Evaluation of immunogenicity and reactogenicity of COVID-19 vaccines in pregnant women

OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnancy is associated with increased risk of adverse maternal and perinatal outcomes. Vaccines are highly effective at preventing severe coronavirus disease 2019 (COVID-19), but there are limited data on COVID-19 vaccines in pregnancy. This study aimed to investigate the reactogenicity and immunogenicity of COVID-19 vaccines in pregnant women when administered according to the 12-week-interval dosing schedule recommended in the UK.

METHODS

This was a cohort study of pregnant women receiving COVID-19 vaccination between April and September 2021. The outcomes were immunogenicity and reactogenicity after COVID-19 vaccination. Pregnant women were recruited by phone, e-mail and/or text and were vaccinated according to vaccine availability at their local vaccination center. For immunogenicity assessment, blood samples were taken at specific timepoints after each dose to evaluate nucleocapsid protein (N) and spike protein (S) antibody titers. The comparator group comprised non-pregnant female healthcare workers in the same age group who were vaccinated as part of the national immunization program in a contemporaneous longitudinal cohort study. Longitudinal changes in serum antibody titers and association with pregnancy status were assessed using a two-step regression approach. Reactogenicity assessment in pregnant women was undertaken using an online questionnaire. The comparator group comprised non-pregnant women aged 18-49 years who had received two vaccine doses in primary care. The association of pregnancy status with reactogenicity was assessed using logistic regression analysis.

RESULTS

Overall, 67 pregnant women, of whom 66 had received a mRNA vaccine, and 79 non-pregnant women, of whom 50 had received a mRNA vaccine, were included in the immunogenicity study. Most (61.2%) pregnant women received their first vaccine dose in the third trimester, while 3.0% received it in the first trimester and 35.8% in the second trimester. SARS-CoV-2 S-antibody geometric mean concentrations after mRNA vaccination were not significantly different at 2-6 weeks after the first dose but were significantly lower at 2-6 weeks after the second dose in infection-naïve pregnant compared with non-pregnant women. In pregnant women, prior infection was associated with higher antibody levels at 2-6 weeks after the second vaccine dose. Reactogenicity analysis included 108 pregnant women and 116 non-pregnant women. After the first dose, tiredness and chills were reported less commonly in pregnant compared with non-pregnant women (P = 0.043 and P = 0.029, respectively). After the second dose, feeling generally unwell was reported less commonly (P = 0.046) in pregnant compared with non-pregnant women.

CONCLUSIONS

Using an extended 12-week interval between vaccine doses, antibody responses after two doses of mRNA COVID-19 vaccine were found to be lower in pregnant compared with non-pregnant women. Strong antibody responses were achieved after one dose in previously infected women, regardless of pregnancy status. Pregnant women reported fewer adverse events after both the first and second dose of vaccine. These findings should now be addressed in larger controlled studies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Comparison of the Efficacy of Different Concentrations of Diclofenac Sodium Phonophoresis (1.16% vs 2.32%) in Patients with Knee Osteoarthritis: a Randomized Double-Blind Controlled Trial

PURPOSE OF THE STUDY The objective of the present study is to compare the efficacy of two different concentrations of diclofenac sodium phonophoresis (DSPH) (1.16% vs 2.32%) in patients with knee osteoarthritis (OA). MATERIAL AND METHODS A randomized, double-blind, controlled design was applied. Ninety patients (mean age± SD, 59.98 ± 8.89 years) who had Kellgren-Lawrence (K-L) grades II to III knee OA were randomly allocated into three groups; 1.16% DSPH, 2.32% DSPH, TUS (30 in each group). Each patient was treated five sessions per week for two weeks. A 100-mm visual analogue scale (VAS) for usual pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated before and after treatment in all groups. RESULTS The VAS pain and WOMAC scores were significantly improved after treatment in all groups (p < 0.05). The 2.32% DSPH showed more significant effects than the 1.16% DSPH, both in improving WOMAC- pain and physical function scores (p = 0.020, p = 0.008) and reducing the VAS pain measure, although it did not reach the level of significance (p = 0.077). The 2.32% DSPH was superior to the TUS, both in reducing the VAS pain measure (p < 0.001) and in improving WOMAC-pain, stiffness, physical function and total scores (p = 0.022, p = 0.016, p < 0.001, p < 0.001 respectively). 1.16% DSPH significantly reduced stiffness and physical function scores compared with TUS (p = 0.042, p = 0.047). CONCLUSIONS DSPH and TUS are effective treatments for knee OA. Our results indicated that 2.32% DSPH produces additional benefits to functional improvement and pain reduction compared with 1.16% DSPH in K-L grades II to III knee OA. Key words: diclofenac sodium, knee osteoarthritis, phonophoresis, therapeutic ultrasound, topical formulation.

