Response of slowly adapting articular mechanoreceptors in the cat knee joint to alterations in intra-articular volume

Recordings were obtained from slowly adapting mechanoreceptors innervating the posterior aspect of the cat knee joint capsule. It was observed that, with rising intra-articular volume, initially both intra-articular pressure and the neural discharge increased. This increase was dependent on the rate of fluid accumulation within the joint. However, the joint nerve discharge invariably levelled out despite increasing intra-articular volume and pressure. This suggests that there exists some limit to capsular distension in the posterior joint region beyond which fluid is diverted to other areas of the knee joint.

Patients with delusional and bizarre thinking

Patients with delusional or other types of bizarre thinking are often incorrectly labeled as schizophrenic. This error has significant medical and social implications to the patient. Delusional thinking has been linked with a variety of nonschizophrenic problems including the use of licit and illicit drugs, a wide variety of medical diseases, and nonschizophrenic psychiatric disturbances. A series of case studies in which the diagnosis of schizophrenia was incorrectly made elucidates the problem and helps the physician consider the alternatives.

In adult acute nonlymphoblastic leukaemia extended maintenance chemotherapy has no benefit

Fifty-two consecutive and previously untreated adults with nonlymphoblastic leukaemia underwent remission induction chemotherapy with a combination of the epipodophyllotoxin VP16-213, cytosine arabinoside, and doxorubicin (Adriamycin). Complete remission was achieved in 23 of the 52 patients (44%) by means of a single course of therapy in 20 individuals, two courses in two, and three courses in one; median duration of complete remission was 48 weeks. Failure to achieve remission status was due to primary drug resistance in 13 patients (25%), and adequate trial of therapy was not possible in 16 patients (31%) owing to their late referral and accounts for the low remission rate. Individuals achieving complete remission were randomly assigned to receive either 6 (n = 8) or 15 months (n = 13) of maintenance therapy; respective median survival was 95 and 78 weeks (P greater than 0.10). These data confirm previously reported results for complete remission induction with this three-drug combination and fail to show any difference between short (6 months) and long (15 months) maintenance chemotherapy.

Comparison of filtration to continuous-flow centrifugation for plasma exchange

The Asahi Plasmaflo Hollow Nylon Fibre Filtration System (n = 13) was directly compared to the NCI-IBM 2990 Continuous-Flow Blood Fraction Separator (n = 10) for plasma exchange. The systems were equally efficient in achieving plasma separation. There were significant differences favouring filtration for clearance of fibrinogen (P less than 0.05), and the fourth component of complement (P less than 0.01). Greater loss of urea (P less than 0.05) was found after plasma exchange, using the cell separator. The flow characteristics were markedly different. In a standardised 4-L plasma exchange, filtration took place at 35 ml/minute, with a procedure time of 109 +/- 45 minutes in contrast to centrifugation at a plasma flow collection rate of 19 ml/minute, requiring 208 +/- 17 minutes. This time advantage for the former procedure was offset by 195 minutes required to regenerate the hollow nylon fibre unit and a further 90 minutes required for cleaning under strictly controlled aseptic techniques prior to reuse. Each filter was regenerated at least twice and reused without infection, but there was incremental loss of filtration efficiency demonstrated by decreasing clearance of an intravascular marker dye. In two of the 13 procedures using the Plasmaflo system, serious reactions necessitated termination of the procedure; this did not occur using the cell separator. Restriction of the number of times that the filter unit could be regenerated without loss of efficiency, the prolonged time required for regeneration and cleaning, coupled with the need for artificial vascular access to meet high blood flow rates required, limit the usefulness of this technique for plasma exchange.

