Concanavalin A stimulation of mouse lymphocytes at low concentration. I. The effect of peritoneal exudate cells

The results presented here show that concanavalin A (Con A) stimulated mouse spleen lymphocytes cultured at 1/10th optimal concentration incorporated less [3H]-TdR than those cultured at the optimal concentration. It was possible to increase the response of 1/10th optimal concentration lymphocytes by supplementing the cultures with macrophage-rich peritoneal exudate cell (PEC) preparations. This effect was dependent on the PEC concentration. [3H]-TdR incorporation by lymphocytes at optimal concentration was inhibited by the addition of PEC to the cultures. Thymocyte cultures at 1/10th optimal concentration also showed increased [3H]-TdR incorporation when supplemented with PEC but there was no inhibition effect at optimal concentration. PEC which had been pretreated with fresh mitomycin C to prevent cell division were as effective as controls at promoting the stimulation of 1/10th optimal concentration lymphocytes. PEC which had been killed were much less effective than controls.

Concanavalin A stimulation of mouse lymphocytes at low concentration. II. The effect of conditioned medium from peritoneal exudate cells and from lymphocyte cultures

The first paper in this series reported that it was possible to reconstitute the response of low concentrations of mouse spleen lymphocytes to concanavalin A (Con A) by adding smaller numbers of peritoneal exudate cells (PEC) to the cultures. In this paper it is shown that the role of the PEC in this system can be partially replaced by conditioned medium (CM) prepared from PEC cultures or completely replaced by CM taken from lymphocytes cultured at optimal concentration. These CM were inactive unless fresh Con A was added to the assay cultures. Activity was present in Cm which was incubated with lymphocytes or PEC for the shortest possible time but maximal activity was found after 24 hr of incubation. Activity was also found in Cm prepared in the absence of Con A. Only in the case of lymphocytes cultured at optimal concentration for 24 hr was there substantially more activity in the CM thus prepared if Con A was present. PEC preparations depleted of T lymphocytes produced as much activity in Cm as the untreated control. CM produced by PEC was less sensitive to heat treatment or to freezing and thawing than that produced by lymphocyte cultures.

Limited usefulness of aortic arch angiography in the evaluation of carotid occlusive disease

The role of aortic arch angiography in the evaluation of cerebral ischemic disease is not well defined. In an attempt to develop guidelines for its optimal use, a prospective study of 100 patients with carotid distribution ischemic events was undertaken. Each patient underwent bilateral selective carotid angiography followed by arch aortography. In only two of the cases did the arch examination affect patient management. In the other individuals, the arch study either added no clinically useful information (69), or demonstrated abnormalities that did not affect patient care (29). The findings of this study support the use of arch aortography only in those patients who have surgical lesions demonstrated by the selective carotid examinations.

Reoperation for glioblastoma

The results of a second operation for tumor removal in 24 adult patients with supratentorial glioblastoma multiforme or anaplastic astrocytoma were analyzed. The median survival time after reoperation was 14 weeks. Five of the 24 patients lived 6 months or longer after reoperation. Only three of these patients maintained a Karnofsky rating (KR) of at least 60 for 6 months or longer after reoperation. Preoperative neurological status (KR) is the most significant determinant of survival after reoperation (p = 0.02). When the KR is at least 60, median survival after reoperation is 22 weeks. When the KR prior to reoperation is less than 60, median survival is 9 weeks. Only one of 13 patients with a KR of less than 60 prior to reoperation survived longer than 6 months after the second operation. The interval between first and second operation is significantly related to survival (p = 0.03), but when adjustment is made for the KR the interoperative interval is no longer significantly related to survival after the second operation (p = 0.39). Age, sex, and location of tumor were not significantly related to duration of survival. This study suggests that reoperation is most likely to produce the best result when the KR is at least 60 and the interval between operations is longer than 6 months. Using these criteria, one-third of the patients could be expected to survive with a KR of at least 60 for 6 months. The study indicates that reoperation should not be carried out when the KR is less than 60.

Theophylline toxicity after the use of aminophylline in the treatment of cerebral vasospasm

We are reporting a case of theophylline toxicity after the initiation of i.v. aminophylline and isoproterenol in the treatment of cerebral vasospasm. The dose of aminophylline (125 mg/hour) previously recommended results in a toxic serum theophylline concentration in a majority of patients if the infusion is continued for more than 24 to 48 hours. The rapid achievement of an optimal serum level is obtained with a standard loading dose of 8.0 mg/kg. The initial infusion rate should be based on calculated pharmacokinetic data. Maintenance dosing adjustments are then based on serum determinations and the presence of toxic effects.

