Damage and the repeated bout effect of arm,leg, and trunk muscles induced by eccentric resistance exercises

This study compared nine resistance eccentric exercises targeting arm, leg, and trunk muscles in one session for changes in maximal voluntary isometric contraction strength (MVC), delayed onset muscle soreness (DOMS), plasma creatine kinase (CK) activity, and myoglobin (Mb) concentration after the first and second bouts. Fifteen sedentary men (20‐25 years) performed 5 sets of 10 eccentric contractions with 80% of MVC load for the elbow flexors (EF), elbow extensors (EE), pectoralis, knee extensors (KE), knee flexors (KF), plantar flexors (PF), latissimus, abdominis, and erector spinae (ES) in a randomized order and repeated the same exercises 2 weeks later. MVC decreased at 1 (16%‐57%) to 4 (13%‐49%) days, DOMS developed (peak: 43‐70 mm), and CK activity (peak: 23 238‐207 304 IU/L) and Mb concentration showed large increases after the first bout. The magnitude of decrease in MVC was greater (P < 0.05) for EF, EE, and PEC than others and for KF than KE, PF, and ES. DOMS was greater (P < 0.05) for EF, EE, and ES than others. Changes in all measures were smaller (P < 0.05) after the second than the first bout, and the magnitude of the repeated bout effect was similar among the muscles. Plasma CK activity and Mb concentration did not increase significantly after the second exercise bout. It was concluded that muscle damage was greater for arm than leg muscles, and muscle proteins in the blood increased to a critical level after unaccustomed whole‐body resistance exercises, but the magnitude of damage was largely attenuated for all muscles similarly after the second bout.     

Preoperative histological grading of meningiomas using apparent diffusion coefficient at 3T MRI

Purpose

We assessed whether a high b-value DWI at b = 4000 s/mm² would discriminate the histopathological differentiation of the tumor grade of meningiomas, and also focused on the relationship between radiologic features and the tumor grade.

Materials and methods

We acquired DWI at 3T with b = 1000 and b = 4000 s/mm² in 77 patients (42, 31 and 4 patients were WHO grades I (G1), II (G2), and III (G3), respectively). The apparent diffusion coefficient (ADC) was measured by placing multiple regions of interest (ROIs) on ADC maps. The ADC values of each tumor were determined preoperatively from several ROIs, and expressed as the minimum (ADC_MIN), mean (ADC_MEAN), and maximum absolute values (ADC_MAX). We evaluated the relationship between ADCs and histological findings, and assessed the radiologic features such as tumor location, tumor size, presence/absence of peritumoral edema, shape of the tumor, presence/absence of bone destruction or hyperplasia, status of contrast enhancement, presence/absence of calcification and cyst.

Results

ADCs of the meningiomas were inversely correlated with the histological grade of meningiomas. According to results of the discriminant analysis, the apparent log likelihood value was greatest for ADC_MIN at b = 4000. Furthermore, only the ADC_MIN value at b = 4000 was significantly correlated with the histological grade of meningiomas when we performed a multiple logistic regression analysis to identify the significant independent factors such as shape of tumor, presence/absence of bone destruction, status of contrast enhancement, presence/absence of cyst and ADC_MIN at b = 4000.

Conclusion

A meningioma with a low ADC_MIN at a high b-value might imply a high-grade meningioma.     

Transesophageal Echocardiographic Findings Are Independent and Relevant Predictors of Ischemic Stroke in Patients with Nonvalvular Atrial Fibrillation

Background and Purpose

Not only clinical factors, including the CHADS₂ score, but also echocardiographic findings have been reported to be useful for predicting the risk of ischemic stroke in patients with nonvalvular atrial fibrillation (NVAF). However, it remains to be determined which of these factors might be more relevant for evaluation of the risk of stroke in each patient.

Methods

In 490 patients with NVAF who underwent transesophageal echocardiography (TEE), we examined the long-term incidence of ischemic stroke events (mean follow-up time, 5.7±3.3 years). For each patient, the predictive values of gender, the CHADS₂ risk factors (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, history of cerebral ischemia), the CHADS₂ score, and the findings on echocardiography, including TEE risk markers, were assessed.

