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The meiotic behaviour of a spontaneous chromosome rearrangement in a natural population of Acanonicus hahni (Stål)(Coreidae, Heteroptera) is described, which is concluded to be a heterozygous inversion. In this holokinetic system the principal consequences of a single cross-over located within the inversion loop are: (a) the appearance of a double bridge at anaphase I, instead of the single dicentric bridge and acentric fragment of monocentric systems; (b) the persistence of the double bridge at telophase I which inhibits cytokinesis; (c) the occurrence of double cells at metaphase II with the restored ‘bivalent’ between the two nuclei; (d) the presence of single bridges at anaphase II; and (e) the production of a high percentage of abnormal spermatids. A possible explanation of all these phenomena is given and discussed.

Striated craniofacial and limb muscles differ in their embryological origin, regulatory program during myogenesis, and innervation. In an attempt to explore the effects of these differences on the striated muscle phenotype in humans, the expression of myosin and myosin-associated thick filament proteins were studied at the single fiber level both in the human jaw-closing masseter muscle and in two limb muscles (biceps brachii and quadriceps femoris muscles). In the masseter, unique combinations of myosin heavy chain (MyHC) and myosin binding protein C (MyBP-C) isoforms were observed at the single fiber level. Compared to the limb muscles, the MyHC isoform expression was more complex in the masseter while the opposite was observed for MyBP-C. In limb muscles, a coordinated expression of three MyHC and three MyBP-C isoforms were observed, i.e., single fibers contained one or two MyHC isoforms, and up to three MyBP-C isoforms. Also, the relative content of the different MyBP-C isoforms correlated with the MyHC isoform expression. In the masseter, on the other hand, up to five different MyHC isoforms could be observed in the same fiber, but only one MyBP-C isoform was identified irrespective MyHC isoform expression. This MyBP-C isoform had a migration rate similar to the slow MyBP-C isoform in limb muscle fibers. In conclusion, a unique myofibrillar protein isoform expression was observed in the human masseter muscle fibers, suggesting significant differences in structural and functional properties between muscle fibers from human masseter and limb muscles.

In this report we show that immunostaining of the capillary basement membrane with an antibody directed against laminin is a useful alternative in detecting the capillaries in human muscle. Using this method, the capillary supply of three embryologically, morphologically and functionally different muscle groups, oro-facial, masticatory and limb muscles, were analysed. Significant differences in capillarization between muscles and muscle groups were found. The oro-facial and masseter muscles showed significantly higher density of capillaries than the limb muscles, taken in consideration the muscle cross-sectional area, with the masseter having the highest capillary density ever reported for human sedentary skeletal muscles. Judged from the number of capillaries per muscle fibre, the limb muscles showed the best capillarization. However, since the three muscle groups investigated differed with respect to fibre diameter, our evaluation of number of capillaries per muscle fibre was related also to fibre diameter. Thus, capillary constants were created which take fibre diameter into account. Based on these new parameters, the oro-facial and masseter muscles were found to be relatively better supplied by capillaries than the limb muscles. These results suggest differences in tasks and functional activity between muscles, and reflect a relatively higher need and demand for blood supply in the masticatory and oro-facial muscles than in limb muscles.

Abstract.: The aim of this study was to investigate whether different mammographic categories of interval cancer classified according to findings at the latest screening are associated with different distributions of prognostic factors or with different survival rates. The series consisted of all patients with invasive interval cancer detected from May 1978 to August 1995 (n = 544). The tumours were evaluated with regard to age, radiological category, interval between the latest screen and diagnosis and tumour characteristics at the time of diagnosis. We investigated possible relationships between the survival rate of patients with interval cancer and the interval between the latest screen and diagnosis, tumour characteristics and radiological category of the interval tumours. The study focused on comparison of patients with true interval and missed interval cancer. Women with mammographically occult tumours were younger than those in the other radiological categories. Comparisons of true interval cancers with overlooked or misinterpreted tumours showed equal distributions of age, tumour size, TNM stage and lymph node status. The overlooked or misinterpreted tumours showed significantly higher proportions of grade-I tumours (22 vs 11 %), tumours with low S-phase fraction (SPF; 44 vs 24 %) and oestrogen receptor (ER) positive tumours (72 vs 57 %). However, analyses of survival rates disclosed no clear differences between the two radiological categories. Radiological category and interval between the latest screen and diagnosis were not genuine predictors of the prognosis in patients with invasive interval breast cancer. No certain prognostic difference existed between true interval cancers and overlooked or misinterpreted interval breast cancers, despite higher proportions of grade-I tumours, ER positive tumours and tumours with low SPF in the latter group.

