Precipitation and temperature drive continental-scale patterns in stream invertebrate production.

Secondary production, the growth of new heterotrophic biomass, is a key process in aquatic and terrestrial ecosystems that has been carefully measured in many flowing water ecosystems. We combine structural equation modeling with the first worldwide dataset on annual secondary production of stream invertebrate communities to reveal core pathways linking air temperature and precipitation to secondary production. In the United States, where the most extensive set of secondary production estimates and covariate data were available, we show that precipitation-mediated, low-stream flow events have a strong negative effect on secondary production. At larger scales (United States, Europe, Central America, and Pacific), we demonstrate the significance of a positive two-step pathway from air to water temperature to increasing secondary production. Our results provide insights into the potential effects of climate change on secondary production and demonstrate a modeling framework that can be applied across ecosystems.

Meta-analysis: abundance, behavior, and hydraulic energy shape biotic effects on sediment transport in streams.

An increasing number of studies have emphasized the need to bridge the disciplines of ecology and geomorphology. A large number of case studies show that organisms can affect erosion, but a comprehensive understanding of biological impacts on sediment transport conditions is still lacking. We use meta-analysis to synthesize published data to quantify the effects of the abundance, body size, and behavior of organisms on erosion in streams. We also explore the influence of current velocity, discharge, and sediment grain size on the strength of biotic effects on erosion. We found that species that both increase erosion (destabilizers) and decrease erosion (stabilizers) can alter incipient sediment motion, sediment suspension, and sediment deposition above control conditions in which the organisms were not present. When abundance was directly manipulated, these biotic effects were consistently stronger in the higher abundance treatment, increasing effect sizes by 66%. Per capita effect size and per capita biomass were also consistently positively correlated. Fish and crustaceans were the most studied organisms, but aquatic insects increased the effect size by 550 x compared to other types of organisms after accounting for biomass. In streams with lower discharge and smaller grain sizes, we consistently found stronger biotic effects. Taken collectively, these findings provide synthetic evidence that biology can affect physical processes in streams, and these effects can be mediated by hydraulic energy. We suggest that future studies focus on understudied organisms, such as biofilms, conducting experiments under realistic field conditions, and developing hypotheses for the effect of biology on erosion and velocity currents in the context of restoration to better understand the forces that mediate physical disturbances in stream ecosystems.

Within-tree distributions of the Sirex noctilio Fabricius (Hymenoptera: Siricidae)--parasitoid complex and development of an optimal sampling scheme.

Little is known about the introduced European woodwasp, Sirex noctilio F. (Hymenoptera: Siricidae), and its hymenopteran parasitoid complex in North America. To assess within-tree and landscape-level densities and distributions of these insects, and develop a more cost effective approach for sampling and monitoring S. noctilio, 18 infested pines (12 P. resinosa Aiton and six P. sylvestris L.) were felled from six stands within three regions in central New York and cut into 0.5-m bolts. Bolts were carefully split to recover all siricids (S. noctilio and native siricids) and parasitoids. In total, 2,558 siricids were recovered; 1,972 siricid larvae and 586 teneral adult S. noctilio. Parasitism of siricids, a majority of which were S. noctilio based on larval rearing results, was 16.4% with Ibalia leucospoides ensiger Norton causing 10.7% of the documented mortality. Numbers of siricids and parasitoids declined 33-86% from the northern to the southern sampling regions, peak insect densities occurred in sections of the bole 15-19 cm in diameter and numbers of insects were generally higher in P. sylvestris than P. resinosa according to the highest ranked zero-inflated poisson and probit regression models. Bark thickness was not correlated with siricid or parasitoid species densities. We also describe sampling plans where as few as two 0.5-m samples from infested trees provided reliable within-tree insect densities.

Condensation of rye chromatin in somatic interphase nuclei of Ph1 and ph1b wheat.

