Development and validation of a self-completed HIV symptom index

Traditional, open-ended provider questions regarding patient symptoms are insensitive. Better methods are needed to measure symptoms for clinical management, patient-oriented research, and adverse drug-event reporting. Our objective was to develop and initially validate a brief, self-reported HIV symptom index tailored to patients exposed to multidrug antiretroviral therapies and protease inhibitors, and to compare the new index to existing symptom measures. The research design was a multistage design including quantitative review of existing literature, qualitative and quantitative analyses of pilot data, and quantitative analyses of a prospective sample. Statistical analyses include frequencies, chi-square tests for significance, linear and logistic regression. The subjects were from a multisite convenience sample (n = 73) within the AIDS Clinical Trials Group and a prospective sample from the Cleveland Veterans Affairs Medical Center (n = 115). Measures were patient-reported symptoms and health-related quality of life, physician-assessed disease severity, CD4 cell count, and HIV-1 RNA viral quantification. A 20-item, self-completed HIV symptom index was developed based upon prior reports of symptom frequency and bother and expert opinion. When compared with prior measures the index included more frequent and bothersome symptoms, yet was easier to use (self-report rather than provider interview). The index required less than 5 minutes to complete, achieved excellent completion rates, and was thought comprehensive and comprehensible in a convenience sample. It was further tested in a prospective sample of patients and demonstrated strong associations with physical and mental health summary scores and with disease severity. These associations were independent of CD4 cell count and HIV-1 RNA viral quantification. This 20-item HIV symptom index has demonstrated construct validity, and offers a simple and rational approach to measuring HIV symptoms for clinical management, patient-oriented research, and adverse drug reporting.

Anastomotic leakage after curative anterior resection results in a higher prevalence of local recurrence

BACKGROUND

The aim of this study was to determine whether leakage from a colorectal anastomosis following potentially curative anterior resection for rectal cancer is an independent risk factor for local recurrence.

METHODS

The study included all patients who had a potentially curative anterior resection with anastomosis for adenocarcinoma of the rectum between 1971 and 1991 at Concord Hospital. The data were collected prospectively, with complete follow-up for at least 5 years. The Kaplan-Meier method was used to compare time to recurrence between strata of categorical variables. Proportional hazards regression was used in multivariate modelling.

RESULTS

There were 403 patients in the study. After adjustment for lymph node metastases, the distal resection margin of resection, non-total anatomical dissection of the rectum and the level of anastomosis, multivariate analysis identified a significant association between anastomotic leakage and local recurrence (hazard ratio 3.8, 95 per cent confidence interval 1.8 to 7.9).

CONCLUSION

Leakage following a colorectal anastomosis after potentially curative resection for adenocarcinoma of the rectum is an independent predictor of local recurrence.

Local recurrence after curative excision of the rectum for cancer without adjuvant therapy: role of total anatomical dissection

BACKGROUND

The wide variability of reported local recurrence rates after curative resection of rectal cancer without adjuvant therapy may be a consequence of many different factors. However, few studies have investigated the potential effects of such factors on local recurrence by multivariate analysis. The present study examined clinical and tumour characteristics, operation type and operative technique as potential predictors of local recurrence in patients treated by surgery alone.

METHODS

Prospective data were analysed by bivariate and multivariate methods including actuarial survival and proportional hazards regression.

RESULTS

Local recurrence (pelvic or pelvic and systemic) was diagnosed in 59 of 596 patients. The 5-year actuarial local recurrence rate was 11.1 (95 per cent confidence interval 8.7-14.3) per cent. Independent predictive factors for local recurrence were: positive nodes (hazard ratio (HR) 5.5, P < 0.01); distal margin of 1 cm or less (HR 3.8, P < 0.01); venous invasion (HR 2.0, P = 0.02) and total anatomical dissection of the rectum (HR 2.0, P = 0.01). There was no difference in local recurrence between patients who had the mesorectum divided and those in whom it was totally excised.

