Low dose radiation 18F-fluoride PET/CT in the assessment of Unilateral Condylar Hyperplasia of the mandible: preliminary results of a single centre experience.

BACKGROUND: Unilateral condylar hyperplasia (UCH) of the mandible, or Hypercondylia, is a pathological condition that determines an abnormal growth of the affected condyle.Bone SPECT with Tc99m-diphosphonates is a successful tool in the diagnosis of UCH. EANM guidelines also suggest the use of 18F-NaF PET/CT, though it leads to a higher radiation exposure. AIM: As UCH patients are young, we aimed to develop a low dose 18F-Fluoride PET/CT protocol and compare it to a standard injected activity scan, to assess if the image quality remains unchanged. MATERIALS AND METHODS: We prospectively enrolled 20 patients (7 males, 13 females, mean age 23.2) with UCH, who underwent 18F-NaF PET/CT to assess the hypercondylia. We administered a low activity of 18F-NaF (2.9 MBq/kg) in 15 patients and a standard activity (5.3 MBq/kg) in 5 patients. Activity range was chosen according to 2015 EANM guidelines.To determine if the scans with low radiotracer activity were "diagnostic" such as those with standard activity, two expert nuclear medicine physicians, unaware of the administered activity, independently reviewed the scans and expressed a final qualitative judgment in terms of "diagnostic"/"non-diagnostic" scan. Furthermore, we compared the effective dose of a low injected activity PET/CT to the standard one and to a Bone SPECT performed with standard injected activity of Tc99m-diphosphonates. RESULTS: Reviewers classified 19 of 20 scans as "diagnostic". Only one of them was classified as "non diagnostic" due to condylar arthrosis that disturbed the correct evaluation of condylar radiotracer uptake. The effective dose of a 18F-Fluoride PET/CT, in patient of 70 kg, is about 3.5 mSv in scans performed with 2.9 MBq/kg [0.017 mSv/MBq × 2.9 MBq/kg × 70 kg] and about 6.3 mSv in ones performed with 5.3 MBq/kg [0.017 mSv/MBq × 5.3 MBq/kg × 70 kg]. The effective dose of 99mTc-MDP bone SPECT is about 3.2 mSv [0.0043 mSv/MBq × 740 MBq of 99mTc-MDP]. DISCUSSION: 18F-NaF PET/CT performed with a low radiotracer activity allows a good assessment of UCH similar to that performed with an ordinary activity. The effective radiation dose of a low-injected activity PET/CT is significantly lower than an ordinary-injected activity and is not significantly higher than the most used Bone SPECT. Moreover PET/CT is performed in 1.5 h while Bone SPECT requires at least 3.5 h. CONCLUSIONS: The 18F-Fluoride PET/CT procedure could be performed with 2.9 MBq/Kg (minimum 185 MBq, recommended at least 200 MBq) of 18F-NaF to minimize the effective radiation dose received, maintaining the quality of the scan. Further studies including a larger number of patients and clinical follow-up are needed to confirm our preliminary findings.

Cysts of the atlantoaxial joint: excellent long-term outcome after posterolateral surgical decompression. Report of two cases.

Articular cysts of the atlantoaxial joint are infrequently described and probably an underreported cause of upper cervical spinal cord compression. The authors report on two patients with cysts located posteriorly of the dens in whom a C-1 and partial C-2 hemilaminectomy with subtotal resection of the cyst provided adequate and stable decompression 1 year postoperatively. The clinical and magnetic resonance imaging features and the surgical approach are discussed after a review of the literature.

Condom use and sexual habits of heterosexual intravenous drug users in northern Italy.

In order to assess modes of human immunodeficiency virus (HIV) transmission from heterosexual intravenous drug users (IVDUs) to their partners, condom use and sexual habits with both steady and occasional partners were investigated. A total of 349 heterosexual IVDUs (247 men and 102 women) who ignored, at the time of interview, their HIV serostatus were interviewed. Respondents were asked for information on condom use and sexual habits for the three year period prior to the interview. Nearly 40% of IVDUs reported sexual intercourse with both steady partners and occasional partners. Fifty-four percent of their steady partners and 48% of their occasional partners were individuals who did not belong to groups at risk for HIV infection. Anal intercourse with steady partners was reported by 29% of IVDUs and 24% of IVDUs with occasional partners. Condom use during vaginal intercourse was seldom reported: 83% of IVDUs never used a condom with steady partners and 75% did not use one with occasional partners. IVDUs who were 1) unmarried, 2) enrolled in the study after 1986, 3) partners of not at-risk individuals, 4) partners of a foreigner and, 5) aware of their partners HIV seropositivity showed significantly higher, albeit still low, frequencies of condom use with steady partners. Conversely, all these factors seemed to have little impact on condom use with occasional partners. Condom use and sexual habits were similarly reported by HIV-positive and HIV-negative IVDUs. The present study shows that high-risk sexual behaviours among IVDUs are very widespread and it stresses the need for intensive counselling to promote condom use among IVDUs.

