The administration of supplementary oxygen to prevent hypoxia during upper alimentary endoscopy

A prospective, randomized, controlled trial was conducted in 200 consecutive patients undergoing endoscopy of the upper alimentary tract. One hundred patients received supplementary oxygen at 4 liters/minute through nasal cannulae, while 100 patients received no additional oxygen. Within each of these two groups, 50 patients were sedated with midazolam and 50 patients with diazepam suspension ("Diazemuls"). The patients' weights were recorded and correlated with their height to assess whether they were over or under their ideal weight. Oxygen saturation was recorded at baseline and throughout the endoscopic procedure. The principal finding of this study was that hypoxia (oxygen saturation less than 93%) was prevented in all cases by the administration of 4 liters/minute of oxygen, whereas 48 of the 100 patients who did not receive oxygen exhibited falls in oxygen saturation to less than 93% (p < 0.0001). Those with the highest risk were the obese patients (p < 0.01). There was no significant difference between the two sedative drug groups in either frequency or severity of associated hypoxia (p = 0.77, patients not given oxygen; p = 0.31, patients receiving oxygen). The cost of administering oxygen during upper gastrointestinal endoscopy would be an average of 95 pence ($1.60) per patient. In conclusion, the administration of oxygen during endoscopy is a worthwhile prophylactic measure to prevent hypoxia and its potential adverse effects.

Effect of stress management on blood pressure in mild primary hypertension

OBJECTIVE

To establish whether stress management had a larger effect than a control treatment on resting blood pressure, ambulatory blood pressure, and left ventricular mass.

DESIGN

A 12 week baseline period of habituation to measurement of blood pressure was followed by randomisation to either stress management or mild exercise for six months and follow up six months later.

SETTING

General practice, district general hospital, and medical school.

PATIENTS

Of the 184 patients aged under 60 with mild primary hypertension who entered the baseline habituation period, 88 were excluded because they failed to meet the entry criteria or they withdrew from the study. The remaining 46 men and 50 women underwent treatment.

INTERVENTIONS

10 clinical sessions and daily practice at home of either stress management based on relaxation or non-aerobic stretching exercises. Mildly stressful 15 minute interviews before and after treatment.

MAIN OUTCOME MEASURES

Diastolic and systolic blood pressure in the clinic and during 12 hours of ambulatory recording, and left ventricular mass measured by echocardiography.

RESULTS

The patients' blood pressure fell during habituation (systolic pressure from 152 mmHg to 140 mmHg, diastolic pressure from 98 to 93 mm Hg), but neither resting nor ambulatory blood pressure was changed by the treatments. Left ventricular mass was also unchanged. Blood pressure rose during the stressful interview, but this rise was reduced by stress management (systolic pressure rose by 7.4 mmHg before treatment and by 3.7 mmHg after treatment).

CONCLUSION

Stress management of a type advocated for treating mild primary hypertension is ineffective in lowering blood pressure in patients who are well habituated to measuring blood pressure.

Serotonin inhibits induction of long-term potentiation at commissural synapses in hippocampus

This study tests the effect of serotonin (5-HT) (1 microM) on the induction of long-term potentiation (LTP) at the commissural/associational (C/A)-CA3 synapse. The C/A input to CA3 was measured by field potentials in rat hippocampal slices. At the concentration used 5-HT had little or no effect on synaptic transmission, but suppressed the induction of LTP. Similar results were observed in normal saline and in saline containing picrotoxin (10 microM) and bicuculline (10 microM) to block GABAA inhibition. Perfusion with methysergide (1 microM), a 5-HT antagonist, had no effect on synaptic transmission, but partially blocked the effect of 5-HT on LTP. The block of LTP by 5-HT could be overcome by using a higher intensity of stimulation suggesting that 5-HT might hyperpolarize the postsynaptic neurons to inhibit LTP induction. We conclude that the activation of serotonergic receptors inhibits the induction of LTP at the C/A-CA3 synapse.

