A family with haemolytic anaemia and three β-globins: the deletion in haemoglobin Atlanta-Coventry (β75 Leu→Pro, 141 Leu deleted) is not present at the nucleotide level

Analyses of haemoglobin from a family with an unstable haemoglobin haemolytic anaemia demonstrated that the affected individuals had three beta-globins, namely, normal (beta A), Atlanta (beta At) with a mutation of beta 75 Leu----Pro, and beta-Atlanta-Coventry (beta At-Co) with mutation of beta 75 Leu----Pro and beta 141 Leu deleted. These were present in the ratio 66:23:11 respectively. The structure of the beta-globin cluster, however, was found to be normal by Southern blotting; also cytogenetic analysis failed to show any abnormality. DNA sequence analyses demonstrated the presence of the beta At mutation in genomic DNA isolated from leucocytes but the Coventry deletion of 141 Leu in beta At-Co was not present in genomic DNA. PCR amplification of the beta-globin cDNA and direct sequencing of the product also failed to demonstrate the Coventry deletion. Thus, it appears that the absence of 141 Leu in the beta At-Co globin is a consequence of the beta At mutation in these patients and that both beta At and beta At-Co are the product of a single gene. This unusual conclusion is paralleled in the bizarre case of Hb Vicksburg where the deletion of a leucine at beta 75 is not coded for in genomic DNA.     

Cytosolic retinoic acid binding protein in the human pancreas.

Cytosolic retinoic acid receptor in carcinoma, chronic pancreatitis, and normal pancreatic tissue were examined using sucrose density gradient centrifugation, isoelectric focussing on agarose gel and saturation analysis. Thirteen patients were studied. Cytosolic retinoic acid binding protein (cRABP) was detected in all the samples with chronic pancreatitis and pancreatic carcinoma, but not in the normal tissue. Using sucrose gradient centrifugation, the highest concentrations of cRABP were found in pancreatic carcinoma tissues, ranging from 5.5-23.9 pmol/mg protein. These concentrations were markedly different than in chronic pancreatitis tissue (0.7-2.7 pmol/mg protein). Saturation analysis of cRABP showed a mean dissociation constant of 21.5 nM and maximum binding sites of 5.2 pmol/mg protein. Cytosolic retinoic acid binding protein was separated at an isoelectric point of 4.5 on agarose gel. The presence of cRABP suggest that retinoic acid may have a role to play in the function of the pancreas.     

Refinement of clinicopathologic staging for localized soft tissue sarcoma of the extremity: a study of 423 adults.

PURPOSE: The prognostic value of factors used in clinicopathologic staging of localized soft tissue sarcoma (STS) of the extremity were analyzed comprehensively. PATIENTS AND METHODS: Four hundred twenty-three patients with STS that was confined to the extremity were admitted to Memorial Sloan-Kettering Cancer Center from 1968 to 1978. Cox models for the hazards rates of tumor mortality, development of a distant metastasis, strictly local recurrence, and postmetastasis survival were developed. Tests of changes in the prognostic value of the important variables over time were performed, as well as an analysis of the effect of a local recurrence on the hazard rate of distant metastasis. RESULTS: Three unfavorable characteristics contained independent prognostic value for the rates of distant metastasis and tumor mortality: high grade (P less than .00001), deep location (P less than .0002), and size greater than or equal to 5 cm (P less than .007). Their Cox model coefficients did not differ significantly (P greater than or equal to .65); thus, a staging scheme based on the risk of ever developing a distant metastasis would assign equal prognostic weights to grade, depth, and size. The tumor grade effect during the initial 18 months was much larger in magnitude than those for depth and size, and its effect disappeared beyond that time (P = .0003). Thus, a staging scheme based on the risk of early metastatic spread would assign a distinctly larger prognostic weight to grade and lesser but equal weights to depth and size. There was no local recurrence effect on the rate of distant metastasis in the high-risk group (high grade, deep, and greater than or equal to 5 cm; P = .75), but there was a significant association among the remaining groups combined (P = .0039). The magnitude of this association actually increased according to the number of favorable characteristics presented (P = .0024). CONCLUSIONS: The refinement of clinicopathologic staging may depend on the choice of outcome variable: ultimate prognosis versus early metastatic spread. Additionally, the observed local recurrence effect may be explained by a tendency for some patients to acquire one or more unfavorable risk factors at the time of local recurrence.     