CONCLUSION

Nodal involvement is the most potent predictor of local recurrence. In patients in whom total anatomical dissection is performed, total mesorectal excision confers no additional protection against local recurrence.

Guanine ribonucleotide depletion inhibits T cell activation. Mechanism of action of the immunosuppressive drug mizoribine

The immunosuppressive drug, mizoribine, has been used to prevent rejection of organ allografts in humans and in animal models. Based on studies in cell lines, mizoribine has been postulated to be an inhibitor of inosine monophosphate (IMP) dehydrogenase (EC1.2.1.14), a pivotal enzyme in the formation of guanine ribonucleotides from IMP. To further characterize the mechanism of action of this drug, we studied the effect of mizoribine on human peripheral blood T cells stimulated with alloantigen, anti-CD3 MAb, or pharmacologic mitogens. Mizoribine (1-50 micrograms/ml) was able to inhibit T cell proliferation by 10-100% in a dose-dependent fashion to all stimuli tested. Measurements of purine ribonucleotide pools by HPLC showed that mizoribine led to a decrease in intracellular GTP levels, and that repletion of GTP reversed its antiproliferative effects. We also examined sequential events occurring after T cell stimulation. Early events in T cell activation, as assessed by steady-state mRNA levels of c-myc, IL-2, c-myb, histone, and cdc2 kinase, as well as surface IL-2 receptor expression, were unaffected. However, cell cycle analysis revealed decreased numbers of cells in S, G2, and M phases, and showed that the G1/S block was reversed with GTP repletion. These data indicate that mizoribine has an effect on T cell proliferation by a mechanism distinct from that of cyclosporine or corticosteroids, and therefore may be useful in combination immunosuppressive regimens.

Patient- and provider-reported adherence: toward a clinically useful approach to measuring antiretroviral adherence

We seek to develop a clinically useful measure of antiretroviral medication adherence. Because there is no gold standard for adherence, we will assess the clinical validity of patient- and provider-reported adherence by the strength of their expected associations with current viral load, depressive symptoms, alcohol and illicit drug use, and homelessness. The Veterans Aging Cohort 3 Site Study (VACS 3) is a multisite study of 881 patients at Cleveland, Houston, and Manhattan Veterans Affairs health care systems. Data was collected on adherence using patient report and provider assessment; depressive symptoms using the Center for Epidemiological Studies Depression (CESD) and provider assessment; alcohol use using the Alcohol Use Disorders Identification Test (AUDIT) and provider assessment; and homelessness using patient report only. Viral load was collected from electronic laboratory data. Although agreement between providers and patients about the patient's adherence was not better than chance (61%; weighted kappa =.07), both patient and provider-reported adherence were related to viral load (P <.001), current alcohol use (P <.01), current drug use (P <.01), and depressive symptoms (P <.001). Patient-reported adherence was also associated with homelessness (P <.05). In multivariate regression models, provider assessment of adherence demonstrated independent associations with viral load (P <.001), current alcohol use (P <.001), current drug use (P <.001), and depressive symptoms (P <.001) after adjustment for the patient's report of adherence (also significantly associated). The consistent and largely independent association between patient and provider reported adherence and a range of variables previously shown to be associated with adherence suggests that patient- and provider-reported adherence independently measure actual adherence. Future work will explore how patient- and provider-reported adherence might best be combined, and whether the measure may be further enhanced with pharmacy refill data.

Anastomotic leakage after resection of colorectal cancer generates prodigious use of hospital resources

OBJECTIVE

The aim of this study was to determine the demand for hospital resources generated by anastomotic leakage, including surgical, medical, imaging, pathology, and other allied health consultations or services and length of postoperative hospital stay.

METHOD

Data were obtained from a comprehensive, prospective hospital registry of all resections for colorectal cancer from January 1995 to December 2004 and from retrospective review of patients' notes.

RESULTS

Forty-one patients with a leak spent 92 days in intensive care, required 129 days of total parenteral nutrition, 69 days of enteric feeding and 41 days on ventilation and had a median postoperative hospital stay of 28 days (range 11-104). These patients required 24 re-operations and 2273 separate medical consultations or allied services.

