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PubMed2003

Effect of different casting methods on adolescent idiopathic scoliosis.

Scoliosis is a three-dimensional spinal deformity. Although orthotic treatment for moderate adolescent idiopathic scoliosis (AIS) has been well recognized, there are few studies documenting the effectiveness of different casting methods in the fabrication of thoracolumbo-sacral orthoses (TLSO). The current study was a retrospective clinical evaluation of the effectiveness of two commonly used casting methods namely, the frame casting method and the supine with traction casting method in the treatment of AIS. Eighty (80) female patients with AIS were recruited and they were all treated by TLSOs. The frame casting method was used in 37 patients while the remaining 43 patients were under the supine with traction casting method. The responses of spinal deformities under the two different casting methods were analyzed for the period from pre-brace to 2 years after bracing. The studied parameters included the AP Cobb's angle, the apical vertebral rotation and the trunk listing (cervico-sacral lateral offset). The results of the current study showed that the orthoses manufactured from the two casting methods could provide an effective control of AIS (change of Cobb's angle within (+/- 5 degrees). For the frame casting, the Cobb's angles at pre-brace and 2 years after off-brace were 36.0 degrees and 33.8 degrees respectively while for the supine with traction casting, the corresponding Cobb's angles were 32.7 degrees and 34.0 degrees. The frame casting method could give a better control of the apical vertebral rotation at the early stage of treatment (pre-brace = 18.2 degrees and the 4th month = 13.8 degrees while the supine with traction casting method was more effective in the long-term control of the trunk listing (pre-brace = 10mm and 2 years after off-brace = 3.3mm).

Adolescent↗
PubMedDate not supplied

Effectiveness of serial stretch casting for resistant or recurrent knee flexion contractures following hamstring lengthening in children with cerebral palsy.

A retrospective review of all cerebral palsy (CP) patients with resistant or recurrent knee flexion contractures treated with serial stretch casting was performed. The protocol consisted of sequential wedging (5 degrees per week) of fiberglass casts until maximum knee extension had been achieved. Measurements were made prior to the initiation of casting, at completion of the casting, and at 1 year after the casting. Forty-six subjects, with 75 involved extremities, met the study inclusion criteria. Mean age at the time of initiation of casting was 12.7 years. Using radiographic measurements, the mean initial degree of knee flexion contracture was -17.6 degrees. At the completion of casting, the mean knee flexion angle was -8.1 degrees. The mean duration of casting was 30 days. At 1 year after completion of the casting, the mean knee flexion angle was -12.2 degrees. Initial correction to within 10 degrees of full extension was achieved in 76% of extremities. Age less than 12 years and initial flexion contracture of less than -15 degrees were statistically significant factors related to maintenance of correction at 1 year. Complications included soft tissue compromise in 13 extremities (17%), transient neurapraxia in 9 extremities (12%), and tibial subluxation in 1 extremity (1%). Serial stretch casting was successful in correcting resistant knee flexion contractures in the majority of cases. Casting was less effective in teenagers and those with larger contractures. Complications were minimized by proper casting technique and controlled rate of correction.

Adolescent↗
PubMed2003

Can the use of a terminal device augment plantar pressure reduction with a total contact cast?

