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Biomedical subjects

C M Lee

Publications and source records attributed to C M Lee.

At least 253 records · Page 14Linked to original sources
PubMed1989

[Prognosis of chronic obstructive pulmonary disease after acute respiratory failure].

We followed the course of 53 patients (male 38, female 15 and average age 66 +/- 10) with chronic obstructive pulmonary disease hospitalized in our intensive care unit due to acute episode of respiratory failure. Etiologies of acute respiratory failure, patient's clinical data and arterial blood gases analysis were recorded. Most of the results showed no significant difference between the initial survival and the non-survival group. Low hematocrit. hypoalbulinemia and severe hypoxemia were found in the dead group but relative hypercapnea in the survival group was noted. Infection was the most common cause of acute respiratory failure and following by congestive heart failure, pneumothorax and asphyxia. Intubation and mechanical ventilator were needed in all patients except 3 cases to whom only conservative treatment was given. Hospital mortality was 50.9 percent (27/53) and most of the cases (22/53) died in the intensive care unit. Twenty six cases (49.1%) were discharged from the hospital and follow-up was continued for at least two years. Fifteen patients died during two year follow-up and except for one suicide case all died of repeated respiratory failure. The two year survival was only 20.8 percent (11/53). The prognosis of patients with chronic obstructive pulmonary disease following an episode of acute respiratory failure is poor.

Acute Disease↗
PubMed1989

Relationship between coronary artery size and ventricular hypertrophy.

The relationship between coronary blood flow and ventricular hypertrophy has been studied in animal models. But, this relationship in the human body is scarcely evaluated. In this study we measured coronary arterial sizes by coronary arteriograms and correlated them with ventricular hypertrophy. Patients who underwent cardiac catheterization and coronary arteriography and showed no significant coronary arterial lesions were included in this study. There were 131 patients, 75 men and 56 women, with a mean age of 53 +/- 10 years (S.D.). After evaluation with electrocardiograms, echocardiograms and left ventriculograms these patients were divided into 4 groups: (1) the non-hypertrophy (NVH) group, 50 cases; (2) the left ventricular hypertrophy (LVH) group, 38 cases; (3) the right ventricular hypertrophy (RVH) group, 23 cases; and (4) the biventricular hypertrophy (BVH) group, 20 cases. The proximal portion of the 3 major coronary arteries and the left main stem were measured from coronary arteriograms with the catheter tip as a size reference. The results showed that the left main stem was larger than the 3 major coronary arteries in the NVH, LVH and BVH groups. But in the RVH group, the left main stem was not significantly larger than the right coronary artery. In all 4 groups the left circumflex coronary artery was the smallest while the left anterior descending coronary artery and the right coronary artery were similar in size. Patients with LVH showed dilatation of all 3 left coronary measurements (left main stem, left anterior descending coronary artery and left circumflex coronary artery) as compared with the NVH patients and the RVH patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Effects of alpha,beta-methylene ATP on potentiation of contractions to field stimulation of rat vas deferens by carbachol.

Carbachol (0.1-300 mumol/L) potentiated contractions to field stimulation (0.1 Hz, 1 ms, supramaximal V) in the rat epididymal and prostatic vas deferens. Desensitization of P2-purinoceptors by exposure to alpha,beta-methylene ATP (30 mumol/L) markedly reduced (greater than 80%) the potentiating effect of carbachol in the prostatic vas deferens but only moderately reduced (about 20%) the maximal stimulated response to carbachol in the epididymal segment. The presence of prazosin (10 mumol/L) and yohimbine (10 mumol/L), being selective alpha 1- and alpha 2-adrenoceptor antagonists, did not modify the attenuation of carbachol potentiation caused by alpha,beta-methylene ATP treatment. At 0.1 mmol/L, alpha,beta-methylene ATP had no significant effect on the binding of [3H]QNB to muscarinic cholinergic receptors. It is concluded that carbachol may potentiate the contractions to field stimulation in the prostatic vas deferens via an enhancement of purinergic neurotransmission. The molecular mechanism of carbachol potentiation in the epididymal vas deferens remains to be established.

Adenosine Triphosphate↗
PubMed1988

Effects of neonatal monosodium glutamate treatment on substance P binding sites in the rat retina.

We have demonstrated a high affinity specific binding of 125I-Bolton Hunter conjugate of substance P (125I-BHSP) to rat retina membranes. The binding was saturable and monophasic with a Kd of 0.2 nM and a Bmax of 290 fmol/mg protein. The rank order of potency of tachykinins and related analogues in inhibiting 125I-BHSP binding conformed to that of the NK-1 (identical to SP-P) tachykinin receptor, with SP greater than NKA greater than or equal to KAS greater than or equal to NKB and [Glp6, L-Pro9]SP(6-11) being 60 times more active than [Glp6, D-Pro9]SP(6-11). After neonatal monosodium glutamate (MSG) treatment, there was a marked reduction in the number but not binding affinity of 125I-BHSP binding sites in the retina. The same treatment had no effect on either the number or binding affinities of NK-1 sites in the salivary gland.

