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PubMed1997

Mitochondrial abnormalities and peripheral neuropathy in inflammatory myopathy, especially inclusion body myositis.

Computer retrieval in a database, comprising 7,225 muscle cases, revealed that mitochondrial myopathies do not occur more frequently in inflammatory myopathies (3.74%) than in the whole series (3.69%). A more detailed study of inclusion body myositis (IBM), however, showed that severe mitochondrial alterations were apparent in about twice as many IBM cases as expected. This confirms recent studies of others although a causal relationship has thus far not been established. Identification of mitochondrial deletions by Southern blotting corresponded to the presence of severe structural abnormalities of mitochondria. Peripheral neuropathy of variable severity was noted in all cases of IBM and mitochondrial myopathy. By contrast, the association of severe mitochondrial abnormalities with polymyositis, systemic scleroderma, and vasculitis observed in some cases of the present series may be incidental or age dependent.

Adult↗
PubMed2003

An unusual case of CV junction tuberculosis presenting with quadriplegia.

STUDY DESIGN: Isolated tubercular involvement of craniovertebral junction in a human immunodeficiency virus-positive patient causing paraplegia and sudden death with radiologic features is presented. OBJECTIVES: Isolated involvement of craniovertebral junction by tuberculosis causing quadriparesis is a rare entity. The role of imaging features is presented in diagnosis of craniovertebral junction tuberculosis, which is a treatable disease. Early detection of this entity with prompt treatment can prevent a fatal outcome. SUMMARY OF BACKGROUND DATA: Tuberculosis of the cervical spine is a rare and potentially dangerous manifestation of extrapulmonary tuberculosis. The incidence is probably less than 1% of all cases of spinal tuberculosis. However, in the developing countries this constitutes an increasingly important cause of craniovertebral junction instability and cervicomedullary compression. Most of the patients present with pain in the neck and local tenderness. Neurologic deficits of varying degrees have been reported in 24-40% of cases of craniovertebral junction tuberculosis. Quadriplegia followed by sudden death is exceptional (as seen in our case). The incidence of craniovertebral junction tuberculosis in immunocompromised patients is not known. Dramatic recovery is possible if craniovertebral junction tuberculosis is detected early in its course. Prompt medical and surgical treatment may avert a potential catastrophic event in such cases. Imaging methods such as computed tomography and magnetic resonance imaging are diagnostic of this condition and aid in the detection and prompt treatment of the same. METHOD: Frontal radiograph of the cervical spine and chest, and lateral view of cervical spine followed by plain and contrast enhanced computed tomography scan of the cervical spine was performed to detect the lesion. RESULT: These radiographic features were correlated with the clinical findings. The computed tomography findings of bone destruction, prevertebral and extradural peripherally enhancing soft tissue and infiltrating opacities in the lung apexes were consistent with tuberculosis. CONCLUSIONS: The computed tomography findings described in this report are very specific for tuberculosis of the craniovertebral junction. Clinical and radiologic correlation could help in making the early diagnosis and prompt treatment possible.

Adult↗
PubMed1990

[Non-invasive monitoring of hemodynamic profile during general anesthesia].

This article presents a general vision of a new non-invasive cardiovascular monitoring technique applied to patients during general anaesthesia. This method employs an esophageal eco-Doppler, able to supply a continuous measurement of the aortic diameter (eco-TM) and of the velocity of aortic blood flow (pulsed Doppler) for the calculation of aortic output; a monitor to survey the ECG and a noninvasive device for the measurement of blood pressure. The resulting data, opportunely processed by the computer, supply the values of aortic output, of systemic peripheral resistances and of stroke volume. The last two parameters are indexed with aortic output. Through the computer analysis of ECG and of the aortic velocity curve, it is possible to trace back the systolic time intervals and find out the left ventricular ejection time, the pre-ejection period and the electromechanical systole. All these values are indexed with heart rate. The validation of this method gave good results. The comparison between aortic output, measured by the eco-Doppler, and the value obtained with the thermodilution gave a correlation of r = 0.97, and comparing it with the one obtained with the electromagnetic ring, the correlation was r = 0.96. The aortic diameter was calculated with computerized tomography and the correlation between the two diameters resulted in 0.978. This method is quite useful because it supplies continuous parameters in an automatic and noninvasive way. Therefore it is possible, through a compete hemodynamic profile, to diagnose the variations and control the evolutions of the hemodynamic profile induced by the therapeutical treatments, on the basis of a correct physiopathological interpretation.

