Supersonic Shear Imaging Elastography in Skeletal Muscles: Relationship Between In Vivo and Synthetic Fiber Angles and Shear Modulus

OBJECTIVES

To verify a relationship between the pennation angle of synthetic fibers and muscle fibers with the shear modulus (μ) generated by Supersonic shear imaging (SSI) elastography and to compare the anisotropy of synthetic and in vivo pennate muscle fibers in the x₂ -x₃ plane (probe perpendicular to water surface or skin).

METHODS

First, the probe of Aixplorer ultrasound scanner (v.9, Supersonic Imagine, Aix-en-Provence, France) was placed in 2 positions (parallel [aligned] and transverse to the fibers) to test the anisotropy in the x₂ -x₃ plane. Subsequently, it was inclined (x₁ -x₃ plane) in relation to the fibers, forming 3 angles (18.25 °, 21.55 °, 36.86 °) for synthetic fibers and one (approximately 0 °) for muscle fibers.

RESULTS

On the x₂ -x₃ plane, μ values of the synthetic and vastus lateralis fibers were significantly lower (P < .0001) at the transverse probe position than the longitudinal one. In the x₁ -x₃ plane, the μ values were significantly reduced (P < .0001) with the probe angle increasing, only for the synthetic fibers (approximately 0.90 kPa for each degree of pennation angle).

CONCLUSIONS

The pennation angle was not related to the μ values generated by SSI elastography for the in vivo lateral head of the gastrocnemius and vastus lateralis muscles. However, a μ reduction with an angle increase in the synthetic fibers was observed. These findings contribute to increasing the applicability of SSI in distinct muscle architecture at normal or pathologic conditions.

Triceps surae elasticity modulus measured by shear wave elastography is not correlated to the plantar flexion torque

Background

Supersonic Shear Imaging (SSI) is a technique which analyses quantitatively the tissue properties in real time. The relation between joint torque and Young's modulus (E) of the agonist muscles is important for obtaining stratification values and ranges of normality. The aim of this study was to evaluate the intra and intersessions reliability of the E values of the Achilles tendon and medial gastrocnemius muscle, bilaterally, during rest, and correlate them with the isometric plantarflexion peak torque.

Methods

Shear modulus maps were acquired bilaterally in Achilles tendon (AT) and medial gastrocnemius (MG) muscle of 24 healthy male volunteers. Two 5-second plantarflexion maximal voluntary contractions were performed with a 40-seconds interval and correlated with E values.

Results

a good intrasession reliability (intraclass correlation coefficient- ICC= 0.821-0.986) and a weak Pearson's correlation was found between E values and peak torque (r= 0.022 to -0.202) for both limbs (P > .05).

Conclusion

E values cannot be predictive of the triceps surae force production in untrained men. It could be helpful, otherwise, to monitor a chronic strength adaptation after an exercise intervention or rehabilitation program.

Level of evidence

IIb, individual cohort study.

Genetic epidemiology of fecal egg excretion during Schistosoma mansoni infection in an endemic area in Minas Gerais, Brazil

There is considerable variation in the level of fecal egg excretion during Schistosoma mansoni infections. Within a single endemic area, the distribution of egg counts is typically overdispersed, with the majority of eggs excreted coming from a minority of residents. The purpose of this study was to quantify the influence of genetic factors on patterns of fecal egg excretion in a rural study sample in Brazil. Individual fecal egg excretions, expressed in eggs per gram of feces, were determined by the Kato-Katz method on stool samples collected on three different days. Detailed genealogic information was gathered at the time of sampling, which allowed assignment of 461 individuals to 14 pedigrees containing between 3 and 422 individuals. Using a maximum likelihood variance decomposition approach, we performed quantitative genetic analyses to determine if genetic factors could partially account for the observed pattern of fecal egg excretion. The quantitative genetic analysis indicated that between 21-37% of the variation in S. mansoni egg counts was attributable to additive genetic factors and that shared environment, as assessed by common household, accounted for a further 12-21% of the observed variation. A maximum likelihood heritability (h2) estimate of 0.44 +/- 0.14 (mean +/- SE) was found for the 9,604 second- and higher-degree pairwise relationships in the study sample, which is consistent with the upper limit (37%) of the genetic factor determined in the variance decomposition analysis. These analyses point to the significant influence of additive host genes on the pattern of S. mansoni fecal egg excretion in this endemic area.

