Altered cellular but not humoral reactions in children with complicated enterovirus 71 infections in Taiwan

Enterovirus 71 (EV 71) infections have high neurovirulence and fatality. Immune responses were assessed in 78 patients with EV 71 infection. EV 71 meningoencephalitis occurred more frequently in younger children and in boys. C-reactive protein levels were not elevated, although total leukocyte counts were increased in these patients. The CD40-ligand expression on T cells significantly decreased in children with meningoencephalitis (P=.041). Polymorphism of the cytotoxic T lymphocyte antigen-4 (CTLA-4) at position 49 of exon 1 showed a higher frequency of G/G genotype in patients with EV 71 meningoencephalitis than in those without meningoencephalitis (18/31 vs. 14/47; P=.045) and in control subjects (18/31 vs. 25/93l; P=.007). Specific EV 71 neutralizing antibody titers were detectable but did not differ in children with and without meningoencephalitis in the acute and convalescent stages. Results from this study suggest that younger children with a certain CTLA-4 polymorphism and altered cellular but not humoral response may be linked to EV 71 meningoencephalitis.

Collaboration of fibronectin matrix and neurotrophin in regulating spontaneous transmitter release at developing neuromuscular synapses in Xenopus cell cultures

Integrins mediate cell-extracellular matrix connection and are particularly important during neuronal development. We here investigated the regulation of fibronectin (FN) matrix and neurotrophins on the embryonic synaptic transmission. Spontaneous synaptic currents (SSCs) were recorded from innervated myocytes of 1-day-old Xenopus cultures by whole-cell recordings. The SSC increasing action of alpha,beta-methylene adenosine triphosphate was enhanced in neurons grown on FN substratum, which was further potentiated by chronic treatment with brain-derived neurotrophic factor (BDNF). The SSC increasing action of thapsigargin, carbonyl cyanide m-chlorophenylhydrazone and N-methyl-D-aspartate was also markedly potentiated in neurons grown on FN-coated glass coverslips and chronically treated with BDNF. FN matrix or BDNF alone only exerts slight potentiation on the SSC increasing action of these three drugs. Our results suggest that FN matrix can collaborate with neurotrophin in regulating synaptic transmission at developing motoneurons, which may play an important role in the maturation of embryonic neuromuscular junction.

Impaired PI 3-kinase activation in adipocytes from early growth-restricted male rats

Epidemiological studies have established a relationship between early growth restriction and subsequent development of type 2 diabetes. Animal studies have shown that offspring of protein-restricted rats undergo a greater age-related loss of glucose tolerance than controls. The aim of this study was to investigate the possibility that this deterioration of glucose tolerance is associated with changes in adipocyte insulin action. Adipocytes from low-protein offspring had higher basal levels of glucose uptake than controls. Insulin stimulated glucose uptake into control adipocytes but had little effect on low-protein adipocytes. Both groups had similar levels of basal and isoproterenol-stimulated lipolysis. Insulin inhibited lipolysis in control adipocytes but had a reduced effect on low-protein adipocytes. These changes in insulin action were not related to altered expression of insulin receptors or insulin receptor tyrosine phosphorylation; however, they were associated with reduced phosphatidylinositol 3-kinase and protein kinase B activation. These results demonstrate that reduced glucose tolerance observed in late adult life after early growth restriction is associated with adipocyte insulin resistance.

Ultrasound evaluation of plantar fasciitis

OBJECTIVE

To investigate the sonographic features of plantar fasciitis (PF).

METHODS

High-resolution ultrasound was used to measure the thickness and echogenicity of the proximal plantar fascia and associated heel pad thickness for 102 consecutive patients with PF (unilateral: 81, bilateral: 21) and 33 control subjects.

RESULTS

The mean thickness of the plantar fascia was greater on the symptomatic side for patients with bilateral and unilateral PF than on the asymptomatic side for patients with unilateral PF, and also control subjects (5.47+/-1.09, 5.61+/-1.19, 3.83+/-0.72, 3.19+/-0.43 mm, respectively, p<0.001). A substantial difference in thickness between the asymptomatic side of patients with unilateral PF and control subjects was also noted (p=0.001). The heel pad thickness was not show different between control subjects and patients with PF. The incidence of hypoechoic fascia was 68.3% (84/123). Other findings among the patients from our test group included intratendinous calcification (two cases), the presence of perifascial fluid (one case), atrophic heel pads (one case), and the partial rupture of plantar fascia (one case).

