Percutaneous ethanol injection of large autonomous hyperfunctioning thyroid nodules

PURPOSE

To verify the effectiveness of percutaneous ethanol injection (PEI) in the treatment of large (>30-mL) hyperfunctioning thyroid nodules.

MATERIALS AND METHODS

Twelve patients (eight women, four men; age range, 26-76 years) with a large hyperfunctioning thyroid nodule (volume range, 33-90 mL; mean, 46.08 mL) underwent PEI treatment under ultrasonographic (US) guidance. US was used to calculate the volume of the nodules and to assess the diffusion of the ethanol in the lesions during the procedure. When incomplete necrosis of the nodule was depicted at scintigraphy performed 3 months after treatment, additional PEI sessions were performed.

RESULTS

Four to 11 PEI sessions (mean, seven) were performed in each patient, with an injection of 3-14 mL of 99.8% ethanol per session (total amount of ethanol per patient, 30-108 mL; mean, 48.5 mL). At scintigraphy after treatment in all patients, recovery of extranodular uptake, absence of uptake in the nodule, and normalization of thyroid-stimulating hormone (thyrotropin) levels were observed. In all patients, US showed volume reductions of 30%-50% after 3 months and 40%-80% after 6-9 months. Side effects were self-limiting in all patients. During the 6-48-month follow-up, no recurrence was observed.

CONCLUSION

PEI is an effective and safe technique for the treatment of large hyperfunctioning thyroid nodules.

Percutaneous ethanol injection under general anesthesia for hepatocellular carcinoma: 3 year survival in 112 patients

OBJECTIVE

percutaneous ethanol injection (PEI) under general anesthesia (One Shot PEI) is a new therapy for large and multiple hepatocellular carcinoma (HCC) by the injection of large amount of ethanol in the tumor. We report our results with 3 years survival rates in patients with HCC on cirrhosis treated with One Shot PEI.

PATIENTS AND METHODS

between October 1992 and July 1996, 112 cirrhotic patients (79 males; age: 45-80; mean: 64 years) with 215 HCC nodules (diameter 0.6-14 cm; mean 4.1 cm) underwent One Shot PEI. Fifty-three patients had a single nodule (diameter=3-14 cm; mean=4. 5 cm), 59 had two or more (two to five) nodules (diameter=0.6-13 cm; mean=4.9). Ethanol injected ranged between 16 and 120 ml per session. Survival rates were calculated according to Kaplan-Meier method and Wilcoxon test was used for statistical analysis.

RESULTS

five patients died within 7 h-10 days after the treatment for rupture of esophageal varices in three cases, rupture of subcapsular HCC in one case and liver failure in one case. In the remaining 107 patients, dynamic CT or spiral CT, performed 72 h-1 month after the treatment, showed complete necrosis in 76 cases (71%) and incomplete necrosis (although always ?50%) in 31. Survival rates at 1, 2, 3 years in all 107 patients were 88, 76, and 76% respectively. Survival rates in Child A Class patients were 100, 92, 92% and in Class B patients were 84, 72, and 72% at 1, 2, 3 years respectively; in Class C were 70 and 40% at 1 and 2 years respectively (P=0.01). Survival rates in patients with single nodule were 95, 82 and 82% at 1, 2 and 3 years, while in patients with multiple nodules were 80, 68 and 58% at 1, 2 and 3 years respectively (P=n.s.). During the follow-up (6-46 months) 48 patients showed intrahepatic recurrences; 41 out of them were retreated with new sessions of One Shot PEI or traditional PEI.

CONCLUSIONS

PEI One Shot is more aggressive than traditional PEI. Survival rates of PEI One Shot seems similar to those obtainable by conventional PEI and even better than surgery.

Ultrasound guided percutaneous drainage of abdominal abscesses in the hands of the clinician: a multicenter Italian study

OBJECTIVE

Image guided percutaneous drainage is a well established therapeutic technique. The results of these procedures, when performed directly by the clinician and under sonographic guidance,in respect to other imaging techniques are not yet clarified.

