What rate of infusion of intravenous nutrition solution is required to stimulate uptake of amino acids by peripheral tissues in depleted patients?

We examined the effect of varying the quantities (0, 0.1, 0.2, 0.3, and 0.4 gN.kg-1.[day]-1) of nitrogen input on N balance, 3-methylhistidine (3MH) excretion, plasma amino acid concentration and the net flux of amino acids across the leg in depleted patients requiring parenteral nutrition. The calorie-to-nitrogen ratio was 140 to 1 (kcal:1 gN) and consequently the patients received varying amounts of calories (8, 14, 28, 42, and 56 kcal.kg-1.[day]-10. There was negative nitrogen balance and net loss of amino acids from the limb during fasting. An infusion of 0.2 gN.kg-1.[day]-1 of IVN reversed the net catabolic process and resulted in equilibrium of peripheral total amino acid flux and of tyrosine flux without a decrease in 3MH excretion. Net uptake of total amino acids and tyrosine in peripheral tissues was achieved with 0.4 gN.kg-1.[day]-1 and 56 kcal.kg-1.[day]-1. This was associated with a fivefold increase in 3MH excretion (p less than 0.01), indicating that net anabolism occurred with increased protein turnover. Fifty per cent of the amino acids taken up by peripheral tissues during infusions of 0.4 gN.kg-1.[day]-1 was due to the uptake of glutamate (Glu) and 20% was due to the uptake of branched chain amino acids (BCAA). Plasma Glu concentration, [Glu], did not increase with increasing IVN infusion, but BCAA concentrations did. Although the mean plasma [Glu] did not change with IVN infusion, there was an independent effect of plasma [Glu] (p less than 0.0001) and of N input (p less than 0.0001) on Glu flux, indicating that even at high infusion rates the maximal capacity of peripheral tissues to take up Glu had not been reached.

Psychosocial factors are associated with health care seeking rather than diagnosis in irritable bowel syndrome

The objective of this prospective study was to test the hypothesis that 6 reportedly important psychosocial factors were useful criteria for diagnosing the irritable bowel syndrome. Ninety-seven new patients with entry complaints of abdominal pain, altered bowel habits, or both underwent full evaluation by board-certified or -eligible gastroenterologists in an outpatient setting. The independent measures were 6 questionnaires concerning anxiety, depression, stress, lack of social support, somatization, and abnormal illness behavior. The dependent measure, irritable bowel syndrome, was defined as the absence of an organic disease explanation for patients' entry complaints. Two other board-certified gastroenterologists, independent of the study, made this determination. Their rating was based on full review of transcripts of patients' clinic visits, laboratory data, and the results of a 9-mo telephone follow-up to patients and their physicians. Sixty-five percent of the sample had no organic disease explanation for the entry symptoms, thereby representing irritable bowel syndrome. The psychosocial predictors did not show a significant association with irritable bowel syndrome; the power of the study was 0.86. Post hoc analysis revealed that patients with organic disease, as well as patients with irritable bowel syndrome, had significantly more (p less than 0.01) psychosocial abnormality than normal subjects, which likely contributed to the inability of the psychosocial predictors to distinguish irritable bowel syndrome from organic disease. It was concluded that psychosocial criteria were of limited value in differentiating irritable bowel syndrome from organic disease but that they were determinants of health care seeking for the entire study group.

Teaching humanistic and psychosocial aspects of care: current practices and attitudes

OBJECTIVE

To assess current practices and attitudes toward teaching humanistic and psychosocial aspects of care in internal medicine residency programs.

DESIGN AND PARTICIPANTS

Survey questionnaires were sent to residency directors at all 434 internal medicine residency programs accredited in 1985-1986. Response rate for two mailings was 71%.

