Optically Excited Entangled States in Organic Molecules Illuminate the Dark.

We utilize quantum entangled photons to carry out nonlinear optical spectroscopy in organic molecules with an extremely small number of photons. For the first time, fluorescence is reported as a result of entangled photon absorption in organic nonlinear optical molecules. Selectivity of the entangled photon absorption process is also observed and a theoretical model of this process is provided. Through these experiments and theoretical modeling it is found that while some molecules may not have strong classical nonlinear optical properties due to their excitation pathways; these same excitation pathways may enhance the entangled photon processes. It is found that the opposite is also true. Some materials with weak classical nonlinear optical effects may exhibit strong non-classical nonlinear optical effects. Our entangled photon fluorescence results provide the first steps in realizing and demonstrating the viability of entangled two-photon microscopy, remote sensing, and optical communications.

The effects of calcium dobesilate on the mechanical function of rat hearts.

AIM: Calcium dobesilate is an angio-protective agent that has positive effects on hemorheological parameters. It decreases blood and plasma viscosity, thrombocyte aggregation, and microvascular hyperpermeability. It is an antioxidant that increases endothelial-derived vasodilator substance secretion. In this experimental study, the effects of calcium dobesilate on myocardial ischemia reperfusion injury were investigated. METHODS: Using the Langendorff setup, 24 adult Wistar albino rat hearts were perfused. MeanP (mean pressure perfusing the coronary arteries), PSP (maximum left ventricle pressure), +dp/dt(max) (change in contraction power over time), -dp/dt(max) (change in relaxing power over time), PP (peak systolic pressure-minimum balloon pressure) and bpm (number of heart beats per minute) were evaluated. The control group (N.=6) was perfused with Tyrode solution alone. The other three groups (N.=6 for each group) were perfused with the Tyrode solution and calcium dobesilate either before ischemia, during the ischemia reperfusion period, or during the reperfusion-only period. RESULTS: The meanP values were significantly higher in groups perfused by calcium dobesilate. For other parameters, calcium dobesilate did not demonstrate a positive effect. CONCLUSIONS: This study showed that calcium dobesilate may have cardio-protective effects in isolated, perfused rat hearts. In hearts perfused by calcium dobesilate, the increase in mean P may be explained by the increase in endothelium-derived vasodilator substances. Further studies are needed to better characterize the myocardial protective effects of calcium dobesilate.

Effect of combining phosphodiesterase III inhibitors with St Thomas Hospital's solution used as transplantation preservative solution in isolated rat hearts.

Improved preservation of the harvested heart with attenuation of the reperfusion injury is important for successful outcomes of cardiac transplantations. The most commonly used cardioplegic solution, to prevent ischemic changes has been St Thomas' Hospital cardioplegic solution (STHCS). However, it is neither ideal nor sufficient to prevent myocardial ischemia and reperfusion injury. Phosphodiesterase inhibitors can attenuate the damage due to the injuries of ischemia and reperfusion. In this study we sought to enrich STHCS with a phosphodiesterase inhibitor to improve preservation of cardiac functions. The harvested hearts of 24 rats were divided into four groups. All hearts were mounted on a Langendorff perfusion system. After a stabilization period, cardiac arrest was maintained by STHCS. The hearts were stored in STHCS alone or with milrinone, amrinone, or enoximone for 6 hours. The reperfusion was maintained using a modified Tyrode's solution. All hearts were compared for their preischemic and postischemic left ventricular developed pressure, +dp/dtmax, -dp/dtmax, duration of systole, ejection time, and time to reach peak systolic pressure. Coronary effluent was collected for lactate dehydrogenase (LDH) measurements. The initial values for all metrics were comparable between the groups. During the postreperfusion period, all hearts showed lower peak systolic pressures than the initial values. Although the amrinone group seemed to have higher values, the 25-minute result was at the border of significance and the 30-minute value, significantly higher. All hearts showed far lower results of maximum changes in contractility during the time period (+dp/dtmax) versus the initial values; comparisons between groups were not significant. For the parameter of maximum changes in relaxation during the time period (-dp/dtmax), while other hearts showed lower results, the amrinone group displayed values comparable to the initial ones after 20 minutes. Comparisons between groups were insignificant. While other hearts had comparable values for time of systole, the hearts applied with milrinone reached these values after 15 minutes. Group comparison for time of ejection revealed that the results at 5-minute postreperfusion were higher in the enoximone and the amrinone groups than the milrinone group. Postreperfusion 5-minute results were higher in the enoximone and the amrinone groups than the milrinone group for time to reach peak systolic pressure. LDH levels were lowest in the amrinone group. In conclusion, our study revealed that adding phosphodiesterase inhibitors to STHCS improved peak systolic pressure and maximum changes in relaxation during the time period (-dp/dtmax, mm Hg/s). It also decreased the LDH leakage, which corresponded to the degree of ischemic tissue damage. Amrinone seemed to result in more favorable results, which may be attributed to its additional effects on inflammation, including those on cytokines and leukocyte aggregation.

