Construction of large DNA segments in Escherichia coli

Recombinant DNA clones containing large pieces of DNA are useful in the study of large genetic units, but these are difficult to make in most bacterial cloning vectors. A strategy is described that uses general and site-specific recombination to construct large pieces of eukaryotic DNA from smaller cloned segments. The large clones are propagated on F factor-based plasmids in Escherichia coli. They can be easily modified to introduce mutations or rearrangements. These techniques were applied to the construction of large DNA segments from the bithorax complex of Drosophila.

Effects of bacterially synthesized recombinant human granulocyte-macrophage colony-stimulating factor in patients with advanced malignancy

STUDY OBJECTIVE

To define the clinical and hematologic effects of subcutaneously administered bacterially synthesized recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF).

DESIGN

Single arm nonrandomized dose escalation study.

PATIENTS

Twenty-one patients with advanced malignancy who were not receiving concurrent myelosuppressive therapy.

INTERVENTIONS

Subcutaneous administration of rhGM-CSF by once-daily injection to groups of two to four patients at doses of 0.3 to 30 micrograms/kg body weight.d for 10 consecutive days. Some patients received a second 10-day period of daily rhGM-CSF treatment after a 10-day nontreatment interval followed by alternate-day treatment. Clinical status and hematologic values were monitored frequently.

MEASUREMENTS AND MAIN RESULTS

All doses of rhGM-CSF caused an immediate transient fall of 84% to 99% in circulating neutrophils, eosinophils, and monocytes. Continued daily dosing caused a leukocytosis of up to 10-fold with increases in numbers of circulating neutrophils, eosinophils, monocytes, and lymphocytes. There appeared to be a plateau in the increase in neutrophils in the dose range 3 to 15 micrograms/kg.d. Marrow aspirates showed increased proportions of promyelocytes and myelocytes. Alternate-day injection of 15 micrograms/kg maintained a leukocytosis. At doses up to 15 micrograms/kg.d, rhGM-CSF was well tolerated but adverse effects included bone pains, myalgias, rashes, and liver dysfunction. At doses exceeding 15 micrograms/kg.d, pericarditis was a dose-limiting toxicity. Idiopathic thrombocytopenic purpura was reactivated by rhGM-CSF in one patient.

CONCLUSIONS

Bacterially synthesized rhGM-CSF induces a leukocytosis in the dose range of 3 to 15 micrograms/kg.d. These doses are appropriate for phase II studies.

Genetic characterization of frameshift suppressors with new decoding properties

Suppressor mutants that cause ribosomes to shift reading frame at specific and new sequences are described. Suppressors for trpE91, the only known suppressible -1 frameshift mutant, have been isolated in Escherichia coli and in Salmonella typhimurium. E. coli hopR acts on trpE91 within the 9-base-pair sequence GGA GUG UGA, is dominant, and is located at min 52 on the chromosome. Its Salmonella homolog maps at an equivalent position and arises as a rarer class in that organism as compared with E. coli. The Salmonella suppressor, hopE, believed to be in a duplicate copy of the same gene, maps at min 17. The +1 suppressor, sufT, acts at the nonmonotonous sequence CCGU, is dominant, and maps at min 59 on the Salmonella chromosome.

Mutants of translational components that alter reading frame by two steps forward or one step back

External suppressors, sufS, of a -1 frameshift mutant cause ribosomes to shift into the -1 frame when reading the sequence CAG GGA GUG. The resulting product is not Gln-Gly-Val but Gln-Gly-Ser with Ser being encoded by the underlined AGU. The alleles investigated are approximately 2% efficient in causing frameshifting. Two other suppressors, hopR and hopE of the same -1 frameshift mutant, cause some ribosomes reading the sequence GUG UG to decode a single amino acid, Val, from the five nucleotides. The possibility is considered that peptidyl-tRNA(Val) dissociates from the mRNA, but re-pairs in a triplet manner after the mRNA slips forward by two bases.

