Large volar plate avulsion fracture of the base of the middle phalanx with rotational displacement: a report of three cases

Three cases of large volar plate avulsion fracture at the base of the middle phalanx with significant displacement are reported. In each case, the fracture fragment involved about 30% of the articular surface and was rotated 90 degrees. The proximal interphalangeal (PIP) joint showed loss of volar stability with hyperextension stress. This unusual variant of volar plate injury is thought to be caused by subluxation of the PIP joint. All patients underwent open reduction and internal fixation. The fracture healed in anatomic alignment without articular incongruity or instability in all cases.

[Surgical result of left ventricular free wall rupture complicating acute myocardial infarction]

From 1980 to 1995, we experienced 20 cases of surgical repair for left ventricular free wall rupture complicating acute myocardial infarction. These were divided into three types based on their clinical symptoms; 10 of the sudden blowout type, 4 of the rapid blowout type and 6 of the oozing type. In the rapid type, unconsciousness following the onset of the blowout rupture was restored by cardiopulmonary resuscitation (CPR) or pericardiocentesis. Seven out 20 cases (35%) survived. In the sudden blowout type, only one case treated by using the pericardial patch gluing technique without cardiopulmonary bypass survived. Three out of 4 cases (75%) of the rapid blow out type survived. Three out 6 cases (50%) of the oozing type survived. The causes of death were classified as table death for 5 cases, LOS for 1 case, and cerebral death for 3 cases of the 9 fatal cases of the sudden blowout type. Hemostasis was very difficult in 1 case of the rapid type. The 3 cases of the oozing type died respectively of LOS, cerebral death and pneumonia after surgery. Pericardiocentesis or subxyphoid drainage was performed preceding the repair of the rupture in 4 cases of the rapid blowout, and in 5 cases of the oozing type. However, re-rupture occurred in 2 cases of the rapid type and in 2 cases of the oozing type. In 7 cases in whom pericardial patch gluing technique was applied, a procedure in use since 1990, all cases were safely weaned from CPB, with 4 cases out of 7 (57%) surviving. Meanwhile, in 13 cases in which infarctectomy and myocardiography was carried out, 5 cases (38%) could not be weaned from CPB. Three cases (23%) survived after infarctectomy and myocardiography. Even some cases of blowout rupture were able to survive as long as blood pressure was elevated and consciousness was restored by CPR or pericardiocentesis as in cases of the rapid type. The pericardial patch gluing technique at the infarct site proved to be an effective procedure.

Waveguide image slicer

A new image slicer with a simple structure has been developed for use in grating spectrometers. The image slicer has polished thin glass plates that work as optical waveguides. It has a square 0.5 mm x 0.5 mm input surface and a steplike output surface with a width of 50 mum that is thin enough for high spectral resolution measurement. The output surface is in the same plane as the input surface so that optical path differences between the plates do not affect the spectrometer optics. The image slicer is efficient, with optical systems with F ratios faster than 10, and can be used at wavelengths that range from visual (lambda = 0.4 mum) to the near infrared (lambda = 2 mum).

Novel germline RET proto-oncogene mutations associated with medullary thyroid carcinoma (MTC): mutation analysis in Japanese patients with MTC

Germ-like and somatic mutations in the RET proto-oncogene are associated with inherited and sporadic medullary thyroid carcinoma (MTC). The majority of patients with multiple endocrine neoplasia type 2A (MEN2A) and familial medullary thyroid carcinoma (FMTC) carry germ-line point mutations that result in the substitution of one of five cysteine residues. We investigated exons 10, 11, 13, 14 and 16 of the RET proto-oncogene in 33 unrelated Japanese patients with MTC. Eleven of the 33 cases (33%) were found to have germ-line mutations. Three previously unreported mutations in exon 10 and 11 were identified: one in codon 620, (TGC-->GGC), resulting in a cysteine to glycine substitution, and two in codon 630, (TGC-->TCC) and (TGC-->TAC), resulting in cysteine to serine and cysteine to tyrosine changes, respectively. The new mutations were present in the germ-line DNA of four unrelated patients for whom a family history of MTC had not been documented. Because the new RET alleles described here involve cysteine residues in a region of protein previously associated with FMTC and MEN2A, it is very likely that they represent mutations that predispose to the development of MTC.

Lack of a point mutation of human DNA topoisomerase II in multidrug-resistant anaplastic thyroid carcinoma cell lines

DNA topoisomerases are major defined targets for a large variety of clinically important anticancer agents, including etoposide, adriamycin, and mitoxantrone. Mutations at amino acids 439, 450 and 803 of DNA topoisomerase II were examined in multiple anticancer drug-resistant anaplastic thyroid carcinomas (ten cell lines and three cancerous tissues) by reverse transcriptase-polymerase chain reaction (RT-PCR) and subsequent DNA sequencing. No mutation was found in these cell lines and tissues, but mdr1, mrp and/or lrp mRNA were expressed to a varying degree, and there was no significant difference in DNA topoisomerase IIalpha content among the cell lines and tissues as evaluated by Western blotting. Our experimental data indicate that overexpression of multidrug resistance-related mRNA is sufficient to confer drug resistance.