CONCLUSION

Anastomotic leakage generates a very considerable demand for hospital resources and diverts these resources from the hospital population at large.

Diagnostic criteria and natural history of catheter-associated urinary tract infections after prostatectomy

Bacteriuria occurred postoperatively in 28 of 122 patients who had sterile urine before transurethral prostatectomy without antibiotic prophylaxis. Prospective monitoring of catheter bacteriuria indicated that a bacterial count of 10(3) colony-forming-units (cfu/ml progressed to significant infection except when the bacterium in the urine was Staphylococcus epidermidis. Bacteraemia developed in 4 bacteriuric patients, including 2 in whom the bacteria in the urine and blood were mixed. Catheter removal without antibiotic therapy resulted in spontaneous resolution of Staph epidermidis bacteriuria in 9 patients but infection persisted in 5 of 6 patients with other bacteria in the urine. This study indicates that a bacterial count of 10(3) cfu/ml in catheter urine is associated with pathological sequelae and that catheter removal does not result in resolution of bacteriuria caused by pathogenic bacteria.

What factors influence survival in patients with unresected synchronous liver metastases after resection of colorectal cancer?

OBJECTIVE

The aim of this study was to determine whether the survival of patients with untreated synchronous liver metastases after resection of a colorectal cancer was associated with any features of the primary tumour.

METHODS

Information for 398 consecutive patients with unresected liver metastases in the period 1971-2001 was examined by multivariate survival analysis.

RESULTS

Of 19 clinical and pathological variables considered, survival was independently associated only with residual tumour in a line of resection (hazard ratio (HR) 1.95), venous invasion (HR 1.87), right colonic tumour (HR 1.68), lymph node metastasis (HR 1.54), and extra-hepatic metastasis (HR 1.16); 8.3% of patients had none of these adverse features. Their 2-year overall survival rate was 39.2%, compared with only 16.5% (P < 0.001) in those with one or more adverse features.

CONCLUSIONS

These findings may assist in selecting patients most likely to benefit from treatment of hepatic metastases and in counselling patients and their relatives.

Adverse histopathological findings as a guide to patient management after curative resection of node-positive colonic cancer

Background

The aim of this study was to identify patient and tumour characteristics that might assist in developing an improved approach to patient selection for chemotherapy after resection of clinicopathological stage C colonic cancer.

Methods

Clinical, pathological and follow-up data have been collected prospectively for all patients undergoing resection for colorectal cancer at Concord Hospital since 1971. From an initial 2980 patients, after exclusions 378 remained who had a potentially curative operation for colonic cancer with nodal metastases and did not receive adjuvant chemotherapy. Associations between several pathological features and survival were examined by proportional hazards regression.

Results

In a multivariate model, both overall and colonic cancer-specific survival rates were negatively associated with serosal surface involvement, apical node metastasis, high histological grade and venous invasion. The survival of patients with stage C disease who had none of these adverse features was not significantly different from that of patients with stage B lesions. However, survival diminished significantly when one or more of the adverse features were present.

Conclusion

Patients with a stage C tumour but with none of the identified adverse features experience relatively good survival and are unlikely to benefit from adjuvant chemotherapy. In this series such patients accounted for 40·5 per cent of patients with stage C disease.

Understanding the anatomy of lymphatic drainage and the use of blue-dye mapping to determine the extent of lymphadenectomy in rectal cancer surgery: unresolved issues

OBJECTIVE

This paper reviews the literature on the pathways of lymphatic drainage of the rectum and their significance in radical cancer surgery.

METHOD

This paper reviews some of the seminal works on the lymphatic drainage of the rectum and its surgical implications when operating on patients with rectal cancer. Publications were searched via Medline, sourced from reference lists and by cross referencing with the most widely cited papers.

