Patient recall and appropriate timing for obtaining informed consent for endoscopic procedures

OBJECTIVES

Although informed consent is an issue in many medical malpractice claims, there is no standardized time or method to obtain informed consent for endoscopic procedures. The objectives of this study were to determine whether sedation for endoscopic procedures interfered with pre-endoscopic informed consent and to determine the appropriate time to obtain informed consent.

METHODS

Patients undergoing a sedated esophagogastroduodenoscopy had informed consent obtained either 48-72 h before the procedure (group 1A, n = 50) or 10-60 min before the procedure (group 1B, n = 50). Patients undergoing an unsedated flexible sigmoidoscopy had informed consent obtained either 48-72 h before (group 2A, n = 47) or 10-60 min before the procedure (group 2B, n = 49). Methods of informed consent consisted of an oral and a written explanation about the procedure. Patients were sedated with midazolam and meperidine. A Trieger test evaluated recovery from sedation. Recall was assessed by asking six questions about the procedure before discharge and again 2-3 days later.

RESULTS

Standard t tests and Mann-Whitney U nonparametric rank tests were used to compare the 1) 1-h recall scores, 2) 2-3-day recall scores, and 3) recall difference scores for groups 1A and 1B, 1A and 2A, 2A and 2B, and 1B and 2B. There were no differences in recall for the different groups.

CONCLUSIONS

This study shows that sedation for endoscopic procedures does not interfere with pre-endoscopic informed consent. Informed consent for endoscopic procedures can be obtained at any time before sedation with similar recall.

Prospective evaluation of a teaching model to determine competency in performing flexible sigmoidoscopies

OBJECTIVE

There are limited objective criteria for determining competency in performing flexible sigmoidoscopies. The authors developed a teaching model using eight objective criteria that measured both cognitive and technical skills in performing flexible sigmoidoscopies. The objective was to determine whether the teaching model was a valid method and then to compare it to a commonly used Overall Competence Score or independent observer method.

METHODS

A total of 120 procedures with 10 residents were evaluated using the two methods. Eight objective parameters had been determined before validating the teaching model. Preset criteria determined competency on a single procedure, and competent performance on five procedures in a row determined certification to independently perform procedures. The teaching model was separately tested for validity and then compared with the independent observer method.

RESULTS

A total of 120 procedures were graded using the teaching model method: 73 competent and 47 incompetent. Six of the seven objective parameters were associated with competency in the teaching model method. The eighth objective parameter was excluded because of lack of variation. Fifty of the 120 procedures were graded using the independent observer method: 36 competent and 14 incompetent. Two of the seven objective parameters were associated with competency in the independent observer method. Comparison of the two methods revealed seven discrepancies regarding competent and incompetent procedures. The correlation between the two methods was 0.71.

CONCLUSION

The teaching model method offers objective criteria to evaluate skill in performing flexible sigmoidoscopies.

Antibiotic prophylaxis in percutaneous endoscopic gastrostomy

OBJECTIVES

The benefit of antibiotic prophylaxis in percutaneous endoscopic gastrostomy is controversial. The aim of this study is to determine whether prophylactic antibiotic treatment with Cefazolin reduces the incidence of peristomal infection after percutaneous endoscopic gastrostomy.

METHODS

Of the 131 hospitalized or nursing home patients referred for percutaneous endoscopic gastrostomy, 115 were enrolled in a prospective randomized double-blind placebo controlled trial. Sixty-one (group 1) were randomized in a double-blind fashion and received either Cefazolin or saline pregastrostomy. Fifty-four patients (group 2) were on antibiotics for prior medical indications pregastrostomy. Patients had their peristomal area evaluated on a daily basis for 1 wk after gastrostomy. Erythema and exudate were scored on a scale from 0 to 4; induration was scored on a scale of 0 to 3; a maximum score of 8 or higher or the presence of pus was criteria for infection.

RESULTS

Wound infection occurred in 4 of 30 (13%) participants receiving Cefazolin and in 6 of 31 (19%) participants receiving saline (p > 0.5). In the 54 patients on antibiotics for prior indications, wound infection was observed in 2 subjects (3%). This finding was a significant difference when compared with the placebo group (p < 0.02).