METHODS

The 886 cases of ultrasound guided drainage were collected from eight italian clinical institutions and the results were analyzed according to location of the abscess, drainage technique, underlying diseases, microbiological findings, immunological patient status and previous surgical intervention.

RESULTS

We observed an overall cure rate of 90.4%. The best results were obtained in hepatic abscesses, both amoebic and pyogenic (cure rate 98.7 and 94.3%). Slightly lower cure rates were obtained in abdominal and splenic abscesses, postoperative collections and severely immunocompromised patients. The frequency of complications was low (6.6%) and mostly related to catheter drainage. No drainage-related deaths occurred.

CONCLUSIONS

The study confirms the high clinical efficiency and safety of ultrasound guided percutaneous drainage, even when performed directly by the clinician. The sonographic guidance showed similar efficacy, more manageability and lower costs than other imaging techniques and it should be preferred whenever possible. For hepatic abscesses, ultrasound guided needle aspiration showed good results and less complications than catheter drainage.

[Ultrasonography-guided percutaneous ethanol injection in large an/or multiple liver metastasis]

INTRODUCTION

Percutaneous ethanol injection (PEI) under sonographic guidance is an effective therapy for hepatocellular carcinoma on cirrhosis, while less favorable results have been reported for liver metastases. Surgery and/or other new treatments (i.e., interstitial thermotherapy) are indicated only for small metastases (< 3 cm) and surgeons no longer perform the palliative debulking of neoplastic masses.

PATIENTS AND METHODS

From March, 1994, to December, 1997, thirty-three patients with 62 large (> 3.5 cm) and/or multiple liver metastases, who were not eligible for surgery nor thermotherapy, were treated with one-shot PEI under general anesthesia. The diameter of the nodules ranged 35-92 mm (mean: 39); the lesions were single in 15 patients and localized in both the right and the left lobe in 19 patients. 25-110 ml ethanol were injected per session. Post-treatment results were assessed with dynamic or dual-phase spiral CT; therapeutic success was defined as the absence of hyperdense lesion areas.

RESULTS

Complete necrosis of the metastases was shown in 10 patients (30.3%). Necrosis rate ranged 70-90% in 21 patients (64%) and was 50% in 2 patients (5.7%). Survival rates were 94%, 80%, 80% and 44% at 12, 24, 36 and 44 months, respectively. No major complications were observed. Seeding of neoplastic cells along the needle tract has been never observed to date.

DISCUSSION

Metastasis diameter and number impact on long-term survival. PEI under general anesthesia allows to treat also the patients who are not eligible for other treatments and to inject large amounts of ethanol per session in different tumor areas because metastases usually set on in an otherwise healthy liver.

CONCLUSIONS

One-shot PEI can cause major, even complete, tumor necrosis in large and multiple liver metastases. The absence of any important complications and the survival rates in our series seem to indicate that one-shot PEI is effective for tumor debulking in patients not eligible for surgery and other alternative treatments.

Clinical efficacy of ultrasound guided percutaneous drainage of abscesses in patients with leukaemia and lymphoma

Ultrasound guided percutaneous drainage (US-PD), a minimally invasive technique, has been reported as highly effective for the treatment of deeply located abscesses, particularly in immunocompromised patients. Therefore, we retrospectively studied its therapeutic efficacy and safety in a series of 14 patients with leukaemia and lymphoma. We collected the clinical and sonographic data of 14 patients with various types of leukaemia and lymphoma. These patients were consecutively observed in four clinical centres with long-term experience with ultrasound guided therapeutic techniques. The cases were analysed according to underlying disease, clinical features, location of the abscess, drainage technique, microbiological data and both short- and long-term outcome. In our series, 11 patients were treated with repeated ultrasound guided needle aspirations (US-NA) and 3 underwent catheter drainage (US-PCD). In 12/14 cases the procedure was successful (86%): the mortality rate was 14%. 5 patients died during the follow-up period because of the underlying disease, without abscess recurrence. No complications were reported. Our data suggest that ultrasound guided percutaneous drainage should be considered the first choice, minimally invasive procedure for the treatment of deeply located abscesses in patients with leukaemia and lymphoma.