The Ph1 locus in hexaploid wheat (Triticum aestivum L.) enforces diploid-like behavior in the first metaphase of meiosis. To test the hypothesis that this chromosome pairing control is exercised by affecting the degree of chromatin condensation, the dispersion of rye chromatin in interphase nuclei in somatic tissues of wheat-rye chromosome translocations 1RS.1BL, 2RS.2BL, 2BS.2RL, 3RS.3DL and 5RS.5BL was compared in Ph1 and ph1b isogenic backgrounds. No significant differences in rye chromatin condensation that could be attributed to the Ph1 locus were detected. Regardless of the Ph1 status, each rye chromosome arm tested conformed to the general Rabl's orientation and occupied portions of the nuclei proportional to their length. Earlier observations that indicated the involvement of Ph1 locus in rye chromatin condensation in wheat could have been due either to specific loci on the studied 5RL rye arm that control the chromosome condensation process or to damage to the genetic system controlling chromatin condensation in the existing ph1b stocks of wheat. That damage might have been caused by homoeologous recombination and uneven disjunction of chromosomes from multivalents.

Treatment of chronic inflammatory demyelinating polyradiculoneuropathy with methotrexate.

We discovered many reports of other immunosuppressive drugs being used in adults with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) but none of methotrexate. As weekly low dose oral methotrexate is safe, effective, and well tolerated in other diseases, we treated 10 patients with otherwise treatment resistant CIDP. Seven showed improvement in strength by at least two points on the MRC sum score and three worsened. Only two showed an improvement in disability and both were also receiving corticosteroids. We discuss the difficulty of detecting an improvement in treatment resistant CIDP and propose methotrexate as a suitable agent for testing in a randomised trial.

Predicting response to treatment in chronic inflammatory demyelinating polyradiculoneuropathy.

OBJECTIVE: To discover whether Inflammatory Neuropathy Cause and Treatment Group (INCAT) electrophysiological criteria for demyelinating neuropathy predict response to immunotherapy in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). METHODS: This was a retrospective case note study of patients who had attended Guy's Hospital Peripheral Nerve Clinic between January 2001 and March 2004, been diagnosed as having CIDP, and given treatment with corticosteroids, intravenous immunoglobulin (IVIg), or plasma exchange (PE). Patients' nerve conduction studies (NCS) were reviewed for evidence of demyelination and whether the abnormalities fulfilled modified INCAT electrophysiological criteria. Patients whose NCS fulfilled the criteria were assigned to the neurophysiologically definite CIDP group, while those that did not were labelled as neurophysiologically probable CIDP. Responses to any of the three immunotherapy agents were compared between the two groups. RESULTS: Out of 50 patients, 27 (54%) were classified as neurophysiologically definite and 23 (46%) as neurophysiologically probable CIDP patients. Twenty (74%) neurophysiologically definite and 17 (73.9%) neurophysiologically probable CIDP patients responded to treatment. CONCLUSIONS: INCAT electrophysiological criteria did not predict a higher rate of response to immunotherapy. Neurophysiologically probable CIDP patients should be given a trial of immunotherapy.

The role of fine needle aspiration cytology (FNAC) in the investigation of superficial lymphadenopathy; uses and limitations of the technique.

Aspirates (n = 163) from 157 patients with enlarged superficial lymph nodes were obtained over a 5-year period in a combined surgical/FNAC clinic. A definitive diagnosis was achieved in over 77% of the cases: benign 52.7%, malignant 25.1%. The diagnostic accuracy was 94.4%, sensitivity 85.4%, and specificity 100%. The false-negative rate was 12.5% but decreased to 3.5% when lymphoma cases were excluded. There were 36 cases of metastatic disease, the majority of which were from a primary breast carcinoma. The main diagnostic difficulty was in distinguishing low-grade lymphoma from reactive hyperplasia. An added advantage was that aspirated material could be used in ancillary tests to help with the differential diagnosis. FNAC has a well-defined role in the investigation of superficial lymphadenopathy. Used in the proper setting it will provide a definitive diagnosis in the majority of cases, especially relating to recurrent malignancy or metastatic disease. Patients with a reactive cytological picture and no clinically suspicious symptoms could be spared unnecessary surgery and reviewed through follow up. This technique is cost-effective, of high diagnostic accuracy, and results in considerable resource savings.

