Intracytoplasmic sperm injection: a novel treatment for all forms of male factor infertility

OBJECTIVE

To demonstrate the effectiveness of intracytoplasmic sperm injection to treat male factor infertility and to report on the achievement of fertilization and pregnancy compared with standard in vitro insemination.

DESIGN

Controlled clinical study.

SETTING

Couples suffering from male factor infertility treated in an academic research environment.

PATIENTS

Two hundred twenty-seven couples in whom the male partners were presumed to be the cause of repeated failed attempts at IVF or whose semen parameters were unacceptable for conventional IVF.

INTERVENTIONS

Oocytes for this study were harvested after superovulation with GnRH agonist and gonadotropins. After removing the cumulus cells, a single spermatozoon was injected directly into the cytoplasm of metaphase II oocytes, and the outcome was analyzed in terms of semen parameters and origin of semen sample.

MAIN OUTCOME MEASURES

Fertilization and pregnancy rates (PRs) in relation to sperm parameters and origin of semen sample.

RESULTS

Two hundred twenty-seven couples were treated by intracytoplasmic sperm injection resulting in an ongoing pregnancy rate of 37.0% per retrieval (84/227). There were 47 singleton pregnancies (5 of which were vanishing twin pregnancies), 30 twin gestations, 6 triplet pregnancies, and 1 quadruplet pregnancy. The concentration of the total motile spermatozoa present in the ejaculate as well as the origin of the samples influenced the fertilization rate but not the pregnancy outcome.

CONCLUSIONS

Intracytoplasmic sperm injection can be used successfully to treat couples who have failed IVF or who have too few spermatozoa for conventional methods of in vitro insemination. Sperm parameters do not clearly affect the outcome of this technique.

Cyclosporine for the treatment of fulminant ulcerative colitis in children. Immediate response, long-term results, and impact on surgery

PURPOSE

Emergency surgery for fulminant colitis is often complicated by high-dose steroid therapy, poor nutrition, and psychologic maladjustment. Cyclosporine is effective for fulminant ulcerative colitis in adults, resulting in avoidance of immediate surgery in 75 percent of patients and a 55 percent long-term remission rate. Over the last five years, we studied the effectiveness of cyclosporine in children with fulminant colitis.

METHODS

Fourteen patients with ulcerative colitis (age, 7-20 years) received cyclosporine after satisfying the following criteria: 1) greater than five bloody diarrheal stools per day; 2) severe abdominal pain; 3) no improvement after ten days of bowel rest, 4) intravenous methylprednisolone (1-2 mg/kg/day); and 5) parenteral nutrition. Treatment was begun with oral cyclosporine (4.6-9.6 mg/kg/day), and the dose was adjusted to achieve whole blood trough levels measured with a monoclonal radioimmunoassay between 150 and 300 ng/ml. If improved, patients were discharged on oral cyclosporine, prednisone, and a regular diet.

RESULTS

Eleven of 14 patients (78 percent) responded within two to nine days and were able to consume a normal diet, had three or less soft stools per day, and had no pain. One did not respond after ten days and underwent an ileal pouch-anal anastomosis procedure. Two patients elected surgery after 20 days of therapy and a partial response. Of 11 patients who left the hospital, 4 had recurrent symptoms after 2 to 11 months of taking therapeutic doses of cyclosporine and 3 flare ups while weaning from cyclosporine after 4 to 8 months. Three patients have been weaned from cyclosporine after 8 to 13 months and have remained in remission from six months to five years. One patient is about to complete a six-month course of cyclosporine. Overall ten (72 percent) have undergone surgery, including 7 of 11 who responded initially to cyclosporine and left the hospital. Weight (P < 0.001), albumin (P < 0.01), erythrocyte sedimentation rate (P > 0.05), and prednisone dose (P < 0.001) improved significantly in the seven patients on cyclosporine who responded initially, left the hospital, and subsequently underwent surgery.

CONCLUSIONS

Cyclosporine is effective in achieving clinical remission in 80 percent of children with refractory fulminant colitis; however, within one year, most initial responders will require colectomy because of a flare up of the disease. In a majority of patients, the role of cyclosporine therapy is to rapidly ameliorate symptoms and prevent precipitous colectomy, improve nutrition and psychologic adaptation, and reduce the steroid dose leading to surgery in a well-prepared patient.

Management of septic shock

Septic shock due to bacterial and other infections remains an increasing cause of hospital mortality and morbidity. Early recognition and prompt management with diagnostic evaluation, antimicrobial therapy, surgery when indicated and advanced life support undoubtedly saves many lives. Once treatment has been instituted, careful and frequent monitoring is required to optimise therapy and detect complications at an early stage. However, once shock and organ failure have become established the mortality remains high and has changed little in the last few years despite improvements in intensive management. A variety of other approaches to treatment are under investigation but as yet there are insufficient data to recommend their use.

