Monocytoid B-cell lymphoma in patients with Sjögren's syndrome: a clinicopathologic study of 13 patients

A recent clinicopathologic study of a series of patients with monocytoid B-cell lymphoma (MBCL) indicated that there is a frequent association between MBCL and Sjögren's syndrome (SS) and raised the possibility of a relationship between these two disease entities. To further investigate the possible relationship of MBCL and SS, we studied pathologic and clinical characteristics of 13 patients with MBCL who had clinically documented SS. In all patients, the lymphoma had the characteristic morphologic features of MBCL, and immunologic and molecular hybridization studies confirmed the B-cell nature of the lymphoma. Twelve of the 13 patients were female, with a median age of 66 years at diagnosis. Eleven had localized disease and presented with either salivary gland or cervical lymph node enlargement; one patient presented with a breast mass, and another with generalized lymphadenopathy and hepatosplenomegaly. In five of 13 patients, the MBCL was associated with or progressed to large cell lymphoma. In two patients, there was bilateral involvement of the parotid gland; one had a synchronous high-grade lymphoma in both parotid glands. In two patients, bone marrow biopsies showed involvement by MBCL. Eleven patients are alive 2 to 55 months after the diagnosis of MBCL. One patient died with the disease 8 months after the initial diagnosis. Another patient died of an unrelated cause without evidence of disease 16 months after the diagnosis of MBCL. We conclude that there is a more than fortuitous association between MBCL and SS. This concept is consistent with previously reported observations of reactive monocytoid B cells in patients with benign lymphoepithelial lesions of salivary glands, which may result from selective homing of reactive monocytoid B lymphocytes to the benign lymphoepithelial lesions and their subsequent neoplastic transformation.

Effects of various fixatives and fixation conditions on DNA ploidy analysis. A need for strict internal DNA standards

DNA ploidy and cell cycle analyses are being used with increasing frequency as additional, sometimes independent, biologic prognosticators of various malignancies. For obvious reasons, most of the large studies published are retrospective, using archival paraffin-embedded tissues likely to have been fixed and processed differently. To assess the effect of various fixation conditions on ploidy analyses, the authors performed a comprehensive study in which five contiguous aliquots from 26 tissue samples were fixed in formalin for 8. 24, and 48 hours; B5; and the ethanol-based fixative Omnifix (Omni, Xenetics Biomed Inc., Irvine, CA), respectively. The samples were prepared and stained with the use of Hedley's method; the DNA analyses were done with a Coulter EPICS V flow cytometer (Coulter Electronics, Hialeah, FL); and the resulting histograms were interpreted with Multicycle software (Phoenix Flow Systems, San Diego, CA). Mean channels and coefficients of variation (CVs) of the G0/G1 peaks were compared. Increasing fixation times in formalin produced slight shifting to the left on the G0/G1 peaks with differences up to 13 channels. Omni caused similar but more conspicuous changes, with maximal shifting of 51 channels. B5 created the opposite effect, with right-shifted G0/G1 peaks up to 22 channels. The CVs deteriorated progressively with increasing fixation times in formalin. B5 and Omni fixatives conferred the worse histograms, with 6 and 15 cases, respectively, displaying CVs greater than 8. Such significant differences preclude the use of any other internal standard but adjacent normal tissue that was processed exactly the same as the tumor. The validity of DNA results obtained otherwise should be considered questionable. These findings may explain some of the previously published controversial reports and emphasize the need to use an internal standard and more stringent criteria to define aneuploidy in paraffin-embedded tissue.

Hospital closure: maintaining staff morale

Closing a large psychiatric hospital is a complex exercise, and one of the main tasks for management is to maintain staff numbers and staff morale during the run-down period, and to help staff find new and rewarding roles in the community based service. Alistair Bailey and Martin Barkley explain how this was tackled at Netherne Hospital.