Workaholism: are physicians at risk?

BACKGROUND

Work addiction (WA), often called 'workaholism', is a relatively recent concept that has not yet been clearly defined. Ongoing studies have found prevalence rates that are highly variable due to the diversity of the models used and the populations studied.

AIMS

To assess the characteristics of WA among hospital medical staff.

METHODS

All physicians practising at a French university hospital were invited to participate in a survey based on two questionnaires: the Work Addiction Risk Test (WART) for WA and the Job Contents Questionnaire (JCQ) to assess psychosocial constraints at work.

RESULTS

There were 444 responding physicians. The response rate was 45%. Thirteen per cent of respondents were considered to be highly work addicted and a further 35% were considered mildly work addicted. Professors had the highest average WART score, but neither age nor sex was associated with WA. Furthermore, all 3D scores obtained using the JCQ correlated with the WART score; the highest correlation coefficient being obtained between the WART score and the job demands score, indicating that workaholics experienced high job demands.

CONCLUSIONS

WA especially affects professors, who have the highest status amongst doctors in the hospital hierarchy. This study highlights the importance of constraints and workload, which are consistent with individual vulnerability factors. These factors may help identify ways of preventing and managing this type of addiction, through improvement of working conditions and organizational structures.

Cross-education of muscle strength: cross-training effects are not confined to untrained contralateral homologous muscle

The aim of this study was to evaluate whether electrical muscle stimulation (EMS) on dominant wrist flexors causes an increase in the muscle strength of the contralateral wrist extensors. Twenty-three healthy, young, adult men were included in this prospective, double-blind, controlled study. Participants were randomly allocated to the EMS group or Control group. Electrodes were placed over the flexor aspect of the right forearm in both groups. In the EMS group, passive wrist extension and (EMS) that caused powerful muscle contraction were simultaneously applied. In the Control group, a conventional mode of transcutaneous electrical nerve stimulation was applied without causing any contraction. A group effect (P=0.0001) and group-by-time interaction were found (P=0.0001) for both the wrist flexor and extensor muscles, but not group-by-time-by-arm interactions. This implies that the effect of the interventions was similar in both arms, but that the response was significantly larger in the EMS than in the Control group. The results of the current study suggest that cross-education is not confined to the untrained contralateral wrist flexors and that the strength increase may also be observed in the contralateral wrist extensors.

Demographic parameters of wrinkling aphid of pistachio leaf, Forda hirsuta Mordv. (Hem.:Pemphigidae) insitu of Rafsanjan's orchards

Wrinkling aphid of pistachio leaf, Forda hirsuta Mordv. (Hem.:Pemphigidae) is one of the pests of pistachio trees. This aphid caused the shrinkage, thickening, and changing the color of the pistachio leaves. Since insect feeds from leave edges, the thick and rolled upward wrinkles were formed, which its green color turned into red. Therefore, its economical damages are out of direct feeding from plant extraction, twisting pistachio leaves, and the decrease of photosynthesis. In this research two orchards and 10 trees that each of them were selected in Rafsanjan region and 58 fundatrix galls, 120 nymphal galls were marked and the demographic parameters for apterus parthenogenesis female of this aphid were calculated via daily observations. The results indicated that intrinsic rates of increase (r) for 1, 2 and 3 generations were 0.01, 0.0638 and 0.0575 femal/femal/days respectively, Doubling time (DT) were 69.31, 10.52 and 12.04 days, respectively, net fecundity rates were 1.71, 11.5 and 7.37 femal/femal/days, respectively, Net fertility rates were 1.11, 8.87 and 5.01 days, respectively, and mean generation times (Tc) were calculated to be 31.5, 32.2 and 31.87 days, respectively. Other reproductive parameters such as gross hatch rate, gross fecundity rate, gross fertility rate, mean age gross fecundity and fertility, mean age net fecundity and fertility, mean age hatch, finite rate of increase (lambda), intrinsic birth rate (b) intrinsic death rate (d) and daily reproductive rate were also calculated. The results revealed that population parameters especially r in the first and second generations were lowest and highest, respectively and mean longevity of fundatrix was 30 days and the born nymphs made separate galls in the edge of pistachio leaves.