[Ultrasonography in diagnostic and therapeutic management of the abscesses due to Actinomyces spp]

A case of abscess of masseter muscle by Actinomyces spp. is described. Ultrasound-guided fine needle aspiration allowed diagnosis by cytology. Specific antibiotic treatment was started and US-follow-up showed complete healing of the lesion with restitution ad integrum of the muscle.

Reverse flow in intrahepatic portal vessels and liver function impairment in cirrhosis

Objectives: Our aim was to describe the hemodynamic patterns and assess the prevalence of reversal of flow (RF) in intrahepatic portal vessels (IPV) in patients with chronic active hepatitis (CAH) and patients with cirrhosis. Patients : 100 consecutive patients with CAH, and 178 consecutive cirrhotic patients (48 Child A, 114 Child B and 38 Child C class) underwent Echo-Color-Doppler for evaluation of flow direction in segmental IPV, right and left portal vein (RPV, LPV), in main portal vein (MPV), splenic vein (SV), superior mesenteric vein (SMV) and porto-systemic shunts (paraumbilical, spleno-renal, left gastric vein). The patients were followed-up clinically for 3-15 months. Results: Patients with CAH showed RF in SV in 1/100 and hepatopetal flow in MPV, SMV, SV, IPV in 99/100 patients. Eleven of 178 (6.2%) cirrhotic patients showed RF only in the SV, 3/178 (1.7%) showed alternating ('back and forth') flow only in IPV, RPV and LPV with continuous hepatopetal flow in PV and 10/178 (5.6%) showed completely RF in IPV. Four of ten patients of this last group showed hepatopetal flow in MPV. The other six patients showed RF in MPV associated with hepatofugal flow through a large left gastric vein in three cases and through the SV in three cases. The other cirrhotic patients (154/178=86.5%) showed hepatopetal flow in IPV, MPV, SMV and SV. In no case RF in SMV was observed. Prevalence of RF in IPV was significantly higher in Child C patients (8/31=25.8%) than Child B patients (5/104=4.7%) and than in Child A patients (0%) (p<0.01). Prevalence of Child C class was significantly higher in patients with RF in IPV (8/13=61.5%) than in patients with RF only in extraepatic portal vessels (2/11=18.2%) and patients without RF (21/154=13.6%) (p<0.001). No patient with RF in IPV was in Child A class. Incidence of death was significantly higher in patients with RF in IPV than in patients without RF and patients with RF only in SV. Conclusions: RF in IPV is not a rare event (9% in our series) that mainly occurs in cirrhosis with advanced liver function impairment. Copyright 1997 Elsevier Science Ireland Ltd.

Percutaneous ethanol injection in the treatment of hepatocellular carcinoma. A multicenter survey of evaluation practices and complication rates

BACKGROUND

Percutaneous ethanol injection (PEI) has become a widely used procedure in the treatment of hepatocellular carcinoma (HCC). However, the criteria for selecting patients are not standardized, and little information is available about the complications of the procedure.

METHODS

A questionnaire was sent to 11 experienced Italian centers. It investigated: the size and the number of HCC nodules suitable for treatment and the Child-Pugh risk class of the associated cirrhosis; the performance of the procedure; the number and characteristics of the patients treated; and, finally, any complications.

RESULTS

Most of the centers performed PEI in single HCC nodules less than 5 cm in diameter or in multiple nodules if fewer than three, the larger being less than 3 cm. Patients in Child-Pugh's classes A, B, and C with single nodules were generally considered for PEI. A prothrombin time of less than 40% and a platelet count of less than 40,000/mm3 contraindicated PEI in most of the centers. PEI was generally performed on outpatients, using Chiba or spinal needles. One thousand and sixty-six patients (8118 sessions) were enrolled; 74% had a single HCC nodule and 26% multiple nodules. All except four had cirrhosis; 53% were in Child class A, 38% in class B, and 9% in class C. The mean number of sessions needed to destroy an HCC nodule was 6.7 (range, 2-14), with a mean alcohol injection volume of 5.0 ml per session (range, 2-20 ml). One death (0.09%) and 34 complications (3.2%) were reported. Among the complications we call attention to the hemorrhagic ones (eight cases) and tumoral seeding (seven cases). Severe pain experienced during the maneuver led to discontinuation of the procedure in 3.7% of the patients; 13.5% of the patients required analgesics and 24% had fever after PEI.