Genetic mapping using microcell-mediated chromosome transfer suggests a locus for Nijmegen breakage syndrome at chromosome 8q21-24

Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder characterized by microcephaly, short stature, immunodeficiency, and a high incidence of cancer. Cultured cells from NBS show chromosome instability, an increased sensitivity to radiation-induced cell killing, and an abnormal cell-cycle regulation after irradiation. Hitherto, patients with NBS have been divided into the two complementation groups V1 and V2, on the basis of restoration of radioresistant DNA synthesis, suggesting that each group arises from a different gene. However, the presence of genetic heterogeneity in NBS has been considered to be controversial. To localize the NBS gene, we have performed functional complementation assays using somatic cell fusion between NBS-V1 and NBS-V2 cells, on the basis of hyper-radiosensitivity, and then have performed a genomewide search for the NBS locus, using microcell-mediated chromosome transfer followed by complementation assays based on radiosensitivity. We found that radiation resistance was not restored in the fused NBS-V1 and NBS-V2 cells and that only human chromosome 8 complements the sensitivity to ionizing radiation, in NBS cell lines. In complementation assays performed after the transfer of a reduced chromosome, merely the long arm of chromosome 8 was sufficient for restoring the defect. Our results strongly suggest that NBS is a homogeneous disorder and that the gene for NBS is located at 8q21-24.

Pristine environments harbor a new group of oligotrophic 2,4-dichlorophenoxyacetic acid-degrading bacteria

2,4-Dichlorophenoxyacetic acid (2,4-D)-degrading bacteria were isolated from pristine environments which had no history of 2,4-D exposure. By using 2,4-D dye indicator medium or 14C-labeled 2,4-D medium, six strains were isolated from eight enrichment cultures capable of degrading 2,4-D. Phylogenetic analyses based on 16S ribosomal DNA (rDNA) sequencing and physiological properties revealed that one isolate from Hawaiian volcanic soil could be classified in the genus Variovorax (a member of the beta subdivision of the class Proteobacteria) and that the other five isolates from Hawaiian volcanic soils, Saskatchewan forest soil, and Chilean forest soil have 16S rDNAs with high degrees of similarity to those of the Bradyrhizobium group (a member of the alpha subdivision of the class Proteobacteria). All the isolates grow slowly on either nutrient media (0.1 x Bacto Peptone-tryptone-yeast extract-glucose [PTYG] or 0.1 x Luria broth [LB] medium) or 2,4-D medium, with mean generation times of 16 to 30 h, which are significantly slower than previously known 2,4-D degraders. Nutrient-rich media such as full-strength PTYG and LB medium did not allow their growth. PCR amplification using internal consensus sequences of tfdA (a gene encoding an enzyme for the first step of 2,4-D mineralization, found in pJP4 of Alcaligenes eutrophus JMP134 and some other 2,4-D-degrading bacteria) as primers and Southern hybridization with pJP4-tfdA as a probe revealed that the isolate belonging to the genus Variovorax carried the tfdA gene. This gene was transmissible to A. eutrophus JMP228 carrying a plasmid with a mutant tfdA gene. The other five isolates did not appear to carry tfdA, and 2,4-D-specific alpha-ketoglutarate-dependent dioxygenase activity could not be detected in cell lysates. These results indicate that 2,4-D-degrading bacteria in pristine environments are slow-growing bacteria and that most of their phylogenies and catabolic genes differ from those of 2,4-D degraders typically isolated from agricultural soils or contaminated environments.

Isolation of extradiol dioxygenase genes that are phylogenetically distant from other meta-cleavage dioxygenase genes

meta-Cleavage dioxygenase genes were isolated from the benzoate-assimilating bacteria Pseudomonas stutzeri A401 and Pseudomonas mendocina KC37. The gene products had the enzymatic activity of 2,3-dihydroxy-biphenyl-1,2-dioxygenase. Phylogenetic analysis based on the alignment of amino acid sequences suggests that these enzymes are distantly related to other meta-cleavage enzymes and may be members of a new family of extradiol dioxygenases.

Vascularized fibular grafts for the reconstruction of segmental tibial bone defects

Free vascularized fibular grafts were employed in seven patients with large tibial defects following trauma or resection of tumour. All patients were followed for more than 5 years. Tibial union and excellent functional results were achieved in all seven patients. Free vascularized fibular transfer seems to be an effective method of treatment for massive segmental bone defects.

