Ageing and degenerative changes of the intervertebral disc and their impact on spinal flexibility

Purpose

Degeneration of the intervertebral disc is associated with various morphological changes of the disc itself and of the adjacent structures, such as reduction of the water content, collapse of the intervertebral space, disruption and tears, and osteophytes. These morphological changes of the disc are linked to alterations of the spine flexibility. This paper aims to review the literature about the ageing and degenerative changes of the intervertebral disc and their link with alterations in spinal biomechanics, with emphasis on flexibility.

Methods

Narrative literature review.

Results

Clinical instability of the motion segment, usually related to increased flexibility and hypothesized to be connected to early, mild disc degeneration and believed to be responsible for low back pain, was tested in numerous in vitro studies. Despite some disagreement in the findings, a trend toward spinal stiffening with the increasing degeneration was observed in most studies. Tests about tears and fissures showed inconsistent results, as well as for disc collapse and dehydration. Vertebral osteophytes were found to be effective in stabilizing the spine in bending motions.

Conclusions

The literature suggests that the degenerative changes of the intervertebral disc and surrounding structures lead to subtle alteration of the mechanical properties of the functional spinal unit. A trend toward spinal stiffening with the increasing degeneration has been observed in most studies.

     

Significance of introduction of alternative dosing schedule for sunitinib during first-line treatment of patients with metastatic renal cell carcinoma

The objective of this study was to investigate the significance of an alternative dosing schedule for sunitinib in metastatic renal cell carcinoma (mRCC) patients. This study included 154 patients treated with sunitinib as first-line systemic therapy for mRCC, consisting of 62, 47, and 45 receiving sunitinib based on a traditional schedule (TS, 4 weeks on and 2 weeks off) alone (TS group), alternative schedule (AS, 2 weeks on and 1 week off) alone (AS group), and TS followed by AS after the development of dose-limiting toxicities (TS-to-AS group), respectively. There were no significant differences in the major clinicopathological characteristics among these three groups. The progression-free survival in the TS group was significantly shorter than in the other two groups, while no significant differences in the overall survival were noted among the three groups. Adverse events (AEs)?≥?grade 3 in the TS and TS-to-AS groups occurred more frequently than in the AS group. Furthermore, there were significant differences in the incidences of AEs, including diarrhea, fatigue, and hypertension, among the three groups, favoring the AS compared with the other two groups. Despite the lack of a significant difference in the incidence of dose reduction among the three groups, the incidences of the interruption and discontinuation of sunitinib in the AS group were significantly lower than in the other two groups. These findings suggest that the introduction of AS for sunitinib during first-line treatment for mRCC patients may promote favorable clinical outcomes regarding the prognosis as well as tolerability compared with treatment on TS alone.     

Functional shoulder radiography with use of a dynamic flat panel detector

Our purpose in this study was to develop a functional form of radiography and to perform a quantitative analysis for the shoulder joint using a dynamic flat panel detector (FPD) system. We obtained dynamic images at a rate of 3.75 frames per second (fps) using an FPD system. Three patients and 5 healthy controls were studied with a clinically established frontal projection, with abduction of the arms. The arm angle, glenohumeral angle (G-angle), and scapulothoracic angle (S-angle) were measured on dynamic images. The ratio of the G-angle to the S-angle (GSR) was also evaluated quantitatively. In normal subjects, the G-angle and S-angle changed gradually along with the arm angle. The G-angle was approximately twice as large as the S-angle, resulting in a GSR of 2 throughout the abduction of the shoulder. Changes in G-angle and S-angle tended to be irregular in patients with shoulder disorders. The GSR of the thoracic outlet syndrome, recurrent dislocation of the shoulder joint, and anterior serratus muscle paralysis were 3–7.5, 4–9.5, and 3.5–7.5, respectively. The GSR of the anterior serratus muscle paralysis improved to approximately 2 after orthopedic treatment. Our preliminary results indicated that functional radiography by FPD and computer-aided quantitative analysis is useful for diagnosis of some shoulder disorders, such as the thoracic outlet syndrome, recurrent dislocation of the shoulder joint, and anterior serratus muscle paralysis. The technique and procedures described comprise a simple, functional shoulder radiographic method for evaluation of the therapeutic effects of surgery and/or rehabilitation.     

