Studies on the venom of Oxyuranus microlepidotus

The Australian Small-scaled Snake, Oxyuranus microlepidotus , recently rediscovered, is the world's most venomous snake, with a murine LD50 of 0.01 mg/kg. Recently developed immunological techniques, combined with a whole animal model, have enabled us to measure accurately the mass of venom actually injected by a striking snake. The venom of this species contains at least six identified protein fractions, and one or more of these possesses potent neurotoxic action. An initial assessment of the molecular weights of each of these is reported. This study describes field biting experiments applicable to potential human snake-bite, and presents data concerning the injected venom:LD50 ratio which is an index of potential human lethality. This snake delivers an average mass of 17.3 mg in a strike, and the injected mass:LD50 ratio is 1730, the highest recorded for any snake. Comparative results for five other Elapidae whose venom contains potent neurotoxins are also presented. An average mass of 0.6 mg of venom is split on the skin surface during a strike, and 40% of this can be recovered within three hours after a simulated bite. As with other Elapidae studied to date, an adequate mass of venom remains on the skin for an accurate species diagnosis to be made in the case of human snake-bite.

Information control and the exercise of power in the obstetrical encounter

Interactions between doctor and patient involve participants with unequal power and possibly different interests. While a number of studies have focused upon the doctor/patient relationship, few have examined the utility of the concept of power and its capacity to help us understand the outcome of these interactions. The information sought by pregnant women from their obstetricians is used to provide a case study of one conceptualization and test of the utility of the concept of power. Pregnant women and their obstetricians are found to have different perceptions of the information that should be exchanged during their interactions. Women generally fail to obtain the information they want. Lower social class patients desire more and obtain less information than their higher status counterparts.

The use of antenatal tests of fetal welfare

The value of antenatal tests of fetal welfare is a constant source of controversy and confusion to obstetricians and general practitioners. The proliferation of such tests indicates that none is ideal and all are relatively imprecise.

The effect of differently worded no-smoking signs on smoking behavior

The effect of positively versus negatively worded no-smoking signs was investigated in an attempt to determine the effectiveness of controlling smoking in a hospital setting. Unobtrusive measurements of smoking behavior were taken in the main lobby before and after the placement of positively and negatively worded no-smoking signs. The results clearly showed that there was less smoking under the experimental sign condition. Positively worded signs appeared to produce better compliance than negatively worded signs.

Preparation of fingernails for trace element analysis

There are substantial differences in the reported elemental composition of human nails. Most investigators have used extensive washing procedures to minimize environmental contamination, however, such washing poses the risk of extraction of elements bound to the nail matrix. To determine if a portion of this variability could be accounted for by the "washing solutions" used by different investigators, nails were washed in nine solvents previously used for cleaning nails and their residual elemental composition measured by atomic absorption spectroscopy or energy dispersion analysis. In general, treatment with organic solvents resulted in less elemental loss than did treatment with aqueous detergents, while aqueous acids caused the greatest loss. Organic solvents more readily extracted iron and magnesium than calcium, copper and zinc. Virtually all of the magnesium was extracted by distilled water or aqueous detergents.

First-aid for snake-bite: efficacy of a constrictive bandage with limb immobilization in the management of human envenomation

A herpetologist was bitten on the thumb by a common brown snake (Pseudonaja textilis). A constrictive bandage to impede lymphatic and capillary flow was applied, and the upper limb was immobilized. Two hours after the bite, there were no signs of symptoms of envenomation and venom (to a sensitivity of 0.5 ng/mL) was undetectable in serum and urine. Within five minutes of removal of the constrictive bandage, significant signs of envenomation developed, and serum and urine levels of venom rose significantly. The patient received two ampoules of brown-snake antivenom, and had recovered within six hours. No anaphylaxis of other allergic phenomena occurred, despite the fact that three other doses of antivenom had been administered in the preceding 36 months for prior elapid envenomation. By means of an experimental whole-mouse technique, and an enzyme-linked immunospecific assay (ELISA) system, the snake involved was shown to deliver 4.91 mg of venom in an average bite. A constrictive bandage properly applied to impede lymphatic and capillary flow, together with limb immobilization, is effective in the field management of human elapid envenomation.

Rethinking the military family syndrome

The author presents prospective data on 140 child and adolescent military dependents and 234 nonmilitary subjects to assess the validity of the "military family syndrome." The only significant diagnostic difference was that military dependents had a lesser prevalence of schizophrenia and schizophreniform psychosis; the few environmental differences did not consistently favor either group. The author concludes that if the military family syndrome exists at all, its effects are more subtle and its causes are less obvious than has been previously stated.

Effects of the herbicide paraquat dichloride on bacteria of human origin

We have found the inhibitory and bactericidal concentrations of paraquat for bacteria of human origin are above levels likely to be often encountered environmentally.