Enzyme-histochemical methods were used to analyse the activities of alkaline phosphatase (AP), dipeptidylpeptidase IV (DPP IV) and adenosine triphosphatase (ATPase) in capillaries of four different human oro-facial muscles, the major and minor zygomatic, the orbicularis oris and buccinator, one masticatory, the masseter and two limb muscles, the biceps brachii and first dorsal interosseus muscles. In all muscles, except for the orbicularis oris, the majority of the capillaries lacked enzyme activity. Therefore, none of these enzymes seems to be reliable as a general marker for human muscle capillaries. In general, the capillaries of the limb muscles and the major and minor zygomatic and the buccinator, were similar in their staining pattern for AP and ATPase, but differed in DPP IV staining. The orbicularis oris muscle differed from the other muscles by showing the largest proportion of capillaries with AP and ATPase activity. The masseter muscle had the largest proportion of capillaries stained for DPP IV. The muscle specific differences in enzyme activity of the capillaries are in agreement with our previous findings of specific differences between limb, oro-facial and masticatory muscles with respect to capillary supply and composition of fibre types and myosins. The results reflect functional specialization of the capillary bed of human muscles.

The extent of apoptosis and the expression of Bcl-2 was investigated in tumor samples from 165 women who underwent surgery for primary breast carcinoma between 1989 and 1990 in South-East Sweden. Apoptosis was assessed by a DNA fragmentation assay for flow cytometry. Bcl-2 protein expression was analyzed with immunocytochemistry Bcl-2 immunoreactivity correlated with estrogen receptor (ER) and progesterone receptor (PgR) positivity and was inversely correlated with p53 accumulation. Apoptosis increased with patient age and a high degree of apoptosis was negatively associated with Bcl-2 immunostaining. Apoptosis showed no significant correlation with any of the other variables studied, including prognosis. The group with Bcl-2-positive tumors tended to have a lower risk of distant recurrence than others, but the association of Bcl-2 with recurrence was different in groups divided by ER and PgR status. Whereas Bcl-2 positivity indicated a low recurrence rate among PgR-negative patients, in the PgR-positive group, those with Bcl-2-positive tumors showed a non significantly higher recurrence rate than Bcl-2-negative cases. In the PgR-positive group, Bcl-2-positive tumors also appeared more frequently to be lymph node positive and DNA aneuploid. The results suggest that hormone receptor status is of importance for the prognostic role of Bcl-2. Likewise, patient age merits consideration when apoptosis is studied in human cancer.

When growing in laternating light-dark cycles, nitrogenase activity (acetylene reduction) in the filamentous, non-heterocystous cyanobacterium Oscillatoria sp. strain 23 (Oldenburg) is predominantly present during the dark period. Dark respiration followed the same pattern as nitrogenase. Maximum activities of nitrogenase and respiration appeared at the same time and were 3.6 µmol C2H4 and 1.4 mg O2 mg Chl a-1·h-1, respectively. Cultures, adapted to light-dark cycles, but transferred to continuous light, retained their reciprocal rhythm of oxygenic photosynthesis and nitrogen fixation. Moreover, even in the light, oxygen uptake was observed at the same rate as in the dark. Oxygen uptake and nitrogenase activity coincided. However, nitrogenase activity in the light was 6 times as high (22 µmol C2H4 mg Chl a-1·h-1) as compared to the dark activity. Although some overlap was observed in which both oxygen evolution and nitrogenase activity occurred simultaneously, it was concluded that in Oscillatoria nitrogen fixation and photosynthesis are separated temporary. If present, light covered the energy demand of nitrogenase and respiration very probably fulfilled a protective function.

