“ A.T. 10 “ AND DIHYDROTACHYSTEROL

The effect of pure dihydrotachysterol (D.H.T.) was compared with that of the old “ A.T. 10 ” in eight patients with hypoparathyroidism, and it was found that the “ A.T. 10 ” available in 1963–1964 was equivalent in therapeutic activity to 0.1 mg. of D.H.T. per capsule (or 0.2 mg. of D.H.T. per millilitre). It is concluded that the new “ A.T. 10 ” (containing 0.25 mg. of D.H.T. per millilitre) is 25% stronger than the old, and that patients whose therapy is changed to the new preparation in the same dose (by volume) may occasionally develop hypercalcaemia as a result. The history of the various changes in the methods of assay of “ A.T. 10 ” is reviewed and the reasons why they were all fallacious are explained. As judged by reported maintenance doses, the “ A.T. 10 ” available in 1963–1964 was only one-third as potent in the treatment of hypoparathyroidism as that available in 1934–1942.     

How Do Physicians Define “Light,”“Moderate,” and “Heavy” Drinking?

Although widely used, terms associated with consumption of alcohol–such as "light,""moderate," and "heavy"—are unstandardized. Physicians conveying health messages using these terms therefore may impart confusing information to their patients or to other physicians. As an initial attempt to assess if informal standardization exists for these terms, the present study surveyed physicians for their definitions of such terms. Physicians operationally defined "light" drinking as 1.2 drinks/day, "moderate" drinking as 2.2 drinks/ day, and "heavy" drinking as 3.5 drinks/day. Abusive drinking was defined as 5.4 drinks/day. There was considerable agreement for these operational definitions, indicating there is indeed an informal consensus among physicians as to what they mean by these terms. Gender and age did not influence these definitions, but self-reported drinking on the part of physicians was a factor. We also asked physicians for their opinions regarding the effects of "light,""moderate," and "heavy" drinking on health in general and specifically on health-related implications for pregnant women, and whether they felt their patients shared these beliefs.     

Cardiac resynchronization therapy: “Nonresponders” and “hyperresponders”

BACKGROUND: Cardiac resynchronization therapy (CRT) is a recognized treatment modality for patients with dilated cardiomyopathy (DCM), left bundle branch block, and severe cardiac failure. However, 30% of patients are "nonresponders." Intriguingly, the opposite case has not been reported until recently: Do some patients treated with CRT have a "complete" recovery and thus can be considered "hyperresponders"? OBJECTIVE: The purpose of this study was to investigate patients treated with CRT who have a "complete" functional recovery, with normalization of left ventricular function after therapy. METHODS: Eighty-four consecutive patients with DCM, sinus rhythm, and left bundle branch block in New York Heart Association functional class III and IV who were implanted with a CRT device were prospectively followed. Patients were considered to be "hyperresponders" if they concurrently fulfilled two criteria: functional recovery and left ventricular ejection fraction > or = 50%. RESULTS: Among the 84 patients with DCM, 11 (13%) were "hyperresponders" within 6 to 24 months after CRT (left ventricular ejection fraction increased from 25% +/- 8% to 60% +/- 6.5%, P = .001). Comparison of baseline parameters between "hyperresponders" and the remaining patients showed that only etiology of the DCM was statistically discriminative. All "hyperresponders" belonged to the group of patients with nonischemic DCM (18% vs 0%, P = .05). CONCLUSION: In a subset of patients successfully implanted with a CRT device, "complete" functional recovery associated with normalization of LV function was observed, giving rise to the concept of "hyperresponders." This finding is observed exclusively in the subgroup of patients with nonischemic DCM and suggests that left bundle branch block may be the causal factor of DCM in this subgroup of patients.     

“Bacteroides” bacteremia

Clinical and bacteriologic data relating to 250 patients with bacteremia due to anaerobic, nonsporulating, gram-negative bacilli, “bacteroides,” were analyzed. A total of 433 human blood culture specimens submitted included nine Bacteroides species and four species of Fusobacterium; twenty-nine were mixed with other microorganisms. The characteristic clinical syndrome consisted of hectic fever, rigors and diaphoresis. The gastrointestinal tract was the probable portal of entry for the majority of Bacteroides, the lung and oropharynx for Fusobacterium species. Prior surgery, malignant neoplasms, diabetes mellitus, and steroid, immunosuppressive or cytotoxic therapy were common associated factors. Emboli, thrombophlebitis, endocarditis and metastatic abscesses were common complications. The over-all mortality of the patients was 32 per cent. The mortality of patients with B. fragilis bacteremia, the most common organism involved, was 34 per cent. The death rate of patients with B. oralis and B. variabilis was approximately 70 per cent, but none of the patients with B. melaninogenicus bacteremia died. Patients treated with tetracyclines, sulfonamides, incision and drainage, or a combination of these, showed the highest survival rate.     

Identification of “substrate fibrillators” and “trigger fibrillators” by pacemaker diagnostics

BACKGROUND: The population of patients likely to respond to selected pacing algorithms for maintenance of sinus rhythm is unknown. OBJECTIVES: The purpose of this study was to identify patients with specific onset patterns of paroxysmal atrial fibrillation (AF). METHODS: Dual-chamber pacemakers with advanced diagnostic functions were implanted in 112 patients with conventional indications for antibradycardia pacing and a history of paroxysmal AF. Pacemaker diagnostic data were analyzed after 97.5 +/- 40.9 days. According to the frequency of premature atrial contractions (PACs) during the 5 minutes before AF onset, patients were assigned to one of three groups: group A (high PAC activity), group B (moderate PAC activity), or group C (low PAC activity). RESULTS: AF burden was lower in group A (4.6% +/- 2.4%) than group B (15.8% +/- 3.0%, P = .003) and group C (15.5% +/- 3.1%, P = .003). Fewer AF episodes occurred in group A (2.1 +/- 1.3 per day) than group B (3.8 +/- 1.2 per day, P = .006). Mean AF episode duration was shorter in group A (11.4 +/- 10.2 hours) than group C (41.4 +/- 27.5 hours, P = .03). CONCLUSION: The coincidence of low PAC activity before AF onset, high AF burden, and extended arrhythmia episode duration appears to be the consequence of a high atrial substrate factor. In these "substrate fibrillators," the efficacy of pacing algorithms for maintenance of sinus rhythm may be limited. In contrast, "trigger fibrillators" exhibiting low AF burden despite high PAC incidence may represent the target population for specific PAC-suppressing pacing algorithms.