Immediate effects of spinal manipulation on thermal pain sensitivity: an experimental study

Background  

The underlying causes of spinal manipulation hypoalgesia are largely unknown. The beneficial clinical effects were originally theorized to be due to biomechanical changes, but recent research has suggested spinal manipulation may have a direct neurophysiological effect on pain perception through dorsal horn inhibition. This study added to this literature by investigating whether spinal manipulation hypoalgesia was: a) local to anatomical areas innervated by the lumbar spine; b) correlated with psychological variables; c) greater than hypoalgesia from physical activity; and d) different for A-delta and C-fiber mediated pain perception.     

Nerve growth factor and tyrosine kinase A in human salivary adenoid cystic carcinoma: expression patterns and effects on in vitro invasive behavior.

PURPOSE: Perineural invasion is a frequent occurrence in salivary adenoid cystic carcinoma (ACC) and may prevent complete surgical resection. Studies have indicated that nerve growth factor (NGF) and its high-affinity receptor tyrosine kinase A (TrkA) may play a role in perineural invasion in several malignancies in which perineural invasion is observed. The present study was conducted to investigate the expression of NGF and TrkA in salivary ACC and to examine the effects of NGF on adhesion, migration and invasion capacities of a salivary ACC cell line (SACC-83) in vitro. PATIENTS AND METHODS: Expression of NGF and TrkA was explored using immunohistochemistry in paraffin-embedded tissues of 32 cases of salivary ACC. The effects of NGF on in vitro adhesion, migration, and invasion capacities of the SACC-83 cell line were examined using an MTT assay and a modified Boyden chamber assay respectively. RESULTS: In ACC specimens, 31 (96.9%) and 32 (100%) tumors showed immunoreactivity for NGF and TrkA respectively. Significant correlations were found between NGF/TrkA expression levels and perineural invasion (P < .05). In cell adhesion assay, the percent adherences of SACC-83 cells co-cultured with 25 ng/ml NGF at 1.5 hours and 5, 25 ng/ml NGF at 6 hours were significantly higher than that co-cultured with 0 ng/ml NGF (P < .05). However, high concentration of NGF (500 ng/ml) resulted in a significant inhibition of invasion (P < .05). CONCLUSION: Overexpression of NGF and TrkA in human salivary ACC tissues may constitute a reason for perineural invasion in salivary ACC.     

The effect of cephalothin prophylaxis on postoperative ventriculoperitoneal shunt infections.

Postoperative infection is an important complication after insertion of a ventriculoperitoneal (VP) shunt in children with hydrocephalus. A randomized double-blind placebo-controlled study was performed to determine the efficacy of cephalothin in preventing postoperative shunt infection. Sixty-three children who presented for elective VP shunt insertion between January 1982 and December 1985 and who did not have a history of shunt infections were randomly assigned to receive four doses of prophylactic cephalothin, 25 mg/kg (32 patients), or of a multivitamin placebo (31 patients). Postoperative infection developed in 6% of the treatment group, compared with 10% of the placebo group, a difference that was not statistically significant, although a clinical significance may have been masked by the small sample size. A large multicentre trial is needed to determine the efficacy of antibiotic prophylaxis in reducing the incidence of postoperative VP shunt infections.     

Alcohol consumption of patients attending two accident and emergency departments in north-west England.

The impact of alcohol use on the workload of two accident & emergency departments in north-west England was assessed by blood alcohol concentration (BAC) measurement, inspection of clinical records and interview of all patients aged 16 and over attending throughout a two-week period. The frequency of intoxication was similar to the previous reported rate in Scotland: 13.2% of all patients had a positive BAC. Inebriated injured patients arrived at all times of the day--varying in frequency from 2.5% of midday attenders to 78% of those presenting after midnight. The incidence of alcohol-related industrial accidents was low, but 60% of all assaulted patients were inebriated, many having sustained head injuries. Of patients attending within 2 hours of an accident at home, 19% also had a positive BAC, but 92% of those with ankle sprains were sober. Patients in lower social classes reported higher rates of alcohol consumption. The popularity of beer in comparison to wines and spirits was inversely related to age and unrelated to social class. Alcohol abuse is commonly associated with injuries sustained at home and with assaults occurring in public places. Prevention campaigns directed at the reduction of these types of incidents should be as concerned with the inebriation of the patient as with the architectural, environmental and legal framework within which the 'accident' occurs.     

The development of a surveillance system to monitor emergency food relief in New York State.

A representative sample of emergency food relief (EFR) programs was selected on the basis of a census of 1,488 EFR programs in New York State. The census was a two-stage telephone survey. EFR was provided in every county although there was considerable variation in the amount of EFR per county. The soup kitchen and food pantry components of EFR had to be differentiated. The surveillance system was operational one year after the census began.     

Health hazards associated with windsurfing on polluted water.

We documented the risks associated with windsurfing on sewage polluted water. Seventy-nine windsurfers and 41 controls were studied over a nine-day period for occurrence of symptoms of gastroenteritis, otitis, conjunctivitis, and skin infection. Relative risks were 2.9 for occurrence of one or more of these symptoms and 5.5 for symptoms of gastroenteritis. Relative risk increased with the reported number of falls into the water.     

Plasma volume in fasted pregnant rats

The effect of a two day fast on maternal plasma volume and plasma protein concentration was explored in pregnant rats. Fasting between days 17 and 19 of gestation prevented the rise in plasma volume observed in ad libitum fed rats. Plasma protein concentration declined between day 17 and day 19 in both fasted and not fasted rats. Placental weight was not reduced by fasting during this stage of gestation. Fetal weight in the fasted group was 91% of the fetal weight of the ad libitum fed group. These results show that acute undernutrition, like longer term food or protein restriction, can prevent adequate plasma volume expansion and slow fetal growth.     

Interrelations between substrate cycles and de novo synthesis of pyrimidine deoxyribonucleoside triphosphates in 3T6 cells.

Degradation of pyrimidine deoxyribonucleoside triphosphates plays a major role in the regulation of their pool sizes in 3T6 cells. During normal growth, these cells excrete deoxyribonucleosides (mostly deoxyuridine) into the medium. When DNA strand elongation is inhibited, de novo synthesis of dCTP and dTTP continues, followed by degradation of the deoxyribonucleotides. We now demonstrate that inhibition of de novo synthesis with hydroxyurea stops degradation of deoxyribonucleotides. We now demonstrate that inhibition of de novo synthesis with hydroxyurea stops degradation of deoxyribonucleotides and leads to an influx of deoxyuridine from the medium. This effect appears to be caused by a large drop in the size of the intracellular dUMP pool. We propose that substrate cycles, involving phosphorylation of deoxyribonucleosides by kinases and dephosphorylation of deoxyribonucleoside 5'-phosphates by a nucleotidase, participate in the regulation of the size of pyrimidine deoxyribonucleoside triphosphate pools by directing the flow of deoxyribonucleosides across the cell membrane. While kinases are regulated mainly by allosteric effects, the activity of the nucleotidase appears to be regulated by substrate concentration.