CONCLUSIONS

A single dose of Cefazolin prophylaxis does not reduce the overall peristomal wound infection in percutaneous endoscopic gastrostomy. Patients receiving prior extended antibiotic therapy have fewer peristomal wound infections.

Methods for enhancement of sperm function

From a review of recent advances in human reproduction, it is apparent that therapeutic approaches to male infertility have been revolutionized. While our understanding of sperm function at the molecular level is steadily increasing, the realization of consistent oocyte fertilization by mechanically bypassing natural barriers has given new perspective for future investigation. This chapter reviews current knowledge of adjuvants that enhance sperm function and lend themselves to clinical application. Each compound is presented with recent publications supporting proposed mechanisms of action. Specifically, follicular fluid, progesterone, pentoxifylline, platelet activating factor and other cytokines have been studied for their impact on the in vitro fertilization capacity of spermatozoa. Intracytoplasmic sperm injection (ICSI) has provided infertile couples with hope for successful reproduction without sperm donation. The precise mechanism that allows subsequent pronuclear formation and syngamy is currently unknown and experimental models are few. Adjuvants that can be used in conjunction with controlled ovarian stimulation and intrauterine insemination are prominent areas for further research as this would provide an alternative to the expense and risks of in vitro fertilization and embryo transfer.

Platelet activating factor and conception

PURPOSE

This review provides evidence for the involvement of platelet activating factor (PAF) in the several facets of pregnancy establishment.

METHODS

A comprehensive literature review and new data.

RESULTS

PAF has a role in spermatozoal function, fertilization, embryo development, and implantation.

CONCLUSIONS

PAF is intimately involved in conception.

Platelet activating factor treatment of spermatozoa enhances rabbit oocyte fertilization following subzonal sperm insertion

PURPOSE

The objective of this study was to evaluate the effects of spermatozoal platelet activating factor (PAF) treatment on fertilization rates employing subzonal sperm insertion in the rabbit.

STUDY DESIGN

Oocytes (n = 130) with distinct first polar bodies were injected with three to seven motile spermatozoa. Half (n = 65) of the oocytes were injected with PAF-treated sperm, whereas the other half (n = 65) served as controls and were injected with nontreated sperm. Fertilization rates were assessed by the formation of two pronuclei followed by cleavage to the two-cell stage.

RESULTS

In the group of oocytes injected with PAF-treated sperm, we noted a significant (P < 0.001) improvement in fertilization rates, 61.5% (40/65), vs. control nontreated sperm, 20.0% (13/65). Subsequent cleavage to the two-cell stage was noted for 95% (38/40) in the treated vs 92.3% (12/13) in the nontreated fertilized zygotes.

CONCLUSION

We conclude that PAF treatment of rabbit spermatozoa prior to subzonal insertion improves fertilization rates and may be of clinical significance in assisted reproductive programs.

Localization of bicarbonate transport along the crypt-villus axis in rabbit ileum

BACKGROUND/AIMS

HCO3- can be absorbed as well as secreted in the rabbit ileum. With 25 mmol/L HCO3- on the serosal side only, a serosa-to-mucosa flux (Jsm) is found; with 25 mmol/L on the mucosal side only, epinephrine elicits a mucosa-to-serosa flux (Jms). This study aimed to localize these two processes along the crypt-villus axis.

METHODS

Excised ileal segments were exposed luminally to 2 mol/L Na2SO4 (hypertonic treatment) or to isotonic Ringer's solution for 15 minutes. Mucosa was then chamber-mounted, and measurements were made of Jsm or Jms and of short-circuit current (Isc) responses to glucose plus alanine and to either theophylline or epinephrine.

RESULTS

With HCO3-/CO2 added to the serosal side only, hypertonically treated tissues showed a 22% decline in Jsm; a 25% decline in Isc response to theophylline; and a 71% decline in Isc response to glucose plus alanine compared with control. With HCO3-/CO2 added to the mucosal side only, tissues showed 92% and 87% declines in Jms and Isc responses to epinephrine, respectively, and a 87% decline in Isc response to glucose plus alanine. Histological examination showed destruction of villus caused by hypertonic treatment but sparing of crypt cells.

