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Biomedical subjects

A Dimitriadis

Publications and source records attributed to A Dimitriadis.

At least 37 records · Page 2Linked to original sources
PubMed1991

Platinum-based chemotherapy followed by radiation therapy of locally advanced nasopharyngeal cancer. A retrospective analysis of 39 cases.

A retrospective analysis was performed of 39 patients with locally advanced nasopharyngeal cancer treated with combined chemotherapy and radiation therapy during the last five years at our departments. There were 26 men and 13 women with median age 55 (24-75) years. Histology was squamous cell carcinoma in 6 patients and undifferentiated carcinoma in the remaining 33 patients. Induction chemotherapy consisted of either regimen A (cisplatin 100 mg/m2 day 1, 5-FU 1,000 mg/m2 days 2-6 as continuous infusion, bleomycin 15 mg days 15 and 29 i.m., mitomycin 4 mg/m2 day 22 and hydroxyurea 1,000 mg/m2 daily days 23-27) or regimen B (carboplatin 300 mg/m2 day 1, 5-FU 1,000 mg/m2 days 1-5 as continuous infusion and methotrexate 1.2 g/m2 day 14 with leucovorin rescue). After completion of induction chemotherapy 13 patients (33%) had complete remission (CR) and 19 (49%) partial remission (PR). The CR rate was increased after radiation therapy to 72%. Survival rates were 88% at 12 and 78% at 24 months. Median time to progression was 29.5 months. In conclusion, induction chemotherapy with a platinum-based regimen followed by radiation therapy achieved a high rate of local control. If the treatment also prolongs survival must, however, be studied by randomized trials.

Adenocarcinoma↗
PubMed1990

Serotonin in the control of blood pressure and ultrafiltration in CAPD.

Urinary 5-OH-Indoloacetic acid (5-HIAA) indicates the turnover of almost all circulating serotonin (5-HT), a potent vasoactive agent. We tried to investigate the possible excretion of 5-HIAA in the dialysate of CAPD patients and its possible effects on blood pressure control (BP) and/or ultrafiltration (UF). The 24 h excretion of 5-HIAA in the urine of 10 patients with chronic renal failure (CRF) and 8 healthy persons (CONTROL), and in the dialysate of 15 patients on CAPD was measured by FPIA. In CRF 5-HIAA excretion was less than that in control (p less than 0.01). In CAPD patients two distinct patterns of 5-HIAA excretion were found. Patients with high excretion (greater than 6 mg) had high BP and low UF, while those with low excretion (less than 3.14) had low BP, high UF and frequent hypotensive episodes. Excretion of 5-HIAA in the dialysate had a negative correlation with UF (r = -0.779, p less than 0.001) and a positive correlation with B.P. (r = 0.487, n.s.). A highly significant (p less than 0.01) correlation between BP and UF was also found. As no differences between the two groups in factors that could affect UF or BP were found, the implication that 5-HT affects ultrafiltration and/or BP regulation is suggested.

Blood Pressure↗
PubMed1990

Tissue reaction to deep cuff of Tenckhoff's catheter and peritonitis.

To define the type of reaction around the deep cuff of Tenckhoff catheters and possible implications in peritonitis development, a histological evaluation of the tissue reaction around and into the deep cuff was done. Eight catheters, functioning for 2 to 40 months and removed for various reasons were studied. In all cases foreign body granulomata and fibrosis were found, with prominent giant cell formation. An inert birefrigent material, probably dacron particles, was found surrounded by giant cells in fibrotic regions and in some cases appearing as cytoplasmic inclusions. In 6 cases an inflammatory infiltration was observed, while in 4 with relapsing peritonitis, polymorphonuclears and microabscesses were also found. It can be suggested that the tissue reaction to deep cuff predisposes to local infections and might be a factor for relapsing peritonitis.

Adult↗
PubMed1990

[Computer tomography of parotid].

Tumors of the parotis and surrounding tissues can be examined by CT, by CT-sialography ot by intravenous contrast medium injection. In five special cases in which we examined parotis and surrounding tissues we report on our experiences with the methods.

Adenoma, Pleomorphic↗
PubMed1987

[Optic nerve neuropathy following a lightning accident--electrophysiologic and computerized tomography findings].

A case is described in which the patient had been struck by lightning, with involvement of one eye and the visual pathways. Ophthalmological examination revealed a posterior capsule cataract in the right eye and peripheral constriction of the visual field of the left eye, although central vision in the left eye was not affected. The peak latency of the pattern reversal-evoked potentials in the left eye was longer and their amplitude lower. The skin ERG was normal. The CT scan revealed a thickening of the left optic nerve. The importance of electrophysiological and CT scan examination in the diagnosis and etiology of abnormalities caused in the eye by lightning is emphasized.

