Evidence that cortisol inhibits basal adrenocorticotropin secretion in the sheep fetus by 0.70 gestation.

To ascertain if reductions in fetal plasma cortisol cause increases in fetal plasma ACTH, we treated pregnant ewes or their fetuses with aminoglutethimide (10 mg/kg BW) and metyrapone (20 mg/kg BW) and measured the hormonal responses with RIAs. When given to fetuses (n = 9) at 0.90 +/- 0.01 gestation (term-145 days), the steroid synthesis inhibitors reduced fetal plasma cortisol from 35.1 +/- 11.9 to 18.5 +/- 6.2 ng/ml (P less than 0.01) and plasma ACTH increased from 37 +/- 7 to 189 +/- 74 pg/ml (P less than 0.02). Thus, late in gestation cortisol from the fetal adrenal suppresses basal fetal ACTH secretion. Blockade of steroid biosynthesis in pregnant ewes carrying intact fetuses at 0.76 +/- 0.02 gestation (n = 11) or adrenalectomized fetuses at 0.81 +/- 0.01 gestation (n = 6) also reduced cortisol and increased ACTH in fetal plasma. In intact fetuses cortisol declined from 9.4 +/- 2.0 to 3.6 +/- 0.9 ng/ml (P less than 0.05), and ACTH increased from 46 +/- 8 to 183 +/- 67 (P less than 0.01); cortisol declined in adrenalectomized fetuses from 2.1 +/- 0.4 to 1.1 +/- 0.3 ng/ml (P less than 0.01), and ACTH increased from 106 +/- 13 to 400 +/- 104 pg/ml (P less than 0.01). Cortisol infusions into intact and adrenalectomized fetuses prevented both the decline in steroid concentration caused by the biosynthesis inhibitors given to the ewe and the increase in fetal plasma ACTH concentration. These data indicate that reductions in plasma cortisol in adrenalectomized fetuses or intact fetuses at a time in development when the fetal adrenal produces little cortisol cause compensatory increases in fetal plasma ACTH concentration. The simplest explanation for these observations is that from approximately 0.70 gestation, basal fetal ACTH secretion is tonically inhibited by cortisol circulating in fetal plasma. This cortisol can originate from sources other than the fetal adrenal.

Haemophilus influenzae type b-specific antibody in infants after maternal immunization.

OBJECTIVE: To study the kinetics of Haemophilus influenzae type b (Hib)-specific antibody in infants born to mothers immunized with an Hib polysaccharide or one of two Hib conjugate vaccines. STUDY DESIGN: Serum antibody to the polyribosylribitol (PRP) moiety of Hib was measured by radioimmunoassay and enzyme-linked immunosorbent assay at birth and at 2 and 6 months of age in infants born to women immunized with Hib polysaccharide or conjugate vaccine (PRP-D and HbOC). A subset of infants > or = 6 months of age was immunized with Hib conjugate vaccine after licensure of this vaccine for infants. A comparison group of 18 infants born to unimmunized women received the same Hib conjugate vaccine on a similar schedule. RESULTS: Total PRP antibody concentrations were 1.50, 14.4 and 20.4 microg/ml in 2-month-old infants born to mothers immunized with polysaccharide, PRP-D and HbOC vaccines, respectively, and 2.54, 1.35 and 2.46 microg/ml in 6-month-old infants. Infants born to mothers immunized with polysaccharide vaccine had significantly less PRP antibody at 2 months of age but similar antibody concentrations at 6 months of age. Persistence or increases in total PRP antibody during 6 months were noted in 21 of 47 (44.6%) study infants. A subset of study and comparison infants was immunized with a mean of 2.6 doses of Hib vaccines between 6 months and 2 years of age, and all infants had total PRP antibody concentrations > or = 0.15 microg/ml. CONCLUSION: Conjugate Hib vaccines administered during the last trimester of pregnancy resulted in significantly higher PRP antibody titers in infants at birth and 2 months of age than did polysaccharide vaccine. A subset of infants born to immunized mothers was subsequently immunized with Hib conjugate vaccine and had antibody concentrations similar to those in infants born to nonimmunized women.

Histologic diagnosis of Hirschsprung's disease. The value of concurrent hematoxylin and eosin and cholinesterase staining of rectal biopsies.

