A new suggestion for the treatment of minimally displaced fractures of the greater tuberosity of the proximal humerus

Fourteen shoulders in 14 patients with minimally displaced fractures of the greater tuberosity of the proximal humerus were evaluated, at an average of 3 years, 7 months (range: 1 year to 6 years, 1 month) after the operation. For comparison this portion of the proximal humerus was measured using 100 Korean adult cadaveric humeri. The results of these preliminary studies suggest that the patients presenting with a one-part fracture of the greater tuberosity of the proximal humerus should be evaluated individually. In most patients in whom the displacement of the fragment is less than 5 mm, good results can be obtained with non-operative treatment. If the displacement of the fragment is more than 5 mm in young active patients, and more than 3 mm in individuals (especially athletes and heavy laborers) involved in overhead activity, the fragment should be mobilized, repaired, and fixed into its original bed or slightly inferolaterally.

Deep vein thrombosis after uncemented total hip replacement

One-hundred-fourteen consecutive cases of venography after primary uncemented total hip replacement were performed in a randomized trial to identify the natural incidence of deep vein thrombosis, the effectiveness of prophylactic regimens such as 1.2 grams of aspirin daily and low-molecular-weight dextran for 3 days, and other relative factors for the development of venous thrombosis. In addition, intraoperative venography was conducted in 10 patients to study the speed of the flow of contrast media in the femoral vein and the development of deep vein thrombosis and the extent of the twisting of the femoral vein during hip joint manipulation. The incidence of venous thrombosis in the control, aspirin, and dextran prophylaxis groups were 20%, 11.5%, and 5.2% respectively. The incidence in the aspirin group was reduced, but this was statistically insignificant. The dextran group showed a marked decrease in incidence, and the difference with the control group was statistically significant. With regard to the development site of venous thrombosis, it was prevalent in iliofemoral, lower femoral, and major calf vein in the control group, while the popliteal and major calf vein were the major site of thrombosis development in the aspirin and dextran groups. The risk factors affecting the incidence of the venous thrombosis are confirmed to be obesity and long-term administration of steroids. Hematologic analysis was meaningless in investigating the development of venous thrombosis. The reliable clinical sign and symptom suggestive of the development of venous thrombosis was the severe swelling on the entire portion of affected lower extremity. In the intraoperative venogram, no correlation was found between the venous blood flow speed and the development of venous thrombi. A remarkable change in the blood flow of the femoral vein was noticed when the hip joint was flexed an average of 40.4 degrees, adducted at 11.5 degrees, and internally rotated at 81.5 degrees. Especially, when the joint was internally rotated, severe kinking of the vein could be observed. Thus it seems desirable to reduce the duration of internal rotation of the hip joint as much as possible to prevent venous thrombosis.

Telomerase activity and its clinicopathological significance in gastric cancer

In order to assess the role of telomerase in development of malignant gastric cancer, we measured the telomerase activity in gastric cancer tissues and normal tissues obtained from 95 patients by employing recently developed sensitive PCR (polymerase chain reaction)-based telomerase assay (telomeric repeat amplification protocol, TRAP). We also investigated how telomerase activity related to other clinicopathological findings including DNA ploidy and K-RAS gene point mutation. The telomerase activity was present in 85 of the 95 gastric cancer tissues, whereas we detected no telomerase activity in any normal tissue. The incidence of telomerase activity in gastric cancer tissues was not correlated to age, sex, tumour stage, histological grade, DNA ploidy or K-RAS mutation. Disease-free or overall survival of patients having tumours with detectable telomerase activity was not significantly different from that of those without telomerase activity. These findings suggest that telomerase may play a key role in the establishment and progression of the gastric cancer and further studies will be needed to elucidate the biological role of telomerase in gastric cancer.

A case of prostate cancer in 34 year old man presenting with generalized lymphadenopathy mimicking malignant lymphoma

We report a case of prostate cancer in 34 year old man presenting with generalized lymphadenopathy mimicking malignant lymphoma without any urinary symptoms. Lymph node biopsy revealed metastatic adenocarcinoma and immunohistochemical stain was strongly positive to prostate antigen (PSA). Serum PSA level was also markedly elevated. Transrectal ultrasonogram showed mild enlargement in right lobe of prostate. Needle biopsy finding of prostate also was consistent with adenocarcinoma. Bone scan revealed multiple metastatic lesions including vertebrae, ribs, pelvis, and both femurs. Generalized lymphadenopathy and elevated PSA level was decreased after bilateral orchiectomy.

