Detection of recombinant and endogenous mouse melatonin receptors by monoclonal antibodies targeting the C‐terminal domain

Melatonin receptors play important roles in the regulation of circadian and seasonal rhythms, sleep, retinal functions, the immune system, depression, and type 2 diabetes development. Melatonin receptors are approved drug targets for insomnia, non‐24‐hour sleep‐wake disorders, and major depressive disorders. In mammals, two melatonin receptors (MTRs) exist, MT₁ and MT₂, belonging to the G protein‐coupled receptor (GPCR) superfamily. Similar to most other GPCRs, reliable antibodies recognizing melatonin receptors proved to be difficult to obtain. Here, we describe the development of the first monoclonal antibodies (mABs) for mouse MT₁ and MT₂. Purified antibodies were extensively characterized for specific reactivity with mouse, rat, and human MT₁ and MT₂ by Western blot, immunoprecipitation, immunofluorescence, and proximity ligation assay. Several mABs were specific for either mouse MT₁ or MT₂. None of the mABs cross‐reacted with rat MTRs, and some were able to react with human MTRs. The specificity of the selected mABs was validated by immunofluorescence microscopy in three established locations (retina, suprachiasmatic nuclei, pituitary gland) for MTR expression in mice using MTR‐KO mice as control. MT₂ expression was not detected in mouse insulinoma MIN6 cells or pancreatic beta‐cells. Collectively, we report the first monoclonal antibodies recognizing recombinant and native mouse melatonin receptors that will be valuable tools for future studies.     

Establishment and characterization of a chronic infectious mononucleosislike syndrome in common marmosets

Epstein-Barr virus (EBV) was inoculated into two species of marmosets. Successful infection was established in the majority of the animals of one species, Callithrix jacchus, as evidenced by the development of high, persistent levels of antibody against virus-specific capsid and early nonstructural proteins. Antibodies also were produced against the major membrane antigen and, in some animals, against EBV nuclear antigen (EBNA) 2 but not against EBNA 1. This is the antibody profile normally noted in individuals with chronic infectious mononucleosis (IM). EBV-induced lymphoproliferation was not seen, and EBV-specific proteins were not detected in the peripheral blood lymphocytes of infected animals. Hence, EBV infection in C. jacchus apparently does not generally include extensive B-cell involvement. However, the marmosets clearly are useful as a model for EBV primary infection and also possibly for chronic IM.     

Cervicobrachial syndrome--work and disability.

The subjects in the study were 114 persons receiving a disability pension or referred for disability assessment. They were placed in two groups of 57 persons each, one with marked cervicobrachial syndrome and the other without. The latter group was chosen by the method of equivalent pairs with regard to sex and age. All subjects underwent a clinical examination and a standardized questionnaire was completed. The questionnaire pertained to the state of health, focussing on the amount and type of physical burdening at the workplace and on activities outside the workplace. Sixty-five percent of the subjects were aged from 51 to 60 years. A statistically significant difference was established between earlier occupation and cervicobrachial syndrome. Cervicobrachial syndrome was found in 31.6% of unskilled workers and 12.3% of the controls (P < 0.05). A forced body posture during work was recorded in 74% of the subjects with the syndrome and in 50% of the control subjects (P < 0.05). Repetitive movements at work were reported by a large number of subjects with cervicobrachial syndrome (71.9:49.1%; P < 0.05) who also claimed to strain the arms (84.2:61.4%; P < 0.05) and burden the cervical spine (68.5:40.4%; P < 0.05) during household activities to a significantly greater extent than the controls. A possible preventive approach to the occurrence and progression of cervicobrachial syndrome is discussed.     

Changes in the anterior segment of the eye in workers in the coke manufacturing industry

An investigation carried out of eye disorders in workers employed in the manufacture of coke demonstrated a high percentage of changes in the anterior segment of the eye. Registered symptoms such as conjunctival hyperemia, pinguecula, pigmentation and conjunctivitis were most probably connected with specific work and exposure to coal dust and irritants. In workers exposed for less than two years there were no changes in lacrimal secretion. In those working for 2-7 years excessive hypersecretion dominated, and after a longer period of exposure the majority of workers had hyposecretion.     

Multiple phenotypic divergence of mammary adenocarcinoma cell clones.

