Spiritual and religious components of patient care in the neonatal intensive care unit: sacred themes in a secular setting.

OBJECTIVE: We hypothesized that spiritual distress was a common, unrecognized theme for neonatal intensive care unit (NICU) care providers. STUDY DESIGN: An anonymous questionnaire form assigned to a data table in a relational database was designed. RESULTS: Surveys were completed by 66% of NICU staff. All respondents viewed a family's spiritual and religious concerns as having a place in patient care. Eighty-three percent reported praying for babies privately. Asked what theological sense they made of suffering of NICU babies, 2% replied that children do not suffer in the NICU. Regarding psychological suffering of families, the majority felt God could prevent this, with parents differing (p = 0.039) from nonparents. CONCLUSION: There exists a strong undercurrent of spirituality and religiosity in the study NICU. These data document actual religious and spiritual attitudes and practices and support a need for pastoral resources for both families and care providers. NICU care providers approach difficulties of their work potentially within a religious and spiritual rather than a uniquely secular framework.

Effort and work of breathing in neonates during assisted patient-triggered ventilation.

OBJECTIVE: This study compares patient-ventilator synchrony, work of breathing and patient effort in neonates during different modes of patient-triggered ventilation. DESIGN: Clinically stable neonates received intermittent mandatory ventilation (IMV), synchronized intermittent mandatory ventilation (SIMV), pressure assist/control ventilation (A/C), and pressure support ventilation (PSV) in a random order for 20 mins. With each mode patient-ventilator synchrony, work of breathing, and patient effort were evaluated. SETTING: Neonatal level III intensive care unit of a university hospital. Measurements and RESULTS: Seven clinically stable neonates (31.4 +/- 2 wks gestation, weighing 1.49 +/- 0.38 kg) were randomly ventilated with the above four modes using a Bird VIP ventilator. Esophageal pressure, airway pressure, and flow were measured using a CP-100 neonatal monitor (Bicore). Data for five consecutive breaths in each mode were analyzed. Patient effort and work of breathing differed significantly among modes of ventilation. The inspiratory pressure time product was least with A/C (0.54 +/- 0.29 cm H(2)O.sec) and increased with PSV (0.60 +/- 0.39 cm H(2)O.sec), SIMV (1.46 +/- 0.55 cm H(2)O.sec), and IMV (2.74 +/- 1.05 cm H(2)O.sec) (p <.05). A similar trend was observed for work of breathing, with work least during A/C (0.07 +/- 0.04 joules per liter [J/L]), followed by PSV (0.17 +/- 0.14 J/L), SIMV (0.33 +/- 0.13 J/L), and IMV (0.41 +/- 0.16 J/L) (p <.05). Marked dyssynchrony between patient-initiated and ventilator-initiated inspiration occurred only during IMV. CONCLUSION: Asynchrony can be avoided by the use of assisted, patient triggered modes of ventilation and, of the available modes, pressure A/C results in the least effort and work of breathing for clinically stable neonates.

Moral and ethical dilemmas in critically ill newborns: a 20-year follow-up survey of Massachusetts pediatricians.

OBJECTIVE: To replicate the 1987 survey, referring to the original 1977 study, regarding opinions about treatment for critically ill neonates. STUDY DESIGN: A long-term follow-up survey of American Academy of Pediatrics Massachusetts membership, maintaining the 1987 instrument, was initiated. RESULTS: A notable demographic shift in respondents from a majority of male practitioners in 1977 (89.6%), to 73% in 1987, to more equal numbers of men and women in 1997 (55% and 45%, respectively; p < 0.001; 1987 vs 1997) was apparent. Pediatricians' attitude changes over the 20-year period were relatively modest and were statistically associated with active medical intervention. In 1997, 75% of respondents rejected review committees as mediators, a marked change from 1987. Regardless of healthcare maintenance organization affiliations, 95% indicated that restrictive fiscal policies would not affect decision-making. CONCLUSION: This study indicates stability and consensus in pediatricians' attitudes toward active intervention for critically ill neonates compared with 1977 and 1987 surveys and reveals several claims to professional autonomy.

Postnatal transient renal insufficiency in the feto-fetal transfusion syndrome.

Twinning and higher-order multiple-gestation pregnancies have become relatively frequent in the current era of assisted reproductive techniques. Vascular interconnections are present in nearly all monochorionic twin placentae, yet hemodynamically significant arteriovenous anastomoses resulting in the feto-fetal transfusion syndrome occur in only 5%-18% of these. When arteriovenous connections through a shared placental cotyledon are present, variable amounts of blood may be transfused from one fetus to the other, and feto-fetal transfusion syndrome may result. While reports of renal failure due to a small non-functioning kidney in the donor infant pre- or postnatally have been published, recoverable renal insufficiency has not been previously delineated in feto-fetal transfusion syndrome. This article describes a case of postnatal transient renal insufficiency in a donor infant from a pair of monozygotic twins.