RESULTS

The classical European description of the anatomy of the lymphatic drainage of the rectum is presented. Early lymphatic mapping techniques and the role of newer technologies in lymphatic mapping, including sentinel lymph node mapping are discussed. The differing philosophies between Western practice, of dissection in the plane of the fascia propria and the Japanese wider pelvic lymphadenectomy are discussed.

CONCLUSIONS

A clear understanding of the regional lymphatic drainage of the rectum and precise anatomical mobilisation of the rectum is the surgical cornerstone to excellent locoregional control of rectal cancer. The success of the differing Western and Japanese philosophies on the degree of pelvic lymphadenectomy suggests a possible role for 'selective wide pelvic lymphadectomy'. Mapping lateral lymphatic drainage pathways could augment the selection process for radiotherapy.

Endoscopic laser stricturotomy and balloon dilatation for benign colorectal strictures

BACKGROUND

A fibrous stricture may develop at the site of a colorectal anastomosis or as a complication following abdominal aortic surgery. A major resection may be necessary if the stricture cannot be released. The authors' experience with endoscopic stricturotomy using neodymium:yttrium-aluminium-garnet laser, together with balloon dilatation, as a conservative method of treating such strictures, is reported here.

METHODS

The case notes of all patients referred for laser treatment of benign distal large bowel strictures at Concord Hospital were reviewed.

RESULTS

Ten patients had endoscopic laser treatment combined with endoscopic balloon dilatation between October 1991 and July 1999. An anastomotic stricture had developed in eight patients and two patients had a fibrous stricture of the upper rectum after abdominal aortic aneurysm surgery. Nine of the 10 patients had their stricture treated successfully without complication or recurrence (median follow up 82 months; range: 14-104 months). The remaining patient re-presented with a large bowel obstruction at the site of his stricture 6 years following initial treatment.

CONCLUSION

A protocol combining laser stricturotomy with balloon dilatation appears to be a safe and effective treatment of such strictures.

Guanidinoacetate methyltransferase deficiency: first steps to newborn screening for a treatable neurometabolic disease

BACKGROUND

GAMT deficiency is an autosomal recessive disorder of creatine biosynthesis resulting in severe neurological complications in untreated patients. Currently available treatment is only successful to stop disease progression, but is not sufficient to reverse neurological complications occurring prior to diagnosis. Normal neurodevelopmental outcome in a patient, treated in the newborn period, highlights the importance of early diagnosis.

METHODS

Targeted mutation analysis (c.59G>C and c.327G>A) in the GAMT gene by the QIAxcel system and GAA measurement by a novel two-tier method were performed in 3000 anonymized newborn blood dot spot cards.

RESULTS

None of the targeted mutations were detected in any newborn. Two novel heterozygous variants (c.283_285dupGTC; p.Val95dup and c.278_283delinsCTCGATGCAC; p.Asp93AlafsX35) were identified by coincidence. Carrier frequency for these insertion/deletion types of GAMT mutations was 1/1475 in this small cohort of newborns. GAA levels were at or above the 99th percentile (3.12 μmol/l) in 4 newborns. Second-tier testing showed normal results for 4 newborns revealing 0.1% false positive rate. No GAMT mutations were identified in 4 of the newborns with elevated GAA levels in the first tier testing.

CONCLUSION

This is the first two-tier study to investigate carrier frequency of GAMT deficiency in the small cohort of newborn population to establish evidence base for the first steps toward newborn screening for this treatable neurometabolic disorder.

Quality of life in patients undergoing treatment for chronic radiation-induced rectal bleeding

BACKGROUND

Laser and formalin therapy have recently been shown to be safe methods of haemostasis in patients with chronic radiation-induced rectal bleeding (CRRB). The effectiveness of this treatment in terms of improved quality of life remains to be determined. The aim of this study was to develop a questionnaire measure of self-perceived quality of life in patients with CRRB.

METHODS

A self-completed Rectal Bleeding Quality of Life Scale (RBQOLS) based on the social and emotional problems experienced by patients with CRRB was developed using standard psychometric methods. Before laser and formalin therapy, 34 consecutive patients completed the questionnaire which was repeated 1 month after treatment and again 5 months later. The validity of the scale was assessed in relation to patient response to treatment.

