Lowering cutoffs for initial and confirmation testing for cocaine and marijuana: large-scale study of effects on the rates of drug-positive results.

A large-scale study was conducted to determine whether lowering the initial testing and confirmation testing cutoffs in urine would significantly affect the positive rates for cocaine (COC) and marijuana (THC). Customary cutoffs for COC are 300 microg/L and 150 microg/L for initial testing (screening) and gas chromatography-mass spectrometry (GC-MS; confirmation), respectively; for THC, the usual respective cutoffs are 50 microg/L and 10 microg/L. By applying a screening cutoff of 100 microg/L for COC and lowering the GC-MS cutoff to 50 microg/L, the COC-positive rate increased from 1.2% to 2.1%. For THC, lowering the screening cutoff to 20 microg/L while leaving the GC-MS cutoff at 10 microg/L increased the THC-positive rate from 2.8% to 4.1%. These increases appear noteworthy.

Snake venom poisoning in the United States: a review of therapeutic practice.

Snake venom poisoning constitutes a medical emergency. It is a complex type of poisoning that not only affects the local bite site but may involve multiple organ systems as well. In the United States, poisonous snakes account for approximately 8,000 bites annually, resulting in about 9 to 15 fatalities. The majority of deaths occur in children, the elderly, and untreated or mistreated individuals. Pit vipers account for almost all bites. Diagnosis and treatment are based on clinical signs and symptoms of envenomation along with identification of the snake. First aid treatment should focus on transporting the victim to the nearest medical facility as soon as possible. Previously advocated first aid measures such as tourniquet, incision and suction, cryotherapy, and electric shock should be avoided. The mainstay of treatment for envenomation is the prompt administration of sufficient quantities of the appropriate antivenin.

A comparison of meconium, maternal urine and neonatal urine for detection of maternal drug use during pregnancy.

A large scale drug screening study was done to determine the prevalence of drug use in a large metropolitan, obstetric population. Meconium and first voided urine, as well as maternal urine were collected from 423 consecutive deliveries. Urine samples and methanolic extracts of meconium were initially screened by Enzyme Multiplied Immunoassay Technique (EMIT) and then confirmed by Gas Chromatography/Mass Spectrometry (GC/MS). Analysis of cocaine metabolite as benzoylecogonine, cannabinoid as carboxy-THC, codeine, morphine and methadone were included in the study. The positive rate for benzoylecgonine was virtually identical for meconium, maternal urine and neonatal urine (12%). Analysis of meconium was found to be more reliable than analysis of maternal or neonatal urine for the detection of benzoylecgonine. Meconium did not appear to offer an advantage over maternal or neonatal urine for detection of cannabinoid, codeine, morphine, or methadone.

What happens to babies exposed to phencyclidine (PCP) in utero?

Fifty-seven infants exposed to phencyclidine (PCP) in utero were followed for the first year of life. Thirty-six (65%) of the 55 for whom birth records were available manifested symptoms of neonatal narcotic withdrawal syndrome, including 16 (52%) of those whose mothers denied opiate abuse during pregnancy. Temperament problems were noted in 47% of the babies and sleep problems in 14%. The majority of infants grew normally, but a larger than expected number started out small and remained small. Testing using the Bayley Scales of Infant Development at age one year revealed a mental development index (mean +/- SD) of 94 +/- 10 and a psychomotor development index of 98 +/- 10. Attachment behavior was abnormal in 17%. Most infants were cared for by their natural mother. Further studies are needed to determine later effects of in utero PCP exposure, as well as effects on the infants being raised by women who have used PCP. Phencyclidine toxicity needs to be considered when evaluating babies with signs of neonatal narcotic withdrawal syndrome.

Rattlesnake bites in southern California and rationale for recommended treatment.

Rattlesnake bite is most common in young men who often are intoxicated and have purposely handled a venomous snake. The incidence of bites is highest in the spring and early summer months, and they most often occur in the afternoon. The hands and feet only are involved in 95% of all bites. First-aid therapy should be limited to splinting the extremity and transporting the victim to a medical facility. Definitive therapy is administering antivenin (Crotalidae) polyvalent intravenously in adequate initial doses and repeating every two hours until the venom is completely neutralized. Serum sickness usually follows all doses of more than five vials but is readily controlled by giving corticosteroids. Bites are avoided by protecting the hands and feet, not handling venomous snakes, and using utmost caution while in the snakes' habitat.

Abnormal sleeping ventilatory pattern in infants of substance-abusing mothers.

