Ulcerative keratitis from overnight contact lens wear compared with other life risks

Wearers of extended wear contact lenses are at increased risk for ulcerative keratitis compared with daily wear contact lens users. Using incidence rates, we compared ulcerative keratitis in contact lens wear with other diseases and serious life risks. "Comparative risk," a theoretical construct for this paper, is a framework through which the incidence rates are compared. Although the risks of ulcerative keratitis in extended wear are greater than with daily wear contact lenses, the risks of extended soft contact lens wear are 2-10 times less than the risks for non-fatal, serious and disruptive occurrences in a general population. Contact lens associated ulcerative keratitis is in the range of 10-20 times greater than the incidence of common causes of death in a low risk, middle-age population.

Recombinant CD4-IgE, a novel hybrid molecule, inducing basophils to respond to human immunodeficiency virus (HIV) and HIV-infected target cells

Basophils and mast cells, as the main effector cells in IgE-mediated type I hypersensitivity, are involved in the elimination of parasites and, according to recent findings, may also play an important role in the defense against bacterial and viral infections. Using a genetic engineering approach we wanted to redirect this potent IgE-mediated defense system against intruding human immune deficiency virus. We constructed a recombinant CD4-IgE molecule, consisting of the two N-terminal domains of CD4 and the CH2-4 domains of the IgE heavy chain, thus providing the IgE with specificity for the gp120 of human immunodeficiency virus (HIV). The binding properties of hybrid CD4-IgE to the high-affinity receptor for IgE (Fc epsilon RI) on basophils as well as to the low-affinity receptor (Fc epsilon RII or CD23) for IgE on lymphoid cells were found to be similar to those of native IgE. At the same time, the CD4 domains of the recombinant molecule retained the gp120 binding specificity with an affinity similar to that of the native CD4. By functional tests, we demonstrated that CD4-IgE armed basophils can be triggered by free HIV and by HIV-infected cells to release their mediators. We further show that HIV-triggered basophils lead to a decreased replication of HIV in susceptible T cells. We, therefore, conclude that the type I hypersensitivity effector cells can be engaged in the elimination of HIV-infected cells, at least in vitro. Because of the strong binding of the CD4-IgE construct to the Fc epsilon RI, we assume that CD4-IgE has a short t1/2 in serum, but may similarly to IgE exhibit prolonged resident time on basophils and mast cells, which are located close to mucosal surfaces or in the connective tissue. Thus CD4-IgE could play an important role in the elimination of HIV also in vivo.

In vivo biotinylated recombinant antibodies: construction, characterization, and application of a bifunctional Fab-BCCP fusion protein produced in Escherichia coli

We describe a novel vector system suitable for the efficient preparation of in vivo biotinylated antibody Fab fragments in Escherichia coli. The previously described pGE20 vector used for the functional expression of truncated heavy (Fd) and light (L) chains of Fab into the bacterial culture medium was modified by inserting the C-terminal 101-amino-acid polypeptide of the biotin carboxyl carrier protein subunit of E. coli acetyl-CoA carboxylase (BCCP*). The secreted Fd-BCCP* fusion and L chain proteins were found to be disulfide linked and Fab-BCCP* complexes of an IgG1 antibody (Mab4) to human tumor necrosis factor alpha (TNF) were shown to retain both antigen and streptavidin-binding activities. The capacity of the Fab4 linked to BCCP* to bind TNF was identical to that observed with unmodified Fab4. Up to 15% of the expressed hybrids were able to interact with streptavidin when exogeneous d-biotin was added into the bacterial culture medium. The Fab4-BCCP* molecules were found to be more efficient than Fab4 linked to an engineered streptavidin-affinity tag for the detection of antigen on solid phase. In addition, we show here that the bacterially expressed Fab4-BCCP* complexes, adsorbed to streptavidin-agarose beads, can be used for the one-step purification of recombinant TNF by immunoaffinity chromatography.

[Late neurologic morbidity of premature infants with intrauterine diagnosis of null- or negative flow of the umbilical arteries]

Absent or reverse enddiastolic flow velocities (AREDFV) of the umbilical arteries are associated with fetal distress and adverse fetal outcome. We studied 68 fetuses with AREDFV with respect to abnormal neurological evaluation up to two years. A control group was matched for gestational age and had normal umbilical artery flow velocity waveforms. Fetuses with AREDFV showed increased abnormal neurological signs, compared with the control group (31% vs. 12%). Our results confirm the significance of AREDFV in growth retarded infants with respect to neurological development in early childhood.