RESULTS

The RBQOLS had high reliability (alpha=0.89) and its concurrent validity was confirmed by a significant association with the pretreatment severity of CRRB assessed endoscopically. The mean RBQOLS score increased from 102 (95 per cent confidence interval 90-114) before treatment to 126 (111-141) after treatment (t=3.1, 33 d.f., P=0.004) and 136 (122-151) at follow-up attesting to its predictive validity.

CONCLUSION

The RBQOLS is a reliable and valid device for assessing quality of life of patients with this uncommon, previously intractable and potentially life threatening complication of radiotherapy.

A novel complex allele and two new point mutations in type 2 (acute neuronopathic) Gaucher disease

Gaucher disease, the most prevalent inherited sphingolipidosis, is characterized by lipid laden histiocytes in the spleen, liver and bone marrow sinusoids of affected individuals. It results from deleterious mutations in the functional gene of glucocerebrosidase (acid beta-glucosidase, EC. 3.2.1.45) and is transmitted as an autosomal recessive trait. Three clinical forms of Gaucher disease have been described: Type 1 non-neuronopathic, type 2 acute neuronopathic, and type 3 subacute neuronopathic. In this report, we describe the identification and characterization of three novel mutations from two patients who died with type 2 Gaucher disease. Two heterozygous missense point mutations, one at cDNA nucleotide 238A (E41L) and the other at cDNA nucleotide 508T (R131C) were identified, both in the context of a cDNA nucleotide 1448C (L444P) mutation in the second allele. One of these L444P mutations was identified as a novel complex allele resulting from a crossover involving the glucocerebrosidase functional gene and pseudogene beginning between genomic nucleotides 5689 and 5723 and extending through the rest of the coding sequence. Based on the recent identification and sequence analysis of the metaxin gene and pseudogene contiguous with the glucocerebrosidase pseudogene and functional gene respectively, we have developed a PCR-based method for the analysis of the origin and extent of this recombination.

Ancient schwannoma of the foot

Ancient neurilemoma (schwannoma) is an uncommon variant of neurilemoma. On the basis of histology, this slow-growing, benign neoplasm has often been confused with sarcoma, and this confusion has resulted in overzealous resection. The authors report a case of this lesion affecting the plantar aspect of the foot. A discussion of the clinical and histological findings that emphasizes diagnosis and treatment is included.

Fractionated SRT using VMAT and Gamma Knife for brain metastases and gliomas--a planning study

Stereotactic radiosurgery using Gamma Knife (GK) or linear accelerators has been used for decades to treat brain tumors in one fraction. A new positioning system, Extend™, was introduced by Elekta AB for fractionated stereotactic radiotherapy (SRT) with GK. Another option for fractionated SRT is advanced planning and delivery using linacs and volumetric modulated arc therapy (VMAT). This project aims to assess the performance of GK Extend™ for delivering fractionated SRT by comparing GK treatments plans for brain targets performed using Leksell GammaPlan (LGP) with VMAT treatment plans. Several targets were considered for the planning: simulated metastasis‐ and glioma‐like targets surrounding an organ at risk (OAR), as well as three clinical cases of metastases. Physical parameters such as conformity, gradient index, dose to OARs, and brain volume receiving doses above the threshold associated with risk of damaging healthy tissue, were determined and compared for the treatment plans. The results showed that GK produced better dose distributions for target volumes below 15 cm³, while VMAT results in better dose conformity to the target and lower doses to the OARs in case of fractionated treatments for large or irregular volumes. The volume receiving doses above a threshold associated with increased risk of damage to normal brain tissue was also smaller for VMAT. The GK consistently performed better than VMAT in producing a lower dose‐bath to the brain. The above is subjected only to margin‐dependent fractionated radiotherapy (CTV/PTV). The results of this study could lead to clinically significant decisions regarding the choice of the radiotherapy technique for brain targets.

