Screening attendance, age group and diabetic retinopathy level at first screen

AIMS

To report on the relationships between age at diagnosis of diabetes, time from registration with the screening programme to first diabetic eye screening and severity of diabetic retinopathy.

METHODS

Data were extracted from four English screening programmes and from the Scottish, Welsh and Northern Irish programmes. Time from diagnosis of diabetes to first screening and age at diagnosis were calculated.

RESULTS

Time from registration with the screening programme to first screening episode is strongly related to age at registration. Within 18 months of registration 89% of 3958 young people under 18 years of age and 81% of 391 293 people over 35 years of age were seen. In 19 058 people between 18 and 34 years of age, 80% coverage was not reached until 2 years and 9 months. The time from diagnosis of diabetes to first screening is positively associated with severity of disease (P < 0.0001).

CONCLUSIONS

This report is the first that to demonstrate that those in the 18-34 year age group are least likely to attend promptly for screening after registration with a higher risk of referable diabetic retinopathy being present at the time of first screen. Date of diagnosis should be recorded and prodigious efforts made to screen all people promptly after diagnosis. Screening programmes should collect data on those who have not attended within one year of registration.

[Glioblastoma multiforme--new hope due to modern therapeutical approaches]

Glioblastoma multiforme (GBM) is the most frequently encountered malignant cerebral tumor. Despite significant improvements in the treatment of GBM, this disease remains associated with a high morbidity and mortality, with more than half of all affected patients dying within the first year after diagnosis. Typical symptoms include focal neurological symptoms, seizures, personality changes and neurocognitive symptoms. GBM can be identified by means of cerebral imaging modalities and subsequently confirmed histopathologically through biopsy or resection. At present, surgical resection followed by radiotherapy with concomitant chemotherapy with temozolomide and subsequent adjuvant chemotherapy with temozolomide is considered the standard therapy for patients with GBM. Currently, many interdisciplinary studies with glioblastoma patients are accomplished with the aim to further improve the prognosis of the affected patients.

The eyes have it: an exploration of eye movements in action disorganisation syndrome

We examined eye movements in a patient, FK, who has action disorganisation syndrome (ADS), as he performed the everyday task of making a cup of tea. We compared his eye movements with those of a person with Alzheimer's disease and with healthy volunteers. Despite showing very disorganised behaviour many aspects of FK's eye movements were relatively normal. However, unlike normal participants FK made no advance glances to objects that were about to be used, and he made increased numbers of fixations to irrelevant objects during the task. There were also differences in the durations of his eye movements during correct actions and during his perseverative and task-addition responses. We discuss the implications for understanding ADS and the cognitive processes required for correctly performing everyday tasks.

[Carpal tunnel syndrome--modern diagnostic and management]

The carpal tunnel syndrome is the most common entrapment neuropathy (about 3% of the adults are affected). It is characterized by pain and paresthesia along the distribution of the median nerve. Thenar muscle atrophy with corresponding muscle weakness is a late manifestation of advanced disease. Electrophysiological tests are helpful in suggesting the diagnosis. An imaging with a magnetic resonance tomography may be used in the diagnosis of atypical cases. Ergonomic manoeuvres, oral steroids and steroidal injections may alleviate symptoms in mild cases. Surgical decompression of the carpal tunnel is the classical treatment of severe cases as well as for those who do not respond to conservative treatment. After surgery patients usually show excellent results. The following article discusses clinical aspects, diagnosis and current therapeutic options.

[Chronic low Back Pain - A Dreaded Vicious Circle!]

Up to 10% of patients with low back pain develop chronic low back pain. By definition, this is a pain that has persisted for longer than three months. Patients with chronic low back pain suffer from a disease, which has serious effects on the psycho-social and physiological integrity of the persons concerned. Pain syndromes of the lumbar region are among the greatest health care system problems in industrialised countries with direct and indirect annual costs of 150 to 250 billion Swiss francs. Despite intensive treatment some patients remain symptomatic. Out of it results a complaint-driven functional under-utilisation, which leads to an alleviation of the performance and increased inactivity - the beginning of a vicious circle. A multimodal treatment concept including physio- and psychotherapy, supported by a targeted medicamentous therapy, normally improves physical functions and achieves a significant discomfort reduction. If resistance to therapy persists, it is suggestive to consider precociously minimal-invasive or invasive therapeutic options.

The genome of the obligately intracellular bacterium Ehrlichia canis reveals themes of complex membrane structure and immune evasion strategies

Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, alpha-proteobacterium, is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, 17 putative pseudogenes, and a substantial proportion of noncoding sequence (27%). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences and a unique serine-threonine bias associated with the potential for O glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly(G-C) tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Genes associated with pathogen-host interactions were identified, including a small group encoding proteins (n = 12) with tandem repeats and another group encoding proteins with eukaryote-like ankyrin domains (n = 7).

CD10 and Bcl-2 expression combined with the International Prognostic Index can identify subgroups of patients with diffuse large-cell lymphoma with very good or very poor prognoses

AIMS

Diffuse large B-cell lymphoma (DLBCL) is characterized by marked biological heterogeneity. The identification of reproducible parameters that can be combined with the International Prognostic Index (IPI) to better predict outcome could lead to the development of effective risk-adaptive strategies.

