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Biomedical subjects

K Partanen

Publications and source records attributed to K Partanen.

At least 109 records · Page 6Linked to original sources

The effect of thoracic epidural analgesia on respiratory function after cholecystectomy.

To assess the effect of thoracic epidural analgesia (TEA) on postoperative respiratory function and pulmonary complications, a prospective randomized trial was conducted in patients undergoing cholecystectomy. One hundred patients were allocated to TEA (n = 30), TEA + general anesthesia (TEA + GA) (n = 30), or general anaesthesia (GA) (n = 40) groups. Respiratory function was analysed by measuring forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC), total lung capacity (TLC), peak expiratory flow (PEF) in the supine and sitting postures, and arterial blood gases. Postoperative pulmonary complications were carefully documented. TEA significantly prevented the postoperative deterioration of respiratory function as compared with general anaesthesia. FVC, FEV1 and PEF decreased by 20% in patients receiving TEA, in contrast to 55% in patients after GA on the day of operation. This improvement continued until the 2nd day after operation, when FVC, FEV1 and PEF and their recovery rates were equal in all groups. In the sitting posture the preoperative FVC, FEV1 and PEF were about 10% greater than in the supine position. After operation, this difference was further increased. The preoperative difference of 27% in FRC between the sitting and supine postures was maintained after operation. PaO2 decreased by 0.8 kPa after TEA, by 1.5 kPa after TEA + GA with the lowest value on the 2nd postoperative day and by 1.5 kPa after GA, with the lowest value immediately after operation. Simultaneous hypercarbia indicated hypoventilation, which may have contributed to impaired respiratory function on the following days.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesia↗

Streak artifacts in dynamic CT. A phantom study of the anterior upper abdomen.

Experiments with a body phantom during dynamic CT scanning with the Somatom 2 CT scanner indicate that the periodic streak artifacts seen on the anterior part of the liver in patients are caused by peristalsis of the stomach and resulting motion of the air fluid level. Therefore, the attenuation values of the anterior portion of the liver artifactually oscillate around the baseline value during the dynamic series of scans. This artifact is produced by a change in the position of the stomach air fluid level and is dependent on the direction of tube rotation. The mean of the artifactually oscillating attenuation readings is close to the mean density but usually useless in dynamic CT because the attenuation values change so rapidly in the dynamic phase that averaging measurements also will cause errors.

Humans↗

Comparison of iohexol and metrizamide in dynamic CT of the upper abdomen.

Contrast enhancement (CE) of the aorta, liver and spleen obtained with non-ionic monomer of contrast media (CM) iohexol and metrizamide, was studied by dynamic computerized tomography in 18 and 14 patients, respectively. Six scans per minute were performed during 2 minutes and then single scans were taken at 3, 4 and 5 minutes after intravenous bolus doses of 18.5 g iodine. The mean CE and the pattern of washout with these two CM were similar in spite of their different molecular structure and physiochemical properties.

Aortography↗

Dynamic topography of the contrast enhancement of the spleen.

Topographic variations of the contrast enhancement (CE) with time were studied in 74 dynamic CT scans of the spleen. After an 8-10 second bolus of urographic contrast medium containing 18.5 g. iodine, six scans per minute were done through the same section for two minutes, and single scan at 3, 4 and 5 minutes with a scanning time of 5.5 seconds. Early inhomogeneous CE of the normal spleen appearing 0-20 seconds after the peak CE of the aorta was found in 38 of 70 patients due to inhomogeneous parenchymal opacification (capillary phase) (19), delayed opacification of intrasplenic veins (8) or both (10) or due to other causes (1). Inhomogeneous CE in normal structures disappeared after 40 seconds from the aortic peak CE had elapsed, while all four pathological focal splenic lesions of different histology appeared as low density areas in postcontrast scans up to four minutes.

Adult↗

MR T2 relaxometry in Alzheimer's disease and age-associated memory impairment.