Quantification of estrogen receptors on paraffin-embedded tumors by image analysis

Emphasis on early detection of breast carcinomas has increased the number of instances in which an insufficient amount of tissue is available for biochemical estrogen receptor (ER) assay. Image analysis, used together with immunohistochemistry, introduces the possibility of quantifying molecules, such as ER, in routinely processed tissues. To explore that possibility, sections from 40 formalin-fixed, paraffin-embedded breast carcinomas with biochemically determined ER values were reacted with H222 anti-ER antibody (ER-ICA) and quantified on a CAS 200 image analysis system. A minimum of ten fields comprising at least 15,000 microns 2 of nuclear area were analyzed in each case. If the antigen distribution were not homogeneous, proportional sampling of the different tumor areas was carried out. Of the 31 ER-positive (10 to 344 fmol/mg) tumors, 27 (87%) were immunoreactive by the ER-ICA assay (greater than 5% positive nuclear area), which represents an improvement over simple microscopic evaluation (68%). Bivariate analyses showed statistically significant, albeit only modest, correlation between ER values and the percentages of positive area (r = 0.556) and positive stain (r = 0.518). The following obstacles were found to interfere with a proper correlation: (a) antigen loss during fixation and processing; (b) intratumoral antigenic heterogeneity; and directly associated with it, (c) interobserver variability. Uniform tissue handling or, alternatively, the use of internal controls to compensate for fixation-induced differences, together with thorough assessment of the tissue, should reduce these obstacles and facilitate accurate and reproducible quantification.

Red cell autoantibodies, multiple immunoglobulin classes, and autoimmune hemolysis

The effects and interrelationships of multiple immunoglobulin coating (i.e., increased red cell [RBC]-bound IgM and/or IgA in addition to IgG) were investigated in 404 patients with warm-reactive RBC autoantibodies on 590 occasions. Multiple immunoglobulins were detected by enzyme-linked direct antiglobulin tests in 218 samples (37%), but in only 87 (15%) by agglutination methods. Differences in populations were examined by chi-square, with p less than 0.005 being required for significance because of the multiple tests. Compared with IgG coating alone, multiple immunoglobulins were significantly associated with larger quantities (greater than 800 molecules/RBC) of IgG, multiple IgG subclasses, IgG3 and C3d bound to the cells, and with serum haptoglobin levels of less than 0.1 g per L. The latter association was still significant when higher levels of RBC-bound IgG and subclass pattern were taken into account. In samples with multiple immunoglobulin coating, there was no significant relationship (p greater than 0.05) between haptoglobins of less than 0.1 g per L and either C3d or multiple IgG subclasses. It was concluded that multiple immunoglobulin coating, even when undetected by agglutination methods, is a major cause of hemolysis: it is part of a more generalized autoimmune response and acts with other factors such as the quantity of bound IgG, the IgG subclass pattern, and complement; it also has an important hemolytic effect in its own right.

Laparoscopic laser cholecystectomy and choledocholithiasis

The management of common bile duct stones during laparoscopic laser cholecystectomy (LLC) is uncertain. Open common bile duct exploration is the least desirable option since it defeats the purpose of LLC. Endoscopic retrograde cholangiopancreatography (ERCP) with papillotomy has become the procedure of choice since it has a high rate of success and results in minimal morbidity. Intraoperative techniques using balloon catheters and the flexible choledochoscope via the cystic duct may obviate the need for ERCP in selected cases.

Erythrocyte autoantibodies, subclasses of IgG and autoimmune haemolysis

The subclass pattern of red cell bound IgG autoantibody was studied in 304 patients on 426 occasions. Subclass interrelationships with time, other cell bound immunoglobulins (IgM, IgA), amount of bound IgG and serum haptoglobin levels were investigated using population proportions; because of the multiple statistical tests, P less than 0.01 was required for significance. IgG1 was most common, being found in 98% of cases and as the sole subclass in 64%; multiple subclasses occurred in 34.5%. The IgG subclass pattern possibly changed with time (P less than 0.02, greater than 0.01), populations being compared at 6 and 12 months. There was a highly significant and important correlation between multiple IgG subclasses and multiple immunoglobulin coating; in our further studies, this necessitated the use of samples where only cell bound IgG was increased. Multiple IgG subclasses strongly correlated with larger amounts of cell bound IgG, groups with greater than 2 and less than 1 OD units by the enzyme-linked direct antiglobulin test being compared (approximately greater than 800 and less than 400 molecules IgG per red cell respectively). Multiple subclasses (P less than 0.05, greater than 0.01), but not IgG3, were possibly associated with low haptoglobin levels; significance was reached, however, if the multiple immunoglobulin effect was ignored. IgG subclass interrelationships are clearly complex and require strictly defined populations for their study.

