Care in a birth room versus a conventional setting: a controlled trial.

A controlled clinical trial was carried out to assess whether a birth room setting would influence the care of mothers and newborns. Of the 163 low-risk women enrolled, 49 (30%) manifested some prenatal risk and were excluded. The remaining 114 were allocated by strict alternation to a birth room or a conventional setting. Of the 56 women allocated to the birth room, 63% of the primiparas and 19% of the multiparas were later transferred. The numbers in the two settings who had oxytocin stimulation, epidural anesthesia, forceps delivery or cesarean section did not show statistically significant differences. The episiotomy rates were slightly lower in the birth room than in the conventional setting, and the rates of an intact perineum were higher in the birth room. Neither the Apgar scores nor the morbidity rates of the infants showed statistically significant differences related to the setting to which the mother had been allocated, although more infants from the conventional setting were admitted to a special care unit. Both "experimental" groups of women less often received routine perineal shaving, enemas or intravenous infusions than did an obstetrically similar nonexperimental comparison group. Despite the apparent inability in this setting for the birth room to influence the rate of major obstetric procedures (except for episiotomy) and outcomes, the authors believe that a birth room is desirable in tertiary care centres as well as in community hospitals.     

Haploid accumulation and translational control of phosphoglycerate kinase-2 messenger RNA during mouse spermatogenesis

The intracellular location of the mRNA for the testis-specific isozyme of phosphoglycerate kinase-2 (PGK-2) has been determined for two spermatogenic cell types. The mRNA activity for PGK-2 from the polysomal and nonpolysomal fractions of pachytene primary spermatocytes or round spermatids has been assayed by cell-free translation with the polypeptide products monitored by immunoprecipitation, followed by one-dimensional or two-dimensional electrophoresis and fluorography. The results reveal that the majority of PGK-2 mRNA activity of round spermatids was present in the polysomal fraction while the relatively less abundant PGK-2 mRNA of pachytene primary spermatocytes was present in the nonpolysomal fraction. No PGK-2 mRNA activity was observed in the cytoplasmic RNA from primitive type A spermatogonia or prepubertal Sertoli cells. These data indicate that mature PGK-2 mRNA first appears in the cytoplasm of spermatogenic cells during the prophase of meiosis and increases in amount after meiosis. Although mature PGK-2 mRNA is present in meiotic cells it is not actively translated until after meiosis has been completed. Thus, mRNA accumulation and translational mechanisms are involved in the control of phosphoglycerate kinase-2 synthesis during spermatogenesis.     

Analysis of sample preparation procedures for enumerating fecal coliforms in coarse southwestern U.S. bottom sediments by the most-probable-number method

The determination of bacterial densities in aquatic sediments generally requires that a dilution-mixing treatment be used before enumeration of organisms by the most-probable-number fermentation tube method can be done. Differential sediment and organism settling rates may, however, influence the distribution of the microbial population after the dilution-mixing process, resulting in biased bacterial density estimates. For standardization of sample preparation procedures, the influence of settling by suspended sediments on the fecal coliform distribution in a mixing vessel was examined. This was accomplished with both inoculated (Escherichia coli) and raw, uninoculated freshwater sediments from Saguaro Lake, Ariz. Both test sediments were coarse (greater than 90% gravel and sand). Coarse sediments are typical of southwestern U.S. lakes. The distribution of fecal coliforms, as determined by the most-probable-number method, was not significantly influenced by sediment settling and remained homogenous over a 16-min postmix period. The technique developed for coarse sediments may be useful for standardizing sample preparation techniques for other sediment types.     

Promotion of breast-feeding in a Chinese community in Montreal.

Following a prospective survey that showed a very low rate of breast-feeding (10%) in 1977-79 among Chinese women in Montreal, a culturally targeted program, which included individual prenatal counselling and a community-wide promotion and education campaign, was developed to improve the rates. The study group consisted of all Chinese women delivering in 1980 and 1981 who had taken their infants to one pediatrician for continuing care. The rates of breast-feeding in the 88 women who had received prenatal counselling and the 93 women who had not were compared. Although the rates were substantially increased for both groups over the 1977-79 rate (54% and 34% in 1980 and 65% and 55% in 1981 respectively), the 2-year rate was significantly higher for the counselled group compared with the uncounselled group in the later study (59% v. 43%). The greatest effect of counselling was seen in young, primiparous women of higher socioeconomic status who spoke French or English in addition to Chinese. However, 33% of the counselled women who had started breast-feeding had stopped by 1 month, compared with only 15% of the uncounselled women. Thus, although the rates of breast-feeding in ethnic groups can be increased with the use of a language- and culture-specific approach, more support and encouragement must be given to women who start breast-feeding so that they will continue longer.     

Urokinase-type and tissue-type plasminogen activators are essential for in vitro invasion of human melanoma cells

This study evaluates the contribution of two types of plasminogen activators (PAs; tissue-type PA (tPA) versus urokinase-type PA (uPA) toward the invasiveness of human melanoma cells in a novel in vitro assay. We identified two human melanoma cell lines, MelJuso and MeWo, expressing uPA or tPA as shown at mRNA, protein, and enzyme activity level. MelJuso cells produced uPA as well as plasminogen activator inhibitor-1 (PAI-1). The latter was, however, not sufficient to neutralize the cell-associated or secreted uPA activity. MeWo cells secreted tPA, but the enzyme was not found to be cell-associated. PAI-1 production by these cells was not detectable. Plasminogen activation and fibrinolytic capacity of both cell lines were reduced by anticatalytic monoclonal antibodies specific for the respective type of PA or by aprotinin. In a novel in vitro invasion assay, antibodies to PA as well as aprotinin decreased the invasiveness of both cell lines into a fibrin gel, Matrigel, or intact extracellular matrix. Our results confirm the importance of uPA-catalyzed plasminogen activation in tumor cell invasiveness. Furthermore, we provide evidence that tPA, beyond its key role in thrombolysis, can also be involved in in vitro invasion of human melanoma cells.     

