Dr. Vitaliano Tugnoli was graduated with honors from the
University of Bologna in 1981 with a degree in Pharmacology. Since
1/4/2000, he has been a researcher in the Faculty of Medicine and
Surgery, within the Department of Biochemistry. Dr.Tugnoli is
teacher of Chemistry and Propaedeutic Biochemistry in several
courses in the Faculty of Medicine and Surgery and in the PhD in
Biochemistry. Dr. Tugnoli published 129 original article papers and
its research activities primarily involve the application of the
Nuclear Magnetic Resonance Spectroscopy (MRS) in vitro, ex
vivo and in vivo in the study of the metabolic processes
which characterize human healthy and neoplastic tissues. Cerebral
and renal tissues have already been studied, and their relative
neoplasms of various histological types and grading of malignancy.
The use of the MRS to study tissues in vitro is an important
and necessary biochemical prerequisite for more comprehensive
understanding of its uses in vivo. Within this scientific
context, Dr. Tugnoli's activities concern the three areas of
application of the MRS in the biomedical field: MR spectroscopy
in vivo, applied directly on the patient, consisting of a
combination of Magnetic Resonance Imaging (MRI) to define the
volume of interest of the examined organ, and spectroscopy for the
identification of the metabolites contained therein; ex vivo
MRS, performed on an intact biopsy of tissues; and, MRS
spectroscopy in vitro, using either aqueous extracts or
lipid fractions of the aforementioned tissues, removed surgically,
which had been studied in vivo. The first part of the
research involves healthy and neoplastic human cerebral tissues.
The use of a molecular investigation technique such as MRS has
permitted a comparative biochemical description of human cerebral
tissue, between functional and neoplastic. Thus, it has become
possible, using MRS, to identify, in vitro, biochemical
markers of healthy cerebral tissue, and of tumors of varying
histological types and grading. The study conducted on healthy
cerebral tissue produced the following results: the MR spectroscopy
in vivo as well as another one in vitro have
identified in N-acetyl-aspartate (NAA) an amino acid marker of
correct neuronal functioning; it has been found near compounds
containing choline (ChoCC) and creatine (Cr) in virtually equal
concentrations; the absence of resonance attributable to the
presence of mobile lipids in the spectrum, both in vivo and
ex vivo has also been noted. In neoplastic tissues we have
also found: a drastic reduction, to the point of disappearance of
signals relating to NAA, due to neuronal loss in the neoplastic
lesion, confirming that this amino acid is a neuronal marker; a
marked increase in the ratio of choline to creatine; an appreciable
increase in compounds containing choline, which is involved in the
synthesis of cellular membranes, due to the proliferation of
neoplastic cells, and we have correlated this with a
histo-pathological parameter (Ki67). Diverse areas within a single
neoplasm, characterized by higher values of Ki67, have shown higher
values of the ratio ChoCC/Cr. This correlation may be of great
significance if one considers the fact that information regarding
Ki67 can only be obtained by way of an invasive biopsy, while the
choline/creatine ration can be determined non-invasively in
vivo; the presence, within the spectrum in vivo and
ex vivo, of resonance attributable to mobile lipids that
originate as a consequence of the disintegration of the cellular
membrane due to necrotic processes. The mobile lipid-necrosis
correlation permits direct identification of a neoplastic lesion at
a high level of malignancy. Mobile lipids detected via
spectroscopy in vivo in patients with brain tumors assume a
strong clinical significance, indicating an unfavorable prognosis.
Oligodendroglioma (WHO grade II) and anaplastic oligodendroglioma
(WHO grade IV) demonstrate a choline/creatine ratio markedly higher
in the latter case, which accords with a more pronounced cellular
proliferation (higher Ki67) in the higher-level lesion. MRN in
vitro of lipid extracts shows a higher relative concentration
of phosphatidyl-choline of similar malignant neoplasms; moreover,
MRS in vitro of lipid extracts evidences the presence of
non-free, but esterified, cholesterol in tumors of a high
malignancy level. We interpreted the presence of esterified
cholesterol (absent in healthy tissues, and in low-grade neoplasms)
by way of the rich vascularization of these neoplasms, and the
neoplastic cellular proliferation. Also studied were functional and
neoplastic human renal tissue. The scope of the research is to
execute a biochemical map of healthy kidneys, of malignant renal
neoplasms (nefrocarcinomas with clear, chromophile and chromophobic
cells), and of benign renal neoplasms (oncocytomas), in order to
individualize their characteristic biochemical markers. Principal
results obtained thus far: the healthy renal parenchyma, rich in
osmolytes, which are distributed among the cortical and medullar
components. These metabolites maintain a normal osmotic balance
within the renal cell; all of these osmolytes drop drastically or
disappear in nefrocarcinomas with clear cells, and can therefore be
considered markers of the correct functioning of the kidney. It
must be emphasized how the resonance of all these osmolytes is
clearly visible with MRS in vivo, thereby enabling its use
as a monitor. Oncocytomas, benign low-grade neoplasm, appear to
show an intermediate metabolic pattern between that of a healthy
tissue and of a clear-celled malignant nefrocarcinoma. Similarly,
when present in highly malignant cerebral tumors (but not in
healthy parenchyma or benign oncocytomas), the esters of
cholesterol in lipid extracts of clear-celled nefrocarcinomas can
serve as a marker of the vascular proliferation of the neoplastic
lesion, in accordance with a histopathological diagnosis. This
correlation may be of great importance if one considers that for a
highly-vascularized renal tumor, the development of metastases is
highly probable. In addition, the elevated level of cholesterol
esters in clear-celled nefrocarcinomas offers consistent
confirmation of their involvement in neoplastic cellular
proliferation. In fact, it has been recently reported that this
class of lipids was linked to the velocity growth of various lines
of neoplastic cells, and in various experimental tumors. In this
regard, it is very interesting to note the case of a chromophobic
nefrocarcinoma which, similarly to healthy tissue and benign
oncocytomas, does not contain esterified cholesterol. This
neoplasm, in effect, while malignant, is not richly vascularized,
and has a more positive long-term prognosis than a clear-celled
nefrocarcinoma. A more recent line of research refers to the
application of MRS conducted ex vivo by way of HR-MAS (High
Resolution Magic Angle Spinning) performed on human adenocarcinomas
of the gastrointestinal tract. This technique, performed directly
on biopsied tissues using a probe that rotates the sample to the
so-called magic angle makes it possible to view high-resolution
spectra of an intact tissue, without any treatment. The possibility
of using the most modern bi-dimensional techniques (COSY, TOCSY,
J-resolved, etc.) allows unambiguous identification of tissue
metabolites, furnishing the metaboloma of the tissue sample
examined.It is thus possible to provide a complete description of a
functional or neoplastic tissue from the point of view of its
biochemical composition, permitting the identification of
biochemical markers of great diagnostic and/or prognostic
importance.