Application of an alkaline phosphatase fusion protein system suitable for efficient screening and production of Fab-enzyme conjugates in Escherichia coli

We report a novel vector system suitable for the efficient preparation of alkaline phosphatase (PhoA)-labelled antibody Fab fragments in Escherichia coli. The previously described pGE20 vector used for the functional expression of truncated heavy (Fd) and light (L) chains of Fab into the bacterial culture medium was modified by inserting the E. coli PhoA coding region 3' to the Fd cloning sites. The secreted Fd-PhoA fusions and L proteins were found to be disulfide linked and Fab-PhoA complexes, prepared with IgG1 antibodies recognizing specifically human tumor necrosis factor alpha, were shown to be useful for the rapid detection of antigen. When an additional short peptide was interposed between the Fd and PhoA domains, nearly all of the recombinant Fab-PhoA conjugates present in the culture supernatant retained both antigen binding and enzymatic activity. A method for the detection and selection of bacterial colonies expressing bifunctional hybrid molecules of desired antigen specificity was also developed. Taken together, the systems described permit the generation and production of Fab-PhoA conjugates in E. coli, which can replace conventionally prepared PhoA-labelled antibodies in appropriate immunoassays.

The significance of plasma progesterone levels during early pregnancies achieved after in vitro fertilization (IVF) treatment

OBJECTIVE

Corpus luteum steroidogenesis is lower for in vivo ectopic pregnancy than for intrauterine pregnancy. There is a progesterone hallmark level distinguishing between viable intrauterine pregnancy and nonviable or ectopic pregnancy. This study attempts to answer whether this is also true for in vitro fertilization-treated patients.

STUDY DESIGN

Using information retrieved from a computerized database, we compared the plasma 17 beta-estradiol (E2) and progesterone during the luteal phase and for every 2 to 3 days for several weeks during early pregnancy between those patients with proven ectopic pregnancies and those with singleton and multiple intrauterine pregnancies. Vaginal ultrasonography to detect an intrauterine gestational sac was performed from day 19. A total of 73 pregnancies resulted from the replacement of fresh embryos in our in vitro fertilization-embryo transfer program.

RESULTS

Only at day 10 post embryo transfer did those patients with ectopic pregnancy show statistically lower mean (SD) serum levels of E2 [2257 (SD, 2351) pmol/L] and plasma progesterone [PP; 221 (SD, 283) nmol/L] compared with patients with intrauterine pregnancy, whose mean E2 was 8846 (SD, 5871) pmol/L and mean PP was 805 (SD, 582) nmol/L (P = 0.008). For the rest of the follow-up until surgery was performed in ectopic pregnancy, there were no differences of statistical significance between extrauterine pregnancy and the intrauterine pregnancy groups. Furthermore, only on day 10 post embryo transfer, did we find a discriminatory zone (confidence interval, 95%) for E2 levels (903 to 3502 pmol/L for EP vs 6116 to 9493 pmol/L for a singleton and 4875 to 9493 pmol/L for multiple pregnancies). PP levels were 26 to 283 nmol/L for ectopic pregnancy versus 496 to 1096 nmol/L for both singleton and multiple pregnancies. An intrauterine gestational sac was visualized at a mean of 23.2 (SD, 4) days after embryo transfer. On this day, the mean P levels were 982.6 (SD, 286.2) nmol/L for intrauterine and 804.5 (SD, 502.4) nmol/L for ectopic pregnancies (P = NS).

CONCLUSIONS

Except for day 10 post embryo transfer, the steroidogenesis in ectopic pregnancy after in vitro fertilization treatment does not differ from successful intrauterine pregnancy. This observation negates an impaired steroidogenesis for ectopic pregnancy after in vitro fertilization and makes the PP level irrelevant in the diagnosis of pregnancy implantation.

