Adjuvant-dependent immune response to malarial transmission-blocking vaccine candidate antigens

Immune responses in major histocompatibility complex (MHC)-disparate congenic mouse strains immunized with sexual stage malaria parasites or purified recombinant protein were adjuvant dependent. Whereas mice exhibited a limited antibody response to immunization with newly emerged Plasmodium falciparum gametes in Freund's adjuvant, all five congenic mouse strains responded to several transmission-blocking vaccine candidate antigens, when parasites were emulsified in a monophosphoryl lipid A (MPL) and trehalose dimycolate (TDM) adjuvant. The humoral response in those animals immunized with the antigen in a MPL/TDM adjuvant was helper T cell dependent, as evident by boosting of the antibody response after a second immunization. If the immunogen consisted of purified recombinant protein, then the immune response was not MHC class II limited in mice immunized with either complete Freund's adjuvant or TDM/MPL. The potential role of adjuvants in overcoming apparent immune nonresponsiveness and the implications for development of a malaria transmission-blocking vaccine are discussed.

A novel 40-kDa membrane-associated EF-hand calcium-binding protein in Plasmodium falciparum

A 40-kDa sexual stage radiolabeled surface protein of Plasmodium falciparum, Pfs40, was previously identified as a potential target antigen of transmission blocking immunity by an immunogenetic approach. Synthetic oligonucleotide "guessmers," based on microsequenced tryptic peptides of Pfs40 purified by two-dimensional gel electrophoresis, were used to clone the full length cDNA and genomic DNA encoding Pfs40. The deduced amino acid sequence predicted an integral membrane protein containing five EF-hand calcium-binding domains. The biological activity of one or more of these domains was confirmed by binding of 45Ca to both native and recombinant Pfs40. Antisera to recombinant Pfs40 immunoprecipitated the native radiolabeled 40-kDa surface protein. The predicted noncytosolic membrane-associated localization of Pfs40 is unique within the EF-hand calcium-binding protein superfamily.

Sudden deaths and apparent life-threatening events in hospitalized neonates presumed to be healthy

We describe 10 apparently healthy newborns who were patients in a level 1 nursery and were found by caregivers to be limp, apneic, and requiring resuscitation. All patients were between ages 15 hours and 3 1/2 days, products of term gestations, and of appropriate weight for gestational age. Prenatal or perinatal complications were present in nine of the 10 patients; in no patient was the complication considered a risk for serious, late-onset neonatal problems. All patients had been examined by a physician and were deemed to be in good health before the apparent life-threatening event. Subsequent to the event, each patient required positive pressure ventilation and seven patients received chest compressions. Five patients died. Autopsies were performed on four of the five patients and in none was an adequate explanation for death established. Intrathoracic petechiae were found in one patient whose sibling had died of sudden infant death syndrome at age 11 weeks. Evaluation of the five survivors failed to determine a cause for the episodes. Of the five survivors, one had normal results of developmental examination at age 6 months, while the remaining four survivors had severe neurologic impairment at age 1 year. Apparent life-threatening events occur in hospitalized newborns presumed to be normal and may be a manifestation of early sudden infant death syndrome or early near-miss sudden infant death syndrome.

Patient dose and associated risk due to radiological investigation of the internal auditory meatus

The radiation doses and associated somatic risks due to four radiological examinations for acoustic neuromata (AN) have been investigated. These examinations were (1) plain film radiography of the internal auditory meatus (IAM), (2) computed tomography (CT) of the IAM, (3) CT of the posterior fossa and (4) CT of the IAM with air contrast. Organ dose measurements were performed using lithium fluoride thermoluminescent dosemeters loaded in a patient equivalent phantom. Dose equivalents to various organs are presented, together with the effective dose equivalent and collective effective dose equivalent for each examination. Hypothetical fatal somatic risks for each examination studied here have been estimated from the effective dose equivalents. The estimated number of hypothetical fatal cancers induced by radiological examinations for AN is between approximately 110 and 820 times lower than the number of detected AN, depending on the method of assessing the radiation dose to the remainder organs. It is concluded that in this particular study the radiological examinations are of net benefit to this group of patients.

Citywide neonatal program. Ten years experience

A citywide neonatal program initiated in Jacksonville, Florida, in July 1978 through December 1988 had incorporated all six hospitals that provide obstetrical services in the metropolitan area. Admissions, occupancy rate, as well as patient care days served by the Regional Perinatal Intensive Care Center (RPICC) and the Level II nurseries have increased to capacity. More "step-down" care beds are made available by this program which has also proved to be cost effective. Areas of concern are discussed.

Rapid method for introducing restriction sites into double stranded plasmid DNA

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The effect of circumcision on transcutaneous PO2 in term infants

To assess the effect of pain on PaO2 in newborns, transcutaneous PO2 (tcPO2) was monitored in ten healthy male infants undergoing circumcision. The tcPO2 was seen to decrease to a lower level with pain and to remain low with continuing pain. After the circumcision, the tcPO2 increased to levels equal to or exceeding those of the preoperative baseline period. Close corcordance of tcPO2 above and below the waist demonstrated no right-to-left shunting through the ductus arteriosus.

The Siemens-Elema Servo Ventilator 900 B for the management of newborn infants with severe respiratory distress syndrome: a 22-month trial

The Siemens-Elema Servo Ventilator 900 B is an electronically-controlled, volume-limited ventilator. To adapt this ventilator for use in newborns with respiratory failure, minute volume control, PEEP valves, air-oxygen blenders, and respiratory tubing circuits were modified. During a 22-month period, 161 newborn infants with severe respiratory distress syndrome (RDS) were managed with this ventilator. The overall survival rate was 66%; the incidence of barotrauma was 20%; the survival rate was 53%. Of the infants studied, 12% developed bronchopulmonary dysplasia, and 79% of these survived. Of the 19% of patients with a symptomatic intraventricular hemorrhage, 6% survived. The experience of the authors with this ventilator modified to manage newborn infants with severe RDS has been extremely encouraging. Furthermore, this ventilator is versatile because it can be readily recalibrated for use in older patients and can be easily adapted for patients requiring surgery. This ventilator has the extremely important advantage of being a volume ventilator which can effectively provide positive pressure ventilatory support to patients of all age and weight groups.