The function and structure of granulocytes collected using the IBM 2997 separator

The effect of oral methylprednisolone and the sedimenting agent, hydroxyethyl starch, on granulocyte recovery, morphology, and function was studied in a volunteer donor programme. Using the IBM 2997, 10 litres of whole blood were processed, with an average procedure time of 2.4 hours and a collection volume of 300 ml. Donors not receiving methylprednisolone (n = 80) had a mean total granulocyte count of 3.5 X 10(9)/litre (range 1.6-5.3 X 10(9)/litre) and mean granulocyte yields were 1 X 10(10) (range 0.2-3.0 X 10(10)). Those receiving 48 mg oral methylprednisolone 6-8 hours before the procedure (n = 320) had a mean granulocyte count of 6.3 X 10(9)/litre (range 3.2-11.4 X 10(9)/litre) and significantly superior mean granulocyte yields of 2.0 X 10(10) (0.3-6.5 X 10(10)) (P less than 0.05). For both groups the mean packed cell volume of 0.08 litre/litre (range 0.02-0.17) and platelet contamination 1.9 X 10(11) (range 0.3-5.0 X 10(11)). In all these procedures, hydroxyethyl starch was added to the blood entering the centrifuge channel. In none of the procedures were any untoward symptoms experienced by the donors. Light microscopy and ultrastructural studies showed no difference between control granulocytes and those collected following the addition of hydroxyethyl starch or after oral methylprednisolone. Similarly, granulocyte function measured with a random migration, chemotaxis, phagocytosis, and intracellular killing was not significantly different between control cells and those exposed to the sedimenting agent or the adrenocorticosteroids (P greater than 0.10). It is concluded that donor premedication with methylprednisolone significantly enhances granulocyte yields in the presence of hydroxyethyl starch and neither agent has any demonstrable effect on granulocyte morphology or function.

Activity of lysosomal cysteine proteinase during differentiation of rat skeletal muscle

Cysteine-proteinase activities were measured in extracts of pre- and post-fusion populations of rat myogenic line L6 cells and in extracts of whole rat muscle. Activities of cathepsins B, L and H were compared. The substrates used included Z-Phe-Arg-NMec (cathepsins B and L), Z-Arg-Arg-NMec (cathepsin B), and Arg-NMec (cathepsin H) (where Z = benzyloxycarbonyl, and NMec = 4-methyl-7-coumarylamide); the enzyme activities were more specifically differentiated by appropriate concentrations of the inhibitors Z-Phe-Phe-CHN2 (CHN2 = diazomethane), bestatin and E-64 [L-trans-epoxysuccinyl-leucylamido(4-guanidino)butane]. These experiments have demonstrated the feasibility of determining the cysteine-proteinase activities of myoblasts from a single (60 mm-diameter) Petri dish, with enzyme concentrations in the range of 5-20 ng/ml. Specific activities of the enzymes in L6 cells increased 2-20-fold after fusion. Concentrations of cysteine proteinases in extracts from cultured myoblasts were two orders of magnitude greater than those in muscle-tissue extracts. Cultured-cell extracts contained endogenous inhibitor(s) to purified rat cathepsins B, L and H.

Linked pools of processed alpha-mannosidase in Dictyostelium discoideum

We are studying the fate of alpha-mannosidase, a lysosomal enzyme, in Dictyostelium discoideum. alpha-Mannosidase is synthesized as a 150,000-dalton precursor which becomes proteolytically cleaved to mature (56,000-62,000 dalton) forms. When cells are shifted into starvation buffer (5 mM phosphate, pH 6.5), the enzyme is secreted. We compared the kinetics of secretion of newly processed alpha-mannosidase with that of bulk forms. After 2 h in phosphate buffer less than 20% of the newly processed forms but as much as 50% of the bulk enzyme activity was secreted. During the course of the experiments, the total alpha-mannosidase activity remains constant, cells remain viable, and there is no evidence of degradation of enzyme. Furthermore, a 4-h chase period prior to starvation is required before the newly processed forms are secreted to the same extent as the bulk forms. On the basis of these results we propose that the enzyme is present in at least two pools and that it is transferred from a newly processed to an efficiently secreted pool.

