Dispersion Relations Alone Cannot Guarantee Causality

We show that linear superpositions of plane waves involving a single-valued, covariantly stable dispersion relation ω(k) always propagate outside the light cone unless ω(k)=a+bk. This implies that there is no notion of causality for individual dispersion relations since no mathematical condition on the function ω(k) (such as the front velocity or the asymptotic group velocity conditions) can serve as a sufficient condition for subluminal propagation in dispersive media. Instead, causality can only emerge from a careful cancellation that occurs when one superimposes all the excitation branches of a physical model. This happens automatically in local theories of matter that are covariantly stable. Hence, we find that the need for nonhydrodynamic modes in relativistic fluid mechanics is analogous to the need for antiparticles in relativistic quantum mechanics.

Synchronous and Metachronous Breast and Ovarian Cancers: Experience from a Single Tertiary Care Cancer Centre in India

Women with either breast cancer (BC) or ovarian cancer (OC) have a 1.5-2 times higher risk of developing the other. Discerning discrete primaries versus metastases from either can be challenging. Clinico-pathological and outcome details of patients diagnosed with both BC and OC from December 1994 to August 2018 were retrospectively evaluated at a single tertiary cancer centre. We report the pattern of presentation and recurrences with case-based illustrations. Out of 139 patients, presentation was BC-first in 66.2%, OC-first in 24.5% and synchronous cancers (SC) in 9.3% of women. The median age at diagnosis in BC-first, OC-first and SC was 42 years, 48 years and 49 years, respectively. The most common histological subtype was invasive breast carcinoma-no special type (74.8%) in BC and serous cystadenocarcinoma (81.3%) in OC. BC presented at an early stage in 67.6% while OC presented at an advanced stage in 48.2% of patients. Germline mutation results were available in 82% with 61.4% of the cohort exhibiting a mutation- BRCA1 mutation being the most common. The median time to development of second cancer was 77.4 months and 39.4 months in BC-first and OC-first, respectively. At a median follow-up of 9.47 years, disease-free survival was 32.6%, 32.4% and 30.8% in BC-first, OC-first and SC, respectively (p < 0.001). In hereditary breast and ovarian cancer, BC-first patients have a better prognosis while synchronous malignancies have worse oncological outcomes. Deaths are mainly due to OC progression. Appropriate surveillance and prophylactic intervention in young patients with breast cancer may improve overall outcomes.

Retrospective audit of the yield of internal mammary lymph node dissection and literature review in the management of breast cancer

BACKGROUND

Treatment of lymph node basins is prognostic and therapeutic for axillary lymph nodes (ALN) as well as internal mammary lymph nodes (IMLNs) in breast cancer. IMLNs can be the first echelon node for the inner/central quadrants of the breast. We evaluated the yield of IMLN dissection (IMLND) mainly in patients with inner and central tumors.

METHODS

IMLND was performed in 199 patients between 2000 and 2018, 127 of whom had tumors in the inner/ central quadrants. Clinico-pathological data were retrieved from Electronic Medical Records (EMR).

RESULTS

The median age was 50 (range: 24-81). Primary surgery was performed in 82 (41.2%), while 117 (58.8%) were operated post-chemotherapy. Overall, 124/199 (62.3%) had nodes identified in the specimen, more often in primary (61/82, 74.4%) than post-chemotherapy settings (63/117, 53.8%) (P = 0.003). A median of 1 (average: 1.24, range: 0-7) lymph nodes was dissected, and 1 (average: 1.5, range: 1-4) was involved. IMLN was positive in 46/199 (23.1%) patients, not significantly different in primary (21/82, 25.6%) versus post-chemotherapy (25/117, 21.4%) settings (P = 0.545). IMLN was involved in 44.8% of patients with ≥4 involved ALN and 8.2% with uninvolved ALN (P < 0.001). In the absence of ALN involvement and <2cm pT size, 9% of patients had positive IMLN in inner/central quadrant tumors. In univariate analysis, ALN positivity (P < 0.001), pT size (P = 0.023), and grade (P = 0.041) in primary and ALN involvement (P = 0.011) in post-chemotherapy patients were associated with IMLN involvement. On logistic regression, tumor size (OR: 13.914, P = 0.017) and ALN involvement (OR: 11.400, P = 0.005) in primary surgery and ALN involvement (OR: 7.294, P = 0.003) in post-chemotherapy patients correlated with IMLN involvement.

