Fernando G. Diaz

Progression of Chronic Hepatitis C to Liver Fibrosis and Cirrhosis in Patients Coinfected with Hepatitis C Virus and Human Immunodeficiency Virus

To evaluate the factors associated with the evolution of chronic hepatitis C in human immunodeficiency virus (HIV)-infected patients, a cross-sectional analysis of 41 HIV-infected patients with chronic hepatitis C (known as HIV-HCV [hepatitis C virus]-coinfected patients) and a control group of patients with chronic hepatitis C who did not have HIV infection (known as non-HIV-infected patients) was performed. The association of histological variables with demographic parameters, HCV load and genotype, HIV load, CD4(+) T cell count, and response to highly active antiretroviral therapy (HAART) was evaluated. HIV-HCV-coinfected patients showed a significantly higher HCV load, more-advanced fibrosis, and a higher liver fibrosis progression rate (FPR) than did non-HIV-infected patients. A high HCV load and a low CD4(+) T cell count were associated with a higher FPR. The immune response induced by HAART did not influence this progression. In conclusion, HIV-HCV-infected patients, mainly such patients with a high HCV load and an immunodepressed state, have a higher FPR. An independent effect of the immune response to HAART was not evident.

The perforating branches of the middle cerebral artery: A microanatomical study

The perforating branches (PFBs) of the middle cerebral artery (MCA) were studied in 34 unfixed brain hemispheres which were injected with a polyester resin and dissected under the operating microscope. Five hundred and eight vessels were identified and their site of origin, branching pattern, outer diameter (OD), and length recorded. Four hundred and two PFBs (79%) originated from the main trunk of the MCA before its division; the remaining 106 vessels (21%) had their origin from branches of the MCA as follows: superior trunk, 43 vessels (8.5%); inferior trunk, 30 vessels (6%); middle trunk, four vessels (0.8%); early temporal branch, 27 vessels (5.3%); and early frontal branch, two vessels (0.4%). The number of PFBs in each hemisphere varied from five to 29 (mean 14.9 +/- 0.7 vessels). The great majority of PFBs (96%) originated along the proximal 17 mm of the MCA. The PFBs arising in the first 10 mm had a mean OD of 0.35 +/- 0.01 mm and a mean length of 9.25 +/- 0.19 mm, and those arising from the second 10 mm had a mean OD of 0.47 +/- 0.02 mm and a mean length of 16.67 +/- 1.4 mm. A clear distinction between a medial and lateral group of PFBs was present in only 14 hemispheres (41%). In nine hemispheres (26%), perforating vessels from the anterior cerebral artery (A1 segment) and from the recurrent artery of Heubner replaced the medial group of PFBs of the MCA. In one case this group originated in an accessory MCA. In three hemispheres (9%) a small anastomosis (OD 0.2 mm) was seen between a PFB of the recurrent artery of Heubner and one of the MCA. From a total of 508 PFBs, 255 vessels (50%) originated as single vessels, while 253 vessels (50%) originated as branches of common stems. The OD of the single vessels ranged from 0.1 mm to 1.1 mm (mean 0.39 +/- 0.02 mm), and the length from 3 to 20 mm (mean 10.8 +/- 0.2 mm). The common stems ranged in OD from 0.6 to 1.8 mm (mean 0.87 +/- 0.04 mm), and in length from 1 to 15 mm (mean 4.1 +/- 0.4 mm). The clinical application of these anatomical data to the management of aneurysms and arteriovenous malformations of the MCA, and in the field of interventional neuroradiology is described. The most frequent pathological entities involving the perforating vessels are also discussed.

Temporary clipping in aneurysm surgery : technique and results

The use of temporary clipping has become an established tool in the armamentarium of the aneurysm surgeon. Our experience with 62 consecutive patients is presented, detailing operative protocols and results. Twenty-two had unruptured aneurysms (35%), 15 were grade I (24%), 16 grade II (25%), five grade III (8%), and four grade IV (7%). The aneurysms were mainly located in the middle cerebral artery (29 patients) and the anterior communicating artery (13 patients). Eleven of our 62 patients (17%) developed a new, persistent postoperative deficit. However, in only one case (2%) was temporary clipping felt to be implicated in the development of the deficit. In three other patients (5%), the effect of temporary clipping, although unlikely, could not be excluded. Overall, 92% of our patients with temporary clipping had good to excellent outcome, with 3% mortality and 5% morbidity. We believe that temporary clipping is a safe procedure that contributes significantly to a better outcome.

