Evaluating predictive factors for determining enteral nutrition in patients receiving radical radiotherapy for head and neck cancer: a retrospective review.

BACKGROUND AND PURPOSE: To identify objective pre-treatment clinical parameters that could be used to predict for patients at high risk of requiring enteral tube feeding prior to head and neck radiotherapy. PATIENTS AND METHODS: A retrospective study was conducted on 160 consecutive patients attending for radiotherapy assessment. Regression analysis was used to determine various pre-treatment nutritional and tumour specific parameters associated with the use of enteral nutrition either before (prophylactic) or during (reactive) radiotherapy (RT). The significant parameters identified were then selected into categorical variables and compared between those who needed reactive enteral nutrition and the remainder of the group who did not. These results were used to generate predictive factors that could be used to identify those at high risk of malnutrition during RT for whom early or prophylactic enteral nutrition should be considered. RESULTS: Fifty patients required enteral feeding of which 60% required this prior to radiotherapy. Multivariate analysis identified the following factors to be significant--body mass index, performance status (PS), advanced stage, pre-treatment weight loss, low serum albumin and protein, age, and smoking. The most significant categorical predictive parameters for reactive enteral feeding were stage 3-4 disease, PS 2-3, and smoking >20/day. The combination of these factors predicted a 75% chance of needing enteral nutrition. CONCLUSION: Nutritional assessment is important prior to radiotherapy and is multifactorial. Using a combination of relatively simple and objective parameters, (performance status, smoking and disease stage) it is possible to identify those at high risk of needing enteral nutrition prior to starting RT.     

Effects of major depression on estimates of intelligence.

This study examined whether patients with major depressive disorder manifest deficits in intelligence during affective episodes and following clinical improvement. WAIS-R scores were contrasted in 100 patients in an episode of major depression with 50 normal controls, matched to the patient sample in terms of demographic variables and estimates of premorbid IQ. The groups were equivalent in verbal IQ, but, in line with previous studies, the depressed patients had a pronounced deficit in performance IQ. A patient subsample was administered the WAIS-R under unlimited time conditions to determine whether the time constraints of performance IQ subtests contributed to the magnitude of the verbal-performance IQ discrepancy. This discrepancy was only slightly reduced with untimed scoring. Subgroups of depressed patients were retested with the WAIS-R within one week (n = 26) or two months (n = 33) following treatment with electroconvulsive therapy. In both subsamples, IQ scores were improved at posttreatment testing relative to pretreatment, but with little change in the verbal-performance IQ discrepancy. These and related findings suggested that a performance IQ deficit is characteristic of depressed patients regardless of affective state.     

Clinical review: Independent lung ventilation in critical care

Independent lung ventilation (ILV) can be classified into anatomical and physiological lung separation. It requires either endobronchial blockade or double-lumen endotracheal tube intubation. Endobronchial blockade or selective double-lumen tube ventilation may necessitate temporary one lung ventilation. Anatomical lung separation isolates a diseased lung from contaminating the non-diseased lung. Physiological lung separation ventilates each lung as an independent unit. There are some clear indications for ILV as a primary intervention and as a rescue ventilator strategy in both anatomical and physiological lung separation. Potential pitfalls are related to establishing and maintaining lung isolation. Nevertheless, ILV can be used in the intensive care setting safely with a good understanding of its limitations and potential complications.     

A comparison of CT- and ultrasound-based imaging to localize the prostate for external beam radiotherapy

PURPOSE: This study assesses the accuracy of NOMOS B-mode acquisition and targeting system (BAT) compared with computed tomography (CT) in localizing the prostate. METHODS AND MATERIALS: Twenty-six patients were CT scanned, and the prostate was localized by 3 observers using the BAT system. The BAT couch shift measurements were compared with the CT localization. Six of the patients had gold markers present in the prostate, and the prostate movement determined by BAT was compared with the movement determined by the gold markers. RESULTS: Using the BAT system, the 3 observers determined the prostate position to be a mean of 1-5 mm over all directions with respect to the CT. The proportion of readings with a difference >3 mm between the observers was in the range of 25% to 44%. The prostate movement based on gold markers was an average of 3-5 mm different from that measured by BAT. The literature assessing the accuracy and reproducibility on BAT is summarized and compared with our findings. CONCLUSIONS: We have found that there are systematic differences between the BAT-defined prostate position compared with that estimated on CT using gold grain marker seeds.     

Elevated plasma homovanillic acid in depressed females with melancholia and psychosis

Plasma free homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured before drug treatment in 29 patients diagnosed as having major depression with melancholia and in 18 control subjects. Plasma HVA was significantly elevated in the total group of female melancholic patients when compared with female controls or male melancholics. Most female patients with psychotic melancholia had elevated HVA levels. These differences were not found in male patients. No significant differences were found for plasma MHPG.     

Polynucleotide phosphorylase: an evolutionary conserved gene with an expanding repertoire of functions

RNA metabolism plays a seminal role in regulating diverse physiological processes. Polynucleotide phosphorylase (PNPase) is an evolutionary conserved 3',5' exoribonuclease, which plays a central role in RNA processing in bacteria and plants. Human polynucleotide phosphorylase (hPNPase old-35) was cloned using an inventive strategy designed to identify genes regulating the fundamental physiological processes of differentiation and senescence. Although hPNPase old-35 structurally and biochemically resembles PNPase of other species, targeted overexpression and inhibition studies reveal that hPNPase old-35 has evolved to serve more specialized functions in humans. The present review provides a global perspective on the structure and function of PNPase and then focuses on hPNPase old-35 in the contexts of differentiation and senescence.