Clinical outcomes after IL-6 blockade in patients with COVID-19 and HIV: a case series

BACKGROUND

In hospitalized people with HIV (PWH) there is an increased risk of mortality from COVID-19 among hospitalized PWH as compared to HIV-negative individuals. Evidence suggests that tocilizumab-a humanized monoclonal interleukin (IL)-6 receptor inhibitor (IL-6ri) antibody-has a modest mortality benefit when combined with corticosteroids in select hospitalized COVID-19 patients who are severely ill. Data on clinical outcomes after tocilizumab use in PWH with severe COVID-19 are lacking.

CASE PRESENTATION

We present a multinational case series of 18 PWH with COVID-19 who were treated with IL-6ri's during the period from April to June 2020. Four patients received tocilizumab, six sarilumab, and eight received an undocumented IL-6ri. Of the 18 patients in the series, 4 (22%) had CD4 counts < 200 cells/mm³; 14 (82%) had a suppressed HIV viral load. Eight patients (44%), all admitted to ICU, were treated for secondary infection; 5 had a confirmed organism. Of the four patients with CD4 counts < 200 cells/mm³, three were treated for secondary infection, with 2 confirmed organisms. Overall outcomes were poor-12 patients (67%) were admitted to the ICU, 11 (61%) required mechanical ventilation, and 7 (39%) died.

CONCLUSIONS

In this case series of hospitalized PWH with COVID-19 and given IL-6ri prior to the common use of corticosteroids, there are reports of secondary or co-infection in severely ill patients. Comprehensive studies in PWH, particularly with CD4 counts < 200 cells, are warranted to assess infectious and other outcomes after IL-6ri use, particularly in the context of co-administered corticosteroids.

Characteristics, Comorbidities, and Outcomes in a Multicenter Registry of Patients with HIV and Coronavirus Disease-19

Background

People with HIV (PWH) may have numerous risk factors for acquiring Coronavirus disease-19 (COVID-19) and developing severe outcomes, but current data are conflicting.

Methods

Healthcare providers enrolled consecutively by non-random sampling PWH with lab-confirmed COVID-19, diagnosed at their facilities between April 1st and July 1st, 2020. De-identified data were entered into an electronic Research Electronic Data Capture (REDCap). The primary endpoint was severe outcome, defined as a composite endpoint of intensive care unit (ICU) admission, mechanical ventilation, or death. The secondary outcome was the need for hospitalization.

Results

286 patients were included; the mean age was 51.4 years (SD, 14.4), 25.9% were female, and 75.4% were African-American or Hispanic. Most patients (94.3%) were on antiretroviral therapy (ART), 88.7% had HIV virologic suppression, and 80.8% had comorbidities. Within 30 days of positive SARS-CoV-2 testing, 164 (57.3%) patients were hospitalized, and 47 (16.5%) required ICU admission. Mortality rates were 9.4% (27/286) overall, 16.5% (27/164) among those hospitalized, and 51.5% (24/47) among those admitted to an ICU. The primary composite endpoint occurred in 17.5% (50/286) of all patients and 30.5% (50/164) of hospitalized patients. Older age, chronic lung disease, and hypertension were associated with severe outcomes. A lower CD4 count (<200 cells/mm³) was associated with the primary and secondary endpoints. There was no association between the antiretroviral regimen or lack of viral suppression and predefined outcomes.

Conclusion

Severe clinical outcomes occurred commonly in PWH and COVID-19. The risk for poor outcomes was higher in those with comorbidities and lower CD4 cell counts, despite HIV viral suppression.

Cell-stimulation therapy of lateral epicondylitis with frequency-modulated low-intensity electric current

In addition to the routine therapy, the patients with lateral epicondylitis included into experimental group were subjected to a 12-week cell-stimulation therapy with low-intensity frequency-modulated electric current. The control group received the same routine therapy and sham stimulation (the therapeutic apparatus was not energized). The efficiency of this microcurrent therapy was estimated by comparing medical indices before therapy and at the end of a 12-week therapeutic course using a 10-point pain severity numeric rating scale (NRS) and Roles-Maudsley pain score. The study revealed high therapeutic efficiency of cell-stimulation with low-intensity electric current resulting probably from up-regulation of intracellular transmitters, interleukins, and prostaglandins playing the key role in the regulation of inflammation.

