Effect of neoadjuvant chemoradiation on preoperative pulmonary physiology, postoperative respiratory complications and quality of life in patients with oesophageal cancer.

BACKGROUND: It remains controversial whether neoadjuvant chemoradiation (nCRT) for oesophageal cancer influences operative morbidity, in particular pulmonary, and quality of life. This study combined clinical outcome data with systematic evaluation of pulmonary physiology to determine the impact of nCRT on pulmonary physiology and clinical outcomes in locally advanced oesophageal cancer. METHODS: Consecutive patients treated between 2010 and 2016 were included. Three-dimensional conformal radiation was standard, with a lung dose-volume histogram of V20 less than 25 per cent, and total radiation between 40 and 41·4 Gy. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and diffusion capacity for carbon monoxide (DLCO) were assessed at baseline and 1 month after nCRT. Radiation-induced lung injury (grade 2 or greater), comprehensive complications index (CCI) and pulmonary complications were monitored prospectively. Health-related quality of life was assessed among disease-free patients in survivorship. RESULTS: Some 228 patients were studied. Comparing pulmonary physiology values before with those after nCRT, FEV1 decreased from mean(s.d.) 96·8(17·7) to 91·5(20·4) per cent (-3·6(10·6) per cent; P < 0·001), FVC from 104·9(15·6) to 98·1(19·8) per cent (-3·2(11·9) per cent; P = 0·005) and DLCO from 97·6(20·7) to 82·2(20·4) per cent (-14·8(14·0) per cent; P < 0·001). Five patients (2·2 per cent) developed radiation-induced lung injury precluding surgical resection. Smoking (P = 0·005) and increased age (P < 0·001) independently predicted percentage change in DLCO. Carboplatin and paclitaxel with 41·4 Gy resulted in a greater DLCO decline than cisplatin and 5-fluorouracil with 40 Gy (P = 0·001). On multivariable analysis, post-treatment DLCO predicted CCI (P = 0·006), respiratory failure (P = 0·020) and reduced physical function in survivorship (P = 0·047). CONCLUSION: These data indicate that modern nCRT alters pulmonary physiology, in particular diffusion capacity, which is linked to short- and longer-term clinical consequences, highlighting a potentially modifiable index of risk.

ANTECEDENTES: El tema de si en el cáncer de esófago la quimiorradioterapia neoadyuvante (neoadjuvant chemoradiation, nCRT) repercute sobre la morbilidad postoperatoria, especialmente sobre la morbilidad pulmonar y la calidad de vida de los pacientes que sobreviven sigue siendo controvertido. Este estudio combina datos sobre resultados clínicos con una evaluación sistemática de la fisiología pulmonar para determinar el impacto de la nCRT sobre la fisiología pulmonar y los resultados clínicos en el cáncer de esófago localmente avanzado. MÉTODOS: Se incluyeron pacientes consecutivos tratados entre 2010-2016. La radioterapia conformal 3D fue la estándar, con un histograma dosis-volumen del pulmón V20 < 25% y radiación entre 40-41,4 Gy. Se evaluaron el volumen espiratorio forzado (forced expiratory volume, FEV1), la capacidad vital forzada (forced vital capacity, FVC) y la capacidad de difusión del monóxido de carbono (diffusion capacity for carbon monoxide, DLCO) al inicio y un mes tras la nCRT. La lesión pulmonar inducida por la radioterapia (EORTC grado ≥ 2), el índice de complicaciones integral (comprehensive complications index, CCI), grado de Clavien-Dindo, y complicaciones pulmonares fueron analizadas de manera prospectiva. Se evaluó la calidad de vida relacionada con la salud entre los pacientes supervivientes libres de enfermedad (EORTC QLQ-C30, OG25, OES18). RESULTADOS: Se estudiaron un total de 228 pacientes. Al comparar los valores de la fisiología pulmonar antes y después de la nCRT respectivamente, la FEV1 disminuyó de 96,8 ± 17,7% a 91,5 ± 20,4% (-3,6 ± 10,6%, P = 0,0002), la FVC de 104,9 ± 15,6 a 98,1 ± 19,8% (-3,2 ± 11,9%, P = 0,005) y la DLCO de 97,6 ± 20,7 a 82,2 ± 20,4% (-14,8 ± 14,0%, P < 0,0001). Cinco pacientes (2,2%) desarrollaron lesión pulmonar relacionada con la radioterapia impidiendo la resección quirúrgica. Los factores predictores independientes de %ΔDLCO fueron el hábito tabáquico (P = 0,005) y la edad avanzada (P < 0,001). El tratamiento con carboplatino/paclitaxel/41,4Gy determinó un mayor descenso de la DLCO en comparación con cisplatino/5-fluorouracilo/40Gy (P = 0,001). En el análisis multivariable, la DLCO tras el tratamiento fue una variable predictora de CCI (P = 0,006), fracaso respiratorio/intubación prolongada (P = 0,020) y reducción de la función física en los supervivientes (P = 0,047). CONCLUSIÓN: Estos datos indican que la moderna nCRT altera la fisiología pulmonar, especialmente la difusión pulmonar, con consecuencias clínicas a corto y largo plazo. La DLCO podría constituir un factor de riesgo potencialmente modificable.

