Lagrangian Supersaturation Fluctuations at the Cloud Edge

Evaporation of cloud droplets accelerates when turbulence mixes dry air into the cloud, affecting droplet-size distributions in atmospheric clouds, combustion sprays, and jets of exhaled droplets. The challenge is to model local correlations between droplet numbers, sizes, and supersaturation, which determine supersaturation fluctuations along droplet paths (Lagrangian fluctuations). We derived a statistical model that accounts for these correlations. Its predictions are in quantitative agreement with results of direct numerical simulations, and explain the key mechanisms at play.

Neutral processes forming large clones during colonization of new areas

In species reproducing both sexually and asexually clones are often more common in recently established populations. Earlier studies have suggested that this pattern arises due to natural selection favouring generally or locally successful genotypes in new environments. Alternatively, as we show here, this pattern may result from neutral processes during species' range expansions. We model a dioecious species expanding into a new area in which all individuals are capable of both sexual and asexual reproduction, and all individuals have equal survival rates and dispersal distances. Even under conditions that favour sexual recruitment in the long run, colonization starts with an asexual wave. After colonization is completed, a sexual wave erodes clonal dominance. If individuals reproduce more than one season, and with only local dispersal, a few large clones typically dominate for thousands of reproductive seasons. Adding occasional long-distance dispersal, more dominant clones emerge, but they persist for a shorter period of time. The general mechanism involved is simple: edge effects at the expansion front favour asexual (uniparental) recruitment where potential mates are rare. Specifically, our model shows that neutral processes (with respect to genotype fitness) during the population expansion, such as random dispersal and demographic stochasticity, produce genotype patterns that differ from the patterns arising in a selection model. The comparison with empirical data from a post-glacially established seaweed species (Fucus radicans) shows that in this case, a neutral mechanism is strongly supported.

NanoStore: A Concept for Logistical Improvements of Compound Handling in High-Throughput Screening

Small molecule screening, the systematic encounter of biology space with chemical space, has provoked the emergence of a whole industry that recreates itself by constant iterative improvements to this process. The authors describe an approach to tackle the problem for one of the most time-consuming steps in the execution of a screening campaign, namely, the reformatting of high-throughput screening test compounds from master plates to daughter assay plates used in the execution of the screen. Through an engineered storage procedure, they prepare plates ahead of the screening process with the respective compounds in a ready-to-use format. They show the biological inertness of the method and how it facilitates efficient recovery of compound activity. This uncoupling of normally interconnected processes provides time and compound savings, avoids repeated freeze-thaw cycles of compound solutions, and removes the problems associated with the DMSO sensitivity of certain assays types.

[A rare case of birenal malacoplakia with renal failure]

HISTORY AND ADMISSION FINDINGS

A 45 year old man was admitted to our hospital because of fever, loss of appetite, and deterioration of general health. For two weeks the patient suffered from diarrhea which had resulted in moderate volume depletion. In addition, he complained of bilateral flank pain at the time of admission. Furthermore, the patient had a history of heavily drinking alcohol as well as cigarette smoking for many years. He had never attended a medical doctor before.

INVESTIGATIONS

The patient presented with the clinical picture of acute renal failure and urosepticaemia which was caused by Escherichia coli. The kidneys were found to be at the upper limit of normal by sonography. Magnetic resonance imaging revealed signal-alterations in both kidneys with hyper- and hypointense zones in the renal parenchyma.

DIAGNOSIS

To clarify the cause of rapid deterioration of renal function, we performed a renal biopsy. The histology of the renal specimen revealed an unusual type acute bacterial interstitial nephritis most likely due to an infection with E. coli. The clinical picture, the laboratory findings and renal histology, lead to the diagnosis of birenal malakoplakia.

TREATMENT AND COURSE

After intravenous and subsequent oral antibiotic therapy the fever and the clinical signs of urosepticaemia subsided and renal function gradually improved. Antibiotic therapy and supplementation with vitamins were continued for 20 weeks. Five years after initial diagnosis, renal function was stable at a glomerular filtration rate of approximately 45 ml/min.

CONCLUSIONS

Malakoplakia of the kidney is a rare form of bacterial interstitial nephritis and requires long-term antibiotic therapy.

