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Objective: Insufflation of the amniotic cavity with carbon dioxide (CO2) is used clinically to improve visibility during complex fetoscopic surgery. Insufflation with heated, humidified CO2 has recently been shown to reduce fetal hypercapnia and acidosis in sheep, compared with use of cold and dry CO2, but the underlying mechanisms are unclear. The aim of this study was to investigate whether differences in placental CO2 and oxygen (O2) exchange during insufflation with heated and humidified vs cold and dry CO2 could explain these findings. Methods: Thirteen fetal lambs at 105 days of gestation (term, 146 days) were exteriorized partially, via a midline laparotomy and hysterotomy, and instrumented with an umbilical artery catheter, an umbilical vein catheter and a common umbilical vein flow probe. Arterial and venous catheters and flow probes were also inserted into the maternal uterine circulation. Six ewes were insufflated with cold, dry CO2 (22°C; 0–5% humidity) and seven with heated, humidified CO2 (40°C; 95–100% humidity) at 15 mmHg for 180 min. Blood‐flow recordings and paired arterial and venous blood gases were sampled from uterine and umbilical vessels. Rates of placental CO2 and O2 exchange were calculated. Results: After 180 min of insufflation, fetal survival was 33% (2/6) using cold, dry CO2 and 71% (5/7) using heated, humidified CO2. By 120 min, fetuses insufflated with heated, humidified CO2 had lower arterial CO2 levels and higher arterial pH compared to those insufflated with cold, dry gas. Insufflation decreased significantly placental gas exchange in both groups, as measured by rates of both (i) fetal CO2 clearance and O2 uptake and (ii) maternal O2 delivery and CO2 uptake from the fetal compartment. Conclusions: Lower arterial CO2 and higher pH levels in fetuses insufflated with heated and humidified, compared to cold and dry, CO2 could not be explained by differences in placental gas exchange. Instead, heated and humidified insufflation appeared to reduce fetal CO2 absorption from the uterus, supporting its use in preference to cold, dry CO2. © 2019 International Society of Ultrasound in Obstetrics and Gynecology [ABSTRACT FROM AUTHOR]

