Blazar spectral variability as explained by a twisted inhomogeneous jet

Blazars are active galactic nuclei, which are powerful sources of radiation whose central engine is located in the core of the host galaxy. Blazar emission is dominated by non-thermal radiation from a jet that moves relativistically towards us, and therefore undergoes Doppler beaming. This beaming causes flux enhancement and contraction of the variability timescales, so that most blazars appear as luminous sources characterized by noticeable and fast changes in brightness at all frequencies. The mechanism that produces this unpredictable variability is under debate, but proposed mechanisms include injection, acceleration and cooling of particles, with possible intervention of shock waves or turbulence. Changes in the viewing angle of the observed emitting knots or jet regions have also been suggested as an explanation of flaring events and can also explain specific properties of blazar emission, such as intra-day variability, quasi-periodicity and the delay of radio flux variations relative to optical changes. Such a geometric interpretation, however, is not universally accepted because alternative explanations based on changes in physical conditions-such as the size and speed of the emitting zone, the magnetic field, the number of emitting particles and their energy distribution-can explain snapshots of the spectral behaviour of blazars in many cases. Here we report the results of optical-to-radio-wavelength monitoring of the blazar CTA 102 and show that the observed long-term trends of the flux and spectral variability are best explained by an inhomogeneous, curved jet that undergoes changes in orientation over time. We propose that magnetohydrodynamic instabilities or rotation of the twisted jet cause different jet regions to change their orientation and hence their relative Doppler factors. In particular, the extreme optical outburst of 2016-2017 (brightness increase of six magnitudes) occurred when the corresponding emitting region had a small viewing angle. The agreement between observations and theoretical predictions can be seen as further validation of the relativistic beaming theory.

Evaluating an Online Family Assessment Activity: A Focus on Diversity and Health Promotion

PROBLEM

A lack of exposure to diverse families and family interactions created a need to identify effective teaching strategies that emphasized diversity and health promotion in a Registered Nurse to Bachelor of Science in Nursing online transition course.

METHODS

A family assessment activity was designed to emphasize diversity and health promotion utilizing the Family Health Systems approach to family assessment and Healthy People 2020 as a framework for family health promotion. The activity was evaluated through faculty observation and student feedback, which is discussed in the article.

FINDINGS

Evaluation data indicated that students believed the activity provided a safe environment to practice assessment skills for working with diverse families, pushed them out of their comfort zones, enhanced their awareness of the need for health promotion, extended their definition of diversity, increased their cultural knowledge, expanded their personal perspectives on families, and provided them with a broader scope of nursing practice in the community.

CONCLUSIONS

Using constructivist strategies that emphasize active learning and the use of cinema to teach family assessment results in increased awareness of diversity and increased knowledge of opportunities for health promotion in families. Smith Jones.

Principles of ploidy analysis by static cytometry

Aims-To examine the basic assumptions made during DNA ploidy analysis of histological sections with an aim to eliminate methodological errors that have lead to conflicting results with this technique.Methods-A rat liver imprint and histological sections together with sections and whole nuclei cytospins of human breast tumour biopsy specimens were stained with azure A Schiff's reagent and used to investigate the effects of computer imaging, histological section thickness, nuclear volume, and shape corrections.Results-The rat liver imprint demonstrated a linear relation between mean nuclear transmittance and nuclear area for each of the three (2C, 4C, 8C) hepatocyte clusters. This finding was used to produce similar, proportional integrated optical density (IOD) measurements from rat liver sections by selecting only nuclei that were sectioned through their centres, as assumed by the mathematics for volume correction. The limitations of computer imaging necessitated an edge (glare) correction for each nucleus so that nuclei of different sizes could be analysed. Shape correction was required to analyse nuclei of different morphologies. Normal human lymphocytes, squamous epithelium and fibroblasts were all measured with similar IODs. DNA ploidy values obtained from 7 mum human breast tumour sections (using lymphocytes as controls) correlated well with those obtained from the whole nuclei cytospins from the same tissue blocks.Conclusions-With an improved understanding of the theoretical and technical aspects of ploidy analysis of tissue sections, reproducible and consistent results are possible. These results can be integrated into routine histopathology investigations alongside immunohistochemistry and molecular diagnostic techniques.

Comparing phosphorus mobilization strategies using Aspergillus niger for the mineral dissolution of three phosphate rocks

Phosphorus deficiencies are limiting crop production in agricultural soils worldwide. Locally available sources of raw phosphate rock (PR) are being recognized for their potential role in soil fertility improvement. Phosphorus bioavailability is essential for the efficiency of PRs and can be increased by acid treatments. The utilization of organic acid producing micro-organisms, notably Aspergillus niger, presents a sustainable alternative to the use of strong inorganic acids, but acid production of A. niger strongly depends on the mineral content of the growth media. This study compared the phosphorus mobilization efficiency of two biological treatments, namely addition of acidic cell-free supernatants from A. niger cultivations to PRs and the direct cultivation of A. niger with PRs. The results show that addition of PR to cultivations leads to significant differences in the profile of organic acids produced by A. niger. Additions of PR, especially igneous rocks containing high amounts of iron and manganese, lead to reduced citric acid concentrations. In spite of these differences, phosphorus mobilization was similar between treatments, suggesting that the simpler direct cultivation method was not inferior. In addition to citric acid, it is suggested that oxalic acid contributes to PR solubilization in direct cultivations with A. niger, which would benefit farmers in developing countries where conventional fertilizers are not adequately accessible.