Comparison of the lipid composition of breast milk from mothers of term and preterm infants

Milk was collected from mothers of 18 very premature (26 to 30 wk gestation age), 28 premature (31 to 36 wk), and six term (37 + wk) infants on day 2 to 3 (colostrum), and at 1, 3, 6, and 12 wk postpartum. Fat content for 154 milk samples was 2.80 g/dl gravimetrically and 2.66 g/dl by quantitative thin-layer chromatography. Fat content increased during lactation, whereas phospholipids and cholesterol declined. Concentrations of medium-chain fatty acids increased from colostrum to mature milk and were highest in preterm milk. Compensatory decreases were observed in very premature and premature oleic acid. Long-chain polyunsaturated fatty acids were highest in colostrum and reduced in mature milk. Long-chain polyunsaturated fatty acids were also higher in very premature and premature milk than in term milk. These elevated levels of readily absorbed medium-chain fatty acids and long-chain polyunsaturated fatty acids in preterm milk may be of special benefit for the needs of premature infants.

White cell and platelet component support in human bone marrow transplantation

Bone marrow transplantation is the preferred form of treatment for patients with severe acute aplastic anaemia and immunodeficiency disease. The procedure has also been used in the treatment of patients with refractory or relapsed acute leukaemia and may result in further disease-free periods in excess of two years in approximately 15% of such individuals.

The patient exhibiting episodic violent behavior

This case presentation describes a 21-year-old white male patient seen for episodic violent behavior. The case is seen as relevant for primary care physicians because of the frequency of violent acting out in the general population, the importance of making an accurate diagnosis, and the many medical, psychological, and social implications involved in diagnosing such disorders. In such cases it is important that the physician keep an open mind and include within the differential diagnosis a variety of psychiatric disturbances such as paranoid schizophrenia, antisocial personality disorder, drug abuse syndromes including a variety of hallucinogens as well as prescription medication, organic diseases affecting the central nervous system, including encephalitis and temporal lobe epilepsy, and a variety of interpersonal difficulties, including spouse abuse and spousal rape. The case presentation method demonstrates how the psychiatric interview and a judicious use of biochemical and physiological testing can lead the practitioner to a correct diagnosis.

Comparison of ranitidine and cimetidine in the treatment of chronic gastric ulcer. A double-blind trial

The aim of the study was to compare the effectiveness of ranitidine and cimetidine in accelerating the healing of chronic gastric ulcer. 44 outpatients with endoscopically proven gastric ulcer whose duration of symptoms was greater than 4 weeks and who were without major systemic disease were studied. Patients were randomly allocated to receive either ranitidine, 150 mg twice a day or cimetidine, 200 mg three times a day and 400 mg at night for 4 weeks. If the ulcer had not healed, treatment was continued for a further 4 weeks, when patient assessment and endoscopy were repeated. By 4 weeks, 13 of 22 patients taking ranitidine (59%) and 14 of 22 patients taking cimetidine (64%) had healed (p2 = 1.0, 95% confidence interval - 20%, 38%). At 8 weeks, 91% on ranitidine and 91% on cimetidine had healed (p2 = 1.0, 95% confidence interval - 18%, 18%). Symptomatic improvement was similar with both drugs. Smoking did not influence healing rates. There were no major side effects with either medication. It is concluded that ranitidine and cimetidine are of similar efficacy in accelerating the healing of chronic gastric ulcer.

Red cell phospholipids in schizophrenia

Phospholipids in red blood cells (RBCs) of schizophrenics and controls were determined. Three different RBC preparations and two different extraction methods were used. Phospholipids were separated by thin layer chromatography and by high pressure liquid chromatography, and were quantified by phosphorus analysis and by ultraviolet absorption. Findings were consistent with values previously reported for normals. However, in contrast to recent reports of elevated phosphatidylserine levels in schizophrenics' RBCs, we observed no differences between populations.