CONCLUSIONS

Both HCO3- and Cl- are secreted mainly by crypt cells and absorbed mainly by villus cells.

Ion transport in rabbit proximal colon: effects of sodium, amiloride, cAMP, and epinephrine

Effects on ion transport of extracellular Na+ and Cl- ([Na+]o and [Cl-]o, respectively), HCO3(-)-CO2, 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), epinephrine, and transport inhibitors were examined in short-circuited rabbit proximal colonic mucosa. Net Na+ flux was independent of Cl- but partially (60%) dependent on HCO3(-)-CO2. Net Cl- flux was partially (70%) dependent on Na+ and totally dependent on HCO3(-)-CO2. Both fluxes peaked between 25 and 60 mM and decreased at higher concentrations. Apical Na+ influx but not Cl- influx obeyed the same pattern. The inhibition resulted from increases in mucosal but not serosal [Na+]o and not from increases in [Cl-]o. Amiloride and benzamil (0.2-0.3 mM) partially inhibited net Na+ absorption, as did 8-BrcAMP, but these effects were independent of the inhibition seen at high [Na+]o. Net Cl- absorption was inhibited by 8-BrcAMP but not by 0.2 mM amiloride. At high [Na+]o and [Cl-]o, there were a residual ion flux suggesting HCO3- secretion and, in the presence of 8-BrcAMP and amiloride or benzamil, net secretions of Na+ and Cl-, the former larger than the latter. Epinephrine, via alpha 2-receptors, reversed the ion-transport effects of high [Na+]o but did not stimulate a mucosal-to-serosal unidirectional HCO3- flux (as shown in rabbit ileum). 4-Acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (0.5 mM) and bumetanide (10 microM) had no effect on ion transport. The results suggest 1) Na+ entry via two Na(+)-H+ exchangers, one inhibited by amiloride and cAMP and the other inhibited by high [Na+]o and stimulated by epinephrine; 2) Cl- entry via Cl(-)-HCO3- exchange; 3) HCO3- secretion at high [Na+]o and [Cl-]o; and 4) cAMP-induced secretion of Na+ and Cl- at high [Na+]o and [Cl-]o.

Expression and role of c-myc protooncogene in murine preimplantation embryonic development

PURPOSE

The present study was conducted to investigate the expression and possible role of the c-myc protooncogene in preimplantation embryos by using reverse-transcriptase/polymerase chain reaction (RT-PCR) technique and microinjection of synthetic antisense c-myc oligonucleotide probe, respectively. Total RNA was extracted from oocytes and two cell-, four cell-, early morula-, late morula-, early blastocyst-, and late blastocyst-stage embryos, and cDNA was constructed using MMLV reverse transcriptase. Sense primer (P1) and antisense primer (P2) used were based on the c-myc gene sequence bp 1609-1629 and bp 3279-3299, respectively, that span a 1.37-kb intron. PCR-amplified products of cDNA from oocyte-, two cell-, four cell-, early and late morula-, and blastocyst-stage embryos demonstrated the expected 313-bp product in Southern blot hybridization using a c-myc specific DNA probe, with an indication of lower levels in oocytes and early morulae.

RESULTS

Cytoplasmic injection of the antisense c-myc oligonucleotide probe (P2) and not the sense probe (P1) into pronuclear-stage zygotes caused a significant (P = 0.02 to 0.0001) inhibition of development to blastocysts in a concentration-dependent manner, with a maximal inhibition at the first cleavage of zygotes to two cell-stage embryos. There was no effect on the P2 antisense injection on pronucleus formation.

CONCLUSION

These results indicate that the c-myc protooncogene is expressed in preimplantation embryos and may have an essential role in normal embryogenesis in mice.