HYPOTHESES/PURPOSE: Total contact casting (TCC) has been shown to promote the healing of plantar neurotrophic ulcers by reducing plantar pressures and has become the established treatment standard by which all others are measured. The purpose of this study was to determine if terminal cast devices (cast shoes and heels) significantly affect the amount of plantar pressure reduction when used with a total contact cast. METHODS/RESULTS: Plantar pressures were measured in the right feet of 28 healthy adult volunteers using the Novel EMED PEDAR system (Novel GmbH, Munich, Germany) for six conditions: athletic shoe (i.e., control), TCC alone, TCC with a conventional cast shoe (EBI, Parsipanny, NJ), TCC with a custom rigid rocker cast shoe (NPS, St. Louis, MO), TCC with a rubber rocker heel (Cast Walker, DM Systems Inc., Evanston, IL), and TCC with a traditional flat rubber heel (Zimmer, Warsaw, IN). Peak plantar pressures were recorded from the forefoot, midfoot, and hindfoot. Analysis of variance (ANOVA) was used to determine statistical significance. The greatest reductions in forefoot plantar pressures compared to the athletic shoe control were seen in the TCC with the conventional cast shoe and the TCC with the rigid rocker shoe; a mean plantar pressure reduction of 30% was observed for both conditions (p < .001). Significant midfoot plantar pressure reductions (p < .001) were achieved with the TCC alone, TCC with the conventional cast shoe, TCC with the rigid rocker heel, TCC with the flat rubber heel, and TCC with the rubber rocker heel. Mean reductions were 42%, 51%, 47%, 40%, and 46%, respectively. While athletic shoe peak hindfoot pressures were only reduced by 15% by TCC alone, the addition of the rubber rocker heel to TCC reduced athletic shoe pressures by 32% and the addition of the flat rubber heel to TCC reduced athletic shoe pressures by 29%. The reductions with TCC and the heels were both significant when using the athletic shoe as the control (p < .001) and the TCC alone as the control (p < .05). CONCLUSION: Plantar pressure reduction with TCC can be augmented with the addition of a terminal cast device and the effects shown in this study are significantly different than previously reported. These results suggest that terminal cast devices should be chosen according to location of the neuropathic ulcer. In this study, forefoot pressures were reduced the most with TCC and either the conventional cast shoe or the rigid rocker shoe. The authors therefore recommend these combinations for forefoot ulcers. TCC alone or combined with any of the terminal devices proved equally effective for midfoot plantar pressure reduction. Hindfoot ulcers should be treated with TCC and the rubber rocker heel or the flat rubber heel as these provided the best hindfoot pressure reductions.

Adult↗
PubMed2006

Above and below-the-elbow plaster casts for distal forearm fractures in children. A randomized controlled trial.

BACKGROUND: Closed fractures of the distal third of the forearm are the most common fractures of childhood, but the method of immobilization after closed reduction is controversial. This study was undertaken to determine whether below-the-elbow casts are as effective as above-the-elbow casts in immobilizing these types of fractures and to identify patient and treatment considerations that are related to loss of reduction. METHODS: We designed a blinded, randomized, controlled trial. The criteria for reduction and remanipulation were set a priori. The primary outcome measure was fracture immobilization as reflected by reangulation in the cast and by the need for remanipulation. Exploratory analysis with use of stepwise logistic regression analysis was undertaken to search for factors predictive of loss of reduction. RESULTS: A total of 102 children were enrolled in the study and were allocated to two groups: the above-the-elbow cast group (fifty-six children) and the below-the-elbow cast group (forty-six children). The mean age was 8.6 years, and sixty-one patients were boys. The groups did not differ with respect to the initial fracture angulation, postreduction angulation, reangulation during cast immobilization, and angulation of the fracture at the time of cast removal. In the above-the-elbow cast group, twenty-three (42%) of fifty-five children with adequate radiographs met the criteria for remanipulation compared with fourteen (31%) of forty-five children with adequate radiographs in the below-the-elbow cast group (p = 0.27); only four of these thirty-seven children actually underwent remanipulation. Children with fractures of both the radius and ulna (p = 0.01) and those with residual angulation after reduction (p = 0.0001) were at the highest risk of meeting the criteria for remanipulation. The rates of complications related to the cast did not differ between the groups. CONCLUSIONS: Below-the-elbow casts perform as well as above-the-elbow casts in maintaining reduction of fractures in the distal third of the forearm in children, and the complication rates are similar. Factors that are associated with a higher risk of loss of reduction include combined radial and ulnar fractures and residual angulation of the fracture after the initial reduction.

Casts, Surgical↗
PubMed2000

Competition induces adaptive shifts in caste ratios of a polyembryonic wasp.

An important transition in insect life-history evolution was the shift from a solitary existence to living in groups comprising specialized castes. Caste-forming species produce some individuals that reproduce and others with worker functions that have few or no offspring. Morphologically specialized castes are well known in eusocial species like ants and termites, but castes have also evolved in less-studied groups like thrips, aphids and polyembryonic wasps. Because selection acts at both the individual and the colony level, ratios of investment in different castes are predicted to vary with environmental factors like competition and resources. However, experimental evidence for adaptive shifts in caste ratios is limited owing to the experimental difficulty of manipulating factors thought to influence caste ratios, and because some species produce behaviourally flexible castes that switch tasks in response to colony needs. Unlike other caste-forming species, the broods of polyembryonic wasps develop clonally, so that increased production of one caste probably results in decreased production of the other. Here we show that the polyembryonic wasp Copidosoma floridanum alters caste ratios in response to interspecific competition. Our results reveal a distinct trade-off by C. floridanum between reproduction and defence, and show experimentally that caste ratios shift in an adaptive manner.