Purification and analytical characterization of an anti-CD4 monoclonal antibody for human therapy

A purification process for the monoclonal anti-CD4 antibody MAX.16H5 was developed on an analytical scale using (NH4)2SO4 precipitation, anion-exchange chromatography on MonoQ or Q-Sepharose, hydrophobic interaction chromatography on phenyl-Sepharose and gel filtration chromatography on Superdex 200. The purification schedule was scaled up and gram amounts of MAX.16H5 were produced on corresponding BioPilot columns. Studies of the identity, purity and possible contamination by a broad range of methods showed that the product was highly purified and free from contaminants such as mouse DNA, viruses, pyrogens and irritants. Overall, the analytical data confirm that the monoclonal antibody MAX.16H5 prepared by this protocol is suitable for human therapy.

CK-BB as indicator of prenatal brain-cell injury in fetuses with absent or reverse end-diastolic flow velocities of the umbilical arteries

The purpose of this study is to determine the levels of brain type isoenzyme of creatine kinase (CK-BB) as a possible indicator of a pre-existing intrauterine brain-cell damage in cord blood sera of fetuses with preceding absent or reverse end-diastolic flow velocities of the umbilical arteries (AREDFV). CK-BB isoenzyme activities were determined in umbilical cord sera of 13 newborn infants with preceding AREDFV and in 14 fetuses with low end-diastolic flow velocities (LEDFV) of the umbilical arteries. 50 newborn infants with elective cesarean section and normal umbilical artery blood flow velocity waveforms were used as controls. Two-tailed Student's t-test and Fischer's exact test were used for statistical evaluation of the results. CK-BB isoenzyme activity did not depend on gestational age. Fetuses with AREDFV showed a significant increase in CK-BB values, whereas fetuses with LEDFV had CK-BB activities within the normal range of the controls. The elevated CK-BB values of the AREDFV group were not correlated with fetal acidosis at birth. Brain-cell injury with leakage of CK-BB isoenzyme might be present in fetuses with AREDFV even before (preterm) delivery.

Presence of an expressed beta-tubulin gene (TUBB) in the HLA class I region may provide the genetic basis for HLA-linked microtubule dysfunction

An expressed beta-tubulin gene (TUBB) has previously been localized to chromosome region 6pter-p21 in man. By using a panel of deletion mutant cell lines and radiation-reduced hybrids containing fragments of chromosome 6, the TUBB locus could be mapped to the HLA class I region at 6p21.3. A long range restriction map including TUBB and several HLA class I genes was then generated by rotating field gel electrophoresis. The results show that TUBB maps to a segment 170-370 kb telomeric of HLA-C. This location suggests that a mutation at the TUBB locus could be the cause for certain forms of HLA-linked microtubule dysfunction, including immotile cilia syndrome.

Treatment of primary insomnia with trimipramine: an alternative to benzodiazepine hypnotics?

A group of 19 middle aged patients suffering from primary insomnia according to the DSM-III-R were treated in a single-blind study with trimipramine, a sedating antidepressant. A total of 15 patients completed the study protocol and were evaluated. The present pilot study aimed at investigating the sleep-inducing properties of trimipramine, and at clarifying the question of whether short- or long-term rebound insomnia occurs after discontinuation of this drug. At four measurement points, i.e. under baseline conditions, under treatment and 4 and 14 days after drug discontinuation, sleep was recorded with an ambulatory-electroencephalogram (EEG) monitoring device in the patient's home environment. Simultaneously, psychometric tests were applied to measure withdrawal symptoms, subjective sleep quality and well-being during daytime. Trimipramine at a mean dose of 166 +/- 48 mg led to a significant increase in sleep efficiency, total sleep time, and stage 2% sleep-period time (SPT), whereas a significant decrease in wake time and stage 1% SPT was noted. Insomniac patients reported an improvement in subjectively perceived sleep quality following trimipramine. Additionally, an improvement in well-being during the daytime occurred. Negative side effects were limited to dry mouth due to the anticholinergic properties of the drug. Discontinuation of trimipramine did not provoke either short- or long-term rebound insomnia in objective and subjective sleep measurements considering mean values of the whole sample, although a subgroup of patients did display total sleep times below baseline values during short- and long-term withdrawal, but generally without a concomitant worsening of sleep quality according to the sleep questionnaire.