Unique sequence organization and erythroid cell-specific nuclear factor-binding of mammalian theta 1 globin promoters

The theta 1 globin gene is an alpha globin-like gene, and started to diverge from the other members of the alpha globin family 260 million years ago. DNA sequencing and transcriptional analysis indicated that it is functional in erythroid cells of the higher primates, but not in prosimians and rabbit. The theta 1 promoter region of higher primates including man consists of GC-rich sequences characteristic of housekeeping gene promoters, and CCAAT and TATA boxes located further upstream. It is shown here that the housekeeping gene promoter-like region of human theta 1 contains two tandemly arranged, GC-rich motifs (GC-I and GC-II). Of these, GC-II interacts with nuclear factor(s) present in the globin-expressing, erythroleukemia cell line K562, before and after hemin induction. GC-I, however, interacts with nuclear factor(s) only present in hemin-induced K562 cells. These factors are different from previously reported erythroid cell-specific factors, and are not detectable in non-erythroid Hela cells. Furthermore, the sequence of the motif GC-I and its location relative to ATG codon have been conserved among all known mammalian theta 1 globin genes. Finally, and most interestingly, the CCAAT box of theta 1 is contained within a 38 bp internal segment of Alu repeat sequence. Immediately upstream from this CCAAT box-containing Alu repeat segment is a 241 bp Alu repeat pointing in the opposite direction. The conservation of this novel arrangement among the higher primates suggests that an inserted Alu family repeat and its flanking genomic sequence have co-evolved, for at least 30 million years, to provide the canonical CCAAT and TATA promoter elements of the theta 1 globin genes in higher primates.

Cardiac injury with damped sine and trapezoidal defibrillator waveforms

To assess defibrillator-induced cardiac damage, 49 anaesthetized greyhounds received either no shocks (control group) or five shocks from a defibrillator delivering one of five waveforms (Lown, Edmark, Belfast damped sine waveforms: 5 and 20 ms trapezoidal waveforms). At 3 days the hearts of the 36 surviving dogs were examined for macroscopic damage. The Belfast and Edmark waveforms caused significantly more damage (mean 21.1 +/- SEM 2.9 g and 16.0 +/- 3.7 g) respectively than the Lown waveform (3.5 +/- 1.3 g) P less than 0.01. The 20 ms trapezoid caused significantly more damage (8.1 +/- 3.1 g) than the 5 ms pulse (0.7 +/- 1.3 g) P less than 0.05). The ventricular ectopic counts per minute were not significantly different in the three sine wave and 20 ms trapezoidal groups at 24 and 48 h (P greater than 0.05), but at 2 and 72 h were significantly greater in the Belfast and Edmark groups than in the Lown group (2 h, Belfast P less than 0.01, Edmark P less than 0.05: 72 h P less than 0.05). At 15 min there was more right chest ST-segment elevation in the Belfast than in the Lown, Edmark and 20 ms trapezoid groups (P less than 0.01), while left chest ST elevation was greater in the Belfast and Edmark than in the Lown (P less than 0.05) and 20 ms trapezoid groups (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Transthoracic defibrillation threshold of sine and trapezoidal waveforms in defibrillation

The transthoracic defibrillation threshold of trapezoidal (2.5-, 5-, 10-, 15-, 20-, 40-, and 55-msec duration) and damped sine waveforms were established in groups of anesthetized greyhounds. Of the seven trapezoidal waveforms, the threshold current was lowest for the 20-msec pulse but was not significantly different for the 5-20-msec pulses (p greater than 0.05). The threshold delivered energy was not significantly different for the 2.5-20-msec waveforms. The 40- and 55-msec pulses had significantly greater delivered energies than the shorter pulses (p less than 0.01). The transthoracic defibrillation threshold of two trapezoidal (5- and 20-msec) and three damped sine waves (Lown, Edmark, and Belfast) showed that the threshold transthoracic current and energy were not significantly different for the 5-msec trapezoid and three sine waves (p greater than 0.05). The threshold transthoracic energy for the 20-msec trapezoid was significantly greater than that of the four other waveforms. The threshold current for the 20-msec trapezoid was significantly less than that of the Belfast and Edmark waveforms only. Thus, none of the three damped sine waveforms was superior, with the 5-msec trapezoid producing similar results. Although the 20-msec trapezoid had the lowest threshold current, it had the highest delivery energy.