CONCLUSIONS

In inner/central quadrant tumors, IMLN is more likely involved with high ALN burden and tumor size >2 cm, whereas those with ≤2cm inner/central quadrant tumors and negative ALN have <10% probability of IMLN involvement.

Determinants of pathological complete response to neoadjuvant chemotherapy in breast cancer: A single-institution experience

Background

Neoadjuvant chemotherapy (NACT) is routinely used in all cases of locally advanced breast cancer and some cases of early breast cancer. We previously reported a pathological complete response (pCR) rate of 8.3%. With the increasing use of taxanes and human epidermal growth factor receptor 2 (HER2)-directed NACT, we conducted this study to understand the current pCR rate and its determinants.

Methods

A prospective database of breast cancer patients who underwent NACT followed by surgery between January and December 2017 was evaluated.

Results

Of the 664 patients, 87.7% were cT3/T4, 91.6% were grade III, and 89.8% were node-positive at presentation (54.4% cN1, 35.4% cN2). The median age was 47 years; median pre-NACT clinical tumor size was 5.5 cm. Molecular subclassification was 30.3% hormone receptor positive (HR+) HER2-, 18.4% HR+HER2+, 14.9% HR-HER2+, and 31.6% triple negative (TN). Both anthracyclines and taxanes were given preoperatively in 31.2% patients whereas 58.5% of HER2 positive patients received HER2-targeted NACT. The overall pCR rate was 22.4% (149/664), 9.3% in HR+HER2-, 15.6% in HR+HER2+, 35.4% in HR-HER2+, and 33.4% in TN. On univariate analysis, duration of NACT (P < 0.001), cN stage at presentation (P = 0.022), HR status (P < 0.001), and lymphovascular invasion (P < 0.001) were associated with pCR. On logistic regression, HR negative status (Odds ratio [OR] 3.314, P < 0.001), longer duration of NACT (OR 2.332, P < 0.001), cN2 stage (OR 0.57, P = 0.012), and HER2 negativity (OR 1.583, P = 0.034) were significantly associated with pCR.

Conclusion

Response to chemotherapy depends on molecular subtype and duration of NACT. A low rate of pCR in the HR+ subgroup of patients warrants reconsideration of neoadjuvant strategies.

Heller myotomy versus Heller myotomy with fundoplication in patients with achalasia: a systematic review and meta-analysis

INTRODUCTION

Heller myotomy (HM) remains the gold standard procedure for achalasia. The addition of different types of fundoplication to HM has been debated in several studies. Given the contradictory reports, this meta-analysis was undertaken to compare different outcomes after HM and HM with fundoplication (HMF).

METHODS

An electronic search was performed among five major databases (PubMed, Ovid, Scopus, Cochrane Library, Google Scholar) from inception to October 2019, identifying all randomised and non-randomised studies comparing HM with HMF. Two authors searched electronic databases using the keywords 'achalasia' AND 'dysphagia' AND 'gastroesophageal reflux' and all data were pooled for random-effects meta-analysis. The primary and secondary outcomes were gastroesophageal reflux and dysphagia, respectively.

RESULTS

A total of six studies were included and involved 576 patients comparing HM and HMF. There was no statistically significant difference between gastroesophageal reflux in the HM vs HMF group (21.3% vs 22.9%, RR 1.32, 95% CI 0.60-2.88, p = 0.49). There was a slightly higher incidence of dysphagia observed in HM vs HMF (14.8% vs 10.8%, RR 1.54, 95% CI 0.98-2.41, p = 0.06).

CONCLUSIONS

There was no statistically significant difference in long-term outcomes between a group of patients undergoing HM and a group who underwent HM with fundoplication.

376 Management of Breast Cancer in elderly patients

Aim

To evaluate the care and outcomes for women with breast cancer over the age of 70 and to compare our performance at AUH against the national outcomes.