Measuring the impact of oesophagectomy on physical functioning and physical activity participation: a prospective study.

BACKGROUND: Oesophagectomy remains the only curative intervention for oesophageal cancer, with defined nutritional and health-related quality of life (HR-QOL) consequences. It follows therefore that there is a significant risk of decline in physical wellbeing with oesophagectomy however this has been inadequately quantified. This study prospectively examines change in physical functioning and habitual physical activity participation, from pre-surgery through 6-months post-oesophagectomy. METHODS: Patients scheduled for oesophagectomy with curative intent were recruited. Key domains of physical functioning including exercise tolerance (six-minute walk test (6MWT)) and muscle strength (hand-grip strength), and habitual physical activity participation, including sedentary behaviour (accelerometry) were measured pre-surgery (T0) and repeated at 1-month (T1) and 6-months (T2) post-surgery. HR-QOL was measured using the EORTC-QOL C30. RESULTS: Thirty-six participants were studied (mean age 62.4 (8.8) years, n = 26 male, n = 26 transthoracic oesophagectomy). Mean 6MWT distance decreased significantly from T0 to T1 (p = 0.006) and returned to T0 levels between T1 and T2 (p < 0.001). Percentage time spent sedentary increased throughout recovery (p < 0.001) and remained significantly higher at T2 in comparison to T0 (p = 0.003). In contrast, percentage time spent engaged in either light or moderate-to-vigorous intensity activity, all reduced significantly (p < 0.001 for both) and remained significantly lower at T2 in comparison to T0 (p = 0.009 and p = 0.01 respectively). Patients reported deficits in multiple domains of HR-QOL during recovery including global health status (p = 0.04), physical functioning (p < 0.001) and role functioning (p < 0.001). Role functioning remained a clinically important 33-points lower than pre-operative values at T2. CONCLUSION: Habitual physical activity participation remains significantly impaired at 6-months post-oesophagectomy. Physical activity is a measurable and modifiable target for physical rehabilitation, which is closely aligned with patient-reported deficits in role functioning. Rehabilitation aimed at optimising physical health in oesophageal cancer survivorship is warranted.