Risk factors for human immunodeficiency virus infection in 581 intravenous drug users, northeast Italy, 1984-1988. The AIDS and Related Syndromes Study Group.

Prevalence and risk factors for human immunodeficiency (HIV) virus infection were assessed in 581 heterosexual intravenous drug users (IVDUs), recruited from eight public drug assistance centres in the northeast of Italy, an area at low risk for AIDS. The overall seroprevalence for HIV antibody was rather high, 39% (95% confidence interval (CI): 35-43%). HIV prevalence had risen from 32% in 1984-1985 to 52% in 1987-1988. Thirty-three per cent of female and 41% of male IVDUs had antibodies to HIV (p = 0.07). Seropositivity rates showed a strong east-west geographical gradient (from 16% to 60%, p = 0.005): IVDUs living in the western part of the study area had a nearly sevenfold higher risk of infection (odds ratio (OR) = 6.9, 95% CI: 4.4-13.9) than those living in the eastern part. Sharing of drug injection equipment (OR = 3.6), duration of drug addiction (OR = 2.6), use of heroin in high-incidence cities (OR = 2.3), use of cocaine in addition to heroin (OR = 1.5) and history of prostitution (OR = 2.3) increased the risk of acquiring HIV infection. Over the study period, the ORs associated with area of residence decreased, whereas those associated with the use of heroin in high-incidence cities and with prostitution increased.

Zipeprol is a newly abused antitussive with an opioid spectrum and hallucinogenic effects.

Zipeprol is a non-opioid cough suppressor agent recently abused in Italy. Clinical reports from 30 street abusers show that the drug in high doses has a definite abuse liability and dependence potential. Many of its effects were identical to those induced by opiates, although specific dysperceptive symptoms were commonly reported by patients. Spontaneous withdrawal symptoms were similar to those of opiates. Withdrawal could be also precipitated by naloxone. It is concluded that zipeprol can induce dependence with a mechanism which may be mediated by some types of opioid receptors.

Risk factors for HIV infection in drug addicts from the northeast of Italy.

Prevalence and determinants of HIV infection were assessed in 313 parenteral drug addicts admitted to five Centers for Drug-Addict Assistance and two prisons located in the northeast of Italy (Friuli Venezia-Giulia), an area some distance from the major Italian cities first reached by the AIDS epidemic. The overall prevalence of HIV positivity was also rather high in this area, ie 30% with 24-36% confidence interval. The most important risk factors (besides syringe sharing applicable to all drug addicts), turned out to be of a geographical nature, ie living in Pordenone province (where a US military base is located) or coming from other endemic areas and having travelled long distances in the past three years. Prostitution also seemed to increase the risk of infection, but duration of drug addiction had little effect. In addition to persistent generalized lymphadenopathy (closely linked to HIV infection), reversal of helper:suppressor T-cell ratio was found in 67% of HIV positive individuals, but also in 31% of HIV negative ones. Clinical signs and symptoms strongly linked with HIV positivity were fatigue, weight loss, splenomegaly, fever and nocturnal sweats.

Selective reduction of the OKT 4 positive 4B4 positive subset during HTLV III infection in humans.

Combinations of monoclonal antibodies defining the OKT 4 positive lymphocyte subset in the peripheral blood of intravenous drug abusers suggest that the 4B4 positive helper inducer population is greatly reduced in subjects infected with HTLV III. No differences were seen instead using different antibodies directed against various epitopes of the T4 molecule. These results suggest that the multiple marker assay could be very useful to define immunological status during HTLV III infection in humans.

Immunological abnormalities in intravenous drug abusers and relationship to the prolonged generalized lymphadenopathy syndrome in Italy.

The prolonged generalized lymphadenopathy syndrome (PGL) has been considered a prodromal condition to the Acquired immunodeficiency syndrome (AIDS), but the clinical, virological and immunological characteristics of patients who will develop AIDS are not known. We report on the immunological profile of intravenous drug abusers with or without PGL in Northeastern Italy. We found a reduction of lymphocyte-absolute numbers with reversal of the T4/T8 ratio and decreased Leu-11b+ cells. The response to mitogens and natural killer activity are compromised in PGL patients. Neutrophil function is reduced both in drug abusers with or without lymphadenopathy. The serological investigations revealed a high prevalence of antibodies against HTLV III and the Epstein-Barr viruses. The recognition of immune dysfunction in the intravenous drug abusers appears to be important since these patients develop AIDS and these abnormalities may precede AIDS.