Patient based method of assessing adverse events in clinical trials in rheumatology: the revised Stanford Toxicity Index

We describe the progress towards developing a patient rated toxicity index that meets all of the patient-important attributes defined by the OMERACT Drug Safety Working Party. These attributes are frequency, severity, importance to patient, importance to the clinician, impact on economics, impact on activities, and integration of adverse effects with benefits. The Stanford Toxicity Index (STI) has been revised to collect all attributes with the exception of impact on activities. However, since the STI is a part of the Health Assessment Questionnaire (HAQ), impact on activities is collected by the HAQ. In particular, a new question asks patients to rate overall satisfaction, taking into consideration both benefits and adverse effects. The next step in the development of this tool is to ensure that the STI meets the OMERACT filter of truth, discrimination, and feasibility. Although truth and feasibility have been confirmed by comparisons within the ARAMIS database, discrimination needs to be assessed in clinical trials.

A ureterocutaneous fistula forty years after nephrectomy

The case of a woman presenting with a ureterocutaneous fistula 40 years after nephrectomy is described. Because of advanced respiratory disease and absence of infective activity, a conservative line of treatment with saline rinse was given. At 3 months follow-up the fistula had become chronic, with a small opening without signs of infection and ultrasound revealed no abscess.

Co-expression of the squamous cell carcinoma antigens 1 and 2 in normal adult human tissues and squamous cell carcinomas

Squamous cell carcinoma antigen (SCCA) serves as a serological marker for advanced squamous cell carcinomas (SCCs) and as an indicator of therapeutic response. Recent molecular studies show that the SCCA is transcribed by two almost identical tandemly arrayed genes, SCCA1 and SCCA2. These genes are members of the high molecular weight serine proteinase inhibitor (serpin) superfamily. Although SCCA1 and SCCA2 are 92% identical at the amino acid level, they have distinct biochemical properties. Paradoxically, SCCA1 is an inhibitor of papain-like cysteine proteinases, such as cathepsins L, S, and K, whereas SCCA2 inhibits chymotrypsin-like serine proteinases, cathepsin G, and mast cell chymase. Using a new set of discriminatory monoclonal antibodies (MAbs) and polymerase chain reaction (PCR) assay, we showed that SCCA1 and SCCA2 were co-expressed in the suprabasal layers of the stratified squamous epithelium of the tongue, tonsil, esophagus, uterine cervix and vagina, Hassall's corpuscles of the thymus, and some areas of the skin. SCCA1 and SCCA2 also were detected in the pseudo-stratified columnar epithelium of the conducting airways. Examination of squamous cell carcinomas of the lung and head and neck showed that SCCA1 and SCCA2 were co-expressed in moderately and well-differentiated tumors. Moreover, there was no differential expression between these SCCA "isoforms" in normal or malignant tissues. In contrast to previous studies, these data indicated that the expression of SCCA1 and SCCA2 was not restricted to the squamous epithelium and that these serpins may coordinately regulate cysteine and serine proteinase activity in both normal and transformed tissues.

[Perforation of the rectum--caused by blunt injury]

A case of perforation of the rectum in a victim of a car crash who suffered pelvic fracture is reported. Seatbelt use, diagnosis, principles of treatment and complications are reported. Rectal perforations caused by blunt trauma is unusual and has a poor prognosis.

Safety of meloxicam: a global analysis of clinical trials

Meloxicam is a new preferential cyclooxygenase-2 (COX-2) inhibitor for the treatment of rheumatic disease. This paper presents a global safety analysis of data from meloxicam clinical studies, focusing on gastrointestinal (GI) adverse events. Meloxicam 7.5 and 15 mg (n = 893 and 3282) were compared with piroxicam 20 mg (n = 906), diclofenac 100 mg slow release (n = 324) and naproxen 750-1000 mg (n = 243). With respect to all GI adverse events, meloxicam 7.5 and 15 mg were significantly better than all comparators in a pooled analysis of double-blind studies in rheumatoid arthritis (RA) and osteoarthritis (OA). When examining non-serious GI events, severe GI events, discontinuous due to GI events, dyspepsia, abdominal pain and upper GI events, both meloxicam doses were significantly better than comparator non-steroidal anti-inflammatory drugs (NSAIDs) in most cases. Where statistical significance was not demonstrated, there was generally a trend in favour of meloxicam. With respect to upper GI perforations, ulcerations and bleedings, the most serious of NSAID-associated side-effects, meloxicam was better tolerated than the comparators, reaching statistical significance for piroxicam and naproxen. Meloxicam's improved GI safety profile is likely to be due to its preferential inhibition of inducible COX-2 relative to constitutive COX-1.

