Functional neuroanatomy of subcomponent cognitive processes involved in verbal working memory

Recent research has used functional magnetic resonance imaging (fMRI) to examine brain regions related to specific subcomponent cognitive processes of verbal working memory, which include initial encoding of material, maintenance of the information over a brief delay interval, and later retrieval of the information. The present study examined each of these subcomponents in 14 healthy adults using a Sternberg verbal working memory task and fMRI. Group analysis revealed several brain regions active during all subcomponent processes, which included dorsolateral and ventrolateral prefrontal, parietal, hippocampal, and premotor cortex. Several other brain regions showed activation limited to specific subcomponent processes.     

Effects of mood state and psychosocial functioning on plasma Interleukin-6 in adult patients before cardiac surgery

OBJECTIVE: The purpose of this study was to examine the potential effect of mood states and psychosocial functioning during the waiting weeks prior to major cardiac surgery on the plasma Interleukin-6 (IL-6) levels in 236 patients immediately before their operation. METHOD: The sample was recruited from patients at the cardiac clinic of the University of Michigan Medical Center (Ann Arbor). Two weeks before cardiac surgery, trained research assistants conducted a face-to-face interview with these middle-aged and older patients on their preoperative physical examination date at the clinic. Standardized instruments were used to assess mood states and psychosocial functioning. The blood samples of 236 patients, obtained on the morning of the operation, were analyzed for plasma IL-6. RESULTS: In bivariate analysis, poor psychological functioning and anxiety, as well as bodily pain and body mass index (BMI), were correlated with plasma IL-6 (p < .05), but sociodemographics, chronic illness and use of psychotropic medications were not. When the effect of bodily pain and BMI were taken into account, partial correlation analysis showed that psychological functioning continued to be associated with plasma IL-6 (p < .05); the association of IL-6 with depression now became significant (p < .05), whereas that with anxiety became even more significant (p < .001). CONCLUSIONS: Preoperative psychological disturbances during the waiting weeks before cardiac surgery may influence the plasma levels of IL-6 immediately prior to the procedure. The clinical implications of these findings remain to be determined.     

Allogenic blood transfusion does not predispose to infection after cardiac surgery

Background

Many retrospective studies report increased postoperative infection after allogenic blood transfusion. To investigate this phenomenon, we prospectively studied 232 patients undergoing cardiac surgery.

Methods

Patients were screened daily for evidence of culture positive infections. Wounds were examined daily and defined on the ASEPSIS score. Chest radiographs and white cell counts and differentials were recorded on days 1, 2, and 4. The use of blood products was monitored blindly and independently. Patients were grouped according to transfusion status and compared using χ² or Fisher's test. Logistic regression analyses were performed to identify predictors of transfusion and infection.

Results

Of 232 patients, 116 (50%) received blood product transfusion. Patients receiving blood had lower preoperative hemoglobin, were older, with a greater proportion of urgent/emergency or revision surgery, and were higher risk. Despite this, there were no differences in the frequency of chest infection (20% versus 15%, p = 0.38), urinary infection (3.5% versus 5.3%, p = 0 0.75), wound infection (3.5% versus 8.0%, p = 0.16), or overall infection (28% versus 30%, p = 0.89) comparing the transfused versus untransfused groups. There was no evidence to suggest that administration of blood products was associated with infection (odds ratio 0.92, p = 0.77).

Conclusions

The administration of blood per se did not lead to increased postoperative infection. Clinicians should reconsider withholding blood transfusion in patients solely owing to concerns of predisposition to infection.     

Peritoneovenous Shunt Insertion for Intractable Ascites-A District General Hospital Experience

Ascites often contributes to patient morbidity and discomfort. When refractory to medical management, it has been managed with repeated paracentesis, implantable ports for drainage, or diversion to the urinary bladder. Peritoneovenous shunt insertion has been a technique that was traditionally performed only by surgeons but is now within the realm of interventional radiologists. Its advantage is that protein-rich ascitic fluid is returned to the intravascular compartment. This retrospective study elaborates on the successes and problems encountered during shunt insertion in our first 13 patients. Two patients are well with a functioning shunt at 14 and 32 weeks. In 6 the shunt functioned until the patients death from the underlying malignancy. Two required revision with variable success and in 2, shunt function could not be salvaged. There was one procedure-related mortality. Radiological insertion of these shunts is feasible and should be considered for selected patients. Options are available for assessment and salvaging of dysfunctional shunts.     

Small volume albumin administration protects against hemorrhagic shock-induced bone marrow dysfunction

BACKGROUND: Unexpected immunomodulatory effects of colloids and crystalloids prompted an investigation of albumin's ability to prevent bone marrow (BM) suppression following trauma/hemorrhagic shock (T/HS: laparotomy + MAP 30 for 90 mins). METHODS: In vitro: Normal rat BM was plated for granulocyte-macrophage (CFU-GM) and erythrocyte colony forming units (BFU-E) with 2% v/v plasma from sham (T/SS) or T/HS rats and albumin (2-8 mg/mL). In vivo: Male rats (n = 4/group) were subjected to T/SS or T/HS and resuscitated with shed blood and twice the volume as Lactated Ringer's (LR) or blood and 1, 2, or 3 mL of albumin (50 mg/mL). Bone marrow harvested 3 hours post-resuscitation was plated for CFU-GM and BFU-E. RESULTS: In vitro: T/HS plasma decreased both CFU-GM and BFU-E growth as compared with T/SS, whereas increasing doses of albumin showed dose-dependent improvement in progenitor growth (p < 0.05). In vivo: The suppression of BM red and white cell progenitor growth seen in T/HS+LR rats as compared with T/SS was fully prevented by as little as 1 mL of albumin (p < 0.05). CONCLUSIONS: Small doses of albumin fully restore CFU-GM and BFU-E to sham values. We postulate that the binding of circulating toxic factors by albumin may play a role in this prevention of T/HS-induced BM suppression.