Prolactin release during exercise in normal and adrenodemedullated untrained rats submitted to central cholinergic blockade with atropine

To study the role of the central cholinergic system in pituitary prolactin (PRL) release during exercise we injected atropine (5 x 10(-7) mol) into the lateral cerebral ventricle of intact or adrenodemedullated (ADM) untrained rats, at rest or submitted to exercise on a treadmill (18 m x min(-1), 5% grade) until exhaustion. The rats were implanted with chronic jugular catheters for blood sampling and with unilateral intracerebroventricular (icv) cannulas placed in the right lateral ventricle. Blood prolactin concentrations were measured before and every 10 min after the start of exercise for a period of 60 min. After the animals started running, plasma prolactin levels rose rapidly in both normal and ADM rats, reaching near maximum at 10 min. Close to exhaustion (19.8 +/- 2.9 min for intact rats and 23.5 +/- 4.1 min for ADM) they were still high, remained increased until 30 min, and returned to preexercise levels at 40 min. Icv injections of atropine decreased the time to exhaustion by 67% in intact rats and by 96.2% in ADM and also reduced the exercise-induced PRL release in both intact (50%) and ADM rats (90%). The results showed that prolactin release induced by exercise was dependent on the exercise workload and could be observed as early as after 10 min of running, remaining increased until 30 min. These data indicate that adrenodemedullation does not affect prolactin secretion induced by exercise, although adrenodemedullated rats proved to be more sensitive to the reducing effect of central cholinergic blockade on their maximal capacity for exercise.

Postoperative necrotizing fasciitis of the thorax in cardiac surgery

Necrotizing fasciitis is a rare soft tissue infection and a life-threatening emergency, often fatal. Its incidence and management are described plentifully in the medical literature regarding the most common anatomical sites involved like the abdomen, lower and upper limbs, and perineum. However, available data and case reports of chest wall necrotizing fasciitis after thoracic procedures are scarce, mainly after major cardiac operations. We report and discuss a case of necrotizing fasciitis of the chest wall occurring in the immediate postoperative period of a cardiac procedure, and include a brief review of the concepts, pathophysiology, and treatment reported in the medical literature. We emphasize the need for early diagnosis and urgent and effective surgical debridement. Of importance is the fact that we have not found any references in the literature to cases similar or equal to the one we describe here, which occurred in the postoperative period of a cardiac procedure.

Partial left ventriculectomy: overall and late results in 44 class IV patients with 4-year follow-up

BACKGROUND

This study reports long-term results of partial left ventriculectomy (PLV).

METHODS

Forty-four patients with dilated cardiomyopathy were operated on in a 4-year study. Echocardiograms, catheterization, and stress tests with oxygen consumption (VO2) were performed.

RESULTS

The survivors' preoperative ejection fractions of 22.1% +/- 4.9% improved to 30.9% +/- 9.4%, left ventricular (LV) end-diastolic diameter decreased from 79.4 +/- 9.3 mm to 61.9 +/- 8.2 mm, and maximum VO2 consumption improved from 8.8 +/- 3.9 mL/kg per minute to 15.8 +/- 6.1 mL/kg per minute at 22.6 months. These data also showed improvements in nonsurviving patients, according to the last evaluation before death. Seven of 12 survivors (58.3%) were in New York Heart Association (NYHA) I and II in December 1998. Twelve patients had elevated pulmonary vascular resistance (PVR) contraindicating heart transplant. In five patients the PVR returned to normal and one high-PVR patient was transplanted at the 16th postoperative month. Survival was 56.8%, 47.7%, 38.4%, and 35.9%, respectively, at 3, 6, 12, and 18 months, with a tendency to stabilize at 32.7% thereafter. Arrhythmias and heart failure were the main causes of death.

