal inflammation or is secondary to mucosal injury. At 2 weeks of age, IL-10 gene-deficient mice show an increase in ileal and colonic permeability in the absence of any histological injury. This primary permeability defect is associated with increased mucosal secretion of interferon-gamma and tumor necrosis factor-alpha, and does not involve an increase in nitric oxide synthase activity. Colonic permeability remains elevated as inflammation progresses, while ileal permeability normalizes by 6 weeks of age. IL-10 gene-deficient mice raised under germ-free conditions have no inflammation, and demonstrate normal permeability and cytokine levels. This data suggests that the intestinal permeability defect in IL-10 gene-deficient mice occurs due to a dysregulated immune response to normal enteric microflora and, furthermore, this permeability defect exists prior to the development of mucosal inflammation.

Interleukin-10 gene-deficient mice develop a primary intestinal permeability defect in response to enteric microflora

The normal intestinal epithelium provides a barrier relatively impermeable to luminal constituents. However, patients with inflammatory bowel disease experience enhanced intestinal permeability that correlates with the degree of injury. IL-10 gene-deficient mice were studied to determine whether increased intestinal permeability occurs as a primary defect before the onset of mucosal inflammation or is secondary to mucosal injury. At 2 weeks of age, IL-10 gene-deficient mice show an increase in ileal and colonic permeability in the absence of any histological injury. This primary permeability defect is associated with increased mucosal secretion of interferon-gamma and tumor necrosis factor-alpha, and does not involve an increase in nitric oxide synthase activity. Colonic permeability remains elevated as inflammation progresses, while ileal permeability normalizes by 6 weeks of age. IL-10 gene-deficient mice raised under germ-free conditions have no inflammation, and demonstrate normal permeability and cytokine levels. This data suggests that the intestinal permeability defect in IL-10 gene-deficient mice occurs due to a dysregulated immune response to normal enteric microflora and, furthermore, this permeability defect exists prior to the development of mucosal inflammation.

Lactobacillus species prevents colitis in interleukin 10 gene-deficient mice

BACKGROUND & AIMS

Intestinal luminal microflora, or their products, are likely an important initiating factor in the pathogenesis of inflammatory bowel disease. The aim of this study was to determine the role of colonic aerobic luminal bacteria and Lactobacillus species in the development of colitis in interleukin (IL)-10 gene-deficient mice.

METHODS

Intestine from 2-16-week-old mice was scored histologically and cultured for bacteria. Lactobacillus sp. repopulation of the colonic lumen was achieved via daily rectal delivery of Lactobacillus reuteri or oral lactulose therapy.

RESULTS

At 2 weeks of age, IL-10 gene-deficient mice showed no colonic injury but did display abnormal colonic bacterial colonization with increased colonic mucosal aerobic adherent and translocated bacteria in conjunction with reduced Lactobacillus sp. levels. In association with the abnormal colonic bacterial colonization, colitis developed by 4 weeks of age. Restoring Lactobacillus sp. to normal levels reduced levels of colonic mucosal adherent and translocated bacteria and attenuated the development of the colitis.

CONCLUSIONS

In the neonatal period, IL-10 gene-deficient mice have decreased levels of colonic Lactobacillus sp. and an increase in colonic mucosal adherent and translocated bacteria. Normalizing Lactobacillus sp. levels reduced colonic mucosal adherent and translocated bacteria and prevented colitis.

"Golf ball liver": agent orange hepatitis

2,4-Dichlorophenoxyacetic acid (2,4-D) is a selective weedkiller which works by uncoupling oxidative phosphorylation and is in widespread use. It is known as "agent orange". A 65 year old man had acute hepatitis, thought to be caused by exposure to 2,4-D. The patient ingested 2,4-D as a result of habitual licking of his golf ball. Clinical and histological data together with a challenge test confirmed the diagnosis of "golf ball liver".

Polymorphonuclear leukocyte-mediated bone degradation and influence of blood mononuclear cells on the mouse calvarial model

OBJECTIVE

To investigate the relationships between degradation of bone and activated blood polymorphonuclear leukocytes (PMNL) and mononuclear leukocytes (ML) as well as their soluble products in vitro.

MATERIALS AND METHODS

A neonatal mouse calvarial bone model was used to assess the activity of degradation (by measuring the amount of 45Ca release) by normal human blood leukocytes, separated PMNL and ML following 24-hour incubation. The effects of conditioned culture medium obtained from Staphylococcus aureus-stimulated ML on PMNL-mediated calvarial bone loss were also studied.

RESULTS

It was demonstrated that isolated human PMNL rapidly degraded bone in a dose and time dependent manner. The PMNL-mediated bone degradation was enhanced by conditioned medium obtained from Staphylococcus aureus-stimulated ML.

CONCLUSION

These findings implicate PMNL as major contributors to early bone loss in infectious diseases such as acute haematogenous osteomyelitis.