METHODS AND RESULTS

Bcl-2 and CD10 expression was determined by immunohistochemistry. The impact of the positivity on survival was evaluated in combination with the IPI in 86 patients with a confirmed diagnosis of DLBCL. Patients were divided according to the IPI into low-risk (no to two factors) or high-risk (three to five factors) groups. Positivity rates were 25% for CD10 and 42% for Bcl-2. In a Cox analysis, the high-risk IPI group [hazard ratio (HR) 5.98, P < 0.0001) and Bcl-2 expression (HR 2.43, P = 0.02) were independent poor prognostic factors, and expression of CD10 (HR 0.41, P = 0.052) predicted a favourable outcome. Among patients in the low-risk IPI group, CD10 positivity was associated with an excellent 8-year overall survival (92% versus 45%, P = 0.06). In the high-risk IPI group, Bcl-2 positivity identified a subgroup with invariably fatal disease.

CONCLUSIONS

The expression of CD10 in the low-risk IPI group, and the expression of Bcl-2 in the high-risk IPI group can identify two subgroups of patients who might benefit from new risk-adaptive treatment approaches.

Rate of perioperative complications in thermal ablation of bone: an animal trial

INTRODUCTION

While only few data are available yet for radioablation of bone tissue, the occurrence of bone marrow embolisms during cryoablation has been documented. It was the aim of this study to assess perioperative complication rates of thermoablation in animals using state-of-the-art ablation probes.

MATERIALS AND METHODS

Eight adult sheep were placed under general anaesthesia, and using a radioprobe, thermoablation was performed on the medial side of the head of the right tibia. In addition, freezing was performed with miniature cryoprobes on both femurs and the head of the left tibia. Haemodynamic monitoring and determination of blood gases and electrolytes were done intraoperatively. The animals were killed 1 week after surgery, and the ablation sites and lung tissue examined macroscopically and microscopically.

RESULTS

None of the animals showed pathological changes in any of these parameters. Blood gases remained unremarkable throughout the operation. All eight animals showed an average drop in haemoglobin of 0.97 g/100 ml. Two animals showed fresh embolisms in the pulmonary vessels.

CONCLUSION

Experimental thermoablation of bone tissue in large animals failed to show any significant perioperative complications following surgery. The lung embolisms which did occur were not clinically relevant. The use of mini-cryoprobes or radioprobes as alternative or complementary measures for treating pathologically altered bone tissue seems viable and does not involve any undue risks.

The genome of a motile marine Synechococcus

Marine unicellular cyanobacteria are responsible for an estimated 20-40% of chlorophyll biomass and carbon fixation in the oceans. Here we have sequenced and analysed the 2.4-megabase genome of Synechococcus sp. strain WH8102, revealing some of the ways that these organisms have adapted to their largely oligotrophic environment. WH8102 uses organic nitrogen and phosphorus sources and more sodium-dependent transporters than a model freshwater cyanobacterium. Furthermore, it seems to have adopted strategies for conserving limited iron stores by using nickel and cobalt in some enzymes, has reduced its regulatory machinery (consistent with the fact that the open ocean constitutes a far more constant and buffered environment than fresh water), and has evolved a unique type of swimming motility. The genome of WH8102 seems to have been greatly influenced by horizontal gene transfer, partially through phages. The genetic material contributed by horizontal gene transfer includes genes involved in the modification of the cell surface and in swimming motility. On the basis of its genome, WH8102 is more of a generalist than two related marine cyanobacteria.

Cryosurgery in long bones with new miniature cryoprobe: an experimental in vivo study of the cryosurgical temperature field in sheep

AIM

The aim of this in vivo study was to determine whether new miniature cryoprobes provide adequate tissue cooling in long bones by measuring the field of temperature under various conditions.

METHODS

Freezings were performed in femoral and tibial bones of 10 sheep under general anaesthesia. Applying one cryoprobe, temperatures of -75 degrees C resp. -51 degrees C could be reached within 0.75 cm resp. 1.00 cm of the probe.

RESULTS

Histological examinations revealed compact bone and marrow necroses along the isotherm in all 10 sheep. Using two cryoprobes simultaneously, a mean temperature decrease to -71 degrees C between the two cryoprobes was achieved thanks to the synergistic freezing effect. Looking at consecutive freezes, it was apparent that with similar cryoprobe end temperatures, the temperature dropped faster if the number of freezing cycles was increased.

CONCLUSION

In conclusion, it was seen that despite its small diameter, the new miniature cryoprobe delivers adequate in vivo tissue cooling in long tubular bones. Employing the synergistic freezing effect by using two or more cryoprobes simultaneously, efficient in vivo freezing of larger bone segments is also possible. Thus, cryosurgery with the new miniature probes can provide a valuable complement to conventional resection of long tubular bones, and offers a viable alternative to surgical treatment of neoplastic diseases of the skeletal system.

The cryosurgical ablation of bone tissue by means of a new miniature cryoprobe -- evaluation of the probe and adaption of the method to in vitro human bone

Until now, modern miniature cryoprobes have been used successfully for the local destruction of soft-tissue tumors without damaging adjacent healthy tissue. In this study, the methodology of cryoablation was applied to bone, and the freezing effect as well as the cooling capacity of the probe were examined. Freezing was performed by cooling one or two probes, with a diameter of 3.2 mm, to -180 degrees C with liquid nitrogen. The cooling capacity of the probes was determined under optic and thermic control in a homogenous reference gel (gelatin), followed by an in vitro measurement on human bone. The simultaneous use of 2 probes resulted in a synergistic effect which produced an almost spherical expansion of frozen area in the homogenous gelatin. In vitro freezing of human tibiae produced equivalent freezing temperatures, with one or two probes, in comparison to the homogenous gelatin. An adequate tissue cooling of bone matrix can be achieved through the use of one or more miniature cryoprobes so that after in vivo testing, the use of this probe could possibly become an alternative or supplement to the surgical resection of pathologic bone processes.

