Search PubMed⌕ Search

Biomedical subjects

D Gross

Publications and source records attributed to D Gross.

At least 109 records · Page 6Linked to original sources
PubMed1989

Treatment of uncontrolled hemorrhagic shock by hypertonic saline and external counterpressure.

The effect of an external counterpressure device (ECPD) on hypertonic saline treatment of uncontrolled hemorrhagic shock (UCHS) was studied in rats. The rats were divided into five groups. In group 1 (n = 11) UCHS induced by incision of three radicals of the ileocolic artery was treated by 5 mL/kg NaCl 0.9% (normal saline). In group 2 (n = 20), UCHS was treated by 5 mL/kg NaCl 7.5% (hypertonic saline). In group 3 (n = 6), UCHS was treated by inflation of ECPD to 50 torr. In group 4 (n = 7), UCHS was treated by ECPD and normal saline; in group 5 (n = 9), UCHS was treated by ECPD and hypertonic saline. Incision of the ileocolic artery in group 1 rats led to a fall in mean arterial pressure to 33 torr (P less than .001) followed by a spontaneous rise to 48 torr (P less than .01) with a mortality rate of 27% and a mean survival time of 161 +/- 9 minutes. Infusion of hypertonic saline during UCHS was followed by a further fall in mean arterial pressure to 18.5 torr (P less than .001); mortality was 80% within 80 minutes with a mean survival time of 35.5 minutes, which was significantly lower than in group 1 (P less than .01). Inflation of ECPD during UCHS in group 3 or treatment with ECPD and normal saline in group 4 did not alter the hemodynamic response and mortality, which were similar to those of group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Quantitative imaging of free and total intracellular calcium in cultured cells.

Techniques of fluorescence and ion microscopies were combined to study the free [Ca2+] and total Ca in NIH 3T3 fibroblast and L6 rat myoblast cells. Free Ca2+ measurements with the Ca2+ indicator fura-2 and digital imaging reveal an inhomogeneous distribution of free cytoplasmic Ca2+ in both cell lines. Fura-2 also reveals a difference in free Ca2+ activity between the nucleus and cytoplasm of cells. Ion microscopic observations on sister cells show that total Ca in the cytoplasm is also inhomogeneously distributed and that mean cytoplasmic levels of total Ca are higher than levels in the nuclei. In the nuclei of NIH 3T3 cells, the mean free [Ca2+] and total [Ca] were 110 +/- 30 nM and 225 +/- 43 microM, respectively, while regions in the cell cytoplasm contained up to 490 +/- 270 nM free [Ca2+] and 559 +/- 184 microM mean total [Ca]. Intracellular total Ca was greater than 3 orders of magnitude higher than intracellular free Ca2+ in either nuclear or cytoplasmic compartments. Perinuclear cytoplasmic regions in 3T3 cells contained higher free and total Ca than the cell nucleus. Loading of cells with fura-2 did not modify the subcellular distribution of total K, Na, Ca, or Mg. This combination of two powerful ion imaging techniques provides a comparison between free and total calcium in cells and introduces a different approach for examining the role of this important element in cell physiology.

Animals↗
PubMed1989

Quantitative measurement of bleeding following hypertonic saline therapy in 'uncontrolled' hemorrhagic shock.

The effect of small volume hypertonic saline in "uncontrolled" hemorrhagic shock (UCHS) induced by partial resection of the tail was studied in rats. The rats were divided into three groups: in group 1 (n = 15) 10% of the terminal portion of the animal's tail was resected to induce UCHS. In group 2 (n = 14) UCHS was induced as in group 1 and after 5 min 5 ml/kg NaCl 0.9% (NS) was infused intravenously. In group 3 (n = 22) UCHS was induced as in group 1 and after 5 min, 5 ml/kg NaCl 7.5% (HTS) was infused intravenously. Resection of the animal's tail was followed by bleeding of 3.5 +/- 0.3 ml within 5 min, fall in MAP to 63 +/- 4 torr (p less than 0.001) and pulse to 300 +/- 18 per min (p less than 0.05). The amount of bleeding, fall in MAP, and pulse after 5 min were similar in the three groups. Further blood loss after 60 min in group 1 was 3.7 +/- 0.8 ml, in group 2, 2.9 +/- 0.5 ml, and in group 3, 6.5 +/- 0.8 (p less than 0.01). Increased bleeding in group 3 showed two peaks: an early peak of 1.3 +/- 0.2 ml after 15 min (p less than 0.05) and a late peak of 1.2 +/- 0.4 ml at 45 min (p less than 0.05) and 1.7 +/- 0.5 ml at 60 min (p less than 0.01). MAP fell after 60 min to 54 +/- 7 torr in group 1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Infusion of small volume of 7.5 per cent sodium chloride in 6.0 per cent dextran 70 for the treatment of uncontrolled hemorrhagic shock.