False positive and negative results can complicate the diagnosis of Hirschsprung's disease (HD) with the acetylcholinesterase (AChE) stain. To improve the diagnostic value of this test, the authors evaluated the concurrent hematoxylin and eosin (H and E) staining of extra sections after the AChE procedure. Flash-frozen (FF), cryostat-cut (CC) sections of rectal suction biopsies from 96 patients with constipation were evaluated by AChE together with H and E staining of additional unstained sections. In 13 of 15 cases of HD with a diagnostic (positive-A) AChE pattern, the H and E sections confirmed the diagnosis. In five cases with other AChE patterns, the H and E sections were instrumental when the diagnosis was made. Of the 76 non-HD subjects with positive-B (n = 8), equivocal (n = 6), and negative (n = 62) AChE patterns, the H and E sections eliminated the diagnosis in 62 (81%). Neuronal and nerve fiber morphologic characteristics were excellent. Rebiopsies were needed in 14 subjects (19%) when there was failure in finding neurons. Simplicity, quickness, and the high quality of the histologic preparations make this procedure a useful adjunct to the AChE stain.

Air gun injuries of the abdomen in children.

From July 18, 1978 to Sept 15, 1982, four boys were treated for air gun injuries of the abdomen at the North Carolina Baptist Hospital, Winston-Salem. Three patients had wounds of one or more of the hollow viscera, and one patient had an injury only of the liver. There was no morbidity or mortality following repair. Some present-day air (pneumatic) weapons have muzzle velocities that equal or exceed those of common civilian handguns, and they are frequently used by unsupervised children. These weapons are not restricted and regulated as are other firearms, and are believed to be incapable of serious injury other than to the eye. These cases and others in the literature dispute that belief.

Surgical management and follow-up of a complex tracheobronchial injury.

Tracheobronchial trauma is an uncommon condition with potentially devastating consequences. Appropriate pre-, intra-, and postoperative management is mandatory for a satisfactory functional outcome. We report a case of extensive tracheobronchial injury secondary to blunt trauma, which was managed successfully with emergent surgical repair and careful endoscopic follow-up. We review the important management decisions made in this case.

Congenital cyst of the pancreas.

The case of a 4-month-old girl with a rare multilocular congenital pancreatic cyst is presented, along with radiological/pathological correlation and a review of the literature. Congenital cyst of the pancreas is a rare lesion most often seen in infant girls, although it may be demonstrated in utero. Conventional radiographic signs and clinical symptoms primarily reflect mass effects, whereas imaging modalities show the cystic nature of the mass. Although rare, this cyst should be considered in the differential diagnosis of fetal and pediatric cystic abdominal masses.

Serum visceral protein levels reflect protein-calorie repletion in neonates recovering from major surgery.

Protein catabolism resulting from acute metabolic stress causes significant postoperative decreases in visceral proteins, including albumin (Alb) and prealbumin (PA). Although clinical trials have suggested an advantage of PA over Alb in monitoring the visceral protein response to nutritional supplementation following surgery, the capability of the neonate to generate such a response has yet to be evaluated. Therefore, this study was undertaken to determine if PA is superior to Alb in assessing postoperative repletion of the visceral protein pool in neonates. Serum Alb and PA levels were measured and energy balance (EB) and protein intake (PI) were recorded in 10 neonates less than 48 hours after major surgery and again following 4 consecutive days of positive EB. Resting energy expenditure (REE) was measured using indirect calorimetric methodology. Mean PI (g/kg/d) was lower (0.78 +/- 0.78) and mean EB (kcal/kg/d) was negative (-2.92 +/- 10.05) less than 48 hours postoperatively compared with mean PI (2.52 +/- 0.57; P = .0006) after 4 consecutive days of positive EB (34.84 +/- 16.5; P = .0004). Mean percent change (mean% delta) from negative EB to positive EB was significantly greater for PA (100%; P = .0002) as compared with Alb (18.5%). These data appear to support the conclusion that serial serum PA levels are superior to Alb to monitor the visceral protein response to nutritional supplementation in neonates following surgery.

Ovine fetal adrenal gland and cardiovascular function.

Given the necessity of the adrenal gland in maintaining cardiovascular function in adults of various species, these experiments were conducted to determine if fetal bilateral adrenalectomy results in altered resting heart rate, hypotension, and decreased basal blood volume as well as a diminished ability of the fetus to maintain arterial pressure and restore blood volume in response to hemorrhage. We studied heart rate, arterial blood pressure, and blood volume changes in response to hemorrhage of 20% of blood volume at 2%/min in seven adrenalectomized and six intact chronically cannulated unanesthetized lambs between 119 and 133 days of gestation. Blood volumes and percent restitution of shed volume were determined using 51Cr-tagged red blood cells and changes in hematocrit. There was no significant difference between groups in basal heart rate, mean arterial pressure, hematocrit, and blood volume. The two groups were similar to hemorrhage-induced changes in these and restitution of volume. Therefore, fetal adrenal glands are not necessary for basal cardiovascular function or regulation subsequent to moderate hemorrhage in the late gestation ovine fetus.

