Agrobacterium-mediated insertional mutagenesis in the mycorrhizal fungus Laccaria bicolor.

Agrobacterium-mediated gene transfer (AMT) is extensively employed as a tool in fungal functional genomics and accordingly, in previous studies we used AMT on a dikaryotic strain of the ectomycorrhizal basidiomycete Laccaria bicolor. The interest in this fungus derives from its capacity to establish a symbiosis with tree roots, thereby playing a major role in nutrient cycling of forest ecosystems. The ectomycorrhizal symbiosis is a highly complex interaction involving many genes from both partners. To advance in the functional characterization of fungal genes, AMT was used on a monokaryotic L. bicolor. A collection of over 1200 transgenic strains was produced, of which 200 randomly selected strains were analyzed for their genomic T-DNA insertion patterns. By means of insertional mutagenesis, a number of transgenic strains were obtained displaying differential growth features. Moreover, mating with a compatible strain resulted in dikaryons that retained altered phenotypic features of the transgenic monokaryon. The analysis of the T-DNA integration pattern revealed mostly similar results to those reported in earlier studies, confirming the usefulness of AMT on different genetic backgrounds of L. bicolor. Taken together, our studies display the great versatility and potentiality of AMT as a tool for the genetic characterization of L. bicolor.

T-DNA transfer from Agrobacterium tumefaciens to the ectomycorrhizal fungus Pisolithus microcarpus.

The model ectomycorrhizal fungus Pisolithus microcarpus isolate 441 was transformed by using Agrobacterium tumefaciens LBA1100 and AGL-1. The selection marker was the Shble gene of Streptoallotecius hidustanus, conferring resistance to phleomycin, under the control of the gpd gene promoter and terminator of Schizophyllum commune. Transformation resulted in phleomycin resistant clones which were confirmed by PCR to contain the resistance cassette. A. tumefaciens-mediated gene transfer would allow the development of RNA interference technology in P. microcarpus.

T-DNA transfer from Agrobacterium tumefaciens to the ectomycorrhizal fungus Pisolithus microcarpus / Transferencia de T-DNA de Agrobacterium tumefaciens al hongo ectomicorrícico Pisolithus microcarpus

The model ectomycorrhizal fungus Pisolithus microcarpus isolate 441 was transformed by using Agrobacterium tumefaciens LBA1100 and AGL-1. The selection marker was the Shble gene of Streptoallotecius hidustanus, conferring resistance to phleomycin, under the control of the gpd gene promoter and terminator of Schizophyllum commune. Transformation resulted in phleomycin resistant clones which were confirmed by PCR to contain the resistance cassette. A. tumefaciens-mediated gene transfer would allow the development of RNA interference technology in P. microcarpus.

El hongo ectomicorrícico modelo Pisolithus microcarpus aislamiento 441 fue transformado utilizando Agrobacterium tumefaciens LBA 1100 y AGL-1. El marcador de selección fue el gen Shble de Streptoallotecius hidustanus, el cual confiere resistencia a fleomicina, bajo el control del promotor y terminador del gen gpd de Schizophyllum commune. La transformación resultó en clones resistentes a fleomicina comprobándose por PCR la presencia del transgen. La transferencia génica mediada por Agrobacterium podría permitir el desarrollo de la tecnología de interferencia por ARN en P. microcarpus.

T-DNA transfer from Agrobacterium tumefaciens to the ectomycorrhizal fungus Pisolithus microcarpus.

The model ectomycorrhizal fungus Pisolithus microcarpus isolate 441 was transformed by using Agrobacterium tumefaciens LBA1100 and AGL-1. The selection marker was the Shble gene of Streptoallotecius hidustanus, conferring resistance to phleomycin, under the control of the gpd gene promoter and terminator of Schizophyllum commune. Transformation resulted in phleomycin resistant clones which were confirmed by PCR to contain the resistance cassette. A. tumefaciens-mediated gene transfer would allow the development of RNA interference technology in P. microcarpus.

Safety and indoor mobility in the elderly.

The aim of this study was to find the basis for developing and adapting the environment to support the easy and safe moving of the elderly. In the field study, the daily activities and previous falls were inquired, the performance of the elderly was examined and the safety of the residential environment was surveyed among 70-80 years old subjects (N15). The second part was performed in the laboratory. 70-80 years old subjects (N55) walked on the test track. The risk level of most houses studied was moderate. In the residential surveying, all subjects had problems to stretch to high levels and most had problems to stretch to low levels. In the laboratory, errors happened often during line walking and zigzag walking in the stick track. Unsteadiness in gait was caused by extra pieces on the track and box carrying in one third of the subjects. The old subjects estimated that stairs somewhat lower than normally recommended were easier to climb. The results indicated, that new criteria and regulations are needed for the residential environment for the elderly and that it is possible to improve the safety of indoor mobility among the elderly in many ways.

A marked increase in the incidence of colorectal cancer over two decades in southwest Finland.

The Finnish Cancer Registry's data on all colorectal cancer cases from 1971 to 1990 in southwest Finland, an area of mean population of 433,000, were analyzed. The age-adjusted incidence of colon cancer per 100,000 population increased in men from 8.5 in 1971-1980 to 13.5 in 1981-1990 and in women from 10.3 to 13.1. The incidence of male rectal cancer increased from 9.8 to 11.1 and in women from 6.4 to 7.1. The proportion of elderly patients clearly rose and, in 1981-1990, patients over 65 years of age had 68.4% of all colon cancers and 73.9% of all rectal cancers. There was a proximal shift in the site distribution of cancers: the proportion of rectal cancers decreased from 45.9% in 1971-1980 to 40.9% in 1981-1990. This change was most marked in men. There was no change in the spread and operability of colorectal cancers during the two decades. There was an increase in colon cancer mortality while the mortality of rectal cancer cancer slightly decreased.