A prolonged MR T2 relaxation time was proposed to mark the presence and severity of Alzheimer's disease (AD). We studied the value of T2 relaxometry in diagnosing early AD. T2 was measured from 54 patients with AD, 25 subjects with age-associated memory impairment (AAMI), 18 elderly and 16 young controls. The AD patients had longer T2 in the right hippocampal head (104 +/- 11 ms) and tail (98 +/- 10 ms) than age-matched controls (95 +/- 5 and 92 +/- 9 ms, respectively). This prolongation was not related to age. In the AD group, the T2 of the left hippocampal head also correlated with the clinical severity. The T2 of the amygdala did not differ across the groups. Increased T2 in the temporal and parietal white matter and the thalamus related to increasing age rather than to the diagnostic category. The AAMI subjects had T2 comparable with those of age-matched controls. Despite the prolongation of T2 in the AD group the possible diagnostic value was compromized by a substantial overlap between the study groups. We, thus, conclude that the T2 relaxometry is not a reliable method for diagnosing early AD.

Adult↗

Image processing in digital chest radiography: effect on diagnostic efficacy.

The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512 x 512 image format) viewed on a 625 line monitor were processed in three different ways: (1) standard display; (2) digital edge enhancement for the standard display; and (3) inverse intensity display. The radiographs were interpreted independently by three radiologists. The diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease and 17 cases with pneumonia/atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases, respectively. The sensitivity of conventional radiography when averaged overall findings was better than that of the digital techniques (P less than 0.001). The differences in diagnostic accuracy measured by sensitivity and specificity between the three digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P less than 0.05) but poorer specificity for pulmonary emphysema (0.85 vs. 0.93; P less than 0.05) compared with inverse intensity display. We conclude that when using 512 x 512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted.

Adolescent↗

MRI of the hippocampus in Alzheimer's disease: sensitivity, specificity, and analysis of the incorrectly classified subjects.

In this study, magnetic resonance imaging (MRI) of the hippocampus for the diagnosis of early Alzheimer's disease (AD) is evaluated. We measured hippocampal volumes and the area of the medial hippocampus with a 1.5 T MR imager in 160 subjects: 55 patients with probable AD according to the NINCDS-ADRDA criteria, 43 subjects fulfilling the NIMH criteria of age-associated memory impairment (AAMI), 42 cognitively normal elderly controls, and 20 controls younger than 50 years. Three methods for normalization were compared. The hippocampi were atrophied in the AD patients, but not in the AAMI subjects or the elderly controls. There was no significant correlation between hippocampal volumes and age in the nondemented subjects. The discrimination based on volumetry resulted in an overall correct classification of 92% of AD patients vs. nondemented elderly subjects, whereas discrimination based on hippocampal area was less accurate, producing a correct classification in 80% of the subjects. We conclude that the hippocampus as assessed by MRI volumetry is atrophied early in AD, and spared by aging or AAMI. A brief critical review of previous studies is in concordance with the presented data: all the previous studies that have used volumetry, have similarly ended up with a good classification, whereas simpler or subjective measurements, subject to various sources of bias, have produced most variable results.

Aged↗

Volumes of the entorhinal and perirhinal cortices in Alzheimer's disease.

We measured the volumes of the entorhinal, perirhinal, and temporopolar cortices on magnetic resonance images by using a recently designed histology-based protocol in 30 patients with early Alzheimer's disease (AD) and 32 healthy control subjects. Compared to the controls, all of these cortical regions were significantly atrophied in AD patients (p < 0.0001). However, the entorhinal cortex was the most severely involved brain region studied, with 40% volume loss, and this region provided the highest discriminative accuracy (92%) in separating patients with AD from healthy control subjects. Importantly, the entorhinal volume loss was evident already in mild AD. In addition, the volume of the entorhinal cortex was not dependent on age, but it did correlate significantly with the severity of the disease. Because it assesses the major site of initial neuropathological changes in AD, magnetic resonance imaging volumetric measurement of the entorhinal cortex can offer a tool for distinguishing AD patients even in the very early stages of the disease from healthy aged subjects.

Aged↗

ABH secretion polymorphism in Icelanders, Aland Islanders, Finns, Finnish Lapps, Komi and Greenland Eskimos: a review and new data.