Exercise Rehabilitation Services Provided by Physiotherapy Departments in Cancer Care in Ireland

Aims This study aimed to identify the physiotherapy exercise rehabilitation services available to patients with cancer in Ireland and to identify barriers to the provision of services. Methods Physiotherapy department managers in specialised cancer centres, public and private hospitals and palliative care settings were surveyed to establish the availability of exercise rehabilitation services for patients with cancer. Results Of 40 managers contacted, 24 responded providing information about 26 services. Ten services employed a dedicated oncology physiotherapist. Exercise classes were offered to patients with cancer by five services, primarily within the palliative care setting. In the 17 hospitals which provided surgery, ten provided oncology specific post-operative exercise rehabilitation and one offered a prehabilitation programme. Limited human and physical resources and absence of established physiotherapy pathways were cited barriers to service provision. Conclusion Exercise rehabilitation is not an element of standard care for patients with cancer in Ireland.

Current practice in the treatment of AO type 31-A2 hip fractures: does sub-specialty and experience of surgeon determine type of fixation?

BACKGROUND: Debate surrounds the optimal treatment of AO type 31-A2 fractures of the hip. Two principal treatment modalities are the compression hip screw (CHS) and cephallomedullary device (CMD). The use of CMD's is steadily increasing, for fixation of this fracture type, despite a lack of supportive evidence. METHODS AND MATERIALS: 100 trauma consultants were asked for their opinion towards treatment of an AO type 31-A2 fracture. Subspecialty and length of time in post were also recorded. RESULTS: A significant proportion of consultants opted to use a CMD. Consultants who had been in post for a shorter time, and those in specialties other than lower limb were more likely to use a CMD. DISCUSSION: NICE guidelines suggest CHS for AO type 31-A2 fractures. CONCLUSION: CMD accounts for a large percentage of treatment in our study, despite NICE guidelines, and other studies suggest their use is rising. We suggest there is a trend of less experienced consultants, and consultants whose specialties are those other than lower limb, using CMD more often. This may be creating an increased cost burden to the NHS, with no evidence to support their use.

The Rib Vertebra Angle Difference and its Measurement in 3D for the evaluation of early onset scoliosis.

The Rib Vertebra Angle Difference (RVAD) as defined by Mehta (1972) is used to predict the progression of early onset scoliosis. No clear physical significance has been established for this measurement. The purpose of this study was to evaluate the RVAD along the thoracic spine and the equivalent measurement on 3D reconstructions of the spine and rib cage of early onset scoliosis patients in order to determine their relationship with the geometry of the chest wall and evolution along the spine. The RVAD was measured on PA radiographs of 42 infantile scoliotic patients (Cobb >20°) from T4 to T10 according to the method described by Mehta. The RVAD 3D was computed using the same landmarks from the 3D reconstruction generated from the calibrated biplanar radiographs. Cases were divided into Phase I and Phase II using Mehta's classification based on the rib head overlap with the apical vertebral body on coronal plane radiographs. A linear relationship exists between the Metha (2D) and 3D RVAD for both Phase I (r = 0.87) and Phase II (r = 0.78) patients. For more severe deformities (RVAD 3D ≥ 35°), a relationship was found between RVAD 3D and the axial rotation of the thoracic vertebrae (r = 0.51) in Phase II patients. However, no significant relationship exists between axial rotation and RVAD 3D for Phase I patients as well as Mehta's RVAD. Maximal RVAD measurements were located 2 &frac12; levels above the apical vertebra. Results indicated that RVAD 3D provides additional information to Mehta's RVAD on the torsional nature of the deformity. Considering the importance of clinical indices to assess the progression of early onset scoliosis, this study raises some questions on looking solely at the RVAD measured on radiographs at the apical vertebra of Phase I patients and suggests considering also levels above the apex of the scoliotic curve and 3D measurements. Further investigation is required to fully understand the 3D nature of the spine and rib cage deformities.

Increasing rates of cervical cancer in young women in England: an analysis of national data 1982-2006.

