Low-temperature storage of bone marrow in nitrogen vapor-phase refrigerators: decreased temperature gradients with an aluminum racking system

Large temperature gradients may exist in nitrogen vapor-phase refrigerators. Cryopreserved cells stored at higher levels may be considerably warmer than those stored closer to the liquid nitrogen reservoir. To decrease this temperature gradient, racking systems constructed of aluminum were placed in marrow storage refrigerators. The higher heat conductivity of aluminum resulted in a vapor-phase temperature gradient of only 5.9 degrees C at 22.5 inches above the liquid, as compared to the gradient of 86 degrees C seen with steel frames in a similar refrigerator. Temperature fluxes were minimal with lid opening or nitrogen filling. The thicker frame size and loss of the lowest storage level resulted in a storage capacity 63 percent of that achievable with steel frames and liquid immersion. Consumption of nitrogen was estimated to be 174 to 220 percent of the static usage in this model of refrigerator with 6 inches of nitrogen, but comparable to the consumption expected with full immersion of the racking system, regardless of frame construction. These data demonstrate the feasibility of achieving very low, stable, cryogenic temperatures in a vapor-phase refrigerator.     

Clostridium difficile after haemolytic uraemic syndrome

Six children are described who developed diarrhoea associated with Clostridium difficile during the course of haemolytic uraemic syndrome. The significance of this infection is discussed within the context of the pathophysiology of haemolytic uraemic syndrome.     

Cardiovascular and thermal responses evoked from the periaqueductal grey require neuronal activity in the hypothalamus

Stimulation of neurons in the lateral/dorsolateral periaqueductal grey (l/dlPAG) produces increases in heart rate (HR) and mean arterial pressure (MAP) that are, according to traditional views, mediated through projections to medullary autonomic centres and independent of forebrain mechanisms. Recent studies in rats suggest that neurons in the l/dlPAG are downstream effectors responsible for responses evoked from the dorsomedial hypothalamus (DMH) from which similar cardiovascular changes and increase in core body temperature ( T _co) can be elicited. We hypothesized that, instead, autonomic effects evoked from the l/dlPAG depend on neuronal activity in the DMH. Thus, we examined the effect of microinjection of the neuronal inhibitor muscimol into the DMH on increases in HR, MAP and T _co produced by microinjection of N -methyl- d -aspartate (NMDA) into the l/dlPAG in conscious rats. Microinjection of muscimol alone modestly decreased baseline HR and MAP but failed to alter T _co. Microinjection of NMDA into the l/dlPAG caused marked increases in all three variables, and these were virtually abolished by prior injection of muscimol into the DMH. Similar microinjection of glutamate receptor antagonists into the DMH also suppressed increases in HR and abolished increases in T _co evoked from the PAG. In contrast, microinjection of muscimol into the hypothalamic paraventricular nucleus failed to reduce changes evoked from the PAG and actually enhanced the increase in T _co. Thus, our data suggest that increases in HR, MAP and T _co evoked from the l/dlPAG require neuronal activity in the DMH, challenging traditional views of the place of the PAG in central autonomic neural circuitry.     

A study of the knowledge and attitude towards pulse polio immunization in semi urban areas of South India

Background

The government of India launched the pulse polio immunization (PPI) programme in 1995 with the aim of eradicating poliomyelitis by the end of 2000. Despite this, 733 children with polio were reported in 2009 alone. Therefore, there is a need to understand the reason underlying such high numbers of cases after so many years of programme implementation. This study was performed to assess the knowledge of the general population about poliomyelitis and PPI and their attitude and practice towards PPI.

Method

This cross-sectional study was undertaken in two semi- urban areas of Mangalore city. Only houses in which children under five lived were included in the study. Data was collected by interviewing any adult member of the household using a pretested questionnaire.

Results

The literacy rate of study participants was 99%. Only 35(10.9%) participants knew the correct mode of transmission of polio. More than one quarter of the study population were under the misconception that polio is a curable disease. The primary source of information about PPI in majority of participants was the television (n = 192; 60%). Two-hundred and eighty eight (90%) participants knew that the purpose of PPI was to eradicate polio. Only 128 (40%) participants knew that polio drops can be given to children with mild illnesses and an identical number of participants knew that hot food stuff should not be given for at least half an hour following vaccination administration. Misconceptions such as PPI causing vaccine overdose was identified among 7 (2.2%) participants, it is a substitute for routine immunization was believed among 30 (9.4%) participants and that oral polio vaccine prevents other diseases was seen among 76 (23.7%) participants. The educational status of the participants was significantly associated with their awareness level (χ² =13.668, DF=6, P=0.033).

Conclusion

This study identified a few important misconceptions associated with polio and PPI which need to be addressed by large scale awareness campaigns in order to achieve polio eradication in the near future.     

Custom-Designed Wells and Flow Chamber for Exposing Air–Liquid Interface Cultures to Wall Shear Stress

The effects of mechanical stimuli such as wall shear stresses (WSS) on cellular processes have been studied in vitro in numerous cell types. In order to study WSS effects on cells cultured under air–liquid interface (ALI) conditions, we developed a custom-designed well that can be disassembled into sub-units that allow installation of the cultured cells in a flow chamber, and then, re-assembled for further incubation or biological tests. Human nasal epithelial cells were cultured in the new wells under ALI conditions, and some of their biological characteristics were compared with those cultured in commercial Millicells. The cultured cells from both types of wells secreted the same amount of mucin and had similar cytoskeletal structures. Preliminary WSS experiments demonstrated the advantage of the new wells and provided initial indications that WSS affects the performance of ALI cultured respiratory epithelial cells.     

Learned self-control of tinnitus through a matching-to-sample feedback technique: A clinical investigation

Two cases are reported in which subjective tinnitus aurium was treated with a matching-to-sample procedure. Following baseline evaluations, the subjects' experienced tinnitus was reproduced audiometrically in terms of loudness, frequency, and quality. This was presented to them in the noninvolved ear and was gradually reduced within sessions. The subjects were required to concentrate on reducing their tinnitus until an equal match had been achieved between it and the stimulus sound at each new decibel level. Both subjects gained control over their tinnitus and were able to reduce it markedly from baseline levels. This procedure is viewed as an advance over other techniques not only in that it significantly reduces the tinnitus but in the fact that it is done through the subject's own control, providing psychological benefit as well.This study was conducted under the joint auspices of the Psychology Service and the Speech Pathology and Audiology Service, Department of Rehabilitation Medicine, Goldwater Memorial Hospital.