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Biomedical subjects

P Bagi

Publications and source records attributed to P Bagi.

At least 37 records · Page 2Linked to original sources
PubMed1993

In vivo evaluation of visco-elasticity in a biological tube. Part 2. Application of a mechanical model.

Based on a theoretical model, the urethral stress-relaxation response following a sudden forced dilatation was studied in ten healthy female volunteers. The energy dissipation following a sudden urethral dilatation proved to follow the function Y = Z + C alpha e-t/tau alpha + C beta e-t/tau beta. Hence, a mechanical model was chosen, consisting of two Maxwell elements and one Hooke element coupled in parallel. The decay in force following deformation may be described as F = F(o) exp (-t.E/eta) for each Maxwell element. Thus, it was possible to determine the elastic E and viscous eta coefficients for the participating mechanical equivalents in the model, and thereby quantitatively describe the visco-elastic properties in the urethra. The reproducibility of the elastic and the viscous coefficients proved to be fairly high, and they seemed to be unaffected by the size of dilatation. On the other hand, the rate of dilatation clearly influenced the computed parameters. However, this phenomenon was easily explained by the duration of the deformation, which allowed the viscous elements to move before any measurements were performed. The present method permits in vivo evaluation of the elastic and viscous properties of the urethra, as well as other accessible biological tubes, and may be of value in the description of normal physiological and pathophysiological behaviour of the structures studied.

Adult↗
PubMed1992

Early local stoma complications in relation to the applied suture material: comparison between monofilament and multifilament sutures.

The frequency and character of early complications following creation of enterostomies, and their relation to the applied suture material, were studied in 50 consecutive patients. The stomas were matured by mucocutaneous eversion and were fixated with Maxon (Davis & Geck, Pearl River, NY) 4-0 and Vicryl (Ethicon, Inc., Somerville, NJ) 3-0 sutures. Half of the stoma circumference was sutured with one suture type, and vice versa. Three patients died within 10 days. Of the remaining 47 patients, 34 (72 percent) had one or more complications diagnosed. Four (9 percent) suffered major complications (one total stoma loosening and three partial stoma necroses), and 30 (64 percent) had mucocutaneous affections only. There was no statistically significant correlation between enterostomy type or surgical procedure and complications, whereas the incidence of mucocutaneous complications was significantly higher following fixation with Vicryl as compared with Maxon sutures. The cause of this difference is uncertain; however, the physical configuration of the sutures, Maxon being monofile vs. Vicryl being braided, seems important. Whether the chemical structure is significant as well remains undetermined at present.

Adult↗
PubMed1991

The effect of arteriovenous fistulas on in situ saphenous vein bypasses.

Intraoperative identification and later development of arteriovenous fistulas were investigated prospectively in 70 in situ saphenous vein bypass procedures. Surveillance was performed by completion arteriography and intra- and postoperative continuous wave Doppler examination. The intraoperative Doppler examination identified 89% of those branches with sufficient flow to opacify the deep venous system on completion arteriogram. Half of the missed fistulas underwent spontaneous thrombosis, and in only one case did the arteriovenous fistula lead to hemodynamic symptoms demanding surgical closure of the fistula. Pursuing a policy of selectively ligating fistulas that only fill the deep venous system on completion arteriography led to an additional nine arteriovenous fistulas. Developed over an average follow-up of six months, four patients presented symptoms of edema and swelling and were relieved upon closure of the fistulas. The incidence of bypass thrombosis did not differ significantly among patients with remaining arteriovenous fistulas, patients who developed fistulas during follow-up, and patients who had no signs of arteriovenous fistulas. It seems justified to continue selective intraoperative ligation of arteriovenous fistulas based on continuous wave Doppler.

Adult↗
PubMed1990

[Delayed diagnosis of bronchial foreign body].

An open safety pin was found in the middle lobe bronchus in a 3-year old girl with pneumonia. The point was directed downwards, and the pin could be removed during bronchoscopy. The lock was found to be partly corroded following months in the bronchial tree. The safety pin had thus most probably been closed when aspirated, and had thereafter remained silent until its spontaneous opening.

Bronchial Diseases↗
PubMed1990

Doppler waveform analysis in evaluation of occlusive arterial disease in the lower limb: comparison with distal blood pressure measurement and arteriography.

Three Doppler waveform parameters were related to ankle/brachial systolic pressure (A/B) index and angiography in 75 patients with lower limb arterial occlusive disease (AOD). Doppler signals were obtained from ankle arteries, and following spectral analysis pulse rise time (PRT), systolic width (SW) and pulsatility index (PI) were calculated. All three waveform parameters were significantly correlated with A/B index, and a 20% reduction could be predicted with an accuracy of 93 to 80% (corrected for chance, kappa, 81 to 52%). A significant correlation was also found between the three Doppler parameters and the angiographic assessment, i.e. the non-diseased, single- and multisegmentally diseased limbs, however, the accuracy in diagnosing angiographic stenoses was not as good as when pressure measurement was used for reference. Thirteen of the patients had high ankle pressures despite significant angiographic stenoses, and generally the Doppler examination was normal in these cases. Considering the waveform parameters individually, PRT and SW demonstrated almost identical results when compared to pressure measurement as well as angiography, whereas PI seemed clearly inferior. It is concluded that simple Doppler waveform parameters may accurately predict the haemodynamic significance of proximal AOD.