BACKGROUND: In England, cervical cancer is the second most common cancer in women aged under 35 years. Overall incidence of cervical cancer has decreased since the introduction of the national screening programme in 1988 but recent trends of incidence in young women have not been studied in detail. METHODS: Information on 71,511 incident cases of cervical cancer in England, 1982-2006, in 20-79-year-olds was extracted from a national cancer registration database. Changes in incidence were analysed by age group, time period and birth cohort. Poisson regression was used to estimate annual percentage change (APC). RESULTS: Overall incidence, during 1982-2006, fell significantly from 213 to 112 per million person years. However, in 20-29-year-olds, after an initial fall, incidence increased significantly during 1992-2006, (APC 2.16). In 30-39-year-olds incidence stabilised during the latter part of the study period. The pattern was most marked in the North East, Yorkshire and the Humber and East Midlands regions. Birth cohorts that were initially called for screening between 60-64 and 35-39 years of age show an incidence peak soon after the age of presumed first screen, whereas younger birth cohorts show a peak at about 35 years of age. Incidence in the 1977-1981 birth cohort has increased relative to that among women born between 1962 and 1976. CONCLUSION: These results have implications for cervical screening, human papilloma virus vaccination and other public health interventions targeting young people.

University students' notebook computer use: lessons learned using e-diaries to report musculoskeletal discomfort.

The objective of this pilot study was to identify if notebook accessories (ergonomic chair, desktop monitor and notebook riser) combined with a wireless keyboard, mouse and participatory ergonomics training would have the greatest impact on reducing self-reported upper extremity musculoskeletal discomfort in university students. In addition to pre-post computing and health surveys, the Ecological Momentary Assessment was used to capture change in discomfort over time using a personal digital assistant (PDA) as the e-diary. The PDA was programmed with a survey containing 45 questions. Four groups of university students were randomised to either intervention (three external computer accessories) or to control. Participants reported less discomfort with the ergonomic chair and notebook riser based on the pre-post survey data and the e-diary/PDA ANOVA analysis. However, the PDA data, adjusted for the effect of hours per day of computer use, showed no benefit of the chair and limited benefit from the riser. Statement of Relevance:University students' use of notebook computers has increased. This study found evidence of a positive effect of an adjustable chair or notebook riser when combined with ergonomic training on reducing discomfort. Daily notebook computer use of 4 h was confirmed as a risk factor. Without some form of ergonomic intervention, these students are likely to enter the workforce with poor computing habits, which places them on the road to future injuries as technology continues to play a dominant role in their lives.

Growth characteristics of virus-transformed cells. Maximum population density, inhibition by normal cells, serum requirement, growth in soft agar, and xenogeneic transplantability.

Virus transformants (like cancer cells, cells transformed by X-ray or carcinogens, or those which have transformed spontaneously) exhibit a number of phenotypic changes which are usually associated, and which may be lost concurrently. That association is, however, not invariable. More particularly, the altered characteristics here studied (escape from contact inhibition of growth and susceptibility to inhibition by other cells, decreased serum requirement, and ability to grow in soft agar) do not, in and of themselves, endow the cell with the capacity to produce a tumor, at least as judged by the methods of assay here used. Although the question as to whether the tumorigenicity of virus transformants is causally linked to any of these associated changes cannot be answered definitively, the evidence suggests a close linkage, rather than identity, between the determinants of oncogenicity and the other properties here studied.

Morbidity and mortality after closure of loop ileostomy.

BACKGROUND: A temporary loop ileostomy is commonly used to protect low pelvic anastomoses. Closure is associated with morbidity and mortality. This study investigated patterns of complications after loop ileostomy closure and factors associated with morbidity and mortality. METHOD: A review was performed of patients who underwent loop ileostomy closure between 1999 and 2005. RESULTS: Three hundred and twenty-five patients underwent closure of loop ileostomy. Reasons for primary surgery were: anterior resection for cancer (n = 160, 49%), ileal pouch-anal anastomosis (n = 114, 35%), diverticular disease (n = 25, 8%), Crohn's colitis (n = 4, 1%) and other conditions (n = 22, 7%). Overall mortality was 2.5% (n = 8) and morbidity was 22.8% (n = 74). Thirty-two patients (10%) developed small bowel obstruction, of whom seven required operative intervention. Overall, the re-operation rate in this series was 28 patients (8.6%). Thirteen (4%) patients had an anastomotic leak of whom 12 patients had re-operation. Preoperative anaemia was significantly associated with leakage (Hb < 11 g/dl; n = 65, P = 0.033). The leakage rate was lower after a stapled anastomosis than a hand-sutured anastomosis (4/203 vs 9/122; P = 0.039). Hypo-albuminaemia (albumin < 34 g/l) was significantly associated with mortality (n = 46, P < 0.001). CONCLUSIONS: Loop ileostomy closure is associated with morbidity and mortality. Anaemia and hypo-albuminaemia may be associated with poor outcome.

