Astrocytes: Role in pathogenesis and effect of commonly misused drugs in the HIV infected brain.

The roles of astrocytes as reservoirs and producers of a subset of viral proteins in the HIV infected brain have been studied extensively as a key to understanding HIV-associated neurocognitive disorders (HAND). However, their comprehensive role in the context of intersecting substance use and neurocircuitry of the reward pathway and HAND has yet to be fully explained. Use of methamphetamines, cocaine, or opioids in the context of HIV infection have been shown to lead to a faster progression of HAND. Glutamatergic, dopaminergic, and GABAergic systems are implicated in the development of HAND-induced cognitive impairments. A thorough review of scientific literature exploring the variety of mechanisms in which these drugs exert their effects on the HIV brain and astrocytes has revealed marked areas of convergence in overexcitation leading to increased drug-seeking behavior, inflammation, apoptosis, and irreversible neurotoxicity. The present review investigates astrocytes, the neural pathways, and mechanisms of drug disruption that ultimately play a larger holistic role in terms of HIV progression and drug use. There are opportunities for future research, therapeutic intervention, and preventive strategies to diminish HAND in the subset population of patients with HIV and substance use disorder.

Bilateral Acute Iris Transillumination Associated with Moxifloxacin Antibiotic Use.

PURPOSE: To describe the clinical and demographic characteristics and associated factors leading to bilateral acute iris transillumination (BAIT) syndrome. METHODS: A retrospective review of patients with BAIT syndrome was performed. RESULTS: Thirty-five patients with a diagnosis of BAIT were identified. The median age at presentation was 53 years; 80% of the patients were female. Twenty-six patients (74%) had recent histories of systemic antibiotic treatment. Of those with such a history, 24 patients (92%) had been receiving moxifloxacin. Two patients within our cohort were prescribed moxifloxacin prophylactically prior to a systemic surgical procedure and had no evidence of systemic illness or recent viral illness. CONCLUSIONS: Our data support the notion that moxifloxacin might be associated with the onset of BAIT syndrome. Notably, within our cohort, two patients received moxifloxacin as surgical prophylaxis and subsequently developed BAIT syndrome. This could suggest a potential association between moxifloxacin and the onset of BAIT, though further studies are needed to confirm this finding.

A clinical comparison of penetrating and blunt traumatic brain injuries.

BACKGROUND: Traumatic brain injury (TBI) is a leading cause of injury death and long-term disability in the USA. It commonly results from blunt (closed) or penetrating trauma. The majority of civilian TBI is caused by falls or motor vehicle collisions, whereas military TBI mainly results from explosions. Although penetrating injuries are less common than closed injuries in the civilian population, they are far more lethal. Unfortunately, the pathophysiologic differences between penetrating and closed TBI remain poorly understood due to the lack of studies on the subject. Many studies on the prognostic factors of mortality and functional outcome after TBI exclude penetrating brain injuries from their series because they are believed to have a different pathophysiology. METHODS: 125 Articles regarding brain injury were reviewed and summarized for this report. RESULTS: Despite the absence of a clear delineation between penetrating and blunt TBI, the current guidelines for penetrating TBI suggest defaulting to management strategies used for closed TBI with limited supportive evidence. Thus, injuries that appear to have different pathophysiologies and outcomes are managed equally and perhaps not optimally. CONCLUSION: In view of the incomplete understanding of the impact of mechanism of injury on TBI outcomes, as demonstrated in the current review, new research studies are required to improve evidence-based TBI guidelines tailored especially for penetrating injuries.

Association of IL-4RA single nucleotide polymorphisms, HLA-DR and HLA-DQ in children with Alternaria-sensitive moderate-severe asthma.