Angiography↗
PubMed1990

Venous muscle pump function during pregnancy. Assessment by ambulatory strain-gauge plethysmography.

The venous muscle pump function was quantitatively assessed through pregnancy weeks 16, 30, 38 and 3 months (week 53) following delivery, in 24 pregnant women who completed a normal pregnancy. A statistically significant increase was found in the mean venous reflux (P less than 0.01), which was restored to initial values postpartum. Expelled calf volume remained stable throughout pregnancy but increased following delivery. Venous outflow from the legs was significantly reduced in the third trimester. Subjective symptoms of venous insufficiency increased through pregnancy, but, these symptoms had virtually disappeared post partum, corresponding to the muscle pump normalization. No statistical correlation was found between venous muscle pump values and changes in hormone concentrations of estradiol, estriol and progesterone. It is suggested that venous insufficiency development in pregnancy is caused primarily by mechanical obstruction, or hormonal influence other than that of estradiol, estriol or progesterone. 17% (4.7-37%) of the women with a normal pregnancy developed a pathological venous muscle pump function.

Adult↗
PubMed1990

Laser treatment of recurrent urethral condylomata acuminata in men.

Fifty-six consecutive men with recurrent condylomata acuminata of the urethra and possibly also of the external genitalia were treated with carbon dioxide or ND: YAG laser or both. In all patients previous conservative treatments had failed. Half the patients responded completely to a single treatment and 86% to a maximum of three treatments. No important side effects were encountered, and the cosmetic results have been excellent.

Adolescent↗
PubMed1989

Laboratory aid in the diagnosis of acute appendicitis. A blinded, prospective trial concerning diagnostic value of leukocyte count, neutrophil differential count, and C-reactive protein.

The diagnostic value of C-reactive protein (CRP), total white blood cell (WBC) count, total neutrophil count, and neutrophil differential count were evaluated in a prospective blinded study of 204 patients submitted with the tentative diagnosis of acute appendicitis. The laboratory tests were performed on blood samples obtained at the time of admission, and the results were stored until the patients were discharged. One hundred patients were operated on: 59 had appendicitis, 3 had other surgically correctable diseases, and 38 had a superfluous exploration. All 104 nonoperated patients recovered spontaneously. The sensitivity, specificity, and predictive values of single tests and test combinations were calculated at different cutoff levels. Using standard reference intervals, WBC count demonstrated the best sensitivity (83 percent) and predictive value of a negative result (88 percent). Combining the tests by an "or" rule enhanced the sensitivity to 100 percent, employing WBC count or CRP or neutrophil percentage above the reference range (triple test), but at the expense of the predictive value of a positive test (37 percent). It was concluded that both single tests and combined tests are of limited value in predicting acute appendicitis. However, the same triple test combination proved a predictive value of a negative result at 100 percent (95 percent confidence limits 92 to 100 percent), indicating that acute appendicitis is unlikely when these tests are simultaneously negative. The triple test combination was valid in 32 percent of the patients who were free from appendicitis. In the study group, 10 of the patients (25 percent) who had a superfluous exploration had a negative triple test, and they might have avoided surgery if it had been used. Therefore, the triple test is recommended as a help in reducing the significant rate of negative laparotomies in patients suspected of having acute appendicitis.

Acute Disease↗
PubMed1989

Real time B-mode mapping of the greater saphenous vein.

Real time ultrasound mapping of the greater saphenous vein (GSV) was performed in 30 consecutive patients admitted for in situ femoro-crural revascularisation. The overall accuracy in predicting the adequacy of the GSV for in situ bypass was 90%. The predictive value of finding the vein usable was 96%, whereas the predictive value of judging the vein inadequate was 50%. The scanning procedure provided morphologic information about the GSVs, including size, tributaries, varicosities, and double segments, which may prevent unnecessary dissection and may further shorten the duration of surgery. In our opinion the technique is sufficiently accurate to replace phlebography for the routine preoperative assessment of GSV in patients considered for in situ bypass. Veins judged inadequate at scanning, however, should be further evaluated.

Adult↗
PubMed1988

Quantitative Doppler ultrasound evaluation of occlusive arterial disease in the lower limb.