CONCLUSIONS

In spite of improvement of ventricular function and quality of life of the survivors, high mortality is a limiting factor. PLV can be indicated as a bridge to heart transplantation in high-PVR patients or if ventricular assist devices or donor hearts are not available.

Holt-Oram syndrome revisited. Two patients in the same family

Holt-Oram syndrome was first described in 1960 as an association of familial heart disease and musculoskeletal abnormalities. The most important findings include atrial septal defects, atrioventricular conduction abnormalities, vascular hypoplasia, and upper limb musculoskeletal deformities. We report two patients with this syndrome in the same family and discuss the variability of the musculoskeletal abnormalities and their association with the cardiac morphologic defects. Both patients in this study had associated eosinophilia, which has not been reported in the literature.

Treatment results of three consecutive Brazilian cooperative childhood ALL protocols: GBTLI-80, GBTLI-82 and -85. ALL Brazilian Group

The Brazilian Cooperative Group for Treatment of Childhood Acute Lymphocytic Leukemia (GBTLI) has started clinical activities trials in 1980. Three consecutive multicenter studies in children with unprevious treated ALL have been completed including 994 patients. The first GBTLI-80 accrued 203 children from 1980 to 1982. It was delineated with the standard three drugs induction therapy, CNS protection for all pts comprised cranial irradiation and intrathecal Methotrexate. For low risk pts cranial irradiation with 18Gy was compared in a randomized trial with 24Gy. Maintenance therapy continued for 120 weeks. The 12 years of the event free survival rates for all risk groups is 50% (SD 5%). Regarding CNS relapses there was no significant statistical difference between pts that received 18 or 24Gy. The treatment strategy of GBTLI-82 (n = 360) from 1982 to 1985, consisted of the same previous induction, consolidation, CNS therapy with cranial irradiation 18 Gy (low risk) or 24Gy (high risk), followed by continuous maintenance for 2 years. The main question in this study was the comparison between sequential rotation or pulses of 3 pairs of drugs during maintenance. At a median follow-up of 10 years, the overall event free survival rates for all children is 58% (SD 4%). There was no significant difference between the two maintenance regimens. The successor GBTLI-85 ran from 1985 to 1988 and registered 431 pts. For the first time no cranial radiation was given to children with very good prognosis. For them, CNS protection was done with triple intrathecal therapy during all treatment. A consolidation therapy with high dose ARA-C was introduced for high risk pts and infants The 6.5 years event free survival for all children is 70% (SD 4%). Significant better results were achieved for high risk and infants pts (EFS 50%). Early intensification therapy and rotational combination chemotherapy improved the outcome in childhood ALL in Brazil.

Preangioplasty complicated coronary stenosis morphology as a predictor of restenosis

To assess whether complicated preangioplasty coronary stenosis morphology is associated with restenosis, 41 patients (47 stenoses) who underwent repeat angiography 6 to 8 months after percutaneous transluminal coronary angioplasty (PTCA) were studied. Stenosis diameter and morphology were assessed by computerized quantitative coronary angiography before and immediately after PTCA and at follow-up angiography. Before PTCA 18 stenoses were concentric (symmetric narrowings with smooth borders), 12 were eccentric (asymmetric narrowings with smooth borders), and 17 were complicated (asymmetric with rough borders and overhanging edges). Restenosis occurred in 18 lesions: two (11%) concentric, four (33%) eccentric, and 12 (70%) complicated (p less than 0.05), whereas 29 lesions remained unchanged. Stenosis diameter before and immediately after PTCA was not significantly different in the 18 patients with and the 23 patients without restenosis. Follow-up angiograms showed that 11 (61%) stenoses in the group with restenosis and 18 (63%) in the group without restenosis had morphology similar to that before PTCA. Restenosis occurred in seven (30%) patients who initially had chronic stable angina and in 11 (61%) who were first seen with unstable angina (p less than 0.05). In patients with stable angina 1 of 13 concentric stenoses, two of eight eccentric stenoses, and four of five complicated lesions restenosed. In patients with unstable angina one of five concentric, two of four eccentric, and 8 of 12 complicated lesions had restenosis. Stenoses that were complicated before PTCA tended to adopt an irregular morphology if they recurred, whereas concentric stenoses rarely occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Marijuana, tetrahydrocannabinol, and pulmonary antibacterial defenses