[Five-year survival of Ile-de-France cancer patients diagnosed in 1994]

BACKGROUND

This study aimed to estimate survival at 5 years by localization, sex and stage of the patients who presented a new cancer in 1994 in the Ile-de-France area.

METHODS

A cohort study began in 1994 by an exhaustive collection of the incidental cancers notified in the Ile-de-France area at the health insurance (27,080 patients). A stratified random sample based on tumor localization was followed at 1 year, 3 years and 5 years. The analysis of the observed survival was carried out according to Kaplan-Meier method. Relative survival was calculated according to Ederer II method.

RESULTS

The follow-up sample concerned 4,166 patients. For all cancers, relative survival at 5 years was 65% for the women and 51% for the men. Relative survival rate at 5 years was 82% for the women with a breast cancer (98% for the patients in stage I) and 66% for those with a cancer of the cervix. Relative survival at 5 years for colonic cancer was 67% for men and 54% for women. For lung cancer, the relative survival rate fell from 47% for patients in stage I to 5% for those in stage IV.

CONCLUSION

Our study produces population-based survival data for a entire geographical area covering 20% of the French population. Survival improves with earlier diagnosis but depends also on quality of care and availability of care: access to medical care can be a favouring factor. While in terms of incidence the situation in the Ile-de-France area is close to the national situation, survival at 5 years for a set of tumors appears to be better in this area than the nationwide figures. Besides providing information useful to determine mortality and incidence, the health insurance data offer additional insight to cancer epidemiology and contribute to better knowledge of this disease.

Oxytocin promotes spermiation and sperm transfer in the mouse

Spermatogenesis is a complex process during which developing germ cells move from the base of the seminiferous tubule towards the lumen where they are shed. Studies in the rat suggest that seminiferous tubule contraction, induced by exogenous oxytocin, promotes spermiation. This study examines the role of testicular oxytocin in development of the testes, spermatogenesis and spermiation in the mouse. Groups of wild-type (WT) mice, oxytocin knockout mice (OTKO) deficient in testicular oxytocin and mice containing an oxytocin transgene (bOT4.2) that over express testicular oxytocin were killed between days 5 and 45 post partum. The testes and epididymides were removed weighed and prepared either for histological and morphometric study by light microscopy, for sperm counts (epididymis), or extracted for determination of oxytocin content (testis - day 45 only). Testicular oxytocin concentrations were significantly greater (p < 0.05) in bOT4.2 mice than in WT or OTKO mice. No differences in testicular and epididymal weight, or in diameter and area of seminiferous tubules between the mice genotypes were found at any given time. Germ cell development was similar in all genotypes and was comparable with previous studies. The timing of spermiation between the groups was significantly different (p < 0.001) with bOT4.2 < WT < OTKO and the appearance of epididymal sperm was significantly different (p < 0.05) with bOT4.2 < WT < OTKO. There were significant correlations between the percentage of tubules containing residual bodies and epididymal sperm count (p < 0.05) and between the percentage of animals containing residual bodies and the percentage of animals containing epididymal sperm (p < 0.01). These data suggest that in the mouse oxytocin, whilst not involved in germ cell development, is important in the process of spermiation and sperm transfer in the mouse.

