Resuscitation of the very immature infant: cerebral Doppler flow velocities in the first 20 minutes of life.

Blood flow velocity of the anterior cerebral artery was investigated by Doppler ultrasonography in five time intervals up to 20 min after birth in 16 non-asphyxiated very immature infants (median birth weight 1,058 g, range 720-1,930 g; median gestational age 30 weeks, range 27-32 weeks) delivered by caesarean section and intubated after birth. Heart frequency, oscillometric mean arterial blood pressure and blood gases were recorded as well. There was a transitory increase in both systolic and end-diastolic velocities (from 29 to 35 and from 1 to 10 cm/s) during the first 5 min after birth which occurred together with an increase in heart frequency. The overall incidence of intracranial haemorrhage was low (3/16, 19%). This observation study shows a transitory increase in cerebral blood flow velocity with a peak at about 5 min after birth in preterm infants < 33 weeks of gestation undergoing standard resuscitation.

Significance of a sonographic secretin test in the diagnosis of pancreatic disease. Results of a prospective study.

In a prospective study the pancreatic duct diameter was measured sonographically before and after secretin stimulation in 20 healthy controls and 59 patients with upper abdominal pain, weight loss, and/or diarrhea. Whereas healthy controls and patients without pancreatic disease after secretin stimulation showed a distinct pancreatic duct dilatation of more than 90% of basal duct diameter, no distinct secretin-induced duct enlargement was observed in most patients with chronic pancreatitis. Patients with circumscript pancreatic duct stenosis even had a marked and longer-lasting duct dilatation after stimulation. In patients with anomalies of the pancreatic duct system, no uniform response was found after secretin injection. In this study the sonographic secretin test showed a sensitivity of 92% and a specificity of 95% for diagnosis of chronic pancreatitis. The results confirm that this diagnostic method can be recommended as a reliable screening test for pancreatic disease.

Sonographic imaging of the pancreatic duct. New diagnostic possibilities using secretin stimulation.

The pancreatic duct or at least parts of this structure can be demonstrated today by sonography in 75-85% of all persons examined. In 84 persons we have now measured the caliber of the sonographically visualized pancreatic duct in the region of the proximal body of the pancreas with special attention to dependence on age. The diameter of Wirsung's duct ranged from 1 to 3 mm (mean 1.9 mm) and increased significantly from the fifth decade of life onwards. After intravenous injection of the hormone secretin, healthy persons usually show a distinct duct enlargement, which also depends on age. Nine persons aged 19 through 35 (median 28) years showed a dilatation of the main pancreatic duct by about 110% following secretion injection. Nine further probands, 50-74 (median 58) years old, had a dilatation of about 70%. Eighteen patients with confirmed chronic pancreatitis and a pancreatic duct diameter not exceeding 4 mm generally showed no duct enlargement after secretin stimulation. We believe that periductal fibrosis, which is common in chronic pancreatitis, is the most important reason for these results. The use of the sonographic secretin test in the diagnosis of chronic pancreatitis should be considered.

Radiographic determination of bone maturation as an aid in predicting chronologic age in the owl monkey (Aotus trivirgatus).

The skeletal development of laboratory-bred owl monkeys (Aotus trivirgatus) ranging from 37 days to 58 months of age was examined radiographically. Femoral length, time of epiphyseal ossification, and fusion of various ossification centers were studied. Chronologic age can be predicted by femoral length determination up to 18 months. Initial ossification of calcaneal, tibial tuberosity, iliac crest, and ischial apophyses occurs between 5.5 and 14 months. Fusion of various secondary ossification centers allows age determination from 7.5 months to 58 months.

Aqueous humor dynamics in the owl monkey with comparison to cynomolgus.

