Anatomical study of serotonergic innervation and 5-HT(1A) receptor in the human spinal cord

Serotonergic innervation of the spinal cord in mammals has multiple roles in the control of motor, sensory and visceral functions. In rats, functional consequences of spinal cord injury at thoracic level can be improved by a substitutive transplantation of serotonin (5-HT) neurons or regeneration under the trophic influence of grafted stem cells. Translation to either pharmacological and/or cellular therapies in humans requires the mapping of the spinal cord 5-HT innervation and its receptors to determine their involvement in specific functions. Here, we have performed a preliminary mapping of serotonergic processes and serotonin-lA (5-HT_1A) receptors in thoracic and lumbar segments of the human spinal cord. As in rodents and non-human primates, 5-HT profiles in human spinal cord are present in the ventral horn, surrounding motoneurons, and also contact their presumptive dendrites at lumbar level. 5-HT_1A receptors are present in the same area, but are more densely expressed at lumbar level. 5-HT profiles are also present in the intermediolateral region, where 5-HT_1A receptors are absent. Finally, we observed numerous serotonergic profiles in the superficial part (equivalent of Rexed lamina II) of the dorsal horn, which also displayed high levels of 5-HT_1A receptors. These findings pave the way for local specific therapies involving cellular and/or pharmacological tools targeting the serotonergic system.

The effects of circulating antigen on the pharmacokinetics and radioimmunoscintigraphic properties of 99m Tc labelled monoclonal antibodies in cancer patients

PURPOSE. This article reports the pharmacokinetics, radiation dosimetry and radioimmunoscintigraphy (RIS) of two (99m)Tc-labelled monoclonal antibodies (MAb) used to detect cancer.

METHODS

The effects of circulating antigen in female cancer patients are explored and their effects on the ability of these MAbs to effectively perform as RIS agents noted. To illustrate the effects of circulating antigen, data using MAb B43.13 (OVAREX, AltaRex Corp., Waltham, MA, USA) from a Pilot study in ovarian cancer patients are presented. The results from a Phase II study of MAb 170H.82 (Tru-Scint AD, BIOMIRA INC., Edmonton, Alberta, Canada) in patients with primary and locally recurrent breast cancer were used to portray the biodistribution patterns when no circulating antigen is present. Data from planar gamma camera images were obtained for both groups and used for pharmacokinetic and radiation dosimetry analyses.

RESULTS

A pharmacokinetic analysis indicated a shorter residence time and higher clearance of (99m)Tc-MAb-B43.13 that was ascribed in part to the circulating CA 125 antigen in this group of ovarian cancer patients.

CONCLUSION

These clearance patterns resulted in acceptable, though higher radiation doses to the spleen and urinary bladder wall for these patients when compared to the MAb-170H.82 group. Both MAbs were found to produce acceptable radioimmunoscintigraphic images

Pre-operative assessment of axillary lymph node status in patients with breast adenocarcinoma using intravenous 99mtechnetium mAb-170H.82 (Tru-Scint AD)

Immunoscintigraphy of the axilla has potential utility for the diagnostic and prognostic assessment of patients with breast adenocarcinoma. mAb-170H.82 is a murine monoclonal antibody (mAb) derived against synthetic Thomsen-Friedenreich (TF) antigen. Tru-Scint AD, a 99mTc-mAb-170H.82 immunoconjugate, has previously been shown to localize in various human adenocarcinomas. The purpose of this study was to evaluate the accuracy of this immunoconjugate in the pre-operative assessment of axillary lymph nodes in patients with known breast adenocarcinoma. Sixteen patients with documented primary breast cancer were injected intravenously with 1 mg of immunoconjugate (radioactivity 1.8 GBq) and imaged 22-24 hrs post-injection. Both planar and single photon emission computed tomographic (SPECT) images were obtained and reviewed in a blinded fashion. Imaging results were compared with surgical and pathological findings. Seven of 16 patients were found to have histologically positive axillary nodes: 5 of these sites were detected by immunoscintigraphy (sensitivity = 71%). Nine patients had pathologically disease-free axillary nodes: only 1 of these was misidentified as positive by immunoscintigraphy (specificity = 89%). These results suggest that immunoscintigraphy with 99mTc-mAb-170H.82 has promise in the detection of axillary lymph node involvement in patients with breast cancer. Further studies are warranted to define the role of immunoscintigraphy in axillary staging.