Although marijuana is now consumed extensively, little is known of its biologic effects on the lung. To study this problem, the intrapulmonary inactivation of an aerosolized challenge of Staphylococcus aureus was quantified in rats exposed to graded amounts of fresh marijuana smoke. Controls inactivated 85.1 percent +/- 0.3 percent of the bacteria six hours after inoculation. Following an in vivo accumulative exposure to smoke from progressively increasing numbers of marijuana cigarettes for periods of ten minutes each hour for five consecutive hours, intrapulmonary bacterial inactivation was impaired in a dose-dependent manner. Evaluation of the effects of parenterally administered delta-9-tetrahydrocannabinol (THC) or of exposure to fresh smoke from THC-extracted marijuana placebo cigarettes indicated that the cytotoxin in marijuana was not related to the primary psychomimetic component. Thus, marijuana smoke is toxic to the lung and impairs the pulmonary antibacterial defense system in a dose-dependent manner.

A prospective cooperative study of complications following flexible fiberoptic bronchoscopy

The frequency of complications following flexible fiber-optic bronchoscopic procedures was studied prospectively in 908 patients from 13 cooperating hospitals. Major complications (respiratory arrest, pneumonia, pneumothorax, and obstruction of airways) occurred in 1.7 per cent (15) of the procedures. There was one death, yielding a mortality of 0.1%. Minor complications, including vasovagal reactions, fever, cardiac arrhythmias, bleeding, obstruction of airways, nausea and vomiting, pneumothorax, psychotic reaction, and aphonia, occurred in 6.5% of the procedures. Pneumothorax occurred after 5% (four) of 85 transbronchial biopsies. Although serious complications occur more frequently than previously reported from retrospective studies, complications after fiberoptic bronchoscopic procedures are still quite infrequent. The relative risks and benefits must always be carefully weighed in patients being considered for a fiberoptic bronchoscopic procedure.

Pleural effusion associated with primary lymphedema: a perspective on the yellow nail syndrome

A 28-year-old woman with bilateral pleural effusions and generalized, primary lymphedema beginning with facial erysipelas at 6 years of age is presented. The pleural effusions were exudates with 250 cells per mm3, 92 per cent of which were lymphocytes. Lymphatic stasis was demonstrated by persistence of the blue dye in the dorsa of her feet 3 months after a lymphangiogram of both lower extremities, pelvis, and abdomen. Her nails were not remarkable. Our patient represents the twentieth recorded case of pleural effusion in association with primary lymphedema. Women have been afflicted more than twice as often as men, and the age of onset has varied from birth to the eighth decade. Yellow dystrophic nails may precede or follow lymphedema or the pleural effusion and have occurred in only 11 of the 20 patients.

Studies on the fate of pancreatic elastase in the hamster lung: 14C-guanidinated elastase

Intratracheal instillation of pancreatic elastase in hamsters produces emphysema, which progresses for up to one year after the insult. To study this process in more detail, a guanidinated derivative of porcine pancreatic elastase labeled with carbon-14 was prepared that was indistinguishable from unmodified elastase with respect to physicochemical properties and in vitro enzymatic activity. Guanidinated pancreatic elastase exhibits the same emphysema-inducing potency as unmodified pancreatic elastase. Two hours after intratracheal instillation of the [14C] guanidinated elastase, the whole lung retained only 40 per cent of the instilled radioactivity, but after 96 hours one per cent was still present. At 2 hours approximately 90 per cent of the radioactivity in the lungs could be removed by bronchopulmonary lavage, and at 96 hours 28 per cent was removable by this method. More than half of the radiolabeled elastase recovered in the lavage fluid at 2 hours was enzymatically active; enzymatic activity diminished to very small amounts by 96 hours. These data support the concept of the long-term binding of active elastase to lung tissue, a phenomenon that may be involved in the progressive nature of elastase-induced emphysema.