Eukaryotic topoisomerase II cleavage is independent of duplex DNA conformation

Alternating purine-pyrimidine (RY) repeats have been identified in naturally occurring DNA and have many intriguing properties. Eukaryotic topoisomerase II displays significant cleavage activity at RY repeats (Spitzner et al. (1990) Nucleic Acids Res. 18, 1-11) due to the homology between RY repeat and the topoisomerase II consensus sequence. Cleavages are remarkably strong on duplex B form DNA. Certain RY elements are known to adopt altered DNA forms, such as Z-DNA, under the influence of superhelical stress. To investigate the dependence of topoisomerase II activity on DNA conformation, a plasmid containing a 40 bp of deoxyguanine-thymine repeat was constructed and the dependence of topoisomerase II cleavage patterns were compared. Although the degree of negative supercoiling strongly affected the overall efficiency of topoisomerase II cleavage, the sequence specificity was identical over a wide range of superhelical densities. These results suggest that topoisomerase II site specific action on duplex DNA is largely independent of DNA conformation. Moreover, since the GT target sequence is known to adopt a Z-DNA structure under conditions of superhelical density used in these experiments, the results reveal that topoisomerase II is a DNA binding protein capable of recognizing Z-DNA structure in eukaryotic cell.

Analysis of mutations of neurofibromatosis type 1 gene and N-ras gene in acute myelogenous leukemia

Neurofibromatosis type 1 (NF1) gene is a tumor suppressor gene, and the NF1 gene product, neurofibromin, can downregulate the N-ras gene. Because the N-ras gene is often mutated in acute myelogenous leukemia (AML), we wondered if the NF1 gene might be mutated in those AML samples not having N-ras mutations. We investigated the mutational status of the N-ras gene and the FLR exon of codons 1371-1423 of the open reading frame of the full-length NF1 cDNA, which has a strong homology with the mammalian ras GTPase-activating protein (GAP), especially for a stretch of three consecutive amino acids (F, L, R), by single-strand conformation polymorphism analysis and direct sequencing in samples from patients with AML. Of 48 AML patients, 10 (21%) had point (missense) mutations of the N-ras gene involving codons 12, 13 and 61. However, mutations in the FLR exon of the NF1 gene were not detected in any of the AML samples. We also examined the difference of clinical response to induction therapy between AML patients with and without N-ras mutation. A significantly lower rate of complete remission was noted in individuals with N-ras gene mutations. These results suggest that mutation of the NF1 gene, at least in the FLR exon, is very rare in AML and the NF1 gene probably is not a functional complement of the N-ras gene mutation. The presence of N-ras gene mutation may be associated with a lower clinical response to antileukemic therapy.

Inactivation of human keratin genes: the spectrum of mutations in the sequence of an acidic keratin pseudogene

Keratins are cytoskeletal proteins encoded by a multigene family. We have identified the first human keratin pseudogene and determined its complete nucleotide sequence. Sequence comparisons indicate that the pseudogene arose from a very recent duplication of the 50-kd keratin (K14) gene. The coding and the intron sequences of the two genes are 95% and 93% identical, respectively. Although the sequence of the regulatory region in the pseudogene is virtually identical to that in the 50-kd functional gene, several deleterious mutations have been identified in the pseudogene. There are three frameshifts in the coding regions, one of which is a perfect 8-bp duplication. A single-base-pair deletion in the first exon and a single-base-pair insertion in the penultimate exon also result in frameshifts. The three remaining deleterious mutations interfere with the mRNA processing signals: two alter the intron/exon boundaries, and the third disrupts the polyadenylation signal. These mutations clearly identify the sequence as a human keratin pseudogene.

Induction of Ia antigens on synovial cells by gamma interferon

Gamma interferon (IFN-γ) is a potent inducer of class II MHC antigens (la) in vitro. Enhanced Ia Expression is a characteristic feature of inflamed rheumatoid synovium. We investigated the potential of Ia induction upon non-inflammatory synovial cells under the influences of gamma interferon, alpha interferon and conditional medium from concanavalin A (Con-A) stimulated peripheral blood lymphocytes cultures (Con-A CM), Ia expression on enzyme dispersed cultured synovial cells decreased with time coincident with the loss of macrophage like cells. Addition of gamma interferon induced Ia molecules upon Ia negative synovial cells in a time and dose dependent manner, whereas alpha interferon treatment failed to induced Ia antigen. Con-A CM exerted the ability to induce Ia upon synovial cells. These findings suggest that: (1) Ia antigen expression by synovial tissue is the result of direct T cell influence: (2) non-inflammatory synovium has a potential to modulate Ia molecules under an altered environment.