Radioimmunoscintigraphy with Tc-99m labeled monoclonal antibody 170H.82 in suspected primary, recurrent, or metastatic breast cancer

Radioimmunoscintigraphy (RIS) with Tc-99m labeled 170H.82, an intact murine monoclonal antibody (MAb) was performed in 27 patients with suspected primary, recurrent, or metastatic breast cancer. For radioimmunoimaging the authors used a double-headed, high-resolution gamma camera. The lesions detected by RIS were evaluated by histopathology, and for metastatic disease by CT, MRI, and bone scan. If the evaluation was made lesion by lesion, RIS with Tc-99m MAb 170H.82 showed 23 true-positive results, 3 false-negative results, 9 true-negative results, 3 false-positive results for primary and recurrent disease; sensitivity was 88% and specificity was 75%. In patients with distant metastases, detection rate was 67% (12 true-positive results and 6 false-negative results). All patients had normal baseline values for human anti-mouse antibodies (HAMA) and 6 weeks after RIS with 2 mg MAb, only 2 of 23 patients had developed a HAMA response (9%). No adverse effects were observed. The authors' clinical experience shows that RIS with MAb 170H.82 is a valuable additional method for detecting breast cancer, especially in patients with uncertain primaries or scar tissue after breast conserving treatment in which differential diagnosis is very difficult.

Radioiodinated peanut lectin: clinical use as a tumour-imaging agent and potential use in assessing renal-tubular function

Peanut lectin (PNA) has been shown to have a high affinity for Thomsen-Friedenreich (T) antigen, which is associated with the membrane of many solid tumour cells. PNA labelled with 131I was used as a tumour-imaging substance in patients with known metastatic cancer. Serial gamma scintiscans were obtained in 17 patients following a single injection of 131I-labelled PNA. Only in 1 patient was this technique able to reveal a known metastasis at analogue imaging. In the remaining patients, no visible uptake of 131I-PNA could be demonstrated at sites of known metastases. PNA is rapidly excreted through the kidneys and localizes in the renal tubules. As a tumour-imaging agent, 131I-PNA appears to be without value, but its renal-excretory characteristics make it a potentially useful agent for the in vivo assessment of renal-tubular disorders.

[Hemodynamic and coronarographic evaluation for identification of high risk patients following myocardial infarction]

The prognosis of patients surviving myocardial infarction is influenced by a high early mortality rate. The aim of this study was to assess the prognostic value of cardiac catheterisation and coronary angiography performed early after infarction to identify patients at high risk. Two hundred patients including 10 women with an average age of 49.1 +/- 8.6 years surviving (greater than 1 month) primary myocardial infarction underwent haemodynamic and coronary angiographic investigations on average 26 days after the onset of infarction (26 +/- 17 days, range 1 to 90 days). All patients were followed up for average period of 43.2 +/- 13.3 months. The overall mortality rate was 13.5% (27/200). The commonest cause of demise was sudden death: 52% (14/27). Most patients died within the first year of infarction (11/27). Indices of left ventricular function (left ventricular end diastolic pressure and ejection fraction) were significantly more pathological in the patients who died. Similarly, there were many more patients with multivessel (93%) and triple vessel disease (63%) in this sub group (p less than 0,001). Analysis of actuarial survival with respect to ejection fraction demonstrated the prognostic importance of this factor, especially during the first year: 38.5% mortality in patients with ejection fractions below 30%. Triple vessel disease was associated with 13% mortality in the first year. When these two factors were combined, the risk of death in the first year was 50%, so identifying a very high risk subgroup. On the other hand, no deaths were observed in patients with a single coronary lesion and normal left ventricular function (ejection fraction greater than 50%) during 72 months follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)