A model for the organization of a regional bank for musculoskeletal tissues in Italy.

The national and local need for human tissues to be used in transplants is a high one, and constantly growing. Human, scientific and financial resources involved in guaranteeing safe and high-quality tissues as defined by the national guidelines for musculoskeletal tissue banks are considerable. For this reason we need to find adequate solutions to the problem of guaranteeing sufficient availability of tissues with the lowest cost possible for supply. The Piedmont Region Musculoskeletal Tissue Bank, which is located in an Azienda Ospedaliera, has been organized to guarantee the quality of its tissues via biological validation and scientific-clinical coordination; it makes use of the collaboration of removal centers that send tissues taken from the central bank for certification and identifies several centers for preservation; it collaborates with a bank of national importance for tissue processing. The publication of regulations and tariffs based on cost analysis improves the procedures.

Identification of a novel protein phosphatase 2A regulatory subunit highly expressed in muscle.

Differential association of regulatory B subunits with a core heterodimer, composed of a catalytic (C) and a structural (A) subunit, is an important mechanism that regulates protein phosphatase 2A (PP2A). We have isolated and characterized three novel cDNAs related to the B' subunit of bovine cardiac PP2A. Two human (B'alpha1 and B'alpha2) and a mouse (B'alpha3) cDNA encode for alternatively spliced variants of the B subunit. The deduced primary sequences of these clones contain 12 of 15 peptides derived from the purified bovine B' subunit. Differences between the deduced sequences of the B alpha splice variants and the cardiac peptide sequences suggest the existence of multiple isoforms of the B' subunit. Comparison of the protein and nucleotide sequences of the cloned cDNAs show that all three forms of B'alpha diverge at a common splice site near the 3'-end of the coding regions. Northern blot and reverse transcription-polymerase chain reaction analyses revealed that the B'alpha transcripts (4.3-4.4 kb) are widely expressed and very abundant in heart and skeletal muscle. The expressed human and mouse B'alpha proteins readily associated with the PP2A core enzyme in both in vitro and in vivo complex formation assays. Immunofluorescence microscopy revealed that epitope-tagged B'alpha was localized in both the cytosol and nuclei of transiently transfected cells. The efficiency of binding of all three expressed proteins to a glutathione S-transferase-A subunit fusion protein was greatly enhanced by the addition of the C subunit. Expression of the B'alpha subunits in insect Sf9 cells resulted in formation of AC.B'alpha heterotrimers with the endogenous insect A and C subunits. These results show that the B' subunit, which is the predominant regulatory subunit in cardiac PP2A, is a novel protein whose sequence is unrelated to other PP2A regulatory subunits. The nuclear localization of expressed B'alpha suggests that some variants of the B' subunit are involved in the nuclear functions of PP2A.

Effect of angiotensin-converting enzyme inhibitor (SQ 20881) on the plasma concentration of angiotensin I, angiotensin II, and arginine vasopressin in the dog during hemorrhagic shock.

The effect of an angiotensin-converting enzyme inhibitor on the circulating levels of angiotensin I, angiotensin II, and arginine vasopressin was studied in dogs subjected to hypotensive hemorrhagic shock. In dogs subjected to hemorrhage but not given the inhibitor, angiotensin II rose 20-fold (from 69 to 1,343 pg/ml of plasma), whereas in dogs subjected to hemorrhage but pretreated with the inhibitor, angiotensin II rose only 2-fold (from 92 to 171 pg/ml of plasma). In the pretreated dogs angiotensin I rose 30-fold (from 108 to 3,232 pg/ml of plasma). There was no statistically significant difference between the vasopressin levels found in the untreated dogs and the levels found in dogs given the inhibitor (1,016 and 1,095 pg/ml of plasma). Of the 15 dogs in the untreated group, five died before retransfusion was completed (four of cardiac failure and one of cardiac arrhythmia); none of the 10 dogs in the inhibitor-treated group died. These observations suggest that the very high levels of angiotensin II observed following severe hemorrhage do not contribute significantly to the increased secretion of vasopressin and that the inhibitor protects against death, possibly by suppressing the very high blood levels of angiotensin II observed following this type of experimental hemorrhagic shock.

Necrotizing fasciitis.

The author's experience of fourteen patients with necrotizing fasciitis is reviewed. The pathognomonic feature of this condition is an extensive necrosis of subcutaneous tissue caused by a vicious cycle of infection, local ischaemia and reduced host defence mechanisms. The diagnosis can only be confirmed by immediate exploratory incision. The reported mortality of 30-40% reflects the inadaquacy of conservative surgery in the treatment of this serious condition. Mortality can be reduced by early recognition followed by radical excision of the necrotic fascia and overlying skin. The preservation and subsequent use of the excised skin has the advantage of economy in the use of donor areas and reduction in morbidity. Hyperbaric oxygen therapy does not halt the spread of the necrotizing process and is not a substitute for radical surgery.

Diagnosis, clinical course and treatment of acute dermal gangrene.

Twenty patients with acute dermal gangrene following surgery, trauma or sepsis are described. In 12 the skin became gangrenous secondary to a necrotizing process affecting the subdermal fascia, and in 8 the condition arose primarily in the skin. In the first group mortality was high unless radical excision of the necrotic fascia was performed at an early stage; in 3 of the recent patients the overlying skin was removed, defatted and stored for later grafting. In the second group, incision and adequate drainage combined with antibiotics seemed to suffice. Hyperbaric oxygen was of dubious value in the first group but appeared to contribute to arrest of the lesion in the second group.