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Biomedical subjects

R L Humphrey

Publications and source records attributed to R L Humphrey.

18 recordsLinked to original sources
PubMed1992

Amyloid myopathy presenting with respiratory failure.

Amyloidosis is a rare cause of myopathy. Its prominent or presenting feature may be respiratory failure. Physiological measurement of transdiaphragmatic pressure and biopsy specimens of muscle show the pathological mechanism to be diaphragm weakness due to amyloid infiltration of the diaphragm rather than parenchymal lung involvement. Thus amyloid myopathy even without the typical macroglossia and muscle pseudohypertrophy should be considered as one of the neurological causes of respiratory failure.

Aged↗
PubMed1979

Studies with murine LPC-1 plasmacytoma using [6-14C]arginine.

[16-14C]Arginine ([6-14C]Arg) was used as an in vivo pulse label to study BALB/c murine LPC-1 plasmacytoma synthesis and secretion of its tumour-associated M component (IgG2a, kappa). With this isotope, an eight- to ten-fold enhancement in the labelling of the gamma globulin region and ten-fold reduction in the albumin labelling were observed. Production and secretion of the M component was detected (within 30 min) after cell transfer. Only mice which received tumour cells showed significant labelling in the gamma globulin region 24 hr after isotope injection. The labelling behaviour of the tumour M component correlated with the administered cell dose. The peak heights of radioactivity in the gamma region increased with increments in cell number. When the percentage radioactivity diverted into M component was plotted as a function of cell dose, a linear relationship was noted. This study demonstrates the feasibility of using [6-14C]Arg as a tool to follow the newly synthesized tumour-associated protein, and provides a means of estimating tumour cell number.

Animals↗
PubMed1979

Temporary disappearance ("eclipse") of LPC-1 plasmacytoma M component synthesis following tumor cell transfer.

The early phase of LPC-1 plasmacytoma development was studied by in vivo labeling with [6-14C]arginine using its M component (immunoglobulin G 2a,kappa) as marker. At a time when M component was not detected or faint by protein staining of electrophoretograms, significant labeling of M component was detectable by autoradiography. Labeling of the M component was fairly constant for the first 10 hr but was markedly decreased from Days 1 to 7. Nadir (0 to 3% of initial 30-min value) was observed on Day 3. Recovery of M component labeling to the 30-min level was complete by Day 13. This period of marked reduction or "eclipse" in newly synthesized M component was shortened by 2 days when mice were pretreated with pristane or cyclophosphamide prior to tumor cell transfer. The eclipse period was also 2 days shorter in athymic BALB/c-nu/nu mice than in normal BALB/c mice. The eclipse period corresponds to the classical "lag" following tumor cell transfer before tumor growth can be detected by conventional methods. The sensitivity of the [6-14C]arginine pulse permits the in vivo detection of small numbers of tumor cells (as few as 10(6) cells) over the early time periods after cell transfer. Modification of eclipse by manipulating host and/or tumor cells may elucidate the accompanying cellular and biochemical events.

Animals↗
PubMed1978

Amino acid sequence of the human myeloma lambda chain Win.

The complete amino acid sequence of the variable region of a human myeloma immunoglobulin light chain (Win) has been determined. The sequence of the constant region has been verified by compositional analysis of its tryptic peptides. The amino acid sequence of the light chain Win corresponds to sub group II and shows no unusual amino acid replacements in its constant or variable regions when compared to other human gamma chains.

Amino Acid Sequence↗
PubMed1978

Renal function in patients with multiple myeloma.