CONCLUSIONS

Some procedural aspects of PEI treatment differ among the various centers a standardization is advisable. In the present survey PEI is a low-risk technique.

Hepatic abscess caused by Salmonella typhi: diagnosis and management by percutaneous echo-guided needle aspiration

Three cases of liver abscesses due to Salmonella typhi (2 solitary, 1 with double localization in the right lobe) are described in which specific diagnosis was based on percutaneous echo-guided aspiration of the lesions. Haemocultures and coprocultures were negative, in all cases, and pus-cultures of aspirated material from cavities grew Salmonella typhi; Widal became significantly positive only in one patient 15 days after discharge. Percutaneous needle drainage, combined with chloramphenicol therapy, was successfully performed under echo guidance; only in one case was a second aspiration needed three days after the first one. Fever disappeared within 48-72 hours after drainage of the abscess. No complications or side-effects were observed.

One-shot percutaneous ethanol injection of liver tumors under general anesthesia: preliminary data on efficacy and complications

PURPOSE

To verify the efficacy of ultrasound (US)-guided injection of large amounts of ethanol into large or multiple liver lesions, in a single session under general anesthesia (one-shot PEI) for percutaneous ablation of hepatic tumors.

METHODS

Twenty-nine patients (27 with 51 hepatocellular carcinoma (HCC) nodules on cirrhosis, diameter range 1.0-9.0 cm; two patients with a single metastasis from the gastroenteric tract, 5.0 and 9.0 cm, respectively, in diameter) were treated with one-shot PEI.

RESULTS

The total volume of alcohol delivered per patient ranged from 16 to 210 ml. Mean ethanol volume in all patients was 49 ml. Dynamic computed tomography (CT) examination showed complete necrosis in 41 of 50 lesions. Two patients died of hypovolemic shock due to massive upper gastrointestinal bleeding, 3 and 7 days, respectively, after the interventional procedure. All the remaining patients are alive (follow-up 5-14 months) except one who died of liver failure 5 months after. New HCC nodules occurred in six patients within 6 months and one intralesional relapse was recorded.

CONCLUSION

In this preliminary experience, one-shot PEI is as effective in inducing liver tumor necrosis as traditional PEI; its advantages are shorter treatment time and the capability of treating larger and multiple liver lesions.

Hepatocellular carcinoma and cirrhosis in 746 patients: long-term results of percutaneous ethanol injection

PURPOSE

To define indications for percutaneous ethanol injection (PEI) in patients with hepatocellular carcinoma (HCC) and cirrhosis.

MATERIALS AND METHODS

Survival rates were determined in 746 patients who had undergone PEI (567 men, 179 women; mean age, 64.3 years; mean follow-up, 36 months).

RESULTS

In patients with Child A (n = 293), B (n = 149), or C (n = 20) cirrhosis and single HCCs 5 cm or smaller, the 3-5 year survival rate was 47%-79%, 29%-63%, and 0%-12%, respectively. In patients with Child A cirrhosis, it was 36%-68% for multiple HCCs (n = 121), 30%-53% for single HCCs larger than 5 cm (n = 28), and 0%-16% for advanced HCC (n = 16). Treatment was associated with a 1.7% rate of severe complications and a 0.1% mortality rate.

CONCLUSION

PEI proved safe, effective, and repeatable and had a low cost. Survival after PEI was comparable to that after surgery, probably because of a balancing between greater radicality of surgery and absence of early mortality and liver damage of PEI.