Successful treatment of a large Buschke-Lowenstein tumour with chemo-radiotherapy.

We report the case of a patient with a large Buschke-Lowenstein tumour which had previously recurred following local excision. A preferred treatment modality for this rare variant of human papillomavirus has not been clearly defined. Treatment with chemo-radiotherapy in this case resulted in complete resolution of the disease without the need for further surgical intervention.

Measuring the migration of the components and polyethylene wear after total hip arthroplasty: beads and specialised radiographs are not necessary.

AIMS: This paper describes the methodology, validation and reliability of a new computer-assisted method which uses models of the patient's bones and the components to measure their migration and polyethylene wear from radiographs after total hip arthroplasty (THA). MATERIALS AND METHODS: Models of the patient's acetabular and femoral component obtained from the manufacturer and models of the patient's pelvis and femur built from a single computed tomography (CT) scan, are used by a computer program to measure the migration of the components and the penetration of the femoral head from anteroposterior and lateral radiographs taken at follow-up visits. The program simulates the radiographic setup and matches the position and orientation of the models to outlines of the pelvis, the acetabular and femoral component, and femur on radiographs. Changes in position and orientation reflect the migration of the components and the penetration of the femoral head. Validation was performed using radiographs of phantoms simulating known migration and penetration, and the clinical feasibility of measuring migration was assessed in two patients. RESULTS: Migration of the acetabular and femoral components can be measured with limits of agreement (LOA) of 0.37 mm and 0.33 mm, respectively. Penetration of the femoral head can be measured with LOA of 0.161 mm. CONCLUSION: The migration of components and polyethylene wear can be measured without needing specialised radiographs. Accurate measurement may allow earlier prediction of failure after THA. Cite this article: Bone Joint J 2017;99-B:1290-7.

Properties of chromosomal proteins of human leukemic cells.

Purified chromatin isolated from lymphocytic cells derived from patients with acute leukemia, or other lymphoproliferative disorders has been compared with chromatin isolated from normal human lymphocytic cells by gel electrophoresis and differential gradient ultracentrifugation. Thermal denaturation studies showed higher Tm values for chromatin from leukemic cells, as compared to that of lymphocytic cells from normal donors or patients with infectious mononucleosis, reflecting the diverse complexity of these chromatins with respect to their varying chemical compositions. There are significant differences in the ratios of DNA:RNA:protein, as well as in the ratios of chromatin-associated histone and non-histone proteins; although chromatin-associated histones were more homogeneous than were the non-histone proteins, as adjudged by amino acid analyses and acrylamide gel electrophoresis. These differences in chromatin structure may relate to the differences in gene expression characteristic of these lymphocytic cells. The chromosomal acidic proteins isolated from the purified chromatin of human leukemic cells greatly stimulated the template activity of the chromatin in in vitro RNA synthesis. The non-histone proteins selectively interact with chromatins and influence the RNA polymerase reactions, indicating that there is selective tissue specificity of non-histone proteins.

Forms and prevalence of intersexuality and effects of environmental contaminants on sexuality in cricket frogs (Acris crepitans).

