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Biomedical subjects

L E Rotstein

Publications and source records attributed to L E Rotstein.

At least 37 records · Page 2Linked to original sources
PubMed1990

Lithiumogenic disorders of the thyroid and parathyroid glands as surgical disease.

Little notice has been paid in the surgical literature to problems with psychoeffective lithium, which by interfering with adenylate cyclase affects thyroid and parathyroid function, causing hypercalcemia, hyperparathyroidism, and hypothyroidism. Seven patients with lithiumogenic hyperparathyroidism occurring after years of lithium therapy underwent treatment and manifested osteoporosis (n = 2), hypertension (n = 2), nephrolithiasis (n = 1), coma (n = 1), rising hypercalcemia (n = 1), goitrous myxedema (n = 4), nephrogenic diabetes insipidus (n = 2), renal failure (n = 2), and hyperlipidemia (n = 1). Disease-directed parathyroidectomy (without morbidity) was curative. Unique laboratory findings included normal serum phosphorus and reduced urinary calcium and cyclic adenosine monophosphate values. Three separate cases of thyroid carcinoma after long-term lithium therapy were also treated, being preceded by myxedema (n = 2) and concurrent with hyperparathyroidism (n = 1). There has been only one previous report of lithium-associated thyroid carcinoma. All patients taking lithium should undergo surveillance for thyroid and parathyroid dysfunction and neoplasia, and appropriate surgical and medical treatment should be considered in each situation. Although hyperparathyroidism may be reversible with lithium discontinuance, such therapy may be obligatory for patient well-being, thus dictating parathyroidectomy.

Adult↗
PubMed1989

Do we really need another localizing technique for parathyroid glands?

To evaluate magnetic resonance imaging (MRI) in the preoperative localization of abnormal parathyroid glands, we examined 16 patients with primary hyperparathyroidism at initial presentation with MRI and ultrasound of the neck. These studies were analyzed prospectively and compared with the findings at bilateral neck exploration. The surgeon was intentionally blinded to the imaging studies. MRI was accurate in the lateralizing of an abnormal gland in 21 of 32 sides (66 percent). Sensitivity was 65 percent and specificity was 66 percent. Ultrasound was accurate in 19 of 32 sides (59 percent). Sensitivity was 50 percent and specificity was 75 percent. The difference was not statistically significant. We do not believe that MRI is indicated prior to initial exploration in patients with primary hyperparathyroidism.

Humans↗
PubMed1989

Hepatocellular carcinoma: pilot trial of treatment with Y-90 microspheres.

The potential use of yttrium-90 glass microspheres in the treatment of hepatocellular carcinoma was assessed in a pilot study of seven patients. The Y-90 microspheres were injected via a hepatic artery catheter. In this group of patients, no toxicity was observed for absorbed doses of between 5,000 and 10,000 cGy to the liver and up to 32,000 cGy to the tumor itself. Tumor response was seen only at the higher absorbed doses. The new Y-90 glass microspheres can safely deliver large doses of internal radiation to hepatic tumors as long as extrahepatic shunting can be excluded. Extrahepatic shunting will be the main limitation to this form of radiation therapy.

Brachytherapy↗
PubMed1989

Orofacial and mandibular reconstruction with the iliac crest free flap: a review of 60 cases and a new method of classification.

Sixty vascularized iliac crest free-tissue transfers were used for oromandibular reconstruction, 46 as osteocutaneous and 14 as osseous flaps. Forty-one patients had preoperative radiotherapy, and 8 had failed previous attempts at reconstruction. Forty-nine of the 60 reconstructions were carried out primarily, most commonly following ablative surgery for radiorecurrent squamous carcinoma. Ages ranged from 19 to 85 years, and follow-up ranged from 2 months to 5 years. Flap survival was 95 percent. Eight-six percent of patients returned to their previous activities. There were 2 perioperative deaths, and 31 patients were alive at follow-up. Horizontal defects from 5 to 16 cm were reconstructed, and in 22 patients, both oral lining and skin coverage were replaced. Radiographic evidence of bone union was noted in 96 percent of synostoses, and clinical union was seen in all but one patient. One patient required bilateral hemimandibular reconstructions for sequential primaries at different operative sittings. Functional and cosmetic results were generally satisfactory and were excellent in bone-only reconstructions. Several surgical principles evolved to minimize bulk and eliminate the need for intermaxillary fixation or external fixation postoperatively. To improve results in large or more lateral through-and-through defects, an accessory pectoralis musculocutaneous flap proved advantageous. Cosmetic and functional results depend largely on three factors: the extent of the surgery, the leanness of the patient, and his or her position on the surgical learning curve.