Endothelin production in the rabbit collecting ducts of acute renal failure models. An immunohistochemical study

Endothelin 1 (ET-1) production was examined in the rabbit nephron in acute renal failure (ARF) induced by uranyl acetate administration or by clamping the renal artery. Uranyl acetate dissolved in saline was injected intravenously at a dose of 0.8 mg/kg (n = 12). In the ischemic kidney experiment, 60 min of left renal artery clamping was carried out 1 week after removing the right kidney (n = 8). Plasma and urine concentrations of ET-1 were measured 0, 24, and 48 h after treatment, and immunohistochemical studies of renal tissues obtained 48 h after the experiments were carried out using ET-1 monoclonal antibody. The fractional excretion of ET-1 increased from 10 to 89% at 48 h in the uranyl acetate treated group and from 6 to 15% at 24 h in the renal artery clamping group, suggesting the existence of ET-1 secretion from the nephron in both types of ARF. By immunohistochemical examination, strong ET-1 expression was noted only in the collecting ducts. No staining was observed in other parts of the nephron in both types of ARF. The present study indicates that the increased expression of ET-1 probably reflects production by the collecting ducts in both rabbit ARF models.

Indole derivatives as a new class of steroid 5 alpha-reductase inhibitors

A series of indole derivatives with varied substituents on the alpha, beta-unsaturated double bond were synthesized and evaluated for their ability to inhibit rat prostatic 5 alpha-reductase. Compounds possessing an ethyl substituent at the beta-position of the double bond showed potent inhibitory activity. Among them, (Z)-4-{2-[[3-[1-(4,4'-difluorobenzhydryl)indol-5-yl]-2-pentenoy l]- amino]phenoxy}butyric acid (16, KF20405) showed the maximum potency with an IC50 value of 0.48 +/- 0.086 nM, which was 20-fold higher potency than 1 (MK-906). Compound 16 effectively inhibited DHT production 4 h after a 3 mg/kg oral administration. Several potent indole derivatives, 1 and 2 ((+/-)-ONO-3805), were tested versus rat and human isozymes. Nonsteroidal inhibitors such as indole derivatives and 2 were 2-3 orders of magnitude less potent for human type 2 isozyme than steroidal inhibitor 1 and expressed a significant species deference for these isozymes.

[Tumor markers: neoplasmas in digestive organs]

Because they show high levels in hepatocellular carcinoma, alpha-fetoprotein and des-gamma-carboxyprothrombin are clinically useful tumor markers for differentiating hepatocellular carcinoma from other hepatic diseases. The two are useful complementary markers of hepatocellular carcinoma because they do not correlate with each other. A typical marker of pancreatic cancer is carbohydrate antigen (CA) 19-9. Over a period of more than 10 years, many markers resembling CA19-9 have been identified, but none are markedly superior to CA19-9, and the sensitivity of these markers in pancreatic cancer is only 65%-80%. Tumor markers are not useful for the early diagnosis of either hepatocellular carcinoma or pancreatic cancer. They are, however, considered to be useful for monitoring after treatment.

Diltiazem preserves direct vasodilator response but fails to suppress intimal proliferation in rat allograft coronary artery disease

BACKGROUND

We investigated the effect of diltiazem on transplant coronary artery disease in rat cardiac allografts both with standard histologic techniques and by measuring coronary vascular resistance and vasodilator response of the coronary arteries.

METHODS

Hearts from Lewis rats were transplanted into Fischer 344 rats in an abdominal position without immunosuppression as a chronic rejection model. The rats were randomly divided into two groups: (1) no drug intervention (control; n = 36) and (2) diltiazem in drinking water (n = 33). Syngeneic transplants, Lewis donor to Lewis recipient, were used for isograft comparison (n = 17). Rat allografts were observed for length of survival, and at 4 months the surviving allografts were transferred to Langendorff perfusion, where coronary vascular resistance and its response to acetylcholine and nitroglycerin were examined. Allografts were also examined histologically and assigned transplant coronary artery disease and cellular rejection grades.