Processing and secretion of alpha-mannosidase forms by Dictyostelium discoideum

We are studying the biosynthesis and processing of acid hydrolases from Dictyostelium discoideum. We prepared antibody to highly purified alpha-mannosidase from the spent medium of stationary phase cultures. It precipitated alpha-mannosidase but not beta-hexosaminidase, alpha-glucosidase, beta-glucosidase, or any of the major proteins in cell lysates or secretions. The antibody precipitated a 150,000- and an 80,000-dalton protein in addition to mature forms (56,000-62,000 daltons) of alpha-mannosidase subunits. The possibility that the 150,000 and 80,000 dalton bands were precursors of mature forms was evaluated by pulse-chase experiments. Following a 20-min pulse labeling period, only the 150,000-dalton protein was detected in the immunoprecipitate. Apparent conversion of this form into 80,000- and 60,000-dalton forms was observed following a 30-min chase. During the next 90 min continued accumulation of 60,000-dalton and appearance of 62,000-dalton forms was observed while the 80,000-dalton form disappeared. The fate of the 150,000-dalton precursor depended on nutritional conditions. In cells conditioned with fresh growth medium intracellular processing predominated. Less than 10% of either the precursor or mature forms was secreted in 8 hr. However, when cells were shifted from growth medium to starvation buffer, secretion of precursor soon predominated. After a 1-hr lag period, cells began secreting 150,000-dalton precursor into the medium. After 4 hr in starvation buffer, the rate of secretion of 150,000-dalton form increased by at least an order of magnitude while processing was markedly diminished. This may be a case where nutritional conditions control the sorting of an acid hydrolase precursor.

Domestic breeding of patas monkeys (Erythrocebus patas)

Two reproductive strategies were used in the management of a patas monkey (Erythrocebus patas) breeding colony. The first strategy involved placement of all animals into one-male harem units for breeding, parturition, and infant rearing. The second strategy involved a reduction in the number of males, movement of pregnant females to individual cages, and formation of new groups with females and neonates. The second strategy resulted in an increased percentage of females having successful births and an increased survival of neonates. The percentage of females becoming pregnant did not change.

Cimetidine impairs the elimination of theophylline and antipyrine

In 7 healthy subjects theophylline and antipyrine elimination were determined before and during a course of oral cimetidine in a dose of 1 g/day. Plasma clearance of theophylline was reduced from 71.2 +/- 10.1 ml/min to 56.0 +/- 18.5 ml/min and the plasma clearance of antipyrine from 53.7 +/- 14.2 ml/min to 48.1 +/- 11.7 ml/min. Elimination half-life of theophylline was prolonged from 5.1 +/- 1.6 to 8.1 +/- 1.4 h. All these changes were statistically significant. Volume of distribution of theophylline (31.7 +/- 8.4 L before and 39.2 +/- 5.6 L during cimetidine administration) and plasma binding of theophylline (44.7 +/- 3.8% before and 44.3 +/- 3.1% during cimetidine administration) were not significantly different. Similarly, volume of distribution of antipyrine (45.8 +/- 14.0 vs. 47.6 +/- 17.9) was not significantly affected by cimetidine administration. We conclude that cimetidine impairs the elimination of theophylline and antipyrine in healthy subjects.

Anaemia: a practical approach for nursing and paramedical specialties

Anaemia is only a symptom and not, in itself, a diagnosis. Its importance lies in the fact that it signals underlying disease which is often correctable. By definiton anaemia is a reduction in red cell mass and this is reflected in reduced haemoglobin, packed cell volume, or red cell count in the peripheral blood. To understand the mechanisms of its development normal blood formation must be briefly reviewed.