Adult↗
PubMed1988

Improvement in upper airway function after weight loss in patients with obstructive sleep apnea.

Overweight patients with obstructive sleep apnea (OSA) are improved by weight reduction, although the underlying mechanisms are not clear. We tested the hypothesis that improvement in OSA after weight loss is associated with improvement in pharyngeal function. Consequently, we measured pharyngeal area at functional residual capacity (AFRC) and at residual volume (ARV), the percent change in pharyngeal area between FRC and RV (delta Aph%) defined as (AFRC - ARV)/AFRC x 100, and lung volume dependence of pharyngeal area (LVD) defined as the difference between AFRC and ARV normalized for the expiratory reserve volume (ERV)--in 12 overweight apneic patients before and after weight loss. We found that after a 26 +/- 18 kg weight loss, there was a significant reduction in the apnea/hypopnea index from 57 +/- 29 to 14 +/- 10 (p less than 0.0005) and increase in the lowest nocturnal oxygen saturation from 54 +/- 20% to 80 +/- 8% (p less than 0.001). This improvement was associated with a significant reduction in delta Aph% from 25 +/- 15% to 9 +/- 18% (p less than 0.05) and a significant decrease in LVD from 1.98 +/- 1.52 cm2/L to 0.16 +/- 0.88 cm2/L (p less than 0.005). There were four patients in whom baseline LVD was low and relatively unchanged after weight loss. Three of these patients exhibited paradoxical inspiratory narrowing of the glottis, which reversed after weight loss; these glottic abnormalities were not present in the rest of the patients with OSA. We conclude that improvement in obstructive sleep apnea after weight loss may be related to improvement in pharyngeal and glottic function.

Adult↗
PubMed1987

Extensive pharyngo-oesophageal reconstruction using multiple jejunal loops.

Two patients underwent subtotal pharyngo-oesophageal reconstruction using jejunum transferred by means of microvascular anastomosis. In both cases, two sets of vascular anastomoses were required, one in the lower neck and the other at the mid-sternal level. In the first patient, a continuous length of jejunum was employed but this led to great redundancy of the bowel on account of coiling as a result of its mesenteric attachment. In the second case, two isolated loops were employed with minimal redundancy. An anatomical study on three fresh cadavers indicated that the maximum defect which can be bridged by a single loop of jejunum lies between 15 and 20 cm. No particular part of the jejunum or ileum seems particularly advantageous in terms of its ability to span large defects.

Adult↗
PubMed1987

Free jejunal grafts in pharyngoesophageal reconstruction.

The free jejunal graft with microvascular anastomosis offers the head and neck surgeon a reliable, single-stage method of repair for small cervical defects and also for more extensive pharyngoesophageal defects where one or more loops of jejunum can successfully be used. If microvascular expertise is available, this method of reconstruction offers early alimentary rehabilitation and a physiologic repair. The free jejunal graft is a reliable method of reconstruction not only after failed gastric pull-up or when that procedure is not feasible, but also, where the facilities exist, as a primary method of pharyngoesophageal reconstruction.

Adult↗
PubMed1985

Radiofrequency hyperthermia as adjuvant therapy following surgical resection of an experimental malignant neoplasm.

Local recurrence after radical surgery is a major problem with many primary solid cancers. The use of radiofrequency hyperthermia (RFHT) as adjuvant therapy to surgery was explored in the Fischer bladder carcinoma (FBCa)/F344 rat tumor system. After subcutaneous innoculation of 34 rats with 10(6) FBCa cells in suspension, RFHT was administered to 17 animals on days 1, 5, 8, and 12. The development of palpable tumors was delayed but not prevented, and tumor growth was retarded in RFHT-treated animals. In another experiment 40 rats were innoculated by subcutaneous trocar injection with a 1 mm3 piece of FBCa. After tumor excision on day 17, adjuvant therapy (untreated control, mitomycin C, RFHT, or RFHT plus mitomycin C) was started on day 20 (10 rats/treatment). The 20 RFHT-treated rats had only 1 incisional recurrence as compared to 9 recurrences in sham-heated rats (P less than 0.005). The authors conclude that RFHT has considerable value as adjuvant therapy to surgery in these tumors. Additional studies of RFHT as adjuvant treatment after surgical excision of tumors are planned.

Animals↗
PubMed1985

Further experience with regional radiofrequency hyperthermia and cytotoxic chemotherapy for unresectable hepatic neoplasia.