Method

Using the online database at AUH we gathered the following data: age, TNM status, surgical management, histology, adjuvant treatment (radiotherapy, chemotherapy, hormone therapy, targeted therapy) and reasons for alterations in planned therapy.

Results

We audited 176 patients between 2018 and 2019. Age varied between 70 and 95 years old. 10 patients suffered from DCIS, 152 from invasive breast cancer and 14 from de novo metastatic breast cancer. 40% of patients with DCIS with underwent WLE, 40% underwent mastectomy and 20% were not offered an operation as they were unfit. Invasive breast cancer accounted for the majority of cases. 86% were ER/PR positive and 12.2% were Her-2 positive. 35.7% underwent mastectomy, 64.4% underwent WLE and 0.8% VAB excision. 51.7% had Sentinel node biopsy, 15.3% underwent axillary clearance and 1.7 % had axillary sampling. 7.9% of patients presented with metastatic disease. 2.6% of those patients had palliative radiotherapy. Primary endocrine therapy was commenced on 21.1% of patients. Factors that lead to PET were that 47% of patients were unfit for an operation, 20.6% refused surgical intervention, 11.7% had concurrent aggressive malignancy and 8.8% were inoperable.

Conclusions

Overall, successful results were achieved for this group of patients compared to the national outcomes. 99.4% of patients in our centre had triple assessment prior to MDT. Further review of functional status and service outcomes will be required to be audited.

Sterilization Rate of the Axilla After Neoadjuvant Chemotherapy: The Scope for Conservative Surgery

PURPOSE

The role of axillary conservation after neoadjuvant chemotherapy (NACT) is debatable. We routinely carry out complete axillary lymph node dissection (ALND). This study was conducted to understand the pathologic axillary complete response (pAxCR) after NACT.

MATERIALS AND METHODS

We evaluated a prospective database of patients with breast cancer who underwent surgery after NACT in the year 2017 at our institution. NACT was administered to downstage locally advanced breast cancer or facilitate breast-conservation surgery.

RESULTS

Of 793 patients who underwent surgery after NACT, 97(12.2%) had cN0 disease, 407 (51.3%) had cN1, 262 (32%) had cN2, and 27 (3.4%) had cN3 at presentation. Eighty-eight patients (11.1%) had cT1-2 primary tumor stage, and 623 patients (78.6%) had cT3-4 primary tumor stage; primary tumor stage details were unavailable for 82 patients (10.3%). The median age was 46 years (range, 21-74 years). On histopathology, the overall pAxCR rate was 52.8%. In the cN1 and cN2 settings, 58.7% and 36.6% of patients achieved ypN0 status, respectively. The overall pathologic complete response rate was 22.64% (161 of 711 patients). On univariable analysis, cN stage, histologic grade, hormone receptor status, NACT duration, and lymphovascular invasion were significantly associated with pAxCR (P <.001). On logistic regression, prechemotherapy cN status (odds ratio [OR], 3.08; 95% CI, 2.18 to 4.37; P <.001), estrogen and progesterone receptor status (OR, 0.34; 95% CI, 0.3 to 0.4; P <.001), and administration of both chemotherapy regimens preoperatively (OR, 0.66; 95% CI, 0.45 to 0.97; P <.05) predicted pAxCR.

CONCLUSION

At least half of patients with cN1 and a third of patients with cN2 breast cancer who develop pAxCR may be suitable candidates for axillary conservation. A careful postchemotherapy assessment followed by a conservative axillary procedure may be an alternative to ALND, but this needs to be studied prospectively.

Blood testis barrier revisited-Analysis of post-chemotherapy germ cell tumor orchidectomy and retroperitoneal lymph node dissection specimens

OBJECTIVE

To assess the response of chemotherapy on the primary tumor, compare it with the response in retroperitoneal disease, and study factors associated with pathological complete response.

METHODS

We conducted a retrospective audit of all high inguinal orchidectomies (HIOs) performed after chemotherapy between 2012 and 2019 at a tertiary cancer center in India. Patient characteristics and histopathological response were extracted from electronic medical records, and predictors of testicular disease response were assessed.

