The upper limb in cerebral palsy: surgical management of shoulder and elbow deformities

The authors report a simple chart that offers a comprehensive picture of spasticity of the upper limb and provides a more objective method of recording data. Distinction is made between fixed postures and the residual active range of motion at the shoulder and elbow. The presence and function of the muscles can be identified easily on dynamic EMG studies, which are essential for understanding the degree of spasticity and dyssynergy related to a single muscle. When spasticity of the upper arm is managed with a global approach and objectives are defined clearly in advance with the patient and caregivers, treatment of shoulder and elbow deformities can achieve important results for personal hygiene or functional targets.

An estimate of the current risk of transmitting blood-borne infections through blood transfusion in Italy

We conducted a retrospective cohort study to estimate the incidence of major blood-borne agents among Italian blood donors and calculated the risk of infection among blood recipients using the 'incidence/window period model'. The study was conducted among 46 180 blood donors enrolled in six blood centres between 1994 and 1999. During follow-up, seven new infections were confirmed: three donors seroconverted for anti-human immunodeficiency virus (HIV); two for anti-hepatitis C virus (HCV); and two showed hepatitis B surface antigen (HBsAg) reactivity; no cases of syphilis were observed. The incidence rates per 100 000 person/years were: 4.06 (95% CI: 0.82-11.85) for HIV; 2.41 (95% CI: 0.29-8.70) for HCV; and 2.70 (95% CI: 0.32-9.77) for HBsAg; the incidence for total hepatitis B virus (HBV) infection was 9.77 per 100 000 person/years (95% CI: 1.16-35.36). The estimated risk of an infectious blood unit not being detected was: 2.45 (95% CI: 0.13-12.33) per 1 million units for HIV; 4.35 (95% CI: 0.30-22.39) for HCV; and 15.78 (95% CI: 1.16-84.23) for HBV. Overall, an estimated 22.58 per 1 million units are infected. In Italy, the risk of transfusion-transmitted infections is low and is similar to that in other western countries. The introduction of new more sensitive screening tests could reduce the residual risk of transfusion-transmitted infection by 40-80%.

Epidemiology of myotonic dystrophy in Italy: re-apprisal after genetic diagnosis

Before the discovery of the myotonic dystrophy (DM) gene, the DM epidemiological rates could not be accurately estimated. The aim of this study was to calculate the DM prevalence rates in Padova (North-East Italy) and in four provinces of North-West Tuscany (Central Italy) and, as of 30 June 1999, to do so using molecular genetic testing. A minimum prevalence rate of 9.31x10(-5) inhabitants was found, consistent with epidemiological rates worldwide, and more than two times as high as those of two previous studies conducted in the same areas during the era prior to molecular genetic testing. This study, the first in Italy since the discovery of the DM gene, underlines the importance of direct genetic diagnosis of DM, especially in detecting mildly affected patients, a fundamental step in correctly estimating the risk of disease transmission in affected families.

Improvement of the bone-pin interface strength in osteoporotic bone with use of hydroxyapatite-coated tapered external-fixation pins. A prospective, randomized clinical study of wrist fractures

BACKGROUND

Achieving adequate fixation strength in osteoporotic bone is a challenge. In this study, we examined the use of hydroxyapatite-coated tapered external-fixation pins for the fixation of wrist fractures in patients with osteoporosis.

METHODS

Twenty female patients with osteoporosis and a fracture of the wrist were divided into two paired groups and randomized to receive either standard tapered pins or hydroxyapatite-coated tapered pins. Two pins were inserted in the distal part of the radius, two pins were inserted in the second metacarpal, and an external fixation device was mounted. All fixation devices were removed six weeks after surgery.