The role of antioxidant supplementation in cardiac transplantation: an experimental study in rats.

BACKGROUND: We investigated three antioxidants, inositol hexaphosphate (IP6), superoxide dismutase (SOD), and catalase (CAT), using a Langendorf model of heart transplantation. METHODS: Rat hearts were mounted on a Langendorf perfusion apparatus with addition of IP6, SOD+CAT, IP6+SOD+CAT to St. Thomas Hospital solution (n=6 for each) versus a control group (n=6), not containing supplementation. Global ischemia was achieved for 6 hours. RESULTS: The worst peak-to-peak (PP) and +dp/dt maximum values were observed in the IP6+SOD+CAT group, the values being significantly lower than those in the SOD+CAT group. The lowest plasma creatine kinase (CK), CK-muscle-band (CK-MB), and lactate dehydrogenase levels were measured from the SOD+CAT group. The highest values for CK were in the control group, and those for CK-MB were in the IP6 group. The lowest myocardial malondialdehyde and adenosine triphosphate values were observed in the SOD+CAT group. CONCLUSIONS: Supplementing St. Thomas Hospital solution with IP6 did not ameliorate myocardial damage following global ischemia. The contractility deteriorated further when IP6+SOD+CAT were used together; however, SOD+CAT improved cardiac mechanical functions, and significantly reduced myocardial damage.

Effects of bupivacaine used with sevoflurane on the rhythm and contractility in the isolated rat heart.

BACKGROUND AND OBJECTIVE: The effects of sevoflurane on bupivacaine cardiotoxicity are mainly attributed to systemic effects. The purpose of this study was to investigate the direct myocardial effects of sevoflurane on bupivacaine toxicity. METHODS: Hearts of 30 Wistar albino rats were isolated and mounted on a Langendorff apparatus perfused by modified Tyrode solution. Experimental groups were: a sevoflurane group (Group S, n = 10)--following baseline and 20 min (Stage 1) recordings, sevoflurane was added in doses of 1.4% (1 MAC) and 2.8% (2 MAC). In the two bupivacaine groups, bupivacaine 5 micromol (Group B5, n = 10) and bupivacaine 10 micromol (Group B10, n = 10) was added to the solution at Stage 1, and sevoflurane was added to the system as in Group S. Haemodynamic variables, i.e. heart rate, PR interval, QRS duration, left ventricular systolic pressure, contractility (+dp/dtmax), relaxation, time to reach peak systolic pressure, change in left ventricular diastolic pressure from baseline, and rate-pressure product were recorded. RESULTS: In Group S, there was no change in cardiac rhythm. In bupivacaine groups, severe rhythm disturbances occurred and both the PR intervals and QRS complexes were prolonged significantly. All contractility variables deteriorated and the rate-pressure product decreased by 67-90% with the addition of bupivacaine. In all groups, 2 MAC sevoflurane lowered +dp/dtmax further. CONCLUSIONS: Sevoflurane does not have any untoward effect on bupivacaine-induced cardiotoxicity in clinically relevant doses in the isolated rat heart.

No beneficial effects of isocolloidoosmotic synthetic colloid addition to St. Thomas Hospital cardioplegic solution in ischemia-reperfusion injury in isolated perfused rat hearts.