Anesthesia, General↗
PubMed1998

[Computed tomography analysis of resected small adenocarcinomas of the lung less than 15 mm in diameter--correlation of radiologic and histologic characteristics].

To analyze the radiographic characteristics of small adenocarcinomas of the lung that can be detected by computed tomography (CT), 46 resected small peripheral adenocarcinomas measuring less than 15 mm in diameter were retrospectively reviewed, and the marginal and internal findings and surrounding vessels of the tumors as shown on thin-section CT images were correlated with six histologic classifications (types A-F) as defined by Noguchi et al. The adenocarcinoma CT images were classified into two patterns: a solid-density type (n = 21) and an air-containing type (n = 25). The lesions of the air-containing type were further divided into two different growth patterns: a complete air-containing type (n = 12) and an incomplete air-containing type (n = 13). The solid-density adenocarcinomas shown in the CT images fell mainly into the C, D, F and Noguchi classifications. Although one sample in the complete air-containing category was type C, the rest were type A. The incomplete air-containing category included 4 type As and 9 type Bs. The CT findings for the 24 adenocarcinomas in the air-containing category (96%) showed an opaque ground-glass internal texture. Plural vascular involvement was observed in all 46 adenocarcinomas examined. Our results suggest that thin-section CT findings can play an important role in differentiating lung cancer and increasing our knowledge of the radiologic and pathologic correlations.

Adenocarcinoma↗
PubMed2006

Continuous cardiac output monitoring by peripheral blood pressure waveform analysis.

A clinical method for monitoring cardiac output (CO) should be continuous, minimally invasive, and accurate. However, none of the conventional CO measurement methods possess all of these characteristics. On the other hand, peripheral arterial blood pressure (ABP) may be measured reliably and continuously with little or no invasiveness. We have developed a novel technique for continuously monitoring changes in CO by mathematical analysis of a peripheral ABP waveform. In contrast to the previous techniques, our technique analyzes the ABP waveform over time scales greater than a cardiac cycle in which the confounding effects of complex wave reflections are attenuated. The technique specifically analyzes 6-min intervals of ABP to estimate the pure exponential pressure decay that would eventually result if pulsatile activity abruptly ceased (i.e., after the high frequency wave reflections vanish). The technique then determines the time constant of this exponential decay, which equals the product of the total peripheral resistance and the nearly constant arterial compliance, and computes proportional CO via Ohm's law. To validate the technique, we performed six acute swine experiments in which peripheral ABP waveforms and aortic flow probe CO were simultaneously measured over a wide physiologic range. We report an overall CO error of 14.6%.

Algorithms↗
PubMed1991

Determining efficacy of monitoring devices: evaluating new technologies.

We point out the connection between electronic monitoring and repeated screening tests, and suggest a flexible and practical method to determine the efficacy of monitoring devices and new technologies. We point out the benefits of the Mantel-Haenszel estimator of an odds ratio for determining diagnostic test indices. From estimates of sensitivities and specificities, we produce receiver operating characteristic (ROC) curves to compare the performance of two or more monitoring devices in a clinical setting.

Algorithms↗
PubMed1994

Anatomy of the prostatic nerves.