The role of continuous-flow blood fraction separators in clinical practice

Continuous-flow blood fraction separators facilitate the efficient exchange of large volumes of plasma or red cells and therefore have clinical application in the rapid correction of abnormalities located predominantly in either of these compartments. Plasmapheresis has been successfully used in managing 2 patients with previously refractory myasthenia gravis, in reducing the antibody titre in a rhesus-sensitized woman, and in diminishing anti-A titre in a patient requiring bone marrow transplantation from an ABO-incompatible but HLA- and MLC-identical sibling. Continuous-flow red cell exchange effectively reduced the haemoglobin S concentration in an individual with sickle cell disease prior to general anaesthesia and abdominal surgery. Complications were not encountered although the procedures were carried out repetitively over prolonged periods of time. All 5 patients tolerated their exchanges without discomfort. As with any new and expensive technique, caution should attend the introduction of continuous-flow plasma or red cell exchange into clinical medicine. Careful evaluation of the safety and the benefits is needed to establish perspective and to distinguish between established and developmental indications.

Effects of frontalis EMG feedback and reinforcement on frontalis EMG level

This experiment employed a between-subjects design (N = 40) to investigate the effects of feedback and reinforcement on the lowering of frontalis electromyographic (EMG) activity. The feedback and reinforcement manipulations were combined in a 2 x 2 factorial design and each subject underwent one baseline and two training sessions on three consecutive days. The analogue feedback signal was a 55 dB tone whose pitch varied as a function of EMG activity, while the reinforcement consisted of points which were exchangeable for money. The training sessions were each divided into 10 2-min baseline periods and 10 2-min trial periods. The results indicated that although analogue feedback did not result in lowered EMG levels, trial period EMG level was significantly lower than baseline level under conditions of reinforcement. These results pose problems for Budzynski and Stoyva's (1972) views concerning the therapeutic usefulness of frontalis EMG feedback training.

Cardiovascular effects of novel amphetamine analogs in anesthetized rats

In albino, adult Sprague Dawley rats, anesthetized with urethane intraperitoneally, the effects of the exo- and endo-isomers of 2-amino-5,8-dimethoxybenzonorbornene were studied on arterial blood pressure and heart rate. Both compounds produced an immediate rise in systemic arterial pressure followed by an immediate maximal depressor response. The depressor effect was sustained beyond 30 minute duration, but declined in intensity with time to nearly preinjection levels. Both compounds decreased heart rate in varying degrees. Evidence of marked bradycardia and onset of toxicity was observed at doses of 12.8 mg/kg (exo) and 19.2 mg/kg (endo). The biphasic response seen after intravenous injection of the compounds suggests an initial vasoconstrictory followed by a vasodilatory effect.

Transfer chemical laser: modeling of a cw DF-CO(2) laser

The chemical kinetics characterizing a DF-CO(2) transfer chemical laser were verified by utilizing a subsonic laser system which, for most conditions, could be approximated as premixed and at constant pressure. In such a laser, fluid dynamic effects are minimized, and the role of the kinetics model in characterizing the DF-CO(2) system is emphasized. Predictions of zero power gain, DF(v) number densities, thermocouple temperatures, and laser power were compared with data for an optical cavity pressure range of 21-79 Torr. The results show that the kinetics model gives an accurate description of the DP-CO(2) optical cavity. Mixing phenomena were found to become important at cavity pressures below 40 Torr.

Regional distribution of a 133Xe labelled gas volume inspired at constant flow rates

We measured the regional distribution of 480 ml of 133Xe labelled gases inspired from FRC at constant inspiratory flow rates ranging from 0.1 to 6 litres/s. The gases used were air and 20% O2 in helium. At low inspiratory flow rates the gas was preferentially delivered to the dependent region of the lung. At maximal inspiratory flows, all regions of the lung were more evenly ventilated. The rate of redistribution was found to be slower and more even than in previous studies using smaller volumes of inspired gas. Assuming equal and synchronous changes of pleural surface pressure, these results can be reasonably predicted by the mechanical time constant theory applied to a simple two-compartment lung model based on equal regional resistances. Breathing the HeO2 mixture did not significantly change ventilation distribution at any flow rate.