An investigation into information provided for patients on home parenteral nutrition

A group of 34 patients who received home parenteral nutrition (HPN) were assessed by questionnaire to determine their knowledge of basic nutritional concepts, parenteral nutrition and the procedures used to monitor HPN. The results indicated that the HPN patients had an adequate knowledge of basic nutritional concepts and that this knowledge was not significantly different from that of 76 randomly selected control subjects. However, the HPN patients had significantly less understanding of parenteral nutrition and the procedures used to monitor HPN. Based on information obtained, a booklet was written to explain HPN to the same group of patients. Eighty-eight per cent of patients found the booklet either interesting or very interesting and 91% of patients reported that the booklet was read by other family members as well as themselves. Patients who had been on HPN for short periods of time learnt more from the booklet than other patients. Many patients would have appreciated more information about HPN when they first began treatment.

Sufentanil to supplement nitrous oxide in oxygen during balanced anaesthesia

Sufentanil in doses of 0.4 and 1.0 microgram/kg was used as an analgesic supplement to nitrous oxide-oxygen anaesthesia in 28 patients whose lungs were ventilated during body surface or lower abdominal surgery. Significant decreases in arterial blood pressure followed drug administration (mean 35.6%). Decreases in arterial pressure of greater than 30% occurred in 5 out of 14 patients in the low dose group, and 12 out of 14 in the high dose sufentanil group. There was a blunting of the pressor response to laryngoscopy and intubation after sufentanil. Increases in blood pressure were seen in both treatment groups at the onset of surgery. The peak responses were 27% increase in mean arterial pressure in the low dose group, and 51% increase in the 1.0 microgram/kg group. There was however no significant change in heart rate. Fourteen patients (8 in the low dose group) required volatile supplementation during surgery for clinical signs of inadequate anaesthesia. This occurred between 21 and 70 minutes after sufentanil administration, and plasma drug concentrations 0.06 and 0.54 ng/ml. Tracheal extubation was successfully achieved at the end of surgery in 26 out of 28 patients at plasma sufentanil concentrations which ranged from 0.03 to 0.37 ng/ml. The two remaining patients, neither of whom had received additional volatile supplementation, required naloxone to overcome postoperative ventilatory depression. No cases of intra-operative awareness were noted.

An evaluation of the incentive spirometer to improve lung function after cholecystectomy

Forty patients who underwent elective cholecystectomy were allocated randomly to one of two groups. Patients in one group used an incentive spirometer as part of their postoperative chest physiotherapy; those in the other received routine postoperative physiotherapy as dictated by their needs. Each group contained equal numbers of smokers and nonsmokers, and the data from each group were analysed separately. The use of the incentive spirometer did not confer any benefits as judged by clinical evidence of pulmonary complications, pulmonary function tests or length of hospital stay.

Muscle strength following anaesthesia with atracurium and pancuronium

Postoperative recovery from muscle weakness was investigated by handgrip strength after general anaesthesia using short- and long-acting muscle relaxants. Handgrip strength was measured on four occasions, preoperatively, before and after premedication, and postoperatively, both as soon as the patient could sustain a five-second headlift and one hour later. Twenty patients received either atracurium 0.6 mg/kg or pancuronium 0.1 mg/kg as part of a general anaesthetic technique with neostigmine reversal. Compared with their initial preoperative hand strengths, the two relaxant groups showed only an insignificant decrease in grip strength to 92% after premedication. Postoperatively when a five-second headlift was achieved, the patients in both groups were weak. The group given atracurium had a mean of 60% of their initial grip strength and those given pancuronium had a mean of 44%. This difference in strength was statistically significant from the initial level and from each other. However, there was no difference between the groups in the time interval from administering reversal to achieving a sustained headlift. One hour later in both groups grip strength was much better, within 80% of that seen after premedication in most patients, and no significant difference in grip strength was seen between the groups. This study demonstrates that patients who receive relaxant anaesthesia have substantial muscle weakness in the recovery phase. When neostigmine reversal is used, pancuronium appears to have a similar return of voluntary muscle power to that seen with atracurium. The marked difference in elimination kinetics of these two relaxants seems to be of little importance when neostigmine reversal is used.

