Postmortem pink teeth phenomenon: an experimental study and a survey of the literature

The appearance of pink teeth after death is a phenomenon long familiar to forensic dentists. Although the application of modern techniques has shed some light on its aetiology, elucidation of the ultimate mechanism underlying the phenomenon is still awaited. In this paper, previous literature on the subject is surveyed, and an experimental approach under standardized conditions to allow analysis of possible causes and biological mechanisms of the pink-teeth phenomenon in rats is described. The experimental results were consistent with most previous observations. It seems probable that colouration of the teeth would be found in those regions of the jaws where the blood is seeking on the basis of gravitation hypostasis. The primary red colouration is most likely due to haemoglobin derivatives within the necrotic pulp tissue in cases in which blood has accumulated in the head and the dependent lividity (hypostasis) is obstructed. The authors discuss the likely causes for the development of the pink teeth phenomenon. It seems that this phenomenon is more dependent on physical than chemical factors after death.     

Effect of mattress and bed frame deflection on real chest compression depth measured with two CPR sensors

Aim

Implementation of chest compression (CC) feedback devices with a single force and deflection sensor (FDS) may improve the quality of CPR. However, CC depth may be overestimated if the patient is on a compliant surface. We have measured the true CC depth during in-hospital CPR using two FDSs on different bed and mattress types.

Methods

This prospective observational study was conducted at Tampere University Hospital between August 2011 and September 2012. During in-hospital CPR one FDS was placed between the rescuer's hand and the patient's chest, with the second attached to the backboard between the patient's back and the mattress. The real CC depth was calculated as the difference between the total depth from upper FDS to lower FDS.

Results

Ten cardiac arrests on three different bed and mattress types yielded 10,868 CCs for data analyses. The mean (SD) mattress/bed frame effect was 12.8 (4) mm on a standard hospital bed with a gel mattress, 12.4 (4) mm on an emergency room stretcher with a thin gel mattress and 14.1 (3) mm on an ICU bed with an emptied air mattress. The proportion of CCs with an adequate depth (≥50 mm) decreased on all mattress types after compensating for the mattress/bed frame effect from 94 to 64%, 98 to 76% and 91 to 17%, in standard hospital bed, emergency room stretcher and ICU bed, respectively (p < 0.001).

Conclusion

The use of FDS without real-time correction for deflection may result in CC depth not reaching the recommended depth of 50 mm.     

Chronic mumps virus encephalitis. Mumps antibody levels in cerebrospinal fluid

To study the outcome of mumps virus encephalitis 47 patients were contacted 1-15 years after the acute encephalitis associated with mumps virus infection. Twenty-three patients experienced clinical sequelae such as difficulties in memory and learning, focal motor or sensory signs, and loss of hearing and visual acuity. Lumbar puncture was performed on 8 patients. Antibodies to mumps virus were detected in 6 cerebrospinal fluid (CSF) specimens using enzyme immunoassay and in 3 patients an abnormal serum/CSF antibody ratio was observed 11, 26 and 58 (controls greater than 85); 14.3, 1.4 and 6.1 years after the acute encephalitis, respectively. Antibodies to other microbes were either undetectable in the CSF or the serum/CSF ratios were normal. The clinical sequelae in about half of the patients and the signs of intrathecal mumps antibody production are suggestive of a chronic process in the central nervous system after encephalitis associated with mumps virus infection.     

Effects of long-term occupational solvent exposure on contrast sensitivity and performance in visual search

Sensitive and easily applicable screening tests are greatly needed for the early detection of nervous system dysfunction in people working with neurotoxic substances. Previous studies have shown that long-term solvent exposure may cause deficits in visual perception. We, therefore, studied the effects of long-term occupational solvent exposure and chronic encephalopathy on performance in three vision tests novel in the present context. Two visual search tasks were used: the letter search test measured the speed of finding a letter in an array of numerals, and the pop-out search test required the observer to detect the presence or absence of a tilted line segment in an array of vertical line segments. With the letter contrast sensitivity test we measured the contrast threshold for the identification of band-pass filtered letters. Before testing, comprehensive eye examination was carried out to reveal any structural or functional abnormality and to ensure correct refraction. The patients had healthy eyes, 2 out of 14 had reduced contrast sensitivity (Vistech) and 5 out of 14 had deficits in colour vision (FM 100). In both visual search tasks, the patients were statistically highly significantly (p < 0.001) slower than the age-matched control observers. Instead, in the contrast sensitivity test, the difference between the patient and the control group was small relative to normal variability although still statistically significant (p < 0.05). The results suggest that visual search tests can be useful in evaluating and characterising the effects of long-term solvent exposure on visual perception. Because our patients’ letter contrast sensitivity was only moderately deteriorated, it seems that the observed defect of visual search cannot be explained by deteriorated letter identification alone, although it can be a contributory factor. Rather, the finding suggests that the speed by which visual information is transmitted and/or processed in the central visual system has become considerably slower.     

Long-Term Prognosis of Haemangioblastoma of the CNS: Impact of von Hippel-Lindau Disease

The aim was to assess the frequency of von Hippel-Lindau disease (VHL) and the long-term prognosis of VHL and non-VHL patients among 110 consecutive patients with haemangioblastoma (HB) of the CNS treated between 1953 and 1993 at one neurosurgical unit. To reveal VHL manifestations we performed a detailed clinical and radiological examination (neuraxis and abdomen) (61/110), VHL-gene mutation analysis (40/110), and collection of all available clinical, imaging, operative and autopsy data from the hospitals involved. All patients were followed-up with a median of 14 years (excluding 14 operative deaths), and no patient was lost to follow-up. Altogether 49 patients died during the follow-up. In the 14 VHL patients (13%), HB(s) of the CNS were detected at a median age of 33 years, retinal HB(s) at 39 years, and renal cell carcinoma (RCC) at 43 years. The frequency of VHL in patients operated on for HB(s) was 29% before the age of 25 years, 19% between 25 and 45 years, and only 2% after 45 years. HB patients not meeting the VHL criteria had internal organ cysts in 14%. One non-VHL patient (4%) had two adjacent HBs in the same cyst wall. The growth rates of non-VHL and VHL-related HBs were similar as indicated by the median time to recurrence and the proliferation indices (MIB-1). Recurrence of the HB in patients whose primary operation was considered radical developed in four of the 10 VHL patients at a median of 19 years, and in nine of the 74 non-VHL patients at a median of 11 years. The median length of life of all VHL and non-VHL patients was 46 and 63 years, respectively. In VHL, RCC and HBs were equal causes of death.