Errors in derivations of the Coburn-Forster-Kane equation for predicting carboxyhemoglobin

An error identified in a 1993 textbook of military medicine led to an investigation of derivations of the Coburn-Forster-Kane equation (CFKE) for predicting carboxyhemoglobin (COHb) levels. Reviews of the scientific literature, military documents, and personal interviews revealed that errors were made in earlier derivations of the CFKE. One flawed derivation was used by the U.S. Army until 1985, and another is still used by the National Institute for Occupational Safety and Health (NIOSH). The original and later CFKE derivations are reviewed and errors in the equations are identified. The effect of the errors is discussed.

Trisomy 15 in hematological malignancies: six cases and review of the literature

We report six cases of trisomy 15 in patients with hematological malignancy. In four cases trisomy 15 was the sole abnormality and in two cases it was associated with sex chromosome loss. The patient age range was 6-91 years, and three patients were male. Four patients had myelodysplasia (refractory anemia), one patient each had acute myeloid leukemia and acute lymphoblastic leukemia. A literature review identified ten other cases of trisomy 15 as the sole abnormality in hematological malignancies. Trisomy 15 as the sole autosomal abnormality in hematological malignancy is uncommon, but can occur in both myeloid and lymphoid malignancies. It appears to occur most frequently in myelodysplasia.

Preliminary investigation of the Irie inferior vena caval filter

PURPOSE

In vitro and in vivo investigations were performed to evaluate the Irie retrievable inferior vena caval (IVC) filter.

MATERIALS AND METHODS

The clot capturing performance of the Irie and five other IVC filters were assessed in both horizontal and vertical orientations within a pulsed-flow circuit with 240 clot challenges for each filter. Subjective comparisons of the flow disturbance characteristics of the Irie and three other filters were also performed. In vivo studies consisted of 13 Irie filter insertions and eight attempted retrievals in 11 pigs. Histologic evaluation of the IVC was performed with the Irie filter in situ and following retrieval.

RESULTS

In vitro testing demonstrated the clot capturing capability and flow disturbance characteristics of the Irie filter to be similar to those of other IVC filters. Filter deployment problems occurred during three of the 13 insertions. Six of the eight retrieval procedures were successful; four filters were retrieved 1 month after insertion. Follow-up cavography demonstrated two tilted filters and three caval perforations.

CONCLUSION

The performance of the Irie filter is similar to that of other currently available IVC filters. The filter can be retrieved after neointimal incorporation of the struts into the IVC wall.

No change in complication rate using spring-loaded gun compared to traditional percutaneous renal allograft biopsy techniques

The previous methods to biopsy renal allografts at our institution involved the use of the Franklin-Silverman or Tru-Cut needles. Unfortunately they had a significant rate of post biopsy bleeding secondary to deep penetration when excess force was used to penetrate a tough transplant capsule. Although spring loaded biopsy devices have been widely used for native kidney biopsies over the past three years, the complication rate for renal allograft biopsies has not been sufficiently evaluated. We describe our experience using a disposable spring loaded biopsy device on transplanted renal grafts. Fifty-four biopsies were performed with the device, all under ultrasound guidance. The ASAP automatic biopsy system by Medi-tech was used comprising of a spring loaded gun with a 15 cm long 15 GA needle echogenic tip and 17 mm specimen notch. All patients were ultrasounded immediately post biopsy to look for hematomas. Compared to 55 previous biopsies performed using Tru-Cut needles, we conclude that the ASAP automated biopsy system proved equally effective in obtaining adequate tissue for diagnosis with fewer post-biopsy hematomas compared to traditional biopsy methods.

Early and late stimulation of ob mRNA expression in meal-fed and overfed rats

ob protein is hypothesized to be a circulating feedback signal in the regulation of energy balance. Obese, overfed rats have high levels of ob mRNA expression and suppressed voluntary food intake, indicating the presence of a potent satiety factor. The objectives of this experiment were to determine whether feeding rats their normal daily intake in three meals, compared with ad libitum feeding, increased ob mRNA expression and to determine the degree of obesity required to stimulate expression of ob mRNA. Rats were fed ad libitum, were tube-fed their normal intake in three meals a day, or were tube-fed twice normal intake, ob mRNA was measured by Northern blot analysis after 0, 2, 7, 14, 21, and 32 d of tube-feeding. After only 2 d ob mRNA was threefold higher in tube-fed animals than in ad libitum controls. By day 21 there was a further increase in ob mRNA expression in overfed rats which were at 130% control weight. These results suggest that a metabolic consequence of meal-feeding increases ob mRNA expression in the absence of increased food intake or weight gain. There is a further increase in ob mRNA expression once significant obesity is established.