Distribution of opioid peptide gene expression in the limbic system of Fawn-Hooded (alcohol-preferring) and Wistar-Kyoto (alcohol-non-preferring) rats

Preprodynorphin and preproenkephalin mRNA expression was examined in the CNS of two rat strains, the alcohol-preferring Fawn-Hooded (FH) and the alcohol-non-preferring Wistar-Kyoto (WKY), using in situ hybridisation histochemistry. Relative to the WKY, the FH showed significantly lower levels of preproenkephalin mRNA in the striatum and nucleus accumbens (-24% and -17% respectively), but a higher level of preprodynorphin mRNA in the hippocampus (+33%). The depressed level of preproenkephalin mRNA in the nucleus accumbens may be implicated in alcohol-seeking behaviour.

Distribution of GABAA receptors in the limbic system of alcohol-preferring and non-preferring rats: in situ hybridisation histochemistry and receptor autoradiography

The present study has employed quantitative receptor autoradiography and in situ hybridisation histochemistry to compare the expression of the mRNA encoding the alpha 1 and alpha 2 subunits of the GABAA receptor and the binding density of mature GABAA receptors in the limbic system of alcohol-preferring Fawn-Hooded rats (FH) with Wistar-Kyoto rats (WKY). Quantifiable levels of mRNA encoding the alpha 1 subunit were found in cortical regions, ventral pallidum, substantia nigra, horizontal limb of the diagonal band and the hippocampus of both rat strains. Interestingly, expression of the alpha 1 subunit mRNA was decreased by approximately 30% in the hippocampus of FH compared to WKY rats. Following a 28-day period with free access to 10% ethanol, expression of the alpha 1 subunit transcript, was significantly increased in the piriform cortex and horizontal limb of the diagonal band, unaltered in the hippocampus but decreased in the substantia nigra of FH rats. Quantifiable levels of mRNA encoding the alpha 2 subunit were found in nucleus accumbens, amygdala, cortical regions, lateral septal nucleus, hippocampus, medial habenula and ventral pallidum of both strains. Expression of the alpha 2 subunit mRNA was decreased by approximately 35% in both the hippocampus and occipital cortex of FH compared to WKY rats. However, consumption of 10% ethanol in FH rats had no impact upon expression of the mRNA encoding the alpha 2 subunit in any region examined. Mature GABAA receptors were studied by autoradiography utilising the antagonist radioligand [3H]SR95531 and the agonist radioligand [3H]muscimol. Topographic binding throughout the limbic system of both strains was observed for both radioligands. Specifically, [3H]SR95531 binding was higher in the occipital cortex, hippocampus, lateral septal nucleus, superior colliculus and ventral pallidum of the FH rats compared to WKY rats; however, in the nucleus accumbens [3H]SR95531 binding was lower in FH compared to WKY. Ethanol consumption had no measurable effect on the binding of [3H]SR95531 in FH rats. In the case of [3H]muscimol, binding was higher in the cortex, lateral septum and ventral pallidum of FH compared to WKY. Furthermore, ethanol consumption resulted in a 25-30% increase in [3H]muscimol binding in the lateral septum and striatum of FH rats. These data provide evidence for differential expression of GABAA receptor subunits in FH and WKY rats, and additionally indicate anatomically defined variations in GABAA receptor binding between the two rat strains.

[3H]zolpidem binding in alcohol-preferring and non-preferring rat brain

The present study has employed in vitro autoradiography to study the distribution and density of [3H]zolpidem binding sites, which are regarded as an index of ethanol-sensitive gamma-aminobutyric acid (GABA)A receptors, in the brains of alcohol-preferring Fawn-Hooded (FH) rats compared to non-alcohol preferring Wistar-Kyoto (WKY) rats. Binding of [3H]zolpidem showed a similar distribution profile in both rat strains examined and included cerebellum, globus pallidus, nucleus of the solitary tract and a number of midbrain/hindbrain nuclei. Densitometric quantitation of binding revealed that FH rats possessed a significantly higher density of [3H]zolpidem binding compared to WKY rats in cortical regions, substantia nigra pars reticulata and the ventral pallidum. These data indicate that FH rats may have an increased number of ethanol-sensitive GABA(A) receptors in regions intimately involved in reward processes, and may partially explain the alcohol-seeking nature of the FH rat.