Objectives: Infants with congenital diaphragmatic hernia (CDH) are predisposed to pulmonary hypertension after birth, owing to lung hypoplasia that impairs fetal pulmonary vascular development. Antenatal sildenafil treatment attenuates abnormal pulmonary vascular and alveolar development in rabbit and rodent CDH models, but whether this translates to functional improvements after birth remains unknown. We aimed to evaluate the effect of antenatal sildenafil on neonatal pulmonary hemodynamics and lung function in lambs with diaphragmatic hernia (DH).Methods: DH was surgically induced at approximately 80 days' gestation in 16 lamb fetuses (term in lambs is approximately 147 days). From 105 days' gestation, ewes received either sildenafil (0.21 mg/kg/h intravenously) or saline infusion until delivery (n = 8 fetuses in each group). At approximately 138 days' gestation, all lambs were instrumented and then delivered via Cesarean section. The lambs were ventilated for 120 min with continuous recording of physiological (pulmonary and carotid artery blood flow and pressure; cerebral oxygenation) and ventilatory parameters, and regular assessment of arterial blood gas tensions. Only lambs that survived until delivery and with a confirmed diaphragmatic defect at postmortem examination were included in the analysis; these comprised six DH-sildenafil lambs and six DH-saline control lambs.Results: Lung-to-body-weight ratio (0.016 ± 0.001 vs 0.013 ± 0.001; P = 0.06) and dynamic lung compliance (0.8 ± 0.2 vs 0.7 ± 0.2 mL/cmH2 O; P = 0.72) were similar in DH-sildenafil lambs and controls. Pulmonary vascular resistance decreased following lung aeration to a greater degree in DH-sildenafil lambs, and was 4-fold lower by 120 min after cord clamping than in controls (0.6 ± 0.1 vs 2.2 ± 0.6 mmHg/(mL/min); P = 0.002). Pulmonary arterial pressure was also lower (46 ± 2 vs 59 ± 2 mmHg; P = 0.048) and pulmonary blood flow higher (25 ± 3 vs 8 ± 2 mL/min/kg; P = 0.02) in DH-sildenafil than in DH-saline lambs at 120 min. Throughout the 120-min ventilation period, the partial pressure of arterial carbon dioxide tended to be lower in DH-sildenafil lambs than in controls (63 ± 8 vs 87 ± 8 mmHg; P = 0.057), and there was no significant difference in partial pressure of arterial oxygen between the two groups.Conclusions: Sustained maternal antenatal sildenafil infusion reduced pulmonary arterial pressure and increased pulmonary blood flow in DH lambs for the first 120 min after birth. These findings of improved pulmonary vascular function are consistent with improved pulmonary vascular structure seen in two previous animal models. The data support the rationale for a clinical trial investigating the effect of antenatal sildenafil in reducing the risk of neonatal pulmonary hypertension in infants with CDH. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Objective: Partial amniotic carbon dioxide (CO2 ) insufflation (PACI) is used to improve visualization and facilitate complex fetoscopic surgery. However, there are concerns about fetal hypercapnic acidosis and postoperative fetal membrane inflammation. We assessed whether using heated and humidified, rather than cold and dry, CO2 might reduce the impact of PACI on the fetus and fetal membranes in sheep.Methods: Twelve fetal lambs of 105 days' gestational age (term = 145 days) were exteriorized partially, via a midline laparotomy and hysterotomy, and arterial catheters and flow probes were inserted surgically. The 10 surviving fetuses were returned to the uterus, which was then closed and insufflated with cold, dry (22 °C at 0-5% humidity, n = 5) or heated, humidified (40 °C at 100% humidity, n = 5) CO2 at 15 mmHg for 180 min. Fetal membranes were collected immediately after insufflation for histological analysis. Physiological data and membrane leukocyte counts, suggestive of membrane inflammation, were compared between the two groups.Results: After 180 min of insufflation, fetal survival was 0% in the group which underwent PACI with cold, dry CO2 , and 60% (n = 3) in the group which received heated, humidified gas. While all insufflated fetuses became progressively hypercapnic (PaCO2  > 68 mmHg), this was considerably less pronounced in those in which heated, humidified gas was used: after 120 min of insufflation, compared with those receiving cold, dry gas (n = 3), fetuses undergoing heated, humidified PACI (n = 5) had lower arterial partial pressure of CO2 (mean ± standard error of the mean, 82.7 ± 9.1 mmHg for heated, humidified CO2 vs 170.5 ± 28.5 for cold, dry CO2 during PACI, P < 0.01), lower lactate levels (1.4 ± 0.4 vs 8.5 ± 0.9 mmol/L, P < 0.01) and higher pH (pH, 7.10 ± 0.04 vs 6.75 ± 0.04, P < 0.01). There was also a non-significant trend for fetal carotid artery pressure to be higher following PACI with heated, humidified compared with cold, dry CO2 (30.5 ± 1.3 vs 8.7 ± 5.5 mmHg, P = 0.22). Additionally, the median (interquartile range) number of leukocytes in the chorion was significantly lower in the group undergoing PACI with heated, humidified CO2 compared with the group receiving cold, dry CO2 (0.7 × 10-5 (0.5 × 10-5 ) vs 3.2 × 10-5 (1.8 × 10-5 ) cells per square micron, P = 0.02).Conclusions: PACI with cold, dry CO2 causes hypercapnia, acidosis, hypotension and fetal membrane inflammation in fetal sheep, raising potential concerns for its use in humans. It seems that using heated, humidified CO2 for insufflation partially mitigates these effects and this may be a suitable alternative for reducing the risk of fetal acid-base disturbances during, and fetal membrane inflammation following, complex fetoscopic surgery. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

The zona pellucida (ZP) is the extracellular matrix that plays important roles in sperm-egg interaction. The ZP is composed of three major glycoproteins that exhibit heterogeneity due to extensive post-translational modifications including glycosylation and sulfation. Because of these modifications the nomenclature of ZP proteins from different species based on electrophoretic mobilities has been confusing. As the cDNAs and genes encoding the different ZP proteins have been isolated and sequenced, it is now possible to relate these ZP proteins according to gene families. Using the mouse ZP nomenclature, the ZP proteins from different mammalian species can be classified into three protein families: ZP1, ZP2, and ZP3. Although some of the structural domains of the ZP proteins of different species are conserved within each family, they exhibit distinct biological properties. In the mouse it has been established that ZP3 is the primary sperm receptor while ZP2 has secondary sperm receptor properties. In the pig, however, ZP1 has been shown to have sperm receptor activity similar to that observed in the rabbit and nonhuman primates. It is of interest that the human ZP2 and ZP3 gene families are 60–70% conserved with respect to the mouse ZP amino acid sequence, while the mouse ZP1 is only 39% conserved with respect to human ZP1. Such differences in protein structure and glysosylation may explain the marked species differences in the biochemical, physicochemical and immunochemical properties of the ZP. Studies have now shown that the proteins of the ZP are expressed in a stage specific manner and that there is increasing evidence that ZP proteins are expressed by both granulosa cells and the oocyte and may play a role in granulosa cell differentiation.Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