Regional blockade for delivery in women with scoliosis or previous spinal surgery

We conducted a prospective observational study between 1992 and 2001 identifying obstetric patients with untreated or surgically corrected scoliosis or lumbar-sacral fusion surgery. The regional techniques for labour and delivery that were offered were epidural analgesia, combined spinal epidural anaesthesia (CSE), single shot spinal or continuous spinal anaesthesia (CSA) depending on the degree of scoliosis, previous surgery, cardio-respiratory compromise and planned mode of delivery. Forty women were included in the study, one woman with two separate deliveries, giving 41 cases for analysis. Twenty-four women presented in labour: 11 required no regional technique, seven received effective epidural analgesia and six received CSA. Seventeen women presented for elective caesarean delivery: two received a CSE technique, two received single shot spinal and 13 had CSA. From a total of 19 CSA techniques attempted sixteen catheters were successfully inserted and produced good analgesia or anaesthesia for vaginal or operative delivery in 12 women (63%). There was one case of post dural puncture headache following a CSA for labour and delivery. We discuss the choices available for regional anaesthetic techniques in scoliotic women and the relative merits of each.

Demonstrating the cost effectiveness of an expert occupational and environmental health nurse: application of AAOHN's success tools. American Association of Occupational Health Nurses

According to DiBenedetto, "Occupational health nurses enhance and maximize the health, safety, and productivity of the domestic and global work force" (1999b). This project clearly defined the multiple roles and activities provided by an occupational and environmental health nurse and assistant, supported by a part time contract occupational health nurse. A well defined estimate of the personnel costs for each of these roles is helpful both in demonstrating current value and in future strategic planning for this department. The model highlighted both successes and a business cost savings opportunity for integrated disability management. The AAOHN's Success Tools (1998) were invaluable in launching the development of this cost effectiveness model. The three methods were selected from several tools of varying complexities offered. Collecting available data to develop these metrics required internal consultation with finance, human resources, and risk management, as well as communication with external health, safety, and environmental providers in the community. Benchmarks, surveys, and performance indicators can be found readily in the literature and online. The primary motivation for occupational and environmental health nurses to develop cost effectiveness analyses is to demonstrate the value and worth of their programs and services. However, it can be equally important to identify which services are not cost effective so knowledge and skills may be used in ways that continue to provide value to employers (AAOHN, 1996). As evidence based health care challenges the occupational health community to demonstrate business rationale and financial return on investment, occupational and environmental health nurses must meet that challenge if they are to define their preferred future (DiBenedetto, 2000).

JCV-specific cellular immune response correlates with a favorable clinical outcome in HIV-infected individuals with progressive multifocal leukoencephalopathy

Most immunosuppressed individuals who develop progressive multifocal leukoencephalopathy (PML) have a rapid fatal outcome, whereas some become long-term survivors. We explored the impact of the cellular immune response against JC virus (JCV) on the clinical outcome of 7 HIV+ and 3 HIV- individuals with PML. Of the 4 HIV+/PML survivors, all had detectable cytotoxic T lymphocytes (CTL) specific for JCV T or VP 1 proteins compared to none of the 3 HIV+/PML progressors tested. Of the 3 HIV-/PML patients, 1 was recently diagnosed with PML and showed evidence of neurologic improvement without any treatment. This patient had CTL specific for the VP1 protein of JCV. The other 2 HIV-/PML survivors were stable 3-8 years after the diagnosis of PML. They did not have any detectable CTL against JCV. These findings suggest that JCV-specific immune response is associated with favorable outcome in HIV+ individuals with PML. The lack of detectable JCV-specific CTL in 2 HIV-/PML survivors might indicate a burnt-out disease without sufficient antigenic stimulation to maintain the cellular immune response. The detection of JCV-specific CTL in an HIV- patient recently diagnosed with PML, who was showing evidence of neurological improvement without any treatment, indicates that this finding may be used as a favorable prognostic marker of disease evolution in the clinical management of patients with PML. As the quest for an effective treatment of PML continues, JCV-specific cellular immune response deserves further attention because it appears to play a crucial role in the prevention of disease progression.

Agreement among three quality of life measures in patients with ALS

AIM

To determine the concurrent validity of three self-administered health-related quality of life (HRQOL) questionnaires when administered to patients with amyotrophic lateral sclerosis (ALS).

