A mechanism of peripheral spread or localization of inflammatory reactions--role of the localized ground substance adaptive phenomenon

It is known that connective tissue-active peptides (CTAP) are released at sites of inflammation. Some of this material diffuses to immediately adjacent tissue and increases ground substance viscosity and fibroblast proliferation. This contributes to host protection against spread of infections and tumors. In a person with normal inflammatory reactivity, it should prevent spread of mediators and products of local inflammation. However, the host with an increased reactivity in sites of increased ground substance viscosity or who is highly reactive to dilution of tissue fluid would respond with more inflammation. A non-infectious, non-malignant process in a host with a highly reactive inflammatory or immune response could end up with peripheral spread. This could occur in any tissue but it occurs with great vigor in the skin. It could present as a peripheral extension of a local disease process, such as psoriasis, or the migration of cyclic lesions with clearing of the central area. There are over a dozen variants of peripherally spreading, ringed lesions described in the dermatologic literature. This includes erythema marginatum of rheumatic fever, erythema gyratum repens associated with cancer, and erythema annulare centrificum associated with allergic reactions to fungi. Many of the ringed dermatologic lesions have an immunologic component. They tend to be associated with inflammatory immune reactions at distant sites. Dermatologists have been gathering information on the ringed phenomenon at least since Hebra in 1854. The acute localized ground substance adaptive phenomenon is a broadly beneficial biologic response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Psoas abscess in chronic dialysis patients

We report 4 cases of nontuberculous psoas abscess occurring in patients with end stage renal disease. Fever and pain were the presenting symptoms but diagnosis was delayed. A computerized tomography scan of the abdomen was the critical test that led to the correct diagnosis. Therapy involved drainage and antibiotics, and was successful in 3 of the 4 patients.     

Peripheral nerve injuries in the adult with traumatic brain injury

Fifty adult patients who sustained a traumatic brain injury (TBI) were screened for the presence of a peripheral nerve injury (PNI). All suspected patients had diagnostic electromyography performed in order to confirm the clinical findings. The incidence of PNI with TBI was 34%. A variety of nerve injuries were seen, the most frequent of which were ulnar nerve entrapment at the elbow (10%) and brachial plexus injuries (10%). No patient initiated a complaint that led to the diagnosis. In addition, all the neuropathies were missed prior to admission. The neuropathies commonly were found in the neurologically impaired extremity and associated with spasticity. The results of this study suggest that patients sustaining a TBI have a significant and higher incidence of PNI as a complication than previously reported.     

Electroencephalography in acute head injury

The established uses of standard and computerized EEG in acute head injury are outlined. Emphasis is placed on EEG correlation with level of consciousness, rostrocaudal deterioration, brainstem lesions, and prognosis. The utility of the standard EEG in seizures and toxic metabolic states accompanying severe head injury is also discussed.     

Evaluation of the mass balance assumption with respect to the two-resistance model of intestinal absorption by using in situ single-pass intestinal perfusion of theophylline in rats.

Methods of analyzing drug absorption data from rat intestinal-perfusion experiments are discussed in terms of mass-transfer resistances, or reciprocal permeabilities, and mass balances. Typically, a two-resistance model is used to determine the dimensionless effective permeability (P*eff) by measuring the disappearance of drug from the perfusing solution. Unstated assumptions in two-resistance models are (1) the portal blood is under sink conditions and (2) complete transfer of drug occurs from the intestinal perfusate to the portal vein. The assumption of sink conditions is generally acceptable, because the drug concentration in portal blood is approximately two orders of magnitude less than in the perfusate. Single-pass intestinal-perfusion experiments were performed on rats with theophylline as a model compound. The drug mass leaving the intestinal perfusate was substantially less than the drug mass appearing in the portal plasma; that is, the assumption of complete transfer did not hold for theophylline in this experimental system. These data indicate that models based on the two-resistance theory can lead to overestimation of P*eff by the ratio of the drug mass leaving the perfusate to the drug mass appearing in the plasma. For compounds for which the assumption of complete transfer does not hold, a more accurate estimate of P*eff may be determined by dividing the value derived from perfusate data by the mass balance ratio (i.e., the drug mass leaving the perfusate divided by the drug mass appearing in the plasma).     

Evoked potentials in head injury and states of increased intracranial pressure

Recent clinical studies have addressed the utility of sensory evoked potentials (auditory, somatosensory, and visual) in head injury. The clinical significance of evoked potentials in head trauma, states of increased intracranial pressure, and post-traumatic syndrome is discussed. Emphasis is placed on up-to-date studies discussing evoked potential correlation with clinical findings, lesion localization, intracranial pressure, brain herniation, and prognosis.     

Ulnar neuropathy at the wrist associated with aberrant flexor carpi ulnaris insertion

A 36-year-old man who sustained an industrial hyperextension injury of the wrist complained of dysesthesia and pain in the ulnar nerve distribution, aggravated for months by wrist movement until exploration. The operation revealed an anomalous insertion of the flexor carpi ulnaris tendon disrupting a major portion of the ulnar nerve proximal to the pisiform. the symptoms were relieved completely after neurolysis and modification of the insertion of the tendon.     

Perturbation of copper (Cu) homeostasis and expression of Cu-binding proteins in cadmium-resistant lung fibroblasts.

To probe mechanisms of cadmium (Cd) damage to the lung extracellular matrix (ECM), we developed Cd-resistant (CdR) rat lung fibroblasts (RFL6) by incubation with graded concentrations of Cd. CdR cells downregulated lysyl oxidase (LO), a copper (Cu)-dependent enzyme essential for crosslinking of collagen and elastin in the ECM, in conjunction with upregulation of other Cu-binding proteins including Cu,Zn-superoxide dismutase (SOD1), copper chaperone for SOD1 (CCS1), metallothionein (MT), and Menkes P-type ATPase (ATP7A), a Cu transporter in the membrane of the Golgi apparatus, as well as gamma-glutamylcysteine synthetase (gamma-GCS), an enzyme for glutathione biosynthesis. Reduction and loss of cytoplasmic distribution of LO in CdR cells were accompanied by its dislocation with the Menkes P-type ATPase and the endoplasmic reticulum marker. CdR cells displayed a defect in LO catalytic activity but an enhancement in Cu,Zn-SOD catalytic activity consistent with the protein expression levels of these enzymes. Although long-term Cd exposure of cells enhanced the Menkes P-type ATPase protein expression, actually, it reduced Cu-dependent catalytic activity of this enzyme in parallel with the deficiency of LO. The low level of 64Cu bound to the LO fraction and the high level of 64Cu bound to the MT fraction provide direct evidence for limitation of Cu bioavailability for LO existing in the CdR cells. These results suggest that downregulation of LO is linked with upregulation of other Cu-binding proteins and with alteration in Cu homeostasis in the CdR phenotype.