Embryo survival after pronuclear microinjection and trophectoderm biopsy

OBJECTIVE

Our purpose was to compare murine embryo development after pronuclear microinjection of a gene construct, followed by trophectoderm biopsy at the blastocyst state, with development after a single micromanipulation, and with cultured controls.

STUDY DESIGN

alpha-Myosin heavy-chain gene sequence was microinjected into the murine embryo pronucleus and cultured to blastocyst. After trophectoderm biopsy the embryos were allowed to re-expand. Re-expanded embryos were transferred to pseudopregnant females; implantation and live birth rates were recorded. In this study group the rates were compared with three control groups of embryos simultaneously cultured after (1) pronuclear microinjection only, (2) trophectoderm biopsy only, and (3) non-micromanipulated, culture only.

RESULTS

A total of 1222 embryos were divided among the four groups. In the study group 472 embryos underwent pronuclear microinjection and trophectoderm biopsy. Of these, 203 (43%) reached the blastocyst stage and underwent biopsy; 183 (38.8%) re-expanded after biopsy. Of 275 pronuclear microinjected only (control 1) embryos, 113 (41.1%) reached the blastocyst stage. Of 336 embryos 148 (44.0%) reached the blastocyst stage and underwent trophectoderm biopsy only (control 2); 129 (39.2%) survived biopsy. The cultured only group (control 3) consisted of 139 pronuclear embryos; 67 (48.2%) developed to the blastocyst stage.

CONCLUSIONS

Murine embryos can survive two micro-manipulations, pronuclear microinjection followed by trophectoderm micro-biopsy. Although there is minimal effect of these procedures on embryonic development in vitro, the live birth rate is tenuous.

Intrauterine insemination in fertile women delivers larger number of sperm to the peritoneal fluid than intracervical insemination

Randomized IUI or intracervical insemination of eight fertile women with 50 x 10(6) sperm was performed to determine whether IUI delivers more spermatozoa to the peritoneal cavity. After IUI (n = 4), 2,053 to 29,450 sperm were recovered in the PF at laparoscopy. No sperm were found in the PF after intracervical insemination (n = 4). After IUI, CM contained 1.0 x 10(6) to 57.0 x 10(6) sperm/mL; after intracervical insemination, 0 to 1.2 x 10(3) sperm/mL were seen. One therapeutic mechanism for IUI is delivery of larger sperm numbers to the fertilization site by rapid (4 hours) transport. In addition, there is greater retrograde colonization of CM that may result in sustained release of sperm.

Bicarbonate secretion in rabbit ileum: electrogenicity, ion dependence, and effects of cyclic nucleotides

BACKGROUND

Ileal HCO3- secretion is not well understood. The aim of this study was to examine its Na+ and Cl- dependencies, electrogenicity, and responses to amiloride, 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonate (SITS), and cyclic nucleotides.

METHODS

The serosa to mucosa HCO3- flux (Jsm) across rabbit ileal mucosa mounted between HCO(3-)-free mucosal solution and HCO(3-)-containing serosal solutions was determined by titration.

RESULTS

In SO4(2-)-containing Ringer's solution, Jsm varied with [Na+] in two phases, one with a high and one with a low affinity for Na+; amiloride inhibited the high- and SITS inhibited the low-affinity phase. Switching from SO4(2-)- to Cl(-)-containing Ringer's solution caused a SITS-inhibitable 42% increase in Jsm. Changes in Jsm were coupled 3:2 with changes in short-circuit current. Cyclic nucleotide effects on Jsm were as follows. In SO4(2-)-containing Ringer's solution at 141 (but not 80) mmol/L Na+, theophylline caused equal increases in Jsm and short-circuit current that equaled the combined effects of 8-Br-5'-cyclic guanosine monophosphate (cGMP) and 8-Br-5'-cyclic adenosine monophosphate (cAMP). Serosal SITS blocked these effects, but amiloride did not. In Cl(-)-containing Ringer's solution, theophylline and bumetanide together (but not separately) increased Jsm.