Müllerian inhibiting substance inhibits branching morphogenesis and induces apoptosis in fetal rat lung.

Müllerian inhibiting substance (MIS) is a glycoprotein hormone required for normal male reproductive tract development; it is presumed to signal through a heteromeric complex of type I and type II receptors. MIS exposure produces a paracrine-mediated regression of the embryonic Müllerian duct with histological changes consistent with apoptosis. MIS has also been shown to inhibit fetal lung development in vitro and in vivo, although the mechanism of this inhibition is unknown. The primordial lung and gonad are anatomically proximate on embryonic day 13.5, raising the possibility of a paracrine-mediated influence of MIS in male embryos on lung as well as MIS effecting dissolution of the Müllerian duct. We hypothesized that a negative regulatory event(s) might occur in the lung, as occurs in the duct, at the onset of MIS protein expression; thus, apoptosis and branching morphogenesis were studied in explanted fetal rat lungs incubated with proteolytically activated MIS. MIS exposure resulted in reduced total lung bud number as well as lung perimeter length. Explanted lungs exposed to MIS also exhibited numerous apoptotic bodies. To assess whether this MIS-induced phenomenon in lung might be mediated by the MIS type II receptor (MIS RII), reverse transcriptase-PCR performed on multiple fetal rat lung RNA samples using oligonucleotide primers designed from the 3'-untranslated region of rat MIS RII complementary DNA showed a product of the expected size that when sequenced was nearly identical to rat MIS RII. Northern blot analysis using polyadenylated fetal rat lung RNA and a 3'-MIS RII probe revealed a 2-kilobase transcript that was also seen in testicular messenger RNA. These studies show that the putative ligand binding receptor for MIS is expressed in embryonic lung, where MIS negatively modulates branching and activates apoptosis. We speculate that the mechanism of MIS-induced inhibition of lung development in the male fetus begins with MIS binding to the MIS RII, followed by a signaling cascade resulting in delayed airway branching temporally associated with enhanced apoptosis.

Reduction of epidermal growth factor receptor phosphorylation by activated Mullerian inhibiting substance is vanadate-sensitive.

The carboxy-terminal domain of recombinant human Mullerian inhibiting substance (MIS) inhibits cellular proliferation in vitro and decreases epidermal growth factor (EGF)-dependent phosphorylation of the EGF receptor. Proteolytically cleaved and undissociated MIS is more potent than carboxy-terminal MIS alone, supporting a functional role for the amino-terminal region of the molecule. MIS does not block EGF binding to the EGF receptor, thus, MIS reduction of EGF receptor phosphorylation must occur distal to receptor ligand binding. The effect of proteolytically cleaved MIS on reduction of EGF receptor phosphorylation in membrane preparations is decreased by a specific phosphatase inhibitor, vanadate, thus implicating a membrane phosphatase in this MIS action at the EGF receptor.

Developmental expression of a candidate müllerian inhibiting substance type II receptor.

We have isolated a candidate Müllerian inhibiting substance (MIS) type II receptor complementary DNA from an embryonic rat urogenital ridge library and have studied its binding to MIS, its developmental pattern of expression and tissue distribution. By in situ hybridization with a full-length riboprobe, the receptor is expressed in the mesenchymal cells surrounding the Müllerian duct at embryonic days 14, 15, and 16 and in tubular and follicular structures of the rat fetal gonads. Expression of the messenger RNA was also seen in the granules cells and seminiferous tubules of pubertal gonads. Northern analysis revealed that the MIS type II receptor messenger RNA is highly expressed in embryonic, pubertal, and adult testes and ovaries, as well as in the gravid uterus. The timing of expression in the gonads of both sexes was also analyzed by Northern analyses that showed high levels of expression at the time of Müllerian duct regression, much lower levels neonatally and prepubertally and then increased expression again with sexual maturation. The tissue and developmental specificity of expression of this receptor, which make it likely that this is the functional MIS type II receptor, can be used to advantage in therapeutic targeting strategies and to decipher the function of MIS in the gonads.

Ultrafilterable hypomagnesemia in neonates admitted to the neonatal intensive care unit.