Survival of family medicine in a corporate health care environment: lessons from the United Kingdom

The preservation of small, independent family practices within a changed health care delivery environment is a goal worth pursuing. Properly organized, such practices would maintain the special fiduciary relationship between physicians and patients. Fundholding practices, which are a growing organizational form of general practice in the United Kingdom, are described as a model that could serve as the basis for an American alternative to corporate medicine.

Intramolecular G-quartet motifs confer nuclease resistance to a potent anti-HIV oligonucleotide

We have identified a potentially therapeutic anti-human immunodeficiency virus (HIV)-1 oligonucleotide composed entirely of deoxyguanosines and thymidines (T30177, also known as AR177: 5'-g.tggtgggtgggtggg.t-3', where asterisk indicates phosphorothioate linkage). In acute assay systems using human T-cells, T30177 and its total phosphodiester homologue T30175 inhibited HIV-1-induced syncytium production by 50% at 0.15 and 0.3 microM, respectively. Under physiological conditions, the sequence and composition of the 17-mer favors the formation of a compact, intramolecularly folded structure dominated by two stacked guanine quartet motifs that are connected by three loops of TGs. The molecule is stabilized by the coordination of a potassium ion between the two stacked quartets. We now show that these guanine quartet-containing oligonucleotides are highly resistant to serum nucleases, with t1/2 of 5 h and >4 days for T30175 and T30177, respectively. Both oligonucleotides were internalized efficiently by cells, with intracellular concentrations reaching 5-10-fold above the extracellular levels after 24 h of incubation. In contrast, single-base mutated variants or random sequence control oligonucleotides that could not form the compactly folded structure had markedly reduced half-lives (t1/2 from approximately 3 to 7 min), low cellular uptake, and no sequence-specific anti-HIV-1 activity. These data suggest that the tertiary structure of an oligonucleotide is a key determinant of its nuclease resistance, cellular uptake kinetics, and biological efficacy.

Serum neural cell adhesion molecule in multiple myeloma and other plasma cell disorders

Serum embryonic neural cell adhesion molecule (eNCAM) levels were measured at diagnosis in 92 patients with plasma cell disorders. Significantly elevated levels of serum eNCAM were detected in patients with multiple myeloma when compared to both normal controls and patients with monoclonal gammopathy of uncertain significance (MGUS). Very high levels of serum eNCAM were seen in patients with high tumour burdens. There was a significant correlation between serum eNCAM and beta 2-microglobulin (beta 2m) (r = 0.33; P = 0.002), but not between serum eNCAM and C-reactive protein or serum albumen. There was a trend towards longer survival for patients with low serum NCAM. The median survival of the low serum eNCAM group (eNCAM < 20 U/ml) was 36 months compared to 16 months for the high serum eNCAM group (log rank test chi 2 = 2.42, P = 0.1). Serum eNCAM is a new marker of tumour mass in multiple myeloma and correlates with clinical stage and beta 2m. Patients with low serum eNCAM levels may have a survival advantage. Serum eNCAM warrants further evaluation as a tumour marker and prognostic factor in multiple myeloma.

Infected right atrial thrombus presenting as pulmonary embolism complicating central venous cannulation

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Staphylococcal enterotoxin B and tumor-necrosis factor-alpha-induced relapses of experimental allergic encephalomyelitis: protection by transforming growth factor-beta and interleukin-10

A study was made of the ability of the superantigen staphylococcal enterotoxin B (SEB) to induce relapses of experimental allergic encephalomyelitis (EAE) in SJL mice that had partially or completely recovered from acute EAE. We find that a single injection of 0.05 mg SEB i.v. induces mild relapses in 50% of such mice. In addition, tumor necrosis factor (TNF)-alpha (0.2 micrograms, i.p.) also induces EAE relapses in 43% of SJL mice when injected 1-2 months after recovery. SEB does not induce a second relapse if reinjected when V beta 17a+T cells are still partially deleted. In these mice, however, TNF-alpha is equally effective in inducing relapses as in mice that did not receive SEB previously. We showed earlier that transforming growth factor (TGF)-beta and TNF-alpha have antagonistic effects on experimental autoimmune diseases; e.g., in spontaneously relapsing EAE, TGF-beta and anti-TNF were protective, while anti-TGF-beta caused disease exacerbation. Interleukin (IL)-10 is also known to counteract certain TNF effects. We now find that both human IL-10 and TGF-beta 2 lower the incidence of EAE relapses when given simultaneously with SEB or TNF-alpha. The protective effect of TGF-beta is significant only against relapses induced by SEB (reduced to 9%), and that of IL-10 only against relapses induced by TNF (reduced to 0%) with the treatment regimens employed. Neutralizing anti-TGF-beta does not increase the incidence of SEB-induced EAE relapses. In contrast, anti-IL-10 increases both the incidence and the severity of such relapses. We conclude that TNF production is probably important in causing EAE relapses, but that other aspects of the SEB-induced reactivation of myelin-specific T cells also contribute. Furthermore, endogenous IL-10 rather than TGF-beta production appears to limit the susceptibility to induction of EAE relapses in this model.

