Control of oxygen affinity of hemoglobin in K562 cells induced by hemin

The oxygen affinity of hemoglobin in K562 cells induced by hemin and the relationship between levels of 2,3-diphosphoglycerate (2,3-DPG) and hemoglobin have been investigated. Absorption spectra of induced cells indicate that the hemoglobin is oxygenated; oxygen dissociation curves are symmetric, with a P50 of 20 +/- 0.9 mm Hg, Hill coefficient of 2.5, and a normal temperature dependence. The intracellular pH measured by phosphorus 31 nuclear magnetic resonance (NMR) was 7.3. The amount of 2,3-DPG was determined by an enzymatic method and by 31P NMR. The level of 2,3-DPG in uninduced K562 cells, containing 0.5 pg of hemoglobin per cell, was low (5 +/- 0.5 mumole/10(8) cells), but increased to 64 +/- 5 mumole/10(8) cells upon induction of hemoglobin accumulation (to a final level of 20 pg hemoglobin/cell). For several experiments, there was a closely coordinated relationship between 2,3-DPG and hemoglobin levels, at about 1:1 stoichiometry of the two molecules. The time course of induction of hemoglobin, and of 2,3-DPG levels, are very similar; both processes are reversible. These data suggest that induction of hemoglobin synthesis in K562 cells by hemin results in hemoglobin-containing cells with normal oxygenation properties and that 2,3-DPG and hemoglobin levels are coordinately controlled in these cells. Elucidation of the mechanism of this effect should be of importance in understanding the erythroid-like differentiation of these cells.

Axillary F central latency: simple electrodiagnostic technique for proximal neuropathy

A simple technique is described for measuring the F-wave conduction time of the proximal segment of peripheral nerves. This should prove helpful in the diagnosis of a proximal neuropathy or myelopathy. The F wave (Fw) and M response at the wrist (Mw) and the M response at the axilla (Ma) can be used to calculate the conduction time, defined as Axillary F Central Latency (AFCL), between the spinal cord and the axilla, covering a horizontal distance of 25cm twice. The calculated AFCL (AFCL = (Mw + Fw) - 2Ma) in our control group of 30 normal subjects was 11.2 +/- 0.8 msec (mean and 1 standard deviation) for the ulnar or median nerve. An AFCL of more than 13.6 msec (mean plus 3SD), or a discrepancy of the AFCL greater than 2.1 msec in the same nerves between the 2 sides or between the median and ulnar nerves on the same side suggests an abnormality involving the proximal nerve segment. The prolonged AFCL has been found in patients with Guillain-Barré syndrome (GBS), brachial plexus lesions, syringomyelia and, in a few cases, with thoracic outlet syndrome (TOS).

Long-term intermittent catheterization in the spinal cord injury patient

Intermittent catheterization was used as a means of long-term bladder management in 85 patients with spinal cord injury. Of these patients followup data revealed that 28 (33 per cent) had reflux and/or hydronephrosis. Treatment in 15 patients consisted of increasing the frequency of catheterization to every 4 hours and avoiding high fluid intake during a relative short interval. Sphincterotomy was done in 3 patients, while 10 were placed on an indwelling catheter because of an inability to adapt to or refusal of other forms of treatment. The upper urinary tract changes noted seemed to be related to increased intravesical pressure, either from too long an interval between catheterizations or from marked detrusor hyperreflexia with sphincter obstruction. Close followup seems necessary in these patients.

Human T cell growth factor (TCGF) produced by repeated stimulation of non-adherent human lymphocytes

T cell growth factor (TCGF) has become a valuable means of maintaining T lymphocytes in long-term culture and of studying T cell function. Numerous problems have been met in the production of TCGF of consistently good quality and in the maintenance of human T cell lines over long periods. We have investigated optimal conditions for TCGF production, and simplified assay systems for TCGF activity. The best TCGF production was obtained by short-term treatment with high concentrations of phytohemagglutinin (PHA). The TCGF producing lymphocytes could be re-used for TCGF production up to 1 month after the first treatment course. Human cultured T cell lines, fresh lymphocytes, short-term PHA stimulated lymphocytes and cultured marmoset T lymphocyte lines were all used for assay of TCGF. We recommend PHA stimulation of human lymphocytes for this assay on a routine basis, comparing results with a standard TCGF batch and calculating a growth index. Adherent cells impair TCGF production. Optimal TCGF production was seen when lymphocyte preparations without adherent cells from different donors were used.

Reusable catheter for long-term sterile intermittent catheterization

A new resterilizable, low cost, and convenient catheter for long-term sterile intermittent catheterization of the neurogenic bladder is described. Average self-catheterization time is 2 minutes. It can be performed successfully in a wheelchair. Estimated average cost per catheterization is 10 to 20 cents. The reduced cost and greater convenience of the Wu Reusable Catheter make sterile long-term intermittent catheterization feasible for spinal cord injured patients. This should lead to reduction of urologic morbidity encountered with indwelling and external catheterization.

RIC-Wu catheter kit: new device for an old problem

A new catheter kit has been developed for sterile urethral catheterization. It is useful for any patient requiring catheterization but has special advantages for the spinal cord injured person with a neurogenic bladder. The RIC-Wu Catheter Kit is simply a straight rubber catheter contained in a sterile clear plastic bag with one end formed into a restricted sterile field and the other into a tear-off chamber for urine laboratory testing. In clinical trials the RIC-Wu Catheter Kit has been found to have several advantages over the conventional sterile catheter tray: staff or self-catheterization is usually easier, faster and can be carried out with the patient sitting in a wheelchair in any private place; it is pocket sized and can be less expensive; less professional staff time is expected for a catheterization program; catheterization-induced infection rates are expected to be the same or less.

An innovative removable rigid dressing technique for below-the-knee amputation

The below-the-knee removable rigid dressing is a below-the-knee plaster cast held by a suspension stockinette to a supracondylar plastic cuff. It has proved to be an effective method for postoperative, pre-prosthetic, and prosthetic care of below-the-knee amputees. Being removable, it permits frequent observation and progressive shrinkage of the stump (by adding socks), and eliminates the need of elastic stump bandaging. In addition, it still maintains the advantages of immobilization of soft tissue (to reduce pain and facilitate wound healing) and prevention of trauma to the stump as does the conventional rigid dressing. It has significantly reduced the incidence of pre-tibial skin breakdown and distal edema, produced fast stump shrinkage, and shortened time to ambulatory discharge with a temporary prosthesis by ninety days.