1. Cardioplegic solutions provide the opportunity to operate on a nonbeating heart and to protect the heart against ischemic injury during cardiac surgery. The components of these solutions are constantly being modified in an effort to find the optimal solution. We studied the effects of colloidal volume replacers such as dextran, HES and gelatin as an isocolloidoosmotic addition to St. Thomas Hospital cardioplegic solution in ischemia-reperfusion injury of isolated rat hearts. 2. In the control group, after a stabilization period of 20 min, the hearts were arrested with St. Thomas Hospital cardioplegic solution for 3 min, then subjected to 30 min of global ischemia. Hearts then were reperfused for 10 min. In the experimental groups, the protocol was the same, but either HES 200/0.5 (50 g/L), modified fluid gelatin (30 g/l) or dextran 70 (25 g/L) were added to the St. Thomas Hospital solution. 3. All hearts were compared for their preischemic and postischemic contractility, heart rate, contractility rate product, coronary flow, lactate dehydrogenase, creatine phosphokinase enzyme leakage and wet/dry weight ratio. 4. All groups had similar contractility (for control, HES, gelatin and dextran groups the values at minute 10 of reperfusion were 59+/-9, 56+/-11%, 61+/-14%, 49+/-14% of initial values [P>0.05, respectively]) and enzyme leakage (lactate dehydrogenase 4.1+/-1.0, 8.1+/-1.5, 5.8+/-1.4, 3.7+/-1.2 [P>0.05] and for creatine phosphokinase 3.9+/-2.5, 6.4+/-3.7, 5.5+/-1.3, 5.5+/-0.8, P>0.05] IU xmin(-1) x g dry tissue(-1) in the reperfusion period, respectively) results as compared with the control group. 5. The addition of isocolloidoosmotic colloids to the cardioplegic solution did not appear to enhance the effectiveness of the crystalloid St. Thomas Hospital cardioplegic solution. If a colloid is to be chosen as a plasma replacer or an additive to priming solution in the preoperative period, or during open-heart surgery, it should be modified fluid gelatin-for no sign of cardiodepression was determined with the use of this agent.

Direct cardiac effects in isolated perfused rat hearts measured at increasing concentrations of morphine, alfentanil, fentanyl, ketamine, etomidate, thiopentone, midazolam and propofol.

The direct cardiac effects of morphine, alfentanil, ketamine, etomidate, thiopentone, midazolam and propofol were measured in isolated Wistar rat hearts. Experiments were performed using a multiple columnar Langendorff apparatus and the hearts were perfused with a modified Tyrode solution under constant pressure. Each drug was applied from a different column in rising concentrations at 5-min intervals. Dose ranges were chosen to compare effects at sub-clinical, clinically relevant and more than clinical concentrations. Six rat hearts were chosen at random for each drug. Only thiopentone reduced contractile force at a clinically relevant concentration: measured as g contractility per g heart weight-1 (mean +/- standard deviation), base-line contractility was 8.8 +/- 2.4, and contractility at 10(-4) mol litre-1 thiopentone was 7.1 +/- 1.5 (P < 0.01). Alfentanil was the only drug to have no significant effect on the isolated heart at any concentration. Propofol was not cardiodepressant at clinically relevant concentrations, but had a lower therapeutic range than the other drugs.

Midazolam is a safe agent by comparison with thiopentone on arrhythmias in ischaemia and reperfusion conditions in isolated perfused rat hearts.

