A multicenter prospective external validation of the diagnostic performance of IOTA simple descriptors and rules to characterize ovarian masses

OBJECTIVES

To evaluate the diagnostic performance of the IOTA (International Ovarian Tumor Analysis group) (clinically oriented three-step strategy for preoperative characterization of ovarian masses when ultrasonography is performed by examiners with different background training and experience.

METHODS

A 27-month prospective multicenter cross-sectional study was performed. 36 level II ultrasound examiners contributed in three UK hospitals. Transvaginal ultrasonography was performed using a standardized approach. Step one uses simple descriptors (SD), step two ultrasound simple rules (SR) and step three subjective assessment of ultrasound images (SA) by examiners. The final outcome was findings at surgery and the histological diagnosis of surgically removed masses.

RESULTS

1165 women with adnexal masses underwent transvaginal ultrasonography, 301 had surgery. Prevalence of malignancy was 31% (n=92). SD were able to classify 46% of the masses into benign or malignant (step one), with a sensitivity of 93% and specificity of 97%. Applying SD followed by SR to residual unclassified masses by SD enabled 89% of all masses (n=268) to be classified with a sensitivity 95% of and specificity of 95%. SA was then used to evaluate the rest of the masses. Compared to the risk of malignancy index (RMI), the sensitivity and specificity for the three-step (SD+SR+SA) strategy were 93% (95% CI: 86-97%) and 92% (95% CI: 87-95%) vs. 72% (95% CI: 62-80%) and 95% (95% CI: 91-97%) for RMI, respectively.

CONCLUSION

The IOTA three-step strategy shows good test performance on external validation in the hands of ultrasonography examiners with different background training and experience. This performance is considerably better than the RMI.

Wild bees visiting cucumber on midwestern U.S. organic farms benefit from near-farm semi-natural areas

Wild bees that provide pollination services to vegetable crops depend on forage resources, nesting sites, and overwintering sites in the agricultural landscape. The scale at which crop-visiting bees use resources in the landscape can vary regionally, and has not been characterized in the Midwestern United States. We investigated the effects of seminatural land cover on wild bee visitation frequency to cucumber (Cucumis sativus L.) and on wild bee species richness on 10 organic farms in Indiana. We estimated the spatial scale at which the effects of land cover were strongest, and also examined the effects of nonlandscape factors on wild bees. The visitation frequency of wild bees to cucumber was positively related to the proportion of seminatural land in the surrounding landscape, and this relationship was strongest within 250 m of the cucumber patch. The species richness of wild cucumber visitors was not affected by land cover at any spatial scale, nor by any of the nonlandscape factors we considered. Our results indicate that wild, crop visiting bees benefit from seminatural areas in the agricultural landscape, and benefit most strongly from seminatural areas within 250 m of the crop field. This suggests that setting aside natural areas in the near vicinity of vegetable fields may be an effective way to support wild, crop-visiting bees and secure their pollination services.

Regulation of methionine synthesis in Escherichia coli: Effect of metJ gene product and S-adenosylmethionine on the expression of the metF gene

The regulation of the expression of the Escherichia coli metF gene, which codes for 5,10-methylenetet-rahydrofolate reductase (EC 1.1.99.15), has been investigated by using a simplified DNA-directed in vitro system that measures the formation of the first dipeptide (fMet-Ser) of the gene product. The synthesis of fMet-Ser directed by a plasmid containing the metF gene is specifically inhibited by metJ protein (repressor protein). S-Adenosylmethionine enhances the inhibition by the metJ protein of metF gene expression. The inhibition by the metJ protein is at the level of transcription and the results suggest that S-adenosylmethionine is functioning as an allosteric effector.

Hematein chelates of unusual metal ions for tinctorial histochemistry

Hematoxylin is oxidized easily to hematein, an excellent stain for metal ions. If it already is bound to a substrate, the metal ion becomes a mordant linking the dye to the substrate. Metal ions added to hematein in solution are chelated by the hematein to form a lake. Most of these chelates stain animal tissues. They usually are bound to the tissue by a combination of hydrogen bonding of the hematein and ionic bonding of the metal ion. When binding of the lake to the tissue occurs by way of the metal ion, the metal ion is a mordant. Mordant staining often is specific. Chromium hematoxylin binds to strong acids; it can be made selective for protein-bound sulfonic acids. Zirconyl hematoxylin is selective for acidic mucins. Mucihematein can be made selective for all acidic mucins or for sulfomucins alone. Bismuth hematoxylin appears to be selective for the guanido group of arginine and there is some evidence that the bonding is covalent. Although it is not a histochemical stain, copper-chrome hematoxylin is an excellent stain for organelles with double membranes, i.e., mitochondria and nuclei.