Toward an understanding of NSAID-related adverse events: the contribution of longitudinal data

The ARAMIS (Arthritis, Rheumatism and Ageing Medical Information System) databanks have been used to objectify and quantify drug toxicity. The relative risk of a gastrointestinal (GI)-provoked hospitalization was more than five times greater in patients taking non-steroidal anti-inflammatory drugs (NSAIDs) than in non-NSAID-treated patients, with an excess hospitalization rate of 1.3% per annum. Additionally, there was an excess GI-related death rate of around 3% in rheumatoid arthritis (RA) patients compared with the normal population. Age, previous NSAID-related GI events, prednisone use, higher doses and greater disability predicted high-risk patients. A toxicity index showed clear differences between NSAIDs, with aspirin, salsalate and ibuprofen emerging as the least toxic, and meclofenamate and indomethacin as the most toxic. Disease modifying anti-rheumatic drugs (DMARDs) were, surprisingly, found to have similar toxicity scores to the NSAIDs. This supports the contemporary practice of employing DMARDs earlier and more aggressively in the course of RA.

[Postmyelographic headache]

Prolonged cerebrospinal fluid leakage from the dural puncture site is considered the most important factor in the development of post-myelography headache. Incidences of post-myelography headache and post dural puncture headache vary a lot--possible reasons are discussed. The statement that patients with a low substance P level in cerebrospinal fluid are prone to developing a post dural puncture headache seems especially interesting. Articles considering clinical as well as experimental studies are reviewed.

Health status instruments / utilities

Rheumatologists and other interested professionals at the OMERACT II conference formed small groups to discuss whether it was sensible to use a generic health status instrument in musculoskeletal disease trials. These instruments promise the possibility of comparison of health status between disease states. However, data is lacking on validity of the current generation of instruments to support their use. Participants had little personal experience with these instruments. After inspection, many voiced strong concerns over comprehensiveness and responsiveness. Many dimensions of health relevant for patients with this group of diseases were felt to be underrepresented. The dimension of adverse effects was universally absent, although this is more a problem of state of the art in trial methodology than a problem of these measures. Although there is little data, the small number of response categories in the dimensions covered, plus the lack of comprehensiveness, make it likely that responsiveness will be low. Further research, especially the adoption of one or more generic measures alongside specific measures, both in trials and in observational studies, is necessary to validate and improve the current generic measures. Until that time, valid conclusions and health policy regarding musculoskeletal diseases cannot be based on generic measures of health status.

Second-trimester echogenic small bowel: an increased risk for adverse perinatal outcome

2267 singleton fetuses who had one ultrasound examination between 15 and 21 weeks' gestation were prospectively evaluated for echogenic small bowel. Thirty-two cases of echogenic small bowel were detected--a prevalence of 1.4 per cent. Echogenic fetal small bowel was divided into two grades: grade 1, where the small bowel was more echogenic than the liver; and grade 2, where the small bowel had the echogenicity of bone. In contrast to 19/23 fetuses with grade 1 small bowel echogenicity, only 2/9 fetuses with grade 2 echogenic bowel had a normal pregnancy outcome (Fisher's exact test; P < or = 0.01). Complications associated with second-trimester echogenic small bowel included in utero cytomegalovirus infection, second-trimester growth restriction, intrauterine fetal demise, and chromosomal abnormalities. Second-trimester fetal echogenic small bowel is associated with an increased risk of an adverse outcome. The prevalence of perinatal and neonatal complications is significantly greater when small bowel echogenicity approaches that of bone.

