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PubMed1975

[Difficulties in the treatment of congenital instability of the hip].

The method of early diagnosis of congenital dislocation of the hip and the results of immediate treatment are described. X-rays are only useful to prove an instability if the hip is dislocated at the moment the X-ray is taken. If the unstable hips are reduced and redislocation is prevented by means of a splint the great majority of the hips show a normal developement. A primarily unstable hip which was stabilised spontaneously or by using a splint for a short time may become unstable again. Nevertheless splinting in the stable positon should not last longer than 1-2 months. The development of a coxa vara in three children rises the question whether the fixation of the hips in a frog position combined with the presence of a contraction of the adductors may impede the blood supply to the epiphysis and metaphysis. Early diagnosis of congenital dislocation of the hip means demonstration of instability of the neontal hip and not diagnosis of "dysplasia" during the first year of life. "Dysplasia" without instability does not mean predislocation. It is either a stable dysplasia or a residual sign of neonatal instability which became stable with or without treatement. Difficulties in diagnosis of neonatal instability are discussed. Etiology, pathogenesis and genetics of congenital dislocation of the hip are mentioned.

Age Factors↗
PubMed2002

P2X receptors and their role in female idiopathic detrusor instability.

PURPOSE: It is clear from previous studies that adenosine triphosphate is released as a contractile co-transmitter with acetylcholine from parasympathetic nerves supplying the mammalian bladder but the physiological significance of ligand gated purinergic P2X receptors in human bladder innervation has not been adequately investigated. We examined the role of these receptors in female patients with idiopathic detrusor instability. MATERIALS AND METHODS: Female patients with idiopathic detrusor instability were recruited for cystoscopy and bladder biopsy with ethics approval. Control tissue was obtained from age and sex matched patients with a urodynamically proved stable bladder. We obtained 4 bladder biopsies per patient from the posterior wall. Samples were analyzed in an organ bath for functional studies of the detrusor muscle to assess the purinergic contribution to its contraction. In addition, we performed quantitative analysis using reverse transcriptase-polymerase chain reaction and immunohistochemical localization of P2X receptors. RESULTS: In patients with idiopathic detrusor instability detrusor P2X2 receptors were significantly elevated, while other P2X receptor subtypes were significantly decreased. A purinergic component of nerve mediated contractions was not detected in control female bladder biopsy specimens but there was a significant component in unstable bladder specimens. It was particularly prominent at stimulation frequencies of 2 to 16 Hz. which are likely to be most relevant physiologically. Approximately 50% of nerve mediated contractions were purinergic in idiopathic detrusor instability cases. CONCLUSIONS: In patients with idiopathic detrusor instability there is abnormal purinergic transmission in the bladder, which may explain symptoms. This pathway may be a novel target for the pharmacological treatment of overactive bladder.

Adult↗
PubMed1998

[The effect of detrusor instability secondary to benign prostatic hypertrophy on the density of acetylcholinesterase-containing nerves].

OBJECTIVE: To study the effect of detrusor instability secondary to benign prostatic hypertrophy (BPH) on the density of cholinesterase-containing nerve in detrusor samples. METHOD: Our present study included 3 groups confirmed by urodynamic evaluation. They were control group (8 cases), obstructive detrusor stability group (7), and obstructive instability group (12). The specimens were obtained from the dome of bladder. The AchE-containing nerves were demonstrated by the method of Karnovsky-Roots staining and AchE silver staining. The density of AchE containing detrusor nerves in specimens was examined with sterologic techniques. RESULT: The density of AchE-containing nerves in the obstructive detrusor instability group and the stability group was significantly decreased as compared with the control group (P < 0.01). The density of AchE positive nerves were also significantly decreased in the obstructive instability group as compared with the obstructive stability group (P < 0.05). CONCLUSION: Detrusor instability secondary to BPH obstruction is related to the decrease of cholinergic innervation density in the detrusor muscles.

Acetylcholinesterase↗
PubMed2002

Incomitant strabismus associated with instability of rectus pulleys.