HTLV-III infection among 315 intravenous drug abusers: seroepidemiological, clinical, and pathological findings.

Seroepidemiological, clinical, immunological, and pathological features were studied in 315 intravenous drug abusers (IVDA) seen in five centers for drug addicts' assistance in the Friuli Venezia-Giulia region of Italy, close to the borders of Austria and Yugoslavia. No case of AIDS has been observed. Sixty-five (21%) were affected by persistent generalized lymphadenopathy (PGL). HTLV-III seropositivity was noted in 86 (27%) of the overall 315 IVDA, in 50 (77%) of 65 patients with PGL, and in 1 (0.5%) of 205 blood donors tested as a control group. Patients with PGL had a significantly lower OKT4/OKT8 ratio than the rest of the IVDA population and controls. Systemic symptoms were present in 52% of the patients with PGL, the most frequent symptoms being fatigue and night sweats. In 20 patients with PGL, DR typing revealed a significant increase in DR-5 frequency and a significant decrease of DR-2 frequency. The predominant histological features in the lymph nodes taken from 25 patients consisted of an exuberant follicular hyperplasia, capillary vessel proliferation, and plasmacytosis. Nineteen (22%) females reporting occasional prostitution were compared to 10 non-IVDA female prostitutes and concomitantly evaluated. HTLV-III seropositivity was noted in 11 (58%) of 19 IVDA female prostitutes and in none of the 10 non-IVDA prostitutes. Thirty-five couples composed of both IVDA were compared to 24 couples composed of an IVDA and a non-IVDA. Among the 24 couples of whom one or both partners were seropositive, concordance in HTLV-III seropositivity was present in 5/11 (45%) couples composed of both IVDA, and in only 1/13 (8%) couples composed of an IVDA and a non-IVDA. This suggests that the sharing of contaminated needles, universally practiced by our IVDA population, plays a more important role in the transmission of HTLV-III than sexual contact.

Are drawing errors different in right-sided and left-sided constructional apraxics?

The drawings of 70 control subjects, 95 right and 118 left brain-damaged patients (BDP) were evaluated by two independent judges having no knowledge of the literature on constructional apraxia, who were requested to give both a quantitative and a qualitative evaluation of each drawing. Scoring made it possible to classify the BDP as affected or not affected by constructional apraxia. Qualitative errors were classified in two groups: (A) "executive" errors: increased number of right angles, structural simplification of the models and omission of details and (B) "visualspatial" errors: inattention to lateral elements or omission of one half of the figures, errors in spatial relations and diagonal orientation of the drawings. Contrary to expectations, no clear qualitative difference was observed between the drawing errors of right and left BDP. The types of errors most frequently observed in constructional apraxics were very similar, irrespective of lesion side, and consisted in difficulty in reproducing the spatial relations between the various parts of the models and in a tendency to oversimplify the most difficult designs. The only type of error which differentiated right apraxics from left apraxics was omission of lines or of whole figures on the half space contralateral to the damaged hemisphere, but this type of error could not be responsible for right-sided constructional apraxia, since judges had been instructed to base their assessment only on the parts of the models actually reproduced by the patients without scoring as errors manifestations of neglect. These results do not support the hypothesis that two different mechanisms, "executive", and "visual-spatial", underlie constructive disabilities of left and right brain-damaged patients.

Lymph node immunohistology in intravenous drug abusers with persistent generalized lymphadenopathy.

Lymph node biopsy specimens from 16 intravenous drug abusers with persistent generalized lymphadenopathy were evaluated by immunohistochemical methods using a panel of antisera to detect different cell populations. The 11 cases that we tested on cryostat sections showed an increased number of Leu-2a-positive cells (cytotoxic-suppressor phenotype) in the follicular centers and a significantly reduced helper-to-suppressor T-cell mean ratio when compared with control tissues. In these 11 patients the peripheral helper-suppressor ratio was at the lower normal limit or inverted. Ten cases tested for anti-human T-cell lymphotropic virus type III antibodies were positive. In all 16 cases, immunohistology of paraffin-embedded sections demonstrated a polyclonal B population; 12 of 15 patients tested had polyclonal hypergammaglobulinemia, mostly IgG. The mixed-cell population of the lymph node sinuses was composed mostly of Leu-M1-positive and lysozyme-positive cells and, to a lesser extent, by alpha 1-antichymotrypsin-positive and S100 protein-positive cells. It seems that many of the immunologic dysfunctions found in these patients appear to be reflected in a fairly repetitive immunohistologic pattern.