Cricket frogs (Acris crepitans) from several different sites in Illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. Of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. There was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. However, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex individuals. A comparison of reference sites with sites that had point polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) contamination revealed a significant relationship between sex-ratio reversal and contamination with PCBs and PCDFs. The sex ratio of juvenile frogs studied from three sites with PCB and PCDF point contamination favored males over females, which was the opposite of the sex ratio in control ponds (p = 0.0007). The statistically significant correlation between organochlorine contamination and sex-ratio reversal suggests PCBs and PCDFs can influence cricket frog sexual differentiation. The current study suggests that in cricket frogs, sex ratios and the prevalence of intersex gonads are altered by environmental contamination.

Changes in thyroid gland morphology after acute acrylamide exposure.

High exposure to the acrylamide monomer has been associated with neuropathy and neurotoxic effects. Chronic lower exposure causes endocrine disruption associated with thyroid, testicular, and mammary tumors. To investigate mechanisms of endocrine disruption, short-term, low-level oral dosing studies were conducted. Weanling female Fischer 344 rats were acclimatized for two weeks before dosing. Controls were given distilled water by gavage and rats in other groups were given acrylamide at doses of 2 mg/kg/day and 15 mg/kg/day for 2 or 7 days by gavage. Twenty-four h after the last dose, the rats were killed by decapitation. Trunk blood was collected for hormone analyses and tissues for histopathological examination. There were no toxicity-related deaths, no clinical signs of toxicity, and no significant difference in the mean body weight of animal groups. Histopathological examination of select tissues showed no lesions of pathologic significance. Plasma thyroxine (T4), thyroid stimulating hormone (TSH), prolactin (PRL), and pituitary TSH and PRL analyses did not reveal significant changes between control vs. treated rats. In the 7-day study, however, there was a slight dose-dependent increase in plasma T4 and a slight dose-dependent decrease in plasma TSH. Thyroid gland morphometry showed a significant (p < 0.05) decrease in the colloid area and a significant increase (p < 0.05) in the follicular cell height of treated rats as compared to controls. The follicular area shrinkage was similar in both studies. These results show a very early endocrine response to very low levels of toxic insult and opens other venues to further investigate the mechanisms of endocrine disruption by acrylamide.

Effect of cell morphology on dead-end filtration of the dimorphic yeast Kluyveromyces marxianus var. marxianus NRRLy2415.

The dead-end filtration characteristics of the dimorphic yeast Kluyveromyces marxianus var. marxianus (formerly fragilis) NRRLy2415 were investigated for a range of mean cell morphologies, ranging from predominantly yeast-like to predominantly filamentous. Semiautomated image analysis was used to measure the mean cell specific surface area, Sv, and the mean ratio of cell length to equivalent cylindrical diameter, Ldm, in each broth. The method of Ju and Ho (Biotechnol. Bioeng. 1988, 32, 95-99) was used to show that for broths with Ldm values between 1.72 and 10.03, the voidage of cell pellets formed by centrifugation increased with increasing Ldm. In the pressure range 30-180 kPa, the specific filter cake resistance, alpha, was found to be related to pressure, DeltaP, through the equation alpha = alpha0(1 + kcDeltaP). The dependence of alpha0/Sv2 on Ldm was found to be qualitatively consistent with the pellet voidage data and the Carman-Kozeny equation. Considerably better agreement with the experimental data was obtained when the Kozeny constant, K, was treated as variable and related to Ldm through the equation K = 4.83 + 7.08 log10 Ldm. The cake compressibility constant, kc, was found to increase with increasing Ldm, a phenomenon consistent with the wide range of voidages that can be displayed by beds of long cylinders.

Canine distemper epizootic in lions, tigers, and leopards in North America.