OBJECTIVE: To evaluate the frequency and clinical correlates of ultrafilterable hypomagnesemia in neonates admitted to the neonatal intensive care unit (ICU). DESIGN: Prospective, observational study. SETTING: Massachusetts General Hospital and Mount Auburn Hospital. PATIENTS: A total of 117 patients (84 neonatal ICU patients and 33 normal newborns) studied over a 2-yr period of time. MEASUREMENTS: Blood samples were collected during the first 48 hrs after admission. The concentrations of magnesium (total and ultrafilterable), ionized calcium, parathyroid hormone, electrolytes, glucose and arterial blood gases were determined. RESULTS: Ultrafilterable circulating magnesium concentrations were determined in 74 of 84 neonatal ICU patients. On admission to the neonatal ICU, 23 (31.1%) of 74 neonates had ultrafilterable hypomagnesemia; two (2.7%) of 74 patients had ultrafilterable hypermagnesemia. Neonatal ICU patients had significantly lower (p < .001) ultrafilterable magnesium concentrations compared with normal neonates. Hypomagnesemic ICU patients required mechanical ventilatory support more frequently than did normomagnesemic ICU neonates (p < .05). Ionized hypocalcemia was a common finding in our patients (34 [42%] of 81). However, ultrafilterable hypomagnesemia was not statistically associated with ionized hypocalcemia (p > .05). Despite the below normal serum concentrations of ultrafilterable magnesium observed in our study, there was no impairment in parathyroid hormone secretion. CONCLUSIONS: Ultrafilterable hypomagnesemia is a common finding in neonates admitted to the ICU. Ultrafilterable hypomagnesemia is associated with the need for mechanical ventilation. To our knowledge, this is the first report of ultrafilterable magnesium concentrations in normal and sick neonates.

Identification of a receptor for human müllerian inhibiting substance.

Müllerian inhibiting substance (MIS), a Sertoli cell-derived glycoprotein and member of the transforming growth factor-beta supergene family, plays a key down-stream role in mammalian sex determination. Identification of a receptor for MIS has now been achieved in a MIS-responsive human vulvar carcinoma cell line, A431, using fluorescein isothiocyanate labeling of recombinant human MIS (FITC-rhMIS) and RRAs with iodinated carboxy-terminal rhMIS. Confocal fluorescence microscopy of A431 cells incubated on ice with 30-nM concentrations of covalently bound FITC-rhMIS reveals specific punctate cell surface fluorescent signal. Cytosolic fluorescent signal is seen after incubation at 37 C for 1 h as well as occasional apparent perinuclear accumulation. FITC-rhMIS coincubated with molar excesses of unlabeled rhMIS in A431 cells eliminates cell surface and cytosolic fluorescent uptake. Double label experiments with FITC-rhMIS and tetramethyl rhodamine isothiocyanate epidermal growth factor establish separate binding of each ligand, displaceable, respectively, by large molar excesses of unlabeled rhMIS or epidermal growth factor. RRAs reveal a single, high affinity (Kd, 5.8 nM), saturable, low abundance binding species for carboxy-terminal rhMIS. Solubilized supernatants of A431 whole cells cross-linked with 125I-carboxy-terminal rhMIS identify a band with a mol wt of 88,000 on electrophoresis and autoradiography. This identification of a MIS receptor in A431 cells now permits the design of affinity purification protocols using rhMIS, followed by direct protein microsequencing.

Müllerian inhibiting substance: new perspectives and future directions.

MIS, as a differentiate and antiproliferative agent, is precisely regulated, for example, at the transcriptional level by such transacting factors as SRY, and posttranslationally by testosterone. Processing of MIS most likely requires an as yet unknown in vivo protease which probably serves to control cleavage of MIS and hence its activation at specific sites wherein a localized program of cell death is initiated via a receptor mediated event. Progress has been made in understanding the molecular domains of MIS; current efforts are focused on characterizing the wild type MIS receptor as well as cloning and expressing the MIS receptor. We need now to understand how to target and efficiently activate MIS at its projected site of action. We must focus, after structural analysis of its receptor, on elucidating the MIS initiated intracellular signals which result in localized cell inhibition. Understanding of these mechanisms will permit design of antitumor agents and therapeutic strategies. Similarly, understanding regulation of MIS expression may lead to therapeutic induction of expression in those states where depressed expression is associated with tumorigenesis, sexual ambiguity, or infertility.

Pediatric intensive care training: confronting the dark side.