On the specificity and effects on transcription of P-element insertions at the yellow locus of Drosophila melanogaster

Fourteen P-element insertion mutants at the yellow (y) gene of D. melanogaster have been analysed by restriction mapping and DNA sequencing. The distribution of the insertion sites is nonrandom, with a preferred target site in the 5'-transcribed but non-translated leader of the gene. Transcription analysis indicates that P-elements inserted into the transcribed region of y can terminate y transcription. While the great majority of the P-element insertions into the preferred target site abolish y activity, this loss of activity is not due to disruption of the insertion site since imprecise excision events which do not restore the wild type sequence at the insertion site can restore y function. We further demonstrate that a mutant caused by a 221bp P-element insertion into the 5' transcribed but non-translated region, which show partial y activity, produces a larger mutant transcript consistent with it being a product of transcriptional readthrough. We present results which suggest that imprecise excision events which restore (or partially restore) y activity can occur by deleting P-element internal sequences which normally act to terminate y transcription.

The implicit memory ability of a patient with amnesia due to encephalitis

The implicit memory ability of a patient (S.S.) with severe amnesia due to encephalitis was assessed using five independent paradigms: Perceptual priming with real words and pseudowords; Word-stem completion with and without contextual cues; Word-stem completion following presentation of high- vs. low-frequency words; Biasing of the spelling of ambiguous (homophonic) words; and Conceptual priming. On the tasks in which previously acquired knowledge could potentially be activated by a prime (e.g., perceptual priming with real words), both S.S. and the Korsakoff patients performed on a normal level. However, when new learning or new associations had to be formed prior to implicit memory testing (e.g., perceptual priming of pseudowords or contextual word-stem completion), S.S.'s implicit memory performance was superior to Korsakoff amnesics. These results suggested that new learning differentially affects the priming abilities of S.S. and alcoholic Korsakoff patients. Since S.S.'s amnesia is as severe as Korsakoff patients, it was also concluded that severity of amnesia is clearly not the sole determinant of priming capacity; etiology may be equally important.

Intermittent negative pressure ventilation in the treatment of respiratory failure in progressive neuromuscular disease

Five men with degenerative neuromuscular diseases (three with amyotrophic lateral sclerosis [ALS] and two with Duchenne's muscular dystrophy [DMD]) who had respiratory failure were treated with intermittent negative pressure ventilation (NPV). One patient with ALS in severe acute respiratory failure was successfully treated with NPV alone. This patient and two other ALS patients in chronic respiratory failure with PaCO2 elevation stabilized or improved their vital capacity (VC) and lowered their PaCO2 after 5 to 11 weeks of therapy. Finally, intermittent NPV was used to replace 24-hour positive pressure ventilation in two patients with DMD. It is concluded that intermittent NPV may stabilize or temporarily improve the respiratory status in patients with progressive neuromuscular diseases.

Disturbed behaviour in dementia--psychiatric or medical problem?

A retrospective clinical analysis of 70 demented patients who were admitted with disturbed behaviour to an acute psychogeriatric assessment and treatment centre revealed that 34.4% of patients had a significant untreated physical illness, 8.5% of patients were suffering from drug-induced toxicity and 11.4% of patients had a superimposed psychiatric illness. In only 39% of patients was progressive dementia alone considered an adequate explanation for their behavioural disturbance. The condition of the majority of patients improved significantly and they returned to the community. This study suggests that all patients with dementia with disturbed behaviour should be assessed carefully. In the majority, a clear treatable cause can be found and a good response can be attained with appropriate management.

Prognostic factors in bulimia nervosa

Factors predictive of outcome were sought from the data from a controlled study of the treatment of bulimia nervosa. Four different indices of outcome were used, and outcome was assessed at four points during a 12-month, treatment-free follow-up period. It was found that the pre-treatment level of self-esteem was a consistent predictor of outcome with those patients having low self-esteem responding least well to treatment. There were no other consistent predictors of outcome.