BACKGROUND

ALS is the most common motor neuron disease among adults. As a rapidly progressive and fatal disease, ALS has devastating effects on the patient's relationships, functional capacity and mental health. HRQOL measures include information about patients' physical impairments, functional level, and psychosocial status. This study compares a tool designed for the ALS population, the Sickness Impact Profile ALS-19 (SIP/ALS19), and two tools designed to be used in any population, the Quality of Well-being Scale SA (QWB SA), and the SF-36 Health Survey (SF-36). Correlation of the scores would suggest that each tool is valid as a stand-alone measurement of quality of life for this patient population.

METHODS

The SIP/ALS-19, the SF-36, and the QWB SA were self-administered to 19 subjects diagnosed with ALS. The scores for each test were ranked and analyzed for agreement using the Spearman rank correlation coefficient.

RESULTS

The SIP/ALS-19 demonstrated moderate to good correlation with the QWB SA and fair correlation with the SF-36. The SF-36 had little to no correlation with the QWB SA.

CONCLUSIONS

The study did not demonstrate significant correlation among the three quality of life measures. The SIP/ALS-19, SF-36, and QWB SA each have a different focus in measuring HRQOL. The healthcare practitioner should consider the patient's stage of disease, treatment goals, and type of interventions planned when selecting a HRQOL tool for the ALS patient.

Gravity-directed calcium current in germinating spores of Ceratopteris richardii

Gravity directs the early polar development in single cells of Ceratopteris richardii Brogn. It acts over a limited period of time during which it irreversibly determines the axis of the spore cell's development. A self-referencing calcium selective electrode was utilized to record the net movement of calcium across the cell membrane at different positions around the periphery of the spore during the period in which gravity orients the polarity of the spore. A movement of calcium into the cell along the bottom and out of the cell along the top was detected. This movement was specific, polarized, and strongest in a direction that opposed the vector of gravity. Treatment with nifedipine, a calcium-channel blocker, diminished the calcium current and caused the cell to lose its responsiveness to the orienting influence of gravity. Results shown suggest that calcium plays a crucial role in the ability of a single cell to respond to gravity and in the subsequent establishment of its polarity.

Circadian variation of portal, arterial and venous blood levels of melatonin in pigs and its relationship to food intake and sleep

Circadian levels of melatonin were determined in the hepatic portal vein, cranial vena cava, and the lower aorta of ten juvenile pigs. Blood was sampled every hour for a total of 24 hr via temporary cannulas introduced into blood vessels under anesthesia. No peak levels of melatonin were found in the mid-scotophase, but hepatic portal concentrations peaked at 06.00 hr. Overall levels of melatonin were highest in the hepatic portal vein (range 35-65 pg/mL), followed by an artery (range 30-55 pg/mL) and the vena cava (range 25-35 pg/mL). Levels of melatonin exhibit strong variation between individual pigs, but generally the average levels from all three sources follow each other's time course. However, on occasion, melatonin levels in the hepatic portal vein varied independently from the levels in the vena cava. Large portal peaks were usually preceded by a feeding period and were associated with a subsequent period of sleep. The data indicate that: 1) there is no clear circadian rhythm of melatonin in the peripheral blood of pigs, 2) relatively little melatonin is metabolized during the first liver passage, 3) food intake may elevate melatonin levels in the hepatic portal vein, and 4) increased levels of melatonin originated in the gastrointestinal tract may induce sleep.

Antiangiogenic therapy of a recurrent giant cell tumor of the mandible with interferon alfa-2a

We report a 5-year-old girl with a large rapidly growing giant cell tumor of the mandible that recurred 2 months after the first surgical excision and 3 months after a second resection. An angiogenic protein, (bFGF), was abnormally elevated in her urine. The patient was treated with interferon alfa-2a for 1 year because this agent inhibits angiogenesis by suppressing bFGF overexpression in infantile hemangiomas and in other human tumors. During this time the bone tumor regressed and disappeared, the urinary bFGF fell to normal levels, and the mandible regenerated. She has remained tumor-free and has been off therapy for 3 years at this writing. This first successful use of interferon alfa-2a to treat a mandibular tumor in a child demonstrates: 1) low grade tumors that overexpress bFGF may respond to interferon alfa-2a, in a manner similar to life-threatening infantile hemangiomas; 2) antiangiogenic therapy, given without interruption for 1 year, was safe and effective in this patient; and 3) treatment may be continued for 1 year without the development of drug resistance.

Determining whether managed care formularies meet the needs of pediatric patients

This activity is designed for healthcare providers making formulary decisions for managed care organizations.

GOAL

To help clinicians determine whether managed care formularies meet the needs of pediatric patients.

OBJECTIVES

1. List general considerations for establishing a pediatric drug formulary. 2. Understand the importance of growth and development when selecting drug therapy for pediatric patients. 3. Discuss potential difficulties with administering medications during school hours. 4. Identify specific medications within the drug classes of antibiotics, asthma medications, endocrine, and gastrointestinal agents that should be available on a pediatric drug formulary.