PURPOSE: Connective tissue pulleys serve as functional mechanical origins of the extraocular muscles (EOMs) and are normally stable relative to the orbit during gaze shifts. This study evaluated pulley stability in incomitant strabismus. METHODS: Contiguous 2- or 3-mm thick magnetic resonance images (MRIs) perpendicular to the orbital axis spanned the anteroposterior extents of 12 orbits of six patients with incomitant strabismus. Imaging was performed in central gaze, supraduction, infraduction, abduction, and adduction. Rectus EOM paths were defined by their area centroids and plotted in a normalized, oculocentric coordinate system. Paths of EOMs ran toward the pulleys. Sharp EOM path inflections in secondary gaze indicated pulley locations in three dimensions. RESULTS: MRI revealed substantial inferior shift of the lateral rectus (LR) pulley of up to 1 mm during vertical gaze shifts in patients with axial high myopia and a posterior shift from abduction to adduction in simulated Brown syndrome. There was substantial LR pulley shift opposite the direction of vertical gaze in a subject with X-pattern exotropia who had undergone repeated LR surgery. The medial rectus (MR) pulley shifted inferiorly with gaze elevation in Marfan syndrome. Pulley instability was associated with significantly increased globe translation during gaze shifts. CONCLUSIONS: Pulley instability, resulting in EOM sideslip during ductions, occurs in some cases of incomitant strabismus. Resultant patterns of strabismus may depend on static pulley positions, pulley instability, and coexisting globe translation that alters pulley locations relative to the globe. Translational instability of pulleys and the globe could produce abnormalities in actions of otherwise normal EOMs, and connective tissue disorders causing these instabilities should be considered as potential causes of strabismus.

Adult↗
PubMed1999

Arthroscopic treatment of shoulder instability: current concepts and techniques.

The incidence of glenohumeral joint instability is estimated to effect between 2 and 8% of the population. It represents at least one third of all shoulder related emergency room visits. When one considers the spectrum of shoulder instability, including transient subluxation, the true incidence of glenohumeral instability is probably grossly under-reported. Although any age group can be affected, shoulder instability is primarily a disease of the young. The occurrence of instability is inversely proportional to the age of the patient and the time of original injury. A patient who dislocates for the first time as a teen can expect a redislocation rate approaching 90% in his or her lifetime. Therefore, many authors recommend early surgical treatment to repair the lesion.

Journal Article↗
PubMed2002

[The effect of cervical spine instability on sympathetic cervical spondylosis].

OBJECTIVE: To investigate the effect of cervical spine instability on sympathetic cervical spondylosis. METHODS: Twelve patients with cervical spondylosis showing sympathetic symptoms from 1992 to 2 000 were evaluated for cervical spine instability, immobilization of collar brace, MRI and surgical results. RESULTS: Radiologic evaluation cervical instability was observed radiologically in 7 of the 12 cases. Collar brace was obviously effective in 5 of the 12 cases and slightly effective in 7 cases. MRI showed abnormal signal for instability of the cervical spine in 7 cases. Surgery was markedly effective in 7 cases and moderately effective in 4 cases. CONCLUSION: Cervical spine instability was an important factor for sympathetic cervical spondylosis, which can be improved effectively by surgery.

Adult↗
PubMed2003

Centrosome abnormalities and chromosome instability occur together in pre-invasive carcinomas.

Centrosomes play critical roles in processes that ensure proper segregation of chromosomes and maintain the genetic stability of human cells. They contribute to mitotic spindle organization and regulate aspects of cytokinesis and cell cycle progression. We and others have shown that centrosomes are abnormal in most aggressive carcinomas. Moreover, centrosome defects have been implicated in chromosome instability and loss of cell cycle control in invasive carcinoma. Others have suggested that centrosome defects only occur late in tumorigenesis and may not contribute to early steps of tumor development. To address this issue, we examined pre-invasive human carcinoma in situ lesions for centrosome defects and chromosome instability. We found that a significant fraction of precursor lesions to some of the most common human cancers had centrosome defects, including in situ carcinomas of the uterine cervix, prostate, and female breast. Moreover, centrosome defects occurred together with mitotic spindle defects, chromosome instability, and high cytologic grade. Because most pre-invasive lesions are not uniformly mutant for p53, the development of centrosome defects does not appear to require abrogation of p53 function. Our findings demonstrate that centrosome defects occur concurrently with chromosome instability and cytologic changes in the earliest identifiable step in human cancer. Our results suggest that centrosome defects may contribute to the earliest stages of cancer development through the generation of chromosome instability. This, together with ongoing structural changes in chromosomes, could accelerate accumulation of alleles carrying pro-oncogenic mutations and loss of alleles containing wild-type tumor suppressor genes and thus accelerate the genomic changes characteristic of carcinoma, the most prevalent human cancer.