The owl monkey is used in experimental ocular studies, but little data are available regarding its aqueous humor dynamics. We determined aqueous humor flow rate (AHF), anterior chamber elimination coefficient (Ke), and corneal endothelial transfer coefficient (Ka) fluorophotometrically; total outflow facility (C) by 2-level constant pressure perfusion; and the facility response to intravenous and intracameral pilocarpine in pentobarbital anesthetized owl monkeys. Baseline values (mean +/- S.E.M., n eyes) were: AHF = 1.52 +/- 0.14 microliter X min-1, n = 24; Ke = 6.54 +/- 0.65 min-1 X 10(-3), n = 24; Ka = 3.84 +/- 0.40 min-1 X 10(-3), n = 24; C = 0.35 +/- 0.03 microliter X min-1 X mm Hg-1, n = 26. Intracameral pilocarpine caused a dose-dependent facility increase, with the maximum response (a tripling of resting facility) occurring between 20 and 100 micrograms; intravenous pilocarpine, 2 mg/kg, also doubled to tripled facility. With certain qualifications, these findings are comparable to those in other primate species and confirm the usefulness of the owl monkey in carefully chosen experimental studies of aqueous dynamics.

Prostaglandin F2 alpha improves oxygen tension and reduces venous admixture during one-lung ventilation in anesthetized paralyzed dogs.

The authors investigated the effect of prostaglandin F2 alpha infused into the pulmonary artery of an acutely atelectatic lung in dogs. Seven dogs were anesthetized with piritramid and pentobarbital and intubated with a Kottmeier canine endobronchial tube. Cardiac output, pulmonary arterial, capillary wedge, and systemic arterial pressure were measured via indwelling catheters. Ventilating both lungs with 66% O2, PaO2 was 327 +/- 15 mmHg (mean +/- SD) and venous admixture (Qsp/Qt) was 11 +/- 3%. One-lung atelectasis reduced PaO2 to 91 +/- 12 mmHg and increased Qsp/Qt to 40 +/- 4%. Prostaglandin F2 alpha in doses of 0.4, 0.6, 1.2, and 1.8 micrograms X kg-1 X min-1 was infused into the pulmonary artery of the atelectatic lung through a second pulmonary artery catheter. Up to a dose of 1.2 micrograms X kg-1 X min-1 there was a dose-dependent reduction in Qsp/Qt to a minimum of 25 +/- 4% and an increase in PaO2 to 168 +/- 25 mmHg, which could be explained by enhanced pulmonary vasoconstriction in the atelectatic lung with increased blood flow diversion toward the ventilated lung. Infusion of 1.8 micrograms X kg-1 X min-1 decreased PaO2 to 156 +/- 32 mmHg and increased Qsp/Qt to 32 +/- 9%. Increased systemic effects of prostaglandin F2 alpha were observed and presumably were related to saturation of prostaglandin-dehydrogenase leading to vasoconstriction in both lungs and thus reduced blood flow diversion toward the ventilated lung.

Lead elimination of ICRF 158 in rats after chronic lead exposure.

Lead elimination by ICRF 158, a lipophilic derivative of ethylene-diaminetetra-acetate (EDTA), was investigated in rats after chronic lead exposure. The animals had received a lead concentration of 550 ppm in their drinking water for 140 days. Subsequent treatment with ICRF 158 for 30 days led to increased mobilization and elimination of incorporated lead, and the lead-induced inhibition of hemosynthesis was removed. ICR 158 produced no renal damage in excess of lead-induced tubular nephrosis. Separate toxicity tests in mice demonstrated that it is less toxic than CaNa2EDTA. ICRF 158 does not form stable complexes with lead ions in vitro. The mechanism of action of this lipophilic EDTA derivative is compared to that of its hydrophilic correspondent, the chelating agent CaNa2EDTA.

The vitreous of the baby owl monkey. A model for rapid and complete gel-liquefaction.

The vitreous body of the baby owl monkey (Aotus trivirgatus) exists as a highly elastic gel composed of a collagen-like network. The owl monkey vitreous liquefies completely within the first 2 years of the Aotus life, corresponding to a human age of 8-10 years. Thus, Aotus provides the only known primate model for the rapid and complete liquefaction of the vitreous gel at an early age, the understanding of which may be of future relevance for clinical induction of therapeutic vitreous liquefaction.

Modulation of lymphocyte stimulation by the vitreous body. A new concept in ocular immunology.

The modulating properties of the vitreous body on lymphocyte stimulation has been investigated in vitro. Vitreous hyaluronic acid suppresses lymphocyte stimulation, depending on the physicochemical properties of the biopolymer, by reducing direct and indirect cell-cell interaction. The presence of a lymphocyte stimulation enhancing factor has been demonstrated, and the name ocular lymphocyte modulating factor (OLMF) has been assigned. The potentially basic importance of OLMF for the general immune response of the body has been outlined.