Management of end-stage renal disease in children

OBJECTIVE

To review the medical literature on management of end-stage renal disease (ESRD) and its complications in the pediatric patient.

DATA SOURCES AND STUDY SELECTION

MEDLINE searches (1970-1997) of the English-language literature. Clinical trials and reviews of drug therapy management were included, and bibliographies were reviewed for relevant articles.

DATA SYNTHESIS

Principles of renal replacement therapy in children have been expanded to include maintenance of fluid and electrolyte balance and to manage the complications of ESRD in children. Types of renal replacement and their complications are reviewed. Complications of ESRD are reviewed with emphasis on drug therapy management of anemia of chronic renal failure, growth retardation, and hypertension. A discussion of the use of vitamins and supplements to maintain bone and mineral homeostasis is provided, and specific recommendations for vaccination of children with ESRD are given.

CONCLUSIONS

Children with end-stage renal failure present a unique challenge to the pharmacist. Renal replacement therapy for children with ESRD involves some form of dialysis and an intensive medication regimen. Complications must be treated with appropriate drug therapy. Drug therapy must be monitored closely for dosage adjustment, clinical response, drug interactions, and toxicity. Patients and families must receive continuous education and follow-up to encourage compliance. The pharmacist must work closely with the healthcare team to optimize drug therapy and improve patient education and compliance.

Melatonin concentrations in serum and tissues of porcine gastrointestinal tract and their relationship to the intake and passage of food

Melatonin concentrations were determined in serum and 10 segments of the gastrointestinal tract (GIT) of 48 pigs (100 kg weight). The animals were fasted for 30 hr and then sacrificed 0, 1, 2, 5, 10, and 20 hr after refeeding. Peak amount of gastric digesta (2,428 g) and ileum digesta (850 g) were observed 1 hr and 5 hr, after refeeding, respectively. Conversely, colon content reached a minimal weight (726 g) at 2 hr after refeeding. Serum levels of melatonin increased from 3.4 pg/ml to 15.5 pg/ml (peak 5 hr after refeeding). Melatonin levels in GIT tissues before refeeding varied from 23.8 pg/g (stomach-fundus) to 62.1 pg/g (rectum). Increasingly higher levels of melatonin were detected in the distal segments of the GIT. Higher melatonin levels after refeeding were observed in most GIT tissues except the rectum. In most tissues, peak melatonin values were detected 5 hr after refeeding. A significant change in weight of digesta across time (P < 0.05) was detected in the stomach, ileum, and cecum. Similar changes in melatonin levels across time were found in most tissues except the esophagus, stomach (cardia and pylorus), and rectum. Adjacent GIT tissues exhibited similar (P < 0.05) melatonin levels. The GIT melatonin levels correlated best with the variation of digesta weight in the ileum. In addition, the increase of serum melatonin levels correlated best with the increase of GIT melatonin levels in the distal part of the GIT. Our results suggest that melatonin produced in the ileum, cecum, and colon may contribute significantly to the short-term increase of serum melatonin levels observed after refeeding.

Episodic versus prophylactic infusions for hemophilia A: a cost-effectiveness analysis

OBJECTIVE

To assess the incremental cost-effectiveness of prophylactic compared with episodic care in boys with severe hemophilia A.

SETTING

Eleven U.S. hemophilia treatment centers.

METHODS

Charge data from a randomly selected cohort of 70 boys receiving episodic infusions for bleeding events and from all 27 boys receiving infusions prophylactically were collected from documents obtained from the hemophilia treatment centers during a period of approximately 2 years. Published and public sources were used for conversion to cost, lifetime earnings, and earnings losses from disability. A model was constructed for a hypothetical patient from ages 3 to 50 years by means of three infusion scenarios.

RESULTS

The cohort receiving prophylactic treatment had fewer bleeding events each year (median, 3 vs 31) but used more concentrate (3323 vs 1015 units/kg per year). Factor VIII concentrate accounted for more than 93% of the cost of both episodic and prophylactic care. Compared with episodic infusion, prophylaxis from ages 3 to 20 years costs $1100 per bleeding event prevented, in comparison with $1380 for prophylaxis from ages 3 to 50 years. The total cost of prophylactic care from ages 3 to 50 years would equal the current total cost of episodic care if the price of the concentrate were decreased by 50%.

CONCLUSION

Prophylactic care markedly reduces the number of bleeding events and should prevent joint function impairment, but at substantial cost.

