Spectral sensitivity of wild-type and mutant Drosophila melanogaster larvae

Wild-type (Canton-S) Drosophila melanogaster larvae are generally repelled by white light. Mutant larval photokinesis A (lphA) larvae are less strongly repelled than controls. Mutant Larval photokinesis B (LphB) larvae are unresponsive to light, as are larvae from LI2, an isofemale line whose progenitors were recently derived from a natural population. To characterize the behavior of larvae from the mutant stocks and the isofemale line more precisely, we determined the range of wavelengths that repel wild-type (Canton-S) D. melanogaster larvae and identified wavelengths to which larvae are most sensitive. In comparison to adult flies, Canton-S larvae are much less sensitive to white light and respond to a narrower range of wavelengths. The wavelengths to which Canton-S larvae are maximally sensitive are 500 nm (green), 420 nm (indigo), and 380 nm (ultraviolet). Mutant lphA larvae respond abnormally to green and indigo light but are as strongly repelled by ultraviolet light as controls. In contrast, mutant LphB larvae and larvae from the LI2 isofemale line are unresponsive to green, indigo, or ultraviolet light. Thus, lphA larvae have a wavelength-specific defect, while LphB and LI2 larvae are generally unresponsive to wavelengths that repel wild-type larvae.     

Acute hand burns in children: management and long-term outcome based on a 10-year experience with 698 injured hands

OBJECTIVE: To document long-term results associated with an coordinated plan of care for acutely burned hands in children. SUMMARY AND BACKGROUND DATA: Optimal hand function is a crucial component of a high-quality survival after burn injury. This can be achieved only with a coordinated approach to the injuries. Long-term outcomes associated with such a plan of care have not been previously reported. METHODS: Over a 10-year period, 495 children with 698 acutely burned hands were managed at a regional pediatric burn facility; 219 children with 395 injured hands were followed in the authors' outpatient clinic for at least 1 year and an average of >5 years. The authors' approach to the acutely burned hand emphasizes ranging and splinting throughout the hospital stay, prompt sheet autograft wound closure as soon as practical, and the selective use of axial pin fixation and flaps. Long-term follow-up, hand therapy, and reconstructive surgery are emphasized. RESULTS: Normal functional results were seen in 97% of second-degree and 85% of third-degree injuries; in children with burns involving underlying tendon and bone, 70% could perform activities of daily living and 20% had normal function. Reconstructive hand surgery was required in 4.4% of second-degree burns, 32% of third-degree burns, and 65% of those with injuries involving underlying bone and tendon. CONCLUSIONS: When managed in a coordinated long-term program, the large majority of children with serious hand burns can be expected to have excellent functional results.     

Percutaneous endoscopic gastrostomy in burn patients

Background: Prolonged enteral feedings are required occasionally in seriously burned individuals. We have employed percutaneous endoscopic gastrostomy (PEG) in selected patients who require particularly prolonged access, thus prompting this review. Methods: The PEG procedure was performed under general anesthesia in combination with another surgical procedure using a variety of commercially available needle and guidewire kits in 14 patients. Results: These 14 patients had an average age of 55.2 ± 6.6 years and a burn involving 38 ± 8% of the body surface. Eleven of these patients had suffered an inhalation injury. The tubes were placed an average of 57 ± 10.5 days after injury through unburned and unharvested skin in four patients (28%), healed donor sites in five patients (35%), healed burn in one patient (1%), and grafted burn in four patients (28%). One patient, whose catheter was placed through a grafted fascial excision, developed moderate local wound erosion. Tubes were known to have been left in place as long as 155 days. However, most were removed in rehabilitation hospitals, and we were unable to determine how long most were left in place. We are unaware of any problems with the tubes occurring after discharge from the acute care setting. Conclusions: In selected patients, PEG can provide more comfortable access for prolonged enteral feedings than nasogastric tubes and can be placed with minimal morbidity. Received: 29 March 1998/Accepted: 1 August 1998     

Microglial proliferation in cortical neural cultures exposed to feline immunodeficiency virus

Microglia are thought to play an important role in neurodegenerative changes due to infection with human or animal immunodeficiency viruses. Using feline immunodeficiency virus and cat neural cultures, we observed a dramatic increase in the accumulation of microglia from a basal rate of 5-7% day(-1) to 25-126% day(-1). Both live virus and heat-inactivated virus induced proliferation. Negligible proliferation was seen in purified microglial cultures. Conditioned medium from astrocytes or mixed neural cultures treated with feline immunodeficiency virus stimulated the proliferation of purified microglia. Disease progression may be facilitated by early non-infectious interactions of lentiviruses with neural tissue that promote the activation and proliferation of microglia.     