RESULTS

Graft survival at 4 months was 43%, 38%, and 100% in control, diltiazem, and isograft groups, respectively. In the control group baseline coronary vascular resistance was much higher than in isografts (243 +/- 52 versus 35.3 +/- 6.2 cm H2O center dot gm center dot min/ml, p < 0.05) and the response to acetylcholine and nitroglycerin was significantly lower than that in the isografts (acetylcholine 6.2% +/- 4.8% versus 16.4% +/- 3.3%, p < 0.05; nitroglycerin 5.6% +/- 4.7% versus 12.6% +/- 5.7%, p < 0.05). In the diltiazem group baseline coronary vascular resistance (191 +/- 72 cm H2O center dot gm center dot min/ml) and the response to acetylcholine (7.3% +/- 2.9%) were similar to those in the control group (p = not significant); however, the response to nitroglycerin was better than that in the control group and in fact similar to that in the isograft group (13.6% +/- 7.0%; p < 0.05 versus control group, p = not significant versus isograft group). Histologic examination showed no coronary artery disease in isografts but equivalent marked transplant coronary artery disease and inflammation in both the control (transplant coronary artery disease grade 2.9 +/- 0.6, cellular rejection grade 3.6 +/- 0.7) and diltiazem (transplant coronary artery disease grade 3.0 +/- 0.8, cellular rejection grade 4.3 +/- 0.9) groups.

CONCLUSION

In this transplant coronary artery disease model, diltiazem did not suppress the development of coronary intimal proliferation, but it did help preserve the vasodilative properties of the allograft coronary arteries in response to nitroglycerin, a direct vasodilator.

Open reduction of chronic lunate and perilunate dislocations

Four patients with chronic lunate and perilunate dislocations were treated by open reduction and internal fixation. The interval between injury and operation was 7, 8, 14 and 18 weeks, respectively. Both palmar and dorsal surgical approaches were needed to reduce the old dislocation in all cases. A case of dorsal trans-scaphoid perilunate dislocation showed concurrent partial disruption of the scapholunate ligament. Transient vascular compromise of either the lunate or the proximal scaphoid fragment was noted in three patients. Despite the delay in treatment, all patients had satisfactory outcomes.

The mechanism of cold-induced platelet aggregation in the presence of heparin

Low temperature induces platelet aggregation, but this phenomenon is slight and poorly reproduced. However, heparin potentiated the reaction in a dose dependent manner. The degree of aggregation increased as the temperature at which the platelet-rich plasma was chilled was lowered, and as the time of chilling lengthened. Acetylsalicylic acid, a cyclooxygenase inhibitor, and staurosporin, an inhibitor of protein kinase C, partially inhibited cold-induced platelet aggregation (CIPA), suggesting that at least part of the reaction mechanism involves production of thromboxane A2 and activation of protein kinase C. Prostaglandin E1 (PGE1), which inhibits platelet responses through elevating platelet cyclic AMP, completely blocked CIPA, suggesting that PGE1 dependent pathway in platelets plays an important role for CIPA. The inhibition of CIPA by these inhibitors suggests that CIPA is aggregation with platelet activation but not platelet agglutination. Extracellular Ca2+ is essential for CIPA because ethylene glycol-bis (beta-aminoethylether) N, N, N', N'-tetraacetic acid (EGTA), extracellular Ca2+ chelating agent, completely inhibited CIPA. Monoclonal antibodies against glycoprotein (GP) IIb/IIIa (10E5, P2) and Ang-Gly-Asp-Ser-peptide (RGDS-peptide) which inhibit fibrinogen binding to GPIIb/IIIa completely blocked CIPA but monoclonal antibodies against GPIb (6D1, SZ2) partially. In addition, CIPA occurred only when fibrinogen was added to washed platelets suspension. These results indicate that CIPA is dependent on binding of fibrinogen to GPIIb/IIIa and GPIb is partly related with the reaction.

[Response-oriented salvage chemotherapy with mitoxantrone, etoposide and enocitabine for previously treated acute myeloid leukemia. Tohoku Leukemia Study Group]

Twenty-two patients with previously treated acute myeloid leukemia (AML) received salvage chemotherapy with mitoxantrone, 5 mg/m2/d on days 1 to 3, etoposide, 70 mg/m2/d on days 1 to 5, and enocitabine, 170 mg/m2/d on days 1 to 7 (BHAC-ME). Additional mitoxantrone, etoposide (both for up to 2 days) and enocitabine (for up to 7 days) were given if the bone marrow obtained on day 8 was not severely hypoplastic. Mitoxantrone and etoposide had been previously administered in 14 and 15 patients, respectively. Seven patients had primary resistance; 14 patients had first relapse (4 early and 10 late): and 2 patients had second relapse. Overall, seven patients (31%) achieved a complete remission; 7/14 with first relapse, and 0/8 with primary resistance or second relapse. Four patients, 3 with primary resistance and 1 with first relapse, died of infectious complication in aplasia. First relapse patients who had been previously treated both with mitoxantrone and etoposide, had a lower CR rate than the other first relapse patients [2/8 (25%) vs 5/6 (86%)], although patient characteristics such as duration of first CR, initial karyotype, and performance status, were similar between the two groups. We conclude that response-oriented BHAC-ME regimen is still active in first relapse AML patients unless they have received both mitoxantrone and etoposide previously.