Renal tubular and glomerular functions were evaluated in 35 consecutive patients with multiple myeloma and were correlated with changes in renal histopathology and myeloma protein patterns. All nine patients without Bence Jones proteinuria had CCr greater than 50 ml/min. In contrast 16/26 patients with Bence Jones proteinuria had CCr less than 50 ml/min and the magnitude of the Bence Jones proteinuria correlated well with the degree of renal insufficiency. Frequent abnormalities in renal tubular acidifying and concentrating ability were observed only in patients with Bence Jones proteinuria and occurred in the absence of significant reductions of glomerular filtration rate. Severely deranged renal histology was seen only in patients with Bence Jones proteinuria and consisted primarily of tubular atrophy and degeneration; glomeruli appeared normal. These data suggest that Bence Jones proteins exert a direct nephrotoxic effect at the tubular level with resultant tubular dysfunction and tubular atrophy. Glomerular filtration rate remains relatively preserved despite the significant abnormalities of tubular function. Although obstructing tubular casts were observed only in patients with severely impaired glomerular filtration rate, many patients with similarly impaired renal function had no evidence of such casts. Instead, tubular atrophy and degeneration correlated best with renal dysfunction.

Adult↗
PubMed1977

Influence of renal insufficiency on levels of serum ribonuclease in patients with multiple myeloma.

Serum RNase levels were measured in 34 patients with multiple myeloma and compared with 51 normal controls and 28 non-myeloma patients on chronic hemodialysis. Nineteen of the myeloma patinets with creatinine clearance (CCr) greater than 50 ml/minute had mean serum RNase levels that were statistically indistinguishable from those of the normal controls. The 15 myeloma patinets with CCr less than 50 ml/minute had mean RNase levels much higher than normal controls or myeloma patients with normal renal function. Patients without myeloma but on hemodialysis for chronic renal failure of varied etiologies had markedly elevated serum RNase levels. A strong correlation between RNase levels and renal insufficiency, as measured by CCr, has thus been demonstrated. In addition, case histories of 5 representative myeloma patients were analyzed in greater detail; they illustrated the rise and fall of RNase levels as a function of the status of their renal insufficiency, regardless of the extent of the underlying myeloma. We concluded that the serum RNase level was an indicator of renal function, and was not a biomarker either for the presence or extent of the plasma cell tumor.

Creatinine↗
PubMed1977

Potassium permanganate reaction in amyloidosis. A histologic method to assist in differentiating forms of this disease.

A simple and reproducible histochemical method for distinguishing different chemical types of amyloid is described. The method is based on the affinity of amyloid for Congo red dye after exposure to potassium permangenate and dilute sulfuric acid. The permanganate method represents a modification of the Romhanyi trypsin technique. It yields comparable results while obviating some of the technical difficulties associated with the latter method. The permanganate reaction was applied to a series of amyloid samples of known amino acid composition, to amyloid samples fixed in a variety of different preservatives, and to tissues obtained at autopsy from 67 amyloidosis patients whose disease had been previously subclassified on the basis of clinical presentation and autopsy observations. This method distinguished amyloid protein AA from other varieties of amyloid and proved effective when applied to amyloid samples preserved in any of several commonly used fixatives. This simple histochemical method proved useful in subclassifying amyloid type in the patient series particularly when used in conjunction with the available clinical history and the organ distribution of amyloid accumulation.

Amyloidosis↗
PubMed1977

Induction of serum stimulation and plasma cell proliferation during chemotherapy of multiple myeloma.

Sequential sera from 45 patients with multiple myeloma (MM) and from 6 patients with solid tumors but normal bone marrows who received cyclophosphamide, 15 mg/kg/day for 4 days, were assayed for their effects on tritiated thymidine (3H-TdR) incorporation by normal bone marrow cells and malignant plasma cells. Pretreatment sera from 23 of the 45 patients with MM inhibited normal marrow cell proliferation relative to the effects of normal sera. Of these 45 sera, 30 inhibited plasma cell proliferation. This humoral inhibition was overcome by the induction of humoral stimulation at a predictable time during chemotherapy. The sera obtained sequentially from patients with MM and patients with normal bone marrows increased 3H-TdR uptake by both cell types by days 12-15 of therapy. Sequential changes in malignant marrow plasma cell 3H-TdR labeling indices paralleled the changes in serum activity, with an increased tumor cell growth fraction occurring at the time of peak serum stimulatory activity. The relationship between serum stimulation and malignant plasma cell proliferation was confirmed in vitro.