FAMTX versus etoposide, doxorubicin, and cisplatin: a random assignment trial in gastric cancer.

PURPOSE: The chemotherapy regimens of high-dose methotrexate, high-dose fluorouracil (FU), Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and leucovorin (FAMTX) and etoposide, Adriamycin, and cisplatin (EAP) have both been reported in nonrandom assignment trials to have high overall response rates and substantial complete response rates in patients with gastric cancer, as well as major toxicities of myelosuppression. Here we report a prospective, stratified, random-assignment comparison of the two combinations in previously untreated patients with advanced gastric cancer. PATIENTS AND METHODS: Sixty patients were entered onto the trial, 30 receiving EAP and 30 FAMTX. All patients had measurable or assessable tumor masses. Patient entry was stopped at the point when significant toxicity differences were seen at interim analysis. RESULTS: Response rates were similar between the two arms (FAMTX, 33% [95% confidence interval (CI), 16% to 50%]; EAP, 20% [95% Cl, 6% to 34%]). Three FAMTX and no EAP patients had complete remissions. The median survival for the two arms were similar (EAP, 6.1 months; FAMTX, 7.3 months). At 1 year, 7% of EAP and 17% of FAMTX patients were alive. EAP caused significantly more myelosuppression (leukopenia, P = .002; anemia, P = .03; thrombocytopenia, P = .0001) than did FAMTX. EAP also resulted in significantly longer hospitalizations per study month (8 v 5 days). Four EAP patients died of lethal toxicity, whereas no FAMTX patients died of treatment-related causes (P = .04). CONCLUSIONS: FAMTX is at least as active as EAP and is significantly less toxic. Although both regimens remain investigational, the toxicities of FAMTX are more manageable. Further studies involving FAMTX in both the adjuvant and advanced disease setting are underway.     

The influence of intraoperative hypotension and perioperative blood transfusion on disease-free survival in patients with complete resection of colorectal liver metastases.

An increased interest in surgical treatment of liver metastases from colorectal origin has evolved recently. However not all patients benefit from this approach, with early recurrence and death still being encountered. To evaluate clinical as well as perioperative factors that might significantly affect the outcome of patients with completely resected colorectal liver metastases, we examined 116 patients who underwent resection between September 1987 and August 1989. Median follow-up time was 13.2 months (0.6 to 31.4 months). The overall survival rate was 91% at 1 year and 75% at 2 years. Median survival was not reached. Median disease-free survival time was 11.5 months, with 49.4% and 21.2% of the patients being free of disease at 1 and 2 years, respectively. By univariate analysis, site of primary colorectal cancer, preoperative carcinoembryonic antigen (CEA) level, size of metastases, number of metastases, length of operation time, percentage mean arterial pressure, number of hypotensive episodes, duration of hypotensive episodes, and whole blood transfusion significantly affected recurrence rate following resection. However only site of primary tumor, CEA, number of metastases, and number of hypotensive episodes remained significant in the multivariate analysis. The most significant single factor that affected recurrence rate was the number of hypotensive episodes during the operative procedure. It is concluded that hypotensive episodes, even when well controlled, should be avoided during operation to maximize the chances of cure and prolong disease-free survival of patients with colorectal liver metastases.     