Infants born to opiate-abusing mothers have a decreased ventilatory response to carbon dioxide and a five to ten times increased risk of sudden infant death syndrome (SIDS). These abnormalities of ventilatory control may be associated with abnormal sleeping ventilatory patterns. Therefore, 28 overnight pneumograms (respiratory pattern recording and electrocardiogram) were obtained from 27 infants of substance-abusing mothers (ISAM) (five opiate, seven phencyclidine hydrochloride, three cocaine, and 12 polydrug abusers) and compared with pneumograms from 43 control infants. Pneumograms were quantitated for total sleep time, greatest duration of apnea, total duration of apnea greater than or equal to 6 s, periodic breathing, and mean heart and respiratory rates. The ISAM had a longer total sleep time, greater durations of apnea, a higher total duration of apneas greater than or equal to 6 s, more periodic breathing, a higher mean respiratory rate, and a lower mean heart rate. Thirty-two percent of pneumograms from ISAM were abnormal compared with 9.3% of the control pneumograms. We conclude that ISAM have abnormal sleeping ventilatory patterns that may be related to their increased SIDS risk.

Differences between dropouts and active participants in a pediatric clinic for substance abuse mothers.

We compared the maternal and birth characteristics of 87 first-year dropouts with 103 active participants of a pediatric clinic which provides long-term follow-up care to offspring exposed in utero to substance abuse mothers. The age, ethnicity, and marital status of the mother; the type of drug used during pregnancy; and the length, gender, number, and type of addiction problems of the newborn were not significantly different between the two groups. However, the dropouts differed significantly from the active participants in many other aspects. More dropout mothers received no prenatal care and did not have children at home at the time of the present birth. More of them were smokers; had gonorrhea, heart, and kidney problems; and had infections complicating their pregnancy. The dropout newborns were found to have lower birthweight and shorter gestation. These clinical parameters defined a suboptimal group of mothers and children requiring more attention and care. The findings also alert investigators of long-term follow-up studies to be aware of basic differences between nonparticipants and participants.

Mucin biosynthesis. Properties of a bovine tracheal mucin beta-6-N-acetylglucosaminyltransferase.

We have characterized a bovine tracheal mucin beta-6-N-acetylglucosaminyltransferase that catalyses the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to the C-6 of the N-acetylgalactosamine residue of galactosyl-beta 1----3-N-acetylgalactosamine. Optimal enzyme activity was obtained between pH 7.5-8.5, at 5mM-MnCl2, and at 0.06-0.08% (v/v) Triton X-100 (or Nonidet P-40), or 0.5-5.0% (v/v) Tween 20. Ba2+, Mg2+ and Ca2+ could partially replace Mn2+, but Co2+, Fe2+, Cd2+ and Zn2+ could not. Sodium dodecyl sulphate, cetylpyridinium chloride, sodium deoxycholate, octyl beta-D-glucoside, digitonin and alkyl alcohols were less effective in enhancing enzyme activity, and dimethyl sulphoxide was ineffective. The apparent Michaelis constants were 1.25 mM for UDP-N-acetylglucosamine, 0.94-3.34 mM for freezing-point-depressing glycoprotein and 0.19 mM for periodate-treated blood-group-A porcine submaxillary mucin. Asialo ovine submaxillary mucin could not serve as the glycosyl acceptor. The structure of the 14C-labelled oligosaccharide obtained by alkaline-borohydride treatment of the product was identified as Gal beta 1----3(Glc-NAc beta 1----6)N-acetylgalactosaminitol by beta-hexosaminidase treatment, gas chromatography-mass spectrometry and 1H-n.m.r. (270 MHz) analysis. The enzyme is important in the regulation of mucin oligosaccharide biosynthesis.

Preparation of a new antivenin by affinity chromatography.

Polyacrylamide gel affinity chromatography was employed to isolate and purify antibodies to the antigens of the venoms of four rattlesnakes. The antivenins were studied for their neutralizing properties on a number of pharmacologic preparations. It was found that the purified antibodies (IgG) were more efficacious than the commercially prepared antivenin in neutralizing the lethal, cytolytic, hemorrhagic, platelet aggregating, and other deleterious effects of the venoms. In addition, the purified antibodies gave no evidence of producing anaphylaxis or anaphylactoid reactions in animals sensitized to horse serum. The proposed technique is also more simple than current production methods, is time-saving, and less expensive.

Medicated versus saline nose drops in the management of upper respiratory infection.

Seventy-four children from three weeks to two years of age with various upper respiratory symptoms were randomly assigned to three groups: two intervention groups (saline nose drops; medicated nose drops) and a control group (no nose drops). Forty-six children returned for check-up two days later. Subjects in all three groups improved between first and second contact. There was no significant difference between the three groups. It is concluded that medicated nose drops are not essential in the treatment of upper respiratory infection and rhinitis.

