Neuroinflammation drives sex-dependent effects on pain and negative affect in a murine model of repeated mild traumatic brain injury

ABSTRACT

The Center for Disease Control and Prevention estimates that 75% of reported cases of traumatic brain injury (TBI) are mild, where chronic pain and depression are 2 of the most common symptoms. In this study, we used a murine model of repeated mild TBI to characterize the associated pain hypersensitivity and affective-like behavior and to what extent microglial reactivity contributes to these behavioral phenotypes. Male and female C57BL/6J mice underwent sham or repeated mild traumatic brain injury (rmTBI) and were tested for up to 9 weeks postinjury, where an anti-inflammatory/neuroprotective drug (minocycline) was introduced at 5 weeks postinjury in the drinking water. Repeated mild traumatic brain injury mice developed cold nociceptive hypersensitivity and negative affective states, as well as increased locomotor activity and risk-taking behavior. Minocycline reversed negative affect and pain hypersensitivities in male but not female mice. Repeated mild traumatic brain injury also produced an increase in microglial and brain-derived neurotropic factor mRNA transcripts in limbic structures known to be involved in nociception and affect, but many of these changes were sex dependent. Finally, we show that the antiepileptic drug, gabapentin, produced negative reinforcement in male rmTBI mice that was prevented by minocycline treatment, whereas rmTBI female mice showed a place aversion to gabapentin. Collectively, pain hypersensitivity, increased tonic-aversive pain components, and negative affective states were evident in both male and female rmTBI mice, but suppression of microglial reactivity was only sufficient to reverse behavioral changes in male mice. Neuroinflammation in limbic structures seems to be a contributing factor in behavioral changes resulting from rmTBI.

Clinical audit. Watching the detectives

An audit of a trust's audit department, first established eight years ago, showed that most managers and clinicians viewed it positively. But it was not seen as capable, on its own, of producing changes in practice. Some departments were unsure about the services of the audit department. A standard form for audit reports is to be adopted in the trust. The evaluation will be repeated in a year's time.

Toward a new urban health model: moving beyond the safety net to save the safety net--resetting priorities for healthy communities

Parkland Health and Hospital System has been successful by every measure of comparison among its peer institutions, yet it recognizes the imperative of adapting to changes in the regulatory, legislative, and market environments. Given its mandate and a desire to preserve its multiple missions and its partnerships with a highly rated medical school, the playing field for achieving robust survival is very uneven. This article describes the evolution of one of the best "sick care systems" in the United States into an integrated, excellent health care system for the 21st century. The problems faced by the safety net in many urban areas of this country are similar. Many problems are structural in nature and will, therefore, require structural solutions at the local, state, and national levels. Parkland will continue and will be needed for many years as the tertiary and quaternary center of a comprehensive service network made up also of a series of outreach Community Oriented Primary Care clinics and special populations projects. In addition, we hope to help create a community-oriented managed-care plan that encompasses the desire to work with both denominator and numerator populations in a real partnership with many other stake-holders.

Bone marrow necrosis at transformation of chronic granulocytic leukaemia treated with interferon

A patient with chronic myeloid leukaemia was treated with interferon without using conventional cytotoxic agents. Bone marrow necrosis developed at the onset of blast transformation. It is suggested that cytotoxic drugs should be given before treatment with interferon for chronic myeloid leukaemia. Cytotoxic drugs may also be needed to prevent rapid bone marrow growth once interferon has been withdrawn.

The decade for natural disaster reduction: the role of health care workers

Disasters are occurring more frequently these days. Pickens, a Geneva-based journalist, examines how the World Health Organization suggests to cope with disasters.

Actinobacillus actinomycetemcomitans endocarditis in hypertrophic obstructive cardiomyopathy

We report a case of bacterial endocarditis due to Actinobacillus actinomycetemcomitans in a man with hypertrophic obstructive cardiomyopathy complicated by a mycotic aneurysm and thrombosis of the right common iliac artery. The patient was successfully treated with a combination of ampicillin and gentamicin, but was left with residual mitral incompetence.

Fatality after hepatic angiography in Zieve's syndrome

A patient with Zieve's syndrome is described. Following hepatic angiography, the patient became shocked and eventually died. The hazards of hepatic angiography are discussed and its use in ill patients questioned.

Infectious mononucleosis in the elderly

Infectious mononucleosis (IM) was diagnosed in four patients over the age of 50 years. Their age, absence of splenomegaly, lack of significant lymphadenopathy in three and an atypical presentation in one all contributed to a delay in the diagnosis. In two patients, in whom complications occurred, the Paul-Bunnell test was repeatedly negative. Confirmation of the diagnosis was made by the measurement of the Epstein-Barr virus IgM using differential sucrose gradient centrifugation. Because the presentation and clinical features of IM can be misleading in the elderly, we believe that a significant number of cases may go unrecognized.

The effects of pre-admission antibiotics on the bacteriological diagnosis of pyogenic meningitis

To assess the effects of pre-admission antibiotics on the accuracy of bacterial diagnosis in pyogenic meningitis, the case records of 154 patients admitted to an infectious diseases unit during a 10-year period (1966-1975) were reviewed. The causative organism was identified in 140 patients (91%). Although 63 patients had received antibiotics before admission, a bacteriological diagnosis was still possible in 57 of these (90%).

Morbidity and mortality in salmonella food poisoning. A review of 47 in-patient cases

Forty-seven new patients with salmonella food poisoning were admitted to the Infectious Diseases Unit at the City Hospital, Edinburgh, during 1975. Although all the patients had diarrhoea at some stage of their illness, the wide variety of presenting symptoms caused some diagnostic difficulties prior to the isolation of the organism. A probable predisposing factor to serious disease was recognised in 15 patients. Twenty patients (42.5%) were seriously ill and 4 patients (8.5%) died. This series stresses the potential severity of this common disease.

Retrobulbar neuritis and infectious mononucleosis

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