CONCLUSIONS

(1) Basolateral HCO3- entry occurs via Na+/H exchange and a SITS-inhibitable process (Na(+)-HCO3- cotransport?). (2) Most HCO3- exit across the brush border occurs by a Cl(-)-independent process and some by Cl-/HCO3- exchange. (3) At low cellular [Cl-], HCO3- can be secreted via anion channels activated by cAMP and cGMP. (4) Ileal HCO3- secretion is electrogenic.

Platelet-activating factor production from in vitro and in vivo fertilized murine embryos is similar

PROBLEM

This study measured platelet-activating factor (PAF) production of in vitro and in vivo fertilized murine embryos to ascertain whether site of fertilization impacted subsequent embryonic PAF production.

METHOD

Oocytes and embryo were collected from stimulated B6D2F1 mice. PAF production throughout the preimplantation phase from the two-celled stage through expanded blastocysts was measured and compared among normally developing embryos with the only difference being site of fertilization.

RESULTS

A striking increase in PAF production was noted for both in vivo and in vitro fertilized embryos over the four days of culture. Significantly higher (P < .001) levels of PAF production were noted with development from the two-celled stage (47.22 +/- 4.13; 44.30 +/- 2.43) to expanded blastocysts (254.31 +/- 24.01; 255.11 +/- 5.35 ng/embryo/24 h) for both in vitro and in vivo fertilized embryos, respectively. There was no significant difference (P > .05) in PAF production between the two groups of embryos.

CONCLUSIONS

Embryonic PAF production in the mouse increases in a stage-specific manner, and specifically the site of fertilization in vitro versus in vivo does not affect PAF production in normally developing embryos.

Embryonic platelet activating factor production in the rabbit increases during the preimplantation phase

OBJECTIVE

This study measured platelet activating factor (PAF) production by rabbit embryos in vitro and ascertained if there is increased PAF production associated with advancing embryonic development.

STUDY DESIGN

Two-cell rabbit embryos were recovered from superovulated New Zealand White does and cultured in vitro for 96 hr. Every 24 hr embryos were scored for developmental stage and PAF activity from the corresponding culture medium was measured by platelet aggregation and organic phosphate analyses.

RESULTS

PAF was detected in culture medium at all stages from two cells to blastocysts and rose significantly (P < 0.001) at each 24-hr interval, reaching maximal levels at the expanded blastocyst stage.

CONCLUSION

Maximal PAF production by expanded blastocysts may be an embryonic paracrine signal that facilitates implantation.

Platelet-activating factor treatment of human spermatozoa enhances fertilization potential

OBJECTIVE

The purpose of this study was to evaluate the effects of platelet-activating factor treatment on human spermatozoa fertilizing capability, as assessed by the zona-free hamster penetration assay.

STUDY DESIGN

Twenty-three semen specimens were divided into two groups on the basis of initial motile sperm count greater or less than 20 x 10(6)/ml. Each sample served as its own treatment control. Twice-washed spermatozoa were treated with 1 x 10(-7) mol/L of platelet-activating factor before performing the sperm penetration assay. For the two groups the percent penetrations and penetration index were compared with the paired t test, and an independent t test was used to compare parameters between groups.

RESULTS

Significant enhancement of both percent penetrations (p < 0.0001) and penetration index (p < 0.005) were noted on platelet-activating factor treatment in both groups. Enhancement of both indices were noted to be independent of initial motile sperm counts.

CONCLUSION

Platelet-activating factor treatment of human spermatozoa may be of potential therapeutic value in certain cases of asthenospermia or fertilization failure in human in vitro fertilization.

Enhanced embryo development of rabbit oocytes fertilized in vitro with platelet activating factor (PAF)-treated spermatozoa

PURPOSE

The purpose of this study was to determine the effects of PAF treatment of rabbit spermatozoa on in vitro fertilization and subsequent blastocyst formation. Rabbit spermatozoa were exposed to PAF (10(-7) M), lyso-PAF (10(-7) M), or HIS (385 mOsm/kg) for 15 min prior to insemination of ovulated oocytes. Fertilized oocytes were cultured to the hatched blastocyst stage.