An immediate early human gene encodes an Id-like helix-loop-helix protein and is regulated by protein kinase C activation in diverse cell types

Transcription factors characterized by the presence of a helix-loop-helix (HLH) domain play a central role in the regulation of cell growth/differentiation and tumorigenesis. We report here the cDNA sequence of a human early-response gene, designated HLH 1R21, encoding a 15-kDa HLH protein that lacks a basic, DNA-binding domain and which by a number of criteria appears to be the human homologue of mouse HLH 462. Like its murine counterpart, HLH 1R21 protein functions as an Id (inhibitor of DNA binding) transcription factor by inhibiting the binding of E2A-containing protein complexes to muscle creatine kinase E-box enhancer oligonucleotide in vitro. However HLH 1R21 does not inhibit the binding of HLH Max protein to a Max-binding oligonucleotide in vitro, indicating that it has limited promiscuity in its ability to antagonize the function of other HLH transcription factors. In addition, HLH 1R21 mRNA transcripts are regulated by phorbol ester treatment of a diverse range of human cell lines and, when overexpressed in mouse NIH3T3 cells, HLH 1R21 induces a morphologically transformed phenotype.

Synaptically activated increases in Ca2+ concentration in hippocampal CA1 pyramidal cells are primarily due to voltage-gated Ca2+ channels

Changes in intracellular Ca2+ concentration ([Ca2+]i) in the soma and dendrites of hippocampal CA1 pyramidal neurons were measured using intracellularly injected fura-2. A large component of the [Ca2+]i elevation caused by high frequency stimulation of the Schaffer collaterals was correlated with the Na+ spikes triggered by the excitatory postsynaptic potentials (EPSPs). These spikes were generated in the soma and proximal dendrites and stimulated Ca2+ entry through voltage-gated Ca2+ channels. Suppressing spikes by hyperpolarizing the soma or by injecting QX-314 revealed a smaller nonspike component of Ca2+ entry. A substantial fraction of this component was mediated by the action of the EPSPs on voltage-gated Ca2+ channels, because it persisted in 2-amino-5-phosphonovaleric acid and because it was usually reduced when Ca2+ channel activity was suppressed by hyperpolarization. Ca2+ entry through the N-methyl-D-aspartate receptor channel could not be detected with certainty, perhaps because it was highly localized.

Cytokine production and immune cell activation in melanoma patients treated with liposomal muramyl tripeptide (CGP 19835A lipid)

We conducted a pilot study using liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) preoperatively in patients with stage III or IV resectable melanoma who were at high risk for recurrence. Patients received L-MTP-PE for 1 month before surgery and then 5 months postoperatively. Several immune parameters were monitored during preoperative therapy to search for correlations with clinical (tumor) response. The 18 patients were classified into three groups according to their responses and disease-free intervals: no evidence of disease (NED) at week 24 of therapy, relapse during therapy and progressive disease on therapy noted at the time of surgery. Six of nine patients in the NED group demonstrated increased monocyte tumoricidal activity (MTA) during week 1 of therapy. MTA increased in three of the six patients in the relapse group. MTA did not increase in the three patients who had progressive disease on therapy. Plasma neopterin levels were elevated by 72 h following the first L-MTP-PE dose in all 18 patients. Circulating levels of tumor necrosis factor were elevated in 15 of 16 patients tested, and IL-6 levels were elevated in all 18 patients. Melanoma cells from all three patients with progressive disease at the time of surgery proliferated well in vitro, whereas tumor cells from 10 of the 15 patients in the other two groups did not proliferate. There were no discernible differences among the three groups in the magnitude of IL-2-induced proliferation of tumor infiltrating lymphocytes. However, IL-2-activated TILs from the NED group exhibited cytotoxicity against autologous tumor cells in vitro. In summary, whereas L-MTP-PE stimulated several immunologic responses in all patients, the only two parameters that correlated with clinical status were MTA and the tumor proliferation assay. These two biologic assays could serve to distinguish potential responders from nonresponders early in the course of treatment.

Effect of anorectal eversion during restorative proctocolectomy on anal sphincter function

Twenty-six patients underwent restorative proctocolectomy with end-to-end ileal pouch-anal anastomosis, without resection of the anal mucosa, by the eversion technique. Before surgery patients underwent tests of anorectal function. These were repeated a median of 8 (range 3-21) months after operation. The median (range) maximum resting anal pressure was 93 (36-149) cmH2O before and 71 (40-131) cmH2O after operation (P = 0.002). The median (range) maximum squeeze pressure before operation was 136 (73-280) cmH2O; it was 149 (69-290) cmH2O afterwards (P not significant). The median (range) length of the anal sphincter was 3.5 (2.5-4.5) cm before and 3.5 (2.0-4.5) cm after operation (P not significant). Thresholds for sensation in the upper, middle and lower thirds of the anal canal before and after operation were, respectively, 8.7 versus 8.7, 6.8 versus 7.4 and 4.2 versus 6.2 mA (P not significant). All 26 patients were continent, although one experienced minor leakage. Function of the anal sphincter is not significantly impaired by eversion of the rectum and anus during restorative proctocolectomy.

