Is it possible to preserve lumbar lordosis after hybrid stabilization? Preliminary results of a novel rigid–dynamic stabilization system in degenerative lumbar pathologies

Purpose of the study

To evaluate the results of a novel rigid–dynamic stabilization technique in lumbar degenerative segment diseases (DSD), expressly pointing out the preservation of postoperative lumbar lordosis (LL).

Materials and methods

Forty-one patients with one level lumbar DSD and initial disc degeneration at the adjacent level were treated. Circumferential lumbar arthrodesis and posterior hybrid instrumentation were performed to preserve an initial disc degeneration above the segment that has to be fused. Clinical and spino-pelvic parameters were evaluated pre- and postoperatively.

Results

At 2-year follow-up, a significant improvement of clinical outcomes was reported. No statistically significant difference was noted between postoperative and 2-year follow-up in LL and in disc/vertebral body height ratio at the upper adjacent fusion level.

Conclusions

When properly selected, this technique leads to good results. A proper LL should be achieved after any hybrid stabilization to preserve the segment above the fusion.

     

Serum spermidine oxidase activity in patients with insulin-dependent diabetes mellitus and microvascular complications

Summary Metabolism of polyamines (spermidine and spermine) is known to be strictly related to the growth processes of eukaryotic cells. Since cell replication processes appear altered in insulin-dependent diabetes mellitus (IDDM), especially when associated with its microvascular complications, the aim of this study was measuring serum spermidine oxidase activity (SOA), a key enzyme in the metabolic pathway of polyamines, in 47 patients with IDDM as compared with 63 healthy control subjects matched for age and sex. Mean SOA levels±SD were significantly lower in IDDM patients (177.4±57.2 μkat/l) than in controls (247.6±68.1 μkat/l; p<0.001), being SOA inversely related with daily insulin dose. SOA was moreover significantly higher (but similar to controls) in the group with increased urinary albumin excretion rate (AER persistently >20 μg/min); (n=17; 213.1±62.6 μkat/l) in comparison with normoalbuminuric subjects (n=30; 156.6±43.5 μkat/l; F=21.78; p=0.0001). SOA was correlated with AER (r=0.45; p=0.001), independently of age, duration of disease, serum creatinine, body weight, blood pressure and metabolic control, as shown by a multiple regression analysis model (p=0.003). Presence of background retinopathy was not associated with modified levels of SOA, which was conversely higher, although not significantly, in the patients with proliferative retinal lesions. In conclusion serum SOA is deeply altered in IDDM patients, being markedly reduced in the whole group of patients and conversely independently increased up to the mean values of controls in presence of increased AER or advanced retinopathy.     

Visual cortex is rescued from the effects of dark rearing by overexpression of BDNF

Visual deprivation such as dark rearing (DR) prolongs the critical period for ocular dominance plasticity and retards the maturation of gamma-aminobutyric acid (GABA)ergic inhibition in visual cortex. The molecular signals that mediate the effects of DR on the development of visual cortex are not well defined. To test the role of brain-derived neurotrophic factor (BDNF), we examined the effects of DR in transgenic mice in which BDNF expression in visual cortex was uncoupled from visual experience and remained elevated during DR. In dark-reared transgenic mice, visual acuity, receptive field size of visual cortical neurons, critical period for ocular dominance plasticity, and intracortical inhibition were indistinguishable from those observed in light-reared mice. Therefore, BDNF overexpression is sufficient for the development of aspects of visual cortex in the absence of visual experience. These results suggest that reduced BDNF expression contributes to retarded maturation of GABAergic inhibition and delayed development of visual cortex during visual deprivation.     

Tobacco use prevalence, knowledge and attitudes, and tobacco cessation training among medical students: results of a pilot study of Global Health Professions Students Survey (GHPSS) in Italy

Aim

The aims of this study were to examine tobacco use prevalence, knowledge and attitudes, and tobacco cessation training among students attending Italian medical schools using the Global Health Professions Student Survey approach and to identify possible factors associated with smoking status.

Subjects and Methods

A multicentre cross-sectional pilot study was carried out in five Italian Schools of Medicine from March to April 2009. Questionnaires were administered in anonymous, voluntary and self-administered form to third year students attending medical schools. The outcome measure was ??being a current smoker??. A logistic regression was used to evaluate possible factors associated with smoking status.