The authors report on 178 patients with unresectable hepatic tumors who have been treated with 1 to 25 (median, 6) courses of radiofrequency hyperthermia (RFHT) and chemotherapy. In 137 patients, the hepatic tumors consisted of metastases from colorectal adenocarcinomas. For patients who had no previous therapy and who had colorectal metastases with no extraheptic disease, cumulative survival at 52 weeks' follow-up was 80.5% and partial tumor regression was seen in 78.4%. Among the 69 patients who previously had conventional treatment for their hepatic disease, partial regression was seen in 43.5%. We are no longer monitoring tumor core temperature routinely, as the invasive methods currently in use yield irreproducible results; the risks to the patient cannot be justified in view of the questionable relevance of the data obtained. A prospective randomized study of systemic chemotherapy with or without RFHT in patients with colorectal hepatic metastases is in progress.

Adenocarcinoma↗
PubMed1985

Reversal of cyclosporine-induced mortality with a synthetic polymeric immunostimulant in a murine model of fecal peritonitis.

We have been investigating the effects of a synthetic immunostimulative polymer known as copovithane (Cpv). This agent appears to enhance humoral immunity in untreated and cyclosporine-immunosuppressed mice and is nontoxic in rodents and man. The purpose of this study was to determine whether cyclosporine (CsA) is deleterious to survival in a murine cecal ligation, puncture, and excision (CLPE) model of fecal peritonitis, and--if so--whether this effect could be ameliorated by Cpv without interfering with skin allograft acceptance. Cpv significantly prolongs survival in the CLPE model; the optimal dose for this effect was found to be 100 mg/kg. CsA was found to have a significant and deleterious effect on survival at several dosage levels when administrated 48 and 24 hr before cecal ligation, and immediately before and 16 hr after cecal ligation. Using a dose of CsA sufficient for skin allograft acceptance and the same schedule of administration outlined above, Cpv 100 mg/kg was administered 48 hr prior to cecal ligation. Mice treated with CsA plus Cpv had significantly longer survival than mice treated with CsA alone; furthermore, the survival of CsA-plus-Cpv-treated animals was not significantly different from that of saline-treated controls. Acceptance and survival of H-2 incompatible skin allografts in mice treated with CsA were not affected by Cpv 100 mg/kg/week. We conclude that CsA-induced mortality in the CLPE model can be abrogated by Cpv without adversely affecting skin allograft survival. It may eventually be possible to reduce the incidence of septic complications in clinical allotransplantation by prophylactically administering Cpv to patients on CsA immunosuppression.

Animals↗
PubMed1985

Pelvic exenteration for advanced primary and recurrent adenocarcinoma.

The authors report on 45 patients who have undergone pelvic exenteration for adenocarcinoma since 1979. Three patients underwent exenteration as the initial treatment for their disease but all others had had previous surgery, radiotherapy or chemotherapy. Operating time and blood loss were lower in previously irradiated patients. There were seven in hospital deaths (15.5%). The number of complications and length of postoperative hospital stay have decreased significantly as experience with pelvic exenteration has been acquired. Symptoms have been controlled in a high proportion of patients. Exenterative surgery is an effective method of treatment in selected patients with pelvic adenocarcinoma but should be undertaken only by experienced surgeons who have access to a wide range of supportive facilities for optimal perioperative management.

Adenocarcinoma↗
PubMed1984

Palliation of advanced head and neck cancer with radiofrequency hyperthermia and cytotoxic chemotherapy.

Fourteen patients with recurrent malignant tumours of the head and neck were treated with radiofrequency hyperthermia and chemotherapy after conventional therapy had failed. After 2 to 11 treatment courses and a follow-up of 30 weeks, the neoplasms in three patients had completely regressed and one had a partial response. Of eight patients who died, two had partial responses initially; a third patient died of complications relating to surgical resection of the tumour after a partial response. Three of five patients whose tumours were unresponsive to methotrexate responded when this drug was given with radiofrequency hyperthermia. There were seven minor skin burns in six patients. Further studies of radiofrequency hyperthermia and chemotherapy for palliation of head and neck cancer are planned.

Adult↗
PubMed1983

The effect of liver cytosol on hepatic regeneration and tumor growth.

