Regulation of pool sizes and turnover rates of amino acids in humans: 15N-glycine and 15N-alanine single-dose experiments using gas chromatography—Mass spectrometry analysis

Gas chromatography—mass spectrometry (GCMS) of plasma amino acid derivatives has been used to determine directly the ¹⁵N-enrichment of plasma glycine and alanine in ten volunteers at various metabolic states. Isotope-enrichment time-decay curves of plasma glycine and alanine, following a single intravenous dose of ¹⁵N-glycine or ¹⁵N-L-alanine were obtained and provide an estimate of the extracellular compartment. Relatively narrow ranges were obtained for the glycine pool ($\text{7.7–11.8 μ}\text{mole}\text{100 g}\text{body wt}$), rate constants of transport (3.7–4.2 hr^?1) and flux ($\text{28–43 μ}\text{mole hr}{}^{\mathrm{?1}}\text{100 g}\text{body wt}$) in the postabsorptive state. In postprandial humans, pool sizes showed only a modest variation whereas the rate constants of transport of glycine and alanine were significantly lower. The plasma ¹⁵N-glycine and ¹⁵N-alanine isotope-enrichment time-decay curves over the first hour following a single i.v. dose of ¹⁵N-amino acid represent mostly the hepatic uptake of glycine and alanine from the extracellular pool. The results presented in this study establish the stable isotope GCMS method as a more accurate, more convenient, and safe alternative to the use of radioactive labeled amino acids in studies of amino acid metabolism in human subjects.     

Inverse correlation between coronary and retinal blood flows in patients with normal coronary arteries and slow coronary blood flow

Background

The “Slow Coronary Flow” (SCF) phenomenon in the presence of angiographically normal coronaries is attributed to microvascular and endothelial dysfunction. The microcirculation can be non-invasively assessed by measuring retinal blood flow velocity.The aim of the present study was to evaluate the efficacy of the “Retinal Functional Imager” (RFI) device as a noninvasive method of diagnosing patients with slow coronary flow.

Methods

Coronary blood flow velocity assessed by corrected TIMI Frame Count and retinal arterioles blood flow assessed by RFI were measured in 28 consecutive patients with normal coronary arteries. The patients were divided into 2 groups: a slow coronary flow (SCF) and a normal coronary flow (NCF) groups.

Results

Inverse correlation was found between retinal and coronary blood flows so that higher retinal arterial flow velocity was observed in the SCF group (3.8 ± 1.1 mm/s vs. 2.9 ± 0.61 mm/s, respectively, p = 0.022). RFI provided 73% sensitivity and 77% specificity for diagnosing SCF using ROC analysis. Additionally, patients with SCF had higher values of serum LDL cholesterol (104.7 ± 18.93 mg/dl vs. 81.55 ± 14.62 mg/dl in NCF, p = 0.005), Glucose (96.9 ± 23.0 mg/dl vs. 83.55 ± 9.7 mg/dl in NCF, p = 0.024), and lower percentage of statin consumption (40.0% vs. 76.9% in NCF, p = 0.049).

Conclusions

Slow coronary blood flow can be non-invasively diagnosed with Retinal Functional Imager. Patients with normal coronary arteries and slow coronary blood flow have high retinal arteriolar blood flow. Early non-invasive diagnosis of SCF might help detect individuals who are at higher risk to develop coronary atherosclerosis, and to provide them with early preventive measures.     

Diagnosis of a small ovarian tumor (androgen secreting) by magnetic resonance: a new noninvasive procedure

Virilizing ovarian tumors are rare and establishing their exact location before operation is difficult. We report a case in which a small left ovarian tumor was seen with magnetic resonance imaging.     

Red Blood Cell Distribution Width (RDW) and long-term survival in patients with ST Elevation Myocardial Infarction

Introduction

High RDW values are associated with adverse prognosis in many clinical conditions including short and medium term outcome of patients with ST Elevation Myocardial Infarction (STEMI). The aim of the present study was to evaluate the association between RDW and long term mortality in STEMI patients undergoing primary angioplasty (PPCI).

Material and methods

A cohort of 535 STEMI patients undergoing PPCI were divided into two groups (RDW > 14%, RDW ≤ 14%) using CHAID and CART methods. The association between RDW and 5-year all-cause mortality was assessed using Cox’s proportional hazards analysis.

Results

A total of 37 patients died during follow up of 5 years (mean: 1059, median: 1013, range 2–2130 days). RDW > 14% was associated with increased risk of all-cause mortality (HR = 5, CI 95% 2.7– 9.9, p < 0.001). In multivariate analysis, RDW > 14 remained significantly associated with increased risk for all-cause mortality (HR = 3.8, CI 95% 1.8– 7.99, p < 0.001). Patients with RDW above 14% did not have lower ejection fraction, higher CPK or more conventional risk factors.

