Wolbachia, doxycycline and macrocyclic lactones: New prospects in the treatment of canine heartworm disease.

Melarsomine dihydrochloride (Immiticide®, Merial) is the only approved adulticidal drug for the treatment of canine heartworm disease (HWD). However, in cases where arsenical therapy is not possible or is contraindicated, a monthly heartworm preventive along with doxycycline for a 4-week period, which targets the bacterial endosymbiont Wolbachia, might be considered. There are published reports on the efficacy of ivermectin and doxycycline in both experimentally and naturally infected dogs, but no data on the use of other macrocyclic lactones (MLs) with a similar treatment regime. Preliminary results of studies in dogs show that a topical formulation of moxidectin, the only ML currently registered as a microfilaricide, is also adulticidal when combined with doxycycline. It is not yet known if the efficacy of these combination therapies is due to pharmacokinetic synergism. A recent study showed that serum levels of doxycycline in dogs treated with the combination protocol were not statistically different compared to dogs treated with doxycycline alone. However, lungs from dogs treated with the combination therapy showed a marked reduction in T regulatory cells, indicating that treatment efficacy may be due to a heightened immune response against the parasite. Further studies are necessary to evaluate the long-term clinical outcome of combination protocols and to establish the most efficient treatment for HWD in dogs.

Detection of suspected primary lung cancer by scintigraphy with indium-111-anti-carcinoembryonic antigen monoclonal antibodies (type F023C5)

Immunoscintigraphy with 111In-labeled anti-CEA-Mab (F023C5i) was carried out in 66 patients strongly suspected for a primary lung cancer and in 8 control patients suffering from different chest diseases. A sensitivity of 0.90, a specificity of 0.45 and an accuracy of 0.85 were calculated. False-negative results were mainly obtained in patients in whom the size of the lesion was below 2 cm and the tumor was centrally located. All patients affected by small-cell carcinoma were correctly identified. In 89% of the patients, a positive immunoscintiscan was associated with the presence of the antigen in the tumor. False-positive results were observed in control patients suffering from different chest diseases due to the nonspecific uptake of the tracer. The tumor definition was generally better after 120 hr than at an earlier time after injection due to the reduction of background activity. SPECT imaging defined the tumor better in each patient but did not reveal any tumor not seen on planar studies.

Differential diagnosis of CT-hypodense cranial lesions with indium-111-oxine-labeled leukocytes.

Scintigraphy using indium-111-oxine-labeled white blood cells was used as a complementary diagnostic study in the differential diagnosis of 20 intracerebral cystic lesions for which computerized tomography scanning did not exclude abscess. To lower the rate of false-positive findings with scintiscanning, three criteria of positivity were tested in the 20 lesions. The most stringent criterion yielded 100% sensitivity, 94% specificity, and 96% diagnostic accuracy. The clinical and surgical implications of these results are discussed.

Clinicopathological findings in sheep from Sardinia showing neurological signs of disease.

Histopathological and bacteriological examinations were performed on 178 brains from Sardinian sheep which were showing neurological signs. The sheep represented the total number of sheep with neurological syndromes submitted for diagnostic investigations over a three-year period in Sardinia. Scrapie was detected in 57 cases, cerebrocortical necrosis in 25, intoxication by a typical Mediterranean plant (Cistus species) was suspected in 25, coenurosis was detected in 11 cases, Listeria monocytogenes in eight cases and focal symmetrical encephalomalacia in six cases. Non-suppurative inflammatory changes were observed in three of the brains and suppurative changes were noted in two. Lesions restricted to the spinal cord were found in three cases. In the remaining 38 cases there were no significant neuropathological changes.

Development and testing of a new disposable sterile device for labelling white blood cells.

AIM: White blood cell (WBC) labelling requires isolation of cells from patient's blood under sterile conditions using sterile materials, buffers and disposables under good manufacturing practice (GMP) conditions. Till now, this limited the use of white blood cell scintigraphy (WBC-S) only to well equipped laboratories with trained personnel. We invented, developed and tested a disposable, sterile, closed device for blood manipulation, WBC purification and radionuclide labelling without exposing patient's blood and the operator to contamination risks. This device prototype and a final industrialized device (Leukokit®) were tested for WBC labelling and compared to standard procedure. Leukokit® was also tested in an international multi-centre study for easiness of WBC purification and labelling. METHODS: On the device prototype we tested in parallel, with blood samples from 7 volunteers, the labelling procedure compared to the standard procedure of the International Society of Radiolabeled Blood Elements (ISORBE) consensus protocol with respect to cell recovery, labelling efficiency (LE), cell viability (Trypan Blue test) and sterility (haemoculture). On the final Leukokit® we tested the biocompatibility of all components, and again the LE, erythro-sedimentation rate, cell viability, sterility and apyrogenicity. ACD-A, HES and PBS provided by Leukokit® were also compared to Heparin, Dextran and autologous plasma, respectively. In 4 samples, we tested the chemotactic activity of purified WBC against 1 mg/ml of lipopolysaccharide (LPS) and chemotaxis of 99mTc-HMPAO-labelled WBC (925 MBq) was compared to that of unlabelled cells. For the multi-centre study, 70 labellings were performed with the Leukokit® by 9 expert operators and 3 beginners from five centers using blood from both patients and volunteers. Finally, Media-Fill tests were performed by 3 operators on two different days (11 procedures) by replacing blood and kit reagents with bacterial culture media (Tryptic Soy Broth) and testing sterility of aliquots of the medium at the end of procedure. RESULTS: Tests performed with the prototype showed no significant differences with the standard procedure but a faster and safer approach. Tests performed with the final Leukokit® confirmed full biocompatibility, sterility and apyrogenicity of all reagents and plastic ware. Average WBC recovery with Leukokit® was comparable to that of the ISORBE protocol (117x106±24x106 vs. 132x106±29x106 cells, P=not significant). No differences in red blood cells and platelet content were observed. LE was 82% ± 3% for Leukokit® and 65±5% for control (P=0.0003) being PBS vs autologous plasma the main reason of such difference. Cell viability was always >99.9% in both conditions. Chemotactic tests showed no differences between all Leukokit® samples and controls. Haemocultures and Media-Fill tests were always sterile. The procedure was well accepted by expert operators and beginners, with a very fast learning curve (confidence after 2±2 labellings). CONCLUSION: The invented device offers high level of protection to operators and patients. The derived Leukokit® is safe and easy to use, and gives a high LE of WBC without affecting cell viability and function. Being a registered closed, sterile medical device, it may allow easier and faster WBC labelling that is not limited to only well equipped laboratories. Also simultaneously labelling of multiple patients is possible.

