Three unrelated cases of paracentric inversions of 1p in individuals with abnormal phenotypes

Paracentric inversions, involving a rearrangement within one chromosome arm, are rare. Although carriers of balanced paracentric inversions should theoretically not be at risk for abnormal offspring, such cases have been reported. We report on 2 unrelated cases of inherited paracentric inversions of 1p with breakpoints at p32 and p36.1 and p32.3 and p36.22 in individuals with abnormal phenotypes. Another case of 2 abnormal monozygotic twins with a de novo paracentric inversion of 1p with breakpoints at p22 and p34 is presented as well.

Tone dependent nitric oxide production in ovine vessels in vitro

We have determined the role of endogenous nitric oxide (NO) in regulation of vasomotor tone in ovine intrapulmonary and mesenteric vessels with resting tension and elevated vasomotor tone. Third generation intrapulmonary vessel rings and mesenteric vessel rings, 2-3 mm in diameter, were isolated from 20 sheep. NO production in the vessels was assessed by the change in tension induced by NG-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of NO synthase. In vessels under resting tension, 10(-4) to 10(-3) M L-NAME induced a significant increase in tension only in veins but not in arteries. When tone was elevated with phenylephrine or U 46,619, a thromboxane A2 analogue, there was now a significant increase in tension in arteries with 10(-4) M L-NAME and in veins with 10(-5) M L-NAME. The increase in tension induced by L-NAME in veins was greater than that in arteries and greater when tone was elevated than under resting tension. Responses of pulmonary and mesenteric vessels were similar. Our data suggest that NO may play a role in regulating venous tone under baseline conditions and that the role of NO in regulation of vasomotor tone becomes more significant in the presence of nonspecific elevation of vasomotor tone in both arteries and veins. We speculate that endogenous NO production may be one mechanism by which pulmonary and systemic vessels counter the effects of vasoconstrictive agents.

Mechanics of the occlusive arm cuff and its application as a volume sensor

Although a common medical instrument, the mechanical function of an occlusive arm cuff has not been fully described in an engineering sense. The occlusive arm cuff is examined here using a mathematical mechanics model and experimental measurements. Cuff stretch was modeled by a nonlinear pressure-volume function. Air compression was represented by Boyle's law. An apparatus was developed to measure pressure due to the air volume pumped into the cuff for fixed arm volume. Data were obtained for two different cuff designs, and reveal a nonlinear cuff pressure-volume relationship that could be represented accurately by the mathematical model. Calibration constants are provided for the two types of occlusive cuff. Thus, the cuff pressure was found to consist of a balance between that produced by stretch of the elastic cuff bladder and that of the compression of the air contained within the bladder. The use of the gas law alone was found to be inadequate to represent the cuff mechanics. When applying the cuff to measure change in arm volume, such as during plethysmography or oscillometry, it cannot be assumed that the cuff sensitivity is constant. More precisely, it was found that the occlusive cuff is a transducer with a volume sensitivity that increases with cuff pressure and volume until it becomes nearly constant at high levels of cuff pressure (150 mmHg). A hypothetical case of a linear elastic artery with constant pulse pressure was used as input to the cuff model to illustrate the change in cuff pressure oscillations that occurs while cuff pressure is released.(ABSTRACT TRUNCATED AT 250 WORDS)

Central line perforation associated with Staphylococcus epidermidis infection

We present detailed case reviews of four very low birth weight (VLBW) infants in whom central venous silastic catheter perforation was associated with Staphylococcus epidermidis sepsis. The diagnostic and therapeutic dilemma presented by the intracavitary fluid collections occurring in all four of these cases proved to be of clinical interest. Additionally, we propose a model that may account for the etiology of catheter displacement--localized phlebitis as a result of S epidermidis infection with resultant extralumenal migration of the central venous catheter.

Inhibition of diabetes-associated complications by nucleophilic compounds

Mono- and diaminoguanidine inhibited ambient glucose-induced glycosylated end product formation of albumin and collagen 125I-labeled albumin covalent binding in vitro. Diaminoguanidine was a stronger inhibitor than monoaminoguanidine. These compounds also inhibited rat eye lens aldose reductase activity in vitro noncompetitively with respect to NADPH with Ki = 30.6 mM for monoaminoguanidine and Ki = 12.5 mM for diaminoguanidine. When administered daily for 98 days at a dose of 25 mg/kg body wt i.p., both compounds lowered eye lens sorbitol and aldose reductase activity in normoglycemic and alloxan-induced diabetic rats. Again, diaminoguanidine was a better inhibitor. Daily long-term administration of mono- and diaminoguanidine (25 mg/kg body wt i.p.) inhibited and prevented experimental diabetes-induced lens opacity in rats, respectively. It appears that diaminoguanidine has a better therapeutic potential in controlling diabetic complications.