It has long been established that there are major variations in both the immunogenicity and antigenicity of native zona pellucida (ZP) proteins. These differences appear to be more pronounced with respect to genetically engineered ZP proteins, which do not have native post-translational modifications (for example glycosylation and sulphation). As the number of animal species that are now included in population management programmes using native porcine zona pellucida (PZP) proteins expands, it is increasingly important to carry out studies to evaluate the immune response variations among different species as well as the individual variation within a species. In an attempt to compare these complex immune responses, we have evaluated antibodies from numerous species immunized with native, genetically engineered ZP and synthetic ZP peptides. Such an immunocontraceptive method could have great potential. These studies are critical not only for the development of predictable immune responses that result in permanent sterilization versus reversible contraceptive effects, but also for predicting which vaccinogens (native ZP protein versus genetically engineered ZP proteins) might have detrimental effects on animal and human populations.

A lactosaminoglycan-associated antigen is associated with a carbohydrate moiety of all three zona pellucida (ZP) glycoproteins of pig and rabbit but is absent in the mouse and rat. A monoclonal antibody (PS1) recognizing this determinant was obtained by immunizing mice with a porcine ZP glycoprotein isoform purified by two-dimensional polyacrylamide gel electrophoresis. Conditions known to remove O-linked or sialic acid carbohydrate moieties (alkaline reduction; O-glycanase or neuraminidase enzymatic cleavage) did not remove the carbohydrate epitope. However, treatment with endo-beta-glycosidase, endoglycosidase F, or combinations of neuraminidase plus beta-galactosidase, totally removed the determinant, indicating that it is associated with a poly-N-acetyllactosaminoglycan structure present on an N-linked oligosaccharide. Molecular morphology studies using immunofluorescence and confocal microscopy techniques demonstrate that the PS1 antigen is localized at the surface of the ZP. Confirmation of this localization was obtained through studies that show that this antibody will inhibit homologous sperm binding to the pig ZP. Additional analyses using modular contrast microscopy and immunocytochemistry demonstrate that this carbohydrate-associated antigen is localized in discrete layers throughout the ZP matrix. These studies are the first to demonstrate the presence of a lactosaminoglycan type carbohydrate moiety in all three ZP proteins using a monoclonal antibody that appears to be involved in sperm recognition and structural organization.

Zona pellucida (ZP) glycoproteins contain numerous antigenic determinants including carbohydrate, protein, and conformational epitopes; and the immunogenicity of these complex glycoproteins varies in different mammalian hosts. Studies have now shown that antibodies from primates immunized with a cDNA-expressed recombinant rabbit ZP protein (the homologue of the human ZP1 [hZP1]) inhibit sperm binding to the ZP without altering ovarian function, unlike immunization with ZP3 and ZP2 protein families. The ZP1 protein or peptides derived from it (recombinant or synthetic) are therefore primary candidates for use in designing safe and reversible human and animal contraceptive vaccines. In order to define peptide epitope(s) that may be critical for eliciting an immune response sufficient to effect immunological contraception without causing any adverse effects on ovarian physiology, studies have been carried out to identify immunodominant B-cell epitopes of the ZP1 protein. The amino acid sequence of the hZP1 was used to design a set of 94 (15-mer) biotinylated peptides having an overlap of 9 amino acids. Using these peptides in a modified enzyme-linked immunoassay, antibodies in sera from rabbits or baboons immunized with native porcine ZP protein were screened for ZP1 peptide recognition. These studies demonstrate that there are a limited number of peptides recognized by primate antibodies but that the overlapping peptides sharing the sequence GPLTLELQI are recognized by both rabbit and baboon antibodies regardless of the adjuvant system used to induce the immune response. This peptide is 100% conserved in amino acid sequence between the human and pig, although the rabbit protein has two conserved amino acid substitutions (100% similar, 77% identical). Because this peptide is immunogenic as well as antigenic in primates, it could play a major role in the development of human contraceptive vaccines.