Animals↗
PubMed1988

Characterization of isolated porcine intestinal mucosal mast cells following infection with Ascaris suum.

Porcine intestinal mucosal mast cells (IMMC) were isolated from intestinal tissues of swine by enzymatic digestion and density gradient separation. Helminth-free swine and swine exposed to the nematode parasite, Ascaris suum, were used as a source of intestinal tissue. Up to 40% of the isolated intestinal cells stained metachromatically with toluidine blue pH 3.0, indicating the presence of IMMC. The histamine content of this cell population ranged from 2.9-8.9 pg per toluidine blue-positive IMMC, regardless of the animal source. Enrichment procedures that increased the proportion of toluidine blue-positive IMMC from the isolated intestinal cell population correlated with an increase in the amount of histamine detected in the cell population, indicating that toluidine blue-positive IMMC were the major source of histamine in this heterogeneous cell population. However, only cells isolated from the intestines of parasite-exposed swine released histamine in vitro after mixing with antigens derived from A. suum. Cells from the intestines of both helminth-free and parasite-exposed swine did not release histamine after mixing with a non-parasite hapten-protein molecule DNP-human serum albumin, but did release greater than 90% of their total histamine after lysis with Triton X-100 or with the Ca2+ ionophore (A23187). The stimulus for acquired responsiveness of IMMC to A. suum antigens in vitro was parasitic infection in vivo because helminth-free swine maintained in confinement on concrete yielded IMMC that specifically released histamine in the presence of parasite antigens only after 3 weeks of daily experimental inoculations with A. suum eggs. IMMC isolated from the entire length of the small intestines of infected pigs were responsive to antigens in vitro, but the relative number of IMMC isolated and their level of histamine release decreased from the anterior to the posterior end. IMMC isolated from infected swine were also stimulated to release histamine in vitro by viable second stage larvae of A. suum and by treatment with anti-swine immunoglobulin. Responsiveness to both parasite antigens and anti-immunoglobulin were totally eliminated, however, by a brief treatment of the cells with acidic buffer, suggesting that an acid-dissociable cell-bound antibody molecule was responsible for specific antigen-induced histamine release by IMMC.

Animals↗
PubMed1988

Neonatal monosodium-L-glutamate treatment reduced lipolytic response of rat epididymal adipose tissue.

1. The effect of neonatal monosodium-L-glutamate (MSG) treatment on lipolysis in rat epididymal adipose tissue was studied. A reduction in the basal lipolysis was observed in the MSG-treated rats. 2. This was accompanied by a decrease lipolytic response to isoprenaline, adrenocorticotropic hormone, forskolin, isobutylmethylxanthine and dibutyryl-cAMP. 3. The addition of adenosine deaminase, which inactivates endogenous adenosine in the medium, did not normalize the basal and the hormone stimulated lipolytic responses. 4. The maximal lipolysis stimulated by adenosine deaminase or 8-(p-sulfophenyl)-theophylline (8-SPT), an adenosine antagonist, was significantly lower in the MSG-treated rats. 5. Moreover, there was no change in the sensitivity of adenosine receptors to its antagonist as reflected by the similar potency of 8-SPT in eliciting the lipolytic response in both the control and MSG-treated rats. 6. In conclusion, neonatal MSG treatment in rats induced a general reduction of lipolytic response in the epididymal adipocytes which cannot be explained by an enhancement of the adenosine inhibitory system.

Adenosine Deaminase↗
PubMed1988

CPAP or CPP?

Explore the source record for details and available documents.

Humans↗
PubMed1988

Human eccrine sweat gland epithelial cultures express ductal characteristics.