The effect of a solution of 7.5 per cent sodium chloride in 6.0 percent dextran 70 was studied in a rat model of uncontrolled hemorrhagic shock induced by partial resection of the tail of the rat. Fifty rats were randomly assorted into five groups of ten rats each. In group 1, uncontrolled hemorrhagic shock was induced by sharp resection of 10 per cent of the terminal portion of the tail of the rat. In group 2, uncontrolled hemorrhagic shock was treated with 5 milliliters per kilogram of 0.9 per cent sodium chloride. In group 3, uncontrolled hemorrhagic shock was treated with 5 milliliters per kilogram of 6 per cent dextran 70. In group 4, rats were treated with 5 milliliters per kilogram of 7.5 per cent sodium chloride, and in group 5, 5 milliliters per kilogram of 7.5 per cent sodium chloride in 6.0 per cent dextran 70 were infused. During the first five minutes, bleeding in rats in group 1 was 3.0 +/- 0.4 milliliters and the mean arterial pressure fell from 105 +/- 5 to 73 +/- 7 torr (p less than 0.001). In group 4, bleeding at 15, 30 and 60 minutes was 1.9 +/- 0.3 milliliters (p less than 0.02), 2.0 +/- 0.7 milliliters (p less than 0.04) and 2.4 +/- 1.1 milliliters (p less than 0.02), and in group 5, 2.5 +/- 0.6 milliliters (p less than 0.02), 2.2 +/- 0.6 milliliters (p less than 0.04) and 3.1 +/- 0.8 milliliters (p less than 0.04), respectively, compared with bleeding in group 1. Increased bleeding was followed by a fall in mean arterial pressure in groups 4 and 5 with a 60 per cent mortality rate (p less than 0.01) in both groups and respective, mean survival times of 135 +/- 29 and 144 +/- 26 minutes, which were significantly increased compared with group 1 (p less than 0.01 for both). The intravenous infusion of 6 per cent dextran 70 alone in group 3 resulted in delayed bleeding of 1.23 +/- 0.6 milliliters (p less than 0.04) after 180 minutes. It is concluded that infusions of small volume of 7.5 per cent sodium chloride or 7.5 per cent sodium chloride in 6.0 per cent dextran 70 solutions in rats in a state of uncontrolled hemorrhagic shock led to increased bleeding, decrease in mean arterial pressure and increased mortality.

Animals↗
PubMed1989

Changing the public image of nursing: development of a community nurses network.

Gross, Frost, and Vance give new meaning to community health nursing. They describe a nursing network that engages in the processes of politics, power, and innovation to bring about community change while enhancing the status of the profession. The community project described here demonstrates to others the expertise and autonomy of professional nurses.

Community Health Nursing↗
PubMed1988

Oxidation of rat insulin II, but not I, leads to anomalous elution profiles upon HPLC analysis of insulin-related peptides.

Rat insulin II, unlike rat insulin I and other non-rodent insulins, contains a unique methionine residue at position B29. Reversed-phase HPLC allows for separation of the two rat insulins, with insulin I typically eluting faster than insulin II. An anomalous peak of insulin immunoreactive material was found eluting even faster than insulin I following acid extraction of rat insulin-producing cells. This early peak co-eluted with [Met-OB29]insulin II suggesting that during cell extraction and subsequent purification steps, rat insulin II is subject to selective oxidation at MetB29. Such oxidation of rat proinsulin II affords improved separation from rat proinsulin I compared to the native form.