Evaluation of out-patient counselling compared with general practitioner care following overdoses

In a randomized prospective treatment study, 80 overdose patients (not requiring intensive psychiatric intervention) received either brief out-patient counselling or were returned to the care of their general practitioners with advice on management. There was little difference in outcome between the two groups. However, two sub-groups of patients benefited more from out-patient counselling than from general practitioner care, these were: (a) women, and (b) patients with dyadic problems. Counselling following overdoses should be focused on groups of patients such as these who are most likely to benefit from it. Further work is needed to identify treatment approaches that will help other groups who take overdoses, especially men.

Maternal narcotic addiction: pregnancy outcome in patients managed by a specialized drug-dependency antenatal clinic

A retrospective analysis has been made of the outcome of pregnancy in 174 women abusing narcotics, managed by a specialist team from a drug-dependency antenatal clinic. These women were cared for through 182 pregnancies of greater than 20 weeks' gestation, resulting in 183 live and 5 stillbirths. The majority of patients were enrolled in a methadone programme and stabilized on the drug before the third trimester. The group was characterized by a high prevalence of previous obstetric and medical problems. The most common antenatal complications were preterm labour (24%) and anaemia (12%). Preterm delivery and small-for-gestational-age each occurred in a quarter of pregnancies. The mean birth-weight for the group was 2,746 g +/- 721 g; mean +/- S.D. Eight perinatal deaths occurred (5 stillbirths, 3 neonatal deaths), giving a perinatal mortality rate of 43/1,000. The data on narcotic abusers have been compared with similar data obtained from randomly selected public antenatal clinic patients who delivered during the same period.

Primary lymphoma of prostate presenting as bladder outflow obstruction

We report on a patient with prostatic lymphoma who presented with symptoms of bladder neck obstruction. Biopsy specimens from transurethral resection confirmed the diagnosis of prostatic lymphoma. There was no evidence of lymphoma spread. Treatment was by local x-ray therapy to the prostate gland. Since prostatic lymphoma is rare, the clinical literature is briefly reviewed.

Alfentanil infusions: relationship between pharmacokinetics and pharmacodynamics in man

Fourteen fit young patients undergoing body surface surgery received an infusion of alfentanil at either 50 or 100 micrograms kg-1 hr-1 to supplement nitrous oxide anaesthesia. The alfentanil infusion was continued for two hours post-operatively at the lower rate of 20 micrograms kg-1 hr-1. Resting ventilation, carbon dioxide responsiveness and pain scores were measured post-operatively. Values for clearance and elimination half life were similar to data following single doses of alfentanil but showed considerable interindividual variation. However, there was a greater systemic clearance (P = 0.02) when determined using the post-infusion decay data compared with that calculated during anaesthesia (527 ml min-1 compared with 434 ml min-1). This is in accord with observations for other intravenous drugs.

Biasing of alcoholic Korsakoff patients' semantic memory

The extent to which the spelling of ambiguous words could be biased and the length of time this biasing could be maintained were investigated in three studies. Biasing occurred for amnesic Korsakoff patients but the effect was consistently more fragile than the biasing pattern of alcoholic control patients. Between-group differences were due to the differential dependency of amnesics' biasing upon the activation of semantic memory. The spelling bias of the alcoholic control patients appeared to be based on both semantic activation and episodic retention.

Solitary (localized) fibrous mesothelioma: evidence against mesothelial cell origin

Five cases of solitary (localized) fibrous mesothelioma were studied immunohistochemically, utilizing monoclonal antibodies against high and low molecular weight cytokeratin, vimentin, carcinoembryonic antigen, epithelial membrane antigen and factor VIII related antigen. In contrast to normal mesothelium and contrary to previous reports from malignant mesotheliomas all the tumours were negative for keratin. They were strongly positive for vimentin. Two cases were studied electron microscopically; no ultrastructural evidence of mesothelial cell differentiation was identified. Our immunohistochemical and ultrastructural findings argue against a mesothelial cell origin, whereas the presence of vimentin suggests a mesenchymal histogenesis. It is postulated that these tumours arise from sub-mesothelial mesenchymal connective tissue.

Preoperative endoscopic retrograde cholangiopancreatography in the surgical management of pancreatic pseudocysts

Preoperative ERCP was performed on 39 patients treated surgically for pancreatic pseudocysts from 1970 to 1982 at the Minneapolis Veterans Administration Medical Center. ERCP-related sepsis was rare (4 percent of patients) and only occurred when surgery was delayed for more than 24 hours. The primary benefit of preoperative ERCP was to provide detailed information on pancreatic and biliary ductal anatomic characteristics other than those specifically related to the pancreatic pseudocyst. These data influenced the choice of operation in 49 percent of the patients. Specific preoperative surgical planning was facilitated and intraoperative pancreatography and cholangiography were obviated. Major postoperative complications occurred in 21 percent of the patients (0 percent mortality) but none were considered to be related to preoperative ERCP. ERCP before operation is a safe and important adjunct to surgical management of pancreatic pseudocysts. We strongly believe, however, that the interval from ERCP to surgery should not exceed 24 hours.

Progression of field loss after trabeculectomy: a five-year follow-up

We report a retrospective study of 60 eyes from 46 patients all with primary open-angle glaucoma who had a trabeculectomy to one or both eyes. A minimum five-year follow-up was available. The percentage pressure reductions at the one and five years postoperatively is shown. In a subgroup of 50 eyes which had Goldman fields documented at least six-monthly for a minimum of five years postoperatively there was a continuation of glaucomatous field loss in 18% of eyes despite postoperative pressures in the normal range. The five-year percentage pressure reduction and the minimum percentage pressure reductions were statistically significant in a comparison between the field loss and no field loss groups. However, in the individual case there seemed no way of predicting which eyes would develop postoperative field loss, and regular postoperative perimetric assessment was found to be essential whatever the pressure measurements recorded.

Identification of a high density lipoprotein binding protein from adrenocortical membranes

A protein band with an apparent molecular weight of 78,000 daltons has been identified in the solubilised plasma membrane extract of sheep adrenal cortex which binds HDL3 devoid of E apolipoprotein. Following 'Western' blotting, and development of the nitrocellulose strips with appropriate antisera and color reagent, the same band, unlike other cortical membrane proteins or albumin, bound AI and AII apolipoproteins. Human LDL bound weakly to the same band but more strongly to another two proteins of higher molecular weight. These studies confirm the same degree of specificity of HDL3 binding found with cultured adrenal cells and strengthen the suggested existence of a specific HDL receptor.

Superficial temporal-middle cerebral artery anastomosis: effects on vascular, neurologic, and neuropsychological functions

In 44 patients, we studied the effects of superficial temporal-middle cerebral artery anastomosis on cerebral blood flow (CBF), neurologic examination, and cognitive functions. At 3 months, there was significant improvement in all variables. At 9 months, CBF was no longer significantly greater, but neurologic examination and cognitive functions had further improved. Patients with TIA had significant postoperative decreases in TIA frequency and did not progress to stroke, but had no significant changes in any variable. In stroke patients, we could not separate the effects of surgery from the natural evolution of changes in CBF and examination after stroke. None of the preoperative measurements predicted postoperative clinical improvement.

Correcting the eating disorder in anorexia nervosa

The aim of the present study was to assess whether direct informational feedback using videotape recordings would improve abnormal eating behaviour in patients with anorexia nervosa. Eight inpatients participated in the study. A statistically significant improvement was noted in the occurrence of obsessional eating behaviour and in table manners. However, there was no change in the speed of eating, disposal of food or behaviours which reduce caloric intake. The implications of these findings for the treatment and prognosis of anorexia nervosa are discussed.

The significance of the neurotic symptoms of bulimia nervosa

The significance of the neurotic symptoms of bulimia nervosa is a subject of current debate. In the present paper, data are reported on changes in these symptoms during the course of psychological treatment directed at the eating disorder itself. A significant association was found between outcome in terms of eating habits and the severity of neurotic symptoms after treatment. There was no association between outcome and the pre-treatment level of neurotic symptoms. These findings suggest that the neurotic symptoms are likely to constitute a secondary psychological reaction.

Relation of respiratory water loss to coughing after exercise

Exercise has been shown to result in bronchoconstriction, the extent of which is related to respiratory heat loss. Some normal subjects report coughing after exercise, and to determine whether this might also be related to respiratory heat loss, we monitored cough frequency after hyperpnea with air of varying temperature and water content in seven such subjects. Hyperpnea with fully saturated air at 37 degrees failed to provoke coughing and was not associated with heat loss or water loss. Hyperpnea with dry air at 37 degrees C resulted in more water loss (P less than 0.0005), less heat loss (P less than 0.01), and more coughing (P less than 0.001) than hyperpnea with subfreezing air. Hyperpnea with ambient air was associated with a similar cough frequency and water loss but with less heat loss (P less than 0.001) than hyperpnea with subfreezing air. There was a direct relation between cough frequency and respiratory water loss but no consistent relation between cough frequency and respiratory heat loss. This study indicates that coughing after hyperpnea with poorly conditioned air is related to the overall rate of respiratory water loss. Since strenuous exercise is associated with marked hyperpnea, coughing after exercise may also result from respiratory water loss.

Peritoneovenous shunt therapy for leaking ascites in the cirrhotic patient

Review of clinical and operative records of 86 patients at the Minneapolis VA Medical Center and Mount Sinai Hospital undergoing peritoneovenous (PV) shunt for intractable ascites revealed a subgroup of patients (n = 9) who developed leaking ascites prior to shunting. The etiology of leaking ascites was as follows: 1) ruptured umbilical hernia ( UH ) (four patients), 2) repeated paracentesis (three patients), and 3) postoperative incisional ascitic fluid leak (two patients). Initial therapy included local sterile compression dressing, intravenous antibiotics, and management of fluid and electrolytes. All nine patients underwent subsequent closure of the fascial defect and PV shunt to prevent reaccumulation of ascites (simultaneous procedures were performed in five patients). No patient developed postoperative septic complications, organ failure, gastrointestinal bleeding, or encephalopathy. There were no early deaths; however, three late deaths (18 months, 2, and 4 years) were due to variceal bleeding and/or liver failure. Ascites was well controlled in seven patients with PV shunt alone, the other two ultimately responding to medical therapy. We conclude that peritoneal fluid leaks can be treated successfully by repairing the fascial defect and placing a PV shunt. In the absence of infected ascites and clinical peritonitis, PV shunt may be performed simultaneously with closure of UH , thus preventing the reaccumulation of ascites during the immediate postoperative period.

Bilateral ovarian carcinoma with bilateral uveal melanoma

A case of bilateral uveal melanoma in a 60-year-old woman in association with primary bilateral ovarian carcinoma is described. This is the first case in which ultrastructural studies have been performed on the ocular tumours. Seven previously described cases are summarised, and the extreme rarity of such reports would suggest that this may indeed be a new syndrome.

Surgical wound infections. A 5-year prospective study of 20,193 wounds at the Minneapolis VA Medical Center

This report describes a 5-year prospective study of postoperative wound sepsis utilizing a careful program of wound surveillance. Surgical wounds following 20,193 operations on all surgical services were surveyed by a trained nurse epidemiologist. Daily examination of wounds, culture of all suspicious wounds, and 30-day outpatient clinic follow-up were performed. Results were disseminated at monthly intervals to all involved surgeons and operating room personnel. Prospective and ongoing analysis of results facilitated identification and rectification of specific problem areas. Wound infection rates demonstrated a steady decline over the course of the study, overall rates dropping from 4.2% to 1.9% (p less than 0.05). This reduction in incidence of postoperative wound sepsis of 55% is estimated to have saved 2740 inhospital days and nearly $750,000.

Improving the cough in patients with spinal cord injury

Eleven patients with complete cervical and two patients with complete thoracic spinal cord injury were evaluated during both a forced vital capacity and cough. The mean peak flow was 3.74 +/- .171 L/sec during the forced vital capacity and 3.73 +/- 1.5 L/sec during the cough. Both values are low. Using the abdominal push assist during cough there is 13.8% improvement in peak flow which was significant. (p less than 0.01). This was not true with the forced vital capacity even though 9/10 subjects did improve. While peak flow is only one aspect of effective cough the improvement plus the increased intrathoracic pressure suggests this maneuver may be an effective modality in individuals with spinal cord injury.

Double blind study comparing the efficacy of zimelidine and amitriptyline in endogenous depression

Thirty-nine (39) patients entered a double blind study conducted to compare the therapeutic efficacy and safety of Zimelidine and amitriptyline in endogenous depression. Following a 3-5 day washout period, patients were randomly allocated to Zimelidine or amitriptyline for 6 weeks period and were assessed regularly. 63% of Zimelidine and 65% of amitriptyline patients showed significant clinical improvement. Side effects recorded with amitriptyline were predominantly anticholinergic and headaches with Zimelidine. It is concluded that while Zimelidine and amitriptyline show equally efficacous antidepressant properties, zimelidine may offer a slight therapeutic advantage due to lack of anticholinergic side-effects.

Kinetic analysis of the specificity of human natural cytotoxicity

Distribution-free analysis of kinetic data for cellular cytotoxicity reactions enables the precise determination of kinetic parameters for the lysis of target cells by individual lymphocyte preparations. This report presents results obtained when this method was used to quantitate the inhibition of human natural cytotoxicity by unlabelled (cold) target cells. In agreement with previous studies, we found that the natural cytotoxicity of a given target cell can be inhibited by heterologous as well as homologous unlabelled cells; however, the strongest inhibition was usually produced when the unlabelled inhibitor cells were homologous to the labelled target cells. The general pattern of inhibition observed for the target and inhibitor cells tested in these experiments was competitive, and when inhibitor cells were homologous to the labelled cells, the observed increase in Kappm agreed with theoretical predictions based on equations derived previously. These results support earlier reports of limited but not absolute antigenic specificity by subsets of human NK cells. Moreover, while Kappm values for cytotoxicity reactions are not simply related to antigen binding, quantitative analysis of the relative inhibition of cytotoxicity by heterologous versus homologous unlabelled cells provides useful estimates of the relative affinity of the effector cell subset(s) that kill a given target cell for various NK target cells.

Liposarcoma. A review of factors influencing prognosis

Tumors of adipose differentiation demonstrate considerable histologic variability as well as a wide variation in behavior patterns. A variety of clinical, gross, and microscopic features are useful in predicting behavior. Unfortunately, a number of different classification systems for liposarcoma with confusing nomenclature appear in the literature. This paper reviews general features affecting prognosis and presents a summary of the major classification systems. A subclassification of tumors into three grades (high, intermediate, and low) is suggested, based on potential for malignant behavior. Our system of grading may be used to guide the surgeon in the course of therapy. In light of the potential for confusion in identification and classification, good communication between surgeon and pathologist is essential to choice of appropriate therapy and ensuing chances for recurrence or survival.

31P NMR spectroscopy of brain and heart

31P NMR technique was applied to monitor changes in the energy metabolism of the brain and heart of unanesthetized cats during shock, stroke, hypoxia and increased functional activity. The results show that in these tissues content of inorganic phosphate, sugar phosphates, phosphocreatine and of ATP can be measured decently in awake animals. At the same time this technique has the great advantage over the disruptive biochemical methods that it gives a semi-continuous reading and it is non-invasive. Our findings are summarized as follows: Hemorrhagic shock resulted in an irreversible deterioration of the energy state of the brain. Our stroke model led to a very marked increase in Pi and a decrease CP in the brain but these changes were reversible. The ATP levels of the brain as it was indicated by 31p NMR spectra were not affected by hemorrhagic shock and stroke which can be attributed probably by the reduced rate of ATP consumption. The verification of this hypothesis needs further work. During increased mechanical performance the levels of SP, and Pi increased, ATP decreased, while CP was not influenced in the heart.