1. Isolated human eccrine sweat glands were cultured in vitro. Cells were harvested and plated onto permeable supports to form confluent cell sheets, area 0.2 cm2. These were used to study the electrogenic transepithelial transport of ions by measurement of short-circuit current (SCC). Epithelial sheets had a basal SCC of 5.89 +/- 0.62 microA cm-2 (n = 33) and a transepithelial resistance of 74.1 +/- 5.6 omega cm2 (n = 33). The transepithelial potential difference varied between -0.2 and -1.8 mV with a mean value of -0.71 +/- 0.09 mV (n = 33). 2. The basal current was abolished by addition of 10 microM-amiloride to the apical bathing solution. The concentration of amiloride which inhibited basal SCC by 50% (EC50) was 0.4 microM. Cultures prepared from the secretory coil of sweat glands, rather than from whole glands, were similarly sensitive to amiloride (EC50 = 0.8 microM). 3. Lysylbradykinin (LBK), carbachol, isoprenaline, prostaglandin E2 (PGE2) and A23187 all increased SCC in cultures from whole glands. LBK responses were obtained with basolateral and not with apical application. Furthermore LBK actions were not substantially altered by cyclo-oxygenase inhibition but showed marked desensitization upon repeated application. Sheet cultures prepared from sweat gland coils also showed SCC responses to both carbachol and LBK. Forskolin, an activator of adenylate cyclase, did not alter SCC in either type of preparation. 4. Replacement of chloride and of chloride and bicarbonate in the bathing solution did not cause attenuation of the responses to LBK or carbachol in whole-gland sheet cultures. Furthermore responses were unaffected by piretanide or acetazolamide. These results were taken to indicate that anion secretion was not the basis for the SCC responses. 5. Responses to LBK and carbachol were significantly reduced by amiloride (10 microM), this effect being reversible. No responses to LBK or carbachol were seen when N-methyl-D-glucamine (NMDG) was used to replace sodium, whereas reintroduction of sodium ions restored responsiveness to these agents. 6. The SCC responses to the muscarinic agonist carbachol and to LBK appear to be due to stimulation of amiloride-sensitive, electrogenic sodium absorption in whole-gland sheet cultures. Further it would appear that, in culture, the pleuripotential capacity of the cells is revealed since both whole-gland and secretory coil cultures exhibit some properties usually associated in vivo with duct cells. Many mammalian epithelia show electrogenic chloride secretion both in response to carbachol and LBK but also in response to activation of adenylate cyclase with forskolin.(ABSTRACT TRUNCATED AT 400 WORDS)

Amiloride↗
PubMed1988

Potentiation of the anti-lipolytic effect of 2-chloroadenosine after chronic caffeine treatment.

The effect of chronic caffeine treatment on lipolysis in rat epididymal adipose tissue was studied. There was a decrease in body weight, epididymal fat pad weight and mean adipocyte diameter in caffeine-treated rats when compared with control rats. No difference in adipocyte triglyceride content or mean adipocyte weight between control and caffeine-treated rats was observed. Lipolysis in adipocytes induced by adenosine deaminase (1 U/ml) decreased by 35% in caffeine-treated rats. This was accompanied by a 2.5-fold increase in the anti-lipolytic potency of 2-chloroadenosine and an increase of adipocyte adenosine A1 receptor number.

2-Chloroadenosine↗
PubMed1988

Trypanosoma lewisi: effects of trace metal contaminants on immunological responses.

The effects of trace metal contaminants (lead, cadmium, and mercury) on the immunologic responses of rats infected with Trypanosoma lewisi were investigated to determine whether chronic exposures to subclinical levels of these metals have adverse effects on the host's ability to respond to an infective agent.Earlier and higher levels of parasitemia were detected in animals exposed to cadmium, lead, and mercury. The variability in length of trypanosome cells in metal-exposed animals became constant at a later time and persisted for a longer time, indicating a delay in antibody synthesis. Serum levels of IgG and IgM were increased in infected animals exposed to trace metals; however, lower levels were observed when compared with infected control animals. Animals exposed only to trace metals showed decreases in serum levels of IgG and IgM. In contact sensitivity to dinitrofluorobenzene (DNFB), animals exposed to trace metals demonstrated no significant difference in sensitization when compared with those infected and exposed to trace metals.

Animals↗
PubMed1987

A novel vasoactive intestinal peptide (VIP) from elasmobranch intestine has full affinity for mammalian pancreatic VIP receptors.

A peptide that cross reacted with N-terminal, but not C-terminal, antisera to vasoactive intestinal peptide (VIP) was isolated from extracts of intestine from the dogfish Scyliorhinus canicula. Microsequence analysis gave the structure His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Ser-Arg-Ile-Arg-Lys-Gln-Met-Ala-Val-Lys - Lys-Tyr-Ile-Asn-Ser-Leu-Leu-Ala-NH2. C-terminal amidation was determined by HPLC analysis of phenylthiocarbamyl amino acid derivatives after carboxypeptidase Y digestion. The peptide differs at five positions from the porcine octacosapeptide. Dogfish VIP was equipotent with its porcine counterpart in inhibiting binding of 125I-labelled VIP to guinea pig dispersed pancreatic acini, and in stimulating amylase secretion by the same preparation. The data indicate a strong conservation of VIP during evolution and permit identification of residues crucial for bioactivity.

Amino Acid Sequence↗