Understanding causal mechanisms in the study of group bias.

Causal mechanisms' portability and their predictions in sometimes counterfactual settings point to the value of studies with details of interactions and/or convenience samples that depart from those in the proximate contexts of the phenomena of interest. The proper role of such contexts must be construed within an explanatory framework attentive to the nature and properties of relevant causal mechanisms.

Resolution of Cannabinoid Hyperemesis Syndrome with Benzodiazepines: A Case Series.

Background: Cannabinoid hyperemesis syndrome (CHS) is under-recognized by clinicians. It is characterized by nausea, severe abdominal pain, and cyclical vomiting in the context of chronic cannabis use. Oral benzodiazepine is a proposed treatment for CHS.

Scintigraphic evaluation of colonic transit in children with constipation using Ga-citrate.

The aim of this study was to assess the colonic transit in children and teenagers with chronic constipation. Twenty patients from 1.5 to 16 years old were included (mean age = 6.

Synovectomy using Samarium-153 Hydroxyapatite in the Elbows and Ankles of Patients with Hemophilic Arthropathy.

This study aimed to evaluate synovectomy with samarium-153 hydroxyapatite (Sm-HA) in synovitis of the elbows and ankles of hemophilic patients. The synovectomy was performed using 185 MBq of Sm-HA in 166 joints of 82 hemophilic patients, with a mean age of 24.4 years and follow-up of 12 and 42 months, comprising 63 ankles and 84 elbows.

Developing the Totality of Evidence for Biosimilars: Regulatory Considerations and Building Confidence for the Healthcare Community.

Biosimilars are highly similar versions of approved branded biologics. Unlike generics, they are not exact replicas of reference products. Minor differences between biosimilars and reference products in some aspects are expected; likewise, biosimilar products will differ from each other.

Quality of measurements of acute surgical and traumatic wounds using a digital wound-analysing tool.

The aim of this study was to assess the reliability of measurements using a wound-analysing tool and their interpretability. Wound surface areas and tissue types, such as granulation, slough and necrosis, in twenty digital photographs were measured using a specific software program. The ratio of these tissue types in a wound was calculated using a wound profile.

Comparison of the effect of knee synovectomy in haemophilic patients with 153Sm- and 90Y-labelled hydroxyapatite 1 year after.

To compare the use of 740 Mbq (20 mCi) of (153) Sm and 185 Mbq (5mCi) of (90) Y, both labelling hydroxyapatite (HA), for knee synovectomy in haemophilic patients, 1 year after the intervention. Thirty three men (36 knees) were studied, divided into two groups: 1 - treatment using 740 Mbq of (153) Sm-HA: 20 knees of 18 patients, with mean age of 21.4 ± 13.

Normative study of tympanic infrared thermometry: a non-invasive index of asymmetric cerebral activity.

Human and primate studies have demonstrated that performance of tasks that induce asymmetrical physiological activation of the cerebral hemispheres leads to a reduction of tympanic temperature (TT) ipsilateral to the most active hemisphere. It is possible that diseases that interfere in an asymmetrical fashion with the degree of cerebral activity cause similar TT changes. There are not, however, normative studies of the acceptable interaural difference in TT in normal subjects at rest.

Ventriculotomy repair during revascularization of intracavitary anterior descending coronary arteries.

Optimal revascularization of the rare variant anomolous intracavitary left anterior descending coronary artery requires, by definition, entrance into the right ventricular cavity. We present a simple method to repair the ventriculotomy without risk of obliterating the left anterior descending coronary artery, septal perforators, or diagonal branches.

Severe deformity of a Palmaz-Schatz stent after normal surgical manipulation.

This report describes a case in which normal surgical manipulation during dissection of the heart while performing a repeat revascularization procedure produced a significant deformity in Palmaz-Schatz stents previously implanted in a saphenous vein graft. The graft had shown satisfactory angiographic appearance immediately before the operation, and consideration was given to leaving it in place. Its replacement, however, prevented a major intraoperative mishap.

Successful myocardial revascularization and neurologic recovery in a patient with prolonged refractory cardiac arrest and a chronically occluded left internal carotid artery.

Heretofore, the longest successfully treated cardiac arrest reported in the literature, secondary to myocardial ischemia, was one that required 45 minutes of cardiopulmonary resuscitation before coronary bypass surgery. We present a unique case of successful resuscitation after a cardiac arrest secondary to myocardial ischemia. The arrest lasted 78 minutes (30 minutes of closed cardiac massage and 48 minutes of open cardiac massage).

Awake discography. A comparison study with magnetic resonance imaging.

This study was undertaken to determine the correlation between awake discography findings and magnetic resonance imaging in the evaluation of symptomatic lumbar disc disease. The study included 164 consecutive patients who underwent evaluation with discography and magnetic resonance imaging for lumbar disc disease from August 1987 to September 1989. Chronic low-back pain, with or without radicular symptoms, was the presenting complaint in each case.

Verapamil versus placebo in relieving stable angina pectoris.

Verapamil and placebo were compared in patients with stable, effort-induced angina. Single-blind dose titration (240, 360 and 480 mg/day) preceded a double-blind crossover. Among the 18 patients who completed graded exercise stress tests with reproducible pretreatment effort-limiting angina, exercise duration increased from 348 +/- 127 seconds (SD) before treatment to 494 +/- 182 seconds after verapamil (p less than 0.

Exercise duration to angina at two and twelve hours after timolol.

Eight patients who improved their exercise duration to angina or marked fatigue (greater than or equal to 25%) on timolol 10 to 30 mg twice daily over that on placebo 8 to 14 mo previously were subjects in a double-blind, randomized, crossover 4-wk study of the effect of timolol on exercise duration 2 and 12 hr after medication. One patient was discontinued from the study because unstable angina developed on placebo. Mean exercise duration on timolol over control was increased at 12 hr (p less than 0.

Effect of acebutolol and propranolol on premature ventricular complexes.

A double-blind, randomized study comparing the efficacy of intravenous acebutolol with propranolol on frequent premature ventricular complexes (PVCs) in 24 patients is reported. Frequent PVCs were abolished or reduced by 75% or more in 10 of 12 patients (83%) given acebutolol and in 10 of 12 patients (83%) given propranolol. The therapeutic effect of acebutolol lasted for at least 1 hr in 4 of 12 patients (33%), for at least 3.

Verapamil in atrial fibrillation and atrial flutter.

A double-blind randomized study was performed to compare the efficacy of intravenous verapamil with saline in 28 patients with a rapid ventricular rate and atrial fibrillation or atrial flutter. Conversion of atrial fibrillation to sinus rhythm occurred in none of 14 patients after saline and in 3 of 20 patients (15%) 7 to 160 min after verapamil. The ventricular rate in atrial fibrillation was slowed greater than or equal to 15% in 2 of 14 patients (14%) by saline, in 17 of 20 patients (85%) by 1 dose of verapamil (p less than 0.