PURPOSE: To describe the dark side of pediatric intensive care fellowship training and offer educational approaches for understanding feelings of fallibility, anger, frustration, and loss. DATA SOURCES: Listening and observing fellows in the courses of their pediatric intensive care training and later careers. STUDY SELECTION: Studies that discussed pediatric residency and fellowship training, especially in the context of intensive care. DATA EXTRACTION: From group meetings, unit conferences, rounds, individual discussions, and child psychiatric consultations. RESULTS OF DATA SYNTHESIS: Pediatric intensive care unit (ICU) fellows gain a sense of mastery from the nature of their work: complex, technological, and frequently lifesaving. They face the usual personal stresses of extended training, including long work hours, limited financial resources, and relative isolation from family and friends. Pediatric ICU fellows confront deeper, "dark" feelings regarding their own high expectations, fallibility, anger, sense of loss, frustration, limited control, and the need to work closely with tense, grieving families. If the dark side is not acknowledged, fellows, team members, and faculty are likely to experience anger, detachment, and depression that may extend beyond work into their personal lives. CONCLUSIONS: Since the dark side is expected, normal, and inevitable, fellowship training programs should help fellows cope with and understand these feelings. Such understanding requires a sense of trust among intensive care staff and can be gained through group discussions, mentorship, specific team conferences, and child psychiatric consultation.

Biochemical immaturity of lungs in congenital diaphragmatic hernia.

Neonates with congenital diaphragmatic hernia (CDH) continue to have unacceptably high mortality rates. To better understand the associated pulmonary pathology we measured biochemical parameters of lung maturity in neonatal rats with or without congenital diaphragmatic hernia created by maternal feeding of a single dose of nitrofen on day 9.5 or day 11.5 of gestation. Lungs from neonatal rats with large CDH (n = 9, 5 right-sided, 4 left-sided) had a significantly lower lung weight (P = .0001), lung weight/body weight ratio (P = .0001), disaturated phosphatidylcholine (DSPC) per microgram DNA (P < .005), total DSPC (P = .0001), total DNA (P < .05), protein per microgram DNA (P < .05), and total protein content (P < .005) when compared with lungs from the litter mates without congenital diaphragmatic hernia (n = 10). The lungs of rats with hernia also had significantly higher DNA concentrations (P < .05) and glycogen concentrations (P < .05). These data demonstrate that lungs in neonatal rats with large CDH are biochemically immature. Treatment directed toward correcting the pulmonary biochemical immaturity of affected fetuses before birth may improve the prognosis for these babies.

Identification of müllerian inhibiting substance specific binding in human cell lines.

The receptor for Müllerian Inhibiting Substance (MIS), a gonadal glycoprotein hormone, has not been previously identified. Plasma membranes from MIS-sensitive human tumor cell lines (HTB-111, endometrial carcinoma; and A-431, vulvar squamous carcinoma) were detergent extracted and incubated with 125I-labeled MIS anti-idiotypic antibody, or radioiodinated human recombinant MIS (125I rhMIS), with and without unlabeled competitors. 125I anti-idiotypic MIS antibody bound to HTB-111 membrane extracts was displaceable by unlabeled anti-idiotypic antibody, but not by anti-isotypic antibody prior to cross-linking. Specific binding of the anti-idiotypic MIS antibody to endometrial carcinoma cells was verified using fluorescence activated cell analysis and fluoresceinated antibody. Furthermore, unlabeled anti-idiotypic MIS antibody competed for 125I rhMIS binding to A-431 vulvar carcinoma membranes. The labeled anti-idiotypic MIS antibody binding complex could be separated from 32P labeled EGF receptor in the A-431 membranes, indicating that EGF, a natural inhibitor of MIS activity, and MIS itself bind to different receptors. These studies demonstrate a specific, displaceable binder for MIS in the plasmalemmae of two human tumor lines. Purification of this cell surface receptor protein will be greatly aided by using the MIS anti-idiotypic antibody.

Mullerian inhibiting substance binding and uptake.

Mullerian inhibiting substance (MIS) is a 140,000 M(r) Sertoli cell derived glycoprotein with a critical regulatory role in the male fetus initiated presumably by ligand binding with receptor. To localize this binding species we performed time course incubations of cultured fetal rat lungs or control tissues with MIS, applied rabbit anti-MIS IgG, and fluorescein conjugated anti-rabbit IgG, and examined specimens with laser confocal microscopy. Punctate surface fluorescence followed by cytosolic and nuclear localization in lung consistent with specific adsorptive endocytosis was seen. Confocal imaging also detected MIS binding to the Mullerian duct in the urogenital ridge. Crosslinking of 125I-MIS with plasma membranes revealed a high molecular mass binder with signal displaceable by excess unlabeled ligand. These data support the hypothesis that a specific plasma membrane binding protein for MIS exists.

Müllerian inhibiting substance blocks epidermal growth factor receptor phosphorylation in fetal rat lung membranes.