The primary structure of two forms of gonadotropin releasing hormone (GnRH) from tunicate (Chelyosoma productum) have been determined based on mass spectrometric and chemical sequence analyses. The peptides, tunicate GnRH-I and -II, contain features unprecedented in vertebrate GnRH. Tunicate GnRH-I contains a putative salt bridge between Asp5 and Lys8. A GnRH analog containing a lactam bridge between Asp5 and Lys8 was found to increase release of estradiol compared with that of the native tunicate GnRH-I and -II. Tunicate GnRH-II contains a cysteine residue and was isolated as a dimeric peptide. These motifs suggest that the conformation plays an important role in receptor activation.

A monoclonal antibody developed against a meiotically expressed porcine oocyte carbohydrate antigen has been shown to recognize an antigen in ovarian surface epithelial cells (OSE) of numerous mammalian species, including the non-human primate and the human (1). Although most of the ovarian surface epithelial cells are lost during aging in the human, a few cells may remain in ovarian crypts. Because the majority of ovarian carcinomas are thought to be derived from the OSE cells in aging women the PS1 antibody has been used to evaluate ovarian tumors. The secretory origin of this carbohydrate antigen in meiotic cells prompted further analyses of peritoneal fluid collected from gynecological surgery patients including those diagnosed with ovarian cancer. The present study demonstrates that ovarian tumor proteins separated on SDS PAGE include an antigen having a heterogeneous molecular weight (> 100 kDa) typical of glycosylated proteins. Additional studies show that peritoneal fluid from 19 patients not having cancer contain PS1 associated glycoproteins. However, of 14 cancer patients, only one had detectable levels of the carbohydrate antigen. These observations suggest that either the secretion of this glycoprotein is altered in ovarian carcinoma or that glycosidases or other proteolytic enzymes are involved in the degradation of these glycoproteins.

A monoclonal antibody developed against a meiotically expressed porcine oocyte carbohydrate antigen has been shown to recognize an antigen in ovarian surface epithelial cells. Immunohistochemical studies of ovaries demonstrated that this antigen is present in the ovarian surface epithelia (OSE) of numerous mammalian species, including the non-human primate and the human (1). Although most of the ovarian surface epithelial cells are lost during aging in the human, a few cells may remain in ovarian crypts. In view of theories that most ovarian carcinomas are derived from the OSE cells in aging women, the PS1 antibody has been used to evaluate ovarian tumors using immunocytochemistry to detect the PS1 antigen in paraffin embedded pathology tissues. The present study found that the PS1 antigen is abundant in a number of malignant ovarian tumors, but is not expressed in a non-malignant Brenner's (ovarian) tumor or granulosa cell tumors. This antibody therefore appears to have great potential for the histopathological and immunochemical analysis of ovarian tumors.

The neuropeptide gonadotropin-releasing hormone (GnRH) is the major regulator of reproduction in vertebrates. Our goal was to determine whether GnRH could be isolated and identified by primary structure in a protochordate and to examine its location by immunocytochemistry. The primary structure of two novel decapeptides from the tunicate Chelyosoma productum (class Ascidiacea) was determined. Both show significant identity with vertebrate GnRH. Tunicate GnRH-I (pGlu-His-Trp-Ser-Asp-Tyr-Phe-Lys-Pro-Gly-NH2) has 60% of its residues conserved, compared with mammalian GnRH, whereas tunicate GnRH-II (pGlu-His-Trp-Ser-Leu-Cys-His-Ala-Pro-Gly-NH2) is unusual in that it was isolated as a disulfide-linked dimer. Numerous immunoreactive GnRH neurons lie within blood sinuses close to the gonoducts and gonads in both juveniles and adults, implying that the neuropeptide is released into the bloodstream. It is suggested that in ancestral chordates, before the evolution of the pituitary, the hormone was released into the bloodstream and acted directly on the gonads.