Pathology of rectal adenocarcinoma following preoperative adjuvant radiotherapy and chemotherapy.

The study group comprised 13 patients (mean age 68 years) with clinically fixed and biopsy proven moderately differentiated rectal adenocarcinoma (8 high rectal, 5 low-mid rectal) who received synchronous courses of preoperative combination chemotherapy and pelvic radiotherapy (radiotherapy alone in 3 cases) over a period of 8-20 weeks prior to surgical resection. All cases showed varying degrees of mural and mesorectal fibrosis. Three cases did not differ otherwise from usual rectal adenocarcinoma while 4 had a 20-30% diminution in expected tumour area. In 6 cases tumour could not be definitely identified grossly--1 showed a 50% reduction in tumour bulk while 5 had only residual microscopic foci from 0.6-4 mm in maximum dimensions. Only 3 cases had involvement of the mesorectal circumferential radial margin. Four involved lymph nodes in 2 cases were partially hyalinised and calcified. Preoperative combination adjuvant therapy can produce marked regressive morphological changes in rectal adenocarcinoma. The implications of this are discussed.

A 3-year audit of thyroid fine needle aspirates.

Fine needle aspiration (FNA) cytology is an important adjunct to the preoperative management of thyroid swellings. It is a simple and highly cost effective procedure with a higher sensitivity for the detection of malignancy than ultrasound and radio-isotope scans. We audited a total of 208 aspirates performed over a 3-year period. In our experience 61% of solitary thyroid swellings can be diagnosed confidently on FNA cytology as either non-neoplastic (46%) or neoplastic (15%). Based on these two groups the sensitivity is 91% and specificity 94%. The specificity, however, decreases to 40% if the group reactive vs neoplastic, which comprises 10-15% of cases and requires surgical intervention, is included. The positive predictive value for malignant disease is 94% while the false-negative and -positive rates excluding the unsatisfactory and reactive vs neoplastic groups are low at 2.7% and 5.4%, respectively (involving non-neoplastic lesions and benign tumours only). There was no case of malignant cytology with a benign biopsy follow up.

A 3 year audit of fine needle aspirates from a symptomatic breast clinic.

A total of 2431 fine needle aspirates of symptomatic breast lumps was performed on 2096 patients over the last three years at the weekly head, neck and breast clinic at the Belfast City Hospital Trust. Diagnostic accuracy was achieved within the recommended standards although the "insufficient" rate was high at 31.8%. False negative and positive rates were low and the positive predictive value for malignancy was 99%. Excision biopsy for benign breast disease had decreased by almost a third during this period. Fine needle aspiration cytology is a highly accurate and cost-effective technique for the investigation of symptomatic breast lumps and results in significant savings.

Ovarian granulomas: a report of 32 cases.

AIMS: To determine the causes of ovarian granulomatous inflammation and to discuss the differential diagnoses. METHODS: The pathological features of all ovarian granulomas identified by pathology SNOMED coding in Northern Ireland over a 13 year period were reviewed. Case notes of patients were also reviewed. RESULTS: The most common cause of ovarian granuloma was a foreign body reaction to suture material introduced at a previous operative procedure (15 cases). Other causes were Crohn's disease (four cases), previous diathermy (two cases), tuberculosis (two cases), a necrotising reaction following previous surgery (two cases), endometriosis (one case), and bacterial tubo-ovarian abscess (one case). In five cases, no cause was apparent for the granulomatous inflammation. In these, varying numbers of small, well circumscribed cortical granulomas were present. These cases correspond to so-called "idiopathic" cortical granulomas. CONCLUSION: The study confirms the wide range of conditions which can give rise to ovarian granulomatous inflammation.