RESULTS

The mean pin-insertion torque (and standard deviation) was 461 +/- 254 Nmm in the group managed with standard pins and 332 +/- 176 Nmm in the group managed with hydroxyapatite-coated pins (p = 0.01). The mean pin-extraction torque was 191 +/- 155 Nmm in the group managed with standard pins and 600 +/- 214 Nmm in the group managed with hydroxyapatite-coated pins (p < 0.0001, power 95%). The mean extraction torque was lower than the corresponding insertion torque at each pin position in the group managed with standard pins (p < 0.05), whereas the mean extraction torque was higher than the corresponding insertion torque at each pin position in the group managed with hydroxyapatite-coated pins (p = 0.001). Two patients managed with standard pins and no patient managed with hydroxyapatite-coated pins had a pin-track infection. Pain during pin removal did not differ between the two groups.

CONCLUSIONS

The present study showed that hydroxyapatite-coated tapered external-fixation pins provided improved fixation in the treatment of wrist fractures in patients with osteoporosis.

Handgrip strength is an independent predictor of distal radius bone mineral density in postmenopausal women

Several cross-sectional studies have reported a positive correlation between muscle strength and local bone mineral density. However, very few studies have evaluated the possible role of confounding variables, which may be substantial as both bone mineral density and muscle strength are multifactorial variables. We studied 140 postmenopausal women who underwent their first osteodensitometry in our hospital. Of these, 102 women affected neither by bone diseases apart from primary osteoporosis nor treated with drugs affecting bone mass were selected. Distal radius bone mineral density of the non-dominant arm was assessed by dual photon absorptiometry. Handgrip strength was measured by a handheld dynamometer. The following factors influencing bone mass were also considered: age, years since menopause, years of cyclic ovarian activity, body weight, body height, body mass index, and both calcium and alcohol dietary intake. Statistical evaluation was performed by stepwise multiple regression analysis. This showed that only two variables were independently related to bone mineral density: handgrip strength (which was the best bone density predictor among the studied independent variables) and years since menopause. R2 value was 0.43 (F=38.04, p < 0.001). All the other variables studied were not significantly related to bone density when the effects of both strength and years since menopause were considered. In conclusion, the data showed that handgrip strength was a strong independent predictor of distal radius bone mineral density in postmenopausal women. Clinical assessment of osteoporosis risk factors, including muscle strength, is recommended: although it is not an adequate substitute for bone densitometry, it can help clinicians to identify the risk groups at which to direct bone density measurement.

Prolonged prophylaxis with unfractioned heparin is effective to reduce delayed deep vein thrombosis in total hip replacement

The aim of this study was to assess the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) until 45 days after elective total hip replacement (THR) and the efficacy of prolonged unfractioned heparin (UH) prophylaxis up to postoperative day 30. To this end 79 of 96 patients admitted consecutively to the University Hospital of Pisa for THR were randomly assigned to short- or long-term UH prophylaxis. Sixty-one patients completed the study: 28 of them received short-term prophylaxis (subcutaneous UH 15,000 IU/24 h for 15 days) and 33 prolonged prophylaxis (subcutaneous UH 15,000 IU/24 h for 30 days). Lower limb phlebography was performed in all patients on day 45 after THR. DVT was demonstrated in 10 (16.3%) cases after hospital discharge. Among them, 2 patients also had symptomatic PE. The incidence of DVT was 21.4% in short- and 12.1% in long-term UH-treated patients. The incidence of only proximal DVT was 17.8% in short- and 3.0% in long-term UH-treated patients; although the difference was only close to significance (p = 0.085), the relative risk of developing proximal DVT was about six times greater in the former group of patients. We concluded that the risk for thromboembolism persists at least until 45 days after surgery in patients subjected to THR. Prophylaxis with UH given up to postoperative day 30 appears more effective and safer in reducing the delayed thromboembolic risk compared to prophylaxis with UH given up to discharge only.