The entire prostate of a 10 year old boy was cut with a microtome in to 4300 serial slices. The nerves were stained using a monoclonal antibody called anti PS 100. All information was recorded using a computer reconstruction programme. The prostatic nerve supply is very abundant. The nerve fibers of the cranial prostate (central zone) follow a pathway parallel to the anterior surface of the seminal vesicles going towards the caudal prostate. The periurethral zone is widely innervated by nerves arising from the periphery. The caudal prostate also contains many nerve fibers of variable size. We identified many nerve fibers along the anterior surface of the seminal vesicles and surrounding the lateral aspect of the prostatic capsule. They penetrate the capsule and the whole circumference of the caudal prostate. The prostatic capsule is covered by numerous nerve fibers and ganglia, which form a true periprostatic nerve network. The urethra is supplied by numerous thick fibers of more than 30 microns in diameter.

Child↗
PubMed2005

Unilateral renal angiodysplasia in a girl with hypertension.

We report a case of very unusual renal vascular anomaly: angiodysplasia. The patient suffered from acute pyelonephritis immediately after birth. Renal ultrasonography, performed at age 1 day, revealed an enlarged left kidney with heterogeneously increased echogenicity, which involuted rapidly in 3 months. At age 10 years, she presented with severe hypertension during a course of acute pyelonephritis. Peripheral plasma renin activity was high. Computed tomographic angiogram revealed a very small but functioning left kidney. A single, narrow, left renal artery did not have focal stenosis. Pathology examination revealed dysplastic arterioles at the subcapsular area. After left nephrectomy, the blood pressure and the plasma renin activity were normalized. In conclusion, this is an unusual case of renal angiodysplasia, which induced renin-dependent hypertension.

Angiodysplasia↗
PubMed1985

A simple algorithm for defining the mean cardiac cycle of aortic flow and pressure during steady state.

A fast procedure for defining a cardiac cycle using simultaneously recorded and digitized aortic flow and pressure is presented. A simple algorithm, based on a double-threshold method, initially involves singling the dicrotic notch of flow in order to separate contiguous cardiac cycles during a given steady state. The individual cycles are carried back to a common origin of time, then they are normalized to the mean length and averaged. As a result of an averaging operation the algorithm gives a "mean cycle" of both pulsatile aortic pressure and flow. An "a posteriori" analysis of the noise components in the data has been carried out in order to justify the averaging operation. The "mean cycle" of aortic flow and pressure are suitable to be used as the input quantities of the automatic identification procedures recently assessed to estimate the parameters of simple models of the arterial input impedance. Our algorithm was defined and implemented as a FORTRAN program for a digital PDP 11/24 computer. This algorithm was tested by using pressure and flow data measured in the ascending aorta of dogs. About 26 sec were necessary to select 10 cardiac cycles (each one being about 200 samples long) of both flow and pressure in sequences of 2500 samples per signal and to compute the respective "mean cycles." Total peripheral resistance, total arterial compliance, and aortic characteristic impedance were estimated by aid of the simple three-element windkessel model. The results obtained by our method of determining parameters on the "mean cycle" of aortic pressure and flow were compared to the results obtained by averaging the parameters determined on each heart cycle.

Animals↗
PubMed1978

Comparison of the human evoked electrospinogram recorded from the intrathecal, epidural and cutaneous levels.

In 30 patients (17 of whom had a clinically normal spinal cord) spinal cord potentials evoked by peripheral nerve stimulation were studied with computer averaging techniques in order to compare the intrathecal, epidural and skin records. In epidural and skin records, segmental spinal cord potentials either recorded from lower cervical or lower thoracic intervertebral levels often had similar shapes and latencies, especially with regard to the first component of the intrathecally recorded responses. The second slow component became less significant and was even absent in some cases. The amplitude of the first component was on average 33% of that recorded intrathecally when recorded epidurally and only 10% when recorded from the skin. In three cases potentials of very prolonged onset latency were recorded epidurally or cutaneously while in the same cases intrathecal records resulted in potentials with normal latencies. Cervical tract responses at the C6--7 intervertebral level after stimulation of the posterior tibial nerve were studied by the 3 recording methods. Epidural and skin records failed to reveal such a response regularly, while intrathecal recording invariably provided the cervical tract response. The 3 recording methods were discussed with respect to clinical applications and research. It can be stated with some reservation that epidural and skin surface recording techniques could be exploited it one could know the time of arrival segmental afferent inputs at the spinal cord.