RESULTS

Of the 260 retroperitoneal lymph node dissections (RPLNDs) performed in the study period, 37 HIOs (14.23%) were carried out after chemotherapy. The median age of presentation was 28 years (16-41). Histopathology was divided into a viable tumor, mature teratoma, and necrosis/scarring. Residual disease was seen in 17 RPLND (46.0%) and 18 HIO (48.6%) specimens respectively. Of these 18, three patients had a residual viable tumor in the testis, and the remaining had a mature teratoma. Clinico-radiological assessment showed an average reduction of 61% in testicular disease size following chemotherapy. On orchidectomy histopathological assessment, the median tumor size was 9, 4, and 1.5 cm in specimens with a viable tumor, mature teratoma, and necrosis/scarring, respectively.

CONCLUSIONS

A low threshold for upfront chemotherapy in patients with a high disease burden may be considered as tumors within the testis respond to chemotherapy in more than half of the patients. Discordance rates of residual cancer in RPLND and HIO specimens exist but post-chemotherapy tumor size in testis correlates with the presence of a residual viable tumor.

Oncology Residency-a Burning Issue, Results of a Questionnaire-Based Survey on Psychological Well-being of Oncology Residents

Residency, in particular oncology residency, is a challenging time with extensive academic demands, long working hours, and uncertainty about the future. Our study aimed to evaluate the prevalence and factors associated with burnout, anxiety and depression among oncology residents at a tertiary cancer centre. An anonymised questionnaire-based study was conducted among medical, surgical, paediatric and radiation oncology resident doctors at a tertiary cancer centre in April 2019. We used Copenhagen Burnout Index (CBI) to assess burnout (which includes personal, work-related and patient-related burnout), Patient Health Questionnaire (PHQ9) for depression and Generalised Anxiety Disorder (GAD7) for anxiety. The questionnaire was served to 201 residents. The overall response rate was 70.6%. High personal, work-related and patient-related burnout was identified in 71.1%, 67.6% and 23.2% of the respondents respectively. Medical oncology residents had the highest rate of personal and work-related burnout (95% and 85%) while head and neck oncology residents had the highest rate of patient-related burnout (33.3%). 27.5% of participants were found to have high levels of anxiety on the GAD7 while 14.8% of participants were detected to have a high score on the PHQ9 for depression. High personal burnout and work-related burnout were associated with both high anxiety and depression scores (p < 0.05). There is a high prevalence of burnout, depression and anxiety among oncology residents. With an expected rise in cancer burden in the next decade, psychological issues in caregivers can be expected to increase. Further studies will be needed to determine interventions to reduce psychological distress.

Merits of Level III Axillary Dissection in Node-Positive Breast Cancer: A Prospective, Single-Institution Study From India

PURPOSE

A complete axillary lymph node (ALN) dissection is therapeutic in node-positive breast cancer. Presently, there is no international consensus regarding anatomic levels to be addressed in complete axillary dissection. We assessed the burden of disease in level III axilla.

MATERIALS AND METHODS

A prospectively maintained database was assessed for 1,591 consecutive patients with nonmetastatic breast cancer registered at Tata Memorial Center, Mumbai, between January 2009 and December 2014.

RESULTS

A median of four (zero to 20) level III ALNs were dissected and a median of two (one to 17) nodes were positive. A total of 27.3% (434 of 1,591) patients had level III ALN metastasis, and 4.7% of patients had positive interpectoral nodes. Some 53.2% of patients had level III metastases in the presence of four or more positive level I and II ALNs. A total of 9.4% of patients had level III involvement when one to three ALNs were positive in level I and II ( P < .001). Some 53.2% of patients had level III metastases in the presence of four or more positive level I and II ALNs. On logistic regression analysis, four or more positive ALNs in level I or II ( P < .001), inner/central quadrant tumor location ( P = .013), and perinodal extension ( P < .001) were associated with level III ALN involvement. At a median follow-up of 36 months, the disease-free survival was significantly worse for level III ALN metastases on univariate analysis ( P < .001). On multivariate Cox regression analysis, histologic grade ( P = .006), four or more positive ALNs ( P < .001), hormone receptor status ( P < .001), and tumor size ( P = .037) were independent prognostic factors for disease-free survival.