Immunohistochemistry was used to determine the myosin composition of defined fibre types of three embryologically different adult muscles, the oro-facial, masseter and limb muscles. In addition, the myosin composition in whole muscle specimens was analysed with biochemical methods. Both similarities and differences between muscles in the content of myosin heavy chains and myosin light chains were found. Nevertheless, each muscle had its own distinct identity. Our results indicated the presence of a previously undetected fast myosin heavy chain isoform in the oro-facial type II fibre population, tentatively termed ‘fast F’. The masseter contained aberrant myosin isoforms, such as foetal myosin heavy chain and a-cardiac myosin heavy chain and unique combinations of myosin heavy chain isoforms which were not found in the limb or oro-facial muscles. The type IM and IIC fibres coexpressed slow and fast A myosin heavy chains in the oro-facial and limb muscles but slow and a fast B like myosin heavy chain in the masseter. While single oro-facial and limb muscle fibres contained one or two myosin heavy chain types, single masseter fibres coexpressed up to four different myosin heavy chain isoforms. Describing the fibres according to their expression of myosin heavy chain isozymes, up to five fibre types could be distinguished in the oro-facial and limb muscles and eight in the masseter. Oro-facial and limb muscles expressed five myosin light chains, MLC1S, MLC2S, MLC1F, MLC2F and MLC3F, and the masseter four, MLC1S, MLC2S, MLC1F, and, in addition, an embryonic myosin light chain, MLCtemb, which is usually not present in normal adult skeletal muscle. These results probably reflect the way the muscles have evolved to meet the specialized functional requirements imposed upon them and are in agreement with the previously proposed concept that jaw and limb muscles belong to two distinct allotypes.

The effects of pea, Pisum sativum L., and lentil, Lens culinaris Medik., development on reproduction and longevity of Thyanta pallidovirens (Stål) were evaluated in the laboratory. Stink bug reproduction and longevity were both significantly affected by the host plants’ developmental stage. The greatest number of eggs, with the highest number of viable eggs and eggs per clutch, were laid and the longest life span occurred on peas or lentils with mature pods. Insects given peas or lentils with flowers and immature pods had shorter life spans and produced significantly fewer total eggs, eggs per clutch, and viable eggs. Almostno eggs were produced by females given seedlings or only flowering host plants.

Insecticides, at the N. lugens LD50 level, were applied in the Potter's spray tower and as a foliage spray to determine their selective toxicity to predators of N. lugens. These included a mirid bug, Cyrtorhinus lividipennis; the ripple bug, Microvelia atrolineata; and the spider Lycosa pseudoannulata. In the Potter's spray tower test, cypermethrin and deltamethrin were highly toxic to the three predator species on contact. Deltamethrin was toxic to C. lividipennis and M. atrolineata when they fed on treated N. lugens prey. Endosulfan and ethylan were not very toxic to the three predators. When the predators were placed on sprayed plants, only deltamethrin was toxic to L. pseudoannulata and M. atrolineata, whereas all of the insecticides were toxic to C. lividipennis, with BPMC being the least and deltamethrin the most toxic. Of the commercially available insecticides, acephate, BPMC, carbophenothion, and endosulfan were the least toxic to natural enemies.

Resurgence of Nilaparvata lugens (Stål) after insecticide application is a common phenomenon in rice in South and Southeast Asia. Among other insecticides inducing resurgence, carbofuran, decamethrin, and methyl parathion were selected for this study. Of the various methods of carbofuran application tested, foliar sprays were most active in inducing resurgence. Extent of resurgence was highly influenced by time of insecticide application. Sprays of methyl parathion and decamethrin applied 50 and 65 days after transplanting (DT) induced resurgence in the third generation of N. lugens at ca. 90 DT, whereas earlier applications had little effect. The cause(s) for resurgence was not definitely established, but stimulation of N. lugens reproduction appeared to be of more significance than destruction of natural enemies.

A laboratory screening method was developed for evaluating resistance of cowpea, Vigna unguiculata (L.) Walp, to Clavigralla tomentosicollis Stål. The technique uses dry cowpea seeds, which were judged better than fresh seeds or fresh pods, to identify protracted nymphal development and high cohort mortality. Two wild cowpea relatives, TVNu 72 and TVNu 73, were highly resistant to C. tomentosicollis. Insect mortalities were >85% on the resistant lines as compared to <25% on the susceptible lines. Survivors on the resistant lines had extended developmental times. The resistant lines are highly pubescent but pubescence may not be the major factor responsible for this resistance. Laboratory results compared well with those obtained from greenhouse findings and field tests, giving correlation coefficients (r) of 0.96 and 0.85, respectively. The laboratory screen is accurate, fast, and inexpensive.

A new class of precursor polymers, as first described by Louwet et al. [1], was used to make organic LEDs. Device properties are relatively independent from the side chain to be eliminated. However introduction of two methyl groups onto the phenyl ring introduces significant changes in absorption, photoluminescence (PL) emission, PL quantum efficiency and electroluminescence spectra. From XRD there is an indication that this effect might be related to a different packing of the polymer chains.