[Current trends in lung cancer mortality in France]

Lung cancer is the first cause of death from cancer in males in France. This cancer is responsible for 19,000 deaths in males and 3,000 deaths in females. We studied the geographical and temporal variations in lung cancer mortality in France. The average increase in mortality clearly decreased in males, changing from 2.4% between 1971 and 1985 to 0.7% between 1985 and 1992. In females, this tendency is reversed. Even though the rates were stable and very low before 1971, we have since observed a progressive increase which has intensified during the past years. Thus the average annual increase changed from 1.5% between 1971 and 1985 to 3% between 1985 and 1992. The geographic comparisons between the two studied periods (1971-78 and 1987-92) showed important differences between males and females. The geographic disparities among males were stable between these two periods. The excess observed mortality rate was maintained in the north-east. Among females, few geographic variations were observed during the first period. The second period however, showed distinct excess mortality rates in urban areas and large conglomerations as compared to the rest of France. In summary, the increase in the mortality rates for lung cancer is more pronounced in females and seems to have diminished in males, particularly in urban areas. This tendency started in the 1980s.

Should patients over 80 years old be operated on for colorectal or gastric cancer?

One hundred and three patients aged 80 years or more were operated on for colorectal cancer (n = 80) or gastric cancer (n = 23). The postoperative mortality rate was 8%. Hospital mortality (12%) was not influenced by the factors age or emergency procedure, but by the factors ASA score (P = 0.06), palliative procedure (p = 0.08), and gastric surgery (P = 0.05). The overall 5-year survival rate was 23% after colorectal surgery, and 10% after gastric surgery (P = 0.001). After colorectal surgery, long-term survivals were observed, even in presence of serosal and/or lymph nodes involvement. Thirteen patients were alive more than five years after surgery. In contrast, after gastric surgery, all patients, except those with early carcinoma, died within one year. Indications for operation must be wide in colorectal cancers, and more restrictive in gastric cancers. Long-term survivals were observed after colorectal surgery in the elderly, even in the presence of lymph node involvement. In contrast, after gastric surgery, all patients, except those with early carcinoma, died within one year.

[Pattern of mortality from ovarian cancer in France 1968-1991]

In a recent meta-analysis of three American case-control studies, Whittermore et al found an increased risk of ovarian cancer in women treated for infertility. We have studied the mortality due to ovarian cancer in France between 1968 and 1991 in order to verify whether the use of these treatments could have modified mortality rates during the 24 years period studied. First, we have noted that among the 3175 deaths from ovarian cancer registered in France in 1991, only 136 occurred in women under 45 years of age, and 943 occurred in women between 45 and 59 years of age. We then observed an important geographical diversity with a higher frequency of ovarian cancer in the North of France as compared to the South. Finally, we observed a 72% increase in mortality during the study period. This increase can be entirely explained by the increase in the mortality rates among women over 60 years of age. Among women under 45, the ovarian cancer rate decreased by 24% between 1968 and 1991. Among women between 45 and 59 years of age, these rates increased by only 8% (or about 0.3% per year). These results imply that a possible effect--in terms of public health--of treatment for infertility does not necessarily translate into a significant increase in mortality from ovarian cancer among women under 60 years of age. This result in no way nullifies the role that epidemiological studies have in verifying the accuracy of risks associated with treatments for infertility.

Radiotherapy alone in breast cancer. Analysis of tumor and lymph node radiation doses and treatment-related complications. The experience of the Gustave-Roussy Institute and the Princess Margaret Hospital

This retrospective analysis was conducted on breast cancer patients treated by radiotherapy alone at The Princess Margaret Hospital and at the Institut Gustave-Roussy. These patients had either operable tumors, but were unfit for general anesthesia, or had inoperable tumors due to local contraindications to surgery. Previous results showed that a radiation dose increase of 15 Gy can decrease the relative risk of tumor or lymph node recurrence twofold. In this third report, the same data were analyzed to determine the treatment-related complication rates and to correlate these to the radiation dose levels. Overall results were analyzed on 453 patients, but detailed analyses on complications were conducted on 372 patients not developing local recurrence in the first 6 months of follow-up. Each complication was graded on a 3-level previously defined scale. Most frequent complications were skin changes of different degrees, which were usually asymptomatic. More disabling complications were arm edema, impaired shoulder mobility, rib fractures and brachial plexopathy. The incidence of disabling complications was low. The only factor significantly increasing the risk of complications was the radiation dose level to the tumor and axilla. Technical factors such as overlapping fields should also be taken into account. As the more effective control of tumor and lymph nodes obtained in patients treated with higher radiation doses is counterbalanced by an increase in the complication rate, the dose to be delivered for each patient should be carefully chosen according to individual risk factors.