Clinical validation of the avidin/indium-111 biotin approach for imaging infection/inflammation in orthopaedic patients

We report here the results of a validation study of the avidin/indium-111 biotin approach in patients with skeletal lesions. This study involved 54 patients with orthopaedic conditions: 20 patients with intermediate suspected osteomyelitis of the trunk, 19 patients with infection/inflammation of prosthetic joint replacements, and 15 patients with suspected osteomyelitis of appendicular bones. Avidin (3 mg) was injected as an i.v. bolus, followed 4 h later by 111In-biotin; imaging was acquired 30 min and 16-18 h after administration of 111In-biotin. Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocyte scintigraphy was performed in 39/54 patients. The overall sensitivity of the avidin/111In-biotin scan was 97.7% (versus 88.9% for 99mTc-HMPAO leucocyte scintigraphy). While the diagnostic performance of avidin/111In-biotin scintigraphy was similar to that of 99mTc-HMPAO leucocyte scintigraphy in patients with prosthetic joint replacements or osteomyelitis of appendicular bones, the avidin/111In-biotin approach clearly performed better than 99mTc-HMPAO leucocyte scintigraphy in patients with suspected osteomyelitis of the trunk (100% sensitivity, specificity and accuracy versus 50% sensitivity, 100% specificity and 66.7% accuracy for 99mTc-HMPAO-leucocyte scintigraphy). These results demonstrate the feasibility of the avidin/111In-biotin approach for imaging sites of infection/inflammation in the clinical setting. Although no systematic advantages of avidin/111In-biotin scintigraphy were found versus 99mTc-HMPAO leucocyte scintigraphy, the newer scintigraphic method is more practicable and involves lower biological risk for the operators.

H reflex excitability following voluntary muscle contraction of different duration

The importance of the duration of contraction on the excitability of the motoneuronal pool was evaluated by measuring the H reflex from soleus muscle after short and long contractions at constant effort equal to 60% maximal voluntary contraction (MVC); the difference between the amplitude of H reflex at rest and after contraction of different duration was evaluated in 10 normal subjects and in one hemiparetic patient. The authors found a significant inhibition of H reflex after contraction of 10 seconds and after 40 seconds and a longer duration of the inhibition after 40 seconds. In the hemiparetic patient the H reflex did not show inhibition which suggests a possible reduction of the presynaptic inhibition, and a lack of modulation of the motoneuronal pool after contraction.

[High-resolution electrocardiography in 102 young healthy subjects]

BACKGROUND

The aim of this study was to evaluate the normal values of the most common indexes used in the analysis of ventricular late potential in 102 young male subjects.

METHODS

The recordings were performed by means of a Marquette electronics Hi-Resolution ECG Mac 15, with filters at 25-250 Hz, 40-250 Hz and 80-250 Hz. The parameters obtained were: filtered QRS duration (QRSD), high-frequency low-amplitude signals duration (HFLA), and the root mean square of the signal expressed in the terminal portion of QRS (RMS). The body surface was also evaluated.

RESULTS

QRSD (121.23 ms-113.9 ms-99.9 ms); RMS (105 uV-42.77 uV-34.3 uV); HFLA (17.5 ms-29.3 ms-29.3 ms). The comparison between our results and those proposed by other authors for normal subjects showed different results, particularly concerning the filtered QRS duration. We suppose that these discrepancies may be due to the different instrumentations used and to the different age and sex of the study population.

CONCLUSIONS

From these results we confirm that a normal range for each index must be done for homogeneous groups of subjects for age and sex, in healthy subjects as well as for different heart disease.

[Discordance between clinical and immunological aspects in a case of chronic B-type lymphoproliferative syndrome]

Chronic lymphoproliferative disorders are extremely heterogeneous from a clinical, morphological and immunological point of view. The paper reports the case of a woman with chronic prolymphocytic leukemia. The neoplastic clone revealed the typical immunological features of pre-B lymphocytes, which are at an earlier stage of differentiation in respect to prolymphocytes. After polychemotherapy (CEOP) the phenotype of the neoplastic cells shifted to an immunological pattern typical of B lymphocytes.