Adolescent↗
PubMed1990

An algorithm for approximating conditional probabilities.

When diagnostic programs are constructed within a probabilistic framework, it is often the case that computation of joint probabilities of exhaustive combinations of events is easy, but computation of the kind of conditional probabilities the user wishes to know, is hard. This paper describes a simple algorithm for computing the required values, and then suggests several heuristic optimizations that may enable suitable approximations to be obtained in a feasible time when the task is otherwise intractable. An account is given of a specific application of the method in the construction of a medical diagnostic program, which is described in more detail elsewhere.

Algorithms↗
PubMed2004

Acoustic radiation force impulse imaging of the mechanical properties of arteries: in vivo and ex vivo results.

We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified commercial scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues' response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method.

Biomechanical Phenomena↗
PubMed1998

Two cases of intrapulmonary lymph node presenting as a peripheral nodular shadow: diagnostic differentiation from lung cancer.

We present two cases of intrapulmonary lymph node. The patients were a 44-year-old woman and a 71-year-old man each with a small peripheral nodule in the lung. On computed tomography (CT) scans, both nodules were spiculated. Since histological diagnosis could not be obtained by bronchoscopic examination or CT-guided needle biopsy, they underwent video-assisted thoracoscopic surgery. Histological examination of the resected material revealed that both nodules were composed of lymph node. Intrapulmonary lymph node has until recently been assigned no clinical significance; however, differential diagnosis of this lesion from lung cancers and other metastatic tumors is now clinically important.

Adult↗
PubMedDate not supplied

A rapid method to identify cytotoxic T-lymphocyte peptide epitopes from HLA-A2 (+) donors.

It would be useful to develop a method to rapidly identify peptide epitopes for vaccine development. We present an algorithm that can predict sequences that have a high binding activity for HLA-A2. These sequences were able to induce specific cytolytic cells from human peripheral blood lymphocytes (PBMC). A computer-assisted algorithm was constructed to predict binding activity for HLA-A2, according to anchoring amino acid combinations. The human papillomavirus (HPV) type 18 E7 oncoprotein was used to test the algorithm. Peptides predicted to bind were synthesized and binding activity was determined by using the T2 cell assay. T2 cells pulsed with HPV-18 peptides were incubated with PBMC. Cytotoxicity assays were performed. From 110 possible sequences, four peptides were found to have a high binding activity. One of these peptides was able to induce significant lysis. Using this selection process only 3.6% of the total number of possible sequences was synthesized to identify an immunogenic peptide. Our algorithm with the T2 binding assay allows a rapid method to detect peptide epitopes.

Algorithms↗
PubMed2001

[Spinal meningioma as differential diagnosis of diabetic polyneuropathy].

HISTORY AND ADMISSION FINDINGS: A 70 year old woman had suffered from diabetes mellitus type 2 since she was 52. Three years before the surgery she had begun to experience weakness together with altered sensitivity in the right leg, which was regarded as having been caused by diabetic polyneuropathy. During the admission examination the level for algesia on the right-hand side was at about D 11, a distal paraparesis of the leg (3-4 degrees, Janda's classification), more intense on the right, hyperactive deep tendon reflexes, Babinski's reflex on both sides, and depressed abdominal cutaneous reflexes. The sensitivity to vibrations on the Malleolus medialis on both sides was 0/8. The patient could walk only with the help of a Rollator. INVESTIGATIONS: Over the three-year period following onset of symptoms the following tests were carried out: motor nerve conduction speeds of the N. tibialis and N. peronaeus, electromyogram of the N. tibialis anterior and the M. gastrocnemius, somatosensory evoked potentials (SSEP) of the N. tibialis, which indicated a lesion in the peripheral nerves or nerve roots. Cranial computed tomography (CCT), CT scan of the lumbar spine (L3-S1) and angiological investigation elicited no significant pathological findings. An MRI of the thoracal spine showed a vertebra-sized dorsal tumor pressing on the spinal cord from left to right. TREATMENT AND COURSE: By means of microsurgery the spinal tumor was completely removed. Suspected meningeoma was confirmed by histological analysis. During the post-surgical period, the incomplete paraplegia quickly regressed, and 7 weeks after the removal of the spinal meningeoma the patient was able to climb stairs. CONCLUSION: In case of slowly-developing paresis of the legs in diabetic patients, diabetic polyneuropathy should not be diagnosed without careful consideration, and rare spinal tumors should be considered as part of the differential diagnosis, especially if the blood glucose level is normal, and intensive physiotherapy brings no improvement in the patient's condition.

