Analysis of the interbeat interval increment to detect obstructive sleep apnoea/hypopnoea.

The prevalence of obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is underestimated and its diagnosis is costly and restricted to specialised sleep laboratories. The frequency component of interbeat interval increment (III) has been proposed as a simple and inexpensive diagnostic tool in OSAHS. In a set of 150 patients with clinically suspected sleep-related breathing disorder, the actual predictive accuracy of the power spectral density of the III of the very low frequencies (%VLFI) was analysed by comparing with the apnoea/hypopnoea index (AHI), as assessed by synchronised polysomnography. OSAHS was defined in 100 patients according to an AHI>or=15 events.h(-1). Receiver operator characteristic curves built for %VLFI confirmed that this variable was able to separate OSAHS positive from OSAHS negative with statistical significance. Using an appropriate threshold (>4%), %VLFI demonstrated a positive predictive value of 80%. Misclassification of false-positive subjects occurred when the patient presented significant sleep discontinuity and sleep fragmentation (sleep fragmentation index>or=50 events.h(-1)) related to insomnia or periodic limb movements. A power spectral density of the interbeat interval increment of very low frequencies>4% allowed correct classification of obstructive sleep apnoea/hypopnoea syndrome when the clinical history suggested sleep-related breathing disorders and when moderate-to-severe cases are considered. Higher power spectral density of the interbeat interval increment of very low frequencies may also indicate disrupted sleep in the absence of clear clinical symptoms of sleep apnoea/hypopnoea syndrome.     

Soft tissue facial volumes and shape in skeletal Class III patients before and after orthognathic surgery treatment.

BACKGROUND: To obtain the best surgical results in orthognathic surgery, treatment planning and the evaluation of results should be performed on measurable three-dimensional reproductions of the face of the patients, and compared to reference subjects. METHODS: Seven women aged 18-35 years, all with a skeletal Class III and mandibular asymmetry, were assessed both before (on average, 2 months) and after (on average, 10.7 months) surgical intervention (mandibular reduction by sagittal split osteotomy and LeFort I maxillary advancement). The three-dimensional coordinates of 50 soft tissue facial landmarks (face, eyes, nose, mouth and lips, ears) were collected with a noninvasive, electromagnetic digitizer; facial volumes were estimated, and compared to reference values collected in 87 healthy women of the same age and ethnic group. Inter-individual modifications in facial shape were also assessed. RESULTS: Before surgery the patients had smaller faces than the reference women, with larger lower lips and noses. A large within-group variability was found. Surgical treatment significantly reduced total facial volume and mandibular volume, increased total and upper lip volumes (Student's t test, p<0.05), and made all values more homogenous within the group. Shape differences were significantly larger before than after surgery. On average, right side gonion was the landmark that moved the most, closely followed by menton, while the tragi and ala nasi moved the least. The three-dimensional approach used in this study enabled quantitative evaluation of the final soft tissue results of surgery, without submitting the patients to invasive procedures.     

Cardiovascular autonomic dysfunction in normotensive awake subjects with obstructive sleep apnoea syndrome

Cardiovascular autonomic function in normotensive awake patients with obstructive sleep apnoea syndrome was studied in 21 normotensive (mean age 48 ± 14 years), drug-free men with obstructive sleep apnoea syndrome. Cardiovascular reflex tests with continuous blood pressure monitoring and biochemical indices were performed the morning after a standard polygraphic sleep recording. A group of 20 agematched (mean age 49 ± 19 years) normal subjects was used as controls. The obstructive sleep apnoea syndrome patients showed higher heart rate and noradrenaline plasma levels (p < 0.05) at rest and a higher blood pressure response to head-up tilt (p < 0.01), suggesting sympathetic overactivity. Respiratory arrhythmia, baroreflex sensitivity index and Valsalva ratio were significantly lower in the obstructive sleep apnoea syndrome group (p < 0.01) whereas the decrease in heart rate induced by the cold face test was significantly higher (p < 0.05) showing a blunting of reflexes dependent on baroreceptor or pulmonary afferents with normal or increased cardiac vagal efferent activity. These abnormalities in autonomic regulation may predispose obstructive sleep apnoea syndrome patients to cardiovascular complications like hypertension and cardiac arrhythmias.     

Mechanical staplers. Personal experience]

The Authors briefly summarise their experience of using various types of mechanical staplers in abdominal and thoracic surgery with excellent results both in general and in terms of reducing operating times.     

