Multi-objective blood glucose control for type 1 diabetes

For people with type 1 diabetes, automatic controllers aim to maintain the blood glucose concentration within the desired range of 60–120 mg/dL by infusing the appropriate amount of insulin in the presence of meal and exercise disturbances. Blood glucose concentration outside the desired range can be harmful to an individual’s health but concentration below 60 mg/dL, a state known as hypoglycemia, is considered to be more harmful than the concentration above 120 mg/dL, a state known as hyperglycemia. In this paper, two techniques to address this issue within a multi-parametric model based control framework are presented. The first technique introduces asymmetry into the objective function to penalize the deviation towards hypoglycemia more than the deviation towards hyperglycemia. The second technique is based upon placing higher priority on satisfaction of constraints on hypoglycemia than on satisfaction of constraints on hyperglycemia. The performance of both the control techniques is analyzed and compared in the presence of disturbances.     

Cancer prognosis using support vector regression in imaging modality

The proposed techniques investigate the strength of support vector regression (SVR) in cancer prognosis using imaging features. Cancer image features were extracted from patients and recorded into censored data. To employ censored data for prognosis, SVR methods are needed to be adapted to uncertain targets. The effectiveness of two principle breast features, tumor size and lymph node status, was demonstrated by the combination of sampling and feature selection methods. In sampling, breast data were stratified according to tumor size and lymph node status. Three types of feature selection methods comprised of no selection, individual feature selection, and feature subset forward selection, were employed. The prognosis results were evaluated by comparative study using the following performance metrics: concordance index (CI) and Brier score (BS). Cox regression was employed to compare the results. The support vector regression method (SVCR) performs similarly to Cox regression in three feature selection methods and better than Cox regression in non-feature selection methods measured by CI and BS. Feature selection methods can improve the performance of Cox regression measured by CI. Among all cross validation results, stratified sampling of tumor size achieves the best regression results for both feature selection and non-feature selection methods. The SVCR regression results, perform better than Cox regression when the techniques are used with either CI or BS. The best CI value in the validation results is 0.6845. The best CI value corresponds to the best BS value 0.2065, which were obtained in the combination of SVCR, individual feature selection, and stratified sampling of the number of positive lymph nodes. In addition, we also observe that SVCR performs more consistently than Cox regression in all prognosis studies. The feature selection method does not have a significant impact on the metric values, especially on CI. We conclude that the combinational methods of SVCR, feature selection, and sampling can improve cancer prognosis, but more significant features may further enhance cancer prognosis accuracy.     

"Very Late" isolated para-aortic nodal recurrence of carcinoma cervix mimicking radiation-induced sarcoma

Only a minority of the patients who develop recurrence after definitive treatment for cervical cancer are detected after 5 years (late recurrence); the numbers are lesser still after 10 years (very late recurrence). Among the infrequent cases that do develop "late" and "very late" recurrence, the commonest site is the pelvis. We report an unusually rare recurrence of treated cervical cancer confined to the para-aortic nodal group after a protracted disease-free interval of 13 years. On the basis of the long disease-free interval, location of the mass at the periphery of the radiation field, and aggressive imaging appearance, a diagnosis of radiation-induced sarcoma was considered. However, the final diagnosis of isolated para-aortic nodal recurrence of cervical cancer was rendered based on the histopathological and immunohistochemistry findings, supported by the absence of disease elsewhere on whole-body imaging.     

Rhabdoid meningioma with cranial nerve involvement: case report of a child

CASE REPORT: A 13-year-old girl presented with off and on headache for 1 year, hearing loss for 6 months and difficulty in closing eyes for 5 months along with mild cerebellar signs. Histopathologic evaluation of the tumor showed a rhabdoid meningioma (WHO Grade III). DISCUSSION: Rhabdoid meningiomas are uncommon in children, and only 4 cases have been reported so far. None of them presented with cranial nerve involvement. This unusual presentation is reported here. CONCLUSION: Though rare, rhabdoid meningiomas can occur in children. This, to the best of the authors' knowledge, is the first case of rhabdoid meningioma presenting with cranial nerve involvement.     