Traditional Chinese medicine in diagnosis and treatment of fibromyalgia syndrome

Fibromyalgia Syndrome (FS) is known for the difficulties arising from classification. The accompanying pain in skeletal muscles, myofascial peri-articular structures and a number of polymorphic symptoms cannot be separated into complexes of symptoms. The application of principles of Traditional Chinese Medicine (TCM) helps in analyzing the symptoms of FS to detect a leading syndrome and thereby establish an individual therapy. Medical histories and objective examinations of 25 patients with FS and 22 patients with vertebrogenic pain syndromes were analyzed according to TCM. A questionnaire was used to determine the leading constitutional type according to the 5-elements-theory. Analyses of the results showed that 83% of patients with FS were of constitutional type of the element earth. The following syndromes were found to be important in FS: 1) liver-Qi-stagnation, 2) Yin and blood deficiency of the liver, 3) Yang-weakness of the spleen and kidney, 4) Yin-weakness of the kidney. Applying TCM for FS allows for separating a group of symptoms and thus individual therapy. The determination of the constitutional type according to the 5-elements-theory may be used for a better understanding of the disharmony pattern.

Results of conservative treatment of achillodynia with application micro-current therapy

Achillodynia describes it as an expression of chronic pain in the Achilles tendon. Pain in the Achilles tendon can be the cause of wear and tear in the tendon tissue, or following an inflammation of the peritendineum, the underlying bursa and/or the tendon insertion at the heel bone. It often occurs after sporting unusual stress and heal after complex conservative treatment by rest, (partial) relief and physical exercise within several weeks to months. The aim was to turn knowledge on the effectiveness of complex conservative treatment measures, in particular to gain by additional stimulation in the treatment of Achilles tendon. 20 patients with a diagnosis of achillodynia were treated 05-2009 to 12-2009 in the orthopedic outpatient therapy center with the help of the extra, micro-current therapy (CellVAS® device) and a complex conservative treatment measures. The analysis was conducted using a questionnaire, clinical examinations, magnetic resonance imaging (MRI) and a radiological examination of the Achilles tendon with the ankle joint. At the beginning and end of the intervention to the Board of subjective symptoms scores (NRS scale) and assessment of treatment results by the doctor for 4-step rating scale were collected. The study compares the treatment response in Achillodynia from a control group. The average age of patients was 46.3 years at the time of treatment. Of these patients: 14 (70%) were females and 6 (30%) male. Of 20 patients were 8 (40%) patients with very good, 7 (35%) patients with good, two (10%) patients with satisfactory and three (15%) patients with poor results. In addition, 17 of 20 patients (85%) with conservative treatment measures were satisfied, 3 patients (15%) were dissatisfied. The subjective assessment of the complaints numerical rating scale (NRS scale) improved significantly (p <0.001) from 8.9 to 2.3 points after treatment. An objective evaluation by the attending physician based on various clinical parameters was assessed in 75% of the cases as good or very good. The study shows that the described complex conservative therapy is the integration of a micro-current treatment is a very good method for the treatment of Achillodynia/Achilles tendon disorders in athletes. The primary goal of treatment is to achieve freedom from pain and was achieved consistently, as the subjective assessment of the complaints was proved using the NRS scale. The high patient satisfaction with the treatment suggests in addition, any therapy must keep in action the long-term development of athletes in mind. In individual must be questioned what treatment method for long-term sports development but also the health history (this is not inevitably always the same) is an advantage. The conservative treatment seems to be advantageous because it leaves open for therapy-resistant complaints, the option of surgical treatment, and has generally very good chance of recovery.

Wider recognition in peripheral vision common to different subtypes of dyslexia

Italian children (n = 125) were classified into dyslexics, poor readers and ordinary readers. The dyslexics were further classified into the Boder and Bakker subtypes. The children were tested with the form-resolving field (FRF), which measures central and peripheral visual recognition. Dyslexics show higher correct identification of letters in the periphery, supporting the notion of a different distribution of lateral masking. A numerical characterization of individual FRFs--C2R--reliably distinguishes between dyslexics and ordinary readers. The wider distribution of recognition, similar across the various subtypes of dyslexia, suggests a general characteristic of visual perception, and possibly a different visual-attentional mode.