Inhibition of digestive proteinases of stored grain Coleoptera by oryzacystatin, a cysteine proteinase inhibitor from rice seed

Electrophoresis of midgut extracts from the rice weevil, Sitophilus oryzae, and the red flour beetle, Tribolium castaneum, in polyacrylamide gels containing sodium dodecyl sulfate and gelatin revealed there was one major proteinase (apparent molecular mass = 40,000) in the rice weevil and two major proteinases (apparent molecular masses = 20,000 and 17,000) in the red flour beetle. The pH optima using [3H]casein as substrate were about pH 6.8 for the rice weevil and pH 5.2 for the red flour beetle. Use of specific inhibitors, including L-trans-epoxysuccinyl-leucylamino-(4- guanidino)-butane (E-64), p-chloromercuriphenylsulfonic acid (PCMS), and oryzacystatin, indicated that nearly all of the proteinase activity against casein was contributed by cysteine proteinases. The estimated IC50 values for oryzacystatin were 2 x 10(-6) M and 4 x 10(-7) M when tested against midgut extracts from T. castaneum and S. oryzae, respectively.     

Renal O2 consumption during progressive hemorrhage

Most mammalian tissues regulate O2 utilization such that O2 consumption (VO2) is relatively constant at O2 delivery (DO2) higher than a critical value (DO2c). We studied the relationship between VO2 and DO2 of kidney and whole body during graded progressive exsanguination. The relationship between whole body VO2 and DO2 was biphasic, and whole body VO2 decreased by 5.6 +/- 14.4% (P = NS) from the initial value to the value nearest whole body DO2c. Kidney DO2 decreased in direct proportion to whole body DO2 such that the average R2 value describing the linear regression of kidney DO2 vs. whole body DO2 was 0.94 +/- 0.02. The relationship between kidney, like whole body, VO2 and DO2 appeared biphasic; however, kidney VO2 decreased by 63.3 +/- 10.4% (P less than 0.0001) from the initial value to the value nearest kidney DO2c. Renal O2 extraction ratio was relatively constant over a wide range of kidney DO2, whereas whole body O2 extraction ratio increased progressively at all whole body DO2 values as whole body DO2 decreased. However, final values of O2 extraction ratio were indistinguishable for whole body (0.86 +/- 0.1) and kidney (0.86 +/- 0.06) (P = NS). We conclude that the pattern of kidney and whole body VO2 response to decreasing DO2 differs during hemorrhage, particularly in the range of DO2 normally associated with tissue wellness.     

Reduced survival of neonates due to vitamin A deficiency during pregnancy in the guinea pig

Neonatal vitamin A stores are limited even in well-nourished full-term infants and are yet smaller in the premature infant. The object of this experiment was to determine whether vitamin A deficiency could be induced in pregnant guinea pigs and, if so, whether it would affect vitamin A status of the neonate. Adult (600 g) guinea pigs were fed a casein-agar diet that was vitamin A deficient (AD). Controls (vitamin A adequate) were orally dosed weekly with 2 mg of retinyl palmitate. Weight gains of dams and birth weights of neonates did not differ. No external signs of deficiency were observed. Six of eight AD and seven of eight vitamin A-adequate dams carried pregnancy to term (greater than or equal to Day 64). One AD dam died during delivery. Liver retinol concentrations were below the detection limit (less than 3 micrograms/g) for all AD neonates and dams and in postpartum serum of AD dams. Of neonates born greater than or equal to Day 64, 15 of 18 AD were dead or moribund compared with 4 of 22 vitamin A adequate. The unexpectedly severe effect on the neonate indicates that the guinea pig will be a sensitive model for investigating the affect of poor maternal vitamin A status on neonatal vitamin A-dependent functions. However, a less severe maternal deprivation should be used for such studies.     

Cathepsin B efficiently activates the soluble and the tumor cell receptor-bound form of the proenzyme urokinase-type plasminogen activator (Pro-uPA)

Action of purified human cathepsin B on recombinant single-chain urokinase-type plasminogen activator (pro-uPA) generated enzymatically active two-chain uPA (HMW-uPA), which was indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot from plasmin-generated HMW-uPA and from elastase- or thrombin-generated inactive two-chain urokinase-type plasminogen activator. Preincubation of cathepsin B with E-64 (transepoxysuccinyl-L-leucylamino- (4-guanidino)butane, a potent inhibitor for cathepsin B) prior to the addition of pro-uPA prevented the activation of pro-uPA. The cleavage site within the cathepsin B-treated urokinase-type plasminogen activator (uPA) molecule, determined by N-terminal amino acid sequence analysis, is located between Lys158 and Ile159. Pro-uPA is cleaved by cathepsin B at the same peptide bond that is cleaved by plasmin or kallikrein. Binding of cathepsin B-activated pro-uPA to the uPA receptor on U937 cells did not differ from that of enzymatically inactive pro-uPA, indicating an intact receptor-binding region within the growth factor-like domain of the cathepsin B-treated uPA molecule. Not only soluble but also tumor cell receptor-bound pro-uPA could be efficiently cleaved by cathepsin B to generate enzymatically active two-chain uPA. Thus, cathepsin B can substitute for plasmin in the proteolytic activation of pro-uPA to enzymatically active HMW-uPA. In contrast, no significant activation of pro-uPA by cathepsin D was observed. As tumor cells may produce both pro-uPA and cathepsin B, implications for the activation of tumor cell-derived pro-uPA by cellular proteases may be considered.