Human chromosome 19 and related regions in mouse: conservative and lineage-specific evolution

To illuminate the function and evolutionary history of both genomes, we sequenced mouse DNA related to human chromosome 19. Comparative sequence alignments yielded confirmatory evidence for hypothetical genes and identified exons, regulatory elements, and candidate genes that were missed by other predictive methods. Chromosome-wide comparisons revealed a difference between single-copy HSA19 genes, which are overwhelmingly conserved in mouse, and genes residing in tandem familial clusters, which differ extensively in number, coding capacity, and organization between the two species. Finally, we sequenced breakpoints of all 15 evolutionary rearrangements, providing a view of the forces that drive chromosome evolution in mammals.

Partitioning methods for multifactorial risk attribution

The epidemiological problem of risk attribution in the framework of multiple exposures has been the subject of intensive research activities in the last decade. In particular, partitioning methods have been developed to define new multidimensional measures of attributable risk putting the task of quantifying a proportion of disease events in a population that can be ascribed to the adverse health effects of certain risk factors into a multifactorial perspective. The parameters generalize the concept of attributable risk to different multifactorial frameworks in which multiple exposures might be arranged in hierarchically ordered classes or in equally ranking groups. Partitioning methods are reviewed and differences between the multifactorial variants of attributable risk are illustrated by a component causes model.

Another look at seasonal variation in patch test results. A multifactorial analysis of surveillance data of the IVDK. Information Network of Departments of Dermatology

There is conflicting evidence concerning seasonal variability of patch test results and no evidence concerning the influence of season on weak-positive, possibly false-positive, irritant reactions, which was analysed in the present study. Data collected in the German Information Network of Departments of Dermatology (IVDK) 1992 to 1997 were combined with external environmental data on temperature and absolute humidity in Germany, and bivariate as well as logistic regression analyses performed concerning the association between reactivity to selected allergens and air temperature and absolute humidity on the respective days of patch testing. Between 39,239 and 41,629 patients had been tested with the 4 allergens considered here. Only formaldehyde exhibited a distinct increase in questionable or irritant as well as weak-positive reactions associated with dry, cold weather. Methylchloroisothiazolinone/methylisothiazolinone and lanolin alcohol showed only a weak, and epoxy resin no, association with climatic conditions. The results indicate that weak-positive reactions, at least to formaldehyde as a prototype of an allergen which is at the same time a marginal irritant, may sometimes be irritant rather than allergic. Patients showing these should be re-tested to improve the poor reproducibilty observed with this allergen.

Native tissue second harmonic imaging improves endocardial and epicardial border definition in dobutamine stress echocardiography

AIMS

Native tissue second harmonic imaging (SHI) implemented in two-dimensional (2D) echocardiography was found to improve left ventricular (LV) endocardial border delineation. Dobutamine stress echocardiography (DSE) depends on the ability to adequately visualize these borders. We analysed whether SHI, compared to fundamental imaging (FI), can improve echogenicity qualitatively and quantitatively, as well as looking at the diagnostic accuracy of the stress test.

METHODS AND RESULTS

Fifty consecutive patients with suspected or known coronary artery disease (history of myocardial infarction and/or coronary artery bypass grafting) underwent DSE sequentially by SHI as well as FI 3 days before or after quantitative coronary angiography. Regional mean echogenicity scores (0=uninterpretable; 4=excellent imaging) for SHI and FI at peak dobutamine titration were 1.8 +/- 0.8 and 1.0 +/- 0.6 (P=0.0020) for the anterior region, 2.3 +/- 0.8 and 1.5 +/- 0.7 (P=0.0002) laterally, 2.7 +/- 1.0 and 1.9 +/- 0.8 (P=0.0001) posteriorly, 2.9 +/- 0.8 and 2.2 +/- 0.7 (P<0.0006) inferiorly, 3.0 +/-0.7 and 2.2 +/- 0.7 (P=0.0001) septally, and 3.1 +/- 1.0 and 2.1 +/-0.8 (P=0.0001) anteroseptally, respectively. Medians [upper; lower quartiles] of a global endocardial visualization index (calculated analogously with the wall motion score index based on a 16-segment model recommended by the American Society of Echocardiography) for the harmonic and the fundamental techniques were 2.59 [2.91; 2.22] and 1.87 [2.19; 1.53] (P=0.0001) at rest, 2.62 [2.94; 2.13] and 1.84 [2.19; 1.50] (P=0.0001) at low dose dobutamine, 2.51 [3.00; 2.13] and 1.74 [2.00; 1.44] (P=0.0001) at peak dose dobutamine, and 2.52 [2.94; 2.19] and 1.76 [2.19; 1.38] (P=0.0001) at recovery, respectively. For repeated quantitative LV volumetry in the harmonic and fundamental modality by the same observer, coefficients of variation were 4.4 +/- 0.4 vs. 6.0 +/- 0.5 (P<0.0001) for end-diastolic volume, 7.4 +/- 0.8 vs. 9.2 +/- 1.1 (P<0.0001) for end-systolic volume, and 5.2 +/- 1.1 vs. 8.2 +/- 1.3 (P<0.0001) for ejection fraction, respectively. Sensitivity and specificity related to coronary angiography for both methods were 80% and 60% as well as 90% and 93%, respectively.