Neonatal males develop respiratory distress syndrome more frequently than females for unknown reasons. The fetal testis secretes testosterone and müllerian inhibiting substance (MIS); MIS has been shown to inhibit fetal lung maturation in vitro and in vivo and to block phosphorylation of epidermal growth factor (EGF) receptors in A431 cells. We hypothesized that MIS would also inhibit membrane phosphorylation of EGF receptors in fetal lung, and that ultrastructural study of MIS-exposed lung might complement the biochemical data by assessing the effect of MIS on tissue morphology. Lung membranes were prepared from 19.5-day fetal rats and phosphorylation assays performed with 3 to 4 micrograms of membrane protein, with or without EGF (26 nmol/L), 0.025 mCi AT32P (0.136 mumol/L), and either recombinant human MIS (rhMIS, 30 pmol) from media of Chinese hamster ovary (CHO) cells, rhMIS dialysis buffer, or wild-type CHO media. The 170,000 molecular weight EGF receptor, visualized by autoradiography of polyacrylamide gels, was phosphorylated in both female and male membranes. rhMIS, when added to EGF-stimulated membranes, caused significant inhibition of EGF receptor phosphorylation (females: 32.42% +/- 11.5%; males: 32.3% +/- 19.1%, P less than 0.001; rhMIS-treated v EGF-stimulated state, P = NS, male v female, Cerenkov counting). Electron microscopy (EM) of rhMIS-exposed lung showed decreased lamellar bodies (LB) in both male alveolar spaces and female parenchyma, and, unexpectedly, increased numbers in female alveoli. Immunoabsorption experiments using coincubation of rhMIS with anti-rhMIS IgG polyclonal antibodies or equiprotein normal IgG demonstrated MIS antibody-specific reversal of rhMIS activity in membrane phosphorylation.(ABSTRACT TRUNCATED AT 250 WORDS)

Sex-specific fetal lung development and müllerian inhibiting substance.

Male neonates develop respiratory distress syndrome (RDS) with a greater incidence and mortality than do female neonates; the cause of this male disadvantage remains obscure. Male fetuses are exposed to higher levels of androgens and Müllerian inhibiting substance (MIS). Androgens have been shown to inhibit fetal lung maturation, and recent evidence in vitro indicates that MIS, a Sertoli cell-derived glycoprotein made early in ontogeny of the testis, may also inhibit lung development. To study whether this fetal regressor might inhibit maturation of the fetal lung in vivo, we injected human recombinant MIS (rMIS) into fetal rats, measured serum levels of rMIS using an enzyme-linked immunosorbent assay, and analyzed fetal lung tissue histologically and for protein, glycogen, DNA, and disaturated phosphatidylcholine content. Peak serum levels of recombinant MIS were measured at 6 h, with an apparent elimination half-life of 3 h, and without leakage into adjacent littermates injected with vehicle alone. Female fetal rat lung tissue exposed to recombinant MIS (10(-9) M, 10(-8) M) revealed depressed disaturated phosphatidylcholine content both 48 and 72 h after injection compared with female vehicle-injected littermates. Male lungs of the same gestational age appeared inhibited at a higher (10(-8) M) rMIS dose. These inhibitory effects observed in vivo confirm those previously seen in vitro and suggest that MIS, as well as androgens, may play a causative or important ancillary role in the sexual dimorphism that characterizes the neonatal respiratory distress syndrome.

Müllerian inhibiting substance depresses accumulation in vitro of disaturated phosphatidylcholine in fetal rat lung.

Respiratory distress syndrome and associated pulmonary surfactant deficiency are more common in male neonates. Androgens have been shown to depress surfactant production. We tested the hypothesis that müllerian inhibiting substance, another fetal testicular product, might inhibit lung maturation measured as disaturated phosphatidylcholine accumulation. Initially, female fetal rat lungs were incubated with fetal testis or ovary or nanomolar concentrations of bovine müllerian inhibiting substance. Cultured lungs produced less disaturated phosphatidylcholine after incubation for 5 days with either testis (p = 0.012) or müllerian inhibiting substance than after coculture with ovary. In more comprehensive experiments, female lung fragments of 17.5 days' gestation, when incubated with nanomolar concentrations of bovine müllerian inhibiting substance or picomolar concentrations of human recombinant müllerian inhibiting substance, showed significant suppression of disaturated phosphatidylcholine accumulation (p less than 0.004) when compared with incubation with vehicle buffer. The suppression of surfactant accumulation produced in vitro by müllerian inhibiting substance, a potent male-specific fetal regressor, may be a factor in the increased susceptibility of male infants to respiratory distress syndrome.