Arrhythmia due to ischaemia and/or reperfusion is an important problem, especially in open heart surgery and for patients with ischaemic heart diseases undergoing non-cardiac surgery. This experimental study is planned to evaluate the effects of midazolam on ischaemia and/or reperfusion-induced arrhythmias by comparison with thiopentone in two sets of experiments (n = 20 for every group). In total ischaemia-reperfusion experiments, hearts were perfused in constant pressure conditions. In the control group, after a stabilisation period, perfusion was totally stopped for 30 min and the hearts were reperfused for 10 min. For the experimental groups, hearts were pretreated for 5 min with either 10-6 mol 1-1 midazolam or 10-5 mol 1-1 thiopentone before total ischaemia and reperfused for 10 min with the same concentrations of the drugs. In low-flow ischaemia-reperfusion experiments, hearts were perfused at a constant flow of 10 ml g-1 heart per min initially. In the control group, after a stabilisation period, perfusion rate was decreased successively 1 ml g-1 heart per min for 10 min (mild ischaemia) and to 0.2 ml g-1 heart per min for another 10 min (severe ischaemia). The ischaemic hearts were then reperfused for an additional 10 min at a flow rate of 10 ml g-1 heart per min. Electrogram recordings were evaluated before ischaemia and at the 5th and 10th min of mild ischaemia, severe ischaemia and reperfusion. Midazolam, 10-6 mol 1-1, or thiopentone, 10-5 mol 1-1, were added to the perfusion solution in the midazolam and thiopentone groups, respectively. In these two groups, hearts were perfused according to perfusion rates mentioned above in the control group. As a commonly used i.v. anaesthetic, thiopentone was arrhythmogenic for hearts exposed to ischaemia-reperfusion by increasing ventricular premature beat (% incidences for control, midazolam and thiopental groups in the 10th min of reperfusion were 25, 15 and 65 in total ischaemia-reperfusion experiments, P < 0.01) and ventricular tachycardia (respective % incidences were 0, 5, 25, P < 0.05) incidences, but in our experiments were found out that the new agent midazolam does not have more arrhythmia incidence than the respective control group in any criteria evaluated. None of the agents exerted atrioventricular conductance abnormalities. So we conclude that midazolam is a safe agent for ischaemic hearts and might also be antiarrhythmic and the mechanism of action of this effect remains to be further investigated.

Human albumin enriched St. Thomas Hospital cardioplegic solution increases reperfusion injury in isolated perfused rat hearts.

In open heart surgery it is very important to protect the heart during the ischaemic period in terms of mortality and morbidity. Many different cardioplegic solutions are in clinical use without being tested experimentally. In this study we intended to investigate the effects of albumin addition to St. Thomas Hospital cardioplegic solution on cardiac protection to ischaemia. Rat hearts were isolated and perfused in Langendorff apparatus (n = 6 for each group). After the stabilisation period, the hearts in the control group were arrested with St. Thomas Hospital cardioplegic solution for 3 min then subjected to 30 min of global ischaemia in cardioplegic solution, this is followed by reperfusion for 10 min. In albumin groups, the experimental protocol was the same but 2.25%, 4.5% or 9% human albumin was added to the cardioplegic solution. All of the hearts were compared for their pre-ischaemic and post-ischaemic contractility, heart rate, coronary flow, LDH and CK enzyme leakage, and wet/dry weight ratio values. The contraction, heart rate (P < 0.01 for both), and coronary flow (only for the 9% albumin group, P < 0.05) values in the albumin group were less than the control group during the reperfusion period. There was no difference between groups in LDH, and CK leakage, and wet/dry weight ratio. The circulation of ischaemic hearts in the albumin group were diminished, possibly due to protein precipitation. This condition negatively affected the performance of the heart. The fact that there is no difference in enzyme leakage and wet/dry weight ratio, indicates that this event is not irreversible.

Methods to enhance in vivo urothelial growth on seromuscular colonic segments in the dog.

PURPOSE: We demonstrated survival and expansion in vivo of urothelial free autografts on demucosalized seromuscular segments. MATERIALS AND METHODS: Four methods of in vivo urothelial expansion were investigated on demucosalized colonic segments in the canine model. Group 1 underwent colonic mucosal removal by manual stripping, group 2 underwent removal of colonic mucosa and submucosa, and group 3 underwent manual stripping of the colonic mucosa followed by treatment with protamine sulfate and urea. In the 3 groups urothelial autografts were then placed on the seromuscular segment and tubularized over a balloon splint. In group 4 the colonic mucosa was removed but the grafts were not tubularized. Instead the colonic segment was sutured to the parietal peritoneum. RESULTS: Group 4 grafts had no epithelial growth and shrinkage of the bowel segment. Group 1 grafts had minimal growth with no expansion and colonic mucosal regrowth. Group 2 grafts demonstrated growth and expansion, although these colonic segments had a significant inflammatory response and fibrosis. Group 3 grafts had the best growth and expansion with the least inflammatory response, and 1 colonic segment was almost completely covered with urothelium. CONCLUSIONS: We demonstrated in vivo expansion of urothelial autografts grown on seromuscular colonic segments. Preservation of the submucosa is essential to prevent fibrosis of the seromuscular colonic segment and a balloon stent is crucial to prevent graft contraction. Treatment of the demucosalized segment with protamine sulfate and urea results in better urothelial expansion and less colonic mucosal regrowth.