Canine distemper virus (CDV) infection occurred in captive leopards (Panthera pardus), tigers (Panthera tigris), lions (Panthera leo), and a jaguar (Panthera onca) in 1991 and 1992. An epizootic affected all 4 types of cats at the Wildlife Waystation, San Fernando, California, with 17 mortalities. CDV-infected raccoons were thought to be the source of infection in these cats. Two black leopards died at the Naibi Zoo, Coal Valley, Illinois, and 2 tigers died at the Shambala Preserve, Acton, California. Initial clinical signs were anorexia with gastrointestinal and/or respiratory disease followed by seizures. Canine distemper virus was isolated from 3 leopards, 3 tigers, and 3 lions that died or were euthanized when moribund. Monoclonal antibody testing identified the virus isolates as CDV. Gross and histopathologic findings were similar to those found in canids with distemper with a few exceptions. There were fewer lesions in the brain, and there was a pronounced type 2 cell proliferation in the lung, with inclusion bodies and CDV antigen demonstrated by immunohistology. Neutralizing antibody to CDV was found in high titers in serum from most animals but was absent or was found only in low titers in some cats that succumbed after CDV infection. There was a marked difference in neutralizing antibody titers when tests were done with different strains of CDV.

Besnoitiosis of the reproductive tract of a Blue Duiker (Cephalophus monticola).

A mature male Blue Duiker that had been born in the United States was submitted for necropsy examination following a brief illness. On histologic examination of the reproductive tract several Besnoitia cysts were found in the epididymis, prostate and bulbourethral gland. The lack of an inflammatory response or any negative effect on fertility, based on histologic evaluation and breeding history, is in contrast with the severe orchitis, epididymitis and infertility of besnoitiosis in cattle. This is the first report of an autochthonous infection of Besnoitia in the United States as well as the first report of besnoitiosis in a Blue Duiker.

Contactless technique for the measurement of electrical resistivity in anisotropic materials.

Measurement of basal plane electrical resistivities in quasi-two-dimensional materials by conventional four-point bridge techniques is extremely difficult. In making measurements of room temperature basal plane resistivities in highly conducting highly anisotropic synthetic metals we have developed an rf inductive technique which is both simple to use and provides accurate results. At the frequency we employ (100 kHz) the method is appropriate for resistivities in the range 10 (-3)-10(-7)Omega cm. Samples are thin square plates 5 mm on a side. The system is calibrated by fitting data from a series of samples of known resistivity to semi-empirical formulae. The theoretical motivation leading to these expressions is discussed and extensive calibration data are presented. The advantages of rf techniques in general have already been discussed. Two advantages commend the particular technique we describe here. First, it is simple in design and easily constructed. Second, with careful calibration, highly accurate resistivity measurements can be made in a very straightforward manner.

Intrathoracic granular cell tumour in a dog.

Multiple granular cell tumours occurred diffusely throughout the pleura of an adult German Shepherd Dog. The growths were scattered over the surface of the lungs, mediastinum and diaphragm. Histologically, the masses consisted of plump cords of cells with eosinophilic, weakly PAS-positive cytoplasmic granules. Electron microscopically, the granules consisted of a pleomorphic population of electron-dense granules. The predilection site in the dog is the tongue and this is the first report of an intrathoracic, pleural site of granular cell tumours in the dog.

Pathology of the corpus luteum of cows.

The corpus luteum (CL) is a transient endocrine organ which can manifest a number of pathologic conditions such as cysts, inflammation, adhesions, dysfunction and neoplasia. Luteal and follicular cysts are the most commonly encountered abnormalities and need to be distinguished from cysts within a normal CL. Inflammatory lesions are also frequently encountered and can be caused by viral, bacterial, or iatrogenic causes. If inflammation is severe, adhesions and subfertility/infertility can result. Luteal dysfunction is a broad classification of another pathologic condition encountered in the cow. Generally this results in abnormal production of progesterone or abnormal luteal lifespan resulting in infertility. Neoplasms are relatively rare in the CL but include both primary and metastatic tumors. Understanding the pathologic conditions that occur within the CL will allow a more accurate clinical assessment of these very dynamic endocrine structures.