We have shown that, with in vitro passage, subclones derived from clonal cell populations of 13762NF mammary adenocarcinoma undergo phenotypic drift and diversification in their cellular properties. Here we examine whether phenotypic divergence of 13762NF cell clones extends to therapeutic treatments used in eliminating mammary tumors and whether the apparent rates of phenotypic divergence vary for different treatments. Six subclones isolated from low passage clone MTF7 (T11 l; tissue culture passage 11) cells were compared to a similar number of subclones isolated from high passage clone MTF7 (T35; tissue culture passage 35) cells. Subclones derived from clone MTF7 (TI l) were relatively homogeneous (not significantly different) in their inherent sensitivities to ionizing radiation, extrapolation coefficients and quasithreshold dose values (D_o = 1·61–1·99 Gy; n=0·89–3·42; D_q = 0–2·34). When the MTF7 (Tll) subclones were examined for their sensitivities to 45°C hyperthermic treatment, the inherent sensitivities and dose-response curve parameters (D_o = 5·24–10·05 min; n = 1·08–10·47; D_q = 0·78–12·31) were heterogeneous (significantly different). In addition, the MTF7 (T1 l) subclones were heterogeneous (significantly different) in their sensitivities and dose-response curve parameters to 5-fluoro-2-deoxyuridine (FUdR) treatment (slope= –0·70 to –1·59; y-intercept = 1·31 × 10² to 47·80 × 10²). The LD₅₀ values for FUdR ranged from 14–150 nm for the MTF7 (T11) subclones. At high passage MTF7 (T35) subclones were heterogeneous in their dose-response parameters to ionizing radiation (D_o = 1·17–2·05 Gy; n = 0·80–41·18; D_q = 1·79-\24·94), hyperthermia (D_o = 3·57–6·32 min; n = 2·08–13·54; D_q = 3·68–9·30) and FUdR (slope= –0·77 to –0·93; y-intercept = 4·64 × 10² to 8·83 × 10²; LD₅₀ = 50–160nm). The results indicate that clonal cells diverge for distinct phenotypic properties at differing rates to form heterogeneous cell populations with unique sensitivities to various therapeutic treatments.     

Countertransference and empathic problems in therapists/helpers working with psychotraumatized persons

Countertransference in therapists working with patients with posttraumatic stress disorder (PTSD) differs from countertransference in other psychotherapeutical settings. In this article we discuss the specificities of counter- transference in treating PTSD patients and its relation to empathy. The most difficult countertransference problems occur in treating multiply traumatized patients. Countertransference may occur towards an event (e.g., war), patients who have killed people, as well as to colleagues who avoid treating PTSD patients, or towards a supervisor who avoids, either directly or indirectly, supervision of therapists working with PTSD patients. Our recommendation for the prevention of problems in treating PTSD patients include : 1) careful selection of the therapist or helper, both in the personality structure and training; 2) prevention by debriefing and team work and peer supervision; and 3) education - theoretical, practical, and therapeutical.     

Prophylaxis and treatment of experimental lung metastases in mice after treatment with liposome-encapsulated 6-O-stearoyl-N-acetylmuramyl-L-α-aminobutyryl-D-isoglutamine

A new lipophilic muramyl dipeptide analog, 6-O-stearoyl-N-acetylmuramyl-L--aminobutyryl-D-isoglutamine, when incorporated in liposomes, was effective in both the prevention and eradication of experimental pulmonary metastases in mice. Multilamellar vesicles composed of synthetic phospholipids (phosphatidylglycerol and phosphatidylcholine) containing saturated myristoyl or unsaturated dioleoyl acyl chains were found to potentiate the antimetastatic activity of this glycopeptide. Prophylactic and therapeutic efficacy was observed against the three murine tumors tested: FSa, an immunogenic fibrosarcoma; NFSa, a nonimmunogenic fibrosarcoma; and B16 melanoma. Neither the administration of empty liposomes or free glycopeptide, nor their coadministration, had a significant antimetastatic effect. This approach is promising for the therapy of cancer metastases in humans, particularly in the prevention of metastatic seeding and in the treatment of micrometastases.This is contribution No. 180 from the Institute of Bio-Organic Chemistry, Syntex Research.     

Increase in radiosensitivity of lung micrometastases by hyperbaric oxygen

Four-day-old artificial pulmonary micrometastases of two murine fibrosarcomas, designated FSA and NFSA, showed increased sensitivity to ionizing radiation by a factor of 1·13 when animals were exposed to hyperbaric oxygen breathing before and during irradiation, implying the presence of hypoxia in the micrometastases. At the time of irradiation the diameter of FSA and NFSA metastases was smaller than 200 and 100m, respectively, which, on the basis of oxygen diffusion, could not be responsible for hypoxia. It is assumed that hypoxia of micrometastases is passive, reflecting the radiobiological hypoxia of lung tissue that could exist under normal breathing conditions.