Serum cholesterol and subsequent risk of cancer: results from the BUPA study

In the BUPA study, a prospective study of 22,000 men attending a screening centre in London, the mean serum cholesterol level of the 267 men who developed cancer was 6.66 mmol l-1, not significantly different from the mean level of 6.72 mmol l-1 among the 525 unaffected controls matched for age, smoking history and the calendar quarter of their attendance at the screening centre. There was, however, a significant difference in serum cholesterol levels among men who were diagnosed as having cancer less than 2 years after the date of blood collection (6.49 mmol l-1 for the 116 cancer subjects and 6.78 mmol l-1 for the 224 controls (P = 0.02)) but not in men who developed cancer 2-11 years after blood collection (6.79 mmol l-1 for the 151 cancer subjects and 6.68 mmol l-1 for the 301 controls). The observation that the association between low serum cholesterol and cancer was confined to men in whom a diagnosis of cancer was made within 2 years after the date of blood collection suggests that the low serum cholesterol is a metabolic consequence rather than a precursor of the cancer. Our results, which are consistent with the majority of other published studies, indicate that a low serum cholesterol is not a cause of cancer.

Fourier analysis of ventricular fibrillation and synchronization of DC countershocks in defibrillation

Spectral analysis of the first 40 seconds of ventricular fibrillation confirmed the presence of a large periodic component in fibrillation, with a dominant frequency of 9.9 +/- 0.7 Hz and a narrow bandwidth. To determine whether less energy was required for defibrillation at any particular phase of the ventricular fibrillation cycle, the authors studied the effect of synchronization of the countershock to the peaks and troughs of the ventricular fibrillation waveform in 12 dogs anesthetized with sodium pentobarbitone (35 mg/kg iv). There was no significant difference in threshold-delivered energy or threshold-delivered current between shocks synchronized to the peaks of ventricular fibrillation, shocks synchronized to the troughs of ventricular fibrillation, and unsynchronized shocks.

Shiley INFUSAID Pump technology

Totally implantable drug delivery devices have been shown to be safe and effective in the delivery of drugs both systemically and regionally. Applications have been developed for continuous infusions of drugs and are currently being developed for variable flow rates with more sophisticated programmable pumps. Some of the potential benefits of such devices include improved drug efficacy with reduced systemic toxicities, more controlled dosing of drugs, improved quality of life, delivery of proteins and peptides, and individualized patient dosing. The potential exists for creating biofeedback closed loop therapies for diabetes, cardiovascular diseases, and some central nervous system diseases in the future.

Serum beta-carotene and subsequent risk of cancer: results from the BUPA Study

In the BUPA Study, a prospective study of 22,000 men attending a screening centre in London, serum samples were collected and stored. The concentration of beta-carotene was measured in the stored serum samples from 271 men who were subsequently notified as having cancer and from 533 unaffected controls, matched for age, smoking history and duration of storage of the serum samples. The mean beta-carotene level of the cancer subjects was significantly lower than that of their matched controls (198 and 221 micrograms l-1 respectively, P = 0.007). The difference was apparent in subjects from whom blood was collected several years before the diagnosis of the cancer, indicating that the low beta-carotene levels in the cancer subjects were unlikely to have been simply a consequence of pre-clinical disease. Men in the top two quintiles of serum beta-carotene had only about 60% of the risk of developing cancer compared with men in the bottom quintile. The study was not large enough to be able to indicate with confidence the sites of cancer for which the inverse association between serum beta-carotene and risk of cancer applied, though the association was strongest for lung cancer. The association may be due to beta-carotene affecting the risk directly or it may reflect an indirect association of cancer risk with some other component of vegetables or with a nonvegetable component of diet that is itself related to vegetable consumption.

Serum vitamin E and subsequent risk of cancer

In a prospective study of about 22,000 men attending a screening centre, serum samples were collected and stored. The concentration of vitamin E (alpha-tocopherol) was measured in the stored serum samples from 271 men subsequently notified as having cancer and from 533 unaffected controls, matched for age, smoking history and duration of storage of the serum samples. The mean vitamin E level of the cancer subjects was not significantly different from that of their matched controls. The mean level in the cancer subjects who were diagnosed as having cancer before the elapse of one year from the date of blood collection was, however, significantly lower than the mean concentration of their matched controls (10.0 and 11.5 mgl-1 respectively, P = 0.003). For subjects whose cancers were diagnosed one or more years after blood collection the difference was not statistically significant either for all cancers or for cancers of six sites considered separately, viz. lung, colon and rectum, stomach, bladder, central nervous system and skin. The most likely explanation for these results is that the low vitamin E levels observed in these subjects were a metabolic consequence, rather than a precursor, of the cancer. This would explain, at least in part, the overall inverse association between serum vitamin E and risk of cancer observed in the published epidemiological studies on serum vitamin E and cancer.