Biliary secretion of sulindac and metabolites in man

The biliary secretion of sulindac and metabolites after a single 400 mg oral dose of the drug was studied in 3 elective gallbladder surgical patients following placement of an occludable T-tube in the common bile duct. Bile and systemic plasma were sampled at frequent intervals for up to 36 h postdose. The apparent biliary clearance (V?_cl,bilc) of the prodrug sulindac is about 25 times greater than that of the pharmacologically active sulfide metabolite. The total biliary flux of drug in normal man with an uninterrupted enterohepatic cycle, calculated from V?_cl,bile and historic mean plasma drug AUC values, averages 144 and 12·2 per cent of the dose as sulindac and the sulfide metabolite, respectively. Thus, enterohepatic recycling of the drug in man is principally in the form of the prodrug which not only limits exposure of the intestine to the active moiety but also sustains systemic concentrations of active drug upon reabsorption of the prodrug.     

Inhibition of bactericidal and bacteriolytic activities of poly-D-lysine and lysozyme by chitotriose and ferric iron.

In a previous report from this laboratory (N. J. Laible and G. R. Germaine, Infect. Immun. 48:720-728, 1985), evidence was presented to suggest that the bactericidal actions of both reduced (i.e., muramidase-inactive) human placental lysozyme and the synthetic cationic homopolymer poly-D-lysine involved the activation of a bacterial endogenous activity that was inhibitable by N,N',N"-triacetylchitotriose (chitotriose). In the present investigation however, we found that the bactericidal and bacteriolytic action of poly-D-lysine could be prevented only by some commercially available chitotriose preparations and not by others. Analysis by physical and chemical methods failed to distinguish protective chitotriose (CTa) and nonprotective chitotriose (CTi) preparations. CTi and CTa preparations displayed equal capacities to competitively inhibit binding of [3H]chitotriose by immobilized lysozyme and were indistinguishable in their abilities to block the lytic activity of lysozyme against Micrococcus lysodeikticus cells. Elemental analysis revealed significantly higher levels of phosphorus, calcium, iron, sodium, manganese, and copper in CTa. Removal of metals from CTa by chelate chromatography completely abolished the poly-D-lysine-protective capacity. Of the metals detected, only ferric iron (5 to 10 microM) mimicked the protective action of CTa. A Fe(III) concentration of 50 microM was required to inhibit lysozyme (5 micrograms/ml). Both Fe(III) and CTa (but not CTi) quantitatively blocked the labeling of poly-D-lysine by fluorescamine, suggesting that the primary amino groups of the lysine residues participate in iron binding. Thus, it appears that the poly-D-lysine-protective capacity of certain chitotriose preparations was due not to the chitotriose itself but to contaminating metal ions which interact directly with the polycationic agent. In contrast, Fe(III) cannot account for inhibition of either the bactericidal or bacteriolytic activity of lysozyme by chitotriose.     

Cutaneous herpetic infections complicating burns

Many people harbor herpes simplex virus, often with a known history of "cold sores". During the relatively immunosuppressed state associated with a serious burn, recrudescence of such infections can occur. We report four adults and two children who developed severe herpetic ulceration, over the face and neck in five patients and in a partial thickness wound in one patient. Herpetic infection was diagnosed by culture and direct immunofluorescence testing and treatment was immediately instituted with systemic and topical Acylovir(R) (Zovirax, Glaxo Wellcome). Ulceration healed under treatment and did not leave visible scarring in any of the patients. Although these infections are rapidly progressive, they respond to prompt treatment with antiviral chemotherapy. Rapidly progressive vesicles and ulceration appearing on the face or in the wounds of burn patients should prompt immediate evaluation for herpetic infection.     

Phenotypic diversity in siblings with partial androgen insensitivity syndrome

The androgen insensitivity syndrome is a heterogeneous disorder with a wide spectrum of phenotypic abnormalities, ranging from complete female to ambiguous forms that more closely resemble males. The primary abnormality is a defective androgen receptor protein due to a mutation of the androgen receptor gene. This prevents normal androgen action and thus leads to impaired virilisation. A point mutation of the androgen receptor gene affecting two siblings with partial androgen insensitivity syndrome is described. One had cliteromegaly and labial fusion and was raised as a girl, whereas the other sibling had micropenis and penoscrotal hypospadias and was raised as a boy. Both were shown to have the arginine 840 to cysteine mutation. The phenotypic variation in this family is thus dependent on factors other than abnormalities of the androgen receptor gene alone.     

Actuarial survival in the premature infant less than 30 weeks' gestation

OBJECTIVE: Because survival from admission to discharge does not provide parents and physicians information about future life expectancy in the premature neonate, we characterized the actuarial survival, defined as the future life expectancy from a given postnatal age, in a large inborn population of premature infants < 30 weeks' gestation. STUDY DESIGN: We determined daily actuarial survival of 1925 inborn infants (23 to 29 weeks' gestation) admitted to the Baylor Affiliated Nurseries from July 1986 through December 1994, stratified by 100-g birth weight and by 1-week gestational-age intervals. RESULTS: In the 501- to 600-g birth weight stratum, actuarial survival improved from 31% at birth, to 61% on day of life 7, and then to 75% on day of life 28; in the 901- to 1000-g birth weight stratum, actuarial survival improved from 88%, to 94%, and then to 98% throughout the same times, respectively. Similar trends were obtained when data were stratified by gestational age. CONCLUSIONS: Survival in the smallest infants improves dramatically during the first few days of life, but there is a significant risk for late death in the smallest of these infants.