CONCLUSION

Increased thickness and hypoechoic plantar fascia are consistent sonographic findings in patients exhibiting PF. These objective measurements can provide sufficient information for the physician to confirm an initial diagnosis of PF and assess individual treatment regimens.

[Studies on saponin accumulative in regularities Panax notoginseng (Burk) F. H. Chen]

OBJECTIVE

To determine the optimal harvest time for P. notoginseng through studying the changes of saponin contents with growth periods.

METHODS

P. notoginseng samples were collected from the experimental plot regularly, and then the contents of total saponin and some main single saponins were analyzed by HPLC.

RESULTS

Total saponin contents decreased from April through July, and increased from August through December.

CONCLUSION

The optimal harvest time is determined as from October through December, which corresponds to the traditional harvest time.

Altered heel-pad mechanical properties in patients with Type 2 diabetes mellitus

AIMS

To compare the heel-pad mechanical properties in patients with Type 2 diabetes mellitus with forefoot ulceration, without forefoot ulceration and age-matched healthy subjects.

METHODS

Heel-pad mechanical properties in 40 heels of 20 healthy subjects (group I) age-matched with the other groups, 42 heels of 21 diabetic patients without forefoot ulceration (group II), and 14 heels of 12 diabetic patients with active forefoot ulceration (group III) were assessed using a self-constructed loading-unloading device and a 10-MHz linear-array ultrasound transducer.

RESULTS

There were no differences in the unloaded heel-pad thickness, compressibility index and elastic modulus between the three groups. When compared with group I subjects (mean +/- SD, 27.9 +/- 6.1%), a significant increase (P < 0.001) was found in both group II (36.1 +/- 8.7%) and group III patients (43.2 +/- 6.6%) for the energy dissipation ratio. This ratio was also significantly different (P = 0.003) between groups II and III.

CONCLUSIONS

The higher impact energy dissipated in the heel-pad may put patients with Type 2 diabetes at higher risk for developing foot ulceration.

Catecholamine levels and receptor expression in low protein rat offspring

AIMS

Low birthweight in humans has been shown to lead to increased resting pulse rate in adult life, suggesting possible increased sympathoadrenal activity. The hypothesis that early growth restriction is associated with permanent alterations in catecholamine metabolism was tested.

METHODS

Circulating catecholamine concentrations (by radioimmunoassay) and adipocyte adrenoceptor expression from different fat depots (by Western blot) were estimated in 12-week-old male offspring of rat dams fed a reduced protein diet during pregnancy and lactation.

RESULTS

In the fed state, median (interquartile range) plasma adrenaline concentrations for male control and low protein offspring rats were: 0.65 (0.48-0.86) vs. 1.42 (0.89-1.87) nmol/l (P < 0.005), respectively. Equivalent noradrenaline concentrations were: 2.71 (2.16-3.46) vs. 3.45 (3.00-4.28) nmol/l (P < 0.05). After 24 h starvation, plasma adrenaline concentrations of controls rose to become similar to those of low protein offspring: 1.03 (0.95-1.31) vs. 1.41 (0.69-1.62) nmol/l (P = 0.3), respectively. Noradrenaline concentrations rose in both groups to become similar: 3.84 (3.33-4.54) vs. 4.32 (3.70-6.54) nmol/l (P = 0.3). In epididymal adipocytes adrenoceptor expression (relative to that of controls) was: alpha2A 0.79 (0.66-0.94) (P = 0.08), beta1 2.60 (2.27-3.07) (P = 0.04), beta3 1.37 (1.27-1.46) (P = 0.02). Similar-pattern differences in adrenoceptor expression were observed in subcutaneous and intra-abdominal adipocytes.

CONCLUSIONS

These results are consistent with the suggestion that long-term alterations in catecholamine metabolism are present in adult offspring of rats fed a reduced protein diet during pregnancy and lactation.