Animals↗
PubMed1988

[Special treatment measures in patients with a stoma].

Psychological, social and technical problems in the management of patients with stomata are discussed. The success of treatment depends on the skill of the doctors and nurses to handle personal problems of the patient, to help him to find his way into the community, to his work, to his hobbies. Problems such as love, sexual life and death have also to be taken into consideration. Each such patient should get detailed and written information in order to have enough time to prepare himself for his new situation. Doctors and nurses must offer time for sufficient discussions with the patient.

Adaptation, Psychological↗
PubMed1988

Imaging the effects of an ectopic spleen on the urinary tract.

A 75-year-old woman with chronic lymphocytic leukemia who presented clinically with urinary frequency was found on physical examination to have a pelvic mass. Ultrasound and computed tomography showed it to be due to a large ectopic spleen lying in the pelvis behind the bladder and compressing it anteriorly. The spleen became smaller and the symptoms regressed with chemotherapy. We review the features of an ectopic spleen as seen on diagnostic imaging studies.

Aged↗
PubMed1988

Electromobile surface charge alters membrane potential changes induced by applied electric fields.

The relation between extracellular electric fields and changes in membrane potential that such fields directly induce has previously been described both theoretically and experimentally. It is clearly established that extracellular electric-field-induced membrane potential changes are well described by Poisson's equation of electrostatics. A modification of this simple theory to include effects of the electric-field-induced redistribution of charged cell surface components is introduced and is shown to produce major alterations in calculated membrane potential changes over times of the order of minutes to hours. Implications for biological systems which respond to extracellular electric fields are discussed.

Electric Conductivity↗
PubMed1988

Imaging asynchronous changes in intracellular Ca2+ in individual stimulated tumor mast cells.

Changes in the level of intracellular free calcium ([Ca2+]i) are associated with the secretion of mediators of immediate hypersensitivity by rat basophilic leukemia (RBL) cells, a mast cell line. Digital fluorescence ratio imaging of fura-2 was used to measure [Ca2+]i in individual RBL cells. Changes in [Ca2+]i that occurred in response to crosslinking of IgE receptors on the cell surface or to application of the Ca2+ ionophore ionomycin were studied. Stimulation of RBL cells with antigen resulted in rapid increases in [Ca2+]i following lag times that varied widely from cell to cell. Simple averaging of the Ca2+ responses of many cells yielded a gradual response profile that closely resembled that of suspensions of cells measured in the fluorometer. The results show that single cells can respond much more rapidly to antigen than has previously been suggested by studies on populations of cells. The lag time between addition of antigen and initiation of the increase in [Ca2+]i varied considerably between cells in the same field of view. Both the rise time and the variability and average duration of the lag time increased with decreasing antigen concentration.

Animals↗
PubMed1988

Decreased neutrophil thromboxane A2 and endothelial PGI2 production in the postoperative period. An in vitro assay for detection of neutrophil and plasma dysfunction.

Severe trauma results in reversible abnormalities in neutrophil function, but the specific role in the pathogenesis of postoperative sepsis is undetermined. Twenty adult patients undergoing elective surgical procedures were studied. Blood samples were obtained prior to and 24 hours after operation. Blood neutrophils were isolated and incubated (10(7) cells/mL) on bovine vascular endothelial cell monolayers. Untreated plasma or zymosan-activated plasma (ZAP) or 65 C inactivated plasma was added, and TxB2 and 6-keto PGF1 alpha production measured after 2 hours. Endothelial damage was detected by light and scanning electron microscopy beginning 2 and 4 hours after treatment. Preoperatively, neutrophil TxB2 release was less than 200 pg/mL; following ZAP it was 2153 pg/mL (p less than 0.001), with untreated plasma 1055 pg/mL (p less than 0.005) and inactivated plasma 764 pg/mL (p less than 0.01). Neutrophil TxB2 release on a plastic dish was not different from incubation on endothelium. Endothelial 6-keto PGF1 alpha release following addition of untreated plasma preoperatively was 1308 pg/mL (p less than 0.01), and with ZAP 1305 pg/mL (p less than 0.01). Activated neutrophils did not alter 6-keto PGF1 alpha production. Postoperatively, neutrophil TxB2 production in response to ZAP was 1092 pg/mL, which was significantly reduced compared to the preoperative response (p less than 0.01). Endothelial damage by activated neutrophils in the postoperative period demonstrated on scanning electron microscopy was also reduced; 6-keto PGF1 alpha release in the postoperative period inducted by ZAP was 569 pg/mL and by untreated plasma 549 pg/mL, which was significantly lower than in the preoperative period (p less than 0.05 and p less than 0.05, respectively). No difference in chemotaxis was demonstrated. It is concluded that operative trauma is followed by lowered neutrophil TxB2 release, appearance of a plasmatic factor that depresses endothelial 6-keto PGF1 alpha production, as well as decreased neutrophil-induced endothelial damage. The neutrophil-endothelial monolayer system is a sensitive method for detection of neutrophil and plasmatic dysfunction.

