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Biomedical subjects

B Chernow

Publications and source records attributed to B Chernow.

At least 109 records · Page 6Linked to original sources
PubMed1985

Angiotensin-converting enzyme activity. A potential marker of tissue hypothyroidism in critical illness.

We measured serum angiotensin-converting enzyme (ACE) activity radiometrically as a possible indicator of reduced thyroid function in 57 euthyroid controls, 27 patients in a noncardiac intensive care unit (13 with medical and 14 with surgical disorders), and 29 patients having coronary artery bypass grafting. In the last group, blood was obtained preoperatively and one day and one month after surgery (group 1; n = 18) or preoperatively and six hours and one day after surgery (group 2; n = 11). Patients in group 1 had significant reductions in levels of serum thyroxine (T4), triiodothyronine (T3), and thyrotropin response to protirelin one day postoperatively. The ACE activity fell significantly. Patients in group 2 had low levels of T4, T3, thyrotropin, and ACE six hours postoperatively. All these levels remained low the next day, and free T4 and free T3 levels were also reduced; the reverse T3 level became elevated. Changes in ACE significantly paralleled changes in T3. The 27 patients without coronary artery bypass grafting also had significant reductions in serum T4, T3, and ACE levels. Dilution studies and dialysis of serum with low ACE activity failed to demonstrate an inhibitor to explain the reduced enzyme function.

Adult↗
PubMed1985

Leukocyte esterase activity in the rapid detection of urinary tract and lower genital tract infections in obstetric patients.

Infections of the vagina and urinary tract are important problems for the obstetrician. Examination of the vaginal discharge and urine for the presence of leukocytes is an important part of the evaluation for vaginitis and urinary tract infections. Neutrophils contain several esterases that are not present in serum, urine, or vaginal secretions. These esterases are not influenced by bacteria, commonly used drugs, or variable compositions of urine or vaginal secretions. A prospective study was performed to assess the sensitivity and specificity of leukocyte esterase activity as measured by dipstick (Chemstrip 9, Biodynamics) for the prediction of vaginitis and urinary tract infections during pregnancy. Results were compared with those obtained from potassium hydroxide smears, wet preps, and urine cultures. The vaginal discharge and urine of 65 patients was tested for leukocyte esterase activity on their initial OB visit. Leukocyte esterase was 100% sensitive and 100% specific for detecting urinary tract infections. It was 100% sensitive and 90% specific for predicting vaginal infections. Trichomonas infections accounted for the positive leukocyte esterase results when the urine culture was negative. On the basis of this study we believe that leukocyte esterase activity is sufficiently sensitive and specific to permit use of this test as a rapid and inexpensive screening procedure for vaginitis and urinary tract infections.

Chlamydia Infections↗
PubMed1985

Unusual manifestations of arsenic intoxication.

A patient with arsenic intoxication is reported, who presented with a variety of gastrointestinal and neurologic disturbances including unilateral facial nerve palsy and acute symptomatic pancreatitis, neither of which have been previously described as sequelae of arsenic poisoning. The patient also suffered hematologic, dermatologic, and cardiopulmonary complications. A review of the literature about this interesting problem is also presented.

Adult↗
PubMed1985

A longitudinal evaluation of thyroid function in critically ill surgical patients.

Thyroid hormone alterations (known as the "sick-euthyroid syndrome") are common following major surgery, but the time course for appearance and recovery from these alterations has not previously been longitudinally studied in a large group of surgical patients. The authors prospectively studied 59 patients undergoing major surgery (coronary artery bypass grafting, pneumonectomy, or subtotal colectomy). Compared with preoperative values, the mean serum T4, T3, free T3, and TSH concentrations decreased significantly (p less than 0.05) following surgery. Serum reverse T3 and T3 resin uptake index increased, while free T4 levels remained unchanged. These changes were seen within 6 hours of surgery and normalized by 1 week after surgery. Although the serum TSH response to TRH was normal before and after surgery in 56 of the 59 patients, the maximal TRH-induced increase in serum TSH and the integrated serum TSH response to TRH were suppressed in the early perioperative period. This postoperative TSH suppression correlated with elevated postoperative plasma dopamine concentrations (r = 0.57, p less than 0.05). Three patients with compensated primary hypothyroidism were detected in the study and represent the first documentation of serial thyroid hormone and TSH levels in hypothyroid patients undergoing major surgery. These patients had similar changes in thyroid hormone values compared with euthyroid patients. The serum TSH response to TRH was suppressed into the normal range in two of these patients on the day following surgery. The authors conclude that the sick-euthyroid syndrome occurs within a few hours of major surgery and remits with convalescence. Postoperative decreases in serum TSH may mask the diagnosis of hypothyroidism. Surgical consultants should be aware of these rapid postoperative changes so that thyroid function tests are properly interpreted in patients who have undergone major surgery.