Conclusion

RDW value above 14 is independently associated with increased long term all-cause mortality in patients with STEMI undergoing PPCI.     

Microbiology and management of neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a clinical syndrome of ischemic necrosis of the bowel of multiple etiological factors that include the presence of intestinal ischemia, abnormal bacterial flora, and intestinal mucosal immaturity. Numerous reports have implied that the fecal microflora may contribute to the pathogenesis of NEC. A broad range of organisms generally found in the distal gastrointestinal tract have been recovered from the peritoneal cavity and blood of infants with NEC. The predominant organisms include Enterobacteriaceae (i.e., Escherichia coli, Klebsiella pneumoniae) , Clostridium spp., enteric pathogens (salmonellae, Coxsackie B2 virus, coronavirus, rotavirus), and potential pathogens (Bacteroides fragilis). The goals of the initial management is preventing ongoing damage, restoring hemostasis, and minimizing complications. Medical management includes withholding oral feeding, placement of nasogastric tube, abdominal decompression, paracentesis, vigorous intravenous hydration containing electrolytes and calories, support of the circulation, administration of antibiotics, and surveillance for deterioration or complications that require surgical intervention. Indications for surgery include clinical deterioration, perforation, peritonitis, obstruction, and abdominal mass. Prevention remains crucial to decrease the incidence of NEC. Preventive methods include cautious feeding regimens, the use of maternal breast milk, and the use of probiotics.     

Transdermal testosterone gel prn application for hypoactive sexual desire disorder in premenopausal women: a controlled pilot study of the effects on the arizona sexual experiences scale for females and sexual function questionnaire

IntroductionSeveral studies suggest that increased plasma testosterone can improve sexual function and desire in post-oophorectomy or postmenopausal women. However, side effects of chronic daily testosterone raise questions about the generalizability of this treatment approach. Sublingual testosterone was reported to cause testosterone levels to peak after 15 minutes and then decline to baseline levels within 90 minutes. Three to 4 hours after reaching testosterone peak, increased genital sensations and sexual lust were reported.AimWe hypothesized that a singe dose of testosterone given 4–8 hours prior to planned intercourse in women with hypoactive sexual desire disorder (HSDD) might increase desire without side effects associated with chronic use.MethodsThe design was randomized double-blind crossover. Premenstrual women with HSDD received eight packets of gel or identical placebo for use before intercourse twice weekly for 1 month. For a second month, the alternate treatment was given.Main Outcome MeasuresRatings were performed using the patient-rated Arizona Sexual Experiences Scale for females and the clinician-rated Sexual Function Questionnaire (SFQ-V1).ResultsTen patients completed the study. On the five-item self-report Arizona, the item “How easily are you aroused?” was significantly improved on testosterone gel vs. placebo, P = 0.03. There were similar trends on the physician-rated SFQ-V1 “arousal–sensation” cluster.ConclusionsThese preliminary results suggest that testosterone gel given prn before intercourse has effects on sexual arousal, and further research is needed to define dosage and time schedule to optimize this effect and determine its clinical relevance. Chudakov B, Ben Zion IZ, and Belmaker RH. Transdermal testosterone gel prn application for hypoactive sexual desire disorder in premenopausal women: A controlled pilot study of the effects on the Arizona Sexual Experiences Scale for females and Sexual Function Questionnaire. J Sex Med 2007;4:204–208.     

Surrogate versus couple therapy in vaginismus

IntroductionWomen who do not have a cooperative partner cannot complete the usual therapeutic process in the treatment of vaginismus, because they cannot progress to the stage of practicing the insertion of the man partner's fingers and the insertion of a penis.AimTo compare traditional couple therapy with therapy utilizing a surrogate partner.MethodsThe study was controlled and retrospective. Data were obtained from the treatment charts of patients who had come to the clinic for treatment of vaginismus. Sixteen vaginismus patients who were treated with a man surrogate partner were compared with 16 vaginismus patients who were treated with their own partners.Main Outcome MeasuresSuccessful pain-free intercourse upon completion of therapy.ResultsOne hundred percent of the surrogate patients succeeded in penile–vaginal intercourse compared with 75% in the couples group (P = 0.1). All surrogate patients ended the therapy because it was fully successful, compared with 69% in the couples group. Twelve percent of the couples group ended the therapy because it failed, and 19% because the couples decided to separate.ConclusionsTreating vaginismus with a man surrogate partner was at least as effective as couple therapy. Surrogate therapy may be considered for vaginismus patients who have no cooperative partner. Ben-Zion I, Rothschild S, Chudakov B, and Aloni R. Surrogate vs. couple therapy in vaginismus.