Adaptation, Physiological↗
PubMed1994

Detection of Candida casts in experimental renal candidiasis: implications for the diagnosis and pathogenesis of upper urinary tract infection.

The distinction between upper versus lower urinary tract infection in patients with candiduria is a commonly encountered and therapeutically important diagnostic dilemma. Candida casts have been reported in the urine of several individual case reports of human renal candidiasis. The specificity of Candida casts would identify unequivocally a patient with upper urinary tract disease. Little is known, however, about the sensitivity and the formation of Candida casts. We therefore studied the diagnostic yield, methods for detection and pathogenesis of Candida cast formation in serially collected urine specimens from immunologically intact and granulocytopenic rabbit models of haematogenous disseminated candidiasis. Refractile blastoconidia and pseudohyphae of Candida encased in the granular matrix were seen on wet mounts while Candida stained a brilliant red in the fuschia pink tubular matrix on periodic acid Schiff (PAS) stained cytopathology filters. Among 24 rabbits with disseminated candidiasis, 11 (46%) had Candida casts detectable by wet mount and PAS-stained urine filters in comparison to none of 10 non-infected immunologically normal controls (P = 0.014). Fifteen (70%) of 21 episodes of Candida casts were detected within the first 3 days of infection, indicating possible utility in the early diagnosis of renal candidiasis. No Candida casts were detected in the urine of granulocytopenic rabbits, possibly due to the rapid destruction of tubules and abrogation of cast formation. This absence of detectable Candida in eight infected granulocytopenic rabbits differed significantly from that of 24 non-granulocytopenic infected rabbits, in which Candida casts were detected in 11 (46%) (P = 0.029). Candida cast formation occurred predominantly in the cortex. Histopathological examination demonstrated invasion of Candida into the glomerular tufts and peritubular capillaries, followed by development of Candida casts in the proximal and distal tubules, respectively. Detection of renal Candida casts may be a useful diagnostic marker in distinguishing upper versus lower urinary tract candidiasis.

Animals↗
PubMed2000

[Comparison of mechanical properties of laser-welded wrought and cast titanium].

OBJECTIVE: This study was aimed to compare the mechanical properties of laser-welded wrought and cast titanium. METHODS: According to relevant reports and clinical demands, the specimens of TA2 were machine milled or cast into certain sizes using LZ centrifuge-vacuum-pressure titanium casting machine. This experiment involved four groups including the laser-welded wrought titanium group, the laser-welded cast titanium group, the wrought titanium group and the cast titanium group. There were 6 complete specimens in each group and the specimens were ultrasonically cleaned with ethyl and distilled water before they were welded with home-made Nd:YAG apparatus, and comparisons of mechanical properties were made among these groups. All tensile specimens were mounted on the Instron universal testing machine to test tensile loads, yield loads and absolute elongations were measured. The cross section of fractured surface was observed under S-2700 Hitachi SEM and Vickers' microhardness values in different areas were detected with AKASHI microhardness tester. RESULTS: It was showed that the tensile load of laser-welded wrought titanium made no difference from that of the original wrought titanium, but the yield load of laser-welded wrought titanium was bigger than that of the original wrought titanium. The tensile load and yield load of cast titanium were slightly bigger than those of wrought titanium. The tensile load and yield load of laser-welded wrought titanium made no statistic difference from those of laser-welded cast titanium. The absolute elongations of cast or welded titanium were lower than those of wrought or non-welded titanium. The fractured surface of cast titanium under SEM appeared lath-like structure and that of welded cast titanium honeycomb-like structure. The honeycomb-like structure of wrought titanium was more obvious than that of laser-welded wrought titanium. The microhardness value of laser-welded cast titanium was slightly bigger than that of laser-welded wrought titanium. CONCLUSION: The mechanical property of laser-welded wrought titanium might be not apparently different from that of laser-welded cast titanium.

Dental Soldering↗
PubMed1984

Scanning electron microscopy of vascular corrosion casts--technique and applications.