CONCLUSION

Native tissue SHI enhances LV image quality in all stress stages of DSE in unselected patients. This translates into beneficial effects on not only qualitative but also quantitative testing and diagnostic accuracy. SHI should be recommended as a standard tool in DSE and extends its applicability to difficult-to-image patients previously deemed unsuitable.

The roles of vision and eye movements in the control of activities of daily living

The aim of this study was to determine the pattern of fixations during the performance of a well-learned task in a natural setting (making tea), and to classify the types of monitoring action that the eyes perform. We used a head-mounted eye-movement video camera, which provided a continuous view of the scene ahead, with a dot indicating foveal direction with an accuracy of about 1 deg. A second video camera recorded the subject's activities from across the room. The videos were linked and analysed frame by frame. Foveal direction was always close to the object being manipulated, and very few fixations were irrelevant to the task. The first object-related fixation typically led the first indication of manipulation by 0.56 s, and vision moved to the next object about 0.61 s before manipulation of the previous object was complete. Each object-related act that did not involve a waiting period lasted an average of 3.3 s and involved about 7 fixations. Roughly a third of all fixations on objects could be definitely identified with one of four monitoring functions: locating objects used later in the process, directing the hand or object in the hand to a new location, guiding the approach of one object to another (e.g. kettle and lid), and checking the state of some variable (e.g. water level). We conclude that although the actions of tea-making are 'automated' and proceed with little conscious involvement, the eyes closely monitor every step of the process. This type of unconscious attention must be a common phenomenon in everyday life.

[Cryosurgical ablation of bone tissue with a newly developed miniature cryoprobe--adaptation of the method for use in bones in vitro and in vivo]

AIM

Up to now, modern miniature cryoprobes have been used successfully for local destruction of soft tissue tumors without damaging adjacent healthy tissue. In this study, the methodology of cryoablation was applied to bone and the freezing effect as well as the cooling capacity of the probe was examined in vivo and in vitro.

METHODS

Freezing was performed by cooling one or two probes, with a diameter of 3.2 mm to -180 degrees C with liquid nitrogen. The cooling capacity of the probes was determined under thermic control by an in vitro measurement on human bone, followed by an in vivo measurement on femoral and tibia bones of a sheep.

RESULTS

The in vitro freezings achieved a sufficient tissue cooling using one or two cryoprobes. The simultaneous use of 2 probes resulted in a synergistic effect between the probes. According to the body heat, the registered temperature curves, during the in vivo freezings, showed a more flat trend. Nevertheless, temperatures below -50 degrees C were achieved at a distance of 1 cm from the probe due to the synergistic effect. Local or systematical intraoperative complications have not been observed.

CONCLUSION

An adequate tissue cooling of bone matrix can be achieved within in vivo freezings through the use of one or more miniature cryoprobes so that the use of this probe could possibly become an alternative or supplement to the surgical resection of pathologic bone processes.

Surfactant treatment of neonates with respiratory failure and group B streptococcal infection. Members of the Collaborative European Multicenter Study Group

OBJECTIVE

Connatal pneumonia caused by group B streptococcal (GBS) infection may be associated with surfactant dysfunction. We investigated the effects of surfactant treatment in term and preterm neonates with GBS infection and respiratory failure, in comparison with corresponding data from a control population of noninfected infants treated with surfactant for respiratory distress syndrome (RDS).

DESIGN/METHODS

The study comprised 118 infants with respiratory failure, clinical and/or laboratory signs of acute inflammatory disease, and GBS infection proven by culture results. They were recruited retrospectively from a database of patients treated with surfactant at 28 neonatology units participating in European multicenter trials (1987-1993) and prospectively from the same units in the following years. A nonrandomized control group of 236 noninfected infants was selected from the same database. The primary parameters evaluated were oxygen requirement, ventilator settings, and incidence of complications.

RESULTS

Median birth weight in the GBS study group was 1468 g (25th-75th percentiles: 1015-2170), and median gestational age was 30 (27-33) weeks. Thirty-one percent of the infants weighed >2000 g. Median age at surfactant treatment was 6 hours. The mean initial surfactant dose was 142 mg/kg (standard deviation: 53). Ninety of the infants were treated with Curosurf (Chiesi Farmaceutici, Parma, Italy), 13 with Survanta (Abboth GmbH, Wiesbaden, Germany), 12 with Alveofact (Dr Karl Thomae GmbH, Biberach, Germany), and 3 with Exosurf (Wellcome GmbH, Burgwedel, Germany). Within 1 hour of surfactant treatment, median fraction of inspiratory oxygen was reduced from .84 (25th-75th percentiles:.63-1.0) to.50 (.35-.80). The incidence of complications in the study group (mortality: 30%; pneumothorax: 16%; intracranial hemorrhage: 42%) was high, compared with infants with RDS.

CONCLUSIONS

Surfactant therapy improves gas exchange in the majority of patients with GBS pneumonia. The response to surfactant is slower than in infants with RDS, and repeated surfactant doses are often needed. The mortality and morbidity are substantial, considering the relatively high mean birth weight of the treated infants.

Atypical antipsychotic drugs in nonschizophrenic psychiatric disorders

This current review looks at the published literature discussing the use of atypical antipsychotics in nonschizophrenic conditions.