Adult↗
PubMed1978

Stapes gusher and Klippel-Feil syndrome.

The stapes gusher which is the most dramatic complication of stapedectomy arises from an abnormal communication between the subarchnoid and perilymphatic spaces. This congenital defect may be associated with other anomalies such as the Klippel-Feil syndrome. Two cases of stapes gusher in patients with congenital fixation of the footplate are described. One of them was combined with Klippel-Feil syndrome. The object of this paper is to emphasize the necessity of a complete preoperative examination of all cases of congenital footplate fixation.

Adolescent↗
PubMed1977

[Vagus neurinoma of the basic of the skull and endocranium (author's transl)].

We are discussing a case of neurinoma of the tenth cranial nerve in the area of the base of the skull with endocranial extension in a 51-years-old female patients. The first symptom was hoarseness of the voice, and three years later more cranialnerves were involved (V-VII-X-XI-XII). The existence and the extension of the tumor was verified by radiological examination of the base of the skull, carotic angiography, myelography and scanning; the diagnosis was proved by biopsy. The treatment of choice is the operation because the tumor is radioresistant.

Cranial Nerve Neoplasms↗
PubMedDate not supplied

The relationship between urine volume and drain volume as determinants of fractional urea clearance in continuous peritoneal dialysis.

A logistic regression model developed and validated in Albuquerque identified 24 hr urine volume (UV) and 24 hr drain volume/(body water) (DV/V) as predictors of fractional urea clearance (KT/V) in continuous peritoneal dialysis (CPD). Solution of this model provided DV/V values consistent with KT/V at least equal to a target KT/V for a given UV. The predictive accuracy of these unique DV/V values was tested in urea kinetic studies performed in 108 CPD patients in Thessaloniki and Athens with UV varying between 0 and 2 L/24 h. Two target weekly KT/V values, 1.70 and 1.90, were investigated. The equation DV/V = (5.2811-3.6996 UV)/ 17.554, derived by solving the logistic regression model, detected weekly KT/V > 1.70 (69/108, or 63.9% of the studies) with a sensitivity of 87.3% and a specificity of 60.4%. According to the same equation, the maximal UV consistent with weekly KT/V < or = 1.70 is 1.427 L/24 hr. The equation DV/V = (5.4994-2.6007 UV)/17.007 detected weekly KT/V > 1.90 (44/108, or 40.7% of the studies) with a sensitivity of 90.3% and a specificity of 79.2%. According to this equation, the maximal UV consistent with weekly KT/V < or = 1.90 is 2.115 L/24 hr. Determination of the lowest daily DV consistent with a target KT/V at any daily UV (within a wide range) is feasible in CPD.

Feasibility Studies↗
PubMedDate not supplied

F-waves in evaluating uremic polyneuropathy: a long-term study after the application of continuous ambulatory peritoneal dialysis.

Electrophysiological parameters were studied in 8 patients with end-stage chronic renal failure (CRF). The patients had complete evaluations of the state of CRF, clinical neurological examinations and EMG studies, performed before starting continuous ambulatory peritoneal dialysis (CAPD) as well as 10 days, 2 months and 6 months after initiation of CAPD treatment. All the conventional electrophysiological parameters studied (motor and sensory conduction velocities, terminal latencies, muscle and nerve action potentials) had a tendency to shift towards normal values, the effect being more pronounced in the upper limbs. F-wave maximum and minimum latencies improved quickly in the upper limbs, but very slowly, if at all, in the lower limbs. F-wave frequency became normal in 82% of the median and ulnar nerves, in 75% of the tibial nerves and remained unchanged in the peroneal nerves. F-wave identically, as represented by the "test of multiplicity", showed a general improvement in all nerves, including the peroneal. Studies of F-wave parameters, in addition to improving the diagnostic results, provide a more sensitive method, whereby the effects of CAPD can be examined quantitatively.

Adult↗
PubMedDate not supplied

Continuous peritoneal dialysis in heavyweight individuals: urea and creatinine clearances.