Bone Marrow↗
PubMed1976

T cell-specific human alloantisera-detecting antigens segregating outside the major histocompatibility complex.

Two sera demonstrated non-HLA lymphocytotoxicity on the basis of reactivity with the cells of siblings genotypically identical to the serum donors for the major histocompatibility complex. These two sera, Bl and Caf, once contaminating HLA antibodies were removed by absorption with pooled platelets, demonstrated allogeneic lymphocytotoxicity that was restricted to T lymphocytes. Reactivity of the absorbed sera segregated independently of the major histocompatibility complex in 3 of 12 families tested. Unlike both cold lymphotoxins and HLA antibodies, the absorbed sera showed little temperature sensitivity against allogeneic cells, although reactivity of the Bl serum to autologous cells and to cells of the donor's HLA identical sibling did show a decrease with increasing temperature and restriction of activity to the 19S-containing fraction. Granulocytes were unreactive with the absorbed sera. Such sera may provide probes of minor transplantation antigens or markers, or both, of lymphoid subpopulations.

Adult↗
PubMed1976

Normal human sera cytotoxic to cells of human acute leukemia.

Eight human sera from healthy individuals with no history of immunization with human transplantation antigens have demonstrated complement dependent cytotoxicity to cells of some patients with active acute leukemia. The antigen(s) detected by these sera are absent from normal and remission lymphocytes and appear most often in ALL patients with a high peripheral lymphoblast count. Some B and T lymphoblastoid cell lines carry the antigen(s) as evidenced by their ability to react with and absorb the antileukemia activity. The data support the existence of at least two overlapping specificities detected by these antileukemia sera. The leukemia antigen(s) show no strong correlation with any known HLA antigen. These observations provide evidence for a human leukemia blast associated antigen or set of antigens which may be immunogenic in man. Their relationship to normal HLA antigens of loci other than A, B or C is unknown.

Antigens, Neoplasm↗
PubMed1975

Acute renal failure in multiple myeloma.

1. The clinical manifestations, laboratory data and renal histologic features of acute renal failure occurring in 14 patients with multiple myeloma are reviewed and contrasted with the data from 29 previously reported cases. 2. Whereas other reports have stressed the role of intravenous pyelography and dehydration in the development of acute renal failure in multiple myeloma, the most common etiologic factor in our experience was hypercalcemia (7 patients). Other factors included potentially nephrotoxic antibiotics (3 patients) and volume depletion (2 patients). Intravenous pyelography could be clearly implicated in ony one patient. 3. The unusually high incidence of Bence Jones proteinuria in these patients is consistent with the possibility that Bence Jones protein excretion is associated with an increased susceptibility to renal injury. This could be due to an adverse effect of Bence Jones proteins on the renal tubules or their tendency to precipitate in tubular lumina during periods of reduced tubular flow. 4. The prognosis of patients with multiple myeloma who develop acute renal failure is poor; only 5 of our 14 patients survived the early period of acutely impaired renal function, and 4 of these subsequently died within 2 months. Preventive measures particularly the prompt correction of hypercalcemia and volume depletion, are the most important aspects of patient management.

Acute Kidney Injury↗
PubMed1975

Renal transplantation in multiple myeloma. A case report.

A patient with plasma cell myeloma presented in severe renal failure but was otherwise considered a good risk candidate for chemotherapy. Supported by hemodialysis she received intensive cyclophosphamide chemotherapy, resulting in a stabilization of all overt manifestations of her disease except for the renal failure. After 11 1/2 months of follow-up without showing any further progression of the myeloma process, she received a successful cadaveric renal transplant, which functioned well until the time of her death 15 months later. No evidence of recurrent myeloma kidney disease was found at postmortem examination.

Bence Jones Protein↗
PubMed1975

Kaposi's sarcoma associated with multiple myeloma.

A 62-year-old black female with Kaposi's sarcoma associated with multiple myeloma is reported. The co-existence of the two entities in the same patient appears more than coincidental. The case is the first woman and only the fifth described with Kaposi's sarcoma associated with multiple myeloma.

Female↗