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Biomedical subjects

L Lynch

Publications and source records attributed to L Lynch.

At least 37 records · Page 2Linked to original sources
PubMed1996

The current status of multifetal pregnancy reduction.

The number of women conceiving three or more fetuses has increased dramatically as a result of successful infertility therapy with ovulation-inducing agents and assisted reproductive technology. Higher-order multiple gestations have an increased risk of premature delivery and its attendant sequelae of increased neonatal mortality or irreversible morbidity. Multifetal pregnancy reduction is a procedure designed to decrease the increased propensity to deliver very prematurely in these patients by reducing the number of live fetuses they are carrying. The procedure has proved to be both safe and effective, and pregnancies reduced to twins proceed as if that were the number of fetuses originally conceived. Nevertheless, this invasive procedure does have the potential to result in loss of the entire pregnancy and causes considerable emotional distress for some couples who view it as their "least bad" alternative. The medical benefits of performing multifetal pregnancy reduction in women with four or more fetuses seem fairly well established, but this is less true for triplets. Serious attention should be paid to reducing the number of higher-order multiple pregnancies resulting from infertility therapy. In the meantime, when three or more fetuses have been conceived, multifetal pregnancy reduction offers a reasonable option to patients whose only choices in the past were either to accept the risk of delivering extremely prematurely or to terminate the entire pregnancy.

Ethics↗
PubMed1996

The clinical outcome of preterm premature rupture of membranes in twin versus singleton pregnancies.

The purpose of this study was to determine the clinical outcome of preterm premature rupture of the membranes (PPROM) in twin versus singleton pregnancies at less than or equal to 36 weeks' gestation. A retrospective cohort study was conducted in 116 twin pregnancies with PPROM at less than or equal to 36 weeks' gestational age and 116 matched singleton pregnancies. The two groups were analyzed for differences in maternal demographics and perinatal and neonatal outcome. Perinatal and neonatal outcomes were similar in the two groups. The median latency period, however, was significantly decreased in the twin group (11.4 hours, Inter Quartile Range: 6.3-26.4) versus the singleton group (19.5 hours, Inter Quartile Range: 10.2-49.3, p < 0.05). The latency period in each group was notably longer when PPROM occurred at less than 30 weeks' gestation, but was still shorter in the twin pregnancies (27.6 hours, Inter Quartile Range: 20-307 versus 75.1 hours, Inter Quartile Range: 15-189, p < 0.05). Twin pregnancies with PPROM at less than or equal to 36 weeks' gestational age have a decreased latency period when compared to matched singletons. The perinatal and neonatal outcomes, however, are similar.

Adult↗
PubMed1996

A sensitive and specific PCR method to detect Helicobacter felis in a conventional mouse model.

Although many detection methods have been used to determine Helicobacter colonization in small animal models, the sensitivity and specificity of these detection methods are limited. To improve the Helicobacter felis conventional mouse model for accurate evaluation of therapeutic regimens, we developed a PCR for detection of, and a competitive PCR for quantitation of, H. felis in viral antibody-free (VAF) mice. The PCR was based on the H. felis 16S rRNA gene. An internal control DNA was used for competitive quantitation of the PCR. VAF conventional Swiss-Webster mice were infected with an H. felis culture by oral gavage. At various times after H. felis challenge and therapy, stomach mucosa was collected and evaluated by PCR. PCR detected approximately 50 to 100 H. felis cells per mouse stomach and showed no cross-reaction with other bacteria commonly found in mouse stomachs. Colonization of H. felis in the mouse stomach was confirmed by culture isolation from germfree mice and histological examination of VAF mice. Response to therapy in this H. felis model correlated well with results seen in human clinical trials with H. pylori. A model utilizing PCR detection which may be useful for discovering new antibiotics and/or vaccines against Helicobacter ulcer disease has been developed.

Animals↗
PubMed1995

Alloimmune thrombocytopenia: fetal and neonatal losses related to cordocentesis.

OBJECTIVE: This report describes the increased risks of cordocentesis in fetuses affected with alloimmune thrombocytopenia. STUDY DESIGN: As part of a multicenter treatment study clinical and laboratory data from five pregnancies with alloimmune thrombocytopenia in which there was a fetal or neonatal loss associated with cordocentesis were reviewed. The fetal or neonatal deaths were all thought to be a result of exsanguination. These fetuses were compared with a group of 44 affected fetuses who underwent the same procedure but who survived. The data were analyzed by the Wilcoxon rank-sum test and the two-tailed Fisher's exact test. A p value < 0.05 was considered significant. RESULTS: The mean platelet count at cordocentesis was significantly lower in the cases than in the controls (5.8 vs 32.8 x 10(9)/L, p = 0.005). The incidence of antenatal intracranial hemorrhage in the untreated sibling of the prior affected pregnancy was significantly greater in the cases than in the controls (two of five vs one of 42, p = 0.02). CONCLUSION: Fetuses affected with alloimmune thrombocytopenia are at increased risk for fatal exsanguination associated with cordocentesis.