Evidence for the indirect utilization of glucose for the synthesis of hepatic glycogen in man

1. This study was designed to test the hypothesis that three-carbon intermediates can be used in the 'indirect' pathway of glycogen synthesis in human liver (i.e. a route additional to the use of glucose by the 'direct' pathway). 2. After an overnight fast, 13 patients were given an infusion of 20% (w/v) glucose before elective abdominal operation. All received a 2.5 g bolus of 2220 kBq of selectively 3H- and 14C-labelled glucose before removal of a 1 g biopsy of liver. 3H and 14C were determined in purified glycogen as well as in glucose and lactate from samples of peripheral blood. 3. The ratio and specific activities of 3H and 14C in glycogen were found to be significantly lower than those in administered glucose. By calculation, 7-74% of glycogen repletion occurred by indirect pathways and not all of this was from the glucose supplied. 4. This study suggests that the operation of a direct pathway in man is not exclusive and that significant repletion of hepatic glycogen occurs by an indirect route.

Modified adriamycin-vincristine-dexamethasone (m-VAD) in primary refractory and relapsed plasma cell myeloma: an NCI (Canada) pilot study. The National Cancer Institute of Canada Clinical Trials Group

The purpose of this single arm phase II study was to test a modified version of the three drug combination vincristine, adriamycin and dexamethasone (m-VAD), in which intravenous vincristine (0.4 mg/d) and adriamycin (9 mg/m2 per day) infusions are administered for only 2 h on days 1-4 of each 28 d cycle, in patients with refractory multiple myeloma. In addition, only two 4 d courses of dexamethasone 40 mg/d was given during each cycle. The entry criteria for 44 patients included plasma cell myeloma and a measurable monoclonal peak, either refractory to initial treatment with melphalan and prednisone, or resistant to melphalan and prednisone after initially responding (resistant relapsed disease, 27 patients). Patients treated previously with chemotherapy other than melphalan and prednisone were excluded. There were no complete responses. Of the 41 evaluable patients who completed at least one course of therapy 11 had a partial response (27%, 95% C.I. 14-40%). The response rates were 19% for primary refractory disease patients, and 32% for those with resistant relapsed disease. The median duration of response was 4 months. The median survival for all 44 patients was 7.6 months (5.5 months for primary refractory patients, and 10 months for relapsed resistant disease patients). Episodes of documented bacterial infection occurred in 12 patients, and 10 patients had minor viral infection. The dexamethasone dose was reduced in 12 patients. The median neutrophil nadir was 1.2 x 10(9)/l, and median platelet nadir was 147 x 10(9)/l. Five deaths were judged as treatment related and occurred during marrow cytopenia. The results of this modified form of VAD are inferior to that reported previously for 4 d continuous infusions of vincristine and doxorubicin. This could be related to either patient selection factors, or to a reduction of the efficacy of the drug combination produced by either the shortened intravenous infusions and/or omission of one 4 d course of dexamethasone.

Drug-patient interactions and their relevance in the treatment of heart failure

The effects of congestive heart failure (CHF) on drug disposition and elimination are many and varied. Indeed, the pharmacokinetics of many of the drugs used to treat CHF are significantly altered by the patient's underlying condition. Reduced gastric emptying in CHF delays absorption and decreases the peak plasma concentrations of furosemide, bumetanide, and digoxin. Moreover, drugs that have a high hepatic extraction ratio (organic nitrates, morphine, prazosin, and hydralazine) achieve higher than expected plasma concentrations in patients with CHF. In contrast, drugs requiring biotransformation to active forms, e.g., angiotensin-converting enzyme (ACE) inhibitors such as enalapril, perindopril, quinapril, and ramipril, generally have lower than expected plasma concentrations. Nevertheless, ACE inhibitors can impair renal function in CHF, leading to an actual increase in plasma concentrations. However, decreases in absorption and first-pass metabolism are often offset by reduced hepatic and renal clearance. The overall absorption of lisinopril may be reduced in some CHF patients; consequently, the onset of effect is delayed but is often more prolonged.