Breast Neoplasms↗
PubMed2003

Microsatellite instability and genetic alterations in ovarian cancer.

Inactivation of the mismatch repair system (MMR) leads to the accumulation of mutations, particularly in highly repeated sequences (microsatellite). The resulting microsatellite instability can profoundly affect the cellular behaviour, since many genes playing important roles in the mechanisms of signal transduction, apoptosis, DNA repair and cell cycle control can be altered in tumors presenting microsatellite instability. Germline mutations in MMR genes are associated with hereditary non polyposis colon cancer. Microsatellite instability and the associated frameshift mutations in genes have been well described in sporadic colon, gastric and endometrium tumors. In this review we collected the data available on the impact of microsatellite instability in ovarian cancer and the possible consequences of this instability to the presence of mutations in genes containing in their coding regions repeated nucleotides and to the response of these tumors to chemotherapy.

Female↗
PubMedDate not supplied

Role of microsatellite instability in borderline ovarian tumors.

This study was designed to establish the role of microsatellite instability (MSI) in the development of sporadic tumors of the ovary. The instability of 6 microsatellites (BAT25, BAT26, NME1, D17S250, D5S346 and D2S123) was determined by comparing MSI in healthy and tumoral tissue in each of 40 patients undergoing surgery for a sporadic ovarian tumor. BAT26 and D2S123 instability was detected in borderline tumors, and ovarian carcinomas were found to present instability in the microsatellites BAT25, NME1 and D17S250. Our findings indicate that microsatellite instability lacks a significant role in the appearance or progression of sporadic ovarian tumors.

Adult↗
PubMedDate not supplied

[Reconstruction of thoracolumbar spine instability: clinical and neuroradiological results of a surgical challenge].

INTRODUCTION: Surgical treatment for thoracolumbar union instability represents a challenge, due to the difficult access to this area of the spine, and to the extreme variability of morphological and biomechanical lesions observed. AIM: To describe the indications and clinical and neuroradiological results obtained with procedures of anterior or combined spinal fusion-instrumentation used for the treatment of instable thoracolumbar lesions. PATIENTS AND METHODS: 17 patients with thoracolumbar instability were treated surgically, being followed-up at least for one year. Causes of instability were classified in three groups: (i) fractures or fracture-luxations (n = 7), (ii) pathologic fractures following tumoral invasion (n = 6) and (iii) infectious or degenerative spondylodiscitis (n = 5). In order to carry out the substitution of the injured vertebral body an anterior approach to the thoracolumbar union was performed in all cases, using a modified technique of thoracophrenolaparotomy in which the diaphragmatic dome was not incised. Depending on the number of columns of Denis damaged, the vertebral corpectomy was followed by either an anterolateral or a combined spinal fusion-instrumentation. RESULTS: Pain in standing position was eliminated postoperatively in 83%. Neurological deficits were improved in 50% of cases. Surgical mortality was null and transient postoperative complications occurred in 11.7% of patients, but no lung atelectasis or respiratory infections were observed. CONCLUSIONS: Chronic pain associated to thoracolumbar instability can be treated successfully by substitution of the damaged vertebral body followed by anterior or combined spinal fusion-instrumentation. Thoracophrenolaparotomy without division of the diaphragm is feasible and it reduces the morbidity associated to postoperative respiratory complications.

Adult↗
PubMed1997

Effect of unilateral functional instability of the ankle on postural sway and inversion and eversion strength.