A cDNA encoding the rabbit 55 kDa ZP protein was expressed using a baculovirus expression system and was evaluated for its ability to elicit antibodies which may interfere with sperm-ZP interaction. The expressed glycosylated protein, BV55, was purified by wheat germ agglutinin lectin affinity chromatography. Antisera made in guinea pigs immunized with BV55 (GP-alpha-BV55) is specific for the 55 kDa rabbit ZP protein. Indirect immunofluorescence studies indicate that GP-alpha-BV55 localizes to a filamentous meshwork on the surface of the ZP of isolated rabbit eggs. Immunohistochemical analysis of rabbit ovaries demonstrated that this antigen is localized within the ZP of primary and more advanced stage ovarian follicles but is not detected in primordial follicles. In addition, the 55 kDa antigen was detected in the granulosa cells of secondary stage follicles but not in the oocyte. GP-alpha-BV55 effectively blocked the binding of rabbit sperm to rabbit eggs in vitro. However, Fab fragments generated from GP-alpha-BV55 failed to block sperm binding, suggesting that the inhibitory effect of GP-alpha-BV55 was due to stearic hindrance rather than specific blocking of a sperm receptor site. Although the Fab fragment did not inhibit sperm binding, additional studies demonstrated that biotinylated BV55 protein bound to rabbit sperm in the acrosomal region in a manner consistent with ligand activity in the sperm-ZP interaction, and that BV55 bound to rabbit sperm in a dose-dependent manner. These studies therefore demonstrate that antibodies against recombinant ZP proteins recognize the native intact ZP and inhibit sperm-ZP interaction. They also provide evidence that the rabbit 55 kDa ZP protein, which is the homolog of the pig ZP3 alpha sperm receptor protein, has sperm receptor activity.

Background: Chronic myelomonocytic leukemia has been associated with various nonspecific cutaneous manifestations. Rarely has the leukemia been reported to directly affect the skin., Methods: This case documents the progression of a patient who ultimately developed chronic myelomonocytic leukemia, by clinical examination, hematologic parameters, dermatopathology, and bone marrow pathology., Results: The skin showed nonspecific cutaneous involvement, progressing to specific leukemic lesions parallel with increasing systemic and hematologic involvement., Conclusions: Chronic myelomonocytic leukemia can manifest with lesions of leukemia cutis. The possibility of nonspecific cutaneous involvement in the preleukemic phase exists.

The effectiveness of zona pellucida antigens in immunizing white-tailed deer to reduce fertility was evaluated by analysing the constituent deer zona pellucida proteins and their immunogenicity. Does were immunized with porcine zona pellucida antigens. The antibodies were characterized using immunohistochemical and immunoblot analysis, in which zona pellucida proteins were separated by one-dimensional and two-dimensional PAGE. Deer anti-porcine zona pellucida antibodies were found to recognize all the major proteins of the porcine zona pellucida. These antibodies also recognized several proteins of deer zona pellucida, indicating that it is possible to break immune tolerance in the deer using such a protocol. The antibodies were also found to recognize peptides of 55 and 75 kDa that were produced by expressing cDNA clones containing antigens of major glycoproteins of rabbit zona pellucida. Furthermore, antibodies against rabbit zonae pellucidae recognized antigens in zonae of paraffin-embedded deer ovaries. Taken together, these experiments demonstrate the crossreactive nature of a number of zona pellucida epitopes found in deer and in several other species. They also illustrate the immunogenicity possible in such an immunization protocol, and provide valuable probes for the investigation of follicular development in this and other species.

Background and Methods: Formaldehyde resins have been used to impart wrinkle resistance to clothing fabrics since 1926. After several patients with positive patch tests to formaldehyde resins had been examined, a study was undertaken of the records of all patch tests performed at the University of Louisville Patch Test Clinic and the Allergy Section of the Skin and Cancer Clinic of New York University Medical Center from January 1988 through April 1990 to determine the prevalence of positive patch-test reactions to formaldehyde-based textile resins and the clinical and demographic patterns associated with textile resin allergy., Results: Seventeen patients were identified at the two centers. Twelve were allergic to formaldehyde as well as to formaldehyde textile resins. Several clinical patterns were found, including accentuation of dermatitis in areas of tight clothing, primary occurrence in clothing-covered areas, and a chronic recalcitrant course. Ethylene urea melamine formaldehyde resin was the best screening agent with 14 definite positive reactions and one equivocal reaction., Conclusion: Formaldehyde textile resin allergy is more common than has been previously recognized. Patch testing with one or more formaldehyde textile resins is indicated in patients with a particular pattern of dermatitis.

A review of the literature reveals that of the eight reported cases of patients with acquired immunodeficiency syndrome acquiring Norwegian scabies, three of these have been complicated by sepsis. We describe such a patient who contracted sepsis from Pseudomonas aeruginosa. We propose that the fissures often seen in severe cases of Norwegian scabies may serve as a port of entry for bacteria, thus placing these patients at a high risk for sepsis. We also believe that empiric antibiotic treatment is justified in these patients and that the choice of agent should be based on the institution's bacterial flora profile.

