Bladder malfunction, urinary tract infection and vesicoureteral reflux in children

A correlation between urinary tract infection, vesicoureteral reflux and voiding disorders has increasingly been reported. Voiding dysfunction increases the incidence of recurrent urinary tract infection, induces and perpetuates vesicoureteral reflux, even after surgical antireflux treatment, and may result in permanent renal damage. The resolution of the primary cause with voiding normalization is essential to achieve good results in the treatment of secondary problems such as urinary tract infection and vesicoureteral reflux. Thirty seven children with vesicoureteral reflux secondary to voiding disorders were diagnosed and treated between 1990 and 1995 (five years). Forty-nine ureters were studied. The subjects became symptomatic between 1 month and 13 years of age, with the occurrence of urinary tract infection. All children were neurologically and morphologically normal. Symptoms suggesting bladder instability were detected in 34 (91.9%) and dysfunctional sphincter obstruction in three (8.1%). These patients were all evaluated with a renal/bladder sonogram and voiding cystogram, complemented in 17 (45.9%) with urodynamic testing that confirmed clinical diagnosis. 99mTc-dimercaptosuccinic acid renal scans performed on 29 (78.4%) children revealed renal damage in 26 (89.6%). A treatment program of bladder retraining and bowel habit normalization was encouraged in every child, anti-cholinergic drugs were associated in 23 (62.2%), muscle-relaxant drugs in three (8.1%), phenoxybenzamine and intermittent catheterization were used in one child (2.7%). Urinary tract infection prophylaxis was instituted in 34 (91.9%) children. Urinary tract infection was completely resolved in 35 (94.6%) patients, and its frequency decreased in two (5.4%). Thirty-two children (86.5%) with vesicoureteral reflux were cured and four (10.8%) were improved. Evidence of voiding disfunction ceased in 22 (59.5%) cases and improved in 14 (37.8%) with a reduction in the frequency and intensity of complaints. Urgency syndrome and vesicoureteral reflux remained unchanged in one child (2.7%). These findings imply that detection and treatment of bladder/sphincter disfunction are essential in every child with the complex of recurrent urinary tract infection and vesicoureteral reflux.     

Trends in infectious disease hospitalizations in the United States, 1980-1994

BACKGROUND: A recent study concluded that between 1980 and 1992, deaths from infectious diseases increased 58%. This article explores trends in infectious diseases as a cause of hospitalization. METHODS: We analyzed data from the National Hospitalization Discharge Survey for 1980 through 1994 using a previously developed approach to evaluate infectious diseases in data coded according to the International Classification of Diseases, Ninth Revision. RESULTS: Between 1980 and 1994, the rate of hospitalizations in the United States declined approximately 33%; hospitalizations occurred at a rate of 133+/-5 per 1000 US population (35 million+/-1 million discharges) in 1994. The rate of hospitalization for infectious diseases declined less steeply--12% during this interval--resulting in an increased proportion of hospitalizations because of infectious diseases. In 1994, the rate of hospitalizations for infectious diseases was 15.4+/-0.7 per 1000 US population (4.0 million+/-0.2 million discharges). The fatality rate associated with hospitalizations for infectious diseases increased from 1.9%+/-0.1% to 4.0%+/-0.3%, attributable to increased hospitalizations of elderly persons and an increased fatality rate among those younger than 65 years. Among selected categories, hospitalizations for human immunodeficiency virus infections and acquired immunodeficiency syndrome, prosthetic device infections, sepsis, and mycosis increased substantially, and hospitalizations for upper respiratory tract infections, pelvic inflammatory disease, and oral infections declined sharply. Hospitalizations for lower respiratory tract infections constituted 37% of all infectious disease hospitalizations in 1994. CONCLUSIONS: Considering hospitalizations as a dimension of the burden of infectious diseases involves an array of factors: secular trends in hospitalization, changing case management practices, demographic changes, and trends in the variety of infectious diseases themselves. Increases in the proportions of hospitalizations because of infectious diseases during years when hospitalizations for all causes were decreasing reflect an increasing burden of infectious diseases in the United States between 1989 and the mid-1990s.     