The secretion of the ABH antigens in saliva was tested in indigenous individuals of several populations: Icelanders in Reykjavik and Husavik (northeastern Iceland), Aland Islanders, Finno-Ugrians (Finns, Finnish Lapps, Komi) and Eskimos (Augpilagtok, northwestern Greenland). The frequencies of ABH non-secretors among the Icelanders (28-36%) were among the highest ever noted in Europeans. Among Alanders and Swedes on the Finnish mainland the frequency (around 20%) was comparable to Swedish values but considerably higher than among Finns (13-14%). The values among northeastern Finns and Komi (about 9%) were intermediate between values among Lapps (below 5%) and Scandinavians (15-26%), excluding Icelanders (28-41%). The average frequency of non-secretors among Lapps in Finland (2.2 +/- 0.5%) was the lowest observed among white populations. Like many other arctic populations of the Mongolian race, the Greenland Eskimos had a very low frequency of non-secretors. It is probable that the non-secretor allele ABH*se was absent from the ancient Lapps and Greenland Eskimos but introduced by invading populations. It is concluded that the ABH*se allele frequencies vary much more among northern European populations than hitherto appreciated. Recent studies indicate that the non-secretor status of the ABH blood group substances in mucous body fluids is associated with pathological conditions of the mucous membranes of the embryologically related digestive and respiratory systems, particularly with duodenal ulcer and gastric (pre)malignancies but probably also with pulmonary dysfunction. In view of these disadvantages of the ABH non-secretor status the high frequency of ABH*se in Icelanders is a paradoxical phenomenon. The frequency of ABH non-secretors among the founders (Vikings) of Iceland may have been considerably higher than among the present populations in northwestern Europe. The increase in northwestern direction of the ABH*se allele frequencies supports this hypothesis; the dilution effect has not been as strong in Iceland as on the European continent.

ABO Blood-Group System↗

Dynamic contrast enhancement of the upper abdomen: effect of contrast medium and body weight.

Contrast enhancement (CE) of the aorta, liver, and spleen was studied in dynamic body computed tomography (CT) in 71 patients. Four contrast media (CM) (diatrizoate, ioxithalamate, ioxaglate, iopamidol) were injected intravenously in equal bolus doses of 18.5 g iodine. Iopamidol produced the highest average peak and 2-minute aortic CE, significantly different from ioxithalamate (P less than 0.001), diatrizoate (P less than 0.01), and ioxaglate (P less than 0.0125) at peak levels. Two-minute CE values of the aorta were highest with iopamidol as were peak and 2 minute CE of the liver and spleen. A linear, inverse relationship between body weight and CE was present both at peak CE and after 2 minutes in all tissues. The nonionic CM appear to have best dose efficiency in the vascular phase of dynamic CT. These results are also applicable to digital angiography. Differences in the CE of parenchymal organs with different CM are so small that they are unlikely to have clinical significance.

Aortography↗

Rapidly progressive multifocal leukoencephalopathy with substantial cell-mediated inflammatory response and with cognitive decline of non-Alzheimer type in a 75-year-old female patient.

Autopsy findings of rapidly progressive and widespread multifocal leukoencephalopathy (PML) in a 75-year-old woman with no known predisposing disease are demonstrated. Originally she was given a clinical working diagnosis of syndrome of progressive supranuclear palsy (PSP). The neuropathological investigation revealed widespread white and gray matter changes consistent with PML, and the JC virus was verified by EM, in situ hybridization and immunohistochemistry. In contrast to the few chronic inflammatory cells generally seen in PML in this case there was a substantial cell-mediated inflammatory response reflected in numerous T-helper and T-killer cells. The uncommon, widespread distribution of lesions and substantial cell-mediated response reported might indicate that the rearrangement of viral genome, previously suggested of importance for viral growth in the central nervous system (CNS), is also important for viral spread within the CNS, infectivity of glial cells and for the activation of cell-mediated immunity.

Aged↗

A prospective study of the value of imaging, serum markers and their combination in the diagnosis of pancreatic carcinoma in symptomatic patients.

The diagnostic accuracy of ultrasound (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and tumour markers CEA, CA 50 and CA 242 in pancreatic cancer (n = 26) was studied in 113 patients with jaundice, in 20 patients with unjaundiced cholestasis, and in 60 patients with the suspicion of chronic pancreatitis or a pancreatic tumour. The sensitivities of US, CT and ERCP were 61.9%, 95.2% and 82.3%, the specificities 93.9%, 92.9% and 94.1%, and the efficiencies 91.6%, 96.6% and 92.1%, respectively. The sensitivities of CEA, CA 50 and CA 242 were 92.3%, 96.1% and 61.5%, the specificities 59.2%, 58.0% and 95.2%, and the efficiencies 63.7%, 63.2% and 90.6% respectively. The combined use of the imaging methods and tumour markers was also analysed. When either the imaging method or the serum marker test was required to be positive, the sensitivities of the combinations were clearly better than those of US and CA 242 alone, but only slightly better than those of CT, ERCP or the tumour markers CEA and CA 50 alone. When both the imaging test and the marker test were required to be positive, the specificities of the combinations were clearly better than those of CEA and CA 50 alone, but they did not exceed the specificity of the imaging methods or CA 242 alone. We conclude that CT, ERCP and CEA and CA 50 are highly sensitive in the diagnosis of pancreatic cancer in symptomatic patients, while the sensitivity of US and CA 242 is lower. The specificity of the imaging methods and CA 242 is high, but that of CEA and CA 50 is low. Imaging methods and serum tumour markers could be more used in clinical practice in a complementary manner. In patients with jaundice and/or cholestasis or with a suspicion of pancreatic tumour or chronic pancreatitis, the combined use may yield higher sensitivity than US alone and higher specificity than CEA or CA 50 alone.