The role of simple non-invasive testing in infra-inguinal vein graft surveillance

A prospective vein graft screening programme was established in order to improve graft patency in the period 1-12 months after operation. Patient assessment consisted of ankle:brachial pressure index (ABPI) measurement before and after exercise, and Duplex scanning. Thirty-nine grafts have been followed up, with 19 stenoses detected in 18 grafts (46%) using Duplex. Of these 18 grafts, six had a serial fall in resting ABPI, median 0.14 (range 0.11-0.33), and nine had a post-exercise ABPI fall, median 0.19 (range 0.13-0.4). The remaining three had a normal ABPI but were unable to exercise. Fifteen grafts have been treated, 12 by percutaneous transluminal angioplasty (PTA), and three by surgery. One stenosis treated with PTA recurred within 3 months and was repaired with a vein patch. Since screening was implemented no grafts in the programme have occluded. This study indicates that simple ABPI measurements can be used to screen "at risk" grafts for evaluation with Duplex scanning, without jeopardising graft patency.     

Unfolding and refolding occur much faster for a proline-free proteins than for most proline-containing proteins.

The kinetics for unfolding and refolding of a parvalbumin (band 5) have been examined as a function of pH near the transition region, using stopped-flow techniques. This protein is rather unusual in that it has no proline residues, and therefore serves as a good example to test the hypothesis that the rate-limiting step seen in denaturation reactions is due to the cis-trans isomerization of proline peptide bonds in the denatured state. The kinetics for parvalbumin unfolding and refolding are complex, with the data being resolvable into two fast phases at 25 degrees. The slower of the two phases seen for the parvalbumin is about 100 to 500 times faster than the slow phase seen for proline-containing proteins under the same conditions! These results argue strongly in support of the proline isomerization hypothesis. It is also suggested that the slower phase seen for parvalbumin and the second-slowest phase seen for proline-containing proteins might be due to the cis-trans isomerization of peptide bonds of non-proline residues.     

Mutation of antitrypsin to antithrombin. alpha 1-antitrypsin Pittsburgh (358 Met leads to Arg), a fatal bleeding disorder

Our previous studies predicted a functional relationship between the plasma proteins alpha 1-antitrypsin and antithrombin III. To elucidate this relationship we investigated the plasma of a 14-year-old boy who had died from an episodic bleeding disorder. A variant alpha 1-antitrypsin was identified in which the methionine at position 358 had been replaced by an arginine. This had converted the alpha 1-antitrypsin from its normal function as an inhibitor of elastase to that of an inhibitor of thrombin. This finding indicates that the reactive center of alpha 1-antitrypsin is methionine 358, which acts as a bait for elastase, just as the normal reactive center of antithrombin III is arginine 393, which acts as a bait for thrombin. The independence of the new thrombin inhibitor from heparin control explains the bleeding disorder; it also indicates that heparin normally acts directly on antithrombin III, revealing its inherent inhibitory activity. The episodic nature of the bleeding was a consequence of the mutant protein's being an acute-phase reactant, the level of which increased several-fold after trauma.     

The role of Mycobacterium leprae phenolic glycolipid I (PGL-I) in serodiagnosis and in the pathogenesis of leprosy

PGL-I (phenolic glycolipid I) emerged in the early 1980s on the one hand as part of intensive efforts to define the typing antigens of a host of Mycobacterium spp. and also from characterisation of the lipids of skin biopsies from highly bacillary positive lepromatous leprosy patients. PGL-I, despite its extreme lipophilicity due to its inherent phthiocerol dimycocerosyl component, is highly antigenic evoking high titre IgM antibodies in lepromatous leprosy patients, attributable largely to the unique 3,6-di-O-methyl-beta-D-glucosyl entity at the non-reducing terminus of its trisaccharide. PGL-I itself or in the form of semisynthetic neoglycoproteins containing the synthetic terminal disaccharide or the whole trisaccharide chemically conjugated to such as bovine or human serum albumin, has found its greatest utility in the serological diagnosis, confirmation and management of lepromatous leprosy. PGL-I has also been implicated in the tropism of M. leprae for Schwann cells, through specific binding to laminin, and to play an important role in downregulation of the inflammatory immune response and inhibition of dendritic cell maturation and activation, thereby facilitating the persistence of M. leprae/leprosy.     

Long-Term Durability of Transcatheter Aortic Valve Prostheses

Background

Very little is known about long-term valve durability after transcatheter aortic valve replacement (TAVR).