OBJECTIVE: The purpose of this study was to determine if individuals with unilateral functional ankle instability had decreased ability to maintain postural sway, as well as decreased isokinetic eccentric strength of ankle evertors and invertors. DESIGN AND SETTING: SUBJECTS WITH NO PREVIOUS HISTORY OF ANKLE INJURY WERE COMPARED WITH SUBJECTS WITH FUNCTIONAL ANKLE INSTABILITY ON THE FOLLOWING TESTS: isokinetic eccentric inversion and eversion strength and measures of single-limb postural sway. SUBJECTS: EIGHTEEN SUBJECTS PARTICIPATED IN THIS STUDY: 9 subjects in the functional instability (FI) group (age = 22.89 +/- 3.18 yr, ht = 181 +/- 6.0 cm, wt = 80.25 +/- 12.2 kg) and 9 noninjured (NI) controls (age = 26.22 +/- 2.34 yr, ht = 170 +/- 10.0 cm, wt = 65.08 +/- 12.03 kg). MEASUREMENTS: Subjects performed postural sway assessment on a balance system under static and dynamic conditions. Ankle inversion and eversion eccentric strength were evaluated at 90 degrees /sec using an isokinetic dynamometer. Additionally, we assessed the degree of mechanical instability in the FI group with a series of stress radiographs. RESULTS: No significant differences in single-limb postural sway measures or in eversion strength between limbs in the FI group or between groups were found. A significant group-by-limb interaction was present in inversion peak torque; however, post hoc testing revealed the only difference to be between the dominant and nondominant limbs of the NI group. CONCLUSIONS: Postural sway and inversion and eversion eccentric peak torque are not affected by functional instability of the ankle. Alternate methods of postural sway assessment and ankle strength measurement are discussed as possible areas for future study.

Journal Article↗
PubMed2006

Association between split selection instability and predictive error in survival trees.

OBJECTIVES: To evaluate split selection instability in six survival tree algorithms and its relationship with predictive error by means of a bootstrap study. METHODS: We study the following algorithms: logrank statistic with multivariate p-value adjustment without pruning (LR), Kaplan-Meier distance of survival curves (KM), martingale residuals (MR), Poisson regression for censored data (PR), within-node impurity (WI), and exponential log-likelihood loss (XL). With the exception of LR, initial trees are pruned by using split-complexity, and final trees are selected by means of cross-validation. We employ a real dataset from a clinical study of patients with gallbladder stones. The predictive error is evaluated using the integrated Brier score for censored data. The relationship between split selection instability and predictive error is evaluated by means of box-percentile plots, covariate and cutpoint selection entropy, and cutpoint selection coefficients of variation, respectively, in the root node. RESULTS: We found a positive association between covariate selection instability and predictive error in the root node. LR yields the lowest predictive error, while KM and MR yield the highest predictive error. CONCLUSIONS: The predictive error of survival trees is related to split selection instability. Based on the low predictive error of LR, we recommend the use of this algorithm for the construction of survival trees. Unpruned survival trees with multivariate p-value adjustment can perform equally well compared to pruned trees. The analysis of split selection instability can be used to communicate the results of tree-based analyses to clinicians and to support the application of survival trees.

Algorithms↗
PubMed1990

Psychosexual study of women with detrusor instability.

Clinical impression suggests that many cases of detrusor instability are psychosomatic. We evaluated 63 women with urinary incontinence and 27 continent controls using the Minnesota Multiphasic Personality Inventory, Uplift and Hassle Scales, and a structured questionnaire screening sexual dysfunction. All incontinent women underwent diagnostic urodynamic studies including uroflowmetry, subtracted water cystometry with provocation, and urethral closure pressure profilometry. Thirty-five women had genuine stress incontinence and 28 had detrusor instability, including nine with mixed incontinence. No differences in psychological test results were noted between the detrusor-instability and genuine-stress-incontinence groups. On the Minnesota Multiphasic Personality Inventory, subjects with detrusor instability scored significantly higher than controls on the hypochondriasis (P = .006), depression (P = .01), and hysteria (P = .0009) scales. Compared with continent controls, the detrusor-instability group reported a lower frequency of uplifts (P less than .05) and a greater intensity of hassles (P less than .05). Both incontinent groups reported more sexual dysfunction than did controls. We conclude that many women with urinary incontinence have abnormal psychological and sexual test results reflecting moodiness, feelings of helplessness and sadness, pessimism, general hypochondriasis/somatization, and sexual dysfunction. These abnormalities appear to be associated with urinary incontinence in general rather than with specific diseases of the urinary tract.

Adult↗
PubMed1984

Bladder instability: concept, clinical associations and treatment.