Standardized measurements and differential spectroscopy in microplates

Microplates (MPs) are excellent devices for the parallel processing of multiple samples for the spectroscopic analysis of chromophores and turbidity, for luminometric measurements, for cell culture applications, or simply for sample storage, library organization, and other high-throughput (HTP) processes. Disadvantages include an ill-defined pathlength, meniscus formation, evaporation, and cross-contamination. Here, we have developed a novel MP and lid system which can serve to minimize these drawbacks. Cup-like lids are inserted into MP wells. Thereby, liquid is pushed aside. The flat bottoms of the cup-like lids guarantee a planar interface and a defined pathlength. In addition, the devised MP system allows for differential spectroscopic analysis of multiple samples comparable to measurements in tandem cuvettes. This was shown by the investigation of the binding of reduced nicotinamide adenine dinucleotide to dihydrolipoamide dehydrogenase. The MP lid system described offers a low-cost solution for standardized spectrophotometric quantitations in any solvent compatible with the MP/lid material. In addition to the system's suitability for routine MP application, it should be advantageous as a simple and noninvasive method, i.e., no labeling and immobilization of analytes is required for detection of the interaction of molecules, for various HTP applications and drug screening purposes.

Intracellular action of the cytokine MIF to modulate AP-1 activity and the cell cycle through Jab1

Cytokines are multifunctional mediators that classically modulate immune activity by receptor-mediated pathways. Macrophage migration inhibitory factor (MIF) is a cytokine that has a critical role in several inflammatory conditions but that also has endocrine and enzymatic functions. The molecular targets of MIF action have so far remained unclear. Here we show that MIF specifically interacts with an intracellular protein, Jab1, which is a coactivator of AP-1 transcription that also promotes degradation of the cyclin-dependent kinase inhibitor p27Kip1 (ref. 10). MIF colocalizes with Jab1 in the cytosol, and both endogenous and exogenously added MIF following endocytosis bind Jab1. MIF inhibits Jab1- and stimulus-enhanced AP-1 activity, but does not interfere with the induction of the transcription factor NFkappaB. Jab1 activates c-Jun amino-terminal kinase (JNK) activity and enhances endogenous phospho-c-Jun levels, and MIF inhibits these effects. MIF also antagonizes Jab1-dependent cell-cycle regulation by increasing p27Kip1 expression through stabilization of p27Kip1 protein. Consequently, Jab1-mediated rescue of fibroblasts from growth arrest is blocked by MIF. Amino acids 50-65 and Cys 60 of MIF are important for Jab1 binding and modulation. We conclude that MIF may act broadly to negatively regulate Jab1-controlled pathways and that the MIF-Jab1 interaction may provide a molecular basis for key activities of MIF.

Amplifiable DNA from gram-negative and gram-positive bacteria by a low strength pulsed electric field method

An efficient electric field-based procedure for cell disruption and DNA isolation is described. Isoosmotic suspensions of Gram-negative and Gram-positive bacteria were treated with pulsed electric fields of <60 V/cm. Pulses had an exponential decay waveform with a time constant of 3.4 micros. DNA yield was linearly dependent on time or pulse number, with several thousand pulses needed. Electrochemical side-effects and electrophoresis were minimal. The lysates contained non-fragmented DNA which was readily amplifiable by PCR. As the method was not limited to samples of high specific resistance, it should be applicable to physiological fluids and be useful for genomic and DNA diagnostic applications.

A quantitative fluorescence-based microplate assay for the determination of double-stranded DNA using SYBR Green I and a standard ultraviolet transilluminator gel imaging system

Various assays are available for quantification of DNA in solution, but none has been described that is both sensitive and specific for double-stranded (ds) DNA and features practical properties such as low dye and equipment costs, speed, and highly parallel microplate formats. Here we show that quantitative and sensitive measurement of ds DNA in solution is achieved using a 96-well microplate SYBR Green I assay and a standard uv transillumination-based gel-imaging system for detection. Specific detection of ds DNA was obtained over a broad concentration range of 0.5-500 ng using a single low dye concentration of up to 1/6250. Measured SYBR Green I fluorescence was not significantly affected by pH variation (4-10), assay volume (50-250 microliter l), and time (4-15 min), and measurements were appreciably compatile with commonly encountered concentrations of contaminating salts, organics, detergents, and other substances. ds DNA yielded up to 13-fold higher fluorescence compared to single-stranded DNA or RNA, but this ratio was dependent somewhat on GC content and fragment size. Of note, linear ds DNA fluoresced significantly stronger than supercoiled plasmid DNA. Our method should be broadly applicable for sensitive, rapid, and inexpensive ds DNA quantification in the average molecular biology laboratory.