An unusual case of organophosphate intoxication of a worker in a plastic bottle recycling plant: an important reminder

A young man was sent to our emergency unit because he had suffered from vomiting and cold sweating for 2 days. At the time he was admitted, he had no acute abdominal pains or gastrointestinal symptoms, and a physical examination revealed nothing but a faster heart rate and moist, flushing skin. The patient had worked for 6 years at a plastic bottle-recycling factory, but none of his co-workers had the same symptoms. Nevertheless, because the plant also recycled pesticide bottles, we suspected organophosphate pesticide intoxication. The patient's plasma acetylcholinesterase level was checked, revealing 1498.6 microU/L (normal range: 2,000-5, 000) on the first day and 1,379 microU/L on the second day. Upon questioning, the patient recalled that one of his shoe soles had been damaged and that his foot had been wet from walking all day in rain collected on the factory floor on the day that his symptoms first occurred. We conducted a study in the change of preshift and postshift acetylcholinesterase levels among six of his co-workers on a rainy day. We used the Wilcoxon signed rank test to compare the preshift and postshift plasma acetylcholinesterase levels; no significant difference was revealed (p = 0.600), leaving contamination via the damaged shoe sole suspect. We reviewed the literature on organophosphate intoxication; pesticide bottle-recycling factories were reported to be at a low risk of organophosphate toxicity in the working environment. However, because the potential risk of intoxication is still present, protective equipment such as clothing, gloves, and water-proof shoes should be worn, and employees should be educated on the potential risks.

Treatment of proximal plantar fasciitis with ultrasound-guided steroid injection

OBJECTIVE

To investigate the efficacy of ultrasound-guided steroid injection for the treatment of proximal plantar fasciitis and to evaluate mechanical properties of the heel pad after steroid injection.

DESIGN

Proximal plantar fascia and heel pad were assessed with a 10-MHz linear array ultrasound transducer. Pain intensity was quantified with a tenderness threshold (TT) and visual analog scale (VAS). The transducer was incorporated into a specially designed device to measure mechanical properties of the heel pad. Evaluations were performed before injection and at 2 weeks and 3 months after injection.

SETTING

An outpatient clinic of a tertiary care center.

PATIENTS

Fourteen consecutive patients with unilateral proximal plantar fasciitis.

INTERVENTION

Ultrasound-guided injection of 7 mg betamethasone and 0.5 mL of 1% lidocaine into the inflamed proximal plantar fascia.

MAIN OUTCOME MEASURES

VAS, TT, heel pad and plantar fascia thickness, and echogenicity of the proximal plantar fascia on sonogram were assessed. Mechanical properties included unloaded heel pad thickness, compressibility index, and energy dissipation ratio.

RESULTS

Both VAS score +/- standard deviation (SD; 5.43 +/- 2.03, 1.39 +/- 2.19, 0.57 +/- 1.40 at the 3 measurements, respectively) and TT +/- SD (5.05 +/- 1.42, 9.34 +/- 1.84, 9.93 +/- 1.98 kg/cm2 at the 3 measurements, respectively) improved significantly (p < .001) after steroid injection. The mean thickness of the plantar fascia was greater in the symptomatic side than in the asymptomatic side before treatment (0.58 +/- 0.13 cm vs 0.40 +/- 0.11 cm, p < .001). The thickness had decreased significantly 3 months after injection (0.46 +/- 0.12 cm at 2 weeks, 0.42 +/- 0.10 cm at 3 months, p < .001). The hypoechogenicity at the proximal plantar fascia disappeared after steroid injection (p < .001). Mechanical properties of the heel pad did not change 3 months after steroid injection (p > .05).

CONCLUSION

Ultrasound offers an objective measurement of the therapeutic effect on proximal plantar fasciitis. Accurate steroid injection under ultrasound guidance can effectively treat proximal plantar fasciitis without significant deterioration of the mechanical properties of the heel pads.

[Studies on initial infection sources and channels of black spot on Panax notoginseng (Burk.) F.H. Chen]

OBJECTIVE

To probe into the occurring and developing regularities of black spot on Panax notoginseng for disease control.

METHODS

After artificial inoculation, observation and analysis on the planting plots were conducted regularly.

