Concurrent Mild Traumatic Brain Injury and Posttraumatic Stress Disorder Is Associated With Elevated Tau Concentrations in Peripheral Blood Plasma

Concurrent mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) are common in U.S. military service members and veterans. Tau and amyloid‐beta‐42 (Aβ42) are proteins that have been linked to cognitive impairment, neurological hallmarks of Alzheimer's disease, and may also relate to recovery from mTBI. However, the role of these proteins in the maintenance or resolution of chronic symptoms has not yet been determined. Participants in the current study were 102 service members and veterans who had sustained an mTBI (n = 84) or injured controls (IC) without TBI (n = 18). They were categorized into three groups based on the presence or absence of mTBI and PTSD: IC/PTSD‐Absent (n = 18), mTBI/PTSD‐Absent (n = 63), and mTBI/PTSD‐Present (n = 21). Concentrations of tau and Aβ42 in peripheral blood plasma were measured using Simoa^TM, an ultrasensitive technology, and compared across groups. Tau concentrations were highest in the mTBI/PTSD‐Present group, F(2, 99) = 4.33, p = .016, compared to the other two groups. Linear multiple regression was conducted to determine the independent effects of PTSD and mTBI on tau concentrations, controlling for gender and sleep medication. PTSD was a significant and independent predictor of tau concentrations, β = .25, p = .009, η_p² = .26. Aβ42 concentrations did not differ between the groups. The results indicated that PTSD was associated with an elevation of tau in peripheral blood and suggest that there may be increased biological effects of PTSD in this young cohort of service members and veterans following mTBI.     

Gd-DTPA-enhanced MR imaging in pediatric patients after brain tumor resection

A prospective study was conducted in 15 pediatric patients who had undergone resection of intracranial tumors. The object of the study was to determine the safety and efficacy of magnetic resonance (MR) imaging performed after the administration of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) in evaluating residual or recurrent tumor. Precontrast T1-weighted, intermediate, and T2-weighted images were obtained at a field strength of 1.5 T. Gd-DTPA was then injected intravenously in a dose of 0.1 mmol per kilogram of body weight. T1-weighted images were obtained within 5 minutes after the injection, intermediate and T2-weighted images were obtained 10 minutes after the injection, and T1-weighted images were obtained approximately 20 minutes after the injection. None of the patients experienced allergic reactions or other side effects. Physical examination findings and laboratory values were unchanged after the Gd-DTPA-enhanced examination. In six patients, contrast-enhanced images depicted tumor not suspected on nonenhanced images. In four other patients, enhanced images provided better definition of the tumor core. The images of one patient with a brain stem tumor showed no evidence of enhancement. Pre- and postcontrast images of three previously treated patients showed no evidence of tumor. Gd-DTPA appears to be a safe and effective contrast agent for MR imaging and provides a more accurate method of imaging in the follow-up of brain tumors in pediatric patients.     

The yield of colorectal cancer among fast track patients with normocytic and microcytic anaemia

Introduction

We receive fast track referrals on the basis of iron deficiency anaemia (IDA) for patients with normocytic anaemia or for patients with no iron studies. This study examined the yield of colorectal cancer (CRC) among fast track patients to ascertain whether awaiting confirmation of IDA is necessary prior to performing bowel investigations.

Methods

A review was undertaken of 321 and 930 consecutive fast track referrals from Centre A and Centre B respectively. Contingency tables were analysed using Fisher’s exact test. Logistic regression analyses were performed to investigate significant predictors of CRC.

Results

Overall, 229 patients were included from Centre A and 689 from Centre B. The odds ratio for microcytic anaemia versus normocytic anaemia in the outcome of CRC was 1.3 (95% confidence interval [CI]: 0.5–3.9) for Centre A and 1.6 (95% CI: 0.8–3.3) for Centre B. In a logistic regression analysis (Centre B only), no significant difference in CRC rates was seen between microcytic and normocytic anaemia (adjusted odds ratio: 1.9, 95% CI: 0.9–3.9). There was no statistically significant difference in the yield of CRC between microcytic and normocytic anaemia (p=0.515, Fisher’s exact test) in patients with anaemia only and no colorectal symptoms. Finally, CRC cases were seen in both microcytic and normocytic groups with or without low ferritin.

Conclusions

There is no significant difference in the yield of CRC between fast track patients with microcytic and normocytic anaemia. This study provides insufficient evidence to support awaiting confirmation of IDA in fast track patients with normocytic anaemia prior to requesting bowel investigations.     