Results

The ischemic stroke rate was significantly correlated with the CHADS₂ score (p<0.05). According to the results of univariate analyses, age ≥75 years, history of cerebral ischemia, CHADS₂ score ≥2, and presence of TEE risk were significantly correlated with the incidence of ischemic stroke. Cox proportional hazards regression analyses identified age ≥75 years and presence of TEE risk as significant predictors of subsequent ischemic stroke events in patients with NVAF. As compared with that in persons below 75 years of age without TEE risk, the ischemic stroke rate was significantly higher in persons who were ≥75 years of age with TEE risk (4.3 vs. 0.56%/year, adjusted hazard ratio=8.94, p<0.001).

Conclusions

TEE findings might be more relevant predictors of ischemic stroke than the CHADS₂ score in patients with NVAF. The stroke risk was more than 8-fold higher in patients aged ≥75 years with TEE risk.     

An Outbreak of Echovirus 11 Meningitis in a Newborn Nursery

In the summer of 1981 an outbreak of echovirus 11 meningitis in a newborn nursery occurred in a general hospital near Tokyo. Ten newborn infants developed febrile illness in a period of 20 days. Nine babies out of ten were diagnosed as aseptic meningitis according to the CSF findings. Virus isolation was successful in 50% (3/6 cases) in the CSF, 80% (4/5 cases) in the stool and 20% (1/5 cases) in the throat swab. Echovirus 11 was proven to be the responsible agent. Clinical manifestations of aseptic meningitis were mild and nonspecific, except in one premature baby which had apnea and exanthema. Mean febrile period was 4.1 days. Pleocytosis of the CSF, dominant in polymorphonuclear cells, was observed in 6/9 cases. EEG about one month after onset revealed abnormal or borderline findings in 6/9 cases. In a community outbreak of echovirus. infection, newborn babies in nurseries are threatened with both horizontol and vertical transmission of virus.     

Analysis of Thyrotropin-Thyroxine Secretory Dynamics in Infantile Hyperthyrotropinemia: An Aid for Early Differential Diagnosis

For the purpose of differentiating neonatal hyperthyrotropinemia, the interrelation between serum thyrotropin (TSH) and thyroxine (T4) was examined in 10 infants with primary hypothyroidism during 12 months of T4 replacement therapy. A significant inverse correlation was obtained between elevated TSH (Y) (above 12 μU/ml) and T4 (X) levels; Y = 324 - 22 X (r = -0.801, p < 0.001). One patient had an abnormally high threshold of TSH-inhibition by T4. Based on this regression line, a scattergram of TSH-T4 correlation and changes in the time course was analyzed in 13 infants with neonatal hyperthyrotropinemia, including eight with transient hyperthyrotropinemia (t-TSH), three with compensated hypothyroidism (c-Hypo) and two with transient hypothyroidism (t-Hypo). All plots from t-TSH were distributed under the regression line and shifted downward with concomitant rise in T4 and free T4 levels. In contrast, plots from c-Hypo and t-Hypo showed a vertical upward shift above the line during 3–4 months of observation without treatment. These results indicate that (1) using the TSH-T4 regression line, differentiation of c-Hypo from t-TSH is possible by 3 months of age, (2) the cause of t-TSH is not an elevated threshold for TSH release, but rather the maturational delay in responsiveness of the thyroid to TSH, and (3) suppression of TSH alone should not be used as the index of adequate T4 dose in infantile hypothyroidism, because of the existence of patients with a high threshold of TSH-inhibition by T4.     

Effects of prolactin on gametes and zygotes during in vitro fertilization in mice

Hyperprolactinemia is one of the major causative factors of infertility. However, the effect of prolactin on gametes during in vitro fertilization has not been elucidated. In the present study, the effects of mouse prolactin on the motility of spermatozoa, in vitro fertilization, and in vitro development of the zygote were investigated in mice using media containing three different concentrations (10, 50, and 100 ng/ml) of mouse prolactin. The development of unfertilized and fertilized oocytes (zygotes) was not affected in vitro by prolactin regardless of the amount of prolactin added to culture media. However, the fertilizing capacity of the spermatozoa was suppressed when they were preincubated for 90 min in culture media containing prolactin at concentrations of 50 and 100 ng/ml. The motility of spermatozoa was not affected by prolactin regardless of the concentration of prolactin used for preincubation. The present study indicates that prolactin may have some effects on the capacitation process of spermatozoa in vitro. This result should be taken into consideration in in vitro fertilization and embryo transfer procedures in humans.     