The present paper states very briefly the main steps leading to the technique of scanning electron microscopy (SEM) of vascular corrosion casts. From the terms presently used (injection method, microcorrosion cast, injection replica, vascular corrosion cast, vascular cast) the use of "vascular corrosion cast" for lymphatic and blood vessels is recommended. Specification and pretreatment (kind, volume, dosage of anticoagulants, vasoactive substances and spasmolytica used) of the animals examined are referenced as they are available from the literature. The recommendation is given to pay more attention to these parameters than done so far. The steps necessary for producing reasonable and suitable vascular corrosion casts are critically described. Special attention is paid to the physical and chemical properties of the casting media and their significance for polymerizations, shrinkage, casting quality, corrosion resistance, and thermal and spatial stability. Emphasis is also focused on the advantages of cutting the vascular corrosion casts embedded in an ice block by a band saw and a self constructed multi-blade cutting device offer. From the drying methods presently used freeze-drying is stressed because of minimal specimen damage. To render casts conductive in most cases sputtercoating is sufficient. It is recommended to run the SEM with 5-10 kV since the resolution received still reveals all details the casting media presently can replicate. Lastly the application of scanning electron microscopy of vascular corrosion casts in fully differentiated normal tissue, in pathologic tissue as well as in developing tissues and organs is stated.

Animals↗
PubMed2003

Mechanical properties and microstructures of cast Ti-Cu alloys.

OBJECTIVES: This study evaluated the mechanical properties of cast Ti-Cu alloys with the hope of developing an alloy for dental casting with better mechanical properties than unalloyed titanium. METHODS: Ti-Cu alloys with five concentrations of copper (0.5, 1.0, 2.0, 5.0 and 10.0 mass%) were made in an argon-arc melting furnace. The alloys were cast into magnesia-based molds using a centrifugal casting machine. The microstructure, microhardness profile of the specimen cross section, tensile strength, yield strength, and elongation were determined for the castings. Scanning electron microscope fractography was undertaken for the fractured surfaces after tensile testing. XRD was performed on the polished specimens. Results were analyzed using one-way ANOVA and the Student-Newman-Keuls tests. RESULTS: The mean tensile strengths of all the cast Ti-Cu alloys were significantly (p<0.05) higher than for cast commercially pure titanium (CP Ti). Of the Ti-Cu alloys tested, the 5 and 10% Cu alloys had significantly higher strength than the rest. The 10% Cu alloy exhibited the lowest mean elongation. CP Ti and the 0.5 and 1% Cu alloys showed higher ductility. The bulk hardness of all the cast Ti-Cu alloys, except for the 10% Cu alloy, and CP Ti was approximately the same. SIGNIFICANCE: By alloying with copper, the cast titanium became stronger. Increases in the tensile strength (30%) and yield strength (40%) over CP Ti were obtained for the 5% Cu alloy. Elongation was approximately 3%, which was similar to cast Ti-6Al-4V. Ti-Cu alloys, such as the 5% Cu alloy, could be used for prosthetic dental applications if other properties necessary for dental castings are obtained.

Copper↗
PubMed2006

New polyurethane-based material for vascular corrosion casting with improved physical and imaging characteristics.

Vascular corrosion casting has been established as a method to reconstruct the three-dimensional (3D) structure of blood vessels of organs and tissues. After replacing the blood volume with a low viscosity resin, the surrounding tissue is removed to replicate the vascular architecture, typically using scanning electron microscopy (SEM). To date available casting resins have had significant limitations such as lack of viscosity, leading to insufficient perfusion of smallest capillaries in organs and tissues of smaller species, interaction with surrounding tissue or fragility of resulting casts. We have reported here about a new polyurethane-based casting resin (PU4ii) with superior physical and imaging characteristics. Low viscosity, timely polymerization, and minimal shrinking of PU4ii produces high quality casts, including the finest capillaries. These casts are highly elastic while retaining their original structure to facilitate postcasting tissue dissection and pruning of casts. SEM images illustrate the high reproduction quality, including endothelial cell imprints, features that allow one to discern arterial and veinal vessels. For quantitative analysis, casts from PU4ii can be imaged using micro-computed tomography to produce digital 3D reconstructions. The inherent fluorescence of PU4ii is sufficient to reproduce casts with or without tissue using confocal microscopy (CM). Because of the simplified casting procedure, the high reproducibility and the superior reproduction quality, a combination of vascular corrosion casting using PU4ii with advanced imaging technologies has great potential to support the description of vascular defects and drug effects in disease models using mutant mice.

Animals↗
PubMed2006

Surface detail, compressive strength, and dimensional accuracy of gypsum casts after repeated immersion in hypochlorite solution.