Anterior decompression and fusion for thoracolumbar fractures with neurological deficits

Anterior spinal decompression and fusion was used as the primary treatment for thoracolumbar fractures in eleven patients with neurological deficits. Each patient achieved stability by interbody fusion. Significant progressive kyphosis did not occur. No patients with a complete neurological deficit was improved by operation, but all eight patients with partial neurological deficits showed improved lower extremity motor function postoperatively. Bladder function improved in five of the eight patients with incomplete lesions. The authors recommend this operative approach for spinal stabilization and removal of anteriorly located bone or disc fragments causing progressing and stable partial neurological deficits, and find second-stage posterior fixation with Harrington rods unnecessary in the great majority of cases.

Early prediction of outcome in head-injured patients

The relationship between Glasgow Coma Scale (GSC) scores obtained during the 1st week after head injury and outcome at 1 year was analyzed in 170 patients. Seventy-two of 76 patients with initial GCS scores of 3 or 4 lived, and only one had a favorable outcome. Favorable and unfavorable outcomes were almost equally divided when the initial GCS scores were in the intermediate range of 5, 6, or 7. No patients with an initial GCS score in this intermediate range that subsequently worsened had a favorable outcome, while over 80% of those improving to a score higher than 7 had a favorable outcome. Only 12% of those persisting with a score of 5, 6, or 7 for 1 week had favorable outcome. Outcome predictions using the multiple logistic model were made for this intermediate group of patients based on GCS scores and data on midline shift derived from computerized tomography (CT). The patients with initial scores of 5, 6, or 7 with midline shifts of less than 4.1 mm on initial CT scanning had a significantly higher favorable outcome rate compared with patients with a larger shift. However, outcome prediction made by combining shift data and initial GCS scores are not significantly more accurate than predictions based solely on initial GCS scores. Combining 48-hour GCS scores and shift data significantly improves predictive accuracy based only on coma scores. The data obtained by combining GCS scores at 72 hours and 1 week and shift data is marginally significant for improving accuracy of outcome predictions. It is concluded that GCS scores and shift data are highly accurate indicators of outcome in head-injured patients.

Percutaneous sacral rhizotomy for neurogenic detrusor hyperreflexia

Ten patients with neurogenic detrusor hyperreflexia were treated by percutaneous radiofrequency sacral rhizotomy. All had low-threshold involuntary micturition. The bladder capacity of seven patients was increased to over 290 cc during a follow-up interval of 3 to 18 months. This convenient percutaneous procedure is particularly suited for controlling detrusor hyperreflexia, which has frequent failures of initial treatment and late recurrence of symptoms.

Studies of experimental cervical spinal cord transection. Part IV: Effects of cervical spinal cord transection on myocardial blood flow in anesthetized dogs

✓ Effects of cervical cord transection on total and regional myocardial blood flow and coronary vascular resistance were studied in anesthetized dogs using 15-µm microspheres. Left atrial catheters were inserted by thoracotomy in 10 dogs and iodine-125-labeled microspheres were injected to measure baseline tissue blood flows by means of the reference flow technique. Four dogs then underwent laminectomy of the C-6 vertebra (control group), and six underwent laminectomy and cord transection (experimental group). Microspheres labeled with cerium-141, strontium-85, and scandium-46 were injected at 15, 30, and 120 minutes, respectively, after surgical intervention. The dogs were sacrificed, and the radioisotope content of specimens of epicardial, mid-myocardial, and endocardial tissues was determined by differential spectrometry, and tissue blood flow was calculated in relation to arterial reference specimens.

No significant differences in baseline endocardial, epicardial, or mid-myocardial blood flow were detected between the control and experimental groups. Tissue blood flows fell significantly in all regions (p < 0.05 or less) at 15, 30, and 120 minutes after transection. No major alteration of the endocardial/epicardial flow ratio occurred, and no electrocardiographic or pathological evidence of ischemia was seen. When corrected for variations in systemic arterial pressure, no differences in coronary vascular resistance between control and cord-transected dogs were observed. These findings suggest that the decreased coronary blood flow following cervical cord transection is secondary to decreased mean arterial pressure rather than to altered coronary vascular resistance. Pharmacological augmentation of perfusion pressure may therefore be necessary to maintain adequate coronary blood flow in patients with acute cord injury who have pre-existent cardiac disease.