Distribution of basal lamina type IV collagen and laminin in normal rat tongue mucosa and experimental oral carcinoma: ultrastructural immunolocalization and immunogold quantitation

The relationship of basal lamina, a form of specialised extracellular matrix which separates epithelial cells and other cell types from adjacent stroma, to the behaviour of malignant neoplasms of epithelial origin is not well understood. However, it is widely acknowledged that the properties of local invasion and metastasis of carcinomas are linked to extracellular matrix (including basal lamina) changes. In the present study, the distribution of the major basal lamina components, type IV collagen and laminin, in normal rat tongue mucosa and experimentally induced oral carcinomas was investigated using post-embedding immunogold techniques and electron microscopy. The expression of these components was also quantitatively analysed using morphometry and immunocytochemistry. Results indicated that type IV collagen and laminin were confined to the lamina densa of normal oral epithelial basal lamina, and that both components were also detected in the lamina densa of basal lamina associated with carcinomas, and in the extracellular matrix of tumours. Furthermore, laminin was detected within stromal fibroblasts in normal tissues and experimental carcinomas. Quantitative analysis indicated that expression of laminin was significantly increased in carcinomas. In contrast, type IV collagen expression was significantly decreased. The quantitative changes observed in the two basal lamina constituents may be related to the process of tumour invasion, reflecting altered metabolic activities of tumour and stromal cells. These observations may be of use in understanding the architectural characteristics of oral mucosa basal lamina and in assessing the malignant potential of epithelial dysplasias or "premalignant" lesions.

Membranous nephropathy with graft-versus-host disease in a bone marrow transplant recipient

A 43-year-old man developed the nephrotic syndrome 26 months after allogeneic bone-marrow transplantation for chronic myeloid leukemia. This occurred during an exacerbation of graft-versus-host disease (GVHD) and both problems remitted after therapy with cyclosporine and prednisolone. Renal biopsy showed ultrastructural and immunofluorescence evidence of membranous nephropathy. Anti-nuclear antibodies (but not antiglomerular or anti-renal tubular epithelial antibodies) were detected in his serum. Experimental GVHD in mice has been associated with immune complex glomerulonephritis and the presence of IgG autoantibodies which has been attributed to abnormal T (donor)/B (recipient) cell co-operation. This association can be extrapolated to the human GVHD where autoantibody formation is better described than immune complex glomerulonephritis.

Hepatocellular carcinoma in hemophilia

A questionnaire-based survey involving 11,801 hemophiliacs from 54 hemophilia centers in the USA and Europe documented the occurrence of hepatocellular carcinoma (HCC) in 10 patients. The crude rate of HCC was 3.2/100,000 patients/year, at least 30 times higher than the background incidence of this tumor in the countries of origin of the patients. All patients were Caucasians with hemophilia A, 39 to 74 years of age, and had liver cirrhosis. All had one or more risk factor for cirrhosis and HCC: 5 were positive for serum hepatitis B surface antigen, 4 had the antibody to hepatitis C virus, and 4 had histories of alcohol abuse. Serum alpha-fetoprotein, measured in 6 patients, was significantly elevated in 4 (range: 807-1399 ng/ml), and only moderately elevated in 2 (25 and 171 ng/ml). The onset of HCC was asymptomatic in 5 patients, whereas it was accompanied by jaundice, abdominal pain, or ascites in the remaining patients. Thus, HCC seems to be a more important secondary disease for hemophiliacs than formerly recognized. Since HCC is often asymptomatic, screening hemophiliacs with chronic liver disease with periodic ultrasound scans might increase the changes of detecting HCC at a stage amenable to surgical treatment.

The Staggered Spondaic Word Test. A ten-minute look at the central nervous system through the ears

We have described three major groupings that encompass most auditory processing difficulties. While the problems may be superimposed upon one another in any individual client, each diagnostic sign is closely associated with particular communication and learning disorders. In addition, these behaviors may be related back to the functional anatomy of the regions that are implicated by the SSW test. The auditory-decoding group is deficient in rapid analysis of speech. The vagueness of speech sound knowledge is thought to lead to auditory misunderstanding and confusion. In early life, this may be reflected in the child's articulation. Poor phonic skills that result from this deficit are thought to contribute to their limited reading and spelling abilities. The auditory tolerance-fading memory group is often thought to have severe auditory-processing problems because those in it are highly distracted by background sounds and have poor auditory memories. However, school performance is not far from grade level, and the resulting reading disabilities stem more from limited comprehension than from an inability to sound out the words. Distractibility and poor auditory memory could contribute to the apparent weakness in reading comprehension. Many of the characteristics of the auditory tolerance-fading memory group are similar to those of attention deficit disorder cases. Both groups are associated anatomically with the AC region. The auditory integration cases can be divided into two subgroups. In the first, the subjects exhibit the most severe reading and spelling problems of the three major categories. These individuals closely resemble the classical dyslexics. We presume that this disorder represents a major disruption in auditory-visual integration. The second subgroup has much less severe learning difficulties, which closely follow the pattern of dysfunction of the auditory tolerance-fading memory group. The excellent physiological procedures to which we have been exposed during this Windows on the Brain conference provide a glimpse of the exciting possibilities for studying brain function. However, in working with individuals who have cognitive impairments, the new technology should be validated by standard behavioral tests. In turn, the new techniques will provide those who use behavioral measures with new parameters and concepts to broaden our understanding. For the past quarter of a century, the SSW test has been compared with other behavioral, physiological, and anatomical procedures. Based on the information that has been assembled, we have been able to classify auditory processing disorders into three major categories.(ABSTRACT TRUNCATED AT 400 WORDS)