Influence of age on colorectal cancer's 5-year survival.

The aim of this study was to ascertain the 5-year survival figures of 171 consecutive colorectal cancer patients in southwestern Finland, the differences between various age groups, and which clinical variables predict poor outcome. The mean age at the time of diagnosis was 67 years in men and 69 years in women. The 5-year survival was lower in older patients, especially in those over 80 years with concomitant diseases. However, the colorectal cancer mortality did not differ between the three age groups: < 65, 65-80, > 80 years. Employing univariate analysis, a poor 5-year outcome was associated with metastases, and the outcome was excellent if the cancer was confined locally (p = 0.0001). As many as 26% of the patients in whom the cancer was confined to the bowel wall (Dukes B) at the time of operation died within 5 years. A poor survival rate was also found if the patients had emergency operations (p = 0.021). The postoperative mortality was 6%. Using logistic regression analysis, the poor 5-year survival rate was correlated strongly with metastasized cancer (p = 0.000) but less so with age (p = 0.040).

Finding colorectal tumours with an immunological faecal occult blood test in symptomatic primary health care patients.

The aim of this prospective study was to investigate whether an immunological double faecal occult blood test (Fecatwin-S/FECA-EIA) can be used in screening patients with symptoms suggestive of colonic or rectal origin in primary health care. Altogether 523 patients were referred to the study by general practitioners. Three kits were used for the faecal samples and each time the sample was taken from two places of the faeces. If the guaiac test (Fecatwin-S) was positive, the immunological test (FECA-EIA) was performed. All 71 patients with an immunotest absorbance value of over 0.8 were investigated with colonoscopy and this group had 13 cancers, eight adenomas and one hyperplastic polyp. A control group of 41 consecutive patients with an absorbance value under 0.8 had one adenoma and three hyperplastic polyps. The uninvestigated FECA-EIA negative patients had no malignant colorectal tumours in the mean follow-up period of 2.2 years according to hospital records. All cancers had very high absorbance values, the mean value being 2.461. With adenomas the mean absorbance value was 1.912 and with hyperplastic polyps 0.814. Most of the diagnosed cancers and adenomas were in patients over 65 years of age. The study indicates that the immunological occult blood test is a useful tool for a general practitioner in finding bleeding colorectal tumours. The number of needless clinical examinations can be lowered which is important especially among elderly patients. However, the test-negative patients should be retested or investigated if symptoms continue.

Delay in diagnosis of colorectal cancer in elderly patients.

The medical histories of 178 colorectal cancer patients were studied retrospectively from hospital records. The average age at the time of diagnosis was 71 years. Visible loss of blood or anaemia were the commonest features. The mean time from first symptom to first medical consultation was 82.8 days. Men under 65 years and women over 80 years waited the longest time before consulting a physician. The mean time from the first medical consultation to diagnosis was 44.7 days. The delay was longer for men than for women but longest for women aged over 80 years. Information about digital rectal examination was lacking in over half of all patients and in two-thirds of patients over 80 years. In patients in whom rectal examination had been made, as many as 60% of rectal cancers were digitally palpable. Barium enema missed the cancer diagnosis in 11.2% of patients at the first examination; the missed cancers were located in the sigmoid area and in the right colon. Colonoscopy can be recommended as the primary investigation method when colorectal cancer is suspected. Re-examination is necessary in elderly patients with sideropenic anaemia if the first examination is negative.

Hearing levels of patients with otosclerosis 10 years after stapedectomy.

Hearing levels of 174 patients (213 ears operated on) with otosclerosis undergoing stapedectomy were analyzed. All patients had followup of 10 years or more, the mean follow-up period being 13.4 years. Eighty-seven ears (41%) underwent posterior crus stapedectomy, and in the remaining 126 ears (59%) a prosthesis was inserted. Large fenestra technique was used in all cases. In the long run, both air conduction and bone conduction thresholds of ears operated on showed remarkable deterioration from the best values obtained 6 to 12 months postoperatively. Ten years after surgery both air conduction and bone conduction thresholds of ears operated on were significantly worse than those of normal controls. At 10 years, 70 percent of the ears operated on had hearing levels (at 0.5 to 2.0 kHz) of 30 dB or better and 88 percent had 40 dB or better. At the last follow-up examination, in 90% of the patients the better hearing ear had a hearing level of 40 dB or better. In 90% of patients with bilateral otosclerosis who had operations in only one ear, the ear operated on had better hearing function than the opposite ear that had not been operated on.

Characteristics of colorectal cancer in elderly patients.

The aim of the study was to examine the characteristics of colorectal cancer in elderly patients. The medical histories of 178 consecutive patients (79 men and 99 women) with colorectal cancer were studied from hospital records. The studied parameters were compared between three age groups: under 65 years old, 65-80 years old and over 80 years old. In the two older age groups, cancer was situated more commonly in the proximal colon than in the youngest age group (p = 0.029). Especially in elderly subjects, rectosigmoidoscopy is not sufficient since up to 40% of cancers are located in the right colon. Colonoscopy is recommended as the method of choice in old patients if colorectal cancer is suspected. Cancers in the oldest age group more often fell into to Dukes' stages C1, C2 and D (metastatic growth) (p = 0.072) and they were greater in size than those of patients under 80 years old (p = 0.029). Small cancers (under 5 cm) had obvious blood in the stools as the main symptom and represented nonmetastatic Dukes' stages. If these cancers could be detected earlier by testing for occult blood, the prognosis of colorectal cancer would improve. The resectability of cancer was lower in patients over 80 years than in other age groups (p = 0.016). However, in logistic regression analysis, the large size, poor or moderate cell differentiation, and distal location of the cancer, but not age, were associated with poor resectability.