Antenatal diagnosis of beta-thalassemia by isoelectric focusing in immobilized ph gradients

A new method for antenatal diagnosis of thalassemias is reported based on the analysis of the major Hb components of fetal cord blood, sampled at week 18 of pregnancy under ultrasonic guidance, by isoelectric focusing in immobilized pH gradients (IPG). In an IPG gel encompassing a pH 6.7-7.6 span, HbA and HbFac are separated by a distance nine times greater than in a conventional carrier ampholyte pH 6-8 gel and three times greater than in an ampholine gel with separators (an equimolar mixture of beta-alanine and 6-amino caproic acid). Band evenness (in terms of uniform protein concentration within a zone) and straightness (in terms of parallel alignment of the bands to the electrodes), because of insensitivity of IPG gels to salt distortions, allows for accurate and reproducible quantitation of HbF, -A, and -Fac levels. The possibility of greatly overloading IPG matrices in total Hbs increases the sensitivity of the technique to the detection of only 0.5% HbA in the total Hb mixture, the lower limit of conventional IEF being only 2.5% HbA. Of 15 fetuses from couples at risk analyzed in the region of Ozieri, three were found to be homozygous beta-thalassemic, eight heterozygous, and four normal with no false-positives or -negatives.

Detection of electrophoretically silent mutations by immobilized pH gradients

The detection of neutral amino acid mutants, by isoelectric focusing in immobilized pH gradients (IPGs), is exemplified by the separation of hemoglobin (Hb) Beirut (126 beta Val----Ala) from Hb A in a shallow pH 7.2-7.6 IPG gradient with 2% Ampholine pH 6-8. The mechanism of these separations appears to involve minute alterations in the pK values of ionizable groups bordering the mutation site, which are in turn reflected in tiny alterations in the net surface charge, delta pI. The delta pI values are of the order of 0.01 to 0.001 pH units, outside the resolving limits of conventional isoelectric focusing, and correspond to changes of the order of 0.1-0.01 unit charge (a proton or an electron).

Pattern electroretinogram in multiple sclerosis

The pattern electroretinogram obtained in patients affected by multiple sclerosis were compared with those in a normal population. The pattern electroretinogram amplitude in multiple sclerosis optic neuritis frequently appeared normal, but pattern electroretinogram amplitude abnormalities were found in patients suffering from recurrent multiple sclerosis optic neuritis. Pattern electroretinogram examination appears a useful method in the differential diagnosis between axonal and demyelinating optic nerve impairment.

[The origin of the electroretinogram induced by structured stimuli in man]

The Authors studied the checkerboard pattern electroretinogram (PERG) behaviour in normal subjects and in patients suffering from traumatic lesion of optic nerve, demyelinating optic neuritis, axonal optic neuritis, retinal vascular disorders and retinitis pigmentosa in order to verify the PERG origin. According to our data the PERG appears to originate from ganglion cells since the signal diminished or disappeared in axonal lesion of optic nerve, as a result of retrograde ganglion cell degeneration. Furthermore, the demyelinating lesions of optic nerve were not able to modify the PERG wave. In patients suffering from retinal receptor disturbances the flash electroretinogram (FERG), which is probably an expression of receptor activity, was greatly impaired, whereas PERGs were either normal or less impaired than FERGs. These data demonstrate the different origin of PERG and FERG.

[The effect of fatigue on the biopotential of muscle fiber cells]

Muscular fatigue is a biological situation which is very difficult to quantify. The Authors studied through a computer analysis the power spectrum of electromyogram, recorded from abductor digiti minimi muscle during maximal and minimal contraction effort before and after fatigue and after muscle prolonged relaxation in 8 normal subjects. No significant spectrum differences were found between maximal and minimal effort in each trial, and between the spectra obtained before fatigue and after muscle prolonged relaxation. On the contrary significant differences were found between the spectra obtained after fatigue and the other conditions. The power spectrum analysis appears, also, to be a reliable neurophysiological parameter for the study of biological aspects of muscular fatigue.

[The effect of thoracic pressoreceptors on heart rate in man]

Sinus arrhythmia (SA) is a physiological event related to the respiratory activity. The aim of this study was to find a relation between SA and different deep breathings. A transductor monitored the chest respiratory movements and a cardiotachometer calculated and plotted the instantaneous heart rate, synchronously during different breathing efforts. In 10 normal subjects a good linear correlation was found between the breathing depth and SA quantifying the relation between the chest receptor activity and SA also with limited chest expansion.