Supersensitivity to electrical stimulation for assessing physical dependence on opioids in isolated tissues

The use of the guinea pig ileum (GPI) and mouse vas deferens (MVD) to quantify opiate tolerance and physical dependence in the same preparation was examined. In the GPI, tolerance to and physical dependence on various opiates were induced by direct incubation with an agonist and tolerance and abstinence were assessed after its rapid removal by extensive washing. Dependence, as evidenced by an increase in twitch height and after removal of the agonist as compared to that before incubation, provided an index of the degree of physical dependence. The extent of the supersensitive response after agonist removal was noted to be related directly to the agonist concentration and the degree of tolerance development. Furthermore, the supersensitive response was found to be stereospecific, naloxone reversible and preferentially mu receptor-mediated. Likewise, tolerance to opiates could be demonstrated in the MVD by direct incubation with an agonist. Unlike the GPI, rapid removal of the agonist by washing did not produce a supersensitive response to electrical stimulation. However, a supersensitive response was demonstrable in the presence of naloxone. Thus, after a tolerant/dependent state was induced by incubation of the vas with a predetermined dose of [D-Ala2, D-Leu5]enkephalin that completely abolished the twitch response, the subsequent addition of naloxone resulted in a supersensitive response to electrical stimulation that was concentration-dependent. The maximum twitch response in the presence of naloxone, compared to that obtained before incubation with the agonist, provided an index of the extent of dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the mortality of a cohort with the mortality of a reference population in a prognostic study

It is standard practice in epidemiological studies to compare the observed mortality of a cohort to the mortality expected in a reference population of the same age and sex distributions computed from national statistics. The same methods can be used in a prognostic study where the effects on survival of potential prognostic factors are studied in a cohort of patients with a given disease. Writing the hazard function in the cohort as the product of the hazard function in the reference population and a function of some characteristics of the patients, one can derive simple estimates and statistical tests of the standardised mortality ratios (Breslow et al.). The study of a cohort of patients with thyroid cancer will provide an example.

Opioid-like properties of seven dynorphin (1-10) analogs

In order to disassociate the k action of dynorphin from its other actions, seven analogs were synthesized and evaluated for pharmacologic activity in comparison with dynorphin (1-13) and dynorphin amide (1-10). Dynorphin (1-10) was modified by protecting the terminal carboxy group, incorporating thioproline at position 10 and substituting methionine for leucine at position 5. All analogs exhibited the ability to inhibit electrically-induced twitches of the guinea pig ileum and mouse vas deferens in a manner that was dose dependent and naloxone reversible. The decapeptide terminating with a pyrrolidine group showed the highest potency in the ilea and mouse vas deferens. None of the analogs showed analgetic activity by the mouse tail flick test. Binding studies using mouse brain synaptosomes showed that all seven analogs can displace the binding of tritiated dihydromorphine (DHM), ethylketocyclazocine (EKC) and D-Ala-D-Leucine enkephalin (DADL). The alterations in chemical structure affected affinity of the analogs to the opiate receptor and their pharmacologic properties differently, suggesting that different opiate subtypes may be involved.

Dynorphin-(1-13) restores the potency of morphine on the tolerant guinea pig ileum

Since it has been reported that dynorphin (1-13) enhances the analgetic effects of morphine in mice tolerant either to morphine or beta-endorphin and modulates opioid agonist binding in the tolerant state, experiments were initiated to determine whether comparable phenomenon could be obtained in vitro with dynorphin-(1-13) on the isolated longitudinal muscle of the guinea pig ileum. In the guinea pig ileum rendered tolerant to morphine dynorphin-(1-13) was found to cause a dose-dependent restoration in sensitivity to the inhibitory action of morphine. This phenomenon appeared specific for dynorphin-(1-13) since [Leu5]enkephalin, beta-endorphin, and ethylketocyclazocine did not change significantly the IC50 of morphine in the tolerant preparation. Furthermore, dynorphin-(1-13) attenuated the contraction elicited by naloxone in the morphine tolerant-dependent tissue. It is concluded, that dynorphin-(1-13) restores sensitivity to morphine in the tolerant-dependent state by a modulatory effect probably on the mu receptor that is distinct from its kappa action.