Characterization of covalently cross-linked pancreatic somatostatin receptors

The receptor for somatostatin present in rat pancreatic plasma membranes was characterized by affinity labeling with [125I-Tyr11]somatostatin utilizing three different heterobifunctional cross-linking agents: N-5-azido-2-nitrobenzoyloxy-succinimide, N-succinimidyl 6-(4-azido 2'-nitrophenylamine)hexanoate, and N-hydroxysuccinimidyl 4-azido-benzoate. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography revealed a broad band of Mr = 92,000 when any of the three cross-linkers was used; N-succinimidyl 6-(4-azido 2'-nitrophenylamine), however, was most efficient. Labeling of the Mr = 92,000 protein band was not affected by reducing agents but was sensitive to somatostatin and guanine nucleotides, particularly GTP gamma S, at concentrations which reduced binding to the receptor. The affinity-labeled protein could be solubilized completely with Zwittergent 3-12, partially with Triton X-100 and 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid, and poorly with Zwittergent 3-08 and digitonin. When exposed to agarose-coupled lectins, the detergent solubilized, labeled Mr = 92,000 protein was completely adsorbed to wheat germ agglutinin, partially to ricin communis II, and not at all to concanavalin A or lotus or lentil lectin. The Mr = 92,000 protein bound to wheat germ agglutinin-agarose was not eluted by N-acetylglucosamine but was by triacetylchitotriose, providing a considerable purification of the somatostatin receptor. These data allow us to conclude that the somatostatin receptor is a monomeric glycoprotein with an Mr = 90,000 binding subunit which probably contains a polymeric arrangement of N-acetylglucosamine residues.

Serum retinol and subsequent risk of cancer

In a prospective study of about 22,000 men attending a well person screening centre, serum samples were collected and stored. The concentration of retinol was measured in the stored serum samples from 227 men subsequently notified as having cancer and from 454 unaffected controls, matched for age, smoking history and duration of storage of the serum samples. The mean serum retinol concentration of the cancer subjects who developed cancer before the elapse of one year since the time blood was collected was significantly lower than the mean concentration of their matched controls (641 and 722 micrograms l-1 respectively, P less than 0.001). For subjects whose cancer developed one to two years after blood had been collected, the difference was less (650 and 701 micrograms l-1 respectively, P less than 0.01). For subjects whose cancer developed three or more years after blood was collected, the mean retinol level was higher than in their controls, although not statistically significantly so (694 and 663 micrograms l-1 respectively). These findings suggest that the inverse association between serum retinol and risk of cancer that was previously observed was due to low serum retinol being a metabolic consequence of cancer rather than a precursor of cancer.

Urinary nicotine concentrations in cigarette and pipe smokers

Urinary concentrations of nicotine were studied in men who did not smoke (27) and in men who smoked cigarettes only (145) or pipes only (48). The median urinary nicotine concentrations were less than 50 ng/ml (the detection limit of the assay for urine tests) in the non-smokers, 1393 ng/ml in the cigarette smokers, and 1048 ng/ml in the pipe smokers. These values were standardised for urinary pH and creatinine concentration to allow for the fact that nicotine excretion is influenced by the acidity of the urine and by urinary flow rate. The high urinary nicotine concentrations in the pipe and cigarette smokers indicated that both types of smoker have relatively high systemic nicotine concentrations. This observation, together with the fact that large prospective studies have shown that pipe smokers have no material excess risk of coronary heart disease whereas cigarette smokers do, provides evidence that nicotine is unlikely to be the major cause of the excess deaths from coronary heart disease in cigarette smokers. This conclusion is consistent with earlier observations based on serum cotinine concentrations in smokers and non-smokers.

Explosive nephrolithopaxy: reality or fiction?