An ultrastructural analysis of the epithelial-fiber interface (EFI) in primate lenses

The purpose of this study was to conduct a comprehensive ultrastructural analysis of the epithelial-fiber interface (EFI) in normal adult primate (Macaque nemestrina and fascicularis; 6-9 years old, n = 10) lenses. Scanning electron microscopy (SEM) was used to initially characterize the gross size, shape and three-dimensional organization of central zone (cz) epithelial cells and the anterior ends of elongating fibers beneath these cells. This fiducial information was essential to properly orient lens pieces in freeze fracture specimen carriers for the production of replicas with unambiguously identifiable EFI. Transmission electron microscopy (TEM) of replicas and thin-sectioned material were used to ultrastructurally analyse the cz EFI. TEM thin-sectioned material was also used to ultrastructurally analyse the pregerminative (pgz), germinative (gz) and transitional zone (tz) EFI. Correlative SEM and TEM of cz EFI components revealed that the apical membrane of both epithelial and elongating fiber cells were irregularly polygonal in shape, and aligned in parallel as smooth, concave-convex surfaces. However, whereas epithelial cell apical surfaces had minimal size variation, elongating fibers were larger and considerably variable in size. Quantitative analysis of > 10000 micron2 cz elongating fiber apical surfaces failed to detect any gap junctions defined in freeze fracture replicas as complementary aggregates of transmembrane proteins (connexons) conjoined across a narrowed extracellular space. However, a comparable frequency of vesicular events was noted in this region as quantified previously in adult and embryonic chick lens. Correlative TEM analysis > 1500 linear micrometers of thin-sectioned EFI from this region confirmed the presence of epithelial-epithelial gap junctions, elongating fiber-elongating fiber gap junctions, and an extreme paucity of epithelial-elongating fiber gap junctions. In contrast, TEM analysis of > 1000 linear micrometers of thin-sectioned pgz, gz and tz EFI, confirmed the presence of epithelial-epithelial gap junctions, elongating fiber-elongating fiber gap junctions, numerous epithelial-elongating fiber adherens junctions and a few epithelial-elongating fiber gap junctions. Thus, the results of this and previous quantitative morphological and physiological studies (electronic and dye coupling) demonstrate that there is limited coupling between cz epithelial cells and underlying elongating fibers. Furthermore, the absence of gap junctional plaques in cz EFI freeze-fracture replicas and either pentalaminar or septalaminar profiles in correlative thin-sections, suggests that this limited coupling could be mediated via isolated gap junction channels. However, the results of this and previous quantitative studies further show that a greater degree of coupling exists across the pgz, gz and tz regions of the EFI and that this coupling is likely to be mediated by gap junction plaques. Finally, this and other studies continue to demonstrate that transcytotic processes play a role in lens physiology at the EFI.     

Capillaria hepatica: a cause of septal fibrosis of the liver

Fine, long, fibrous septa were observed as a late change developing in the acinar zone III of the liver of rats experimentally infected with the helminth Capillaria hepatica. Hepatic septal fibrosis begun 30 days after inoculation of embryonated eggs into the stomach of rats and became clearly evident from the 40th day onwards. Experimental observation was undertaken for 170 days. Septal fibrosis increased progressively with time and was most marked when the parasitic nodules formed around larvae, disintegrating worms and eggs were involving. Septal fibrosis of the liver has not been previously recognized as a manifestation of hepatic capillariasis. The presence of sequestered parasite antigens, probably being slowly released within the liver, appears to be a major factor in the pathogenesis of hepatic septal fibrosis observed in rats with C. hepatica infection.     

Surface wave excitation on a microstrip ring antenna

A theoretical analysis of the excitation of surface waves on a microstrip ring antenna is presented. The problem is formulated using dyadic Green's functions in a layered medium with magnetic-type equivalent current sources. The integral equation for the fields is solved in the wave number complex plane so that the fields from space and surface waves are obtained separately. The space wave radiation efficiency is calculated for the TM₁₁, TM₁₂, and TM₁₃ modes for various values of the normalized dielectric substrate thickness, d/λ₀. It is noted that the TM₁₃ mode radiates more efficiently than the TM₁₁ and TM₁₂ modes. The results are of importance in the design of these antennas     

Exposure workups

Exposure workups are an important responsibility for infection control personnel. A well-designed plan for investigating exposures, which includes appropriate algorithms, will enable infection control personnel to evaluate exposures rapidly and consistently so that nosocomial transmission is minimized. Infection control personnel should use their own data to develop policies and procedures that suit the needs of their facility. After they have implemented the plan, infection control personnel should continue to collect data on exposures so they can continuously improve their performance.     

Methods for investigation and estimation of individual chemosensitivity of tumors (review)

A review of the current methods for the estimation of tumor sensitivity to antiblastomic drugs is presented. Methods for the in vitro and in vivo cultivation of tumor cells are discussed. Among them the following methods are reviewed: the method for the cultivation of tumor heterotransplants in diffusion chambers and its various modifications, the method for the cultivation of human tumors under the kidney capsule, the method for the cell cultivation in primary short-term suspensions, the methods using enriched media, the methods for the cell cultivation on acetate cellulose fibres, in monolayers, etc.