Metabolite phantom correction of the nonuniform volume-selection profiles in MR spectroscopic imaging: application to temporal lobe epilepsy

BACKGROUND AND PURPOSE: In MR spectroscopic imaging (MRSI), the volume-selection profiles of metabolites differ from each other. These differences cause variations in metabolite intensities, which are particularly prominent when the hippocampi are evaluated. We hypothesize that the errors arising from these effects cause notable artifact when temporal lobe epilepsy (TLE) is lateralized with MRSI. METHODS: We examined a metabolite phantom, control subjects, and patients with TLE by using MRSI. We calculated the error arising from the different volume-selection profiles of metabolites in vitro and evaluated this correction in the examination of the control subjects and in the lateralization of epilepsy in the patients. RESULTS: Without a correction, a considerable error in the metabolite content existed, even deep inside the spectroscopic volume of interest. The result was false asymmetry (P < .008) in the hippocampi of control subjects. Among the 11 patients, TLE was correctly lateralized in three only after the correction was made, and in one, TLE was incorrectly lateralized. CONCLUSION: The volume-selection profiles of N-acetylaspartate, choline, and creatine differ enough to cause a significant error, even in the metabolite ratios, when patients with TLE are examined with MRSI. We propose a simple phantom method to correct for this error without a need to modify the pulse sequence.     

Growth hormone selectively improves intestinal cholesterol absorption after jejunoileal autotransplantation in pigs

Background/Purpose

Small bowel transplantation impairs enteric function and causes malabsorption of cholesterol and bile acids. Growth hormone stimulates intestinal absorptive function. The authors hypothesized that long-term growth hormone therapy could improve absorption of bile acids and cholesterol after autotransplantation of the jejunoileum.

Methods

Sixteen pigs with similar food, cholesterol, and fat intake underwent either sham laparotomy or a model of jejunoileal autotransplantation, including extrinsic autonomic denervation, lymphatic interruption, and in situ cold ischemia. Five randomly chosen autotransplanted animals received daily growth hormone treatment for 8 weeks. Serum lipids, absorption, and excretion of cholesterol, bile acids, and fat were determined after 8 weeks. Mucosal morphometrics, proliferation, and enzyme activities were determined. Plasma cholesterol precursors and plant sterols, respective markers of cholesterol synthesis and absorption, were measured after 2 and 8 weeks.

Results

After jejunoileal autotransplantation, growth hormone treatment significantly increased body weight gain, cholesterol absorption efficiency from 45.1% to 62.1%, plasma campesterol to cholesterol proportions, and biliary secretion of cholesterol. With or without growth hormone treatment, autotransplantation significantly increased fecal bile acid excretion, plasma cholesterol precursors, fecal bacterially modified neutral sterols, mucosal thickness of the ileum (but not jejunum), and intestinal transit time when compared with sham-operated animals. Crypt cell proliferation, mucosal enzyme activities, and microvilli showed no differences between the groups.

Conclusions

These findings suggest that growth hormone treatment selectively improves cholesterol, but not bile acid absorption, after autotransplantation of the jejunoileum.     

Accuracy of axillary staging using sentinel node biopsy or diagnostic axillary lymph node dissection--a case-control study

We aimed to compare the accuracy of axillary staging in breast cancer between sentinel node biopsy (SNB) and axillary lymph node dissection (ALND). The prevalence of axillary metastases was studied in 166 breast cancer patients with SNB and pair-matched control patients with ALND. The matching factors included age of the patient and grade, histological type and histological size of the tumour. There were 37% of patients with axillary metastases in the SNB group and 31% in the ALND group. Altogether, 57 pairs were discordant in relation to axillary metastases. In 34 discordant pairs the SNB patient and in 23 the ALND patient had axillary metastases, p=ns. Among the 36 discordant pairs with invasive ductal carcinoma (IDC), axillary metastases were detected as often in the SNB and the ALND patients. In the 21 discordant pairs with other histological types, the SNB patient had axillary metastases in 16 pairs and the ALND patient in 5 pairs, p<0.03. SNB seems to be as accurate a method for axillary staging as ALND. However, SNB generated no upstaging effect in IDC, only in other histological tumour types.     