Pertussis antibody levels in infants immunized with an acellular pertussis component vaccine, measured using whole-cell pertussis ELISA

A commercially available whole-cell pertussis IgG ELISA was used to test the response of 137 2-month-old infants to immunization with a trivalent acellular pertussis vaccine. The pre-immunization geometric mean (GM) IgG index was 6.96 (95% confidence interval (CI) 5.88-8.04) and the postimmunization GM index was 13.16 (95% CI 12. 20-14.11), P < 0.001. Eighty percent of subjects (110/137) had a significant 1.5-fold increase of pertussis IgG index (97/137, 71%) or a postimmunization IgG index > 10 (93/137, 68%). In single antigen ELISA, 83% showed at least a fourfold increase in pertussis toxin-specific IgG (PT-IgG) and 91% showed an increase in IgG specific for filamentous haemagglutinin (FHA-IgG). Four percent had high pre- immunization antibody levels (index > 20), likely to reflect recent maternal exposure to pertussis. This correlated with a smaller increase in pertussis IgG index. A decline in pertussis IgG index postimmunization occurred in 17/24 infants (71%) whose pre-immunization IgG index was > 10. This postimmunization pertussis IgG index was not significantly different to that of infants with a low pre-immunization index. A similar trend was noted with PT-IgG and FHA-IgG results. The whole-cell ELISA can detect a response to acellular pertussis vaccination in most infants if both antibody index and degree of seroconversion are calculated and at least one criterion is satisfied.

Functional impairment and cognition in bipolar disorder

Bipolar disorder is a common, chronic and severe mental disorder, affecting approximately 2% of the adult population. Bipolar disorder causes substantial psychosocial morbidity that frequently affects the patient's marriage, children, occupation, and other aspects of the patient's life. Few studies have examined the functional impairment in patients with affective illness. Earlier outcome studies of mania reported favorable long-term outcomes. However, modern outcome studies have found that a majority of bipolar patients evidence high rates of functional impairment. These low reports of functional recovery rates are particularly surprising. The basis for such limited functional recovery is not entirely clear. Factors associated with functional dysfunction include presence of inter-episode symptoms, neuroleptic treatment, lower social economic class, and lower premorbid function. Cognitive dysfunction, a symptom domain of schizophrenia, has been identified as an important measure of outcome in the treatment of schizophrenia. Recently, there has been some suggestion that there may be impaired neuropsychological performance in euthymic patients with recurring mood disorders. Whether impaired neuropsychological performance in associated with the functional impairment in bipolar patients who have achieved syndromal recovery is an intriguing question. The literature on functional impairment and cognition in bipolar disorder is reviewed.

Behavioural evidence for polarisation vision in stomatopods reveals a potential channel for communication

Polarisation sensitivity (PS) - the ability to detect the orientation of polarised light - occurs in a wide variety of invertebrates [1] [2] and vertebrates [3] [4] [5], many of which are marine species [1]. Of these, the crustacea are particularly well documented in terms of their structural [6] and neural [7] [8] adaptations for PS. The few behavioural studies conducted on crustaceans demonstrate orientation to, or local navigation with, polarised sky patterns [9]. Aside from this, the function of PS in crustaceans, and indeed in most animals, remains obscure. Where PS can be shown to allow perception of polarised light as a 'special sensory quality' [1], separate from intensity or colour, it has been termed polarisation vision (PV). Here, within the remarkable visual system of the stomatopod crustaceans (mantis shrimps) [10], we provide the first demonstration of PV in the crustacea and the first convincing evidence for learning the orientation of polarised light in any animal. Using new polarimetric [11] and photographic methods to examine stomatopods, we found striking patterns of polarisation on their antennae and telson, suggesting that one function of PV in stomatopods may be communication [12]. PV may also be used for tasks such as navigation [5] [9] [13], location of reflective water surfaces [14] and contrast enhancement [1] [15] [16] [17] [18]. It is possible that the stomatopod PV system also contributes to some of these functions.

Averaging attributable fractions in the multifactorial situation: assumptions and interpretation

In multifactorial situations, the concept of attributable fraction quantifying the population impact of exposure factors on the disease load needs special methodologic care to take the interrelationship between exposures into account. Recently, new epidemiologic parameters have been introduced to address this issue. These approaches are reconsidered here from a game-theoretical perspective. The derivation of game-theoretical properties of these parameters provides additional motivation for their use in epidemiologic practice and offers new insights into their interpretation in epidemiologic studies. The nontechnical description of the results is illustrated by examples from the Hordaland study on obstructive lung disease.

Structure and expression of the Caenorhabditis elegans protein kinase C2 gene. Origins and regulated expression of a family of Ca2+-activated protein kinase C isoforms

The molecular and cellular basis for concerted Ca2+/lipid signaling in Caenorhabditis elegans was investigated. A unique gene (pkc-2) and cognate cDNAs that encode six Ca2+/diacylglycerol-stimulated PKC2 isoenzymes were characterized. PKC2 polypeptides (680-717 amino acid residues) share identical catalytic, Ca2+-binding, diacylglycerol-activation and pseudosubstrate domains. However, sequences of the N- and C-terminal regions of the kinases diverge. PKC2 diversity is partly due to differential activation of transcription by distinct promoters. Each promoter precedes an adjacent exon that encodes 5'-untranslated RNA, an initiator AUG codon and a unique open reading frame. PKC2 mRNAs also incorporate one of two 3'-terminal exons via alternative splicing. Cells that are capable of receiving and propagating signals carried by Ca2+/diacylglycerol were identified by assessing activities of pkc-2 gene promoters in transgenic C. elegans and visualizing the distribution of PKC2 polypeptides via immunofluorescence. Highly-selective expression of certain PKC2 isoforms was observed in distinct subsets of neurons, intestinal and muscle cells. A low level of PKC2 isoforms is observed in embryos. When L1 larvae hatch and interact with the external environment PKC2 content increases 10-fold. Although 77- and 78-kDa PKC2 isoforms are evident throughout post-embryonic development, an 81-kDa isoform appears to be adapted for function in L1 and L2 larvae.

