Relationship between the extent of the hypoperfused zone of the myocardium and the occurrence of ventricular fibrillation

Ventricular fibrillation and subsequent death frequently occur so soon after coronary artery occlusion that infarct size cannot be determined; thus the systematic study of their relationship is impossible. Recently, however, a technique has been developed that permits the assessment, in vivo, of the extent of the myocardial hypoperfused zone (HZ). Accordingly, in 55 open-chest dogs, 99mTc-labeled (8 mCi) albumin microspheres (15 microns in diameter) were injected into the left atrium 1 minute after coronary artery occlusion. The zone of hypoperfusion was analyzed in 28 dogs that had ventricular fibrillation (group A) and 27 dogs that had no ventricular fibrillation (group B). In group B, the HZ was 26.3 +/- 1.7% of the left ventricle vs 31.6 +/- 1.3% of the left ventricle in group A (p less than 0.05), showing that ventricular fibrillation occurred in dogs with larger zones of hypoperfusion.     

Training and Education Requirements for Authorized Users of Therapeutic Radiopharmaceuticals: Changes Under Consideration for 10CFR35.390 and Their Potential Impact

The US Nuclear Regulatory Commission (NRC) and 38 Agreement States have the regulatory authority to promulgate and enforce regulations related to the use of radioisotopes for medical purposes. Elements of these regulations include training and experience (T&E) requirements for individuals authorized to use the agents. These regulations are specified in 10CFR35.390. At this time, the NRC is considering significant revisions to the T&E requirements. This article describes current regulations and concerns related to the proposed changes and details the ACR organizational response.     

Captopril (SQ 14,225) (d-3-mercapto-2-methylpropanoyl-l-proline): A novel orally active inhibitor of angiotensin-converting enzyme and antihypertensive agent

Relatively potent and specific in vitro and in vivo (oral or intravenous) inhibition of angiotensin-converting enzyme by a nonpeptidic compound, captopril (SQ 14,225; d-3-mercapto-2-methylpropanoyl-l-poline), was demonstrated in excised guinea pig ileum and in rats, rabbits, cats, dogs, and monkeys. The design of captopril was based on a hypothetical model of the active site of the enzyme. Captopril, in vitro or in vivo, was about ten times as potent as teprotide. Inhibition of angiotensin-converting enzyme was evaluated in vitro and in vivo by inhibition of the contractile or vasopressor activity of angiotensin I or by augmentation of the contractile or vasodepressor activity of bradykinin. Acute of subacute dosage with captopril moderately to markedly lowered the blood pressure of the renin-dependent aorticligated and the conscious two-kidney Goldblatt hypertensive rat; in the latter, the effect was intensified by concomitant dosage with a thiazide diuretic. Furthermore, the life-prolonging effects of captopril in renal hypertensive rats were augmented by a thiazide diuretic. In the two-kidney Goldblatt rat, acute captopril (p.o.) was about ten times as potent as teprotide (s.c.) in lowering blood pressure. Acute or subacute oral doses of captopril moderately reduced the blood pressure of the spontaneously hypertensive Wistar-Kyoto rat; chronic dosage almost normalized blood pressure. Captopril produced little or no hypotension in the saltreplete normotensive Wistar-Kyoto rat. Bilateral nephrectomy virtually abolished the hypotensive activity of captopril in the spontaneous hypertensive rat. The results suggest that captopril acts in large part by inhibiting the renin-angiotensin-aldosterone system to reduce elevated blood pressure, especially in renindependent models of hypertension; the roles of the kallikrein-kinin-prostaglandin systems and sodium balance remain to be elucidated. Captopril also lowers blood pressure in apparently non-renin-dependent types of hypertension by mechanisms that are as yet undefined.     

Guide to CAT scanning in hospital psychiatry : Overview of clinical practice and criteria for use

Advances in imaging techniques have resulted in increasing use of computed axial tomography (CAT) in clinical psychiatry. Treatable brain lesions predominantly manifesting as emotional and behavioral symptoms can be detected with relative ease and safety by CAT scanning. Criteria to select these high-risk psychiatric patients for CAT exam are vague and sparse compared to more abundant guidelines for scanning neurologic and medical patients with focal signs of physical abnormality. The few existing surveys of inpatient psychiatry CAT scanning reveal a 65–70% range of normal findings. As more and more patients are scanned, such an obviously large group of “normals” should not be exposed to current CAT exam costs and risks; at the same time, it is necessary to ensure that those psychiatric patients warranting the procedure are not neglected in referral. This article highlights clinical aspects of CAT brain imaging, summarizes the existing literature on inpatient psychiatry CAT scanning, and recommends initial criteria for CAT brain examination of hospitalized patients.     

The nosology of parapsoriasis

Parapsoriasis is a group of uncommon but not rare disorders that was created in 1902 as part of a now long forgotten scheme to classify all inflammatory dermatoses. This artificial grouping has led to an enormously confused nosology of these disorders, that are, for the most part, otherwise unrelated. The use of a number of different terms at different institutions and by different physicians to denote the same diseases, together with the use of particular, single terms to denote different diseases, has caused much unnecessary confusion, In this review these terms are examined and an attempt is made to propose a new, unambiguous classification. Using this system, physicians with different views regarding which of the parapsoriases constitute distinct entities should have no difficulty communicating, and should have a clearer frame of reference within which to work. An attempt is made to evaluate critically which of the parapsoriases are distinct entities and whether one or more of them should be considered an early form of cutaneous lymphoma in light of currently available data.     

Cellular and molecular mechanisms in wound healing: selected concepts

The interactions among cells, structural and other proteins, and large and small molecules in the dermis is an extremely complex, and largely unknown subject in normal skin, so that these interactions in wounded skin are incapable of complete comprehension at present. The problem is compounded by the further reaction and interaction of formed structures within the dermis, such as blood and lymphatic vessels and nerves of all types, and adnexal structures, as well as interactions with the epidermis, which are separately reviewed in the following chapter. In spite of all of this, there are several areas in which research has provided rather extensive insight into the wound healing process. These areas will now be reviewed. A separate review has been provided in this volume of the results obtained using in vitro systems for studies of the wound healing process (Chapter 6).Wound healing has been traditionally divided into three phases: (1) the inflammatory phase, also known as the exudative, lag, or substrate phase; (2) the fibroblastic phase, also known as the connective tissue or proliferative phase; and (3) the remodeling phase, also known as the resorptive or differentiating phase. Although these phases are somewhat arbitrary, we will use them to organize our approach to the problem, dividing our discussion into the inflammatory phase—to which we shall give emphasis—and later developments. Various aspects of the phases of wound healing overlap extensively.