OBJECTIVE: To study whether or not continuous peritoneal dialysis (CPD) can provide acceptable levels of normalized urea and creatinine clearance in heavyweight individuals. DESIGN: Retrospective analysis of urea and creatinine clearance studies. SETTING: CPD patients followed in four dialysis units in Albuquerque, two dialysis units in Thessaloniki, and two dialysis units in Athens. PARTICIPANTS: One hundred and ninety-nine patients on CPD with 266 clearance determinations between 1991 and 1995. INTERVENTIONS: The heavyweight group consisted of 22 patients (24 clearance studies) weighing 100 kg or more (109 +/- 8.7 kg) at the time of the clearance study. All subjects were obese. The reference group consisted of 177 CPD subjects (242 clearance studies) of normal weight (68.7 +/- 12.2 kg). Urea fractional clearance (KT/V) and normalized creatinine clearance (Ccr) were compared between the heavyweight and the reference groups. MAIN OUTCOME MEASURES: The lowest acceptable weekly levels were set at 1.70 for KT/V and 54.4 L/1.73 m2 for Ccr. RESULTS: Weekly KT/V was 1.75 +/- 0.41 in the heavyweight group and 1.94 +/- 0.52 in the reference group (p = 0.047). Corresponding weekly Ccr levels were 64.0 +/- 24.3 and 77.6 +/- 40.3 L/1.73 m2, respectively (p = 0.021). In the heavyweight group, 13 studies (54.2%) had acceptable KT/V values compared to 160 studies (66.1%) in the reference group (NS). Corresponding values for acceptable Ccr were 17 (70.8%) and 165 (68.2%), respectively (NS). Drain volume was 12.96 +/- 4.40 L/24 hours in the heavyweight group and 9.63 +/- 2.58 L/24 hours in the reference group (p = 0.001). High daily exchange volume was delivered by a combination of daily continuous ambulatory peritoneal dialysis (CAPD) and nocturnal automated peritoneal dialysis (APD) in 13/16 heavyweight studies. This combination was tolerated better than any other method of delivering a large daily exchange volume. CONCLUSION: Although normalized urea and creatinine clearances are lower in obese, heavyweight individuals than in lean CPD subjects with lower weight, approximately equal percentages of these two groups achieve acceptable clearance levels. However, heavyweight individuals require larger-than-usual daily exchange volumes. The preferred way to deliver these large dialysate volumes is a combination of daily CAPD and nocturnal APD.

Body Weight↗
PubMedDate not supplied

Fractional urea clearance estimates using two anthropometric formulas in continuous peritoneal dialysis: sex, height, and body composition differences.

OBJECTIVE: To compare estimates of urea volume (V) and KT/V obtained by the Watson and Hume anthropometric formulas, and to identify the similarities and differences between these estimates. DESIGN: Theoretical analysis applying wide variations in the determinants of anthropometric V (age, height, weight) in hypothetical women and men. Analysis of urea kinetic studies performed in patients on continuous peritoneal dialysis (CPD). SETTING: Four dialysis units in Albuquerque, two in Athens, and two in Thessaloniki. PARTICIPANTS: Three hundred and two CPD patients who had 440 urea kinetic studies. INTERVENTION: Standard urea clearance was performed by 24-hour collections of urine and drained dialysate followed by blood sampling. V was estimated by both the Watson and Hume formulas. MAIN OUTCOME MEASURES: Estimates of V and KT/V were compared separately in women and men by Student's t-test, linear regression, and limits of agreement (mean difference +/- 2 SD). The agreement of the KT/V estimates was also tested by the kappa ratio using a value of 1.70 weekly as the lowest acceptable K/TV. RESULTS: The theoretical analysis indicated important disagreement only in extreme variations from the ordinary in height and, to a lesser extent, weight. Differences due to height variation were pronounced only in hypothetical women. CPD patient findings were as follows: in women, Watson V and weekly KT/V were 30.4 +/- 4.4 L and 2.10 +/- 0.61, respectively. Corresponding Hume estimates were 30.3 +/- 5.4 Land 2.1 2 +/- 0.66, respectively. Corresponding estimates for men were 40.5 +/- 5.7 L and 1 .92 +/- 0.57 (Watson) plus 41.4 +/- 5.6 L and 1.88 +/- 0.57 (Hume), respectively. By linear regression, KT/V(Hume) = -0.083 + 1.052 (KT/V(Watson)), r = 0.961 (women); and KT/V(Hume) = -0.026 +/- 0.992 (KT/V(Watson)), r = 0.985 (men). Limits of agreement were -1.41 L and 2.10 L for V, and -0.15 and 0.14 weekly for KT/V. In 94.3% of the cases, KT/V(Watson) and KT/V(Hume) agreed (both > 1 .70 or both < 1 .70 weekly). Kappa ratio was 0.875 (excellent agreement). The concordant and discordant groups differed in height and degree of obesity, in agreement with the theoretical analysis. CONCLUSION: The Watson and Hume formulas provide similar estimates of V and KT/V in CPD patients. Differences may be noted only if women's height or, to a lesser extent, both sexes' weight is at a great variance with the ordinary values.

Adult↗