Which parts of the road guide steering?

A driver steering a car on a twisting road has two distinct tasks: to match the road curvature, and to keep a proper distance from the lane edges. Both are achieved by turning the steering wheel, but it is not clear which part or parts of the road ahead supply the visual information needed, or how it is used. Current models of the behaviour of real drivers or 'co-driver' simulators vary greatly in their implementation of these tasks, but all agree that successful steering requires the driver to monitor the angular deviation of the road from the vehicle's present heading at some 'preview' distance ahead, typically about 1 s into the future. Eye movement recordings generally support this view. Here we have used a simple road simulator, in which only certain parts of the road are displayed, to show that at moderate to high speeds accurate driving requires that both a distant and a near region of the road are visible. The former is used to estimate road curvature and the latter to provide position-in-lane feedback. At lower speeds only the near region is necessary. These results support a two-stage model of driver behaviour.

Peroxisomal membrane protein PMP68 of mouse liver: cloning of a cDNA encompassing the nucleotide binding fold and epitope mapping of monoclonal antibodies to the expressed protein

We have isolated and sequenced a cDNA which encodes 376 amino acids toward the carboxy-terminus, and encompassing the putative nucleotide binding fold, of PMP68 (mouse liver peroxisomal integral membrane protein of 68 kDa) the major integral membrane protein of mouse liver peroxisomes. The protein sequence predicted from this cDNA shows 97.9% amino acid identity to this same region of rat liver PMP70, a member of the ATP-binding cassette protein superfamily (K. Kamijo, S. Taketani, S. Yokota, T. Osumi, and T. Hashimoto, 1990, J. Biol. Chem. 265, 4534-4540). The section of the cDNA encoding the hydrophilic and putative cytoplasmic domain of PMP68 was expressed as a recombinant fusion protein in bacteria. Two monoclonal antibodies raised against this protein have been epitope-mapped to peptides generated by cyanogen bromide cleavage of the fusion protein. Antibody 1A4 recognizes a peptide whose sequence contains the first motif of the putative nucleotide binding fold of PMP68, and antibody 8F11 recognizes a carboxy-terminal peptide which includes the second motif of this nucleotide binding fold. These antibodies are expected to be useful in the elucidation of the biological function of this putative membrane transporter.

Origin, properties, and regulated expression of multiple mRNAs encoded by the protein kinase C1 gene of Caenorhabditis elegans

Recently, we cloned and characterized cDNA encoding a novel, protein kinase C (designated PKC1B) from Caenorhabditis elegans. PKC1B (707 amino acid residues) is a developmentally regulated, calcium-independent kinase that is expressed exclusively in sensory neurons and related interneurons. We have now discovered a mechanism by which a second, distinct mRNA (PKC1A mRNA) with increased protein coding potential is generated from the C. elegans PKC1 gene. PKC1A mRNA is produced in a process that involves the utilization of an alternative, distal promoter, the incorporation of two unique exons into the mRNA, and alternative cis/trans splicing. Diversity among PKC1 gene transcripts is increased substantially by trans-splicing. The 5' end of PKC1A mRNA contains an acceptor site that is modified by the addition of either a classical spliced leader sequence 2 or one of four novel spliced leaders. PKC1A mRNA encodes a predicted kinase that contains the entire sequence of PKC1B as well as an N-terminal extension of 56 residues. The extension contains a preponderance of basic amino acids. The levels of transcripts arising from the distal (1A) and proximal (1B) promoters for the PKC1 gene are differentially regulated during C. elegans development. The ratio of 1B mRNA:1A mRNA varies from 40:1 to unity as the nematodes progress from early larval stages to mature adults. The novel exons in the PKC1A structural gene are not contiguous with the PKC1A promoter but are instead positioned downstream from a second gene, kinase upstream gene-1, in the context of a multicystronic operon. PKC1A and kinase upstream gene-1 mRNAs are coordinately expressed in a fixed ratio throughout C. elegans post-embryonic development, suggesting that a shared upstream promoter regulates transcription of both genes. Finally, PKC1A and PKC1B mRNA levels are differentially regulated by phorbol esters in a process that may involve the participation of another PKC isoform that is analogous to mammalian PKC delta.

Structure and expression of a novel, neuronal protein kinase C (PKC1B) from Caenorhabditis elegans. PKC1B is expressed selectively in neurons that receive, transmit, and process environmental signals

The nematode Caenorhabditis elegans provides an advantageous system for investigating the regulation, expression, and functions of protein kinase C (PKC) isoforms. We cloned and characterized cDNAs encoding a novel C. elegans PKC designated PKC1B. The predicted PKC1B polypeptide contains features characteristic of the nPKC subfamily of PKC isoforms. The levels of PKC1B and its cognate mRNA vary over a 7-fold range during C. elegans postembryonic development. PKC1B protein and mRNA are abundant at the earliest larval stage, but their relative concentrations decrease coordinately in late larvae. Embryos, which are enriched in PKC1B mRNA, contain little PKC1B protein. Thus, PKC1B expression is regulated at a translational or post-translational level during early development. Cells engaged in PKC1B gene transcription were identified in transgenic C. elegans that carry the lacZ gene under the regulation of the PKC1B promoter. Staining for beta-galactosidase revealed PKC1B promoter activity exclusively in sensory neurons and interneurons. Immunofluorescence microscopy disclosed that the PKC1B polypeptide is located in the processes (axons and dendrites) and perinuclear regions of approximately 75 neurons that constitute the sensory circuitry of the nematode. The intracellular localization of PKC1B and the enzyme's differential solubility in ionic and nonionic detergents suggest that the kinase is associated with membranes and the cytoskeleton.