Heavy metal effects on beta-glucosidase activity influenced by pH and buffer systems

Inhibition of beta-glucosidase activity by Cu(II), Zn(II) and Ni(II) was investigated as a function of pH and buffer type. Both factors were found to exert a strong effect on the activity of the enzyme. All three of the investigated heavy metals inhibited the enzyme activity in acetate buffer. At metal concentrations of 0.6 mM, Zn and Ni reduced the enzyme activity by 25-30% under optimal pH conditions (pH 5-5.2). Under the same conditions, Cu showed an even more pronounced inhibitory effect than Zn and Ni. In presence of 0.6 mM Cu, the enzyme activity was lowered by more than 90% in comparison to metal free systems. In contrast to these results, no enzyme inhibition was observed in citrate buffer, even in the presence of 1 mM Cu. The inhibition of beta-glucosidase activity by Cu increased with increasing pH. Inhibition by Zn and Ni was less pH-dependent in the observed pH range (pH 4-5.5). Copper caused a distinct shift in the pH optimum of enzyme activity, whereas this was not the case for Zn or Ni. The effects of buffer and pH on enzyme inhibition by Cu, Zn and Ni were successfully described using a chemical speciation model, based on the assumption that enzyme activity depends on the protonation of the amino acids at the reactive site and that enzyme activity is inhibited by complexation of the reactive sites by the heavy metal cations. The results show the importance of taking chemical conditions and speciation into account when investigating the effect of heavy metal cations on biological systems.

Moving towards an electronic patient record: a survey to assess the needs of community family physicians

OBJECTIVE

To determine the needs of community family physicians regarding electronic patient records (EPRs).

DESIGN

A comprehensive survey was sent to 101 community family physicians in Hamilton, Ontario, who had expressed an interest in EPRs.

RESULTS

46 physicians responded (46%). 87% felt that an EPR would result in their providing better patient care. A wide variety of items were deemed to be important to be included on the EPR "front page". Desired functionality emphasized labs, medications, consultation, hospital follow-up and health maintenance. Family physicians tended to prefer templates to other data entry methods such as typing and dictating. Respondents were more willing to view information from the hospital than to let the hospital view information from their own offices.

CONCLUSION

This survey provided useful information on the perceived EPR needs of community-based family physicians. It will be repeated post-computerization.

What is an electronic patient record?

While organizations develop their Electronic Patient Records, there will be a transition period during which computerized and paper records will both exist, possibly on multiple clinical information systems. This paper describes a model that defines the patient system of record and its constituent paper elements and electronic components. The model has been adopted by a large academic health science center for their development of an electronic patient record. The model has clarified which systems and data constitute the patient system of record and the standards and policies that apply to these systems.

[Comparison of two methods of age determination in teeth of known age from wild carnivores]

Two age-determining methods were conducted on representatives of known age from the Order Carnivora (4 red foxes, 3 tree martens, 3 stone martens, 2 racoons, 2 badgers, 2 polecat and one otter). Age determination employed with the aid of tooth wear nearly agrees with the real age of the animals. Dating based on the formation of the age-dependent cement zone coincided well with the known ages of the individual specimens. However, in real foxes the figure one must be added to the number of cementum layers counted determining the definitive age of individuals. For representation of the cementum layers transverse sections of the apical part of the tooth root of canini, P2 and P3, stained with methylene blue, should be used. It is important to note that the dentino-cemental line should not be considered when counting the year rings in the cement.

Technical note: Rationale, development, use and evaluation of an equipment management and image storage system

Lack of space and organization have become significant problems in the contemporary business world. Modern industries must eliminate mountains of paper and better organize themselves. With the incorporation of a fully automated equipment management system and image storage system, the Jacobi Medical Center has succeeded in correcting these problems. This technical note shows how the use of computer software and hardware components can be integrated to manage electronic patient care equipment. The adoption of this new technology was applied to equipment maintenance, tracking and record-keeping, thereby accomplishing the aims of space conservation and organization. As the components became more advanced, the technology included computer software products that could store more information and electronically effect a more rapid document retrieval. This will eventually allow for a paperless operation. The latest available equipment management software is supported by an image storage system that may contain important signature documents and outside vendor information. The applicability of these systems to the biomedical engineering field is obvious: (a) space efficiency eliminates folders and files; (b) simultaneous technician access to equipment history; and (c) rapid archive retrieval of data as well as vendor information and safety alerts.

Soil bacteria sensitivity towards heavy metals ? Experimental system optimisation using chemical speciation calculations

The ecotoxicological relevance of many laboratory studies on soil bacteria sensitivity towards heavy metals is limited because culture conditions are chosen which do not adequately represent field conditions. The influence of the composition of culture media on the speciation of copper in an oligotrophic model soil system has been investigated. The expected chemical speciation has been calculated to obtain information on the concentration of the bioavailable fraction and the totally dissolved copper. For control measurements of totally dissolved copper, vacuum filtration has been used. The results of the measurements are in a good agreement with the calculations. Therefore, the use of speciation calculations is postulated as a useful tool for the assessment of free metal concentrations at higher pH, where the concentrations of dissolved metals are too low to be measured by simple methods.

