Sexual precocity: sex incidence and aetiology

The aetiology of 197 girls and 16 boys presenting with sexual precocity was reviewed. Ninety one girls and four boys had central precocious puberty (M:F 23:1); a cause was identified in all the boys but in only six girls. All boys with precocious puberty need detailed investigation; in girls investigation should be based on clinical findings, particularly the consonance of puberty.     

Propofol and fentanyl anaesthesia for patients with low cardiac output state undergoing cardiac surgery: comparison with high-dose fentanyl anaesthesia

We have compared the haemodynamic effects of an infusion ofpropofol 8mg kg^–1 h^–1 followed by 4mg kg^–1h–1 and fentanyl 15µg kg^–1 (group 1) withmidazolam 3–6mg and fentanyl 60 µg kg^–1 (group2) in patients with a low cardiac output state undergoing cardiacsurgery. Heart rate was lower in group 1 throughout the periodbefore cardiopulmonary bypass. There were no significant differencesbetween the groups in other measured variables. Arterial pressuredecreased in both groups after induction, by 21% in group 1and 18% in group 2. Thermodilution assessment of right ventricularejection fraction was unchanged. Myocardial contractility wasnot affected adversely. Patients in group 1 who received aninfusion of propofol and a smaller dose of fentanyl awakenedsooner and the trachea was extubated earlier.     

Increased human erythrocyte sodium-Iithium countertransport in hyperlipidaemic patients may indicate increased membrane lipid fluidity

Abstract. Erythrocyte sodium-lithium countertransport (SLC) activity, membrane fluidity, plasma trigly-ceride and cholesterol were measured in hyperlipidaemic patients and normal subjects. Fluidity was assessed by the fluorescence anisotropy (inversely related to fluidity) of the probes 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1,4-trimethylammonium-3,5-hexatriene (TMA-DPH). In a second group of patients the maximum velocity (Vmax) and external sodium affinity constant (k_m) of SLC was also measured.
In the first group of patients, SLC activity was increased compared with the controls (0.279 ± 0.019 vs. 0.213 ± 0.013, P = 0.006) as was membrane fluidity in the deep hydrophobic regions (DPH anisotropy 0.211 ± 0.0007 vs. 0.215 ± 0.0011, P = 0.007). There was a strong correlation between SLC and DPH anisotropy (Rs= -0.72, P= < 0.001) which was due to the correlation between Vmax and DPH anisotropy (Rs=-0.90, P= < 0.001).
Increases in Vmax of SLC in hyperlipidaemic patients may be due to differences in lipid organisation in the deep hydrophobic regions of the membrane which may affect the turnover rate of the transporter.     

Reduction of sound levels with antinoise in MR imaging

A combination of active and passive techniques was used to reduce the sound levels in magnetic resonance imagers. These techniques were integrated into an existing audio system. Measurements of sound reduction varied with the protocol being used and averaged 9.9 dB with coaxial cabling and 14.2 dB with fiberoptic conduction of the feedback signal to a controller. Patient comfort and communication were improved.     

Infant botulism in Australia — a case report

ABSTRACT. The syndrome of infant botulism was first recognised in late 1975 and the majority of cases reported have been from the United States of America. One case has been reported from the United Kingdom and one from Canada.
A three-month-old male infant from Victoria, Australia presented with constipation, marked hypotonia, limb weakness, ptosis, facial weakness and inability to suck and swallow. These abnormalities resolved and he returned to normal over the ensuing months.
A diagnosis of infant botulism was confirmed after the isolation of Clostridium botulinum type B from the faeces.
Infant botulism has now been recognised in four different countries and it is likely than with increasing awareness of this striking clinical syndrome, more cases will be identified.     

Validation and reproducibility of computerised cell-viability analysis of tissue slices

Background

The identification of live cells using membrane integrity dyes has become a frequently used technique, especially with articular cartilage and chondrocytes in situ where tissue slices are used to assess cell recovery as a function of location. The development of a reproducible computerised method of cell evaluation would eliminate many variables associated with manual counting and significantly reduce the amount of time required to evaluate experimental results.

Methods

To validate a custom computerised counting program, intra-person and inter-person cell counts of nine human evaluators (three groups – unskilled, novice, and experienced) were compared with repeated pixel counts of the custom program on 15 digitised images (in triplicate) of chondrocytes in situ stained with fluorescent dyes.

Results

Results indicated increased reproducibility with increased experience within evaluators [Intraclass Correlation Coefficient (ICC) range = 0.67 (unskilled) to 0.99 (experienced)] and between evaluators [ICC = 0.47 (unskilled), 0.85 (novice), 0.93 (experienced)]. The computer program had perfect reproducibility (ICC = 1.0). There was a significant relationship between the average of the experienced evaluators results and the custom program results (ICC = 0.77).

Conclusions

This study demonstrated that increased experience in cell counting resulted in increased reproducibility both within and between human evaluators but confirmed that the computer program was the most reproducible. There was a good correlation between the intact cell recovery determined by the computer program and the experienced human evaluators. The results of this study showed that the computer counting program was a reproducible tool to evaluate intact cell recovery after use of membrane integrity dyes on chondrocytes in situ. This and the significant decrease in the time used to count the cells by the computer program advocate its use in future studies because it has significant advantages.

     

The maturation of respiratory patterns in normal full term infants during the first six postnatal months. I: Sleep states and respiratory variability.

ABSTRACT. Four term healthy infants had their respiratory pattern monitored during a 2-hour afternoon nap recording period at monthly intervals up to six months of age. The time spent asleep significantly decreased with a marked reduction in active sleep (66% to 10%) while maintaining one long epoch of quiet sleep (mean 31 mins). Mean breathing rate at one week was higher in active sleep than quiet sleep (47 vs 41 breaths/min.) and decreased by 6 months in both sleep states (31 breaths/min. in both). Variability of breathing rate at 1 week was significantly increased in active sleep compared to quiet sleep and both decreased by 6 months. These findings confirm a significant maturational change in the respiratory pattern and variability of normal infants in the afternoon nap from 1 to 6 months.