Seizures and sodium hydrogen exchangers: potential of sodium hydrogen exchanger inhibitors as novel anticonvulsants

Advances in the understanding of mechanisms underlying the pathophysiology of epilepsy have led to the identification of sodium hydrogen exchanger (NHE) as one of the possible targets for future antiepileptic drugs (AEDs). There are indicators from several experimental studies that NHE inhibitors could be of significant value as potential anticonvulsants. Various in-vitro reports (brain slices) have suggested anticonvulsant potential of these agents. Recently we provided the in-vivo data on anticonvulsant efficacy of amiloride (an NHE inhibitor) in different animal models of seizure and epilepsy. In addition to blocking NHE, these agents are known to affect other traditional targets like voltage-gated Na(+) channels, Ca(2+) channels, glutamate concentration, etc. Thus NHE inhibitors may represent a novel class of AEDs and surely deserve more scientific attention. In this review, we focus on the role of NHE in epilepsy and provide the experimental evidence available so far on the effect of NHE inhibitors in various animal models.     

Tension pneumoventricle following exposure of shunt chamber

Pneumocephalus is the presence of air within the intracranial vault. Intraventricular pneumocephalus, also known as pneumoventricle is relatively rare and commonly occurs following cerebrospinal fluid diversion procedures. This may occur immediately or be delayed. Although a small amount of pneumoventriculus is asymptomatic and may not require any treatment, when present under tension it needs to be evacuated. We present a case of tension pneumoventricle following exposure of the shunt chamber, which resulted in deterioration of the patients' neurological condition and required evacuation.     

Henoch-Schonlein purpura with ischaemic bowel

Henoch-Schonlein purpura is a vasculitis affecting small arterial vessels. Occasionally, cases are referred for a general surgical opinion due to bowel involvement in the form of abdominal pain with or without rectal bleeding. However, surgical intervention is rarely required. We describe a case of Henoch-Schonlein purpura in a young man who went on to develop ischaemic bowel requiring resection.     

Allergen inhalation challenge in smoking compared with non‐smoking asthmatic subjects

Background Smoking asthmatics experience more severe symptoms, require more rescue medication and have more asthma‐related hospitalizations than non‐smoking asthmatics. However, studies in mice suggest that mainstream cigarette smoke may reduce airway inflammation and may attenuate airway hyperresponsiveness. A comparison of allergen‐induced airway inflammatory responses of smoking and non‐smoking atopic asthmatics has not been examined previously. Objectives To determine whether allergen‐induced airway responses and inflammatory profiles are attenuated in smoking when compared with non‐smoking mild allergic asthmatic subjects. Methods Allergen inhalation challenges were performed in 13 smoking and 19 non‐smoking mild allergic asthmatic subjects. The forced expired volume in 1 s (FEV₁) was measured up to 7 h after allergen inhalation. Methacholine airway responsiveness was measured before and at 24 h after allergen and sputum was induced before and at 7 and 24 h after allergen. Results Both the smoking and non‐smoking groups developed similar allergen‐induced falls in FEV₁ during the early and late asthmatic responses and similar increases in allergen‐induced airway eosinophils. The mean maximum fall in FEV₁ during the late response was 16.3±4.3% in non‐smokers and 12.9±7.2% in smokers. The smoking asthmatics, however, did not develop allergen‐induced methacholine airway hyperresponsiveness, whereas the non‐smoking controls developed a 1.18 doubling dose shift in methacholine PC₂₀ (P<0.05). Conclusions and Clinical Relevance Mild allergic asthmatic subjects, who were current smokers with a mean 6‐year pack history, develop allergen‐induced eosinophilic airway inflammation and late responses, similar in magnitude to non‐smoking asthmatics, but do not develop methacholine airway hyperresponsiveness associated with the allergen‐induced airway eosinophilia. Cite this as: Z. Meghji, B. Dua, R. M. Watson, G. M. Gauvreau and P. M. O'Byrne, Clinical & Experimental Allergy, 2011 (41) 1084–1090.