The effect of trisomy 18 on transverse cerebellar diameter

The transverse cerebellar diameter was measured in 19 fetuses with trisomy 18. Eleven of the cerebellar measurements (57.9%) were greater than 2 SD below the mean for the patient's gestational age. If fetal biometry rather than last menstrual period were used to determine gestational age, four of the 19 (21.0%) cerebellar measurements were greater than 2 SD below the mean. Both intrauterine growth retardation and intrinsic central nervous system abnormalities associated with trisomy 18 appeared to affect cerebellar size.

The role of the transcerebellar view in the detection of fetal central nervous system anomaly

The current resolution of antenatal ultrasonography permits the sonologist to visualize and critically evaluate the cerebellum and cisterna magna. Abnormalities in the size and shape of these structures will assist the sonologist in the detection of the majority of central nervous system malformations.

The transverse cerebellar diameter in estimating gestational age in the large for gestational age fetus

The transverse cerebellar diameter was measured in 62 nondiabetic and 30 diabetic women with large for gestational age fetuses. Using reference curves from 675 women with normal gestations between 14-42 weeks, head circumference and abdominal circumference overestimated gestational age significantly in both study groups, whereas the transverse cerebellar diameter did not.

P & T committee review of misoprostol: prevention of NSAID side effects is key--roundtable discussion

Misoprostol, a prostaglandin of the E series, was recently introduced for the prevention of NSAID-induced gastric ulcers. Misoprostol was classified as "1A" (denoting a new chemical entity that is a significant therapeutic advance) for purposes of review priority by the Food and Drug Administration in 1988. A dosage of 200 micrograms qid is recommended for prophylaxis, for the duration of NSAID therapy. Misoprostol is generally well-tolerated, with some patients reporting diarrhea. Misoprostol should not be given to pregnant women because of its uterotonic effects. (Please see full prescribing information for a discussion of the safety profile of misoprostol.) Because of the magnitude of the problem of NSAID-induced gastric ulceration and the expense of treatments and hospitalizations, the use of misoprostol in preventing these ulcers should be clinically beneficial, and may contribute to significant cost savings in the hospital and other managed-care settings.

Radiometric analysis of infrared sensor performance

The performance of IR sensors for target detection is analyzed with model SENSAT. The model calculates the radiometric relations for passive IR sensors with up to three homogeneous objects in the instantaneous field of view. For the atmospheric part, the computer code LOwTRAN-6 is used within SENSAT. The sensor model has been improved by introducing a noise model for quantum detectors. It takes into account photon noise, thermal detector/preamplifier noise, and g-r and 1/f noise. In combination with a spectral band optimization with respect to the SNR an efficient tool for the radiometric analysis of IR sensor performance is presented. The comparison of model calculations in the 3-5-micro and 8-14-microm bands with experimental measurements yields excellent agreement.

Pyrimidine pathways enzymes in human tumors of brain and associated tissues: potentialities for the therapeutic use of N-(phosphonacetyl-L-aspartate and 1-beta-D-arabinofuranosylcytosine

The activities of aspartate transcarbamylase (de novo pyrimidine biosynthesis pathway) and of deoxycytidine kinase as well as deoxycytidine deaminase (salvage pyrimidine biosynthesis pathway) were determined in extracts prepared from 40 brain tumors of different types in comparison with extracts from normal nervous tissues. Aspartate transcarbamylase, which is undetectable in normal brain tissue, is present in all tumor samples and in some cases rises to very high activities. Deoxycytidine kinase activity is present in all tissues but its level is generally higher in tumors. Deoxycytidine deaminase is present in all the tissues which were analyzed, although its activity is lower in some of the tumor samples. 1-beta-D-Arabinofuranosylcytosine is a substrate for both deoxycytidine kinase and deaminase in all the samples used except one. These results suggest some potential for the utilization of 1-beta-D-arabinofuranosylcytosine and N-(phosphonacetyl)-L-aspartate in the treatment of brain tumors.

Comparative toxicity of total lymphoid irradiation and immunosuppressive drug treated patients with intractable rheumatoid arthritis

Outcomes were compared between consecutive patients who had received either total lymphoid irradiation (TLI) or immunosuppressant treatment for intractable rheumatoid arthritis (RA). There were 33 TLI and 32 immunosuppressive recipients; all patients had failed standard therapy. Average followup from the start of therapy was 2.7 years for TLI and 5.9 years for immunosuppressive recipients. Final disability levels were the same in both groups; mortality was equal in both groups as well. There were more hospitalizations for infections in the TLI group and the infecting organisms tended to be staphylococcus or gram negative organisms. Apart from infections, there were more adverse effects reported in the immunosuppressive therapy group.