Posttraumatic epilepsy prophylaxis

Despite a large body of experimental evidence suggesting that posttraumatic epilepsy can be prevented, there is no generally accepted pharmacological regimen for posttraumatic seizure prophylaxis. This article describes a phenytoin anticonvulsant regimen specifically tailored for the patient with acute head injury and designed to provide immediate and sustained plasma concentrations of phenytoin between 10 and 20 microgram/ml. Initially, an intravenous phenytoin dose of 11 mg/kg body weight is immediately followed by an intramuscular dose of 13 mg/kg body weight. This is followed by daily intramuscular maintenance doses, usually 8.8 mg/kg body weight, until oral medication can be tolerated. Maintenance dosage adjustments, when necessary, are based on serial plasma concentrations of the drug. Eighty-four patients with severe head injuries with substantial risk of posttraumatic epilepsy were administered this regimen. Only 6% of these patients had seizures during the first year after injury (first week excluded), and this is considerably less than the rates reported elsewhere in the literature. Only one-third of these patients are known to have continued to take phenytoin after the first month, and only half of these had plasma phenytoin concentrations above the desired minimal level. The greatly reduced incidence of posttraumatic seizures in these patients, despite the low rate of long-term drug compliance, suggests that a prophylactic effect, rather than a suppressive effect, is produced.

Impeded cerebellar development and reduced serum thyroxine levels associated with fetal alcohol intoxication

Pregnant albino rats were placed on a complete liquid diet (Ensure) containing either 9% ethanol or an isocaloric amount of sucrose between the third and twentieth day of gestation. The pups born to these rats were sacrificed either day 11 or day 14 postnatum and morphometrical, histological and biochemical analyses were done on their cerebellums and cerebrums. Pups that were exposed to ethanol in utero had significantly smaller body weights, cerebrums and cerebellums than pair-fed controls. The cerebellar mass was reduced by 10% and the cerebral weight by 3% in the pups exposed to alcohol when body weights were normalized to that of pair-fed controls. Cerebellar aspartyl aminotransferase (EC 2.6.1.1) activity was reduced at day 11 and 14 in ethanol treated pups compared with controls. Serum T4 levels were also reduced in the ethanol treated group. Histological analyses revealed that the external granule cell (EGC) layer of ethanol treated pups was significantly thicker at 11 and 14 days postnatum than that of pair-fed control pups. Cerebellar ornithine decarboxylase (ODC, EC 4.1.1.17) activity was higher at day 11 in the ethanol treated pups than in controls. The reduced mass, AAT activity, T4 serum levels and the increased thickness of the ECG layer indicate a delayed or impeded maturation of cerebellum in ethanol treated pups. These data are considered from the viewpoint that ethanol, other drugs such as methadone and prenatal stress (malnutrition) may cause delayed cerebellar maturation by reducing serum T4 levels in the early postnatal period (day 5-14).

Studies of experimental cervical spinal cord transection. Part III: Effects of acute cervical spinal cord transection on cerebral blood flow

Regional cerebral blood flow (CBF) was measured by the microsphere technique in anesthetized, mechanically ventilated dogs before and after cervical laminectomy in four (control group), or cervical laminectomy followed by cervical cord transection (CCT) at the C-6 level in six (experimental group). No significant differences in arterial pH, pO2 or pCO2 were observed between control and experimental dogs. Baseline values for mean arterial pressure (MAP) were also similar in the two groups, but MAP fell in all experimental dogs after CCT (p less than 0.025). At 120 minutes after CCT, three of the six dogs had an MAP greater than 60 torr (66 +/- 4 torr), and in three the MAP was greater than 50 torr (45 +/- 3 torr). Regional CBF in cortical gray matter, white matter, and medulla did not change significantly after CCT in dogs with MAP greater than 60 torr. The CBF fell significantly at 120 minutes after CCT in all regions sampled in the dogs with MAP less than 50 torr (p less than 0.025). At 30 and 120 minutes after CCT, cerebellar blood flow fell significantly in all experimental animals (p less than 0.05). These findings indicate that, despite hypotension and sympathetic denervation of cerebral vessels, CBF in cortical gray matter, white matter, and medulla is maintained at normal levels after CCT by autoregulation as long as MAP exceeds 60 torr. Decreased cerebellar blood flow in the experimental group suggests redistribution of CBF after CCT with relative preservation of flow to gray matter, white matter, and medulla. Reduced CBF in the acutely cord-injured patient with significant hypotension (MAP less than 60 torr) may stimulate or complicate coexistent head injury.