The use of silver and lead azide explosive charges for the percutaneous distintegration of renal calculi has been investigated. Charges of 10 mg or more reliably reduced calculi to fragments of extractable size; however, the concomitant tissue effects would preclude the use of such charges clinically. Smaller charges require multiple applications. High-speed flash photography demonstrated the unfocussed nature of these discharges. Considerable improvements are anticipated when the shock waves are focused. The use of Nonel tubing is described, and future developments are discussed.

Relative intakes of tar, nicotine, and carbon monoxide from cigarettes of different yields

The relative intakes of tar, nicotine, and carbon monoxide were estimated in 2455 cigarette smokers, who freely smoked their usual brands of cigarette. The estimates were derived by using an objective index of inhaling based on the measurement of carboxyhaemoglobin divided by the carbon monoxide yield of the cigarettes smoked, after background and carry over carboxyhaemoglobin effects had been allowed for. Separate analyses were performed according to the yield and type (plain, filter, etc) of cigarette smoked. The analyses based on yield indicated that the extent of inhaling was adjusted sufficiently to achieve similar intakes of nicotine/carbon monoxide regardless of the nicotine/carbon monoxide yield. It was not, however, sufficiently increased to achieve a similar intake of tar as the tar yield of the cigarette decreased. The analyses based on type of cigarette indicated that the extent of inhaling was adjusted to achieve similar intakes of tar and nicotine regardless of the type of cigarette smoked, but that this led to a greater intake of carbon monoxide among filter cigarette smokers than that among smokers of plain cigarettes--more so than would have been expected from their relative carbon monoxide yields. Two conclusions arise from these results. Firstly, any harmful effects of nicotine/carbon monoxide are unlikely to be materially reduced by smoking cigarettes with lower yields of nicotine/carbon monoxide, but the harmful effects of tar are likely to be reduced by smoking cigarettes with lower tar yields. These predictions appear to be borne out by epidemiological observations. Secondly, any harmful effects of carbon monoxide on the cardiovascular system will be greater in smokers of modern filter cigarettes than in smokers of modern plain cigarettes, provided that these two groups of smokers are otherwise similar with respect to risk of cardiovascular disease.

Insulinlike growth factors bind to specific receptors in isolated pancreatic acini

Recently we have demonstrated the existence of specific receptors for insulin on pancreatic acini. Employing 125I-labeled insulinlike growth factors (IGFs) and insulin, we report the existence of distinct receptors for IGF-I and IGF-II on mouse pancreatic acini. Insulin competes with 125I-IGF-I with 1,000-fold less potency. By contrast, insulin increases the binding of 125I-IGF-II to its receptor. IGF in turn inhibits 125I-insulin binding to its receptor but with 250-fold less potency. Thus, distinct receptors exist on acini for IGF-I, IGF-II, and insulin. Moreover, IGF, like insulin, stimulates sugar transport by acini. The mechanism of IGF stimulation may be similar to insulin, as the effect of maximal concentrations of the two peptides when added together is not additive. These results raise the possibility, therefore, that IGFs may be a new class of physiological regulators of pancreatic acinar cell function.

Development of myometrial electrical activity during the first half of pregnancy in the sheep

Uterine myoelectrical activity was recorded in seven pregnant sheep covering the period between 13 and 75 days post-coitum. Activity in the myometrium was present at day 13 and took the form of intermittent spikes of low amplitude. Bursts of spikes of irregular duration became noticeable between days 25 and 40 but most were not coordinated throughout the myometrium. Coordinated bursts of myoelectrical activity, which could be recorded at several sites simultaneously, first appeared between 40 and 65 days. These bursts had similar characteristics to the myoelectrical activity associated with uterine contractions during the last third of gestation. The myoelectrical activity showed a progressive increase in amplitude during the first half of gestation. There was no relationship between plasma progesterone levels and the increase in amplitude or appearance of coordinated bursts of uterine activity.