Adult↗
PubMed1985

Assessment of calcium homeostasis in the critically ill surgical patient. The diagnostic pitfalls of the McLean-Hastings nomogram.

Hypocalcemia is a common problem in critically ill surgical patients. We prospectively evaluated whether measurement of the total serum calcium (Ca) concentration or calculation of the serum ionized Ca level (by the McLean-Hastings nomogram) accurately reflects the measured serum ionized Ca level. Although 71% and 58% of 156 predominantly surgical intensive care unit (ICU) patients were hypocalcemic by the total serum Ca or calculated ionized Ca level, respectively, only 12% were hypocalcemic by directly measured serum ionized Ca measurement. The total serum Ca and calculated ionized Ca concentrations were sensitive (95% and 89%, respectively) but lacked specificity (32% and 46%, respectively) in predicting ionized hypocalcemia. Analyses of Ca binding to albumin in the serum of surgical ICU patients and normal subjects suggested that there is a circulating factor in critically ill patients that increases the binding of Ca to albumin. These observations may explain why the McLean-Hastings nomogram underestimates the protein-induced changes in serum Ca in critically ill surgical subjects. We conclude that: total serum Ca and calculated ionized Ca concentrations are poor indicators of the true serum ionized Ca status in critically ill surgical patients, and we recommend direct measurement of serum ionized Ca levels in these patients; and variability in the affinity of Ca for binding proteins in critical illness may explain the poor correlation between serum total and ionized Ca measurements.

Blood Proteins↗
PubMed1985

Evidence of extraocular muscle restriction in autoimmune thyroid disease.

Patients with Graves' disease lacking eye symptoms frequently have abnormal intraocular pressure (IOP) increases on upward gaze (greater than or equal to 3 mm Hg) indicative of apparent subclinical ophthalmopathy. Because of the close relationship between Graves' disease (GD) and Hashimoto's thyroiditis (HT), we examined 30 patients with a history of HT as well as 26 patients with a history of GD, 4 patients with a history of subacute thyroiditis, 1 patient with a history of silent thyroiditis, and 25 normal subjects for the presence of IOP abnormalities at 15 degrees and 25 degrees upgaze. While all of the patients were asymptomatic, had no exophthalmos, and were euthyroid at the time of the exam, Hertel exophthalmometer readings (mean +/- SD) for the patients with GD were significantly higher (P less than 0.005) than those for either the HT patients or normal subjects (17.1 +/- 2.4 vs. 14.5 +/- 2.3 vs. 14.4 +/- 4.2 mm, respectively). At 15 degrees upgaze, IOP abnormalities occurred in 25% and 13% of patients with GD and HT, respectively. At 25 degrees upgaze, these figures rose to 54% for the GD patients and 37% in HT patients. Only 1 of 25 normal subjects had elevated IOP changes on upgaze, as did the 1 patient with silent thyroiditis, but the patients with subacute thyroiditis did not. These data suggest the frequent presence of extraocular muscle restriction in patients with a history of HT as well as in patients with a history of GD. Maximal detection of these IOP abnormalities requires that patients be examined at 25 degrees upgaze. These data support the belief that the autoimmune bases of both GD and HT are closely linked, at least as manifested by eye muscle involvement.

Adult↗
PubMed1985

The hemodynamic and plasma catecholamine responses to routine restorative dental care.

Eleven healthy, normotensive males undergoing routine restorative dental care were evaluated during treatment for possible hemodynamic alterations in response to potential sympathetic nervous system stimulation. It is concluded that once acceptable local anesthesia is achieved, the hemodynamic and sympathetic responses to routine restorative dental care are minimal. These findings serve as a baseline for further studies evaluating the response of medically and pharmacologically compromised patients to similar dental procedures.

Adult↗
PubMed1985

Hypercalcemia and disseminated cytomegalovirus infection in the acquired immunodeficiency syndrome.

Two patients with the acquired immunodeficiency syndrome and disseminated cytomegalovirus infection developed hypercalcemia associated with suppressed parathyroid gland activity. Neither patient had evidence of a malignant, endocrinologic, granulomatous, or drug-related cause for hypercalcemia. Increased osteoblastic bone resorption induced by cytomegalovirus infection may have been the cause for the hypercalcemia. Physicians should be alert for the occurrence of endocrinologic and metabolic problems in immunosuppressed patients.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Specific cardiovascular drugs utilized in the critically ill.