The scope of hyaluronic acid as an experimental intraocular implant.

The inflammatory potential of hyaluronic acid (HA) varies from batch to batch of HA independent of tissue origin, concentration, or amino acid composition. The inflammatory potential can be determined by intravitreous testing only, not by intracameral testing. Retention of HA in the eye depends on molecular weight and concentration of HA, not on the ocular inflammatory response. Concentration, molecular weight, and inflammatory grade of any HA batch used in intraocular surgery should be specified. Monitoring of the postoperative intraocular pressure is recommended.

Effect of splenectomy on B- and T-lymphocytes and a benzpyrene-induced murine sarcoma.

UNLABELLED: The investigation of 400 adult mice had the objective to find out 1. The influence of splenectomy on genesis and growth of a benzpyrene-induced sarcoma and 2. The behavior of B- and T-lymphocytes under the influence of splenectomy. RESULTS: 1. A significantly lower number of tumors developed in splenectomized animals (28.5%) as compared to controls (49.5%). 2. A significant decrease of B-lymphocytes and an increase in T cells after splenectomy were found in the peripheral blood. 3. The examination of the tumor marginal zone showed a decreased number of B-lymphocytes and an increase of T-lymphocytes, while the total count of round cells remained unchanged. These results are discussed and compared with results of other authors.

Effect of generalized graft-versus-host-reaction on B- and T-lymphocytes and a benzpyrene-induced murine sarcoma.

UNLABELLED: The investigations of 400 adult hybrids from A/Jax fem. BALB/c male were aimed at answering the following questions: 1. What is the influence of a generalized graft-versus-host-reaction (GVHR) on the induction and growth of benzpyren-induced sarcoma? 2. What is the behavior of B- and T-lymphocytes during GVHR, and during induction and growth of benzpyren-induced sarcoma? 3. Which are the deductions to be drawn with regard to the effect of B- and T-lymphocytes during tumorigenesis and tumor growth? RESULTS: 1. The number of tumors was significantly greater in the GVHR animals (74.5%) than in the controls (49.5%). 2. A significant decrease of T-lymphocytes and increase of B-lymphocytes during GVHR were found in the peripheral blood. 3. The examination of the tumor marginal zone showed a marked decrease of the total round cell count and the T cells, while the count of B-lymphocytes remained uninfluenced. These results are discussed and compared with results of other authors.

The influence of embryonal bursectomy on benzpyrene-induced sarcoma of the chicken.

160 chickens hormonally bursectomized before hatching, and 160 controls were twice given a dose of 10 mg 3,4-benzo(a)pyrene 2 weeks and 6 weeks after hatching. After 24 weeks the controls had developed muscle sarcomas at a significantly higher rate than the bursectomized animals (49.6--32.1%). The tumors were identified as malignant polymorphocellular rhabdomyosarcomas in light and electron microscopy. When the experiment was stopped after 27 weeks, the controls showed more tumors than the bursectomized chickens (65.1% versus 58.9%). The effect of bursectomy lies in a prolongation fo tumor latency. The frequency of metastases is equally decreased to a significant degree (41.7% versus 21.7%). These results are interpreted as an illustration of the disturbed equilibrium between the T and B cell responses.

Bursa-independent plasma cells in the Harderian gland of the chicken (Gallus domesticus). Histomorphometrical investigations.

Morphometric investigations of the Harderian gland in normal and bursectomized chickens at the 16th, 30th, and 60th day after hatching, show a significcant suppressive effect of bursectomy on the volume of the plasma cell compartment in this organ. However, the suppression of the plasma cell population in the Harderian gland is not complete. The plasma cells remaining in the Harderian gland after bursectomy are probably components of a bursa-independent B cell population.

Peripheral uveitis in the owl monkey. Experimental model.

Primary intravitreous HA injections cause a great variation in ocular inflammatory response, ranging from slight Tyndall effect (LI-HA) to severe inflammation (HI-HA). Both slight and severe inflammation are transient and subside completely within 10-30 days (early inflammatory response), whereas multiple injections ( greater than 3 times) cause a peripheral uveitis, which can be of interest as an experimental model. Control experiments with endotoxin (endotoxin uveitis) fail to produce the same or similar pathological alterations.