[Therapeutic approach in the treatment of acute cervico-brachial Herpes zoster]. / Approccio terapeutico nella terapia in fase acuta dell' Herpes zoster cervico-brachiale.

A highly specialized experimental treatment was used in the therapy of Herpes zoster, which was aimed at inducing good control over acute pain and the prevention of post herpic neuritis using poly-pharmacologic al infiltration of ganglia and of relevant roots.

[Strychnine poisoning. A clinical case]. / Avvelenamento da stricnina. Un caso clinico.

A patient was admitted following ingestion of 300 mg of strychnine. Early diagnosis and timely reanimation treatment led to his full recovery though he had swallowed a quantity of strychnine greater than the medium lethal dose (50-100 mg for adult).

Estimation of glomerular filtration rate using chromium-51 ethylene diamine tetra-acetic acid and technetium-99m diethylene triamine penta-acetic acid.

Simultaneous measurements of the clearance rate of chromium-51 ethylene diamine tetra-acetic acid (51Cr-EDTA) and technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) were performed in 54 patients with a range of function between 9 and 176 ml/min. Using multiple blood samples the two clearance values correlated well (r = 0.97, SEE 8.6 ml/min) and DTPA clearance was higher by 2.9%. For each radiopharmaceutical the plasma clearance rates obtained using multiple blood samples were compared with those obtained with simplified methods, i.e., the 60-180 min two-sample method of Russell and the mono-exponential method with the Brochner-Mortensen correction. For both radiopharmaceuticals the clearance values correlated well with the Russell method (r = 0.99, SEE = 4.1 ml/min for EDTA; r = 0.99, SEE 4.9 ml/min for DTPA) and the mono-exponential method (r = 0.99, SEE 3.6 ml/min for EDTA; r = 0.99, SEE 3.9 ml/min for DTPA). The mean plasma clearance obtained using multiple blood samples did not differ significantly from that obtained with the Russell method, either in patients with a glomerular filtration rate (GFR) < 30 ml/min or in patients with GFR > or = 30 ml/min. The mean plasma clearance obtained using multiple blood samples differed significantly from that obtained with the mono-exponential method because of the great difference observed in patients with GFR > or = 30 ml/min. It is concluded that the Russell two-sample method after injection of 99mTc-DTPA is accurate enough for routine clinical use.

Indium-111 labelled white blood cell scintigraphy in cranial and spinal septic lesions.

Cranial and spinal infections are severe events that require timely diagnosis and treatment. Physical and neurological examination, laboratory tests and radiological imaging may be insufficient for assessing cranial and spinal septic lesions. This study aimed to evaluate the accuracy of indium-111 white blood cell (WBC) scan in assessing the presence of leucocytes in intracranial and spinal lesions, and in the diagnosis, management and follow-up of primary, post-traumatic and post-surgical infections. One hundred and twenty-four subjects were included in the study (48 with post-traumatic or post-surgical lesions, 73 with primary cerebral lesions, and 3 with spinal lesions). All patients underwent a diagnostic work-up including planar scans with 111In-labelled WBCs, at 4 and 24 h post tracer injection. All subjects underwent surgical treatment. Patients who did not recover from the infection as suggested by clinical evolution underwent further treatment (up to three times) and further WBC scans (up to four times). WBC scintigraphy correctly identified all the areas of leucocyte accumulation, as confirmed after surgery. WBC scintigraphy also correctly excluded the presence of leucocytes in all other lesions, as demonstrated at surgery. The results of this study confirm the accuracy of WBC scan for the assessment of patients with cranial and spinal lesions, in whom the demonstration of leucocyte accumulation can ease the diagnosis of infection, and indicate that the method is also accurate for the follow-up and management of neurosurgical patients.

Cerebral scintigraphy with 111indium oxine-labelled leukocytes in the differential diagnosis of intracerebral cystic lesions.

CT scanning and scintigraphy with 111Indium-oxide-labelled white blood cells were used to study 32 cases of intracerebral cystic lesions. The results and the criteria of positivity used to lower the false positive rate are discussed. A new criterion, designed to assess the time course of the scintiscan and so reduce still further the frequency of false positives is put forward.