STATEMENT OF PROBLEM: One method used to disinfect a dental cast is immersion in a disinfecting solution. Repeated immersion of a cast in disinfectant may affect surface detail as well as other physical properties. PURPOSE: The purpose of this study was to evaluate the changes in surface detail quality, dimensional accuracy, and wet compressive strength of dental casts as a result of repeated disinfection in slurry containing 0.525% sodium hypochlorite solution. MATERIAL AND METHODS: Two different test specimen configurations were used, one for evaluating surface detail quality and dimensional accuracy and the other for compressive strength. Sixty specimens each were made of type III and type IV dental stone (Excalibur). Thirty specimens were immersed in slurry, a supernatant solution of calcium sulfate in distilled water (control casts), and 30 in slurry with sodium hypochlorite (test casts) solutions for 30 minutes and air dried for 24 hours. This process was repeated 7 times before testing. Linear dimensional change, surface detail quality, and wet compressive strength were determined according to American National Standards Institute/American Dental Association (ANSI/ADA) standards. The data were analyzed using 2-way analysis of variance and 2-sample independent t tests (alpha=.05). RESULTS: For specimens prepared with type III and type IV stone, treatment by immersion in slurry (control casts) and in slurry with sodium hypochlorite (test casts) resulted in an increase (P<.0001) in linear dimensional change. The type IV casts treated with slurry with sodium hypochlorite showed significantly less (P<.0001) mean linear dimensional change (0.025%) compared with type III stone casts (0.063%), and the values remained within the ANSI/ADA specified standards. Both test solutions caused some degree of erosion or damage to the surface quality of casts made from type III and type IV stones. However, the difference between the control and test casts was not significant. Slurry with 0.525% sodium hypochlorite solution decreased the compressive strength of both types of stones significantly (P<.001) compared with distilled water slurry. However, the values remained close to ANSI/ADA standards. CONCLUSION: The results demonstrated that repeated immersion of type III and type IV stone specimens in slurry with distilled water and slurry with 0.525% sodium hypochlorite, along with drying in air, caused a significant increase in linear dimension and a significant decrease in wet compressive strength. Although both the solutions caused some degree of damage to surface details for type III and type IV stones, the difference was not significant.

Calcium Sulfate↗
PubMed1999

Effect of surface contamination on adhesive bonding of cast pure titanium and Ti-6Al-4V alloy.

STATEMENT OF PROBLEM: There is little information regarding bond strengths of resin cements to cast titanium surfaces contaminated by investment material. PURPOSE: This study examined the effect of surface contamination on the shear bond strength of resin cements to cast titanium and Ti-6Al-4V alloy. MATERIAL AND METHODS: Two types of disks were cast from commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy ingots using an argon-arc pressure casting unit and a phosphate-bonded Al2 O3 /LiAlSiO6 investment. After casting, disks were subjected to 3 surface treatments: (1) cast surface sandblasted (50 microm-sized Al2 O3 ) for 30 seconds; (2) metal surface sanded with silicon-carbide paper (600 grit) after grinding the contaminated cast surface (approximately 200 microm in thickness); and (3) metal surface sandblasted for 30 seconds after treatment 2. Surface structures were examined after each treatment with SEM and optical microscopy. Each type of disk was then bonded with 2 types of luting materials. Bonded specimens were subjected to thermocycling for up to 50,000 cycles, and shear bond strengths were determined after 0 (baseline) and 50,000 thermocycles. Results were statistically analyzed with 3-way ANOVA (P <.05). RESULTS: Microscopic observation of cast CP-Ti and Ti-6Al-4V exhibited noticeable structures on the cast surfaces apparently contaminated with investment material. However, there were no statistical differences (P >.05) in the bond strengths of both cements between contaminated (treatment 1) and uncontaminated surfaces (treatment 3) for both metals at baseline and after 50,000 thermocycles. The bond strength of specimens sanded with silicon-carbide paper (treatment 2) deteriorated dramatically after 50,000 thermocycles. CONCLUSIONS: Contamination of the cast metal surfaces by elements of the investment during casting did not affect bond strengths of the luting materials to CP-Ti and Ti-6Al-4V.

Alloys↗
PubMedDate not supplied

Marginal integrity of direct and indirect castings for implant abutments.