Mucin immunohistochemistry in the diagnosis and mapping of extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a rare skin cancer of the genital region in which cancer cells with enlarged nuclei and pale cytoplasm are scattered singly in the affected epidermis. These cancer cells, called Paget cells, contain mucin, which is never found in normal epidermis. The oligosaccharide side chains of Paget cell mucin end with sialic acid. Sialic acid is easily detected by zirconyl haematoxylin or alcian blue. The other sugars in the oligosaccharide chains can be detected by the periodic acid-Shiff reaction. Rarely, the diagnosis of EMPD is complicated by the absence of mucin from the Paget cells. We have examined such an atypical case. The oligosaccharide side chains, including the sialic acids, are absent. In both this case and a typical case, the Paget cells contain epithelial membrane antigen mucin (MUC1) core protein and usually contain gastric surface-type mucin (MUC5AC) core protein, which can be stained by antibodies. Since neither core protein is found in normal epidermis, epithelial membrane antigen core protein may be the most reliable diagnostic marker for extramammary Paget's disease. In both the atypical case and the typical case of Paget's disease, some cells that look like keratinocytes contain mucin core proteins. These may be incipient Paget cells. We suggest that using th epithelial membrane antigen core protein as a marker for the true extent of extramammary Paget's disease could facilitate complete excision and reduce the rate of recurrence.

Trends in ixodid tick abundance and distribution in Great Britain

The popular, but rarely documented, view in Britain is that ticks have increased in distribution and abundance over recent years. To assess this, we gathered evidence for changes in tick distribution and abundance by distributing a survey questionnaire throughout Britain and by analysing trends in the prevalence of tick infestation on red grouse chicks Lagopus lagopus scoticus Latham (Galliformes: Tetranoidae), gathered over 19 years at three Scottish sites, and on deer (Cetartiodactyla: Cervidae) culled over 11 years on 26 Ministry of Defence (MoD) estates. Based on the survey, the current known distribution of Ixodes ricinus Linnaeus (Acari: Ixodidae) has expanded by 17% in comparison with the previously known distribution. The survey indicated that people perceive there to be more ticks today than in the past at 73% of locations throughout Britain. Reported increases in tick numbers coincided spatially with perceived increases in deer numbers. At locations where both tick and deer numbers were reported to have increased, these perceived changes occurred at similar times, raising the possibility of a causal link. At other locations, tick numbers were perceived to have increased despite reported declines in deer numbers. The perceptions revealed by the survey were corroborated by quantitative data from red grouse chicks and culled deer. Tick infestation prevalence increased over time on all grouse moors and 77% of MoD estates and decreased at six locations.

An improved formulation of the zirconyl hematoxylin stain for acidic mucins

Zirconyl hematoxylin stains acidic mucins darkly and specifically using a solution of 100 mg hematoxylin, 5 ml ethanol, 5 ml 0.5% sodium iodate, 400 mg zirconyl chloride octahydrate, and 30 ml 25% aqueous glycerol. The stain is especially advantageous for studying goblet cells and Paget cells.

Evaluation of the effects of premedication on gastroduodenoscopy in cats

OBJECTIVE

To evaluate the effects of hydromorphone, hydromorphone and glycopyrrolate, medetomidine, and butorphanol premedication on the difficulty and time required to pass an endoscope into the stomach and duodenum of cats anesthetized with ketamine and isoflurane.

DESIGN

Randomized complete block crossover study.

ANIMALS

8 purpose-bred adult female cats.

PROCEDURES

Each cat was premedicated and anesthetized 4 times with an interval of at least 7 days between procedures. Cats were premedicated with hydromorphone, hydromorphone and glycopyrrolate, medetomidine, or butorphanol administered IM. Twenty minutes after premedication, sedation was assessed by use of a subjective ordinal scale. Cats received ketamine administered IM, and 10 minutes later a cuffed orotracheal tube was placed and anesthesia maintained with isoflurane. Cats breathed spontaneously throughout the procedure. When end-tidal isoflurane concentration was stable at 1.4% for 15 minutes, endoscopy was begun. The times required to pass the endoscope through the cardiac and pyloric sphincters were recorded, and the difficulty of endoscope passage was scored by use of a subjective ordinal scale.

RESULTS

No significant differences in difficulty or time required to pass the endoscope through the cardiac and pyloric sphincters were found among premedicant groups. Premedication with medetomidine resulted in the greatest degree of sedation and longest time to return to sternal recumbency.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that hydromorphone, hydromorphone and glycopyrrolate, medetomidine, and butorphanol at the doses tested can be used satisfactorily to premedicate cats prior to general anesthesia for gastroduodenoscopy.