CONCLUSION

The axillary nodal burden is high in patients with breast cancer in developing countries like India. One of two women with four or more positive level I and II ALNs may have residual disease in level III if it is not cleared during surgery. Intraoperative interpectoral space clearance should be considered in the presence of either palpable interpectoral lymph nodes or multiple positive ALNs.

Management of clinically node-negative groin in patients with penile cancer

Malignant penile neoplasms are commonly squamous etiology, with the inguinal nodes being the first echelon of spread. The disease spreads to the pelvic lymph nodes only after metastases to the groin nodes, and this is the most important prognostic factor in penile carcinoma. While treatment of penile carcinoma with proven metastases to the inguinal lymph nodes mandates ilioinguinal lymph node dissection, the treatment of patients with impalpable nodes is more controversial. Overtreatment leads to excessive treatment-related morbidity in these patients, while a wait-and-see policy runs the risk of patients presenting with inguinal and distant metastases, which would have been curable at presentation. Unfortunately, no single imaging modality has been proved to be convincingly superior in the staging, and hence, management of the clinically negative groin has been subject to debate. While some high volume centers have promoted the use of dynamic sentinel lymph node biopsy, others advocate the use of the modified inguinal lymph node template to stage the groin adequately. Newer techniques such as video endoscopic inguinal lymph node dissection have been introduced as an alternative to the original radical inguinal lymphadenectomy to reduce morbidity.

Características relevantes das instalações e da gestão de abrigos públicos de animais no estado do Paraná, Brasil, para o bem-estar animal

RESUMO Animais podem ser eventualmente recolhidos em abrigos públicos no Brasil e o ambiente de alojamento afeta diretamente sua qualidade de vida. Este trabalho estudou características relevantes das instalações físicas e da gestão dos estabelecimentos vinculados ao poder público municipal que abrigam cães, gatos e cavalos no estado do Paraná. Foram registrados 17 municípios com 20 abrigos, dos quais 18 participaram da pesquisa. Todos os municípios mantinham cães, sete (41,2%) mantinham gatos e oito (47,1%) mantinham cavalos. Todos os abrigos apresentavam recintos coletivos; dois (11,8%) de cães e cinco (71,5%) de gatos mantinham um animal por recinto; quatro (22,2%) mantinham recintos sem visualização além do próprio recinto; 11 (64,7%) realizavam limpeza adequadamente; cinco (29,4%) abrigos de cães e um (14,3%) de gatos não tinham área para quarentena ou isolamento sanitário; camas estavam disponíveis em 15 (88,2%), cinco (71,4%) e um (12,5%) dos recintos de cães, gatos e cavalos, respectivamente. Os abrigos de animais no Paraná devem banir recintos de isolamento social, incluir uma cama por animal e socializar os animais. Adicionalmente, há oportunidade de aumentar o grau de bem-estar animal por meio de melhorias no manejo dos animais e no manejo sanitário, as quais não dependem de reformas nas instalações.

Laparotomy for blunt abdominal trauma-some uncommon indications

Trauma laparotomy after blunt abdominal trauma is conventionally indicated for patients with features of hemodynamic instability and peritonitis to achieve control of hemorrhage and control of spillage. In addition, surgery is clearly indicated for the repair of posttraumatic diaphragmatic injury with herniation. Some other indications for laparotomy have been presented and discussed. Five patients with blunt abdominal injury who underwent laparotomy for nonroutine indications have been presented. These patients were hemodynamically stable and had no overt signs of peritonitis. Three patients had solid organ (spleen, kidney) infarction due to posttraumatic occlusion of the blood supply. One patient had mesenteric tear with internal herniation of bowel loops causing intestinal obstruction. One patient underwent surgery for traumatic abdominal wall hernia. In addition to standard indications for surgery in blunt abdominal trauma, laparotomy may be needed for vascular thrombosis of end arteries supplying solid organs, internal or external herniation through a mesenteric tear or anterior abdominal wall musculature, respectively.

