Posted by Ellen on October 29, 1999 at 17:00:55:
I wrote to this researcher and asked specifically "Are you currently doing human trials of islet transplantation? I read the abstract of your report which appeared in Transplantation, September 1999." He replied "yes", but didn't give me any details. Anyone know anymore about this research?
Dr Lorenzo Piemonti MD
Human Islet Team
Lab. Experimental Surgery
Ospedale San Raffaele HSR
Department of Surgery II
via Olgettina 60
20132 milano italy
tel (39)02 26432961
fax (39)02 26412015
e-mail: piemonti.lorenzo@hsr.it
Transplantation 1999 Sep 15;68(5):655-62
Effects of cryopreservation on in vitro and in vivo long-term function
of human islets.
Piemonti L, Bertuzzi F, Nano R, Leone BE, Socci C, Pozza G, Di Carlo V
Department of Surgery, Istituto Scientifico San Raffaele, Universita
degli Studi di Milano, Milan, Italy. piemonti.lorenzo@hsr.it
BACKGROUND: The possibility of performing transplantation several days
after explant seems to be a peculiarity of islet grafts, and the
opportunity to cryopreserve human islets may permit an indefinite period
for modulating the recipient immune system. The aim of the present study
was the evaluation of in vitro and in vivo functional properties of
cryopreserved human islets. METHODS: We used six consecutive human islet
preparations not suitable for an immediate transplantation in diabetic
patients because the limited islet mass separated. The in vitro function
of cryo and fresh islets was studied by determination of insulin and
glucagon secretion in response to such classical stimuli as glucose
(16.7 mM), glucose (16.7 mM) + 3-isobutyl-1-methylxanthine (0.1 mM),
arginine (10 mM), and tolbutamide (100 microM). In vivo islet function
was assessed through intravenous glucose tolerance tests performed at
15, 30, 60, and 90 days after transplantation of 1000 hand-picked fresh
or cryopreserved islets in nude mice. RESULTS: Basal secretion of true
insulin was significantly higher in cryopreserved islets than in fresh
ones. The response of cryopreserved islets to arginine and glucose +
isobutyl-1-methylxanthine seemed partially impaired. Proinsulin-like
molecule secretion seemed higher in cryopreserved than in fresh islets
in response to all secretagogues used, and the difference was
statistically significant for arginine. The capacity of human
cryopreserved islets to maintain a correct metabolic control in diabetic
nude mice was progressively lost in 3 months. CONCLUSIONS: These
findings showed that cryopreservation affects the function of isolated
human islets, maintaining in vivo function for a limited period of time.
Comments:
•Comment in: Transplantation 1999 Sep 15;68(5):597-8
PMID: 10507485, UI: 99435319