[Not Available]

Authors describe three cases of liver abscesses due to Salmonella typhi (2 solitary, 1 with double localization in the right lobe) in which specific diagnosis was based on US examination with aspiration and culture of the pus. In all cases cultures of biologic fluids were negative; Widal test became significantly positive only in one patient 15 days after discharge. Percutaneous drainage was performed under US guidance; only in one case a second aspiration was needed three days after the first one. Fever disappeared within 48-72 hours after abscess's drainage. Complications and side-effects were never observed.

Pyogenic liver abscesses: 13 years of experience in percutaneous needle aspiration with US guidance

PURPOSE

To determine the efficacy of percutaneous needle aspiration (PNA) with antibiotic therapy in treatment for pyogenic liver abscess (PLA).

MATERIALS AND METHODS

One hundred fifteen patients (59 male; 56 female; age range, 16-86 years; mean age, 45.3 years) with 147 PLAs (mean diameter, 6.8 cm; range, 3-16 cm) underwent PNA with ultrasound (US) guidance and antibiotic therapy. Needle caliber (22-16 gauge) was tailored to PLA volume. If necessary, PNA was repeated every 3-7 days.

RESULTS

Three hundred one PNAs were performed (range, 1-4 per patient; mean, 2.2 per patient). A single puncture was sufficient in 57 patients. Cure (normalization of clinical and laboratory parameters and resolution of hepatic lesions) was achieved in 113 patients (98.3%). Two patients with large PLAs required surgery. Patients were hospitalized 7-24 days (mean, 9 days). In the last eight patients, all abscesses were evacuated in one session. Neither complications nor deaths ensued. Recurrence of PLA was not observed in any patient during follow-up (6-36 months).

CONCLUSION

US-guided PNA with antibiotic therapy in treatment for PLA is a valid alternative to prolonged catheter drainage.

Echographic epidemiology of cystic hydatid disease in Italy

This study was carried out in order to establish the actual prevalence of cystic hydatid disease in Italy using ultrasound. In fact, there is a great difference between the official reports of the disease and epidemiological investigations. From 1988 to 1990, 424 cases of cystic hydatid disease were diagnosed in 333,144 examinations performed in nineteen Italian Echographic Departments, giving a mean incidence of 0.16%. Most of the examined persons arriving at the 19 Echographic Departments had symptoms independent from hydatidosis, were affected with other pathologies, or they were patients attending follow-up for neoplasms. The authors note that human hydatidosis has a high incidence in the south and in the isles; hepatic lesions were 85.61% of all cases of abdominal hydatidosis, asymptomatic cystic hydatid disease was present in 60% of the total number; the average age of the sample examined was 45.38 years without significant differences between men and women. Finally the Authors suggest the importance of echography in planning therapeutic programs.

Hepatic abscesses in immunocompromised patients: ultrasonically guided percutaneous drainage

Ultrasonically guided percutaneous drainage (US-PD) is considered first-line therapy for hepatic abscesses, but no data are available on its efficacy in severely immunocompromised patients. Therefore, we examined 15 such patients in whom one or more hepatic abscesses of different etiology were treated with US-PD. Eleven patients underwent needle aspiration and four had catheter drainage under US guidance. In 12 cases we achieved complete healing of the abscesses. In one case, clinical improvement was obtained but surgery was required for cure. In another case (fungal abscess in AIDS), we had no improvement and the patient died. No procedural complications were observed. Seven patients died during the follow-up periods of up to 49 months from their underlying disease. We conclude that US-PD must be considered the therapy of choice for hepatic abscess (except the fungal lesions) in severely immunocompromised patients.