Bladder instability is a term that describes the occurrence of detrusor contractions whilst the patient is attempting to inhibit micturition. Bladder instability has enormous importance in the pathogenesis of many symptoms associated with lower urinary tract dysfunction. Although bladder instability may be suspected from the patients' history, absolute diagnosis depends on cystometry. The treatment of bladder instability is difficult and characterised by frequent patient relapses. Simple measures such as bladder training may be employed. Drug treatment is often effective but current therapies frequently result in unwanted side effects. Many surgical techniques have been developed to treat bladder instability. The unfortunate characteristic of most of these operations is that following an initial excellent response the patients' symptoms recur. It is essential that research should continue into the aetiology and treatment of this important condition.

Electric Stimulation Therapy↗
PubMed1980

[Instability and kyphosis following cervical laminectomy and occipital craniectomy in children (author's transl)].

The authors analyse the various factors of spinal instability and their respective importance in a series of 113 patients in which, either the occipital cerebellar pits or the cervical spine had been approached surgically. The essential cause was mechanical failure consecutive and related to the number of levels of laminectomies performed, even when the articular processes and their capsule were left intact. While craniectomy and ablation of the posterior arch of the Atlas was rarely, if ever, responsible for instability, the frequency rises to 25% once the Axis, the spinous processes and laminae have been removed. Instability was present in 80% of the cases in which three or more levels are involved. Moreover, cervical laminectomy was nearly always followed by instability, above all when the cervico-dorsal transitional zone was involved and even when only a small number of vertebral levels had been operated on. Location of the instability was always at the limit between the lowest level of laminectomy and the lover lying intact vertebra. Diagnosis has gone unrecognized until presently: the severity of the possible complications have led the authors to propose preventive surgical management. It this serie, an anterior vertebral bone graft was prefered. Consciousness of the risks involved should lead to better prevention, be it at the moment of neurosurgical surgery or in the follow-up period. However, preventive treatment creates several problems, which may only be solved by a currently undertaken prospective study.

Adolescent↗
PubMed1984

[Urethral instability: diagnosis and clinical significance].

Simultaneous urethrocystometry, the advantages of which are outlined, enabled us to diagnose 27 cases of pure urethral instability (male and female) and 16 cases of mixed instability (urethral and bladder instability). We analysed the relationship between the main symptom, this urethral dysfunction and the competence of the bladder neck. Definition, characteristics and frequency of urethral instability are discussed. It is responsible of: frequency or urgency, in the absence of bladder instability, when the bladder neck is closed, intermittent sphincteric incontinence, in the presence of a normal closure pressure on the urethral pressure profile, when the bladder neck is incompetent, enuresis, particularly in case of stable bladder; a new treatment is proposed for this entity. The clinical interest of this diagnosis is stressed in these three situations.

Adolescent↗
PubMed1982

Vesical instability: urodynamic parameters by microtip transducer catheters.

Thirty-two women with vesical instability underwent detailed urodynamic evaluation with microtip transducer catheters. Dynamic urethral profilometry demonstrated combined incontinence (genuine stress incontinence and vesical instability) in 13 patients (41%). Supine cystometry with the subject at rest demonstrated vesical instability in only 21 patients (66%). In 11 patients (34%) either provocative maneuvers or erect cystometry was required to make a diagnosis of vesical instability. Seven patients (22%) had evidence of urethral instability before the onset of involuntary detrusor contractions.

Adult↗
PubMed1980

Anterior instability of the shoulder.

A detailed computer-assisted evaluation of eighty-nine patients whose shoulders were surgically treated for anterior instability was done. Three types of anterior instability of the shoulder were identified: Type I, subluxation without prior dislocation; Type II, recurrent dislocation with interval subluxation; and Type III, recurrent dislocation without interval subluxation. This series included fifty patients with Type-I, twenty-nine with Type-II, and ten patients with Type-III instability. Selected variables from the computer analysis of forty-five preoperative and post-operative parameters were related to the type of instability diagnosed preoperatively. The surgical procedure used in all shoulders was a modification of the Bankart procedure. Chronic glenohumeral instability is a disabling entity which can be controlled by surgical stabilization of the anterior capsule to the glenoid rim.

Follow-Up Studies↗