Antigens, Tumor-Associated, Carbohydrate↗

Clinical value of serum tumour markers CEA, CA 50 and CA 242 in the distinction between malignant versus benign diseases causing jaundice and cholestasis; results from a prospective study.

A prospective study of 113 patients with jaundice and 20 patients with unjaundiced cholestasis was carried out to evaluate the value of serum tumour markers, carcinoembryonic antigen (CEA) and monoclonal antibodies CA 50 and CA 242, in the distinction between benign and malignant diseases causing jaundice and/or cholestasis. In the patients with malignant disease (n = 37) the serum values of all tumour markers were significantly higher than in the patients with benign disease (n = 96). The sensitivities of CEA, CA 50 and CA 242 in detecting malignancy were 70.2%, 94.5% and 56.7%, respectively, while the specificities were 57.2%, 33.3% and 77.0%, respectively. Serum alkaline phosphatase and bilirubin levels had a high positive correlation with CA 50, and CA 242 correlated positively with serum bilirubin levels. No correlation was seen between CEA and alkaline phosphatase or bilirubin levels. The CEA, CA 50 and CA 242 tests may be used as useful complements to other investigative methods in the distinction between benign and malignant causes of jaundice and/or cholestasis. In particular, the rather high specificity of the CA 242 test for malignant diseases seems promising.

Acute Disease↗

Diagnostic accuracy of ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography in the detection of pancreatic cancer in patients with jaundice or cholestasis.

A prospective study of jaundiced and/or cholestatic patients (N = 220) was carried out to evaluate the diagnostic accuracy of ultrasound (US), computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) in the detection of pancreatic cancer. Thirty-one patients had the final diagnosis of pancreatic cancer and two patients had a cancer of the papilla of Vater. The sensitivities of US, CT and ERCP were 60%, 97%, 89% and specificities were 92%, 92%, 94%, respectively. The differences in sensitivity between US and other methods were statistically significant (US vs. CT p less than 0.01, US vs. ERCP p less than 0.05). In US studies, most false negative results were caused by unsatisfying visualization. On the basis of this study, we recommend CT as a diagnostic test of pancreatic cancer, if pancreatic cancer is suspected as a cause of jaundice and/or cholestasis.

Aged↗

The value of clinical assessment in the diagnosis of icterus and cholestasis.

We studied the reliability of the clinical assessment and the discriminatory value of different symptoms and signs in diagnosing obstructive and non-obstructive diseases causing icterus and/or cholestasis. During a period of two-and-a-half years, clinical assessment done by both physicians-in-training and by senior physicians was completed for 266 patients, and the usefulness of different symptoms and signs was tested in 220 of these. Clinical assessment was found to be a reliable method in distinguishing between obstructive and non-obstructive conditions causing icterus, with the sensitivity of 92% and specificity of 86%. In cases of anicteric cholestasis, the sensitivity and specificity of clinical assessment were 74% and 80%, respectively. Abdominal pain and abdominal tenderness were significantly (p less than 0.01) associated with obstructive diseases, whereas an enlarged liver, fever and excessive consumption of alcohol were associated with non-obstructive diseases (p less than 0.01, p less than 0.05, p less than 0.05, respectively). Itching, vomiting, intolerance to fatty foods, previous cholecystectomy, abdominal tumour and clinical icterus had no discriminatory value. Clinical evaluation is a reliable method in the diagnostic workup of a patient with icterus or anicteric cholestasis, and it is still of crucial importance in directing further investigations.

Cholestasis↗