Unilocular hydatid liver cysts: treatment with US-guided, double percutaneous aspiration and alcohol injection

Sixteen hydatid liver cysts in 14 patients were treated with a percutaneous double puncture-aspiration-injection (D-PAI) technique with alcohol used as the scolecidal agent. With ultrasound guidance, fine-needle drainage of cysts was performed, and 95% sterile alcohol was injected and left in situ to partly refill the cystic cavities. The same procedure, without reaspiration of the injected alcohol, was performed 3 days later. Viability of scoleces was assessed at each aspiration. Benzoimidazolic drugs were administered 1 week before and 3 weeks after the procedure, to reduce the risk of seeding scoleces. Follow-up ranged from 8 to 28 months (mean, 14 months). Six cysts disappeared within 40-75 days of completion of D-PAI. In the other patients, smaller liquid areas or hypo- or hyperechoic solid masses were observed. Anaphylactoid reactions did not occur. In one patient, a biliary fistula developed after the first aspiration; the second ethanol injection was postponed until 6 months later but was effective. Viable scoleces were found at the second aspiration in only two patients whose hepatic liver cysts completely healed. Serologic titers substantially decreased in seven cases and became negative in two.

Intravascular circulation and distribution of human 51Cr-DBBF stroma-free hemoglobin

Male B6C3HF1 mice were infused with 51Cr-labeled DBBF (bis 3,5-dibromosalicyl fumarate) crosslinked stroma-free hemoglobin (SFH). The intravascular halftime (T50) of the DBBF-SFH, determined from plasma hemoglobin levels, was 0.5 hours in the first 10 minutes and 4.3 hours during the next 50 minutes. At 24 hours, less than 5% of the DBBF-SFH remained. Elution of 51Cr was reflected in a lower T50 determined from the radioactivity levels: during the first 10 minutes the T50 was 0.3 hours; in the next 50 minutes it was 1 hour. The radioactivity sequestered in each organ in the first hour following DBBF-SFH infusion was as follows: 11.2% of the infused radioactivity was in the skin, 11.4% in muscle, 9.1% in the skeleton, and 5% in the liver. After 24 hours, the percentages in skin, muscle, skeleton and liver were 15.4, 10.3, 16.6 and 6.7% respectively. The percentage of infused radioactivity in the gastrointestinal tract and kidney at 1 hour and 24 hours ranged from 3.5 to 5.5%. Less than 0.4% was found in the spleen and lung. At 24 hours, 25% of the radioactivity was recovered in urine and 3% in feces.

[Percutaneous therapy of hydatid cyst of the liver with ultrasound-guided double puncture-aspiration and alcoholization]

Fourteen patients (9 females, 5 males; age range: 22-80 years) with 16 univesiculated hydatid cysts of the liver (O ranging 4.2-14 cm) underwent two sessions of puncture-aspiration-alcohol injection (D-PAI) under real-time US guidance at 3-day intervals. Two patients had postoperative recurrences. One patient was pregnant (9 weeks' gestation): her cyst doubled its volume over 2 months. One patient had HBV chronic hepatitis treated by means of interferon: also in this case the cyst doubled its volume. The remaining were high-risk patients for surgery or had refused operation. At US follow-up (ranging 4-24 months) 6 cysts exhibited complete reconstitution of liver parenchyma. In the extant patients two different US patterns were observed: 1) liquid areas with detached inner membranes (4 cysts); 2) solid inhomogeneous areas (6 cysts). In these cases the volume was reduced by 50-80%. No allergic complication occurred either during or after the procedure. Two patients only were affected with vomiting and fever, which resolved in a few hours. Our results indicate D-PAI of univesiculated hydatid cysts of the liver to be an effective alternative to surgery.