Cholecystitis: detection with MR imaging

The role of magnetic resonance (MR) imaging in the detection of gallbladder disease was evaluated in 39 individuals (16 healthy, five with asymptomatic gallstones, and 18 with clinical symptoms of gallbladder disease). MR imaging was performed after they fasted for 12 hours. Imaging sequences included a combination of repetition times (TR) of 0.5 and 1.5 sec and echo times (TE) of 28 and 56 msec. On the images obtained at TR = 0.5 sec and TE = 56 msec, gallbladder bile was hyperintense compared with the liver in all healthy and asymptomatic subjects and was hypointense (n = 9), isointense (n = 4), or hyperintense (n = 5) in symptomatic patients, eight of whom had surgical confirmation of cholecystitis. Comparison of normal versus pathologically proved cases for the presence of gallbladder disease yielded a specificity of 100%, sensitivity of 75%, and a significant difference of P less than .01. Thus, with a pulse sequence of TR = 0.5 sec and TE = 56 msec, MR was sensitive in detecting gallbladder disease. However, the role of MR in the radiologic workup of gallbladder disease will be determined by more experience with this modality.     

Benign extraaxial tumors: contrast enhancement with Gd-DTPA

Meningiomas, acoustic neuromas, and other benign extraaxial tumors have little contrast with adjacent brain tissue on conventional magnetic resonance (MR) images. The contrast enhancement produced by intravenous administration of 0.1 mmol/kg of gadolinium-DTPA in these tumors was measured on T1 MR images. Acoustic neuromas showed the greatest enhancement (average, 310%), meningiomas the next greatest (average, 180%), and neurofibromas, glomus tumors, and pituitary microadenomas the least enhancement. The degree of enhancement was almost always greater at 3 minutes than at 25 or 55 minutes. Contrast between the tumor and adjacent tissue resulted from tumor enhancement in neuromas, meningiomas, and neurofibromas and from enhancement of the surrounding tissue in pituitary microadenomas.     

Small bowel phytobezoars: detection with radiography

The authors reviewed the radiographic findings in 19 patients with phytobezoars of the small bowel. The most common predisposing causes were previous gastric outlet surgery and persimmon ingestion. Twelve patients underwent contrast material-enhanced studies of the upper gastrointestinal tract, and one patient underwent a barium enema study. These examinations revealed four gastric, two duodenal, and eight small bowel phytobezoars in 10 patients. The obstruction caused by small bowel phytobezoars frequently occurred in the jejunum or proximal ileum, more proximally than has been reported in previous series. Barium studies are useful in differentiating obstruction due to postoperative adhesions from obstruction caused by bezoars. In addition, barium studies enable the detection of residual gastric bezoars. This information has important implications in patient treatment because bezoar obstruction is unlikely to respond to conservative treatment, and concurrent gastric bezoars must be removed to prevent recurrent bowel obstruction.     

Detection of cytomegalovirus in blood donors by the polymerase chain reaction

A polymerase chain reaction (PCR) assay was developed and optimized to detect cytomegalovirus (CMV) DNA in the blood of 86 normal donors who had originally tested seropositive for CMV. Evidence of previous or current infection with CMV was determined by rescreening of the blood for CMV antibodies and by detecting the presence of infectious virus in the white cells by cell culture. DNA was extracted from the blood of donors by a manual or an automated method and amplified by PCR using primers from the major immediate early gene of CMV DNA. The amplified product was detected by visualization of a fluorescent 435-base pair DNA band in an electrophoretic agarose gel after ethidium bromide staining and confirmed by slot-blot DNA hybridization using an oligonucleotide probe with complementarity for the major immediate early gene. Seven (8%) of the 86 donors were positive for CMV DNA in both fluorescence and hybridization studies. These donors were also antibody positive. While 74 (86%) of the 86 donors were positive for the presence of CMV antibodies in enzyme-linked immunosorbent assay, none was positive for virus in cell culture. PCR has the potential to be an effective and reliable procedure for the detection of CMV DNA in donor blood, but further study is required for this technique to be used for diagnostic or routine screening purposes.     

Prestorage removal of Yersinia enterocolitica from red cells with white cell-reduction filters

Prestorage removal of phagocytic white cells (WBCs) may increase the survivability of contaminating bacteria in units of stored red cells. Fourteen units of whole blood were inoculated with 65 colony-forming units per mL of Yersinia enterocolitica (serotype O:3) and processed into AS-3-preserved red cells. Five red cell units were filtered with a prototype third-generation filter and five red cell units with a second generation filter. WBC reduction was performed on the day of collection. Four red cell units were not filtered. Three noninoculated whole blood units served as negative controls; two were filtered (one with each type of WBC-reduction filter) and one remained unfiltered. All red cell units were then stored at 4 degrees C for 42 days. One of the five filtered red cell units (20%) in each filter group supported growth of Y. enterocolitica. In contrast, 4 (100%) of 4 unfiltered inoculated red cell units had growth (p = 0.04). Overall, 2 (20%) of 10 units of WBC-reduced red cells supported the growth of Y. enterocolitica, as compared to 100 percent of unfiltered red cell units after inoculation (p = 0.015). Bacterial contamination was not detected in any of the three noninoculated units. It can be concluded that prestorage WBC filtration significantly reduces the potential for growth of Y. enterocolitica in red cells stored at 4 degrees C for 42 days.