Adult↗
PubMed1988

Is hypertonic saline resuscitation safe in 'uncontrolled' hemorrhagic shock?

Hypertonic saline treatment of hemorrhagic shock (HS) results in increased systemic blood pressure, cardiac output, and splanchnic blood flow. To determine whether this elevation in blood pressure and flow would augment blood loss from injured intra-abdominal vessels and thus enhance mortality rate, "controlled" HS was induced by bleeding of 20 ml/kg from an arterial cannula that was immediately occluded after hemorrhage, and "uncontrolled" HS was induced by incision of three major radicals of the ileocolic artery leading to continuous intra-abdominal blood loss. Seventy rats were divided into eight groups: Group I (n = 5) underwent carotid artery and jugular vein cannulation and was observed for 3 hr; in Group II (n = 10) "controlled" HS was induced by arterial hemorrhage of 20 ml/kg; in Group III (n = 7) "controlled" HS was treated by 5 ml/kg NaCl 0.9%; in Group IV (n = 8) "controlled" HS was treated by 5 ml/kg NaCl 7.5%; in Group V (n = 4) midline laparotomy and identification of the ileocolic artery was performed; in Group VI (n = 9) "uncontrolled" HS was induced by incision of three major branches of the ileocolic artery; in Group VII (n = 9) "uncontrolled" HS was treated by 5 ml/kg NaCl 0.9%, and in Group VIII (n = 18) "uncontrolled" HS was treated by 5 ml/kg NaCl 7.5%. In untreated "controlled" HS (Group II), mean arterial pressure (MAP) fell to 35 torr followed by a spontaneous rise to 62 torr (p less than 0.001) after 3 hr with a survival of 80% of the animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effect of prostaglandin and leukotriene antagonists in acute mesenteric artery occlusion.

Superior mesenteric artery occlusion leads to mesenteric ischemia, activation of arachidonic acid metabolism and release of endotoxins into the systemic circulation. The effect of leukotriene and prostaglandin antagonists on hemodynamic response and survival of rats after superior mesenteric artery (SMA) occlusion was investigated. The animals were divided into five groups: in group 1 (n = 105) the SMA was clamped for 2 h and mortality assessed after 24 h. Group 2 animals (n = 20) were pretreated with 5 mg/kg indomethacin and the SMA clamped similarly to group 1, group 3 animals (n = 15) were pretreated with 5 mg/kg Voltaren, group 4 animals (n = 20) received 20 mg/kg BW 755C before mesenteric artery occlusion, and group 5 animals (n = 50) were pretreated with 100 mg diethylcarbamazine. The blood pressure and pulse response as well as histologic appearance of the bowel 1 h after declamping was similar in all five groups. The mortality rate after 24 h was 34% in the control group, 36% with indomethacin treatment, 36% with voltaren, 47% with BW 755C and 40% with diethylcarbamazine. The mortality rate in all the treated groups was not significantly different from the control group. Plasma thromboxane B2 levels were inhibited significantly by indomethacin and Voltaren and to a lesser extent by BW 755C. There was a paradoxical rise in thromboxane B2 following diethylcarbamazine treatment. It is concluded that inhibition of the cyclooxygenase and/or the lipoxygenase pathways of arachidonic acid did not alter the hemodynamic response and mortality following 2 h of acute superior mesenteric artery occlusion.

Acute Disease↗