RESULTS

Fertilization rates with PAF were significantly higher than those of fresh (P < 0.001), lyso-PAF-treated (P < 0.01), HIS-treated (P < 0.05) spermatozoa. Two-cell embryos produced from oocytes inseminated with PAF-treated spermatozoa had significantly higher hatched blastocysts than oocytes inseminated with fresh (P < 0.01), lyso-PAF-treated (P < 0.05), or HIS-treated (P < 0.05) spermatozoa.

CONCLUSION

We conclude that PAF treatment of spermatozoa increases fertilization rates and subsequent embryonic development.

Treatment of sperm with high-ionic strength medium increases microsurgical fertilization rates of rabbit oocytes fertilized by subzonal placement of sperm

This study was conducted to investigate the requirement for sperm processing in microsurgical subzonal placement of sperm in rabbit oocytes. Fertilization rates with standard in vitro fertilization and microsurgical subzonal sperm placement were found to be similar (56 and 55%) when sperm treated with high-ionic strength Brackett's defined medium to initiate capacitation were used. Statistically significant reductions in fertilization rates for both standard in vitro fertilization and subzonal placement were noted when twice-washed spermatozoa were used. Initiation of capacitation of spermatozoa results in higher fertilization results even when the zona pellucida is bypassed during fertilization.

Platelet activating factor enhances in vitro fertilization of rabbit oocytes

Capacitation of spermatozoa is essential for fertilization. Rabbit spermatozoa are particularly difficult to capacitate in vitro and require treatment with high-ionic-strength Brackett's defined medium. Spermatozoa treated with platelet activating factor had significantly higher fertilization rates when compared with nontreated (fresh, twice washed) spermatozoa (63% vs 34%). Fertilization rates of spermatozoa treated with platelet activating factor, although higher than those of high-ionic-strength capacitated spermatozoa, were not significantly different (63% vs 57%). Spermatozoa treated with lyso-platelet activating factor, the biologically inactive form of platelet activating factor, were noted to have fertilization rates similar to those of the untreated (noncapacitated) group. These data show that synthetic platelet activating factor treatment of uncapacitated spermatozoa induces fertilization of rabbit oocytes in vitro in a manner similar to that for spermatozoa capacitated by high-ionic-strength media and significantly higher than that for untreated spermatozoa or after treatment with the biologically inactive form of platelet activating factor (lyso-platelet activating factor).

Survival and cell acquisition rates after preimplantation embryo biopsy: use of two mechanical techniques and two mouse strains

Two strains of mouse embryos at the four- and eight-cell stages had biopsy specimens obtained by means of two different mechanical techniques: aspiration and displacement. Embryos and biopsy specimen cells were evaluated for survival and development. Blastomere acquisition rates were significantly higher with the displacement biopsy technique; however, no difference in survival or developmental rates was found in blastomere biopsy specimens removed from either four-cell or eight-cell embryos. A maximum of one blastomere can be removed from a four-cell embryo, whereas three blastomeres can be taken at biopsy from an eight-cell mouse embryo without significantly affecting embryo development, although mouse strain differences were noted. Intact, viable, biopsied blastomeres will develop in vitro when cocultured with morphologically intact embryos. Births of live offspring after embryo biopsy are reported.

Effects of platelet activating factor on mouse oocyte fertilization in vitro

Platelet activating factor is rapidly gaining acceptance as a potent mediator in many reproductive processes. This study presents data that indicate a direct role of platelet activating factor in fertilization. Platelet activating factor was shown to significantly increase (p less than 0.001) the fertilization rate of mouse oocytes in vitro. Furthermore, CV3988, an inhibitor of platelet activating factor, was noted to significantly decrease in vitro fertilization rates at 10(-5) and 10(-4) mol/L concentrations.

The effects of platelet-activating factor on the motility of human spermatozoa

Our laboratory has recently detected the presence of platelet-activating factor (PAF)-like activity in human spermatozoa. To gain further insight into the role of PAF on the male reproductive system, this study, using videomicroscopy, evaluated the effects of synthetic PAF on the motility of human spermatozoa. Treatment of 20 human semen samples with 3.69 x 10(-7) to 3.69 x 10(-13) M PAF resulted in statistically significant increases in motility. Treatment of spermatozoa with lyso-PAF (the biologically inactive form of PAF) showed no change in motility. Treatment of spermatozoa with PAF in severely asthenozoospermic males may be of therapeutic value.

