Hoechst staining and exposure to UV laser during flow cytometric sorting does not affect the frequency of detected endogenous DNA nicks in abnormal and normal human spermatozoa

Controlling the sex of offspring by the separation of X and Y chromosome-bearing spermatozoa using flow cytometry has been reported as a clinical technique aiding prevention of X-linked diseases. Although this technique has resulted in several hundred normal births in animals and at least one human birth, there is still concern over its genetic safety due to the involvement of two potentially mutagenic agents: UV light and the fluorochrome dye, Hoechst 33342 (H33342). Human spermatozoa, particularly those considered abnormal, may be more likely to suffer DNA damage following exposure to mutagenic agents, compared with other mammalian species. The stability of normal fresh and decondensed human spermatozoa were examined after exposure to a range of levels of UV and H33342 staining, using an assay that detects endogenous nicks in the DNA of spermatozoa. The stability of abnormal and normal, fresh and frozen-thawed human spermatozoa was examined following UV laser, H33342 staining and flow cytometry treatments utilizing the same assay. There was an increase in the presence of endogenous nicks when spermatozoa were decondensed compared with fresh spermatozoa. There was no increase in the incidence of nicks in any group of spermatozoa after UV and fluorochrome exposure compared with controls without exposure.      

A serologic follow-up of the 1942 epidemic of post-vaccination hepatitis in the United States Army

An epidemic of icteric hepatitis in 1942 affected approximately 50,000 U.S. Army personnel. This outbreak was linked to specific lots of yellow-fever vaccine stabilized with human serum. To identify the responsible virus and the consequences of the epidemic, during 1985 we interviewed and serologically screened 597 veterans who had been in the army in 1942. These subjects were selected from three groups. Group I consisted of patients who had received the implicated vaccine and had jaundice; Group II had received the implicated vaccine but remained well; Group III had received a new, serum-free vaccine, with no subsequent jaundice. Ninety-seven percent of Group I, 76 percent of Group II, and 13 percent of Group III were positive for antibodies to hepatitis B virus. Only one subject had hepatitis B surface antigen, for a carrier rate of 0.26 percent among recipients of the implicated vaccine. The prevalence of hepatitis A antibody was similar in all three groups, and no subject had antibody to hepatitis delta virus. We conclude that hepatitis B caused the outbreak, that about 330,000 persons may have been infected, that the hepatitis B virus carrier state was a rare consequence, and that the outbreak induced hepatitis B antibodies that appear to persist for life.     

Randomized, double-blind, placebo-controlled, multicentered trial of the efficacy of a single dose of live oral cholera vaccine CVD 103-HgR in preventing cholera following challenge with Vibrio cholerae O1 El tor inaba three months after vaccination

CVD 103-HgR is a live oral cholera vaccine strain constructed by deleting 94% of the gene for the enzymatically active A subunit of cholera toxin from classical Inaba Vibrio cholerae O1 569B; the strain also contains a mercury resistance gene as an identifying marker. This vaccine was well tolerated and immunogenic in double-blind, controlled studies and was protective in open-label studies of volunteers challenged with V. cholerae O1. A randomized, double-blind, placebo-controlled, multicenter study of vaccine efficacy was designed to test longer-term protection of CVD 103-HgR against moderate and severe El Tor cholera in U.S. volunteers. A total of 85 volunteers (50 at the University of Maryland and 35 at Children's Hospital Medical Center/University of Cincinnati) were recruited for vaccination and challenge with wild-type V. cholerae El Tor Inaba. Volunteers were randomized in a double-blind manner to receive, with buffer, a single oral dose of either CVD 103-HgR (2 x 10(8) to 8 x 10(8) CFU) or placebo (killed E. coli K-12). About 3 months after immunization, 51 of these volunteers were orally challenged with 10(5) CFU of virulent V. cholerae O1 El Tor Inaba strain N16961, prepared from a standardized frozen inoculum. Ninety-one percent of the vaccinees had a >/=4-fold rise in serum vibriocidal antibodies after vaccination. After challenge, 9 (39%) of the 23 placebo recipients and 1 (4%) of the 28 vaccinees had moderate or severe diarrhea (>/=3-liter diarrheal stool) (P < 0.01; protective efficacy, 91%). A total of 21 (91%) of 23 placebo recipients and 5 (18%) of 28 vaccinees had any diarrhea (P < 0.001; protective efficacy, 80%). Peak stool V. cholerae excretion among placebo recipients was 1.1 x 10(7) CFU/g and among vaccinees was 4.9 x 10(2) CFU/g (P < 0.001). This vaccine could therefore be a safe and effective tool to prevent cholera in travelers.     

A genetic and clinical study of individuals with nonsyndromic retinopathy consequent upon sequence variants in HGSNAT,the gene associated with Sanfilippo C mucopolysaccharidosis

Pathogenic variants in the gene HGSNAT (heparan‐α‐glucosaminide N‐acetyltransferase) have been reported to underlie two distinct recessive conditions, depending on the specific genotype, mucopolysaccharidosis type IIIC (MPSIIIC)—a severe childhood‐onset lysosomal storage disorder, and adult‐onset nonsyndromic retinitis pigmentosa (RP). Here we describe the largest cohort to‐date of HGSNAT‐associated nonsyndromic RP patients, and describe their retinal phenotype, leukocyte enzymatic activity, and likely pathogenic genotypes. We identified biallelic HGSNAT variants in 17 individuals (15 families) as the likely cause of their RP. None showed any other symptoms of MPSIIIC. All had a mild but significant reduction of HGSNAT enzyme activity in leukocytes. The retinal condition was generally of late‐onset, showing progressive degeneration of a concentric area of paramacular retina, with preservation but reduced electroretinogram responses. Symptoms, electrophysiology, and imaging suggest the rod photoreceptor to be the cell initially compromised. HGSNAT enzymatic testing was useful in resolving diagnostic dilemmas in compatible patients. We identified seven novel sequence variants [p.(Arg239Cys); p.(Ser296Leu); p.(Phe428Cys); p.(Gly248Ala); p.(Gly418Arg), c.1543‐2A>C; c.1708delA], three of which were considered to be retina‐disease‐specific alleles. The most prevalent retina‐disease‐specific allele p.(Ala615Thr) was observed heterozygously or homozygously in 8 and 5 individuals respectively (7 and 4 families). Two siblings in one family, while identical for the HGSNAT locus, but discordant for retinal disease, suggest the influence of trans‐acting genetic or environmental modifying factors.     