RESULTS

The main infection sources include diseased seeds, seedlings, plants and soils. On the plot of new cropping, the initial infection sources are diseased seeds and seedlings while diseased plants and soils with pathogens are the main sources onplot of old cropping.

CONCLUSION

Wiping out the infection centre and sources are the major effective means for control of black spot on P. notoginseng.

Metabolic engineering of an aerobic sulfate reduction pathway and its application to precipitation of cadmium on the cell surface

The conversion of sulfate to an excess of free sulfide requires stringent reductive conditions. Dissimilatory sulfate reduction is used in nature by sulfate-reducing bacteria for respiration and results in the conversion of sulfate to sulfide. However, this dissimilatory sulfate reduction pathway is inhibited by oxygen and is thus limited to anaerobic environments. As an alternative, we have metabolically engineered a novel aerobic sulfate reduction pathway for the secretion of sulfides. The assimilatory sulfate reduction pathway was redirected to overproduce cysteine, and excess cysteine was converted to sulfide by cysteine desulfhydrase. As a potential application for this pathway, a bacterium was engineered with this pathway and was used to aerobically precipitate cadmium as cadmium sulfide, which was deposited on the cell surface. To maximize sulfide production and cadmium precipitation, the production of cysteine desulfhydrase was modulated to achieve an optimal balance between the production and degradation of cysteine.

Haptoglobin is a natural regulator of Langerhans cell function in the skin

Langerhans cells (LC), the best-understood antigen presenting cells (APC) of the skin, are functionally plastic. Freshly obtained LC readily activate allogeneic T cells, but are incapable of activating autologous, naive T cells. When placed in culture in the presence of GM-CSF, LC up-regulate surface expression of class I and II MHC molecules along with co-stimulatory molecules, such as B7, CD40 and IL-12. This functional transformation enables the cells to activate naive, autologous T cells in vitro. It is paradoxical that intracutaneous administration of exogenous GM-CSF fails to induce intraepidermal LC to undergo functional transformation in situ. It has been reported that serum contains a factor that prevents fresh LC from undergoing functional transformation in culture, and the relevant serum factor has now been identified as haptoglobin (Hp), based on the following experimental results: (a) SDS-PAGE, amino acid sequencing, and mass spectrometric analyses of the inhibitory factor purified by high performance liquid chromatography (HPLC) from normal human serum revealed molecules completely homologous to Hp alpha-1 chain; (b) pure human Hp, but not serum depleted of Hp, inhibited fresh LC from acquiring the capacity to activate autologous T cells in vitro; (c) abundant Hp was detected in cytoplasmic compartments of fresh, but not cultured, LC. It was concluded that Hp, an acute phase protein, is a systemically-derived factor that prevents epidermal LC from spontaneously undergoing functional maturation in the skin. This novel property of Hp may be important in ameliorating or preventing certain T cell-dependent inflammatory skin diseases.

[Study of bracket placement with the preadjusted appliance for extraction cases]

OBJECTIVE

To determine the bracket placement with the preadjusted appliance for extraction cases.

METHODS

Sixty finishing occlusions were chosen as Andrews stated at debonding. The placement of the incisor teeth bracket was in the middle of the clinical crown, and retention arch wire was straight wire without step bends. The measurement from the incisal or occlusal edges to the bracket center was the height of the placement of the bracket. In order to produce bracket placement chart, the values of measurements +0.5 mm and +1.0 mm were added for larger teeth, and -0.5 mm and -1.0 mm for smaller teeth.

RESULTS

The placement in the second bicuspid and first molar was different between extraction cases and nonextraction cases.

CONCLUSION

The bracket placement chart improves the accuracy of bracket placement with the preadjusted appliance for extraction cases.

[Effect of pantoprazole on non-variceal bleeding]

The treatment effect of 101 non-variceal bleeding(NVB) patients treated with pantoprazole was observed, and it was compared with 57 NVB patients treated with omeprazole.

RESULTS

87.1% of the patients in 48 h and 97% of the patients in 72 h with Pantoprazole bleeding-stopped. And the result was almost equal to omeprazole group. The side-effect of pantoprazole was few and slight. It is suggested that pantoprazole is effective and safe on treating NVB.