The effect of chloroquine on the binding, intracellular distribution, and action of insulin on isolated mouse pancreatic acini

The effects of chloroquine on the binding, intracellular distribution, and action of insulin were studied in isolated pancreatic acini prepared from diabetic mice. Chloroquine had three effects on these cells. First, chloroquine altered cellular morphology by inducing an increase in the number and size of autophagic vacuoles and vesicles in the Golgi-lysosomal region. Second, chloroquine, in a dose-dependent fashion, increased the amount of 125I-insulin associated with acini. A detectable effect of chloroquine was seen at 10 microM, and a maximal effect was seen at 30-100 microM where cell-associated insulin was more than doubled. Employing electron microscope autoradiographs, this accumulation of hormone was observed in the Golgi-lysosome area of the pancreatic acinar cell. Third, chloroquine had selective effects on the action of insulin. Preincubation with chloroquine had no effect on basal [3H]2-deoxy-D-glucose uptake, but in a dose-dependent fashion it decreased the stimulatory effect of insulin on this function; at 100 microM chloroquine, the effect of insulin was abolished. In contrast, chloroquine had negligible effects on the stimulation of 2-deoxy-D-glucose uptake into acini by cholecystokinin. Chloroquine in dose-dependent fashion partially inhibited basal [3H]leucine incorporation into acinar cell protein, but in contrast to its effects on 2-deoxy-D-glucose uptake, the drug had no effects on the stimulation of this function by insulin.+2

Inhaling and lung cancer: an anomaly explained

An objective index of inhaling cigarette smoke based on carboxyhaemoglobin concentrations and the carbon monoxide yields of cigarettes was used to investigate possible systematic differences in the extent of inhaling among light and heavy smokers when classified according to their self described inhaling habits. A total of 2108 men who smoked cigarettes were studied. Heavy smokers (20 or more cigarettes a day) had a higher average inhaling index than light smokers (fewer than 20 cigarettes a day) both among those who said that they inhaled and among those who said that they did not. This observation, together with indirect evidence that heavy smokers who inhale deeply may to some extent avoid depositing smoke condensate on their main bronchial epithelium, explains a hitherto unresolved anomaly--namely, that the risk of lung cancer is less among heavy cigarette smokers who say that they inhale than it is among those who say that they do not inhale.

Effects of proglumide on pancreatic acinar cell function

Proglumide, a putative gastrin receptor antagonist, inhibited cholecystokinin (CCK)-stimulated amylase release and [3H]-2-deoxy-D-glucose uptake by isolated mouse pancreatic acini. Inhibition was reversible and competitive in nature with a KI of 0.7 mM. Proglumide also competitively inhibited the binding of 125I-CCK to its receptor in pancreas and brain; the KI for this interaction was 1.0 mM. In contrast, proglumide did not inhibit carbachol-stimulated amylase release, insulin-stimulated glucose transport and protein synthesis, or the binding of insulin to its receptors. Proglumide at 10 mM did, however, reduce both basal [3H]-2-deoxy-D-glucose uptake and [3H]-leucine incorporation into protein. We conclude that proglumide is a competitive and specific, albeit weak antagonist of CCK receptors. Higher concentrations of the drug may have other more nonspecific effects.

Relationship of cholecystokinin receptor binding to regulation of biological functions in pancreatic acini

Cholecystokinin (CCK) was conjugated to 125I-Bolton-Hunter reagent (125I-BH-CCK), and the binding of this ligand to CCK receptors in isolated mouse pancreatic acini was correlated with the regulation by CCK of both amylase release and the transport of 2-deoxyglucose and alpha-aminoisobutyric acid. Stimulation of amylase release by CCK was biphasic. At low CCK concentrations (less than 200 pM), amylase release was progressively stimulated, whereas at higher CCK concentrations (greater than 200 pM), amylase release was progressively reduced. In contrast, stimulation of 2-[3H]deoxyglucose transport and inhibition of alpha-[3H]aminoisobutyric acid transport were monophasic, being one-half maximal at 0.85 and 0.44 nM, respectively. Under incubation conditions identical to those employed for measuring biological functions, the binding of 125I-BH-CCK to receptors in acini was rapid and reversible. Competition-inhibition curves and Scatchard plots of equilibrium binding were compatible with two orders of binding sites. Employing a computer program for analysis of multiple binding sites, a high-affinity, low-capacity binding component having a Kd of 26 pM and a lower-affinity, higher-capacity binding component having a component Kd of 2.2 nM were resolved. Regulation of 2-[3H]deoxyglucose and alpha-[3H]aminoisobutyric acid uptake appeared, therefore, to be the result of fractional occupancy of the lower-affinity CCK receptors. Regulation of amylase released was more complex and appeared to be due to the concomitant occupancy of both the high- and low-affinity CCK receptors.