Jaundice. Clinical pearls and perils revisited

I recount some clinical "pearls and perils" to help reassess the contributions of abdominal ultrasound, cholangiography, needle biopsy of the liver, and laparoscopy. Abdominal ultrasound demonstrates stones in the gallbladder in approximately 98% of cases, but in only 15% in the common bile duct, whereas computerized tomography scan reveals them in greater than or equal to 50%. On cholangiography a blood clot (in hemobilia) may closely resemble a common duct stone, as may spasm or tumor of the distal duct. Iatrogenic stricture at the junction of the left and right hepatic ducts may be indistinguishable from a Klatskin tumor. Differentiation of extrahepatic from intrahepatic cholestasis is frequently impossible in needle specimens of the liver. Needle biopsy provides the best means of establishing a diagnosis of alcoholic hepatitis. Laparoscopy is particularly valuable in the diagnosis of cirrhosis missed in blind biopsy specimens.     

The historical profile

Sir William Osler once said one should "never treat a stranger." His statement is especially applicable to the practice of dentistry in which the physical and emotional stability of the patient is determined primarily by using the medical history. However, patients do not always appreciate the significance of medically related questions asked by a dentist. The accomplished clinician must, therefore, not only master the science of inquiry and the art of observation but must also establish the rapport that precedes the unguarded flow of pertinent information from the patient. This information is germinal to successful treatment.     

Patterns of contrast enhancement of benign and malignant hepatic neoplasms during bolus dynamic and delayed CT

Bolus dynamic and delayed computed tomographic (CT) scans of the liver were evaluated in 43 patients with 54 hepatic hemangiomas and 111 patients with primary or secondary malignant hepatic neoplasms. Twelve patterns of contrast enhancement were recognized during the bolus dynamic phase and delayed scanning. A "typical" CT pattern for hemangiomas (present in 29 of 54 hemangiomas [53.7%]) was established: (a) diminished attenuation prior to intravenous contrast medium administration (excluding lesions arising in a liver with diffuse fatty infiltration), (b) peripheral contrast enhancement during the bolus dynamic phase, and (c) complete isodense fill-in on delayed scan images. Using these criteria, we distinguished hemangiomas from malignant neoplasms in most patients. Only one of 63 (1.6%) malignant neoplasms manifested these typical CT criteria of hemangioma. There is an 86% chance that a lesion with the typical CT appearance of hemangioma is actually a hemangioma, even when found in a patient with a known nonhepatic primary neoplasm.     

Pregnancy outcomes among visually impaired women in Washington State, 1987–2014

BackgroundWomen with visual impairment may have reduced ability to access standard care resources, however, information on their pregnancy and neonatal outcomes is limited.ObjectiveTo assess risk of adverse pregnancy and neonatal outcomes among visually impaired women in Washington State from 1987 to 2014.MethodsWe conducted a retrospective cohort study using linked Washington State birth/fetal death hospital discharge records to compare outcomes among women with and without visual impairment noted at their delivery hospitalization. Pregnancy conditions and outcomes evaluated included gestational diabetes, pre-eclampsia, labor induction and cesarean delivery. Neonatal outcomes included preterm delivery and birth weight <2500 g. We assessed length of maternal and infant delivery hospitalization. We performed Poisson regression to estimate relative risks (RR) and 95% confidence intervals (CIs) for each outcome, adjusting for year of delivery, maternal age, and parity.ResultsMost adverse pregnancy and neonatal outcomes were similar for visually impaired (N = 232) and comparison women (N = 2362). However, visually impaired women had increased risks of severe pre-eclampsia (RR 3.77, 95% CI 1.69–8.43), labor induction (RR 1.33, 95% CI 1.10–1.61) and preterm delivery (RR 1.60, 95% CI 1.06–2.42). They were also more likely to have delivery hospitalizations of 3 or more days following a vaginal (RR 1.86, 95% CI 1.41–2.47). Among cesarean deliveries, infants of visually impaired women had increased risk (RR 1.24, 95% CI 1.02–1.51) of hospitalization for 3 or more days postpartum.ConclusionOur findings may be useful for obstetric providers in counseling their visually impaired patients.     

Drug formularies: myths-in-formation

Drug formularies are pivotal tools for delineating and directing prescribing to the "drugs of choice." Full realization of their potential has been hampered by insufficient comparative data on drug efficacy/safety and local resources for formulary development. However, misconceptions concerning fundamental formulary concepts pose an even more formidable obstacle. This article identifies statements illustrating formulary misconception a) made by physicians attending Pharmacy and Therapeutics Committee meetings during a three-year period and b) appearing in published sources. The paper highlights basic objectives and operational requirements of an effective formulary, and contrasts this definition with 20 myths and misinformation culled from these two sources. Not only does such misinformation impair formulary development, many critics are so preoccupied with alleged shortcomings that progress in minimizing the real limitations of formularies has been impeded.