摘要:

Metabolic acidosis is associated with increased calciuria and ammoniagenesis. This study evaluated the effects of oral sodium bicarbonate (NaHCO3) or combined potassium bicarbonate-calcium carbonate supplementation on urinary mineral excretion during the ketoacidosis of a very-low-energy protein diet. Seventeen healthy obese subjects (BMI: 37.5 ± 3.2 kg/m2, weight: 100 ± 3 kg) were given a 1.72 MJ all protein (93 g) liquid formula and a multivitamin-mineral supplement daily for 3 weeks. Subjects in groups 1 (n = 6) and 2 (n = 5) received 16 mmol KCl. In addition, subjects in group 1 received 60 mmol Na+daily as sodium chloride, subjects in group 2, 60 mmol Na+as NaHCO3. The subjects in group 3 (n = 6) were given 32 mmol K+as bicarbonate and 16 mmol Ca++as carbonate daily. Metabolic acidosis was prevented in groups 2 and 3 with bicarbonate and bicarbonate-carbonate administration. This was reflected in significant curtailment of the augmented ammonium nitrogen excretion found in group 1. The additional oral K+in group 3 improved K+balance and probably also inhibited ammoniagenesis. Urine calcium was greater (p < 0.04) in group 1 subjects, but similar in groups 2 and 3, despite higher calcium intake in group 3. Urinary phosphorus decreased with time in all groups, but more so in the group 2 subjects who received NaHCO3. Acidosis was associated with the reverse effect on urinary magnesium, which decreased in group 1 subjects. Thus adding the potassium bicarbonate-calcium carbonate preparation to a very low energy ketogenic diet spared both nitrogen and calcium in a manner similar to added NaHCO3, but also maintained better K+balance.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A dose-related curve of wound tensile strength was derived following exposure to three doses of predominantly UVA (Ultraviolet A) radiation (98.3% between 315 nm and 400 nm, 1.7% < 315 nm). Forty female hairless guinea pigs were divided into four equal groups: Group 1 (controls); Group 2 (40 J[Joules]/cm2/day); Group 3 (80 J/cm2); and Group 4 (160 J/cm2). Preoperatively, the experimental groups were irradiated on alternate days for 16 weeks. Serial dorsal punch biopsies (4 mm) were taken prior to the initial exposure and subsequently at 2, 4, 8, 12, and 16 weeks and examined histologically and microscopically. Then, standard 6 cm midline dorsal surgical wounds were made and allowed to heal for 21 days. Wounds were excised and wound tensile strength was assessed. Significant decreases (p < .05) were noted in wound tensile strength of Groups 2, 3, and 4 compared to the controls, with the decrease being directly related to the dose received. Dermal changes were noted in all irradiated groups as early as four weeks after initial UVA/B exposure. Electron microscopy revealed elastosis and disruption of collagen fibers. Prolonged exposure to radiation, predominantly in the UVA range, appears to impede wound healing in a dose-related fashion and elicits elastosis and collagen disruption.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The hypothesis that improved energydelivery and defibrillation efficacy can be achieved by using two widely separated endocardial electrodes and a cutaneous patch electrode was explored by positioning two 6.5 F electrodes (NuMed, Hopkinton, New York) with 5 cm platinum-iridium coils in the right ventricular apex (RVA) and the right ventricular outflow (RVO) in eight dogs. In another 12 dogs, an additional electrode was positioned in the RVA. A cutaneous patch (P) was placed at the cardiac apex. Biphasic pulses were delivered, the first pulse (6 ms) positive, the second negative (2 ms). The leading edge of the second was equal to the trailing edge of the first. RVO-/P+and RVA-/P+were compared with RVA-/P+at a constant voltage setting required to achieve a 60% probability of success (P60) for RVA-/P+. At a constant voltage output, the probability of success for RVA-RVO-/P+was significantly higher (81%) than RVO-/P+(60%) or RVA-/P+(67%) (p < 0.03). The current delivered was greater for RVA-RVO-/P+(9.9 ± 2.3 amps) than for either RVA-RVO-/P+(8.7 ± 1.9 amps) or RVO-/P+(9.0) ± 2.0 amps) (p < 0.0001). Similarly, the impedance was significantly lower for RVA-RVO-/P+(66 ± 12 ω) than for RVA-/P+75 ± 12 ω) and RVO-/P+(72 ± 9.6 ω) (p < 0.0001). Although no significant differences were found in current, impedance, or energy delivered when RVA-RVO-/P+was compared to RVA-RVA-/P+, the probability of success was higher for RVA-RVO-/P+(93%) than RVA-RVA-/P+(77%) (p < 0.01). The probability dose-response curves were defined for all four configurations in six dogs. RVA-RVO-/P+was superior to all other configurations at P20, P50, P70, P80and P90(p < 0.05). At P90, there was no significant difference between RVA-RVA-/P+and RVA-RVO-/P+.This study suggests that at constant voltage settings, current or voltage gradients are more favorably distributed using two widely separated internal electrodes (cathode) and a cutaneous patch (anode). This is probably a result of improved energy distribution and is probably independent of the electrode surface area effect.