Analytic Solution of the Boltzmann Equation in an Expanding System

For a massless gas with a constant cross section in a homogeneous, isotropically expanding spacetime we reformulate the relativistic Boltzmann equation as a set of nonlinear coupled moment equations. For a particular initial condition this set can be solved exactly, yielding the first analytical solution of the Boltzmann equation for an expanding system. The nonequilibrium behavior of this relativistic gas can be mapped onto that of a homogeneous, static nonrelativistic gas of Maxwell molecules.

Survey of paediatric case management practices in Australia for children and young people with acquired brain injury (ABI)

AIM

To investigate the characteristics of paediatric acquired brain injury (ABI) case managers and their organizations in Australia, and to determine the ways in which case managers deliver their service, maintain professional development and evaluate outcomes.

METHODS

Postal survey of 57 known paediatric ABI case managers working at 24 separate organizations in Australia.

RESULTS

Out of 40 questionnaires returned (70%), the majority of respondents had been providing case management for over 5 years (55%). Co-ordination of services was ranked the most important component of case management, with services most frequently delivered by telephone. Evaluation of case management outcomes was reported by only 52% of the case managers. Whilst the majority of case managers had received some form of training (83%), this varied widely from informal in-house training, to workshops run by insurance companies and government agencies.

DISCUSSION

This survey provides information about current case management practices for children with ABI in Australia. Detailing what case managers do is a first step towards developing controlled research designs which are required to demonstrate whether case management is effective in terms of clinical outcomes and cost-benefit.

Co-packaging of sense and antisense RNAs: a novel strategy for blocking HIV-1 replication

Retroviral vectors were engineered to express either sense (MoTiN-TRPsie+) or sense and antisense (MoTN-TRPsie+/-) RNAs containing the human immunodeficiency virus type-1 (HIV-1) trans -activation response (TAR) element and the extended packaging (Psie) signal. The Psie signal includes the dimer linkage structure (DLS) and the Rev response element (RRE). Amphotropic vector particles were used to transduce a human CD4+ T-lymphoid (MT4) cell line. Stable transductants were then tested for sense and antisense RNA production and susceptibility to HIV-1 infection. HIV-1 production was significantly decreased in cells transduced with MoTiN-TRPsie+ and MoTN-TRPsie+/-vectors. Efficient packaging of sense and most remarkably of antisense RNA was observed within the virus progeny. Infectivity of this virus was significantly decreased in both cases, suggesting that the interfering RNAs were co-packaged with HIV-1 RNA. Vector transduction was not expected to occur and was not observed. Inhibition of HIV-1 replication was also demonstrated in human peripheral blood lymphocytes transduced with retroviral vectors expressing antisense RNA. These results suggest that (i) both sense and antisense RNAs were co-packaged with HIV-1 RNA, (ii) the co-packaged sense and antisense RNAs inhibited virus infectivity and (iii) the co-packaged sense and antisense RNAs were not transduced. Sense and antisense RNA-based strategies may also be used to co-package other interfering RNAs (e.g. ribozymes) to cleave HIV-1 virion RNA.

A critical analysis of mathematical procedures for the evaluation and design of in-container thermal processes for foods

Kinetic data on thermal destruction of spoilage and quality factors coupled with the temperature history of a product during a heat sterilization cycle are the basic information needed for the evaluation and the design of thermal processes through a physical-mathematical approach. A critical review on the available physical-mathematical procedures used for thermal process calculations of in-container processed foods is presented. The origin and the limitations of each method are discussed. The equations associated with each method, for internal product temperature predictions, are explicitly given. The relative performance of selected methods under identical processing conditions is illustrated. Several problems associated with thermal process calculations are discussed.

Evaluation of the integrated time-temperature effect in thermal processing of foods

In this review, current methods used to evaluate the integrated impact of time and temperature upon preserving a food product by a heat treatment are considered. After identifying the basic premise any preservation scheme shall meet, the central role of a feasible description for the heat activation kinetics of microorganisms, their spores, and other quality attributes are stressed. Common concepts to quantify a thermal process are presented. Shortcomings of the prevalent evaluation methods are highlighted and attention is given to the development, restrictions, and possibilities of time-temperature-integrators as "new" evaluation tools to measure the impact of a "classical" in-pack heat treatment and more modern heating techniques such as continuous processing of solid/liquid mixtures on foods.