Spontaneous zona reaction in the mouse as a limiting factor for the time in which an oocyte may be fertilized

This study evaluated the effect of ovum aging on the in vitro fertilizability of mouse ova. Over 1347 ova were evaluated. Serial trypsin digestion of in vitro and in vivo aged ova revealed an increase in zona digestion time (0.25% trypsin) beginning at 40 hr, which increased over a 40-hr period and resulted in the unfertilized zona becoming as "hard" as the fertilized embryo zona. In vitro fertilizability showed a rapid decrease as zona hardening occurred with loss of cortical granules as assessed by electron microscopy. These data suggest that the window of fertilizability is "closed" by a spontaneous zona reaction occurring at about 55 hr post-human chorionic gonadotropin with loss of cortical granules and zona hardening as manifested by increasing zona digestion time with 0.25% trypsin.

Quantitative Assay of Faecal X Porphyrin in Normal Healthy Indians, A Spectrophotometric and Computerised Analysis

The faecal X normal healthy India have been determined by urea-triton solvent extraction method and its importance in the laboratory diagnosis of variegate porphyria has been discussed. The values ranged from:0.058 to 5.424 with a mean value of 1.64 + 1.32 microgram per gram dry weight of faeces. X porphyrin excretion was higher in males having non vegetarian diet. It increased with age and body weight. A statistically significant coefficient of correlation existed between all the three types of faecal porphyrins.

Superovulation and recovery of zygotes from Nubian and Alpine dairy goats

Thirty-five purebred dairy goats (18 Alpines and 17 Nubians) were subjected to a superovulating hormone program consisting of an 11-d 6alpha-methyl-17alpha-acetoxy-progesterone; (MAP; 60 mg) intravaginal sponge treatment; 125 ug i.m. injections of the prostaglandin F(2alpha) analogue cloprostenol on d 1 and 9 of vaginal sponge treatment; and a 3-d, twice-a-day injection of 2.5 mg of pituitary follicle stimulating hormone (FSH-P) i.m. starting at day 9. Vaginal sponges were pulled the morning of day 11 at the time of the fifth FSH-P injection. Of 40 initiated superovulatory cycles, 33 does (10 Alpines and 23 Nubians) responded with an average of 17.7 (range 1 to 29) ovulations. There was no significant difference between the breeds with respect to corpora lutea (CLs) plus follicles ovarian response. A significantly greater (P< 0.05) number of Nubian does were in estrus and mated by 36 h after MAP sponge removal. All does that responded to treatment had done so within 72 h of sponge removal. Of the seven (17.5%) does that showed no estrous response to hormone treatment, six were Alpines (P < 0.01). Six goats (two Alpines and four Nubians) were subjected to a second hormone treatment cycle after a 45-d rest. Five of six does responded to a second hormone treatment cycle with four of five responding with a lower total ovarian response. The interval from sponge removal to mating did not affect the stage or quality of eggs harvested. Rather, the interval from mating to surgical flushing determined the stage of egg development. All animals examined from 24 to 32 h after initial mating had not ovulated. By 50 h, 20 of 22 does had ovulated. A total of 242 ovulated eggs (63%) was harvested, of which 199 (82%) were fertilized. Day 7 flushings yielded 36 eggs (67%), of which 28 (78%) were fertilized. This rate of superovulation, fertilization, and embryo recovery lends credibility to this technique in its ultimate objective of rapidly increasing the number of offspring from superior animals.

Visualization of pronuclei in living bovine zygotes

Bovine embryos were surgically collected from the oviducts of superovulated crossbred heifers 48 h postonset of estrus. The one-celled ova were treated with 4'-6'-diamidino-2-phenylindole (DAPI) and observed under ultraviolet light by fluorescence microscopy. Both male and female pronuclei were visualized, identified and subjected to micromanipulation.