Kinetics of DNA replication in a dicentric X chromosome formed by long arm to long arm fusion

Utilizing the 5-bromo-deoxyuridine (BrdU) incorporation technique, we have recently studied the DNA replication kinetics in a dicentric X chromosome, formed by long arm-to-long arm fusion at band q23, for a 16-year-old black female with primary amenorrhea. The patient has a karyotype 45,X/46,X,dic(X)(q23). In the buccal smear the presence of X chromatin was found in 33% of the cells examined. The Barr bodies are large and 21% of them are bipartite. DNA replication studies were performed on the patient's lymphocytes by the thymidine pulse (T-pulse) method and confirmed comparatively by the BrdU pulse (B-pulse) method. The results indicate that the dicentric X chromosome is always late-replicating. The replication pattern is symmetric on both sides of the breakpoint and the replication sequence is, in order, p11, p22, q1(1-3), q22, q23, p21, and q21. This finding is comparable to those of other investigators and supports the theory that there exist two inactivation centers in the dicentric X chromosome, located on or near the q21 band.

Poor antenatal attendance and obstetric performance

A survey of attendance for antenatal care at a public hospital in Brisbane was carried out. "Poor attenders" were more likely to be young, unmarried, grande multiparous, or aboriginal, and to live in a poorer area of the City. This group comprised 6.5% of the total population, but accounted for 14.6% of all low Apgar scores, 23% of all low birth weight babies, 23.1% of all stillbirths, and 18.2% of all neonatal deaths.

Digitalis and myocardial infarction in man

The use of digitalis after acute myocardial infarction is controversial. The effect of digoxin on computer-quantitated thallium-201 perfusion scintigrams (Tl-201), left ventricular (LV) ejection fraction (EF), and percentage of abnormally contracting LV regions (% ACR) was determined in 23 patients. A correlation was established between creatine kinase MB isoenzyme release and initial radionuclide-gated blood pool wall motion estimates of EF (r = -0.73) and % ACR (r = 0.71). After radionuclide assessments, 14 patients received digoxin 18 +/- 23 hours (mean +/- SD) after the rise in CK-MB from baseline, while the remaining nine patients served as controls. In the control group, the mean EF was 0.33 +/- 0.12 on the first study and 0.30 +/- 0.08 on the second study (p = NS). In the digoxin group, the EF after digoxin administration (mean 0.33 +/- 0.11) was significantly different from the initial EF (mean 0.29 +/- 0.09, p less than 0.03); however, digoxin had no apparent effect on infarct size as assessed by sequential % ACR and Tl-201 perfusion data. These data indicate that digoxin resulted in a minimal but significant improvement in EF that did not occur at the expense of LV perfusion or regional wall motion.

Obstetric practice amongst Queensland general practitioners: a survey of needs and attitudes

A survey of Queensland general practitioners was carried out to assess their needs and attitudes regarding obstetric practice. Less than half of the respondents now practise obstetrics, and many general practitioners felt a lack of support from specialist obstetricians, paediatricians, and anaesthetists. Many of the respondents expressed needs for further obstetric training, especially in labour ward management and neonatal care; however, few were able to attend extended courses.

Adult psychiatric disorders in parents of hyperactive children

The family histories of 140 children and adolescents with hyperactive child syndrome were compared with the family histories of 91 psychiatrically ill, age- and sex-matched patients who had a primary diagnosis other than hyperactive child syndrome. Parents of hyperactive children were more likely to have antisocial personality and Briquet's syndrome (hysteria) than were parents of nonhyperactive children; 11% of the hyperactive children had a parent with such a diagnosis. Parents of nonhyperactive children were more likely to have endogenous psychosis. The diagnosis of alcoholism did not significantly differentiate parents of the two groups of probands. These data support earlier studies and suggest a specific association between hyperactive child syndrome and the personality disorders of antisocial personality and hysteria.

Classical caesarean section in preterm deliveries

A series of 14 classical Caesarean sections is reported, and the place of operation in certain preterm deliveries is discussed.

Aspiration after overdosage of sedative or hypnotic drugs

We have reviewed the charts of 329 patients admitted to our hospital because of overdosage from sedative or hypnotic agents. Of this population 11.2% were believed to have aspirated. Included in this group were 13 patients who were observed to aspirate and 24 who were suspected of aspiration because of the appearance of radiographic infiltrates associated with compatible microbiologic studies. In the observed group, seven became febrile, four were hypotensive, eight had radiographic infiltrates, three had complications, and one died. In the group suspected of aspiration, 23 became febrile, ten became hypotensive, five had complications, and none died. We believe the low mortality from aspiration in this setting justifies caution in the use of steroids and antibiotics.