Antigens, Human Platelet↗
PubMed1995

First-trimester multifetal pregnancy reduction: acute and persistent psychologic reactions.

OBJECTIVE: Our purpose was to determine acute and persistent psychologic impacts of multifetal pregnancy reductions and patients' ability to cope with fetal loss while simultaneously bonding to surviving infants. STUDY DESIGN: The first 100 women to undergo a multifetal reduction were invited to participate in a retrospective telephone study assessing their emotional reactions and attitudes toward multifetal reduction. The semistructured interview elicited demographic and obstetric data and contained scales used in previous studies of reproductive loss, which assessed repetitive thoughts about reduced fetuses, catastrophic fears, and lingering depressive feelings. RESULTS: More than 65% of the sample recalled acute feelings of emotional pain, stress, and fear during the reduction procedure. Mourning for the lost fetuses was reported by 70% of women, but most grieved for only 1 month. Thoughts about reduced fetuses occurred moderately frequently after the reduction but rarely at follow-up. Persistent depressive symptoms were mild, although moderately severe levels of sadness and guilt continued for many. Nonetheless, 93% would make the same decision again. Emotional reactions of patients who miscarried differed little. The small subsample who continued to be most affected were younger (p < 0.02), were more religious (p < 0.003), and had viewed the multifetal pregnancy on ultrasonography more often (p < 0.009). CONCLUSIONS: Multifetal reductions, although highly stressful psychologically, are well tolerated. Sadness and guilt may persist, especially for an identifiable subgroup. Normal maternal bonding and achievement of parenthood goals facilitate grief resolution. The large majority were reconciled to the termination of some fetuses to perserve the lives of a remaining few.

Abortion, Spontaneous↗
PubMed1995

The effect of multifetal pregnancy reduction on serum relaxin.

OBJECTIVE: To determine the effect of multifetal pregnancy reduction on circulating relaxin levels. METHODS: Patients with multifetal pregnancies had relaxin levels determined on the day of multifetal pregnancy reduction, after the procedure, and late in pregnancy. RESULTS: Forty-eight women (26 presenting with three fetuses and 22 with four or more) were studied. All pregnancies followed some form of ovulation induction. All pregnancies (except for one, which was reduced to a singleton) were reduced to twins. Pre-procedure, post-procedure and late-pregnancy relaxin levels were significantly higher in the in vitro fertilization (IVF)-gamete intrafallopian transfer (GIFT) group compared with the human menopausal gonadotropin (hMG)-alone group (P < .05). The initial number of fetuses had no significant effect on relaxin levels. Although post-procedure relaxin levels were significantly lower than pre-procedure levels (P = .002), relaxin levels continued to decrease throughout pregnancy, as evidenced by even lower levels later on (P = .0001). CONCLUSIONS: Serum relaxin levels were significantly higher in the IVF-GIFT group than in the hMG-alone group, which probably reflects more aggressive ovulation induction in the former. Because relaxin levels continued to decrease throughout pregnancy, the difference observed between pre- and post-procedure levels are not considered to be due to the procedure itself.

Female↗
PubMed1995

Accuracy of ultrasound estimation of fetal weight in multiple pregnancies.

Our objective was to assess the accuracy of ultrasonographic estimation of fetal weight in twins and triplets as compared to singleton pregnancies. Retrospective analysis was undertaken of ultrasound data of all fetuses who underwent an examination within 1 week of delivery (singletons 1832, twins 518, triplets 51). At birth weights below 2500 g, there was a significant overestimation of fetal weight in twins as compared to singletons, but the accuracy of the estimate was the same, except in twins between 1500 and 2499 g, when the weight was based on abdominal circumference and femur length alone. At birth weights of more than 2500 g, no difference was detected between twins and singletons. At all birth weights below 2500 g, the accuracy of weight estimation in triplets was equal to that in singletons and there were no triplets above this weight. We conclude that ultrasonographic estimation of fetal weight is as accurate in twins and triplets as it is in singletons.