Sex-linked pattern of collaterals in iliac artery occlusive disease

Aorto-femoral angiography carried out in 839 patients revealed that 139 males and females had uni- or bilateral occlusion of the common or external iliac arteries. Pelvic or lumbar/intercostal arteries served as collaterals in 786 patients. In the remaining 53 patients the collateral blood supply originated from the thoracic arteries. Among the 53 patients, only 7 were females. A chi 2-test revealed the difference to be significant (p less than 0.0005), indicating a sex-linked difference, a male preponderance, in the development of collateral circulation of thoracic origin.

A case of Sjögren's syndrome with severe anemia due to myelitis

An unusual case of Sjögren's syndrome presenting with severe anemia as the predominant clinical feature is described. Histological examination of a bone marrow biopsy specimen demonstrated that the patient's anemia was caused by myelitis and vasculitis of the small intraosseous vessels. Our report might stimulate a more thorough investigation of bone marrow in patients with connective tissue diseases and anemia.

Iohexol and ioxithalamate for intravenous urography. A comparative parallel study

Omnipaque (iohexol) 350 mg I/ml has been compared with Telebrix (ioxithalamate) 380 mg I/ml in 48 patients undergoing intravenous urography. The contrast medium dose corresponded to 400 mg I/kg body weight. No cardiovascular reactions (BP and pulse rate) were observed. Subjective reactions occurred somewhat more frequently after Telebrix than after Omnipaque. Sensation of warmth was significantly less with Omnipaque (p less than or equal to 0.05). The overall radiological quality was equally good for the two contrast media.

[Undifferentiated cutaneous angiosarcoma of the head: identification by the endothelial marker Ulex europaeus agglutinin I]

Cutaneous angiosarcoma of the head is a rare tumor of the elderly and can occur in an undifferentiated form without any clinical or histological signs of the vascular origin of this tumor. In these cases, the tumor can be identified by using endothelial cell markers, such as factor-VIII-related antigen and ulex europaeus agglutinin I, in an immunofluorescence technique or a peroxidase-antiperoxidase method. A 78-year-old patient is described who died within 18 months from such a tumor, which was diagnosed using the endothelial cell marker, ulex europaeus agglutinin I.

Rapidly progressive glomerulonephritis in IgA/IgG cryoglobulinemia

Mixed IgA/IgG cryoglobulins were found in the serum of a 48-year-old man suffering from rapidly progressive glomerulonephritis (RPGN) with crescent formation. The type-II cryoglobulins were composed of monoclonal IgA1-kappa and polyclonal IgG, with the IgA possessing antibody activity against the IgG. The RPGN was of the immune complex type with granular deposits of IgA, IgG, and C3 on immunofluorescence microscopy and preponderant subendothelial deposits on electron microscopy. Occluding protein thrombi could be demonstrated in several glomerular capillary loops. Removal of the cryoglobulins from the patient's serum by plasmapheresis and immunosuppression was paralleled by a remarkable improvement in renal function with fall of serum creatinine values from 13.6 mg/dl (1,202.2 mumol/l) to 2.8 mg/dl (247.5 mumol/l), a resolution of the glomerular lesions, and clinical improvement as well. Our observations suggest that the crescentic glomerulonephritis may be due to an immune complex-like deposition of the cryoproteins. We conclude that crescentic glomerulonephritis in IgA/IgG cryoglobulinemia has to be considered as an autoimmune form of RPGN.