Intracranial Germ Cell Tumors: A Single Institution Experience and Review of the Literature

There is little literature to guide therapy in children and young adults with intracranial germ cell tumors. We present 17 consecutively diagnosed intracranial germ cell tumors at The Children's Hospital, Denver, from 1995 to 2001. Of 17 patients, 3 had considerable delay in diagnosis. Two with suprasellar tumors presented with dementia, blindness and pan-hypopituitarism and another with recurrent subarachnoid hemorrhage. Seven had germinoma, three were metastatic at diagnosis. Ten had non-germinomatous germ cell tumors (NGGCT), 5/10 were alpha feto-protein (AFP) positive only, one beta-human chorionic growth (betaHCG) factor positive only, 3 positive for AFP and betaHCG, and 1 malignant teratoma. Therapy for metastatic patients consisted of chemotherapy followed by craniospinal radiation (CSI). Patients with localized disease received chemotherapy followed by focal radiation. Two patients received chemotherapy only, one because she died of sepsis while receiving chemotherapy and one because of neurologic injury incurred during surgery parents elected for no therapy. Three patients have died, one of tumor recurrence, one from a remote complication of surgery and one of sepsis. Twelve patients are alive without evidence of disease from 10 to 68 months (median 31.5 months). All five children with only AFP positivity, treated with chemotherapy and focal radiation are alive without evidence of disease at 10, 16, 22, 41 and 41 months. Thus, there is little evidence that CSI is necessary in non-metastatic germinomas and AFP positive NGGCTs when combined chemotherapy and radiation therapy is used. However, complications of delayed diagnosis, surgery and chemotherapy are important causes of mortality, with only one patient dying of tumor.

Rising burden of immature sheep ticks (Ixodes ricinus) on red grouse (Lagopus lagopus scoticus) chicks in the Scottish uplands

The sheep tick Ixodes ricinus (L.) (Acari: Ixodidae) is an ectoparasite of major economic and pathogenic importance in Scotland. Its distribution in the Scottish uplands is assumed to be governed by the abundance and distribution of its definitive hosts (deer and sheep) and climatic variables such as temperature and rainfall. As the numbers of its major host in Scotland, red deer, have increased dramatically and climatic conditions have become more favourable, the level of parasitism could have been expected to rise. We use data gathered from tick counts on over 4000 red grouse chicks Lagopus lagopus scoticus Latham (Galliformes: Tetraonidae) in various experiments over the past 19 years to ascertain whether the intensity and prevalence of parasitism has been increasing. From 1985 to 2003 the average tick burden of a parasitized red grouse chick has grown from 2.60 +/- 1.12 ticks per chick to 12.71 +/- 1.44. Over this period the percentage of chicks of a given brood parasitized has also increased from 4 +/- 2% to 92 +/- 3%. The possible implications of this increase in parasitism for red grouse production are discussed.

Oxygen supplementation before or after submaximal exercise in patients with chronic obstructive pulmonary disease

BACKGROUND

Evidence for improved exercise tolerance or relief of breathlessness by short term use of oxygen before or after exercise in patients with chronic obstructive pulmonary disease (COPD) is scant, and guidelines for this treatment are lacking despite widespread provision in the UK.

METHODS

The effect of oxygenation either before or after exercise on perception of breathlessness and walk distance was studied in a group of patients with moderate to severe COPD (mean forced expiratory volume in 1 second (FEV(1)) 34% of predicted, mean 6 minute walk distance on air 283 m), all of whom desaturated by at least 4% on submaximal exercise. Oxygen (28%) or air was delivered double blind and in random order, either for 5 minutes before a standard 6 minute walk test (n=34) or for 5 minutes following the end of the test (n=18). Exercise tolerance was measured as the distance achieved and breathlessness was assessed using visual analogue scales (VAS) which were scored before and after exercise and during recovery.

RESULTS

No increase in mean walk distance after oxygen (288 v 283 m) and no improvement in mean breathlessness scores (58 v 54 mm) or recovery times occurred with oxygen taken either before (177 v 184 seconds) or after exercise (182 v 151 seconds).

CONCLUSIONS

This group of patients with COPD derived no physiological or symptomatic benefit from oxygen breathed for short periods before or after submaximal exercise. Domiciliary oxygen should only be prescribed for such patients if they have shown objective evidence of benefit on exercise testing.

