The influence of zinc iontophoresis on in vitro adherence of fibroblasts to periodontally-diseased cementum

This in vitro study examined whether iontophoresis of zinc ions aided adherence of fibroblasts to the root surfaces of periodontally-diseased teeth. Iontophoresis of zinc ions into extracted, periodontally-diseased human teeth was performed. Controls consisted of untreated diseased teeth and healthy unerupted teeth. Comparison was also made with teeth that were rinsed in zinc fluoride solution or in 45% phenol. Fibroblasts (L929) adherence was measured by trypan blue staining or by cell counting. The results demonstrate that fibroblasts adhere equally well to: 1) healthy root surfaces, 2) diseased root surfaces treated with 45% phenol, or 3) diseased root surfaces treated by iontophoresis of zinc ions. Cell adherence in these groups was significantly greater than adherence in groups of periodontally-diseased teeth which were either untreated or rinsed with ZnCl2. Iontophoresis with zinc ions appears to be an effective method of increasing cellular adherence to periodontally-diseased roots.     

Use of all-trans retinoic acid in the treatment of acute promyelocytic leukemia

Twenty-four patients with acute promyelocytic leukemia (APL) were treated with all-trans retinoic acid (45 to 100 mg/m2/day). Of these, eight cases had been either nonresponsive or resistant to previous chemotherapy; the other 16 cases were previously untreated. All patients attained complete remission without developing bone marrow hypoplasia. Bone marrow suspension cultures were studied in 15 of the 24 patients. Fourteen of these patients had morphological maturation in response to the retinoic acid (1 mumol/L). Chloroacetate esterase and alpha-naphthyl acetate esterase staining as well as electronmicroscopic examination confirmed that retinoic acid-induced cells differentiated to granulocytes with increased functional maturation (as measured by nitroblue tetrazolium reduction, NBT). The single nonresponder to retinoic acid in vitro was resistant to treatment with retinoic acid but attained complete remission after addition of low-dose cytosine arabinoside (ara-C). During the course of therapy, none of the patients showed any abnormalities in the coagulation parameters we measured, suggesting an absence of any subclinical disseminated intravascular coagulation. The only side effects consisted of mild dryness of the lips and skin, with occasional headaches and digestive symptoms. Eight patients have relapsed after 2 to 5 months of complete remission. The others remain in complete remission at 1+ to 11+ months and are still being followed up. We conclude that all-trans retinoic acid is an effective inducer for attaining complete remission in APL.     

Early child health in Lahore, Pakistan: X. Mortality

Mortality during the first two years of life among 1476 Pakistani infants born between September 1984 and March 1987 is described according to age, causes of death, area of living, season of the year and sex. The mortality rate (deaths under two years/1000 live births) projected over the whole population of Pakistan was 127 and under one year 114. During the first two years of life, the mortality rate was 133/1000 in the village, 159 in the periurban slum, 107 in the urban slum and 17 in the upper middle class group. In the latter group all deaths had occurred within 72 hours after birth. The overall major causes of death were acute and prolonged diarrhoea (36%), asphyxia neonatorurn (13%), respiratory infections (13%), septicaemia (11%) and tetanus (9%). A clear age dependency was noted with 14% of deaths occurring during the first 24 hours of life (asphyxia neonatorum in 86%), and 57% dying within the first 28 days of life. In the later age groups, infections were mainly responsible for 82% of total deaths. Early mortality was therefore extremely high in the poorer areas studied and the cause of death was highly age dependent. Any interventions for reducing mortality must therefore be directed towards better antenatal care and safe delivery and postnatally, towards preventing infections, especially during the first six months of life.     

Hoarseness in a child with gastroesophageal reflux

Hoarseness is not generally appreciated to be a manifestation of pediatric gastroesophageal reflux. We describe a case in which treatment of well-documented gastroesophageal reflux and esophagitis in a young girl with hoarseness and nocturnal cough led to resolution of these symptoms. Possible pathogenetic mechanisms and the difficulty in associating hoarseness with reflux by standard reflux testing are discussed.     

Prevalence of risk factors associated with human papillomavirus infection in women living with HIV