PURPOSE: Current implant systems with screw-retained abutments permit direct laboratory fabrication of castings. Computer aided drafting systems further enhance the fabrication of computer-milled abutments (CMAs) and castings. The purpose of this study was to compare marginal accuracy, as measured by gap size, of castings made directly on CMAs with those made indirectly on epoxy and stone dies. MATERIALS AND METHODS: Castings were made directly for 10 CMAs. Marginal gap measurements were made with the castings seated on the abutments (group A). Castings were also made indirectly on stone and epoxy dies obtained from impressions of the abutments. Marginal gap measurements were made with these indirectly made castings seated on their CMAs (groups B and E). In addition, the directly made castings were transferred between CMAs and marginal gap measurements made (group D). Marginal gap measurements of the groups were compared with analysis of variance (ANOVA) and pair-wise comparisons (Scheffé test). RESULTS: Groups A and D had marginal gaps of less than 100 microm. These marginal gaps were significantly smaller (P < .05) than the gaps of groups B and E, made on dies, which were approximately 200 to 500 microm. DISCUSSION AND CONCLUSIONS: With CMAs, it is possible to make an exact duplicate of the abutment. This permits the laboratory to make castings on duplicate abutments with greater precision than can be obtained using the indirect technique. Direct fabrication of castings resulted in smaller marginal gaps, which in turn allows a better marginal seal and improved retention of castings.

Dental Abutments↗
PubMed1982

Energy costs of walking in lower-extremity plaster casts.

The energy cost of walking with axillary crutches and each of three types of plaster casts (long, short, and cylinder) on the lower extremity was measured in twenty normal adult men. The knee and ankle joints were immobilized unilaterally in the neutral positions. Oxygen uptake was measured using a modified Douglas-bag technique. Heart rate, respiratory rate, and step frequency were telemetered from transducers that were attached to the subjects. When walking and bearing full weight on a cast without the use of crutches, the average rates of energy expenditure for subjects wearing the three varieties of casts did not significantly differ from the value for normal walking. Velocity, however, was reduced depending on the extent of immobilization. The average velocity of the subjects was fifty-six meters per minute in a long cast, sixty-four meters per minute in in a cylinder cast, and seventy meters per minute in a short cast, compared with seventy-eight meters per minute without immobilization of the limb. The subjects' average oxygen cost per meter was 0.24 milliliter per kilogram in a long cast, 0.20 milliliter per kilogram in a cylinder cast, and 0.19 milliliter per kilogram in a short cast, compared with 0.15 milliliter per kilogram for normal walking. Using a unilateral non-weight-bearing swing-through gait, the average rate of oxygen uptake for subjects wearing the three types of casts did not differ from the mean value without a cast (21.2 milliliters per kilogram per minute). All values were at least 60 per cent higher than the average for normal level walking.

Adult↗
PubMed2004

Directional migration in the Hindu castes: inferences from mitochondrial, autosomal and Y-chromosomal data.

Genetic, ethnographic, and historical evidence suggests that the Hindu castes have been highly endogamous for several thousand years and that, when movement between castes does occur, it typically consists of females joining castes of higher social status. However, little is known about migration rates in these populations or the extent to which migration occurs between caste groups of low, middle, and high social status. To investigate these aspects of migration, we analyzed the largest collection of genetic markers collected to date in Hindu caste populations. These data included 45 newly typed autosomal short tandem repeat polymorphisms (STRPs), 411 bp of mitochondrial DNA sequence, and 43 Y-chromosomal single-nucleotide polymorphisms that were assayed in more than 200 individuals of known caste status sampled in Andrah Pradesh, in South India. Application of recently developed likelihood-based analyses to this dataset enabled us to obtain genetically derived estimates of intercaste migration rates. STRPs indicated migration rates of 1-2% per generation between high-, middle-, and low-status caste groups. We also found support for the hypothesis that rates of gene flow differ between maternally and paternally inherited genes. Migration rates were substantially higher in maternally than in paternally inherited markers. In addition, while prevailing patterns of migration involved movement between castes of similar rank, paternally inherited markers in the low-status castes were most likely to move into high-status castes. Our findings support earlier evidence that the caste system has been a significant, long-term source of population structuring in South Indian Hindu populations, and that patterns of migration differ between males and females.

Adult↗
PubMed2001

Vascular Corrosion Casting: Review of Advantages and Limitations in the Application of Some Simple Quantitative Methods.