Effects of early protein restriction and adult obesity on rat pancreatic hormone content and glucose tolerance

Rats were fed a diet containing either 20% ("control") or 8% ("reduced-protein") protein throughout pregnancy and lactation. Their female offspring were weaned onto the same respective diets. At 63 days of age one set of control and reduced-protein rats (n = 16 per group) underwent intraperitoneal glucose tolerance tests and one week later were killed and their pancreatic hormones extracted and measured. The reduced protein rats had better glucose tolerance (p < 0.001) and lower pancreatic insulin (p < 0.01) and amylin (p < 0.01) contents. Further sets of control and reduced-protein rats were then fed either chow or a cafeteria-style diet (n = 16 in each of the four groups). These rats underwent intraperitoneal glucose tolerance tests at 133 days of age, which showed the cafeteria-fed animals to have a worse glucose tolerance than the chow-fed animals irrespective of previous diet exposure (p < 0.0001). One week later reduced-protein rats still had lower pancreatic insulin contents (p < 0.05) (and a trend for lower amylin contents), but also had increased pancreatic glucagon contents (p < 0.05). There were no detectable differences in pancreatic somatostatin-like immunoreactivity or pancreatic polypeptide contents. These results are consistent with pancreatic beta- and alpha-cells being selectively susceptible to effects associated with early dietary protein restriction.

[Introduction of wide spectrum rice bacterial blight resistance gene Xa21 into two-line genic male sterile rice variety Pei'ai 64S]

Agrobacterium-mediated transformation of two-line genic male sterile Indica rice variety Pei'ai 64S was conducted using a cloned gene, Xa21, as the foreign gene and mature embryo calli as the recipients. A total of 46 transgenic plants had been obtained. The PCR analysis and Southern blotting showed the integration of Xa21 gene into the genome the transgenic plants. Results of inoculation with philippine race 6 of Xanthomonas oryzae pv. oryzae indicated that most of transgenic plants obtained high resistance to rice bacterial blight disease (Xoo). Analyses of T1 plants of the tested transgenic lines showed that integrated Xa21 gene could be steadily inherited and segregated in a 3:1 ratio.

Depot-specific effects of early growth retardation on adipocyte insulin action

Male offspring of rats protein restricted during pregnancy and lactation are growth restricted and have changes in insulin action on epididymal adipocytes. Adipocytes from different anatomical depots are thought to have distinct metabolic functions. The aim of the present study was to determine whether the alterations in metabolism of adipocytes from early growth restricted rats is depot-specific or more generalised. Epididymal, intra-abdominal and subcutaneous adipocytes were studied from three-month-old male offspring of control and protein restricted dams. Basal glucose uptakes were higher in low protein adipocytes (p<0.01) compared to controls. However, insulin stimulation was less in the low protein group in all depots compared to controls (p<0.05). Isoproterenol-stimulated lipolysis was greater in low protein adipocytes (p<0.0001), but the magnitude was greater in epididymal (p<0.0001) and intra-abdominal (p<0.0001) adipocytes than in subcutaneous adipocytes. Epididymal and intra-abdominal adipocytes from low protein offspring were also resistant to the anti-lipolytic action of insulin. These results suggest that certain changes associated with early growth retardation are depot-specific, being enhanced in the more metabolically active intra-abdominal and epididymal tissues.

Foot complications in people with diabetes: a community-based study in Taiwan

BACKGROUND AND PURPOSE

This comparative cross-sectional and community-based study was aimed at defining foot complications in diabetic patients. These data have not yet been reported for Asian societies.

METHODS

Of a population of 3,602 subjects aged 35 years or more in Chin-Shan, Taipei, 309 diabetic patients were identified. Two hundred and nineteen (71%) of those patients were compared to 100 individuals randomly selected for the nondiabetic control group in the same community.

RESULTS

Three diabetic patients underwent lower extremity amputation and four had skin ulcerations. Diabetic patients had a significantly higher prevalence of peripheral neuropathy (32.4% vs 16%), arterial insufficiency (12.6% vs 3.0%), and medial arterial calcification (13.6% vs 5.0%), when compared to the nondiabetic controls. The age and sex-adjusted rates of hallux valgus, loss of skin hair on the dorsum of the foot, tinea unguium, arterial insufficiency, medial artery calcification, and peripheral neuropathy were significantly higher in diabetic than nondiabetic subjects. Aging and hyperglycemia (> 140 mg/dL) increased the prevalence of foot complications in both groups. Foot complications were also remarkably associated with the duration of diabetes (p = 0.003).