Congenital coagulation protein deficiencies in the perinatal period

Less common than acquired bleeding disorders in the perinatal period, congenital deficiencies of the clotting proteins, particularly the hemophilias A and B, can be just as devastating. Detection of these disorders may be delayed because a suspect family history is lacking in up to one third of the cases of hemophilia, and parents are usually asymptomatic in the other congenital factor deficiencies. Physiologically low levels of the liver-dependent and contact factors can make the interpretation of the common hemostasis screens difficult. Hence, the use of age-adjusted tables such as those presented here is essential. Congenital deficiencies of clotting proteins should be suspected when serious CNS bleeding occurs in an otherwise healthy baby generally after a day or two. Factor XIII or other less common factor deficiencies should be sought when there is prolonged bleeding from the umbilical stump. Bleeding after circumcision is a rare early indicator nowadays with better techniques. The availability of bedside ultrasound to detect CNS hemorrhage early and of fresh frozen plasma for treatment preceding the results of specific factor assays should prevent serious sequelae. Elective cesarean section is currently recommended when an unborn infant is known to have hemophilia.

The structure of the normal human glomerular basement membrane. Ultrastructural localization of type IV collagen and laminin

Structural models of the glomerular basement membrane (GBM) have been based solely on the localization of antigens in animal kidneys. These models depict a type IV collagen lattice as the structural skeleton along the central portion of the membrane, with the glycoprotein laminin attached predominantly in the laminae rarae where it is thought to be involved with endothelial and visceral epithelial cell attachment. The human GBM is also known to contain type IV collagen and laminin. The present study localizes both of these structural antigens in normal human GBM using the ultrastructural immunogold technique. Type IV collagen is situated in the sub-endothelial third of the GBM and is continuous with the type IV collagen within the mesangial matrix. Laminin is localized throughout the entire thickness of the GBM and mesangial matrix. These results indicate that the structure of human GBM is significantly different from that proposed in animal models. A structure for the normal human GBM is discussed, depicting a thin type IV collagen lattice which is asymmetrically placed in the sub-endothelial third of the membrane, with laminin distributed as an integral component of the membrane in addition to its role in cell attachment.

Thin membrane nephropathy: a clinico-pathological study

Thin membrane nephropathy is common, representing approximately 11% of non-transplant renal biopsies. A family history of renal disease is present in at least 40% of patients. Electron microscopy is essential for its diagnosis. There are no immunofluorescence markers but light microscopic changes, usually mild, are invariably present and predict the ultrastructural findings although there is no correlation with their degree. The extent of the morphological changes bears no obvious relationship either to clinical or familial features. Immunogold studies indicate that there is reduction or loss of the subepithelial portion of the basement membrane, which apparently contains normal amounts of type IV collagen. Unnecessary urological investigations may be avoided by awareness of the condition and microscopic examination of urine for dysmorphic red blood cells. Prospective long-term studies are necessary to determine the nature and consequences of the condition.

Localization of a 23,000 MW antigen of Cryptosporidium by immunoelectron microscopy

Rabbit antiserum was raised against a 23,000 molecular weight (MW) antigen prepared from Cryptosporidium oocysts by electro-elution from polyacrylamide gels. The antiserum was tested for specificity by immunoblotting against solubilized oocyst preparations. Several antigens including the 23,000 MW antigen were recognized suggesting that it shared common epitopes with higher MW proteins. The antiserum was then used in conjunction with a protein A-colloidal gold conjugate to locate antigenic sites within exogenous and endogenous developmental stages of Cryptosporidium. The pellicles of both sporozoites and merozoites exhibited specific labelling, particularly around their anterior ends. No specific labelling was observed for any other membrane determinants or organelles in these or other life cycle stages.

The effect of treatment with prednisolone or cyclophosphamide-warfarin-dipyridamole combination on the outcome of patients with membranous nephropathy

Between 1973 and 1986, 109 patients with membranous nephropathy have been evaluated with respect to clinical presentation, pathological features and factors determining prognosis. Secondary disease was present in 21, and a further 21 were lost or followed for less than 12 months. The remaining 67 with idiopathic membranous nephropathy were allotted to one of three groups. Group 0 (26 patients) received no active treatment, Group 1 (12 patients) a combination of cyclophosphamide, dipyridamole and warfarin, and Group 2 (21 patients) high dose alternate day prednisolone therapy. Eight patients received other treatment or presented with end stage renal disease. No significant difference in outcome could be detected between the groups. Remission rates were equivalent as were numbers of patients judged as having progressive disease. There was no statistical difference with respect to duration of nephrotic syndrome, plasma creatinine at the end of study and change in plasma creatinine. No demonstrable benefit was obtained in predicting the outcome of disease or response to treatment from conventional pathological grading of stages I to IV as approximately equal numbers of each stage fell into good and bad categories of outcome. Similarly unusual histological features such as mesangial proliferation and immunofluorescence for deposits other than IgG and C3 were not helpful. A different approach to treatment of idiopathic membranous nephropathy is strongly recommended.