The role of isocolloidoosmotic synthetic colloid addition to St. Thomas Hospital cardioplegic solution for cardioprotection in isolated perfused rat hearts.

Cardiac transplantation is a prominent development in the treatment of patients with severe cardiac diseases. If it is not possible to transplant the heart immediately after removing it from the donor, procedures for preparing, protecting, storing and transferring of the heart constitute a major portion of this study. Selecting the best method among those used for cardioprotection is still been debated. This experimental study investigated whether isocolloidoosmotic solution in addition to St. Thomas Hospital cardioplegic solution would give better cardioprotection. Wistar rat hearts were isolated and perfused by the Langendorff method (n = 6 for each group). In the control group after stabilisation, the hearts were arrested while perfused with St. Thomas Hospital cardioplegic solution for 3 min, then they were placed in cardioplegic solution at 4 degrees C for 6 h. Afterwards the hearts were reperfused. In the experimental groups, modified gelatin fluid (30 g/l) or HES 200/0.5 (50 g/l) or dextran 70 (25 g/l) was added to the cardioplegic solution. Maximum contractility, +dF/dtmax, -dF/dtmax, heart rate, contractility rate product, coronary flow and lactate dehydrogenase, creatine phosphokinase enzyme leakage were measured in all groups during pre-ischemic and post-ischemic periods (10 min after reperfusion). At the end of each experiment, the hearts were weighted and tissue levels of lipid peroxide, expressed in terms of thiobarbituric acid reactive substances, malondialdehyde, glutathione (an important intracellular antioxidant) and ATP were measured. Non-ischemic tissue levels of malondialdehyde, glutathione and ATP were also measured in another group (n = 6). There was no statistically significant difference among the simultaneous experimental and control groups in any criteria evaluated (P > 0.05). The addition of synthetic colloids to the standard cardioplegic solution did not provide further protection except for the gelatin group in which recovered contractile force was not significantly different from the group's initial values. This effect may be explained by its degradation to amino acids which may play a substrate role.

Benefits of supplementing St Thomas' Hospital cardioplegic solution with tetraethylammonium on functional and metabolic recovery of isolated rat hearts.

This study was designed to evaluate whether the addition of potassium channel blockers, tetraethylammonium, 4-aminopyridine or glibenclamide, to St Thomas' cardioplegia improved myocardial preservation over that achieved by St Thomas' cardioplegic solution alone. Initially, isolated rat hearts were subjected to 30 min of continuous normothermic hypoxic cardioplegia. Control hearts were arrested with St Thomas' cardioplegia followed by tetraethylammonium, glibenclamide or 4-aminopyridine-enriched cardioplegia. Subsequently, in a second experiment, hearts were subjected to 45 min of normothermic global ischaemia, after 3 min of cardioplegia with either tetraethylammonium-enriched or standard St Thomas' cardioplegia. In both regimens, hearts arrested with tetraethylammonium-enriched St Thomas' cardioplegia showed better recovery of contractile function than controls (P<0.001). Creatine kinase levels were significantly lower in the tetraethylammonium group (P<0.001). 4-Aminopyridine treatment caused similar contractility to that of the control group but raised creatine kinase and lactate dehydrogenase levels (P<0.001). Glibenclamide diminished coronary flow autoregulation, and increased lactate dehydrogenase leakage in reperfusion (P<0.05) with similar contractility to controls. The results of this preliminary in vitro study demonstrate that, in rat heart, St Thomas' cardioplegia enriched with tetraethylammonium improves post-ischaemic contractile function and reduces creatine kinase release. It is concluded that high potassium blocks the membrane at the rapid depolarization phase with rapid sodium influx and tetraethylammonium further prevents repolarization by blocking voltage-dependent potassium channels.

Results of the Mitrofanoff procedure in urinary tract reconstruction in children.