CONCLUSIONS

This study shows that diabetes mellitus is associated with an increased likelihood of foot complications in this geographically defined Taiwanese population. Patient age and diabetic duration are associated with the significantly higher prevalence of foot complications.

Extracellular regulated kinase (ERK) interaction with actin and the calponin homology (CH) domain of actin-binding proteins

An interaction between extracellular regulated kinase 1 (ERK1) and calponin has previously been reported (Menice, Hulvershorn, Adam, Wang and Morgan (1997) J. Biol. Chem. 272 (40), 25157-25161) and has been suggested to reflect a function of calponin as a signalling molecule. We report in this study that calponin binds to both ERK1 and ERK2 under native conditions as well as in an overlay assay. Using chymotryptic fragments of calponin, the binding site of ERK on calponin was identified as the calponin homology (CH) domain, an N-terminal region of calponin found in other actin-binding proteins. ERK also bound, in a gel overlay assay, alpha-actinin, a protein with two tandem CH domains, as well as a 27 kDa thermolysin product of alpha-actinin containing the CH domains of alpha-actinin. The CH domain of calponin could compete with intact calponin or alpha-actinin for ERK binding. Titration of acrylodan-labelled calponin with ERK gave a K(a) of 6x10(6) M(-1) and titration of acrylodan-labelled calponin with a peptide from the alphaL16 helix of ERK gave a K(a) of 1x10(6) M(-1). Recombinant ERK was found to co-sediment with purified actin and induced a fluorescence change in pyrene-labelled F-actin (K(a)=5x10(6) M(-1)). The interaction of ERK with CH domains points to a new potential function for CH domains. The interaction of ERK with actin raises the possibility that actin may provide a scaffold for ERK signalling complexes in both muscle and non-muscle cells.

Noninvasive assessment of the viscoelasticity of peripheral arteries

Currently used methods of examining the mechanical properties of blood vessel walls are either indirect or invasive, or measure vessel diameter and pressure waveforms at different sites. We developed a noninvasive technique to assess the mechanical properties and viscoelasticity of peripheral arteries. The pressure-strain elastic modulus (Ep) and the viscoelastic properties (energy dissipation ratio, EDR) of the common carotid artery (CCA), brachial artery (BA), radial artery (RA) and dorsalis pedis artery (DPA) were determined by means of palpating pressure and diameter distension waveforms extracted from high-resolution ultrasonography. The methodology was validated in vitro using an elastic tube phantom, as well as in vivo. In vivo study in 10 healthy volunteers (mean age 22 y) showed that the pressure-diameter curves were nonlinear, with an inflection at about 85-90 mmHg, and routed clockwise with slight hysteresis. The CCA (n = 5) had a mean diameter of 6.74 mm and the pulsatile diameter distension was 12.2%. The Ep calculated at the CCA was 0.44 x 10(6) dyne/cm2 with an EDR of 7.18%. The BA, RA and DPA (n = 10) had mean diameters of 3.91 mm, 2.21 mm and 2.12 mm; arterial strains of 4.60%, 4.25% and 8.91%; mean Ep of 1.39, 1.45, 0.90 x 10(6 )dyne/cm2; and mean EDRs of 6.34%, 6.15% and 5.60%, respectively. The method presented is relatively simple to implement clinically and has potential as a new diagnostic tool for detecting local vascular changes.