Pain- and morphine-associated transcriptional regulation of neuropeptide FF and the G-protein-coupled NPFF2 receptor gene

Neuropeptide FF (NPFF) is involved in pain modulation, especially plasticity during inflammatory and neuropathic pain, and opiate interactions. Its nociceptive functions may be mediated by the NPFF2 receptor. To elucidate the role of the NPFF system in plasticity associated with pathologic pain, we studied the changes of NPFF mRNA and NPFF2 receptor mRNA in rat models of acute colonic inflammation, inflammatory pain, and neuropathic pain. Furthermore, we studied the mRNA levels of both NPFF and NPFF2 receptor in morphine-tolerant rats and after acute morphine injections. We found an activation of spinal NPFF and NPFF2 receptor during early inflammatory pain. Supraspinally, we found an up-regulation of NPFF2 receptor mRNA during acute colonic inflammation and neuropathic pain. Acute, but not chronic, morphine activated the genes supraspinally. The results give further evidence for the involvement of the NPFF system in pain modulation and may provide new therapeutic opportunities for pathologic pain.     

High-resolution genomic and expression profiling reveals 105 putative amplification target genes in pancreatic cancer

Comparative genomic hybridization (CGH) studies have provided a wealth of information on common copy number aberrations in pancreatic cancer, but the genes affected by these aberrations are largely unknown. To identify putative amplification target genes in pancreatic cancer, we performed a parallel copy number and expression survey in 13 pancreatic cancer cell lines using a 12,232-clone cDNA microarray, providing an average resolution of 300 kb throughout the human genome. CGH on cDNA microarray allowed highly accurate mapping of copy number increases and resulted in identification of 24 independent amplicons, ranging in size from 130 kb to 11 Mb. Statistical evaluation of gene copy number and expression data across all 13 cell lines revealed a set of 105 genes whose elevated expression levels were directly attributable to increased copy number. These included genes previously reported to be amplified in cancer as well as several novel targets for copy number alterations, such as p21-activated kinase 4 (PAK4), which was previously shown to be involved in cell migration, cell adhesion, and anchorage-independent growth. In conclusion, our results implicate a set of 105 genes that is likely to be actively involved in the development and progression of pancreatic cancer.     

Interaction between caregivers and families expecting a malformed child

BACKGROUND: Earlier research has shown that the care of families expecting a malformed child should be intensified and that the topic is understudied. AIM: This study aimed at generating a practical nursing theory of interaction between caregivers and families expecting a malformed child, as experienced by families. METHODS: A grounded theory study was undertaken at a university hospital, Finland. Data consisted of semi-structured interviews with 29 mothers and fathers, analysed using the constant comparative method. FINDINGS: The interaction process starts with the confirmation of the diagnosis. It usually comes as a shock to the parents, and gives rise to questions about the nature of the malformation, family members' relationship with themselves, family relationships and relationships with people outside the family. These questions are crucial to the family's coping and form the core of interaction. Families' own coping strategies are either reinforced or undermined by caregivers' actions and are reflected in parents' expectations about caregivers, which in part account for their actions and experiences of interaction. The care system as an interactive environment is part of a process which results in the experiences of being helped or being left without help. The core of the interaction process comprises two dimensions: gaining strength and losing strength in relation to malformation issues. CONCLUSIONS: The findings of the study are consistent with earlier research and complement it by providing a detailed delineation of the interaction from the perspective of the family. They can be used to formulate recommendations for improving caregivers' interactive skills and awareness of the topic through training. The care system should be developed to ensure that families receive psychological support and that the family as a whole receives proper care. Consideration of the viewpoint of siblings is a challenge for further research.     

Interaction as an ethically sensitive subject of research

In this paper, Hanna Maijala, P?ivi Astedt-Kurki and Eija Paavilainen discuss ethically sensitive family nursing research. A study of the interaction between caregivers and families expecting a child with an abnormality is used as an example: 29 parents and 22 caregivers were interviewed. Complementary data were obtained from essays written by five parents. This sensitive subject required discretion, especially when the parents were first asked to participate in the study, and during subsequent interviews. From the perspective of the data analysis, it was essential to obtain the informants' personal experiences unaltered. The constant comparative method of grounded theory was used to analyse the data. In the study findings, special attention was paid to presenting the results truthfully, while safeguarding the informants' anonymity. In conclusion, the ethical questions related to the subject of the study are discussed from the point of view of both the participant and the researcher.