OBJECTIVES: To evaluate the success and long-term complications associated with the use of continent catheterizable conduits based on the Mitrofanoff principle in children. PATIENTS AND METHODS: The records of 43 patients (21 female and 22 male) who underwent the construction of a continent catheterizable stoma based on the Mitrofanoff principle between 1987 and 1996 were reviewed retrospectively. The mean age at surgery was 10 years (range 3-21) and the mean follow-up was 3 years (range 0.5-6.5). Twenty-eight of the 43 children underwent augmentation cystoplasty in conjunction with the Mitrofanoff procedure, using ileum in 17, sigmoid in seven, caecum in two and stomach in one; detrusormyectomy was performed in one child. Fifteen patients had only a continent catheterizable stoma formed. The most common type of conduit was appendicovesicostomy (36 of 43 children): other conduits were constructed with ureter (four), tapered ileum (two) and fallopian tube (one). RESULTS: Stomal continence was achieved in 42 of 43 patients (98%). The most common late complication was difficulty in catheterization, which occurred in 14 patients (32%). Stomal prolapse requiring revision occurred in one patient (2%). Conduit dilatation was initially attempted in all patients with difficult catheterization, although it failed in 11 who then required surgical revision. Therefore, the overall revision rate was 28% (12 of 43). The site of stomal placement (umbilical or abdominal) did not significantly influence the risk of difficulty with catheterization. CONCLUSION: The Mitrofanoff procedure can simplify catheterization in children who are dependent upon intermittent catheterization. The vermiform appendix appears to be the best source for constructing the conduit. While stomal continence is excellent, conduit stenosis remains a frequent complication regardless of stomal location.

Activity of the enzymes participating in purine metabolism of cancerous and noncancerous human kidney tissues.

In this study, activity of some of the key enzymes participating in purine metabolism was measured in cancerous and noncancerous human kidney tissues from 18 patients with renal cell carcinoma. Twelve cancerous tissues were at stage T1-T2 and 6 tissues were at stage T3-T4. Adenosine deaminase (ADA) and guanase (GUA) activity was increased and xanthine oxidase (XO) activity decreased in cancerous tissues compared to noncancerous ones. No difference was, however, found between 5'-Nucleotidase (5'-NT) activity of the tissues. There were also no statistically meaningful differences between the enzyme activities of the cancerous tissues at stage T1-2 and T3-4. Results suggest that the changes observed in the activity of the enzymes participating in purine metabolism result from accelerated DNA turnover in the cancerous tissues and cells, and these changes might provide selective advantage, possibly by causing acceleration of salvage pathway activity, to the cancer cells to grow and develop more rapidly.

In vitro drug sensitivity testing of human testicular germ cell tumours with cytostatic drugs and interferon alpha-2b.

In spite of the significant advances in the chemotherapy of germ cell neoplasms, some patients do not achieve disease-free status and ultimately die from their diseases. Therefore, it is reasonable to select the best chemotherapeutic agents in these patients by in vitro drug sensitivity assay (IVDSA) in order to apply the most effective agent in case of resistance to primary chemotherapy. Fresh operative cells from 12 testicular germ cell tumours (TGCT) were cultured in vitro. Sensitivity of the tumour cells to interferon-alpha (IFN-alpha), cisplatin, mitomycin C, vinblastine, doxorubicin, etoposide, bleomycin, vincristine (VCR) were tested by a colorimetric assay using MTT. A preexposure viability over 75% was essential for IVDSA. Sensitivity was determined by a more than 50 +/- 2 SD% reduction from the control absorbance. All eight drugs in their high concentrations exhibited cell proliferation inhibition in 83.3 +/- 100% of TGCT. But in low concentrations efficacy of IFN and VCR were found to be lower than the others (33.3% and 58.3%, respectively). The results indicated that although TGCT are highly sensitive to various agents IVDSA may help to identify the effective agents which might be necessary for second line chemotherapy in a small percentage of patients.

Stone disintegration: effect of shock wave projection and electrode age on this parameter in a standard stone model.