Studies of experimental cervical spinal cord transection. Part II: Plasma norepinephrine levels after acute cervical spinal cord transection

Plasma concentrations of norepinephrine (NE) were measured by a radioenzymatic assay technique before and serially after laminectomy at the C-6 level in 14 anesthetized dogs. In half the animals, no further procedures were carried out (control group); in the other dogs, cervical cord transection was performed in addition to laminectomy (experimental group). Mean plasma NE levels were similar in both groups after laminectomy and before cord interruption. In the control group, NE levels increased gradually for 2 hours after the procedure. In the group with cord transection, however, NE rose immediately after transection to 267% of the baseline value, then fell to 25% of the plasma NE level in the control group at 30 minutes, 29% at 60 minutes, and 15% at 120 minutes. Cervical spinal cord transection, therefore, results in an abrupt but short-lived increase in plasma NE concentrations. These changes in plasma NE levels may explain, at least in part, the hemodynamic alterations and the acute central hemorrhagic necrosis that occur after high spinal cord trauma.

Hydrocephalus and elevated intracranial venous pressure. Case report

An infant with a large arteriovenous malformation and communicating hydrocephalus is described. The author suggests that the hydrocephalus is caused by impaired absorption of cerebrospinal fluid due to increased intracranial venous pressure.

Rubella-vaccinated students. Follow-up in a public school system

In a 7 1/2-year follow-up evaluation of the duration of rubella-vaccine-induced immunity of students who received either HPV-77 DK-12 or Cendehill vaccine, both groups showed a continous decline in hemagglutination-inhibition antibody from seven weeks after vaccination but a lower decline between 4 1/2 and 7 1/2 years after vaccination. However, at 7 1/2 years only 16 students (8%) receiving the Cendehill vaccine and one student (0.5%) receiving the HPV-77 DK-12 vaccine lacked detectable antibody. Despite the persistence of antibody titers, there was evidence of subclinical rubella among both groups of vaccinated students. These results emphasize the importance of continued evaluation of the conditions of persons receiving rubella vaccine.

Automatic intracranial pressure regulation

This paper emphasizes our approach to control increased ventricular fluid volume and pressure; it utilizes an improved device based upon hydrostatic pressure principles. Intracranial pressure may be maintained at any preselected value, usually 25 cm H2O. Pressure increases beyond this value will result in a venting of fluid into a calibrated reservoir. The hydrostatic column will act to cushion the surrounding ventricular mass, helping to prevent ventricular collapse. The method overcomes the hazards of techniques, using intermittent withdrawal of fluid which requires human judgment. Ventricular pressure response curves performed on a number of patients showed a marked stability with a response less than 2 mm Hg/ml. This indicates a favorable influence on the intracranial compliance. The system is completely closed and its use in 52 neurosurgical patients in over 400 patient days has not been associated with any infection problem.

Studies of experimental cervical spinal cord transection. Part I: Hemodynamic changes after acute cervical spinal cord transection

Two distinct and sequential patterns of hemodynamic alteration were observed after acute cervical spinal cord transection in anesthetized dogs. Interruption of the cord initially caused a 45% increase in mean arterial pressure (p less than 0.01), a 34% increase in systemic vascular resistance (p less than 0.05), and a 92% increase in left ventricular dp/dt (p less than 0.01), reflecting a generalized sympathetic response to trauma. Concomitant bradycardia and escape arrhythmias suggested relative parasympathetic hyperactivity. Resolution of the brief pressor response was followed by a second, more prolonged, period characterized by a fall in arterial pressure to 71% of control levels (p less than 0.05), a 16% decrease in systemic vascular resistance, and a 58.5% decrease in left ventricular dp/dt (p less than 0.01). These latter hemodynamic changes are consistent with sympathetic denervation and failure of regulatory mechanisms mediated by both alpha- and beta-adrenergic peripheral vascular and myocardial receptors.