Forty consecutive patients with lower limb arterial disease were evaluated using a multi-gated pulsed Doppler system. Doppler signals were sampled at 4 sites in each limb, and following spectral analysis, the pulse rise time (PRT) was measured. The value obtained at the location giving the longest duration of PRT was used for comparison with ankle/brachial pressure index (A/B index) and angiography. A highly significant correlation was found between PRT and A/B index (r = -0.75, P less than 0.001). Based on receiver operating characteristic curves an overall diagnostic accuracy of 90% in diagnosing a pressure reduction greater than 20% was obtained. The diagnostic accuracy in detecting an angiographic stenosis greater than 50% was almost identical. Based on combined quantitative and qualitative analysis of Doppler signals sampled at the common femoral and popliteal artery, the aorto-iliac segments and the femoro-popliteal segments were evaluated separately. Comparison with arteriography revealed overall accuracies of 96% in the aorto-iliac segments and 87% in the femoro-popliteal segments. It is concluded that simple quantitatively measurable parameters in the Doppler spectrum may accurately predict and localize hemodynamically significant arterial lesions of the lower extremities.

Adult↗
PubMed1988

Evoked acoustic emissions from the human ear. IV. Final results in 100 neonates.

Evoked acoustic emissions were recorded from both ears in a series of 100 consecutive normal newborns. We used the same stimulus, a 2-kHz click, and recording technique as previously described. Analysis of the data showed that evoked emissions could be identified in all ears, except one at 70 dBaud (i.e. approximately 30 dB nHL). No significant differences could be demonstrated between males and females or between left and right ears with regard to the latency of the emissions, the peak-to-peak amplitude, the main frequency component, or the waveform correlation between the two 70 dBaud recordings in each ear. However, a significant correlation between left and right ears was found for the amplitude and frequency of the emissions. Practical and methodological problems related to the recording were elucidated. The tail of the stimulus artifact sometimes interfered with the first part of the emissions even though the recordings were made in a time window delayed 5 ms relative to the stimulus onset. We tried to solve this artifact problem by different off-line techniques, but found no useful solution. We therefore continued to use only a cosine tapering of the first 2 ms of the time window. Three different ways of determining latencies were evaluated and we found that the 'envelope' technique was the most simple and reliable. Recording of evoked acoustic emissions is a quick and non-invasive method and provided that the presence of the emissions is related to normal cochlear function, it can be used as a screening test in newborns.(ABSTRACT TRUNCATED AT 250 WORDS)

Audiometry, Evoked Response↗
PubMed1988

Early secondary suture versus healing by second intention of incisional abscesses.

A controlled trial was set up to compare the treatment of wound abscesses, occurring after laparotomy, with either early secondary suture combined with cefuroxime and metronidazole given intravenously or by healing by second intention. The secondary suture was performed two days after wound drainage and resulted in a significant reduction (p less than 0.01) in healing time without complications. No reinfections occurred.

Abscess↗
PubMed1987

Percutaneous drainage of appendiceal abscess. An alternative to conventional treatment.

Twenty-seven consecutive patients with ultrasonically verified appendiceal abscesses, measuring from 2 to 10 cm in diameter, were studied. Ultrasonically guided percutaneous drainage was performed in 19 by means of one to five punctures, and in eight with one or two catheters. In 16 and 7 patients, respectively, the abscesses resolved without further intervention. Four patients were operated on, two for suspected (but unverified) abscess perforation, one for bowel obstruction, and one because of failed drainage, resulting in a success rate of 85 percent. Hospitalization ranged from 3 to 23 days; however, normal sonograms were not obtained until after nine to 62 days. Follow-up revealed no diagnostic errors. Two patients (8 percent) had recurrent appendicitis, and late sequelae were observed in four patients, three of these after surgery. Ultrasonically guided percutaneous drainage of appendiceal abscesses with the technique described is indicated whenever feasible, as a safe, gentle, and relatively atraumatic procedure with few complications and late sequelae.

Abscess↗
PubMed1987

The prognostic significance of virus-associated changes in grade 1 cervical intra-epithelial neoplasia.

Virus-associated changes of the cervix uteri were assessed in patients treated for grade 1 cervical intra-epithelial neoplasia (CIN). Of 106 patients evaluated, 67 (63%) had virus-associated changes. The patients were treated without regard to the presence/absence of virus-associated changes. In 26 patients the treatment was unsuccessful (persistence, recurrence, or progression of the neoplasia). The frequency of treatment failure was 33% in patients with, and 10% in patients without virus-associated changes (p less than 0.025). It is recommended that patients with CIN 1 and virus-associated changes should, after initial treatment, be followed-up with increased attention.

Adolescent↗
PubMed1987

Surgical treatment of anuria caused by renal artery occlusion. Case report.

A patient with anuria caused by renal artery occlusion is presented. Revascularization was performed 42 days after onset of renal failure, and resulted in complete normalization of kidney function. The case demonstrates that surgical treatment of prolonged renal artery occlusion with subsequent return of renal function is possible.

Aged↗
PubMed1987

Ureteric obstruction as a complication to the appendicular abscess. Case report.

In three patients an appendicular abscess caused right-sided ureteric obstruction, and temporary decompression of the upper urinary tract was necessary in two. All recovered completely following combined appendectomy and drainage of the abscess. Since early treatment is essential, the possibility of obstructive uropathy must be kept in mind in the treatment of the appendiceal abscess, especially when nonoperative management is favored.

Abscess↗