Despite the real effectiveness and successful results of shock wave application, the effect of some varying parameters, namely number of shock wave (SW) electrical discharge value (kV), projection of the shock waves and electrode age are still to be evaluated. By using a standard stone model, we evaluated the real effect of the projection of shock waves and electrode age on the degree of stone disintegration. Our results indicated no significant relationship between the kV value and the degree of stone disintegration. However, as the number of SW increased, the rate of disintegration became evident. On the other hand, application of the same number of SW from two different angles revealed more effective disintegration rate on standard stone model. Thus SW number, age of the electrode and the projection of shock waves seemed to be important in the disintegration of the stones.

Testicular torsion: evaluation of contralateral testicular histology.

Infertility may occur in patients with unilateral testicular torsion whose contralateral testis is intact. Depending on this observation, the physicians have begun to examine the contralateral testis. In the present prospective study we aimed to examine the histopathologic alterations occurring in the contralateral testicle with time. Sixty adult male albino rats were included in the programme, and following experimental torsion the histopathologic findings, especially those in the contralateral testis, were evaluated after 4-12 weeks. Long-term and high degree torsion of the testicle led to varying degrees of deterioration in the germinal epithelium and interstitial cells of the contralateral testicle. Histopathologic alterations were reversed in 12 weeks. Tubular diameter and testicular volume also decreased in accordance with the histopathologic alteration. In our opinion, orchiectomy following torsion of one testicle will limit potential histopathologic alterations in the contralateral testicle.

Determination of in vitro drug sensitivity to a panel of cystostatic drugs and interferon alpha-2b in patients with renal cell carcinoma.

Fresh operative cells from 27 renal cell carcinomas (RCC) were cultured in vitro for the determination of in vitro drug sensitivity. Two samples were not culturable. Incubation was carried out in triplicate in the presence and absence of various concentrations of chemotherapeutic agents. Sensitivity of the tumour cells to interferon-alpha (IFN-alpha), cisplatin (CDDP), mitomycin C (MMC), vinblastine (VBL), doxorubicin (DOX), etoposide (ETOP), bleomycin (BLM), vincristine (VCR) were tested by a colorimetric assay using MTT. A preexposure viability over 75% was essential for in vitro drug sensitivity assay (IVDSA). Sensitivity was determined by a more than 50 +/- 2 SD% reduction from the control absorbance. All eight drugs in their low concentrations exhibited cell proliferation inhibition in 0-12% of RCCs. On the other hand, IFN-alpha in its higher concentration (60 IU/ml) was effective in 88% of RCCs. After IFN, CDDP was found to be the second most effective drug in its higher concentration (36% efficacy). The results indicate that IFN appears to be the most effective in vitro agent in our 25 RCCs and the clinical trials either as a monotherapy or multiple combinations of various agents should include IFNs for the treatment of RCC.

Color Doppler imaging in the diagnosis of the acute scrotum.

OBJECTIVES: To determine the value of color Doppler imaging (CDI) in the diagnosis of acute scrotum. MATERIALS AND METHODS: We evaluated 102 consecutive patients referred to our institution with scrotal pain. All patients were evaluated by physical examination, ultrasound with stethoscopic Doppler followed by CDI. Radionuclide scanning was performed only in 14 patients. Patients with a diagnosis of testicular torsion by CDI underwent surgical exploration. Patients with CDI diagnosis of epididymorchitis were treated with intravenous antibodies and underwent repeat CDI evaluation after treatment. RESULTS: Of the 102 patients evaluated ages 11-44, CDI diagnosed 18 patients with testicular torsion and 78 patients with epididymorchitis. Cases of testicular torsion were found to have absent flow on CDI. CDI findings of normal or increased flow were present in all patients with epididymorchitis. All cases of torsion were confirmed on surgical exploration, 11 patients underwent orchidopexy and 7 patients underwent orchiectomy. No cases of testicular atrophy were encountered on long-term follow-up in patients with epididymorchitis. Diagnoses in the remaining patients were testicular tumor 1, testicular abscess 2, scrotal hematoma 2 and incarcerated hernia 1. CDI was found to be 100% sensitive and 100% specific in the diagnosis of the acute scrotum. CONCLUSION: We found CDI to be more accurate and reliable than physical examination in conjunction with gray-scale ultrasound and Doppler stethoscopic examination in the differential diagnosis of the acute scrotum. CDI is practical and can be performed in a rapid manner. CDI should become an integral part of the urologist's armamentarium in the differential diagnosis of the acute scrotum.