Precocious Sexual Maturation in Atlantic Salmon (Salmo salar) Postsmolts Reared in a Seawater Impoundment

Female Atlantic salmon, Salmo salar, usually become sexually mature following a minimum of one winter at sea. Between 4 and 16% maturation was observed for both sexes in two different stocks of salmon placed in sea water as 1+ yr smolts and subsequently reared one summer. Only the larger females and the smaller males matured. Egg size and fertility appeared normal. Smoltification at an early age or accelerated growth rates may be responsible for this phenomenon. Key words: Salinity tolerance, pen-rearing, brood stock, growth rates

A device for intracranial pressure regulation. Technical note

✓ The authors describe a device that monitors and automatically regulates intracranial pressure.

Evaluation of influenza A/New Jersey/76 split-product virus vaccine in a summer camp

An evaluation of two doses of split-product A/New Jersey/76 virus vaccines was conducted at a boys' summer camp. Two doses of either 200 chick cell-agglutinating (CCA) or 400 CCA units of vaccine were administered four weeks apart. There were no significant side effects. Of 60 subjects, 59 developed a significant titer of serum antibody after two doses. There was no correlation between titer of antibody and total dose of vaccine. Younger subjects developed a higher titer than older subjects. A single dose of vaccine was insufficient to achieve a protective level of antibody.

Maintenance of therapeutic phenytoin plasma levels via intramuscular administration

A parenteral dosing regimen was designed for the immediate attainment and maintenance of therapeutic plasma levels of phenytoin in patients requiring anticonvulsant therapy, but not able to tolerate oral medication. An intravenous dose of 10.7 mg/kg body weight infused at a rate of 25 mg/min immediately followed by an intramuscular dose of 12.7 mg/kg body weight were administered initially. This was followed by daily intramuscular maintenance doses, generally 8.6 mg/kg body weight, until oral medication could be tolerated. Due to variability between subjects, primarily in metabolism, the predicted maintenance doses had to be adjusted in approximately one third of the patients. This regimen for the dosing of phenytoin was evaluated in 98 patients and consistently yielded therapeutic levels.

Constraints on classificatory skills in young children

On three occasions over a one-year period 23 children aged 3-4 were asked to match target objects with other objects which were similar to the target in shape or in colour but not in both. A sequence of matches to each target was asked for. The structure of these sequences is examined for evidence of classifacatory abilities. Many subjects appear to be attempting (not always successfully) to follow a strategy of 'holding fast' to their original choice of matching criterion (colour or shape) on subsequent trials. The striking differences between performance after a first-trial colour-match and after a first-trial shape-match are described. It is argued that development during this period involves an increasing ability to ignore the more salient attribute (shape) when matching by colour. The general developmental significance is discussed.

Early post-traumatic epilepsy prophylaxis

An anticonvulsant regimen is described using diphenylhydantoin specifically designed for use in the acutely head injured patient. Initial doses of diphenylhydantoin based on body weight and maintenance doses determined by plasma concentrations of the drug are utilized to provide immediate and maintainable anticonvulsant blood levels.

Genetic determination of the constitutive biosynthesis of phospho- -glucosidase A in Escherichia coli K-12

Escherichia coli wild-type cells form constitutively the enzyme phospho-beta-glucosidase A, which has a high affinity for phosphorylated aromatic beta-glucosides and a low affinity for phosphorylated beta-methyl-glucoside. Phospho-beta-glucosidase B and beta-glucoside permease I are formed in aromatic beta-glucoside-fermenting mutants. Mutants lacking phospho-beta-glucosidases A and B have been isolated. These mutants showed a reduced rate of inducibility of the beta-glucoside permease I. The restoration of phospho-beta-glucosidase A or B activity resulted in an increased rate of induction of the beta-glucoside permease I. The presence of the phospho-beta-glucosidases was not required for the constitutive biosynthesis of the beta-glucoside permease. Mutants selected for growth on beta-methyl-glucoside as carbon source showed an increased level of constitutive phospho-beta-glucosidase A activity. Gene bglD, the structural gene for phospho-beta-glucosidase A, was mapped between the pyrE locus and the cluster bgl loci, whereas bglE, the regulatory site determining the hyperproduction of phospho-beta-glucosidase A, was mapped between the bgl and ilv clusters. The bglE locus appears to have a regulatory effect on the expression of the bglD gene.

Documented enlargement and rupture of a small arterial sacculation. Case report

✓ Small aneurysms may sometimes be considered junctional dilatations but may also progressively enlarge and cause spontaneous subarachnoid hemorrhage, as in the case reported. These small aneurysms should be treated precisely as an aneurysm directly responsible for bleeding. When found in conjunction with other aneurysms, they should either be treated simultaneously or followed until clinical developments indicate the need for such surgery.