Complications and long-term outcome of upper cervical spine arthrodesis in patients with Down syndrome

STUDY DESIGN

A retrospective review of 15 patients with Down syndrome who had undergone arthrodesis of the upper cervical spine for instability.

OBJECTIVES

To determine the complication rate and long-term outcome after posterior cervical arthrodesis for upper cervical instability in patients with Down syndrome.

SUMMARY OF BACKGROUND DATA

Atlantoaxial instability is common in patients with Down syndrome, and fusion of the upper cervical spine has been recommended for patients who have instability, with or without myelopathy. Unfortunately, the results of posterior cervical arthrodesis are not well reported, and the natural history of this condition is unknown.

METHODS

Fifteen patients with an average follow-up period of 74.6 months (range, 24-142 months) were reviewed after posterior arthrodesis of the upper cervical spine. Twelve patients were reexamined by the investigators specifically for the purpose of this study, and three patients had long-term follow-up results available from chart review.

RESULTS

Eleven of 15 patients (73%) sustained 23 major complications including nonunion, loss of reduction, neurologic deterioration, late subaxial instability, infection, and wound dehiscence. Six patients (40%) required seven reoperations to address a complication. Ultimately, 12 patients (80%) obtained osseous union, but a definite clinical improvement was identifiable in only three patients, whereas two others had worsened neurologically at latest follow-up evaluation.

CONCLUSIONS

A high complication rate should be anticipated after posterior arthrodesis of the upper cervical spine in patients with Down syndrome. A cautious approach to asymptomatic instability in this condition is advocated.

Aseptic loosening in uncemented total hip arthroplasty in a canine model

An in vivo canine model was developed to investigate the histologic and biochemical parameters associated with aseptic loosening. Thirty-eight canines had cementless total hip arthroplasty. Experimental groups were designed specifically to investigate the relative contributions of implant motion and particulate debris (cobalt chrome alloy, titanium aluminum vanadium, and polyethylene) on the resultant periprosthetic tissues. Tissues from a stable, well-ingrown prosthesis provided a control. Importantly, the histologic and biochemical characteristics of the experimentally induced membranes consistently correlated with previous in vitro reports of tissues retrieved at revision surgery for aseptic loosening. Implant motion and all 3 particulate debris groups resulted in increased numbers of macrophages in the periprosthetic membranes. The histologic findings paralleled the increase in levels of biochemical mediators of bone resorption as measured by collagenase, gelatinase, prostaglandin E2, and interleukin-1 activity. The most striking results were seen in the histology and biochemistry of the particle groups with highly cellular membranes showing increased biochemical activity when compared with controls. The clinical relevance of this work lies in the description of an in vivo model of aseptic loosening that can be used to investigate the effects of numerous variables implicated in aseptic loosening. Ultimately, the model may serve as a basis for developing therapeutic interventions.

Angiodysplasia and ileal carcinoid

A case of angiodysplasia, symptomatic for 18 years, is presented. This case highlights the difficulty of establishing a diagnosis. Associated findings included aortic stenosis and a carcinoid tumour of the ileum. Despite transfusion of a total of 1200 units of blood the liver was normal at necropsy.

Granulomatous gastritis: part of a vasculitic syndrome

The previously unreported association of granulomatous gastritis and mononeuritis multiplex occurring in the setting of a vasculitic syndrome is described. The two conditions are considered to be associated and to be immune mediated. The previously accepted concept of isolated granulomatous gastritis is disputed.

Audit of cranial computerised tomography in a general medical unit

Over a two year period 108 patients had cranial computerised tomographic (CCT) scans while under the care of a general medical team. Sixty eight scans showed 70 abnormalities. Completed stroke, transient ischaemic attacks (TIA), epilepsy and headache were the most common indications for CTT while infarct, atrophy, haemorrhage and tumour were the most common abnormalities. Eight tumours were identified comprising 12% of epileptics and 9% of stroke patients.

Vasoactive intestinal peptide: behavioral effects in the rat and hamster

The behavioral effects of intracerebroventricular (ICV) injection of the brain-gut peptide vasoactive intestinal peptide (VIP) were quantified with a behavioral sampling technique in home-caged, nondeprived, male and female albino rats and golden hamsters. ICV VIP sex-dependently decreased observed resting behavior during 1 hr after injections in both rats and hamsters at 0.1-10.0 micrograms. Grooming behavior was increased in hamsters, and rearing and standing behaviors were increased in rats, sex-dependently at VIP doses that decreased resting. Drinking behavior was suppressed in rats by VIP at 10.0 micrograms. Intraperitoneal (IP) VIP (100.0 micrograms/kg) increased 5% ethanol intake and decreased eating behavior in fluid-deprived male rats. The increase in ethanol intake produced by IP VIP was prevented by IP cholecystokinin octapeptide (CCK, 4.0 micrograms/kg). VIP potently controls resting and ingestive behaviors, suggesting a role for this neuropeptide, along with CCK, in the feedback regulation of rodent behavior.