This report further evaluates the concept that the interaction of factors that originate within the liver can contribute, regulate or even initiate the actual development of hepatic regeneration after liver cell necrosis or partial hepatectomy. The effect of liver cytosol (100,000 g supernatant), both from intact adult rat liver (NLC) and from adult rat liver remnants that had been regenerating for 24 hours after 70% partial hepatectomy (PH) in posthepatectomy liver regeneration in the rat was studied. The specificity of the growth-controlling properties in liver cytosol was determined using tumor cells. The intraperitoneal administration of NLC after PH resulted in approximately 70-80% inhibition of the peak 3H-DNA specific activity seen in controls at 18 and 24 hours post-PH, with a significant increase in DNA synthesis at 31-40 hours post-PH. The intraperitoneal administration of RLC after PH, augmented the hepatic regenerative response normally produced. Autoradiographic determination of hepatic nuclear labeling confirmed the inhibitory and stimulatory properties of NLC and RLC respectively. Syngeneic NLC or RLC at six and 24 days after subcutaneous tumor inoculation resulted in significant inhibition of tumor growth for both a methylcholanthrene-induced bladder carcinoma (FBCa) and an HTC-hepatoma. The retardation of FBCa growth could be enhanced by administering NLC or RLC every three or seven days. Syngeneic and xenogeneic liver cytosol resulted in dose-dependent inhibition of P815 mastocytoma cell proliferation in vitro. It is apparent from these studies that both stimulatory and inhibitory factors can be extracted from liver tissue that not only influence liver cell regeneration, but also affect tumor growth. Further isolation and characterization of these factors may lead to an understanding of more fundamental problems such as the control of normal and malignant cell growth.

Animals↗
PubMed1983

Effect of radiofrequency hyperthermia and chemotherapy on primary and secondary hepatic malignancies when used with metronidazole.

Hyperthermia is selectively toxic to neoplastic tissue. Since August 1981, 357 patients with incurable tumors in various body areas have been treated with chemotherapy and radiofrequency hyperthermia (RFHT) with adjuvant metronidazole at this center. Of this group, the cases of 102 patients with hepatic tumors are reported here. Patients received one to ten treatment courses, each course consisting of two to five daily RFHT sessions. Systemic temperature rose 0.6 +/- 0.3 degrees C during treatment, and tumor core temperature (measured by percutaneous transhepatic thermistor) reached 39.5 +/- 1.2 degrees C in 38 monitored patients. Results have been encouraging; in particular, among 15 patients with newly diagnosed colorectal metastases limited to the liver (and as yet untreated for their secondary disease), there has been objective partial tumor regression in 66.7%. Side effects have been few. Skin burns and subcutaneous fat necrosis were seen in 3.9% and 13.7% of patients, respectively. Tumor temperature is difficult to measure reliably and does not correlate with machine power or tumor response. A phase III trial is currently underway to determine the efficacy of RFHT and chemotherapy for patients with hepatic metastases from colorectal adenocarcinoma.

Adult↗
PubMed1983

Systemic thermochemotherapy in a rat model.

The purpose of this study was to determine the effects of systemic hyperthermia, with and without Adriamycin, on two rat tumour models. Fischer rats were implanted subcutaneously with either a methylcholanthrene-induced sarcoma or a transitional cell carcinoma. In the first experiment, 32 rats with tumour volumes of 1 cm3 were divided into four groups of 8 rats receiving: (a) Adriamycin alone (2 mg/kg intraperitoneally) (group 1), (b) systemic hyperthermia alone (water bath immersion to a rectal temperature of 41.5 degrees C for 30 minutes) (group 2), (c) Adriamycin and systemic hyperthermia (group 3) or (d) immersion in water bath at 37 degrees C for 30 minutes (control group) (group 4). Serial tumour volume and animal survival were monitored. No differences were seen among the groups in either tumour system. In a second experiment, an identical protocol was used except that each animal received its respective treatment three times, at weekly intervals. In the rats implanted with methylcholanthrene-induced sarcoma, tumour volume was lower in group 3 than in control group 4, beginning at day 23 (37.5 +/- 8.2 cm3 vs. 52.3 +/- 9.6 cm3 [p less than 0.05]). Systemic hyperthermia or Adriamycin alone did not alter tumour growth in relation to the control group. In the transitional cell carcinoma system, tumour volume was decreased in both groups 1 and 3 at day 35 (group 1 = 32 +/- 5.4 cm3, group 3 = 28.1 +/- 12 cm3 vs. group 4 = 48.8 +/- 9 cm3 [p less than 0.05 for each]). Adriamycin with systemic hyperthermia was no more effective than Adriamycin alone. Tumour growth was similar in groups 2 and 4. These data demonstrate that multiple treatments with Adriamycin and systemic hyperthermia were effective in decreasing the rate of tumour growth in rat tumour models, whereas a single exposure had no effect.

Animals↗