Dental treatment of handicapped patients using endotracheal anesthesia

Dental treatment using endotracheal anesthesia is indicated where acute odontogenic infections, accidental injuries, or multiple caries and periodontitis marginalis require surgical and/or restorative treatment. It is also indicated where it is not possible to use psychological support during local anesthesia or during premedication or analgosedation. Dental treatment of handicapped patients using endotracheal anesthesia is described, along with indication and frequency of such treatment. The state of the dentition is illustrated, along with its relationship to the oral hygiene the handicapped patients receive. The main points of the intraoperative dental procedures and the follow-up of patient care are reported. Postoperative dental or general medical complications have not occurred within the patient population under study.

An analysis of the paper-based health record: information content and its implications for electronic patient records

An analysis of paper-based charting was carried out at Sunnybrook Health Sciences Center as a prelude to developing a strategic plan to implement an electronic patient record. A relational model of the Sunnybrook paper chart was developed, describing each of its forms in terms of specific data fields. Three hundred and forty nine different forms are in current use at Sunnybrook, containing 64 types of data fields such as Patient Demographics, Vital Signs, and Doctor's Orders. The extent of data field duplication at the level of hospital forms was significant. A Patient Demographics field was present on all forms and on all pages of a patient's chart, as would be expected. Twenty seven other fields were duplicated on more than ten different forms, including Working Diagnosis which was present on 110 forms, History of Past Illness on 42 forms, and History of Present Illness on 32 forms. Current Medications were recorded on 32 forms and Allergy fields were present on 29 separate forms. Only five data fields of the total 64 were present on only one form. The duplication of data fields within complete patient charts was then examined to confirm that data field duplication was occurring within the actual healthcare delivery process. Using the relational model of the charting system, 143 acute care in-patient encounters were abstracted into the database. The charts were selected randomly from each of the hospital inpatient services. The numbers and types of forms within each chart were recorded, amounting to 18,654 physical pages and using 165 of the different forms. The average in-patient encounter within the model was 130.4 pages long, with a minimum of 27 pages, a maximum of 559 pages, and containing on average 25.8 different forms. The duplication of data fields within actual charts followed a pattern similar to the duplication found on the forms. Initial diagnosis was present on an average of 20.4 pages within the charts, with a minimum of 2 pages and a maximum of 152 pages containing this data field. Other frequently occurring data fields included History of Past Illness present on an average of 12.2 pages per chart, History of present illness on 10.2 pages per chart, and allergies on an average of 9.1 pages per chart. The results obtained through the examination of Sunnybrook charts should be generalizable to most paper-based systems. This study did not measure the workload associated with duplicating chart data. however, the magnitude of the duplication seen in this study leaves little doubt that significant amounts of time could be saved with appropriate modification of health care delivery processes. Multiple copies of the same data field within a database are referred to as aliases of each other. This study demonstrates that hospital charts contain many copies of the same information, such as medication lists, allergies etc. Due to manual replication of data fields, there is no mechanism to ensure that each copy of a data element within a chart actually contains the same information. This aliasing of data through manual duplication compromises the integrity of data within paper-based charts. Decisions and therapy based upon contradictory or inaccurate data are likely to lead to inefficient or erroneous care delivery; this has significant implications for hospital liability and quality of patient care. A growing recognition of the costs and risks of data replication within paper-based charting systems is driving the healthcare industry toward Electronic Patient Record systems. Better quality patient care data, provided by computerized records, is likely to be necessary but not sufficient to improving the efficiency and effectiveness of the healthcare system. Intelligent application of this information will be essential.

[The histology of mastopathy and cumulative ipsilateral breast cancer sequence]

In a retrolective and follow-up study the ipsilateral cumulative risk of breast carcinoma after histological benign diseases in women under 66 years of age (n = 1397) is investigated. The subtypes are mastopathy I (= changes without proliferative lesions), mastopathy II (= proliferative lesions without atypia), and mastopathy III (id sunt atypical ductal and lobular hyperplasias). The cumulative risk with mastopathy I and II over a 15 year time period corresponds with the ordinary age related risk, the cumulative risk with mastopathy III is four times higher (p = 0.001). There is no difference between atypical ductal and lobular hyperplasia (p = 0.7). Women in reproductive age have a higher risk (p = 0.03), which exists even after a carcinoma-free survival of more than 10 years. The mastopathy is more a stigma for a higher breast cancer risk than a direct precancerous lesion.