Mucin biosynthesis: characterization of rabbit small intestinal UDP-N-acetylglucosamine:galactose beta-3-N-acetylgalactosaminide (N-acetylglucosamine----N-acetylgalactosamine) beta-6-N-acetylglucosaminyltransferase.

We have characterized a UDP-GlcNAc:Gal beta-3-GalNAc (GlcNAc----GalNAc) beta-6-N-acetylglucosaminyltransferase from rabbit small intestinal epithelium by using freezing point depression glycoprotein as the acceptor. Optimal enzyme activity was obtained at pH 7.0-7.5, at 3 mM MnCl2, and at 0.08% Triton X-100. Ca2+, Mg2+, and Ba2+ also enhanced enzyme activity. The apparent Michaelis constant was 4.80 mM for freezing point depression glycoprotein, 0.59 mM for periodate-treated porcine submaxillary mucin, 0.49 mM for Gal beta 1----3 GalNAc alpha Ph, and 1.03 mM for UDP-GlcNAc. No enzyme activity was observed when asialo ovine submaxillary mucin was used as the acceptor. The 14C-labeled oligosaccharide obtained by alkaline borohydride treatment of the product was shown to be a homogeneous trisaccharide by compositional analysis, Bio-Gel P-4 gel filtration, and high-performance liquid chromatography. The structure of the trisaccharide was identified as Gal beta 1----3-(GlcNAc beta 1----6)GalNAc-H2 by (a) identification of 2,3,4,6-tetramethyl-1,5-diacetylgalactitol and 1,4,5-trimethyl-3,6-diacetyl-2-N-methylacetamidogalactitol by gas-liquid chromatography-mass spectrometry and (b) the complete cleavage of the newly formed glycosidic bond by jack bean beta-hexosaminidase. The structure of the trisaccharide was confirmed by 1H nuclear magnetic resonance (270 MHz) and also by periodate oxidation of the trisaccharide followed by NaBH4 reduction, 4 N HCl hydrolysis, a second NaBH4 reduction, and the identification of threosaminitol on an amino acid analyzer. By acceptor competition studies, the enzyme activity was shown to be a much N-acetylglucosaminyltransferase. We postulate that this glycosyltransferase may play a key role in the regulation of mucin oligosaccharide synthesis.

Prolonged defibrination after a bite from a 'nonvenomous' snake.

The distinction between venomous, potentially dangerous snakes and snakes considered to be harmless to humans is not always clear. A man was bitten by an assumed harmless pet snake, Rhabdophis subminatus (the red neck keelback), that had been obtained from a pet store. The patient experienced a severe coagulopathy with life-threatening hemorrhage unresponsive to transfusion. Since this snake frequently is sold legally in the United States, we wish to alert the medical community to its potential danger and to discuss the pathophysiological mechanism by which the coagulopathy was produced.

Attachment interaction behavior between young teenage mothers and their infants.

Behavioral interaction between teenage mothers and their infants was explored. Twenty-six (low income level) Hispanic teenage mothers (mean age 15 years) and their infants (mean age 13.5 months) were compared with an older control group of 30 mothers (mean age 26 years) and their infants (mean age 14.0 months). Infant attachment, exploration, and stress-adaptation behaviors and maternal ability to contact, encourage, and comfort the infant were evaluated. Twenty-six percent of the control infants showed limited ability to cope with stress compared to 47% of infants of teenage mothers. Control mothers differed significantly from teenage mothers in effective eye, verbal, physical contact, and smiling behaviors. These findings suggest that limited teenage maternal behaviors may potentially have a negative psychologic effect for both infants and their young mothers.

Infants with birth weight under 1500 g: physical, neurological, and developmental outcome.

One hundred and seventy-eight infants with birth weights less than or equal to 1500 g born in 1973-1975 were followed for a period of 1-3 years, and the physical, neurological, and developmental outcome evaluated. Although there was a high incidence of maternal problems, these did not correlate with outcome. Asphyxia at birth followed by neonatal complications leading to ventilatory assistance was significantly correlated with poor outcome. Over 50% of infants less than 100 g birth weight required assisted ventilation, but the outcome in small ventilated infants was comparable to that of ventilated infants of 1001-1500 g birth weight. Infants with neurological abnormality showed a high incidence of associated abnormalities in growth, vision, hearing, and development. Spastic quadriplegia emerged as the most common neurological diagnosis. Despite the many perinatal problems, 82% of the group were normal neurologically and 66% developmentally. The overall outcome was generally favorable in these infants even for those requiring ventilation.