MEASUREMENTS AND MAIN RESULTS

78% OF RESIDENCY DIRECTORS and 70% of department chairpersons had high or moderately high levels of commitment to teaching humanistic/psychosocial aspects of care, but only 44% of responding programs offered mandatory training, and only 18% offered elective training in these areas. Obstacles to expanded teaching of the humanistic/psychosocial aspects rated high or moderately high by residency directors included insufficient curriculum time (51%), lack of trained faculty (44%), and pressures to reduce both training costs (40%) and patient-care costs (37%).

CONCLUSIONS

Most of the training that does occur in the humanistic/psychosocial aspects of care probably happens informally via mentoring and role modeling. Appeals to expand teaching in these areas raise questions regarding what to include in medical training and the proper scope of internal medicine. Sustainable change will depend on the politics of resource distribution and the influence of general internal medicine and primary care on traditional training.

Refractive changes in silicone filled eyes

In this study we examined refractive changes of 34 eyes in 34 patients treated with silicone oil injection. Six patients presented with aphakic retinal detachment, another 14 were rendered aphakic after silicone oil injection, one was pseudophakic and 13 were still phakic at the time of writing this report. Silicone oil in the vitreous cavity induced a myopic shift in aphakic eyes and a hypermetropic shift in phakic eyes. This tended to render phakic high myopes and aphakes closer to emmetropia. The resultant refraction was dependent on the shape of the silicone oil bubble inside the eye and influenced by the posture of the patient. In phakic patients the ability to accommodate was markedly reduced.

Raman scattering and in-water ocean optical properties

Inelastic (transpectral) scattering may contribute significantly to the in-waterlightfield. Major mechanisms for inelastic scattering include Raman scattering, which we show is important in clear ocean waters, and fluorescence from a variety of sources, which may be important in more turbid waters. We have determined the Raman cross section for liquid water, 8.2 x 10(-30) (cm(2) sr(-1) molecule(-1)), which is in agreement with the lower range of published values. The influence of Raman scattering, based on predictions of a modified two-stream model, is in agreement with measured values of spectral reflectance R(lambda,z) and the spectral diffuse attenuation coefficient for irradiance K(lambda,z). Inelastic scattering has important ramifications for several aspects of marine biooptics including the determination of in-water spectral absorption, the estimation of clear water ocean optical properties, and possibly various aspects of algal photobiology.

Raman scattering and in-water ocean optical properties

Inelastic (transpectral) scattering may contribute significantly to the in-waterlightfield. Major mechanisms for inelastic scattering include Raman scattering, which we show is important in clear ocean waters, and fluorescence from a variety of sources, which may be important in more turbid waters. We have determined the Raman cross section for liquid water, 8.2 x 10(-30) (cm(2) sr(-1) molecule(-1)), which is in agreement with the lower range of published values. The influence of Raman scattering, based on predictions of a modified two-stream model, is in agreement with measured values of spectral reflectance R(lambda,z) and the spectral diffuse attenuation coefficient for irradiance K(lambda,z). Inelastic scattering has important ramifications for several aspects of marine biooptics including the determination of in-water spectral absorption, the estimation of clear water ocean optical properties, and possibly various aspects of algal photobiology.

Major pancreatic resections

A personal series of 50 major pancreatic resections has been reviewed to assess some issues of the operative decision in relation to a patient's expected outcome. An accurate histological diagnosis was not always available at the time of operation. At operation, 25 were thought to have invasive carcinoma of the pancreas and 14 to have ampullary carcinoma but the final histology demonstrated these diagnoses as accurate in 21 and 12 cases, respectively. The remaining 17 patients had a variety of histological findings which necessitated resection. Thirty-eight per cent of patients had major postoperative morbidity resulting in a median postoperative stay of 21 days after a Whipple procedure and 28 days after total pancreatectomy. The perioperative mortality rate was 6%. The median survival was 12 months for patients with invasive pancreatic carcinoma, 37 months for patients with ampullary carcinoma and 19 months for the whole group; the 5-year survival results were 13%, 40% and 25%, respectively. It is concluded that surgical resection of small pancreatic tumours is justified because some patients gain long-term survival with an acceptable risk of perioperative mortality and because the exact diagnosis may not be established at the time of surgery.

Cystic lymphangioma in the adult: an unusual axillary mass

Magnetic resonance imaging (MRI) has rapidly become an effective technique for the diagnosis and localization of most musculoskeletal diseases. Because MRI lacks ionizing radiation and has superior soft tissue contrast as compared with computed tomography without the need for intravenous contrast material, MRI is emerging as the study of choice for soft tissue masses. This report describes the use of MRI in the evaluation of an unusual axillary soft tissue mass in an adult, a cystic lymphangioma.

Validity of urinary urea nitrogen as a measure of total urinary nitrogen in adult patients requiring parenteral nutrition

The validity of the urinary urea nitrogen (UUN) estimate of total urinary nitrogen (TUN) was tested in patients who required iv nutrition. UUN and TUN were determined in 120 urine collections from ten preoperative, 13 postoperative, and 11 stressed patients. The relationship between TUN and UUN was examined by linear regression, and analysis of covariance was used on log-transformed data to assess differences between the patient groups. Although there was a close relationship between UUN and TUN for the preoperative patients (r2 = .94, total range of differences = 3.85 g N), this was not as accurate in postoperative and stressed patients (r2 = .69 and .76, respectively, total range of differences = 16.8 and 10.7 g N, respectively). There was no significant difference between the slopes of the regression lines for the relationship between UUN and TUN for three groups (f = 1.1, df = 2114, p less than .3), but the intercepts of the regression lines differed between the preoperative and stressed patient groups (t = 3.47, v = 114, p less than .001). The relationship between TUN and UUN for the whole group was improved by the inclusion of the independent variables of both the patient's clinical state and the urinary creatinine excretion. Arm muscle circumference, which is an estimate of muscle mass, may replace creatinine excretion with little loss in prediction accuracy.

Improvement of nutritional measures during preoperative parenteral nutrition in patients selected by the prognostic nutritional index: a randomized controlled trial

Patients undergoing major gastrointestinal surgery who had a prognostic nutritional index (PNI) score of greater than 30% were randomized to receive a preoperative course of 10 days of intravenous nutrition or to undergo surgery at the next convenient operation list. Two groups of 17 patients were well matched for age, sex, and nutritional status. Although they underwent diverse operations, the extent of these was similar: 12 +/- 3 days of parenteral nutrition resulted in weight gain, 3.2 +/- 2.3 kg p less than 0.01; increased triceps skinfold, 0.6 +/- 1.2 mm p less than 0.05; improved immunological state, p less than 0.02; and improved PNI, 5.5 +/- 10.1% p less than 0.05. The changes in serum albumin and transferrin were not significant. There were only three major complications with one death in the treatment group but this was not significantly different from the control group which had six major complications and three deaths. This study suggests that patients with demonstrable nutritional depletion who require major gastrointestinal surgery will benefit from a preoperative course of parenteral nutrition, but to conclusively prove this a large and probably multicentre study will be required.

Hemolysis of chicken erythrocytes by t-butyl hydroperoxide and protection by plasma

Chicken erythrocytes treated with 100-microM t-butyl hydroperoxide (t-BHP) were more than 80% hemolyzed in 2 h and more than 90% hemolyzed after 4 h of incubation. Autologous plasma retarded the rate of hemolysis of chicken red cells produced by t-BHP. Dialysis of chicken plasma resulted in a marked decrease in the ability of plasma to protect erythrocytes from hemolysis by t-BHP. Low molecular weight components of plasma such as uric acid are hypothesized to account for much of the dialyzable material that protects red cells from hemolysis.

Expression of a histone H1-like protein is restricted to early Xenopus development

Genes whose expression is restricted to oogenesis and early development may have important functions in these processes. Northern analysis showed that Xenopus B4 mRNA is expressed in oogenesis and embryogenesis through to the neurula stage. Immunocytochemistry with anti-B4 antibodies showed that B4 protein is only detectable in preneurula stages; it is localized to nuclei and is associated with metaphase chromosomes. Immunoblotting revealed approximately constant levels of B4 protein per embryo for the first 2 days of development. Thus, as the number of nuclei increases during early development, the amount of B4 protein per nucleus is diluted out. Sequencing of two B4 cDNA clones revealed that the predicted B4 translation product is a 29-kD protein with 29% identity with histone H1, distributed over the entire length of its sequence. The B4 protein also has certain other H1 protein characteristics--a tripartite structure consisting of a mainly hydrophobic central domain flanked by an amino-terminal segment and a long hydrophilic carboxyterminal tail containing a tandemly repeated amino acid motif. However, in contrast to histone H1 mRNA, B4 mRNA has a classic polyadenylation signal, is polyadenylated, and lacks the histone H1 3' noncoding consensus sequence involved in RNA processing.

Cortisol responses to cholinergic drugs in Alzheimer's disease

Patients with Alzheimer's disease participated in a trial of two sessions in which they received physostigmine and neostigmine in a double-blind crossover design. Most of these patients subsequently participated in a scopolamine vs saline double-blind crossover trial using a similar design. Physostigmine increased plasma cortisol relative to neostigmine, with the greatest difference at time points greater than 90 min post drug oral administration. Physostigmine also significantly decreased plasma cholinesterase (ChE). There was a significant positive correlation between the effects of physostigmine on increasing cortisol and decreasing ChE; there was no correlation between the increase in cortisol of cholinesterase inhibitor following neostigmine administration, but neither of these chemical parameters is related to the drug's effects on cognitive functioning.

Destruction of a translationally controlled mRNA in Xenopus oocytes delays progesterone-induced maturation

The maternal mRNA D7 is a moderately abundant transcript in Xenopus laevis whose expression is highest in, and perhaps restricted to, oogenesis and early embryogenesis. The nucleotide sequence of cloned D7 cDNA was determined and shown to have the capacity to code for a 31-kD protein. This amino acid sequence was searched against a protein data base, and no homologous proteins were found. Antibodies directed against D7 recognize in Xenopus embryos a soluble, cytoplasmic protein with an apparent molecular weight on SDS gels of 36,000. The D7 protein is absent from oocytes and first begins to accumulate during oocyte maturation. Its levels are highest during the first day of embryonic development and then decrease; D7 protein was not detected in adult tissues. D7 mRNA was selectively destroyed by injection into oocytes of antisense oligodeoxynucleotides. Analysis of injected oocytes by Northern and Western blotting showed site-specific cleavage and subsequent degradation of the D7 mRNA and the failure of the D7 protein to accumulate during progesterone-induced maturation. The loss of D7 protein affects the maturation process itself, significantly delaying the time course of germinal vesicle breakdown. Thus, D7 is a newly described protein involved in oocyte maturation.

Operative cholangiography using a modified disposable vascular clip

After frequent use of this modified disposable clip, obtaining cholangiograms has been both easy and quick while minimizing trauma to the tissues of the cystic duct. The clip can be used safely through any incision, small or large, and it is a good tool in facilitating the interoperative cholangiogram.

Serum concentrations of oestradiol and progesterone, and sexual behaviour during the normal oestrous cycle in the leopard (Panthera pardus)

Three mature nulliparous female leopards were studied for 5 years. During three separate 6-month periods serum oestradiol and progesterone concentrations were measured at weekly intervals. Oestradiol was elevated over 21 pg/ml for 54 weeks during these 3 periods, and 36 oestradiol peaks (65.8 +/- 6.3 pg/ml (mean +/- s.e.m.), range 21-172 pg/ml) were identified. Daily frequency of feline reproductive behaviours averaged over each week increased from 1.9 +/- 0.2 (n = 93) during weeks with low serum oestradiol concentrations (less than 21 pg/ml) to 5.3 +/- 0.6 (n = 54) during weeks when serum oestradiol concentrations (greater than 21 pg/ml) were high. Increased serum progesterone concentrations (13-98 n/gml) were observed on 5 occasions in 2 leopards housed together. These presumptive luteal phases lasted from 1 to 5 weeks. Baseline progesterone values were 1.6 +/- 0.4 ng/ml (n = 131). No progesterone increments were observed in isolated animals, and serum concentrations remained at baseline levels. These limited observations suggest that female leopards do not require intromission to induce ovulation and luteal function. The average interval between oestradiol peaks for cycles with no progesterone increment was 3.4 weeks (range 1-6 weeks). The interval for the 3 complete cycles associated with elevated progesterone concentrations was 7.3 weeks. Analysis of sexual behaviours over the 5-year study period revealed no evidence of seasonality in these captive leopards.

Polymerization of vertebrate non-muscle and smooth muscle myosins

We investigated how light chain phosphorylation controls the stability of filaments of vertebrate non-muscle myosins (from bovine thymocytes and chicken intestine epithelial brush border cells) and smooth muscle myosin (from chicken gizzard) in vitro. Using a sedimentation assay, the solubilities of the myosins were determined by measuring the amounts of myosin monomers (Cm) and filaments (Cp) present under a given set of conditions as a function of the total myosin concentration (Ct). Below 200 mM-NaCl, each myosin displayed distinct "critical monomer concentrations" (Cc) for polymerization, which were dependent on the salt concentration, the state of light chain phosphorylation and the presence of MgATP. At 150 mM-NaCl, MgATP increased the Cc of non-phosphorylated brush border myosin approximately five to tenfold, thymus myosin approximately 10 to 15-fold, and gizzard myosin approximately 25 to 50-fold. When these myosins were phosphorylated, MgATP had little effect on their solubilities, and their Cc values remained low. Analytical ultracentrifugation and electron microscopy demonstrated that the myosins were present in three different conformational states under the conditions used in the sedimentation assays, i.e. filaments, extended monomer (6 S) and folded monomer (10 S). Since at equilibrium only filaments and monomers were observed, we suggest that the polymerization pathway for these myosins can be analysed in terms of a dynamic monomer-polymer equilibrium (polymer in equilibrium 6 S monomer in equilibrium 10 S monomer). At roughly physiological ionic strength, light chain dephosphorylation (in the presence of MgATP) promotes the folded state (10 S), whereas phosphorylation promotes the extended state (6 S), and thereby favours filament assembly. The relevance of the monomer-polymer equilibrium to the state of organization of the myosin in vivo is discussed.

Effects of light chain phosphorylation and skeletal myosin on the stability of non-muscle myosin filaments

The effect of light chain phosphorylation and the presence of skeletal muscle myosin on the stability of non-phosphorylated non-muscle myosin filaments was investigated. Purified skeletal, brush border and thymus myosins were assembled in vitro into hybrid filaments consisting of varying proportions of (1) non-muscle and skeletal myosins, or (2) phosphorylated and non-phosphorylated non-muscle myosins. The stability of these hetero- and homopolymers in the presence of MgATP was determined using sedimentation, gel electrophoresis and immunochemical techniques. In addition, the effect of a monoclonal antibody, binding to the tip of brush border myosin tail, on the assembly of the homo- and heteropolymers, was tested. Filamentous non-phosphorylated non-muscle myosin was disassembled by MgATP to the same extent whether in homo- or heteropolymers, indicating that skeletal myosin has no stabilising effect on the hybrid filaments. The presence of small amounts of phosphorylated non-muscle myosin was, however, found to prevent the complete disassembly by MgATP of non-phosphorylated non-muscle myosin filaments, indicating that light chain phosphorylation stabilizes co-operatively non-muscle myosin filaments. The monoclonal antibody prevented the assembly of brush border myosin into both homo- and heteropolymers, and its effect on the filaments was compared with that of MgATP.