Body Weight↗
PubMed1995

Maternal serum levels of alpha-fetoprotein and fetal fibronectin as markers of labor in the third trimester.

Unexplained elevations of maternal serum alpha-fetoprotein (MSAFP) in the second trimester have been found to be associated with a two- to fourfold increase in the rate of preterm delivery, but the sensitivity is low. Therefore, we reasoned that MSAFP levels in the third trimester could prove to be a more useful biochemical marker to predict labor. The presence of placental and membrane-derived fetal fibronectin (FFN) in cervicovaginal secretions has recently been shown to predict preterm delivery with a sensitivity of 81.7% and specificity of 82.5%. We postulated that damage to membranes and microscopic breakdown of fetomaternal blood barrier during labor might result in release of AFP or FFN into maternal serum. Maternal serum alpha fetoprotein and fetal fibronectin levels were measured prospectively in 29 patients in active labor at term and in 25 controls undergoing elective cesarean section. Neither MSAFP nor serum FFN levels were associated with labor at term. We did, however, note significantly higher MSAFP levels in mothers bearing male fetuses versus female fetuses (p < 0.01). Since the current literature supports a sex difference in the MSAFP levels in the second trimester, this does not appear to change as gestation advances. Further studies are needed to determine if, in addition to maternal weight and race, MSAFP levels should be also adjusted for fetal sex diagnosed on sonography.

Adult↗
PubMed1995

In vitro evaluation of the pneumocandin antifungal agent L-733560, a new water-soluble hybrid of L-705589 and L-731373.

Lipopeptide L-733560 is a hybrid analog of L-731373 and L-705589. All are water-soluble semisynthetic pneumocandin Bo derivatives. In vitro susceptibility testing of L-705589, L-731373, and L-733560 against more than 200 clinical isolates consisting of eight Candida species, Cryptococcus neoformans, and three Aspergillus species was performed by the broth microdilution methods. All three pneumocandins exhibited potent anti-Candida activity and moderate anti-C. neoformans activity. However, anti-Aspergillus activity was demonstrated only by an agar disk diffusion method. Antifungal agent-resistant Candida species and C. neoformans showed susceptibility comparable to that of susceptible isolates. Growth inhibition kinetic studies against Candida albicans revealed fungicidal activity within 3 to 5 h. Drug combination studies with pneumocandins and amphotericin B revealed indifferent activity against C. albicans and additive effects against C. neoformans and Aspergillus fumigatus. The activities of the compounds were not dramatically affected by the presence of serum. Resistance induction studies showed that the susceptibility of C. albicans MY1055 was not significantly altered by repeated exposure to subinhibitory concentrations of L-733560. Erythrocyte hemolysis studies indicated minimal hemolytic potential with pneumocandins. Results from preclinical evaluations and development studies performed thus far indicate that the pneumocandins should be safe, broad-spectrum fungicidal agents and potent parenteral antifungal agents.

Animals↗
PubMed1994

Evaluations of children who have disclosed sexual abuse via facilitated communication.

OBJECTIVE: To review the findings of interdisciplinary team evaluations of children who disclosed sexual abuse via facilitated communication. DESIGN: Case series. SETTING: Tertiary care hospital outpatient child sexual abuse program in central New York. PATIENTS: Between January 1990 and March 1993, 13 children who disclosed sexual abuse via facilitated communication and were referred to a university hospital child abuse referral and evaluation center. The range of previously determined developmental diagnosis included mental retardation, speech delay, and autism. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Medical records were reviewed for (1) disclosure, (2) physical evidence, (3) child's behavioral and medical history, (4) disclosures by siblings, (5) perpetrator's confession, (6) child protective services determinations, and (7) court findings. RESULTS: Four children had evidence of sexual abuse: two had physical findings consistent with sexual abuse, one also disclosed the allegation verbally, and one perpetrator confessed. CONCLUSIONS: These results neither support nor refute validation of facilitated communication. However, many children had other evidence of sexual abuse, suggesting that each child's case should be evaluated without bias.

Adolescent↗
PubMed1994

Confined placental mosaicism in CVS and pregnancy outcome.

The perinatal outcome of 26 patients with confined placental mosaicism (CPM) detected in chorionic villus sampling (CVS) who wished to continue their pregnancies was compared with that of two controls per patient matched for age and parity (n = 52). There were no significant differences in birth weight or gestational age at delivery between patients with CPM and controls. There were no cases of intrauterine growth retardation (IUGR) in the CPM patients as compared with two (2/52, 3.8 per cent) in the control group (P > 0.05). There was no significant increase in fetal loss between the study group (1/26, 3.6 per cent) and the controls (1/52, 1.9 per cent) (P > 0.05).