BACKGROUND: Asthma afflicts 6% to 8% of the United States population, and severe asthma represents approximately 10% of asthmatic patients. Several epidemiologic studies in the United States and Europe have linked Alternaria sensitivity to both persistence and severity of asthma. In order to begin to understand genetic risk factors underlying Alternaria sensitivity and asthma, in these studies we examined T cell responses to Alternaria antigens, HLA Class II restriction and HLA-DQ protection in children with severe asthma. METHODS: Sixty children with Alternaria-sensitive moderate-severe asthma were compared to 49 children with Alternaria-sensitive mild asthma. We examined HLA-DR and HLA-DQ frequencies in Alternaria-sensitive asthmatic by HLA typing. To determine ratios of Th1/Th2 Alternaria-specific T-cells, cultures were stimulated in media alone, Alternaria alternata extract and Alt a1. Sensitivity to IL-4 stimulation was measured by up-regulation of CD23 on B cells. RESULTS: Children with Alternaria-sensitive moderate-severe asthma trended to have increased sensitivities to Cladosporium (46% versus 35%), to Aspergillus (43% versus 28%), and significantly increased sensitivities to trees (78% versus 57%) and to weeds (68% versus 48%). The IL-4RA ile75val polymorphism was significantly increased in Alternaria-sensitive moderate-severe asthmatics, 83% (0.627 allele frequency) compared to Alternaria-sensitive mild asthmatics, 57% (0.388 allele frequency). This was associated with increased sensitivity to IL-4 stimulation measured by significantly increased IL-4 stimulated CD23 expression on CD19+ and CD86+CD19+ B cells of Alternaria-sensitive moderate-severe asthmatics. IL-5 and IL-13 synthesis was significantly increased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics to Alternaria extract and Alt a1 stimulation. The frequency of HLA-DQB1*03 allele was significantly decreased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics, 39% versus 63%, with significantly decreased allele frequency, 0.220 versus 0.398. SUMMARY: In children with Alternaria-sensitive moderate severe asthma, there was an increased Th2 response to Alternaria stimulation and increased sensitivity to IL-4 stimulation. This skewing towards a Th2 response was associated with an increased frequency of the IL-4RA ile75val polymorphism. In evaluating the HLA association, there was a decreased frequency of HLA-DQB1*03 in Alternaria-sensitive moderate severe asthmatic children consistent with previous studies suggest that HLA-DQB1*03 may be protective against the development of mold-sensitive severe asthma.

Surgical management of melanoma-in-situ using a staged marginal and central excision technique.

Melanoma-in-situ (MIS) represents 45% of all melanomas. The margins of MIS are often poorly defined with extensive subclinical disease. Standard fusiform excision with 5-mm margins results in positive margins in up to a third of cases. To decrease the incidence of involved margins, we use a staged excision approach for MIS. First, patients undergo excision under local anesthesia of a 2- to 3-mm "contoured" rim of tissue optimally 5 mm beyond the visible extent of the lesion. Formalin-fixed paraffin-embedded en face sections from this excision are then evaluated, if necessary with the aid of immunohistochemical stains. Any positive margins are further excised. When all margins are negative, the central area is then excised and reconstructed. A total of 61 patients with MIS or lentigo maligna melanoma underwent staged contoured excisions from 2004 to 2007 at Moffitt Cancer Center. We analyzed data only from patients with MIS of the head and neck. Patients with known invasive melanoma or non-head and neck primary disease were excluded. Demographics, tumor characteristics, margin status, number of stages, and type of reconstruction and recurrences were evaluated. Forty-nine patients with MIS of the head and neck, 28 (57%) male and 21 (43%) female, 42 to 88-years-old (median 72; mean 70), underwent staged contoured margin excision before definitive central tumor excision and reconstruction. The final surgical defect size ranged from 2 to 130 cm(2) (median 16 cm(2)). Twelve patients (24%) required reexcision of at least one margin; the median number of reexcisions was 1 (range 1-2). There seemed to be a positive association between lesion size and margin status (as well as number of excisions needed to clear the margin). Unsuspected invasive melanoma was found in the central specimen in six patients (12%). Even small tumors could have unsuspected invasive melanoma: invasive cancer was seen in 4 (21%) of 19 tumors < or =2 cm in greatest dimension and 2 (7%) of 30 > 2 cm, respectively. Surgical defects were reconstructed with flaps in 18 (37%), full-thickness grafts in 20 (41%), and split-thickness grafts in 10 patients (20%). Median time from first margin excision to completion/final reconstruction was 7 days (range 7-63 days). No local recurrences have been reported at a median follow-up of 14 months (range 1-36 months). This technique allows for careful margin analysis and subsequent central tumor excision with simultaneous reconstruction. This approach minimizes the need for a second major operation, which would have been necessary in 24% of our patients if treated by a one-stage excisional approach. It is noteworthy that 12% of MIS patients had invasive melanoma in the final excision specimen. This reinforces the importance of adequate full-thickness biopsies of suspicious pigmented lesions before any type of surgical management. With short follow-up, local control has been achieved by this technique in 100% of cases.