Reduction in factor VII, fibrinogen and plasminogen activator inhibitor-1 activity after surgical treatment of morbid obesity

The aim of this study was to determine the effects of the surgical treatment of morbid obesity on some aspects of haemostatic and fibrinolytic function. Measurement of haemostatic and fibrinolytic factors was performed before and again 6 and 12 months after operation in 19 patients suffering from morbid obesity. Surgical treatment resulted in a mean decrease in body weight of 50 kg at 6 months and 64 kg at 12 months. Weight loss was accompanied at 12 months by significant reductions in median (interquartile range) concentrations of serum cholesterol from 5.3 (4.5-6.2) mmol/l to 3.6 (2.9-4.6) mmol/l; factor VII from 113 (92-145)% of normal to 99 (85-107)%; of fibrinogen from 3.5 (3-9.3) g/l to 2.8 (2.4-3.8) g/l; and of plasminogen activator inhibitor-1 (PAI-1) activity from 21 (11-30) IU/ml to 6.3 (5-10) IU/ml. The decrease in PAI-1 activity probably accounted for a significant reduction in euglobulin clot lysis time. Tissue plasminogen activator activity was undetectable in most patients pre-operatively but increased slightly after 1 year to 110 (100-204) mIU/ml. There were no significant changes in plasma levels of KCCT, factor VIII, von Willebrand factor antigen, alpha-2-antiplasmin, antithrombin III, protein C antigen, beta thromboglobulin, platelet factor 4, fibrinopeptide A or platelet count. These findings provide support for the hypothesis that the surgical treatment of morbid obesity may have a long-term beneficial effect on mortality from cardiovascular and thromboembolic disease.

Early gastric cancer: 46 cases treated in one surgical department

Forty six consecutive patients with early gastric cancer were treated between 1970 and 1990. The proportion of cases of early gastric cancer increased significantly (p < 0.01) from 1% of all cases in the first five year period to 15% in the last five year period, because of greater awareness of the condition and more widespread use of endoscopy. There were 33 men and 13 women, of median age 69 years (range 38-86). Most patients (91%) presented with symptoms indistinguishable from those of peptic ulceration. The median duration of symptoms was four months (range 0.1-36 months). All 46 patients were treated surgically. Three patients (6.5%) died after operation and a further 10 (22%) suffered postoperative complications. None of the surviving patients has been lost to follow up and 25 have been followed up for a minimum period of five years. Five year survival by life table analysis was 98%. These findings suggest that in Britain in the 1990s, as in Japan, it may be possible to diagnose an increasing proportion of patients with gastric cancer at a relatively early pathological stage, when most patients can be cured by radical surgical resection with lymphadenectomy.

NMDA-receptor-independent long-term potentiation

Although NMDA-R-dep LTP in the hippocampus has received much attention, it is clear that many types of LTP do not involve NMDA receptors. While early studies of NMDA-R-indep LTP were done in invertebrates, an NMDA-R-indep LTP is also seen in at least three excitatory pathways of the hippocampus. There would appear to be quite diverse mechanisms of induction of NMDA-R-indep LTP, although in most cases there is evidence, or at least a suggestion, that Ca2+ is involved. At the hippocampal CA3 MF synapse, activation of voltage-gated Ca2+ channels has been proposed as a trigger for LTP induction, and this may also be the case for certain types of LTP at the SC synapse in CA1 (25, 40). The modulation of both MF LTP and Ca2+ channels by beta-adrenoreceptor and muscarinic agonists suggests that specifically the L-type channel is critical for MF LTP induction. L-type Ca2+ channels may also be involved in NMDA-R-indep LTP at SC synapses (6, 40). Clearly more work is needed to test these possibilities. In addition, it will be interesting to discover whether voltage-gated Ca2+ channels play a role in LTP in other areas of the brain such as the cerebral cortex and amygdala (24).

Morphometry of gastric carcinoma: its association with patient survival, tumour stage, and DNA ploidy

Morphometric image analysis of nuclear features was performed on tissue from 46 patients who had had curative resections for gastric cancer. Clinical, pathological, flow cytometric, and follow-up data were available for these patients, which were drawn from a larger, previously reported series. The morphometric data were compared with patient survival, clinico-pathological status, and DNA ploidy. Univariate survival analysis revealed that morphometric parameters were not significantly related to survival, but examination of clinico-pathological data showed lymph node involvement, involvement of the resection margin, and lymphatic invasion to be significantly associated (P < 0.01) with patient prognosis. Multivariate survival analysis using the Cox model found only lymph node and resection margin involvement to be independently related to survival. Comparison of morphometric results with the clinico-pathological parameters showed various features, relating to nuclear size, and its variation to be significantly associated (P < 0.01) with the presence of lymphatic invasion, resection margin involvement, and tumour pattern (intestinal/diffuse). A comparison of morphometry with flow cytometric analysis in these cases showed that nuclear size was not significantly related to either DNA aneuploidy or the DNA proliferative index.