Amniocentesis↗
PubMed1994

Patient exposure to ionising radiation in the intensive care unit due to portable chest radiography.

The chest X-ray is the most commonly performed radiological examination in the intensive care unit. We used TLDs to measure the radiation exposure in 30 ICU patients due to portable chest radiography. The mean number of CXR was 3 (range 1-11). The mean surface entry dose at the xiphisternum was 1.8 mGy (range 0.43-5.14 mGy) per patient and 0.63 mGy per CXR. Very small amounts of radiation were detected at the symphysis pubis and in more than half of the patients no radiation was detected at this site. These values are well above accepted norms. Patient exposure may be reduced by ordering fewer X-rays or by changing to a faster screen-film combination.

Humans↗
PubMed1994

Unexpected neurological deficits following recovery from anaesthesia.

Two cases of neurological dysfunction are presented. Neurological deficits after recovery from anaesthesia are unusual in young women perioperatively. In the first case, a 39-yr-old woman presented at 36-wk gestation with antepartum haemorrhage and in labour. Pregnancy had been complicated by pre-eclampsia and she underwent emergency Caesarean section under general anaesthesia without complication. The trachea was extubated when she was awake but almost immediately she became hypertensive, obtunded and reintubation was required. Her pupils became fixed and dilated but the Computerised Axial Tomogram (CT) was normal. A coagulopathy was evident. She made a full neurological recovery within 24 hr. On the same day, a previously healthy 41-yr-old woman who had undergone uneventful surgery for uterine prolapse 24 hr previously developed headache, nausea and over the next four hours signs of progressive brainstem ischaemia. The CT scan showed oedema of the mid- and hindbrain. Brainstem death was confirmed 12 hr later and the post-mortem revealed acute dissection of the vertebral artery secondary to cystic medial necrosis. Such dramatic neurological sequelae are rare but the importance of identifying "at risk" groups is underlined as is early recognition of neurological injury postoperatively.

Adult↗
PubMed1994

Low concentrations of vaginal fetal fibronectin as a predictor of deliveries occurring after 41 weeks.

OBJECTIVE: This study sought to determine whether low concentrations of fetal fibronectin in the cervical and vaginal secretions of patients at 39 weeks' gestation predicted pregnancies progressing beyond 41 weeks' gestation. STUDY DESIGN: A retrospective cohort study was undertaken using cervical and vaginal samples collected from 75 consenting patients during the thirty-ninth week of gestation. Levels of fetal fibronectin were measured by immunoassay. Demographic, obstetric, neonatal, and laboratory data were analyzed by Fisher's exact test, Student t test or Wilcoxon's rank-sum test, multiple logistic regression, and receiver-operating characteristic curve analysis. RESULTS: There was a 35.5-fold increase in vaginal fetal fibronectin concentrations among patients delivered at < 41 weeks compared with those delivered at > or = 41 weeks. The receiver-operating characteristic curve analysis indicated that the optimal fetal fibronectin predictor of prolonged pregnancies was a vaginal fetal fibronectin value < 60 ng/ml present between 39 weeks 0 days and 39 weeks 6 days' gestation (sensitivity 95.7%, 95% confidence interval 87.3% to 100.0%; specificity 44.2%, 95% confidence interval 30.7% to 57.7%; positive and negative predictive values 43.1% [95% confidence interval 29.5% to 56.7%] and 95.8% [95% confidence interval 87.8% to 100.0%], respectively). The relative risk for a prolonged pregnancy resulting from a vaginal fetal fibronectin value < 60 ng/ml was 10.4 (1.5 to 72.4). Among patients with a vaginal fetal fibronectin value > or = 60 ng/ml, 80.8% were delivered within 1 week and 92.3% within 10 days of sampling. In contrast, among patients with vaginal fetal fibronectin value < 60 ng/ml 63.3% remained undelivered after 1 week. After parity and cervical dilation were controlled for, multiple logistic regression demonstrated that a vaginal fetal fibronectin value < 60 ng/ml was a significant independent predictor of pregnancies delivered at > or = 41 weeks (adjusted odds ratio 12.8 [95% confidence interval 1.5 to 107.2]). CONCLUSIONS: A vaginal fetal fibronectin value > or = 60 ng/ml at 39 weeks' gestation is predictive of delivery within 10 days, whereas values < 60 ng/ml identify 95% of pregnancies progressing past 41 weeks' gestation. This data may allow for the prediction of postdates pregnancies, thus facilitating appropriate obstetric interventions.