Interaction of human alpha fetoprotein with bilirubin

Human alpha fetoprotein (AFP) binds bilirubin with an affinity somewhat lower than albumin. Free bilirubin was found to have an extinction maximum at 440 nm with an extinction coefficient of 4.97 x 10(4) M-1cm-1. AFP binding with the bile pigment elicits a blue shift while albumin interaction produced red spectral shift.

Uses and limitations in the demonstration of specific circulating immune complexes in patients with amoebiasis

A micro-enzyme linked immunosorbent assay (micro-ELISA) has been evaluated as a diagnostic test to detect amoebic antigen in polyethylene glycol (PEG) precipitated circulating immune complexes (CIC) in sera from patients with amoebiasis. The immune complexes were captured on rabbit anti-amoebic IgG-coated wells of microtitration plates and the complexed antigen was detected by enzyme linked antihuman immunoglobulins. A titre of greater than 160 for the immune complexes was considered to be of clinical significance. The immunoassay detected amoebic, antigen-specific CIC in 35 (94.5%) of 37 patients with confirmed amoebic liver abscess. Twenty (55.5%) of 36 clinically suspected cases of amoebic liver abscess had amoebic antigen-specific CIC and responded favourably to anti-amoebic chemotherapy. Only two (20%) of 10 cases of non-dysenteric symptomatic intestinal amoebic infection had amoebic antigen-specific CIC. One (10%) of 10 patients with non-amoebic intestinal disorders also had amoebic antigen in CIC. However, none of 15 cases of non-amoebic hepatic disorders that included hydatid disease, metastatic adenocarcinoma, hepatocellular carcinoma, cholecystitis and choledocal cyst, 13 cases of rheumatoid arthritis and 25 apparently healthy subjects had amoebic antigen in CIC. The levels of the amoebic antigen-specific CIC did not correlate (p greater than 0.05) with either the number of abscess(es) or lobe(s) of the liver involved. However, the levels of antigen-specific CIC were higher (p less than 0.01) in patients with a liver size of more than 5 cm below the right costal margin. Antigen-specific CIC levels tended to decline or disappear during 3-6 months following completion of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of an inexpensive and rapid two site microenzyme linked immunosorbent assay kit for human alpha fetoprotein

Laboratory scale development of a two site micro enzyme linked immuno assay kit is described. The kit comprises rabbit anti human alphafetoprotein (AFP), anti human AFP IgG peroxidase conjugate and standard AFP. All the above reagents were prepared in the laboratory. The kit is eminently suitable for early screening of blood sample of pregnant women for neural tube defects of their fetuses and for the quantitation of AFP as a tumor marker. The assay kit was used to determine AFP in 76 sera from women at different stages of pregnancy. During 1st trimester AFP level was 18 to 119 ng/ml, during 2nd trimester the concentration varied from 85 to 302 ng/ml and during 3rd from 103 to 580 ng/ml. No evidence for maternal antibody to AFP was found. The above data agree with AFP level in pregnant women reported by earlier workers, using RIA or ELISA. The present ELISA kit would hopefully be much cheaper than internationally available ELISA kits for human AFP.

Alpha fetoprotein levels in newborn infants with reference to sex, gestational age and birth weight

Alpha fetoprotein (AFP) concentration was higher in the mature full term male infants than age matched females. An inverse correlation, at birth, between cord serum AFP level and duration of pregnancy was observed. In contrast no correlation between body weight and AFP levels exists in babies of either sex at identical gestational age.

Retrospective glycemic status of diabetic patients: glycosylation of blood proteins in diabetes and chronic renal failure

In vivo and in vitro studies were carried out to evaluate the clinical application of glycosylated hemoglobin and plasma proteins in the diagnosis and management of diabetes mellitus. Glycosylated hemoglobin registered an almost 80% fall in diabetic patients following controlled glycemia for two months while glycosylated plasma protein level registered an 80% fall in the patients after fifteen days of blood glucose homeostasis. Human serum proteins were glycosylated in vitro and glycosylation was linearly proportional to the glucose concentration and incubation time. Polyacrylamide gel electrophoresis of glycosylated serum proteins revealed that albumin and transferrin are the major proteins that are significantly glycosylated. Glycosylated hemoglobin and plasma protein levels were also increased in chronic renal failure patients without any history of diabetes.

Hyperosmolality in the burn patient: analysis of an osmolal discrepancy

In our study of 262 hospitalized flame burn patients, serum hyperosmolality, defined as having at least two reported osmolality values greater than 310 mOsm/kg, was observed in 15 patients (6%). From this group, nine patients were found to have an osmolal discrepancy (reported serum osmolality minus calculated serum osmolality). All patients in this group had a burn surface area greater than 35% TBS. The discrepancy between reported osmolality values of two patients from this group, determined by freezing point depression and vapor point analysis, suggested that a volatile substance was contributing to the osmolality. Further analysis by gas chromatography revealed propylene glycol as the agent accounting for most of the osmolal discrepancy. The only exposure to this polyalcohol was from the topical antibiotic cream (silver sulfadiazine) used in their treatment.