Women's lives and sex: implications for AIDS prevention

Preliminary findings from the Women and AIDS program, a research grants program of the International Center for Research on Women in Washington, D.C. that supports 17 studies in developing countries worldwide, provide a glimpse into the complex interaction between women's social and economic status and risk of HIV infection. In many settings, the cultural norms that demand sexual fidelity and docile and acquiescent sexual behavior among women permit--and sometimes even encourage--early sexual experimentation, multiple partnerships, and aggressive and dominating sexual behavior among men. Drawing upon the finding from the program, the paper analyzes how such cultural norms, together with women's social and economic dependency, can limit a woman's ability to negotiate safer sex with her partner; restrict her access to information and knowledge about her body; force her to sometimes barter sex for survival; increase her vulnerability to physical violence in sexual interaction; and compromise her self-esteem. The findings highlight the limitations of the current HIV/AIDS prevention strategy for reducing women's risk of HIV, and underline the urgency for an approach to prevention that is grounded in the realities of women's lives and sexual experiences--an approach that recognizes the relationship between the dynamics of gender relations, sexual behavior, and HIV risk.

Immunohistological and immuno-electron microscopic localization of fibronectin in chicken bone marrow

Fibronectin (FN) was immunolocated in chicken bone marrow with the PAP-technique by light and electron microscopy. A pre-embedding method was employed for immunolabelling the specimen for electron microscopy. Blood vessels and lining cells of capillaries and sinusoids were labelled for FN. Monocytes, intrasinusoidal macrophages, and stromal elements in the extrasinusoidal compartment. The distribution of FN in the chicken bone marrow supports the assumption that FN facilitates extravascular haematopoiesis, especially migratory processes, whereas its contribution to intravascular haematopoiesis seems less likely and needs further investigation.

Bacterially expressed Fabs of monoclonal antibodies neutralizing tumour necrosis factor alpha in vitro retain full binding and biological activity

Antibody fragments specific for the human tumour necrosis factor alpha (TNF alpha) have been cloned from lambda combinatorial expression libraries using total RNA obtained from three different hybridoma cell lines of therapeutic interest. The previously described bacteriophage lambda vectors, lambda HC2 and lambda LC1, were modified to create unique antibody cloning sites in the combinatorial construct and a novel tag peptide was inserted at the C-terminal end of the expressed Fd chain. Sequence analysis of the cloned Fabs indicated that two of them were derived from a single B cell. Expression in E. coli showed that the amount of recovered Fab in the bacterial culture medium was related to the sequences of the variable coding regions. Hybrid Fabs created by chain exchange of similar antibodies were as active as the originally paired Fabs in binding assays. The relative affinities and the capacities of the bacterially expressed Fabs to neutralize TNF alpha cytotoxicity in vitro were identical to those of the parental antibodies. The results demonstrate that, using an in vitro approach, it is possible to generate from existing hybridoma cell lines high affinity Fabs which retain antigen specificity. The cloning sites incorporated into the C-terminal parts of these Fabs will now permit their further modification to include additional functional characteristics not possible with the original hybridoma antibodies.

[Analysis of perinatal mortality as an obstetric quality factor exemplified by the Hessian Perinatal Study 1981-1989]

In a retrospective study, the perinatal mortality between 1981 and 1989 in Hesse is analysed with the help of the Hessische Perinatalerhebung (Hessian Perinatal Study, HEPE). The frequencies of antepartum, subpartum, and neonatal death (< or = 7th day) are studied in relation to the birthweight of the newborn. For the first time in 1982, the neonatal mortality was below the rate of the stillborn foetuses. The subpartum mortality is remarkably low since 1985 (< 0.3%). The number of stillbirths with antepartum death is unchanged since 1985 and their relative amount increases as the neonatal mortality decreases further. The improvement in neonatal mortality concerns particularly the very low birthweight infants below 1500 g, and especially those below 1000 g. The survival of the born alive fetuses below 1000 g birthweight show an additional improvement, when they are born in a perinatal centre. The death of the stillborn babies occurs antepartum in 90% and concerns approx. 80% of fetuses with more than 1499 g and in nearly 50% fetuses weighing more than 2499 g. Lethal malformations are of no importance in antepartum mortality. An improvement in antepartum foetal losses seems to be possible in Hesse and could lead to a decrease in perinatal mortality to below 5% in the years to come.