BACKGROUND: Concurrent infection with HIV and human papillomavirus (HPV) in women is associated with increased rates of cervical dysplasia and shorter survival following the development of cervical cancer. The authors examined risk factors for HPV infection at study entry in HIV-positive women enrolled in the Canadian Women's HIV Study, a prospective open cohort study. METHODS: Subjects eligible for this analysis included the 375 HIV-positive women in the Canadian Women's HIV Study for whom HPV test results were available. Questionnaires on behavioural and clinical information, Pap smears, cervicovaginal lavage specimens and vaginal tampon specimens for HPV detection and typing by polymerase chain reaction were obtained at study entry. RESULTS: Overall, 67.2% (252/375) of the women were HPV-positive; the global prevalence of intermediate- and high-risk oncogenic HPV types was 49.1% (184/375). Women with squamous cell dysplasia (32/294) were more likely to have HPV infection than those without dysplasia (90.6% v. 62.6%; p = 0.002). Multivariate logistic regression analysis, with adjustment for number of lifetime partners and history of STD, revealed that the following risk factors were independently associated with HPV infection: CD4 count of less than 0.20 x 10(9)/L (adjusted odds ratio [OR] 1.99 [95% confidence interval (Cl) 1.17-3.37 (p = 0.011)]), non-white race (adjusted OR 2.00 [95% Cl 1.17-3.42 (p = 0.011)]), inconsistent condom use in the 6 months before study entry (adjusted OR 2.02 [95% Cl 1.16-3.50 (p = 0.013)]), and lower age, with women age 30-39 years (adjusted OR 0.51 [95% Cl 0.30-0.87 (p = 0.013)]) and age 40 years or older (adjusted OR 0.52 [95% Cl 0.26-1.01 (p = 0.052)]) compared with women less than 30 years of age. INTERPRETATION: Close monitoring for HPV-related effects is warranted in all HIV-positive women, particularly younger, non-white women who do not always use condoms. Counselling for women living with HIV, particularly younger women, should emphasize the importance of regular cytological screening, with increasing frequency as the CD4 count falls.     

Early repair of episiotomy dehiscence

Early repair of episiotomy dehiscence was performed in 22 women with an initial fourth-degree episiotomy, four with third-degree episiotomy, and five with a mediolateral episiotomy. Early complications were limited to development of a pinpoint rectovaginal fistula in two women, both subsequently repaired by a rectal mucosal flap procedure. Of the 27 women now 1 year or more post-repair, all are completely continent and report resumption of normal coital activity.     

Human halothane metabolism, lipid peroxidation, and cytochromes P 4502A6 and P 4503A4

OBJECTIVE: Halothane undergoes both oxidative and reductive metabolism by cytochrome P450 (CYP), respectively causing rare immune-mediated hepatic necrosis and common, mild subclinical hepatic toxicity. Halothane also causes lipid peroxidation in rodents in vitro and in vivo, but in vivo effects in humans are unknown. In vitro investigations have identified a role for human CYPs 2E1 and 2A6 in oxidation and CYPs 2A6 and 3A4 in reduction. The mechanism-based CYP2E1 inhibitor disulfiram diminished human halothane oxidation in vivo. This investigation tested the hypotheses that halothane causes lipid peroxidation in humans in vivo, and that CYP2A6 or CYP3A4 inhibition can diminish halothane metabolism. METHODS: Patients (n = 9 each group) received single doses of the mechanism-based inhibitors troleandomycin (CYP3A4), methoxsalen (CYP2A6) or nothing (controls) before a standard halothane anaesthetic. Reductive halothane metabolites chlorotrifluoroethane and chlorodifluoroethylene in exhaled breath, fluoride in urine, and oxidative metabolites trifluoroacetic acid and bromide in urine were measured for 48 h postoperatively. Lipid peroxidation was assessed by plasma F2-isoprostane concentrations. RESULTS: The halothane dose was similar in all groups. Methoxsalen decreased 0- to 8-h trifluoroacetic acid (23 +/- 20 micromol vs 116 +/- 78 micromol) and bromide (17 +/- 11 micromol vs 53 +/- 49 micromol) excretion (P < 0.05), but not thereafter. Plasma F2-isoprostanes in controls were increased from 8.5 +/- 4.5 pg/ml to 12.5 +/- 5.0 pg/ml postoperatively (P < 0.05). Neither methoxsalen nor troleandomycin diminished reductive halothane metabolite or F2-isoprostane concentrations. CONCLUSIONS: These results provide the first evidence for halothane-dependent lipid peroxidation in humans. Methoxsalen effects on halothane oxidation confirm in vitro results and suggest limited CYP2A6 participation in vivo. CYP2A6-mediated, like CYP2E1-mediated human halothane oxidation, can be inhibited in vivo by mechanism-based CYP inhibitors. In contrast, clinical halothane reduction and lipid peroxidation were not amenable to suppression by CYP inhibitors.     

Development of gut hormone responses to feeding in neonates

The development of the effects of a human milk feed on plasma concentrations of motilin, neurotensin, gastric inhibitory polypeptide, enteroglucagon, gastrin, and secretin were studied in 158 healthy preterm neonates (mean gestation 33 1/2 weeks) at mean postnatal ages of 2 1/2, 6, 13, or 24 days. Pronounced progressive changes occurred in postprandial hormone responses; these were absent or small in the first days of life and were large by age 24 days. These changes may have important consequences in the adaptation to postnatal life.