Ischemic complications after combined internal carotid artery occlusion and extracranial-intracranial anastomosis

Seven of 120 aneurysm patients admitted to the Henry Ford Hospital from October 1978 to August 1981 had giant internal carotid artery aneurysms that were treated by a combined internal carotid artery occlusion and extracranial-intracranial anastomosis. Three of these patients developed postoperative ischemic complications during the progressive closure of the carotid artery. These complications included the transient onset of syncope, hemiparesis, hemisensory deficits, and dysphasia. These complications resolved after the clamp was reopened and/or intravenous heparin was given. The possible mechanisms involved in the development of ischemia included the development of emboli at the occlusion site or inadequate flow originating from the area of the anastomosis. Prolonged occlusion of the vessel over a 7- to 10-day course with concurrent administration of intravenous heparin is recommended.

Implication of inflammation-related cytokines in the natural history of liver cirrhosis.

Abstract: Background/Aims: Increased serum concentrations of pro‐inflammatory cytokines have been detected in patients with liver cirrhosis. However, their role in the natural history of cirrhosis and portal hypertension, in the absence of infection, and the prognostic significance of inflammation‐related cytokines have not been reported. Our objective was the analysis of the prognostic value of inflammation‐related cytokines in cirrhotic patients.

Biomechanical properties of calvarium prosthesis.

Abstract There are many materials available for the reconstruction of calvarial defects. Even though their biomaterial properties are well known, the biomechanical properties as part of the calvarium have not been investigated. In this article, calvarial implants are reviewed with their historic development into modern cranioplasty. Materials for trephined skulls are classified by their category. Individual parameters to describe their mechanical properties are collected and revealed in detail. The laboratory testing methodology for cranioplasty material is introduced to understand each parameter. At last, we discuss an engineering technique to look into the implant behavior. Since there is no standard goal for the biomechanical and biomaterial point of view for cranioplasty, this article suggests the finite element method for evaluation of the implant behavior and the degree of damage upon the impact injury. [Neurol Res 2001; 23: 267-276]

Experimental cerebral ischemia

The basic concepts of the pathology and pathophysiology of cerebral ischemia are presented. Special emphasis is given to the changes that occur in the microcirculation and in autoregulation because of their primary role in the pathogenesis of cerebral infarction. The effects of adrenal steroids, barbiturates, and cerebral revascularization are reviewed.

Vascular injury in neurotrauma.

Abstract Traumatic vascular lesions can occur after severe or even the most mild of head and cervical trauma. The initial evaluation of the injured patient must be thorough and the clinical suspicion of vascular injury must be highly suspected based on the mechanism of injury. Traumatic vascular injuries can be broadly classified into traumatic aneurysms, dissections and occlusions and fistulae of the carotid or vertebral arteries. The current management and treatment options of each condition are discussed. [Neurol Res 2001; 23: 291-296]

Sulfadiazine-Induced Multiple Urolithiasis and Acute Renal Failure in a Patient with AIDS and Toxoplasma Encephalitis

OBJECTIVE: To report a patient with sulfadiazine-induced urolithiasis and acute renal failure. CASE SUMMARY: A patient with AIDS who was being treated with pyrimethamine and sulfadiazine for Toxoplasma encephalitis developed lumbar pain, dysuria, urinary frequency, and hematuria. Acute renal failure was found and numerous crystals of sulfadiazine were seen in the urine. Multiple calculi of up to 2 cm in diameter in both kidneys were noted on ultrasound. The patient was treated with intravenous fluids and alkalinization of the urine with rapid improvement. An intravenous urographic study performed 2 days later showed no evidence of calculi and renal function was normal. DISCUSSION: Patients with AIDS and Toxoplasma encephalitis may have several predisposing conditions that can lead to the development of sulfadiazine-induced crystalluria, including poor fluid intake, fever, diarrhea, and hypoalbuminemia, in addition to the high doses of the drug required and the prolonged period of treatment. CONCLUSIONS: This potentially serious complication can be managed easily with conservative treatment. Clinicians should be aware of this complication as it is expected to occur more frequently as more patients are treated with sulfonamides and patients with AIDS experience longer survival rates.

Mycobacterium chelonae infection associated with adalimumab therapy

Tumour necrosis factor (TNF) is primarily produced by activated macrophages and lymphocytes and is essential for host defences against mycobacterial infection; its levels are increased systemically...