Femotosecond switching in a dual-core-fiber nonlinear coupler

We report all-optical switching of 100-fsec pulses in a fused-quartz dual-core-fiber directional coupler. The length of the device is 0.5 cm, and the switching power is 32 kW. Pulses are routed to either of two separate fiber guides, depending on the input power. Measurements of pulse reshaping by the nonlinear coupler provide compelling evidence of the device's ability to response on a femotosecond time scale.

Ultrastructural immuno-gold localization of immune deposits in human renal biopsies

Ultrastructural immunolocalization of immunoglobulins has the potential to supply new information about immune-mediated glomerulonephritides. Most previous studies have used immunoperoxidase pre-embedding techniques to identify the components of glomerular deposits. These techniques have not been satisfactory as they only allowed the identification of one antigen (immunoglobulin) in each portion of tissue under investigation and also caused obliteration of labelled structures by the dense reaction product. Several studies have used colloidal gold as a post-embedding label, but these have been unable to localize immunoglobulins or complement components in epoxy resin embedded tissue. The present study uses glutaraldehyde-fixed tissue which is embedded in a polar acrylic resin. This technique results in good ultrastructural detail while allowing maximum antigen retention and, when combined with colloidal gold labelling, it provides the optimal procedure for ultrastructural immune localization. A spectrum of immunologically induced renal diseases is examined using this technique, the results of which correlate well with immunofluorescence.

Lymphocytic bronchiolitis associated with HIV infection

Patients with the acquired immune deficiency syndrome (AIDS) frequently develop interstitial lung disease. This is due most commonly to opportunistic infections, but malignancy and lymphocytic interstitial pneumonitis have also been associated with the syndrome. In contrast, there has been little reported about airways disease in patients with HIV infection. We describe a patient with AIDS-related complex who presented with symptoms and radiographic evidence of micronodular interstitial lung disease. Transbronchial biopsy revealed a lymphocytic bronchiolitis but no evidence of interstitial lung disease and a marked T-suppressor lymphocytosis was found on analysis of the bronchoalveolar lavage (BAL) specimen. Routine fungal, viral and bacterial cultures did not yield an etiologic agent. This case raises the possibility that lymphocytic bronchiolitis may represent another pulmonary manifestation of HIV infection.

Oncogenic osteomalacia

Severe osteomalacia (confirmed by the examination of thin undecalcified bone biopsy sections) associated with hypophosphataemia developed in a 60 year old woman. A skeletal x-ray survey showed a lytic lesion in the right proximal femur, and this was curetted, showing a vascular tumour. The patient's symptoms improved almost immediately and serum phosphate concentrations returned to normal. Some time later the syndrome and the tumour recurred. The tumour was excised, and again the patient improved. Morphological examination of the tumour showed a lesion which closely resembled haemangiopericytoma. Review of published reports confirmed that most reported cases have been associated with "vascular" mesenchymal tumours both in intraosseous and extraosseous sites.

Circadian and circannual rhythms of melatonin in plasma of male white-tailed deer and the effect of oral administration of melatonin

Circadian levels of melatonin (M) were determined in plasma of four male white-tailed deer sampled hourly in September for 24 h via indwelling jugular catheter. Concentrations of M, detected by the radioimmunoassay rise with the onset of darkness, peak at 1.00 h (265 pg/ml) and then quickly decline to baseline levels (60 to 70 pg/ml) maintained during the scotophase. Orally administered M (5 mg, given at 13:00 h) induced a rapid elevation of plasma M (peak 980 pg/ml at 15:00 h) followed by a decline to baseline (100 pg/ml) reached at 22:00 h. The usual midscotophase peak was abolished by exogenous M administration. Seasonal midscotophase levels of M (determined in three samples taken 45 min apart between 23:00 and 1:00 h reach maximum in December (1530 pg/ml) followed by decline to minimum (69 to 90 pg/ml) observed between May and July. The data indicate that: 1) similarly to other mammals, deer exhibit peak levels of M during the dark phase; 2) 5 mg of M given orally caused a rapid elevation of M levels in blood followed by a depression of the normally present night-time peak; and 3) midscotophase levels of M exhibit very pronounced seasonal fluctuations which might be related to yearly cycles, such as the reproduction, hair molt, and antler growth.