Effect of graft material on loss of erythrocytes after aortic operations

It has been suggested that loss of erythrocytes after abdominal aortic grafting is influenced by the type of synthetic graft used. A prospective randomized study was done to compare loss of erythrocytes in patients receiving Dacron (polyester fiber, Meadox woven double velour) and Gore-Tex (polytetrafluoroethylene [PTFE]) grafts during the perioperative period. A total of 25 patients (13 Dacron and 12 PTFE) was studied, including 21 with abdominal aortic aneurysms and four with aortoiliac occlusive disease. Erythrocyte volume (EV) was measured using 51Cr-labeled autologous erythrocytes on the day prior to the operation, one to two hours after the operation when the patients were hemodynamically stable and 24 hours postoperatively. In addition to measurements of 51Cr EV and the volume of intraoperatively salvaged washed erythrocytes, the length of storage of the units of homologous liquid preserved erythrocytes at 4 degrees C. prior to transfusion were recorded. The mean intraoperative erythrocyte loss (+/- S.D.) for the Dacron group was 892 +/- 543 milliliters and for the PTFE group, 842 +/- 403 milliliters (p = NS). Patients in the Dacron group received intraoperatively 2.2 +/- 1.6 (units +/- S.D.) milliliters with a range of zero to 4 units of homologous liquid preserved erythrocytes and patients in the PTFE group received 1.2 +/- 1.2 milliliters with a range of zero to 3 units of homologous liquid preserved erythrocytes (p = NS). The mean total loss of erythrocytes (+/- S.D.) was 1,055 +/- 649 milliliters for the Dacron group and 978 +/- 503 milliliters for the PTFE group (p = NS). Despite inherent differences in graft material, there were no significant differences in intraoperative or post-operative loss of erythrocytes or in the number of homologous units of liquid preserved erythrocytes transfused with a p value of less than 0.05 considered significant.

Iatrogenic haemobilia: ultrasound appearance of intragallbladder haemorrhage. A report of two cases

Ultrasound appearance of intragallbladder haemorrhage in two patients with haemobilia is presented. Gallbladder lumina were occupied by non-shadowing, firm masses of mixed echogenicity representing blood clots. In both cases iatrogenic trauma following percutaneous transcholecystic cholangiography and blind hepatic biopsy caused bleeding in the biliary tree.

Decreased in vivo survival of hydrogen peroxide-damaged baboon red blood cells

In this study we attempt to establish the consequence of in vitro hydrogen peroxide (H2O2)-induced membrane damage as manifested by spectrin-hemoglobin (Sp-Hb) complex formation and decreased red blood cell (RBC) deformability to in vivo RBC survival in baboons. After exposure to 135 to 581 mumols/L H2O2 and reduction with dithiothreitol (DTE), baboon RBCs were infused into the animal, and the fraction of cells remaining in circulation after 24 hours and the lifespan of surviving cells were quantitated. In a dose-dependent fashion, a positive correlation was observed between in vitro membrane alterations and the 24-hour in vivo survival. While 12% of the control cells were removed from circulation in 24 hours, 23% were removed after treatment with 339 mumols/L H2O2, and 36% following exposure to 581 mumols/L H2O2. Pretreatment with carbon monoxide before exposure with H2O2 increased the survival of oxidized RBCs. RBCs not removed from circulation in the first 24 hours had a normal lifespan. Moreover, by selectively isolating biotin-labeled, peroxide-treated cells that survived the first 24-hour posttransfusion period, a significant decrease in Sp-Hb crosslinking was observed in these cells. These results suggest that a subpopulation of cells sensitive to oxidation were removed during the first 24 hours. To identify this population, the survival of density-fractionated RBCs exposed to oxidant stress was quantitated. No differences in either the 24-hour survival or RBC life span were observed between untreated low-density (MCHC less than or equal to 32g/dL) and high-density cells (MCHC greater than or equal to 37g/dL). However, striking differences were noted after treatment with 339 mumols/L H2O2, with the 24-hour survival of high-density cells showing a marked decrease compared with low-density cells. These data support our hypothesis that during peroxidative membrane damage, Hb oxidation initiates a sequence of events resulting in skeletal changes that lead to membrane alterations and, eventually, in vivo destruction, and that the dense, dehydrated cells are more susceptible to oxidant damage.

A simple and rapid method to evaluate lymphocyte response to mitogens

A new method to evaluate lymphocyte response to mitogens is proposed. The method is based on the observation in fluorescence of the stimulated cells after their supravital staining on slides prestained with acridine orange in alcoholic solution. The results are expressed as Blast Index (IB). The method is very practical, easy to reproduce and shows a good correlation with 3H-thymidine uptake.