Dyslexic children learn a new visual strategy for reading: a controlled experiment

Recent studies by Geiger, Lettvin and Zegarra-Moran have proposed a new non-reading test for the diagnosis of dyslexia, and a new method for remediation. The latter involves the learning of a "visual strategy". On adult dyslexics the test was reliable and the remediation apparently effective. The purpose of this study is to confirm the usefulness of the remediation and test with children. Dyslexic children (3rd-6th grade) were divided into two groups. The experimental group (9) was given a new remedial regimen of practise. The control group (6) continued the remedial process given in their school. After 3 months of practising their separate regimens all the dyslexic children who were in the two groups were retested and compared. The "experimental" dyslexics improved in reading by 1.22 grade level on average while the "control" dyslexics improved by 0.17 grade on average. The form-resolving field (FRF) plots narrowed significantly for the experimental dyslexics while they changed little for the control dyslexics. At the end of the second testing the control dyslexics were also given the new regimen of practise. Five months later all the dyslexic children were tested for the third time. The initial control dyslexics who later practised the regimen (2) improved in reading by 2-2.5 grades and their FRF plot narrowed. The experimental dyslexics continued to improve yet further. All the dyslexic who practised the new regimen started at an average of 2.5 grades behind their expected grade/age level and after 8 months were at an average 0.75 grades behind their expected grade/age level. This is on average 1.75 grade level improvement in reading within 8 months, a rate of improvement larger than that of ordinary reading subjects. The dyslexic children were compared with matched grade/age ordinary reading children for reference. The study confirms the usefulness of the test and the applicability of the remediation method for children. It also shows that improvement under that method is quite rapid.

Visual recognition in the peripheral field: letters versus symbols and adults versus children

The plot of the form-resolving field (FRF) was obtained by tachistoscopically presenting two figures in each stimulus, one in the center of gaze and the other in the peripheral field. The figures in the periphery were placed at various eccentricities in different presentations. The ensuing plot of average letter recognition as a function of eccentricity is the FRF. Only the horizontal components of the FRFs were used in the comparisons. Three sets of figures were used as stimuli: regular-size letters, large-size letters, and symbols. Three groups of subjects were compared: adult ordinary readers, reading children, and pre-reading-age children. The last were tested with symbols only. In letter recognition, the FRFs for young and adult ordinary readers are similar and fall off monotonically and symmetrically with eccentricity, hence conforming with the first Aubert-Foerster law (1857). However, the FRFs tested with symbols are narrower than those tested with letters of the same sizes and stroke widths, which is not in accordance with the first Aubert-Foerster law. In addition, the FRFs of symbols are different for each subject group. It is suggested that recognition in the peripheral field is not determined by visual acuity alone; rather, it is further confined or determined by the visual strategy employed to accomplish the task, and its associated distribution of lateral masking.

[Micromorphological studies of the blood vessels of the dental pulp of small ruminants]

The blood vascular supply of the dental pulp of 15 domestic sheep of varying age and sex was investigated using light and electron microscopy. The pulp vascular system is showing arterioles with a media of varying thickness and with endothelial cells of variable structure. In the transitional zone between crown and root pulp, the arterioles are taking a typical S- or U-shaped course. The capillary network of the crown pulp is denser and more regular than that in the root pulp. In addition to the capillaries lined by a continuous endothelial tube, there may be others with a typically fenestrated endothelial lining. Specialised vascular structures of the peripheral blood vessels, especially arterio-venous anastomoses as described in man, have not been observed in the sheep.

Task-determined strategies of visual process

Lateral masking in the peripheral field of vision obscures letter recognition and is not accounted for by diminished acuity. In measuring lateral masking between letters in the peripheral visual field we accidentally discovered that ordinary readers and severe dyslexics differ markedly in tachistoscopic letter recognition tasks. Tests were devised to measure the differences accurately. Ordinary readers recognize letters best in and near the center of gaze. Recognition falls off rapidly with angular distance in the peripheral field. Severe dyslexics recognize letters farther in the periphery in the direction of reading (English-natives to the right, Hebrew-natives to the left). They have marked lateral masking in and near the center of the field when letters are presented in aggregates. With dyslexia as an example, we proposed that the distribution of lateral masking is a task-dependent strategy in visual perception. To test this notion we designed an active practise regimen for 4 severe adult dyslexics, who within a few months improved sharply in reading. At the same time their test results changed to those of ordinary readers. We conclude that there are switchable task-determined pre-cognitive strategies of vision that can be learned and that the distribution of lateral masking may be part of what is learned.

