Muscle necrosis in the extremities: evaluation with Tc-99m pyrophosphate scanning--a retrospective review

A retrospective review was done of 34 extremities studied between 1981 and 1985 with technetium-99m pyrophosphate scanning; 22 were subsequently amputated. Results of detailed pathologic examination or immediate postoperative examination of the resected extremity were available in 16 cases. In these cases, scanning had allowed correct prediction of the level of amputation and of the specific areas of muscle infarction in 13 cases. In the one case in which amputation was performed for infection rather than muscle necrosis, the lack of necrosis was correctly predicted with the scan. The limited results of this study indicate that the Tc-99m pyrophosphate scan allows the location of necrotic muscle to be predicted accurately and may therefore be a useful adjunct in determining the best level for ultimate amputation. Special caution is required in those cases in which muscle necrosis is due to acute causes (e.g., traumatic thrombosis) rather than chronic vascular disease.     

Prenatal diagnosis of neural tube defects.

A prospective program for the prenatal detection of neural tube defects in a high-risk pregnancy group has been under way for one year. Twenty high-risk mothers have undergone a complete prenatal work-up, including sonography, amniocentesis, and amniotic fluid and maternal serum alpha-fetoprotein quantitation. Within this group, two cases were prospectively diagnosed and were later confirmed.     

Autosomal dominant polycystic kidney disease in pregnancy complicated by twin gestation and severe preeclampsia: a case report

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD), an autosomal dominant genetic disorder with a reported prevalence of 1 in 1,000, may be associated with hypertensive disease in pregnancy. The evaluation of a pregnant woman with an adult-onset genetic disorder is complex and involves counseling about inheritance, prenatal diagnosis and management of the current pregnancy. CASE: A 33-year-old woman presented for obstetric care with a history of hypertension and ADPKD for 6 years. The patient had secondary infertility, which was treated by in vitro fertilization. The case was complicated by twin gestation and superimposed severe preeclampsia, leading to preterm cesarean delivery at 26 weeks' estimated gestational age. CONCLUSION: Because of the heritable nature of ADPKD and the long-term risk of end-stage renal disease requiring dialysis and/or renal transplantation, the evaluation and counseling of women with ADPKD who are pregnant or considering pregnancy should include a discussion of the modes of inheritance, natural history, available prenatal diagnostic options, and pregnancy risks and management options. Specific counseling issues in this case include the genetic concepts of variable expression and penetrance and the medical management of chronic hypertension and preeclampsia.     

Pulse sequence optimization for MR imaging using a paramagnetic hepatobiliary contrast agent

Paramagnetic agents enhance contrast between tissues in magnetic resonance (MR) imaging by altering tissue relaxation times. The effect of these changes on MR image intensity depends in part on the choice of operator-controlled pulse sequence parameters. With the newly described paramagnetic hepatobiliary contrast agent, iron(III) ethylenebis-(2-hydroxyphenylglycine), Fe(EHPG)-, an in vivo experimental analysis of pulse sequence optimization was performed on the rat. We compared the enhancement of the liver divided by background noise, EL/N, of standard inversion-recovery (IR) and spin-echo (SE) T1-weighted pulse sequences and several pulse sequences theoretically predicted to have improved EL/N. Optimization of the echo time (TE = TEmin) gave a substantial (greater than 60%) increase in EL/N over the standard IR and SE pulse sequences. Images obtained with optimized repetition rate and inversion time gave only a slight additional improvement. Within the uncertainties of our relaxation measurements, the measured changes in EL/N with pulse sequence optimization corresponded well with theoretical predictions. With the experimental and theoretical data, the importance of using a short echo time to obtain maximal T1 contrast in contrast-enhanced MR imaging and the relative merits of optimized SE versus IR pulse sequences for contrast-enhanced MR imaging are discussed.     

Noncontingent footshock attenuation of retrograde amnesia: a generalization effect

Mice were either well trained and rendered amnesic with transcorneal electroconvulsive shock (ECS) or poorly trained on a one-trial inhibitory avoidance task and given a retention test 24 and 48 hr later. Noncontingent footshock administered either 1 hr after the training or 1 hr after the 24 hr test significantly increased retention latencies of groups which had received training and ECS, as well as those of groups which were poorly trained. These findings suggest that animals which are partially amnesic or poorly trained are able to generalize the effects of a subsequent NCFS experience to the inhibitory avoidance training task.     

Novel transient receptor potential vanilloid 1 receptor antagonists for the treatment of pain: structure-activity relationships for ureas with quinoline, isoquinoline, quinazoline, phthalazine, quinoxaline, and cinnoline moieties

Novel transient receptor potential vanilloid 1 (TRPV1) receptor antagonists with various bicyclic heteroaromatic pharmacophores were synthesized, and their in vitro activity in blocking capsaicin activation of TRPV1 was assessed. On the basis of the contribution of these pharmacophores to the in vitro potency, they were ranked in the order of 5-isoquinoline > 8-quinoline = 8-quinazoline > 8-isoquinoline > or = cinnoline approximately phthalazine approximately quinoxaline approximately 5-quinoline. The 5-isoquinoline-containing compound 14a (hTRPV1 IC50 = 4 nM) exhibited 46% oral bioavailability and in vivo activity in animal models of visceral and inflammatory pain. Pharmacokinetic and pharmacological properties of 14a are substantial improvements over the profile of the high-throughput screening hit 1 (hTRPV1 IC50 = 22 nM), which was not efficacious in animal pain models and was not orally bioavailable.     

Factors influencing outcome of lamivudine in anti-HBe-positive chronic hepatitis B

BACKGROUND/AIMS: Lamivudine has been shown to benefit patients with anti-HBe/HBV-DNA-positive chronic hepatitis B. The aim of the study was to evaluate factors influencing outcome of lamivudine therapy during two years of post-treatment follow-up in a prospective clinical trial. METHODOLOGY: Thirty-one consecutive patients, submitted to liver biopsy, were treated with lamivudine at 100mg/daily for twelve months and followed-up for twenty-four months. The patients were never treated before with interferon or stopped at least six months before starting lamivudine. ALT was measured monthly and HBV-DNA every three months. RESULTS: At the end of therapy 25 (81%) patients had both biochemical and virological response; 2 (6%) patients showed persistent viremia and 4 (13%) patients developed viral resistance during treatment. Twenty-three (92%) out of 25 responders relapsed during the follow-up; over 50% of all cases relapsed within 6 months. The relapse is related to higher HBV-DNA baseline levels. At relapse, 4/23 (17%) patients had symptomatic acute hepatitis. CONCLUSIONS: Lamivudine is associated with the risk of developing viral mutants and, after therapy discontinuation, to high rate of relapse. In relapsing patients severe acute recurrence of hepatitis B may occur. Decisions about lamivudine monotherapy should take into account the limited long-term efficacy, effects of relapse, costs and predictive factors for response.