Evolving management of pectus excavatum based on a single institutional experience of 664 patients.

Most pediatricians and family physicians believe that children with pectus excavatum require surgery only for cosmetic indications and then only in teenagers. We believe pectus excavatum should be repaired in childhood (1) to relieve structural compression of the chest and allow normal growth of the thorax; (2) to prevent pulmonary and cardiac dysfunction in teenagers and adults; and (3) to obviate the cosmetic impact that may cause a child to avoid sports and gymnastics. Preoperative CT scans now help select those children who need repair to prevent progressive deformities. Pulmonary function studies during vigorous exercise can document respiratory dysfunction in teenagers. These features are reversible if repair is completed before the pubertal growth spurt. The ideal age for repair is 4 to 6 years, which permits enough emotional maturity for a positive hospital experience and avoids later psychological effects. Repair at an earlier age has no operative advantages. Our operative technique consists of the removal of three to four overgrown costal cartilages, repositioning of the sternum with a transverse osteotomy, and internal support using the child's lowest normal ribs, avoiding any prosthetic support. To prevent recurrence in teenagers, we add a temporary bar beneath the sternum to prevent depression of the sternum from the weight of the chest-wall muscle mass. Six hundred sixty-four patients have been followed for 1 to 40 years; 95% have excellent long-term results and only 5% have mild to moderate recurrences. Our current techniques of patient selection and surgery will be presented.

Dexamethasone treatment during ventilator dependency: possible life threatening gastrointestinal complications.

Corticosteroids in high doses have been used effectively to decrease the duration of ventilator dependency in very low birthweight infants at risk for chronic lung disease. Randomised prospective studies have shown benefit, with only minimal complications being reported. However, review of our experience over 2.5 years with high dose steroids in 80 premature neonates yielded three major complications: one case each of perforated duodenal ulcer, perforated gastric ulcer, and upper gastrointestinal haemorrhage. Two of the three patients died. Thus the use of steroids in neonates may not be without risk, and significant complications can occur. When high dose corticosteroids are to be used in very low birthweight neonates, H2 receptor antagonist treatment and gastric pH monitoring are recommended. The physician must remain alert to the possibilities of upper gastrointestinal bleeding and ulcer perforation in these patients.

Fibrosarcoma of the sacrum in a child: management by sacral resection and reconstruction.

We describe the diagnosis and surgical management of fibrosarcoma of the sacrum in a pediatric patient. We retrospectively reviewed the literature and a case report. Total sacrectomy is a viable treatment option in the management of large malignant sacral tumors. The techniques used in adult patients can be extended to and improved upon for pediatric patients. The input of multiple surgical specialties is essential in the management of these lesions.

Increasing doses of purified influenza virus hemagglutinin and subvirion vaccines enhance antibody responses in the elderly.

The reactogenicities and immunogenicities of two influenza virus vaccines were compared in a placebo-controlled clinical trial among healthy ambulatory persons > or = 65 years old (mean age, 72 years). Volunteers were assigned randomly to receive 15-, 45-, or 135-micrograms doses of monovalent influenza A/Taiwan (H1N1) hemagglutinin (HA) or subvirion (SV) vaccine intramuscularly or a placebo. Increasing doses of SV vaccine were associated with a higher rate of injection site discomfort (P < 0.05; chi-square test for linear trend), but all doses of both vaccines were well tolerated. Increasing the dose of the HA or the SV vaccine resulted in increasingly higher postimmunization levels of serum hemagglutination inhibition and neutralizing antibody levels (P < 0.001; multiple linear regression). Mean serum antibody titers at 1 month increased two- to threefold with a ninefold increase in dose; the frequencies of fourfold or greater rises in titer likewise increased. An increase in the dose of the HA or the SV vaccine also resulted in increased frequencies of rises in immunoglobulin A or G antibody titers in nasal wash specimens. The frequencies increased approximately twofold for each vaccine with a ninefold increase in the dose. These data suggest that increasing the HA vaccine dose is a promising approach to the development of improved influenza virus vaccines for use in elderly people.