Effects of growth hormone on testicular dysfunction induced by cyclophosphamide (CP) in GH-deficient rats

Growth hormone (GH) is known to accelerate spermatogenesis and maintain gonadal function. In this study, we evaluated the effect of GH on recovery from testicular damage induced by cyclophosphamide (CP). Eleven- to fourteen-week-old GH-deficient Lewis rats (dw/dw) were divided into 4 groups (n = 10 each), with one group serving as controls. In the CP group, CP was intravenously administered in daily doses of 50 mg/kg for 2 days, followed by daily doses of 10 mg/kg for the next 3 days. In the GH group, rat GH was subcutaneously administered at a daily dose of 0.3 mg/kg until the rats were sacrificed. In the CP/GH group, GH and CP administration were started simultaneously. In the CP/preGH group, GH administration was started 14 days before CP administration. Five rats from each group were sacrificed at days 14 and 28 after administration of CP. Spermatogenesis was then evaluated morphometrically by counting numbers of cells at several stages of the spermatogenic cycle. On day 14, there were no significant differences in the numbers of the spermatocytes between CP and CP/GH group. On day 28, the numbers of spermatocytes and motility of spermatozoa in CP/GH group were greater than those of CP group were. In the CP/preGH group, these effects of GH administration were not observed. These results suggested that administration of GH improved testicular function damaged by CP under GH-deficient condition, when GH and CP administration are started simultaneously.     

Complete penetration of the optic chiasm by an unruptured aneurysm of the ophthalmic segment: case report

BACKGROUND: It is well known that aneurysms of the ophthalmic segment sometimes elevate the optic nerve or chiasm, and in case of large or giant aneurysms, the optic apparatus can be dramatically thinned. Nonetheless, they rarely penetrate the optic pathway completely. To our knowledge, no previous reports have dealt with the complete penetration of the optic chiasm by unruptured aneurysms of the ophthalmic segment. CASE DESCRIPTION: A 70-year-old woman presented with visual dysfunction in her left eye that she had experienced for several months. Her left visual acuity had rapidly deteriorated to the level of finger counting and visual field testing demonstrated nasal hemianopsia in the left eye and upper temporal quadrant hemianopsia in the right eye. Left internal carotid angiograms and three-dimensional digital subtraction angiograms showed an aneurysm of the ophthalmic segment projecting superomedially. Intraoperative findings revealed complete penetration of the optic chiasm by the fundus of the aneurysm. The optic pathway adjacent to the dome had become remarkably thin and dark yellow. After clipping was completed, the fundus of the aneurysm was punctured to decompress the optic chiasm. Postoperatively, patient's visual acuity in the left eye gradually recovered, but the visual field deficit persisted after the operation. CONCLUSION: This rare case demonstrates the potentially aggressive behavior of unruptured aneurysms of the ophthalmic segment. Patients with unruptured aneurysms of the ophthalmic segment who present with visual symptoms should be treated with surgical clipping to decompress the optic pathway as soon as possible.     

Improvement of muscle healing through enhancement of muscle regeneration and prevention of fibrosis

Skeletal muscle is able to repair itself through regeneration. However, an injured muscle often does not fully recover its strength because complete muscle regeneration is hindered by the development of fibrosis. Biological approaches to improve muscle healing by enhancing muscle regeneration and reducing the formation of fibrosis are being investigated. Previously, we have determined that insulin-like growth factor-1 (IGF-1) can improve muscle regeneration in injured muscle. We also have investigated the use of an antifibrotic agent, decorin, to reduce muscle fibrosis following injury. The aim of this study was to combine these two therapeutic methods in an attempt to develop a new biological approach to promote efficient healing and recovery of strength after muscle injuries. Our findings indicate that further improvement in the healing of muscle lacerations is attained histologically by the combined administration of IGF-1 to enhance muscle regeneration and decorin to reduce the formation of fibrosis. This improvement was not associated with improved responses to physiological testing, at least at the time-points tested in this study.