The ability to pharmacologically manipulate cardiovascular function is important in caring for critically ill patients. Catecholamines have been the primary agents used for this purpose. Opiate receptor antagonists, neuropeptides like glucagon, and prostaglandin synthesis inhibitors provide new pharmacologic possibilities for physicians in the critical care unit. The cardiovascular actions of these and other agents are reviewed and their potential clinical indications are listed.

Calcium↗
PubMed1985

Hemodynamic and plasma catecholamine responses to epinephrine-containing perianal lidocaine anesthesia.

Despite the frequent use of large volumes (30-40 ml) of epinephrine-containing local anesthetic solutions for ano-rectal surgery, little is known about the anesthetic-induced hemodynamic consequences. Therefore, we measured the heart rate, blood pressure, and plasma catecholamine (norepinephrine and epinephrine) responses to the perianal injection of 40 ml of 0.5% lidocaine alone (n = 8) or 0.5% lidocaine with 1:200,000 epinephrine (n = 10) in 18 healthy adults undergoing outpatient ano-rectal surgery. The mean +/- SEM plasma epinephrine concentration increased from a baseline of 42 +/- 7 pg/ml to a peak of 622 +/- 94 pg/ml 4 min after injection of epinephrine-containing anesthetic (P less than 0.001), whereas lidocaine alone increased the mean plasma value from 36 +/- 9 pg/ml (baseline) to only 69 +/- 16 pg/ml (not significantly different) at its peak. Despite the increases in plasma epinephrine levels in the group receiving epinephrine-containing anesthesia, no changes in blood pressure, heart rate, or plasma norepinephrine levels were observed. Given the advantages (including prolongation of the duration of anesthesia) of adding epinephrine to perianal local anesthetics, our data support its safe use in healthy adults.

Adult↗
PubMed1984

Dystonia in 61-year-old identical twins: observations over 45 years.

We examined 61-year-old identical twin women of Jewish extraction with a probable autosomal recessive form of torsion dystonia. The dystonia in each was relatively mild and discovered only because a young relative developed dystonia. The twins were said to be discordant for dystonia, but personal evaluation led to the diagnosis of dystonia in both. Their slow course, with prolonged spontaneous remission in one twin, is in contrast to that described in most published reports. Although similar in mode of onset and initial course, the twins were dissimilar in age at onset, influence of pregnancy, diurnal variation in symptoms, need for medication, later course, and degree of disability at age 61. Normal plasma levels of norepinephrine and dopamine-beta-hydroxylase are consistent with autosomal recessive hereditary torsion dystonia. The importance of personal evaluation of key family members in establishing the correct genetic basis for a heterogeneous group of disorders, such as the hereditary dystonias, is stressed.

Chromosome Aberrations↗
PubMed1984

Plasma catecholamine and hemodynamic responses to the placement of epinephrine-impregnated gingival retraction cord.

A double-blind randomized crossover study was conducted to measure the changes in heart rate, mean arterial blood pressure, pulse pressure product, and plasma catecholamine levels for 60 minutes after the placement of racemic (r) epinephrine- or alum-impregnated retraction cords in intact gingival sulci of nine healthy volunteers. The r-epinephrine-impregnated cord produced significant (p less than 0.01) increases in plasma epinephrine concentrations after 60 minutes, but there were no epinephrine-induced hemodynamic changes. According to these findings, r-epinephrine-impregnated gingival retraction cord placed in an intact, nonlacerated gingival sulcus in a healthy young adult should produce no significant hemodynamic response. It is not known how the placement of epinephrine-impregnated retraction cord would affect elderly or medically compromised patients or patients with lacerated or periodontally involved gingivae.

Adult↗
PubMed1984

Measurement of urinary leukocyte esterase activity: a screening test for urinary tract infections.

We evaluated the efficacy of testing for the presence of esterase (an enzyme released only from leukocytes) in the urine as an indicator of the presence of pyuria. We hypothesized that a "dipstick" test for urinary leukocyte esterase activity would be a rapid and simple screening technique for detecting urinary tract infections (UTI). To test our hypothesis we collected fresh urine specimens from 203 patients (148 outpatients, 55 inpatients) with a suspected UTI. Each specimen was divided into three aliquots; one was used for reagent strip testing (for leukocyte esterase, nitrite, and blood), one for microscopy, and one for culture. Of the 203 specimens, 49 showed significant bacteriuria (greater than or equal to 10(5) organisms/mL). The leukocyte esterase test was 100% sensitive (0% false negatives) with a 76% specificity (24% false positives) in predicting significant bacteriuria. Although a positive nitrite reaction was more specific (99% specificity, 0.6% false positives), it was insensitive (27% sensitivity, 73% false negatives). The high sensitivity of reagent strip leukocyte esterase testing for pyuria makes it a valuable screening test that should lead to the elimination of many needless urine cultures and microscopic examinations.

Adult↗