The mechanical properties of the heel pad in unilateral plantar heel pain syndrome

Plantar heel pain syndrome has been attributed to entrapment neuropathy, plantar fasciitis, calcaneal spurs, and stress fractures of the calcaneus. Although deteriorated mechanical properties of the heel pads may play an important role in the pathogenesis of heel pain syndrome, this has received little notice. In this study, a specially designed compression relaxation device with a push-pull scale and a 10-MHz linear array transducer was used to determine thickness of the heel pad under different loading conditions. Twenty consecutive patients aged 29 to 77 years with unilateral plantar heel pain syndrome were enrolled. Thickness of heel pad bilaterally was measured when the heel pad was compressed by serial increments of 0.5 kg to a maximum of 3 kg and then relaxed sequentially. The load-displacement curve during a loading-unloading cycle was plotted, and the compressibility index and energy dissipation ratio of the heel pad were calculated accordingly. Phase I displacement of the heel pad (from 0 to 1 kg load) on the painless side was greater than that on the painful side (P < 0.01), but there was no statistically significant difference between painless and painful sides in thickness of unloaded heel pads, compressibility index, or energy dissipation ratio (P > 0.05). In conclusion, the affected heel pad in plantar heel pain syndrome was stiffer under light pressure than the heel pad on the painless side. The changed nature of chambered adipose tissue in a painful heel pad may be responsible for its increased stiffness under light pressure.

Sonographic detection of occult fractures in the foot and ankle

PURPOSE

The purpose of this retrospective study was to determine whether high-resolution sonography can aid in the diagnosis of radiographically occult fractures in the foot and ankle.

METHODS

High-resolution sonography with a 10-MHz linear-array transducer was performed in 268 patients with foot and ankle injuries whose initial plain x-ray films were negative for fracture.

RESULTS

Twenty-four patients had occult fractures demonstrated by sonography. On sonography, the occult fractures appeared as a discontinuity of cortex echogenicity. The fractures were found at the calcaneus (n = 8), metatarsus (n = 6), talus (n = 3), navicular bone (n = 3), cuboid bone (n = 2), cuneiform bone (n = 1), and lateral malleolus (n = 1). Review of the patients' radiographs revealed tiny fractures at the sonographically identified locations in 2 patients. The first 5 patients underwent bone scans, which confirmed the presence of the fractures. The first 11 patients received follow-up sonographic examination 6 weeks after diagnosis; in all 11, an echogenic line over the previous fracture site, presumably representing callus formation, was noted.

CONCLUSIONS

Sonography-a readily available, noninvasive imaging technique-can provide important information about soft tissue injuries and cortical discontinuities in the foot and ankle area. Using this procedure, occult fractures can be identified and delineated, and costly procedures such as MRI can be avoided.

Sonographic evaluation of the posterior cruciate ligament in amputated specimens and normal subjects

The purpose of this study was to define the sonographic appearance and echogenicity of the normal posterior cruciate ligament. We examined the posterior cruciate ligament of five amputated specimens and five normal subjects using a 10 MHz linear array transducer. One K-wire was inserted into the substance of the posterior cruciate ligament of the amputated knee specimens to verify the location of the ligament on the sonogram. Various angles of insonation were used to examine the echogenicity of the posterior cruciate ligament. The results showed that the in situ posterior cruciate ligament appeared as a hypoechoic band relative to the surrounding tissue on sonograms, but it appeared hyperechoic when it was isolated and immersed in a water bath. The specific spatial orientation of the posterior cruciate ligament and anisotropy phenomenon contributed to the hypoechogenicity of the posterior cruciate ligament in situ on sonogram.

Ultrasonographic measurement of the mechanical properties of the sole under the metatarsal heads

The sole under the metatarsal heads functions as a shock absorber during walking and running. The mechanical properties of the sole provide the primary defense against the development of metatarsalgia and foot ulceration. However, limited information about these properties has been documented. In this study, we used ultrasonography to evaluate the mechanical properties, including unloaded thickness, compressibility index, elastic modulus, and energy dissipation ratio, of the sole in 20 healthy subjects. The unloaded thickness decreased progressively from the first to the fifth metatarsal heads, with values of 1.50, 1.36, 1.25, 1.14, and 1.04 cm. The sole under the first metatarsal head had the greatest values for the compressibility index and elastic modulus (55.9% and 1.39 kg/cm2), and the sole under the third metatarsal head had the smallest values (50.8% and 1.23 kg/cm2). The sole under the fifth metatarsal head had the greatest energy dissipation ratio (33.7%), followed by that under the third, second, first, and fourth metatarsal heads. Multivariate adjusted linear regression showed that the unloaded thickness, compressibility index, and elastic modulus values increased significantly with age and body weight (p < 0.05) and that the energy dissipation ratio increased significantly with body weight (p < 0.05)