Human infestation with bird mites in Wollongong.

This is a report of a case of bird mite infestation which occurred in Wollongong in mid-December 1996. The individual suffered hundreds of bites, most of which were marked by itchy red papules 3-4 mm in diameter. Tiny mobile parasites (< 1 mm) collected from the skin and adjacent bedroom wall were identified as bird mites from the family Gamasidae, most probably from the genus Ornithonyssus. The source of the infestation was a starling nest under the eaves adjacent to the bedroom. The report summarises the ways bird mite bites can be distinguished from other insect and arachnid bites. If bird mite infestation is not correctly diagnosed, families who attempt to repeatedly treat it as if it were lice or scabies may incur considerable expense until the source of infestation is eliminated.     

An inexpensive, self-assembly pressure algometer

We have developed a simple instrument for pressure algometry. It can be made easily using components found in most anaesthetic rooms. Ten students were able to make the device using written instructions. All the resulting algometers performed within 10% accuracy limits for values up to 4 kgcm⁻².     

Effects of Repeated Deep Inspirations on Recovery from Methacholine-Induced Airway Narrowing in Normal Subjects

Background. A single deep inspiration (DI) is known to be a potent bronchodilator but it is not known if repeated DI can accelerate sustained recovery from bronchoconstriction. Methods. We induced sustained bronchoconstriction using increasing concentrations of nebulized methacholine (Mch) during tidal breathing and assessed airway narrowing by measuring respiratory resistance (Rrs) using forced oscillation in six healthy subjects. On separate days we examined the effects of DI every 3 minutes and of prohibition of DI on recovery of Rrs for 30 minutes after the end of Mch nebulization. Results. Bronchoconstriction (Rrs ∼ 150% above baseline) was induced. DI during recovery had a transient bronchodilator effect but no cumulative effect. At 30 minutes after end of nebulization (and 2 minutes after the last DI) Rrs was 87% above baseline compared to 93% above baseline when DI was prohibited. Conclusion. Recovery from induced bronchoconstriction with methacholine was slow (∼ 2%/min) and not accelerated by frequent DI.     

Cultured human granulosa cells as a model for corpus luteum function: relative roles of gonadotrophin and low density lipoprotein studied under defined culture conditions.

In primates, corpus luteum development involves both gonadotrophin stimulation and exposure to low density lipoprotein (LDL) delivered through vascularization of the granulosa cell-derived layer. These regulatory influences were modelled in vitro using granulosa cells obtained during in-vitro fertilization (IVF) cycles controlled with gonadotrophin releasing hormone (GnRH) analogue, human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG). Granulosa cells were cultured in defined medium on extracellular matrix. Without gonadotrophin or LDL in the medium, progesterone production declined progressively. With LDL alone, there was a short-lived elevation of progesterone output which subsequently declined. Culture with HCG alone resulted in a relatively unchanged rate of steroid production over 5 days despite morphological development. This contrasted with a marked and sustained increase in progesterone output over the same time when granulosa cells were cultured with combined HCG/LDL. Cultures were challenged with combined HCG/LDL on day 5. Where initial incubation included HCG, the challenge resulted in a recovery of progesterone output to values comparable to those of granulosa cells exposed to continuous HCG/LDL. Initial incubation without gonadotrophin led to a reduced response. Results suggest that LDL delivery to granulosa cells of the early corpus luteum causes a short-lived period of progesterone production. Sustained luteinization of granulosa cells and maintenance of gonadotrophin responsiveness requires continued exposure to gonadotrophin in the luteal phase.     

Identification of Alcohol Abuse and Alcoholism with Biological Parameters

The prevalence and incidence of heavy alcohol consumption are major problems which have been increasing in many countries in recent years. It is crucial for physicians to consistently identify early drinking problems as well as the various end disease states in order to minimize suffering and maximize recovery. This paper reviews the evolutionary development of clinical tools for detection of alcohol abuse. The focus is primarily on clinical/biochemical indicators of alcohol abuse, emphasizing but not limited to changes in hematological characteristics, liver enzyme activity, lipids, immune function factors, hormones, neurological factors, and some physically based tests. Use of test combinations and sophisticated statistical analysis of pattern changes in test batteries evidence increased diagnostic efficiency.     

Hyperglycemia reduces the extent of cerebral infarction in rats

Although hyperglycemia is known to exacerbate neuronal injury in the setting of reversible brain ischemia, its effect on irreversible thrombotic infarction is less well understood. In this study, unilateral thrombotic infarction was induced photochemically in the parietal cortex of Wistar rats. Seven days later, brains were perfusion-fixed for light microscopy. Infarct areas were measured by computer-assisted planimetry on multiple coronal sections at 250-micron intervals; these data were integrated to yield infarct volumes. Fasted, normoglycemic rats were compared with hyperglycemic rats that had received 1.2-1.5 ml of 50% dextrose i.p. 15 minutes prior to the induction of infarction. Infarct volume averaged 12.5 +/- 4.0 mm3 (mean +/- SD) in rats (n = 14) with plasma glucose levels of 72-184 mg/dl; this differed statistically from the average volume of 9.3 +/- 3.3 mm3 observed in rats (n = 13) with elevated plasma glucose (range 264-607 mg/dl). Spearman rank correlation analysis confirmed a significant correlation of larger infarct volumes with lower plasma glucose levels. In contrast, rats receiving mannitol i.p. to produce an osmotic load comparable with that of the dextrose-pretreated animals showed larger infarct volumes than saline-treated controls. The small but definite beneficial effect of hyperglycemia in this end-arteriolar thrombotic infarction model is possibly attributable to improved local energy metabolism at the periphery of the lesion during the early period of lesion expansion.