Role of the rectum in the physiological and clinical results of coloanal and colorectal anastomosis after anterior resection for rectal carcinoma

This study investigated the relationships between length of residual anorectum, anorectal physiological function and clinical outcome after anterior resection for rectal carcinoma. Thirty-four patients were studied a median of 13 (range 4-100) months after anterior resection. They were compared with a control group of ten patients who had undergone sigmoid colectomy for carcinoma without rectal excision. Resting anal pressure was found to be lower after coloanal than after colorectal anastomosis, and the capacity of the (neo)rectum was less after coloanal than after colorectal anastomosis. The (neo)rectoanal inhibitory reflex was found to be present in each patient, but maximum anal pressure during this 'sampling' reflex was significantly lower (P < 0.01) after coloanal than after colorectal anastomosis, and the volume required for maximal inhibition of the sphincter was also less (P < 0.01). At 1 year after operation, median bowel frequency was greater after coloanal (4 per day) than after colorectal (2 per day) anastomosis and the degree of urgency of defaecation was also greater (P < 0.01). Quality of life in terms of anorectal function after anterior resection is thus significantly influenced by the length of rectum that is left. This, in turn, influences the functional capacity of the neorectum and the degree of inhibition of the anal sphincter during the neorectoanal inhibitory reflex.

Laparoscopic cholecystectomy as a routine procedure for gallstones: results of an 'all-comers' policy

A total of 165 consecutive patients with gallstones were considered for laparoscopic cholecystectomy. Three were excluded. The median age was 52 years and 76 per cent were women. Eighteen patients underwent urgent operation. Laparoscopic cholecystectomy was successful in 160 of the 162 patients (99 per cent). The two failures were the result of dense adhesions and stones in the bile duct. There were no deaths but major complications occurred in three patients: fenestration of the colon sutured laparoscopically; bleeding from a cannulation site and subsequent laparotomy for a strangulated hernia; and subphrenic abscess. There were 13 minor complications, but no bile duct injuries or peritonitis. The median postoperative hospital stay was 1 day. Bile duct stones were present in 14 patients (9 per cent) and were removed by endoscopic sphincterotomy (11 patients), by laparoscopic exploration of the common duct (two) and by conversion to laparotomy (one). These results suggest that laparoscopic cholecystectomy is applicable to the large majority of patients who require elective or urgent cholecystectomy, if appropriate radiological and endoscopic support is available.

CI-973, a new platinum derivative with potential antileukemic activity

We examined the effects of CI-973 (supplied by Parke-Davis) on several human leukemia cell lines and a Chinese hamster ovary (CHO) line and their drug-resistant counterparts. The cell lines used were HL-60, HL-60/mAMSA, HL-60/DOX, KBM3, KBM3/mAMSA 6, KBM3/mAMSA 6(85), CHO, and CHO/AC-7. DOX, mAMSA, and AC-7 indicate resistance to doxorubicin, amsacrine, or 1-beta-D-arabinofuranosylcytosine, respectively. Cells were incubated with CI-973, and the effect was evaluated by two methods: growth inhibition assay and inhibition of colony formation. All cell lines examined were inhibited by CI-973; two of three amsacrine-resistant lines and the one cytarabine-resistant line demonstrated collateral sensitivity. At equivalent dosages, a 4-day exposure provided much greater cell kill than a 1-h exposure. Clonogenic assay showed exponential killing over 3 log units. Maximum CI-973 levels required to kill 50% of cells were 10-fold lower than the peak plasma levels achieved in a phase I solid tumor study. A continuous infusion phase I study in acute leukemia has been initiated.

The enantiomeric resolution of ciprofibrate and related compounds by HPLC using chiral stationary phases

The attempted chromatographic resolution of the drug ciprofibrate and a range of related compounds, containing the chiral moiety 2,2-dichlorocyclopropylbenzene, using five different chiral stationary phases is described. Aqueous mobile phases were used throughout and the successful separation of nine out of 12 pairs of enantiomers was achieved. Structures remote from the chiral centre were seen to affect chiral recognition.