PACS numbers: 87.53.Ly, 87.55.D‐

Metastatic cervical teratoma of infancy

The first case of a documented metastatic cervical teratoma of infancy is presented with a review of diagnostic considerations. Early biopsy of suspicious neonatal head and neck masses is recommended. Complete resection of the teratoma should be considered as soon as clinically possible.

Mesothelin-specific Immune Responses Predict Survival of Patients With Brain Metastasis

Background

Patients with advanced malignancies, e.g. lung cancer, ovarian cancer or melanoma, frequently present with brain metastases. Clinical presentation and disease progression of cancer is in part shaped by the interaction of the immune system with malignant cells. Antigen-targeted immune responses have been implicated in the prolonged survival of patients with cancer. This includes the tumor-associated antigen (TAA) mature mesothelin, a 40 kDa cell surface-bound antigen that is overexpressed in several malignancies including lung ovarian and pancreatic cancer. We examined in an observational, prospective study the survival of patients with brain metastases in association with clinical parameters and cellular immune responses to molecularly defined TAAs or viral (control) target antigens.

Methods

Immune cells in peripheral blood obtained from thirty-six patients with brain metastases were tested for cytokine production in response to a broad panel of defined viral and TAA target antigens, including full-length mesothelin. Incubation of immune cells with antigenic targets was carried out in i) medium alone, (ii) in a cytokine cocktail of interleukin (IL)-2/IL-15/IL-21, or (iii) IL-2/IL-7. Supernatants were tested for interferon gamma (IFN-γ) production, after which univariate and multivariate analyses (Cox stepwise regression model) were performed to identify independent clinical and immunological factors associated with patient survival. Patients were followed-up for at least 500 days after surgery or until death.

Findings

Univariate analysis identified age, gender, radiotherapy and mutational load as clinical parameters affecting survival of patients with brain metastases. Cox multivariate analysis showed that radiotherapy (P = 0·004), age (P = 0·029) and IFN-γ responses to mature mesothelin, conditioned by IL-2/IL-7 (P = 0·045) were independent predictors of the survival of patients from surgery up to follow-up or death.

Interpretation

This is the first evidence that immune responses to mesothelin serve as a marker of increased overall survival in patients with brain metastases, regardless of the primary tumor origin. Analyses of immunological markers could potentially serve as prognostic markers in patients with brain metastases and help to select patients in need for adjunct, immunological, treatment strategies.

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Mesothelin-specific cellular immune responses (CIR) can be detected in the blood of patients with brain metastases

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This response can be amplified using cytokine cocktails i.e. interleukin (IL) 2 & IL-7 or IL-2, IL- 15 & IL-21

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Mesothelin epitope-specific CIR can predict survival of patients with brain metastases, with implications for immunotherapy

Mesothelin expression, its role in metastasis, and its immunodiagnostic potential in several hard-to-treat solid tumors has been described. The present study shows that mesothelin-directed peripheral cellular immune responses can be detected in patients with brain metastases, and furthermore, may influence their survival, underlining that the host’s ‘immunological fitness’ is vital to control transformed cells. T cells recognizing mesothelin epitopes may be developed for immunotherapy of patients with brain metastases lacking anti-mesothelin responses. The current study also warrants the discovery of other biologically and clinically relevant cellular targets in patients with brain metastases, which may provide robust tools for improving healthcare decisions, complementing surgery and radiotherapy.

Rectal mobilization: the place of Denonvilliers' fascia and inconsistencies in the literature

Confusion remains as to what is meant by Denonvilliers' fascia. This review searched the literature on pelvic surgical anatomy to determine whether there is agreement with Denonvilliers' original description and its implication in defining the correct anterior plane of dissection when mobilizing the rectum. The original French description of the fascia was translated into English and then compared both with French and with English studies identified by searching PubMed, Medline and Scopus from 1836 to June 2015. Special emphasis was given to the years between 1980 and 2015 in order to capture the literature pertinent to, and following on from, the description of total mesorectal excision for rectal cancer. The final literature search revealed 16 studies from the original 2150 citations. Much of the debate was concerned with the origin and development of the fascia, arising from either the 'fusion' or the 'condensation' of local primitive tissue into a mature 'multilayered' structure. Controversy regarding the correct plane of rectal mobilization occurs as a result of different interpretations by surgeons, anatomists and radiologists and bears little resemblance to Denonvilliers' original description. This may reflect wide anatomical variability in the adult pelvis or a form of dissection artefact. Further study is required to investigate this. Logically, for both men and women, the plane of rectal mobilization should be behind Denonvilliers' fascia and between it and the fascia propria of the rectum.