A rapid and simple method for the quantitative determination of tolerance development to opiates in the guinea-pig ileum in vitro

The rate and degree of tolerance development of morphine, normorphine and methadone were assessed in vitro on the guinea-pig ileum. After the half-maximal concentration to inhibit electrically induced contractions (IC50) for each compound was determined, tolerance to a fixed concentration representing 0.5, 1 or 2 times its IC50 was induced by incubation at 37 degrees C for 1, 2 or 4 hr. The IC50 was then redetermined and the ratio of the IC50 after and before incubation provided a quantitative index of the degree of tolerance development to each agonist. For any given concentration or time, morphine induced the highest, whereas normorphine the intermediate and methadone the lowest degree of tolerance. Tolerance to opiates was associated with some degree of physical dependence as evidenced by the fact that the application of naloxone at the end of each experiment elicited a muscular contraction. Specificity of tolerance development to opiates was demonstrated by several experiments. Coincubation of morphine with naloxone under the same conditions resulted in an inhibition of tolerance development. The stereospecificity of the process was demonstrated by the fact that levorphanol and I-methadone induced a high degree of tolerance, whereas, under the same conditions the less active d-isomers, dextrorphan and d-methadone, did not. Moreover, subsensitivity to acetylcholine, norepinephrine and adenosine monophosphate did not develop in the presence of tolerance to morphine. The validity of this method for investigating mechanisms involved in tolerance and physical dependence was further demonstrated by obtaining data compatible with earlier experiments in vivo that cyclic AMP enhances tolerance development and cycloheximide inhibits this phenomenon. The present method should facilitate studies on the mechanisms involved in opiate tolerance and physical dependence development.

Hypersensitivity of the opioid-tolerant guinea pig ileum to electrical stimulation after abrupt agonist removal

Studies were initiated on the myenteric plexus of the guinea pig ileum to ascertain whether a supersensitive response by abrupt withdrawal could be elicited after tolerance development to opioids. After an optimal twitch response to a given electrical stimulus was established and its height measured, the mean concentration of an opioid to inhibit half maximally the response (IC50) was determined. Subsequently, the tissues were rendered tolerant by incubating with 1x to 5x the IC50 of the agonist for two hours. The agonist was then removed by thorough washing with Ringer solution and the twitch height to the same electrical stimulation was remeasured. The increase in twitch height after washing over that before incubation provided an index of the degree of hypersensitivity of the tolerant-dependent tissue. The degree of hypersensitivity was found to increase in relation to the concentration of morphine. Stereo-specificity of agonist action was evinced by a hypersensitive response to levorphanol and not to dextrorphan. The development of hypersensitivity was blocked by naloxone and by chloramphenicol. Ethylketocyclazocine, a k ligand, did not show a hypersensitivity response. It is concluded that physical dependence on u-opioids can be developed in vitro and that it can be quantified by a super-sensitivity response.

K receptor activities of the three opioid peptide families

A large number of opioid peptides derived from the three established precursors, pro-opiomelanocortin (POMC), pro-enkephalin A (pro-enk A), and pro-enkephalin B (pro-enk B) were tested for their ability to inhibit electrically induced contractions of the isolated rabbit vas deferens, a preparation sensitive to k but not to mu opioid ligands. In the presence of enzyme inhibitors, all peptides exhibit roughly similar potencies, but the shorter peptides display lower potencies in the absence of enzyme inhibitors. This suggests that the loss in activity is due to their enzymatic degradation. It is concluded that the pro-enk B gene codes peptides with high k-receptor activities, whereas peptides produced by the POMC gene are devoid of k-receptor activity and the peptides, coded by the pro-enk A gene exhibit weak to moderate k-receptor activity.