Vascular corrosion casting has been used for about 40 years to produce replicas of normal and abnormal vasculature and microvasculature of various tissues and organs that could be viewed at the ultrastructural level. In combination with scanning electron microscopy (SEM), the primary application of corrosion casting has been to describe the morphology and anatomical distribution of blood vessels in these tissues. However, such replicas should also contain quantitative information about that vasculature. This report summarizes some simple quantitative applications of vascular corrosion casting. Casts were prepared by infusing Mercox resin or diluted Mercox resin into the vasculature. Surrounding tissues were removed with KOH, hot water, and formic acid, and the resulting dried casts were observed with routine SEM. The orientation, size, and frequency of vascular endothelial cells were determined from endothelial nuclear imprints on various cast surfaces. Vascular volumes of heart, lung, and avian salt gland were calculated using tissue and resin densities, and weights. Changes in vascular volume and functional capillary density in an experimentally induced emphysema model were estimated from confocal images of casts. Clearly, corrosion casts lend themselves to quantitative analysis. However, because blood vessels differ in their compliances, in their responses to the toxicity of casting resins, and in their response to varying conditions of corrosion casting procedures, it is prudent to use care in interpreting this quantitative data. Some of the applications and limitations of quantitative methodology with corrosion casts are reviewed here.

Journal Article↗
PubMedDate not supplied

Ultrastructure of tubular casts.

Tubular casts are found in a variety of conditions. Ultrastructural evaluation of casts has not been critically and systematically performed to define its usefulness. A total of 157 renal biopsies routinely processed for light microscopy (LM), immunofluorescence (IF), and electron microscopy (EM) were subjected to blind ultrastructural evaluation. The majority of the casts were in the distal nephron, and most of them (41.4%) were hyaline (HC). One-third (35%) of the cases showed admixed HC and granular casts (GC), and 25 cases (16%) had exclusively GC. In 7% of the cases, the morphology of the casts was distinctive enough to indicate specific composition. Four cases with red blood cell casts (5.6%) were associated with necrotizing glomerulopathy and IgA nephropathy. Four cases of myoglobulin casts were identified. Two cases with crystalized light-chain casts (1.3%) were associated with an underlying plasma cell dyscrasia. One case of acute pyelonephritis demonstrated polymorphonuclear cells casts (0.64%). A case of aminoglycoside toxicity revealed casts with myeloid bodies. Ultrastructural evaluation of casts may provide useful information that may be critical to establish or suggest a specific diagnosis.

Adolescent↗
PubMed2002

The farsighted studies of the Italian Carlo L. Rovida (1844-1877) on the nature of urinary casts.

Carlo L. Rovida (1844-1877) was an Italian physician who graduated in Pavia (1866) and worked in Milan (1868) and Turin (1874), where he ran the Institute of Clinical Medicine at the university. Between 1870 and 1876 Rovida published several studies on the nature of urinary casts, which can still be considered valid today. He distinguished two main types of casts, i.e., "colorless" (hyaline) and "yellowish" (waxy). By painstaking microscopic observation of the urine, performed mainly by microchemical techniques, and histological examination of the kidneys, he came to the conclusion that both types of casts were produced by tubular cells. In addition, he found that the colorless casts were composed of a unique protein, which was different from any other protein known at the time, and which he called "cilindrina" (cylindrine). Instead, Rovida found that the yellowish casts contain a different, ill-defined protein, which was also present in the lateral and basal membrane of the tubular cells. Rovida should be remembered today because his views were much ahead of the prevailing theories of the time, which considered the casts as coagulated fibrin (a view sustained mainly in Germany) or as elements derived from either tubular degeneration or tubular production (a view sustained mainly in the United Kingdom and Sweden); his results concerning the site of production of hyaline casts and their unique nature were confirmed 90 years later, in the early 1960s, when it was demonstrated that these casts are made of Tamm-Horsfall glycoprotein, a protein which is produced by the cells of Henle's loop; and his conclusions about the special nature of waxy casts were also correct. In fact, even though the true composition of these casts is still not yet totally clear, there is now evidence that they contain a substance different from Tamm-Horsfall protein. Rovida is also a paradigm of how the progress of science is strictly dependent on the development of technology. In fact, it was only when appropriate techniques (e.g., electrophoresis, immunoelectrophoresis, and immunofluorescent microscopy) became available that the nature of casts could be defined with certainty.

History, 19th Century↗