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Individuals with mitral valve prolapse(MVP) frequently show symptoms of a hyperadrenergic state. β adrenergic receptor characteristics were compared in the lymphocytes of subjects with symptomatic MVP and control subjects during rest and exercise. At rest, the proportion of receptors binding agonist with high affinity, as determined from isoproterenol competition for (-)[125I]-iodopindolol binding sites, was greater in MVP subjects than in controls. With exercise, the proportion of high-affinity receptors in MVP subjects decreased to control levels. Isoproterenol stimulation of lymphocyte 3',5'-cyclic adenosine monophosphate (cyclic AMP) also was greater in MVP subjects than in controls at rest, but not during exercise. Plasma catecholamine concentrations in MVP subjects were normal during both rest and exercise. Unlike exercise, isoproterenol infusion elicited clinical manifestations of increased adrenergic responsiveness in MVP subjects. The β receptor in exercised MVP subjects exhibited unusually high affinity agonist binding (i. e. a lower dissociation constant KHthan in either the same subjects at rest or exercised controls) and also abnormal coupling to the stimulatory guanine nucleotide-binding regulatory protein (Gs) of adenylate cyclase, as reflected by the inability of guanine nucleotide to convert the receptor to a low-affinity state. These findings suggest that functional alteration of the β adrenergic receptor, in the absence of abnormal plasma catecholamine levels, might contribute to the hyperadrenergic state of MVP subjects at rest. However, desensitization of high affinity β receptors or altered receptor-Gs coupling might preserve normal adrenergic responsiveness during exercise.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Pneumocystis cariniiis the most common cause of opportunistic pulmonary infection in AIDS patients and disseminated disease is being recognized with increasing frequency. We describe a patient with cavitary pulmonary disease, lymphadenopathy, thyroiditis, and associated hypothyroidism, all a result ofP. carinii.The organism was easily demonstrated in a fine-needle aspirate specimen of the thyroid. This is the second reported case of clinically apparentPneumocystisthyroiditis and the first reported case of hypothyroidism due to an opportunistic infection in a patient with AIDS. Clinicians should be aware of this entity and request a Grocott-Gomori methenamine-silver nitrate stain of appropriate cytology specimens to make the diagnosis.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A five-year-old boy with Crouzon Syndrome, short stature, and delayed bone age was found to have partial growth hormone deficiency. Accelerated growth was observed after human growth hormone replacement. Children with Crouzon Syndrome should be followed closely for all growth parameters, not just head circumference.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Pleural effusion due to hepatic cirrhosis and ascites is well known. We describe three patients with right-sided hepatic hydrothroax in the absence of ascites. The formation of pleural fluid in these patients is probably a result of fluid movement from peritoneal to pleural space across diaphragmatic defects before ascites can form. The differential diagnosis of a right-sided transudative pleural effusion in a patient with chronic liver disease with or without ascites includes congestive left ventricular failure and nephrotic syndrome. These diseases are usually ruled out with standard clinical tests. Patients with hepatic hydrothorax should be treated with fluid restriction and diuretics. Patients with severe symptoms due to refractory hepatic hydrothorax might benefit from pleural sclerosis and surgical closure of diaphragmatic defects.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Early in the course of a painful crisis, a 19-year-old man with known sickle cell anemia (SCA) developed a clinical picture that resembled either early cavernous sinus thrombosis or retroorbital and bifrontal microinfarcts. A brain computer tomography scan demonstrated bilateral retroorbital hemorrhages along with a left frontal epidural hematoma. In the absence of trauma, thrombocytopenia, or any other detectable hemostatic defect, this type of hemorrhagic manifestation in the setting of SCA has not, to our knowledge, been previously reported in the literature.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Endocrine manifestations of HIV infection include both pathological changes and disturbances in function. Mechanisms include direct infection of glands by HIV or opportunistic organisms, infiltration by neoplasms, side effects of drugs, and production of humoral factors that may alter metabolism. The adrenal gland is most often affected, but virtually every endocrine system may be involved. Dysfunction is often subtle, with symptoms overlapping those of the HIV infection itself. Endocrine manifestations may be found at any time in the course of the disease, from the asymptomatic HIV-positive stage through full-blown AIDS. Optimal management of these patients may include a careful search for, and appropriate treatment of, associated endocrine abnormalities.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In this brief review, we describe the clinical manifestations of Duchenne's muscular dystrophy (DMD) and other similar syndromes, outline the history of the dystrophin gene's identification and its relationship to these muscular dystrophies, and relate the importance of the gene's discovery to clinical neurology. We do not discuss treatment.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID