Evidence that cocaine slows cardiac conduction by an action on both AV nodal and His-Purkinje tissue in the dog

The effects of intravenous cocaine (2 mg/kg) were tested on several indices of cardiac electrical activity in sedated dogs. These included sinus rate, PR, AH, and HV intervals; AV nodal effective refractory period (AVNERP); ventricular effective refractory period; QRS duration; and the QT interval. Cocaine induced significant changes in six control animals with an intact-functioning autonomic nervous systems. After pharmacologic autonomic blockade with propranolol plus propantheline, cocaine increased the PR interval (+ 11 +/- 4.0 ms, p less than 0.05), primarily by slowing conduction at the AV nodal level. However, with constant atrial pacing at a rate above the sinus cycle length, prolongation of both the AH and the HV intervals (+ 15 +/- 2.5 and 6.7 +/- 1.7 ms, respectively) occurred. There was also a significant increase in the AVNERP (+ 29 +/- 5.9 ms, p less than 0.05). Consistent with the observed rate-dependent HV prolongation, cocaine decreased the rate of rise of phase 0 of the transmembrane action potential of Purkinje fibers. These data indicate that cocaine impairs cardiac conduction by direct actions on AV nodal and His-Purkinje cells.

Nuclease P1-mediated fluorescence postlabeling assay of AAF modified DNA model d(TACGTA) and calf-thymus DNA

Fluorescence postlabeling assay for DNA damage combines enzymatic digestion of modified DNA to nucleoside monophosphates and fluorescence postlabeling. However, to facilitate the quantitative release of bulky adducts that are not readily obtained as mononucleotides, a different mechanism is essential. In order to test the application potential of nuclease P1-mediated fluorescence postlabeling to assay bulky adduct, d(TACGTA) was reacted with N-acetoxy-2-acetylamino-fluorene. The major product, characterized by nmr as AAF adduct of the guanine moiety at the C-8 position, was used as a DNA model. Nuclease P1 digestion of the modified oligomer excised the adduct in two forms (3:1) which were identified as AAF modified d(pGpT) and dpG respectively by cochromotography with authentic markers. Fluorescence postlabeling assay of AAF modified d(TACGTA) detected both forms of the excised adduct. The application of the overall procedure to assay AAF modified calf-thymus DNA demonstrated that the extension of fluorescence postlabeling technique from the mononucleotide to the dinucleotide version expands the scope of the assay.

Receptor-mediated immunomodulation by corticotropin-releasing factor

In both normal and adrenalectomized rats, exogenous corticotropin-releasing factor (CRF) suppresses immune function, and stress-induced immunosuppression can be partially reversed with either CRF antibody or CRF antagonist, suggesting a role for CRF in immunomodulation. We now report binding of CRF to human monocyte-macrophages and T-helper lymphocytes but not to T-suppressor or B lymphocytes. Bound CRF was displaced by synthetic CRF as well as CRF antagonist. CRF binding at these sites was accompanied by increases in the concentration of cAMP (but not cGMP) in the cells, with minimal and maximal effective CRF doses of 10(-13) and 10(-6) M for the monocyte-macrophage and 10(-12) M and 10(-8) M for the T-helper cell. Production of cAMP in response to CRF was effectively inhibited by CRF antagonist in both cell types. Moreover, rat splenocyte proliferation induced by interleukin 2(IL-2; 110 IU) was blocked by CRF, half-maximally at a CRF dose of 2.2 x 10(-10) M and completely at 3.5 x 10(-9) M. Finally, when CRF was added together with a 50-fold molar excess of CRF antagonist the IL-2 effect was fully restored. This demonstration of specific, physiologically relevant CRF receptors on two key immunocytes, the monocyte-macrophage and the T-helper lymphocyte, along with in vitro immunosuppression concomitant with CRF binding reinforces the growing body of evidence for a prominent role for CRF in immunomodulation.

Corticotropin-releasing factor modulates the immune response to stress in the rat

We examined the role of CRF, a key mediator of the endocrine response to stress, in modulating immunosuppression during the subacute stress of intermittent electrical shock over 1 h. Administration of shock to intact rats resulted in a 74% decrement in T-lymphocyte proliferation and a 59% decrease in natural killer cytotoxicity. Similar suppression of these two parameters of immune function in response to shock was noted in adrenalectomized rats as well. The immunosuppressive effects of this shock were significantly and comparably blunted when both intact and adrenalectomized animals were pretreated 1) iv with either a highly potent polyclonal CRF antibody or a specific CRF antagonist or 2) intracerebroventricularly with either a high affinity monoclonal antibody to CRF or a specific CRF antagonist. An immunomodulatory role for CRF is further supported by the findings that administration of exogenous CRF, either iv (10 micrograms/animal) or intracerebroventricularly (1 microgram/animal), resulted in significant decrements in lymphocyte proliferation and natural killer cytotoxicity, similar to those seen with the stress paradigm. Our observations indicate that CRF plays a significant role in modulating the immune response to subacute stress, largely by adrenal-independent mechanisms.

Structure-activity relationship of antiestrogens. Studies on 2,3-diaryl-1-benzopyrans

A series of 2,3-diaryl-1-benzopyran analogues substituted at position 4 of 2-phenyl with a hydroxy or pyrrolidinoethoxy residue were synthesized as models for (E)-triarylpropenones constrained in the s-trans conformation. The prototypes, belonging to five chemical series, were evaluated for their estrogen receptor affinity and for estrogen agonist-antagonist activities. The 4H-1-benzopyran-4-one, the 2,3-dihydro-4H-1-benzopyran-4-one, the 4H-1-benzopyran, and the 2,3-dihydro-1-benzopyran derivatives were found to be inactive or only marginally activate as receptor ligands or estrogen agonists-antagonists. In the 2H-1-benzopyran category the parent phenol was also inactive whereas the basic ethers 16 and 26 were modest receptor ligands while being quite active as antiestrogens. In a comparative study the benzopyran 16 was found to be more effective antiestrogen than tamoxifen while being as effective as LY-117018. The benzopyrans have thus emerged as a new class of potent antiestrogens.

Peripheral blood lymphocyte subpopulations in Indian women with cervical intraepithelial neoplasia and invasive cancer--an immunocytochemical study using monoclonal antibodies

The peripheral blood lymphocyte subpopulations in Indian women with various grades of cervical intraepithelial neoplasia [33], invasive cancer [22] and matched controls [30] were studied using specific monoclonal antibodies and biotin avidin immunofluorescence technique. Our results showed a significant fall in peripheral T (CD2) B(CD22) cells in patients with CIN III and invasive cervical cancer lesions compared to controls (P less than 0.001). Similarly the quantum of T helper cells (CD4) decreased according to the severity of cervical lesions (P less than 0.01 - P less than 0.001), whereas the T suppressor cells (CD8) depicted an increasing trend in patients with higher grade of cervical lesions (CIN III and invasive cancer, P less than 0.001) as compared to controls. Further, the CD4/CD8 ratio showed a significant downfall with the severity of cervical lesions (P less than 0.01 - P less than 0.001), indicating a perturbance in the homeostasis of host cellular immunity.

Balloon dilatation of esophageal strictures

The Gruntzig balloon dilatation catheter is an invaluable tool for the dilatation of long and narrow oesophageal strictures which are not amenable to other forms of dilatation. We present our experience of 43 dilatations of oesophageal strictures in 14 patients without any significant complications. This procedure resulted in significant symptom-free periods in all patients, and the resultant improved nutritional status of these patients prepared them for surgery.

Ultrasound guided percutaneous intervention in the complicated renal transplant

We successfully performed 19 ultrasound guided percutaneous interventional procedures on 10 renal transplant recipients with urological complications. Seven of the procedures were diagnostic (antegrade pyelograms) and 12 therapeutic (aspiration of pelvic fluid collections 9, and percutaneous nephrostomies 3). All procedures were without major complications. The diagnostic procedures provided information which' contributed to better patient management. The therapeutic procedures improved the renal functions of patients and stabilized them for surgical management when necessary. We conclude that ultrasound guided percutaneous interventional procedures are safe and they may be helpful in the management of urological complications in renal transplant recipients.

Intestinal ornithine decarboxylase: half-life and regulation by putrescine

Ornithine decarboxylase (ODC) is the primary rate-limiting enzyme for polyamine synthesis. ODC levels are increased in most tissues, including the intestinal mucosa, by growth-promoting agents. This enzyme has a brief half-life of from 5 to 30 min in mammalian tissues and is regulated by its product; putrescine. The current study examines the turnover and regulation of ODC in the mucosa of the small intestine. With the use of scraped intestinal mucosa from cycloheximide-treated rats, the time course of the decline in ODC activity yielded a half-life of approximately 22 min. Labeling enzyme protein with [3H]difluoromethylornithine (DFMO) resulted in a nearly identical estimation of half-life. ODC activity of mucosa from isolated gut segments stimulated by luminal glycine (0.1-0.4 M) was enhanced 60-100% by 10 mM putrescine administered luminally. Putrescine alone had no effect on ODC. In contrast, 10(-7) M putrescine prevented 80% of the ODC activity stimulated by asparagine in IEC-6 cells (a rat intestinal crypt cell line). The half-life of ODC in unstimulated IEC-6 cells was 20 min and increased to 35 min in cells exposed to 10 mM asparagine. These data demonstrate that ODC of nonproliferating villous cells is regulated differently from the identical enzyme in proliferating crypt cells. Therefore, conclusions regarding mucosal growth should not be based totally on ODC activity from whole mucosa, since it is essentially a measure of only the enzyme present in the villous cells.

Intestinal glucoamylase & other disaccharidases in children with protracted diarrhoea

Brush border lactase, sucrase and glucoamylase activities were assessed in jejunal mucosal biopsy specimens from 34 children (median age 11 months; range 1.5-38) having protracted diarrhoea with failure to thrive and 8 well nourished children with normal jejunal mucosal histology (median age 10.2 months; range 2-37). All enzymes showed progressive decrease in activity which was directly in relation to increasing degree of mucosal injury (P less than 0.002). Lactase was significantly reduced even in patients with protracted diarrhoea and normal mucosa (P less than 0.05). Glucoamylase and sucrase were significantly reduced only in the presence of mucosal injury (P less than 0.01). Our data suggest that most children with protracted diarrhoea may not tolerate lactose containing feeds and may need lactose-free diets preferably based on starch. A small number of children with protracted diarrhoea, who have severe mucosal injury may not be able to handle even starch and may require diets based on short chain glucose polymers. The findings of this study, need to be corroborated with well-controlled metabolic balance studies.

Serum anti-gliadin antibody profile in childhood protracted diarrhoea due to coeliac disease and other causes in a developing country

Serum anti-gliadin antibody (AGA) titres were estimated by diffusion in a gel enzyme-linked immunosorbent assay in children with coeliac disease (n = 11), protracted diarrhoea of non-coeliac causes (n = 110), acute gastroenteritis (n = 20), protein energy malnutrition (n = 20), and asymptomatic, well-nourished children (n = 66). The mean IgG and IgA AGA titres were significantly higher (p less than 0.001) in children with coeliac disease than in any other groups. There was no significant difference (p greater than 0.01) in AGA titres in relation to age, nutritional status, or severity of villous injury. In patients with coeliac disease AGA titres showed a good correlation with disease activity. The specificity and sensitivity of the assay are discussed.

Frequency of puncture injuries in surgeons and estimated risk of HIV infection

To evaluate the occupational risk of human immunodeficiency virus (HIV) infection, we surveyed 202 surgeons working in the New York City metropolitan area. One hundred seventy-three (86%) surgeons reported at least one puncture injury in the preceding year (median number, 2 per year; interquartile range, 1 to 4 per year). Seventy-six percent of the injuries occurred during surgery, and the median injury rate was 4.2 per 1000 operating room hours. Twenty-five percent of the surgeons sustained yearly injury rates of 9 or more per 1000 operating room hours, and these high rates were independent of sex, age, type of practice, operative work load, or hospital location. Fifty-three percent of all injuries involved the index finger of the nondominant hand. If the prevalence of HIV infection in surgical patients is 5%, then the estimated 30-year risk of HIV seroconversion is less than 1% for 50% of the group, 1% to 2% for 25% of the group, 2% to 6% for 15% of the surgeons, and greater than 6% for 10% of the surgeons.

A delay-based approach for congestion avoidance in interconnected heterogeneous computer networks

In heterogeneous networks, achieving congestion avoidance is difficult because the congestion feedback from one subnetwork may have no meaning to sources on other subnetworks. We propose using changes in round-trip delay as an implicit feedback. Using a black-box model of the network, we derive an expression for the optimal window as a function of the gradient of the delay-window curve.The problems of selfish optimum and social optimum are also addressed. It is shown that without a careful design, it is possible to get into a race condition during heavy congestion, where each user wants more resources than others, thereby leading to a diverging condition.It is shown that congestion avoidance using round-trip delay is a promising approach. The approach has the advantage that there is absolutely no overhead for the network itself. It is exemplified by a simple scheme. The performance of the scheme is analyzed using a simulation model. The scheme is shown to be efficient, fair, convergent, and adaptive to changes in network configuration.The scheme as described works only for networks which can be modeled with queueing servers with constant service times. Further research is required to extend it for implementation in practical networks. Several directions for future research have been suggested.

Structure-activity relationship of antiestrogens: a study using triarylbutenone, benzofuran, and triarylfuran analogues as models for triarylethylenes and triarylpropenones

In a study of the structure-activity relationship (SAR) of antiestrogens use has been made of certain 1,2,3-triarylbutenones, of 2-arylbenzofurans carrying aryl or aroyl substituents at C3, and of 2,3,4-triarylfurans as conformationally constrained models for triarylethylene (TAE) and triarylpropenone (TAP) prototypes. The position-specific contributions of substituents to receptor affinity and to agonist-antagonist profiles were used as aids in characterizing the relative binding orientation of the prototypes. Although most compounds were found to be weak receptor ligands and poorly active in vivo, the following conclusions could be drawn about their SAR: (i) (Z)-TAPs and TAEs interact with the receptor in an analogous manner using the trans-stilbene core, with their agonist-antagonist profiles depending on the nature of other substructures. (ii) Incorporation into the benzofuran framework introduces a stereoelectronic constraint that compromises the normal binding interactions of TAE, as well as TAP, prototypes, resulting in their poor affinities and weak biological activities. (iii) (E)-TAPs can interact with the receptor through their S-cis conformation, but such a binding mode is unlikely to account for their behavior as antagonists.

Characteristics of spermidine uptake by isolated rat enterocytes

Eukaryotic cells require polyamines for growth. The supply of polyamines to growing cells may be increased either by new synthesis or increased uptake. We have recently shown that putrescine uptake by isolated rat enterocytes is energy dependent, saturable, and ouabain insensitive. Although putrescine uptake was inhibited by putrescine and cadaverine, it was not inhibited by equal concentrations of spermine and spermidine. These data indicated that a carrier mechanism separate from that putrescine existed for spermidine and spermine. In the current study spermidine uptake by isolated enterocytes was saturable, temperature dependent, and inhibited by 1 mM KCN. Kinetic analysis resulted in a Km = 2.51 x 10(-6) M and a Vmax = 3.57 x 10(-12) mol.10(6) cells-1.15 min-1. Spermidine uptake was 70% inhibited by 1 mM ouabain. Replacement of sodium by choline, lithium, tetramethylammonium, or N-methyl-D-glucamine also inhibited spermidine uptake. Replacement of Na+ by mannitol or sucrose, however, depressed uptake but not significantly. Spermidine uptake was inhibited by 1 mM ouabain. Spermidine uptake was inhibited by relatively low concentrations of spermine and high concentrations of putrescine; while putrescine uptake was inhibited by relatively high concentrations of both spermine and spermidine. Kinetic data indicated that spermidine and spermine share a carrier that is distinct from the one mediating the uptake of putrescine. While spermidine uptake does not appear to depend on Na+ cotransport, it may be dependent on the electrical gradient established by the Na+-K+-ATPase.

Increased faecal alpha-1-antitrypsin excretion in children with persistent diarrhoea associated with enteric pathogens

The random faecal alpha-1-antitrypsin (AT) excretion (mg/g dry weight of stool) was measured in 30 infants and children (mean age 10.8 +/- 8 mo.) with protracted diarrhoea (duration greater than or equal to 21 days) and failure to thrive and 27 normally nourished children (mean age 13 +/- 4.5 mo.) without any gastrointestinal symptoms in the preceding 12 weeks. The associated factors in patients with protracted diarrhoea and their mean faecal AT during active disease and 3-4 weeks after recovery were as follows: Enteropathogenic E. coli 5 (7.9 +/- 5.5; 3.2 +/- 0.6), Giardia lamblia 4 (3.9 +/- 1.8; 2.5 +/- 0.7), Salmonella typhimurium 3 (4.0 +/- 0.2; 3.8 +/- 0), secondary carbohydrate intolerance 11 (2.5 +/- 0.9; 2.4 +/- 0.8), and others 7 (3.4 +/- 0.7; 3.0 +/- 0.5), respectively. Of all the patients with protracted diarrhoea the mean AT in the E. coli, Giardia and Salmonella groups were significantly higher than the mean in the control group (2.1 +/- 0.8) and following treatment and recovery the values were comparable to that in the controls. All the 6 patients with very high faecal AT (greater than mean + 3 SD of controls) were associated with an enteric pathogen.

Outcome of low birth weight babies with special reference to some maternal factors

Neonatal outcome of 178 low birth weight (LBW) babies in this study was associated with 26.4% neonatal mortality. A significantly higher mortality rate was noted in presence of adverse maternal factors, birth weight less than 1.5 kg, prematurity and respiratory distress at birth. Premature rupture of membranes and leaking (greater than 12 h) were recorded in 75 cases. Significant association was observed for septicemia. Maternal postpartum weight less than 40 kg was associated with higher incidence of neonatal infections than when mother's weight was greater than 45 kg.

Recent advances in the development of a diagnostic test for irradiated foodstuffs

Recent advances in the development and application of diagnostic tests for irradiated foodstuffs are reviewed. Exposure of water, the major chemical constituent of most foodstuffs to a source of ionising radiation initially generates the highly reactive radical species H., .OH and e- (aq) which react very rapidly with a wide variety of biological molecules. The detection of foodstuffs subjected to irradiation processing requires the identification and/or quantification of 'unnatural' chemical species (i.e. those not usually formed by normal metabolic processes) produced by the attack of .OH radical or e- (aq) on suitable 'target' molecules. Modern methods for the analysis of a series of these 'unnatural' products arising from the interaction of radiolytically-generated .OH radical or e- (aq) with polyunsaturated fatty acids, DNA, aromatic compounds and other biologically important scavenger molecules are examined. It is concluded that the analytical test to be conducted is highly dependent on the nature of the foodstuff to be tested.

Quantitative measurement of renal perfusion following transplant surgery

We developed an easily implemented clinical procedure for quantitative perfusion measurements in transplanted kidneys using intravenously administered [99mTc]DTPA and the tracer fractionation technique. F = Ak(T)/0 integral of T [Aa(t)/Va] dt, where F = renal blood flow, Ak(T) = DTPA activity in kidney at time = T, Va = ultrasonographically measured femoral artery segment volume, T = time postinjection of F determination, and Aa(t) = time course of DTPA activity in femoral artery segment. The technique was applied to a group of 80 studies in 35 patients in whom an independent clinical determination of transplant function was available. Blood flow (units of ml/min) measured 439 +/- 83 in normally functioning transplants, 248 +/- 63 in transplants with acute tubular necrosis, 128 +/- 62 in transplants with rejection, and 284 +/- 97 in transplants with cyclosporine toxicity. These preliminary results indicate potential usefulness of this method in the evaluation of renal function following transplant surgery.

Reverse and pseudo redistribution of thallium-201 in healed myocardial infarction and normal and negative thallium-201 washout in ischemia due to background oversubtraction

While the interpolative background subtraction used in quantitative planar thallium scanning can significantly overestimate the background overlying the heart, the effects of background oversubtraction on quantitative analysis have not been well defined. A mathematical model that relates myocardial washout determined using interpolative background subtraction to true myocardial washout is presented. The model was validated using phantoms and applied to myocardial and pulmonary thallium kinetic data in 100 patients, 85 with and 15 without coronary artery disease. The model showed that when using interpolative background subtraction, measured washout equals true washout in normally perfused myocardium; however, depending on the relation between myocardial and pulmonary thallium clearance, myocardial washout in ischemic regions and areas of infarction can be substantially over- or underestimated. Based on generally accepted quantitative criteria, this incorrect washout determination can at times lead to misdiagnosis of infarction as ischemia and ischemia as normally perfused tissue. It can also cause both "reverse redistribution" and "pseudo redistribution" of thallium in myocardial infarction in the absence of a physiologic basis.

Vitamin status in patients undergoing single or multiple plasmapheresis

Folate, thiamin, nicotinate, biotin, riboflavin, pantothenate, vitamins A, B6, B12, C, E, and beta-carotene were determined in: (a) eight patients before and after one plasma exchange; (b) in one patient after five consecutive treatments; (c) in three patients before and 2-8 weeks after plasmapheresis. Vitamin B12, beta-carotene, vitamin B6, and vitamins A, C, E were depressed after acute or chronic plasmapheresis. Concentrations of folate, thiamin, nicotinate, biotin, riboflavin, and pantothenate were essentially unchanged after one plasma exchange.

A theoretical model for water flux through the artery wall

A two layer model for water flux through the artery is studied using a mathematical model based on the theory for the consolidation of water saturated soils. The matrix is considered to be constituted by two layers with different permeabilities and different elastic constants and the two systems of equations are coupled with the condition of continuity of pressure, total stress, solid displacement and fluid seepage velocity at the interface. The luminal pressure is considered to be harmonic in time. Exact solutions are obtained for displacements and pressures in both the layers. For large consolidation times, large pressure gradients are found to exist near the boundaries and at the interface. The heterogeneous model may not only be useful to understand the mechanics of transport in the physiological system but it will also help the bioengineers to choose proper implant materials to design artificial vascular organs for the purpose of prosthesis.

Stimulation of ornithine decarboxylase activity in digestive tract mucosa

Refeeding fasted rats with normal rat food and with a variety of amino acids increases ornithine decarboxylase (ODC) activity considerably. The time course of that increase, the areas of the digestive tract directly affected, and the effective concentrations of stimulants are unknown. By use of isolated 5-cm segments of rat jejunum, we determined that maximal activation of ODC occurred after a 2-h exposure to 0.6 M glycine. Increased activity was first apparent after a 1-h exposure to glycine and was significant after a 2-h exposure to 0.05 M glycine. ODC activity increased the most in segments of jejunum, followed by segments of ileum and then duodenum. Glycine (0.4 M) failed to increase ODC activity in gastric and colonic mucosa. Interestingly, D-alanine was more effective than L-alanine in stimulating ODC activity in the jejunum. Enzyme activity was not dependent on osmotic activity of the test substances. Glucose increased enzyme activity, but mannitol and fructose were without effect. The effects of glycine were significantly greater than those of glucose. In summary, ODC of the small intestinal mucosa is increased by direct contact with amino acids and glucose within 2 h after exposure. Increased enzyme activity depends on the nature of the stimulant rather than the osmotic activity of the solution in contact with the mucosa.

Destabilized carbocations. Nuclear magnetic resonance detection and reactivities of aryl α-thioformamidyl cations

A series of α-aryl and diarylthioformamidyl cations were observed by low-temperature nuclear magnetic resonance spectroscopy. These ions undergo efficient cyclization and deprotonation to give benzothiophenes.

Motion stereo using ego-motion complex logarithmic mapping

Stereo information can be obtained using a moving camera. If a dynamic scene is acquired using a translating camera and the camera motion parameters are known, then the analysis of the scene may be facilitated by ego-motion complex logarithmic mapping (ECLM). It is shown in this paper that by using the complex logarithmic mapping (CLM) with respect to the focus of expansion, the depth of stationary components can be determined easily in the transformed image sequence. The proposed approach for depth recovery avoids the difficult problems of establishing correspondence and computation of optical flow, by using the ego-motion information. An added advantage of the CLM will be the invariances it offers. We report our experiments with synthetic data to show the sensitivity of the depth recovery, and show results of real scenes to demonstrate the efficacy of the proposed motion stereo in applications such as autonomous navigation.

Differential effects of 4-hydroperoxycyclophosphamide on limb development in vitro

Cyclophosphamide must be metabolically activated to produce malformations in limbs developing in culture; 4-hydroperoxycyclophosphamide is an analog of the active metabolite of cyclophosphamide, 4-hydroxycyclophosphamide, that breaks down spontaneously in solution to form 4-hydroxycyclophosphamide. To study the mechanism by which metabolites of cyclophosphamide produce limb malformations in vitro we determined the effects of exposure of cultured limb buds to 4-hydroperoxycyclophosphamide. Fore- and hindlimbs were excised from ICR mice on day 12 of gestation and cultured in roller bottles for 6 days. Limbs were exposed to 4-hydroperoxycyclophosphamide for the first 20 hours of the culture period. Addition of 10 micrograms/ml of 4-hydroperoxycyclophosphamide to forelimb or to hindlimb buds in culture produced limb reduction malformations. A dramatic decrease in total limb bone area in fore- and hindlimbs was observed with 10 micrograms/ml of 4-hydroperoxycyclophosphamide. In forelimbs, the long bone area decreased and the paw area remained constant so that the relative contribution of the long bone area to total limb bone area was decreased. In hindlimbs treated with 10 micrograms/ml of 4-hydroperoxycyclophosphamide, no paw skeleton was observed. The DNA, RNA, and protein contents of the limbs were not affected by exposure to 1 microgram/ml of 4-hydroperoxycyclophosphamide, but were decreased by exposure to 10 micrograms/ml of this compound. Exposure to the higher concentration of 4-hydroperoxycyclophosphamide also decreased alkaline phosphatase activity, a marker for osteogenesis, in both fore- and hindlimbs; in contrast, neither concentration of 4-hydroperoxycyclophosphamide had an effect on creatine phosphokinase activity, a marker for myogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucose homeostasis during anesthesia and surgery in infants

Baseline, preinduction, postinduction, and postsurgical plasma samples were collected for glucose, insulin, and cortisol in 16 neonates and infants. Glucose infusion rate was maintained constant (mean +/- SD 4.1 +/- 1.2 mg/kg/min) prior to and during surgery; additional fluid losses during surgery were replaced by fluids without dextrose. The weight at the time of surgery was 3,038 +/- 1,397 g. Postnatal age at the time of study ranged from one day to 40 weeks and the duration of surgery was 83 +/- 35 minutes. Plasma glucose values were higher than baseline values soon after induction of anesthesia (88 +/- 11 v 130 +/- 36 mg/dL; P less than .05); postsurgical glucose values were significantly higher than postinduction values (210 +/- 109 mg/dL v 130 +/- 36 mg/dL, P less than .01). Postsurgical plasma glucose had a negative correlation with weight of infants at the time of study (P less than .01; r = .61). Insulin changes were minimal and variable. Cortisol values did not change significantly from baseline values until the end of surgery (11.9 +/- 8.3 v 22.2 +/- 10.6 micrograms/dL; P less than .05). Hyperglycemia (greater than 150 mg/dL) was noted in 10/16 infants. This study indicates that glucose levels should be monitored and that additional fluid losses should be replaced by fluids without dextrose in neonates undergoing surgical procedures since hyperglycemia is a common occurrence.

A pyramid-based approach to segmentation applied to region matching

In this paper, we attempt to place segmentation schemes utilizing the pyramid architecture on a firm footing. We show that there are some images which cannot be segmented in principle. An efficient segmentation scheme is also developed using pyramid relinking. This scheme will normally have a time complexity which is a sublinear function of the image diameter, which compares favorably to other schemes. The efficacy of our approach to segmentation using pyramid schemes is demonstrated in the context of region matching. The global features we use are compared to those used in previous approaches and this comparison will indicate that our approach is more robust than the standard moment-based techniques.

A study of pseudocholinesterase induction in experimental obesity

Liver pseudocholinesterase (PChE) activity was significantly higher in genetically obese (ob/ob) mice than in lean littermates as early as 23 days after birth. By cytochemical electron microscopy, increased staining for PChE was observed in the rough endoplasmic reticulum of ob/ob mice. Albino mice with different diets showed that high-protein diets produced the greatest increase in PChE activity in the liver compared to carbohydrate or high fat. Mice fed a normal mouse diet ad lib had significantly higher liver PChE activity than those fed a restricted diet of 2 g of a normal mouse chow per day. In albino mice liver PChE activity varied directly with the protein content in the diet. These studies suggest that liver PChE induction is a function of the level of protein in the diet.

Pulmonary and renal responses to furosemide in infants with stage III-IV bronchopulmonary dysplasia

Pulmonary and renal responses to furosemide were evaluated in ten infants with stage III-IV bronchopulmonary dysplasia. Furosemide was given intravenously for two doses, 1 and 2 mg/kg, at approximately 24-hour intervals. The following indices were evaluated in series before and after entry into study: clinical respiratory distress syndrome score; blood pH; partial pressure of arterial carbon dioxide; alveolar-arterial oxygen gradient; urine output; glomerular filtration rate; fractional excretion of filtered sodium, chloride, potassium, and calcium; osmolar clearance; water clearance; and concentrations of serum electrolytes and calcium. A significant decrease in the respiratory distress syndrome score and in the partial pressure of arterial carbon dioxide was seen only transiently at two hours following each dose. There was no significant improvement in the alveolar-arterial oxygen gradient during the study. Furosemide induced diuresis and urinary excretion of sodium, chloride, potassium, and calcium. A significant decrease in serum chloride and potassium concentrations was seen at 48 hours after entry into study; serum sodium and calcium concentrations remained unchanged. This study has demonstrated that furosemide administration has only a short-term effect in the lung but has a potential for long-term complication on electrolytes and calcium balance in infants with well-established stage III-IV bronchopulmonary dysplasia.

Prevention of gastric inflation during mask ventilation in newborn infants

Ten premature infants who had recovered from the respiratory distress syndrome were subjected to cricoid compression during mask ventilation. Each infant was ventilated with an AMBU face mask for 3 min with the nasogastric (NG) tube, without the NG tube, and without the NG tube but applying cricoid pressure during ventilation. The results of the study indicated that, similar to insertion of an NG tube, cricoid compression can prevent gastric inflation during mask ventilation.

Studies in spiro heterocycles. Part 4(1): Investigation of the reactions of fluorinated 3-aroylmethylene-indol-2-ones with hydrazine and phenylhydrazine and synthesis of spiro [indole-3,3'-pyrazol]-2-ones

Reactions of various 3-aroylmethylene-indol-2-ones with hydrazine and phenylhydrazine under exactly similar conditions have been carried out. The reaction with phenylhydrazine has not been investigated earlier. It was found that although the reaction with hydrazine hydrate afforded a spiro derivative viz., spiro[3H-indole-3,3'-(3H)pyrazol]-2(1H)-one, that with phenylhydrazine yielded simply a hydrazone derivative. Representative spiro compounds have been screened for antifertility activity but none was found active at a dose of 10 mg/kg in adult female rats.

Nutritional support: enhancing the quality of life of the terminally ill patient with cancer

The clinical dietitian on the palliative-care unit is actively involved in initiating, implementing, and evaluating individualized nutrition care plans for all patients. The dietitian can add to the comfort of the patient by facilitating the maintenance of good nutritional health for as long as possible. Undoubtedly, this involvement contributes to overall success of the program.

Determining motion parameters for scenes with translation and rotation

A study of methods that determine the rotation parameters of a camera moving through synthetic and real scenes is conducted. Algorithms that combine ideas of Jain and Prazdny, using hypothesizeand-verify paradigm, are developed to find translational and rotational parameters. An argument is made for using hypothesized motion parameters rather than relaxation labeling to find correspondence. Some work with real scenes shows the difficulties introduced by noise, the lack of resolution, and the need for better low-level techniques.