Blastomycotic cranial osteomyelitis

This is the second case report of a temporal bone osteomyelitis caused by Blastomyces dermatitidis, which presented as a chronic serous otitis media. The presenting serous otitis media was refractory to conventional medical and surgical management and progressed to a temporal bone osteomyelitis prior to diagnosis. B. dermatitidis is a rare fungal pathogen that causes a systemic pyogranulomatous disease that primarily manifests itself in the skin, bones, pulmonary, and genitourinary systems. If left untreated it is associated with a high rate of mortality. The otologic presentation of this rare disease is emphasized, while the clinical and therapeutic features are reviewed.

Glycerol-induced unraveling of the tight helical conformation of Escherichia coli type 1 fimbriae

Glycerol was found to unravel the helical conformation of Escherichia coli type 1 fimbriae without appreciable depolymerization. The linearized fimbrial polymers have a diameter of 2 nm, react strongly with a monoclonal antibody directed at an inaccessible epitope on native fimbriae, and display greater mannose-binding activity and trypsin sensitivity than native fimbriae. Removal of glycerol by dialysis results in spontaneous reassembly of the linear polymers into structures morphologically, antigenically, and functionally indistinguishable from native fimbriae.

The accuracy of simple ordinal scoring of tooth attrition in age assessment

Tooth wear is frequently used as a method of ageing skeletal remains. Fundamental to this method is the ability to measure the amount of tooth wear. The Brothwell chart based on the Miles method of ageing, uses simple ordinal scoring and is frequently used by archeologists. The purpose of the present investigation was to evaluate the accuracy of simple ordinal scoring in recording tooth wear and ageing skulls. A group of Chinese skulls of known age at death was used. The age range was from 16 to 60 years. A single score per molar tooth was used to record occlusal wear. The data were analysed by regression methods using BMDP statistical software. The results showed that molar tooth wear continues throughout the life of the individual. The first molar teeth wear significantly more quickly than do second molar teeth. Use of a simple ordinal score method for recording wear gives an inaccurate estimate of an individual skull's age at death with a very wide 95% confidence interval.

A comparison of the position of the mental foramen in Chinese and British mandibles

The antero-posterior position of the mental foramen was studied in 68 Chinese and 44 British skulls of known or calculated age at death. All skulls showed low pre-mortem tooth loss and had a good occlusion. The position of the foramen was related to the body of the mandible as well as to the standing mandibular teeth using two previously published methods. There was no significant difference in the size of the Chinese and British mandibles. There was a significant difference between the two groups when measurements relating the foramen to the body of the mandible (symphysis menti) were considered, the foraminal position being more distal in the Chinese group. The modal position of the foramen in the Chinese sample was along the long axis of the second premolar, whereas in the British sample it lay between the apices of the first and second premolar. The foraminal position apparently moved distally in both groups with age and this was likely to be associated with mesial tooth drift and age-related attrition.

Identification of a mineralocorticoid receptor binding substance in the urine of patients with congenital adrenal hyperplasia

Increased amounts of circulating mineralocorticoid receptor binding substances presumed to be natural antagonists were previously demonstrated in congenital adrenal hyperplasia. In this study the feasibility of using urinary extracts for the identification of such binding substances was investigated. Urinary extracts from patients with the 21-hydroxylase defect did contain greater than normal amounts of mineralocorticoid receptor binding material. When subjected to chromatographic separation using a radioreceptor assay to follow the course of fractionation, a major aldosterone binding competitor was identified. On the basis of its chromatographic mobility in comparison with the labeled steroid, radioimmunoassay, ultraviolet absorption and radio-receptor assay of the native and acetylated derivative, the component was identified as 11-deoxycorticosterone and its structure confirmed by mass spectrometry. Although the major mineralocorticoid receptor binding component proved not to be an antagonist but an agonist, the results are in keeping with other evidence for overproduction of 11-deoxycorticosterone in the simple virilizing form of the disorder. Our finding did not disprove the existence of a circulating mineralocorticoid antagonist in congenital adrenal hyperplasia, but demonstrate that the major receptor binding substance in urinary extracts in that disorder is the mineralocorticoid agonist, 11-deoxycorticosterone.

Evidence for the secretion of an antimineralocorticoid in congenital adrenal hyperplasia

Plasma extracts from patients with congenital adrenal hyperplasia were found to contain substances that competed with aldosterone for mineralocorticoid receptor-binding sites in a rat kidney cytosol system. In normal subjects and patients with other disorders, the mineralocorticoid receptor-binding activity in such extracts could be entirely accounted for by the sum of the contributions of the steroids known to bind to the mineralocorticoid receptor. The secretion of these binding substances in patients with the C-21 hydroxylation defect was ACTH dependent. While these substances could be either mineralocorticoid agonists or antagonists, the latter is more likely. Production of mineralocorticoid antagonists would account for the compensatory hyperaldosteronism that occurs in the simple virilizing form, in which there is minimal impairment of aldosterone secretory reserve, and for the tendency to Addisonian crisis in patients with the salt-losing form, who have a more severe defect in aldosterone biosynthesis.