Suppressive action of enflurane on dorsal horn neurons in rabbits

The neurophysiologic mechanism of the suppressive action of enflurane on spinal nociceptive transmission was examined in rabbits with intact and with transected spinal cords. Enflurane suppressed nociceptive responses in both intact and transected spinal cord groups. The suppressive effects of enflurane were significantly greater in the intact group than in the transected group. The suppressive effects of enflurane were not reversed by the addition of 0.2 mg·kg⁻¹ of naloxone. These results suggest that enflurane suppresses nociceptive responses by activating descending inhibitory systems and directly suppressing activity at the spinal level. This suppressive action of enflurane does not interact with the opioid receptor.     

Regulatory DNA required for vnd/NK-2 homeobox gene expression pattern in neuroblasts.

Vnd/NK-2 protein was detected in 11 neuroblasts per hemisegment in Drosophila embryos, 9 medial and 2 intermediate neuroblasts. Fragments of DNA from the 5'-flanking region of the vnd/NK-2 gene were inserted upstream of an enhancerless betagalactosidase gene in a P-element and used to generate transgenic fly lines. Antibodies directed against Vnd/NK-2 and beta-galactosidase proteins then were used in double-label experiments to correlate the expression of beta-galactosidase and Vnd/NK-2 proteins in identified neuroblasts. DNA region A, which corresponds to the -4.0 to -2.8-kb fragment of DNA from the 5'-flanking region of the vnd/NK-2 gene was shown to contain one or more strong enhancers required for expression of the vnd/NK-2 gene in ten neuroblasts. DNA region B (-5.3 to -4.0 kb) contains moderately strong enhancers for vnd/NK-2 gene expression in four neuroblasts. Hypothesized DNA region C, whose location was not identified, contains one or more enhancers that activate vnd/NK-2 gene expression only in one neuroblast. These results show that nucleotide sequences in at least three regions of DNA regulate the expression of the vnd/NK-2 gene, that the vnd/NK-2 gene can be activated in different ways in different neuroblasts, and that the pattern of vnd/NK-2 gene expression in neuroblasts of the ventral nerve cord is the sum of partial patterns.     

Histologic Characteristics of Renal Cell Carcinomas with Lymph Node Metastasis

Background :
This study was conducted to determine if there are any specific histologic features that are associated with lymph node metastasis in renal cell carcinoma (RCC).
Methods :
TNM classification, histologic grade, mean nuclear volume, cell type, and histologic architecture of the tumors were evaluated in 66 patients who had undergone nephrectomy and lym-phadenectomy for RCC. In the 18 patients with positive lymph node metastasis, both primary lesions and metastatic lymph nodes were evaluated.
Results :
Lymph node status was correlated with primary tumor stage, venous involvement, and distant metastasis. The tumor grade was higher, and the mean nuclear volume was larger, in both primary and metastatic lesions of RCCs with lymph node metastasis than in tumors with no metastasis. In primary lesions of RCCs with lymph node metastasis, clear cell, alveolar, or cystic patterns were observed less frequently, and granular or spindle/pleomorphic cells and papillary or solid patterns, were observed more frequently, as compared to those lesions without metastasis. Comparison between primary and metastatic lesions in individual patients revealed no significant difference in grade or mean nuclear volume. The development of new cell types or histologic architectures, which was not noted in the primary lesions, was also a rare event in the metastatic lesions.
Conclusion :
Several characteristic histologic features, which may reflect the increased metastatic potential of the tumor, were observed in both primary and metastatic lesions in cases of RCC with lymph node metastasis. No substantial difference in histologic features was observed between the primary or metastatic lesions of individual patients.     

Perceived morbidity and health behaviour in a Dogon community.

The episodes of morbidity over a 6 month period were recorded at 179 households comprising 1715 people living in the district of Bandiagara (Mali). This population was subdivided into groups according to their distances from the nearest district health centre and educational services, their scholarization, socio-economic and hygiene levels. The subjects interviewed were asked to report illnesses using their vernacular names, the type of therapy selected, the decision process, the time-lapse between onset and remedial action, the treatment undergone and its effect. Subsequent analysis of the data recorded indicates that the frequency of morbidity episodes is inversely proportionate to the household's level of hygiene. It also appears that factors such as the household's hygienic, socio-economic and educational levels along with the type of illness and its duration, are more decisive when resorting (or not resorting) to treatment than is the proximity factor. This seems particularly true in the case of traditional medicine, chosen even where cosmopolitan resources are available and by people with a relatively high socio-economic, hygienic and educational level. In the specific situation under study this paper indicates those areas for further study with a view to improving public health education.