Results

The prevalence of current smokers was 31.4%. More than half considered health professionals as models for patients, and around 90% thought health professionals have a role in giving advice or information about smoking cessation. Only 5.8% of responders had received smoking cessation training during medical school. Medical students who considered healthcare professionals as behavioural models had lower likelihood of smoking (OR?=?0.52).

Conclusions

Given the high prevalence of smokers among medical students and the poorness of smoking cessation programmes, it is important to create tobacco control training programmes addressed to healthcare students.     

Long-term central venous catheterization via persistent left superior vena cava

We report a case of a cancer patient who displayed a persistent left superior vena cava (PLSVC) after implantation of a central venous catheter (Port-a-Cath), as revealed by angiography. This anomaly is rather rare (0.3% of healthy individuals), and the few studies on the long-term maintenance of an implant in situ are not very informative. Nevertheless, based on the acceptable venous caliber and the patient's serious clinical situation, we decided to leave the catheter in place and perform infusional chemotherapy and supportive therapy with careful and continuous control. The patient died after 8 months of this therapy. No complications attributable to the catheter were observed. We think that the risk is acceptable in similar conditions.     

Effects of a 4-week training with voluntary hypoventilation carried out at low pulmonary volumes

This study investigated the effects of training with voluntary hypoventilation (VH) at low pulmonary volumes. Two groups of moderately trained runners, one using hypoventilation (HYPO, n=7) and one control group (CONT, n=8), were constituted. The training consisted in performing 12 sessions of 55 min within 4 weeks. In each session, HYPO ran 24 min at 70% of maximal O(2) consumption ( [V(02max)) with a breath holding at functional residual capacity whereas CONT breathed normally. A V(02max) and a time to exhaustion test (TE) were performed before (PRE) and after (POST) the training period. There was no change in V(O2max), lactate threshold or TE in both groups at POST vs. PRE. At maximal exercise, blood lactate concentration was lower in CONT after the training period and remained unchanged in HYPO. At 90% of maximal heart rate, in HYPO only, both pH (7.36+/-0.04 vs. 7.33+/-0.06; p<0.05) and bicarbonate concentration (20.4+/-2.9 mmolL(-1) vs. 19.4+/-3.5; p<0.05) were higher at POST vs. PRE. The results of this study demonstrate that VH training did not improve endurance performance but could modify the glycolytic metabolism. The reduced exercise-induced blood acidosis in HYPO could be due to an improvement in muscle buffer capacity. This phenomenon may have a significant positive impact on anaerobic performance.     

An annotated ventricular tachycardia (VT) alarm database: Toward a uniform standard for optimizing automated VT identification in hospitalized patients

Background

False ventricular tachycardia (VT) alarms are common during in-hospital electrocardiographic (ECG) monitoring. Prior research shows that the majority of false VT can be attributed to algorithm deficiencies.

Purpose

The purpose of this study was: (1) to describe the creation of a VT database annotated by ECG experts and (2) to determine true vs. false VT using a new VT algorithm created by our group.

Methods

The VT algorithm was processed in 5320 consecutive ICU patients with 572,574 h of ECG and physiologic monitoring. A search algorithm identified potential VT, defined as: heart rate >100 beats/min, QRSs > 120 ms, and change in QRS morphology in >6 consecutive beats compared to the preceding native rhythm. Seven ECG channels, SpO₂, and arterial blood pressure waveforms were processed and loaded into a web-based annotation software program. Five PhD-prepared nurse scientists performed the annotations.

Results

Of the 5320 ICU patients, 858 (16.13%) had 22,325 VTs. After three levels of iterative annotations, a total of 11,970 (53.62%) were adjudicated as true, 6485 (29.05%) as false, and 3870 (17.33%) were unresolved. The unresolved VTs were concentrated in 17 patients (1.98%). Of the 3870 unresolved VTs, 85.7% (n = 3281) were confounded by ventricular paced rhythm, 10.8% (n = 414) by underlying BBB, and 3.5% (n = 133) had a combination of both.

Conclusions

The database described here represents the single largest human-annotated database to date. The database includes consecutive ICU patients, with true, false, and challenging VTs (unresolved) and could serve as a gold standard database to develop and test new VT algorithms.