Specific staining of tissue components with metal-hematoxylin complexes

The older metal-hematoxylin stains stain a broad spectrum of tissue components. Several recently introduced metal-hematoxylin stains are highly selective. This selectivity is usually bought at the price of severe limitations on the choice of fixative. A very dilute (2 x 10(-4)M) aluminum hematoxylin is selective for nucleic acids in tissues fixed in organic solvents alone. Vanadate hematoxylin is selective for basic proteins in tissues fixed in formaldehyde or mercuric salts. Bismuth hematoxylin is selective for arginine residues and thus for histones and myelin basic protein in tissues fixed in strong acids (Bouin's fluid or SUSA fluid). Zirconyl hematoxylin is selective for acidic mucins. Zirconyl hematoxylin does not restrict the choice of fixative.

Structural determinants for potent, selective dual site inhibition of human pp60c-src by 4-anilinoquinazolines

The kinetic mechanisms for the inhibition of pp60(c-src) tyrosine kinase (Src TK) by 4-anilinoquinazolines, an important class of chemicals as protein kinase inhibitors, were investigated. 4-Anilinoquinazolines with a bulky group at the 4'-position of the anilino group were shown to be competitive with both ATP and peptide, whereas molecules lacking such a bulky group only displayed an inhibition pattern typical of those competitive with ATP and noncompetitive with peptide. Modifications of the substituents on the carbocyclic ring did not perturb the inhibition pattern although the affinities of these modified inhibitors for Src TK were affected. Structural modeling of Src TK with inhibitor and peptide substrate bound indicated a direct atomic conflict between the bulky 4-position group and the hydroxy of the peptide tyrosyl to which the gamma-phosphate of ATP is transferred during the kinase reaction. This atomic conflict would likely prevent simultaneous binding of both inhibitor and peptide, consistent with the observed kinetic competitiveness of the inhibitor with peptide. The dual site inhibitors appeared to have both enhanced potency and selectivity for Src TK. One such inhibitor, 4-(4'-phenoxyanilino)-6,7-dimethoxyquinazoline, had a 15 nM potency against Src TK and was selective over receptor tyrosine kinases VEGFR2 by 88-fold and C-fms by 190-fold.

Upper limb free flap reconstruction after tumor resection

Free tissue transfer is the autologous transplantation of composite tissue and its arterial and venous blood supply to a distant site. Free tissue transfers, also called free flaps, may include skin, fascia, muscle, or bone. Free flaps were once considered highly complex procedures; now they are frequently used as the reconstructive option of choice. While several variables must be considered when one plans a free tissue transfer, the most important consideration is the size and location of the defect created by the tumor resection. Free tissue transfer is a multistep procedure, including preparation of the recipient site, harvesting of the flap, and transfer and revascularization of the flap. For upper extremity reconstruction, the gracilis muscle flap has been particularly useful, as has the lateral arm fasciocutaneous flap. Semin. Surg. Oncol. 19:246-254, 2000.

Distribution and inducibility of P-glycoprotein in the catfish: immunohistochemical detection using the mammalian C-219 monoclonal

Mounting evidence suggests that the P-glycoprotein (pgp) efflux pump may be a modulator of bioavailability and a mode of excretion for xenobiotics. Immunohistochemistry was utilized to examine the distribution and inducibility of a pgp like protein in catfish. Immunoreactivity to the MDR C-219 monoclonal antibody was noted primarily in bile canaliculi or bile preductules of the liver, discrete areas of the extratubular region of the kidney and the columnar epithelia of the intestine. Regional differences in pgp content were noted in the intestine with the distal region containing greater pgp levels than the proximal intestine. Dietary administration of vincristine, a prototypic pgp inducer and beta-naphthoflavone an Ah agonist resulted in induction of the C-219 immunoreactivity in the liver and the distal intestine. These results are consistent in location and inducibility with pgp like proteins and support a possible relationship to xenobiotic absorption and/or excretion in the catfish.

Zirconyl hematoxylin: a new stain for acidic mucins

Most stains for acidic mucins are time-consuming to prepare and have poor stability. Zirconyl hematoxylin is easily prepared and works for a year or more. It is made by adding 5 ml freshly-made 0.1% aqueous sodium iodate, 400 mg zirconyl chloride octahydrate, and 40 ml 25% aqueous glycerol, in that order, to 100 mg of hematoxylin in 5 ml of absolute ethanol and stirring for 5 min. Stain 10 min and do not "blue" the stain. Chlorazole black or kernechtrot and fast green are good counterstains. Zirconyl hematoxylin stains acidic mucins violet or red violet, regardless of how they are fixed. It stains the same mucins as alcian blue in mouse and sheep salivary glands. It shows goblet cells in mouse rectum as well as alcian blue. It stains the same stomach regions in a lizard as alcian blue. Like alcian blue and colloidal iron, zirconyl hematoxylin stains the mucin of cancerous prostate, but not normal prostate.