The Occupational Health Partnership Program: a new paradigm for occupational health services

For a variety of reasons, occupational health services at Army Material Command installations became severely strained during the 1980s. The Occupational Health Partnership Program, developed to improve this support, describes control, responsibility, and cost sharing between Army Materiel Command and Army Medical Command. This innovative approach is finding new solutions to challenging problems. The authors describe the history, principles, status, and possible future of the partnership program.

Spinal stabilisation in plasma cell disorders

Five patients with plasma cell disorders and vertebral body lesions who presented with severe localised back pain associated with spinal instability are described. They underwent a total of six surgical spinal stabilisation procedures with excellent symptomatic relief. Spinal stabilisation was performed at presentation in 1 patient with a cervical spine lesion, and at sites of previously irradiated disease or recurrent disease in the other 4 patients. Stabilisation was achieved using various internal fixation techniques, and in 2 cases external fixation was obtained with a halo brace. The procedures were performed with minimal operative morbidity, and resulted in good symptom control. Spinal instability should be considered as a cause of severe localised back pain exacerbated by movement in patients with plasma cell disorders and vertebral body lesions. Operative spinal stabilisation should be considered as part of their management.

Late withdrawal of cyclosporine in stable renal transplant recipients

The use of cyclosporine (CsA) in renal transplantation has been associated with an improvement in 1-year graft survival, but has not changed the rate of late graft loss. We sought to determine whether the intent to withdraw CsA late after renal transplantation affects renal transplant survival and whether there is a racial difference in the effect of CsA withdrawal. This retrospective study included 384 consecutive patients receiving a renal transplant during the 1984 to 1991 period who were treated with CsA/azathioprine/prednisone and who had a functioning allograft 6 months following transplantation. Of these, 97 were electively withdrawn from CsA at a median of 22 months following transplantation. Factors significantly associated with the decision to withdraw CsA included white race, older age, and lower serum creatinine. Acute rejection within 6 months of stopping CsA occurred in 12 patients (12.4%), including nine of 78 (11.5%) white patients and three of 19 (15.8%) black patients. For the group of 287 patients who were not withdrawn from CsA, the 6-year graft survival rate was 59% (95% confidence interval, 52%, 66%). For the group of patients taken off of CsA, the 6-year graft survival rate was 84% (95% confidence interval, 76%, 92%). Cox proportional hazard survival analysis indicated that the intent to discontinue CsA was associated with better graft survival, with a hazard ratio of 0.37 (95% confidence interval, 0.20, 0.70), independent of other variables that may affect graft survival. A separate analysis controlling for waiting time bias also favored the CsA withdrawal group. There was no detectable racial difference in the effect of CsA withdrawal on graft survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Longstanding proliferation of CD3 negative large granular lymphocytes preceding the development of high grade non-Hodgkin's lymphoma

A patient with a persistent CD3 negative large granular lymphocyte (LGL) proliferation with immunophenotypic and functional characteristics of natural killer cells is described. The LGL proliferation persisted and six years after diagnosis the patient developed a high grade B cell non-Hodgkin's lymphoma. Molecular studies demonstrated clonal B cell populations in the peripheral blood, distinct from that identified in the lymphoma, both at presentation with non-Hodgkin's lymphoma and at complete remission following combination chemotherapy. It is postulated that T cell dysregulation associated with the CD3 negative LGL proliferation may have led to B cell dysfunction and loss of normal B cell control, with the subsequent development of a clonal B cell lymphoproliferative disorder.

Transmission of cancer with cadaveric donor organs

A case is presented in which each of the recipients of a pair of cadaveric kidneys developed metastatic carcinoma. One of the recipients died, and the other demonstrated involution of metastatic deposits after graft nephrectomy and withdrawal of immunosuppression. By the use of polymerase chain reaction of minisatellite regions of donor and recipient DNA, the donor origin of the tumor was conclusively demonstrated. Although a relatively uncommon complication of cadaveric renal transplantation, the transmission of cancer with cadaveric organs may become more frequent as older donors are accepted for organ donation.