Adult↗
PubMed1994

Efficacy of second-trimester selective termination for fetal abnormalities: international collaborative experience among the world's largest centers.

OBJECTIVE: Our goal was to develop the most comprehensive database possible to counsel patients about selective termination for fetal abnormalities, because no one center has sufficient data to assess much more than crude loss rates. STUDY DESIGN: A total of 183 completed cases of selective termination from 9 centers in 4 countries were combined (169 twins, 11 triplets, 3 quadruplets). Variables included indications, methods, (potassium chloride, exsanguination, air embolus), gestational age at procedure, pregnancies lost (< or = 24 weeks), gestational age at delivery, and neonatal outcome. RESULTS: Indications for selective termination were 96 chromosomal, 76 structural, and 11 mendelian. Selective termination was technically successful in 100% of cases. In 23 of 183 (12.6%) miscarriage occurred before 24 weeks; 2 of 37 (5.4%) occurred when the procedure done at < or = 16 weeks and 21 of 146 (14.4%) when it was done thereafter. Air embolization had a higher loss rate: 10 of 24 (41.7%) compared with 13 of 156 (8.3%) by potassium chloride (chi 2 = 117, p < 0.0001). Three cases of selective termination performed in monochorionic pregnancies all resulted in pregnancy loss. Among 183 potentially viable deliveries, 7 occurred before 28 weeks, 19 at 29 to 32 weeks, 41 at 33 to 36 weeks, and 93 at > or = 37 weeks. Gestational age at delivery was not influenced by the technique used or the indication but was negatively correlated with gestational age at the time of selective termination. No coagulopathy or ischemic damage was observed in survivors. There was no maternal morbidity. CONCLUSIONS: (1) Selective termination in experienced hands for a dizygotic abnormal twin is safe and effective when done with potassium chloride. A total of 83.8% of viable deliveries occurred after 33 weeks and only 4.3% at 25 to 28 weeks. (2) Gestational age at the procedure correlated positively with loss rate and inversely with gestational age at delivery; this emphasizes the need for early diagnosis in multifetal pregnancies. (3) Coagulopathy tests are probably unnecessary.

Abortion, Therapeutic↗
PubMed1994

Transabdominal versus transcervical and transvaginal multifetal pregnancy reduction: international collaborative experience of more than one thousand cases.

OBJECTIVES: Two major approaches for multifetal pregnancy reduction have been developed over the past several years: transabdominal potassium chloride by injection and pelvic procedures by either transcervical aspiration or transvaginal potassium chloride injection or by an automated spring-loaded puncture device. The purpose of this study was to create the largest database from among the world's largest centers to assess possible differences in efficacy and complication rates by transabdominal or transcervical or multifetal pregnancy reduction. STUDY DESIGN: Data on over 1000 completed pregnancies that underwent multifetal pregnancy reduction by both methods from major centers with among the highest worldwide experience were combined. Transabdominal cases were divided temporally (1986 through 1991 and 1991 through 1993). RESULTS: Transabdominal multifetal pregnancy reduction was successfully performed on 846 patients and transcervical or transvaginal on 238 patients. Transcervical or transvaginal reduction is performed earlier and starts and finishes with fewer embryos. In 12.6% of cases transcervical or transvaginal reduction left a singleton as opposed to 4.4% for transabdominal reduction. Pregnancy losses (up to 24 weeks) were observed in 13.1% of transcervical or transvaginal cases and in 16.2% of transabdominal cases early in the series and 8.8% of late transabdominal cases. Transcervical or transvaginal reduction may be safer very early in gestation and transabdominal safer later in the first trimester. Premature deliveries were comparable, with only about 5% delivered between 25 and 28 weeks. The smaller starting numbers for transcervical and transvaginal reduction may explain a slightly higher term delivery rate. The transabdominal route tends to reduce the fundal embryos and the transcervical and transvaginal the lower ones. The significance of this is not clear. CONCLUSIONS: (1) Multifetal pregnancy reduction by either method is a relatively safe and efficient method for improving outcome in multifetal pregnancies. (2) More than 84% are delivered at > 33 weeks. (3) The experience and preference of the operator are probably the key determinants for an individual patient. (4) An inverse relationship of starting and finishing number to loss rates and gestational age at delivery suggests that there still is a cost of iatrogenic multifetal pregnancies, even if multifetal pregnancy reduction can be successfully performed.

Abdomen↗