Compete or complement? An interdisciplinary approach to training health professionals

The recommendation that future practitioners have the competency to work effectively in interdisciplinary teams is not new, but educating students for this type of practice remains a challenge for the health care professions (1-4). Early interdisciplinary teams usually worked in parallel. There were no common goals, but each group's goals stemmed from its professional education (5). In the traditional model, medical doctors were the "team leaders." Current recommendations challenge health professions educators "to move beyond traditional discipline-bound educational models to future-oriented interdisciplinary teaching/learning models" (6). Taking this recommendation seriously, educators from the University of South Florida (USF) formed a team to develop a model to guide the education of students from four health professions. Our goal was to model, by our philosophy, actions, and words, the art of teaching as an interdisciplinary team. This article describes the first phase of the process and four critical steps--establishing a common goal, developing a team process, creating a model to guide our interactions, and developing support networks within the community.

Phosphorylation of ganciclovir phosphonate by cellular GMP kinase determines the stereoselectivity of anti-human cytomegalovirus activity

A racemic mixture of ganciclovir phosphonate was resolved by stereoselective phosphorylation using GMP kinase. The R-enantiomer of ganciclovir phosphonate was active against human cytomegalovirus but the S-enantiomer was less active. We show that enantiomeric selectivity of antiviral for ganciclovir phosphonate was conferred by stereoselective phosphorylations by mammalian enzymes, not by stereoselective inhibition of DNA polymerase from human cytomegalovirus.

Impaired pulmonary diffusion during exercise in patients with chronic heart failure

BACKGROUND

Pulmonary diffusion is impaired at rest in patients with chronic heart failure (CHF) and has been implicated in the generation of symptoms and exercise intolerance. The aim of this study was to determine whether pulmonary diffusion is impaired during exercise in CHF, to examine its relationship to pulmonary blood flow, and to consider its functional significance in relation to metabolic gas exchange.

METHODS AND RESULTS

Carbon monoxide transfer factor (TLCO) and pulmonary blood flow (Q(C)) were measured by a rebreathe technique at rest and during steady-state cycling at 30 W in 24 CHF patients and 10 control subjects. Both patients and control subjects were able to raise TLCO and Q(C) during exercise. However, the patient group had a lower diffusion for a given blood flow (TLCO/Q(C)) both at rest (3.6+/-0.16 and 4.8+/-0.23 mL x L(-1) x mm Hg(-1); P<0.001) and during exercise (2.8+/-0.16 and 3.4+/-0.13 mL x L(-1) x mm Hg(-1) for CHF patients and control subjects, respectively; P<0.05). TLCO/Q(C) was related to the ventilatory equivalent for carbon dioxide (VEVCO(2)) production at 30 W (TLCO/Q(c) versus VEVCO(2), r = -0.58, P<0.01) and to peak exercise oxygen consumption measured during a progressive test (TLCO/Qc versus VO(2peak), r = 0.57, P<0.01) in these patients.

CONCLUSIONS

Patients with CHF are able to recruit reserves of TLCO and Q(C) during exercise. However, the TLCO/Q(C) ratio is consistently impaired in these patients and relates to both exercise hyperpnea and peak exercise oxygen consumption. Whether this impairment in alveolar gas exchange is reversible in CHF and therefore is a potential target for therapy has yet to be determined.

Perceived family dynamics of persons with chronic pain

This qualitative study was conducted to gain an understanding of the experiences of persons with chronic pain and their relationships with family members and the family as a whole. The framework of systemic organization was used to define the areas of investigation guiding the formulation of broad questions relative to family functioning. Thirty persons with chronic pain (age 31-82 years, 73% women, 83% married, 83% European-American, 17% African-American) participated in the study. A semi-structured interview was conducted to elicit narrative descriptions of the participants' perspective of the pain experience and family functioning. The data were analysed using a constant comparison method of analysis described by Strauss. The dominant themes that emerged included: (i) emotional distress, (ii) distancing from family members, (iii) inability to share difficult feelings, (iv) intense mutual involvement with family members and identification with others' problems, (v) family isolation from community, and (vi) attempt at healing. A mid-range theory developed out of the data and explicated with the framework of systemic organization, was one of balancing and counterbalancing connectedness (spirituality) with personal autonomy or separateness (control) in order to find congruence for the family and individuals within. The pain sometimes acted as a mechanism regulating the distance and closeness among family members. Based on this information, nurses can facilitate better understanding among family members, encourage autonomy, assist individuals to express feelings and needs more directly, and facilitate members to respond to each other.