A quantitative method for measuring regional in vivo fatty-acid incorporation into and turnover within brain phospholipids: review and critical analysis

An experimental method and its associated mathematical model are described to quantitate in vivo incorporation rates into and turnovers of fatty acids (FAs) within stable brain metabolic compartments, particularly phospholipids. A radiolabeled FA is injected i.v. in a rat, and arterial plasma unacylated FA radioactivities and unlabeled concentrations are sampled until the animal is killed after 15 min, when the brain is analyzed biochemically or with quantitative autoradiography. Unbound unacylated label in blood easily crosses the blood-brain barrier; rapidly equilibrates in the unacylated FA, acyl-CoA and phosphatidate-diacylglycerol brain pools; then is incorporated into phospholipids and other stable metabolic compartments. Uptake and incorporation of labeled FAs are independent of cerebral blood flow at constant brain blood volume. Different labeled FAs enter specific sn positions of different brain phospholipids, suggesting that a combination of probes can be used to investigate metabolism of these phospholipids. Thus, [9,10-3-H]palmitate preferentially labels the sn1 position of phosphatidylcholine; [1-14C]arachidonate the sn2 positions of phosphatidylinositol and phosphatidylcholine; and [1-14C]docosahexaenoate the sn2 positions of phosphatidylethanolamine and phosphatidylcholine. The FA model provides an operational equation for rates of incorporation of FAs into brain phospholipids, taking into account intracerebral recycling and de novo synthesis of the FA, as well as entry into brain of FA from acylated blood sources. The equation is essentially independent of specific details of the proposed model, and can be used to calculate turnovers and half-lives of FAs within different phospholipid classes. For the model to be most applicable, experiments should satisfy conditions for pulse-labeling of the phospholipids, with brain sampling times short enough to minimize exchange of label between stable metabolic compartments. A 15-20 min sampling time satisfies these criteria. The FA method has been used to elucidate the dynamics of brain phospholipids metabolism in relation to brain development, brain tumor, chronically reduced auditory input, transient ischemic insult, axotomy with and without nerve regeneration, and cholinergic stimulation in animals with or without a chronic unilateral lesion of the nucleus basalis magnocellularis.

The effect of positioning on the hand function of boys with cerebral palsy

The effect of positioning (sitting and prone standing) on the hand function of 10 boys (mean age = 12.5 years, SD = 1.2 years) with spastic diplegic cerebral palsy was studied. Two groups of subjects were tested twice (Tests 1 and 2) with the Jebsen-Taylor Hand Function Test (Jebsen, Taylor, Treischmann, Trotter, & Howard, 1969; Taylor, Sand, & Jebsen, 1973) to measure rate of manipulation. In addition, a scale modified from Hohlstein (1982) was used to measure quality of grasp on each subtest of the Jebsen-Taylor test. No significant differences between the mean scores of the two groups were found on the total scores of the Jebsen-Taylor test, either between Tests 1 and 2 or between sitting and prone standing. When the data from Tests 1 and 2 were combined, it was found that on one subtest--simulated feeding--the subjects performed significantly faster while in a prone standing position. On another subtest--picking up small objects--the subjects performed significantly faster while in a sitting position. Except during the simulated feeding subtest, the quality of the subjects' grasp was observed to be mature and tailored to the objects manipulated. This paper presents considerations for analyzing positioning in relation to upper extremity tasks.

Bilateral adrenal myelolipomas with Cushing's syndrome

A 24-year-old woman with non-pituitary dependent Cushing's syndrome was found to have bilateral adrenal myelolipomas at surgery. These benign tumors consist of bone marrow and fat and are uncommon incidental findings that are discovered by computed tomography. Myelolipomas have rarely been associated with Cushing's syndrome, but the cause of the syndrome has not always been defined, because the reports preceded modern diagnostic methods. Careful examination of the adrenal glands from our patient showed a fusion of myelolipoma elements and adrenal cells without distinct adenomas or the typical nodular pattern of adrenal hyperplasia. This report suggests that adrenal myelolipomas and atypical hyperplasia of the zona fasciculata may be anatomically and functionally related.