Root pressure-volume curve traits capture rootstock drought tolerance

BACKGROUND AND AIMS

Living root tissues significantly constrain plant water uptake under drought, but we lack functional traits to feasibly screen diverse plants for variation in the drought responses of these tissues. Water stress causes roots to lose volume and turgor, which are crucial to root structure, hydraulics and growth. Thus, we hypothesized that root pressure-volume (p-v) curve traits, which quantify the effects of water potential on bulk root turgor and volume, would capture differences in rootstock drought tolerance.

METHODS

We used a greenhouse experiment to evaluate relationships between root p-v curve traits and gas exchange, whole-plant hydraulic conductance and biomass under drought for eight grapevine rootstocks that varied widely in drought performance in field trials (101-14, 110R, 420A, 5C, 140-Ru, 1103P, Ramsey and Riparia Gloire), grafted to the same scion variety (Vitis vinifera 'Chardonnay').

KEY RESULTS

The traits varied significantly across rootstocks, and droughted vines significantly reduced root turgor loss point (πtlp), osmotic potential at full hydration (πo) and capacitance (C), indicating that roots became less susceptible to turgor loss and volumetric shrinkage. Rootstocks that retained a greater root volume (i.e. a lower C) also maintained more gas exchange under drought. The rootstocks that previous field trials have classified as drought tolerant exhibited significantly lower πtlp, πo and C values in well-watered conditions, but significantly higher πo and πtlp values under water stress, than the varieties classified as drought sensitive.

CONCLUSIONS

These findings suggest that acclimation in root p-v curve traits improves gas exchange in persistently dry conditions, potentially through impacts on root hydraulics or root to shoot chemical signalling. However, retaining turgor and volume in previously unstressed roots, as these roots deplete wet soil to moderately negative water potentials, could be more important to drought performance in the deep, highly heterogenous rooting zones which grapevines develop under field conditions.

Adaptive hypofractionated gamma knife radiosurgery for a large brainstem metastasis

Background:

To demonstrate how adaptive hypofractionated radiosurgery by gamma knife (GK) can be successfully utilized to treat a large brainstem metastasis - a novel approach to a challenging clinical situation.

Case Description:

A 42-year-old woman, diagnosed with metastatic nonsmall cell lung cancer in July 2011, initially treated with chemotherapy and tyrosine kinase inhibitors, developed multiple brain metastases March 2013, with subsequent whole brain radiotherapy, after which a magnetic resonance imaging (MRI) showed a significant volume regression of all brain metastases. A follow-up MRI in October 2013 revealed a growing brainstem lesion of 26 mm. Linear accelerator-based radiotherapy and microsurgery were judged contraindicated, why the decision was made to treat the patient with three separate radiosurgical sessions during the course of 1 week, with an 18% tumor volume reduction demonstrated after the last treatment. Follow-up MRI 2.5 months after her radiosurgical treatment showed a tumor volume reduction of 67% compared to the 1^st day of treatment. Later on, the patient developed a radiation-induced perilesional edema although without major clinical implications. An MRI at 12 months and 18-fluoro-deoxyglucose positron emission tomography of the brain at 13 months showed decreased edema with no signs of tumor recurrence. Despite disease progression during the last months of her life, the patient's condition remained overall acceptable.

Conclusion:

GK-based stereotactic adaptive hypofractionation proved to be effective to achieve tumor control while limiting local adverse reactions. This surgical modality should be considered when managing larger brain lesions in critical areas.