Low target birth weight or growth retardation? Umbilical Doppler flow velocity waveforms and histometric analysis of fetoplacental vascular tree

OBJECTIVE

The placental vascular architecture of small-for-gestational-age fetuses seems to have an impact on the flow patterns in the umbilical arteries.

STUDY DESIGN

Blood flow velocity waveforms of the umbilical arteries were measured by Doppler ultrasonography in nine small-for-gestational-age fetuses with elevated systolic/diastolic ratios of the umbilical arteries, seven small-for-gestational-age fetuses with normal flow patterns, and 14 appropriate-for-gestational-age fetuses with normal flow patterns. After delivery histomorphometric placental investigations were performed.

RESULTS

Reduced end-diastolic flow velocities were significantly associated with both a reduction of vascularization within the terminal villi and adverse diffusion conditions, indicating insufficient functional maturity. The perfusion and diffusion capacity of small-for-gestational-age placentas with normal umbilical artery flow velocity waveforms was similar or even slightly better compared with the appropriate-for-gestational-age control values.

CONCLUSION

These data suggest that Doppler flow velocimetry in the umbilical arteries is predictive of a vascular lesion within the placentas of small-for-gestational-age fetuses.

[Brain-specific creatine kinase (CKBB) in umbilical cord blood. A prognostic parameter in chronic intrauterine hypoxia?]

Elevated levels of brain type creatine isoenzyme (CKBB) have been demonstrated in serum after brain cell injury in neonates. A hypoxic lesion of the membrane permeability of the CKBB rich brain cells may lead to an increased enzyme leakage into the serum. As an increased release from the fetal brain as a result of intermittent compression and decompression of the fetal head during labour and after rupture of membranes may occur without hypoxic damage, only pregnancies which were terminates by cesarean section were studied. No mother went into first stage of labour and no rupture of membranes occurred. Three study groups were defined. The control group (elective cesarean section for breech presentation) showed CKBB enzyme activities below 15 U/l. A group with emergency cesarean sections had low CKBB values too, despite acidotic pH-values (pH < 7.20) at birth. The third group included fetuses which were delivered by cesarean section because of a pathological fetal heart rate tracing and intrauterine growth retardation. 6 out of 40 umbilical cord sera in this group showed elevated CKBB enzyme activities. If there was an additional fetal acidosis an increased neurological morbidity and neonatal mortality was seen.

Condition at birth of infants with previously absent or reverse umbilical artery end-diastolic flow velocities

In a case control study we assessed 47 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical artery with respect to the mode of delivery, fetal acidosis, and abnormal neurological evaluations at the time of discharge from the department of pediatrics. We also studied a control group which was matched for gestational age and had normal umbilical artery flow velocity waveforms. Fetuses with AREDFV were delivered almost exclusively by cesarean section which was usually done for fetal distress. The number of fetuses with abnormal neurological signs was significantly increased compared to the control group. Fetuses with AREDFV showed an increased incidence of fetal acidosis. Forty per cent of these fetuses were delivered within one day of the first abnormal flow measurement; Sixty per cent were observed clinically for up to four weeks before delivery.

[Light and electron microscopic studies of calf kidneys after exposure to subtoxic lead levels]

Eight calves were fed from the fourth to the twentieth week of age a milk powder diet containing 40 mg lead acetate per kg dry substance. This is twice the lead concentration legally permitted. In average, each animal has daily taken up 0.834 mg lead per kg body weight. Eight calves were used as controls. The animals gained the usual fattening weights and did not show clinical symptoms. Beginning with week 14, increased levels of blood urea were encountered in the animals which received lead in their diet. Morphologically, severe renal lesions were found in these calves. The kidneys were increased in weight, pale and of firm consistency. Histologically, fibrosis and periglomerular interstitial non-purulent nephritis were found. Light- and electronmicroscopically, numerous intranuclear inclusion-bodies typical for lead poisoning were demonstrated in epithelial cells of proximal tubules. The results show, that daily uptake of less than 1 mg lead per kg body weight must be considered as a toxic dose for calves, and not 5-7 mg as stated in literature.