18-oxocortisol, a naturally occurring mineralocorticoid agonist

Two C-18-oxygenated corticosteroids, 18-hydroxy- and 18-oxocortisol, have recently been isolated from the urine of patients with primary and genetic (dexamethasone-suppressible) aldosteronism and from adrenal tissue. The relevance of these steroids to the manifestations of mineralocorticoid excess in these disorders was investigated by measuring their affinity to rat renal corticosteroid receptors. 18-Oxocortisol showed greater affinity than the 18-hydroxy derivative for both mineralocorticoid and the glucocorticoid receptors and was accordingly assayed in vivo for mineralocorticoid activity. The 18-oxo derivative was found to be an agonist with a sodium-retaining and kaliuretic action qualitatively similar to that of aldosterone. Although 18-oxocortisol was one-third as active as 11-deoxycorticosterone in this assay, it was a more potent mineralocorticoid at the same total plasma concentration because of its lower affinity for corticosteroid-binding globulin.

Biosynthesis of 18-oxocortisol by aldosterone-producing adrenal tissue

Aldosterone-biosynthesizing adrenal tissue contains an angular methyl oxidase which converts corticosterone to 18-hydroxycorticosterone and aldosterone. Cortisol, when incubated with an active source of this oxidase, the bullfrog interrenal gland, was converted to 18-hydroxycortisol and a new C-18-oxygenated steroid identified as 11 beta, 17 alpha,21-trihydroxy-3,20-diketo-4-pregnene-18-al, or 18-oxocortisol. Proof of structure was based on the evidence that it was an alpha, beta-unsaturated ketone biosynthesized from cortisol with an empirical formula of C21H28O6. Low resolution gas chromatography-mass spectrometry of its fully derivatized methoxime trimethylsilyl ether confirmed a trioxopregnenetriol structure in which one aldehyde group was partially masked as an internal hemiacetal. That the oxo group had replaced the C-18 angular methyl was shown by oxidative degradation of the side chain with either periodic acid or sodium bismuthate to yield an hydroxy gamma-lactone rather than an etioacid. It is suggested that the corticosterone methyl oxidase system of aldosterone-producing cells has diminished substrate specificity enabling it to accept cortisol as a suboptimal substrate. Angular methyl oxidation of cortisol to its 18-hydroxy and 18-oxoderivative in two hypertensive disorders is attributed to a derangement in adrenocortical functional zonation permitting access of glucocorticoid products into the mineralocorticoid-biosynthesizing system.

Pharmacists' clinical role expanded

A hospital used management engineering to achieve more effective utilization of its pharmacy staff so that pharmacists' clinical role could be expanded without increases in staff or costs.

Interrelation of the pituitary-thyroid system at birth in man

Samples of cord blood derived from 105 normal babies after uncomplicated deliveries were assayed for thyroxine (T4), tri-iodothyronine (T3), reverse tri-iodothyronine (rT3), thyroxine-binding globulin (TBG) and thyrotrophin (TSH). The values for T3, rT3 and TSH were log-normally distributed (geometric means 0.62 nmol/l, 3.28 nmol/l and 10.9 mu./l respectively) and those for T4 and TBG were normally distributed (means 126 nmol/l and 13.7 mg/l), The data were systematically analysed and no evidence was obtained to suggest that the concentration of TSH, which varied widely, was regulated by any of the thyroid hormones alone or in combination. There was a direct relation between the concentrations of T4 and T3 in the cord blood at birth but not between either of these and rT3. There is thus no evidence of a functional interdependence of the hypothalamic-pituitary-thyroid system in man at birth.

Reverse triiodothyronine, thyroid hormone, and thyrotrophin concentrations in placental cord blood

Reverse triiodothyronine (rT3), triiodothyronine (T3), thyroxine (T4), thyroxine binding globulin (TBG), and thyrotrophin (TSH) were measured in sera from placental cord blood in an unselected series of 272 deliveries. In this series the concentrations of rT3 (mean 3.33 nmol/l, 95% confidence limits 1.6--7.0 nmol/l), were log normally distributed and did not overlap the adult normal range (0.11--0.44 nmol/l). There were no correlations between the cord blood concentrations of rT3, T3, T4, and TSH. The cord serum rT3 concentration was not influenced by maturity, birth-weight, or neonatal risk factors, whereas these factors did affect the concentrations of T3, T4, AND TBG. There is no arteriovenous rT3 concentration difference across the placenta, therefore the cord rT3 reflects the systemic rT3 concentration in the baby at birth. As rT3 in the neonate largely, if not entirely, derives from thyroxine from the fetal thyroid, measurement of the cord rT3 concentration may be a good immediate screening test for neonatal hypothyroidism.

Radioaffinity assay, a new approach to binding assays applied to the measurement of serum albumin

The affinity adsorbent Cibacron Blue F3GA-Sepharose 4-B has been used to develop a binding assay for human serum albumin. The method is simple, accurate and precise. It agrees well with the 'rocket' immunoelectrophoretic method and is proposed as an alternative technique for the re-estimation of albumin levels in the low range (less than 30 g/l) where the bromocresol green dye-binding method overestimates. Bilirubin, several drugs, gammaglobulin, haemoglobin and heparin do not interfere with the estimations.