[Scanning electron microscopic studies of the odontoblasts and the pulpodentinal border in domestic sheep (O. ammon aries Linnaeus, 1758)]

In order to investigate odontoblasts and predentin surfaces using SEM techniques, teeth of sheep with one or several roots were subjected to critical point drying. The odontoblasts of the root pulp are distinguished in their shape and arrangement pattern from those in the crown pulp. They regularly are detaching only one process of Tomes, which is extending up to the border between dentin and enamel and which shows a dendritic ramification in the dentin next to the enamel. The distal cell portions of the odontoblasts are joined together by a system of terminal bars. The collagen structures observed between the odontoblasts and predentin are considered to be von Korff's fibres as found in man.

[Micromorphologic studies of the odontoblasts of sheep in different development and maturation stages]

The fine tissue structure of ovine odontoblasts was studied in various developmental and maturational stages. Odontoblasts differentiate from the peripherally-located mesenchymal cells of the dental papilla. On the basis of cytological parameters, it was possible to divide the odontoblasts into the following groups: pre-odontoblasts, juvenile (light) odontoblasts and mature (dark) odontoblasts. The three maturational stages of odontoblasts exhibit substantial differences with respect to their form and to the number and arrangement of their cytoplasmatic organelles. Structural differences in the three cell types appear to be closely correlated to the level of cellular activity.

[Fine tissue studies of the nerve supply to the dental pulp in domestic sheep (O. ammon aries Linné, 1758)]

The nerve supply of the pulp was investigated in 17 sheep of various breeds and age groups belonging to both sexes, using light and electron microscopy. The following results were obtained: The dental pulp of sheep is supplied with myelinated and unmyelinated nerve fibres. The subodontoblastic plexus of Raschkow, as found in man, is absent in sheep. Single axons may be found in the predentine between the odontoblasts and near Tomes' processes. The rare occurrence of both subodontoblastic nerve fibres and cells of the immune system in the ovine pulp is discussed in relation to evolutionary processes, in light of the fact that sheep are relatively resistant to caries.

Deterioration of PTFE-prostheses wall. A SEM study

Specimens of long-term femoro-popliteal ePTFE bypass implants were examined by means of scanning electron microscopy in order to analyze the structure of the prosthetic wall. Twelve months after implantation, the structure of the ePTFE wall was inhomogeneous with a widening of the micropores, and both compressed and ruptured fibrils. The most significant disturbances were observed in the knee joint area. Our results suggest that deterioration of the prosthetic wall is possible and indicate the necessity for a wrap to protect against aneurysm formation, as well as an external supportive device to prevent the graft from bending.

[Ameloblast proliferation within dentigerous cysts of the jaw bone]

The presence of ameloblastic structures in dentigerous cysts in a 26-year-old female patient and a 42-year old male patient is reported. Their non-invasive growth distinguished the present circumscribed ameloblastic tissue structures from classic ameloblastomas. Enucleation of the cysts resulted in undisturbed healing of the surgical area; none of the ameloblastomas recurred. These cases emphasize the importance of careful pathologic-histological examination of all tissues removed.

[Conjunctival oxygen partial pressure, hemorheology and circulatory parameters in acute cerebral infarct before and following infusion of 6 percent low molecular hydroxyethyl starch]

A prospective clinical trial was performed on the effects of a three hour infusion of 500 ml 6% low-molecular-weight hydroxyethyl starch in patients with acute ischemic stroke. Hemorheology and conjunctival oxygen tension were found to be disturbed prior to treatment. After the infusion there was a marked improvement of the pertinent parameters, indicative of an increase in cerebral microcirculation and oxygen supply. Even 3 h later persistent significant effects were observed. The infusion was well tolerated. Blood pressure and cardiac index remained unchanged.

Konjunktivaler Sauerstoffpartialdruck, Hämorheologie und Kreislaufparameter bei akutem zerebralem Insult vor und nach Infusion von 6prozentiger niedermolekularer Hydroxyäthylstärke

In einer prospektiven Studie untersuchten wir bei 12 Patienten mit akutem zerebralem Insult die Wirkung einer dreistündigen Infusion von 500 ml 6%iger niedermolekularer Hydroxyathylstarke. Die an-fangs gestörte Hämorheologie wurde deutlich verbessert, ebenso der anfangs erniedrigte konjunktivale Sauerstoffpartialdruck. Dies kann als Hinweis auf eine Steigerung der zerebralen Mikrozirkulation und Sauerstoffversorgung gewertet werden. Auch 3 h nach Infusionsende waren noch signifikante Veränderungen nachzuweisen. Die Volumen-belastung durch die Infusion wurde gut toleriert. Blutdruck und Herzminutenvolumen blieben stabil.