We used a monoclonal antibody (PS1) to a carbohydrate antigen to study the development of the oocyte and follicle during early stages of differentiation in several mammalian species. This antigen has been shown to localize within the cytoplasm of oocytes in primordial follicles as well as in growing oocytes. It is also localized within distinct layers of the zona pellucida (ZP) of developing follicles. Although this antibody was made against a specific ZP glycoprotein, the antigen also appears to be abundant in cells of the ovarian surface epithelium (OSE). The localization of this carbohydrate moiety has been observed in ovaries of rabbits of different ages as well as in the ovarian surface epithelium of other mammalian species including cat, cynomolgus monkey, baboon, and human. These studies demonstrate that there is an abundant carbohydrate antigenic determinant which is associated with both the mammalian oocyte and the ovarian surface epithelium but which is not apparent in other ovarian cell types or in non-ovarian secretory epithelium. This antibody probe should provide a valuable tool for studying the development and differentiation of the ovary, since this antigen is associated with two highly differentiated but distinct cell types.

Six-mercaptopurine and its Pt, Pd and Bi complexes were used at various dosage levels to treat Dunning ascitic leukemia in rats. Significant anticarcinogenic activity was found in all compounds with toxicity apparent at the highest dosage level of all but the platinum compound.

Changes in rabbit ovarian hormonal responses and cellular differentiation of ovarian follicles after immunization with porcine zona pellucida (ZP) have been examined. Steroid and peptide hormone levels were monitored after immunization to evaluate ovulation and pseudopregnancy cycles in immunized and control animals. All immunized rabbits developed serum antibodies to specific ZP antigens and failed to form functional corpora lutea in response to hCG administration, as evidenced by the absence of elevated serum progesterone concentrations. This is in contrast to control rabbits, which had elevated progesterone levels 8-9 days after hCG administration. Furthermore, all immunized animals showed greatly increased serum levels of FSH and LH compared to those of control animals. These effects on ovarian function were apparent within 20 weeks of the primary immunization. Follicular development was analyzed by light and electron microscopies. The numbers of primary, secondary, and tertiary follicles in ovaries of immunized animals were markedly reduced within 7 weeks compared with control values. By 23 weeks, few if any growing follicles were present. Although numerous distinct clusters of cells with ultrastructural properties that resemble those of normal follicular cells were present in immunized animals, they contained no oocytes. These studies suggest that antibodies to ZP glycoprotein alter ovarian function by interfering with cells during the stage of follicle differentiation at which the ZP proteins are being synthesized and secreted. This system should provide an excellent model with which to study the early events associated with ovarian follicular cell differentiation and subsequent hormonal responsiveness.

Six-mercaptopurine was compared with its palladium and its bismuth complexes with regard to its effects upon the activity of adenosine deaminase (E.C.3.5.4.4.) in rat tissues. Spectrophotometric and high pressure liquid chromatography analyses were utilized in the determinations of enzyme activity. No effect upon enzyme activity was seen to result from treatment with any of the complexes.

In order to study the immunogenicity as well as tissue specificity of zona pellucida (ZP) antigens, the present studies have been designed to examine the effects of alloimmunization of male and female rabbits with rabbit zonae pellucidae. These studies are the first to demonstrate that high titers of antibodies to homologous ZP antigens are developed in male rabbits while no detectable antibodies are developed in females. As demonstrated using the ELISA assay, the antibodies from these males immunized with rabbit ZP, have a greater reactivity against rabbit ZP antigens than do antibodies from female rabbits heteroimmunized with porcine ZP. The antibodies from the male rabbits immunized with rabbit ZP also recognize antigenic determinants of porcine ZP. Methods for the immunoaffinity purification of antibodies from serum were developed to determine whether low levels of antibodies against ZP are present in sera of alloimmunized female rabbits. They also allow more detailed analysis of antibodies used to detect antigenic determinants which are cross-reactive between different mammalian species. Although this method was effective in isolating low levels of antibodies from male alloimmunized rabbits or from female rabbits heteroimmunized with porcine ZP proteins, no specific antibodies could be isolated from the serum of females alloimmunized with rabbit ZP. These studies more clearly demonstrate that zona pellucida antigens are specific to the ovary in that female rabbits do not develop significant antibody levels against rabbit ZP antigens, even following active immunization with adjuvant, while male rabbits develop high titers of antibodies.

Six-mercaptopurine in the free form and complexed with Pt, Pd, or Bi metals was used at various dosage levels to treat L1210 leukemia in mice. Anticarcinogenic activity was shown by six-mercaptopurine and the Pd and Bi complexes, inactivity by the Pt complex, and toxicity by the highest dosage level of six-mercaptopurine.