Effect of 4-aminopyridine and verapamil on the inhibitory action of normorphine on the guinea-pig ileum

The ability of normorphine to inhibit the muscular twitches elicited by electrical stimulation of the longitudinal muscle of the guinea-pig ileum was antagonized by 4-aminopyridine (4-AP). Incubation with 4-aminopyridine (4-AP) caused a marked increase of the normorphine IC50 and this effect was not modified by naloxone or by the Ca2+ channel blocker, verapamil. Although verapamil caused a significant decrease of the normorphine IC50 it also caused a potent reduction of the contractile effect of acetylcholine. The results suggest that 4-AP and verapamil act on different Ca2+ pools and that verapamil does not primarily affect the presynaptic Ca2+ pool involved in opiate action.

A method for the rapid development of opiate tolerance in the guinea pig ileum

The rate and degree of in vitro tolerance development to morphine, normorphine and d,1-methadone were assessed on the excised guinea pig ileum. Agonists in fixed concentrations at 1/4, 1/2, 1 and 2 x IC50 were incubated with the tissue for 1, 2 or 4 hours. The degree of tolerance development was expressed as a ratio of the IC50 after and before incubation. A high degree of tolerance developed to all three agonists and the effect could be prevented by co-incubation with naloxone. Tolerance development was stereo-specific; levorphanol and 1-methadone developed much higher degrees of tolerance than their respective d-isomers. Furthermore, under the same conditions, subsensitivity to acetylcholine, norepinephrine, and adenosine monophosphate did not develop. The in vitro tolerance was accompanied by physical dependence development as evidenced by the fact that naloxone elicited muscular contracture in the tolerant ileum. cAMP enhanced the development of tolerance to normorphine and cycloheximide could reduce this phenomenon. It is concluded that the procedure may facilitate studies on the mechanisms involved in the development of opiate tolerance and physical dependence.

The effects of unsatisfactory working conditions on the epidemiology of unauthorised absenteeism in an old textile factory in Isfahan, Iran

Comparison of unauthorised absenteeism rates were made between two large textile factories in Isfahan, Iran. The working conditions in the study factory were rather unsatisfactory, unlike the control factory. Comparison showed significantly higher rates for the study factory: the average annual duration per person was 7 days in the study factory versus 2.5 days in the control factory, and lost time percentage was 2.4% in the former versus 0.84% in the control. Inception rate of persons was 0.73 versus 0.48, and point prevalence rates 0.002 versus 0.001, whilst period prevalence rates were 0.016 versus 0.011 for the study and control factories respectively. Examination of the study factory data was made to determine any possible relationship between unauthorised absenteeism rates and age and length of employment. It was found that higher unauthorised rates were found amongst the younger workers, 100% for those age 19 and under, versus 59.6% for those age 50 and over. 9.16% of workers employed for 1--4 years took such leave against 70.14% of those employed for 10 or more years. Only 18.8% of all workers took certified sickness absenteeism and the rate increased with age. It was suggested that worker dissatisfaction toward unsatisfactory working conditions may be expressed in terms of unauthorised absenteeism. In view of the widespread consequences of such absenteeism, it is recommonded that closer attention be paid to improve the quality of working life.

Synthesis and local anesthetic activity of benzo[b]furan derivatives

Several 2-dialkylaminoethyl 3-methyl-2-benzo[b]furancarboxylates, 2-dialkylaminoethyl 3-methyl-2-benzo[b]furancarbamates, and 3-methyl-2-benzo[b]furancarboxamide derivatives were prepared and tested for local anesthetic activity. Piperidinoethyl 3-methyl-2-benzo[b]furancarbamate, 2-diethylaminoethyl 3-methyl-2-benzo[b]-furancarboxylate, and N-(2-diethylaminoethyl)-3-methyl-2-benzo[b]-furancarboxamide were the most potent.

[Cancer mortality in France. New Aspects of the presentation and analysis of data]

In France mortality statistics are the only complete source of information on cancer. Investigation of the annual figures and the application of statistical methods to their presentation and analysis has facilitated fresh studies of geographical pathology, utilizing methods of analysis with simple and multiple correlations (analysis of correlations). Certain groupings were thus revealed, notably in the case of death from bronchial carcinoma, urinary bladder and gall bladder. Two groups of departements appeared the nearest to the national levels for deaths from cancer for all body sites.