Significance of PBMC response of rheumatic fever patients and control individuals to immunodominant streptococcal M5 protein epitopes

β-hemolytic streptococcal infection in developing countries still causes thousands of cases of Rheumatic Fever (RF). Molecular mimicry between streptococcal M protein (strep M) and heart components has been proposed as the triggering factor leading to autoimmunity in individuals with genetic susceptibility, which is linked to different HLA-DR alleles in different populations. In our hands, RF was significantly associated to HLA-DR7/53. Previous work in our lab has shown that heart-infiltrating T cells that simultaneously recognize strep M and heart proteins. Further, such T cells predominantly recognized the 81-103 strep M5 epitope. In this work, we analysed the proliferative response of peripheral blood mononuclear cells of 99 RF patients and 40 normal controls. Eighty-nine of the RF patients were HLA-typed. As among heart-infiltrating T cells, the 81-103 strep M5 protein epitope is the most frequently recognized epitope among RF PBMC (35.4%), against a 7.5% frequency of proliferation among normal controls (p=0.0018, chi square). However, the 81-103 epitope was as frequently recognized by HLA-DR7,53 positive as by negative individuals (45.2% vs 54.8%, respectively). Taken together, the results suggest that the 81-103 strep M5 epitope may be the immunodominant epitope, “promiscuously” recognized by T cells in a genetically diverse population. The demonstration that molecular mimicry is targeted to a discrete immunodominant “promiscuous” epitope in strep M5 may allow the development of a safe anti-streptococcal synthetic vaccine devoid of such epitopes.     

Clustering of Y chromosome deletions in subinterval E of interval 6 supports the existence of an oligozoospermia critical region outside the DAZ gene.

Y chromosome molecular analysis was performed using the STS-PCR technique in 50 patients with oligozoospermia. Microdeletions of interval 6 of the Y chromosome were detected in seven patients, in six of whom subinterval E was affected. All patients retained the RBM1 and DAZ genes, while in one deletion involved the SPGY gene. The size of the deletion was not apparently related to the severity of the disease. These results suggest the presence of an oligozoospermia critical region on the Y chromosome within subinterval E of interval 6.     

Intracranial capillary hemangiomas: literature review in pediatric and adult population

Neurosurgical Review - Capillary hemangiomas (CHs) of the central nervous system represent a rare diagnosed pathology. CHs are benign vascular tumors whose most common manifestations are dermal and...     

Managing (In)differently: The management and delivery of Australian nursing care under the economic rationalists

Conclusion Economic (mis)management in Australia has understandably been influenced by the experiences of countries such as the UK and the USA with which Australia has traditionally had a close relationship. However, the uncritical acceptance of economic rationalism is an indication of our nation's seduction by the possibility of a quick fix for a struggling economy. In accepting economic rationalism there has been a dismissal, or at least a failure to take account of, both past Australian experiences and the overseas experience—including the recent experience of a close neighbour, New Zealand, whose health system is under severe strain.The introduction of economic rationalist programmes into the Australian health sector was an attempt to contain expenditure and at the same time reduce dependence on the public system. This has failed to happen on both counts. Its only real achievement has been to produce yet more evidence of the practical inadequacies of economic rationalism in general.     

Digital film viewer versus conventional view boxes in the identification of bone and joint disorders

PURPOSE: To compare the diagnostic accuracy of a digital film viewer (Smartlight 2000 Plus) versus a conventional view box for the identification of bone and joint disorders. MATERIAL AND METHODS: In order to evaluate the qualitative and quantitative differences of digital and conventional film viewers, 100 plain films of patients with bone and joint disorders taken in an emergency room January through May 1998 were reviewed utilizing both types of view boxes. Three radiologists expert of bone and joint disorders, independently compared the films, filled a form about the qualitative and quantitative analysis of the lesions depicted for each patient, and reported a few notes on the technical quality of the plain films in terms of exposure. The results were compared using the chi-square test (p < 0.005). RESULTS: Data analysis showed that the digital film viewer permitted a quicker reading of the film while decreasing the perception threshold for elementary lesions and ocular fatigue. All the radiographs read with the digital film viewer were considered technically adequate: the film quality was considered good in 10 cases and sufficient in 2. Two of the same radiographs read with the conventional view box were considered of good quality, nine were considered sufficient and one was considered insufficient due to overexposure. There were six cases of agreement and six of disagreement for the diagnosis: four were due to overexposure of the radiograph and two to better conspicuity provided by the digital film viewer. DISCUSSION: Correct image illumination is the first element a radiologist evaluates when reading a radiograph. A conventional view box may, when it is not properly maintained or when the radiograph is overexposed, decrease the radiologist's visual capacity. This increases the time required to read the radiograph and, therefore, physical and ocular fatigue, which in turn increases the risk of missing or misevaluating a lesion. A digital film viewer emits light with a variable intensity which is proportional to the optical density of the film. This increases the visual capacity of the radiologist and the lesion contrast, while reducing the factors which affect the radiograph reading. CONCLUSIONS: The use of a digital film viewer increased the visual capacity of the radiologist and eliminated the negative elements which complicated the radiograph reading and permitted the use of radiographs that would otherwise have been considered of poor quality due to overexposure. This, combined with the experience of the radiologist, decreased of the risk of missing or misevaluating a lesion.