[Surgical treatment of cerebral hemorrhage. Considerations on 11 cases]

After brief comments about the angiographic findings on 298 consecutive cases of isquemic or hemorrhagic cerebral vascular strokes, cerebral angiography is emphasized as the main diagnostic method, owing to the variety of physiopathogenic and ethiologic factors involved in the genesis of this syndromes. The results of surgical treatment on eleven patients with spontaneous intracerebral hematomata are discussed in detail. Despite the great divergence among the authors about the management of massive intracerebral hemorrhage, the rapid improvement in 54.6% of the patients in this series, in our opinion justifies surgery in the majority of the cases.

Depressant effect of marihuana smoke on antibactericidal activity of pulmonary alveolar macrophages

Other than the potentially therapeutic bronchodilatory influences of marihuana, very little is known of its biologic effects on the lung. To evaluate this problem, alveolar macrophages were harvested from rats by bronchopulmonary lavage and incubated in vitro with Staphylococcus albus and marihuana smoke of standardized 2.2-percent tetrahydrocannabinol content in graded amounts. After three hours, control alveolar macrophages inactivated 78.0 +/- 5.0 percent of the staphylococcal challenge. There was a dose-dependent depression of alveolar macrophage bactericidal activity, with 66.7 +/- 7.1 percent, 23.7 +/- 7.0 percent, 20.5 +/- 7.0 percent, and 11.4 +/- 7.6 percent of the bacteria killed following exposures to 2 ml, 4 ml, 6 ml, or 8 ml of marihuana smoke, respectively. Differential filtration of marihuana smoke revealed that the alveolar macrophage cytotoxin was present in the gas phase of the smoke and was water-soluble. Studies on purified tetrahydrocannabinol and on tetrahydrocannoabinol-extracted marihuana revealed that the impairment in alveolar macrophage function was not related to the psychomimetic or bronchodilatory components of marihuana.

Fever and pneumonia after flexible fiberoptic bronchoscopy

The frequencies of fever, parenchymal infiltration, and bacteremia were studied prospectively after 100 flexible fiberoptic bronchoscopies performed transnasally under topical anesthesia. Fever occurred after 16 per cent, and parenchymal infiltration, after 6 per cent of the procedures. Most complications were mild and transient; however, one patient developed rapidly progressive pneumonia and died. No organisms were isolated from cultures of blood drawn at the time of the procedure or during complications. The organisms most commonly isolated from the sputum of the patients who developed pneumonia were the aerobic and anaerobic bacteria normally found in the mouth. Isolation of a significant pathogen before the procedure did not predispose to development of a complication. Advanced age (greater than 60 years) and the endoscopic findings of abnormalities were significant predisposing factors. Bronchial brushing, but not bronchial biopsy or bronchial washing, was associated with significantly higher complication rates in patients with bronchial carcinomas than in those without a neoplasm. The mechanism of the fever and parenchymal infiltration is thought to be related to obstructive atelectasis and infection produced by organisms present in the airways at the time of the procedures.

Subcostal loculated pleural effusion in congestive heart failure: an unusual case of vanishing tumor

Localized collection of fluid in an interlobar fissure as a consequence of congestive heart failure is a well-known entity. It has been termed vanishing tumor because of its appearance as a mass lesion in the lung and its propensity to resolve with diuretic therapy. We report a case of loculated pleural effusion in the subcostal pleural space without interlobar fluid collection. This was initially thought to represent an occult metastatic malignancy; however, the cause of the density became obvious when it disappeared with therapy of heart failure and recurred concurrent with cardiac decompensation. Loculated pleural effusion must be included in the differential diagnosis of roentgenographic densities in the chest when seen in subcostal as well as in interlobar locations.

A study of the electron impact promoted fragmentation of promazine sulphoxide and promazine using specifically deuterated analogues

The mass spectra of some promazine sulphoxide derivatives have been examined. Specifically deuterated analogues of promazine and promazine sulphoxide were prepared and their mass spectra used to determine the specificity of the hydrogen transfer processes observed in the unlabelled compounds.