Aged↗
PubMed2002

Quantitative kinetics of glucose appearance and disposal following a 13C-labelled starch-rich meal: comparison of male and female subjects.

In the UK, starch contributes up to 25 % of energy intake in adults (). The present study investigated the acute response to a starchy meal on whole-body glucose metabolism and assessed insulin sensitivity in men compared with women. Low insulin sensitivity has been postulated to pre-dispose individuals to a cluster of associated abnormalities known to increase the risk of CHD. Metabolic responses to a 13C-labelled meal were determined in conjunction with a primed continuous infusion of d-[6,6-2H]glucose in groups of healthy age- and BMI-matched men and women. Peripheral plasma glucose disposal (Gd) was computed using non-steady state kinetics in a single compartment model, simultaneously with determination of whole-body net glucose oxidation by indirect calorimetry. Insulin sensitivity was derived using cumulative Gd as the dependent variable, and time and the integrated insulin concentration as independent variables. The female group had the higher fractional rate of glucose appearance in plasma from starch (P=0.019) immediately after ingestion. Females also had a higher rate of plasma Gd and a significantly higher insulin-dependent Gd (6.8 v. 5.6 microg glucose/(min.kg) per pmol insulin, P<0.05) compared with the males. A smaller absolute pool of endogenous glucose in females allowed the rate of exogenous 13CO2 production to be significantly higher in the females (P=0.007) corresponding also to a significantly higher (P<0.05) carbohydrate oxidation rate obtained by indirect calorimetry. The present study suggests that during the ingestion of a starchy meal, females exhibit higher glucose flux and greater whole-body insulin sensitivity than males.

Adult↗
PubMed2006

Respiration correlated cone-beam computed tomography and 4DCT for evaluating target motion in Stereotactic Lung Radiation Therapy.

An image-guidance process for using cone-beam computed tomography (CBCT) for stereotactic body radiation therapy (SBRT) of peripheral lung lesions is presented. Respiration correlated CBCT on the treatment unit and four dimensional computed tomography (4DCT) from planning are evaluated for assessing respiration-induced target motion during planning and treatment fractions. Image-guided SBRT was performed for 12 patients (13 lesions) with inoperable early stage non-small cell lung carcinoma. Kilovoltage (kV) projections were acquired over a 360 degree gantry rotation and sorted based on the pixel value of an image-based aperture located at the air-tissue interface of the diaphragm. The sorted projections were reconstructed to provide volumetric respiration correlated CBCT image datasets at different phases of the respiratory cycle. The 4D volumetric datasets were directly compared with 4DCT datasets acquired at the time of planning. For ten of 12 patients treated, the lung tumour motion, as measured by respiration correlated CBCT on the treatment unit, was consistent with the tumour motion measured by 4DCT at the time of planning. However, in two patients, maximum discrepancies observed were 6 and 10 mm in the anterior-posterior and superior-inferior directions, respectively. Respiration correlated CBCT acquired on the treatment unit allows target motion to be assessed for each treatment fraction, allows target localization based on different phases on the breathing cycle, and provides the facility for adaptive margin design in radiation therapy of lung malignancies. The current study has shown that the relative motion and position of the tumour at the time of treatment may not match that of the planning 4DCT scan. Therefore, application of breathing motion data acquired at simulation for tracking or gating radiation therapy may not be suitable for all patients - even those receiving short course treatment techniques such as SBRT.

Carcinoma, Non-Small-Cell Lung↗