Solvent effects on allosteric equilibria: stabilization of T and R conformations of Escherichia coli aspartate transcarbamylase by organic solvents

The activity of Escherichia coli aspartate transcarbamylase (ATCase) is markedly influenced by the addition of organic solvents to the assay medium. The cosolvents tested, which include simple aliphatic alcohols, amides, and ureas, as well as acetone and dioxane, fall into two different classes: the most polar ones (formamide, acetamide, N-methylformamide, and urea) stimulate the enzyme activity for all concentrations tested. In contrast, solvents that are less polar than water inhibit the enzyme at low concentrations but stimulate it at higher concentrations. No comparable effects are observed in the case of the isolated catalytic subunits, a non-regulated form of ATCase. Extensive kinetic studies on ATCase and on two of its Michaelian derivatives, 2-thioU-ATCase and carbamylated ATCase, indicate that solvents modulate the same allosteric transition that is responsible for homotropic interactions between the catalytic sites. The stabilization of the R state of ATCase by comparatively high concentrations of cosolvents is reminiscent of similar findings made on hemoglobin and glycogen phosphorylase, suggesting a common underlying mechanism. Addition of organic cosolvents to water is known to reduce hydrophobic interactions, and we suggest that this effect may preferentially stabilize the more "relaxed" conformations of allosteric proteins, because they have a larger surface exposed to solvent [Chothia, C. (1974) Nature (London) 248, 338-339]. On the other hand, we suggest that the stabilization of the T state by low concentrations of all but the most polar cosolvents simply reflects stronger electrostatic interactions in this conformation.

Rupture of supra-aortic neck arteries due to lesions caused by tracheal tubes

Haemorrhages from the common carotid or innominate artery caused by tracheal tubes are rare but dramatic complications of head and neck surgery. Patients with metal tracheostomy cannulas or patients in the phase of wound healing after radical tumour resections of the pharynx and larynx run a greater risk. Following extensive tumour resections and radiation of the upper respiratory and digestive tracts in 680 patients, acute bleeding of the larger neck arteries occurred in 18 patients. In four of these cases, fistulae developed in the innominate or common carotid artery. These ruptures were caused by both plastic and metal tracheal tubes.

Intravenous digital subtraction angiography. Collateral circulation to 'empty leg'

Among 60 patients with uni- or bilateral occlusion of the common or external iliac arteries or both, 12 patients had collateral blood supply originating from the internal mammary or lateral thoracic arteries, or both. By means of intravenous digital subtraction angiography the thoracic arterial pathways and the non-occluded arteries of both legs, simultaneously, were easily demonstrated using the 30 cm effective field size of a Sirecon 33 triplex N image intensifier.

A patient-administered questionnaire for arthritis assessment

A patient-administered arthritis record system has been in use for 4 years. Thirty patients with various chronic arthritic conditions were studied to compare patient responses on the questionnaire to those obtained at the physician interview. Comparisons were also made between the "review of symptoms" and the actual physical findings documented in the medical record. The self-administered inventory of functional activities is a reliable and useful way to document specific activity achieved by a patient. Further, the questionnaires also aid in the evaluation of any therapeutic intervention and give a patient-perceived measurement of the clinical outcome in terms of quality of life. As a patient self-administered record, it allows for a major saving of physician time while acquiring accurate, complicated, but important, repetitive, time-oriented information. This system includes the American Rheumatism Association's Uniform Data Base for Rheumatic Diseases. An important set of questions has been added which improves functional assessment that is necessary to evaluate the success of surgical therapy.

The single hot joint

Several points may be stressed. (1)When in doubt, perform joint aspiration and look for crystals of micro-organisms. A joint tap is nearly always indicated. (2)Do not rely on a coincidental elevated serum uric acid level. Question the patient regarding drug therapy and other causes of secondary hyperuricemia. (3)Examine all of the patient, looking for tophi (gout), skin lesions (gonococcal infection, psoriasis), erythema nodosum (allergic reactions, fungal infections), and other clues. (4)Monoarticular rheumatoid arthritis is a rare cause of a single hot joint, but it is much more common that the real rarities (e.g., pigmented willondular synovitis). (5)Anky-losing spondylitis and Reiter's syndrome are common, yet frequently overlooked. (6)Radiologic examination is usually not helpful. (7)Having ruled out infection, crystal synovitis, and hemorrhage, it is sufficient to introduce symptomatic treatment and await the natural development of the joint disease. Follow-up in four to six weeks and simple blood studies often reveal the definitive diagnosis. Most of the time, natural healing processes are effective , and reward the patience of the conservative physician. Blind management must always be avoided.