Doppler velocimetry of the fetal middle cerebral artery in patients with preterm labor and intact membranes

A prospective cohort study was conducted to determine whether preterm labor is associated with changes in the impedance to blood flow of the fetal middle cerebral artery. Doppler velocimetry studies were performed in 194 consecutive patients with preterm labor and intact membranes. Pulsatility indices of the middle cerebral artery and umbilical artery were determined on admission. Results were expressed as ratio of the observed pulsatility index to mean value for gestational age expressed as delta MCA PI and delta UA PI, respectively. The prevalence of preterm delivery (< 37 weeks) and delivery within 24 hours of admission was 55.2% (107/194) and 15.5% (30/194), respectively. Patients with an examination-to-delivery interval within 24 hours had significantly lower mean delta MCA PI than that of patients delivered at > or = 37 weeks and > or = 4 weeks after the examination (P < 0.01). Fetuses with a delta MCA PI at or below 0.88 had a relative risk of 2 (95% confidence interval, 1.32 to 2.9) who were delivered within 24 hours compared to controls (sensitivity 76.7%, specificity 62.8%, positive predictive value 26.7%, negative predictive value 93.5%). Stepwise logistic regression analysis indicated that the relationship between delta MCA PI and examination-to-delivery interval remained statistically significant after correcting for cervical dilatation (P < 0.001). Our data indicate that preterm parturition is associated with a decrease in the impedance to flow in the fetal cerebral circulation.

Highly effective method of human oocyte activation

Fresh and aged unfertilised human oocytes were activated by electroporation and by exposure to isotonic solution of mannitol supplemented with low concentrations of calcium, magnesium and chloride. Over 95% of the fresh oocytes were activated, all showing formation of one pronucleus and extrusion of the second polar body. Oocytes activated 1 and 2 days post-collection showed activation rates of 66.6% and 64.1%, respectively; however, the proportion of one-pronucleate oocytes in these groups was significantly lower (61.6% and 23.5%, respectively). There was no difference in the activation efficiency between the two activation modes. Twelve activated oocytes from the freshly collected group cleaved when left in culture. It is concluded that, in the human, a brief exposure to isotonic solution of mannitol with low concentrations of calcium, magnesium and chloride is a very effective activation stimulus.

[Antigenic types of circulating rotavirus in children with acute diarrhea in Santiago de Chile]

Protective immunity against rotavirus infection is directed against antigenic epitopes on the outer capsid proteins VP7 and VP4. The aim of this study was to characterize the VP7 and VP4 antigenic types circulating in different hospital areas of Santiago, Chile, over different time periods. Between April 1993 and April 1994 a total of 1206 stool samples were obtained from children consulting for acute no bloody diarrhea in 5 hospitals representative of the 5 major health areas of Santiago. In addition, 256 rotavirus positive samples, obtained from children with acute diarrhea consulting in the north health area of Santiago between 1985-1987 were studied. All samples were processed for rotavirus by an ELISA and all rotavirus positive samples were VP7 typed (types G1-G4) by a monoclonal antibody based ELISA. 50 rotavirus positive samples were selected for VP4 typing by PCR (types P1-P4). A total of 782 rotavirus positive samples were obtained of which 618 (79%) were typable for one specific VP7 type. VP7 type G1 represented 63% of the rotavirus positive samples and predominated in all areas evaluated throughout the entire period of observation. VP7 type G2 represented 13% of rotavirus samples, following G1 in predominance. G2 types decreased progressively in all areas in both study periods. G4 types were detected mainly during 1985-1987, and G3 types have so far not been detected. Preliminary analysis of VP4 types suggests that P1 types are predominant and closely associated with VP7 G1 type. These results are relevant for the adoption of appropriate preventive strategies for rotavirus infection, specifically aimed to the development of effective vaccines.

Implications of small reductions in diastolic blood pressure for primary prevention

OBJECTIVES

To estimate the impact of small reductions in the population distribution of diastolic blood pressure (DBP), such as those potentially achievable by population-wide lifestyle modification, on incidence of coronary heart disease (CHD) and stroke.

DESIGN

Published data from the Framingham Heart Study, a longitudinal cohort study, and from the National Health and Nutrition Examination Survey II, a national population survey, were used to examine the impact of a population-wide strategy aimed at reducing DBP by an average of 2 mm Hg in a population including normotensive subjects.

SETTING/PARTICIPANTS

White men and women aged 35 to 64 years in the United States.

MAIN OUTCOME MEASURES

Incidence of CHD and stroke, including transient ischemic attacks (TIAs).

RESULTS

Data from overviews of observational studies and randomized trials suggest that a 2-mm Hg reduction in DBP would result in a 17% decrease in the prevalence of hypertension as well as a 6% reduction in the risk of CHD and a 15% reduction in risk of stroke and TIAs. From an application of these results to US white men and women aged 35 to 64 years, it is estimated that a successful population intervention alone could reduce CHD incidence more than could medical treatment for all those with a DBP of 95 mm Hg or higher. It could prevent 84% of the number prevented by medical treatment for all those with a DBP of 90 mm Hg or higher. For stroke (including TIAs), a population-wide 2-mm Hg reduction could prevent 93% of events prevented by medical treatment for those with a DBP of 95 mm Hg or higher and 69% of events for treatment for those with a DBP of 90 mm Hg or higher. A combination strategy of both a population reduction in DBP and targeted medical intervention is most effective and could double or triple the impact of medical treatment alone. Adding a population-based intervention to existing levels of hypertension treatment could prevent an estimated additional 67,000 CHD events (6%) and 34,000 stroke and TIA events (13%) annually among all those aged 35 to 64 years in the United States.

CONCLUSIONS

A small reduction of 2 mm Hg in DBP in the mean of the population distribution, in addition to medical treatment, could have a great public health impact on the number of CHD and stroke events prevented. Whether such DBP reductions can be achieved in the population through lifestyle interventions, in particular through sodium reduction, depends on the results of ongoing primary prevention trials as well as the cooperation of the food industry, government agencies, and health education professionals.

Assessment of numeric abnormalities of X, Y, 18, and 16 chromosomes in preimplantation human embryos before transfer

OBJECTIVE

Our purpose was to determine the feasibility of ascertaining aneuploidy for chromosomes X, Y, 18, and 16 by use of multiple-probe fluorescence in situ hybridization in blastomeres from preimplantation human embryos.

STUDY DESIGN

A short fluorescence in situ hybridization procedure involving the simultaneous use of four deoxyribonucleic acid probes detected with red, green, blue, or a mixture of red and green fluorochromes was developed to determine numeric abnormalities of chromosomes X, Y, 18, and 16. Embryos underwent biopsy, and all or most cells were analyzed to distinguish true aneuploidy from mosaicism and to assess technique variations within the same embryo (n = 64).

RESULTS

The analysis of all the blastomeres of an embryo was achieved in 91% of the embryos. Successful analyses including biopsy, fixation, and fluorescence in situ hybridization were achieved in 87.8% of the blastomeres. Of the four chromosomes tested, numeric aberrations were found in 23% and 42% of normally and abnormally developing embryos, respectively, including aneuploidy, polyploidy, haploidy, and mosaicism. When diploid embryos containing one or several tetraploid cells are counted as chromosomally abnormal, then 49% and 61% of normally and abnormally developing embryos, respectively, were chromosomally abnormal. Aneuploid embryos consisted of two monosomies for chromosome 16, one for chromosome 18, and a trisomy for chromosome 16. There was a tendency for aneuploidy to increase with maternal age.

CONCLUSIONS

Fluorescence in situ hybridization is a more efficient method than cytogenetic analysis to study specific aneuploidies at preimplantation stages of development in human embryos. In addition, the preimplantation genetic diagnosis of two blastomeres per eight-cell embryo may be sufficient to ensure successful analysis of polyploidy, haploidy, and specific aneuploidies without endangering the survival of the embryo. The technique can be easily modified to consider other chromosomes, including 13 and 21. Because most chromosomally abnormal embryos do not develop to term, the use of this technique may increase the delivery rate per embryo by allowing only transfer of embryos normal for the tested chromosomes. This technique would be most useful for older women undergoing in vitro fertilization, because aneuploidy appears to increase with advancing maternal age.

The use of first polar bodies for preimplantation diagnosis of aneuploidy

A large proportion of patients undergoing in-vitro fertilization (IVF) are aged > or = 35 years. It has been estimated that in this age group, 50% of embryos are chromosomally abnormal, with aneuploidy being the major contributing factor. Since the origin of most aneuploidies is maternal meiosis I non-disjunction, unfertilized oocytes could be safely screened for aneuploidy by analysing their first polar bodies. To determine the feasibility of first polar body aneuploidy analysis, polar bodies were analyzed by fluorescence in-situ hybridization (FISH) using probes simultaneously for chromosomes X, Y, 18, 13/21 or X, Y, 18 and 16. Within 6 h of retrieval, 88% showed a normal segregation involving a single chromosome of each kind, with double-dotted hybridization signals, corresponding to dyads (chromosomes in metaphase I composed of two chromatids). The rest showed non-disjunction of full dyads (6%), or an unbalanced pre-division of dyads (6%), which gives a segregation of one chromatid or one dyad and a chromatid with the first polar body. But only 34% of polar bodies analysed 24 h after retrieval or later showed a normal segregation, with most of the other polar bodies showing balanced pre-division, with two separated hybridization signals for all the chromosomes analysed. The rates of non-disjunction and unbalanced pre-division after > or = 24 h in culture were similar to the rates in fresh oocytes. When both types of aneuploidy were considered together, an increase of aneuploidy with maternal age was detected, which although slight, was significant (P = 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

The anti-lipid A monoclonal antibody E5 binds to rough gram-negative bacteria, fixes C3, and facilitates binding of bacterial immune complexes to both erythrocytes and monocytes

Treatment of patients with septic shock using monoclonal antibodies (mAbs) to endotoxin is still controversial. Clinical trials of E5, one of the mAbs directed against the lipid A moiety of lipopolysaccharide (LPS), are currently in progress. The mechanisms of action of this, and other antibodies under clinical evaluation, are, however, poorly understood. In this study we examined in vitro the ways in which E5 interacted with Gram-negative bacteria, complement, erythrocytes and monocytes. By fluorescence-activated cell sorter (FACS) analysis we showed direct, dose-dependent binding of E5 to Escherichia coli (E. coli) and Salmonella minnesota (S. minnesota). Antibody binding to S. minnesota was enhanced by treatment with the beta-lactam antibiotic amoxycillin, but not by treatment with the aminoglycoside gentamicin. Immune complexes formed between E5 and both species of Gram-negative bacteria activated both classical and alternative complement pathways, but only in the case of S. minnesota did this facilitate binding to erythrocyte CR1 and monocyte CR3. Bacterial C3b and iC3b fixation by E5 was quantified using specific mAbs. These observations suggest that E5 may enhance bacterial clearance in several ways: (1) by facilitating direct complement fixation; (2) by facilitating the binding of opsonized bacteria to cells of the mononuclear phagocyte system; (3) by enabling bacteria to bind to erythrocyte CR1 (CD35), allowing safe carriage in the circulation to the fixed macrophages of the liver and spleen; (4) by acting synergistically with beta-lactam antibiotics.

Extensive regeneration in vitro by early embryonic neurons on immature and adult CNS tissue

The failure of axon regeneration in the injured adult CNS has been ascribed to axon growth inhibitory molecules expressed by the resident glial cell populations, especially oligodendrocytes. Unlike their adult counterparts, however, early embryonic neurons are able to send lengthy axons through myelinated fiber tracts when transplanted into the adult brain. One explanation is that they have yet to express receptors for factors that inhibit the growth of older neurons. To test this possibility, we have used the cryoculture technique to study the regeneration of rat central and peripheral neurons, over a developmental period that encompasses the stages before, during, and after target contact, when cultured on either unmyelinated (neonatal) or myelinated (adult) optic nerve tissue sections. Early embryonic (days 14-15) retinal ganglion cells extended neurites on neonatal optic nerve, but few grew on adult optic nerve. In the case of early embryonic dorsal root ganglion neurons, however, neurite outgrowth on either neonatal optic nerve or on adult optic nerve was extensive. This response declined sharply with age. In contrast, neurite outgrowth by dorsal root ganglion neurons on laminin substrata remained relatively constant (> 80% extended neurites) over the same period. This suggests that (a) inhibition of neurite outgrowth within the optic nerve is mediated not only by oligodendrocytes, but also by molecules expressed prior to the onset of myelination; (b) neurons acquire receptors for these inhibitors only late in embryonic development; (c) differences exist between developing central and peripheral neurons in the response to myelin-associated axon-growth inhibitors.

Male and female genomes associated in a single pronucleus in human zygotes

The ploidy of single-pronucleated human zygotes obtained after conventional in vitro fertilization was determined by fluorescent in situ hybridization (FISH) using multiple simultaneous probes for gonosomes and autosomes. After zona removal the single-pronucleated zygotes were exposed to cytochalasin B, and the pronucleus, surrounded by scant cytoplasm and the plasma membrane (karyoplast), was divided from the rest of the egg (cytoplast). The karyoplasts and the corresponding cytoplasts were analyzed separately by FISH. Of the 16 zygotes analyzed, 10 had haploid pronuclei and 6 were diploid. Four diploid pronuclei contained XY chromosomes, and 2 contained XX chromosomes. These results suggest that during the course of their interaction, human gamete nuclei can associate together and form diploid, single-pronucleated zygotes. These findings confirm a newly recognized variation of human pronuclear interaction during syngamy.