The role of androstenedione and testosterone in the reproduction and antler growth of a male white-tailed deer

Seasonal levels of androstenedione and testosterone were investigated in plasma of mature intact and castrated male white-tailed deer. In four intact bucks, androstenedione concentrations were low in February and March (around 1 nmol/l) and then increased significantly (P less than 0.05) from April to November (peak 2.34 nmol/l). Testosterone remained low (below 3.5 nmol/l) from February to August and then rose significantly (P less than 0.01) till November (peak 36.78 nmol/l). Both hormones declined from November to February. In three castrates, androstenedione levels remained virtually unchanged (averaging around 0.5 nmol/l) between January and September. After a rapid significant increase (P less than 0.05) till November (peak value 2.45 nmol/l), androstenedione concentrations declined quickly to a baseline level. Testosterone in castrates remained around 0.3 to 0.7 nmol/l for most of the year with a non-significant peak (1.45 nmol/l) in October. These data indicate that the spring and summer increase in androstenedione in the intact deer is of testicular origin; the fall peak, however, may be a result of increased production in the adrenal glands. It can be speculated that the increase in androstenedione in the blood of the male deer during the spring may be responsible for the seasonal initiation and support of antler growth as well as being supportive to the re-activation of the reproductive system.

The histological and ultrastructural features of the epiphyseal plate in Morquio type A syndrome (mucopolysaccharidosis type IVA)

Tissue from the epiphyseal plate of a patient with Morquio type A syndrome (mucopolysaccharidosis type IVA) was studied by undecalcified histological and electron microscopical techniques. Cartilage cells in the plate were vacuolated to a variable degree. The orderly proliferating structure of the epiphyseal plate was absent and calcification was markedly reduced. The related bone tissue was morphologically normal although reduced in quantity.

The effect of orally administered melatonin on the seasonality of deer pelage exchange, antler development, LH, FSH, prolactin, testosterone, T3, T4, cortisol and alkaline phosphatase

Five milligrams of melatonin (M) per day was administered orally to four male white-tailed deer on a schedule that mimicked first decreasing and then increasing lengths of natural photoperiod. The following seasonal phenotypic and hormonal responses were observed: Pelage exchange, antler mineralization, velvet shedding, and rutting behavior of experimental animals were advanced by 50-55 days. Prolactin (PRL) levels exhibited a bimodal curve with peaks in May and August, as compared to a monomodal curve of controls (peak in June). Peak FSH levels of M-fed deer were advanced 2 months as compared to controls (June vs August). LH concentrations of both groups reached maxima in July; however, in the experimental group, LH levels declined much faster than in controls and then rose again in October-November. Testosterone (T) concentrations of M-fed bucks were elevated 2 months ahead of controls. Melatonin treatment had no significant effect on seasonal variation of T3, or T4. No seasonal rhythm of cortisol was seen in either group and no detectable effect of M was evident. No statistical differences in levels of alkaline phosphatase were seen between groups, although concentrations in experimental bucks sharply dropped to basal levels two months ahead of controls.

Anaerobic mediastinitis complicating median sternotomy

Two cases of mediastinitis and bacteremia caused by Bacteroides species following median sternotomy are described. In both patients, purulent sternal drainage and signs of systemic toxicity led to the diagnosis. Surgical reexploration and administration of appropriate antibiotics effected clinical cure. Although there is only a single previous case of anaerobic mediastinitis following median sternotomy incision reported, these two cases suggest that this unusual infection may not be so rare as previously thought.

The prolonged bleeding time in hemophilia A: comparison of two measuring technics and clinical associations

The authors simultaneously performed the Ivy (IBT) and the Simplate I (SBT) bleeding time in 17 volunteers with classic hemophilia A to determine whether a prolonged Simplate bleeding time was indeed indicative of impaired primary hemostasis, as has been postulated recently, or whether the technic itself accounted for the observed changes. They also assessed platelet function and Factor VIII-related activities on blood drawn that day. The SBT was prolonged in 11 patients, while the IBT was consistently normal. The platelet aggregation studies and the levels of Factor VIII-related antigen (VIII R:Ag) and ristocetin cofactor (VIII R:Rc) were normal, providing no evidence of von Willebrand's disease. The patients with a prolonged SBT were all younger than 20 years of age, bled two to three times more often than those with a normal SBT, and consumed more Factor VIII concentrate. A prolonged SBT with depressed VIII:C therefore is not indicative of von Willebrand's disease but is shared by a substantial proportion of hemophiliacs, who may be a greater risk of bleeding.

The benefits of comprehensive care of hemophilia: a five-year study of outcomes

Eleven of 22 federally funded Comprehensive Hemophilia Centers have collected data on outcomes, before and after five years of this program's existence. Improved health, decreased hospitalization, decreased absenteeism, and a decrease in the unemployment rate from 36 per cent to 13 per cent were accompanied by decreased costs of care. In this model of a chronic handicapping illness, the early application of comprehensive care is preferable to the previous emphasis on end-stage rehabilitative efforts.