Expression of reverse cholesterol transport proteins ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI) in the retina and retinal pigment epithelium.

AIMS: Excessive lipid accumulation in Bruch's membrane (BrM) is a hallmark of ageing, the major risk factor for age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cells may utilise reverse cholesterol transport (RCT) activity to move lipid into BrM, mediated through ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI). METHODS: ABCA1 expression was assessed by reverse transcription polymerase chain reaction (RT-PCR) and western blotting of human RPE cell extracts. Lipid transport assays were performed using radiolabelled photoreceptor outer segments (POS). ABCA1 and SR-BI expression was examined in normal mouse eyes by immunofluorescence staining. BrMs of ABCA1 and SR-BI heterozygous mice were examined microscopically. RESULTS: Human RPE cells expressed ABCA1 mRNA and protein. The ABCA1 and SR-BI inhibitor glyburide (also known as glibenclamide) abolished basal transport of POS-derived lipids in RPE cells in the presence of high-density lipoprotein. Mouse retina and RPE expressed ABCA1 and SR-BI. SR-BI was highly expressed in RPE. BrMs were significantly thickened in SR-BI heterozygous mice, but not in ABCA1 heterozygous mice. CONCLUSION: RPE cells express ABCA1 and SR-BI. This implies a significant role for SR-BI and ABCA1 in lipid transport and RCT in the retina and RPE.

Acute subdural hematoma: direct admission to a trauma center yields improved results.

We studied 128 patients admitted over a 12 1/2-year period to the Cook County Hospital Trauma Unit with acute subdural hematoma (ASDH): 82 were admitted directly and 46 were admitted after transfer from another hospital; 59% of the entire group died and only 27% obtained a functional recovery. As a group, the transferred patients, who suffered delays of several hours before receiving definitive surgical care, fared significantly worse than the patients with equivalent trauma who were admitted directly. The mortality of the transferred patients was 76%, compared to 50% of the direct admit patients. The outcome was also worse for transfer patients who experienced a 'lucid interval' or with alcohol intoxication. We conclude that the delays associated with failure to admit patients with ASDH directly to a head trauma center cause an excessive mortality and morbidity which could potentially be avoided by proper triage.

Colloid or crystalloid in the resuscitation of hemorrhagic shock: a controlled clinical trial.

The object of this article is to assess the value of human serum albumin (HSA) in the initial resuscitation of hypotensive trauma victims. Thirty-six patients (mean age = 30 years) in shock from trauma who underwent laparotomies were randomly assigned to either Ringer's lactate solution (RL) resuscitation or 4% HSA in RL resuscitation. Both groups received approximately 8L of test fluid and 6U of washed red cells. The only death in the study occurred in a patient assigned to the RL group. Two patients in each group required mechanical ventilation for longer than 24 hours. No differences were noted in a battery of pulmonary function tests performed daily for 5 days. These results demonstrate that HSA is not essential in this clinical setting for safe and effective resuscitation.

Intestinal disruption due to blunt abdominal trauma.

Twenty-three patients with thirty-one disruptions of the intestines due to blunt abdominal trauma are reviewed. The bowel disruptions occurred in the stomach (2 perforations), duodenum (9), proximal jejunum (18), and sigmoid colon (2). The causes of injury, diagnostic difficulties, delays in treatment, associated trauma, surgical correction, and results are analyzed. Deaths (4) and complications (6) are presented in detail. Intestinal disruptions can be due to a variety of types of blunt trauma, with the automobile being the most common etiologic agent. The bowel can perforate anywhere in its course. Intestinal perforations are often associated with severe injuries which will probably be the determining factors in survival. Persistence, particularly repeated physical examination, is required for the diagnosis of bowel injury. Routine diagnostic tests for duodenal injury are not reliable. Retroperitoneal hematomas around the duodenum must be explored. The injuries themselves are easy to repair, and repair is secure when performed at the primary operation. Prophylactic antibiotics are recommended.

Pancreatoduodenectomy for penetrating pancreatic trauma.

Six cases of pancreatoduodenectomy performed for combined injuries of the pancreas, duodenum, and/or distal common duct are reported. Pancreatoduodenectomy is indicated when there is extensive destruction of the pancreatic head in conjunction with major injuries of the duodenum, distal common duct, and/or retropancreatic portal vein, necessitating complete division of the pancreatic head. Reconstruction is best achieved by end-to-end pancreatiocieiunostomy, end-to-side choledochojejunostomy, antrectomy, and vagotomy.

Crystalloid vs colloid in the etiology of pulmonary failure after trauma: a randomized trial in man.

One possible cause of pulmonary failure after trauma is the type of asanguinous fluid used for resuscitation, i.e., crystalloid or colloid. To investigate this issue, patients having a laparotomy for trauma randomly received either Ringer's lactate (RLS) alone or Ringer's lactate with albumin (ALB). Both groups received washed red cells. Test fluids and red cells were given before and during operation to restore vital signs and hematocrit to normal. Pulmonary function tests were performed for 5 days after operation. One hundred and forty-one cases were studied (84 RLS, 57 ALB). The volume of asanguinous resuscitation fluid infused was 5.37 +/- 3.38 liters (-x +/- SD) for RLS and 5.87 +/- 3.05 liters for ALB. ALB cases received 213 +/- 130 gm of albumin. Red cell transfusions were 1.5 +/- 2.9 units for RLS and 2.0 +/- 3.1 for ALB. Six patients died (three RLS, there ALB). Three RLS and six ALB patients received intermittent mandatory ventilation or continous positive air pressure after operation. Pulmonary function results were not significantly different between the two groups for any parameter on any day after operation. Results of a randomized trial in human subjects of resuscitation with crystalloid and colloid solutions for acute trauma requiring laparotomy did not reveal significant differences in (1) survival rate, (2) incidence of pulmonary failure, or (3) postoperative pulmonary function.

Penetrating trauma of the neck.

Two hundred forty-six patients admitted to the Trauma Unit of Cook County Hospital with penetrating neck wounds have been reviewed. A policy of mandatory neck exploration combined with a systematic approach to resuscitation and a diagnostic evaluation including neck and chest X-rays, endoscopy, and arteriography has been employed. The study has revealed a high incidence of negative neck explorations (63%) but minimal morbidity (less than 1%), no mortality, and a brief duration of hospitalization in the negative exploration group. Patients with positive explorations had an 8% morbidity and a 9% mortality rate. In addition, 13 of the patients with positive explorations had clinically negative wounds which might have been overlooked if selective management had been utilized in this series. We conclude that a policy of mandatory neck exploration is justified and advisable for patients sustaining penetrating neck injuries.