Sociobiology and the structural stability of behavior patterns

A structural stability approach to population-genetic systems and to dynamic evolutionary games is attempted in order to examine the theoretical significance of sociobiological selection models. A criterion of weak selection is derived that is not restricted to differential reproduction in polymorphic systems but describes possible directions of evolutionary change in time scales governed by genetic mutation rates. The criterion applies to the problems of how the initial mutational basis of an adaptive trait may be established and how this may happen, for analogous traits, independently in different species. Two basic sociobiological concepts are reconsidered with reference to the criterion. It is shown that W. D. Hamilton's condition of increases in inclusive fitness due to altruistic interactions among kin expresses the structural instability of populations against the evolution of altruistic behavior. Using the dynamic approach to evolutionary game theory, it is demonstrated that if a behavioral phenotype is an evolutionarily stable strategy, it is structurally stable against perturbations of the fitness payoffs, provided selection is weak. These results are applied to material problems of the evolution of animal social behavior.

Comparison of the beta-adrenoceptor affinity and selectivity of cetamolol, atenolol, betaxolol, and ICI-118,551

The objective of the present study was to compare the quantitative differences in the beta 1- vs. beta 2-adrenoceptor affinity and selectivity of cetamolol and its enantiomers to the reference compounds atenolol, betaxolol, and ICI-118,551, using isolated tissues obtained from the dog, guinea pig, and rat. Cetamolol antagonized the beta-adrenoceptor-mediated responses induced by isoproterenol, epinephrine, norepinephrine, and salbutamol, in tissues from both the dog and guinea pig, in a concentration-dependent manner. For a given tissue, the beta-adrenoceptor antagonist activity of cetamolol (measured as a pA2 or pKB value) was independent of the agonist used. In the dog tissues, cetamolol was more potent at inhibiting responses in the coronary artery (beta 1-adrenoceptors) than in the saphenous vein (beta 2-adrenoceptors). In the guinea pig tissues, the potency of cetamolol was approximately the same in the trachea (mixed beta 1- and beta 2-adrenoceptors) and atria (predominately beta 1-adrenoceptors), but lower in the soleus muscle (beta 2-adrenoceptors). Studies with the S-(-) and R-(+) enantiomers of cetamolol demonstrated that the S-(-) enantiomer was approximately 100-fold more potent at beta 1-adrenoceptors than the R-(+) enantiomer. In rat brain, cetamolol displaced [3H]-dihydroalprenolol bound to homogenates of cortex (beta 1-adrenoceptor binding sites) and cerebellum (beta 2-adrenoceptor binding sites). The potency of cetamolol at beta 1-adrenoceptors was found to be similar to that of betaxolol but greater than that of atenolol. However, the magnitude of the beta 1-adrenoceptor selectivity displayed by atenolol and betaxolol was greater than that displayed by cetamolol. In contrast, ICI-118,551 was found to possess potent and selective affinity for beta 2-adrenoceptors.

In vitro isolated tissue studies with atiprosin (AY-28,228): a new antihypertensive compound

Using in vitro isolated tissue and binding studies we have defined a receptor activity profile for atiprosin. The most prominent action of the compound was significant alpha-adrenoceptor antagonist activity (pA2 = 8.11) that was less potent than prazosin (pA2 = 8.78) but more potent than either ketanserin (pA2 = 7.34) or indoramin (pA2 = 7.85). In addition, atiprosin was selective for alpha 1-adrenoceptors, since the compound was over 100-fold less potent as an antagonist at alpha 2-adrenoceptors (pA2 = 6.04). Atiprosin also displayed selective serotonin 5-HT2-receptor antagonist activity similar to that seen with ketanserin, but with a lesser potency (pA2 atiprosin, 6.87; ketanserin, 8.61). Although atiprosin also displayed significant histamine H1-antagonist activity (pA2 = 7.32), it was less potent as an H1-antagonist than as an alpha 1-adrenoceptor antagonist. In contrast, both indoramin and ketanserin displayed H1-antagonist activity (pA2 8.77 and 8.83, respectively) greater than their respective alpha 1-adrenoceptor antagonist activities. Atiprosin had little or no activity at either beta 1- or beta 2-adrenoceptors, muscarinic or histamine H2-receptors, nor any marked ability to produce smooth muscle relaxation either by a direct effect or via calcium entry blockade.