Bone marrow granulomas in infiltrating lobular breast cancer.

A 50 year old woman with a history of infiltrating lobular breast carcinoma presented with back pain. Bone scan and magnetic resonance imaging were not conclusive. A bone marrow aspirate appeared normal. A routine trephine biopsy specimen showed granulomas but no obvious infiltration by carcinoma. Immunohistochemical staining with epithelial markers demonstrated carcinoma cells in the trephine specimen. This case illustrates the difficulty of detecting infiltrating lobular carcinoma in bone marrow and the value of immunological techniques in this context. It also describes the development of bone marrow granulomas as a response to infiltration by carcinoma.

Malignant eccrine spiradenoma with carcinomatous and sarcomatous elements.

A case of a 60 year old man with malignant eccrine spiradenoma involving the perineum is described. Areas of typical eccrine spiradenoma were admixed with carcinomatous and sarcomatous elements. Immunohistochemical and ultrastructural analysis revealed no evidence of epithelial differentiation in the sarcomatous areas. The tumour qualified for the designation carcinosarcoma arising in eccrine spiradenoma. The clinical course was aggressive with rapid development of nodal and pulmonary metastases.

Fine needle aspiration cytology of gastric carcinoma.

Four patients between 58 and 81 years of age undergoing investigation and endoscopic biopsy for gastric carcinoma also were subjected to direct-vision fine needle aspiration cytology of their mucosal lesions which yielded malignant cells. The relevance of this technique is discussed regarding both intrinsic and extrinsic lesions of the gastrointestinal tract.

Experience with schistosomiasis in Northern Ireland.

Five cases of schistosomiasis have been recorded in the Belfast City Hospital Histopathology Laboratory over the last three years. The sites of infection have included the colon, bladder, uterus and seminal vesicles. All the infected individuals had visited Africa. Three of them were health care workers. The clinician must maintain a high index of suspicion when treating those with a history of travel and risk of exposure to this infection. Diagnosis is made even more critical as the condition is treatable, and serological markers can identify those with occult infection.

A comparison of the pathophysiologic effects of carbon dioxide, nitrous oxide, and helium pneumoperitoneum on intracranial pressure.

BACKGROUND: Previous studies have suggested that diagnostic laparoscopy may be contraindicated in multiple trauma patients with closed head injuries because of the detrimental effects of carbon dioxide (CO2) pneumoperitoneum on intracranial pressure (ICP). In this study we compared the effects of two alternative inflation gases, helium (He) and nitrous oxide (N2O), against the standard agent used in most hospitals, CO2. ICP was monitored in experimental animals both with and without a space occupying intracranial lesion designed to simulate a closed head injury. METHODS: Twenty-four domestic pigs (mean, 30 kg) were divided into four groups (6 CO2, 6 He, 6 N2O, and 6 control animals without insufflation). All animals were monitored for ICP, intraabdominal pressure, mean arterial pressure, end-tidal CO2 (ETCO2), and arterial blood gases. These parameters were measured for 30 minutes prior to introducing a pneumoperitoneum and then for 80 minutes thereafter. The measurements were repeated after artificially elevating the ICP with a balloon placed in the epidural space. RESULTS: The mean ICP increased significantly in all groups during peritoneal insufflation compared with the control group (P < 0.005). The CO2-insufflated animals also showed a significant increase in PaCO2 (P < 0.05) and ETCO2 (P < 0.05), as well as a decrease in pH (P < 0.05). After inflating the epidural balloon the ICP remained significantly higher in animals inflated with CO2 as compared with the He and N2O groups (P < 0.05). CONCLUSIONS: Peritoneal insufflation with He and N2O resulted in a significantly less increase in ICP as compared with CO2. That difference was most likely due to a metabolically mediated increase in cerebral perfusion (PaCO2) in the CO2 group. Further studies need to be conducted to determine the safety and efficacy of using He and N2O as inflation agents prior to attempting diagnostic or therapeutic laparoscopy in patients with potential closed head injuries.